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Home  »  PMR FELLOWSHIP REPORT 2

WRITE-UP FOR PMR FELLOWSHIP FROM JAN 2020-OCT 2020

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JOBIN VARUGHESE

Mountainous regions are unique elevated landscapes holding half of the global biodiversity hotspots. Increasing human population and its consequences have had pronounced alterations in tropical mountains. Modified landscapes are often highlighted for their negative spin-offs. Planted forests – one such modified habitat – constitute ~7% of global forests and are on a steady increase. My study focuses on specific ecological settings that permit establishment of native biodiversity in such modified landscapes.

Land-use modification is an important driver of biodiversity change in tropical mountains, but climate change poses moderate and long-term threats to biodiversity at higher elevations particularly since local climate could vary dramatically over short distances in mountains. Since, climate and land cover on mountains are spatially autocorrelated, it becomes essential to study the interactions between changing climate and land use on changes in species distribution.
Generalist species are usually favored by habitat transformation, but certain transformations benefit range-restricted and threatened faunal species, as well. Thus, some ecological settings within modified habitats can have improved biodiversity. In order to work towards conservation of specialist species, quantification of the spatial and structural aspects of such ecological settings becomes a prerogative.

Differences in ecological conditions in modified habitats like plantations, particularly in the overstory vegetation, have been known to vary the patterns of distribution of plant species in the forest regeneration in the undergrowth. Understanding understory at landscape level can be potentially useful for monitoring the process of natural restoration of native vegetation, invasion of non-native vegetation and consequent long-term forest dynamics. There are several global products procured from satellite data which, if validated with ground reference data of simultaneous structural properties of under- and overstory vegetation, can ease the extrapolation of understory conditions to a large-scale level. Generalist species are usually favored by habitat transformation, but certain transformations benefit range-restricted and threatened faunal species, as well. Thus, some ecological settings within modified habitats can have improved biodiversity. In order to work towards conservation of specialist species, quantification of the spatial and structural aspects of such ecological settings becomes a prerogative.

Collecting attributes of under- and overstory vegetation in each sampling plot can be extremely time consuming and labor intensive. Several sampling methods have been derived to obtain precise data with efficient field processes. Image-based angle count sampling have demonstrated efficient, effective and inexpensive ways to estimate stand level attributes in temperate-region based plantations and can prove to be useful in tropical woodlands over larger extents, as well. Effects of understory vegetation, inconsistent exposure in variable lighting conditions and sloping terrain can pose several challenges, and hence needs to be tested.

Objectives of my chapters :

Chapter 1: What are the patterns of landscape change in tropical mountainous regions and how does the interaction with climate change affect across the range?

Manuscript completed, in internal review.

Chapter 2: What are the specific ecological settings in a modified landscape that permit return of faunal (avian) biodiversity?

30% completed. Field work continuing.

Chapter 3: Could the compositional and structural attributes of overstory reflect the floral regeneration / understory vegetation parameters and hence, validate the extrapolation of the correlation to a landscape level through satellite imagery?

20% completed.

Chapter 4: Would a photo-based sampling technique used for rapid assessment of forest stand level attributes equally feasible when used in wooded areas with dense undergrowth in tropical mountainous regions?
In proposal and trial data collection stage.

Courses done during PhD

  1. Quantitative Methods in Ecology I
  2. Behavioral Ecology
  3. Bioacoustics
  4. Advanced Ecology

Teaching Assistantships:

  1. Foundations of Biology I: Basic Principles.
  2.  Biology Lab III: Ecology and Evolution.