Developing a geochemical quality index for mangrove systems in the South Western Coast of Indian Peninsula

Abstract

Abstract Mangroves are vital components of the environment providing diverse functions from biodiversity conservation to climate regulation. Understanding the soil quality in these systems is essential for appropriate decision making and developing strategies for sustainable mangrove soil management. The objective of the study was to develop a Geochemical Quality Index (GQI) and Relative Geochemical Index (RGQI) for soil quality assessment of the mangrove systems. A total of 63 soil samples were collected from the surface layer 0 to 30 cm, for assessing the physico – chemical parameters from the mangrove systems along the South Western Coast of Penisnsular India. The datasets were subjected to principal component analysis (PCA) to derive the minimum data set for the GQI and RGQI. The selected parameters were ranked based on their performance of soil functions and combined to form the indices. The PCA results showed that, percent sand, percent silt, percent clay, Cu, EC, Fe and K were the most representative variables of mangrove ecosystem health. The RGQI values indicated the relative quality of mangrove soils in the region with respect to maximum attainable geochemical health and classified the mangrove systems into 3 types vis - a - vis; good, medium and poor. Evaluation of the existing mangrove systems using RGQI revealed that majority of the mangrove systems in the South Western coast of Peninsular India had a high probability to progressively alter from ‘good’ to the ‘poor’ category, hence mandate crucial management strategies.