Search results for "Landscape"
showing 10 items of 1561 documents
Flood risk assessment and mapping in peri-urban Mediterranean environments using hydrogeomorphology. Application to ephemeral streams in the Valencia…
2012
Abstract This paper proposes a methodology for mapping flood risk in ephemeral streams, based on assessing flood hazards and global exposure. The method has been applied to the peri-urban area of Valencia, extended over the floodplains of the Barranco del Carraixet and Rambla de Poyo catchments. Hazard was assessed using hydrogeomorphological methods. Global exposure was estimated as a combination between the economic value of land use and human exposure, following a previous study carried out by Camarasa, A.M., Lopez, M.J. and Soriano, J., 2011. Mapping temporally variable exposure to flooding in small Mediterranean basins using land-use indicators, Applied Geography 31 (19), 136–145. Synt…
Unintentional dispersal of aquatic invertebrates via footwear and motor vehicles in a Mediterranean wetland area
2010
1. Several human activities, such as actions for nature conservation, research and recreational activities, are closely associated with inland aquatic habitats that are usually considered as isolated island habitats. In this study, the possibility of unintentional dispersal of aquatic invertebrates among water bodies via footwear and motor vehicles was investigated. 2. Mud samples collected from boots and from the tyres and wheel cases of cars used for field work by biologists (Camargue, Southern France) were hatched under laboratory conditions and also checked for the presence of unhatched propagules. A large number of organisms hatched and invertebrate propagules from a wide range of taxa…
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 (…
The Madonie: Highlands in Sicily
2019
This chapter presents the results of the archaeological survey of selected areas across the Madonie mountain range in Sicily, at different heights. Several archaeological features have been mapped, documenting the human presence on these highlands over different millennia and dating it back at least to the Middle Neolithic. Traces of ancient cultures of Sicily have been recognized in the area, emphasizing the importance of this mountainous territory.
Environment in Megacities: Tehran Waterscapes
2021
Defining contemporary urban paradigms is the challenge of this time, especially when the urban dynamics are so fluid they spread uncontrollably in overextended and overpopulated territories. This is the case for megacities, metropolitan areas with more than 10 million inhabitants, which place the emphasis on how to manage energy consumption in such filled places. In this frame, the city of Tehran, the capital of the Islamic Republic of Iran, scene of political and cultural disputes, administrative and economic headquarter of the country, with its nearly 15 million residents and a daily traffic of more than 20 million people, is currently one of the most populous cities in the world and repr…
Nutrient impoverishment and limitation of productivity after 20 years of conservation management in wet grasslands of north-western Germany
2009
Abstract European wet grasslands are characterized by high diversity of plant and animal species but are threatened by intensive land use. Although preservation or restoration of species-rich wet grasslands requires low nutrient availability that could be achieved by long-term management, studies monitoring nutrient removal are lacking. Our objective was to assess the long-term effect of management (mowing twice a year without or with PK fertilization for 20 years) on (i) productivity and nutrient removal with the harvest, (ii) the type of nutrient limitation, and (iii) plant species richness in wet grasslands in north-western Germany considering the differences between organic and mineral …
Tarsius tumpara: A New Tarsier Species from Siau Island, North Sulawesi
2008
Abstract: A new, critically endangered species of tarsier, one of the world's 25 most endangered primates, is described from the remote island of Siau, North Sulawesi, based on distinguishing characteristics of the tail tuft, pelage coloration, skull, and vocalizations. Siau is part of the Sangihe Island chain, a volcanic arc composed of islands that rise from the ocean floor. There is a single previous record of a tarsier from Siau; a skull in the Dresden Museum that Meyer (1897) classified with tarsiers from Sangihe Island as Tarsius sangirensis. Sangihe and Siau Islands are geologically separated by about 60 km of ocean that greatly exceeds 1,000 m in depth. Genetic data for the new spec…
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…