Current Projects
Ecological Bases of Forest Growth
How is the growth and inter-specific competition of beech and oak affected by changing climate conditions With increasing temperature and declining (summer-) precipitation competition between tree species in Baden-Württemberg will change. Shifts in the relationship between Norway spruce and silver fir, but also between pedunculate and sessile beech are of particular interest for forest management in Baden-Württemberg. In the context of the PhD-project we will investigate how changing climate conditions will affect the competition between sessile oak and beech.
Growth responses and cell characteristics of silver fir (Abies alba) and Norway spruce (Picea abies) at different altitudes in south-western Germany This research project investigates the effect of climate and weather conditions on the growth of silver fir and Norway spruce. In the southern Black Forest, sites were selected based on the soil conditions, a south-west exposure and altitude. A differentiation has been made between the growth reaction of young (40-60 years) and older (80-120 years) trees. Radial growth and height data are supplemented by intra-annual parameters, such as cell structure (cell wall thickness, cell diameter) and wood density. These parameters will give more insight in the physical conditions the trees experienced. This data is combined with climate data, derived from the German Climate Service. This research will enable to derive estimates about tree-growth reactions, related to a different seasonality of precipitation patterns and drought events expected from future climate change scenarios.
Dendrochronological studies of driftwood in North-East Greenland. Reconstruction of postglacial climate variability, Arctic Ocean current and uplift process The “Karupelv Valley Project” in North-East Greenland is an ongoing long term study of lemming population dynamics and their interactions with predators.
Tree ring based reconstructions of cultural, environmental and climatic change in central Europe throughout the Holocene In this project, we will perform the first systematic extraction of climatic information contained in over 9000 oak (Quercus spp.) and silver fir (Abies alba) tree ring series spanning the past 3000 years. These data were collected over the past decade primarily from archaeological sites in northeast France and southwest Germany, and we believe this compilation has reached a critical mass (e.g., length, sample replication, no gaps) to allow paleoclimatic, ecological, and historical questions to be comprehensively addressed. By capitalizing upon the rich data archives and interdisciplinary synergies, the group of experts involved in this project expect to i) develop regional multi-millennial oak and fir chronologies, ii) analyze the within and between species reactions to drought, iii) reconstruct the intensity and spatiotemporal patterns of precipitation extremes and episodes (e.g., droughts), iv) link reconstructed changes in high to low-frequency hydroclimatic variation with synoptic forcing, and v) provide new assessments for the relationships between climate variation and human history.
Analysis of the influences of changing environmental conditions on radial displacement and secondary growth of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) along an altitudinal gradient in the south-western Black Forest
Climate-sensitive growth dynamics and drought resistance of Douglas-fir provenances (Pseudotsuga menziesii [Mirb.] Franco) The growth response of Douglas-fir provenances to climatic alterations is the main scope of this project. Differences in intra-annual growth dynamics between various provenances to changes in climate conditions will be investigated. Since growth reactions to meteorological variations are strongly genetically controlled differences in cambial activity responses between different provenances will be examined in order to detect differences in drought resistance. Particular attention will be given to extreme events such as heat and drought. Growth patterns will be studied on different temporal scales. The sensitivity of growth as well as the elasticity of growth under different climate scenarios will be assessed for the different provenances. Analyses of density variations and cell structures within tree rings are of special interest.
Forest growth research in the tropics and subtropics Increment zones in tropical trees can be induced by seasonally altering growth conditions like dry seasons or flooding periods (e.g., Varzéa forests in the Amazon region). The knowledge of the growth dynamics of tropical trees and their growth behavior under different and varying environmental conditions allows a better understanding of important structures and processes in tropical forest ecosystems. This knowledge forms the basis for the development of sustainable management strategies for different tropical forest ecosystems. Further it will help to get a better understanding of the functioning of tropical forests in the global climate system.The Institute for Forest Growth in collaboration with partners from the Universidade Federal do Paraná (Curitiba, Brazil) investigates the intra- and interannual growth dynamics of domestic tree species of the Brazilian Atlantic Rainforest (Mata Atlântica), one of the most endangered ecosystems of the World. At the same time the knowledge on the climatic impact on growth and wood quality of economically important plantation tree-species (such as Eucalyptus spp.) will be deepened. The Institute for Forest Growth aims to develop and apply innovative measurement and analysis methods adapted to tropical trees. In particular the newly developed method of High-Frequency Densitometry, by which large numbers of samples can be measured automatically, will be used.
Growth monitoring of spruce, pine, aspen and birch in the middle Taiga zone, Komi, NW-Russia In a close to nature mature mixed species stand at the Forest Research Station Lyaly the changes in radial dimension of the stems of spruce (Picea obovata), pine (Pinus sylvestris), aspen (Populus tremulus) and birch (Betula spec.) is measured in high time resolution. On a subset of the sample trees the electrical conductivity of the stem is measured in five minutes time steps. Simultaneously air temperature, precipitation, air humidity, as well as soil moisture is measured. At the site changes in the earth magnetic field are registered with a magnetometer. The analyses of the data will help to better understand the role of different environmental factors for tree growth with respect to short-, medium- and long-term responses of tree growth.
Project website: http://mekri.joensuu.fi/cambiforrus/
Monitoring the growth of Norway spruce, European beech and Scots pine in the Black Forest, on the Swabian Alb and in the upper Rhine valley On the Schauinsland near Freiburg, on the ARINUS plots in the forest district of Schluchsee, on research plots in the forest district of Tuttlingen and in the upper Rhine valley close to Hartheim, on various sites, changes in radial growth of the trunks of Norway spruce, European Beech and Scots pine are measured continuously with high resolution. In addition, at selected trees, radial variation of stem expansion in higher parts of the stem, on branches, as well as on roots are measured. Also, temperature (air temperature, cambial and soil temperature), air humidity and soil humidity, and phenophase dates are measured. It is expected that the analysis will provide information on the effects of various site factors on the research sites on the short-, medium- and long-term tree growth reactions. By comparing growth reactions at various elevations, a more detailed insight into the environmental effects on tree growth is expected.
This interdisciplinary research project (http://www.grancampo.de/) is co-ordinated by PD Dr. Rolf Kilian from the University of Trier, Germany. The aim is to examine the recent climate as well as highly resolving climate and environmental archives of the southernmost Andes. The project intends to improve the knowledge of global climatic changes and the human impact on it. Besides dendroecological analyses of tree-ring sequences, lake sediment archives, peat, pollen and tephra profiles are analysed. Cross sections and increment cores of Pilgerodendron uviferum, Nothofagus betuloides, N. antarctica and N. pumilio have been sampled along an East-West Transect in the southernmost Andes of Chile. Some of these samples are prepared, measured and analysed in the tree-ring laboratories of the Institute for Forest Growth. In addition to retrospective studies, radial growth of sample trees is continuously measured at field measurement stations using point dendrometers.
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