Search results for "RICH"
showing 10 items of 3360 documents
Two new antarctic species of the genus Schizotricha Allman, 1883 (Cnidaria, Hydrozoa)
1998
Two new antarctic species of the genus Schizotricha Allman have been studied. The material comes from the Scotia Sea (Antarctica) and was collected by the Spanish antarctic expedition `Antartida 8611'. Both species are described and figured and the systematic position is discussed. A general survey of the geographical and bathymetrical distribution of the antarctic and subantarctic species of the genus is given. Finally, a key for the identification of the antarctic and subantarctic species of the genus, together with a comparative table including main features, are presented.
Palaeoenvironmental significance of the mammalian faunas of Italy since the Pliocene
2002
The evolution of mammalian communities is a significant tool for reconstructing past environments and climate. In this paper, a palaeoecological and palaeoenvironmental reconstruction based on the study of the Italian mammal faunas ranging from Middle Pliocene to the Holocene is presented using the cenogram method and quantification of temperatures based on arvicolid species richness. These analyses reveal open and arid conditions during glacial periods and less open and more humid conditions during interglacials, with some differences between north and central–south Italy. Northern and Southern communities reflect similar trends in the evolution of palaeoenvironments and in the variation o…
Inter-annual variation in macroinvertebrate communities in a shallow forest lake in eastern Finland during 1990–2001
2003
As a part of the Integrated Monitoring (IM) Programme of Air Pollution Effects on Ecosystems, the macroinvertebrate community of a pristine forest lake was monitored from 1990 up to the present. Lake Iso Hietajarvi is a small and shallow, weakly stratified oligotrophic headwater lake situated in Patvinsuo National Park, eastern Finland. Benthic macroinvertebrates were sampled annually, once in autumn at depths of 3 - 4 m (sublittoral zone) and at 7 m (profundal zone). The water quality of the lake and meteorological characteristics in the area were monitored during the same period. The inter-annual variation in macroinvertebrate abundance and taxonomic composition in the lake unaffected by …
Urbanization and stability of a bird community in winter
2009
Abstract: The main objective of this study was to analyze between-winter stability of bird communities along latitudinal (950 km) and urban gradients (from small village to towns) in Finland. Birds were surveyed at the same 30-ha study plots using the same methods in 31 villages and town centres in the winters of 1991–1992 and 1999–2000. Species richness did not differ between the 2 study winters, but variation in total abundance of birds increased with increasing urbanization. However, urbanization reduced variation in wintering bird community structure. Species richness, density of wintering birds, and dissimilarity of wintering bird communities did not vary with latitude. According to ou…
Hotspots in cold climate: Conservation value of woodland key habitats in boreal forests
2011
The concept of Woodland Key Habitats (WKH, small-scaled presumed hotspots of biodiversity) has become an essential component of biodiversity conservation in Fennoscandian and Baltic forests. There have been debates over the importance of WKHs in relation to the conservation of biodiversity in production forests. We applied a systematic review protocol and meta-analysis to summarize knowledge on comparisons of biodiversity qualities, such as dead wood and species richness, between WKHs and production forests in relevant countries. We also summarized the knowledge on the impact of edge effects by comparing WKHs surrounded by production forests to WKHs surrounded by clear cuts. Studies had bee…
Geographical patterns of species turnover in aquatic plant communities
2001
1. A classic theory in biogeography predicts that high latitude communities are unstable. This may be because of decreased species richness or decreased environmental predictability and productivity towards the poles. 2. We studied latitudinal patterns in long-term community persistence of aquatic vascular plants in 112 Finnish lakes, situated within a 1000-km range from the northernmost to the southernmost lake. 3. Contrary to theoretical predictions, we found that the turnover rate of plant species in 45 years was inversely related to latitude. That is, plant communities in northern lakes were more persistent than communities in southern lakes. When we used multiple regression to find the…
Long-Term Observations of Soil Mesofauna
2010
General problems connected with planning, sampling, and data processing of long-term research of soil mesofauna are discussed, based on two case studies: (i) the Bremen study of predatory mites (Gamasina) covering 20 years of secondary succession on a ruderal site in northern Germany and (ii) the Mazsalaca study of the effects of climate warming on Collembola of coniferous stands in the North Vidzeme Biosphere Reserve, Latvia, covering 11 years. The findings from both sites are embedded in an array of environmental data. The results from Bremen document the asynchrony of different biota in successional dynamics. The long-lasting increase of the species numbers of soil predatory mites (Gamas…
Assessing physical surrogates for biodiversity: Do tributary and stream type classifications reflect macroinvertebrate assemblage diversity in runnin…
2006
Landscape classifications are increasingly being used in conservation planning and biodiversity management, although there is a dearth of studies actually showing concordant patterns between such classifications and biodiversity. We studied the utility of tributary and stream type classifications in accounting for the variability of invertebrate biodiversity in a boreal drainage system. We found that only weak, although significant, differences existed between the studied three tributaries and four stream types in macroinvertebrate assemblage structure, species distributions, and taxonomic richness. Further, the classification strengths, calculated as mean within-group-similarity minus mean…
Updated description and distribution of the Patagonian moss Ulota macrodontia Dusén ex Malta (Orthotrichaceae)
2021
Ulota macrodontia Dusen ex Malta is an Andean-Patagonian epiphytic moss that has been misunderstood in recent times (Garilleti et al. 2016). This may be due partly to the fact that it is a rarely c...