Agricultural ecosystem services under climate change – Modelling grassland biodiversity

<p>European permanent grasslands not only represent a backbone for dairy and meet production, but also are hotspots of biodiversity, providing important ecosystem services to society. Understanding how climate variability and change affect the botanical composition of permanent grasslands is therefore essential for informing adaptation and helping farmers targeting sustainable development goals. It is also a key requirement for gauging climate change effects on forage quality, an aspect often overlooked in impact assessments. In this contribution, we present results of a modelling effort to understand short- and long-term changes in grassland biodiversity in response to climatic variations. We use <em>DynaGraM</em>, a recently developed process-based model for simulating community dynamics in multi-species managed grasslands. Earlier we demonstrated that <em>DynaGraM</em> is capable of representing the composition of permanent grasslands in the French Jura Mountains inferred from floristic relevés. In these earlier investigations, we also showed that the model predicts highest, resp. lowest vegetation diversity for extensive grazing, resp. extensive mowing. We further found that the time scales of responses to external perturbations largely dependent on management, with shorter time scales (of the order of 5 to 10 years) under grazing than under mowing (of the order of 50 years).</p><p>Here we apply the model to examine how increasing summer aridity affects the species composition of pastures in the same geographic area. To drive the model, we use a set of climate change scenarios obtained from the CMIP5 repository, which we downscaled with the help of the LARS-WG stochastic weather generator. The results underline that management intensity modulates the impact of summer drought on both yield as well as botanical diversity, with largest changes over time in the latter under extensive grazing. Apart from presenting the results in more detail, we also discuss their practical implications and opportunities to extend in future the scope of this work.</p>

Effects of Climate Change on Grassland Biodiversity and Productivity

Associated with livestock farming, grasslands with a high diversity of plant species are at the core of low-input fodder production worldwide [...]

Evolution of species complementarity in response to drought in a grassland biodiversity experiment

Growing threats from extreme climatic events and biodiversity loss have raised concerns about their interactive consequences for ecosystem functioning. Evidence suggests that biodiversity is crucial to buffer ecosystem functioning facing climatic extremes. However, whether evolutionary processes in species mixtures underpin such biodiversity-dependent stabilizing effects remains elusive. We tested this hypothesis by exposing experimental mixtures of grassland species to eight recurrent summer droughts vs. control in the field. Seed offspring of 12 species were subsequently grown individually, in monocultures or in 2-species mixtures and subjected to a novel drought event in the glasshouse. Comparing mixtures with monocultures, drought-selected plants showed greater between-species complementarity than ambient-selected plants when recovering from the drought event, which led to greater biodiversity effects on community productivity and better recovery of drought-selected mixtures after the drought. These findings suggest biodiversity can buffer the impacts of extreme climatic events through evolution of species complementarity.

Local Small Ruminant Grazing in the Monti Foy Area (Italy): The Relationship Between Grassland Biodiversity Maintenance and Added-Value Dairy Products

The literature indicates that grazing small ruminants, when adequately managed, contributes to grassland biodiversity maintenance. On the other hand, milk and cheese from grazing animals show higher nutritional and aromatic quality than those from stall-fed animals. The relationship between the two issues has rarely been addressed. This article provides information for a discussion of this relationship. First, two case studies are reported. Local breeds of small ruminants fed by grazing on pastures within the Special Area of Conservation “Monti Foy” in the Northwestern Basilicata region (Italy), with a stocking rate of 4.0 LU ha−1 year−1, showed the best effectiveness for the maintenance of grassland botanical biodiversity. Milk and cheese from pasture-fed goats showed higher contents of beneficial fatty acids, phenols, and vitamins A and E; higher degree of antioxidant protection; and richer volatile compound profiles, in particular for terpenes content. Finally, some recommendations for the management of grazing systems in similar mountain areas are offered, including a viable approach for land managers to preserve the grassland biodiversity of pastures and provide high-quality products that are valuable both for their nutritional quality and for their contribution to the economic sustainability of mountain communities.