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Planning conservation strategies
Forest Management
has undergone a major shift in its philosophy. Initially, management emphasised
mostly on using the forests without substantial loss in their productivity. At
present, however, the thrust is mainly on the conservation of biological
resources of our forests and harvesting them is viewed tenable only when their
sustainable use can be ensured. In fact a total ban on felling of trees in
several forests of the world is an indication of such a shift. Unfortunately the
classification of the forests, a primary requirement for a proper management has
not undergone a parallel change. The current methods of forest classifications
have several problems:
- They are mostly based on the
canopy structure and to a very less extent on the herb and shrub layers and on
the other components of the forests.
- These classificatory processes
fail to identify small scale vegetation heterogeneity and demarcate the
forests in to large discrete units such as scrub,deciduous and evergreen
forests which are assumed to be internally homogenous.
- They do not reflect the
conservation value of the forests such that the management efforts can be
accordingly allocated.
- Field ecologists have realized
that the forest does not change from one vegetation type to the other abruptly
as suggested by the demarcating line of the existing methods rather are highly
heterogeneous spatial mosaics which can be hierarchically combined in to fewer
and fewer types.
Thus there is a
need to arrive at fresh methods of classifying the forests and we are attempting
to develop new protocols that are objective, incorporate the information on all
layers of vegetation and also are possibly useful in the context of the
conservation of biological resources. Accordingly we propose two distinct
methods of classifying the forests based on the need and level of management
efforts available. These methods rely on collecting the quantitative data on
vegetation composition of all the three layers viz., trees, shrubs and herbs in
grids evenly spread out at as finer scale as possible in the whole of forests.
Using this data, forests can be classified in two different ways depending upon
the need.
- Biological richness maps: The conservation value of
these grids can be computed by a suitable combination of the diversity
estimates of the three different vegetation layers and mapped in a spatial
format. From such data, using suitable mapping software, contours of
conservation values can be developed and derived for the whole forest.
Hypsographic or 3-D views developed from these contours suggest gradient of
conservation values in the forests from which areas of high conservation
importance can be located by identifying the peaks of diversity. Similar maps
can also be developed for the economic richness of the forests based on the
density and distribution of the economically important species.
- Vegetation cluster maps: Based on the vegetation
composition, the grids that are similar can be identified using the
multivariate statistical tools and clustered together to suggest the areas of
similar vegetation composition. Mapping such clustered grids offers a spatial
perspective of the vegetation types of the forest. This clustering process can
be repeated hierarchically to arrive at fewer groups and the level of grouping
can be decided by the management team depending upon the resources available
and the intensity of management required.
Contours of conservation: towards a national agenda
The present century
has witnessed an unprecedented loss of biodiversity the world-over.
Therefore
conservation of biological resources is viewed as one of the immediate tasks we
should embark on, at a global scale. It is prescribed that every country shall
consider it a responsibility to conserve its biological resources for a
sustained and healthy global posterity. But launching of any such national
conservation program is contingent upon the knowledge of what, where and how to
conserve. In this sense it has become very essential that we develop perspective
maps of our biological resources that are as detailed as possible. In fact such
atlases are being constructed by different groups, but it is important to
develop a common protocol to integrate them to arrive at national maps of
biological diversity.
We are hence working towards a national approach for mapping and integration of the various biological and spatial elements of conservation so as to prioritize the conservation needs. We suggest that strategies to conserve the biodiversity of the country should be based on development of country-wide maps for conservation - what we refer to as contours of conservation. These maps which would result from integrating data from various layers and of different elements provide a composite map of the spatial structuring of biodiversity for the country and can guide national conservation efforts. In other words, just as we are systematically preparing maps depicting the physiognomy of our country, we should also aim to develop maps depicting the biognomy or the biodiversity profiles of our country for a sound national conservation strategy and for
an appropriate allocation of resources to the conservation activities. We
suggest a bottom-up approach for developing these biodiversity atlases and
contours of conservation and suggest that they could be done in three steps,
namely (i) mapping the biological elements for conservation, (ii) mapping the
spatial (habitat) elements for conservation and (iii) mapping the contours of
conservation. We describe below these steps with examples of the efforts made at
our centre and elsewhere.
The contours of
conservation, the biodiversity atlases and their accompanying data will have
widespread application in guiding national conservation plans and in the
effective allocation of scarce resources. These maps could be used to evaluate
the relevance of protected areas and accordingly restructure them. Because of
the strong visual outputs generated by these maps, they would serve both the
generalist and specialists alike in making decisions in conservation action.
Besides addressing issues related to conservation of biological diversity, these
maps would help direct attention to basic issues pertaining to the distribution
pattern of species. For example, the biodiversity contour maps will enable
determining the anomalous distribution patterns, if any, of taxa and their
implications.
Deforestation and Land Use Change
This programme,
mainly by the scientist working at Ashoka Trust for Research in Environment and
Ecology (ATREE, Bangalore) is currently concentrated in two regions: the Western
Ghats and the Eastern Himalayas. The objectives of the program are to assess the
extent of change in land cover, particularly deforestation and forest
degradation, identify causes of change and examine consequences.
Using remote sensing imagery, archival maps,
and ground surveys, the scientists at ATREE in collaboration with
other teams¹ have examined land use changes and deforestation in the
Western Ghats and Arunachal Pradesh. In addition, land use change
and deforestation have been studied in detail in three other areas:
Agasthyamalai Hills and Biligiri Rangan Hills in the Western Ghats,
and Darjeeling Hills in the Eastern Himalayas. Detailed maps showing
the nature and extent of change have been prepared, and statistics
on deforestation, forest fragmentation, and conversion of forest
land to other types of usage have been compiled.
¹University of Massachussetts, Boston, U.S.A; Ashoka Trust for Research in Ecology and Environment, Bangalore; National Remote Sensing Agency, Hyderabad; Jawaharlal Nehru Centre for Advanced Scientific Research, Banglore; and Karnataka Forest Department; Forest Survey of India, Bangalore.
²International
Plant Genetic Resources Institute, Mc Arthur Foundation, Centre for
International Forest Research Organisation, Karnataka State Department of Forest
Ecology and Environment.
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