Rewetting Denmark's organic soils

Historically, large areas of Danish meadows and wetlands have been used for grazing livestock, but since late19th century, state-led projects accelerated land reclamation and drainage of wetlands and cultivation of organic (peat) soils. Livestock were increasingly taken out of the open land and put into barns. Here they were fed with silage and concentrate (grain, corn and rapeseed) produced on the many drained organic soils. This transformation of the Danish agro-landscape contributed to the high-input, livestock intensive farming sector we see dominating today. A sector that is currently responsible for 30% of the national greenhouse gas (GHG) emissions with drained organic soils making up 1/3 of these emissions despite only occupying 7% of the arable land. Furthermore, emissions from high yielding cows are significant and a host of technical solutions including feed additives are researched and implemented as concerns for the ecological polycrises we face, grow in society.

To meet GHG emission reduction goals set in the ambitious Climate Law and new Tripartite agreement, Danish landscapes and the agricultural sector face radical changes. Reducing emissions from organic soils is considered the most cost-effective GHG mitigation solution for the agricultural sector. The issue is how to undo modernization’s legacies by rewetting Denmark’s 140.000 hectares of organic soils.

Two scenarios

The point of departure in Rewetting Futures is the widely used – and state encouraged – practice of populating rewetted organic soils with large herbivores to boost biodiversity and prevent natural colonization of shrubs and trees. Thereby a historically favored cultural landscape of river valleys, open and free of trees but hopefully full of biodiversity is created. However, these perceptions of particular landscapes with ruminants must be carefully thought through. Herbivores’ effect on landscape practices must also be investigated in depth in order to avoid pollution swooping – that is reducing emissions from former drained land with animals that ruminates and treats the wetlands in ways that result unintentionally leads to emissions.  In this project we explore how different types of biomes and agricultural production systems influence rewetted lands given the planetary crisis of our time?

This project identifies two possible rewetting futures where our research will investigate knowledge gaps and deliver robust public sector services on realistic GHG reduction potentials after rewetting of organic soils. The scenarios explore effects of 1) grazing cattle and 2) encroachment (no grazing) with swamp forests on peat carbon (C)/nitrogen (N) cycles and resultant climate effects.

In addition, REWETTING FUTURES also aims to build capacity at UCPH by bringing together anthropologists, historians, veterinarians and ecosystem scientists, as well as provide multidisciplinary science-based recommendations for the relevant political authorities (public sector services) for efficient and realistic assessment of Danish wetlands’ climate mitigation potential in the context of different future ecosystem trajectories that are currently not considered.