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Copyright © CES 1995, Last update : 10th November 1995 by avn
Wild relatives of cultivated plants (WRCP) range over an
entire spectrum of ecological habitats, natural, semi-natural, as
well as highly human-impacted. Conserving multiple populations of
a multitude of such species calls for ecologically wise
management of the entire landscape; going beyond the traditional
approach of conservation of a few pockets of natural habitats
through a system of protected areas.
Such an approach calls for establishment of conservation priorities at the habitat level. For any region, these may be arrived at through a series of steps :
(i) Inventory of WRCPs as congenerics of cultivated plant species on the basis of published literature and herbarium collections.
(ii) Mapping the distribution of habitat types in the region as types of landscape elements (LSE) with the help of satellite imagery along with field surveys.
(iii) Association of groups of WRCPs with different types of LSEs on the basis of field surveys.
(iv) Assessment of rates of transformations of LSE types with the help of satellite imagery of earlier years, official records and oral histories.
(v) Assessment of threats to different WRCPs as a result of ongoing landscape changes, and other causes such as commercial harvests.
(vi) Assignment of conservation priorities to WRCPs on the basis of threats to their populations, rarity, endemicity and taxonomic distinctiveness.
(vii) Assignment of conservation priorities to different
types of habitats or landscape elements on the basis of richness
and conservation significance of the WRCP species they harbour.
The protected area systems of the region should then be assessed in terms of their coverage of habitats significant for conservation of WRCPs, and appropriately strengthened.
It is equally important to wisely manage habitats valuable from the perspective of WRCP conservation outside the protected areas systems by providing appropriate inputs to the process of development planning.
It is essential to create institutions and systems of
positive incentives to involve local communities as active
partners in the efforts to conserve WRCPs both within and outside
the protected areas.
The hill chain of Western Ghats in South India has been
recognized as one of the world's 18 biodiversity hot spots. At
the centre of this hill chain lies the district of Uttara Kannada
(13°55'-15°32'N lat 74°05'-75°05'E long) with over 60% of its
area under a forest cover. The district harbours 177 species in
53 genera with at least one cultivated species. These WRCPs are
distributed across the whole diversity of 54 types of elements of
landscape and waterscape present in the district. The
distribution of the LSE types over the districts has been mapped
with the use of satellite imagery coupled to field studies.
Sampling representative examples of various LSE types permits
association of WRCP species with specific types of habitats, as
well as identification of sets of WRCP species that tend to occur
together. For instance, an evergreen tree species related to
nutmeg, Myristica fatua and wild pepper Piper hookeri occur
together in a special habitat known as Myristica swamps in wet
valleys in evergreen forests. A species of wild yam,
Amorphophallus paeoniifolius and a berry Carissa congesta occur
in humid secondary scrub formations. An examination of successive
satellite images, official records and oral history suggests that
Myristica swamps are amongst the most rapidly disappearing
habitat types of the district, while the area under secondary
scrub is being reduced more slowly with the development of
plantations of exotic species such as Acacia auriculiformis. WRCP
species occurring in Myristica swamps also merit high levels of
conservation priority on grounds of limited geographical ranges,
narrow habitat preference and as belonging to families with
relatively small numbers of species. Myristica swamps thus stand
out as the habitat type which deserves the highest priority from
the perspective of conservation of wild relatives of cultivated
plants. Scrub habitats harbour a much larger number of WRCP
species; however, these species individually tend to rank much
lower on conservation priority, having, for instance, much wider
geographical ranges and habitat preferences. These and other WRCP
habitats of the district are currently protected in several
different ways. For instance, considerable areas of scrub are
included in the Dandeli Wild Life Sanctuary, and the best
surviving patch of a Myristica swamp is protected as a research
plot within a reserved forest area. Earlier this Myristica swamp
was being protected as a sacred grove. Myristica swamps clearly
require special protection through appropriate extension of
protected areas system. While areas of scrub within the Dandeli
Wild Life Sanctuary are well protected, extensive tracts outside
the sanctuary are being managed as open access common property
resources and are subject to degradation. These scrub habitats
would best be managed as repositories of WRCPs through the
important new initiative of Joint Forest Planning and Management,
involving local communities. It would be worthwhile including
special incentives for the conservation of WRCPs as a part of
this system. Special incentives may also be created to promote
conservation of WRCPs on private lands.
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1. People depend on plants in many, many different ways; as sources of food for themselves or their livestock, of fibre for weaving clothes, mats or baskets or for fabricating shelters, of organic manure for replenishing the fertility of cultivated lands, or medicinals for maintaining bodily health, of flowers for decorating their bodies and of pigments for dyeing their clothes or painting their dwellings. So people have been gathering material from an incredible variety of plants; herbs, shrubs, climbers, trees, epiphytes; growing in water, salt and fresh, stagnant or flowing; and on land, from rain forests to deserts, from lowlands to mountain tops, from tropics to boreal regions. A fraction of these have been husbanded, with people deliberately encouraging their survival, growth and propagation. These cultivated species belong to a whole range of growth forms, and the entire spectrum of terrestrial and aquatic habitats. Cultivated plants by no means come only from the more natural, primeval habitats. Rather, people have been apt to select for husbanding plants that occur in their proximity, in relatively more human impacted habitats. Plants preferring such successional habitats tend to allocate a larger proportion of their biomass to nutrient rich reproductive parts. Since such plant organs are of particular value as food, it renders these plants all the more attractive for domestication. Cultivated plants therefore often come from habitats such as scrub and grasslands, many of which owe their existence to repeated fires set by people.
2. Wild relatives and related taxa of cultivated plants (WRCP)
therefore naturally encompass the full spectrum of plant growth
habits and come from the entire range of plant habitats. In
particular, a significant proportion prefer human impacted
habitats (Pimentel et al. 1992). The primary motivation for the
conservation of WRCPs is the potential application of their
genetic material in the enhancement of the performance of the
cultivated plants. Such genes may pertain to a variety of
characters ranging from size and density of root hair or stomata
to seasonality in leaf shedding or fruiting, from amino acid
composition of the endosperm proteins to the nature of
allelopathic substances released from roots into the soil. There
is therefore a strong interest in maintaining the total range of
genetic diversity of WRCPs; an objective that calls for the
preservation of multiple populations in the wild over the whole
geographical range of the concerned species Food and Agriculture
Organization, 1989; 1993, Swaminathan and Jana, 1992).
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3. These requirements, the need to conserve multiple
populations of plant species preferring a wide range of natural
and human impacted habitats imply that the traditional approach
of conserving biological diversity in a few protected islands of
natural habitats needs to be considerably modified to effectively
address conservation of WRCPs. Multiple populations of a number
of species preferring a whole spectrum of habitat types can be
effectively conserved only through prudent management of the
entire landscape (and waterscape) of a whole region. Such
extensive tracts cannot be set aside exclusively for conservation
purposes, so the conservation oriented management will have to be
pursued in conjunction with use and development of the natural
resources of the region to fulfill human aspirations (Ingram
1990). Of course, a proportion of the landscape, either as a
single unit, or as a series of dispersed sites, may be set aside
explicitly for conservation purposes. A significant challenge in
this context is to motivate local human communities to positively
participate in the conservation effort. An even greater challenge
is to inject conservation considerations in the process of
development planning. These challenges will often have to be
addressed in the context of high levels of multifarious demands
of rural people on land for cultivation, for grazing and for
supply of fuelwood and small timber; as well as growing pressures
of agricultural and industrial development. These guidelines are
an attempt to address these broad issues in the context of
conservation of wild relatives and related taxa of cultivated
plants. The text of these guidelines is divided into two parts; a
general discussion and an illustrative case study. These are set
in different fonts, and may be read independently.
Our case study pertains to the district of Uttara Kannada
(UK) (13°52' to 15°30' N lat and 74°05' to 75°05' E long) in
the south Indian state of Karnataka. This is a part of the hill
tract of the Western Ghats, recognized as one of the world's 18
biodiversity hot spots (Myers 1990). It is a region of low
undulating hills, around 600 m in altitude, merging to the east
with the Deccan plateau, and abruptly dropping on the west to the
Arabian Sea. The rainfall ranges over 3000 mm on the coast, upto
5000 mm at the crestline and 800-1000 mm on the eastern edge. The
district is drained by several short, rapidly flowing rivers
joining the Arabian sea to the west, as well as eastward flowing
tributaries of the Krishna river. Over 60% of the 10200 sq km
area of the district is covered by forest vegetation with varying
degrees of human impacts. Around 12% of the area is under
cultivation, aided by a series of small scale irrigation tanks on
the plateau. The main crops include brackish water paddy in the
estuarine tract, wet paddies, coconut orchards, multistoreyed
spice gardens of cardamom, pepper, banana, cocoa and arecanut and
on the eastern edge, cotton (figure 1).
4. The first step in an endeavour to work out a strategy for the
conservation of WRCPs will be to establish priorities in terms of
(i) species of WRCPs, (ii) habitats of these species, (iii)
specific localities, and (iv) processes of environmental change
impinging on the localities, habitats and populations of WRCPs
(Daniels et.al. 1993). To do this, one should select the region
on which the conservation effort is to be focussed, and then
prepare an inventory of the WRCPs occurring in that region. Such
an inventory could include as WRCPs all species of genera in
which at least one species is under cultivation. Floras and
checklists of plants as well as publications in systematic and
ecological journals pertaining to part or all of the region under
consideration could provide a basis for the preparation of such
an inventory. Other sources of information could be herbarium
collections maintained by surveys or museums or research
institutions. These sources - literature, as well as collections,
would also contain information on the growth habits, preferred
habitats and occasionally levels of abundance of these species. A
list of the WRCPs of the region, and their preferred habitats
compiled from literature and plant collections would form the
basis of the conservation effort.
C.J. Saldanha, author of the Flora of Karnataka (1984)
prepared a checklist of flowering plants of UK on the basis of
Cooke (1901-08), Talbot (1909) and various publications of the
Botanical Survey of India. His checklist includes 1741 species
belonging to 826 genera in 139 families. Additional field work
and review of the collections at the herbarium of the Botanical
Survey of India, Southern Circle, Coimbatore augmented the list
to 1761 species of 833 genera in 141 families. Of these 53 genera
have at least one species under cultivation, leaving aside
forestry plantations and gardens of medicinal herbs (Arora and
Nayar 1984). The 177 species of UK belonging to these 53 genera
may be considered as WRCPs of the region. Table 1 lists 32 of
these species that will be discussed further to illustrate these
guidelines.
Table 1
-------------------------------------------------------------- Cultivated species WRCP from U.K. -------------------------------------------------------------- Abelomoschus esculentus Abelomoschus angulosus Acacia sinuata Acacia sinuata Amorphophallus campanulatus Amorphophallus paeoniifolius Artocarpus heterophyllus Artocarpus heterophyllus Artocarpus heterophyllus Artocarpus hirsutus Carissa congesta Carissa congesta Cinnamomum wightii Cinnamomum malabathrum Dioscorea alata Dioscorea oppositifolia Dioscorea alata Dioscorea pentaphylla Emblica officinalis Emblica officinalis Garcinia indica Garcinia acuminata Garcinia gummi-gutta Ipomoea batatas Ipomoea pes-caprae Mangifera indica Mangifera indica Murraya koenigii Murraya koenigii Murraya paniculata Myristica fragrans Myristica dactyloides Myristica malabarica Myristica fatua Oryza sativa Oryza nivara Oryza rufipogon Oryza coarctata Piper nigrum Piper nigrum Piper hookeri Sapindus laurifolius Sapindus laurifolius Sesamum orientale Sesamum orientale Solanum melongena Solanum anguivi Terminalia chebula Terminalia chebula Vigna mungo Vigna khandalensis Zingiber officinale Zingiber purpureum Zingiber montanum Ziziphus jujuba Ziziphus oenoplia
-------------------------------------------------------------- These WRCP species show a whole gradation from belonging to the same species, and diferring little from cultivated forms, to differing a great deal from a cultivated species in the same genus. They include a whole range of growth forms : herbs (Oryza species), creepers (Ipomoea pes-caprae), climbers (Dioscorea species), lianas (Acacia sinuata), shrubs (Carissa congesta), and trees (Artocarpus hirsutus). They come from a wide variety of habitats as well (see Figure 3).
Life on earth is based on trillions of
organisms belonging to millions of different
species of plants, animals and microbes.
Individual organisms belonging to the same
species resemble each other in their physical
requirements, as well as in their
relationships with other living beings. Thus
all individuals of the evergreen forest tree
Myristica fatua var. magnifica of the Western
Ghats of south India require highly moist soil
conditions for their growth, and can tolerate
waterlogged soils. Their fleshy seeds are
dispersed by fruit bats. The term HABITAT
refers to the kind of environment members of a
species occur in. This environment may be
described in physical and chemical terms and
often by elevation, topographic position and
so on. Thus the habitat of M. fatua is swampy
valleys and valley slopes at low elevations in
high rainfall tracts where the minimal
temperature in winter remains above 15°c.
Other plant species with similar habitat
requirements co-occur with M. fatua, as do
several species of microbes and animals.
Together they constitute a BIOLOGICAL
COMMUNITY - a system of organisms living
together and linked by their effects on one
another and the environment they share. All
biological communities have an intimate,
reciprocal relation to the environment, as
energy and matter are taken from the
environment, transferred amongst members of
the community and released back to the
environment. A community and its environment
treated together as a functional system is an
ECOSYSTEM. Thus M. fatua and its associated
organisms living together in a swampy habitat
constitute the Myristica swamp biological
community, and along with the environment the
Myristica swamp ecosystem (Whittaker, 1970).
Defining the boundaries of such
biological communities or ecosystems
necessarily involves subjective judgment and
depends on the organisms of primary interest.
Thus the boundaries would be perceived very
differently if, instead of trees like M. fatua
our focus was on leaf litter dwelling mites or
fruit bats. One way of arriving at a more
standardized system of classification would be
to focus on the dominant plant forms in a
community; trees in forest biomes, shrubs in
scrubland, grasses in grasslands. Variations
in topography, moisture regime and human
interventions create a mosaic of communities
of dominant plant forms that are readily
apparent to the human eye, as also to our eye
in the sky, the satellite. Viewed from a
vantage point, or with the aid of satellite
imagery landscapes appear as mosaics dominated
by associations of different plant species or
of aquatic habitats. Each distinctive
association thus seen has a scale of around a
hectare and constitutes a landscape element
(Forman and Godron 1987). The total
landscape includes several repetitions of a
few different types of elements. Thus on the
southern Western Ghats a Myristica swamp will
appear as a distinct type of landscape element
in the valleys. Closed canopy evergreen forest
dominated by Diospyros and Persea species
could be another type of element in the same
landscape. The landscape could also include
more human impacted elements such as
grasslands and arecanut orchards. Since
satellite imagery is now readily available for
the entire surface of the earth, use of
landscape elements identified from the
satellite imagery is the most effective way of
looking at the biological communities of the
world (Jensen 1986, Roy et al. 1990; 1992).
5. Along with a checklist of WRCPs, one should also
simultaneously undertake an exercise to compile an inventory of
the elements of landscape and waterscape making up the region.
The landscape, of course, varies on many different scales.
Variation over the scale of a few meters of a rotting log
governs the life of a wood boring beetle, that over several
hundred square kilometers of forest governs the life of an
elephant. For our purpose, the spatial scale of a hectare may be
considered most appropriate. This is because most maps in use are
on scales such that areas smaller than a hectare cannot be dealt
with. Furthermore, satellite imagery, which is now a very
significant source of information on the landscape of any region
on earth has quite adequate resolution on the scale of a hectare.
So we may view our region as a mosaic of different types of
landscape elements of a hectare or more in size. It would then be
appropriate to begin by determining how many different types of
landscape elements occur in the region of interest. For practical
reasons, a distinct type may be considered as a type that
generates a sufficiently distinct signal in the wavelength bands
employed by remote sensing satellites. This would enable the use
of satellite information in mapping the entire region; the most
effective way of setting about such a task.
6. The exercise of setting conservation priorities could begin by
a reconnaissance field survey of the region equipped with a
topographic map on a scale of 1:50,000 or better, as well as a
false colour composite satellite imagery, preferably printed on
the same scale as the map. Armed with these one may identify the
main landscape element types, of a hectare or more in size, that
can be discerned in the field and with the false colour
composite. One may then select a few sample areas representative
of the main types of landscapes of the region for more detailed
field work. In the selected study sites the positions of a few
examples of each type of landscape element may be marked
carefully on the topographic maps taking advantage of locations
where two or more linear elements, such as streams, rivers,
roads, electricity lines join or cross. This would enable the
location of these elements to be ascertained with accuracy in the
satellite imagery as well, since the topographic maps and
satellite imagery would not match perfectly. These ground control
points whose positions can be properly matched on the satellite
imagery and topographic maps could then be used to correct the
distortions in the satellite imagery and to ensure proper
matching of the entire image. Information on the landscape
elements adjacent to the control points can be used to create
training sets, i.e. sets of information on ground truth and
nature of the signal received by the satellite. Using these
training sets, it is possible to determine the identity of other
elements of landscape where no ground truth has been ascertained.
Such a process is known as supervised classification; i.e.
classification carried out automatically by computers using
information on known ground truth in a few localities with
accurately determined positions. The entire region could thus be
mapped as a mosaic of landscape elements of a hectare or greater
in size. Such a map could be generated as a visual image printed
on photographic paper, on a computer monitor, or as digitized
information handled by the computer.
1 Aquatic - freshwater LSE types
1.1 Flowing
1.1.1 Perennial
1.1.1.1 Stream/ river along steep slope (>30°)
1.1.1.2 Stream / river along medium slope (15°-30°)
1.1.1.3 Stream/ river on low slope to plain (<15°)
1.1.1.4 Sewage water canal
1.1.2 Seasonal
1.1.2.1 Stream/ river along steep slope (>30°)
1.1.2.2 Stream/ river along medium slope (15°-30°)
1.1.2.3 Stream/ river on low slopes (<15°)
1.1.2.4 Irrigation canals
1.1.3 Waterfall
1.1.3.1 Perennial
1.1.3.2 Seasonal
1.1.4 Riparian
1.1.4.1 River/stream bank
1.1.4.2 River/stream bed (including exposed rocks)
1.2 Stagnant
1.2.1 Seasonal, clear
1.2.2 Seasonal, almost covered with floating / emergent natural vegetation
1.2.3 Perennial clear
1.2.4 Perennial, almost covered with floating / emergent natural vegetation
1.2.5 Perennial, almost covered with exotic water weeds like Pistia, Eichhornia, Salvinia etc.
1.2.6 Dams and reservoirs
1.2.7 Sewage pond
2. Terrestrial natural LSE types
2.1. Forest
2.1.1 Evergreen
2.1.2 Disturbed evergreen
2.1.3 Semi-evergreen
2.1.4 Disturbed semi-evergreen
2.1.5 Moist deciduous
2.1.6 Disturbed moist deciduous
2.1.7 Dry deciduous
2.1.8 Disturbed dry deciduous
2.2. Non-forest
2.2.1 Scrub
2.2.2 Savanna
2.2.3 Grassland
2.2.4 Landslides
3. Terrestrial man-made LSE types
3.1 Human habitation
(To include homestead gardens, hedges, wall, compost pits etc.)
3.2 Quarries, mines, mine dumps
3.3 Roads, cart tracks, foot paths
3.4 Cultivation- annual/ biennial/ seasonal crops
3.4.1 Banana
3.4.2 Ginger
3.4.3 Groundnut
3.4.4 Jowar
3.4.5 Pine apple
3.4.6 Potato
3.4.7 Ragi
3.4.8 Paddy
3.4.9 Sugarcane
3.5 Perennial plantation/ orchard crops (LSE to be named after dominant spp.)
3.5.1 Arecanut
3.5.2 Cardamom
3.5.3 Cashew
3.5.4 Cinchona
3.5.5 Clove
3.5.6 Coconut
3.5.7 Coffee
3.5.8 Mango
3.6 Forest tree/ other timber plantations
3.6.1 Acacia auriculiformis
3.6.2 Albizzia
3.6.3 Casuarina
3.6.4 Eucalyptus
3.6.5 Silk cotton
3.6.6 Tectona grandis
A 5 Km x 5.5 Km area in Siddapur taluk of Uttara Kannada
(lat. 14°16' to 14°18' N; long. 74°51'to 74°54'E) was classified
using an IRS 1B satellite image of March 1994. Based on a field
survey, 7 major types of landscape elements were distinguished :
Acacia plantations, Casuarina plantations, paddy fields,
grasslands, savanna, scrub and disturbed evergreen forest. The
satellite image was rendered distortion free by standard
transformation techniques involving the comparison of coordinates
of points identified on the image as well as on a standard survey
of India 1 : 50,000 scale toposheet. Roads and rivers were
digitized from the toposheet and overlaid onto the image.
Representative "training sets" of each of the 7 LSE type
identified were located accurately on the image and used as
inputs to classify the image (Figure 2). The accuracy of the
classified image was estimated after a field crosschecking at
88.24%. It is reasonable to extend the same system of supervised
classification to a larger tract of about 2500 sq.km. in the
eastern part of the Uttara Kannada district with a very similar
landscape.
7. One thus has two basic elements of information needed to
develop a conservation strategy; the identity of biological
elements of interest, the WRCPs and the identity and spatial
distribution of various types of landscape elements. The next
step is to determine the distribution of the plant species of
interest with respect to the distribution of the landscape
elements over the region as a whole. For this a representative
sample of the different types of landscape elements must be
investigated in the field. Two kinds of considerations will go
into designing this programme of field investigation :
statistical and logistic. Ideally, the different types of
landscape elements should be selected for investigation on the
basis of stratified random sampling. However considerations of
ease of accessibility and of field work may influence the choice
so that effort is not unduly wasted in working under difficult
circumstances. Having finalized the selection of individual
examples of different types of landscape element for
investigation, the next step is to decide on a plan for plant
sampling.
8. There are two possible approaches to such plant sampling,
corresponding to the taxonomic and ecological approaches. The
taxonomic approach involves an all-out-search for different
species from any given locality; the ecological approach a
quantitative assessment of populations of different species on
the basis of some plan of sampling within that locality. Either
of these could be combined with the landscape approach. Thus one
may undertake an all-out-search for the different species of
interest (such as WRCPs) in each individual landscape element
selected for sampling. Alternatively one may undertake
quantitative ecological sampling employing either a plotless
technique such as point-centred-quarter method, or transects or
quadrats. Since the habitat within a given type of element would
be relatively homogeneous, quadrats of dimensions of 10m x 10 m
every 50 m along a transect of a few hundred meters in length
might be an appropriate choice. Subquadrats of 1m x 1m could be
used for sampling herbaceous plants within the quadrat. Of
course, some other sampling plan may be more appropriate for a
particular locality and could be selected in consultation with a
statistician.
Plant communities were investigated at the Siddapur 5 km X
5.5 km study site by selecting 27 individual landscape elements
representing all major patches of each of the 7 LSE types for
quantitative sampling. A transect, ranging in length from 200 m
to 1350 m depending on the dimensions of the particular patch,
was laid along the longer axis of each element (Figure 2).
Quadrats of 10 m X 10 m for sampling trees, with nested
subquadrats of 5 m X 5 m for sampling shrubs and 1 m X 1 m for
sampling herbs were laid at intervals of 50 m along these
transects. These 282 sets of nested quadrats corresponding to a
little over 0.1% of the total area were considered reasonably
adequate for our purpose.
9. It would be desirable to record the occurrence or the
abundance of all WRCPs of interest in the landscape elements
sampled along with information on the composition of the
structurally dominant components of the vegetation such as trees.
It would also be appropriate to record information on
environmental parameters pertaining to topography, soils,
climate, and levels of human impacts such as fire, grazing,
harvest of fuelwood or timber, air and water pollution. One
should mark on a topographic map, and if possible also on a false
colour composite print of satellite imagery the location of the
sampling site, the type of landscape element it represents, the
size of the particular element being sampled and how it is
situated with respect to elements of other types and other
elements of the same type.
10. The information so generated should be computerized using an
appropriate software such as DBASE or FOXPRO. The major objective
of analyzing this data would be to delineate the patterns of
distribution of the WRCPs over the entire landscape. This may be
approached by identifying groups of species of WRCPs that occur
together. An appropriate clustering method, for instance, average
linkage dendrograms based on a measure of pairwise association
such as the Jaccard coefficient would permit the identification
of such groups of co-occurring WRCP species (Gauch 1982). Each of
these groups may be expected to be favoured by certain
environmental parameters and characteristically occur in certain
types of landscape elements. Again appropriate methods of
statistical analysis such as ordination might be employed to
ascertain the association of particular sets of WRCP species with
specific environmental parameters or specific types of landscape
elements. In conjunction with a suitable Geographical Information
System such as IDRISI or ARCINFO, this information could be used
to visualize the distribution of particular environmental
regimes, or sets of landscape elements that tend to favour
particular groups of WRCP species (Jensen, 1986).
Field surveys on the distribution of different WRCP species
provide data on the extent to which different species may occur
together. Such information may be displayed in the form of a
'tree' diagram, technically known as a dendrogram. Here the
length of branches joining any two species reflects differences
in their habitat use. Thus the wild rice Oryza nivara and soapnut
Acacia sinuata prefer entirely different types of landscape
elements; hence the branches joining them extend all the way to
the origin. On the other hand Acacia sinuata and Murraya koenigii
often co-occur in similar LSE types, hence they are connected by
a very short branches. Figure 3) is a schematic dendrogram of 32
WRCPs of Uttara Kannada indicating the extent of association of
various species, and their LSE type preferences.
Figure 3 : A schematic dendrogram for 32 species of wild relatives of cultivated plants of Uttara Kannada district. The shorter the length of branches connecting any group of species, the greater the similarity in the types of habitats they occur in. The broad habitat types of the major species groups are indicated to the right of dendrogram.
11. This exercise of mapping the landscape and sampling
biological communities would give a picture of the current
distribution of WRCPs and their potential habitat over the
region. The multispecies, multipopulation conservation strategy
may be visualized as striving to appropriately manage the
landscape of the entire region so as to conserve and hopefully
augment the populations of the more valuable and more threatened
species of WRCPs. The next significant piece of information
required to formulate such a strategy is an understanding of the
on-going changes in the landscape, and the processes underlying
these changes. One may tap four major sources of information to
generate an understanding of this dynamic. These include maps,
satellite imagery, official documents and oral history. Quite
accurate maps dating to early 20th century are available for many
parts of the world. Satellite imagery is available since 1972.
Additionally aerial photographs may be available for the past
several decades. One may visually compare this material to deduce
changes taking place in the landscape. Maps or photographs may be
scanned to convert the information into a computer usable format.
The satellite information is also readily available in such
digital format. It is then possible to compare features of the
landscape some five, ten, fifty years ago with the present day
landscape to assess the ongoing changes. A variety of official
documents such as town plans, forest working plans, or plans of
land development in the command area of an irrigation project
also provide an idea of changes taking place in specific
localities. People living in a particular locality for a length
of time, especially those relating intimately to the natural
resources such as farmers or graziers would further provide
useful accounts of landscape changes. Such oral histories are
likely to be quite accurate for the past 20 to 30 years at least.
The official documents and oral histories would give insights
into the processes involved in transforming the landscape as
well. Putting all this information together would provide a broad
picture of the major forms of the ongoing landscape and
waterspace transformations, and the socio-economic processes
underlying these transformations.
Satellite imagery is available for several earlier years for
the 5 Km x 5.5 Km area in Siddapur (Figure 2). Comparing the
identity of LSE types inferred from the earlier imagery with
those in the current imagery, and oral histories recounted by
local people have provided many insights into the way this
landscape is changing. Table 2 summarizes this information.
Columns refer to the LSE type which are changed into others
indicated in the rows. Thus grasslands and savannas are commonly
converted to paddy fields, but all land under paddy fields
continues to remain under that land use.
Extent of changes in the various LSE types of Siddapur
0 = No change, 1 = Occasional, 2 = Common, 3 = Frequent
----------------------------------------------------------------------------------
From Paddy Grassland Acacia Casuarina Savannas Scrub Disturbed
Plantation Plantation Evergreen
To Forest
----------------------------------------------------------------------------------
Paddy - 2 0 0 2 0 0
Grassland 0 - 0 0 3 1 0
Acacia 0 1 - 0 2 2 2
Plantation
Casuarina 0 1 1 - 2 2 2
Plantation
Savanna 0 0 0 0 - 2 1
Scrub 0 0 0 0 1 - 2
Disturbed 0 0 0 - 0 1 -
Evergreen
Forest
----------------------------------------------------------------------------------
Myristica swamps, as figure 3 indicates is a unique plant
community of the Uttara Kannada district characterized by tree
species such as Myristica fatua var. magnifica, M. malabarica,
Gymnacranthera farquhariana, the palm Pinnanga dicksoni and the
climber Piper hookeri (Krishna Moorthy, 1960, Pascal, 1988).
Several tree species of the swamp possess stilt roots and
pneumatophores. But the Myristica swamps are also ideal sites for
cultivation of paddy and arecanut, and have therefore been
steadily encroached on in spite of many of them being legally
protected as Reserve Forests. Indeed there is now only one
relatively extensive Myristica swamp persisting in the district;
that at Katlekan, an erstwhile sacred grove subsequently
designated as a Linear Tree Increment Research Plot by the Forest
Department. Myristica swamps today constitute the most threatened
type of landscape element of Uttara Kannada.
12. These exercises of mapping the landscape, sampling plant communities and assessing landscape changes would yield two major pieces of information pertinent to the design of a conservation strategy :
(i) Environmental regimes and landscape elements preferred by different groups of WRCP species.
(ii) Ongoing changes in the landscape, and consequently in the
environmental regimes of the region.
13. One may expect these ongoing environmental changes to favour
certain species, be neutral with respect to some, and be
detrimental to yet other groups of WRCP species. This would
permit ranking of the WRCP species of the region in terms of the
extent to which they are susceptible to adverse impacts of
ongoing developments. Clearly, the species most threatened by
such changes should be accorded higher levels of conservation
priorities. On the other hand, no special conservation efforts
would be required in case of WRCP species whose populations are
being favoured by the ongoing landscape changes.
Populations of some WRCPs of Uttara Kannada are at low
levels and dwindling rapidly; these are clearly in danger. They
are threatened either because their habitats - the LSE types they
prefer are being transformed into other LSE types unfavourable to
them, or because their populations are subject to excessive
levels of harvest. Some species may be affected in other ways as
well, for instance, by the loss of pollinators due to extensive
use of insecticides, but little information is available on such
threats. In decreasing order of severity of threats from loss of
habitat, stand species of Myristica swamps (Myristica fatua and
Piper hookeri) that are brought under cultivation, of estuaries
(Oryza coarctata) converted to aquaculture, margins of freshwater
ponds (Oryza nivara and O. rufipogon) encroached for paddy
cultivation, and scrub and savanna (Ziziphus oenoplia, Carissa
congesta, Amorphophallus paeoniifolius) felled to raise Acacia
auriculiformis plantations. Interior species of natural evergreen
forests (e.g. Garcinia gummi-gutta and Piper nigrum) are also
affected by fragmentation of such forest patches. Other WRCP
species may on the contrary be favoured by ongoing habitat
changes. These include species occurring along road verges and in
highly disturbed soils around habitation, e.g. Abelomoschus
angulosus and Sesamum orientale.
14. While assessment of threats would be a key element, other
factors as well need to be taken account of in the assignment of
conservation priorities. Important amongst these are pressures of
commercial exploitation, rarity, endemicity and taxonomic
distinctiveness (Usher, 1986; Daniels et al. 1991). Certain WRCP
species may be valued commercially, for instance, as medicinal
plants and may therefore be threatened even though their
preferred habitats may not be being transformed at a high rate.
Other species may be present in their preferred habitats at very
low densities everywhere and may therefore need special
consideration. Yet others may be very restricted in their
geographical range, endemic to a small region or a country.
Finally, certain WRCP species may have very few other
taxonomically closely related species and may therefore harbour a
larger complement of exclusive genes than others. Such WRCP
species subject to heavy levels of human exploitation, occurring
everywhere at low population densities, with restricted
geographical range and with few related species merit higher
conservation priority along with species whose habitats are being
lost at a rapid rate as a result of ongoing developmental
processes.
Assignment of conservation priorities should take into
account threats to WRCPs from direct harvests, even if their
habitats are not threatened. In Uttara Kannada the remaining
natural evergreen forest tracts, are by and large safe, apart
from special cases such as Myristica swamps. All cutting of live
trees in the evergreen forests has also been stopped since
1980's. In spite of this Myristica malabarica, a relative of
nutmeg, suffers extensive damage from unregulated lopping for its
fruit. Also threatened is mango, Mangifera indica much in demand
by the plywood industry, since a significant number of mango
trees occur on private lands.
High levels of conservation priorities would also be
attributed to species that are restricted to a narrow
geographical range. Thus many species characteristic of natural
evergreen forest habitat are restricted to the Western Ghats, or
to Western Ghats and Sri Lanka. Examples of such endemics include
Myristica fatua, Piper hookeri, Artocarpus hirsutus and Murraya
koenigii. WRCP species with much wider geographical distribution,
e.g. Ziziphus oenoplia that occurs pantropically would be ranked
lower on this criterion. Species with narrow habitat preference
such as Myristica fatua and Piper hookeri largely restricted to
Myristica swamps would be assigned higher conservation priorities
in comparison with species with broader habitat preference such
as Mangifera indica. Similarly, species which occur in very low
numbers everywhere, such as Oryza coarctata, a wild relative of
rice now very occasionally encountered in estuarine habitats
would be considered high on conservation priority. Lastly WRCP
species which belong to genera with few species, and families
with few genera would be ranked higher. Thus genus Murraya has
only 5 species. Solanum anguivi, on the other hand belongs to a
genus with over 700 other species and would be ranked lower on
grounds of taxonomic distinctiveness.
15. This exercise will generate conservation priorities in terms
of WRCP species, perhaps tens or hundreds in a region. Several of
these may be accorded high levels of conservation priority on
varied grounds. Furthermore, it would be desirable to attempt to
conserve multiple populations of each of these species. One of
the most effective ways of approaching such a problem would be to
focus on management of the habitats of these high priority
species, although some species by species action would also be
necessary. A habitat based conservation programme would require
translating the conservation priorities assigned to different
species into conservation priorities for different types of
landscape elements within the region. This could be accomplished
by assessing the occurrence of WRCP species of different levels
of conservation priorities in each type of element. Landscape
elements harbouring a rich diversity of WRCP species of high
conservation priority would then be accorded high conservation
value, compared to those harbouring very few such taxa or taxa of
low conservation priorities. This would automatically reflect the
level of threats of transformation to the types of landscape
elements as well. This is because WRCP species characteristic of
threatened habitats would tend to be assigned high conservation
priorities, and the environmental regimes they occur in would
therefore be seen to harbour species of high conservation
priorities. These habitat level conservation values would also
reflect the rarity or restricted range of geographical
distribution of the habitats under consideration, since WRCP
species characteristics of such habitats are likely to be
assigned high conservation values. It is then readily possible to
move from species level conservation priorities to habitat level
conservation priorities. Habitats may be most conveniently dealt
with as different types of landscapes elements discernible from
satellite imagery. Conservation priorities assigned to different
types of landscape elements would then provide an important basis
for chalking out a conservation strategy for WRCPs.
A series of Uttara Kannada habitats are identified in the Section 7c (Plants in Danger)
above as highly threatened. Of these scrub and savanna harbour a
large number of WRCP species, Myristica swamps a moderate number,
fresh water ponds and estuaries just a few. However the WRCP's
occurring in Myristica swamps are endemic species with narrow
habitat preferences, and are more distinctive taxonomically.
Individually these species would be highly valued and therefore
Myristica swamps would be assigned the highest priority in
habitat level conservation. Daniels et al (1991) discuss in
detail how multidimensional conservation priorities assigned to
species may be translated into ranking of various specific
localities, using as an example bird communities of Uttara
Kannada. Such a procedure could be applied to WRCPs of any region
to arrive at priorities in terms of the various LSE types or
specific localities of that region.
16. The conservation strategy should then focus on maintaining,
and as far as possible restoring landscape elements of types
assigned high levels of conservation value. This could be
approached in two ways; (i) By including such landscape elements
in the system of protected areas, and (ii) By providing inputs to
the development process to promote maintenance of landscape
elements of high conservation value, and to encourage conversion
of elements of low conservation value into elements of high
conservation value.
17. A first step towards the development of a conservation
strategy for WRCPs would then be a survey of the terrestrial and
aquatic habitats enjoying different levels of protection, whether
this be as parts of national parks, as forest reserves or as
sacred groves or ponds protected by local communities. Such a
survey would show the extent of protection available to landscape
elements of high conservation value under the protected area
system, and point to major lacunae in the system. Attempts could
then be initiated to plug the gaps and to extend protection to
significant elements currently lacking adequate protection.
Habitats of WRCPs are protected in Uttara Kannada in a
number of different ways. The Dandeli Wildlife Sanctuary with a
small core primarily protects moist and dry deciduous forest,
savanna and scrub. Of these savanna and scrub have been ranked as
fairly high in conservation priorities. Most of savanna and scrub
in the rest of the district however falls in the category of
Minor Forest established to fulfill biomass needs of village
communities. These have been little protected so far, and have
been extensively converted into Acacia auriculiformis
plantations. Such conversion has very adverse effects on the WRCP
populations. Recent years however have witnessed a promising
initiative in the form of the programme of Joint Forest Planning
and Management. This system of management is much more favourable
to the WRCP populations of savanna and scrub and deserves to be
encouraged. The Myristica swamps are part of the Reserve Forest,
now well protected with the suspension of felling of live trees
since mid 1980's. However this has not deterred illegal
encroachment on these swamps for conversion to paddy fields and
arecanut orchards. The best patch of Myristica swamp in Uttara
Kannada was earlier a sacred grove and is now a Linear Tree
Increment Research Plot and thereby better protected. The rest of
evergreen forest areas are largely under Reserve Forest. It would
be desirable to declare the still surviving Myristica swamps as
specially protected areas. The best protected of these are some
of the sacred groves. Other habitats of high priority from the
perspective of WRCP conservation, namely, freshwater ponds and
estuaries are increasingly threatened by continual expansion of
cultivation and habitation and enjoy no legal protection.
18. It would be desirable to adopt a broad approach to protected
areas, not confining attention to control over the protected
areas as parts of wildlife sanctuaries or national parks, guarded
by the official machinery through exclusion of all local use
patterns (Heywood et al. 1990). This is because certain levels of
human use may be quite compatible with maintenance of certain
types of landscape elements, and WRCP populations, and a rigid
guards and guns approach may turn out to be counterproductive.
Furthermore, local communities may often have their own
conservation practices such as sacred groves which deserve fuller
official support.
Farmers and local communities of Uttara Kannada have many
practices friendly to the conservation of WRCP populations. Thus
A.P. Rayas, a farmer of Kumta taluk maintains plants of Solanum
torvum on his farm to serve as root-stock for grafting cultivated
egg plant, Solanum melongena. The farming communities of Halakar
and Kallabbe villages, also in Kumta taluk have guarded well for
decades extensive areas as village forests. These maintain much
higher levels of overall plant diversity, including WRCP species
such as Myristica malabarica. In the last few years farmers have
become enthusiastic partners in the new programme of Joint Forest
Planning and Management. This involves local communities
participating in preparation of the management plan and
protection of forests in the vicinity of villages. In return they
share in the usufruct. Because local communities value a great
diversity of non-timber-forest-produce their participation in the
management encourages maintenance of a much greater diversity of
plant species, including WRCPs (Deb and Malhotra 1993). The
participation of the local communities also leads to much better
protection and maintenance of higher plant biomass levels
(Malhotra and Poffenberger 1989). Local communities of Uttara
Kannada continue to give protection to an extensive network of
sacred trees, groves and ponds. It is estimated that this network
once covered about 6 per cent of the land area. Even today the
network survives in a remnant form. Thus there are 50 sacred
trees and 52 sacred groves covering a total of 8 hectares in the
5.5 km x 5 km mapped area of Siddapur taluk discussed above
(Chandran and Gadgil, 1993). A sacred grove has been responsible
for the protection of the best surviving patch of Myristica swamp
in the district. Official policies which were at one time adverse
to the protection of the sacred groves now recognize their value
as a conservation device.
19. Finally, the conservation strategy should also aim to
promote a WRCP friendly landscape outside the protected areas
system. This would require a systematic assessment of the
development pressures that are leading to transformation of
landscape elements of high conservation value into those of low
value. Ways and means should then be considered of halting the
pace of such adverse transformations. At the same time, there may
be processes promoting the transformation of landscape elements
of low conservation value into those of higher conservation
value. Such conservation friendly transformations should be
encouraged through the development process (Gadgil et al 1986. It
is only through such a combination of maintenance of a dispersed
system of protected areas and promotion of conservation friendly
development processes that multiple populations of WRCPs
inhabiting a wide range of habitats could be conserved on a long
term basis.
20. Development policies in Uttara Kannada, as in many other
parts of the world encourage conversion of natural or seminatural
into cultivated vegetation. This they do by excluding local
communities from benefits to be derived from non-cultivated
lands, while recognizing their rights over the usufruct of
cultivated lands, even if such land has been initially brought
under cultivation in an illegal fashion. Secondly development
policies also encourage intensification of cultivation practices,
including the use of insecticides and weedicides. Both these
kinds of policies have an adverse impact on WRCP populations. In
their place we need to promote policies which would create a
stake for local communities in good management of natural and
semi-natural vegetation. The programmes of community involvement
in forest management now being encouraged in many parts of the
world are a positive step in this direction. It would be
desirable to create special incentives in such programmes for
maintenance of WCRP populations, perhaps through some system of
special grants (Gadgil et al. 1986). It would also be desirable
to encourage individual farmers to maintain WRCP populations on
privately owned lands. This could be done, for instance, through
an annual competition and cash awards for farmers supporting
healthiest populations of particular WRCP species in or around
their farms. Finally special rewards may be instituted at the
community level to encourage continued protection to sacred
groves and trees (Gadgil and Rao 1994).
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