from 1863 to 1870 by the New Majorca Land Company (Picornell & Ginard ..... Ambient, Ordenació del Territori i Littoral, Govern Balear, Palma de Mallorca.
58
Monitoring t he status a nd co nservatio n ma nagement of the ra re orchid Orchis robus ta by Flor ent Prunier, Inm aculada Férr iz & Nick J Riddifor d Rationale for the st udy Recent DNA based work on the Albufer a m arsh orchid, previo usly known as Orchis palustris Jacquin, suggests that it is a separate sp ecies, Orchis robu sta (T. Stephenson) Gölz & H.R. Reinh. Whether Orchis robusta or Orchis palu stris robusta, the taxon is only kno wn from S’ Albufer a and sin gle sites in Algeria an d Morocco. Therefore it is one of the priority species in P. N. S’Albufera de Mallorca. Because of its special conservation value and habitat requirements, it was selected as a key species for a m onitoring program me as lon g ago as 1991. Since then it has been m onitored every year. The basis of the surv ey is an annual census of the flo werin g spikes, wh ich are thought to be representative of the true population estim ates, an d mappin g of its distribution. In 1991 there wer e 624 f lowerin g spikes in 1991 and in 2006 there were 383. Ho wever, the ann ual variation h as been m uch greater, from 166 to 3057. The survey has improved o ur under standin g of habitat requir em ents. One o bservation has been that grazin g livestock can have either a helpf ul or damagin g im pact on the Orchis population. Cattle, horses and buffalo permanently in place h ad a negative effect at s’Albufera on the n umbers of Orchis in flo wer, but the partial presence of stock co uld be beneficial. One of the objectives of the Orchis surv ey in recent year s has been evaluatin g the effects of rotational grazing by the Parc in one exper imental plot at Cam í de Ses Polls. The results of these 15 year s of monitoring are reported her e, and include an analy sis of ann ual fluctuation s, their causes, the ecolo gical requirem ents of the species and recommendations for the conservation an d enhancement of the only Europ ean pop ulation of this internationally rare taxon. Taxonom y There is no curr ent consen sus on the taxonom y of the Mar sh orch id in S’ Albufer a de Mallorca Natural Park, Alcudia (Mallorca, Sp ain). Traditionally n am ed Orchis palustris Jacqin 1787 ( synonymy by Ker guélen 1999 appear s in Annex 1), som e authors con sider it a subspecies of Orchis la xiflora Lam arck 1779 ( Galán Cela & Gam arra 2003) but this view is curr ently in a m inority am ong taxonomists an d genetic research tends to prove the two species are diff erent (e.g. Ar duino et al. 1996). S’Albufera plants have been identified as Orchis robusta (T.Stephenson 1931) Gölz & H. R. Reinh 1976 in recent years by various botanists and the park staff (Co zzolino in litt. from DNA analysis of leaves; Delfor ges 1994, Her bar i virtual de la Univ ersitat de les Illes Balears 2006) while this later name is ar gued to be a synonym by others ( Aedo 2005, Kerguélen 1999). More recent genetic advances show that the genus Or chis is polyphy letic so that the O. laxiflora s.l. gro up belon gs in fact to the genus Anacamptis (Batem an et al. 2003) an d our species to the taxon Anacam ptis robusta (T. Stephen son 1931) R.M. Batem an 2003 (Bateman et al. 2003, Cozzolino et al. 2003). The debate seems still to be in progress, and the taxon robu sta rem ain s “controversial” ( in Bateman & Ho llin gsworth 2004). However, because the species is widely r eco gnised by the botanical authorities of the Balear ic I slan ds, we ref er to the taxon as Orchis robusta for this report.
59 As a footnote, it should be noted that an hybrid Anacamptis x albuferensis R.M. Bateman 2004 bet ween O. robusta an d O. fragans (the O. co riophora s.l. gro up) was recently described from S’ Albufera (Batem an & Hollingsworth 2004). Morphology Orchis robu sta is a tall, ro bust species with spectacular pink an d m agenta flo wers. Detailed descriptions of the sp ecies can be fo und in Flora I berica ( Aedo 2005) an d the Balear ic Red Data Book (Sáez & Ro sseló 2001) am on g others. Habitat Gener ally, the Marsh orchid gro up Orchis palu stris s.l. pr efer s sunny open h abitats, an d m ost typically fenland, swamps, wet meado ws and fen meado ws on wet calcar eous substrates. Due to these habitat preferences, the distribution is at low altitude: 0-500 m ; and the gro up can occur on saline substrates (Aedo 2005, Société Fran çaise d’ Orchidoph ilie 1998, g ). The etymology is also consistent, from the latin paluster, meanin g swam p, marsh. In Catalan this orchid gro up is called “Orquidia de pr at” (meanin g marsh orch id). Phenology There are no records of wh en exactly the leaves of Orchis robusta appear but this is th thought to be bet ween Jan uary an d March. The first flo wers appear aro un d 20 April th and the m ain flo wer ing season is the last week of April through to abo ut 10 May. Ecolo gy Orchis robu sta is an opportunist, taking advantage of ar eas of m arsh which have been opened up in or der to flower an d set seed before the gro wth of the reedbed clo ses the space again. An indiv idual Orchis robusta plant at s’ Albuf era may liv e for no m ore than 4 years an d it is thought that the entire population attempts to flower ev ery year (Terry W ells, p erson al com munication). In this way it invests heav ily in its seed. Recor ds of flo wer in g plants after a zone has been open ed up for the fir st time for many years suggest that the seeds survive for lon g per iods in the substrate, or that the species has high powers of co lonization. Corology Orchis palustris is widespread througho ut the W estern Palearctic: it covers the eurom editeranean area from Anatolia (Turkey) to Tunisia an d reach es north as far as Sweden. In the I berian Peninsula, it is pr esent in 13 Span ish provinces, fun dam entally the eastern calcareo us an d Mediterranean ones, but extendin g as far west as Valladolid
60 without bein g r ecor ded in Portugal ( Aedo 2005). In the rest of Europe ( e.g. Fr ance, Italy, Sweden), it is scar ce with a localised distribution and is rar ely abun dant in its localities ( Société Française d’ Orchidophilie 1998, Gr ünan ger 2000, Ho egstroem 1991). The five lar gest Italian pop ulations, centred aro un d the Po, add up to slightly m ore than 800 individuals [ran ge: 100-5000] (Cozzo lino et al. 2003) an d in Gotlan d there are about circa 4000 in dividuals [interann ual ran ge: 600-7000] (Hoegstroem 1991). It is also pr esent in vario us Mediterranean islan ds such as Crete an d Kos in Greece ( Ettlinger 1996) and Corsica ( Société Fran çaise d’ Orchidophilie 1998). By contrast, Orchis robusta is only known from north Africa an d the Balearic Islands (Delforges 1994); and its only locality in the Balearic archip alego is s’ Albufer a de Mallorca ( Sáez & Ro sseló 2001, Mus i Am ézquita 1993). Status Orchis robusta was not reported by the ear ly botanists in Mallor ca ( Cam bessèdes 1827, Barceló y Combis 1867, Willkom m 1876, Barceló y Com bis 1879-1881, Marès & Virgin eix 1880, Burnat & Bar bey 1882, Knoche 1921-1922). It app ear s that although S’Albufera was already som ewhat of a classical locality for its wildlife, it did not attract the attention of the botanists who wer e drawn more by the en dem ics of the Tramuntana m ountains an d the surro un dings of Palma. A dramatic chan ge was witnessed by later botanists. When the wetlan d was drained and canalized in the 19th century, especially from 1863 to 1870 by the New Major ca Land Com pany (Picornell & Gin ar d 1995), an d farmed so that the ecosystem had lost m ost of its naturalness, marshland, the natural habitat of Orchis robusta was amongst the first habitats to be lost. The first mentions of “the Marsh orchid” in p ublish ed lists appeared as late as the 1970s (Duvigneau 1979, Bonaf é 1978). There is a similar story for Orchis palu stris. Throughout its glo bal area of distribution, Orchis palu stris has experien ced a dram atic decline in its populations due to the destruction of its biotopes. It has dim inished an d disappeared from m any regions of Europ e (e.g. Hoegstroem 1991, Société Française d’Or chidophilie 1998, Gr ünan ger 2000) and has not been seen in Belgium since 1936 (Flora database 2006). No p articular threat has been identified in mainland Spain ( Aedo 2005). Nevertheless, in the Balearic archipelago, ( Sáez & Ro sseló 2001) classified it (as Orchis palustris) as “ Vulner able”. If we accept the taxon as Orchis robu sta taxon, the status of the species is of even greater concern, S’ Albufer a bein g one of very f ew strongholds for the species. W hatever the taxonom ical approach chosen, the Marsh orchid is one of the priority species in S’ Albuf era for its special con servation value and, because it is greatly appreciated for its beauty and rarity, contributes very positively to the public use of the park by the lo cal com munity, tourists an d natur alists.
61 Parc management P.N. S’Albufera de Mallorca is recognised in num ero us conv entions, designations an d published m aterial as an internationally im portant Mediterran ean co astal wetland. Through tim e an d h um an actions, the wetlan d h as been transform ed from a lagoon wetlan d (albufera) to a lan dscape dom inated by emer gent vegetation. It now con stitutes one of Europe’ s lar gest reed Phragmites australis an d sedge Cladium mariscu s beds, fringed by substantial areas of salt marsh, coastal and inland (fossil) dunes. In total, the protected ar ea of S’Albufera cover s an ar ea of more than 1600 h a. An im portant part of the wetland is m anaged by the use of domestic livestock to control the gro wth of the reed and provide open ar eas. Since 2005, after m odifications of som e enclo sures, there are 19 grazin g compartments coverin g 385 ha in the park (15 pre-2005 compartm ents are consider ed in this paper) which contribute to the conservation of the m arsh ecosy stem . Information relative to the management of the park by cattle can be foun d in regular reports from the grazings m anager ( unp ublished r eports to the park). Three types of herbivores ar e used: Mallor can cattle (equivalent to 0,8 LU “Livestock unit” /ha), Camar gue hor ses (1 LU/ha) an d Water buffalo s (1,5 LU/h a) all of them special, regional breeds perf ectly adapted to life in wetlands an d with a lon g tradition of human exploitation. It is known that Mallorcan cattle have been present in the archipelago for th th two m illennia an d had their maxim um number s in the 13 and 14 cent uries. Another outstandin g exam ple is the Water buff alo s which has been the base of the econom y of m any wetlan ds throughout the History, such as the Arab Mar shes in Iraq (Thesiger 1964) and the Greek wetlan ds up to a recent perio d ( Kazo glo u & Jerr entrup 2005). Both W ater buffalo es an d Camar gue hor ses were introduced in Mallorca for the ecolo gical m anagem ent of the park. The intention of the grazing in the park is to create and m aintain habitat that wo uld en courage wadin g bird species, maxim ise plant diver sity and in crease visibility of the m arsh (Anonymous 1998). Riddifor d (2005) describes the general philo sophy of the grazin g m anagement an d p uts particular emphasis on the link between open areas and success of waterfo wl. Number s of animals present in Decem ber in the park and areas gr azed each year are well kno wn to the staff so that the overall gr azin g pressure during the period that S’Albufera has been a park is known (Figure 1). However, precise details of the gr azin g regim e (i.e. which compartment the animals were in and for ho w long) for the first 10 years of this study ar e often lackin g. It is on ly possible to calculate an estimate of the overall grazin g pressure from data regarding cattle present in December. This lack of data at times lim its conclusion s which can be dr awn on the effects of grazin g on the flo wer in g of Orchis robusta. Since 2003 a systematic collection of gr azin g data has been p ut in place.
62
200
400
150
300
100
200
50
100
03 20
01 20
99 19
97 19
95 19
93 19
91
0 19
19
89
0
Grazed surface in ha (Open circles)
Livestock in December (Plain square)
Figure 1: grazi ng pressure in S’Albufera during 1989 -2004 (from park data )
Ye a r
Two main perio ds can be distin guished: the fir st one corr esponds with a strong increase in the am ount of open ar ea each year from 1989 (75 ha) to 1993 (385 ha) as a result of a programm e of restoration of marshland which had previo usly been den se r eedbed (Anonym ous 1998) and the secon d per iod correspon ds with a phase of stabilization of the grazed surface ar ea (aro un d 385 h a). Conver sely there has been a general decrease of the grazin g pressure up to 1994 (0,4 LU/ha) and a certain stability since then (0,3 LU/h a), apart for an intermittent loss of animals in year s 1997 an d 1998. Note: the number of grazin g animals per compartment and per year varies considerably so that in some areas grazing pressure will hav e been much greater than the overall m ean. The Monitoring Program me In s’Albufera, Orchis robusta has been selected as a bio-in dicator for the health of the grazin g co astal m ar shes for its special conservation value and habitat requir ements. A m onitoring progr am me dedicated to this species wa been established in 1991 in order to guide the park m anagem ent in the conserv ation of this sp ecies (Elzin ga et al. 2001). The m ain objectives of the m onitoring program me are as follo ws: • To m easure the abundance an d map the location of Orch is robu sta each year in the different compartm ents of the park. • To study the ch anges of abundance of the pop ulation in f unction of the park’s management (i.e. grazing regime). • To improve the management, esp ecially when it has negative effects on the orchids. In 1991, Terry Wells, an orchid specialist from Britain, initiated the study of Orchis palustris an d survey s were carried o ut by t wo scientific groups: Earthwatch Europe follo wed by The Albufer a International Bio diversity group (TAI B). From 1991 to 2006, data h ave been collected ann ually usin g slight variations of the same methodolo gy. The Park has been k ept inform ed of the results but, to date, no on e document has been produced wh ich contain s all these data.
63
Methodology of the survey Survey areas Survey ar eas were based on habitat and management hom ogeneity, follo win g Pamela Hill’s work in the sprin g of 2003 season ( unpublish ed) an d m odified in Apr il 2004. Figure 2 belo w illustrates the lo cation of the survey areas. In the spr in g of 2004, follo win g investigation of all the Orchis robusta data collected, key m onitoring areas were identified based on homogeneity criteria. It was decided to def ine ar eas in f unction of orchid abundances, of their position in the m anagem ent compartm ent and the presen ce of practical phy sical barriers. Map s were pro duced for each of these ar eas and a database created to hold all the survey results. This database will be up dated annually and is available for any con sultation. Figure 2: Survey areas for the monitori ng of Or chis robusta
Each one of the areas (or plots) A to L have been divided into different sub- areas an d allocated to one of the grazin g com partment set up by the park (Annex 2). This has been worked o ut in collaboration with Miquel Cantallops, the grazings manager.
64 Survey m ethods An annual survey of flo wering Orchis robusta spikes is carried o ut each y ear between the last two weeks of April an d fir st two weeks of May, depending on the timing of flo wering which m ay vary slightly between y ear s. The survey is tim ed to coincide with the peak flowerin g. All r ecor ds are entered in a database. Tools for further survey s have been added as annexes. These ar e a protocol for the cen sus (Annex 3) and a set of blank maps for entering data ( Annex 4). W ithin the data, absence is recor ded as a “zero”. Ho wev er within the first year s of surv ey, “zero” may have at times indicate a lack of survey rather than a true absence. The establishment of the database and reinforced protocol h as been design ed to ensure m ore accurate results.
Data analysis It should be stated at the very outset that census r esults represents absolute num ber s of the Balearic pop ulation. Despite bein g m ost frequently used to evaluate trends in wildlife pop ulations, the freeware TRIM (Pannekoek & Van Strien 2002) was not used for two m ain reasons. Fir stly, co unt values from the data set sho ws very high level of ov er-depo sition (>100 calculated by TRIM) so that they does not fit well a Poisson distribution. Secon dly, the strength of the software which calculates in dices in place of m issing v alues is not usable in our context where we m ust assum e that absent values from the database m ean a co unt of zero. Pear son corr elation coeff icients were calculated to look the synchrony of the flo wer in g sp ikes bet ween plots. Results
Results of the cen sus for each area by year Figure 3 presents the results of the survey of Orchis robu sta counts acro ss the park. The total for 2006, 383 spikes, is only 61% of the 624 flowerin g spikes recor ded in 1991. However, a ran ge of 166 to 3057 over the m onitoring period reflect the fact that the situation is f ar from being either a trend of steady decrease nor within the range of oscillation s of a stable population. Closer an aly sis of the data reveals that the large variations were both in time and between com partments. A dramatic incr ease of the Orchis robusta population in s’Albufera in 1994 resulted from the conver sion of lar ge Phragm ites au stralis beds through fire and subsequent grazin g m anagem ent to open water and mar sh. The gen eral decrease after 1997 is best explained as the results of over gr azin g, or poor gr azin g m anagem ent. The poor success of orchids in 1995 is not explained. Examination of
65 census results (Ann ex 4) shows that no linear regression fits the trends of the orchid populations. It was also noted that few areas showed a continuo us presence of the orchids. No signif icant correlations wer e fo un d (Pear son’s co efficients of correlation wer e not signif icantly diff erent from zero an d ar e not presented h ere) bet ween the Managem ent compartm ents results (8 compartm ents) and bet ween Census areas results (38 subareas). W ithin any one flowering season, there is no con sistency in the am ount of flo wer in g across differ ent com partments in contrast toe what is often foun d in surv eys of other orchid species. Each lo cal sub-pop ulation has f luctuated indepen dently.
3000
Total
2000
1000
4
3
20 0
2
20 0
1
20 0
0
20 0
9
20 0
8
19 9
7
19 9
6
19 9
5
19 9
4
19 9
3
19 9
19 9
19 9
19 9
2
0 1
Number of fl owering spikes
Figure 3: Developm ent of Or chis rob usta at S’Albufera from 1991 until 2004 .
Yea rs
Habitat preferences Historical recor ds for S’ Albufer a in dicate that the Orchis was found in wet areas, close to Font de Son Sant Joan (Lloren s in Bonafè 1978). The first short report written in 1989 stated that “casual observations had sho wn that many orchids were to be fo un d on tracks through the m arsh es and on the more open, grassy areas an d on the dunes, but not in the reed- beds” (Ecker sley et al. in Wood 1989). The present distribution of Orchis palustris acro ss the park continues to reflect that descr ibed in 1989 (observation s by N. Riddifor d an d P. Vicen s) except for its do ubtful presence in the dunes. Howev er, it has been foun d in sm all pon ds in the fossil dune at Can Eix ut. Table 1 presents the results sorted for each grazing compartm ent between 1991 an d 2004 of orchids foun d in each com partment. On 15 com partments, the most im portant for orchids ar e Cami des Polls (Plot G), Es Ras (Plot L) and Sa Sinia (Plot B), the three of them are marshland of fresh an d slightly m ixohaline waters. Var ious compartm ents have never hosted Mar sh orchids because they are salmarsh es ( Es Cibo llar) or lagoons with high water lev els in sprin g (T uró Ses Eres, Es Racó) an d, apart from a few plants along the Camí d’es Senyals, orchids have n ever o bserved in the north of the park. Despite bein g lar ge com partments, Es Ras an d Sa Sinia had their orchids localized in the same small areas at Siquia Aigua Bona in Es Ras and alon g the path in Sa Sin ia. It is also important to note that an im portant proportion of Orchids are fo und ev ery year outside of any grazin g compartment (none) so that the conservation of the species is not totally depen dant of the grazing management.
66 Table 1: R esults of census by Grazi ng Compartment (1991-2004) and % of total counted spikes (n= c.14000 s pikes). Main
Grazing compartment
Plot Ha ecos ys 1991 1992 199 3 199 4 199 5 1996 1997 199 8 199 9 200 0 2001 2002 200 3 200 4 tem
C amí Pe p i P ujol
D
M alecó C anal Sol M alecó Siuran a C asa S es P un tes
C
Turó d es Bl at
2,9
P
2,4
P
52
1,5
P
3,5
FD
3
FD
Am arad or
I
28,6
FM
C amí dels Polls Orq uídies
G
7,8
FM
C ami Es Polls Son C arbon nel
H
15,6
FM
Es Forca det
22,5
MM
Es Racó
8,7
MM
Es Ras
L
122,5
MM
7,8
MM
54,7
MM
Turó ses Eres
33,2
MM
Es Cibollar
25,2
MS
S’Almacen Sa Sínia
B
N one
E,J,K
78
7
162
10
30
3
1
286
7
3
8
3
15
8 1
163 1700 1694
35
313
134
320
72
5
645
326
3
1
246
76
48
8
163 7 42
515
859
948
64
3
16
5
19
6
392
143
3
227
109
457
186
56
21
27
136
128
130
224
91 24 178 59 72 50 30 28 140 8 126 48 72 206 P:Path; Fossil dune (FD) ; Fresh Mar sh (FM) ; Mixohaline Ma rsh (MM) ; Saltmarsh (SM)
Table 2 presents the results per habitat type for each sub- census ar eas (note that this classification can differ from the one using the grazin g compartm ent nomenclature). Data sho w that from 1994 on war ds follo win g the establishment of the fire break in Cami des Polls, the bulk of the population lies in marshes, open ed up in the reed- bed after fire events or m anagement activities (i.e. grazin g). Significant habitat can also be foun d along the track s and their adjacent canals. This habitat was particularly im portant when management activities r esulted in a lack of marshland habitat. This was the case prior to 1994 when p aths m ay have acted as a ref uge for this sp ecies. In y ear s of poor success in the m arsh es ( e. g. 1995) the proportion of orchids in both biotopes ten ds to equalize. In the last three year s of the survey, a tendency for the paths to be proportionally m ore important has been o bserved. Shallo w ponds in the fossil dunes at Can Eix ut (Plot E) are interesting in that they are con sidered lik ely to mim ic a natural habitat of the species befor e desiccation of the lagoon s of S’ Albufera but these are un der threat because of the development of a golf cour se. Table 2: Results of census by Ha bitat type (1991-2004 ) Ty pe
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Canal
24
90
Mars h
121
48
81
1667
Pat h
503
387
137
295
Pond
271 2237 2576 1006 489 243
423
467 14
198
65 25
151
452
766
395
300
15
34
143
147
200
9
13
3
67 Figure 4: Pro portion of orchids by habitat types 1 00% 80% 60%
Oth ers
40%
Path Marsh
20%
200 4
200 3
200 2
200 1
200 0
199 9
199 8
199 7
199 6
199 5
199 4
199 3
199 2
199 1
0%
Management of the gr az ing mars hes Two areas fo un d to support large num bers of flower in g Orch is robusta have been selected for f urther com parison. These areas are the fr esh marsh Cam i des Polls (7,8ha) and the slighty salty marsh Es Ras (122,5ha) (in fact Siquia Aigua Bona repr esents a fifth of it). Up to 2005, these areas had different grazin g regim es, one has been m anaged for Orchis robu sta since the late 1990 s an d to m aintain a fire- break (0,78 LU/year in 2003), while the other site has had grazing animals on a perm anent basis since the mid1990s (0,15 LU/year in 2003), including water buff alo s. Figure 5 below sho ws the developm ent of the Orchis robusta populations in the t wo surv eyed areas through the years. Figure 5: Developm ent of the Orchis rob usta population a t Camí des Polls (G) and at Es Ras (L).
Orchids spi kes
Cam i des Polls Es Ras
1500 1000 500
04
20
03
20
02
20
01
20
00
20
99
98
19
19
97
96
19
19
95
19
94
93
19
92
19
19
19
91
0
Ye ar
In both cases, the areas contain ed few or no orchids befor e they wer e opened up and grazed. Spectacular flower in g occurred in 1994 in Es Ras and in 1996 an d 1997 in Cam i des Polls in imm ediate response to habitat creation. The almost total failure of Orchids in Es Ras in 1995 was due to the destructive po wer s of the buffalo. They had op ened up the area to the benef it of the Orchis in 1994 but by 1995 h ad severely dam aged the vegetation by grazin g an d tramplin g. Because they had used up all the forage in this area, they cro ssed the canal into the western part of Es Ras, open ing up an ar ea which had pr eviously been den se Cladium mariscus m arsh. Orch ids took advantage of this
68 newly op ened part of Es Ras, contributing to the up sur ge in n umbers from 1996. Unfortunately, by 1999 the buffalos had lar gely eliminated the supportin g vegetation which pr evio usly gav e the orchids protection again st gr azing and tram pling and the population was lo st. A diff erent management was p ut into place in Cami des Polls, based on grazing cattle which were rem oved from Jan uary to May, a critical gro win g perio d for the orchids. Thus a different tenden cy was o bserved at the two sites: a population crash in Es Ras (1999) and a steady pop ulation gro wth in Cam i des Polls after the 1998 crash. The main difference bet ween these t wo sites seems to lie in the grazin g regime. The removal of stock from Jan uary to May (as a management action set up for or chids) at Cami des Polls has allo wed for the gr adual but progr essiv e increase in orchid n um bers at this site. The continuo us presen ce of grazin g anim als in Es Ras, however appears to have been detrim ental to orchid f lo wering. The apparent overgrazin g in Es Ras wo uld have resulted in changes in the vegetative sp ecies composition and an increase in bare soil coverage con ducing to a depleted Orchis palustris population with its disapp earance pr edicted at this site in a f ew year s. This scenar io is our best proposed hypothesis, although we need exper im ental confirmation. It is also supported by direct observations of orchids gr azed by cattle and in som e places by the better success of orchids beyon d the fence, wher e grazers h ave no access. Grazing is not the only way to provide early succession al stage in place of dense reedbed. Recurrent fires occur in the m argin s of the park (and som etimes devastate it) and also create regularly suitable conditions such as in Son Sant Joan, plot K, outside the bo un daries of the park. Her e, the num bers of orchids have been v aryin g in f unction of fire frequency an d ar e glo bally diminishing now as a consequence of the invasion of the sm all pop ulation s by reedbed (Phragm ites australis) an d Provencal cane ( Arundo donax). Son Bosc In spring 2005, Parc naturalist Pere Vicens discovered a substantial n ew pop ulation just outside the Parc boun dary at Son Bo sc. It was not only a n ew site but a differ ent habitat, comprisin g botanically r ich dune gr assland – which it shared with high densities of other orchids. The count for this new colony was 266. In 2006 this n um ber rose to 441, substantially m ore than the entire count within the Parc. Discussion Grazing management at s’Albu fera – a review In the early years, the gr azing sy stem worked extremely well at achievin g its conservation an d public use objectives - givin g m any opport unistic species the ch ance
69 to prosper. Som e of these, such as the m arsh orchid an d Scirpus maritimus (an im portant food source for ducks) ar e key sp ecies for S’Albufera. Both species are indeed very important for the park, demonstrating a clear example of the advantages of grazin g as a tool to enhance bio div ersity. In addition, the buffalo s were som ething of a visitor attraction in their o wn right. Those o bservation s are comm on with the Greek experien ce of grazing wetlan ds with buffalos (Kazoglo u & Jerr entrup 2005). Nevertheless after three year s of the introduction of the buff alo s in the enclosure of Es Ras, they had eaten an d trampled much of the vegetation and Orchis robusta declined sever ely. Because the buffalo s had eaten everythin g, they went in sear ch of foo d elsewhere. A deep canal kept cattle away from the pur e Clad ium stand the other side of the grazin g area, but the water was no obstacle for the buff alo which crossed over an d gradually over a per iod of y ear s trampled an d ate their way through the stand so that today it is represented by lo w scattered plants. Due to continual presence of livestock, and Scirpus being their f avourite foo d plant, new shoots were being eater virtually as they app eared. The only Scirpu s to flo wer was that growing am ongst clumps of Juncu s acutu s or sim ilar den se vegetation. Towards the end of the 1990 s, there was con cern regar ding the lack of flo wering S cirpus in the park. The winter duck numbers, however, continued to gro w an d new species wer e breedin g (includin g the fir st Balearic breeding Shov eler s Anas clypea ta). Concern was that the duck s wo uld eventually use up the Scirpus seed r eserves leadin g to a consequent reduction in n um ber s of winterin g duck s. Observations of invertebrates, especially Orthoptera (Pr unier 2004) also pointed out that a greater diver sity is ach ieved in the parts of the m arsh which retain denser grassland an d tussocks than in much tram pled areas by cattle: Tropidopola cylind rica, Conocephalu s cono cephalu s, Ruspolia n itidu la, Eyprepocnemis plorans were m uch m ore numerous in den se vegetated marsh. Trigonidium cicindeloides and Acrida ungarica are also likely to be favor ised by this habitat. However Eyp repocnemis plo rans is widely dispersed i n the wetland, mostl y present in sunny places li ke woodland edges and especi all y in Juncus acutus tussocks. For Water beetles ( Coleoptera Adephaga an d
Polyphaga) ( unp ublished data), it was o bserved that waters covering m ud an d large patches of bare soil due to the continual pr esence of the Buffalos were ho sting very few individuals in Es Ras, Sa Sinia an d Turó Ses Eres. Coastal lagoon s are natur ally poor for aquatic invertebrates an d those are m ost often associated with vegetation, m acrophyte beds or detritus accum ulation. Early successional stages are indeed very im portant for rare invertebrates but less so in m eadows which floo d (Kir by 1992). This situation of contin uous grazin g leads to the incr easin g population of Juncu s acutus in heavily gr azed areas. Several zones ar e no w dominated by this plant, in the form of scattered but den se clum ps of in dividual plants. Observation s in dicate that it is the least favour ed of all the emergent plant species for S’ Albuf era liv estock. A similar response has been observed in the Lavour s m arsh es ( France) where h eavy grazin g stock to eliminate Phragmites reed finally favor ised the growth of Alnus glutino sa, a m uch less palatable species, thus hinderin g the or iginal goal of the grazing pro gram me (Darinot & Morand 2001).
70 Marsh o rchid respon ses to m anagement by the marsh orchid The m arsh orchid population h as follo wed com plex p atterns of distribution over tim e in the park. As an opportunist species, the local pop ulation reacts strongly to its changin g environm ent. It colonizes new sites quickly when conditions ar e appropriate an d disapp ear s equally fast. It is though that park management, especially gr azin g througho ut the park, is the key factor in explainin g the success or failure of orchids in the m arshland areas. Positive an d negative effects of management have been identified for Orchis robusta. a) Positive effects of m anagem ent. Introduction of gr azin g livestock creates: 1) W et meadows instead of dense reed an d sedge beds; 2) bare gro und and ear ly successional stages. Such featur es of the habitat are favo urable to the colonization by opportunistic sp ecies, such as Orchis robusta. Other species sho win g the same explosive colonisation pattern include the crick et Pteronem obius heyd ennii. b) Negative effects of m anagement. 1) The absence of grazing animals leads to plant succession, com prisin g denser an d taller vegetation. The orchids are unable to compete an d are shaded o ut. 2) At the other end of the scale contin uous grazin g leads to a dram atic decrease in Orchis robu sta num ber s after a few years. Anim als present durin g the Orchis gro win g perio d wer e either tram plin g plants or actually eating the leaves. Perm anent grazing also leads to fertilization of the habitat, which m ay be a negative f actor as is kno wn for wetland orchids of the gen us Dactylo rhiza (Dijk & Eck 1995), although this wo uld need to be st udied m ore because those authors noted im portant variations between species. As a general r ule, m anagem ent recomm endations for levels of gr azin g of wet meado ws and m ar shlan d are 0,5 to 1 LU/ha ( VVAA 1997, Colas & Hébert 2000), 2LU/ha (Bur ges & Al 1995), 0,25-1 LU/ha ( Ausden & Treweek 1995). Overall grazin g levels at S’Albufera m eet this rule, but m any compartm ents are not equally grazed an d the presen ce of high water levels in som e of them (Es Rás, Ses P untes) r educes the usef ul abov e water grazing surface for stock and incr eases the im pact. Son Bosc The remarkable find at Son Bo sc was a surprise. The Orchids her e grew taller an d m ore robust than those in the marsh and were app arently gro win g in much drier soil. However, a glance at the accom panyin g vegetation which included scattered plants of Phragmites australis an d extensive patches of Pan icum repen s, a grass asso ciated with damp so ils, in dicated that the water table was not far from the surf ace – at least at certain times of the year. The habitat had previo usly been grazed by hor ses, but had lain fallo w for some years.
71
Because of the ro bust natur e of the orchids, they were very noticeable to passers- by. A track runnin g past the site is well used by visitors and local people alike, so a notice was erected askin g peop le to resp ect this rare p lant and not to pick it. The request appeared to be well respected. Ho wev er, the colony does lie in an area proposed for incorpor ation into a golf co urse. The area is generally botanically rich an d with an important fauna too. Indeed Son Bosc m ay support one of the highest biolo gical diversities in the whole of Mallorca. The Orchis robusta can be seen as the flagship species for a very r ich habitat wh ich needs to be valued an d protected. It must be of con siderable concern to the Parc Directorate and management team that m ore than half of the Albufera an d the Europ ean pop ulation lies beyon d their protection. Management r ecommendations There is no strong reason for the livestock to be in the zone in the first half of the year because vegetation growth is at its minimum and there is little grazin g available for the stock. Because of the shortage of fodder dur in g this period, the Orchis leaves may be m ore vulner able to grazing anim als (M. Cantallop s, per sonal com munication). Monitoring has sho wn that the Cam i des Polls population has benefited from a grazin g regim e which comprises the removal o f livestock from the beginning o f the year until after the flo wering p eriod (mid to late May) follo wed by hea vy grazing until the end o f the year. This m anagem ent system has m aintained a substantial population of Orchis robusta for ten year s. The only other sub-pop ulation exceedin g 100 flowerin g spikes is outside of the Parc an d its protection. The species remains v uln erable in other parts of the parc and to have only one substantial guar anteed sub-pop ulation for a taxon wh ich is not known elsewhere in Europ e places that population at unn eccesarily high risk. In current circum stances, priority consideratio n should be given to implem enting a sympathetic ro tatio nal grazing regime in other traditiona l sites for the species within the Parc, so that the vulnerability of a good pop ulation only at Cami dels Polls can be sev erely r educed. Siquia Aigua Bona a t Es Ra s and Sa S ínia app ear to be the m ost suitable candidates for such sym pathetic m anagem ent. The selection of additional sites wo uld also allow for some experimentatio n, for instance by va rying the tim ings and d ensity o f livestock and m onitoring the results, in order to further improve m anagem ent. There is still m uch to learnt abo ut Orchis robu sta at s’Albufera an d its ecolo gical requirem ents. The curr ent population level at Cam i des Polls, tho ugh still substantial, is less than it was at its p eak. Clear ly grazin g m anagement is just one of the issues an d others, such as v ariation s in aspects of hydrolo gy or m eteorological con ditions will also affect population lev els. Fifteen years of m onitoring have proved of im mense value in un der stan din g the ecolo gy of the species, but more intensive investigation of the m any factors determining the ecological needs of Orchis robusta is r equired to protect the taxon in the long term . Our final recomm endation, therefore, is that an in-depth
72 ecolo gical study, p referab ly a t docto ral level, is required througho ut the yea r to understa nd better the needs o f the taxo n and the m ost app ropriate m ana gem ent actio ns to co nserve a nd enhance S’ Albufera’ s unique Europea n pop ulation. Acknowledgments: W e gratefully ackno wledge all the m any participants in The Albufera International Biodiver sity team activities for their help with fieldwork and other aspects of the study; and the staff of the Parc Nat ural S’ Albufera de Mallorca for their frien dly support an d in particular Matias Rebassa, Biel Perello, Pere Vicens (naturalist) and Miquel Cantallops (grazings manager) all of who prov ided important additional inform ation. This part of the report was prepared by F Prunier, N Riddiford, I Férr iz an d C Portero. Bibliography Aedo, C. (2005). Orchis palustris. In: Smilaceae Orchidaceae. Flora iber ica Volumen, Eds C. Aedo & A. Herrero. Real Jár din Botánico/CSI C, Madrid, XXI, pp 144-145. Anonymous (1998). Pla d’ Ús i Gestió d el Parc Na tura l de S’Albufera 1998-2002 De la restau ració a la con servació. Do cuments tècnics de conservació. Con seilleria Medi Ambient, Or denació del Territori i Littoral, Govern Balear, Palma de Mallorca. Ar duino, P., Verra, F., Cian chi, R., Ro ssi, W., Corrias, B. & Bullini, L. (1996). Gen etic variation and nat ural hy bridization bet ween Orchis laxif lora an dOrch is p alustris (Orchidaceae) Plant System atics and Evolution, 202(1-2), 87-109. Ausden, M. & Treweek, J. (1995). Grasslan ds. In: Manag ing habitats for conservation, Eds W .J. Suthertlan d & D. Hill. Cam bridge University Press, Cam bridge. Barceló y Com bis, F. (1879-1881). Flo ra de la s islas Baleares. Gelabert, Palma de Mallorca. Barceló y Com bis, F. (1867). Ap untes p ara una Flora de las islas Baleares. Revista d e los p rogreso s de las cien cia s exa cta s, físicas y natu rales, 17(5), 294-317 [Publicado en do s partes. Parte 2, 7(6), 345-369]. Batem an R.M. & Hollin gsworth P.M. (2004). Morphological and molecular investigation of the parentage an d m aternity of Anacamptis × albuferensis (A. fr agrans × A. robusta), a new hy brid orchid from Mallorca, Sp ain. Taxon, 53(1), 43-54. Batem an, R.M., Hollingworth, P.M., Preston, J., Luo, Y- B., Pr digeon, A. & Chase, M.W. (2003). Molecular phy lo genetics an d evolution of Orchidin ae and selected Haben ariinae (Orchidaceae). Bo tanica l Jou rnal of the Linnean So ciety, 142(1), 1-40. Bianor, F. (1917). Plantes de Mallorca. Butll. In st. Cata lana ist. Nat, 17, 133-152. Bolò s, O. & Vigo, J. (1984-1995). Flo ra dels Països Catalan s. Barcino, Barcelona. Bonaf é Barceló, F. (1978). Flo ra de Ma llo rca. Moll, Palm a de Mallor ca. Burgess, N., War d, D., Hobbs, R. & Bellam y, D. (1995). Reedbeds, f ens and acid bo gs. In: Managing habita ts for conservation, Eds W .J. Suth ertland & D. Hill. Cam bridge University Press, Cam bridge.
73 Burnat, E. & Bar bey, W. (1882). No tes sur un voyage botanique dan s les Iles Baléa res. H. Geor g Editeur, Lyon. Cafasso, D. Pellegrino, G. Musacchio, A., Widmer, A. & Cozzolino, S. (2001). Char acterization of a minisatellite repeat locus in the chlorop last genome of Orchis palustris (Or chidaceae). Curren t Genetics, 39(5-6), 394-398. Cam bessèdes, J. (1827). En umeratio plantar um quas in insulis Balearibus. Mémoires du Muséum d’Histoire Natu relle, 14, 173-335. Colas, S. & Hébert, M. (Eds) (2000). Guide d' estim ation des coûts de gestion des m ilieux ouverts natu rels. Ed ition 2000. Esp aces Natur els de France. Cozzolino, S., Noce, M.E., Musacchio, A. & W idm er, A. (2003). Variation at a chloroplast m inisatellite locus reveals the signatur e of habitat fragmentation and gen etic bottleneck s in the rare or chid Anacamptis palu stris (Or chidaceae) Am erican Journa l of Botany, 90(12), 1681-1687. Cozzolino, S., Pellegrino, G., M usacch io, A. & W idm er, A. (2003). Fine- scale phylogeo graphical analy sis of Mediterranean Ana cam ptis palu stris (Orchidaceae) populations based on chloroplast m inisatellite and microsatellite variation. Molecular Ecology, 12(10), 2783-2792. Darinot, F. & Moran d, A. (2001). Man agem ent of wet meado ws in the Lavo urs marsh, im plementing grazin g. Resto ration and Eco logica l Engen eering, 3, 86-93. Delfor ges, P. (1994). Guide des Orchid ées d’Europe d’Afrique du No rd et du Pro che Orient. Delachaux et niestlé, Lausanne. Dijk, E. & Eck, N. (1995). Axen ic in v itro nitrogen an d phosphor us responses of som e Dutch marsh orchids. New Phyto logist, 131, 353-359. Duvigneaud, J. (1979). Catalogue p roviso ire de la flo re des Baléa res. Deuxième édition. Société pour l' Echan ge des Plantes Vasculaires de l' Europ e Occidentale et du Bassin Méditerranéen, Liège. Elzin ga, C., Salzer, D., Willo ugh by, J.W. & Gibbs, J. (2001). Monito ring Plant and Anim al Populations. Black well, Oxfor d. Ettlinger, D.M.T. (1996). L' existence d'Orchis palustris s. l. en Crète et dans l' île de Kos (Dodécanèse, Grèce). Natu ralistes b elges, 77, 111-118. Flora Database (2006). Orchis palu stris. In: http://flor a.in stnat.be/flora/Flor aInlo g. do. Galán Cela, P. & Gamarra, R. (2003). Check list of the Iberian an d Balear ic orch ids. 2. Ophrys L. – Sp iranthes Rich. Anales Ja rdín Bo tánico Mad rid, 60(2), 309-329. Gr ünanger, P. (2000). Orchidacee d’Italia. Quaderni d i Botan ica App lica ta, 11, 3-80. Herbari de la Un iver sitat de les Illes Balears (2006). Orchis robusta. In: http://herbar ivirtual. uib. es/cat/especie/5297.html. Hoegstroem, S. (1991). Orch is p alustris, its history an d present status on Gotlan d, Sweden. Svensk Botanisk Tidskrift, 85(5), 355-376. Kazo glo u, Y. E. & Jerrentrup, H. (2005) Managem ent of wetland vegetation with water
74 buffaloes in Greece. In: Reviving wetlands – sustainable m anagement of wetland s and shallo w lakes, Eds M. Hammerl-Resch, U Gattenlöhner & S. Jantschke. Glo bal Nature Fund, Radolf zell. Kerguélen, M. (1999). Index synon ymique de la flo re d e France. In: http://www.inra.fr/flore-france/index.htm. Kirby, P. (1992). Gr asslands. In : Habitat m anagem ent for inverteb rates. RSP B, San dy. Knoche, H. (1921-1922). Flore Balearica. Etudes Phytogéog raphique su r les Illes Baléa res, Montpellier. Marès, P. & Vignin eix, G. (1880). Catalogu e raisonn é des plantes vasculaires des îles Baléa res. Masson, Paris. Mus i Am ézquita, M. (1993). Plans de con servació dels vegetals amenaçats de Balears. I Mallorca. Documents tècnics de conserv ació. Conseller ia d’ Agricultura i Pesca, Govern Balear, Palm a de Mallor ca. Pannekoek, J. & Van Strien, A. J. (2002). TRIM 3.4 fo r Windo ws (Trends and Indices for Monitoring data). Research pap er. CBS, Voor bur g. Picornell, C. & Ginar d, A. (1995). John Frederic Latrobe Bateman. Monografíes de la Societat d'Histo riò Natural de les Balea rs, 4, 39-46. Porta, P. (1887). Stirpium in insulis Balearicum anno 1885 collectar um enum eratio. Nuovo Giornale Botanico Ita liano, 19, 276-324. Prunier, F (2003). Monitorin g grazing activity and its impact on biodiver sity: invertebr ate diver sity, using Orthoptera as bio-indicators. In: A Mediterranean m odel for th e study of b iodiversity and en vironmental change. The Albufera Interna tional Biodiversity Group Annual Report 2003, Ed N. Riddiford, TAI B, Alcudia. Riddifor d, N. (2005). Grazin g as a management tool at PN S’ Albufer a de Mallorca. In: A Mediterranean model for the stud y of biodiversity and environm ental change. The Albufera International Biodiver sity Gro up Ann ual Report 2004, Ed N. Riddifor d, TAIB, Alcudia. Sáez, L & Rosseló, J.A. (2001). Llibre vermell de la flora va scular d e les Illes Balears. Documents tècnics de conservació. Conselleria Medi Ambient, Direcció General de Biodiver sitat, Palma de Mallorca. Société Fran çaise d'Orch idophilie. (1998). Les Orchidées de Fran ce, Belgique et Luxembo ur g. Parthénope co llection, Paris. Thesiger, W. (1964). The Ma rsh Arabs. Reissued 1983 Penguin Book s Ltd, Lon don. VVAA. (1997). The wet gra ssland guide, m anaging the floodplain and coastal wet grassland s fo r wildlife. RSP B, San dy. W illkom m, M. (1876). Index plantarum vascularium quas in itineres ver e 1873 suscepto in insulis Balearibus, legit et observarit Mauritius Willkom m. Linnaea, 40, 1-134. W ood, B. (Ed.). (1989). A m onitoring p rog ramme for s’Albufera, Mallorca. Discussion papers in con servation n º 52, M. Sc. Conservation Co ur se 1989, Ecolo gy an d conservation un it. Univer sity College Lon don, Lon don.
75
ANN EX ES A nnex 1: Synonymy followi ng Kerguél en 1999 O rchis palustris Jacq. [1786, Collect. Bot., 1 : 75] 2n = 42 Co, Ga 2, 3, 5 •
subsp. la xiflora ( Lam.) Trabut in Batt. & Trabut [1895, Fl. Algér., Monocot. : 30] [com b. illeg.] ≡ O. laxiflor a
•
subsp. m editerranea ( Guss.) Malagarriga [1968, Acta Phytotax. Barcinon., 1 : 62] var. mediterranea
•
var. m editerranea ( Guss.) Schlechter [1926, Orchid. Eur. : 192] + Ga ? probable
•
var. m inor Bréb. [1859, Fl. Norman die, éd. 3 : ] = var. palustris
•
var. palustris
O rchis laxiflora Lam. [1779, Fl. Fr., 3 : 504] subsp. laxiflora 2n = 36 Co, Ga 1, 2, 3, 4, 5, 6 •
subsp. dielsianus Soó [ ] = O. p alustris var. palustris
•
subsp. elegans ( Heuff el) Soó [ ] = O. palustris ? var. p alustris
•
subsp. laxiflora 1, 4, 6
•
subsp. palustris (Jacq.) Bonn ier & Layens [1894, Fl. Fr. : 311] ; ead. comb. Corb. [1894, No uv. Fl. Normandie : 558] O. p alustris var. palustris 2n = 42 1, 4, 6
•
subsp. p alustris var. m editerranea (Guss.) D. Rivera-Nuñez & G. López Velez [1987, Or quid. Prov. Albacete : 140] O. palustris var. Mediterranea
•
subsp. ro busta (T. Steph enson) Sun dermann [1980] = O. palustris ? var. m editerranea
76
A nnex 2: Characteri stics of sample sites Census_ Are a
Name
Grazing compartment (up 2004)
Type
Note
A1
Cami d es S en yals - WE ST
none
Path
A2
Cami d es S en yals - EA ST
none
Path
B1
Ses P unt es
Sa Sínia
M arsh
B2
Cami d'e n P ep (E ast) # 1 NORTH
Sa Sínia
Path
Sa Sínia
Path
ag greg ation whe n d ata recording is no t e no ug h precis e
B2/B3/B 4 Cami d'e n P ep (cluster) /B5 B3
Cami d'e n P ep (E ast) # 1 SOUTH
Sa Sínia
Path
start at gate
B4
Cami d'e n P ep (E ast) # 2 NORTH
Sa Sínia
Path
along th e pat h
B5
Cami d'e n P ep (E ast) # 2 SOUTH
Sa Sínia
Path
start at fence, wit hin the fe nce : g razed
B5_bis
Cami d'e n P ep (E ast) # 2 SOUTH
none
Path
start at fence, b e yon d t he fe nce: ungrazed
C1
Cami d e Ses Punt es - (North) EAST
none
Path
C2
Cami d e Ses Punt es - (So ut h) EAST
Casa S es P unt es
Path
along dry fi eld, st art a t gat e
C3
Cami d e Ses Punt es - WEST
Casa S es P unt es
Path
along wall
C4
Cami d'e n P ep (Ce ntral) NORTH
Casa S es P unt es
Path
along dry fi eld
C5
Cami d'e n P ep (Ce ntral) SOUTH
none
Path
D2
Cami d'e n P ep ( West) NORTH
Camí Pep i P ujol
Path
Pep
D3
Cami d'e n P ep ( West #1) NORTH
Camí Pep i P ujol
Path
Pep
D4
Cami d'e n P ep ( West) SOUTH
none
Path
D5
Cami d'e n P ep ( West #2) SOUTH
none
Path
D8
Cami d'e n P ujol
Camí Pep i P ujol
Path
E2
Ca'n Et xut / par k bou nd ary
none
Pond
F2
Cami d'e n M olin as (NORTH)
¿?
Path
F3
Cami d'e n M olin as (SOUTH)
¿?
Path
I4
Canal d'en M oix
none
Canal
G1
Son Sa nt J oan
Camí dels Polls Orq uídies
M arsh
G2
Cami d es P olls - EAST
Camí dels Polls Orq uídies
Path
H1
Son C arbo nell
Cami Es Polls S on Carbon nel
M arsh
H2
Cami d es P olls - EAST
Cami Es Polls S on
Path
Pujol
77 Census_ Are a
Name
Grazing compartment (up 2004)
Type
Note
Carbon nel H3
Cami d es P olls - WEST
Cami Es Polls S on Carbon nel
Path
I1
Amar ador
Amarador
M arsh
J1
Son Serra / p ark boun dary*
none
Path
J3
Son Serra / p ark boun dary*
none
Path
J4
Son Serra / p ark boun dary*
none
Path
K3
Cami d es P olls - WEST
none
M arsh
K4
Sa Marjal / C ami des Polls
none
M arsh
L1
Es Ras
Es Ras
M arsh
L10
Es Ras
Es Ras
M arsh
L6
Canale t Es R as (EAST & WEST)
Es Ras
M arsh
Es Ras
M arsh
L9
Siquia Aig ua Bon a
Siquia Aig ua Bon a
78
A nnex 3: Census protocol (by Pamela Hill) INTRODUCTIO N The surv ey m ethod to be used will dep end on the area bein g surveyed. NB: Please, copy the m aps of survey and use them as far as you can to locate orchids spikes. It is usefull to understand the differences within an sample sites. LINEAR AREA: VERGES ALONGSIDE P ATHS, WATERW AYS. 5M WIDE No. of OBSERVERS : 3 (mini mum) EQUIPMENT: Rangi ng rods (8 - as t wo sets of four), Recording form, Map, Penci l, Clipboard, Wellingt on boots METHOD: The area shoul d be surveyed i n stri ps. Use one of the edges of t he block area as the initi al li near boundary feature t o follow (e. g. fence, dit ch) The widt h of each survey stri p is dependant on t he number of observers and vegetati on height. The surveyors shoul d be spaced suffi ciently close together so they can view the enti re area bet ween themselves and the person to their left. The surveyor who wal ks the line furthest away from the initi al boundary feature shoul d set ranging pol es at t he start and at int ervals approximately ¼ ½ and ¾ along their line. The recorder should wal k the central line through the strip in order to be abl e to hear t he observations of t he other surveyors. If there is a high densit y of orchi ds, each surveyor should compl ete a recordi ng form for t hei r respecti ve stri ps. Each surveyor shoul d not e the orchid spi kes to their l eft hand side onl y to ensure t hat dupli cate records are not made.
79 The surveyor responsi ble for setting the first set of rangi ng pol es shoul d remove them on their ret urn wal k in strip 2. A second surveyor should set the next boundary wit h the second set of 4 ranging pol es. In order to mai ntain surveyi ng on t he l eft hand side the surveyor will need to cross their survey area at ¼ ½ and ¾ int ervals t o set t he surveying rods i n pl ace. The same procedure wil l need t o be repeat ed t o remove the rods w hen t he surveyor wal ks up t heir section of strip 3.
STRIP 1
ST RIP 2
STRIP 3
DATA BA SE
On compl etion of t he survey the result s shoul d be ent ered onto a map (mast er copy in the Orchis pal ust ris fil e i n l ab cabinet) showing all t he areas surveyed and the areas where O.pal ustris was found. This wi ll all ow us t o build a cl earer picture of it s dist ribution over t he years. Count dat a should be entered onto t he computer under: TAIB/ AUDIT_Speci es_dat a /5. 2 PL ANT S/5. 2.1_Orchis_palustris_census
COM M ENTS
NB. The above prot ocol may only be vi able when the ground conditions are suit ably firm. As wit h all field work t he leader should undertake a risk assessment once onsit e. Experi ence has shown that t he conditi ons at each of t he mai n bl ock survey areas can vary consi derably each year as a result of t he wat er l evel in the park. W here there are open areas of wat er t here is no need t o survey, primaril y because t his is unsuit abl e habitat for Orchis pal ustris and secondly because of t he increased likeli hood that wadi ng birds such as Himantopus himantopus (black-wi nged stilt) are breedi ng there. W here there i s deep mud( > 30cm) whi ch will make progress di ffi cult t hen surveying shoul d be done wit h binocul ars using the foll owing procedure: The surveying team should agree the secti on t o be vi ewed. Thi s should foll ow di stinct li near features where possibl e e.g. a raised bank; line of Juncus acutus. A ranging rod should be set at each accesi bl e corner of t he area. The survey should be undertaken on as many si des of the area as possibl e in order t o achieve t he wi dest visual cover. If onl y one si de is accesible, t he surveyors should be spaced evenl y along this linear rout e. Using bi nocul ars each surveyor shoul d count all the Orchis palustris spikes t hey can see in t he area. Total numbers from each surveyor should be compared and repeat count s made i f t he fi gures are greatl y di fferent (> 5%).
80
A nnex 4: Maps for survey areas
81
82
83
84
85
86
A nnex 5: Resul ts per area
2004
1
0
0
A2 B1
45
14
B2
1 89
B2/B3/B4/B5 347
12
13
0
28 43 24
19
2
11
80 21
2
0
105 3
1
1
445
B3
78
B4
7
1
143
B5
11 3
52
20
138 158
13 14 14 108 80 94
B5_bis
89
C1
1
C2 C3
1
C4
162 10
C5
75
8
3
285 6
3
D2 D3
16 52
6
18
2
D4
91
30
14
14
6 28
1
1
D5 D8
1 1
36 26
1
12
1
E2
1
25
3
4 13
0
0
7
0
1
0
7
0
1
0
0
0
0
0
0
0
0
9
13
1
14
F2 F3
3
0
0 12
8
G1
10
0
163 1700 1694 35 313 134 320 645 325 241
G2
1
1
5
1
0
H2
0
0
H3
0
H1
3
I1 I4
8
72
24
90
J1
5
J3
7
J4
11
K3
5
3
4
52
1
1
69
1
0
34 55 17 0 2
2
2006
2003
2
2005
2002
2
2001
1
2000
1999
1997
1996
1995
15
1998
A1
1994
1993
1992
Census_Area
1991
Survey results for f lo wering Orchis palustris for each area from 1991 to 2004. In 2003 and 2004, absence of flo wering spikes were recor ded as “zero ”. Previous to 2003, “zeros” have not been used.
8
348 42
L10
70 172 626 29 415 102
L6
1126
L9
163
30 585 322 35
0
27
3
19
6
7
5
9 0
2006
6 103 13
2005
21 43
2002
14
2001
1998
22
2000
1997
1999
1996
1995
26
2004
76 48
70
2003
L1
1994
K4
1993
1992
Census_Area
1991
87
88
Grazing compartments COMPA RTIMEN TO ECO SISTEMA S
SUPER O BJETIVOS FICIE “ FISICOS” (H a)
OBJETIVOS PRIO RITARIO S BIODIVERSIDAD
VEG ETA CIÓN
1.- Amarador
Marisma dulce
28,6
Mantenercortafuegos
Aves acuáticas
Carrizo, masiega y vegetación ruderal
2.- Camí Pep i Pujol
Camino
2,9
Mantenervía de paso
-
Camino (Carrizo, masiegay vegetación ruderal)
3.- Camí dels Polls
Marisma dulce
15,6
Mantenercortafuegos
Aves acuáticas
Carrizo, juncos y vegetación ruderal
4.- Camí dels Polls O rquídies
Marisma dulce
7,8
Mantenercortafuegos
Orchis palustris ; Aves acuáticas
Carrizo, juncos y vegetación ruderal
5.- Casa Ses Puntes
Duna fósil
3,5
Explotar zona de cultivo
-
Cultivos y ruderales
6.- Es Cibollar
Marisma salada 25,2
Manteneraguas libres Aves acuáticas
Juncos y salicornia
7.- Es Forcadet
Marisma ligeramente salada (mixohaline)
22,5
Manteneraguas libres ; Mantener Aves acuáticas cortafuegos ; Explotar zonade cultivo
Carrizo y ruderales ; Bosquede tamarindos
8.- Malecó Canal Sol
Camino
2,4
9.- Malecó Siurana
Camino
1,5
10.- Es P atrimoni
Marismas dulces i otras saladas
11.- Es Racó
Mantenervía de paso
-
Camino (Caña y ruderales)
Mantenervía de paso
-
Camino (Caña y ruderales)
36,6
Mantener aguas libres ; Mantener cortafuegos
Aves acuáticas
Vegetación variada: salicornia carrizo, caña, juncos, etc.
Marisma ligeramente salada (mixohaline)
8,7
Manteneraguas libres Aves acuáticas
Carrizo ; pequeño pinar
12.- Es Ras
Marisma ligeramente salada (mixohaline)
122,5
Manteneraguas libres Aves acuáticas
Carrizo y masiega. En menor cantidad encontramos juncos y salicornia
13.- Sa Sínia
Marisma ligeramente salada (mixohaline) + Duna fósil
54,7
Manteneraguas libres Aves acuáticas
Carrizo, masiega ; pinar ¿ El pinar esta realmente en el compartimento?
14.- S’A lmacen
Marisma ligeramente salada (mixohaline)
7,8
Mantener aguas libres ; Mantener cortafuegos
Salicornia, juncos ; pequeño bosque de tamarindos.
15.- Turó ses Eres
Marisma ligeramente salada (mixohaline) + Duna fósil
33,2
Manteneraguas libres Aves acuáticas
16.- Turó des Blat
Duna fósil
3
Explotar zona de cultivo
Aves acuáticas
Carrizo, juncos ; pequeño pinar.
Orquídeas,Euphorbia terracina, nidos Cultivos y ruderales. alcaraván
Till 2003. In 2004 an d 2005, some com partments were redesigned.
89
A nnex 6: Final recommendation, expert in-depth i nvestigation
Need for experimentation Knowledge have been certainly acquired, an d results mostly descriptive. Explanations remain essentially hypothetical and/or are based on general plant ecology. To be pr ecise in term of grazing management we need to m anip ulate the var iables and perform experiments in- situ or accept guidance as experts’ point of view.
Translocation In 1991, a translocation of 36 or chids in dividuals was carried out in the path of Cam i en Pujol ( D8). Result of the survey of this pop ulation are sho wn in the next table. Table 3: C ensus_Area 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 D8
36
26
1
12
1
1
1
No recruitment was observed. Aft er a few years of resili ence, the popul ati on disapperead. This result i s not surprising in t hat a col onist speci es should have est abli shed in the path i f t he condit ions were good enough. The l ack of suit ability of the biot ope hampered the t ranslocation. In light of these resul ts, no further translocations have been impl ement ed as they cannot be relied upon to provide a good management tool for t his species.
Seedlings in reed-bed Are seedlings present in the reedbed?
What is the seed availability for germination? Does Or chids have seed bank into the soil? What factor trigger s germ ination?
What is the availability of pollinators? In orchids, cross-pollinisation is achiev ed by means of insects. For that, orch ids have developed sp ecial ( an d sometime “sexy”) flowerin g str uctur es to appeal to their potential pollinators. This is lon g known and spectacular in the case of Ophrys species. Auto-pollinisation is another mechan ism orchids use, especially im portant in the absen ce of in sects. The genus Orch is pr esents a medium size and lar ge sp ur. This is indeed the case with O. robustas. This type of str ucture is particularly ( co-)adapted for in sects with m edium size tongue, such as hym enopterans: Apoid ea (e. g. bees, bum ble- bees) and Scoliidae. Less frequently Orch is species can be pollinisated by flies ( Diptera). Though no pollinator has been yet described for the O. pa lustris gro up it is likely to belon g to these group s of insects (reviewed in SOCIETE FRANÇAI SE D’ORCHIDOP HILIE 1998).
90 Some of the Apoidea an d S coliidae ar e abun dant species. In S’Albufera, the abun dant species include Apis mellifera, Bom bus sp., Doufourea sp, Campsoscolia ciliata, Scolia flavifron s (Riddifor d 2002). Note that, in the absence of pines, active and fossil dunes are richer an d m ore div erse than any other eco system in the park for Hymenoptera. Diptera ar e also abun dant in S’ Albufer a. No data are available concernin g pollinisation of O. robusta in the park. At first sight, a paucity of pollinators is unlikely to be a m ajor constrainin g factor for O. palustris because the types of insects likely to be involved are norm ally comm on and widespread. If they are lackin g orchids can potentially com pen sate by auto-fertilization. Nevertheless, it wo uld be interesting to test this hypothesis. Does the destruction of fossil dunes habitats an d the simplification of its str uctures lead to insect population depletions and a con sequent im poverishment of wet m eadows an d O. robusta populations? These ar e questions which can only be an swered by an inten sive, in-depth study, best carried o ut at doctoral level. Because of the extreme rarity of this taxon and because of its flagsh ip importance for s’ Albufer a, Mallorca an d the Balear ic I slan ds as the only Europ ean site, we stron gly urge that such m easures be taken with som e ur gen cy.
