Factors limiting regeneration of a Near Threatened deciduous tree Pterocarpus marsupium Roxb. in Central India

Abstract

In the tropical dry deciduous forests of Central India, changes in population structure and regeneration of a Near Threatened tree Pterocarpus marsupium Roxb. (Fabaceae) was monitored over 4 years. Focussing on the effects of biotic disturbance, the study examined seven potential sites, for future restoration measures and management. We examined 46 plots of 0.1 ha size laid in these seven sites from 2017 to 2021. Results compared in all sites revealed that there were hardly any individuals surviving or growing at ‘Sapling’ stage, which is counted as crucial for successful regeneration of a tree species. Among all the study sites, SARA recorded highest average density of seedlings per sample plot followed by BAHO and LAMT. Positive change in ‘Seedlings’ category was recorded only at BAHO (+17.8%) and SARA (+9.1%). Whereas, BIRS recorded highest decline in average density of seedlings (−42.2%) followed by SEMA (−24.3%) and BARH (17.2%). Correlation analysis of biotic pressure on the species, revealed that weed infestation (−0.59) has highest adverse effect on the seedling density followed by Lopping/cutting (−0.33) and livestock & human population (−0.12), indicating an urgent need to undertake assisted natural regeneration (ANR) activities for this species in its natural ranges. Although there were few positive changes in the seedling stage (BAHO +17.8%; SARA +9.1%), but conditions of most sites did not meet the standards necessary for the survival and growth of a tree species. Therefore, the study concludes that lack of ability of seedlings to grow into saplings due to biotic pressure is the main limitation for the natural habitats of P. marsupium in Central India.