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Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A warming global climate will elicit changes in the distribution of plant species around the planet, and this will become most apparent where biomes converge. Climate exerts the strongest control over the geographic location of ecotones at the continental scale and many, including the boreal forest - temperate forest ecotone (BTE), are expected to shift to higher latitudes under climate change. Fine-scale drivers that define biome boundaries at the sub-continental scale are less well understood for many ecotones. We assembled studies addressing whether a modern distributional shift is occurring at the BTE and what biotic and abiotic factors are driving such a shift. Current research suggests a northward shift is occurring; yet, scant data are available to identify the processes involved. Abiotic and biotic factors are repeatedly identified as key drivers of change, though not all claims are evidence-supported and the interacting effects of these non-climatic factors are poorly understood. [ABSTRACT FROM AUTHOR]

A common method for estimating forest biomass is to measure forest height and apply allometric equations. However, changing forest density or structure heterogeneity increases the variability of the known allometric relationship. Here, we investigated the potential of allometric relationships based on vertical forest structure for biomass inversions with a global potential. First, vertical biomass profiles, which were calculated from ground forest inventory data, were used to model forest vertical structure. Then, a vertical structure ratio based on Legendre polynomials was proposed as a structural descriptor and its sensitivity to biomass was evaluated. Finally, we developed a structure-to-biomass inversion expression that could be extrapolated for aboveground biomass estimations. This is a case study based on inventory data from the Traunstein and Ebersberg test sites, two temperate forests located in southeastern Germany with different forest structural conditions. Results from the structure-to-biomass inversion algorithm show a clear improvement with respect to traditional height-to-biomass expressions, with increasing correlation factor ( r2) from 0.52 to 0.73 for Traunstein and from 0.51 to 0.76 for Ebersberg and reducing the root mean square errors from 75.32 to 47.56 Mg·ha−1 and from 73.25 to 48.31 Mg·ha−1, respectively. [ABSTRACT FROM AUTHOR]

A cloud belt frequently forms on the windward side of Madeira Island, between 800 and 1600 m a.s.l., as a result of adiabatic cooling of the northeastern trade winds that are forced upward. Temperate laurel forest is the most common vegetation inside that cloud belt altitudinal range. Cloud water interception was estimated by comparing precipitation and throughfall during a hydrological year. It totalled 200 mm (8% of rainfall) during 65 days (3 mm d−1) and seems to constitute a larger fraction of water input during drier months. Multiple linear regression between gauge standard deviation and throughfall throughout rain events shows that cloud interception is common before the onset of rainfall. Its role in the ecohydrology of laurel forest and in the island's hydrology should be acknowledged. Further studies on this issue should be a priority in order to better understand these dynamics and provide tools for the correct management of this protected forest and the island's groundwater resources. [ABSTRACT FROM AUTHOR]

Plant species distribution and plant community composition vary along environmental gradients. At the continental scale, climate plays a major role in determining plant distribution, while at the local and regional scales vegetation patterns are more strongly related to edaphic and topographic factors. The projected global warming and alteration of the precipitation regime will influence tree physiology and phenology, and is likely to promote northward migration of tree species. However the influence of soil characteristics on tree species migration is not as well understood. Considering the broad tolerance of most tree species to variations in soil factors, soils should not represent a major constraint for the northward shift of tree species. However, locally or regionally, soil properties may constrain species migration. Thus, while climate change has the potential to induce a northward migration of tree species, local or regional soil properties may hinder their migratory response. These antagonistic forces are likely to slow down potential tree migration in response to climate change. Because tree species respond individualistically to climate variables and soil properties, new tree communities are likely to emerge from climate change. [ABSTRACT FROM AUTHOR]

Abstract: To determine the performance of Global Positioning System (GPS) for habitat studies in free-ranging animals, we tested differential 6- and 8-channel GPS collars under six representative canopies and one open-field reference site in the ‘Parc national des Cévennes’, southern France. The proportion of successful locations decreased under taller trees and worsened with snow accumulation in mixed coniferous habitats. The mean location success of seven free-ranging red deer fitted with 6-channel GPS collars in the same study area increased with a shorter interval between location attempts and during the leaf-off period. Our data suggested that the differences in location success between leaf-on and leaf-off periods might reflect shifts in habitat use rather than a leaf effect under deciduous trees. To cite this article: G. Janeau et al., C. R. Biologies 327 (2004). [Copyright &y& Elsevier]

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)