Effect of Disturbance on Micro-environment, Soil Properties and Microbial Biomass in Subtropical Broadleaved Forests of Meghalaya, India

Abstract

Disturbance of forest ecosystem causes changes in vegetation structure, micro-environmental conditions, soil properties and microbial biomass. Therefore, an understanding of the role of microbes and its activities in sustaining and regulating the soil fertility in forest ecosystems along a disturbance gradient are necessary. The present study investigates the effects of human disturbances on micro-environmental parameters, soil properties and microbial biomass in subtropical broad leaved forests of Cherrapunjee plateau of Meghalaya, northeast India. The results for micro-environmental parameters (light intensity, relative humidity, air, and soil temperature) varied significantly (p < 0.05) along a disturbance gradient. Disturbance also had a significant effect on soil properties with high values of soil moisture content (SMC, 24.93–25.57%), soil organic carbon (SOC, 5.23–5.60 g/kg), total kjeldahl Nitrogen (TKN, 3.45–3.87 g/kg) and extractable Phosphorous (Ex. P, 4.24–5.12 mg/kg) in low disturbed sites as compared to highly disturbed sites (SMC = 21.01–23.93%; SOC = 4.26–4.53 g/kg; TKN = 2.70–3.35 g/kg; Ex. P = 3.62–3.90 mg/kg). The soil microbial biomass Carbon, Nitrogen and Phosphorous (MBC, MBN and MBP) also varied significantly (p < 0.05) across the disturbance gradient and seasons. It showed a strong correlation with SOC, TKN and Ex. P indicating a close relationship between microbial biomass and the status of the soil nutrient pool. Percentage contribution of MBC to SOC, MBN to TKN and MBP to Ex. P ranged from 1.15 to 1.40%, 1.82–2.43 and 4.91–6.91%, respectively. The present study highlights the complex relationships between disturbance, micro-environmental conditions, soil- properties and -microbial biomass in these forests. Therefore, sustainable practices that minimize disturbances and promote ecosystem restoration require rights-based land-use practices, prioritizing biodiversity conservation, and creating awareness among local communities.