Algal Community Dynamics and Underlying Driving Factors in Some Crenic Habitats of Kashmir Himalaya

Given the authoritative and well-documented publication records that crenic habitats support the substantial aquatic biodiversity, understanding of algal dynamics in response to anthropogenic and natural stressors in these crenic systems seems paramount. We sampled and monitored twelve freshwater springs for a period of 2 years from 2014 to 2015 to observe algal dynamics and the factors govern the distribution and dynamics. We used ANOVA, nMDS, PCA, ANOSIM, SIMPER, and BIOENV to reveal the key physicochemical variables influencing the distributional pattern and dynamics of algae. The analysis of variance (ANOVA, Tukey’s post hoc test) revealed significant difference among the springs with dominance of Bacillariophyceae (62%) followed by Chlorophyceae (18%) whereas nMDS ordination of abundance data in two-dimensional space resulted in a significant separation between spring sites (stress value of 0.13). One-way nested ANOSIM produced a significant distinction between periphytic algal communities in springs (global test R = 0.928, p = 0.001). The results of SIMPER revealed the highest average dissimilarity (60.95%) between springs S4 and S5, with the top five contributing families including Cyanophyceae (30.25%), Bacillariophyceae (25.98%), Rhodophyceae (16.74%), Chlorophyceae (13.64%), and Chrysophyceae (13.39%). BIOENV analysis of the periphytic algal data suggested that the assemblage pattern in all crenic habitats were controlled by discharge, conductivity, dissolved oxygen, total alkalinity, and total phosphorus. Since, springs are groundwater-dependent ecosystems acting as ecohydrologic refugia, any small change in groundwater discharge could strongly influence the ambient conditions (including water quality and temperature), which in turn influences the biological assemblage patterns and ecosystem services. Therefore, changes in discharge may provide information on possible future ecological change in the springs in relation to rising aridification.