Search results for "Diversity."
showing 10 items of 3811 documents
A mysterious dwarf: Suthepiidae nov. fam., a new harvestman family from mountains of northern Thailand (Arachnida: Opiliones: Laniatores)
2020
A new family of laniatorean harvestmen from northern Thailand is proposed, Suthepiidae fam. nov., which comprises one new genus and one new species, Suthepia inermis sp. nov. This family stands out by characters hitherto unknown or rarely recorded for Opiliones, and close relatives of this taxon are presently not discernible. Important characters are a short and compact penis with a massively enlarged distal part with a rich armament of sclerites and membranes which can be moved and everted by hemolymph pressure during mating; the pedipalp of males and females is without raptorial adaptations, i.e. elevated sockets (= apophyses) carrying strong distal spines are completely absent, therefore…
Responses of boreal carabid beetle assemblages (Coleoptera, Carabidae) to clear-cutting and top-soil preparation
2006
Today, forestry is the most important disturbance force in Fennoscandian boreal forests, having remarkably altered fauna and flora in this biome. However, since the late 1900s, forest-management practices have been modified to better consider biodiversity while harvesting timber. For example, green-tree retention, gap felling, and lighter top-soil preparation methods (harrowing) have been introduced, but little is known about the ecological effects of these changes. We sampled carabid beetles in seven clear-cut stands that were subsequently harrowed. We studied the effects of (1) clear-cut size by comparing carabid catches of small gaps (ca. 0.16 ha) with those of larger clear-cuts (ca. 2 h…
Accounting for species interactions is necessary for predicting how arctic arthropod communities respond to climate change
2021
Species interactions are known to structure ecological communities. Still, the influence of climate change on biodiversity has primarily been evaluated by correlating individual species distributions with local climatic descriptors, then extrapolating into future climate scenarios. We ask whether predictions on arctic arthropod response to climate change can be improved by accounting for species interactions. For this, we use a 14-year-long, weekly time series from Greenland, resolved to the species level by mitogenome mapping. During the study period, temperature increased by 2 degrees C and arthropod species richness halved. We show that with abiotic variables alone, we are essentially un…
Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica)
2019
Hydrozoans are a conspicuous component of Antarctic benthic communitites. Recent taxonomic effort has led to a substantial increase in knowledge on the diversity of benthic hydroids from some areas of the Southern Ocean, including the Weddell Sea, the largest sea in the Antarctic region. However, the study of many hydrozoan taxa are still pending, and the diversity in this huge region is expected to be higher than currently known. In order to contribute to the knowledge of taxonomy, ecology and distribution of these cnidarians, a study of unpublished material collected by several German Antarctic expeditions aboard the RV Polarstern in the eastern sector of the Weddell Sea has been conducte…
Benthic hydroids (Cnidaria: Hydrozoa) from off George V Coast (East Antarctica)
2018
Hydrozoans are one of the main and most characteristic zoological groups of Antarctic benthic communities, yet there are Antarctic areas where the hydrozoan fauna is completely unknown or scarcely known as off George V Coast (East Antarctica). Hitherto, only two studies have dealt with hydroids from this area and only 16 species have been reported. The present study contributes to increase knowledge of the benthic hydroid fauna off George V Coast by studying material collected during a sampling survey associated with the CEAMARC project. A total of 12 species of benthic hydroids were found. Anthoathecata is only represented by Bimeria corynopsis, the remaining species, including Schizotrich…
Species ofAntarctoscyphusPeña Cantero, García Carrascosa and Vervoort, 1997 (Cnidaria: Hydrozoa: Symplectoscyphidae) collected by US Antarctic expedi…
2017
ABSTRACTAntarctoscyphus is one of the most characteristic genera of Antarctic benthic hydroids, with nine of the 10 known species considered to be endemic to the Antarctic; only Antarctoscyphus elongatus is also present in the sub-Antarctic region of Kerguelen. Accordingly, the genus was considered to have an Antarctic–Kerguelen distribution. Here we present the results of the study of the species of Antarctoscyphus collected from different Antarctic areas and from the Magellan region, during several expeditions under the United States Antarctic Research Program between 1958 and 1986. A scanning electron microscopy survey of all known species of the genus was carried out. Eight of the 10 kn…
Coexistence and resource competition.
2000
How large numbers of species coexist on a seemingly limited number of different resources is a classic problem in ecology1, and attempts have been made to solve it experimentally. But we are not convinced that Huisman and Weissing's2 proposal to add non-stationary dynamics in species abundance to the list of possible explanations offers any new insight into this biodiversity enigma.
Analysis of spatial patterns informs community assembly and sampling requirements for Collembola in forest soils
2018
Abstract The relative importance of niche separation, non-equilibrial and neutral models of community assembly has been a theme in community ecology for many decades with none appearing to be applicable under all circumstances. In this study, Collembola species abundances were recorded over eleven consecutive years in a spatially explicit grid and used to examine (i) whether observed beta diversity differed from that expected under conditions of neutrality, (ii) whether sampling points differed in their relative contributions to overall beta diversity, and (iii) the number of samples required to provide comparable estimates of species richness across three forest sites. Neutrality could not…
Taxonomy 2.0: computer-aided identification tools to assist Antarctic biologists in the field and in the laboratory
2020
Species inventories are essential to the implementation of conservation policies to mitigate biodiversity loss and maintain ecosystem services and their value to the society. This is particularly topical with respect to climate change and direct anthropogenic effects on Antarctic biodiversity, with the identification of the most at-risk taxa and geographical areas becoming a priority. Identification tools are often neglected and considered helpful only for taxonomists. However, the development of new online information technologies and computer-aided identification tools provides an opportunity to promote them to a wider audience, especially considering the emerging generation of scientists…
Degradation in landscape matrix has diverse impacts on diversity in protected areas.
2017
Introduction: A main goal of protected areas is to maintain species diversity and the integrity of biological assemblages. Intensifying land use in the matrix surrounding protected areas creates a challenge for biodiversity conservation. Earlier studies have mainly focused on taxonomic diversity within protected areas. However, functional and especially phylogenetic diversities are less studied phenomena, especially with respect to the impacts of the matrix that surrounds protected areas. Phylogenetic diversity refers to the range of evolutionary lineages, the maintenance of which ensures that future evolutionary potential is safeguarded. Functional diversity refers to the range of ecologic…