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Similar local and landscape processes affect both a common and a rare newt species.

Denoël M, Perez A, Cornet Y, Ficetola GF - PLoS ONE (2013)

Bottom Line: We tested this hypothesis by examining, through an information-theoretic approach, the importance of ecological processes at multiple scales in the great crested newt Triturus cristatus, regionally endangered and protected in Europe, and the more common smooth newt, Lissotriton vulgaris.The results show that environmental pressures threaten both common and rare species, and therefore the more widespread species should not be neglected in conservation programs.On the other hand, in agreement with the umbrella species concept, targeting conservation efforts on the most demanding species would also protect part of the populations of the most common species.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Fish and Amphibian Ethology, Behavioural Biology Unit, Department of Biology, Ecology and Evolution, University of Liège, Liège, Belgium. Mathieu.Denoel@ulg.ac.be

ABSTRACT
Although rare species are often the focus of conservation measures, more common species may experience similar decline and suffer from the same threatening processes. We tested this hypothesis by examining, through an information-theoretic approach, the importance of ecological processes at multiple scales in the great crested newt Triturus cristatus, regionally endangered and protected in Europe, and the more common smooth newt, Lissotriton vulgaris. Both species were similarly affected by the same processes, i.e. suitability of aquatic and terrestrial components of their habitat at different scales, connectivity among breeding sites, and the presence of introduced fish. T. cristatus depended more on water depth and aquatic vegetation than L. vulgaris. The results show that environmental pressures threaten both common and rare species, and therefore the more widespread species should not be neglected in conservation programs. Because environmental trends are leading to a deterioration of aquatic and terrestrial habitat features required by newt populations, populations of the common species may follow the fate of the rarest species. This could have substantial conservation implications because of the numerical importance of common species in ecosystems and because commonness could be a transient state moving towards rarity. On the other hand, in agreement with the umbrella species concept, targeting conservation efforts on the most demanding species would also protect part of the populations of the most common species.

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Effect of local and landscape variables on spatial variation in newt abundance in ponds.Panels represent conditional partial regression plots, based on the best selected model for both Triturus cristatus (grey bands and full lines) and Lissotriton vulgaris (green bands and interrupted lines). The “number of wetlands” were square-root transformed values; the other variables are components extracted by PCAs: see methods for more details. Shaded areas represent 95% confidence bands.
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pone-0062727-g003: Effect of local and landscape variables on spatial variation in newt abundance in ponds.Panels represent conditional partial regression plots, based on the best selected model for both Triturus cristatus (grey bands and full lines) and Lissotriton vulgaris (green bands and interrupted lines). The “number of wetlands” were square-root transformed values; the other variables are components extracted by PCAs: see methods for more details. Shaded areas represent 95% confidence bands.

Mentions: The model that most likely explained the distribution of T. cristatus (i.e. the model with rank 1 in Table 3) suggests that this species is influenced by present landscape features (scale, 100 m), past landscape (scale, 500 m), fish presence, local features and connectivity (scale, 100 m) (Tables 3 and 4a). Three further models showed weight greater than 0.1. All the models with weight greater than 0.1 included local features, connectivity and present and past landscape composition (Table 3). Fish presence was included in three out of the four models with weight greater than 0.1. Examination of individual variables included in the best AIC model showed that T. cristatus was associated with large and deep ponds with abundant aquatic vegetation but without fish, surrounded by a high number of wetlands within 100 m, in landscapes that are currently open and that had low urbanization in the past (Figure 3, Table 4a).


Similar local and landscape processes affect both a common and a rare newt species.

Denoël M, Perez A, Cornet Y, Ficetola GF - PLoS ONE (2013)

Effect of local and landscape variables on spatial variation in newt abundance in ponds.Panels represent conditional partial regression plots, based on the best selected model for both Triturus cristatus (grey bands and full lines) and Lissotriton vulgaris (green bands and interrupted lines). The “number of wetlands” were square-root transformed values; the other variables are components extracted by PCAs: see methods for more details. Shaded areas represent 95% confidence bands.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3643927&req=5

pone-0062727-g003: Effect of local and landscape variables on spatial variation in newt abundance in ponds.Panels represent conditional partial regression plots, based on the best selected model for both Triturus cristatus (grey bands and full lines) and Lissotriton vulgaris (green bands and interrupted lines). The “number of wetlands” were square-root transformed values; the other variables are components extracted by PCAs: see methods for more details. Shaded areas represent 95% confidence bands.
Mentions: The model that most likely explained the distribution of T. cristatus (i.e. the model with rank 1 in Table 3) suggests that this species is influenced by present landscape features (scale, 100 m), past landscape (scale, 500 m), fish presence, local features and connectivity (scale, 100 m) (Tables 3 and 4a). Three further models showed weight greater than 0.1. All the models with weight greater than 0.1 included local features, connectivity and present and past landscape composition (Table 3). Fish presence was included in three out of the four models with weight greater than 0.1. Examination of individual variables included in the best AIC model showed that T. cristatus was associated with large and deep ponds with abundant aquatic vegetation but without fish, surrounded by a high number of wetlands within 100 m, in landscapes that are currently open and that had low urbanization in the past (Figure 3, Table 4a).

Bottom Line: We tested this hypothesis by examining, through an information-theoretic approach, the importance of ecological processes at multiple scales in the great crested newt Triturus cristatus, regionally endangered and protected in Europe, and the more common smooth newt, Lissotriton vulgaris.The results show that environmental pressures threaten both common and rare species, and therefore the more widespread species should not be neglected in conservation programs.On the other hand, in agreement with the umbrella species concept, targeting conservation efforts on the most demanding species would also protect part of the populations of the most common species.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Fish and Amphibian Ethology, Behavioural Biology Unit, Department of Biology, Ecology and Evolution, University of Liège, Liège, Belgium. Mathieu.Denoel@ulg.ac.be

ABSTRACT
Although rare species are often the focus of conservation measures, more common species may experience similar decline and suffer from the same threatening processes. We tested this hypothesis by examining, through an information-theoretic approach, the importance of ecological processes at multiple scales in the great crested newt Triturus cristatus, regionally endangered and protected in Europe, and the more common smooth newt, Lissotriton vulgaris. Both species were similarly affected by the same processes, i.e. suitability of aquatic and terrestrial components of their habitat at different scales, connectivity among breeding sites, and the presence of introduced fish. T. cristatus depended more on water depth and aquatic vegetation than L. vulgaris. The results show that environmental pressures threaten both common and rare species, and therefore the more widespread species should not be neglected in conservation programs. Because environmental trends are leading to a deterioration of aquatic and terrestrial habitat features required by newt populations, populations of the common species may follow the fate of the rarest species. This could have substantial conservation implications because of the numerical importance of common species in ecosystems and because commonness could be a transient state moving towards rarity. On the other hand, in agreement with the umbrella species concept, targeting conservation efforts on the most demanding species would also protect part of the populations of the most common species.

Show MeSH
Related in: MedlinePlus