Forest Ecology and Management
Species distributions in relation to soil resources.
Investigator: Ankila Hiremath
Location: Mudumalai wildlife sanctuary, Tamil Nadu
Funded by: Center for Tropical Forest Science
Duration: 2004-2005
Annual dry season fires, and periodic perturbations (e.g., browsing, uprooting) by
elephants and other large mammalian herbivores are amongst the most visible ecological
factors underlying the large scale patterns of structure and dynamics in India’s dry
tropical forests. Long-term data from the 50 ha forest dynamics plot in Mudumalai,
South India, clearly support the importance of both these factors in affecting
species’ mortality and recruitment.
When viewed through a finer lens, however, these forests reveal subtler patterns of
species distribution and dynamics, for example the clumped distribution of some species,
the positive (and negative) density dependence in mortality and recruitment of other
species, and species’ aggregation along topographic habitats that, presumably, vary
in underlying edaphic characteristics. Clearly, the large-scale effects of elephants
uprooting trees, or of fires sweeping through the understory, are insufficient to
account for these patterns, and it is necessary to seek explanations elsewhere.
We are investigating soil resource availability in the 50 ha forest dynamics plot
to assess whether differences in soil resources underlie fine-scale patterns in
species distribution in these South Indian tropical dry forests. Understanding the
mechanistic basis of plant distribution in relation to soil resources can provide
insights into species selection for reforestation and restoration.
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