By Bindia Gupta on 01 December 2019.
According to Murphy and Lugo, tropical dry forests, though less species-rich than rainforests are most exploited by locals for both living and livelihood. As trees form the skeleton of a forest ecosystem, I intended to know about the current status of tree diversity and regeneration in dry deciduous forest areas of south-west Bengal, India in terms of impacts of climate, disturbance and soil factors. Jhargram, previously a part of Paschim Medinipur district, is under Joint Forest Management, an agreement between the state forest department and forest fringe people for protection and conservation of forests in exchange of specific benefits.Our study was carried out at five Forest Protection Committees located in the fragmented forest patches.
Key observations
- Species number was on the lowest side with 36 species recorded in the sampling sites (tree species number ranged from 35-90 as documented by previous studies). Rotational felling by the forest department and coppicing property of Shorea robusta Gaertn. shaped the tree species composition to a large extent.
- Seasons, habitat characteristics and disturbances like grazing and invasive species strongly influenced seedling community attributes. Seedling diversity and density were recorded to be highest in summer and lowest in winter. Here long dry seasons with sporadic rainfall and thick leaf litter on the forest floor change the soil nutrient recycling dynamics. Moreover, as both humans and livestock can act as media of seed dispersal, seedling richness was highest in high and medium grazing areas and lowest in low grazing areas. Seedling density was least in medium grazing areas while it was highest in low grazing areas.
- 60 % of the important stand species showed “poor” and “new” or “no” regeneration status.
- Surface soil potassium and soil texture were the best predictors of seedling abundance.
- Accidental germination of exotic planted species like Acacia auriculiformis A. Cunn. ex Benth. (Akashmoni), Eucalyptus globulus Labill. (Eucalyptus) and Anacardium occidentale L. (Cashew) was reported in the natural forests of the study area that may threaten the growth and survival of indigenous species.
Recommendations to the state forest department
- FPC members and forest managers should be more vigilant and strict to prevent illegal logging and over-exploitation of Non-Timber Forest Produce by private agencies.
- Concerned authorities should also focus on a systematic management plan required for plant species conservation involving control of human interference during regeneration like grazing and browsing, forest resource extraction, man-made fire and invasive species that will, in turn, lead to conservation of forest ecosystem services vital for the survival of flora and associated fauna.
In the context of red listing of ecosystems by IUCN, the case study results on this threatened ecosystem that is continually exposed to fragmentation and other forms of human interference like regular utilization of forest resources by the locals etc. will form a firm baseline for awareness as well as future assessment of its conservation status and efforts.
More details on the study can be had here.
Bindia Gupta, is doing her Ph. D at Department of Environmental Science, University of Calcutta, Kolkata, India. Bindia is also a member of the IUCN Commission on Ecosystem Management.