Remarkable plant species associated with habitats of Paphiopedilum canhii in its home area 9
Brief conclusions and recommendations for Paphiopedilum canhii protection 9
Literature cited 10
Technical and financial report 10
Appendix 1 List of collected species 13
Appendix 2 Notes to report illustrations 15
Summary. Research program funded from The Rufford Small Grant Foundation, American Orchid Society and Chicago Zoological Society, Chicago Board of Trade Endangered Species Fund for field assessment of recently discovered Paphiopedilum canhii was completed during 2010-2011. New original data were obtained for habitat and natural conditions of five discovered species subpopulations. Associated plant species and vegetation were described and documented with about 5000 collected herbarium specimens. Negative factors leading to fast species extinction are analyzed and discussed. It is suggested present status of the species as critically endangered, approaching to full extinction in the near future. Conservation of the species in its natural habitats needs very urgent actions that look unrealistic. Cultivation of species may be alone way to its salvation. Among accompanied plants in native area of P. canhii were discovered 2 new genera (Phylacium and Sinocrassula) and 14 species new for the flora of Vietnam (Ophiopogon, Saccolabiopsis and Appendicula torta, Bulbophyllum violaceolabellum, Coelogyne micrantha, Cuscuta formosana, Cymbidium cyperifolium, Dendrobium dixanthum, D. findlayanum, D. senile, Holcoglossum amesianum, Monomeria gymnopus, Phylacium majus, Pyrrosia nummulariifolia, Schoenorchis fragrans and Sinocrassula indica). One genus (× Lockia) and 11 species (from such genera as Begonia,Bulbophyllum, Chirita, Cleisostoma, Dendrobium, Hippeophyllum,Peliosanthes,Sarcoglyphis and Schoenorchis) are proposed for description as a new for science. Observations and plant records are illustrated with high-resolution images. Some recommendations for approaches to orchid protection are proposed as brief summary of the survey.
BACKGROUND AND INTRODUCTION Recent field explorations outlined rocky limestone areas of northern Vietnam with their highly endangered primary forests as unique very significant center of Paphiopedilum speciation and diversity (Averyanov et al., 2003). These studies reveal on this territory more than 25 geographically isolated local endemics of this genus with dramatically restrict and disjunctive distribution (Averyanov, 2008; Liu Zhong-Jian, et al., 2009a, b). Many of them were formally described outside of Vietnam on the base of specimens exported from the country by plant traders. Very often in this situation, biological sciences got no any reliable information about nature of such species, populations of which were extinguished before professional botanical study. Sometime such field investigations were organized too late, when species already extinct in the wild due to total over collecting as it happened, for example, with Paphiopedilum vietnamenseand P. tranlienianum (Averyanov et al., 2001; Averyanov, 2003, 2004). Despite obvious significance of botanical explorations in unexplored areas for informal understanding and discovery of plant diversity for timely protection, such projects are poorly funded. Without such studies a great number of strictly endemic species become extinct before their discovery and description by scientific annals of our civilization in conditions of commercial collecting, wide deforestation and total collapse of native their habitats.
This report presents results of completed 2-year scientific exploration program for field study of Paphiopedilum canhii, species recently discovered in northwestern Vietnam (Averyanov et al., 2010; Averyanov, 2010). Main goals of these investigations were identification of the species distribution, natural conditions of habitats, status in nature and elaboration of strategy for its possible protection.
For the first time Paphiopedilum canhii appeared on the local markets of Dien Bien and Son La cities without any exact information about plant origin. Limestone areas of these provinces allied to Laotian border are known as a home of such highly prized endemical orchid species as Bulbophyllum paraemarginatum, Dendrobium farinatum, Dendrobium trantuanii, D. vietnamense, Hayata glandulifera,Paphiopedilum aspersum, P. coccineum, Sunipia nigricans, etc. (Perner, Dang, 2003; Schildhauer, Schraut, 2004; Averyanov, 2004, 2005, 2007, 2008, 2009). Following to simplest logic it was primarily expected that P. canhii with high probability has also restricted, very limited and disjunctive distribution and its habitats should be associated with rocky karstic limestone regions of northwestern part of Vietnam. Such areas were accepted as presumptive regions for priorital field searches of relictual species populations (Fig. 1, 2).
HISTORY OF DISCOVERY AND STUDIES OF PAPHIOPEDILUM CANHII Vietnamese people like orchids. More or less large orchid collections or small family orchid home gardens may be often seen in any city, town or even village all over the country. Various orchids for cultivation may be bought easily on neighbour local markets or just along roads where they cross-areas with remains of primary woods. Plants are usually offered for sale by local people. They commonly crop these plants in nearest vicinities, regularly in degraded primary forest, logging and burning for primitive agricultural fields. Such fields are permanently expanded and successively replace primary forests in many botanically unexplored areas. Orchid collecting in such places time to time brings to the market rare, interesting and even undescribed orchids. Similar story was happen with discovery of Paphiopedilum canhii.
Local orchid growers in Dien Bien and Son La cities were first people denoted samples of unusual slipper orchid that were appeared on the local market at the end of 2009. This plant reflected certain attention of many orchid lowers and plant dealers who reasonably suspect that unusual plant may represent new undescribed species. First persons who introduced the plant to world orchid society were Mr. Chu Xuan Canh and Mr. Bui Xuan Dang observing fresh collected market plants in Dien Bien city and in Hanoi.
In fact, Paphiopedilum canhii was described on the base of few plants that were brought at the end of 2009 by people of H’Mong (Meo) minority from remote mountain area to office of “Civilian Governmental Service for Care of Natural Resources and Connections with Local Minorities” (Natural Resources Governance, CARE International in Vietnam). At the office, plants were received by Service Officer – Mr. Chu Xuan Canh, who kept plants for cultivation and further study. Cultivated plants developed flowers in March next year. Even preliminary research revealed unique character and very isolated taxonomical position of collected plants. This resulted in immediate description of new species for science – Paphiopedilum canhii (Averyanov et al., 2010; Averyanov, 2010), named after owner of first blossomed specimens.
First publication with description of P. canhii appeared in May issue of the American Orchid Society Magazine (Orchids). This publication mentioned two elements as species type. Rules of International Code of Botanical Nomenclature (ICBN) cannot regard such description as valid thought description was actually based on the same plant (in fruits and in flowers). Month later the species was re-described in supplement to second part of Prof. Averyanov’s monograph – “The orchids of Vietnam. Illustrated survey. Part 2. Subfamily Orchidoideae” published as 2 quarter issue of 13 volume of Siberian botanical magazine – “Turczaninowia”. This description fulfilled in accordance with formal rules of ISBN was dated as 15 June 2010.
Publication of newly discovered species attracted a great attention of people involved in orchidology and horticulture. It also activated interests of domestic and international orchid trade. The increasing of market demands for newly described species leaded to rapid rise of plant costs and stimulated plant collecting in the nature. As a result, large lots of plants appeared on the local markets immediately. At the same time, native area of species long time remained unknown being “know-how” of dealers and local collectors. Indirect data gave obvious evidence that species represents very restricted local endemism of limestone areas in limits of Dien Bien or Son La provinces. It was reasonably expected, that this plant probably may be found in alone or few localities and its populations may be very small approaching to full extinction. Discovery of remnant populations, description of species habitats, assessment of present distribution and status of P. canhii was main goal of the proposed exploration program with field works started in December 2010.
METHODOLOGY APPROACHES According to elaborated plan of investigation following actions were successively fulfilled in present exploration program.
Firstly, all available indirect relevant information was obtained from numerous talks in local orchid markets, from interviews with orchid lovers, growers and local dealers in the area of Dien Bien and Son La provinces. Additional data were obtained by talks with local peoples, village authorities, local foresters in cooperation with officers of Forest Protection Department of the Ministry of Agriculture and Rural Development (FPD). Eventually, on the base of all obtained data, it was preliminarily detected that species should occur in the area of Dien Bien and Son La provinces near Laotian border, most probably on rocky limestone. All slipper orchids are obligate element of intact primary forests. Wide extinction of such forests strongly restricted possible regions for perspective field searches. Our field overview and special surveys (Collins, Sayer, Whitmore, 1991) indicate that more than 99.5% of primary forests in the area presently completely extinct due to shifting primitive agriculture, forest logging and timber exploitation for fuel-wood. Miserable pieces of remained primary forests may be estimated now as covering less than 1% of total territory. Such unique remnant forest stands were located in few remote mountain regions of studied area in close cooperation with local representatives of FPD. As only primary forests support populations of sensitive aboriginal species including all species of Paphiopedilum, just only these localities were selected for field explorations (Fig. 2).
On the base of elaborated search strategy, principal plan of reconnaissance expedition trips for field study of most probable species localities was elaborated and realized during January 2010. At this field session alone locality of Paphiopedilum canhii (with five subpopulations) was found in Dien Bien province near Laotian border. Next year, during P. canhii flowering time, detailed field investigation of this locality was organized. Vast areas of Vietnam and Laos allied to area of P. canhii discovery were studied additionally during March-April field session. During this session, more than 48 localities in rocky limestone areas of both countries were investigated (Fig. 2). Although many localities selected for study exhibited identical or very similar natural conditions (as well as basic plant species composition) with those observed in discovered habitats of P. canhii, this species was not more found elsewhere.
On the base of field explorations, description of discovered P. canhii habitats was made along with description of vegetation and natural conditions. It was also made approximate estimation of number of plants in five discovered subpopulations and expected area of species distribution, as well as identification species status in the wild on the base of original field investigations. Also, on the base of direct field observations were preliminary studied species phenology and seed production with identification of optimal time for seed collecting for possible seed propagation and possible repatriation. Recommendations for reliable strategy of species conservation on the base of obtained data, including training educational aspect for local people in the area of species were discussed and proposed.
Methodology of car and feet routes in remote mountain areas for the species searches and personal investigations of the flora and vegetation in possible regions of P. canhii occurrence (NW Vietnam and NEE Laos areas allied to Son La and Dien Bien provinces of Vietnam) was used in current exploration program. These trips were connected with hire of local people and foresters as a field guides and in close cooperation with Forest Protection Department officers. Estimation of number of plants, number and size of populations, as well description of habitat conditions and vegetation were fulfilled according to standard geobotany and plant geography methods. Voucher specimens for documentation of plant species records and descriptions of plant communities will be housed in Herbarium of The Center for Plant Conservation (CPC), LE, MO and VNM Herbaria. Field exploration work and most observed plants were illustrated with high-resolution photography.
LANDSCAPE AND TYPICAL LANDFORMS IN STUDIED AREA First information about existence of Paphiopedilum canhii came from northwestern Vietnam. Eventually, after extensive field explorations it was found in alone locality of Dien Bien province near Laotian border. The area initially accepted for priorital study as most probable native land of P. canhii is shown on figures 1. The northern part of this area (except granite Hoang Lien Son Range) represents a number of spacious successive alluvial valleys with shale rolling hills and low mountains up to 1500 (2000) m a.s.l. Valleys are appeared as wide, broad depressions covered by unconsolidated Quaternary sediments or occasionally with olivine basalt (Chu Van Ngoi, Luong Thi Thu Hoai, 2007) with valley bottoms elevated to 500-600 m a.s.l. Often they exhibit scattered, more or less isolated systems of remnant, rocky mesa-like hills or mountains, composed with highly eroded, marble like Devonian and Triassic limestone (Fig. 3-5). These spectacular formations with karstic rocky vertical cliffs elevated commonly up to 800-1000 m a.s.l., but sometime reach 1300-1400 m a.s.l. (Fig. 6-10).
Some limestone massifs in SW part of studied area represent more or less highly eroded peneplains that forms continues lines of more or less dissected limestone plateaus extending from NW to SE direction. Largest of them are Son La and Moc Chau Plateaus with elevations up to 1500-1700 m a.s.l. They spread along the Song Da River. Narrow canyons or very deep river valleys separate these plateaus and associated ridges. This zone of Devonian and Triassic limestone within the peripheral areas of these plateaus appears as a spectacular area of highly eroded karst impressive rocky topography (Averyanov et al., 2003).
SPECIFIC CHARACTER OF LANDSCAPE AND LANDFORMS IN AREA OF DISCOVERED HABITAT OF PAPHIOPEDILUM CANHII In the course of field works according to present exploration program, about 53 localities of remnant primary forests were found and studied (Fig. 2). Nearly all studied localities represent last highly degraded remnants of primary forests in the area that nevertheless still remain intact relictual nucleus of aboriginal flora with very rich aboriginal species composition. Highest level of species diversity and endemism was observed in the area on rocky limestone formations. During our field works in such native conditions were found numerous rarest strictly endemical plant species including Paphiopedilum canhii.
Alone locality of Paphiopedilum canhii was found during current exploration program in Dien Bien province, to the SW of Dien Bien City, in Dien Bien District on the territory of Na U Municipality very near to Laotian border. Few subpopulations of the species inhabit very small isolated massif of few scattered remnant limestone hills composed with highly eroded marble-like rocky limestone with numerous steep slopes and vertical cliffs (Fig. 12-16). These limestone formations topographically are inserted between rolling shale hills on watershed of western tributaries of Nam He River (Fig. 11), but some of them are towered just on flat river valley (Fig. 13). Total square of this hilly limestone massif not exceed 4 km2 (Fig. 11, 12). Tops of limestone remnant hills elevated from 950 to 1200 m a.s.l. retain severely fragmented degraded pieces of primary forest that give home to remains of aboriginal species. At the same time this limestone refuge is surrounded by shale hills covered with poor weedy secondary plant communities and valleys occupied by agricultural fields (Fig. 12). High anthropogenic transformation of landscape gives no chance to find populations of rare sensitive native species like P. canhii in any vicinities of this area outside studied fragments of rich humid primary limestone forest.
In discovered native area of Paphiopedilum canhii were found and studied nine last remained very small primary forest stands that potentially may be support habitats of P. canhii. In fact, species was found only in five sites with very small subpopulations in each habitat (Fig. 11).
MAIN KINDS OF VEGETATION IN STUDIED AREA Rich primary broad-leaved evergreen closed submontane tropical forests represent typical original pristine zonal vegetation formation in the area of Paphiopedilum canhii discovery. Very rich species composition, specific horizontal and vertical forest structure, permanent shade and humidity, as well as absence of exotic or weed species is typical feature of such aboriginal vegetation kind. However, sometime, it is not too easy to reconstruct and understand real structure and composition of pristine forest that were spread everywhere in studied area in prehistoric ages. Different stages of successions more or less deep degradation of vegetation is typical picture in our days all over studied area. Very poor secondary woods, secondary scrubs or herbaceous plant communities with high participation of exotic or weedy alien species, are most typical regrettably picture in landscapes in all area of the project explorations.
Field studies of this project revealed following picture of forest structure and species composition in the area of Paphiopedilum canhii habitats.
First forest (canopy) stratum includes numerous trees, which belong to different families. These trees reach on hill slopes regularly 20-25 m tall with canopy coverage 80-100%. Most of trees are evergreen, but participation of deciduous trees may be more or less considerable, particularly on south-faced slopes and on cliffs (Fig. 17-20). Species listed below in Table 1 were observed as more common co-dominant of this and lower strata in primary limestone forest.
Co-dominant species of different strata in primary broad-leaved evergreen closed submontane tropical forests on hill slopes in Paphiopedilum canhii native area
1 FOREST (canopy) STRATUM
20-25 m tall
PLANT SPECIES NAME
Allospondias lakonensis Stapf.
Choerospondias axillaris (Roxb.) B.L.Burtt et A.W.Hill