9 resultados para Sand dune plants

em SAPIENTIA - Universidade do Algarve - Portugal


Relevância:

90.00% 90.00%

Publicador:

Resumo:

Inland sand dune systems are amongst the most threatened habitat types of Europe. Affected by severe conditions, these habitats present distinct community compositions, which makes them excellent for studying possible interactions among their integrating species and the environment. We focus on understanding the distribution and cooccurrence of the species from dune plant assemblages as a key step for the adequate protection of these habitats. Using data from an extensive survey we identified the shrub species that could be considered indicators of the different xerophytic scrub dune communities in South West Portugal. Then, we modelled the responses of these species to the environmental conditions using Ecological Niche Factor Analysis. We present some preliminary results elucidating whether using species distribution models of indicator species at a regional scale is a valid approach to predict the distribution of the different types of communities inhabiting these endangered habitats.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

European-wide conservation policies are based on the identification of priority habitats. However, research on conservation biogeography often relies on the results and projections of species distribution models to assess species' vulnerability to global change. We assess whether the distribution and structure of threatened communities can be predicted by the suitability of the environmental conditions for their indicator species. We present some preliminary results elucidating if using species distribution models of indicator species at a regional scale is a valid approach to predict these endangered communities. Dune plant assemblages, affected by severe conditions, are excellent models for studying possible interactions among their integrating species and the environment. We use data from an extensive survey of xerophytic inland sand dune scrub communities from Portugal, one of the most threatened habitat types of Europe. We identify indicator shrub species of different types of communities, model their geographical response to the environment, and evaluate whether the output of these niche models are able to predict the distribution of each type of community in a different region.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Communities can be defined as assemblages of species coexisting under particular environments. The relationship between environment and species are regulated by both environmental requirements –which ultimately determine the species capacity to establish and survive in a particular environment– and the ecological interactions occurring during assembly processes –which also determine community composition by conditioning species coexistence. In this context, plant functional traits are attributes that represent ecological strategies and determine how plants respond to environmental factors and interact with other species. Therefore, the analysis of how traits vary through the dynamics of communities, such as along successions, can give insights about how environmental requirements and species interactions may determine the composition and functional structure of these communities. The xerophytic shrub communities inhabiting inland sand dunes in SW Portugal are characterized by successional processes that are mainly driven by local (edaphic gradients and human disturbance) and regional (climate) processes. Therefore, they constitute an appropriate system for studying species interactions and environmentcommunity co-variations based on functional terms. Using these communities as a model, we evaluate the hypothesis that successional community changes in species composition of xerophytic shrub communities can result in concurrent changes in functional diversity

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertação de mest. em Estudos Marinhos e Costeiros Ramo Gestão Costeira, Faculdade de Ciências do Mar e do Ambiente, Univ. do Algarve, 2002

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação mest., Engenharia Biológica, Universidade do Algarve, 2009

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação mest., Gestão da água e da costa, Universidade do Algarve, 2007

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tese de doutoramento, Ciências Biotecnológicas (Biotecnologia Vegetal), Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2010

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the present experiment, we studied the interaction between copper (Cu) and iron (Fe) in strawberry plants grown in nutrient solutions containing different concentrations of Fe. Plants grown in the absence of iron (Fe0) had the characteristic symptoms of Fe deficiency, with smaller chlorotic leaves, less biomass, acidification of the nutrient solution, and roots that were smaller and less ramified, while no symptoms of Fe deficiency were observed in plants grown with Fe. A greater amount of Cu was found in roots of chlorotic plants than in those grown with Fe, while plants grown with 20M of Fe (Fe20) in the nutrient solution had a greater amount of Fe compared with plants from the other treatments. Chlorotic plants (Fe0) and plants grown with the greatest level of Fe (Fe20) had a greater root ferric chelate reductase (FC-R; EC 1.16.1.17) activity compared with the other treatments with 5 or 10M Fe in the nutrient solution. The same pattern was obtained for relative FC-R mRNA concentration and for the sum of Fe and Cu contents in shoots (leaves plus crowns). The DNA obtained from amplification of the FC-R mRNA was cloned and several of the inserts analysed by single strand confirmation polymorphism (SSCP). Although there were different SSCP patterns in the Fe20 treatment, all the inserts that were sequenced were very similar, excluding the hypothesis of more than one FC-R mRNA species being present. The results suggest that Cu as well as Fe is involved in FC-R expression and activity, although the mechanism involved in this regulation is unknown so far. Both small contents of Fe and Cu in plants led to an over-expression of the FC-R gene and enhanced FC-R activity in strawberry roots.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The use of spices, common nowadays, was once a sign of high position, luxury and wealth. The value of food ingredients is thus determined by the time in which one lives, that is, it is a product of fashion, since they are always used in a social context. Many plants used as spices enjoyed fame and undeniable importance in the past but their reign was more or less ephemeral, as they were rejected in favour of others for food seasoning, or simply upstaged and/or used for other purposes.