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Environmental gradients explain species richness and community composition of coastal breeding birds in the Baltic Sea.

Nord M, Forslund P - PLoS ONE (2015)

Bottom Line: The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists.Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately.Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.

ABSTRACT
Scientifically-based systematic conservation planning for reserve design requires knowledge of species richness patterns and how these are related to environmental gradients. In this study, we explore a large inventory of coastal breeding birds, in total 48 species, sampled in 4646 1 km2 squares which covered a large archipelago in the Baltic Sea on the east coast of Sweden. We analysed how species richness (α diversity) and community composition (β diversity) of two groups of coastal breeding birds (specialists, i.e. obligate coastal breeders; generalists, i.e. facultative coastal breeders) were affected by distance to open sea, land area, shoreline length and archipelago width. The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists. The number of specialist bird species per square increased with decreasing distance to open sea, while the opposite was true for the generalists. Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately. Fourteen species were nationally red-listed, and showed similar relationships to the environmental gradients as did all species, specialists and generalists. We suggest that availability of suitable breeding habitats, and probably also proximity to feeding areas, explain much of the observed spatial distributions of coastal birds in this study. Our findings have important implications for systematic conservation planning of coastal breeding birds. In particular, we provide information on where coastal breeding birds occur and which environments they seem to prefer. Small land areas with long shorelines are highly valuable both in general and for red-listed species. Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection.

Show MeSH
Species richness patterns of coastal specialist and generalist species.The archipelago is situated in the Baltic Sea off the east coast of Sweden. Observed number of species per square for (A) generalist species and (B) specialist species. The location of the counties are shown in (B).
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pone.0118455.g001: Species richness patterns of coastal specialist and generalist species.The archipelago is situated in the Baltic Sea off the east coast of Sweden. Observed number of species per square for (A) generalist species and (B) specialist species. The location of the counties are shown in (B).

Mentions: The study area was situated in the Baltic Sea on the east coast of Sweden, and ranged from 58°36’N, 16°48’E in the south to 60°39’N, 17°33’E in the north (Fig. 1). The Baltic Sea is a non-tidal brackish sea (salinity varies between 3.5 and 7.0‰). The post-glacial land uplift in the archipelago region is approximately 5 mm/year, which has resulted in a general gradient where islands are larger closer to the mainland and smaller closer to the open sea. Thus, larger islands are generally less exposed to waves and winds, partially covered with forest and often contain agriculture and settlements. In the middle and outer zones, scattered groups of smaller islands are found that are more exposed and typically dominated by bare bedrock, heather moor, bushes and a few stunted trees or tree groups [21]. The archipelago is widest in the central part and narrows at the northern and southern limits (Fig. 1).


Environmental gradients explain species richness and community composition of coastal breeding birds in the Baltic Sea.

Nord M, Forslund P - PLoS ONE (2015)

Species richness patterns of coastal specialist and generalist species.The archipelago is situated in the Baltic Sea off the east coast of Sweden. Observed number of species per square for (A) generalist species and (B) specialist species. The location of the counties are shown in (B).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4340961&req=5

pone.0118455.g001: Species richness patterns of coastal specialist and generalist species.The archipelago is situated in the Baltic Sea off the east coast of Sweden. Observed number of species per square for (A) generalist species and (B) specialist species. The location of the counties are shown in (B).
Mentions: The study area was situated in the Baltic Sea on the east coast of Sweden, and ranged from 58°36’N, 16°48’E in the south to 60°39’N, 17°33’E in the north (Fig. 1). The Baltic Sea is a non-tidal brackish sea (salinity varies between 3.5 and 7.0‰). The post-glacial land uplift in the archipelago region is approximately 5 mm/year, which has resulted in a general gradient where islands are larger closer to the mainland and smaller closer to the open sea. Thus, larger islands are generally less exposed to waves and winds, partially covered with forest and often contain agriculture and settlements. In the middle and outer zones, scattered groups of smaller islands are found that are more exposed and typically dominated by bare bedrock, heather moor, bushes and a few stunted trees or tree groups [21]. The archipelago is widest in the central part and narrows at the northern and southern limits (Fig. 1).

Bottom Line: The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists.Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately.Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.

ABSTRACT
Scientifically-based systematic conservation planning for reserve design requires knowledge of species richness patterns and how these are related to environmental gradients. In this study, we explore a large inventory of coastal breeding birds, in total 48 species, sampled in 4646 1 km2 squares which covered a large archipelago in the Baltic Sea on the east coast of Sweden. We analysed how species richness (α diversity) and community composition (β diversity) of two groups of coastal breeding birds (specialists, i.e. obligate coastal breeders; generalists, i.e. facultative coastal breeders) were affected by distance to open sea, land area, shoreline length and archipelago width. The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists. The number of specialist bird species per square increased with decreasing distance to open sea, while the opposite was true for the generalists. Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately. Fourteen species were nationally red-listed, and showed similar relationships to the environmental gradients as did all species, specialists and generalists. We suggest that availability of suitable breeding habitats, and probably also proximity to feeding areas, explain much of the observed spatial distributions of coastal birds in this study. Our findings have important implications for systematic conservation planning of coastal breeding birds. In particular, we provide information on where coastal breeding birds occur and which environments they seem to prefer. Small land areas with long shorelines are highly valuable both in general and for red-listed species. Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection.

Show MeSH