Modelling of co-occurrence patterns of grassland species: reciprocal shifting between competition and facilitation

Abstract

In plant community, competition and facilitation are widely studied themes across the globe however, their reciprocal shifting, if existed, requires more empirical efforts. In this study, temporal behaviour of co-occurrence patterns with relation to the nature and magnitude of deterministic control of soil, plant community and site quality factors were evaluated in grassland species of Indian arid zone. In this study, co-occurrence patterns during the three seasonal events were detected by using quantitative variable (relative importance value). Results revealed that competition among individuals was the major process during resource condition (rain) that shifted to facilitation during stress condition (summer). Soil organic carbon—soil phosphorus, diversity (Shannon index, evenness)—dominance (Simpson index), community maturity index—bare surface area were identified as major switch on and off points for such shifting, while soil moisture and grazing intensity were non-significant for such patterns. Results demonstrate that grassland species of the Indian arid region requires experimental quantification for the upper limits of significant exploratory variables.