Enhancing ecosystem services through collaborative grass removal and fire exclusion in the Eastern Ghats

Abstract

Human activities in mesic savanna ecosystems have resulted in plant communities that are heavily dominated by fire-tolerant grass species, are less diverse, and offer fewer ecosystem services such as palatable plant biomass. Experimental studies ma- nipulating fire and grass presence have mostly been conducted in ecosystems invaded by exotic grass species. However, these experiments are also relevant to ecosystems that have become dominated by native grass species due to changes in human ac- tivities. Our study compared three different management treatments in the Eastern Ghats of India, where mesic savanna ecosystems are highly dominated by the unpal- atable native Cymbopogon grasses, specifically: (1) control (both Cymbopogon grasses and fire are present), (2) fire exclusion, and (3) manual removal of Cymbopogon grasses and fire exclusion. We found that both grass removal and fire exclusion were neces- sary to significantly increase palatable herbaceous plant biomass and species diver- sity, and that species diversity responses were only significant at larger spatial grains of investigation. High site-to-site variation in the grass removal and fire exclusion treatment prevented us from detecting significant differences in species composition across treatments, even though particular palatable grass species benefited from the treatment. Our study is in line with research from other mesic savanna systems show- ing that fire management alone is not sufficient to transition ecosystems to a desired or historical state. We demonstrate how normally costly management practices, such as manual removal of dominant grasses, can be reasonably achieved through collabo- ration between scientists, community governed village institutions, and government and nongovernment agencies in socioecological systems.