Search results for "conservation."
showing 10 items of 1994 documents
Ecological variation between marginal and central populations of Potamogeton polygonifolius, a rare and endangered species in Central Europe
2012
Abstract The present study is focused on Potamogeton polygonifolius – the species considered to be endangered in Germany, the Czech Republic, Poland and Switzerland. Field studies were carried out in Lower Silesia and Lusatia in southwestern Poland in order to verify the present state of the marginal populations of P. polygonifolius, to determine the habitat preferences of the species in the study area, to compare the ecological data between marginal and central populations and finally to recognise the factors constraining the easternmost limit of the P. polygonifolius. In total, 18 populations were examined, and 11 releves were collected. The releves gathered were compared with 95 releves …
Conservation of threatened habitat types under future climate change – Lessons from plant-distribution models and current extinction trends in southe…
2015
A higher risk of future range losses as a result of climate change is expected to be one of the main drivers of extinction trends in vascular plants occurring in habitat types of high conservation value. Nevertheless, the impact of the climate changes of the last 60 years on the current distribution and extinction patterns of plants is still largely unclear. We applied species distribution models to study the impact of environmental variables (climate, soil conditions, land cover, topography), on the current distribution of 18 vascular plant species characteristic of three threatened habitat types in southern Germany: (i) xero-thermophilous vegetation, (ii) mesophilous mountain grasslands (…
Syntaxonomic survey of the class Pegano harmalae‐Salsoletea vermiculatae Br.‐Bl. & O. Bolos 1958 in Italy
2013
After a general outline on the syntaxonomical framework of the class Pegano harmalae-Salsoletea vermiculatae Br.-Bl. & O. Bolos 1958, the occurrence of this vegetation in the Italian territory is examined. In Italy, this vegetation is mostly found on clayish or marly substrata, particularly if slightly enriched with nitrates and chlorides. With reference to the Rivas-Martinez bioclimatic classification, the Italian stands have an infra- to thermo-Mediterranean thermotype (marginally up to the meso-Mediterranean one) with dry or arid ombrotype. In particular, this vegetation is well represented in Sicily, while in Sardinia and along the Italian Peninsula, it progressively becomes more rare a…
Cottus gobio Linnaeus, 1758 Community Interest Species Conservation in Upper Târnava Mare River Basin, Through Fish Populations Rehabilitation for Br…
2017
Abstract The ADONIS: CE software has been used for two fish species, Cottus gobio, of conservation interest and Salmo trutta fario, of economic interest, to design an on-site (upper Târnava Mare River) adapted support-system model for management decision-making. Habitat needs and indicators of favourable conservation status have been investigated, pressures and threats to these fish species have been determined, and management elements have been suggested. This management system allows the proper organization of management measures for the renaturation of the local natural fish associations in the local brown trout zone.
The role of competition and rarity in the restoration of a dry grassland in Finland
2001
Semi-natural grasslands have become scarce throughout Europe. Preservation of their plant species requires either the maintenance of the existing grasslands or the creation of new ones. To study the establishment and regeneration ability of plant species typical of dry grasslands we laid out an experiment on a former arable field in central Finland. We compared the success of 13 grassland species both in a theoretical situation with minimal competition and in competition with weeds. More than half of the species used were regionally rare. As a group, grassland plants reached the highest cover in the experimental plots in which outside competition was minimised by weeding. However, the total…
Trophic cascades in benthic marine ecosystems: lessons for fisheries and protected-area management
2000
An important principle of environmental science is that changes in single components of systems are likely to have consequences elsewhere in the same systems. In the sea, food web data are one of the few foundations for predicting such indirect effects, whether of fishery exploitation or following recovery in marine protected areas (MPAs). We review the available literature on one type of indirect interaction in benthic marine ecosystems, namely trophic cascades, which involve three or more trophic levels connected by predation. Because many indirect effects have been revealed through fishery exploitation, in some cases we include humans as trophic levels. Our purpose is to establish how wi…
Large-scale drainage and breeding success in boreal forest grouse
2007
Summary 1 The breeding success of Finnish grouse has been in decline for decades. While it has been shown that fragmentation and modern forestry practices such as clear-cutting affect the viability of grouse populations, little is known about effects of large-scale drainage. The drainage network in Finland has increased dramatically during the past decades. By 1988, 6 million ha of bog ecosystems had been drained. This is likely to have had a profound direct and indirect effects on grouse productivity. Because ditches persist in time, large-scale drainage may therefore have strong potential for affecting the long-term breeding success of three forest grouse species in Finland. 2 Using a mix…
Comparison of social-ecological resilience between two grassland management patterns driven by grassland land contract policy in the Maqu, Qinghai-Ti…
2018
Embraced for decision-making, resilience has evolved as a meaningful term in areas such as ecology, the economy and society. After a policy of grassland contracts was implemented on the Qinghai-Tibetan Plateau, two grassland management patterns evolved: the multi-household management pattern (MMP) and the single-household management pattern (SMP). Within a resilience-driven perspective, this study compared the outcomes of these grassland management patterns by measuring their effects on the resilience of grazing, ecological, economic and social systems. Resilience indicators for each of the four systems were: grazing system (grazing space, transhumance, water source and reproduction); ecolo…
Distribution patterns, ecological characteristic and conservation status of endemic plants of Tadzhikistan – A global hotspot of diversity
2011
Abstract Based on literature data and own fieldwork in Tadzhikistan (Middle Asia), the taxonomic structure, distribution, habitat preferences as well as conservation state of a group of 1486 species of vascular plants of endemic and sub-endemic character are presented. In addition to verifying the number of endemics, the present study has shown that Tadzhik endemics are the most numerous in the northwest of the country, in the Gissar-Darvasian and Zeravshan regions. An analysis of average richness of endemics per surface unit has revealed that Gissar-Darvasian F is the richest area. An assessment of the taxonomic similarity of geobotanical regions based on endemic species composition has sh…
Morphological characterization, germination ecology and conservation of narrow endemic plant species of the Aeolian Islands (Sicily)
2016
This stusy is focused on four narrow endemic species of the Aeolian fora: Anthemis aeolica, Erysimum brulloi, Cytisus aeolicus and Silene hicesiae. Morphological characterization of seeds, seed germination and dormancy regulation have been investigated for these species.