Division of Agronomy

Extensive global wetland loss over the past three centuries - Article in Nature

08 February 2023: In an article published today in Nature an international research team led by Stanford University has reconstructed where and when wetlands were converted between the years 1700 and 2020, and why this was done. The Division Agronomy was involved in the study by providing information on agricultural projects to convert wetlands as well as about drainage in irrigated agriculture.

At least 3.4 million square kilometres of wetlands were mostly converted for use as farmland during the period studied: an area roughly the size of India. Wetland ecosystems have declined by about 21 to 35 percent over the past 300 years due to human intervention. This is far less than the 50 to 87 per cent loss estimated in previous studies. The lower estimate is probably due to the fact that the study did not focus solely on regions with historically high wetland losses. Wetland loss was greatest in the mid-20th century, with regional concentrations in Europe, the USA and China. More than 80 per cent of the former natural wetlands have been drained in Ireland, Hungary, Lithuania, Germany and Italy. In general, the former wetlands in the temperate regions have been particularly badly affected, while the remote boreal-arctic peatlands have remained comparatively intact.

This first systematic, data-based analysis of the extent of wetland loss worldwide over such a long period of time will contribute to a better understanding of the causes of wetland loss and the new data will enable to better quantify the effect of these land use changes in follow-up studies, for example on climate change, the loss of biodiversity, as well as on productivity increases in agriculture.

Additional information:
Article published in Nature
Article published in Nature (for readers without subscription to the journal
Link to a commentary by Nicholas J. Murray (James Cook University, Townsville, Australien)
Press release of the University Göttingen

Contact at the Division Agronomy:

Top: The Pietzmoor is the largest natural wetland in the Lüneburger Heide, Northeast Niedersachsen.
Center: Map of cumulative percent wetland loss per pixel estimated from 1700 to 2020 (yellow to red colors) and map of regions with dense present-day wetland and with low rates of loss (blue colors). This map shows the differences in the geographic distribution of anthropogenically-impacted wetlands versus non impacted wetlands and can be used to prioritize regions of wetland protection and restoration.
Bottom: The Orshinski Mokh peatland in Tver Province of the Russian Federation. A quarter of the peatland was drained for peat extraction between 1950-1990 primarily as fuel for a power station and supported a large settlement (Foto: Kirill Shakhmatov).

Snowmelt risk telecouplings for irrigated agriculture - Article in Nature Climate Change


31 October 2022: Climate change is altering the timing and magnitude of snowmelt, which may either directly or indirectly via global trade affect agriculture and livelihoods dependent on snowmelt.

In an article published today in Nature Climate Change global patterns of snowmelt and agricultural water uses are analyzed together with global trade flows of agricultural products to identify regions and crops most dependent on snowmelt water resources at the location of crop production and at the location of the consumption of the products.

We estimate that 16% of snowmelt used for irrigation is for agricultural products traded globally, of which over 70% is from five countries. Globally, we observe a prodigious snowmelt dependence and risk diffusion, with particularly evident importing of products at risk in western Europe. In Germany and the UK, local fraction of surface-water-irrigated agriculture supply exposed to snowmelt risks could increase from negligible to 16% and 10%, respectively, under a 2 °C warming. For Germany, the origin of the production at risk is Spain and Italy (fruits, vegetables and maize) and Pakistan, India and China (rice products).

The Division Agronomy contributed simulation results for crop specific monthly irrigation water requirements at global scale to the study and collaborated with research teams in the United States and China.

Link to the article in Nature Climate Change
Shared-Link to the article (for readers without journal subscription

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Development of an operational, multisectoral global drought hazard forecasting system - project OUTLAST funded by BMBF

dry soil global

01 September 2022: The Federal Ministry for Education and Research (BMBF) is funding the development of the first operational, multisectoral, global drought hazard forecasting system by the collaborative research project OUTLAST. The forecasting system will cover the sectors 1) water supply, 2) riverine ecosystems, 3) non-agricultural land ecosystems, 4) rainfed agriculture, and 5) irrigated agriculture. It will be implemented as a component of the Global Hydrological Status and Outlook System (HydroSOS) of the World Meteorological Organization (WMO) and will provide, with monthly updates, spatial indicators of drought hazard for a six month forecasting period.

OUTLAST will be coordinated by the Division Agronomy with partners at the Institute of Physical Geography (IPG) of the University of Frankfurt am Main, at the Institute of Meteorology and Climate Research (IMK-IFU) at the Karlsruhe Institute of Technology and at the International Centre for Water Resources and Global Change (ICWRGC) at the German Federal Institute of Hydrology Koblenz. In addition, the Division Agronomy will develop operational seasonal drought forecasts for irrigated and rainfed agriculture, integrate the forecasting system into the overall multi-sectoral forecasting system, and systematically evaluate the multi-sectoral forecasting system at a global scale as well as at a regional scale in cooperation with the regional pilot users.

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