ena-STUDY-NEIKER TECNALIA-19-06-2015-13:06:40:961-125
Evaluation of soil health in mountain pastures using bacterial and fungal community structure combined with physicochemical and biological parameters
Mountain pastures provide critical socio-economic and ecological services. Poor management of these agroecosystems, or cessation of grazing, can cause loss of biodiversity and ecological functioning, disturbing e.g. carbon sequestration or resistance to erosion. Microorganisms, including fungi, are instrumental to soil ecosystem processes regulating these services, such as organic matter decomposition and nutrient cycling. Yet, the impact from pasture management and environmental parameters on microbial communities remain poorly understood. To this end, Agroecosystem Health Cards were designed, including important physicochemical and biological parameters, and amplicon sequencing targeting both prokaryotic and fungal community structure. Here, we utilise this approach to survey over 100 mountain and valley pasture sites, located in or near the Gorbeia Natural Park (Basque Country / Northern Spain) representing an area with pastoral tradition dating from the early neolithic, recently under threat from cessation. We also evaluate the impact from several controlled treatments. Clearing of bushes was found to significantly alter the prokaryotic and fungal community structure, and in sites with calcareous bedrock also the use of herbicide vs. mechanical clearing of ferns. Other treatments (fertilisation and liming) did not show significant effects. A striking correlation was noted between fungal and prokaryotic diversity (phyologenetic and functional). Although not evident from correlation network analysis, this was interpreted as an indication of interactions between fungal and prokaryotic taxa. Further, pH was indicated as the most important factor structuring microbial biodiversity, composition and interactions. Results verify the sensitivity and utility of the approach used, but also highlight the complexity and heterogeneity of natural soil habitats.
Mountain pastures provide critical socio-economic and ecological services. Poor management of these agroecosystems, or cessation of grazing, can cause loss of biodiversity and ecological functioning, disturbing e.g. carbon sequestration or resistance to erosion. Microorganisms, including fungi, are instrumental to soil ecosystem processes regulating these services, such as organic matter decomposition and nutrient cycling. Yet, the impact from pasture management and environmental parameters on microbial communities remain poorly understood. To this end, Agroecosystem Health Cards were designed, including important physicochemical and biological parameters, and amplicon sequencing targeting both prokaryotic and fungal community structure. Here, we utilise this approach to survey over 100 mountain and valley pasture sites, located in or near the Gorbeia Natural Park (Basque Country / Northern Spain) representing an area with pastoral tradition dating from the early neolithic, recently under threat from cessation. We also evaluate the impact from several controlled treatments. Clearing of bushes was found to significantly alter the prokaryotic and fungal community structure, and in sites with calcareous bedrock also the use of herbicide vs. mechanical clearing of ferns. Other treatments (fertilisation and liming) did not show significant effects. A striking correlation was noted between fungal and prokaryotic diversity (phyologenetic and functional). Although not evident from correlation network analysis, this was interpreted as an indication of interactions between fungal and prokaryotic taxa. Further, pH was indicated as the most important factor structuring microbial biodiversity, composition and interactions. Results verify the sensitivity and utility of the approach used, but also highlight the complexity and heterogeneity of natural soil habitats.