Impact of mining on tree diversity of the silica mining forest area at Shankargarh, Allahabad, India

The Shankargarh forest area is rich in silica, a major mineral used in glass industry. Extensive open cast silica mining has severely damaged the forest as well as productivity of the region. An understand- ing of the impact of mining on the environment particularly on vegetation characteristics is a prerequisite for further management of these mining sites, especially in the selection of species for reclamation works. The present paper deals with the study of the tree composition of silica mining area of Shgankargarh forest, at both disturbed and undisturbed sites. Tree vegetation study was conducted at undisturbed and disturbed sites of Shankargarh forests using standard quadrate method. Density, abundance and frequency values of tree species were calculated. Species were categorized into different classes according to their frequency. The importance value index （IVI） for each species was determined. Species diversity, Concentration of dominance, Species richness and Evenness index were calculated for the undisturbed and disturbed siteS. The distribution pattern of the species was studied by using Whifford＇s index. Similarity index between tree composition of disturbed and undisturbed sites was determined by using Jaccard＇s and Sorenson＇s index of similar- ity. Tree species showed a drastic reduction in their numbers in disturbed sites compared to that of the undisturbed sites. The phytosociological indices also illustrated the impact of mining on the tree composition of the area. The present study led to the conclusion that resultant tree vegetation analysis can be used as important tool for predicting the suitability of particular species for revegetating the mined areas.

Tropical forest canopies and their relationships with climate and disturbance： results from a global dataset of consistent field-based measurements

Background： Canopy structure, defined by leaf area index （LAI）, fractional vegetation cover （FCover） and fraction of absorbed photosynthetically active radiation （fAPAR）, regulates a wide range of forest functions and ecosystem services. Spatially consistent field-measurements of canopy structure are however lacking, particularly for the tropics. Methods： Here, we introduce the Global LAI database： a global dataset of field-based canopy structure measurements spanning tropical forests in four continents （Africa, Asia, Australia and the Americas）. We use these measurements to test for climate dependencies within and across continents, and to test for the potential of anthropogenic disturbance and forest protection to modulate those dependences. Results： Using data collected from 887 tropical forest plots, we show that maximum water deficit, defined across the most arid months of the year, is an important predictor of canopy structure, with all three canopy attributes declining significantly with increasing water deficit. Canopy attributes also increase with minimum temperature, and with the protection of forests according to both active （within protected areas） and passive measures （through topography）. Once protection and continent effects are accounted for, other anthropogenic measures （e.g. human population） do not improve the model. Conclusions： We conclude that canopy structure in the tropics is primarily a consequence of forest adaptation to the maximum water deficits historically experienced within a given region. Climate change, and in particular changes in drought regimes may thus affect forest structure and function, but forest protection may offer some resilience against this effect.

A comparative study of manglicolous lichens and their distribution inside Bhitarkanika National Park(Odisha),India

The manglicolous lichens are a specific group of lichens which occur in association with mangrove plants.Mangrove ecosystems have limited accessibility and the lichen study in mangrove forests are less studied and reported.The present study is the first-time report on lichen diversity,their distribution and its associated host mangrove species at eight different sites within the mangrove forests of Bhitarkanika Wildlife Sanctuary and National Park(Odisha),India.The study recorded a total of 49 lichen species which belongs to 26 genera and 14 families.The comparison of growth forms showed presence of 28 species of crustose,18 species of foliose and three species of fruticose type of lichens from the study sites.The analysis of host mangrove species showed Excoecaria agallocha as the most preferable mangrove species as it housed 38 lichen species on its surface(i.e.,45%crustose,47%foliose,and 8%fruticose).The comparison of growth forms of the total recorded lichen species from Bhitarkanika National Park,resulted 57%species crustose,37%foliose and 6%of fruticose type of lichens.The mangrove species,Avicennia officinalis and lichen of the genus Chrysothrix were found as common to all the study sites.The Jaccard similarity index study of lichen species between the study sites showed Kalibhanjadiya Island and Habelikhati as more similar in comparison of lichen species composition(i.e.,0.64).The occurrence of foliose and fruticose type of lichens showed the healthy and undisturbed mangrove forest conditions at many sites within Bhitarkanika National Park.