Search results for "Specie"
showing 10 items of 4389 documents
Nunatak survival vs. tabula rasa in the Central Pyrenees: a study on the endemic plant species Borderea pyrenaica (Dioscoreaceae)
2007
14 páginas, 4 figuras, 2 tablas.
Dynamics of Ostracoda (Crustacea) assemblages in a Mediterranean pond system (Racó de l'Olla, Albufera Nat. Park) with focus on the exotic speciesCan…
2013
Coastal pond systems can account for a rich aquatic faunal diversity and complex functioning due to interplay between freshwater wetlands and marine influences. Within the large Albufera wetland Natural Park, Raco de l'Olla is constituted by a set of permanent and temporary ponds with strict protection level for migrating bird conservation. Its terrestrial faunal diversity and dynamics has been partially characterized in previous studies, but nothing was known about its ostracod communities. Benthic samples collected monthly for 1 year in 11 points through the pond system, together with limnological information, allowed establishing a sound knowledge on its ostracod community and population…
The Status of Romanogobio uranoscopus (Agassiz, 1828) Species, in Maramureş Mountains Nature Park (Romania)
2017
Abstract The condition of aquatic habitats typically occupied by Romanogobio uranoscopus within the Maramureş Mountains Natural Park fluctuates, in the best cases, between reduced to average. Good or excellent conservation status is now absent for populations of this species in the researched area. The identified human impact types (poaching, minor riverbeds morphodynamic changes, solid and liquid natural flow changes, destruction of the riparian vegetation and bush vegetation, habitat fragmentation/isolation of population, organic and mining pollution and displaced fish that are washed away during the periodic flooding in the lotic sectors uniformized by humans) are contributing to the dim…
Conservation value of forest plantations for bird communities in western Kenya
2008
Tree plantations of native and exotic species are frequently used to compensate for forest loss in the tropics. However, these plantations may support lower species diversity and different communities than natural forest. We therefore investigated bird communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. We compared birds differing in habitat specialisation, i.e. forest specialists, generalists, and visitors. We recorded significant differences in mean species richness and number of individuals among the different forest types. Stands of natural forest and plantations of indigenous tree species comprised more sp…
High seedling recruitment of indigenous tree species in forest plantations in Kakamega Forest, western Kenya
2009
Tree plantations are often used to compensate for the destruction and conversion of natural forests in the tropics. An important question is whether these plantations allow for the regeneration of indigenous tree species and are expected to transform into more natural forests in the future. To evaluate the potential of differently managed forest types for seedling recruitment of indigenous tree species we studied structural characteristics as well as tree and seedling communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. Forest types differed considerably in structural characteristics and tree composition with st…
Structural variables drive the distribution of the sensitive lichen Lobaria pulmonaria in Mediterranean old-growth forests
2015
a b s t r a c t We tested the hypothesis that structural variables related to old-growth features affect the distribution of Lobaria pulmonaria in a Mediterranean National Park of Italy. A total of 36 plots, with old-growth characteristics and representing overall three forest types (beech- oak- and mixed- forests) were studied. The lichen was absent in about half of the sites, suggesting that the selection of old-growth forests based solely on structural features is not sufficient to predict the presence of this species, which therefore proves to be rather sensitive and selective. Its abundance was related to high tree circumference and basal area, and to availability of deadwood, confirmi…
Listado taxonómico comentado de los Capitélidos (Annelida, Polychaeta) de la península Iberica, islas Chafarinas, Baleares y Canarias
2013
[EN] The present annotated checklist has been elaborated after revision of preserved materials (from the Museo Nacional de Ciencias Naturales, Madrid and the reference collection of the Marine Biology Laboratory of the University of Valencia) and published literature related to capitellids from the Iberian Peninsula, Chafarinas, Balearic and Canary Islands. Twenty-four species and subspecies belonging to thirteen genera are recognized as valid taxa. With this checklist we include some taxonomic details and information on distribution at both global and regional levels. This work includes the setal formula and diagrammatic representation of capitellid taxa treated in this study.
Effect of restoration on zooplankton community in a permanent interdunal pond
2013
Restoration projects in wetlands are becoming increasingly frequent to recover or to create new aquatic ecosystems, after the significant impact and high degradation they have undergone. In the present study, we focused on the changes in the zooplankton community in a permanent peridunal pond where a restoration was carried out in order to increase its surface as a main objective. For this purpose, the community was compared before and after the restoration (15 years before, the year after and between 3 and 6 years later). Significant changes in environmental variables were observed after pond restoration: chlorophyll a concentration decreased and dissolved oxygen increased. Substantial mod…
Unravelling the bacterial diversity found in the semi-arid Tablas de Daimiel National Park wetland (central Spain)
2010
Our knowledge of microbial diversity in the environment is still limited, and there are many species as yet unidentified in both soil and water. Studies of the microbial diversity of wetland ecosystems have been neglected for years, as is the case of Tablas de Daimiel National Park (TDNP), a Spanish semi-arid wetland system of international importance in terms of waterfowl. We report the bacterial diversity of water column, sediment (upper and lower layers) and biofilm samples from the TDNP system using a 16S rRNA gene library approach. A sequence comparison of the 703 clones obtained revealed a number of bacterial phylogroups unreported to date. Bacterial diversity was high (Shannon values…
Potential Impact of Global Climate Change on Species Richness of Long-Distance Migrants
2003
Little evidence exists demonstrating that global climate change leads to systematic changes in the struc- ture of ecological communities. For avian communities, one would expect warmer winters to lead to declines in numbers of long-distance migrants if resident birds benefit from warmer winters and impose increasing competi- tive pressure on migrants. To study the potential influence of global climate change on long-distance migrants, we correlated the number of all species of land birds and the number and proportion of long-distance migrants, short- distance migrants, and residents in 595 grid cells across Europe. We used mean temperature of the coldest month, mean spring temperature, and …