Evaluating grassland ecosystem responses to management practices and climate change: results from the Global Change Experimental Facility in Bad Lauchstädt (Germany)

Abstract

Aims: Grassland ecosystems play a vital role in carbon (C) and nitrogen (N) cycling, influencing climate regulation and ecosystem resilience. However, their responses to different management practices and future climate conditions remain insufficiently understood. This study, conducted at the Global Change Experimental Facility (GCEF) in Bad Lauchstädt, Germany, examines how intensive and extensive grassland management under ambient and future climate scenarios affects plant productivity, soil C and N dynamics, and nutrient fluxes. Methods: Using the process-based CANDY model, we simulated key ecosystem parameters, including dry matter (DM) yield, net primary production (NPP), soil organic carbon (SOC), total nitrogen (Ntot), mineral nitrogen (Nmin), and N emissions. We hypothesized that intensive management enhances biomass production and SOC sequestration but increases N losses, whereas future climate conditions reduce productivity and alter nutrient cycling dynamics. Results: Model simulations revealed that intensive management significantly increased DM yields and NPP across climate scenarios, although future conditions slightly reduced productivity. SOC and Ntot increased in all treatments, underscoring the SOC sequestration potential of grasslands, whereas Nmin exhibited stronger seasonal fluctuations under intensive management due to fertilization effects. Notably, N emissions were highest in winter, likely due to reduced plant uptake. Conclusions: These results highlight the trade-offs between maximizing productivity and minimizing environmental impacts, emphasizing the need for optimized nutrient management to sustain ecosystem functions under changing climatic conditions. Our findings provide mechanistic insights into plant-soil interactions in managed grasslands, supporting the development of sustainable land-use strategies that balance productivity and long-term ecosystem stability.