Journal of Tropical Ecology Jamaican limestone forests

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Jamaican limestone forests: ﬂoristics, structure and environment of three examples along a rainfall gradient D. L. Kelly, E. V. J. Tanner, V. Kapos, T. A. Dickinson, G. A. Goodfriend and P. Fairbairn Journal of Tropical Ecology / Volume 4 / Issue 02 / May 1988, pp 121 156 DOI: 10.1017/S0266467400002649, Published online: 10 July 2009

Link to this article: http://journals.cambridge.org/abstract_S0266467400002649 How to cite this article: D. L. Kelly, E. V. J. Tanner, V. Kapos, T. A. Dickinson, G. A. Goodfriend and P. Fairbairn (1988). Jamaican limestone forests: ﬂoristics, structure and environment of three examples along a rainfall gradient. Journal of Tropical Ecology, 4, pp 121156 doi:10.1017/S0266467400002649 Request Permissions : Click here

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Journal of Tropical Ecology (1988) 4:121-156. With 8 figures

Jamaican limestone forests: floristics, structure and environment of three examples along a rainfall gradient D. L. KELLY1*, E. V. J. TANNER2, V. KAPOS3, T. A. DICKINSON 1 !, G. A. GOODFRIEND4^ and P. FAIRBAIRN5§ 1 Department of Botany, University of the West Indies, Mona, Kingston 7, Jamaica 2 Botany School, University of Cambridge, England 3 Botany Department, Washington University, St Louis, Missouri, USA 4 Committee on Evolutionary Biology, University of Chicago, Illinois, USA 5 Natural Resources Conservation Department, Kingston 8, Jamaica

ABSTRACT. We describe forests from three areas of Jamaica, all on White Limestone but with markedly different rainfall regimes. The areas are Hog House Hill in the north-east with lower montane rain forest at c. 450 m altitude with a rainfall of c. 4000 mm yr"1; Broom Hall in the centre of the island with evergreen seasonal forest at c. 670 m altitude and with a rainfall of c. 1600 mm yr"1 and a marked dry season; and Round Hill near the south coast with dry semievergreen forest at c. 300 m altitude with an irregularly distributed rainfall of c. 1000 mm yr"1. Species lists were made from c. 180 ha at Hog House Hill, c. 5 ha at Broom Hall and c. 50 ha at Round Hill, and detailed inventories made of five sample sites of c. 1000 m2, two at Hog House Hill, one at Broom Hall and two at Round Hill. At Hog House Hill we listed 280 vascular plant species, including 118 species of trees and larger shrubs; at Broom Hall 247 and 135; at Round Hill 129 and 81. Species-area and speciesindividuals curves confirm that Broom Hall was richer in tree species than Hog House Hill. The wetter forests contain high proportions of species endemic to Jamaica: 40% of the total flora at Hog House Hill and 36% at Broom Hall. Canopy height decreased from c. 26-28 m at Hog House Hill to c. 13-24 m at Broom Hall to c. 8-15 m at Round Hill. Predominant leaf size decreased from mesophyll at Hog House Hill to notophyll at Broom Hall to microphyll at Round Hill. Compared with forests on other Caribbean islands, the Jamaican forests appear to be as species-rich as any, but lower in stature than natural forest in Trinidad and Dominica. Continental Neotropical forests are both more species-rich and taller. KEY WORDS: Caribbean region, diversity, island floras, Jamaica, leaf size, life form, Neotropics, rain forest, species-richness, xeric forest. Present addresses: * School of Botany, Trinity College, University of Dublin, Ireland, f Department of Botany, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada M5S 2C6. % Isotope Department, The Weizmann Institute of Science, 76 100 Rehovot, Israel. § 20 Marcia Road, Watertown, Massachusetts, USA. (121)

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INTRODUCTION

Tropical forest over limestone Hard limestones weather under tropical conditions to produce uplands of extremely rugged terrain, with much outcropping of naked rock. The residual products of prolonged weathering accumulate as soils of terra rossa type, reddish clayey loams composed largely of iron and aluminium oxides (Duchaufour 1970). Natural forest survives mostly where soils are thin and patchy. All our study areas are in rocky upland terrain, with many characteristic karst features: fissures, cliffs, caves, sink-holes and closed depressions, and an absence of surface water. The most pervasive effect of this geomorphology is the very rapid drainage and low water-holding capacity of the substratum. In his structuralphysiognomic classification of Neotropical vegetation, Beard (1944, 1955) distinguished a series of 'Dry Evergreen Formations' on 'well-drained lands with constant lack of available moisture', either limestones or deep sands. He emphasized that seasonal water stress due to drought is accentuated by the very rapid drainage on limestone terrain (also Beard 1946). Detailed accounts of tropical forests over limestone are rather few, partly because they are of restricted distribution, and partly because they can be difficult to work in. Limestone is a major rock type in the Caribbean region. All of the Greater Antilles (Cuba, Hispaniola (i.e. Dominican Republic and Haiti), Puerto Rico and Jamaica) have extensive limestone regions. The Lesser Antilles include an outer arc of limestone islands, from the Virgin Islands to Barbados. The Bahamas and the subtropical region of Florida are entirely limestone. Most of the limestone islands are small and with low relief; hence the natural vegetation is a more or less xeric forest of low stature. Wet forests over limestone are found only in the larger mountainous islands, viz. the Greater Antilles. At the extreme of year-round high rainfall, rain forest vegetation develops, the composition of which appears to be little affected by the underlying rock-type (cf. Borhidi, in press, Ciferri 1936). The Evergreen Seasonal Forest formation of Beard (1944) is characteristic of regions with short but marked dry seasons. This is the climatic zone most suited to agriculture, and it is in this zone that deforestation and forest alteration have been most pervasive (cf. Borhidi, in press, Ciferri 1936, Ewel & Whitmore 1973). The xeric forest or scrub vegetation present on so many of the islands has been treated in a relatively large number of publications (see below); however, many of these do not provide much of detail. The island of Jamaica Jamaica is an island of 11,290 km 2 , which shows great diversity of topography, geology and rainfall. Altitude rises to 2254 m; mean annual rainfall ranges from < 7 5 0 mm to >7000 mm per annum (Jamaican Meteorological Service, ms; cf. Figure lb). Winds are generally light, and are predominantly

123

Jamaican limestone forests The Cockpit Country Broom Hall Lydford

John Crow Mountains Hog

1

Siliceous rocks Limestone Alluvium

Hellshire Hills

(a)

Round Hill Portland

Ridge

j_

50 Km

Hog House Hill

(0

Round Hill

Broom Hall

(d)

(e)

Figure 1. (a) Map of Jamaica showing overall geology, and location of study areas and other areas mentioned in the text. (Source: Jamaica Geology 1:250,000 Geological Survey of Jamaica 1958). (b) Map showing distribution of mean annual rainfall, (c), (d) and (e) Maps showing precise locations of each study area. Circles show approximate locations of sample sites.

trade winds from the north-east. Hurricanes occur at long intervals and cause extensive damage (in eastern Jamaica in 1944, 1951 and 1980). The land of Jamaica was entirely submerged throughout the late Eocene and Oligocene periods and did not begin to re-emerge until the mid-Miocene (Eva & McFarlane 1985). The island has never had any subsequent land connection to the continents or to other islands; the flora was apparently constituted through immigration across a marine barrier that was probably never less than

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100 km wide (cf. Lack 1976). The native and naturalized flora today contains some 3000 species of flowering plants; 27.6% of these are considered endemic to the island (cf. Adams 1972, Proctor 1982). Of the 579 Pteridophyte species, 11.6% are considered to be endemic (Proctor 1985). The surface rocks are mainly limestone but there are extensive areas of siliceous rocks at high altitude and alluvium near sea level (Figure la). The predominant deposits are the very pure White Limestone Formation, which forms the surface of some 54% of the island; its age ranges from Middle Eocene to Lower Miocene (Hose & Versey 1956). All our study areas were on this formation. The Yellow Limestone Formation of the Middle Eocene forms the surface of a further 5% of the island. Small areas of Cretaceous limestone occur at scattered localities. Younger limestones occur in coastal areas, including raised coral-reefs of Quaternary age. Coastal vegetation on the Quaternary limestones of the north coast was described by Asprey & Loveless (1958). All other published work about Jamaican vegetation on limestone referred to below concerns the prevailing White Limestone Formation. The island was almost completely covered by forest in pre-Columbian times. Extensive clearance took place in the seventeenth and eighteenth centuries AD, with the development of plantation agriculture (Asprey & Robbins 1953). Estimates of the proportion of the total land area under well-stocked forest have fallen in this century from 32% in the early 1920s (Zon & Sparhawk 1923) to 18% in the early 1950s (Asprey & Robbins 1953) to 6-7% in the 1970s (Lanly 1981). The northeastern corner of the island, with year-round high rainfall, would once have supported lowland rain forest, but none now remains. Lower montane rain forest (sensu Grubb et al. 1963) survives only on the limestones of the John Crow Mountains: our Hog House Hill study area (HHH) is representative (cf. also Kelly 1986). Brief prior accounts of this forest appear in Asprey & Robbins (1953) and Grubb & Tanner (1976). Variants of upper montane rain forest clothe the John Crow Mountains from about 950 m upwards, and the upper parts of the Blue Mountains (Asprey & Robbins 1953, Grubb & Tanner 1976, Tanner 1977). The Blue Mountains are composed almost entirely of siliceous rocks; a small limestone outlier at 1750-1800 m supports a distinctive 'dry limestone scrub forest' 2-4 m high (Grubb & Tanner 1976). Forest communities with a lower and more seasonal rainfall are still widespread in the limestone uplands of central and western Jamaica. The Cockpit Country forest is the most extensive but has been remarkably little studied;brief accounts are given by Asprey & Robbins (1953) and Proctor (1986a). Our Broom Hall study area (BH) is representative of the same forest type; the only detailed prior account of forest in this intermediate-rainfall zone is that for the Lydford area by Howard & Proctor (1957a, b). The dry 'rain shadow' areas of southern Jamaica support considerable areas of xeric forest and scrub over limestone; these have however been much cut over and degraded in recent decades. The best-known areas are Portland Ridge and the Hellshire Hills (Adams & Du Quesnay 1970, Loveless & Asprey 1957). Our study area at Round Hill (RH) was

Jamaican limestone forests (a) Ecclesdown

3835 - 500

125

(b) Cave Valley

II I 1 -

20

"

1 1 1 1 J F M A M J J A S O N D

0 N D

J F M A M J J A S O N D

Figure 2. Climate diagrams (sensu Walter & Leith 1960) for stations close to our study areas. Curves are monthly means of rainfall and temperature over a 30-year period (1931-1960). Rainfall data are from the meteorological stations closest to our study areas; mean annual rainfall is shown at the top right of each diagram. Temperature data are extrapolated from other meteorological stations, (a) Ecclesdown, 5 km SE of Hog House Hill, altitude c. 275 m. (b) Cave Valley, 2 km NE of Broom Hall, altitude 552 m. (c) Milk River (Rest), 3 km NE of Round Hill study area, altitude 27 m. Source: Meteorological Division, Ministry of Communications and Works, Government of Jamaica.

chosen as one of the least disturbed areas of well-developed forest remaining in the south of the island (cf. also Kapos 1986). The forest and scrub vegetation of the surrounding district was described by Kelly (1981, unpublished), and of the nearby district of Nain (25 km WNW of Round Hill) by Howard & Proctor (1957a, b). Mangrove forest and freshwater swamp forest survive close to sea level, but well-developed stands are of very limited extent (Asprey & Robbins 1953, Coke et al. 1982 (unpublished), Proctor 1986b). We describe here three forests growing within 120 km of each other, on the same bedrock, but with markedly different total rainfall and seasonality of rainfall (Table 1, Figure 2). The study areas are (1) Hog House Hill (HHH), grid reference 768433 on sheet M of Jamaica 1:50,000 3rd edition (1967) (Figures 1, 3); (2) Broom Hall knoll (BH), grid reference 418475 on sheet G (Figure 1; cf. Figure 6); (3) Round Hill (RH), grid reference 419347 on sheet H (Figures 1, 7). The study areas were not precisely delimited and the areas given (Table 1) are rough estimates. We make use of our results for comparisons: (1) between our three forest study areas; (2) between our forest areas and other descriptions of Jamaican forests; (3) between Jamaican forests on limestone and forests elsewhere in the tropics. METHODS

Within each study area, one or two sample sites, each c. 1000 m 2 , were chosen for detailed study. The sites were chosen as representative of the least-disturbed forest in each area. Within each site we recorded the species and diameter at breast height (DBH) of every tree of 3 cm DBH or over (4 cm or over for the HHH plots; the difference is insignificant for our data). We tried to list all

20

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Table 1. The study areas and sample sites: summary of environmental data and forest structure.

Area of study area (ha) (approximate) Altitude (m) Mean annual rainfall (mm) Months with mean rainfall < 100 mm

Hog House Hill (HHH)

Broom Hall (BH)

Round Hill (RH)

180 400-500 >3800 0

5 625-725 c. 1600 4

50 200-350 900-1200

HHH-A Area of sample site (m2) 1033 Aspect S Slope (degrees) 25-42 Per cent cover of field layer (0-2 m high) 40 (includes tree and shrub regeneration) Per cent cover of tree and shrub regeneration 15 (0-2 m high) 20 Per cent cover of ferns in field layer Height of tallest tree (m) 27.5 Height of canopy (m) (estimated) 27 Dbh of largest tree (cm) 59 Mean dbh of trees > 3 cm dbh (cm) 19 2 1 47 Tree basal area (m ha" ) 166 Number of tree individuals > 3 cm dbh Number of tree species > 3 cm dbh 42

7

HHH-B

BH-C

RH-A

RH-B

1125 _ 3-8 50

1000 NW 25-30 8

1000 N 5-15 c. 1

1000 N 25 c. 3

c. 1

c. 1

0 15 8-15 42 9.5 36 512 51

0.1 12 8-12 25 7.3 28 659 42

5 40 26 26 35 13 32 245 27

5 1 24 16-24 36 7.9 32 347 75

species of saplings, shrubs and herbs, with rough estimates of cover/abundance. Epiphytes and climbers were listed; only at HHH were they investigated quantitatively (Kelly 1985). All species were assigned to life form categories, based on the systems of Raunkiaer (1934) and Richards (1952). Borderline cases were noted between many of the categories. It was found particularly difficult to delimit the categories of dependent life forms; the classification used in the present work is somewhat simplified compared to that used in Kelly (1985). Other life form characteristics of the trees were investigated, including leaf size (using the spectrum of Raunkiaer 1934, as modified by Webb 1959), and leaf seasonality. We distinguished the categories of evergreen, deciduous (seasonally leafless) and partially deciduous (having a marked seasonal reduction in foliage). We tried to list all vascular plant species under forest cover within each study area (5-180 ha), making repeated walks at different seasons in the period 19761985. Our site lists (Appendix) are certainly not complete; we suppose they represent around 95% of the real totals for each area. A few independent records by G. R. Proctor are included for HHH and BH. Species growing in clearings, at forest margins and by trails are excluded from our lists, also any species that were evidently planted and not naturalized. Many voucher specimens were collected; most are lodged at the herbarium of the University of the West Indies, Mona, Jamaica (UCWI), some at the Institute of Jamaica (IJ), Trinity College Dublin (TCD) and Florida State Museum (FLAS). Nomenclature follows Adams (1972) and Proctor (1982) for Angiosperms, Proctor (1985) for Pteridophytes.

Jamaican limestone forests

127

Figure 3. Forest profile at Hog House Hill, by side of recently-cut trail (near Slope site, HHH-A). The palm is Calyptronoma occidentalis. The three aroid climbers are Philodendron lacerum, P. scandens and Syngonium auritum. The scandent fern is Polybotrya osmundacea (lower right). Weedy species colonizing the trail margin include Heliconia caribaea, Bocconia frutescens and a Cecropia peltata seedling (bottom right). Holding scale pole: Dr W. A. Watts. March 1979. Photograph by Dr A. C. Podzorski.

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Soils To represent the heterogeneous soil conditions within each site, 50 or 100 random points were taken, and at each point total soil depth and depth of raw humus layer (if present) were measured. Descriptions were made of one or more sample soil profiles at each site, and samples of the top 5 or 10 cm were taken for analysis. The pH was tested on fresh samples, using a 1:1.5 soihwater paste and a glass electrode pH meter. The samples were dried at 100°C, then tested for loss on ignition, by heating at 500°C for 4 hours. THE STUDY AREAS: DESCRIPTIONS AND RESULTS

Hog House Hill (HHH) The HHH study area appears to be representative of the least disturbed native tall forest in the wettest part of the island. The nearest climatic record is from Ecclesdown, 5 km SE of our site and about 200 m lower in altitude (Figure 2a). This station recorded a mean annual rainfall of 3840 mm; our site was probably somewhat wetter. Every month had a mean rainfall exceeding 100 mm, i.e. was a 'wet month' as defined for the Caribbean region by Beard (1946). Relative humidity probably exceeded 80% for most of the time; however, even in a depression in closed forest, epiphytic ferns and mosses were observed to be shrivelled after a dry spell (Kelly 1985). The area showed an irregular pattern of steep rocky hills and deep depressions. At the beginning of our field studies (1976), disturbance to the forest appeared to be largely confined to depressions and the vicinity of trails. However, sporadic removal of valued timbers, notably Cedrela odorata, had probably occurred over a long period (Kelly 1986). Over half of our study area was clear-felled in 1977-1979, and subsequently replanted with various silvicultural species, mostly exotic. Two sample sites c. 15 X 75 m were selected for enumeration. The Slope site (HHH-A) was chosen as representative of the general forest (cf. Figure 3). It showed no evidence of past disturbance. It was clear-felled in 1977. The Gully Bottom site (HHH-B) was chosen to represent the extreme of shelter, shade and humidity. The forest near to the site showed occasional traces of past human activity, with relict specimens of banana (Musa cv.), cacao (Theobroma cacao), breadfruit (Artocarpus altilis) and planted blue mahoe {Hibiscus elatus). This site was still intact in 1985, apart from some damage caused by the fringe of a hurricane in 1980. Recording of the vegetation was carried out by DLK, TAD, EVJT, N. Allen and others, mainly in 1977-1979. Soils were very variable in depth (Table 2). Even in the Gully Bottom site, there were only scattered pockets of deep soil: median soil depth was actually less than in the Slope site. (Some of the larger depressions in the area had deeper soils, but these had been cleared for cultivation). The surface horizon was a mull humus of loamy texture and well-developed crumb structure, moist at all seasons. The profile shows a more or less gradual change to a mineral soil


129

Table 2. Soil characteristics of the study areas. N = sample size. Hog House Hill Depth of leaf litter, where present (cm) Median depth of raw humus (cm) Median depth of soil (cm)

1-3 0

Broom Hall 1-3

Round Hill 3-5

7

2

(N = 96)

(N = 92)

17.5 9 (N = 96) (N = 95) Colour of upper humic horizon Yellowish brown (10YR 5/6) Dark brown to very dark brown (5YR 2/2) (Munsell scale) (10YR2/2) Reddish brown Colour of upper mineral soil Variable; usually yellowish brown (10YR 4.5/4 to (5YR 4/6) (Munsell scale) 10YR5/8) pH of surface mineral soil 6.4 7.2 (0-5 cm) (0-10 cm) (N = 5) (N = 5) — pH of raw humus 7.9 (N = l) Loss on ignition (%) of surface 42 29 (0-10 cm) mineral soil (0-5 cm) (N = 2) (N = 5) — Loss on ignition (%) of raw 80 (N = 2) humus

8.5

(N = 192) Dark brown (10R 2/2) Reddish brown (5YR 3/3 to 5YR 3/4) 7.5

(0-10 cm) (N = 5) 7.2 (N = 15) 18

(0-10 cm) (N = 4) 80

(N = 4)

with a high clay content and weak crumb structure, sometimes with orange mottlings indicating some degree of anoxia. Unlike the other two study areas, there was evidence of surface leaching: mean pH in the top 5 cm was 6.4 (N = 5) (Table 2), whilst at 20-30 cm depth it rose to 7.3 (N = 5). Floristics and life form spectrum. The largest taxonomic group were the ferns: 46 Polypodiaceae sensu lato, 9 Hymenophyllaceae, 3 Cyatheaceae and 1 Marattiaceae. The ferns dominated the field layer in terms of cover (20-40%), numbers of individuals and numbers of species; they were most abundant and diverse in the depressions. The best-represented Angiosperm families were Orchidaceae (25 species, mostly epiphytes), Rubiaceae (21 species, mostly shrubs or small trees), Euphorbiaceae (11 species, trees and shrubs) and Melastomataceae (11 species, mostly shrubs or small trees). Mechanically dependent species were well represented (Table 3). The greatest numbers of epiphyte species were in the Polypodiaceae (29 species) and Orchidaceae (20 species); the greatest numbers of individuals were probably in the Bromeliaceae (8 species, of which 7 were 'tank epiphytes'). Rootclimbing aroids were abundant (Philodendron spp., Syngonium auritum). The large climbing fern Polybotrya osmundacea was conspicuous in the lower strata (cf. Figure 3). Bryophytes were abundant on tree trunks, rotting timber and rock outcrops. Epiphyllous leafy liverworts were common on understorey trees and saplings. In the two enumerated sites there were about 52 tree species (Table 4) of

130

D.L.KELLY et al.

Table 3. Distribution of life form categories within the study areas, and within a sample site from each. Study areas: Area:

Hog House Hill (HHH) .

% of total

0 135 6 30 0 0 32 37 1 1 2 3

Round Hill (RH) ic 50 ha

0 54.7 2.4 12.1 0 0 13.0 15.0 0.4 0.4 0.8 1.2

247

Sample sites:

Mesophanerophytes Microphanerophytes Ms/Me present as saplings only Shrubs under 2 m Herbs (autotrophs) Climbers Epiphytes Epiphytic hemiparasites Woody hemiepiphytes Stranglers

Broom Hall (BH) c. 5 ha

No. 4 cm dbh. Species are listed in descending order of average Importance Value (% individuals + % basal area/2). Abbreviations: %I = % individuals, %BA = % basal area, Me = microphanerophyte, Ms = mesophanerophyte, Str = strangler, Mac = macrophyll, Mes = mesophyll, Mic = microphyll, Not = notophyll. Slope Species Cyathea grevilleana Calophyllum calaba Omphalea triandra Dendropanax arboreus Calyptronoma occidentalis Turpinia occidentalis Hemandia catalpifolia Clethra occidentalis Alchornea latifolia Guarea swartzii Beilschmiedia pendula Rondeletia portlandensis Drypetes alba Sapium jamaicense Pouteria multiflora Macrocnemum jamaicense Nectandra patens Hyeronima jamaicensis Comocladia pinnatifolia Casearia sylvestris Andira inermis Trichilia moschata Coccoloba longifolia Trophis racemosa Eugenia amplifolia Conostegia icosandra Gyrotaenia microcarpa Nectandra antillana Coccoloba swartzii Sloanea jamaicensis Ocotea leucoxylon Ficus sp. (1 sp.) Cordia laevigata Cedrela odorata Exothea paniculata Faramea occidentalis Plumeria obtusa Cinnamomum montanum Mammea americana Wallenia subverticillata Piper arboreum var. arboreum Picramnia antidesma Psychotria foetida Chimarrhis cymosa Nectandra sp. Palicourea sp. (1 sp.) Allophylus cominia + jamaicensis Eugenia other spp. (3-4 spp.) Undetermined

Gully Bottom

%I

%BA

%I

%BA

1.2 7.8 25.1 10.2 3.6 1.8 1.8 0.6 0.6 3.0 3.6 — 1.8 — 1.8 6.6 2.4 0.6 1.2 0.6 1.2 1.2 1.2 1.2 1.8 — — 0.6 0.6 0.6 0.6 0.6 0.6 — 0.6 0.6 _ 0.6 0.6 0.6 0.6 _ 0.6 _ 0.6 — 1.8 4.8 3.6

0.2 14.0 16.9 10.4 3.4 9.9 1.5 0.8 0.4 4.2 5.7 — 5.7 — 4.7 1.3 3.0 4.7 0.0 0.0 1.3 0.8 0.2 0.4 0.2 — _ 0.8 0.0 0.0 0.2 0.4 0.0 _ 0.4 0.0 — 0.4 0.2 0.2 0.0 _ 0.0 _ 0.0 — 0.2 1.1 6.3

36.4 5.7 3.6 5.3 0.8 2.8 6.1 3.2 2.0 4.5 — 2.0 0.4 0.4

14.2 14.2 1.6 12.6 2.5 11.7 6.9 6.9 0.9 4.1 — 6.9 — — 0.3 0.9 0.3 0.6 — _ 0.3 0.6 — 0.9 0.6 _ 0.3 0.6 _ — 0.6 _ 0.6 _ _ — — 0.0 — 0.0 — 0.0 10.1 0.3

2.4 1.2 — — 0.8 0.4 — 0.8 0.8 — 0.4 0.4 — _ 0.4 — _ 0.4 — — — — 0.4 — 0.4 — 0.4 16.6 0.8

Life form Me Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Me Ms Ms

Ms Ms Ms Me Ms Ms Ms Ms Ms Ms Str Ms Ms Ms Me Ms Ms Ms Me Me Me Me Ms Ms Me Ms Ms •?

Leaf /leaflet size

Mes Mac Mes Mes Not Mac Not Not Not Not Mic Not Mes Mes Mes Not Not Not Not Mic Mes Mac Mes Mac Mes Not Not Mic Mes Not Mes Mes Mes Not Mes Mes Not Mes Mes Mic/Not ?

132

D. L. KELLY et al. 80

70

o

80

,

Broom Hall

70

60

60

50

50 o

40

I

d)

a

CO

o

30

Hog House Hill

40

Round Hil Hog House Hill

30

5 =

20

20

10

10

(a)

8 12 16 Area (m 2 x 1 02)

20 (b)

400 800 Number of trees

1200

Figure 4. Tree species diversity in the three forests, (a) Tree species-area curves, (b) Tree species against numbers of individuals. In both graphs, each curve follows the order of enumeration within the sample sites.

canopy species; a middle stratum at 10-13 m contained a conspicuous society of the palm Calyptronoma occidentalis: a lower stratum at 2-7 m was composed largely of the tree-fern Cyathea grevilleana. In HHH-B the trees were more slender than HHH-A and the total basal area was lower (Table 1). Site HHH-B included several fallen rotting trunks of large trees, apparently blown down. Thus the lower biomass may reflect past hurricane disturbance, human disturbance, or both. The general vegetation was evergreen, but Ceiba pentandra was deciduous, and we noticed that several other trees were leafless or nearly so for a short time when flushing new leaves (Ficus sp., Coccoloba longifolia, Sapium jamaicense and Erythroxylum areolatum; observations of 17 January 1983). Leaves of the trees are mostly mesophylls sensu stricto, followed in frequency by notophylls (Figure 5). There was a very great range of leaf size among herbaceous species, from megaphyll (e.g. Heliconia caribaea) (Figure 3) to leptophyll (e.g. Peperomia emarginella). Broom Hall (BH) This study area was chosen as a relatively undisturbed example of the limestone forests of the intermediate-rainfall areas of central Jamaica. The study area was on a knoll at the northern edge of a tongue of rugged limestone terrain. At the start of our study, the steeper hillslopes in this area retained an extensive cover of more or less undisturbed native forest. To the north and east of the site is a wide alluvial valley, largely cultivated. A few kilometres to


133

60

Hog House Hill 40

20

T&P

Na

Mi

No

Me

Broom Hall

40

71—1

20

T&P

80

Na

M

No

Me

Ma

-

/

60

40

Ma

Round Hill

-

/

-

/

/

20

^-r~i F~l T&P

Na

7~\—[/-

/ Mi

No

Me

Ma

Leaf size

Figure 5. Leaf size spectra of the trees in the forest sites, by species (shaded columns) and by species weighted by basal area (open columns). Classification of Raunkiaer (1934) as modified by Webb (1959). Na = nanophyll, Mi = microphyll, No = notophyll, Me = mesophyll sensu stricto, Ma = macrophyll, T & P = palms and tree ferns.

the south is the siliceous 'Central Inlier', an area largely covered by cultivations and secondary vegetation. Mean annual rainfall at Cave Valley, 2 km north-east and about 100 m lower in altitude, was 1570 mm (Figure 2b). There is a fairly well-marked dry season, with four months each having a mean rainfall below 100 mm ('dry months' sensu Beard 1946). The forest at this study area had probably been 'creamed' of occasional timbers. Also, relics of cultivation were twice found under the forest canopy (isolated plants of coffee, Coffea arabica and yam, Dioscorea alata). Adjacent parts of the hillside had been more or less cleared for small-scale cultivations. However, we consider that the floristic composition of the forest had been little altered from the natural condition, except at the margins and by the

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trails. In 1984/85 the main forest area was cut over and drastically altered by the removal of a half to two-thirds of the trees and most of the shrubs and climbers. Preliminary listing of species was done by GG in 1978. Two subsites, each 10X50 m, separated by about 25 m, were enumerated in 1983 by DLK, EVJT, VK and assistants. The upper sub-site (BH-A) followed an irregular ridge, the lower (BH-B) a weakly-marked gully; the general slope was about 23-30°. Data for the two sub-sites are combined into a single, mildly heterogeneous 'Broom Hall combined site' (BH-C 1000 m 2 ; altitude c. 670 m). The BH study area was much smaller than the other two (Table 1), mainly because of the drastic alteration of the forest cover prior to our last visit (1985). Figure 6 illustrates a somewhat disturbed stand of a similar forest in the same region. A discontinuous mat of raw humus, held together by roots, lies on and among the loose limestone rubble and on outcrops of bedrock and pockets of mineral soil. This has the physical characteristics of a mor humus but differs in its alkaline reaction (Table 2). Where the raw humus was underlain by mineral soil, the transition between the two horizons was abrupt. The mineral soil was a clayey loam with dense hard aggregates; it contained few fine roots. Floristics and life form spectrum. The ferns were again the largest taxonomic group, with 28 species, all Polypodiaceae sensu lato; however, there were no tree ferns or large climbing ferns, and the total cover of ferns in the field layer was only about 1% (Table 1). The Angiosperm flora was rich in Orchidaceae (16 species) and Bromeliaceae (13 species) - both groups largely epiphytic also Rubiaceae (13 species, mostly shrubs and small trees) and Myrtaceae (12 species, all trees). The bromeliad flora was richer than at HHH, with large tankepiphyte forms occurring right down to ground level (Aechmea paniculigera being the most abundant), and xeric Tillandsia species predominating at higher levels. The ground flora was poor in Angiosperm species; 22 out of 30 ground herbs were Pteridophytes (Appendix). Sub-site BH-B had a richer and more mesic ground flora than BH-A. Mosses were plentiful on rock outcrops and tree bases, covering 5-10% of the ground area. Thirty-four lichen taxa were recorded from the study area by Ms J. Dixon (pers. comm.). The two 500 m 2 sub-sites differed considerably. In BH-A (ridge sub-site) a single species, Guapira fragrans, comprised 21.6% of all tree individuals, whereas BH-B (gully sub-site) contained only a single individual of this species. In BH-B no one species predominated. The latter sub-site was distinguished by the presence of Cinnamomum montanum and of Terminalia latifolia, an endemic tree especially characteristic of depressions in Cockpit Country terrain. Many tree species (27 out of 75) were represented in the combined site enumeration by only a single individual, and a further 12 species by two individuals only (Table 5). The species-area curve indicates that the beginning of an asymptote had probably been reached (Figure 4a). Forest structure and physiognomy. The canopy was irregular and variable in


135

Figure 6. Intermediate-rainfall forest at Cedar Valley, 4 km NNE of Broom Hall. The physiognomy was similar to the Broom Hall forest, except that many of the larger trees had been removed by selective cutting. The large ground bromeliad is Aechmea paniculigera and the large leaves above it belong to a sapling of Ocotea staminea. Photograph by GG.

height. In BH-A it was c. 16-20 m, with few large trees; in BH-B Cedrela odorata and Terminalia latifolia reached c. 24 m. There was no evident demarcation of strata. The vegetation was largely evergreen, except for Terminalia which is fully deciduous. We do not have records of deciduous/evergreen behaviour at this site, but of the 17 species recorded at RH as variously deciduous only two (Bauhinia divaricata and Guettarda argentea, both partially deciduous at RH) were recorded as present at BH. Leaves of the trees were mostly notophylls, but microphylls and mesophylls are also common (Figure 5). Round Hill (RH) This hill was selected as retaining some of the least disturbed stands of native tall forest remaining in the dry southern part of the island. The nearest long-term rainfall record is from Milk River (Rest), 3 km NE of our study area and about 300 m lower in altitude. For this station, the mean annual rainfall for the period 1931-60 was 1219 mm (Figure 2c). For the period 1951-80, complete records exist for 20 years; the mean annual rainfall for these is only 899 mm. However, the use of long-term averages obscures the character of drought-prone climates, especially where, as in Jamaica, the seasonality of rainfall is highly irregular (cf. discussion in Whitmore 1975). Examination of data from Milk River for suites of individual years reveals a mean of 8.9

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Table 5. Tree species composition in the combined Broom Hall site (BH-C), including all trees > 3 cm dbh. Conventions as in Table 4. WHE = woody hemiepiphyte.

Guapira fragrans Bumelia nigra Drypetes lateriflora Nectandra patens (sensu lato) Pisonia subcordata Coccoloba swartzii Cinnamomum montanum Bauhinia divaricata Prunus myrtifolia Terminalia latifolia Cordia gerascanthus Amyris balsamifera Eugenia axillaris vel aff. Hyperbaena prioriana Clusia rosea Dendropanax arboreus Ocotea staminea Pouteria multiflora Xylopia muricata Cedrela odorata Cupania glabra Comocladia pinnatifolia Ficus pertusa Jatropha divaricata Zuelania guidonia Ficus trigonata Exothea paniculata Fagara culantrillo Allophylus cominia Casearia sylvestris Calyptranthes chytraculia Gyrotaenia spicata A teramnus integer Alchornea latifolia Coccoloba longifolia Xylosma fawcettii Allophylus jamaicensis Blakea trinervia Pimenta dioica Licaria triandra Brosimum alicastrum Calyptranthes pallens Fagara elaphantiasis Krugiodendron ferreum Tabebuia platyantha Tetrazygia hispida var. laevior Matayba apetala Pithecellobium alexandri var. troyanum Sapium cuneatum Nectandra coriacea Ficus maxima Simarouba glauca Nectandra antillana Roystonea altissima Lonchocarpus latifolius Oxandra lanceolata

%I

%BA

Life form

Leaf size

14.2 1.1 4.8 2.9 1.1 3.4 1.4 3.1 3.4 1.1 2.3 2.6 2.3 0.6 2.0 2.6 2.0 1.1 2.0 0.3 2.3 2.6 1.4 2.3 1.1 2.0 1.7 1.1 1.1 1.1 1.4 1.1 0.9 0.6 1.1 0.9 0.9 1.1 0.6 1.1 0.6 0.9 0.3 0.9 0.3 0.9 0.9 0.6 0.6 0.3 0.3 0.6 0.6 0.3 0.3 0.6

13.3 7.4 3.6 5.0 5.4 3.1 4.7 2.4 2.1 3.8 2.5 2.1 1.9 3.6 2.1 1.4 1.6 2.4 1.5 3.0 1.0 0.6 1.7 0.8 1.8 0.5 0.8 1.3 1.0 0.9 0.4 0.5 0.7 0.9 0.6 0.6 0.5 0.3 0-.7 0.2 0.6 0.2 0.8 0.2 0.8 0.4 0.2 0.4 0.4 0.7 0.7 0.3 0.2 0.5 0.5 0.1

Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms Ms WHE Ms Ms Ms Ms Ms Ms Me Str Me Ms Str Ms Ms Ms Ms Me Me? Ms Ms Ms Ms Ms Climber Ms Ms Ms Ms Ms Me? Ms Me Ms Ms Ms Ms Str Ms Ms Ms Ms Me?

Mic Not Mic Not Not Mic Not Mes Not Mes Mes Not Mic Not Mes Mes Mes Mes Mic >Not? Not Not Mic Mes Not Mes Not Mic Mes Not Mic

3 cm dbh. Coventions as in Table 4. Leaf size: Nan = nanophyll. Leaf seasonality: D = deciduous, E = evergreen, SD = partially deciduous (see Methods). Hill top site Species Metopium brownii Thrinax parviflora Ateramnus lucidus Drypetes lateriflora Bumelia salififolia Diospyros tetrasperma Brosimum alicastrum Coccoloba krugii Piscidia piscipula Calyptranthes zuzygium Calyptranthes pallens Bursera simaruba Guettarda argentea Tabebuia riparia Hypelate trifoliata Amyris elemifera Eugenia axillaris Coccoloba diversifolia Nectandra coriacea Eugenia foetida Fagara spinosa Krugiodendron ferreum Erythroxylum confusum Bauhinia divaricata Bunchosia media Canella winterana Guapira fragrans Guapira obtusata Erythroxylum rotundifolium Laetia thamnia Calliandra paniculata May tenus jamaicensis Ouratea laurifolia Polygala jamaicensis Erythroxylum sp. Bourreria venosa Ficus pertusa May tenus clarendonensis Manilkara sideroxylon Trichilia glabra Gyminda latifolia Coccoloba longifolia Croton eluteria Exothea paniculata Fagara flava Citharexylum fruticosum Simarouba glauca Coccoloba swartzii Erythroxylum areolatum Schoepfia obovata Rondeletia stipularis Ziziphus sarcomphalus Casearia hirsuta Eugenia monticola Pseudalbizzia berteroana Amyris balsamifera/elemifera Astrocasia tremula Guettarda elliptica Bemardia dichotoma Casearia guianensis Comocladia velutina Myrsine acrantha

Slope site

%I

%BA

%I

%BA

form

2.3 15.0 19.0 13.5 1.2 3.1 15.8 2.9 0.2 0.8 3:5 0.2 — 2.0 1.4 1.0 1.2 0.8 3.3 0.4 — 1.6 0.2 1.2 — 0.2 1.0 0.4 — 1.0 _ 0.8 0.8 0.4 — — 0.2 0.2 0.2 0.2 0.2 0.2 0.4 0.2 0.2 0.2 0.2 0.4 0.4 0.2 0.2 0.2 0.2 _ 0.2 0.2 0.2 — 0.2 0.2 0.2

12.6 14.5 8.1 8.3 13.6 2.5 8.2 1.4 0.6 0.5 6.3 0.5 — 4.3 1.8 0.2 0.6 2.0 0.7 0.0 — 1.5 0.6 0.6 _ 0.2 0.7 1.2 _ 0.3 — 1.5 0.9 0.9 — — 0.8 0.7 0.6 0.6 0.3 0.2 0.4 0.3 0.2 0.1 0.2 0.3 0.1 0.3 0.2 0.1 0.1 — 0.1 0.1 0.1 — 0.0 0.0 0.0

19.4 2.0 4.7 2.9 2.9 11.2 — 1.1 4.0 5.0 0.3 2.4 5.5 0.6 1.7 3.5 2.7 0.9 1.2 3.1 3.0 0.8 1.2 1.1 2.1 1.4 0.6 0.6 1.5 1.1 1.4 — _ 0.3 0.8 0.6 — — — — 0.2 0.3 — 0.2 0.3 0.2 0.2 _ 0.2 — — — 0.2 _ 0.2 — — — 0.2 _ — —

36.1 4.9 1.7 2.0 4.4 6.1 — 3.7 6.8 4.3 0.2 6.2 2.7 0.8 1.8 1.4 1.4 1.9 0.5 1.6 1.3 0.5 1.7 0.4 0.6 1.2 0.5 0.5 1.1 0.4 0.7 — — 0.2 0.8 0.4 — — — — 0.1 0.1 — 0.1 0.1 0.3 0.2 _ 0.4 — — — 0.1 _ 0.2 — — — 0.0 _ — —

Ms Ms Ms Ms Ms Ms Ms Me Ms Me Ms Ms Me Ms Ms Me Me Ms Ms Me Me Me Me Me Me Ms Me Ms Me Me Ms Me Me Me Mc(?) Ms Str Ms Ms Ms Me Ms Ms Ms Ms Ms Ms Ms Ms Me Me Ms Me Ms Ms Ms/Me Me Me Me Me Me Me

size

Leaf seasonality

Mic (Palm) Mic Mic Mic Mic Mes Mic Not Mic Mic Mic Mes Mic Mic >Nan Mic Not Not Mic Mic Mic Mic Mes Mic Mic Mic Not Nan Mic Nan Mic Not Mic ? Mic Mic Mic Not/Mes Mic Mic Mes Mic Not Not Not/Mes Mic Mic Mic/Not Mic Mic Mic Not Mic Nan Nan/Mic Not/Mic Mic Not Not Mic Mic

D E E E E E E E SD E E D SD SD E E E E E E E E SD SD E E E E SD E E E E SD E SD E E E SD E E E E D SD E E E E E E SD E SD E E SD E E E E

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a greater degree of past disturbance. Metopium ('Burnwood', Anacardiaceae) is avoided by tree-cutters because of its caustic sap, and Bursera because in Jamaica its timber is considered worthless for charcoal. (Both these species were prominent in dry secondary forest at Nain, 25 km WNW of RH, but not in adjacent primary forest (Howard & Proctor 1957a)). The species-area curve (Figure 4a) shows that a sufficiently large area was enumerated to be representative of the forest as a whole. Forest structure and physiognomy. The canopy was generally continuous but not dense, 8-15 m high, without large emergents. In RH-A there was a moderately distinct understorey with abundance of the fan-palm Thrinax parviflora 1-9 m high (cf. Figure 6), also Ateramnus lucidus. Forty-four of the 60 tree species in the sites were found to be evergreen and 16 species either deciduous or partially deciduous (Table 6). The variously deciduous species represent 27% of the species, 24% of the individuals and 37% of the basal area of the Round Hill combined sites. The leaf size was mainly microphyll (Figure 5).

DISCUSSION: A COMPARISON OF THE THREE FORESTS

Human influence and other biotic factors The degree of human influence on our study areas is difficult to assess. All areas had been affected to some extent by selective removal of prized timbers, e.g. Cedrela odorata from the HHH district and Bumelia salicifolia from RH (see above). We consider that in sites RH-B, HHH-B and BH-C the forest structure had been altered to some degree by timber extraction (producing larger numbers of smaller trees; cf. Table 1), but the floristic composition had remained essentially that of primary forest. Introduced species, mostly pantropical food plants and weeds, were present in all study areas along trails and forest margins and in clearings. In the case of three tree species, we were uncertain whether the individuals in our study area were planted, spontaneously derived from planted trees, or indigenous to the forest of the area: Ceiba pentandra, Hibiscus elatus (cf. Adams 1971), Pimenta dioica (cf. Adams 1971, Howard & Proctor 1957a). In no case was there evidence of introduced species becoming naturalized to any significant extent within the forest area away from trails. No signs of grazing or browsing by animals were observed in any of the forest areas. Two herbivorous mammals are apparently widespread in the John Crow Mountains, the endemic rodent Geocapromys brownii (Fisher), (Oliver 1982) and the feral pig (Sus scrofa); however, we saw no evidence of either at HHH. Floristics and life form spectra compared The total number of species recorded from each study area increased from the driest, RH, through the intermediate, BH, to the wettest, HHH (Table 2). However, the BH study area was much smaller than the others, and it seems probable that the total vascular plant flora was actually higher in this inter-


141

mediate-rainfall area than in the rain forest area. The number of tree species recorded at BH was considerably greater than at either of the other areas. The richness of the tree flora is further explored by species-area and speciesindividual curves (Figure 4a, b). When cumulative number of species is plotted against cumulative number of individual trees enumerated, BH is richest by far, i.e. it has the highest alpha-diversity. The curves for HHH and RH are remarkably similar. Comparisons are complicated by the fact that individual trees are on average much larger at HHH than at the other study areas (Table 1). Thus, at HHH there are far fewer trees per unit area. Hence the greater number of tree species per unit (small) area at RH compared with HHH is merely a result of the high density of trees at RH. At all sites, tree seedlings and small saplings comprised a substantial proportion of the total ground cover (Table 1). The herb flora declined steeply from the wettest to the driest forest: HHH had 47 species, including 21 ferns; BH 30 species, including 21 ferns, and RH only 8 species, including 3 ferns (Table 3 and Appendix). The total cover of herbs declined in parallel (Table 1). Holosaprophytic herbs were recorded at both wet and dry sites (Leiphaimos spp. (Gentianaceae) at HHH and RH, Gymnosiphon spp. (Burmanniaceae) at HHH only). The numbers of epiphyte species fell steeply from the wettest to the driest forest: HHH had 73 species, including 33 ferns, BH 37 species, including 7 ferns, and RH only 7 species, including 1 fern. BH was richer in bromeliads than any other site, but poorer in orchids than HHH. The proportion of climbers in the total flora increased from wet to dry (Table 3). Stranglers (Ficus spp.) and other woody hemiepiphytes (mainly Clusia spp.) were frequent in all three areas. The epiphytic endoparasite Pilostyles globosa (Rafflesiaceae) - a life form previously unreported from the West Indies - was discovered at BH by GG (Proctor 1982). The results of an analysis of floristic similarity between the tree lists from our study areas are presented in Figure 8; comparisons are also made with forest at Lydford (Howard & Proctor 1957a, b) and at Portland Ridge (Loveless & Asprey 1957). The results show that the BH area is closer to HHH than to RH. They also demonstrate a strong floristic resemblance between RH and Portland Ridge, and a weaker resemblance between BH and Lydford. Comparisons of the total floras give a similar picture. It appears that tree and shrub species tend to have wider ecological ranges than herb and epiphyte species. Ten tree species were common to all study areas, also one strangler, one climber and one mistletoe. Only a single herbaceous species was common to all sites, the facultative epiphyte Anthurium grandifolium. In terms of the herb and epiphyte floras, BH was intermediate between HHH and RH, with rather few species in common with either. Within the Jamaican context, the BH study area clearly has a remarkably rich flora within a small area. This richness relative to both high- and lowrainfall extremes may be partly explained in terms of greater niche diversity (cf. Connell 1978). The karst terrain and markedly seasonal climate interact

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D. L. KELLY et al.

100 -,

Round Hill

Portland Ridge

Broom Hall

Lydford Hog House Hill

75-

•5

50-

I

25-

o-i Figure 8. Dendrogram analysing degrees of similarity between the tree floras of the three study areas, and of forest at Lydford (Howard & Proctor 1957a, b) and at Portland Ridge (Loveless & Asprey 1957). Single-linkage cluster analysis following SLC and TREE programmes of Orloci & Kenkel (1985), using the Index of Similarity of Sorensen (1948) (S = 100X 2c/a + b, where a = number of species in area A, b = number of species in area B, and c = number of species common to both areas).

to produce a fine-scale environmental patchiness, so that plants adapted to a wide range of soil and atmospheric moisture regimes co-exist in close proximity. Thus moisture-demanding species such as Lastreopsis effusa and Guzmania lingulata, both present also at HHH, grow at BH within a few metres of drought-adapted species such as Polypodium polypodioides and Hylocereus triangularis, both present also at RH. These intermediate-rainfall forests also appear to show great variation between adjacent sites (beta-diversity): not only between hilltop, midslope and depression, but also between nearby sites of identical topographic situation. This unpredictable element is commented on by Howard & Proctor (1957a) with regard to the Lydford area: 'Species and genera present, often dominant in one mixed forest on one hilltop, will be fewer in number or absent on the adjacent hill.' Structure and physiognomy Tree stature was lowest by far in the drought-prone RH area (Table 1). The greater height and girth of trees at HHH compared to BH is perhaps best explained in edaphic terms: soil at HHH was considerably deeper, and probably more fertile (Table 2). Grubb & Tanner (1976) consider that the general canopy of the Lower Montane Rain Forest of the John Crow Mountains at 770 m was 24-30 m high, which agrees with our data for HHH. Mean tree leaf size showed a marked decline from HHH (mesophylls preponderant) through BH (notophylls preponderant) to RH (68% of species microphylls sensu stricto) (Figure 5). There is also a decrease in leaf size diversity, the RH trees being remarkably uniform in this respect. Microphylls sensu lato were preponderant at Portland Ridge (Loveless & Asprey 1957), but leaf size was less uniform than at RH. Decreasing leaf size with increasing aridity is a trend found in many tropical regions (Richards 1952). There is a gradient from overwhelmingly evergreen forest at HHH, through


143

evergeen with a handful of deciduous species at BH, to forest with a major deciduous component at RH (Table 6). At BH only a single canopy species was known to be deciduous (Terminalia latifolia), whereas at RH 27% of tree species were deciduous or partially deciduous, including five of the 15 most important species. Loveless & Asprey (1957) found that at Portland Ridge 50% of mesophanerophytes were deciduous or partially deciduous, but only 21% of microphanerophytes; at RH this stratification was less marked. The proportion of trees with compound leaves was 22% at HHH, 20% at BH and 26% at RH, showing no evident trend. Physical armament increased with increasing aridity: spines were recorded on 4 species at HHH (4 trees/shrubs), 7 species at BH (4 trees, 3 climbers) and 9 species at RH (6 trees/shrubs, 3 climbers). Caustic sap and/or irritant hairs were noted for two species in each study area. Trees with well-developed buttresses (Ceiba pentandra) and stiltroots (Symphonia globulifera, Cecropia peltata) were seen only at HHH. The only cases of cauliflory were the tree Malpighia punicifolia at RH and the woody climber Passiflora oblongata (all areas). The stem succulent life form was absent from HHH; it was represented at BH by two cacti (both epiphytic/rootclimbing), and at RH also by two cacti, one a root-climber and one a microphanerophyte. Basal areas for our forest sites range from 28-47 m 2 ha"1 (Table 1). There is no consistent difference between the three forests. The mean for all our sites is 35 m 2 ha"1, close to the 36 m 2 ha"1 given by Dawkins (1961) as a global mean for tropical lowland rain forest. Proctor et al. (1983a, b) found a basal area of 37 m 2 ha"1 in rain forest on limestone in Sarawak; in a lowland karst region of west Malaysia (rainfall 2000-3200 mm yr"1), Crowther (1982) found values ranging from 16-63 m 2 ha"1, with a mean of 27 m 2 ha"1. Soils The patchy distribution of soil in these rocky sites is analysed in Table 2. The substantially greater volume of soil at HHH is probably an important ecological factor, independent of rainfall. The basic soil type at BH and RH is a terra rossa, a reddish clayey loam composed largely of iron and aluminium oxides, formed by prolonged weathering of hard limestones under tropical conditions. Such soils are usually leached of calcium carbonate and acid in reaction (cf. Duchaufour 1970); our samples of the upper mineral horizon were mostly alkaline (Table 2), which is not surprising since they were from small soil pockets surrounded by limestone rock. This soil type is classified in the Jamaican Soils Survey as Bonny Gate Stony Loam (Anon. 1958-64). The most remarkable feature of the skeletal soils at BH and RH was the patchy accumulations of a raw humus (mean loss on ignition 80%), like mor but alkaline in reaction, reaching depths of over 30 cm at both sites (Table 2). The accumulation of raw humus under such conditions appears to be very unusual, and warrants further investigation. No accumulations of raw humus

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were found at HHH; however in lowland rain forest over limestone in Sarawak, Proctor et al. (1983a, b) recorded organic soils with loss on ignition values of 82%. The general effect of the very limited soil volume and very rapid drainage in these forests is for the vegetation to be more xerophytic than would be expected from consideration of the rainfall regime alone (cf. Beard 1944, 1946; and see below). Biogeography The wet and intermediate-rainfall areas contain a high proportion of Angiosperm species endemic to Jamaica: 40% of all species at HHH and 36% at BH (Table 7). These figures include significant numbers of local endemics, species each confined to a restricted region of the island. Species new to science have been described from both study areas during the time-span of our investigations: HHH is the type locality for Eugenia kellyana Proctor, Aechmea decurva Table 7. Phytogeographical analysis of the forest flora in each study area. Each species is classified according to the limit of its geographical range, based on information in Adams (1972) and Proctor (1982, 1985). Greater Antilles = Cuba, Hispaniola, Jamaica, Puerto Rico and Cayman Islands. West Indies as delimited in Howard (1974). Hog House Hill (HHH) No. of species

1.1-3 contiguous parishes (local endemic) 2. Jamaica (endemic) 3. Greater Antilles 4. West Indies 5. New World 6. Old and New World (+/— pantropical) Total number of species included in analysis Excluded (identification uncertain at species level)

20 65 16 19 91 2

% of total /. Angiosperms 9.4 30.5 7.5 8.9 42.7 0.9

Broom Hall (BH) No. of species

%of total

Round Hill (RH) No. of species

9

4.4

1

0.8

65 24 10 96 2

31.6 11.7 4.9 46.6 1.0

26 16 14 64 3

21.0 12.9 11.3 51.6 2.4

213

206

124

6

11

1

1.1-3 contiguous parishes 2. Jamaica , 3. Greater Antilles 4. West Indies 5. New World 6. Old and New Worlds

0 6 7 1 42 5

Total number of species included in analysis Excluded (identification uncertain at species level)

61

//. Pteridophytes 0 9.8 11.5 1.6 68.8 8.2

%of total

0 2 1 5 19 2 29

0 6.9 3.4 17.2 65.5 6.9

0 0 0 0 4 0

0 0 0 0 100 0


145

Proctor (Proctor 1982) and Wercklea flavovirens Proctor ex Fryxell (Fryxell 1981) and BH for Jacaima parviflora (Proctor 1982). The highly endemic flora of the John Crow Mountains finds parallels in the fauna, notably the land snails. A possible explanation of this endemism may relate to the geological history of the region. It is possible that during the emergence of the island in the Middle Miocene (Eva & McFarlane 1985), the eastern block, consisting of the Blue and John Crow Mountains, may have emerged as a land mass separate from the large block of central and western Jamaica. Differentiation of the biotas could have occurred before emergence of the area of the Wagwater Trough which connects the two blocks. There is at present no geological evidence which can either support or refute this scenario (G. Draper, in litt., 1.XII.1986). The reason for the high proportion of local endemics in the upland forests of central Jamaica is less clear (cf. Adams, in press). (Howard (1974) comments that the flora of the Antilles has been worked on by many taxonomists commonly regarded as 'splitters'; however, whilst a few taxa may be not really endemic and/or not really worthy of species rank, there seems no reason to doubt the general picture emerging). The dry areas of southern Jamaica are relatively low in endemism. At RH only 24% of the Angiosperm flora was endemic to Jamaica, and only one species, Calliandra paniculata, is known only from the locality. The numbers of Jamaican endemics in the Pteridophyte lists increases from dry to wet: RH has none, BH has 2 and HHH has 6 (Table 7). Surprisingly, even at HHH the endemism rate (9.8%) is lower than for the island Pteridophyte flora as a whole (cf. Proctor 1985). THE JAMAICAN FORESTS IN RELATION TO OTHER TROPICAL FORESTS

Our HHH forest is clearly lower montane rain forest, a formation characteristic of a climate with no significant dry season, but significantly cooler than lowland rain forest. This formation is characterized more fully by Grubb et al. (1963): it differs from lowland rain forest in the lower canopy height, the infrequency of well-developed buttresses on the trees, the absence of cauliflorous trees, the rarity of thick-stemmed lianes (Entada gigas was the only one at HHH) and the great abundance of vascular epiphytes. The best-developed lowland rain forest surviving in the West Indies today is in Dominica, on siliceous rock (Beard 1949, Lugo et al. 1981). Lower montane rain forest occurs (or occurred) throughout the more mountainous islands of the West Indies between c. 260-800 m (Beard 1944). Cuba has a range of limestone forests, from very wet to very dry (Borhidi, in press, Borhidi et al. 1979, Borhidi & Muniz 1980, Seifriz 1943, Smith 1954). Our wet study area (HHH) corresponds to the Alliance CalophylloDipholion Borhidi 1979, Order Dipholi-Calophylletalia Knapp 1964. In a 625 m 2 plot in rain forest on limestone at 350 m altitude, Borhidi (in press) records 80 vascular plant species, including 48 trees and shrubs, indicating a flora of

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similar richness to HHH. Twelve trees/shrubs and two epiphytes were common to Borhidi's plot and the HHH study area. Ciferri (1936) (a major but rarely-cited work) classified the forests of Hispaniola into rain forest, mesophytic, subxerophytic, hyperxerophytic and alpine forest. He distinguished two types of rain forest, the Spondias-Oreodoxa association on neutral soil and the Sloanea-Ormosia association on acid soil. Both types were recorded over calcareous rock. The former type was largely destroyed in pre-Columbian times; the few remaining fragments were in areas with a welldistributed rainfall of 1500-2500 mm yr"1. Unlike HHH, the upper tree strata were partially deciduous, tree ferns were absent and epiphytic ferns were inconspicuous. The Sloanea-Ormosia association was found where rainfall exceeded 2500 mm yr"1. The upper soil horizon had a pH (4.8—) 5.0-6.0, with a stratum of litter decomposing slowly and incompletely (suggesting an incipient mor humus). Tree ferns were present and the epiphytic flora was richer than in the other association. Ciferri lists 38 species (including 19 trees and shrubs) as typical of or frequent in the Sloanea-Ormosia association; however, of these only one palm, one climber, two epiphytes and two ground herbs were present in the HHH study area. The BH forest seems to come closest to the Evergreen Seasonal Forest formation of Beard (1944), though lower in stature and smaller-leaved than the typical formation. This formation is characteristic of regions with short but marked dry seasons. Borhidi et al. (1979) and Borhidi (in press) describe several seasonal evergreen forest communities in Cuba, but none resembles closely our BH forest. Ciferri (1936) described the relics of Hispaniolan 'mesophytic forest' as a Catalpa-Swietenia association. These were in areas with a rainfall of 11251250 (—1500) mm yr"1; the dry seasons were never rigorous. This type was moderately rich floristically, and very rich in local elements. Swietenia mahagoni, the West Indian mahogany, was stated to be one of the most characteristic species. In Jamaica this species was formerly a conspicuous component of upland forest on limestone in central Jamaica (e.g. Long 1744), but it is now rare in natural forest. A representative list of 26 species from the Catalpa-Swietenia association includes two trees and one woody hemi-epiphyte present in the BH study area. The RH forest comes closest to the Dry Evergreen Formation-series of Beard (1944, 1955); it has, however a major component of deciduous species in the canopy, and had better be described as 'semi-evergreen'. Beard (1955), following Fanshawe (1952), distinguishes (a) a 'Dry Evergreen Woodland', with a discontinuous emergent layer between 18-24 m high and below it a canopy of 'densely-packed, attenuated trees, not larger than 45-50 cm diameter and about 6-12 m high' and (b) a 'Dry Evergreen Thicket' with a canopy between 6-12 m high, the trees with slender stems not larger than 15-20 cm diameter, with occasional larger emergents. Our RH sites seem to be intermediate between these types. The forest at Portland Ridge was classified by Loveless & Asprey (1957) as Dry Evergreen Thicket. As already noted, Portland Ridge is close to


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RH both floristically and physiognomically; however, the trees are lower and more slender in the former area. From Cuba, Borhidi et al. (1979) and Borhidi (in press) describe a number of dry forest communities, of which the closest to RH floristically is the Order Eugenio-Metopietalia toxiferi Knapp 1964. From Hispaniola, Ciferri (1936) described a subxerophytic forest from areas with annual rainfall 750-1000 mm yr"1. He noted that the total rainfall was not much less than in mesophytic forest, and that the aridity was due especially to the unequal distribution of rainfall (as we have noted above for RH). He distinguished an Acacia-Krugiodendron association on rocky soil; three of the four most characteristic species are present at RH. The Hispaniolan community differed in the absence of lianes. Natural forest or scrub on rocky arid limestone terrain is still widespread in the West Indies, albeit usually much degraded by cutting and burning. It is described also from Anegada (Beard 1949), Anguilla (Squire 1937, unpublished report summarized in Beard 1949), Antigua (Harris 1960), Barbuda (Beard 1949, Harris 1960), the Bahamas (Coker 1905), Guadeloupe, Marie-Galante & Desirade (Stehle 1935, 1945-6), Martinique (Stehle 1941) and Puerto Rico (Gleason & Cook 1926). McGuire & Brown (1974) described two plots from subtropical 'hammock' vegetation on the coral limestone of the Florida Keys. The Florida forest resembled Jamaican dry limestone forest but was poorer in species. A fundamental limiting factor to tree stature in the Caribbean region (north of Trinidad) is the occasional passage of hurricanes. In the period 1885-1977 some 761 tropical cyclones reaching at least tropical storm intensity (Force 11 on Beaufort scale) have passed through the Greater Caribbean region (Neumann et al. 1978). Soriano-Ressy et al. (1970) note that in the Palmist Ridge rain forest on Dominica (mean altitude 275 m), adjacent peaks shelter the trees from hurricane winds, and here the trees reach up to 44 m in height and 200 cm dbh. Lower montane rain forest in Cuba (Borhidi, in press) and Puerto Rico (Odum 1970) is comparable in stature to HHH. Neotropical forests outside the hurricane belt are substantially taller. The evergreen seasonal forest of Trinidad was 23-30 m high, with emergents to 55 m (Beard 1946). In lowland rain forest in Guyana the general canopy height was 23-26 m with emergents to c. 57 m (Davis & Richards 1933). Comparisons between data on species richness of forests from different authors are hampered (a) by differences in sample area, (b) by differences in definition of life form category (or by lack of definitions). From the very limited data available, it appears that Jamaican lower montane rain forest and intermediate-rainfall forest are of comparable richness (in tree species and in total flora) to forest in the same climatic zones in Cuba, Puerto Rico (Brisco & Wadsworth 1970, Little 1970) and Dominica. As already noted, the composition of rain forest vegetation in the West Indies appears to be rather little affected by the geology. However, Proctor et al. (1983a, b), in their study of four forest types in lowland rain forest in Sarawak, found that forest on limestone differed markedly from the other types (Alluvial, Dipterocarp and Heath

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forest). Tree species richness on limestone was only about 73 ha"1, compared to 123-223 ha"1 in the other types. Whitmore et al. (1985) summarize data on total vascular plant species counts in species-rich vegetation; our sites (Table 3) are clearly much poorer than sample sites from lowland rain forest in Costa Rica or Ecuador. Whitmore et al. (1985) analysed exhaustively the life form composition of a 100 m 2 plot. They found a high proportion of mechanically dependent species (48.5% of total), similar to our result for HHH-A (46.7%: Table 3). They found a relatively low proportion of tree species (31.3%, the majority being represented only by seedlings). However, as already noted, the large size of the individual means that tree species are bound to be underrepresented in life form analyses of small plots.

CONSERVATION AND FUTURE RESEARCH

The detrimental effects of deforestation in hilly tropical regions have been summarized for the Caribbean by Lugo et al. (1981), and are explored in the Jamaican context in Thompson et al. (1986). Active deforestation has been in progress in the vicinity of all our sites during the period of our investigations, and all may be regarded as more or less endangered. One of the most striking results of our study is its demonstration of the remarkable richness of the intermediate-rainfall forest (BH). At the beginning of our studies, this forest was probably one of the finest stands of its kind outside the Cockpit Country. It is now so damaged (since 1983/84) that alternative sites within this climatic zone need to be identified, studied and protected. Our study highlights the richness of the wet and intermediate-rainfall forests in endemic species, including numbers of highly localized endemics, and of species new to science. We would emphasize the urgency of further research and the need for active conservation of Jamaican forest in all its diversity.

ACKNOWLEDGEMENTS

For logistic support we thank the Forests Department of the Government of Jamaica, the Botany Department of the University of the West Indies, and in particular Professor G. Sidrak, and the Natural Resources Conservation Department of the Government of Jamaica. For meteorological data we thank the Meteorological Division, Ministry of Communications and Works, Government of Jamaica. We gratefully acknowledge the financial support given to DK by Trinity College Dublin Trust, by the Botany Department of Trinity College Dublin, and by Higher Education for Development Cooperation (Ireland); to ET by the Royal Society, by Gonville and Caius College Cambridge, by Cambridge University Travel Fund, and by the Cory Fund of the Cambridge University Botanic Garden; to VK by Sigma Xi, by Missouri Botanic Garden, and by the Biology


149

Department and Graduate School of Washington University, St Louis (including a Graduate Fellowship from the Division of Biology and Biomedical Sciences of Washington University). For assistance in the field we are grateful to Mr N. Allen, the late Mr D. Brown, Mr P. Clarke, Ms J. Dixon, Mr H. Gregory, Ms A. Haynes, Ms D. Hunter, Ms M. Mais (nee Campbell), Dr A. Podzorski, Ms H. Richards, Dr M. Shaik, Mr K. Taylor, Mr D. Thompson, Ms Y. Shields. For help in plant identification we are grateful to Dr G. R. Proctor, Dr C. D. Adams, the late Ms M. Allwood, Dr A. Podzorski and Dr P. Bretting. For helpful information and comments during the preparation of this article we thank Dr A. Sugden, Dr G. Draper, Dr M. Swaine and Professor D. Richardson. LITERATURE CITED ADAMS, C. D. 1971. The Blue Mahoe and other bush. Sangsters, Kingston, Jamaica/McGraw Hill, Singapore. ADAMS, C. D. 1972. Flowering plants of Jamaica. University of the West Indies, Mona, Jamaica. ADAMS, C. D. (in press). Phytogeography of Jamaica. In Biogeographical aspects of insularity. Symposium of Accademia Nazionale dei Lincei, Rome, 1987. ADAMS, C. D. & DU QUESNAY, M. C. 1970. Vegetation. Pp. 49-119 in Woodley, J. D. (ed.),Hellshire Hills scientific survey. University of the West Indies, Mona, Jamaica. ANON. 1958-1964. Soil and land-use surveys. Regional Research Centre for the British Caribbean. Imperial College of Tropical Agriculture, St Augustine, Trinidad. ASPREY, G. F. & LOVELESS, A. R. 1958. The dry evergreen formations of Jamaica. II. The raised coral beaches of the north coast. Journal of Ecology 46:547-570. ASPREY, G. F. & ROBBINS, R. G. 1953. The vegetation of Jamaica. Ecological Monographs 23:359-412. BEARD, J. S. 1944. Climax vegetation in tropical America. Ecology 25:127-158. BEARD, J. S. 1946. The natural vegetation of Trinidad. Oxford Forestry Memoir 20. Clarendon Press, Oxford. BEARD, J. S. 1949. The natural vegetation of the Windward and Leeward Islands. Oxford Forestry Memoir 21. Clarendon Press, Oxford. BEARD, J. S. 1955. The classification of tropical American vegetation types. Ecology 36:89-100. BORHIDI, A. (in press). The main vegetation units of Cuba. BORHIDI, A. & MUNIZ, O. 1980. Die Vegetationskarte von Kuba. Ada Botanica Academiae Scientarum Hungaricae 26:25-53. BORHIDI, A., MUNIZ, O. & DEL RISCO, E. 1979. Clasificacion fitocenologica de la Vegetacion de Cuba. Acta Botanica Academiae Scientarum Hungaricae 25:263-301. BRISCO, C. B. & WADSWORTH, F. H. 1970. Stand structure and yield in the Tabonuco forest of Puerto Rico. Pp. 879-889 in Odum, H. T. & Pigeon, R. F. (eds). A tropical rainforest: a study of irradiation and ecology at El Verde, Puerto Rico. US Atomic Energy Commission, Oak Ridge, Tennessee. CIFERRI, R. 1936. Studio geobotanico dell'Isola Hispaniola (Antille). Atti dell'Istituto Botanico e Laboratorio Crittogamico Italiano della Universita diPavia Serie IV 8:1-336. COKE, L. B., BERTRAND, R. & BATCHELOR, S. 1982 (unpublished). Macrophyte Vegetation of the Negril and Black River morasses, Jamaica. Appendix V (29 pp). to Bjork, S. Environmental feasibility study of peat mining in Jamaica. University of the West Indies, Kingston, Jamaica/Petroleum Corporation of Jamaica, Kingston, Jamaica. COKER, W. C. 1905. Vegetation of the Bahama islands. Pp. 185-270 in Shattuck, G. B. (ed.). The Bahama islands. Geographical Society of Baltimore, John Hopkins University Press. CONNELL, J. H. 1978. Diversity in tropical rain forests and coral reefs. Science 199:1302-1310. CROWTHER, J. 1982. Ecological observations in a tropical karst terrain, West Malaysia. 1. Variations in topography, soils and vegetation. Journal of Biogeography 9:65-78. DAVIS, T. A. W. & RICHARDS, P. W. 1933. The vegetation of Moraballi Creek, British Guiana: an ecological study of a limited area of tropical rain forest. Part 1. Journal of Ecology 21:350-384. DAWKINS, H. C. 1961. Estimating total volume of some Caribbean trees. Caribbean Forester 22:62-63. DUCHAUFOUR, P. 1970. Precis de Pedologie (3rd edn). Masson, Paris. EVA, A. & McFARLANE, N. 1985. Tertiary to early Quaternary carbonate facies relationships in Jamaica. Transactions of the Fourth Latin American Geological Congress (Trinidad and Tobago 1979).

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EWEL, J. J. & WHITMORE, J. L. 1973. The ecological life-zones of Puerto Rico and the US Virgin Islands. Forest Service Research Paper ITF-18. Forest Service, US Department of Agriculture, Institute of Tropical Forestry, Rio Piedras, Puerto Rico. FANSHAWE, D. B. 1952. The vegetation of British Guiana - a preliminary review. Imperial Forestry Institute, Oxford, Institute Paper 29. FRYXELL, P. A. 1981. Revision and expansion of the neotropical genus Wercklea (Malvaceae). Journal of the Arnold Arboretum 62:457-486. GLEASON, H. & COOK, M. T. 1926. Plant Ecology of Porto Rico. Scientific survey of Porto Rico and the Virgin Islands, Vol. VII. 173 pp. New York Academy of Sciences. GRUBB, P. J., LLOYD, J. R., PENNINGTON, T. D. & WHITMORE, T. C. 1963. A comparison of montane and lowland rain forest in Ecuador. I. The forest structure, physiognomy and floristics. Journal of Ecology. 51:467-601. GRUBB, P. J. & TANNER, E. V. J. 1976. The montane forests and soils of Jamaica: a reassessment. Journal of the Arnold Arboretum 57:313-368. HARRIS, D. R. 1960. The vegetation of Antigua and Barbuda, Leeward Islands, the West Indies. Government Research Report. US Department of Commerce, Office of Technical Services, Washington DC. HOSE, H. R. & VERSEY, H. R. 1956. Palaeontological and lithological divisions of the Lower Tertiary limestones of Jamaica. Colonial Geology and Mineral Resources 6:19-39. HOWARD, R. A. 1974. The vegetation of the Antilles. Pp. 1-38 in Graham, A. (ed.). Vegetation and vegetation history of northern Latin America. Elsevier, New York. HOWARD, R. A. & PROCTOR, G. R. 1957a. The vegetation on bauxitic soils in Jamaica. Part I. Journal of the Arnold Arboretum 38:1-50. HOWARD, R. A. & PROCTOR, G. R. 1957b. The vegetation on bauxitic soils in Jamaica. Part II. Journal of the Arnold Arboretum 38:151-169. JAMAICAN METEOROLOGICAL SERVICE, ms. Monthly and annual rainfall totals in Jamaica (averages for the period 1931-1960). KAPOS, V. 1986. Dry limestone forests of Jamaica. Pp. 49-58 in Thompson, D. A., Bretting, P. K. & Humphreys, M. (eds). Forests of Jamaica. The Jamaican Society of Scientists and Technologists, Kingston, Jamaica. KELLY, D. L. 1981, unpublished. Terrestrial ecology: vegetation. In Final Report: Ecological Preaudit Study for an Alumina Plant, Jamaica, W.I. Natural Resources Conservation Department, Kingston, Jamaica. KELLY, D. L. 1985. Epiphytes and climbers of a Jamaican rain forest: vertical distribution, life forms and life histories. Journal of Biogeography 12:223-241. KELLY, D. L. 1986. Native forests on wet limestone in North-eastern Jamaica. Pp. 31-42 in Thompson, D. A., Bretting, P. K. & Humphreys, M. (eds). Forests of Jamaica. The Jamaican Society of Scientists and Technologists, Kingston, Jamaica. LACK, D. 1976. Island biology, illustrated by the land birds of Jamaica. Blackwell Scientific Publications, Oxford. LANLY, J. P. 1981. Projecto de evaluacion de los recursos forestales tropicales: los recursos forestales de la America tropicale. Food and Agriculture Organization of the United Nations, Rome. LITTLE, E. L. 1970. Relationships of trees of the Luquillo experimental forest. Pp. B47-B58 in Odum, H. T. & Pigeon, R. F. (eds). A tropical rain forest; a study of irradiation and ecology at El Verde, Puerto Rico. US Atomic Energy Commission, Oak Ridge, Tennessee. LONG, E. 1774. The history of Jamaica. Lowndes, London. LOVELESS, A. R. & ASPREY, G. F. 1957. The dry evergreen formations of Jamaica. I. The limestone hills of the south coast. Journal of Ecology 45:799-822. LUGO, A. E., SCHMIDT, R. & BROWN, S. 1981. Tropical forests in the Caribbean. Ambio 10:318-324. McGUIRE, R. J. & BROWN, S. 1974. A phytosociological analysis of two subtropical hammocks in Elliott Kay, Dade County, Florida. Journal of the Elisha Mitchell Scientific Society 90:125-131. NEUMANN, C. J., CRY, G. W., CASO, E. L. & JARVINEN, B. R. 1978. Tropical cyclones of the North Atlantic Ocean, 1871-1977. National Climatic Center, National Oceanic and Atmospheric Administration, Asheville, North Carolina. ODUM, H. T. 1970. The El Verde study area and the rain forest systems of Puerto Rico. Pp. B3-B32 in Odum, H. T. & Pigeon, R. F. (eds). A tropical rain forest: a study of irradiation and ecology at El Verde, Puerto Rico. US Atomic Energy Commission, Oak Ridge, Tennessee. OLIVER, W. L. R. 1982. The coney and the yellow snake: the distribution and status of the Jamaican hutia Geocapromys brownii and the Jamaican boa Epircates subflavus. Dodo, Journal of the Jersey Wildlife Preservation Trust 19:6-33. ORLOCI, L. & KENKEL, N. C. 1985. Introduction to data analysis. International Co-operative Publishing House, Fairland MD. PROCTOR, G. R. 1982. More additions to the flora of Jamaica. Journal of the Arnold Arboretum 63: 199-315.


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PROCTOR, G. R. 1985. Ferns of Jamaica. British Museum (Natural History), London. PROCTOR, G. R. 1986a. Cockpit country forests. Pp. 43-48 in Thompson, D. A., Bretting, P. K. & Humphreys, M. (eds). Forests of Jamaica. The Jamaican Society of Scientists and Technologists, Kingston, Jamaica. PROCTOR, G. R. 1986b. Vegetation of the Black River morass. Pp. 59-65 in Thompson, D. A., Bretting, P. K. & Humphreys, M. (eds). Forests of Jamaica. The Jamaican Society of Scientists and Technologists, Kingston, Jamaica. PROCTOR, J., ANDERSON, J. M, CHAI, P. & VALLACK, H. W. 1983a. Ecological studies in four contrasting rain forests in Gunung Mulu National Park, Sarawak. I. Forest environment, structure and floristics. Journal of Ecology 71:237-260. PROCTOR, J., ANDERSON, J. M., FOGDEN, S. C. L. & VALLACK, H. W. 1983b. Ecological studies in four contrasting lowland rain forests in Gunung Mulu National Park, Sarawak. II. Litterfall, standing crop and preliminary observations on herbivory. Journal of Ecology 71:261-283. RAUNKIAER, C. 1934. The life forms of plants and statistical plant geography. Oxford University Press, Oxford. RICHARDS, P. W. 1952. The tropical rainforest. Cambridge University Press, London. SEIFRIZ, W. 1943. The plant life of Cuba. Ecological Monographs 13:375-426. SMITH, E. E. 1954. The forests of CubaMarin Moors Cabot Foundation. SORENSEN, T. 1948. A method of establishing groups of equal amplitude in plant sociology based on similarity of species content. Det Kongelige Danske Videnskabernes Selskab Biologiske Skrifter 5:1-34. SORIANO-RESSY, M., DESMARAIS, E. P. & PEREZ, J. W. 1970. A comparison of environments of rain forests in Dominica, British West Indies, and Puerto Rico. Pp. B329-B346 in Odum, H. T. & Pigeon, R. F. (eds). A tropical rain forest: a study of irradiation and ecology at El Verde, Puerto Rico. US Atomic Energy Commission, Oak Ridge, Tennessee. SQUIRE, F. A. 1937 (unpublished). Report on a visit to Anguilla. Report to Imperial College of Tropical Agriculture, St Augustine, Trinidad, on Cotton Pest Investigation. STEHLE, H. 1935. Flore de la Guadeloupe. I. Essai d'ecologie et de geographie botanique. Basseterre, Guadeloupe. STEHLE, H. 1941. Esquisse des associations vegetales de la Martinique. Bulletin agricole de Martinique 6:194-264. STEHLE, H. 1945-46. Forest types of the Caribbean Islands. Caribbean Forester, supplements to Volumes 6 and 7. TANNER, E. V. J. 1977. Four montane rain forests of Jamaica: a quantitative characterization of the floristics, the soils and the foliar mineral levels, and a discussion of the interrelations. Journal of Ecology 65:883-918. THOMPSON, D., BRETTING, P. & HUMPHRIES, M. (eds.) 1986. Forests of Jamaica. The Jamaican Society of Scientists and Technologists, Kingston, Jamaica. WALTER, H. & LIETH, H. 1960. Klimadiagramm Weltatlas. Fischer, Jena. WEBB, L. J. 1959. A physiognomic classification of Australian rain forests. Journal of Ecology 47:551570. WHITMORE, T. C. 1975. Tropical rain forests of the Far East. Clarendon Press, Oxford. WHITMORE, T. C, PERALTA, R. & BROWN, K. 1985. Total species count in a Costa Rican tropical rain forest. Journal of Tropical Ecology 1:375-378. ZON, R. & SPARHAWK, W. N. 1923. Forest resources of the world. Vol. I. McGraw-Hill, New York.

Accepted 23 July 1987 Appendix. Lists of all vascular plants species recorded under forest canopy within each study area, except those confined to trails, and those that were obviously planted and not naturalized. Nomenclature follows Adams (1972) and Proctor (1982) for Angiosperms, and Proctor (1985) for Pteridophytes. The following symbols are used: B = Broom Hall study area, H = Hog House Hill study area, R = Round Hill study area, * = species appearing under different life form categories in different study areas. 1. Trees and shrubs over 2 m high (Mega-, Meso- and Microphanerophytes) Acalypha laevigata Acidoton urens Alchornea latifolia Allophylus cominia Allophylus jamaicensis Amyris balsamifera

B B H B H B H B

B R

Amyris elemifera Andira inermis Annona jamaicensis Antirhea coriacea Antirhea jamaicensis Astrocasia tremula

H H B

H B H B

152 Ateramnus ellipticus (Gymnanthes elliptica Sw.) Ateramnus integer (Gymnanthes integra F. & R.) Ateramnus lucidus (Gymnanthes lucida Sw.) Ateramnus sp. (JCM 1555) (Gymnanthes sp.) Bauhinia divaricata Beilschmiedia pendula Bemardia dichotoma Boehmeria jamaicensis Bourreria venosa Brosimum alicastrum Brunfelsia plicata Bumelia americana Bumelia aff. montana Bumelia nigra Bumelia rotundifolia Bumelia salicifolia Bunchosia jamaicensis Bunchosia media Bursera simaruba Calliandra paniculata Calophyllum calaba Calyptranthes pollens Calyptranthes zuzygium Calyptronoma occidentalis Canella winterana Capparis cynophallophora Capparis ferruginea Capparis flexuosa Casearia hirsuta Casearia guianensis Casearia sylvenstris Cecropia peltata Cedrela odorata Ceiba pentandra Cestrum diurnum Charianthus fadyenii Chimarrhis cymosa ssp. jamaicensis Chrysophyllum oliviforme Cinnamodendron corticosum Cinnamomum montanum Citharexylum caudatum Citharexylum fruticosum Clethra occidentalis Coccoloba diversifolia Coccoloba krugii Coccoloba longifolia Coccoloba swartzii Comocladia pinnatifolia Comocladia velutina Conostegia icosandra Conostegia superba Cordia gerascanthus Cordia laevigata Cordia troy ana Croton eluteria Cupania glabra Cyathea grevilleana Cyathea parvula Daphnopsis occidentalis

D. L. KELLY et al. H

R B R

H B R H R H B R H B R B R B H B B R H B B R R R H B H B R B R H R B R R B R B R H B H H B H B B H B H H B H B R H R R H B R H B R H B R H H B R H B B H R B R H H B

Dendropanax arboreus Diospyros tetrasperma Drypetes alba Drypetes lateriflora Erithalis quadrangularis Erythrina sp. Erythroxylum areolatum Erythroxylum confusum Erythroxylum rotundifolium Esenbeckia pentaphylla Eugenia amplifolia Eugenia axillaris Eugenia biflora Eugenia confusa Eugenia fadyenii Eugenia foetida Pers. (E. maleolens) Eugenia glabrata Eugenia isosticta Eugenia kellyana Eugenia monticola Eugenia rhombea Eugenia sp. (1) Eugenia sp. (2) Exostema caribaeum Exothea paniculata Fagara culantrillo Fagara elephantiasis Fagara flava Fagara harrisii vel aff. Fagara martinicensis Fagara rhodoxylon Fagara spinosa Faramea occidentalis Garcinia humilis Gesneria calycina Guapira fragrans Guapira obtusata Guarea jamaicensis Guarea swartzii DC (G. glabra Vahl) Guettarda argentea Gyminda latifolia Gynoxys incana Gyrotaenia microcarpa Gyrotaenia spicata Hernandia catalpifolia Hibiscus elatus Hirtella jamaicensis/multiflora Hyeronima jamaicensis Hypelate trifoliata Hyperbaena prioriana Jatropha divaricata Krugiodendron ferreum Lacistema aggregatum Laetia thamnia Licaria triandra Lonchocarpus latifolius Lunania polydactyla Lunania racemosa Macrocnemum jamaicense Malpighia punicifolia Malvaviscus arboreus Mammea americana Manilkara sideroxylon

H B R H B R B B H R R R B H B? R B B H B R B R H R R H H R H B R B B R B H B B R H B H B H B R R B H B H B R R H H B H

H H H R B B B R B B R B B H H H R H B H H B R

Jamaican limestone forests Margaritaria nobilis Matayba apetala Maytenus clarendonensis May tenus jatnaicensis Meriania leucantha Metopium brownii Miconia impetiolaris vel aff. Morinda royoc Mosquitoxylum jamaicense Myrcianthes fragrans Myrsine acrantha Mytranthes sp. Nectandra antillana Nectandra coriacea s. str. Nectandra patens s. lat. Neea nigricans Ocotea exaltata (Sw.) Proctor Ocotea floribunda Ocotea leucoxylon Ocotea staminea Omphalea triandra Oplonia armata var. pallidior Oplonia jamaicensis Ossaea micrantha Ouratea laurifolia Oxandra lanceolata Oxandra laurifolia Palicourea wilesii Petitia domingensis Phyllanthus angustifolius Phyllanthus cladanthus Phyllanthus nutans Picramnia antidesma Picrasma excelsa Pimenta dioica Pimenta jamaicensis Piper amalago Piper arboreum var. arboreum Piper arboream var. stamineum Piper discolor Piper hispidum Piper murrayanum Piper verrucosum Piscidia piscipula Pisonia subcordata Pithecellobium alexandri var. troyanum Pithecellobium arboreum Plumeria obtusa Poly gala jamaicensis Portlandia microsepala Pouteria multiflora Prunus myrtifolia Prunus occidentalis Pseudalbizzia berteroana Pseudolmedia spuria Psidium albescens Psidium montanum Psychotria dolphiniana

H H B B? R R H R B R H B R B H B H B R H B H B B B H B H R B H B R B R H H R R H B H B B B B R H B H H H H B B R H B B H H B R B H B H B H B R H B H H H

Psychotria foetida Psychotria glabrata Psychotria hirsuta Psychotria pedunculata var. caudata Psychotria pedunculata var. pedunculata Randia aculeata Randia aculeata var. mitis Rondeletia elegans Rondeletia laurifolia Rondeletia pallida Rondeletia polita Rondeletia portlandensis Rondeletia stipularis Roystonea altissima Rytidophyllum grande var. grande Salpixantha coccinea Sapindus saponaria Sapium cuneatum Sapium harrisii Sapium jamaicense Schaefferia frutescens Schoepfia multiflora Schoepfia obovata Simarouba glauca Sloanea jamaicensis Solanum havanensis Spathelia glabrescens Stenocereus hystrix Symphonia globulifera Tabebuia platyantha Tabebuia riparia Tabernaemontana rendlei Terminalia latifolia Ternstroemia glomerata Temstroemia hartii Tetrazygia hispida var. hispida Tetrazygia hispida var. laevior Tetrorchidium rubrivenium Thrinax parviflora Trichilia glabra Trichilia moschata Trichilia reticulata Trophis racemosa Turpinia occidentalis Viburnum alpinum Wallenia grisebachii Wallenia laurifolia Wallenia subverticillata Wallenia sylvestris Wallenia venosa Wallenia xylosteoides Xylopia hastarum Xylopia muricata Xylosma fawcettii Ziziphus chloroxylon Ziziphus sarcomphalus Zuelania guidonia

153 H H H H B B R R H H H B H R H B H B B B H H R B R H B R H B B R H R H B R H B B B H B H H B R B R H B R H B H B B B H

H B B B B B H B R B

[continued

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2. Shrubs under 2 m high (Nanophanerophytes) Acalypha scabrosa Agave sobolifera Begonia purpurea Besleria lutea Buxus laevigata Capsicum baccatum Clidemia erythropogon Clidemia grisebachii Clidemia septuplinervia Cnemidaria horrida

R R B H R R H H H H

Cordia globosa var. humilis Hamelia axillaris Malpighia fucata Miconia laevigata Miconia triplinervis Oplonia acicularis Pedilanthus tithymaloides var. jamaicensis Psychotria nervosa Rondeletia harrisii vel aff.

H B B H B H

B B

3. Herbs (on soil or rock only) Adiantum latifolium H Adiantum melanoleucum Adiantum pulverulentum H Adiantum pyramidale Adiantum tenerum H Anisosorus hirsutus H Anopteris hexagona *Asplenium auritum (H: Epiphyte) Asplenium myriophyllum var. brevisorum Asplenium trichomanes-dentatum var. trichomanes-dentatum Blechnum occidentale Blechum killipii H Bolbitis nicotianifolia H Bolbitis pergamentacea H Cheilanthes microphylla Columnea rutilans H Cranichis muscosa Ctenitis hirta H Ctenitis subincisa H H Danaea nodosa H Dennstaedtia obtusifolia Diplazium grandifolium H Diplazium pectinatum H H Erythrodes hirtella Erythrodes plantaginea H Gesneria acaulis H Gesneria pumila H Gymnosiphon fawcettii (HoloH saprophyte) Gymnosiphon sphaerocarpus (HoloH saprophyte) Habenaria quinqueseta Heliconia caribaea H Ichnanthus nemorosus Ichnanthus pollens H Lastreopsis effusa H Leiphaimos aphylla (HoloH saprophyte) Leiphaimos parasitica (Holosaprophyte) Lobelia grandifolia H Lobelia innominata H Lomariopsls jamaicensis Lomariopsis underwoodii H Malaxis spicata

R B B

B B B B

R B

B

R B B R

B B

*Nephro lepis rivularis (H: Epiphyte)B B Panicum glutinosum Pavonia schiedeana Steudel (P. rosea H auct.) *Peperomia clusiifolia (H?: Epiphyte) R Pharus glaber B R H Pharus latifolius H Pilea ciliata B Pilea crassifolia H Pilea inaequalis Pilea elizabethae H H Pilea grandifolia H Pilea lamiifolia var. puberula Pilea rufa H Pilea yunckeri H Pitcaimia bromeliifolia var. gramiH nifolia *Pleurothallis racemiflora Lodd. (H: Epiphyte) B Polybotrya cervina H *Polypodium dispersum (B: Epiphyte) R Polypodium heterophyllum B Polypodium pectinatum B *Polypodium polypodioides B (R: Epiphyte) Polystichum echinatum B Polystichum harrisii B Prescottia stachyodes H Psychotria discolor H Psychotria uliginosa H H Renealmia sylvestris Scleria lithosperma' R Scybalium jamaicense (Holoparasite) H Selaginella subcaulescens H B Selaginella sp. Stigmatopteris gemmipara H H Stigmatopteris jamaicensis Tectaria apiifolia H B Tectaria heracleifolia B Tectaria incisa H Thelypteris grandis B Thelypteris hastata B Thelypteris poiteana B Thelypteris reptans B Thelypteris serrulata H Thelypteris tetragona var. guadaluB pensis Trichomanes holopterum H

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Jamaican limestone forests 4. Climbers Adelobotrys adscendens Angadenia lindeniana Begonia glabra Blakea trinervia Canavalia altipendula Chiococca alba Chiococca parvifolia Cionosicys pomiformis Cissampelos pareira Cissus microcarpa Cissus sicyoides Clematis dioica Cynanchum sp. Dioscorea polygonoides Entada gigas Fischeria crispiflora Forsteronia floribunda Forsteronia wilsonii Galactia pendula Gonolobus rhamnifolius Gouania lupuloides Hillia tetrandra Hylocereus triangularis Ipomoea horsfalliae Ipomoea rubella Ipomoea ternata Ipomoea tiliacea Jacaima parvifolia Jacquemontia havanensis Lasiacis divaricata Mandevilla torosa Marcgravia brachysepala

H B H H B H B B B R H B H B R H B R B R B H H B H R B B H B R R H B B B R R B R H

Notoptera hirsuta Passiflora oblongata Passiflora perfoliata Passiflora suberosa Paullinia barbadensis Paullinia jamaicensis Philodendron lacerum Philodendron scandens Philodendron schottii Pisonia aculeata Polybotrya osmundacea Rajania cordata Rhynchosia erythrinoides Salmea scandens Schlegelia parasitica Schradera involucrata Securidaca brownei Selenicereus grandiflorus Senecio hollickii Britton ex Greenm. (Odontocline hollickii) Smilax balbisiana Smilax domingensis Stigmaphyllon emerginatum Syngonium auritum Toumefortia maculata Tournefortia volubilis Triopteris paniculata Vanilla claviculata Vanilla inodora Vitus tiliifolia Malpighiaceae (BH 4338)

B R H B R R R R H B H B H H R H B B H H B H H B B B B R H R H B B R R R H H B

5. Epiphytes (including facultative epiphytes) Aechmea decurva H Aechmea paniculigera B Anetium citrifolium H Anthurium grandifolium H B R *Asplenium auritum H (B: terrestrial) H Asplenium cuneatum Blechnum fragile H H Brassia caudata Broughtonia sanguinea R Campylocentrum micranthum B Catopsis floribunda H Catopsis nitida H Cochleanthes flabelliformis H B Columnea fawcettii H Dendrophylax barrettiae B Elaphoglossum crinitum (L.) Christit H (Hymenodium crinitum) Elaphoglossum denudatum H Elaphoglossum herminieri H Elaphoglossum simplex H Elleanthus capitatus H Epidendrum anceps H Epidendrum cochleatum B Epidendrum fragrans H Epidendrum polybulbon H Epidendrum ramosum H

Epidendrum secundum B Grammitis exornans H Grammitis harrisii H Grammitis mollissima H Grammitis serrulata H Guzmania lingulata H B Guzmania monostachia B Hohenbergia penduliflora H Hohenbergia polycephala B Hymenophyllum hirsutum H Hymenophyllum polyanthos H Isochilus linearis B Jacquiniella globosa H H Lepanthes cochlearifolia Lepanthes elliptica vel aff. H H Lepanthes loddigesiana Lepanthes quadrata H H Lepanthes rotundata Lycopodium dichotomum H Maxillaria crassifolia B H Maxillaria purpurea Nephrolepis biserrata H *Nephrolepis rivularis H (B: terrestrial) Oleandra articulata (Sw.) C. Presl H (O. nodosa) Oncidium luridum B R

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Oncidium pulchellum B Peperomia distachya H Peperomia amplexicaulis (H?)B Peteromia amplexicaulis/clusiifolia H Peperomia emarginella H Peperomia tenella H Pleurothallis alpestris H Pleurothallis corniculata H B Pleurothallis delicatula B *Pleurothallis racemiflora H (B: terrestrial) Pleurothallis ruscifolia H Pleurothallis sertularioides H Pleurothallis tribuloides B Polypodium angustifolium B Polypodium aureum H B Polypodium costatum H Polypodium crassifolium H *Polypodium dispersum B (R: terrestrial) Polypodium latum B Polypodium lycopodioides H B Polypodium phyllitidis B Polypodium piloselloides H *Polypodium polypodioides (B: terrestrial) R Polypodium sororium H Polypodium squamatum B Polystachya cerea B Polytaenium feei H Psilotum nudum B

Rhipsahs baccifera Stelis trigoniflora (Sw.) Garay & Sweet (S. ophioglossoides) Tillandsia balbisiana Tillandsia bulbosa Tillandsia compressa Tillandsia fasciculata Tillandsia juncea Tillandsia polystachia Tillandsia pruinosa Tillandsia recurvata Tillandsia setacea Tillandsia utriculata Tillandsia valenzuelana Trichomanes alatum Trichomanes crispum Trichomanes hookeri Trichomanes hymenophylloides Trichomanes punctatum ssp. sphenoides Trichomanes scandens Vittaria graminifolia Vittaria lineata Vittaria remota Vriesea platynema Vriesea ringens Vriesea sanguinolenta

B H

H B B B B B B B B H H H H H H H H H B H H

6. Epiphytic hemiparasites Dendrophthora opuntioides Oryctanthus occidentals

H H B R

Phoradendron trinervium Psittacanthus claviceps

H

Oreopanax capitatus Schefflera sciadophyllum

H B H

Ficus pertusa Ficus trigonata

H B H B

R R

7. Epiphytic holoparasite Pilostyles globosa

8. Wobdy hemiepiphytes Clusia flava Clusia rosea Clusia stenocarpa Urb. (C. havetioides)

R B

H

9. Strangle™ Ficus maxima Ficus perforata

B H

R