Stellvertretende Institutsleitung

Office substitute

Katja Pilop 

Laura Feßler

wo-sekretariat@thuenen.de

Office

Daniela Hohenstern
Institute of Forest Ecosystems

Alfred-Möller-Straße 1, Haus 41/42
16225 Eberswalde
Phone: +49 3334 3820 300
Fax: +49 3334 3820 354
daniela.hohenstern@thuenen.de

Contact persons for



Forest conversion and water budget

Project

 (c) Thünen-Institut für Waldökosysteme

Hydrological effects of forest conversion of pure pine stands in broadleaf forests and mixed pine-broadleaf forests

The present pattern of forests in Germany is dominated by spacious spruce stands in the south and large-scale Scots pine forests in the north. These stands are endangered by calamities. The future distribution of forests should be formed by multifariously structured mixed stands as possible. This intention is pursued by the forest conversion of the federal state Brandenburg as well. The programme of forest conversion needs scientific attendance and foundation.

Background and Objective

Along with the question for the contribution of mixed forests to landscape water budget, investigations of water consumption and growth of forests form a substantial research focus. These research fields have to consider increasing water shortage within the vegetation period. Against the background of climate change this question gains in importance.

Underplanting of pure Scots pine stands with beeches and oaks is partly restricted by the hydro-ecological conditions of the local region. It has to be scrutinised how these conditions are modified by silviculture and how they can be influenced by changes of stand structure.

Focal point of research are changes of water budget in up-growing mixed stand of pine, beech and oak in comparison with pure Scots pine stands and resultant relevant consequences.

In the foreground there are the following questions:

  • How are the water fluxes modified by the upgrowing understorey of beeches and oaks and how change the particular components of evaporation by the structural conversion from pure pine stands toward mixed stands?
  • How does the modified water flux influence the amount of seepage water and thereby the gains of water management?

Approach

In order to investigate the hydrological conditions of just established mixed stands, existing pure Scots pine stands at large lysimeters of the research station Britz were underplanted with beech and oak in the year 2000. Besides the investigations concerning the water budget of younger mixed stands, cause-and-effect-relationships between drought and tree growth are researched. The great advantage of large lysimeters consists in the opportunity of balancing of energy and water fluxes with high temporal resolution under exactly differentiating conditions. This trait of lysimeters enables the research under miscellaneous questions. By use of dendrometers, for instance, climate-growth relationships can be analysed. Lysimeters serve as an important tool to parameterise process models for energy and water fluxes if innovative measuring techniques are used (weighing cells for determination of moisture changes and seepage fluxes, soil moisture sensors and tensiometers to observe seepage water movement).

Besides of large lysimeters for the determination of evapotranspiration of beeches and oaks in the understorey, special, weighable lysimeters were developed and mounted into mixed stands of pine, beech and oak.

The evapotranspiration of beeches and oaks, grown at undisturbed soil monoliths, can be determined with an accuracy of 0,1 mm. Another field of application of weighable lysimeters consists in the investigation of effects of watershortage on growth and water budget of young beeches and oaks exposed to different degrees of withering.

Preliminary Results

First results show that by management of the stand density can influence the water factor regarding tree growth and landscape water balance positive for long-term. In the course of the conversion process positive effects develop besides the soil moisture also at the plant nutrient matter with effects on the tree growth.

 

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Involved Thünen-Partners


More Information

Projekt type:
Project status: ongoing

Publications

Results 6 - 10 of 14

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  1. Müller J (2014) Bewertung der "Wasserdienstleistung" im Zuge des Waldumbaus vom Kiefernforst zum Buchenwald. In: Wälder der Zukunft : Lebensraum, Ressourcenschutz und Rohstoffversorgung; Tagungsband zur 13. Forstwissenschaftlichen Tagung an der Technischen Universität Dresden, Fachrichtung Forstwissenschaften Tharandt, vom 17. bis 20. September 2014. Dresden: Technische Univ, p 15
  2. Müller J (2013) Die Bedeutung der Baumarten für den Landschaftswasserhaushalt. In: Bericht / 15. Gumpensteiner Lysimetertagung : Lysimeterforschung als Bestandteil der Entscheidungsfindung ; am 16. und 17. April 2013 . Irdning: Lehr- und Forschungszentrum für Landwirtschaft Raumberg-Gumpenstein, pp 49-56
  3. Beck W, Müller J, Sanders TGM (2013) Intra-annual weather conditions, ecosystem water fluxes and tree growth reactions - hydroecological and dendroecological findings from intensive sampling plots with different forest tree species. In: Helle G, Gärtner H, Beck W, Heinrich I, Heußner KU, Müller A, Sanders TGM (eds) Proceedings of the Dendrosymposium 2012: May 8th - 12th, 2012 in Potsdam and Eberswalde, Germany, (Scientific Technical Report), 11th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) . Potsdam: Deutsches Geoforschungszentrum, pp 94-102, DOI:10.2312/GFZ.b103-13058
  4. Müller J (2012) Auswirkungen von waldstrukturellen Veränderungen auf die hydroökologischen Bedingungen in den Beständen im Zuge des Waldumbaus. In: Grünewald U (ed) Wasserbezogene Anpassungsmaßnahmen an den Landschafts- und Klimawandel. Stuttgart: Schweizerbart, pp 280-291
  5. Müller J (2012) Die Buche - das "Wasserwerk" im Walde : Die Bedeutung der Buche für den Landschaftswasserhaushalt. In: Moog M (ed) Wald, Umwelt, Energie : FowiTa - Forstwissenschaftliche Tagung 2012 ; Tagungsband zur 12. Forstwissenschaftlichen Tagung an der Technischen Universität München vom 19. bis 22. September 2012 . Bad Orb: Sauerländer, p 33

Results 6 - 10 of 14

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