195 research outputs found
Adaptive diversity of beech seedlings under climate change scenarios
The ability of beech (Fagus sylvatica L.) populations to adapt to the ongoing climate change is especially important in the southern part of Europe, where environmental change is expected to be more intense. In this study, we tested the existing adaptive potential of eight beech populations from two provenances in N.E. Greece (Evros and Drama) that show differences in their environmental conditions and biogeographical background. Seedling survival, growth and leaf phenological traits were selected as adaptive traits and were measured under simulated controlled climate change conditions in a growth chamber. Seedling survival was also tested under current conditions in the field. In the growth chamber, simulated conditions of temperature and precipitation for the year 2050 were applied for 3 years, under two different irrigation schemes, where the same amount of water was distributed either frequently (once every week) or non-frequently (once in 20 days). The results showed that beech seedlings were generally able to survive under climate change conditions and showed adaptive differences among provenances and populations. Furthermore, changes in the duration of the growing season of seedlings were recorded in the growth chamber, allowing them to avoid environmental stress and high selection pressure. Differences were observed between populations and provenances in terms of temporal distribution patterns of precipitation and temperature, rather than the average annual or monthly values of these measures. Additionally, different adaptive strategies appeared among beech seedlings when the same amount of water was distributed differently within each month. This indicates that the physiological response mechanisms of beech individuals are very complex and depend on several interacting parameters. For this reason, the choice of beech provenances for translocation and use in afforestation or reforestation projects should consider the small scale ecotypic diversity of the species and view multiple environmental and climatic parameters in connection to each other
Modélisation de la qualité des stations et de la croissance individuelle des arbres dans des peuplements purs et mélangés de Pinus brutia dans le nord-est de la Grèce
International audienc
TRY plant trait database – enhanced coverage and open access
Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores
A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació
Phalaena trapezina
<p>Mediterranean forests are characterized by high complexity and biological richness at all levels. Genetic diversity of Mediterranean forest species has been found to be higher than the one of central and northern Europe. It is important for the maintenance of forest cover and the adaptation of forests under adverse conditions towards environmental change. Genetic diversity in the Mediterranean forests has been shaped by the climatic and the geographical history of the region. However, the most important factor influencing diversity is the presence of human in the region. The impact of forest management techniques and other human activities on genetic diversity is analyzed. Sustainable forest management in the Mediterranean should take this information in account and include measures for the maintenance of genetic diversity of forest species. This will then secure the long-term character of forestry in the region and the production of goods and services for the society.</p>
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<p>Presentation during the annual meeting of the Mediterranean Forest Externalities (MEDFOREX) project in Solsona, Catalunya, Spain 2004.</p
Chemical profiles based on terpene composition in Cupressus sempervirens L. show large diversity in Western Crete
<p>The terpene composition of twigs in 106 trees from 6 provenances of Cupressus sempervirens L. grown in Western Crete were used in order to create chemical profiles for individual trees. The aim was to describe the diversity of the chemical profiles within and among the populations of the study and to investigate the utility of the specific methodology to study the genetic variation. Comparisons with other studies on chemical and genetic diversity on the same populations were used for comparison. Twenty nine compounds were detected in cortex resin of all trees, twenty one of which identified. The major constituents were cedrol, α-pinene, 3-δ-carene and α-terpinyl acetate. A cluster analysis classified all the trees in eight chemical profiles. All provenances have been found highly variable. A possible adaptive character in the geographic patterns of terpenic profiles over the provenances is discussed. Chemical profiles, combined with other kinds of markers, seem to be a useful tool to describe diversity and adaptation perspectives of tree populations.</p
The genetic component of biodiversity in forest ecosystems
<p>What is the position of genetic diversity in biodiversity texts and strategies? How does this apply to forest biodiversity and what can be done manage forests sustainably? The importance of forest genetic diversity as a component of biodiversity.</p>
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Genetic diversity as a parameter for managing agroforestry systems
<p>This is a pdf file of a lecture held during the Summer School "Mediterranean Agroforestry and its role in the<br>Present Environmental Challenges", Athens, Greece, 4 – 15 July 2011. This lecture is at graduate level, prepared for a non-genetic audience. For this reason, a basic introduction in population genetics and evolution is done in the first part. The second part includes suggestions for management and conservation guidelines for agroforestry systems. This file contains some useful ideas of how to address the need for conservation and management of "genetic systems" of natural populations. In general it addresses the importance of genetic diversity in nature management.</p
Mediterranean forest genetic diversity and adaptive conservation strategies
<p><strong>Mediterranean forest genetic diversity and adaptive conservation strategies</strong></p>
<p>Genetic diversity and the genetic system of a forest population</p>
<p>Biodiversity is clearly classified at three levels (genes, species and ecosystems) in almost all conservation policy documents and strategies and the importance of its genetic component for the adaptation and survival of the other two components is broadly recognized. However, genetic diversity is usually a small part of global, regional and local biodiversity conservation plans and strategies, mainly due to the practical difficulty for its description and quantification. At the same time, a major misunderstanding occurs, as most stakeholders and several scientists consider an expensive laboratory genetic inventory as the primary necessity prior any conservation decision and frequently consider the genes recorded in the laboratories as the target for future conservation activities. However, the role of genetic research in conservation is not to assess genetic variation per se, but rather to describe the parameters that shape genetic diversity, to identify threats, to model scenarios and to monitor the results of conservation measures.</p>
<p>More than maintaining genetic diversity of species in an ecosystem, it is important to maintain the mechanisms that produce high levels of diversity and connect subsequent generations with each other. This “genetic system” includes all evolutionary forces that act on a certain forest population and its function secures adaptability in the future.</p>
<p>Mediterranean forest genetic diversity and climate change</p>
<p>Mediterranean forests are characterized by high biological diversity at all levels. Mediterranean populations of tree species having a broader European expansion are genetically more diverse than populations located in northern latitudes. Populations and species often have a patchy distribution and are highly differentiated. At the same time, several species have a large and extensive distribution over different environments. The reasons for this genetic richness are the mountainous relief that forces species to adopt under different environmental conditions, the geographical location of the Mediterranean basin that allows migration between continents and the existence of important glacial refugia. While Mediterranean forests are rich in terms of genetic diversity, at the same time they are highly endangered due to the pressure of human activities since thousands of years. Furthermore, climate change scenarios show that the Mediterranean basin will suffer most from global warming and that the forests of the region will face severe survival problems.</p>
<p>Climate change is expected to have direct impact on forests in the Mediterranean, where trees will need to survive under severe environmental conditions and their populations will be forced to react evolutionary and adapt or migrate. Yet, some indirect impacts can act faster and have more significant effects on forest populations; change of climatic conditions will probably cause wildfires and large outbreaks of insects and disease. At the same time, social and economic changes caused by climate change can increase pressures on forests. Deforestation will lead to extinction of rare species having a small expansion. Tree species with larger distribution range will lose valuable populations and their locally adopted genetic structures. At the same time, when parts of a species range will be missing, fragmentation will occur, which will gradually lead to loss of diversity and extinction.</p>
<p>Tree populations having initially high levels of genetic diversity may adapt under the new climatic conditions. Yet, due to severity of the climate change, populations are expected to reduce their size and density, where genetic diversity can be reduced due to stochastic events, drift or inbreeding. At the same time, tree populations will need to specialize in the new conditions so much, that the genetic diversity in total and the adaptability in future changes will decline.</p>
<p>Climate change may also shift the limits of geographical range of plants, as it happened during the interglacial periods of the past. Populations that manage to migrate through seeds to the north or to move higher on the mountains experience founder effects and bottlenecks, as only a sample of their initial genetic pool is represented in the new populations. This can lead to loss of genetic diversity and future adaptability. However, it seems that migration will not be easy for plants in the Mediterranean, since human settlements, infrastructure and activities have already fragmented the natural areas and it seems unlikely that seeds will be able to spread gradually to new directions. Furthermore, migration of plants is a very slow process and the expected changes of climatic conditions in the Mediterranean will be rapid, leaving not enough time for natural evacuation of plant populations.</p>
<p>Adaptive conservation and management strategies</p>
<p>We have reasons to worry about the effects of climate change on Mediterranean forest populations, but at the same time we hope that the high genetic diversity of these populations will manage to lead to new adaptations, as it happened with some of these species in the past. Since deforestation is not an option and migration is rather problematic, we should focus how to develop efficient conservation and adaptive management strategies for the Mediterranean forests. Priority in such strategies should be the maintenance and the enhancement of the function of the genetic system that secures the transfer of genetic diversity from one generation to the other and allows evolution to take place.</p>
<p>Strategies for adaptive conservation and management of Mediterranean forests can take place in situ or ex situ. In situ strategies receive an increased attention, as they are more dynamic and allow the forest populations to evolve on site. As far as managed forests are concerned, most management approaches in the Mediterranean are imported from Central Europe, where forestry tradition is much older. These plans need to be adjusted to the Mediterranean conditions, to extend the targeted marketed and non-marketed values and to include all types of wild terrestrial ecosystems, not only productive forests in terms of timber. Emphasis should be given in the avoidance of measures that disturb the genetic system of forest populations. In order to secure pollen and seed movement, fragmentation of forests and low forest density should be avoided. Connectivity between forests should be maintained or restored. Restoration activities should focus in the protection of natural regeneration and where planting occurs, the used material should derive from local seed. Besides management, climate refugia and primary forests should be given priority for protection, mainly through networks of connected protected areas, including the main forest species and their ecotypes.</p>
<p>However, even the best adaptive management strategies will not be able to prevent the loss of species or populations that will not be able to adapt. For this reason, we need to develop ex situ measures for the maintenance of genetic diversity. Frequent and representative collections of seed for the main and most threatened forest tree species should be prioritized. These can be maintained in gene banks, plantations and can contribute to the increase of the genetic base of natural populations through the creation of seed orchards that will provide variable seed for restoration activities. Other measures for conserving local adaptations would be to evacuate certain areas of the south and create copies of populations further in the north. This however is rather complicated, very expensive and can occur only for a few populations. It is probably better to promote management strategies for the existing forests that do not alter the dynamics of the genetic system and allow pollen and seed movement with natural regeneration.</p>
<p>The development of adaptive management and conservation strategies needs effort and collaboration from different stakeholders. A new forest management approach, adjusted to the Mediterranean conditions and focused on the maintenance of natural processes, should be developed and implemented. At the same time, the importance of forests for the communities and settlements should be broadly recognized and an effective forest protection framework should be established.</p>
<p>Mediterranean forests have accumulated an important adaptation potential through different geological and climatic periods. The best strategy against climate change is to protect and manage them, in a way that the adaptation mechanisms will continue their function.</p>
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<p><em>Presented during the IUCN / WWF workshop on “Adaptation to climate change in Mediterranean forest conservation and management” Athens, April 14-16 2008.</em></p>
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