Time filter

Source Type

Cornille A.,French National Center for Scientific Research | Cornille A.,University Paris - Sud | Cornille A.,Agro ParisTech | Giraud T.,French National Center for Scientific Research | And 14 more authors.
Molecular Ecology | Year: 2013

Understanding the way in which the climatic oscillations of the Quaternary Period have shaped the distribution and genetic structure of extant tree species provides insight into the processes driving species diversification, distribution and survival. Deciphering the genetic consequences of past climatic change is also critical for the conservation and sustainable management of forest and tree genetic resources, a timely endeavour as the Earth heads into a period of fast climate change. We used a combination of genetic data and ecological niche models to investigate the historical patterns of biogeographic range expansion of a wild fruit tree, the European crabapple (Malus sylvestris), a wild contributor to the domesticated apple. Both climatic predictions for the last glacial maximum and analyses of microsatellite variation indicated that M. sylvestris experienced range contraction and fragmentation. Bayesian clustering analyses revealed a clear pattern of genetic structure, with one genetic cluster spanning a large area in Western Europe and two other genetic clusters with a more limited distribution range in Eastern Europe, one around the Carpathian Mountains and the other restricted to the Balkan Peninsula. Approximate Bayesian computation appeared to be a powerful technique for inferring the history of these clusters, supporting a scenario of simultaneous differentiation of three separate glacial refugia. Admixture between these three populations was found in their suture zones. A weak isolation by distance pattern was detected within each population, indicating a high extent of historical gene flow for the European crabapple. © 2013 Blackwell Publishing Ltd.


Daume S.,University of Gottingen | Daume S.,University of Stockholm | Albert M.,Northwest German Forest Research Institute | von Gadow K.,University of Gottingen | von Gadow K.,Stellenbosch University
Forest Ecology and Management | Year: 2014

Forest monitoring captures human impacts and other biotic and abiotic influences on forests and is a pre-requisite for the sustainable use and protection of forest ecosystems. Forest inventories for example are a key tool to plan sustainable harvesting, whereas Forest Observational Studies provide the empirical basis for an improved understanding and long-term evaluation of forest ecosystem dynamics. To that end detailed data is collected at stand level, often integrated in larger forest observational networks, which feeds into forest ecosystem models. Forests exist however in a constantly changing societal context and the direct or indirect impact of human activity has become a crucial driver on all types of ecosystems. The Millenium Ecosystem Assessment underlines the linkage between social and ecological systems, highlighting the centrality of ecosystem services to human well-being and the requirement for ecosystem monitoring in the anthropocene to provide a holistic view of ecosystems as social-ecological systems. Framing information about the social context of a forest ecosystem, gaining the expertise and providing resources to collect this type of information is usually outside the scope of data collection for forest inventories and monitoring. Studies in other domains faced a similar challenge and turned to data mining informal online information sources to supplement traditional monitoring and data collection strategies. This paper explores how forest monitoring approaches especially Forest Observational Studies with their long-term and large-scale focus may be complemented by social media mining. We outline (a) how social media mining methods from other domains could be applied to forest monitoring, (b) discuss identification of stakeholders, events and demands on forest ecosystems as examples of social contextual information that could be obtained via this route and (c) explain how this information could be automatically mined from social media, online news and other similar online information sources. The proposed approach is discussed on the basis of examples from a broad set of other domains. © 2013 Elsevier B.V.


PubMed | University of Tübingen, Helmholtz Center Munich, Albert Ludwigs University of Freiburg, University of Hohenheim and 3 more.
Type: | Journal: Journal of microbiological methods | Year: 2016

In an inter-laboratory trial, gaseous (CFE) and liquid fumigation (Resin) based methods for measuring microbial phosphorus (Pmic) were compared, based on the analysis of soil samples from five forests, which differ in their P stocks. Both methods reliably detected the same Pmic gradient in the different soils. However, when the individual recovery rates of spiked P were taken into account, the CFE based methods consistently generated higher Pmic values (factor 2) compared to the Resin based approaches.


Bittner S.,Helmholtz Center for Environmental Research | Talkner U.,University of Gottingen | Talkner U.,Northwest German Forest Research Institute | Kramer I.,University of Gottingen | And 4 more authors.
Agricultural and Forest Meteorology | Year: 2010

This modeling study used recent observations at a temperate broad-leaved forest in Central Germany to calculate water balances of a Fagus sylvatica monoculture and mixed stands of F. sylvatica, Tilia spp., Acer spp., Carpinus betulus, Fraxinus excelsior and Quercus robur. To simulate soil water flow the modeling framework Expert-N was applied which combines models that describe the physiological and hydrological processes of the plant-soil system including models of evapotranspiration (Penman-Monteith equation), interception (revised Gash model) and soil water flow (Richards equation). Measurements of rainfall partitioning, volumetric soil water content, evapotranspiration and tree transpiration provided reliable data for the parameterization and the calibration of the model for three stands of different diversity levels. They allowed to include species specific physiological (transpiration rates, response to dry soil water conditions) and structural (leaf area dynamics) characteristics. During the 3-year long observation period 2005-2007 the mean yearly precipitation was 652. mm, the simulated mean yearly interception loss of the three observed forest stands was between 219 and 272. mm, the transpiration accounted for 197-225. mm, the forest floor evaporation for 96-104. mm, the drainage for 16-60. mm and the runoff for 13-50. mm. The calculations of the water balance were sensitive to the species composition of the forest and showed differences of rainfall interception and root water uptake between the stands. The applied stand-level model was able to simulate the water dynamics of the monospecific and mixed forest stands. It was shown that differences in drought tolerance of tree species can have a strong impact on the simulated soil water extraction during periods when available soil water is low. © 2010 Elsevier B.V.


Isik K.,Akdeniz University | Kleinschmit J.,Lower Saxony Forest Research Institute | Steiner W.,Northwest German Forest Research Institute
Forest Science | Year: 2010

Heights of rooted cuttings from 40 clones of Norway spruce (Picea abies [L.] Karst) were measured at ages 3, 5, 8, 10, 13, and 17 from rooting at seven test environments in northern Germany. To determine the optimal age for juvenile selection for height, age-related changes in variance components, clone-mean heritability, and age-age correlations were estimated. Partitions of variance components were essentially constant after age 8. Clone-mean heritabilities were highest at age 3 (0.94) and were essentially stable after age 5. Age-age correlations were generally high between similar ages but declined as the difference between pairs of measurement ages increased. Genetic correlations were greater than corresponding phenotypic correlations but were similar in value. Trait-trait correlations between height and diameter (rG 0.83) and height and volume (G 0.90) at age 17 were also high. Simple linear regressions of genetic and phenotypic age-age correlations on LAR (natural log of the ratio of younger age to older age) were significant (R2 ≥ 0.76). Predicted efficiencies of selection suggested that for a rotation age of 60 years, the optimum selection age would be as early as 13 years. Furthermore, gains per year would be increased by about 1 1/2 times if selections were made at about age 15 rather than age 60.


Bubner B.,Thunen Institute of Forest Genetics | Wunder S.,Humboldt University of Berlin | Zaspel I.,Thunen Institute of Forest Genetics | Zander M.,Humboldt University of Berlin | And 3 more authors.
Fungal Biology | Year: 2014

Melampsora willow rusts are the most important fungal pathogens in short rotation coppices of biomass willows. In the past, breeding programmes for rust resistant biomass willows concentrated on the distinction of races within the forma specialis Melampsora larici-epitea f. sp. larici-epitea typica that colonized Salix viminalis and related clones. In a new breeding program that is based on a wider range of willow species it is necessary to identify further Melampsora species and formae specialis that are pathogens of willow species other than S. viminalis. Therefore, three stock collections with Salix daphnoides, Salix purpurea, and other shrub willow species (including S. viminalis) species were sampled in north-eastern Germany. A fourth stock collection in central Germany contributed rusts of tree willows (. Salix fragilis and S. alix alba) and the large shrub Salix caprea. Out of 156 rust samples, 149 were successfully sequenced for ITS rDNA. A phylogenetic analysis combining Neighbour-Joining, Maximum-Likelihood and Bayesian analysis revealed six species: Melampsora ribesii-purpureae, Melampsora allii-salicis-albae, Melampsora sp. aff. allii-fragilis, Melampsora larici-pentandrae, Melampsora larici-caprearum, and Melampsora larici-epitea. The first four species were found exclusively on the expected hosts. Melampsora larici-caprearum had a wider host range comprising S. caprea and S. viminalis hybrids. Melampsora larici-epitea can be further differentiated into two formae speciales. The forma specialis larici-epitea typica (59 samples) colonized Salix viminalis clones, Salix purpurea, Salix×. dasyclados, and Salix×. aquatica. In contrast to this relatively broad host range, f. sp. larici-daphnoides (65 samples) was found exclusively on Salix daphnoides. With the distinction and identification of the rust species/formae speciales it is now possible to test for race-specific resistances in a more targeted manner within the determined pairings of rust and willow species. © 2014 The British Mycological Society.


This study underlines the often under-estimated importance of forest ownership and land tenure in European forest biodiversity studies which are crucial for the management, structure, and tree species composition of woodland. In particular it is assumed that, in regions with both state-owned forests and smaller private forests, the latter contain more relict habitats shaped by historical woodland management practices. A government decree of 1721, a political compromise, was crucial to the present-day woodland ownership pattern and distribution of woodland habitats in the Osnabrück region (northwest Germany). It resulted in the privatization of woodlands held in common for centuries and created a huge number of small, private forest parcels in the 18th century. These developments are discussed in relation to Europe-wide processes in forest affairs. Mainly due to the low economic importance of these forest parcels, as well as the individualism of the forest owners, coppice structures providing valuable habitats have persisted until today. For instance, over-aged coppice stands provide important habitat conditions for saproxylic species and unique herbaceous layers. These valuable habitats must be protected while creating new coppice stands to eventually take their place in future decades. Management plans for Natura 2000 sites in the Osnabrück region should address this problem while reconciling any conflict of interests between private owners and nature conservation organizations. Researchers are encouraged to give more consideration to the important relationship between current woodland biodiversity and the history of forest ownership patterns. © SISEF.


Hennig A.,University of Gottingen | Hennig A.,Northwest German Forest Research Institute | Kleinschmit J.R.G.,Northwest German Forest Research Institute | Schoneberg S.,University of Gottingen | And 3 more authors.
Frontiers in Plant Science | Year: 2015

Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites. © 2015 Hennig, Kleinschmit, Schoneberg, Löffler, Janßen and Polle.


Talkner U.,University of Gottingen | Talkner U.,Northwest German Forest Research Institute | Kramer I.,University of Gottingen | Kramer I.,Leibniz Institute for Baltic Sea Research | And 2 more authors.
Plant and Soil | Year: 2010

Atmospheric deposition is an important nutrient input to forests. The chemical composition of the rainfall is altered by the forest canopy due to interception and canopy exchange. Bulk deposition and stand deposition (throughfall plus stemflow) of Na+, Cl-, K+, Ca2+, Mg2+, PO43-, SO42-, H+, Mn2+, Al3+, Fe2+, NH4+, NO3-and Norg were measured in nine deciduous forest plots with different tree species diversity in central Germany. Interception deposition and canopy exchange rates were calculated with a canopy budget model. The investigated forest plots were pure beech (Fagus sylvatica L.) plots, three-species plots (Fagus sylvatica, Tilia cordata Mill. or T. platyphyllos Scop. and Fraxinus excelsior L.) and five-species plots (Fagus sylvatica, T. cordata or T. platyphyllos, Fraxinus excelsior, Acer platanoides L., A. pseudoplatanus L. or A. campestre L. and Carpinus betulus L.). The interception deposition of all ions was highest in pure beech plots and was negatively related to the Shannon index. The stand deposition of K+, Ca2+, Mg2+ and PO43- was higher in mixed species plots than in pure beech plots due to higher canopy leaching rates in the mixed species plots. The acid input to the canopy and to the soil was higher in pure beech plots than in mixed species plots. The high canopy leaching rates of Mn2+ in pure beech plots indicated differences in soil properties between the plot types. Indeed, pH, effective cation exchange capacity and base saturation were lower in pure beech plots. This may have contributed to the lower leaching rates of K+, Ca2+ and Mg2+ compared to the mixed species plots. However, foliar analyses indicated differences in the ion status among the tree species, which may additionally have influenced canopy exchange. In conclusion, the nutrient input to the soil resulting from deposition and canopy leaching was higher in mixed species plots than in pure beech plots, whereas the acid input was highest in pure beech plots. © 2010 The Author(s).


PubMed | Institute for Plant Protection in Horticulture and Forests, Northwest German Forest Research Institute and Staatsbetrieb Sachsenforst
Type: | Journal: Pest management science | Year: 2016

Several rodent species can damage forest trees, especially at young tree age in afforestation. Population outbreaks of field voles (Microtus agrestis L.) and bank voles (Myodes glareolus Schreber) in particular can cause losses.Analyses of long-term time series indicate good synchrony of population abundance in rodent species associated with damage in forestry. This synchrony could be related to the effect of beech (Fagus spec.) mast in the previous year on population growth rates of both species. In shorter time series from Eastern Germany, damage in forestry was mostly associated with autumn abundances of rodents. Environmental factors such as beech mast and snow cover did not explain additional variation in rodent damage to trees.Beech mast is a good indicator of long-term rodent abundance in Northern German afforestation areas. However, rodent damage to forestry in Central Germany did not seem to depend on environmental parameters other than rodent abundance at large scale. As a result, there is still uncertainty about the link between environmental predictors and rodent damage to forestry, and further experimental work is required to identify suitable environmental drivers and their interplay with other potential factors such as the local predator community. 2016 Society of Chemical Industry.

Loading Northwest German Forest Research Institute collaborators
Loading Northwest German Forest Research Institute collaborators