0000000000400307
AUTHOR
Ari Rajasärkkä
Disentangling the effects of area, energy and habitat heterogeneity on boreal forest bird species richness in protected areas
Aim One of the few general laws in ecology is that species richness is a positive function of area. However, it has been proposed that area would merely be a proxy for energy. Additionally, habitat heterogeneity has been found to be an important factor determining species richness. Yet the relative importance of those relationships is little known, and it is still unclear how they are brought about. We aimed to dissect which factors drive the species richness of boreal forest birds, and to identify the most probable mechanisms. Location Forested protected areas in Finland. Methods Using bird line census data collected in 104 protected areas, we ran simultaneous autoregressive models to e…
Degradation in landscape matrix has diverse impacts on diversity in protected areas.
Introduction: A main goal of protected areas is to maintain species diversity and the integrity of biological assemblages. Intensifying land use in the matrix surrounding protected areas creates a challenge for biodiversity conservation. Earlier studies have mainly focused on taxonomic diversity within protected areas. However, functional and especially phylogenetic diversities are less studied phenomena, especially with respect to the impacts of the matrix that surrounds protected areas. Phylogenetic diversity refers to the range of evolutionary lineages, the maintenance of which ensures that future evolutionary potential is safeguarded. Functional diversity refers to the range of ecologic…
Energy density and its variation in space limit species richness of boreal forest birds
Aim An area’s ability to support species may be dependent not only on the total amount of available energy it contains but also on energy density (i.e. available energy per unit area). Acknowledging these two aspects of energy availability may increase mechanistic understanding of how increased energy availability results in increased species richness. We studied the relationship between energy density, its variation in space and boreal forest bird species richness and investigated two possible mechanisms: (1) metabolic constraints of organisms, and (2) increased resource availability for specialists. Location Protected areas in Finland’s boreal forest. Methods We tested whether bird spe…
Protected areas enhance expanding populations and mitigate declines on range edges under climate change
Warming climate is changing geographical distributions of species. However, keeping pace with the climate may be complicated. The climate is indeed changing faster than species are capable of following it. Other environmental changes can hamper the ability of species to move if they face difficulties following climatic preferences in a fragmented landscape. This may lead to increased extinction risk especially for species inhabiting high latitudes and altitudes. These species are expected to be particularly exposed to the consequences of climate change due to the lack of space into which they can retreat. Evidence is mounting that this may indeed be the case, since boreal and montane specie…