Search

Ecological interactions are important for maintaining biodiversity and ecosystem functions. Particularly in stream biofilms, little is known about the distributional patterns of different taxonomic groups and their potential interactions along elevational gradients. Here, we investigated the bacterial and fungal community structures of stream biofilms across elevational gradients on Mount Kilimanjaro, and explored patterns of their distribution, diversity, community structures, and taxa co-occurrence. We found that fungal and bacterial richness were more convergent at higher elevations, while their community structures became significantly more divergent. Inferred network complexity and stability significantly decreased with increasing elevation for fungi, while an opposite trend was observed for bacteria. Further quantitative analyses showed that network structures of bacteria and fungi were more divergent as elevation increased. This pattern was strongly associated with shifts in abiotic factors, such as mean annual temperatures, water PO 4 3--P, and stream width. By constructing bipartite networks, we showed the fungal-bacterial network to be less redundant, more clustering, and unstable with increasing elevation. Abiotic factors (e.g., temperatures and stream width) and microbial community properties (i.e., structure and composition) significantly explained the dynamic changes in fungal-bacterial network properties. Taken together, this study provides evidence for the interplay of biotic and abiotic factors structuring potential microbial interactions in stream biofilms along a mountainside elevational gradient. • Differences in richness and structure of bacteria and fungi covaried with elevation. • Network complexity and stability were significantly higher for bacteria than fungi. • Network properties of bacteria and fungi were more divergent at higher elevations. • The stability of fungal-bacterial network strongly decreased at lower temperatures. • Biotic and abiotic factors significantly explain patterns in microbial co-occurrence. [ABSTRACT FROM AUTHOR]

Chemical nutrient amendment by human activities can lead to environmental impacts contributing to global biodiversity loss. However, the comprehensive understanding of how below- and above-ground biodiversity shifts under fertilization regimes in natural ecosystems remains elusive. Here, we conducted a seven-year field experiment (2011–2017) and examined the effects of different fertilization on plant biodiversity and soil belowground (prokaryotic and eukaryotic) communities in the alpine meadow of the Tibetan Plateau, based on data collected in 2017. Our results indicate that nitrogen addition promoted total plant biomass but reduced the plant species richness. Conversely, phosphorus enrichment did not promote plant biomass and exhibited an unimodal pattern with plant richness. In the belowground realm, distinct responses of soil prokaryotic and eukaryotic communities were observed under fertilizer application. Specifically, soil prokaryotic diversity decreased with nitrogen enrichment, correlating with shifts in soil pH. Similarly, soil eukaryotic diversity decreased with increased phosphorous inputs, aligning with the equilibrium between soil available and total phosphorus. We also established connections between these soil organism communities with above-ground plant richness and biomass. Overall, our study contributes to a better understanding of the sustainable impacts of human-induced nutrient enrichment on the natural environment. Future research should delve deeper into the long-term effects of fertilization on soil health and ecosystem functioning, aiming to achieve a balance between agricultural productivity and environmental conservation. • Soil prokaryotic and eukaryotic diversity decreased under nitrogen and phosphorus fertilization respectively. • Phosphorus fertilizer can alleviate nitrogen fertilizer induced soil acidification and promote soil diversity. • The changes of soil biodiversity were attributed to soil physicochemical characteristics induced by different fertilizer. • Soil prokaryotes and eukaryotes diversity was linked with the plant richness and biomass respectively. [ABSTRACT FROM AUTHOR]