Bijay Thakur

Metal contaminants such as Cadmium, Chromium, Nickel, and Lead are released and deposited in Reserved Forest soils as a result of heavily travelled roads. Their pollution interrupts the biogeochemical cycle in the natural environment, affecting plant productivity. However, this pollution's source, their ecological risks, and its effects on tree biomass productivity have yet to be examined. In order to examine this, an ecological study was conducted in two Assam Reserved Forests that are crossed by the National Highway (NH-15). Several ecological risk indices were used to assess potential ecological risks. Metal impacts on tree biomass stocks were predicted using regression analysis and Pearson's coefficient. The results showed that metal concentrations in soil samples collected near roads were much higher than those away from roads. However, the overall mean concentration was within the Indian guidelines. Indices of soil contaminations and pollutions ranged from mildly conta...

Abstract An ecological study was conducted to evaluate the levels and effects of heavy metals on forest surface soils along highways. We hypothesized that vehicles in highways emit considerable levels of metals, affecting plant diversity and productivity. Pearson correlation, cluster, and regression analysis were used to prove these relationships. Furthermore, ecological risk assessments were quantified using the geo-accumulation index, pollution index, pollution load index, and ecological risk index. Results indicated soil samples from Site II (roadway) had higher levels of metals than Site I (control), suggesting that highway traversing via forests emit considerable amounts of metals into the surface soil. The most intriguing aspect is that species such as Bidens Pilosa and Arundo donax were frequently recorded at Site II. The predominance of such species indicates contaminated sites favouring metal tolerance species. Ecological risk indices revealed that Cd, Mn, and Pb contributed to ecological risk; their pollution ranged from unpolluted to heavily polluted ecosystem. Correlation analysis found a pronounced negative link between metals and diversity; the correlation matrix was −83%, −94%, −65%, −75%, −47%, −57% and − 38% for grass diversity, and − 59%, −74%, −89%, −66%, −81%, −81% and − 83% for forb diversity with Cd, Cr, Ni, Pb, Zn, Cu and Mn, respectively. Furthermore, negative correlations for tree production of −80%, −79%, −76%, −71%, −67%, −53% and − 41% were recorded with Cd, Cr, Ni, Pb, Zn, Cu and Mn, respectively. Nevertheless, metals accounted for 74% variance in tree productivity. The strong negative link observed in this study demonstrates the effects of metals on diversity and productivity, which requires monitoring for preventing serious environmental consequences. Highlights • Excessive road traffic contributes to the release of heavy metal in forests. • Heavy metals in surface soils threaten plant diversity and productivity. • Cd, Mn and Pb are the most substantial contributors to ecological risks.