CatchHedge - Carbon sequestration of hedgerows and field copses

Background and Objective

Hedges and field copses provide a variety of ecosystem services, such as soil and erosion protection, improvement of the microclimate, production of firewood and fodder, and make an important contribution to the conservation of biodiversity. So far, little attention has been paid to the potential of planting new hedgerows for climate protection. When new hedges are planted, additional CO₂ is bound in the growing biomass and as soil organic carbon in the long term.

According to the Federal Climate Protection Act, the land use, land-use change and forestry (LULUCF) sector has to improve its carbon binding potential (carbon sink). The planting of hedgerows offers a promising way to improve carbon storage in agricultural landscapes. From a farm managers’ view, such new plantings, however, raise additional costs such as increased labour input for maintenance, loss of arable land or lower yields due to shading.

In the CatchHedge project, we want to comprehensively quantify and evaluate the new planting of hedgerows and field copses as a climate protection option. We take into account the possible positive or negative side effects on neighbouring agricultural land and biodiversity as well as different use options and the profitability of hedges. With an overall economic assessment, we develop an efficient design and implementation paths for a hedgerow expansion support programme.

Target Group

Politics, agricultural practice, consultants, science, interested professional public

Approach

The project is carried out by the Thünen Institutes of Climate-Smart Agriculture, Biodiversity, Farm Economics, Rural Studies and Organic Farming. To optimise hedgerow expansion as a climate protection option and enhance implementability, we carry out the following steps:

• Collect data on the local water balance of hedgerow landscapes, yield effects of adjacent agricultural crops, and species richness at 12 existing hedgerow sites.
• Modelling of the biodiversity effect of hedgerows and development of scenarios for hedgerow planting in agricultural landscapes in order to optimise the positive effects for biodiversity and habitat connectivity.
• Analyse additional options for the use of hedgerows such as foliage fodder, shelterwoods for animals, wooden crops, agrowood production and use of biochar.
• Analyse the profitability of different options for the use of hedgerows including revenues from trading CO₂
• Specify target regions for the establishment of hedgerows, considering legal restrictions and synergies
• Assessment of the national implementation potential for climate protection hedgerows.
• Evaluate potential implementation options for promoting hedgerows and derive implementation costs based on the profitability analyses.

Our Research Questions

• What contribution can new hedgerows make as CO₂ sinks to climate mitigation in Germany?
• What is the optimal proportion and spatial distribution of hedge areas to support the biodiversity goals?
• Which are the use and exploitation options for economic valorisation of hedgerows?
• What are the individual farm costs of the establishment and maintenance of hedgerows in different regions of Germany?
• How should the legal and institutional framework for promoting new hedgerow establishment be designed?