Seasonal variation of soil enzyme activities in relation to nutrient and carbon cycling in Senna alata (L.) Roxb invaded sites of Puducherry region, India

摘要

The present study is to understand the intrinsic ecological trait of invasive plant Senna alata relating to soil characteristics and seasonality distributed in the Puducherry region located under tropical climate. Plant biomass, soil parameters linked with soil enzyme activities are examined in six sites where S. alata is found growing. From the study, it is demonstrated that invasive species S. alata exhibits heterogeneity in invaded soil characteristics but variation in aboveground biomass (AGB) of S. aalata is not significant. Soil moisture and soil enzymes activities and AGB are significantly positively correlated whereas pH and EC negatively correlated. Seasonal variation in total nitrogen, phosphorus, and elements viz. Mg, Ca, and Na is inconsistent in their seasonality. Based on observations made and results obtained in the study, it is stated soil characteristics and their seasonality in the S. alata invaded soil is, site-specific resulting in heterogeneity; but such heterogeneity is not exhibited in AGB in six sites and it is, therefore, reported that such an idiosyncratic trait of S. alata is one of the potential traits influencing successful invasion by S. alata as mono-species population. The statistical analyses also confirmed the observation made. The outcome of the study would help to prepare management programmes to check spreading of invasive species so as to restore native plant diversity in and around Puducherry region.