Climate response of tree growth in Ethiopia along an altitudinal transect and implications on local climate and regional atmospheric circulation dynamics

• Applicant: Professor Dr. Achim Bräuning
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2007 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 42082865

• Final Report Year: 2010

Final Report Abstract

During the past 28 months of the project, 28 high-resolution electronic dendrometers were installed on 8 different tree species in Munessa Forest, Ethiopia, to register stem diameter variations in 30 min. intervals. Monthly wood samples wer collected from all trees to analyze the number and type of newly formed wood cells. Analyses of dendrometer curves indicated an ability of evergreen conifer tree species to initiate growth at the beginning of the short rainy season, whereas deciduous broadlefed species only showed stem swelling due to water uptake, but cambial growth was initiated only at the beginning of the rainy season. The combination of wood anatomical studies with stem increment measurements shows a high potential to distinguish stem diameter variations by water uptake from cambial growth phases and to determine the length of the growing season and the rate of wood cell fonmation. Strong growth increases of exotic plantation pnes and native Podocarpus trees indicate their potential to increase stem diameter increments after release from competition. Conifer species may form wood density variations that are not easily distguished from annual ring boundaries. First analyses of wood density measurements indicate living ages of the conifer Podocarpus falcatus of ca. 400 years, which offers excellent opportunities to reconstruct past climate variations by stable isotope analyses.

Publications

• Growth dynamics and their climatic control in new woHd (Ecuador) and old world (Ethiopia) Tropical Mountain forest trees of the Podocarpaceae family, gtö and ATBC Conference, Marburg (27.-30. July 2009)
  Bräuning A
  
• Seasonal growth dynamics of different tree species and their climatic control in Munessa Forest, Ethiopia. Annual Meeting AK Biogeographie, Bayreuth (15.-16. May 2009)
  Krepkowski J, Bräuning A, Gebrekirstos A
  
• Seasonal growth dynamics of different tree species in Munessa forest (Ethiopia) and their climatic control, gtö and ATBC Conference, Marburg (27.-30. July 2009)
  Krepkowski J, Bräuning A, Gebrekirstos A
  
• Seasonal growth dynamics of different tree species in Munessa forest (Ethiopia) and their climatic control. TRACE 2009, Otocec Slovenia (16.-19. April 2009)
  Bräuning A, Gebrekirstos A, Krepkowski J
  
• (2010): Seasonal growth dynamics of different tree species and their climatic control in Munessa Forest, Ethiopia. TRACE - Tree Rings in Archaeology, Climatology and Ecology Vol. 8:146-150
  Bräuning A, Krepkowski J, Gebrekirstos A
  
• Identifying species-specific growth boundaries from dendrometer measurements and wood anatomy in tropical mountain forests in Ethiopia. TRACE 2010, Freiburg (22.-25. April 2010)
  Krepkowski J, Bräuning A, Gebrekirstos A
  
• The comparison of four different tree species in Munessa Forest (Ethiopia): Seasonal growth dynamics and their climatic control. WorldDendro 2010 - 8th Conference on Dendrochronology (Rovaniemi, Finland, 13.-18. June 2010), poster contribution and conference abstract volume p. 338
  Krepkowski J, Bräuning A, Gebrekirstos A