Search results for "ef"
showing 10 items of 32085 documents
The cost-effectiveness of using raptor nest sites to identify areas with high species richness of other taxa
2016
Abstract Given the limited resources available for conservation, it is important that the areas to preserve are selected in a cost effective manner. However, the cost effectiveness of the surrogate species strategy (the use of information on one or more species to identify areas of value for other species for which there is no, or more limited, available information) has seldom been evaluated. In this study, we investigate the opportunity cost of setting aside breeding sites of two forest raptor species (the surrogate species) by evaluating their individual and combined contribution to preserve diversity of polypores (wood-decaying fungi) and birds against the contributions of previously es…
Land-use and climate related drivers of change in the reindeer management system in Finland: geography of perceptions
2021
Drivers of change in the reindeer management system are rather well-known. But when developing the gover-nance to support the traditional livelihoods, it is crucial to understand also practitioner perceptions. Systematic research on these is lacking. We analyzed the land-use and climate related drivers within the reindeer man-agement area (RMA) in Finland, and, using a perception geography approach, studied the herder perceptions towards these. We conducted an on-site questionnaire survey with herders from 51 herding districts. Factors directly affecting the welfare of reindeer were perceived as crucial by herders, for example basal icing affecting the forage availability, and land-use rela…
Grazers increase β-diversity of vascular plants and bryophytes in wood-pastures
2016
Questions How does the presence of grazers impact plant diversity at various spatial scales? What are the effects on plant β-diversity and its two components, species turnover and nestedness? Are the effects caused by defoliation, trampling or defecating? Location Twenty-four currently grazed and 24 abandoned wood-pasture sites in Central Finland. Methods The species richness of vascular plants and bryophytes was studied at four spatial scales: within 4-m2 subplots (α1), within 100-m2 plots (α2), within sites (α3) and within the landscape (γ). β-Diversity was studied between subplots within plots (β1), between plots within sites (β2) and between sites within the landscape (β3). Results Curr…
Differences in Cellular Encapsulation of Six Termite (Isoptera) Species Against Infection by the Entomopathogenic FungusMetarhizium anisopliae
2011
Termites (Isoptera) are eusocial insects, which live in an environment that can favor the spread of pathogens. To reduce the chance of an epizootic within a colony, termites have evolved many defense mechanisms. Most studies have focused on the social aspect of disease resistance, while the individual capacity of a termite to survive an infection remains poorly documented. We previously showed that when the eastern subterranean termite, Reticulitermes flavipes (Kollar), was exposed to the entomopathogenic fungus, Metarhizium anisopliae (Metch.) Sorokin, cellular encapsulation of the penetrating fungus was one of the last lines of defense for individual termites to prevent internal mycosis. …
Population dynamic consequences of delayed life-history effects
2002
Evidence from wildlife and human populations indicates that conditions during early development can have marked effects on the subsequent performance of individuals and cohorts. Likewise, the effects of maternal and, more generally, parental environments can be transferred among individuals between generations. These delayed life-history effects are found consistently and suggestions have been made that they can be one source of both variability and of delayed density dependence in population dynamics. Assessments of several different time series indicate that population variability and delayed density dependence are common and that understanding the mechanisms giving rise to them is crucia…
Adapted conservation measures are required to save the Iberian lynx in a changing climate
2013
The Iberian lynx ( Lynx pardinus ) has suffered severe population declines in the twentieth century and is now on the brink of extinction 1 . Climate change could further threaten the survival of the species 2 , but its forecast effects are being neglected in recovery plans 3,4 . Quantitative estimates of extinction risk under climate change have so far mostly relied on inferences from correlative projections of species’ habitat shifts 5 . Here we use ecological niche models coupled to metapopulation simulations with source–sink dynamics 6,7 to directly investi- gate the combined effects of climate change, prey availabil- ity and management intervention on the persistence of the Iberian lyn…
The mechanistic basis of demographic Allee effects: The search for mates
2017
In Focus: Berec, L., Kremer, A.M., Bernhauverova, V., & Drake, J.M. (2017). Density-dependent selection on mate-finding Allee effects. Journal of Animal Ecology, 87, 24-35. https://doi.org/10.1111/1365-2656.12662 In Focus: Shaw, A.K., Kokko, H., & Neubert, M.G. (2017). Details of mate finding drive dynamics of sex structured invasions. Journal of Animal Ecology, 87, 36-46. https://doi.org/10.1111/1365-2656.12658 Lowered population growth ability at low abundances is called the demographic Allee effect. The difficulty of finding mates in a sparse population is the best documented pathway through which a demographic Allee effect might arise. The articles in focus here aim to establish the mec…
Pervasive declines in monkfish (Lophius americanus) size structure throughout the northwest Atlantic
2020
Abstract Shifts in size structure have been documented for many commercially exploited marine fish stocks, thought to be attributed to size-selective harvesting practices coupled with changing oceanic conditions. Northwest Atlantic monkfish (Lophius americanus) is a commercially valued species in the United States that is commonly caught as bycatch in Canadian scallop and groundfish fisheries. This uniquely positioned stock is bisected by the Canadian–American jurisdictional boundary, with considerable differences in exploitation and management across its range. The status of this species was assessed two decades ago (2000) in the Maritimes region of Canada and more recently (2016) in the U…
Occurrence and impact of interactions between small-scale fisheries and predators, with focus on Mediterranean monk seals (Monachus monachus Hermann …
2017
Abstract Antagonistic interaction between Mediterranean marine mammals, including the endangered monk seal ( Monachus monachus ), and small-scale fisheries is a growing problem in the Aegean Sea. Effective management measures are needed to ensure both the survival of the monk seal population, and its coexistence with the small-scale fisheries. In this study, data from 371 fishing journeys by 8 different boats was collected between March and November 2014. Evidence of depredation by monk seals was recorded in 19.1% of fishing journeys, by cetaceans in 5%, and by other predators in 16.5%. Analysis of landings data showed that gear and depth were the variables most likely to influence the occu…
The ormer (Haliotis tuberculata): A new, promising paleoclimatic tool
2015
International audience; This study aimed to investigate the environmental controls on the oxygen isotope composition of shells of the European abalone, Haliotis tuberculata. Seasonal delta O-18 profiles from the outer prismatic layer of four abalone shells, collected live in northwest Brittany (France) in 2002 and 2012, were compared to local temperatures and salinities. According to the findings herein, delta O-18 variations in abalone shells corresponded to seasonal variations, and thus, shell composition represented a reliable tool for aging and growth studies. Seawater temperatures estimated from the abalone collected in 2012 reflected the in situ measured temperatures, but the reconstr…