Structure, floristic composition and natural ... - Wiley Online Library

JBI347.fm Page 141 Tuesday, April 25, 2000 1:27 PM

Journal of Biogeography, 27, 141–157

Blackwell Science, Ltd

Structure, floristic composition and natural regeneration in the forests of Cat Tien National Park, Vietnam: an analysis of the successional trends L. Blanc*, G. Maury-Lechon and J.-P. Pascal Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Claude Bernard, Lyon 1, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex—France. E-mail: [email protected]

Abstract The forests in Cat Tien National Park, appear as a mosaic of different communities, distinct from each other with respect to their floristic and structural parameters. The objectives of this study are (1) to characterize the different formations occurring in the lowland part and (2) to identify the main successional trends in the area. Understanding forest succession is important for silviculture and restoration of forests and land rehabilitation, as adequate information on the ecological role of local species in the functioning of the forests is not available in Vietnam. Five plots (1 ha each) were established in the lowland part of Cat Tien National Park, where all the trees ≥ 10 cm d.b.h. (diameter at breast height) were located, measured and identified. A systematic sampling was made to assess the regeneration. Three plots (A, C and D) can be considered as secondary forests on the basis of their structural parameters. Plots A and C are dominated by Lagerstrœmia calyculata and plot D by Dipterocarpus alatus. The other two plots can be regarded as mature forests. Plot B corresponds to a semideciduous formation dominated by Lagerstrœmia calyculata and Fabaceae species, and plot E to an evergreen one dominated by dipterocarp species. The floristic composition of plots A and C will change in the future because dominant canopy species are rare or absent in regeneration. A correspondence analysis performed on the number of trees per species shows two kinds of successional trends: one from A to B on shallow and drier soils, and another from C to E on deeper and wetter soils. Keywords Secondary forests, semideciduous forests, Vietnam, diversity, reciprocal ordination, Lagerstrœmia calyculata, Dipterocarpaceae.

Nomenclature: Leconte (1905–52) and Ho (1991–93). INTRODUCTION Vietnamese forests, especially the lowland dense forests in the southern part of the country, suffered severe damage during the last century (Durand, 1994). The causes were mainly land clearing for farming, collection of forest products by the local population, over-logging and use of herbicides during the last war that degraded a large number of forests, especially mangroves (Tschirley, 1969; Orians & Pfeiffer, 1970; Boffey, 1971; Norman, 1974). At present, only 17% *Correspondence: Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Claude Bernard, Lyon 1, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex–France, E-mail: [email protected]

© 2000 Blackwell Science Ltd

(5.5 million hectares) of Vietnam’s total area is under forest cover (Collins et al., 1991) whereas about 44% was forested in 1944. Depletion of forest is considered to be one of the most important environmental threats in Vietnam, challenging the economic development of the rural areas. It is estimated that more than 6 million hectares have to be reforested in Vietnam (Mai, 1983) and hence there is an urgent need for rehabilitation of land and restoration of forests as in many other Asian countries (Lamb, 1994). Instead of planting exotic species, future programmes should emphasize the use of local species as mentioned in the National Plan for Environment and Sustainable Development (SRV et al., 1991). The aim is to recreate an ecosystem which would satisfy the basic forestry needs of rural populations. The priority therefore is to study forest ecosystems in order to understand their dynamics, especially the processes


142 L. Blanc, G. Maury-Lechon and J.-P. Pascal

of secondary succession. This basic knowledge is necessary for reforestation programmes as well as to manage the existing secondary forests. Very little quantitative data is available for the south vietnamese lowlands forests. Some studies have given a general floristic description of these forests (Maurand, 1943; Trung, 1966; Schmid, 1974) and of similar formations (Vidal, 1960 for Laos; Rollet, 1972 for Cambodia). However, there is no information on descriptive parameters such as density, basal area, floristic richness, diversity, etc., and very little data is available on the dynamics of these forests (Rollet, 1960). According to Trung (1966) and Schmid (1974), natural lowland forest is a closed deciduous tropical forest dominated by L. calyculata associated with Dipterocarpaceae (D. turbinatus, D. dyeri) and Fabaceae. They estimated that Lagerstrœmiadominated stands belong to ‘climax forests’ whereas Rollet (1960) regarded them as secondary forests. He considered this formation as the probable result of shifting cultivation. It is then necessary to clearly describe the stages of the forests to distinguish secondary from mature forests. Corlett (1994) defined secondary forest as forest regenerating after complete clearing. In this study, we consider, as Brown & Lugo (1990), ‘secondary forests as those formed as a consequence of human impact’. When structural and floristic parameters of the forests do not reflect past degradations, we call it mature forests, as Hartshorn (1980). These works include the Nam Cat Tien area now classified as Cat Tien National Park where the current studies were carried out. Satellite data analyses (De Cauwer & De Wulf, 1994) showed that the forests of Cat Tien National Park appear like a mosaic of forest formations more or less dominated by Lagerstrœmia species, confirming the field observations of Vandekerkhove et al. (1993). The objectives of this study are to (1) describe the main forest types of Cat Tien National Park with structural and floristic parameters; (2) focus on the distinction between secondary and mature forests; (3) study the floristic links between these types of forests. MATERIALS AND METHODS Study area Nam Cat Tien Reserve Forest is located in the southern part of Vietnam, approximately 130 km north-east of Hochiminh City (Dong Nai Province, Fig. 1). It was created in 1978 and became a National Park in 1992. It lies at the foot of the central Vietnamese highlands (11°20′50″–11°32′13″ N and 107°11′13″–107°28′20″ E) and covers an area of 40,000 hectares. The few scientific studies made in the park were limited to inventories of flora and fauna (Schmid, 1974; Boulbet, 1960; Vandekerkhove et al., 1993; De Cauwer & De Wulf, 1994). The park is subjected to a tropical monsoon climate with two distinct seasons: a rainy season from April to November and a dry season from December to March. The mean annual rainfall is 2450 mm. August and September are the most rainy months in the year. The temperature amplitude is very

low, varying from 24 to 29 °C, and the mean annual temperature is 25.4 °C. Two major topographical areas can be distinguished (Fig. 1). (a) The eastern part, delimited by Dong Nai river, is a low and flat area with altitude not exceeding 150 m. All the plots studied were established in this area. (b) The western part is a hilly area with altitude ranging from 150 to 375 m. These two parts are separated by a large swampy area with lakes at elevations below 130 m. The bedrock is mainly basalt with stony outcrops. Very fertile, black ferrallitic soils developed on this bedrock. They mostly occur in the low eastern part of the park. In the other parts, impoverished and poorly drained grey soils developed on schist. Along the Dong Nai river, the soil is made of different layers of sediments. Data collection Field work was carried out from January 1995 to November 1996. Five plots were established in the forest mosaic, each one different from the other with respect to their floristic and structural parameters. Four plots (A, B, C and E) were on basaltic soils and the fifth (plot D) on schist. A detailed vegetation map of this area is not available except for the satellite data analysis of De Cauwer & De Wulf (1994) which has, however, not been fully verified in the field. Plots were selected from aerial photos and after discussion with Vietnamese foresters and researchers. Each plot covers 1 ha, divided into small quadrats of 10 × 10 m. All the trees with a diameter ≥ 10 cm d.b.h. (d.b.h.: diameter at breast height or at 1.3 m) were numbered, measured, plotted on a map and identified. The trees were classified into two groups (depending on the potential maximum height of the species): canopy and emergent species more than 25 m (G1) and understorey species less than 25 m (G2). Regeneration was studied by systematic sampling to compare floristic composition with adult trees. Sub-quadrats (4 × 4 m) were established in the middle of alternate 10 × 10 m quadrats, accounting for 8% of the plot area. All saplings ≥ 2 m high with d.b.h. < 10 cm were counted, identified and classified under G1 or G2. Species which can’t reach 10 cm diameter even at maturity were grouped under G3. Trees were considered as adult when they attained the critical size to produce fruits. If not they belong to natural regeneration. For canopy species (G1), we considered that trees are adult when they are ≥ 20 cm d.b.h. For species belonging to G2, all trees ≥ 10 cm d.b.h. were considered to be adult. Soil humidity was measured in plots A, B, C and E (four borings for each plot and four soil samples per boring). The ratio between the weight of the sample before and after drying (48 h in an oven at 100°C) was taken as the humidity rate. The soil was measured down to 2 m depth or down to the mother rock if found before (twenty-five borings for each plot). A herbarium was created with specimens of trees and saplings collected systematically from the plots. Except for a few rare species, all the other specimens were identified up to the species level. © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157


Forest typology in Cat Tien National Park 143

Figure 1 Map of the Nam Cat Tien area (Cat Tien National Park) and location of the five 1 ha plots.

Data analysis As a first approach, Jaccard’s Index of similarity was used to compare vegetation types. I = 100*c/(ux + uy + c) where c is the number of species common to both plots X and Y; and Ux and Uy, the number of species found only in plots X and Y, respectively. Differences in species diversity in the forest stands were assessed using two indices, derived from shannon-Wiener species diversity index and Simpson’s (Gimaret-Carpentier et al., 1998). Their estimators are: Sˆ

ni ˆ ′ = –∑ --H n-log i=1

ni  --2 n 

Sobs

ni ( ni – 1 ) ˆ –1 ˆ = 1 − λ with λ = ∑ -------------------+ S---------- and D n(n – 1) 2n i=1

ˆ)= 4 --nwith a theoretical variance Var(D

n

n

∑---n-i

3

–λ

2

i=1

© Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157

where S is the species richness of the population, Sobs the number of species observed in the sample, n the sample size and ni the abundance of species i in the sample. Hurlbert’s species richness curve gives the expected number of species E(Sx) in a sample of x individuals selected at random (without replacement) from a plot containing n individuals and S species (Hurlbert, 1971). The species richness of different plots for a given number of species can thus be compared. n – ni  x  E(Sx) = ∑ 1 – ---------------n i=1 x S

An index derived from the Importance Value Index (Curtis & McIntosh, 1950) was used to study the floristic structure.



RESULTS Soil property

Figure 2 Relationship between soil humidity and depth (mean and confidence interval) in plots A, B, C and E.

Like Pascal & Pelissier (1995), we also consider IVIi as the sum of the relative density Di and relative basal area Gi for species i in one plot. The sum of all the species in one plot is equal to 200. IVIi = Di + Gi, Di = (ni/n)·100, Gi = (gi/g)·100. Correspondence analysis and reciprocal scaling were performed with ADE.4 software (Thioulouse et al., 1997). Reciprocal scaling was performed from a correspondence analysis of the species (lines) × diameter class (columns) table. This statistical technique allows a joint display of species and diameter classes. From the coordinates of diameter classes ordered on a factorial axis seen as a gradient, the conditional mean and variance of species can be calculated. Variance of the means is maximized. The conditional means and variances of diameter classes can be obtained reciprocally (Thioulouse & Chessel, 1992). The range of diameter classes for each species can thus be derived.

The soils of plots A, B, C and E are developed on basalt. They all have good chemical properties (P. Deturck, pers. comm.) but differ physically. The soil is shallow, less than 50 cm deep, in A and B, and deeper, around 1 m, in C and E (Fig. 2). Using Bonferroni Test, significant differences are found between A and C (P = 0.0027), A and E (P = 0.0008), B and C (P = 0.0011) and B and E (P = 0.0003). Soil humidity at the end of the dry season is also significantly different between A and C (P = 0.0001), B and C (P < 0.0001) and B and E (P = 0.004). Root system is superficial in shallow soils inducing more frequent tree falls resulting in opening the canopy. Plot D has poor grey soil developed on schist, poorly drained and flooded during several months in the year. Stand structure The diameter class distributions for all the trees with a d.b.h. ≥ 10 cm in each plot are shown in Fig. 3. The distribution pattern of plots B and E is a negative exponential distribution or reverse ‘J-shaped’ curve, typical of mature forests (Rollet, 1978). Compared to this, the distribution patterns of plots A, C and D indicate a disturbed forest. Plots A and C show also a negative exponential distribution but with a high frequency of trees in medium diameter class for A and a very high frequency of trees in the first diameter class as well as in the last (diameter ≥ 110 cm) for plot C. Diametric distribution for plot D is very different from the four others with the highest frequencies for the medium class, which is characteristic of stands with poor regeneration (Knight, 1975). Density and basal area are given in Table 1. Density in plot D is much lower (195 trees/ ha) than in the other four plots (389–540 t/ ha). This plot appears like a very disturbed forest. The basal area of plots A and C is high: 69.41 and 54.89 m2/ha, respectively, whereas it is around 31 m2/ha for the other three plots. In plot C, the twenty trees belonging to the last diameter class (3.7% of the total number of trees) account for 71.4% of the total basal area.

Figure 3 Diameter class distribution of trees ≥ 10 cm d.b.h. for the five plots. © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157



Table 1 Density, basal area, percentage of deciduous species and trees, diversity indices and species richness for all the trees ≥ 10 cm d.b.h. in the five plots. Plots

A

B

C

D

Table 3 Jaccard’s index of similarity for the five plots (trees with d.b.h. ≥ 10 cm). Plots

A

B

C

D

E

A B C D E

—

32.3 —

26.8 22.3 —

0 2.7 0 —

32.5 27.8 33.3 4.2 —

E

Density (trees/ ha) 419 389 540 195 469 Basal area (m2/ ha) 69.41 31.71 54.89 29.30 31.33 Deciduous species (%) 26 35 13 11 10 Deciduous trees (%) 47 27 17 1 6 Simpson’s index 0.84 0.92 0.97 0.51 0.96 Shannon’s index 4.15 4.64 5.62 1.98 5.41 Species richness 70 57 91 18 81

Table 2 Number of species of the main families in the five plots. Family

Nb species

A

B

C

D

E

Rubiaceae Lauraceae Fabaceae Euphorbiaceae Meliaceae Anacardiaceae Ebenaceae Annonaceae Clusiaceae Myrtaceae Verbenaceae Sterculiaceae Dipterocarpaceae Oleaceae Moraceae Combretaceae

15 15 12 11 11 11 9 9 8 6 5 5 5 4 4 4

7 4 6 4 3 4 4 5 5 — 1 3 — 2 3 1

5 2 6 4 2 3 3 5 2 1 2 2 2 2 2 3

6 9 3 8 8 3 8 7 2 1 1 3 — 3 4 1

— — 1 2 — — — — 2 3 1 — 4 — — —

7 6 1 7 5 5 4 5 4 2 4 2 3 2 1 1

Floristic composition In the five plots, trees with d.b.h. ≥ 10 cm belong to 176 species. Rubiaceae and Lauraceae have the highest number of species (Table 2). The most abundant families are mainly

Figure 4 Hurlbert’s species richness curve for the five plots. © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157

dominated by species of the understorey (G2), except for Dipterocarpaceae and Combretaceae whose species all belong to G1 (see Appendix). Some differences can be observed in the five plots. Dipterocarpaceae is absent in plots A and C. Fabaceae has six species in plots A and B, but only three in plot C and one in plots D and E. In contrast, species richness is higher in plots C and E for Lauraceae, Euphorbiaceae and Meliaceae. Floristic composition in plot D is very different from the other four. It contains four species of Dipterocarpaceae but most of the main families are absent (Table 2 and Appendix). Jaccard’s Index of similarity is very low (Table 3) between this plot and B or E, and nil for A and C. None of the species is common to all the five plots due to the highly specific composition of plot D. However, sixteen species are common to plots A, B, C and E, four of them represented by a large number of trees: Lagerstrœmia calyculata (197, Lythraceae), Diospyros longebracteata (151, Ebenaceae), Ochrocarpus siamensis (87, Clusiaceae) and Alphonsea philastreana (69, Annonaceae). Jaccard’s Index ranges for these four plots from 22.3 to 33.3 (Table 3). It is highest (over 30%) between A and B, A and E and C and E. The percentage of deciduous species (and trees) is higher in plots A and B than in the other three plots (Table 1). Substantial difference was also observed in the species richness which varies from eighteen species in plot D to ninety-one species in plot C (Table 1). The shape of the Hurlbert’s species richness curve (Fig. 4) is similar for plots B, C and E.



Figure 5 Percentage of Importance Value Index {IVI = Di ( ) + Gi (h)} for the main G1 (j) and G2 (

The slope is steeper for plot A and shallow for plot D. Plots dominated by evergreen species (C and E) have a higher species richness than plots dominated by deciduous species (A and B). However, plot D, although evergreen, has a low species richness. The same trend is observed for species diversity (Table 1). For the two pairs of plots, disturbed forests are richer. But plot A is less diverse than plot B, whereas diversity in plot C is slightly higher than in plot E in terms of Simpson’s and Shannon’s indices. Plots A, C and D are strongly dominated by one species (Fig. 5). IVI of Lagerstrœmia calyculata is 53% and 39.9%, respectively, in A and C and IVI of Dipterocarpus alatus accounts for 75.1% in D. The pattern of species importance is quite different for B and E where quite a few species have similar IVI values. In B, L. calyculata and Fabaceae species like Afzelia xylocarpa and Dalbergia mammosa are the most dominant G1 species mixed with Anogeissus acuminata and Lagerstrœmia ovalifolia. Plot E contains a mixture of L. calyculata and Dipterocarpus turbinatus. Dipterocarpus alatus and Afzelia xylocarpa have only two trees in the plot but with very big diameter. It should be noted that both, B and E, are dominated by Cleistanthus sumatranus and Diospyros longebracteata in the understorey. Another important feature is that L. calyculata is dominant in all the plots except in D. However, its density is higher in plot A than in the others where it is represented by few trees but with larger diameter.

) species (IVI ≥ 2) in the five plots.

Floristic relationships To study the floristic relationships, a between-plots correspondence analysis was performed on the number of trees per species and per subplot (20 × 20 m). Only species with more than five trees in the four plots taken together were selected. Plot D was not included in the analysis due to its very distinct floristic composition. The results are given in Fig. 6. Several points can be formulated. The floristic composition of the plots A and C is very distinct and there is no specific floristic link between these two plots (Fig. 6a,b). Plots E and B are close on axes 1 and 2 because they share two very common species: Cleistanthus sumatranus and Diopsyros longebracteata (Fig. 6b). However, most of their subplots have a distinct floristic composition and are separated on axis 3 (Fig. 6c). There is a clear floristic link between plots C and E with a succession of species present only or mainly in these two plots (Fig. 6b). From Fig. 6(b) (axes 1 and 2), it is not possible to determine the floristic links between A on one side and B or E on the other side. This can be analysed through the third axis (Fig. 6c). The canopy or emergent species (G1) are positioned between A © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157



Figure 6 Correspondence analysis performed on the number of trees per species (species with more than five trees in the four plots) and per subplot (20 × 20 m). The figure shows the results of the between-plot analysis for (a) the subplots; (b) the species on axes 1 and 2; and (c) the species on axes 1 and 3. Axes 1 and 2 account for 41.5% and 35.3%, respectively, of the total variance of the scatterplot. The observed dispersion of the centres of gravity of the four plots is highly significant. No higher value was found in 1000 simulations. Species with a high relative contribution are underlined for the first axis and in bold for the second axis. Species code are given in the Appendix.

and B. They are Afzelia xylocarpa and Dalbergia mammosa, which are two typical species of B, Tetrameles nudiflora which is also in C, Beilschmiedia micranthopsis also found in E and Pterospermum diversifolium also in C and E. Only Vitex pinnata doesn’t belong to A but to B and E. Other species belong to the understorey (G2) and occur in all the © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157

four plots: Alphonsea philastreana, Streblus taxoides, Diospyros longebracteata, Polyalthia luensis, Garcinia nigrolineata, Linociera pierrei, Antidesma velutinosum and Madhuca pierrei. Nephelium melliferum and Cleistanthus sumatranus occur in three plots (A, B and E). Garcinia vilersiana and Dehasia caesia are the only species found in A and E. The distribution of



Figure 7 Ordination by reciprocal scaling after a correpondence analysis performed on the number of trees in eleven diameter classes for fortyfour species. The dot (proportional to the number of trees) and the associated line represent the conditional mean and variance, respectively, for (a) the species of the 5 plots and (b) the diameter classes, on the first axis (inertia = 28.9%). (c) show the diametric class distribution of Lagerstrœmia calyculata in plot A and Dipterocarpus alatus in plot D. Species code are given in the Appendix.




Table 4 Estimated density (and confidence interval) of saplings from the systematic sampling (≥ 2 m and < 10 cm d.b.h.) and species richness in the five plots. Plots Density Estimated number of saplings (per ha) Species richness Total number of species % G3 species % G3 saplings

A

B

C

D

E

4275 (3646 –4904)

6338 (5480 –7195)

8150 (7450 –8885)

2850 (2393 –3307)

6175 (5372– 6978)

63 52 60.8

57 42 41

111 35 36.2

29 59 85.5

82 35 55.1

the species on axes 1 and 3 thus shows a clear floristic link between plot A and plot B. Stand ordination A correspondence analysis was performed on the number of trees in each diameter class for all species with more than two individuals. The first axis distinguishes the first two diameter classes from the others. When Lagerstrœmia calyculata of plot A (152 trees) and Dipterocarpus alatus of plot D (135 trees) are not included in the analysis, the diameter classes are more spread out on the first factorial axis. From the results, a reciprocal scaling was made (Fig. 7) as proposed by Thioulouse & Chessel (1992). (i) Plot A is composed of two groups of species. Four species, Afzelia xylocarpa, Tetrameles nudiflora, Haldina cordifolia and Bursera serrata are only in the higher diameter classes (≥ 50 cm diameter). Moreover, only few trees of Lagerstrœmia calyculata are in the first three diameter classes (Fig. 7c). These species show very poor regeneration. In contrast, Dalbergia mammosa and Pterospermum diversifolium are restricted to the smallest diameter classes indicating an obvious change in the future floristic composition in this plot. (ii) A discontinuity is also observed in plot C. Lagerstrœmia calyculata is restricted to the large diameters (out of a total of twenty-seven trees, only three belong to the first diameter class and twenty to the last one). The majority of species is in the smallest classes. But for Lagerstrœmia calyculata, this plot appears like a regenerating area. (iii) Plot D has few small diameter trees of Dipterocarpus alatus (Fig. 7c). The dominance of this species will dramatically decrease to the benefit of nondominant species like Garcinia benthami and Parinari annamensis. (iv) Plots B and E show a more uniform distribution with several species present in a large array of diametric classes including the smallest ones: Pterospermum diversifolium, Dalbergia mammosa, Sindora siamensis, Anogeissus acuminata, Lagerstrœmia ovalifolia in B, Dipterocarpus turbinatus, Lagerstrœmia ovalifolia and Pterospermum diversifolium in E. Only Afzelia xylocarpa in B and Lagerstrœmia calyculata in E do not have trees in the smallest diameter classes and might disappear in these two plots. In B, six trees of Lagerstrœmia calyculata were counted in the first two diameter classes. Three are on one side of the plot which is a part of a large gap and a fourth is a sprout of a © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157

Table 5 Percentage of deciduous species and species richness of mature trees and natural regeneration of G1 and G2 species in the five plots. The trees of G1 species in the first diameter class (10 ≤ cl1 < 20 cm) are not considered as adult trees and are added to the data from the systematic sampling only when they were present in the subquadrats (4 × 4 m). Two trees with d.b.h. < 20 cm were added in plots A and B, 3 in plots C and E and none in the plot D. Plots Percentage of deciduous trees G1 adult trees G1 regeneration G2 adult trees G2 regeneration Species richness G1 adult trees G2 adult trees Total G1 regeneration G2 regeneration Total

A

B

C

D

E

92 50 4 2

83 52 3 0

53 20 12 3

1 1 12 8

43 24 0 2

16 48 64 5 26 31

22 33 55 12 21 33

15 70 85 9 66 75

9 7 16 5 4 9

19 57 76 11 43 54

larger tree (diameter 200.6 cm). Thus in plots B and E, the canopy and emergent species that have attained large diameters are in general seen to be regenerating and the floristic composition is therefore unlikely to change. Natural regeneration Sapling density (≥ 2 m high and < 10 cm d.b.h.) was estimated from the fifty subquadrats sampled in each plot. Concerning density, the same conclusions can be drawn (Table 4) as for trees with d.b.h. ≥ 10 cm. It is significantly lower in plots D and higher in plot C. In all the plots, saplings are dominated by understorey species (G3) both in the number of species and individuals (Table 4). In plot D, Colona auriculata (Tiliaceae) accounts for 70.2% of the total number of individuals. The comparison of floristic parameters between adult trees and natural regeneration is shown Table 5 and Fig. 8. The canopy of plots A and B is almost deciduous whereas the canopy of plots C and E is semideciduous (Table 5). The frequency of deciduous trees in regeneration is about half



Figure 8 Simpson’s index of species diversity for G1 + G2 species (Nx) and for only G1 (G1x) for mature trees (s) and regeneration (j) for each plot (x = A, B, C, D or E).

Plots

A

B

C

Dalbergia mammosa Pierre Lagerstrœmia calyculata Kurz. Garcinia benthami Pierre HCT822 Vitex quinata Williams Firmania simplex (L.) W. F. Wight Mangifera foetida Lour. Terminalia calamansanai (Bl.) Rolfe Xylia xylocarpa (Roxb.) Taubert Vatica odorata (Griff.) Sym. subsp odorata Lagerstrœmia ovalifolia Teijsin. & Binn. Garcinia ferrea Pierre Disoxylum loureirii Pierre Vitex pinnata L. Cryptocarya ferrea Bl. Aphanamixis polystachia J. N. Parker Disoxylum cauliflorum Hiern Hibiscus macrophyllus Roxb. ex Horbem Neolamarckia cadamba (Roxb.) Bosser Anisoptera costata Korth. Callophyllum calaba var. bracte. (Wight) Stevens Dipterocarpus alatus Roxb. Crypteronia paniculata Bl. var affinis (pl.) Beus Beilschmiedia micranthopsis Kost. Melanorrhea usitata Wall. Pterospermum diversifolium Bl. Dipterocarpus turbinatus Gaertn. f.

1* 3* 4 1 1

2 2 1

1

D

E

1 1 1

1 1 2* 1 3* 2 5 3 4

2**

1* 2

1 1 2 2

1 1* 1 1* 1

3* 1 1 2 4 1 1 1 2

Total

Table 6 Floristic composition of regeneration of G1 species in the five plots.

3 6 6 2 2 1 1 2 1 3 4 8 5 6 1 1 1 1 4 1 1 2 4 1 1 1 2

*Represents one tree with diameter ≥10 cm (see legend table 5).

that of adult trees in these four plots. Adult trees and regeneration of G2 species are almost evergreen. Plot D is evergreen. The species richness decreases from plot A to B and from C to E for adult trees (Table 5), but this decrease is only due to G2 species as species richness of G1 shows an increase. The same trend is observed for regeneration. Species diversity of G1 adult trees is significantly lower than that of their regeneration for plots A, C and D (Fig. 8). For plots B and

E, Simpson’s index values for adult trees and regeneration are high and not significantly different. In all the five plots, there is no significant difference (χ2 = 0.20; 8ddl; NS) between G1 species number represented only by adult trees, or only in regeneration, or by both adult trees and regeneration. Table 6 shows the number of saplings measured for regeneration in each plot, together with the nonadult (G1) trees with ≥ 10 cm d.b.h. Regeneration of Lagerstrœmia calyculata © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157



Figure 9 Stand dominated by Lagerstrœmia calyculata with bright grey bark (photo L. Blanc).

is not abundant compared to the number of adult trees in each of the four plots. It shows very poor regeneration in the understorey, confirming the results given in Fig. 7(c). We can conclude that in all the plots where this species is dominant, it tends to disappear (C and E) or decrease drastically (A and B). In A and C, regeneration is too poor for a clear trend to be observed (Table 6). In D, the dominant species, Dipterocarpus alatus, has poor regeneration in contrast to Crypteronia paniculata. In B, some of the more important species like Dalbergia mammosa, Terminalia calamansanai, Vatica odorata, Lagerstrœmia ovalifolia and Vitex pinnata regenerate well. In E, Mangifera fœtida, Vitex pinnata, Neolamarckia cadamba and Dipterocarpus turbinatus show good regeneration. Five regenerating species are common to both B and E. DISCUSSION A dynamic view of forests in southern Vietnam is necessary because primary forests disappeared almost completely and were replaced by a mosaic of forest formations disturbed in varying degrees of several kinds of degradations in the past. Satellite data analyses (De Cauwer & De Wulf, 1994) showed that the forests of Cat Tien National Park appear like a mosaic of forest formations more or less dominated by Lagerstrœmia species. De Cauwer & De Wulf (1994) distinguished three forest formations in the lowland area: primary, secondary and mixed forests but floristic composition are not precise. Primary forests are found mainly in the middle of the lowland area, i.e. in the most inaccessible part of the park, and the other two types are localized along the river. Our results give some elements to establish a better typology of the formations in Cat Tien. The mature or nonmature stage of the plots was analysed from floristic and structural parameters and from differences in the floristic © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157

composition between trees and regeneration. In plot A, diameter class distribution of all the species shows a high frequency of medium diameters (Fig. 3) which is a reflection of the distribution of the very dominant species, Lagerstrœmia calyculata (Fig. 7c). This plot appears like a ‘pure stand of Lagerstrœmia’ (Fig. 9) as defined by Rollet (1960). The floristic composition of the plot is not stable and will change in the future with the progressive disappearance of Lagerstrœmia calyculata and all the other main species Tetrameles nudiflora, Haldina cordifolia, Afzelia xylocarpa (deciduous) and Bursera serrata (evergreen) which have no or poor regeneration. On the other hand, there will be an increase in Dalbergia mammosa and Garcinia benthami, and also a slight increase in the total number of evergreen species. Plot C appears as a regenerating plot with a diameter class distribution characterized by a high number of trees with small diameters (below 20 cm), which have not yet reached the adult size (Fig. 3). This could be one reason to explain the relatively small number of regenerating stems. Lagerstrœmia calyculata, which is dominant among the big trees, has poor regeneration and will become less dominant. The regeneration, with a high number of species, indicates that the stand will evolve towards a more evergreen composition. Thus, these two plots are both characterized by the high dominance of L. calyculata, inducing a low diversity of G1 species and a high basal area. They have a nonstable floristic composition and should be regarded as secondary forests or secondary stages of succession. These two plots differ however, by their diametric distribution. Plot A has a high frequency of medium diameters whereas plot C is strongly dominated by big L. calyculata trees. Data available do not support the hypothesis that C is a more degraded stand than A. Furthemore, no successional trends are observed between A and C in the correspondence analysis. In contrast, plots B and E can be considered as mature forests from their diameter



Figure 10 Large tree of Lagertsrœmia calyculata (photo L. Blanc).

distribution, basal area, and also because most of the G1 species have reached large diameters and regenerated well. Both these plots occur on basaltic soils, but with different depths and humidity. Plot B, which is on shallow soil (like A) is dominated by L. calyculata and species of Fabaceae. It can be described as a semideciduous stand (with 27% of

deciduous trees). Plot E occurs on deeper soil (like C) and is an almost evergreen forest dominated by dipterocarp species, mainly Dipterocarpus turbinatus, and a few L. calyculata. This evergreen nature will be accentuated in the future as L. calyculata is not regenerating. The correspondence analysis based on the floristic composition clearly shows a floristic link between A and B on one hand, and C and E on the other, confirming the distribution of the two pairs of plots on two different soil conditions. Both Jaccard’s index and correspondence analysis show that plots B and E share a pool of common species which seem to be not affected by the edaphic differences. Others species, more sensitive to the depth and the humidity of these soils, make the difference in the floristic composition and phenological nature (deciduous/evergreen) between these two formations. Thus from our results, we can conclude that (i) two mature formations are present in the studied area of Cat Tien: one semideciduous, dominated by Lagerstrœmia calyculata and Fabaceae species (plot B) and another, almost evergreen, dominated by dipterocarp species (plot E); (ii) two successional trends can be discerned from A to B and from C to E; (iii) as suggested by Jaccard’s index of similarity and the pure evergreen nature of the stand, plot D appears to be a third formation dominated by Dipterocarpus alatus whose successional relationships are not easy to predict. Lagerstrœmia calyculata seems to be a key species in the succession. We agree with Rollet (1960) who considered Lagerstrœmia-dominated stands to be secondary forests. This species can be considered as a secondary species with a long life span and large diameters (Fig. 10), not typical of mature forests. Its regeneration is very poor and limited to large openings. It appears to be a very good competitive species able to regenerate on denuded areas: along roads and on land abandoned after cultivation. Human disturbances have mostly affected dipterocarps for resin and Fabaceae for their wood, thus reducing the number of trees of these species and creating favourable conditions for regeneration of Lagerstrœmia calyculata. In plot B, Lagerstrœmia calyculata is still maintained. One hypothesis is that treefalls are more frequent on this shallow soil, due to poor rooting, creating gaps which allow the regeneration of this secondary species and its occurrence as rare individuals in mature forests.

Table 7 Comparison of mean density and basal area in some tropical forests of Asia.

Location

Minimum gbh (cm)

Mean density (ha-1)

Mean basal area (m2.ha-1)

Uppangala, India Danum Valley, Sabah Pasoh, Malaysia

30 30 31.4

625 470 530

39.7 26.6 25.2

Sungei-Menyala, Malysia Mulu, Sarawak Cat Tien Vietnam, Plot E Cat Tien Vietnam, Plot B Xishuangbanna, China

31.4 31.4 31.4 31.4 31.4

493 739 469 389 386

32.4 57.0 31.3 31.7 30

References Pascal & Pelissier (1995) Newbery et al. (1992) Kochumen, Lafrankie & Manokaran (1990), Manokaran & Lafrankie (1990) Manokaran & Kochumen (1987) Proctor et al. (1983) Present study Present study Cao et al. (1996)




Rollet (1960) observed that Lagerstrœmia and Fabaceae forest type has maximum stability on rocky black basaltic slopes. This edaphic condition favours treefalls. The maintenance of this forest type could be the result of this frequent natural disturbance. Table 7 shows that the density and basal area of the two mature formations (plots E, evergreen, and B, semideciduous) are quite comparable to other forests in Asia. The next step will be to focus on the biology of the main species involved in the successional processes and colonization of the open areas. As this region is in urgent need of land rehabilitation, it is necessary to obtain this data at the earliest. ACKNOWLEDGMENTS The authors are grateful to the Programme Environnement, Vie et Sociétés, of CNRS for supporting the project and to the board of Cat Tien National Park for allowing the research work. They also thank Nguyen Manh Sum, Nguyen Tran Vy, Luu Huong Truong, Laurence Curtet, Bruno Dutreve and students from the Department of Botany and Ecology, University of Ho Chi Minh City for field assistance; Prof. Le Cong Kiet, Vu Van Bien, Nguyen Thien Thich for their help in species identification; Drs My Hanh Diep and Pol Deturck for soils description and analyses and S. Dolédec for data analyses. The authors thank also two anonymous reviewers for useful critiques. L. Blanc received a grant from the Ministère de l’Enseignement Supérieur et de la Recherche and additional financial support from the Rhône-Alpes Region. REFERENCES Boffey, P. M. (1971) Herbicides in Vietnam: AAAS study finds widespread devastation. Science, 171, 43 – 47. Boulbet, J. (1960) Description de la végétation en pays Ma′. Bulletin de la Société d’Etudes Indochinoises, 35, 545– 574. Brown, S. & Lugo, A. E. (1990) Tropical secondary forests. Journal of Tropical Ecology, 6, 1–32. Cao, M., Zhang, J., Feng, Z., Deng, J. & Deng, X. (1996) Tree species composition of a seasonal rain forest in Xishuangbanna, Southwest China. Tropical Ecology, 37, 183 –192. Collins, N. M., Sayer, J. A. & Whitmore, T. C. (1991) Conservation atlas of tropical forests. Asia and the Pacific. Macmillan Press. London. Corlett, R. T. (1994) What is secondary forest? Journal of Tropical Ecology, 10, 445– 447. Curtis, J. T. & McIntosh, R. P. (1950) The interrelations of certain analytic and synthetic phytosociological characters. Ecology, 31, 434 – 455. De Cauwer, V. & De Wulf, R. (1994) Contribution to management planning in Nam Bai Cat Tien National Park, Vietnam, using spatial information techniques. Thesis, University of Gent. Durand, F. (1994) Les forêts en Asie du Sud-Est. L’Harmattan, Paris. Gimaret-Carpentier, C., Pelissier, R., Pascal, J.-P. & Houillier, F. © Blackwell Science Ltd 2000, Journal of Biogeography, 27, 141–157

(1998) Sampling tree species diversity in a dense moist evergreen forest with regard to its structural heterogeneity. Journal of Vegetation Science, 9, 161–172. Hartshorn, G. S. (1980) Neotropical forest dynamics. Biotropica, 12 (Suppl.), 8 –15. Ho, Pham Hoang (1991–93) Cây Co Viêt Nam An illustrated flora of Vietnam, 6 volumes. Mekong Printing, Santa Ana, California. Hurlbert, S. H. (1971) The nonconcept of species diversity: a critique and alternative parameters. Ecology, 52, 577–586. Knight, D. H. (1975) A phytosociological analysis of species-rich tropical forest on Barro Colorado Island, Panama. Ecological Monographs, 45, 259 –284. Kochumen, K. M., La Frankie, J. V. & Manokaran, N. (1990) Floristic composition of Pasoh Forest Reserve, a lowland rain forest in Peninsular Malaysia. Journal of Tropical Forest Science, 3, 1–13. Lamb, D. (1994) Reforestation of degraded tropical forests lands in the Asia-Pacific region. Journal of Tropical Forest Science, 7, 1–7. Leconte, P. (1905–52) Flore Générale de l’Indochine, 7 volumes. Masson, Paris. Mai, To Dinh (1983) Le Viêt-Nam forestier. Revue Forestière Française, 25, 227–243. Manokaran, N. & La Frankie, J. V. (1990) Stand structure of Pasoh Forest Reserve, a lowland rain forest in Peninsular Malaysia. Journal of Tropical Forest Science, 3, 14 –24. Manokaran, N. & Kochumen, K. M. (1987) Recruitment, growth, and mortality of tree species in a lowland dipterocarp forest in Peninsular Malaysia. Journal of Tropical Ecology, 3, 315 –330. Maurand, P. (1943) L’Indochine forestière. Institut des recherches agronomiques et forestières de l’Indochine, Hanoi. Newbery, M. D., Campbell, E. J. F., Lee, Y. F., Ridsdale, C. E. & Still, M.J. (1992) Primary lowland dipterocarp forest at Danum Valley, Sabah, Malaysia: structure, relative abundance and family composition. Philosophical Transactions of the Royal Society of London B, 335, 341–356. Norman, C. (1974) Academy reports on Vietnam herbicides damage. Nature, 248, 186 –188. Orians, G. H. & Pfeiffer, E. W. (1970) Ecological effects of the war in Vietnam. Science, 168, 544 –554. Pascal, J. P. & Pelissier, R. (1995) Structure and floristic composition of a tropical evergreen forest in south-west India. Journal of Tropical Ecology, 12, 191–214. Proctor, J., Anderson, J. M., Chai, P. & Vallack, H. W. (1983) Ecological studies in four contrasting lowland rain forests in Gunung Mulu National Park, Sarawak. I — Forest environment structure and floristics. Journal of Ecology, 71, 237– 260. Rollet, B. (1960) Note sur la végétation du Vietnam au sud du 17 éme parallèle Nord. Commentaire de la carte au 1/1,000,000. Institut de Recherche Agronomique, Saigon. Rollet, B. (1972) La végétation du Cambodge (article in three parts). Bois et Forêts des Tropiques, 144, 3 –15, 145, 23 –38, 146, 3 –20. Rollet, B. (1978) Description, functioning and evolution of tropical forest ecosystems: organization. Tropical forest ecosystems (ed. by UNESCO, UNEP and F.A.O.), pp. 112–142. UNESCO, Paris. Schmid, M. (1974) Végétation du Viet-Nâm. ORSTOM, Paris.



SRV State Committee for Sciences, U.N.D.P., SIDA, UNEP & IUCN (1991) Vietnam, national plan for environment and sustainable development. 1991–2000. Project VIE /89/021. Trung, Thai Van (1966) Phytogénèse et classification de la végétation forestière au Vietnam. Acta scientiarum Vietnamicarum Section Biology Geography and Geology, 1, 88 –100. Thioulouse, J. & Chessel, D. (1992) A method of reciprocal scaling of species tolerance and sample diversity. Ecology, 73, 670 – 680. Thioulouse, J., Chessel, D., Dolédec, S. & Olivier, J.M. (1997) ADE-4: a multivariate analysis and graphical display software. Statistics and Computing, 7, 75 – 83. Tschirley, F.H. (1969) Defoliation in Vietnam. Science, 163, 779 –786. Vandekerkhove, K., De Wulf, R. & Chin, N.N. (1993) Dendrological composition and forest structure in Nam Bai Cat Tien National Park, Vietnam. Silva Gandavensis, 58, 41–83. Vidal, J. (1960) La végétation du Laos: groupements végétaux et flore (IInd part), 582pp. Thesis, Université de Toulouse.

BIOSKETCHES Lilian Blanc is a tropical forest ecologist. He spent 2 years in Vietnam (1995–6) on fieldwork for his Ph.D. thesis. He graduated in July 1998. Géma Maury-Lechon and Jean-Pierre Pascal are researchers at CNRS (Centre National de la Rechereche Scientifique) and have worked in Asia for more than 20 years. Géma MauryLechon is a dipterocarp specialist (phylogeny and forest dynamics) and has collaborated mainly with Malaysia and Vietnam. She is the leader of a reforestation project in Cat Tien National Park. Jean-Pierre Pascal is head of the research team ‘nodelisation and dynamics of tropical rain forest at the laboratory UMR CNRS 5558. For 10 years he was the director of the French Institute of Pondichery (India).

Appendix IVI values (in %) of tree species in the five plots established in Cat Tien National Park. The unidentified species are named after their reference number in the herbarium (HCT xxx). Plots Family

Species

Code

G

Anacardiaceae

Allospondias lakonensis (Pierre) Stapf. Bouea poilanei Evr. HCT575 Mangifera Mangifera dongnaiensis Pierre Mangifera duperreana Pierre Mangifera fœtida Lour. HCT103 Melanorrhoea usitata Wall. Semecarpus graciliflora Evr. & Tard. Semecarpus reticulata Lec. Spondias pinnata (Koenig & L. f.) Kurz Alphonsea philastreana (Pierre) Fin. & Gagn. Cananga latifolia (Hook. f. & Thoms.) Fin. & Gagn. HCT821 Polyalthia HCT899 Polyalthia Mitrephora thorelii Pierre Polyalthia corticosa (Pierre) Fin. & Gagn. Polyalthia luensis (Pierre) Fin. & Gagn. Sageraea elliptica (A. DC.) Hook. & Thoms. Xylopia vielana Pierre ex Fin. & Gagn. Alstonia scholaris (L.) R. Br. Kibatalia laurifolia (Ridl.) Woods HCT050 Ilex cochinchinensis (Lour.) Loesen. Markhamia stipulata var. pierrei (Dop) Sant. Stereospermum colais (Dillw.) Mabb. Bombax insignis Wall. Bursera serrata Wall. ex Colebr. Lophopetalum wightianum Arn. Callophyllum calaba var. bracteatum (Wight) Stevens Garcinia benthami Pierre Garcinia ferrea Pierre Garcinia nigrolineata Pl. ex T. And. Garcinia vilersiana Pierre

Allak Boupoi Hct575 Mandon Mandup Manfoe Hct103 Melusi Semgra Semret Spopin Alpphi Canlat Hct821 Hct899 Mittho Polcor Pollue Sagell Xylvie Alssch Kiblau Hct050 Ilecoc Marsti Stecol Bomins Burser Lopwig Calcal Garben Garfer Garnig Garvil

2 1 2 1 1 1 1 1 2 2 1 2 1 2 2 2 2 2 2 2 1 2 2 2 1 1 2 1 1 1 1 1 2 2

Annonaceae

Apocynaceae

Aquifoliaceae Bignoniaceae Bombacaceae Celastraceae Clusiaceae

A

B

0.34

1.52

C

D

E

0.36 0.97 0.27

0.53 1.15 3.41

0.59 0.42 0.26 0.25

0.25 0.23

4.83

0.25 0.54 0.25 0.57 0.79

2.03 7.09 0.41 0.91 0.45 0.69

3.63

2.60 3.48

0.41 0.20 1.51 1.66 0.25 4.60

3.26 0.53 1.08

2.04 1.26

0.25 0.45 2.02

0.24 0.24 0.36 2.73

7.60 0.40 1.31

0.32 2.77

5.31 14.80 1.96 2.78 0.28 2.10 0.78

1.04

0.40

2.13 0.79




Appendix continued Plots Family

Combretaceae

Crypteroniaceae Cycadaceae Datiscaceae Dilleniaceae Dipterocarpaceae

Ebenaceae

Elaeocarpaceae Euphorbiaceae

Fabaceae

Hypericaceae Icacynaceae Irvingiaceae Lauraceae

Species

Code

G

HCT397 Garcinia HCT535 Garcinia Ochrocarpus siamensis T. Anders. Anogeissus acuminata (DC.) Guill. & Perr. Terminalia calamansanai (Bl.) Rolfe Terminalia corticosa Pierre ex Lan. Terminalia pierrei Gagn. Crypteronia paniculata Bl. var. affinis (Pl.) Beus. Cycas circinalis L. Tetrameles nudiflora R. Br. Dillenia hookeri Pierre Anisoptera costata Korth. Dipterocarpus alatus Roxb. Dipterocarpus turbinatus Gaertn. f. Hopea odoata Roxb. Vatica odoata (Griff.) Sym. subsp odoata Diospyros castanea (Craib.) Fletcher Diospyros filipendula Pierre ex Lec. Diospyros frutescens Bl. Diospyros hasseltii Zoll. Diospyros longebracteata Lec. Diospyros longipedicellata Lec. Diospyros maritima Bl. Diospyros nitida Merr. Diospyros rubra Lec. Elaeocarpus petiolatus (Jack.) Wall ex Kurz. Elaeocarpus stipularis Bl. Antidesma velutinosum Bl. Aporusa dioica (Roxb.) Muell.-Arg. Aporusa planchoniana H. Baill. ex Muell. Aporusa yunnanensis (Pax. & Hoffm.) Metc. Baccaurea ramiflora Lour. Cleistanthus sumatranus (Miq.) Muell.-Arg. Erismanthus sinensis Oliv. Exccaria oppositifolia Griff. HCT773 HCT822 Suregada multiflora (Juss.) H. Baill. Adenanthera pavonina L. Afzelia xylocarpa (Kurz.) Craib. Albizia lucidior (Steud.) J. Niels. Albizia vialenea Pierre Dalbergia mammosa Pierre Milletia diptera Gagn. Milletia nigrescens Gagn. Ormosia tonkinensis Gagn. Peltophorum dasyrrachis var. tonkinensis (Pierre) K. & S. S. Larsen Pterocarpus macrocarpus Kurz. Scolopia spinosa (Roxb.) Warb. Sindora siamensis Teysm. ex Miq. var. siamensis Xylia xylocarpa (Roxb.) Taubert Cratoxylon cochinchinensis (Lour.) Bl. Gonocaryum lobbianum (Miers.) Kurz. Irvingia malayana Oliv. ex Benn. Beilschmiedia foveolata Kost. Beilschmiedia laotica Kost.

Hct397 Hct535 Ochsia Anoacu Tercal Tercor Terpie Crypan Cyccir Tetnud Dilhoo Anicos Dipala Diptur Hopodo Vatodo Diocas Diofil Diofru Diohas Diolon Diolog Diamar Dionit Diorub Elapet Elasti Antvel Apodio Apopla Apoyun Bacram Clesum Erisin Excopp Hct773 Hct822 Surmul Adepav Afzxyl Albluc Albvia Dalmam Mildip Milnig Ormton

2 2 2 1 1 1 1 1 2 1 2 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 2 2 1 1 2 1 2 2 2

Peldas Ptemac Scospi Sinsia Xylxyl Cracoc Gonlob Irvmal Beifov Beilao

2 2 2 1 1 2 2 1 2 2


A

B

C

D

E

0.51 17.13 0.57

3.26 9.94 4.23

2.22

0.55 4.55

1.45

1.39

1.48 1.78 0.25 2.19

1.27

0.61 0.43 0.20

3.11

2.14 150.2 0.43 2.60 0.30 0.28 2.09 6.54 0.59

25.50

3.96

0.50

0.47

0.25

1.64 0.59 1.88 2.34 7.92 0.20 1.19

6.83 10.70 2.16

20.11 2.98 0.52

2.90 6.59 0.41 0.22 1.15 0.21 0.21 0.61

6.17

0.52 1.01 0.69

2.12 0.25

22.16 3.76

1.78 11.71

2.61 0.23

1.97 0.61

2.00 0.25 0.25 6.68

19.69

4.15 0.81 0.25 1.55 1.15

0.54 0.54 5.53 0.55

1.65 0.50

8.59 2.26 0.57

0.26 0.25 0.24 1.76 0.90 0.87

0.21 0.42

0.25 1.55

0.50 1.38




Lecythidaceae

Lythraceae

Malvaceae Meliaceae

Moraceae

Myristicaceae Myrtaceae

Oleaceae

Oleaceae Proteaceae Rhizophoraceae Chryso balanaceae Rubiaceae

Species

Code

G

Beilschmiedia micranthopsis Kost. Cinnamomum iners Reinw. Cryptocarya ferrea Bl. Cryptocarya obovata R. Br. Cryptocarya ochracea Lec. Dehaasia caesia Bl. Dehaasia poilanei Liouhe. HCT093 HCT439 Dehaasia HCT846 HCT879 Persea mollis (W. W. Sm.) Kost. Phoebe pallida Nees. Barringtonia acutangula (L.) Gaertn. Barringtonia pauciflora King. Careya arborea Roxb. Lagerstrœmia calyculata Kurz. Lagerstrœmia duperreana Pierre ex Gagn. Lagerstrœmia ovalifolia Teijsin. & Binn. Hibiscus macrophyllus Roxb. ex Hornem Aglaia hoaensis Pierre Aglaia pirifera Glance Aphanamixis polystachia J. N. Parker Disoxylum arborescens Miq. Disoxylum binectariferum Hook. f. Disoxylum cauliflorum Hiern Disoxylum loureirii Pierre HCT097 Disoxylum Disoxylum tpongense Pierre HCT569 Walsura robusta Roxb. Artocarpus nitida ssp. lignanensis (Merr.) Jarr. Artocarpus rigida ssp. asperulus (Gagn.) Jarr. HCT102 Streblus taxoides (Heyne) Kurz Knema lenta Warb. Cleistocalyx nigrans Gagn. Merr. & Perry. HCT211 Syzygium Syzygium grandis Wight Syzygium jambos (L.) Alston. HCT115 Syzygium zeylanicum (L.) DC. Linociera microstigma Gagn. Linociera pierrei Gagn. HCT551 Linociera Olea macrophylla Gagn. Heliciopsis terminalis (Kurz) Sleumer Carallia brachiata (Lour.) Merr. Parinari annamensis Hance Aidia pycnantha (Drake) Tirv. Haldina cordifolia (Roxb.) Ridsd. HCT436 HCT525 HCT543 HCT572 HCT814 Randia HCT860

Beimic Cinine Cryfer Cryobo Cryoch Dehcae Dehpoi Hct093 Hct439 Hct846 Hct879 Permol Phopal Baracu Barpau Cararb Lagcal Lagdup Lagova Hibmac Aglhoa Aglpir Aphpol Disarb Disbin Discau Dislou Hct097 Distpo Hct569 Walrob Artnit Artrig Hct102 Strtax Knelen Clenig Hct211 Syzgra Syzjam Hct115 Syzzey Linmic Linpie Hct551 Olemac Helter Carbra Parann Aidpyc Halcor Hct436 Hct525 Hct543 Hct572 Hct814 Hct860

1 2 1 2 1 2 2 2 2 2 2 1 2 2 2 1 1 1 1 1 2 2 1 1 2 1 1 2 2 2 2 2 2 1 2 2 2 2 1 2 2 2 2 2 2 2 2 2 1 2 1 2 2 2 2 2 2

A

B 0.93 0.77

C

D

E

4.58

0.80 0.50 0.30 0.21 0.71

1.28

1.63

1.17 0.82

0.27 0.95 0.44 0.20 1.58 0.43

0.24

0.27 0.25 106.1 0.40 0.94

0.67 30.30 7.56

0.79

0.64

0.25

0.68

0.25 0.52 0.60 0.25

0.32 2.58

79.86

14.22

1.32 1.96 0.43 0.22 2.13 0.21

2.81

0.22

0.76

0.20 1.26

0.29

0.29

9.39 1.06

0.42 0.48 0.21 0.46 0.21 7.21

1.02 0.51

0.81 2.00 0.37 2.54

1.23 1.15 3.75 0.27 2.61

0.31 0.58

0.85 0.41 0.40

2.90 7.50

0.55 12.51

0.24 1.22 2.77

0.29 10.64 0.28 0.25

0.57 0.41

0.31

0.25 0.28 0.20

0.26





Rutaceae Sapindaceae

Sapotaceae

Staphyleaceae Sterculiaceae

Symplocaceae Theaceae Tiliaceae Verbenaceae

Species

Code

G

Hymenodictyon orixense (Roxb.) Malb. Neolamarckia cadamba (Roxb.) Bosser. HCT924 Randia Rothmania encodon (K. Schum.) Brem. Rothmania vietnamensis Tirv. Tarenna disperma (Hook. f.) Pit. HCT391 Tarenna Acronychia pedunculata (L.) Miq. Murraya paniculata (L.) Jack. Arytera littoralis Bl. Nephelium melliferum Gagn. Xerospermum noronhianum (Bl.) Bl. Madhuca pierrei (Williams) H. J. Lam. Palaquium obovatum (Griff.) Engleter var. obovatum Xantolis dongnaiensis (Dub.) Aubr. HCT178 Pterospermum diversifolium Bl. Pterospermum grewiaefolium Pierre Sterculia foetida L. Sterculia lanceolata Cav. Sterculia tonkinensis A. DC. Symplocos longifolia Fletcher Camelia fleuryi (Chev.) Sealy. Grewia paniculata Roxb. ex DC. HCT617 Vitex Vitex pinnata L. Vitex quinata Williams HCT925 Vitex Vitex tripinnata (Lour.) Merr.

Hymori Neocad Hct924 Rotenc Rotvie Tardis Hct391 Acrped Murpan Arylit Nepmel Xernor Madpie Palobo Xandon Hct178 Ptediv Ptegre Stefoe Stelan Steton Symlon Camfle Grepan Hct617 Vitpin Vitqui Hct925 Vittri

2 1 2 2 1 2 2 2 2 2 2 2 2 1 2 2 1 2 1 2 2 2 2 2 2 1 1 2 2


A

B

C

D

E

0.62 0.25 0.27

1.33 0.41 2.70

0.23 0.42 0.34 0.21

3.49 0.51 0.26

0.25 4.22 1.58

0.30

1.28 0.25 1.01

3.15 1.92 1.76

1.88

0.36

1.27

3.19

1.46 0.37

1.83

1.27

0.52 0.61

0.25

1.49 0.91

0.24 0.98 10.70 1.04 3.41 1.05

0.20 1.20 0.79

3.06

0.64 0.22 0.36 0.62 1.58

1.08 0.24 5.10 0.36

0.93 0.93 0.71 9.95

2.45