Impacts and future of land use
Land provides the basis for our livelihoods – but the current extend of human influence, magnitude and rate of change of resource use is historically unprecedented and not sustainable. The way humans make use of terrestrial ecosystems clearly will have to improve, especially since changing climate and rising CO2 concentrations will become additional key factors, which affect growing conditions for crops, pastures, and forests. With climate change, the productivity of different regions will shift, at the same time that changing population and economic growth cause new patterns of demand. As global patterns of land use change in response, those land-use changes will feed back onto climate change through, for example, the absorption or release of CO2.
Forests are especially vulnerable to climate change, because the life-span of trees means that adaptation is slow at the ecosystem level. On the other hand, forests take up and store large amounts of carbon, and thus could help counteract climate change. Forests in Europe are strongly managed, including planting of species outside their natural range, where they are even more sensitive to droughts and increasing temperatures. Future climate- and CO2-mediated changes in productivity will occur alongside deforestation, forest planting, and management to determine exactly what the forests of the future look like.
It is impossible to predict exactly how land use will evolve in the future, and how that evolution will affect ecosystems, the climate and society. However, policymakers and other stakeholders need to get a sense of the possibilities in order to, for example, make informed decisions about the effectiveness of possible climate change mitigation strategies.
The Land Ecosystem Modeling Group is engaged in several lines of research using the LPJ-GUESS dynamic global vegetation model to investigate the future of land-use change in the Earth system.
We are using LPJ-GUESS to investigate how climate change, land use/cover change and agricultural management can affect soil properties and yields. With a regional focus on Eastern Africa, where severe land degradation is a major challenge, we explore how alternative crop management strategies (such as no-tillage, cover crops, fertilizer and manure application) and forest planting could restore degraded soils and return multiple benefits such as improved drought resilience, enhanced fertility, and increased carbon sequestration.
In regard to an improved consideration of managed forests, we are incorporating different types of forest management into LPJ-GUESS to explore how management has affected carbon pools and fluxes in Europe’s forests in the past, as well as how future management options can support climate change mitigation policy.
And in the Land System Modular Model (LandSyMM), LPJ-GUESS is coupled with the PLUM land-use model to explore future land use (e.g., agriculture, forestry) based on simulated crop, pasture and forest productivity under different climate, and management strategies, to produce maps of land use areas and management inputs. This allows us to explore, for example, the impacts of climate change and associated land-use change on ecosystem services under a range of possible future scenarios. In work ongoing the IMOGEN climate emulator will also be coupled, seeking to better account for feedbacks between land-use change and climate change.