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Productivity and vegetation structure of three differently managed temperate grasslands

Author:
Zeeman, Matthias J., Shupe, Heather, Baessler, Cornelia, Ruehr, Nadine K.
Source:
Agriculture, ecosystems & environment 2019 v.270-271 pp. 129-148
ISSN:
0167-8809
Subject:
aboveground biomass, anthropogenic activities, automation, carbon, carbon dioxide, climatic factors, ecosystems, leaf area, meadows, nitrogen, simulation models, spring, vegetation structure, Germany
Abstract:
An improved regional assessment of the productivity of grasslands depends on comprehensive knowledge of the interactions between climatic drivers, vegetation properties and human activity. Managed grasslands in Europe display highly dynamic responses, which contribute to the challenge in making representative model simulations. Therefore, we investigated the relationships between vegetation state changes and productivity of meadow grasslands by comparing three study sites in Southern Germany (DE-Fen, DE-RbW, DE-Gwg), which are characterised by different management intensities and elevations. Weekly observations of vegetation height, leaf area, above-ground biomass and plant functional types were compared to estimates of the gross ecosystem productivity (GEP) determined from atmospheric surface exchange of carbon dioxide. We found that the cumulative GEP of these grasslands correlated positively with management intensity and negatively with elevation at the seasonal scale. The differences in above-ground vegetation properties among the three sites were most pronounced during spring and contributed to significant differences in annual carbon (200%) and nitrogen (4%) biomass yields. Nevertheless, when periods between harvests were considered individually, the relationship between GEP and above-ground biomass, leaf area and vegetation height appeared to follow unified patterns for all sites. In addition, our study highlights a substantial potential for systematic error based on the techniques used to quantify vegetation properties and a mitigating approach was evaluated that includes continuous automated observations of vegetation height. These outcomes can serve as a reference for modelling studies on the seasonal allocation of carbon and vegetation properties in managed humid temperate grassland systems.
Agid:
6227716