Western Ghats forests losing vitality despite green cover expansion: Study
https://www.heraldgoa.in/goa/western-ghats-forests-losing-vitality-despite-green-cover-expansion-study/455568/ Satellite imagery shows an expansion in green cover, yet a steady erosion of ecological function in the northern Ghats, where Goa’s major rivers, aquifers and biodi vesity corridors originate
The State’s river systems, groundwater recharge zones, forest soils and wildlife habitats depend not just on the presence of trees but on the functional strength of the Ghats as a living ecological engine..
Thus conservation planning cannot rely solely on canopy cover or tree-density figures. Long-term functional indicators, particularly NPP, are essential to capture how forests are actually performing under climate stress.
A long-term scientific analysis of the Western Ghats has found that the region’s forests are losing vitality even as satellite imagery shows an expan sion in green cover. The study reveals a steady erosion of ecologi cal function in the northern Ghats, where Goa’s major rivers, aquifers and biodi versity corridors originate. At a time when the State is witnessing erratic monsoons, water shortages in several talukas and visible stress in its hinterland eco systems, the findings suggest that conventional can opy assessments may be missing a deeper shift that is already underway. The research was carried out by Sanjay Kumar, Jyothi ka Karkala, Joyal Arya and Dr Rajiv Kumar Chaturvedi of BITS Pilani Goa, who is a co-author of the study. The team examined 22 years of satellite-derived Net Prima ry Productivity (NPP) data from 2001 to 2023 to un derstand how forests across the Ghats are responding to rising temperatures, chang es in monsoon behaviour and land-use pressures. NPP, which measures the amount of biomass vegetation produced after res piration is accounted for, is treated by ecologists as one of the clearest indicators of ecosystem health and the ability of forests to absorb and store carbon. The authors point to what they describe as a “produc tivity paradox”. Over the last two decades, tree cover has expanded across several parts of the Ghats, but the underlying ability of these forests to generate biomass has declined. The publicly available abstract indicates that vegetation character istics, climatic shifts and land-use changes interact in ways that reduce produc tivity, particularly in areas experiencing warmer temperatures. This finding sug gests that satellite-detected greening may no longer reflect the true functional strength of forest systems. A strong regional divide is evident in the data. The southern Western Ghats, in cluding Kerala, Tamil Nadu and Karnataka, continue to show higher and more sta ble NPP values because of their dense wet evergreen forests and more consistent moisture regimes. In con trast, the northern Ghats, which include Goa, Mahar ashtra and Gujarat, record ed lower productivity levels and significantly more fluc tuations across the 22-year period. This variability, the researchers note, indicates deeper ecological stress that may not be captured by an nual forest-cover statistics. For Goa, the implications are far-reaching. The State’s river systems, groundwater recharge zones, forest soils and wildlife habitats de pend not just on the presence of trees but on the functional strength of the Ghats as a living ecological engine. A decline in forest productivity can influence river flows, reduce soil moisture, weaken forest re generation and alter habitat stability.
These shifts may also have cascading consequences for agriculture, coastal ecosystems and the State’s long-term water security. The timing is particularly significant, as Goa has seen increasingly unpredictable monsoon patterns, flash-flooding in some pockets and dry spells in others, all of which are linked to changes in forest and climate sys tems. The authors state that conservation planning cannot rely solely on canopy cover or tree-density figures. They argue that long-term functional indicators, particularly NPP, (A scientific analysis of an ecosystem's ability to produce and store organic matter through photosynthesis after accounting for the plants' own respiration.) are essential to capture how forests are actually performing under climate stress. For Goa, this means that the appear ance of dense or expanding forests may mask weakening ecological processes beneath. The study suggests that fu ture environmental policy will need to incorporate such functional assessments to ensure that the State’s forest-de pendent systems remain resilient