Khảo sát về cây thuốc trong Vườn Quốc gia Ba Vì, Việt Nam. Tác động của các phương pháp đối với bảo tồn và sử dụng bền vững Conservation of medicinal plant resources is a critical ecologic, cultural and economic issue in Vietnam, as with other parts of South-east Asia, and the tropics and sub-tropics generally. The paper describes the development and application of a survey methodology, using standard phytosociological techniques, for the quantitative inventory of medicinal plants in BaVi National Park, northern Vietnam. One hundred and twenty-six permanently marked transects, each 50 10 m, were established over the ranges of altitudes and characteristic vegetation structural types present in the Park. Over 200 medicinal plant species used by Dao people were sampled (of a documented total of about 300 species including introduced species grown in home gardens), in vegetation types ranging from closed evergreen forest at high altitude (>1000 m), through secondary forest formations, bamboo thicket, open grassland and plantation, distributed generally along a declining altitude gradient. Forty-one of 44 economically important medicinal species were sampled also. Important medicinal plant species, half being vines, were concentrated particularly in more-orless intact, late secondary closed forest habitats at higher elevations. The status of most important medicinal plant species was found to be rare or uncommon, and to exhibit scattered (as opposed to clumped) distributions. The paper discusses implications of the applied methodology and the assembled data for the inventory, conservation, and sustainable use of medicinal plants at local and broader regional scales. # 2001 Elsevier Science Ltd. All rights reserved.
Trang 1A survey of medicinal plants in BaVi National Park, Vietnam: methodology and implications for conservation and sustainable use
Tran Van Ona, Do Quyena, Le Dinh Bicha, Bill Jonesb, Josette Wunderb,
Jeremy Russell-Smithc,*
a Hanoi College of Pharmacy, Viet Nam
b Association for Research and Environmental Aid, Sydney, Australia
c Parks Australia (now included within Environment Australia), Jabiru, Australia Received 10 November 1999; received in revised form 20 June 2000; accepted 7 July 2000
Abstract
Conservation of medicinal plant resources is a critical ecologic, cultural and economic issue in Vietnam, as with other parts of South-east Asia, and the tropics and sub-tropics generally The paper describes the development and application of a survey methodology, using standard phytosociological techniques, for the quantitative inventory of medicinal plants in BaVi National Park, northern Vietnam One hundred and twenty-six permanently marked transects, each 50 10 m, were established over the ranges of altitudes and characteristic vegetation structural types present in the Park Over 200 medicinal plant species used by Dao people were sampled (of a documented total of about 300 species including introduced species grown in home gardens), in vegeta-tion types ranging from closed evergreen forest at high altitude (>1000 m), through secondary forest formavegeta-tions, bamboo thicket, open grassland and plantation, distributed generally along a declining altitude gradient Forty-one of 44 economically important medicinal species were sampled also Important medicinal plant species, half being vines, were concentrated particularly in more-or-less intact, late secondary closed forest habitats at higher elevations The status of most important medicinal plant species was found to be rare or uncommon, and to exhibit scattered (as opposed to clumped) distributions The paper discusses implications of the applied methodology and the assembled data for the inventory, conservation, and sustainable use of medicinal plants at local and broader regional scales # 2001 Elsevier Science Ltd All rights reserved
Keywords: Medicinal plants; Ethnobotany; Conservation; Inventory; Vietnam; South-east Asia; East Asia
1 Introduction
Considerable and growing attention has been given in
recent years to issues surrounding the in situ
conserva-tion, and ecologically- and economically-based
sustain-able use, of wild (i.e undomesticated) populations of
medicinal plants (MPs) (e.g Akerele et al., 1991; Plotkin
and Famolare, 1992; Balick et al., 1996) Most
con-servation focus has been given to individual,
inter-nationally and regionally economically signi®cant,
over-exploited MP species (Anon., 1995±1997) Nowhere are
these issues more acute as in tropical and sub-tropical
regions (e.g Africa, the Americas, Asia), where still
today most people rely on medicinal, timber, and an array of other non-timber vegetable/animal products, derived principally from increasingly degraded, frag-mented, species-diverse forest and savanna biomes (e.g Farnsworth and Soejarto, 1991; Toledo et al., 1992; Iwu, 1996; Voeks, 1996; Caniago and Siebert, 1998) Medicinal plant conservation has an extensive con-temporary literature covering a range of subject areas Schippmann (1997) provides 590 references for the per-iod 1990±1996, derived from over 50 relevant journals, newsletters, and databases This work covers, in ranked thematic order, mostly: economic and trade aspects (181 entries); status and threat issues pertaining typically to individual taxa (166); cultivation and harvesting issues (120); regional/culturally focused ethnobotany studies (110 entries); species descriptions and identi®cation (100); and policy and legislation issues, including intel-lectual property rights (71) Most listed regional studies
0006-3207/01/$ - see front matter # 2001 Elsevier Science Ltd All rights reserved.
PII: S0006-3207(00)00125-7
www.elsevier.com/locate/biocon
* Corresponding author at Centre for Indigenous Natural and
Cultural Resource Management, Northern Territory University,
Darwin, Northern Territory 0909, Australia.
E-mail address: jeremy.russell-smith@nt.gov.au (J Russell-Smith).
Trang 2have focused on the Indian subcontinent, followed by
the Americas then China, with relatively few concerning
Africa and South-east Asia (Schippmann, 1997)
Few studies address, or provide regional empirical
examples of, quantitative ecological survey (i.e resource
inventory), sustainability, and associated database
designs As noted by Hall and Bawa (1993), however,
the undertaking of ecological surveys focusing on the
distribution, abundance and population structures of
MPs is fundamental to the assessment of the
conserva-tion status of wild populaconserva-tions, and prerequisite for
addressing harvesting sustainability of key or target
species Principles and guidelines concerning MP
con-servation database design, networking and
main-tenance, are outlined in Synge and Heywood (1991)
Toledo et al (1992) provide a rare example of a national
MP database then under development for tropical forest
regions in Mexico, combining data from regional
ethno-botanical studies with plant species inventories undertaken
at a range of scales (e.g sites, 4 1 ha; localities, 1±10 ha;
regions, up to ca 1000 ha)
In this paper, we describe the application of a standard
quantitative ecological survey design for assessment of
the distribution, abundance and status of MPs, as used by
the Dao ethnic group, in BaVi National Park, northern
Vietnam The design has potential also for various
inventory, conservation, and sustainability assessment
applications at broader regional scales As discussed
below, the assessment and conservation of MPs in
Viet-nam is a critical ecologic, cultural and economic issue in
that country; Schippmann (1997) lists just two
Vietna-mese references, and single references for neighbouring
Kampuchea and Laos The project was undertaken
col-laboratively between the Vietnam National University
(Centre for Resource and Environmental Studies), Hanoi
College of Pharmacy, the Association for Research and
Environmental Aid (an Australian Non-Government
Organisation aid agency), and the Australian Nature
Conservation Agency (now included within
Environ-ment Australia)
2 Regional context and study area
Spanning the tropical, monsoon climatic zone,
Viet-nam has a high biodiversity with more than 10,000
described species of higher plants (Pham, 1999), of
which 3200 species have been recorded as having
med-icinal properties (Vo, 1997) However, with a high
population density and increasing demands for
eco-nomic development, Vietnam has lost more than 50%
of its forest cover over the past ®ve decades (Vietnam
Ministry of Science, Technology and Development,
1995) Current rates of deforestation of remnant dense
(>40% canopy cover) broad-leaved forests in Vietnam
are estimated to be >1% p.a (Blasco et al., 1996)
Vietnam now faces over-exploitation of its plant resources, including MPs Given the importance of native MPs in the domestic economy (Nguyen, 1996), investigation of the conservation and sustainable use of MPs in Vietnam is an urgent matter
BaVi National Park is located generally between
21010±210070N and 105180±1050250E in the BaVi Dis-trict, Ha Tay Province, northern Vietnam, approxi-mately 50 km north-west of Hanoi (Fig 1) BaVi was established as a National Park in 1992 The Park covers
an area of 7377 ha, including a Strictly Protected Area (i.e core area) above 400 m elevation of 3000 ha sur-rounding three mountain peaks where there is still rela-tively pristine tropical montane and semi-evergreen forest (sensu Blasco et al., 1996) at higher elevations The Park is surrounded by a Particular Use Zone (i.e buer zone) of approximately 15,000 ha, previously under the control of Park authorities but now falling under District jurisdiction, but where a range of non-Park activities (e.g growing of crops, cattle grazing) is permitted Alti-tude ranges from 100 to 1296 m above sea level Average rainfall is 1660 mm, 90% of which is received during the wet season months, June to October Geology comprises mostly ®ne-textured sedimentary rocks (AREA, 1993) Towards the end of the nineteenth century, the French botanist, Balansa, collected 5000 plant speci-mens from the BaVi region Recent investigations have revealed more than 800 plant species, occurring in 427 genera and 98 families At present the Park's ¯ora is estimated to comprise 1500±2000 higher plant species (Nguyen, 1990) Amongst the described species are 13 local endemics (AREA, 1993), and 10 species recorded
in the Vietnamese Red Data Book for rare and endan-gered plants (Tran and Tran, 1998) More than 300 local plant species have been recorded as having medic-inal value; a preliminary listing of these species is pro-vided in AREA (1993)
There is a population of some 45,000 people, belong-ing to Kinh, Muong and Dao groups livbelong-ing in the Par-ticular Use Zone (PUZ) of the Park Outside the PUZ population densities are high, with an estimated popu-lation of around 15 million living in the Red River delta lowlands, comprising 14,700 km2 (Le and Tran, 1993)
Of the three ethnic groups, the Dao constitute the major users of MPs in the Park, and this paper focuses on MPs
as de®ned and used solely by this ethnic group
Shifting cultivation commenced in the mountainous BaVi region as late as the 1920s when Dao people migrated to the area Since 1965, Dao people have been resettled in the PUZ where they now reside in two main communes consisting of about 2000 people Transition
to a settled agricultural lifestyle has been dicult, how-ever, and most Dao families continue to depend on harvesting of natural resources to some extent at least Controlled harvesting of some natural products (fuel-wood, fodder, medicinal plants and other vegetative
296 T Van On et al / Biological Conservation 97 (2001) 295±304
Trang 3resources) is permitted in rehabilitation plantation
areas; regardless, illegal removal of both plant and
ani-mal resources continues throughout the Park Dao
people daily collect and process substantial quantities of
MPs from the Park and its surrounds, both for domestic
and commercial purposes Along with the cultivation of
cassava and other agricultural crops, the exploitation of
MPs constitutes a major economic activity MP
pro-ducts are sold extensively by the Dao in surrounding
towns and communities (including the capital Hanoi),
for both wholesale and retail markets
3 Methods
3.1 Medicinal plants
MPs used by Dao people were recorded in interviews
and participatory ®eld surveys, particularly with
herb-alists and collectors, over 2 years Specimens of all MPs
were collected during ®eld trips One complete set of
reference specimens is lodged with the Herbarium of the
Hanoi College of Pharmacy (HNP)
Throughout the paper, reference is made to a subset
of MPs, the Important Medicinal Plant (IMP) species
IMPs were identi®ed using standard Participatory Rural
Appraisal (PRA) techniques where herbalists were
asked to rank a list of regularly used local MPs
com-piled on the basis of extensive participatory ®eld
obser-vations IMPs were determined on three criteria: (1)
proportion of herbalists using each listed species; (2) frequency of use; and (3) market value Details (and results) of the applied PRA methodology, along with information concerning the medicinal properties ascri-bed to MPs by Dao herbalists, processing techniques, and other ancillary data, are not presented here but form part of continuing studies being undertaken by the
®rst author as part of a PhD research program
2.2 Vegetation habitats and medicinal plant survey
As a means for developing a habitat framework for describing the distributions and ecological relations of MPs in BaVi National Park, 126 permanent transects, each 50 10 m, were established over the ranges of altitudes and characteristic vegetation structural types (primary and secondary forest, bamboo thicket, grass-land, and plantation) present in the Park Based on advice provided by Dao informants, four of the above transects were established speci®cally in areas known to contain certain rare IMPs
Vegetation data recorded at each transect included the identi®cations and densities of all tree species (55 cm DBH), canopy height of the three tallest stems, bamboo cover (%), other grass cover (%), and indices for canopy cover [1=closed canopy (5 75%); 2=partial canopy; 3=open canopy (< 10%], and disturbance (1= primary/ intact forest; 2=secondary forest/thicket vegetation; 3=mostly cleared/replanted) Recorded environmental data included altitude, slope, aspect, geology, water
Fig 1 Location of BaVi National Park, Vietnam.
Trang 4availability (0=absent; 1=seasonal; 2=permanent), and
slope position (1=valley bottom; 2=footslope;
3=mid-slope; 4=top3=mid-slope; 5=crest)
At each transect, the abundance of individual MP
species was recorded using the following scale: 1=1
individual present; 2=2±6 individuals; 3=7±20
indivi-duals; 4=21±50 indiviindivi-duals; 5=51±100 indiviindivi-duals;
6=101±200 individuals; 7=201±500 individuals; 8=
>500 individuals An estimate of the total abundance
of MP individuals occurring at an individual transect
was calculated by summing the maximum values
possi-ble for respective classes (e.g 20 individuals for
abun-dance class 3) for all MP species sampled on the
transect
3.2.1 Analysis
Preliminary analysis of the survey data was
under-taken using standard numerical pattern analysis
techni-ques incorporating classi®cation (i.e grouping of
transects based on ¯oristic similarity) and ordination
(i.e relative ordering along one to few dimensions, or
vectors, of transects based on ¯oristic similarity) While
a wide variety of classi®cation and ordination
proce-dures are available (e.g see Gauch, 1982; Causton,
1988; Legendre and Legendre, 1998), we employed
widely used, complementary classi®cation
(TWIN-SPAN; Hill, 1979a) and ordination (Detrended
Corre-spondence Analysis (DCA); Hill and Gauch, 1980)
procedures based on reciprocal averaging (Hill, 1973),
contained in the simple-to-use, computationally
e-cient, DECORANA package (Hill, 1979b) While both
procedures have limitations (e.g Knox and Peet, 1989;
Van Groenewoud, 1992), they aord generally eective
solutions especially where (as in this study Ð see
Results) vegetation patterning is under the in¯uence of
one dominant vegetation gradient and species'
respon-ses are predominantly unimodal (Peet et al., 1988;
Mucina and van der Maarel, 1989)
As a means for developing a habitat framework,
polythetic divisive classi®cation was undertaken with
TWINSPAN on a data matrix comprising 126 transects
94 tree species (presence/absence) occurring in at least
®ve transects Classi®cation was truncated at the third
division level, and yielded six readily interpreted
trans-ect groups (see Results) Complementary Detrended
Correspondence Analysis (DCA) ordination was
undertaken to derive transect scores for the ®rst two
vectors
Using the six groups as a framework, subsequent
analyses involved: (1) calculation of group frequencies
for nominal (e.g species occurrence) and ordinal (e.g
slope position) variables; and (2) calculation of group
means and standard errors for measurement variables
(e.g no IMPs, stem density, altitude) To assist
inter-pretation of major trends in these data, a range of
environmental, vegetation structure, and MP data were
correlated (Pearson's r) with the ®rst two DCA vectors derived from ordination of the matrix of 126 transects
94 tree species Correlations were also undertaken between MP variables and other environmental and structural variables, over all transects All data manip-ulation was performed with the DECODA package (Minchin, 1990)
4 Results 4.1 Medicinal plants
A total of 207 MPs, of about 300 recorded in the BaVi area (AREA 1993), were sampled in the 126 transects Many of those unrecorded, however, occur as exotics grown only in home gardens Forty one IMP species, of a total of 44 determined through the PRA process, were sampled in transects; the three unrecorded species are all considered to be very rare in the local area by Dao herbalists Of the 44 IMPs, three are grown already in home gardens (Alstonia scholaris, Cinnamo-mum zeylanicum, Tradescantia zebrina), and at least two others could readily be grown (Piper retrofractum, Tra-vesia palmata) from layered cuttings and seed, respec-tively
A listing of IMPs is provided in the Appendix A, along with information concerning their lifeforms, abundance in transects, and frequency of occurrence in each of the six habitat groups derived through classi®-cation (see below) Using these data we have classi®ed the current occurrence of IMPs in BaVi National Park as follows: (1) status, where occurrence in 1±2 transects= rare, 3±9 transects=uncommon, and 10+ transects= common; and (2) dispersion, where modal abundance in transects of 1±6 individuals=scattered, and 7+ indivi-duals=clumped These data are summarised in Fig 2
Of note in Fig 2 is that the status of over half the IMPs
is either rare or uncommon, and dispersion of the great majority is scattered Half the IMPs, including three species not sampled in transects, are vines (see Appen-dix)
4.2 Habitat framework TWINSPAN classi®cation of a data matrix, compris-ing 126 transects 94 tree species occurrcompris-ing in ®ve or more transects, yielded six readily interpreted habitat types (groups) The ®rst dichotomy separated 38 highly disturbed and plantation transects all occurring at low altitude, from other secondary and primary forest trans-ects occurring up the mountainside Plantation transtrans-ects (with very low tree species diversity Ð Group 6) were distinguished from other open low altitude transects (Group 5) in the second dichotomy For the 88 transects occurring at higher altitudes, two further divisions yielded
298 T Van On et al / Biological Conservation 97 (2001) 295±304
Trang 5four site groups more-or-less neatly partitioned along
the altitudinal gradient as follows: a group of nine
transects comprising mostly undisturbed (primary)
montane forest vegetation atop the mountain peaks, at
a mean elevation of 1200 m (Group 1); 24 transects
comprising mostly disturbed, closed canopy, late
sec-ondary forest at a mean of 1000 m (Group 2); the
majority of transects (43) representative of partly
canopied, early secondary forest on midslopes, at a
mean of 650 m (Group 3); and 12 transects
representa-tive of closed canopy, late secondary forest, associated
particularly with creeklines, at a mean elevation of 450
m (Group 4)
The frequency of occurrence of common tree species
(i.e occurring at 10 or more transects) in each of these
six groups is presented as a sorted table in Table 1
Means and modal values for a range of environmental,
vegetation structure, and MP variables, are given for
each of these groups in Table 2 Given that all transects
were found to be located on similar sedimentary parent
materials, substrate (geology) data are not included in
Table 2
The predominant in¯uence of the altitudinal gradient
on the ¯oristic and structural patterning of vegetation
habitats in BaVi National Park is indicated by the
highly signi®cant negative correlation between altitude
and DCA scores for the ®rst vector (Table 3) This
interpretation is reinforced by: highly signi®cant
nega-tive correlations between DCA vector 1 scores and tree
species diversity per transect, and canopy height; and
corresponding highly signi®cant positive correlations
with disturbance, canopy cover, and grass cover indices
(Table 3) The second major axis of variation in these
data is evidently related to moisture availability (Table 3)
4.3 Distribution and abundance of medicinal plants Whereas the complement of useful MP species occur-red under all habitat conditions in BaVi National Park, including in plantations and highly disturbed open-canopy situations, IMP species were mostly restricted to secondary growth and primary forest conditions on the mountainside and peaks, particularly between 600 and
1000 m elevation (Table 2) Overall, non-important MP species were found mostly at lower elevations in typi-cally disturbed habitats, and IMPs were found mostly in relatively species diverse, undisturbed forest conditions
at higher elevations (Table 4)
MPs were most abundant in association with creek-lines in late secondary forest vegetation at lower eleva-tions (Group 4), then early secondary forests at intermediate elevations (Group 3) and plantations (Group 6), and least abundant at high elevations (Groups 1 and 2; Table 2) Overall, MP abundance was shown to be strongly negatively correlated with altitude and better structurally developed forest habitat condi-tions, and strongly positively correlated with relatively disturbed, open-canopied, grassy situations (Table 4)
5 Discussion 5.1 Status of medicinal plant species in BaVi National Park
Data presented here were derived from 126 transects sampling just 6.3 ha, or 0.09% of the total area of BaVi National Park The sampling eort was not randomly distributed; rather, plots were located mostly with respect to a strati®ed design focusing on sampling major habitats across the full altitudinal range This resulted in uneven sampling intensity over the Park area; for example, 80 transects were used to sample vegetation in the core area of the Park above 400 m, at a sampling density approaching 0.13% As well, some sampling eort was intentionally focused on areas high on the mountainside known to contain certain rare IMP spe-cies Despite these design limitations, it is evident that assembled data aord useful insights into the distribu-tions and `natural' habitat condidistribu-tions of many indivi-dual MP species, but especially the sub-set of naturally occurring, culturally and economically IMP species The data indicate that while there was a substantial
MP resource base for Dao people occurring in BaVi National Park, much of this was associated with species occupying modi®ed, open-canopy habitats and planta-tions, typically at lower elevations Such disturbance-adapted species, furthermore, presumably will continue
to be advantaged (in the short term at least) by ongoing degradation of remaining forested areas Prior to the establishment of the Park in 1992, it was estimated that
Fig 2 Relationship between status and dispersion of 44 important
medicinal plant species in BaVi National Park (refer to text for
details).
Trang 6as much as 150 ha of forest habitat was being cleared
annually (Vietnam Ministry of Forestry, 1989) with the
result that probably as little as 1,500 ha of intact forest
habitat remained by the early 1990s (AREA, 1993) In
modi®ed tropical settings many studies have noted the
singular importance of degraded secondary, and
culti-vated vegetation types as repositories of regional
phar-macopeia (e.g Kohn, 1992; Toledo et al., 1992; Voeks,
1996) Species and structural diversity in tropical and
sub-tropical forests declines nevertheless with increasing
modi®cation (e.g Whitmore, 1984)
In contrast, the great majority of IMP species were
found to be associated mostly with remnant, relatively
intact secondary forest formations at higher elevations;
however, at least 10 IMP species were recorded at least
once in substantially modi®ed habitats (Groups 5 and 6; see Appendix), or were already being grown in home gardens Most remaining IMP species were found to be rare or uncommon, occurring typically in dispersed populations, and comprising a disproportionately large number of vines Given their domestic and economic value, such species evidently are most at risk from ongoing local exploitation In the absence of remedial attention, however, the fate of IMPs may be likened to that of vertebrates in the Park where, following surveys conducted in 1962 and 1991±1992, it was concluded that
``mammal species richness in BaVi is poor, large mam-mals have become locally extinct, small-medium size mammals remain, but in small numbers'' (AREA, 1993,
p 19)
Table 1
Sorted table of frequency of common tree and tall shrub species (occurring in 10 or more plots) in each of six classi®cation groups a
Species code Group 1 Group 2 Group 3 Group 4 Group 5 Group 6
(n=9) (n=24) (n=43) (n=12) (n=9) (n=29)
Tabernaemontana kwangsiensis 4 5 11
a n=no transects per group Where given, voucher specimens as lodged at Hanoi College of Pharmacy (HNIP).
300 T Van On et al / Biological Conservation 97 (2001) 295±304
Trang 7A critical issue facing conservation of the Park's
remaining biodiversity thus is to assist local
commu-nities develop alternative means for deriving or growing
natural products outside the Park Such an approach
has been taken with the establishment of fast growing
timber species, albeit mostly exotic Acacia and
Eucalyptus spp., on land formerly cleared and in need of
rehabilitation These endeavours have reduced the
extent of ®rewood removal from the Park, as well as
providing income for the local community through the
sale of thinnings, poles, etc.; further, as supply has increased, the value of these products has decreased markedly (AREA, 1993)
IMPs likewise are signi®cant in this regard Challenges have included developing eective, simple propagating techniques, developing successful establishment regimes
in home garden situations (presumably requiring at least wind-protection and semi-shade), appropriate training, cultural acceptance, and ultimately, raising awareness of the need for sustainable harvesting of medicinal plant species in the wild To these ends an integrated program, involving over 200 herbalists and farmers, was initiated in the PUZ of the Park in 1993 and completed recently One of its priorities was to encourage the cultivation of MPs as an agricultural crop
in home gardens, and to replant threatened species in degraded areas of the Park as a regenerative strategy
To date, 23 IMP species have been collected, propa-gated (using simple, culturally appropriate techniques), and successfully planted in trials under suitable habitat conditions (e.g initial protective shade) at several loca-tions in the PUZ area
5.2 Inventory, sustainability and regional MP conservation
Both in Vietnam and in broader regional contexts, there is an evident requirement for addressing the conservation status of MPs and associated sustainability issues, as there is for conserving biodiversity generally The Vietnamese population comprises at least 54 ethnic groupings, most of whom depend heavily still on native
Table 3
Correlations between independent environmental, vegetation and
medicinal plant variables with vectors 1 and 2 from DCA ordination
of 126 transects 94 common tree species
Variable Vector 1 Vector 2
Altitude ÿ0.91 <0.0001 0.02 NS
No tree species ÿ0.85 <0.0001 ÿ0.05 NS
Grass cover 0.81 <0.0001 ÿ0.06 NS
Canopy height ÿ0.80 <0.0001 ÿ0.09 NS
Disturbance 0.74 <0.0001 ÿ0.16 NS
Canopy cover 0.64 <0.0001 ÿ0.12 NS
Slope ÿ0.56 <0.0001 0.12 NS
No important medicinal species ÿ0.51 <0.0001 0.09 NS
No other medicinal species 0.58 <0.0001 ÿ0.19 NS
Abundance of medicinal plants
(all species) 0.54 <0.0001 ÿ0.01 NS
Stem density ÿ0.56 <0.0001 ÿ0.18 0.04
Slope position ÿ0.33 <0.0001 ÿ0.26 0.003
Water availability ÿ0.10 NS 0.46 <0.0001
Table 2
Mean ( S.E.M.) and modal values of environmental, vegetation structure, and medicinal species variables, for six ¯oristic groups de®ned by classi®cation of 126 transects 94 tree species occurring at ®ve or more transects a
Variable Group 1 Group 2 Group 3 Group 4 Group 5 Group 6
(n=9) (n=24) (n=43) (n=12) (n=9) (n=29) Environmental
Altitude (m) 120325 99832 65430 44331 29326 21415 Slope ( ) 36.44.7 383.3 32.52.3 21.63.5 18.54.6 181.6 Modal water availability Absent Absent Absent Present Absent Absent
Modal disturbance class Primary Secondary Secondary Secondary Secondary Plantation Modal canopy cover Closed Closed Half Closed Open Open Modal slope position Topslope Midslope Midslope Creekline Lowerslope Lowerslope Vegetation structure
No tree species 20.61.8 20.71.2 13.90.8 6.51 40.5 1.70.4 Stem density (no./ha) 82856 62845 54338 26148 14420 32592 Canopy height (m) 27.82.7 23.10.7 18.91 11.61.2 8.31.4 6.10.7 Bamboo cover (%) 8.32.3 10.84.4 13.73 16.68.3 17.89.7 3.11.8
Medicinal species
No important medicinal species 3.40.6 5.60.9 5.40.4 3.60.8 0.80.3 0.40.1 Total no medicinal species 8.11.0 11.31.3 14.90.9 9.31.1 13.92.6 13.3 1.0 Modal medicinal species abundance per transect 26±50 51±100 201±500 >500 101±200 201±500
a n, No transects per group.
Trang 8MPs for domestic purposes However, despite the
undertaking of qualitative inventories of MPs in various
parts of Vietnam over the past few decades (Le, 1997),
the development of quantitative, systematic approaches
remains, as elsewhere, elusive
An objective of the present study has been the
regio-nal application of a standard numerical methodology
for assessing the distribution, abundance and status of
MPs Such assessment is an essential ®rst step for
addressing the ecological sustainability of harvesting
Non-timber Tropical Forest Products (NTFPs),
includ-ing MPs (Hall and Bawa, 1993) For example, data
assembled here may be used in spatial analyses [e.g
using Geographic Information Systems (GIS)] to
pre-dict, hence map the probable distributions of MP taxa,
and ultimately derive baseline population estimates of
target species The statistical con®dence with which
spatial analyses are undertaken, however, obviously
depends especially on sampling intensity, and
repre-sentativeness/strati®cation of plot locations
Further, being digital, the database assembled for
BaVi National Park may be readily extended with
inventory data from other sampled locations (e.g
within the Park itself, other reserves, regions), including
surveys undertaken at dierent sampling times for
ongoing monitoring and sustainability assessment
pur-poses Additionally, such digital data may be
incorpo-rated into other databases, thereby informing local
through to broader regional contexts Once assembled,
such data sets are amenable for quantitative analyses
using a broad range of numerical tools and approaches (e.g Margules and Austin, 1991; Legendre and Legendre, 1998)
While the compilation of numerical NTFP and MP databases is evidently still in its infancy in south-east and east Asian contexts (Schippmann, 1997), quantita-tive MP sampling approaches are evident, for example,
in the work of Toledo et al (1992) for Mexico, Voeks (1996) for disturbed Brazilian Atlantic forests, and Caniago and Siebert (1998) for a localised study in rapidly deforesting Kalimantan, Indonesia A useful regional model is provided also by a current, major integrated MP conservation and resource development project in Sri Lanka, which includes quantitative assessment of the in situ conservation status and har-vesting sustainability of MPs in four key national loca-tions (World Bank, 1997) Such approaches have broader regional potential
Acknowledgements
We are extremely grateful to Professor Vo Qui and
Dr Peter Bridgewater, and contributing organisations, for the support and foresight to undertake this project
Mr Le Van Lanh and Mr Phung Tien Huy assisted with organising the initial ®eld program Tracey May produced Fig 1 William Milliken and two anonymous referees are thanked for their constructive comments on the manuscript
Table 4
Correlations between medicinal plant variables and other independent environmental and vegetation structure variables from 126 transects a
Variable No important medicinal species No other medicinal species Abundance of medicinal species
Grass cover ÿ0.54 <0.0001 0.23 0.01 0.36 <0.0001
No tree species 0.52 <0.0001 ÿ0.32 0.0003 ÿ0.39 <0.0001 Canopy height 0.49 <0.0001 ÿ0.32 0.0002 ÿ0.38 <0.0001 Disturbance ÿ0.48 <0.0001 0.48 <0.0001 0.34 <0.0001 Altitude 0.37 <0.0001 ÿ0.52 <0.0001 ÿ0.55 <0.0001
Canopy cover ÿ0.33 <0.0001 0.34 <0.0001 0.36 <0.0001
a NS, not signi®cant, where =0.05.
302 T Van On et al / Biological Conservation 97 (2001) 295±304
Trang 9References
Akerele, O., Heywood, V., Synge, H (Eds.), 1991 The Conservation
of Medicinal Plants Cambridge University Press, Cambridge.
Medicinal Plant Conservation, 1995-1997, Vols 1±4 Bundesamt fur
Naturschutz, Konstantinstrasse 110, D-53179 Bonn, Germany.
AREA (1993) BaVi National Park Management Plan Association for
Research & Environmental Aid (AREA), Sydney; Centre for
Nat-ural Resource Management & Environmental Studies, Vietnam
National University, Hanoi/Australian National Parks & Wildlife
Service, Canberra.
Balick, M.J., Elisabetsky, E., Laird, S.A (Eds.), 1996 Medicinal Resources of the Tropical Forest Columbia University Press, N.Y Blasco, F., Bellan, M.F., Aizpuru, M.A., 1996 Vegetation map of tropical continental Asia at scale 1:5 million Journal Vegetation Science 7, 623±634.
Caniago, I., Siebert, S.F., 1998 Medicinal plant ecology, knowledge and conservation in Kalimantan, Indonesia Economic Botany 52, 229±250.
Causton, D.R., 1988 An Introduction to Vegetation Analysis Unwin Hyman, London.
Farnsworth, N.R., Soejarto, D.D., 1991 Global importance of
Table 5
The frequency of occurrence of Important Medicinal Species in each of six classi®cation groups, and modal abundance of individuals per 0.05 ha transect is given below Three other Important Medicinal Species (all vine species) not recorded in the survey are not included n=no transects per Group Where given, voucher specimens as lodged at Hanoi College of Pharmacy (HNIP)
Species Lifeform Modal abundance Total frequency Group 1
(n=9) Group 2(n=24) Group 3(n=43) Group 4(n=12) Group 5(n=9) Group 6(n=29)
Trang 10medicinal plants In: Akerele, O., Heywood, V., Synge, H (Eds.),
Conservation of Medicinal Plants Cambridge University Press,
Cambridge, pp 25±51.
Gauch, H.G., 1982 Multivariate Analysis in Community Ecology.
Cambridge University Press, Cambridge.
Hall, P., Bawa, K., 1993 Methods to assess the impact of extraction of
non-timber tropical forest products on plant populations Economic
Botany 47, 234±247.
Hill, M.O., 1973 Reciprocal averaging: an eigenvector method of
ordination Journal of Ecology 61, 237±249.
Hill, M.O., 1979a TWINSPAN:A FORTRAN Program for
Arran-ging Multivariate Data in an Ordered Two-way Table by
Classi®-cation of the Individuals and Attributes Dept Ecology and
Systematics, Cornell University Ithaca, NY.
Hill, M.O., 1979b DECORANA Ð a FORTRAN Program for
Detrended Correspondence Analysis and Reciprocal Averaging.
Dept Ecology and Systematics, Cornell University Ithaca, NY.
Hill, M.O., Gauch, 1980 Detrended correspondence analysis: an
improved ordination technique Vegetatio 42, 47±58.
Iwu, M.W., 1996 Resource utilization and conservation of
biodi-versity in AfricaÐMedicinal Resources of the Tropical Forest In:
Balick, M.J., Elisabetsky, E., Laird, S.A Columbia University
Press, New York, pp 233±250.
Knox, R.G., Peet, R.K., 1989 Bootstrapped ordination: a method for
estimating sampling eects in indirect gradient analysis Vegetatio
80, 153±165.
Kohn, E.O., 1992 Some observations on the use of medicinal plants
from primary and secondary growth by the Runa of eastern lowland
Ecuador Journal of Ethnobiology 12, 141±152.
Le, T C (1997) Conservation of Medicinal Plants under the National
Biodiversity Conseravtion Action Plan Unpublished paper
pre-sented to the Conference on Conservation of Traditional Medicinal
Plants, 7 October 1997, Hanoi Vietnam Ministry of Health, Hanoi
(in Vietnamese).
Le, T.C and Tran, D.V (1993) An overview of the Red River Delta
Environment In: Too Many People, Too Little Land Le, T.C.,
Rambo, A.T Occasional paper No 15 pp 1±10 East±West Center
Program on Environment, Honolulu.
Legendre, P., Legendre, L., 1998 Numerical Ecology, 2nd Edition.
Elsevier, Amsterdam.
Margules, C.R., Austin, M.P (Eds.), 1991 Nature Conservation: Cost
Eective Biological Surveys and Data Analyses CSIRO,
Mel-bourne.
Minchin, P.R., 1990 DECODA User's Manual Research School of
Paci®c Studies, Australian National University, Canberra.
Mucina, L., van der Maarel, E., 1989 Twenty years of numerical
syntaxonomy Vegetation 81, 1±15.
Nguyen, D.K (1990) Evaluation of Materials in BaVi National Forest
Region and Plans for Protection, Exploitation and Development.
Unpublished paper presented to the General Association of Vietna-mese Biological Branches, the Agriculture and Forest Oce of Hanoi, and the Centre of Application of Biological Research to Medicine, Hanoi (in Vietnamese).
Nguyen, D.T (1996) Earning from the Biodiversity of Medicinal Plants Unpublished paper presented to the Conference on Exploi-tation of Biodiversity, Hanoi, hosted by DANIDA and the Vietnam Ministry of Science, Technology and Environment (in Vietnamese) Peet, R.K., Knox, R.G., Case, J.S., Allen, R.B., 1988 Putting things
in order: the advantages of detrended correspondence analysis American Naturalist 131, 924±934.
Pham, H.H., 1999 Illustrated Flora of Vietnam Youth Publishing House, Hanoi (in Vietnamese).
Plotkin, M., Famolare, L (Eds.), 1992 Sustainable Harvesting and Marketing of Rain Forest Products Island Press, Washington DC Schippmann, U (1997) Medicinal Plant Conservation Bibliography, Vol 1 IUCN Species Survival Commission, Medicinal Plant Spe-cialist Group, Bonn.
Synge, H., Heywood, V., 1991 Information systems and databases for the conservation of medicinal plants In: Akerele, O., Heywood, V., Synge, H (Eds.), Conservation of Medicinal Plants Cambridge University Press, Cambridge, pp 147±164.
Toledo, V.M., 1992 Batis, A, I., Becerra, R., Martinez, E and Ramos, C H Products from the tropical rain forests of Mexico:an ethnological approach In: Plotkin, M., Famolare, L (Eds.), Sus-tainable Harvesting Marketing of Rain Forest Products Island Press, Washington DC, pp 99±109.
Tran, C.K and Tran, V.O 1998 Investigations for Sustainable Use of Medicinal Plants in Vietnam Unpublished paper presented at the Conference of Pharmaceutical Science and Technology, Hanoi Col-lege of Pharmacy, Hanoi (in Vietnamese).
Van Groenewoud, H., 1992 The robustness of correspondence, detrended correspondence, and TWINSPAN analysis Journal of Vegetation Science 3, 239±246.
Vietnam Ministry of Forestry, 1989 Economic and Technical Feasi-bility of BaVi National Park, Hanoi Unpublished report, Vietnam Government, Hanoi (in Vietnamese)
Vietnam Ministry of Science Technology Development, 1995 The National Action Plan for Biodiversity Vietnam Government, Hanoi (in Vietnamese).
Vo, V.C., 1997 The Dictionary of Medicinal Plants of Vietnam Medical Publishing House, Hanoi (in Vietnamese).
Voeks, R.A., 1996 Tropical forest healers and habitat preference Economic Botany 50, 381±400.
Whitmore, T.C., 1984 Tropical Rainforests of the Far East, 2nd edi-tion Clarendon Press, Oxford.
World Bank (1997) Sri Lanka Conservation and Sustainable Use of Medicinal Plants Project: Detailed Project Description Unpub-lished Sta Appraisal Report of the World Bank, Colombo.
304 T Van On et al / Biological Conservation 97 (2001) 295±304