238 research outputs found
A forest typology for monitoring sustainable forest management: The case of European Forest Types
Sustainable forest management (SFM) is presently widely accepted as the overriding objective for forest policy and practice.
Regional processes are in progress all over the world to develop and implement criteria and indicators of SFM. In continental
Europe, a set of 35 Pan-European indicators has been endorsed under the Ministerial Conference on the Protection of
Forests in Europe (MCPFE) to measure progress towards SFM in the 44 countries of the region. The formulation of seven
indicators (forest area, growing stock, age structure/diameter distribution, deadwood, tree species composition, damaging
agents, naturalness) requires national data to be reported by forest types. Within the vast European forest area the values
taken by these indicators show a considerable range of variation, due to variable natural conditions and anthropogenic
influences. Given this variability, it is very difficult to grasp the meaning of these indicators when taken out of their ecological
background. The paper discusses the concepts behind, and the requirements of, a classification more soundly ecologically
framed and suitable for MCPFE reporting than the three (un-informative) classes adopted so far: broadleaved forest,
coniferous forest, mixed broadleaved and coniferous forest. We propose a European Forest Types scheme structured into a
reasonably higher number of classes, that would improve the specificity of the indicators reported under the MCPFE process
and its understanding.L'articolo è disponibile sul sito dell'editore www.tandf.co.uk/journals
Habitat-related seed germination traits in alpine habitats
Understanding the key aspects of plant regeneration from seeds is crucial in assessing species assembly to their habitats. However, the regenerative traits of seed dormancy and germination are underrepresented in this context. In the alpine zone, the large species and microhabitat diversity provide an ideal context to assess habitat-related regenerative strategies. To this end, seeds of 53 species growing in alpine siliceous and calcareous habitats (6230 and 6170 of EU Directive 92/43, respectively) were exposed to different temperature treatments under controlled laboratory conditions. Germination strategies in each habitat were identified by clustering with k-means. Then, phylogenetic least squares correlations (PGLS) were fitted to assess germination and dormancy differences between species' main habitat (calcareous and siliceous), microhabitat (grasslands, heaths, rocky, and species with no specific microhabitats), and chorology (arctic-alpine and continental). Calcareous and siliceous grasslands significantly differ in their germination behaviour with a slow, mostly overwinter germination and high germination under all conditions, respectively. Species with high overwinter germination occurs mostly in heaths and have an arctic-alpine distribution. Meanwhile, species with low or high germinability in general inhabit in grasslands or have no specific microhabitat (they belong to generalist), respectively. Alpine species use different germination strategies depending on habitat provenance, species' main microhabitat, and chorotype. Such differences may reflect adaptations to local environmental conditions and highlight the functional role of germination and dormancy in community ecology
Influence of microclimate and geomorphological factors on alpine vegetation in the Western Swiss Alps
Among the numerous environmental factors affecting plant communities in alpine ecosystems, the influence of geomorphic
processes and landforms has been minimally investigated. Subjected to persistent climate warming, it is vital to understand
how these factors affect vegetation properties. Here, we studied 72 vegetation plots across three sites located in the Western Swiss
Alps, characterized by high geomorphological variability and plant diversity. For each plot, vascular plant species were inventoried
and ground surface temperature, soil moisture, topographic variables, earth surface processes (ESPs) and landform morphodynamics
were assessed. The relationships between plant communities and environmental variables were analysed using non-metric multidimensional
scaling (NMDS) and multivariate regression techniques (generalized linear model, GLM, and generalized additive
model, GAM). Landform morphodynamics, growing degree days (sum of degree days above 5°C) and mean ground surface temperature
were the most important explanatory variables of plant community composition. Furthermore, the regression models for species
cover and species richness were significantly improved by adding a morphodynamics variable. This study provides
complementary support that landform morphodynamics is a key factor, combined with growing degree days, to explain alpine plant
distribution and community composition
Lichenological exploration of Algeria: historical overview and annotated bibliography, 1799-2013
yesDespite more than two centuries of almost uninterrupted surveys and studies of Algerian lichenology, the history and lichen diversity of Algeria are still poorly understood. During the preparation of a forthcoming checklist of Algerian lichens it was considered necessary to provide the present historical overview of lichenological exploration of the country from 1799 to 2013, supported by a reasonably comprehensive annotated bibliography of 171 titles
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