Past On-Site Experience,Crowding Perceptions,and Use Displacement of Visitor Groups to a Peri-Urban National Park

Past on-site experience was linked to the crowding perceptions and use displacement of 383 on-site visitors to the peri-urban Danube Floodplains National Park, Austria. Three visitor groups were determined according to their area experience: local residents from Vienna and rural communities, having the highest level of experience; regional visitors from the city and eastern Austria; and tourists from Austria and abroad with the lowest degree of experience. Crowding perceptions were significantly different across the user groups. More than 50% of local residents perceived the national park as crowded, whereas only 27% of regional visitors and 19% of tourists reported such an evaluation. Even among local residents and regional visitors, respondents with more on-site experience expressed a greater impression of a crowded park. Differences in crowding evaluations between local rural and urban residents and between regional rural and urban visitors were not found. For 27% of local residents and 15% of regional visitors, use levels were so unacceptable that they displaced temporally and spatially, whereas use displacement was relatively irrelevant for tourists. The use displacement strategies involved differ among the three user groups. Management implications were discussed, taking the specific situation of the small national park on the urban-rural fringe into consideration.     

Clean development mechanism: an incentive for waste management projects?

The Clean Development Mechanism (CDM) was introduced by the Kyoto Protocol to provide a financial incentive to establish project activities in developing countries for reducing greenhouse gas emissions while also fostering sustainable development. This article shows that waste management project activities play an important role in achieving the aims of the CDM. It describes how these activities have to prove additionality, how the emission reductions must be calculated and monitored in order to be eligible and in order to lead to Certified Emission Reductions (CERs). The article further provides an analysis about the various challenges that are involved in applying the CDM scheme to waste management project activities, which require a new specific set of technical skills and regulatory standards.     

Effects of Regional Reductions in Sulphur Deposition on the Chemical and Biological Recovery of Lakes within Killarney Park, Ontario, Canada

The lakes in KillarneyProvincial Park, located 40–60 km southwest ofSudbury, Ontario, were some of the first lakesin North America to be acidified by atmosphericpollutants. Acidification affected thousandsof fish and invertebrate populations in dozensof lakes. Since the 1970's, water quality hasimproved in response to atmospheric pollutionreductions and some lakes have alreadyrecovered to approximately their pre-industrialpH levels, as inferred from diatom microfossilsin lake sediments. Since the 1970's, fishspecies richness has not changed substantially,but zooplankton species richness has increasedin acidified lakes. The critical sulphur load,the amount of SO₂-derived acid depositionthat can occur while still maintaining suitable water quality, was estimated to beexceeded in 38% of the park area in 1997. Depending on which of four possible NorthAmerican emission control scenarios (CLR =currently legislated reduction; CLR + 25%; CLR+ 50%; CLR + 75%) is achieved by 2010, theprojected critical loads will be exceeded inabout 0-30% of the park area in the future. There are many factors that can affectbiological recovery rates of damaged lakes, butit is expected that biological recovery willlag considerably behind observed chemicalrecovery rates.     

Organotins in marine mammals and seabirds from Norwegian territory

An increasing number of studies indicate that marine mammals and some seabirds are exposed to organotins. However, results from northern and Arctic areas are few. Here results from analysis of tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT) in harbour porpoise (Phocoena phocoena), common seal (Phoca vitulina), ringed seal (Phoca hispida) and glaucous gull (Larus hyperboreus) from Norwegian territory are presented. Relatively high concentrations of DBT, TBT and MBT were observed in muscle, kidney and liver from harbour porpoises caught in northern Norway in 1988, just before restrictions on the use of tributyltin (TBT)(mainly on small boats) were introduced in several European countries. The concentrations in harbour porpoise muscle tissue were reduced significantly 11 years later, possibly as a result of the introduced restrictions. Considerably lower concentrations of butyltins were observed in the seals compared to porpoises. The lowest levels of organotins were found in ringed seals from Spitsbergen, where only traces of dibutyltin (DBT) and monobutyltin (MBT) were observed. Traces of DBT and MBT were also found in some individual glaucous gulls from Bear Island. The sum of the degradation products MBT and DBT in liver samples from all analysed species were generally higher than TBT itself. Triphenyltin (TPhT) was observed in all porpoise samples and in livers of common seals. Also the sum of the degradation products MPhT and DPhT in liver samples from porpoise and common seals were higher than TPhT. No traces of phenyltins were found in ringed seals from Spitsbergen or in glaucous gulls from Bear Island. The limited data available indicate low to moderate exposure to organotins in northern areas (Spitsbergen and Bear Island). Marine mammals are however more exposed further south along the Norwegian Coast.     

Grazing,forest density,and carbon storage: towards a more sustainable land use in Caatinga dry forests of Brazil

Grazing is the main land use in semi-arid regions of the world, and sustainable management practices are urgently needed to prevent their degradation. However, how different grazing intensities affect forest density and ecosystem functions is often not sufficiently understood to allow for management adaptations that safeguard the ecosystems and their functions in the long run. We assessed the aboveground carbon stocks and plant densities along a grazing gradient in the semi-arid seasonally dry tropical forest of north-eastern Brazil (Caatinga). On 45 study plots, we analysed the aboveground carbon stocks of the vegetation and determined forest density and recruitment as well as the population structure of the most abundant tree species. Grazing intensity was accounted for based on the weight of livestock droppings and classified as low, intermediate, or high. Mean aboveground carbon stock was 15.74?±?1.92 Mg ha^?1 with trees and shrubs accounting for 89% of the total amount. Grazing at high intensities significantly reduced aboveground carbon stocks of herbs but not of other plant functional types. Instead, aboveground carbon stocks of trees and shrubs were negatively related to altitude above sea level, which is a proxy for reduced water availability along with lower anthropogenic impact. The population structure of the most common tree species was characterised by abundant recruitment, irrespective of grazing, whereas the recruitment of less frequent woody species was negatively affected by grazing. Overall, our data imply that grazing and forage management need to be adapted, including the reduction of free-roaming livestock and storage of fodder, to maintain carbon storage and forest density.     

Climate change,fisheries management and fishing aptitude affecting spatial and temporal distributions of the Barents Sea cod fishery

Climate change is expected to influence spatial and temporal distributions of fish stocks. The aim of this paper is to compare climate change impact on a fishery with other factors impacting the performance of fishing fleets. The fishery in question is the Northeast Arctic cod fishery, a well-documented fishery where data on spatial and temporal distributions are available. A cellular automata model is developed for the purpose of mimicking possible distributional patterns and different management alternatives are studied under varying assumptions on the fleets’ fishing aptitude. Fisheries management and fishing aptitude, also including technological development and local knowledge, turn out to have the greatest impact on the spatial distribution of the fishing effort, when comparing the IPCC’s SRES A1B scenario with repeated sequences of the current environmental situation over a period of 45 years. In both cases, the highest profits in the simulation period of 45 years are obtained at low exploitation levels and moderate fishing aptitude.     

Within- and between-individual (co)variance partitioning reveals limited pleiotropic effects of testosterone on immune function,sexual signaling,and parental investment

Behavioral Ecology and Sociobiology - An individual’s home range, or how much space it requires to obtain resources and meet its needs for survival and reproduction, affects the scale of many...     

Ground-based measurements and modeling of solar UV-B radiation in Lhasa,Tibet

We present results from measurements by a NILU-UV Irradiance Meter of solar UV-B radiation in Lhasa, Tibet for the period from 7 July 1999 to 17 November 2002. The measured maximum UV-B dose rate was 1.50 W/m² during the winter, and 3.96 W/m², during the summer. The clear-sky values were below 3.00 W/m². Comparisons between measured and calculated UV-B dose rates on clear-sky days in Lhasa show good agreement. Comparisons of UV-B radiation levels in Lhasa (Tibet), Oslo (Norway), and Dar-Es-Salaam (Tanzania) show that the UV-B dose rates during the summer in Lhasa are higher than the maximum value in Dar-Es-Salaam, which is at the sea level in the equatorial region, and 60% higher than in Oslo, which is at the sea level but 60 degrees North. We conclude that the UV-B dose rates during the summer on the Tibetan plateau are among the highest levels in habituated regions of the world. Maximum measured daily-integrated UV-B doses in Lhasa range from about 10 kJ/m² in the winter to about 65 kJ/m² in the summer.