Mapping of tree endemism in the Western Ghats
Funding Agency(ies):

Axis 1. of the Ecology Department /


The area of the Western Ghats that the DoE and the IFP have been studying for almost 40 years is truly remarkable for an ecological perspective. This area is internationally renowned for being very rich in number of species in all endemic species. Endemic species, such as vegetable animal, are only here on earth, and deserve to be protected especially for this reason. The population growth of the Indian population and the limited area of this strip of land wedged between the Indian Ocean and the mountain range Ghats reduced each day a little more habitats that host these species (eg evergreen forests, those which do not lose their leaves). But where is distributed endemism levels the highest? Of how this rate is superior between richer and poorer areas of the Ghats region? How have protected areas

The DoE has collected an extensive set of data on attendance and absence of endemic tree species in the evergreen forests of Western Ghats (Fig. 1). He has published an atlas that refers to the subject (Pascale & Ramesh, publications link). We were so close to estimate the spatial distribution of the rate of endemism.

Figure 1: Spatial distributions of elevation (left) and floristic samples (right) used in this analysis of endemism in Western Ghats (Bouchet et al. 2010).

We modeled the rate of endemism in several recent methods of spatial analysis and complementary (methods by nuclei, MaxEnt, MHM card) into a set of maps of spatial distribution. So instructive, they show similar overall distributions, although different in detail (Fig. 2). All confirm the north-south gradient of endemism, whose causes are not yet fully identified. In detail an additional analysis from the CMP software (link?) Confirms that MaxEnt which focuse on the influence of environmental factors does not place the highest endemism in the same place as those nuclei that rely solely on the distribution of samples. We believe it is the combination of these cards, disagree in Kerala where the rate of endemism is highest, which gives the most accurate vision of endemism.



Figure 2: Spatial distributions of endemism of evergreen trees in the Western Ghats, obtained by several complementary methods: the nuclei (left), HM (center) and MaxEnt (right).

When we compare the final map the distribution of endemism (by summing the three resulting maps) with protected areas in Kerala, we can see where the areas are located so appropriate or not. Not to mention the probable sampling bias, one can go up to offer optimal coverage of the territory with the same effort of preservation (Fig. 3). With approximately 500 square kilometers of protected area in Kerala, one could indeed better protect the endemism of 26% by allocating different areas. Of course, should not our focus on vegetation maps are the only source of recommendation.

Normal consequence of this work is to understand what are the mechanisms that led to this spatial distribution, whether they are current factors or processes paleoecological, not just to observe and quantify the distribution at a given .


Figure 3: Spatial distributions of endemism of evergreen trees in Kerala, masked by the current protected areas (left) and such that it would be masked by areas which cover the same surface but maximizing the protection of endemism (right).