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Responses of diversity, productivity, and stability to the nitrogen input in a tropical grassland
Author(s) -
Verma Preeti,
Sagar R.
Publication year - 2020
Publication title -
ecological applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.864
H-Index - 213
eISSN - 1939-5582
pISSN - 1051-0761
DOI - 10.1002/eap.2037
Subject(s) - grassland , biomass (ecology) , productivity , ecosystem , ecology , environmental science , agronomy , zoology , biology , macroeconomics , economics
Atmospheric nitrogen (N) deposition is a matter of serious concern for the structure and functioning of global ecosystems, but the effect of N application of species diversity ( D ), primary productivity ( P ), and stability ( S ) of tropical grassland ecosystems is not known. The present study reports the effects of different levels of N application on species composition, and the D , P , S , and their relationships in a tropical grassland. Within the experimental grassland, 72 1 × 1 m plots with 6 N‐input levels and with 12 replicates, were established in 2013. For 3 yr, different doses of urea as a source of N were applied to the plots. Data on individuals and biomass of each species were recorded and statistically analyzed. The study revealed that the N applied caused variations in species composition, D , P , and S . Below the 90 kg N dose, D was positively related to P and S while, above this level, the relations were negative due to N‐induced responses of species and functional group composition as well as biomass distribution among them. The optimum applied N levels for maximum D (50–60 kg N), P (120 kg N), and a positive relationship of S with D (up to 90 kg N treatment) suggested that the 90‐kg N dose could be the maximum dose of N that the grassland can tolerate. Hence, N application should not exceed the 90‐kg level for sustainability of the structure and functioning of tropical grassland ecosystems.