Unraveling the Relationship between Percentage Cover and Biomass of Various Herbaceous Species in the Dry Tropical Grassland

Abstract

The estimation of biomass and cover is an ideal variable for determining ecosystem productivity, vegetation abundance, and community structure of any ecosystem. Biomass estimation by harvest method causes a huge loss of biomass and biodiversity. Non-destructive methods are helpful for repeated and regular sampling of the same plot to measure any change in biomass at the fixed time interval. There are already several regression equations established between biomass and cover in various ecosystems for finding above-ground biomass but there was an urgent need for such studies in dry tropical grasslands. The experiment was performed in the entire campus of Banaras Hindu University, Varanasi. 115 Quadrats were sampled in the entire university campus during year 2019-2020. For each quadrat, species-wise individual numbers were recorded and above-ground biomass was estimated by harvest method. Herbage cover was recorded for each species and measured by gridding each 1×1 m2 quadrat into 100 cells of 10 × 10 cm cells, each representing 1% cover. We found 59 herbaceous species of 28 different families. The family Asteraceae was the most common while only single species represented the other seventeen families. Most of the species like Dichanthium annulatum, Sida acuta, Ageratum conyzoides, Malvastrum coromandelianum, Rungia pectinate, and Vernonia cinerea showed linear regression equation, Parthenium hysterophorus, Alternenthera sessilis, Boerhavia diffusa showed quadratic polynomial trendlines. Species like Zephyranthes citrina and Ruellia tuberosa showed a power regression equation. Only Andrographis paniculata, and Chenopodium album showed an exponential regression equation. A power regression equation was found between pooled biomass and cover. Using the regression equations biomass of the listed 59 species could be calculated easily without disturbing the vegetation of the study area which will eventually help in the conservation of nature.