Search results for " Habitat quality"
showing 5 items of 5 documents
Interannual variation and long-term trends in proportions of resident individuals in partially migratory birds
2016
Partial migration - a part of a population migrates and another part stays resident year-round on the breeding site - is probably the most common type of migration in the animal kingdom, yet it has only lately garnered more attention. Theoretical studies indicate that in partially migratory populations, the proportion of resident individuals (PoR) should increase in high latitudes in response to the warming climate, but empirical evidence exists for few species. We provide the first comprehensive overview of the environmental factors affecting PoR and the long-term trends in PoR by studying 27 common partially migratory bird species in Finland. The annual PoR values were calculated by divid…
Assessing the importance of nursery areas of European hake (Merluccius merluccius) using a body condition index
2017
Abstract In this study, we analysed the variability of reserve storage in juvenile European hake (Merluccius merluccius) off the western coasts of Italy (Central Mediterranean Sea). Reserve storage was measured by the hepatosomatic index (HSI), in relation to environmental and population covariates. HSI has been proved to be a consistent measure of energy storage in gadoids, thus reflecting quantity and quality of food availability for growth. Generalized Additive Models for Location, Scale and Shape (GAMLSS) were used to model the effect of depth, bottom temperature, bottom currents, fish density and fish body size on HSI of juvenile European hake. The results revealed that reserve storage…
Data from: Inter-annual variation and long-term trends in proportions of resident individuals in partially migratory birds
2016
Partial migration – a part of a population migrates and another part stays resident year-round on the breeding site – is probably the most common type of migration in the animal kingdom, yet it has only lately garnered more attention. Theoretical studies indicate that in partially migratory populations, the proportion of resident individuals (PoR) should increase in high latitudes in response to the warming climate, but empirical evidence exists for few species. We provide the first comprehensive overview of the environmental factors affecting PoR and the long-term trends in PoR by studying 27 common partially migratory bird species in Finland. The annual PoR values were calculated by divid…
Structural variables drive the distribution of the sensitive lichen Lobaria pulmonaria in Mediterranean old-growth forests
2015
a b s t r a c t We tested the hypothesis that structural variables related to old-growth features affect the distribution of Lobaria pulmonaria in a Mediterranean National Park of Italy. A total of 36 plots, with old-growth characteristics and representing overall three forest types (beech- oak- and mixed- forests) were studied. The lichen was absent in about half of the sites, suggesting that the selection of old-growth forests based solely on structural features is not sufficient to predict the presence of this species, which therefore proves to be rather sensitive and selective. Its abundance was related to high tree circumference and basal area, and to availability of deadwood, confirmi…
Wpływ zanieczyszczeń komunikacyjnych na glebę i uprawną roślinność przydrożną
2014
Celem pracy było rozpoznanie wpływu zanieczyszczeń komunikacyjnych na glebę i roślinność uprawnianą przy pasie drogowym. Zanieczyszczenia te, to nie tylko spaliny, ale również pyły powstające w wyniku tarcia opon o nawierzchnie drogi, płyny wyciekające z nieszczelnych instalacji oraz śmieci wyrzucane przez kierowców w trakcie jazdy. Roślina bytująca w takim środowisku, jest narażona na liczne stresy i uszkodzenia. Główną przyczyną wpływającą niekorzystnie na rozwój roślin, a nawet powodującą ich śmierć, jest potęgujące się stale zanieczyszczenie powietrza, zwłaszcza w rejonach śródmiejskich jak i wzdłuż obciążonych tras komunikacyjnych. Na skutek używania soli do zwalczania gołoledzi, naraż…