INVASION ECOLOGY
My work identifies the patterns of forest regeneration in human-modified habitats – the stands of invasive trees established over natural grasslands of Shola landscapes in the Western Ghats. I’ve looked into the colonisation of biodiversity ranging from native to non-native/ invasive plant species and the endemic bird species of these mountains in such stands of invasive trees.
Questions asked: 1. What are the patterns of understory plant regeneration in invasive timber landscapes for a. Native forest species? b. Invasive species? 2. What are the specific ecological settings in a modified landscape that permit the colonisation of native faunal biodiversity? Publications 1. Jobin, V., Das, A., Harikrishnan, C. P., Chanda, R., Lawrence, S., & Robin, V. V. (2023). Patterns of understory invasion in invasive timber stands of a tropical sky island. Ecology and Evolution, 13(4), e9995. Upcoming publications 1. Jobin, V., Das, A., Harikrishnan, C. P., Chanda, R., Lawrence, S., & Robin, V. V. Stand structure of non-native timber influences native forest tree regeneration in the understory. In prep. To be sent to Forest Ecosystems. 2. Jobin, V., Harikrishnan, C. P., Chanda, R., Lawrence, S., Jathanna, D., Robin, V. V. Specific ecological settings in invasive tree stands that permit colonisation of avian biodiversity. In prep. To be sent to PNAS/ Proceedings B/ Nature Ecology and Evolution. CLIMATE AND LANDSCAPE CHANGEI study the patterns of landscape change in tropical mountainous regions and define how the interaction with climate change affects the range. To study the interactive impacts of climate and land cover change, the mountain range needs to be mapped based on the intensity of these changes. Understanding the overlap between the future changes in climate and land cover will help mark the regions across the range based on the extent of alteration and the driver of the changes those regions might face. Annual precipitation and annual minimum temperature are important climatic variables that define the distribution of floral and faunal components on most mountaintops. With the land cover change, such maps can help decide the most vulnerable zones in a mountain range, which can help focus the conservation actions.
Upcoming publications 1. Jobin, V., Meera, M., Dharmarajan, G., Gupta, P., Mukherjee, S., and Robin V.V. Patterns of landscape change in a tropical mountain, and interaction with climate change across the range. In prep. To be sent to Biotropica. FOREST MENSURATION A. I use a photo-based technique as an alternative to measuring vegetation attributes in a fast-expanding invasive landscape in tropical mountains. Angle count sampling (ACS) is a technique used in temperate forests that provides stand-level attributes of the sampled areas (Bitterlich, 1984). 360° spherical cameras, in combination with the ACS technique, offer an inexpensive and effective option for obtaining direct stand-level measurements (Wang & Kershaw, 2020) of basal area. This study uses photo-based sampling techniques with conventional methods to estimate stand-level attributes in wooded areas with limited light and dense undergrowth. The primary goal of this study is to examine the efficacy of ACS and to compare this with traditional field methods.
B. I am analysing data on LiDAR-based forest measurements at the University of New Brunswick, Canada. Using the R program, I am currently calculating the structural complexity metrics like depth and openness using single-point terrestrial laser scanning point clouds and comparing stands with varying degrees of thinning. Upcoming publications 1. Jobin, V., Meera, M., Dharmarajan, G., Gupta, P., Mukherjee, S., and Robin V.V. Patterns of landscape change in a tropical mountain, and interaction with climate change across the range. In prep. To be sent to Biotropica. 2. Jobin, V., and Kershaw J., Structural Complexity Metrics for East Canadian Forests from Single Terrestrial Lidar Scans. In prep. AVIAN BREEDING BIOLOGY
Edges of forests (Ecotones, as we have learnt in our ecology lectures) with transitioning vegetation often have several predators, and studies have pointed out that these edges have a low breeding success rate. The survival of a bird species is determined by its breeding success. So, if predation over the eggs and chicks is high, the chances are that the bird's survival also decreases. My study was trying to understand if various vegetation components of the forest, just around the nest, impact nest predation in these birds. We also look at the parental provisioning rates and how it might affect the predation patterns, if any.
This work was based out of North West Bengal. Upcoming publications 1. Jobin, V., Chanda R., and Supriya K., Vegetation attributes and parental provisioning rate determine the probability of nest predation for tropical song birds in nest boxes. In prep. Other publications
1. Chanda, R. & Jobin, V. (2020) Oriental Pied Hornbill Antracoceros albirostris preying upon a Black-crested Bulbul Pycnonotus falviventris nestling. Indian Birds. 16, 58-59. 2. Jude, D., Aravind, P.S., Chanda, R., Subash, M., Jobin, V., (2021) Provisioning behaviour of Malabar Starling Sturnia blythii. Indian Birds. |