Sustainable use of alpine and pre-alpine grassland soils in a changing climate

Project number: 031B0027 A-E
Contact: PD Dr. Ralf Kiese, Karlsruhe Institute of Technology
Project team: Technische Universität München, Universität Bayreuth, Helmholtz Zentrum München, WWL Umweltplanung und Geoinformatik GbR, Bayrische Landesanstalt für Landwirtschaft

Duration: 01.10.2018-31.10.2021

Project aim 
SUSALPS aims to provide a holistic, evidence-based and process-focused understanding of the responses of key pre-alpine and alpine grassland soil functions to present day and future climate and land management changes, thereby considering specific socio-economic conditions in given regions. Based on this, we want to develop and implement sustainable climate smart management practices for pre-alpine and alpine grassland ecosystems 
Alpine and pre-alpine grasslands of S-Germany cover an area > 1 Mio ha and provide important economic value via fodder used for milk and meat production. Grassland soils also support environmental key functions such as carbon and nitrogen storage, water retention, erosion control and biodiversity. At present, these soils functions are jeopardized by climate change and moreover rapid land use and management changes, which both are likely to be accelerated in coming decades 
Expected results 

SUSALPS experimental work quantifies impacts of climate and land management changes on plant and microbial diversity, nutrient use efficiencies, biomass production and quality, soil carbon and nitrogen storage and turnover, greenhouse gas emissions and nutrient leaching at several sites covering different elevations and thus, climatic conditions. Results will be used to


   1. develop early warning systems (agri-ecological indicators) indicating potential negative impacts on grassland ecosystems and

   2. inform and validate biogeochemical models which will be used in scenario studies to evaluate best management options for sustainable use of        grassland ecosystems.


To allow the assessment of joint socio-economic impacts of current and climate smart grassland management practices the biogeochemical model will be coupled to a socio-economic model. This decision support system will represent a practical tool which will help stakeholders and farmers to understand consequences of grassland management on soil functions and other ecosystem services.


Project results from phase 1

The holistic SUSALPS approach improved the understanding of pre-alpine/ alpine grasslands carbon and nitrogen cycling, importance of plant and microbial diversity and activities for nutrient cycling and ecosystem resilience and an assessment of the socio-economic role of grasslands in the study region. Key findings are that grassland plant nitrogen (N) uptake is high and grassland N losses are dominated by N2 and by NH3 emissions after manure application, leading to overall small losses and low environmental risks for nitrate leaching and N2O emissions. Plant N export and ecosystem N losses are higher than N inputs, which indicates that plant growth is also promoted by release of N from soil organic matter mineralization. On the long term this can lead to decreasing soil C and N stocks with negative effects on e.g. soil fertility.


Expected results phase2

Based on the findings of phase 1, the research goals were expanded and adjusted as follows:

Disentangle interactions of climate and management effects on soil organic matter (C and N) dynamics and identifying consequences on grassland soil functions Assess impacts of climate and legislation (DüV) driven management changes on grassland nutrient use efficiency/ environmental losses, quantity and quality of yields

Assess impacts of climate and management on microbial and plant diversity and yields and testing of new seed mixtures.