Dossier

Forests and water

Marko Natkhin, Tanja Sanders | 19.02.2025

WO Institute of Forest Ecosystems

Forests fulfil a variety of functions. Clean water is particularly important. With climate change, we are experiencing ever longer periods of drought, interrupted by heavy rainfall events. What effects this has on infiltration and therefore also on groundwater is an important research question.

Drone shot of a forest from above with a bare area in the forest. — View of various conifers with disturbed area in the foreground.

The face of forests in Germany is marked by extensive a spruce populations in the south and large scale pine population in the north. This is a result of the human activity over the past 250 years.

In future, the forest landscape should be characterised by mixed stands of coniferous and deciduous trees with as diverse a structure as possible. This is the aim of forest reorganisation throughout Germany. This also influences the water balance of the forests. How the water balance changes in the individual phases of forest reorganisation is an important research topic at the Thünen Institute.

Further Informations

Spathelf P, Natkhin M, Thom D, Puhlmann H, Bolte A, Sass-Klaassen U, Bauhus J, Sanders TGM (2025); Fakten zum Thema: Wald und Wassermangel. AFZ Der Wald 80(1):36-40 (in German)
Natkhin M, Sanders TGM, Holzhausen M; (2022) Der Einfluss von Wald und Witterung auf die Tiefenversickerung. Eberswalde: Thünen-Institut für Waldökosysteme, 2 p, Project Brief Thünen Inst 2022/03, DOI:10.3220/PB1643027675000 (in German)
Bolte A, Sanders TGM, Natkhin M, Czajkowski T, Chakraborty T, Liesebach H, Kersten B, Mader M, Liesebach M, Lenz C, Lautner S, Löffler S, Kätzel R; (2021); Coming from dry regions Norway spruce seedlings suffer less under drought. Eberswalde: Thünen-Institut für Waldökosysteme, 2 p, Project Brief Thünen Inst 2021/16a, DOI:10.3220/PB1623066406000

Expertise

2025: Poor starting conditions for forests

Forests are affected by an unusually dry spring: On our research site “Britz”, only a quarter of the usual precipitation since March. The result: poor growing conditions and hardly any groundwater recharge.

2024: Good conditions for spring budburst

There has not been this much rain in winter since the series of measurements began in 1993: between November 2023 and February 2024, 311 millimetres of precipitation fell at the Thünen research station in Britz. This means that the plant world has the best conditions for spring - at least on the permeable sandy soils of Brandenburg.

The role of tree types on the agricultural water household

The impact of different tree species on the course of new ground water development of is a focus of our study with large lysimeters.

How do different provenances of Scots pine respond to drought?

Drought tolerance in pine forests is a topic with increasing impotrance, due to the climate change. In a joint project, researchers have tested various provenances of Scots pine.

Water deficiency – Forests in danger?

During dry periods in spring the forest thirsts. Does this drought cause any damage at that time? We know that the tree species show different adaptations to drought.

FAQ

Forest and floods

Floods are a regular feature of riverine landscapes. Their occurrence depends on various factors: Precipitation, relief and subsoil, vegetation and soil management. Whether a flood occurs, however, is largely determined by how saturated the forest floor is with water.

Forest damage due to drought and heat

Forests in Germany are still suffering from the hot and dry weather in 2018 to 2020 and. The situation only eased slightly in 2023 with precipitation above the long-term average. Especially the winter of 2023/24 set a new record. Our FAQ provides answers to questions on forests and climate.

Video

The Field Laboratory "Drylab"

Scientists in Eberswalde are using the "Drylab" field laboratory to investigate how young beech trees of different origins react to drought. The film presents the "Drylab".

Forests and water

Filtering water, storing water, using water: those are among the life maintaining functions of our forests. This film shows how we observe and study the trees at work (in German).