High-alpine life forms and ecosystems exist at the limits of habitable environments, and thus, ar... more High-alpine life forms and ecosystems exist at the limits of habitable environments, and thus, are especially sensitive to environmental change. Here we report a recent increase in the elevational limit of anurans following glacial retreat in the tropical Peruvian Andes. Three species have colonized ponds in recently deglaciated terrain at new record elevations for amphibians worldwide (5244–5400 m). Two of these species were also found to be infected with Batrachochytrium dendrobatidis (Bd), an emerging fungal pathogen causally associated with global amphibian declines, including the disappearance of several Latin American species. The presence of this pathogen was associated with elevated mortality rates of at least one species. These results represent the first evidence of upward expansion of anurans to newly available habitat brought about by recent deglaciation. Furthermore, the large increase in the upper limit of known Bd infections, previously reported as 4112 m in Ecuador, to 5348 m in this study, also expands the spatial domain of potential Bd pathogenicity to encompass virtually all high elevation anuran habitats in the tropical Andes.
The abundance of agricultural plants tends to lognormal frequency distributions and power rank-ab... more The abundance of agricultural plants tends to lognormal frequency distributions and power rank-abundance distributions [characteristic of a self-organised critical state]
A method is proposed to determine the presence of true adaptations originating by natural selecti... more A method is proposed to determine the presence of true adaptations originating by natural selection from characters of any other origin.
Liolaemus huacahuasicus lives above 3700 m in the Cumbres Calchaquíes, Tucumán. The description o... more Liolaemus huacahuasicus lives above 3700 m in the Cumbres Calchaquíes, Tucumán. The description of its habitat includes data on the climate, the soils, the vegetation, the existence of ecoclines, the temperatura. Other observations are presented on its diet, the enemies, parasites, diseases and population structure. The behaviour is mainly determined by the cold and the sun.
... 0.67+ 0.91'+ 0.99*-0.86* Soil temperature Growth rates -0.63-0.80* + 0.89* -... more ... 0.67+ 0.91'+ 0.99*-0.86* Soil temperature Growth rates -0.63-0.80* + 0.89* -0.77* + 0.56 + 0.51 -0.99* Species richness Diversity (Shannon) + 0.86*-0.84 ... at many thousands or even tens of thousands of years (eg Populus tremuloides > 10 000 years old, Kemperman and Barnes ...
A theoretical framework is proposed to explain how and where complex systems break up into agents... more A theoretical framework is proposed to explain how and where complex systems break up into agents or species. Splits lead to diversification and to abundance distributions which are similar to power functions on a rank-abundance representation and to lognormal functions on a frequency-abundance representation. The combined manifestation of power and lognormal functions is a polo distribution, a situation toward which
... tnc.org Jorge Cole1, jcole@tnc.org Mercedes Ibáñez1, mibanez@tnc.org Juan José Rodríguez1, jj... more ... tnc.org Jorge Cole1, jcole@tnc.org Mercedes Ibáñez1, mibanez@tnc.org Juan José Rodríguez1, jjrodriguez@tnc.org Stephan Halloy1, 2 ... TNC´s Amistad-Bocas del Toro Program identified important ecosystem and wildlife conservation targets, such as jaguars, tapirs, paramos ...
High-alpine life forms and ecosystems exist at the limits of habitable environments, and thus, ar... more High-alpine life forms and ecosystems exist at the limits of habitable environments, and thus, are especially sensitive to environmental change. Here we report a recent increase in the elevational limit of anurans following glacial retreat in the tropical Peruvian Andes. Three species have colonized ponds in recently deglaciated terrain at new record elevations for amphibians worldwide (5244–5400 m). Two of these species were also found to be infected with Batrachochytrium dendrobatidis (Bd), an emerging fungal pathogen causally associated with global amphibian declines, including the disappearance of several Latin American species. The presence of this pathogen was associated with elevated mortality rates of at least one species. These results represent the first evidence of upward expansion of anurans to newly available habitat brought about by recent deglaciation. Furthermore, the large increase in the upper limit of known Bd infections, previously reported as 4112 m in Ecuador, to 5348 m in this study, also expands the spatial domain of potential Bd pathogenicity to encompass virtually all high elevation anuran habitats in the tropical Andes.
The abundance of agricultural plants tends to lognormal frequency distributions and power rank-ab... more The abundance of agricultural plants tends to lognormal frequency distributions and power rank-abundance distributions [characteristic of a self-organised critical state]
A method is proposed to determine the presence of true adaptations originating by natural selecti... more A method is proposed to determine the presence of true adaptations originating by natural selection from characters of any other origin.
Liolaemus huacahuasicus lives above 3700 m in the Cumbres Calchaquíes, Tucumán. The description o... more Liolaemus huacahuasicus lives above 3700 m in the Cumbres Calchaquíes, Tucumán. The description of its habitat includes data on the climate, the soils, the vegetation, the existence of ecoclines, the temperatura. Other observations are presented on its diet, the enemies, parasites, diseases and population structure. The behaviour is mainly determined by the cold and the sun.
... 0.67+ 0.91'+ 0.99*-0.86* Soil temperature Growth rates -0.63-0.80* + 0.89* -... more ... 0.67+ 0.91'+ 0.99*-0.86* Soil temperature Growth rates -0.63-0.80* + 0.89* -0.77* + 0.56 + 0.51 -0.99* Species richness Diversity (Shannon) + 0.86*-0.84 ... at many thousands or even tens of thousands of years (eg Populus tremuloides > 10 000 years old, Kemperman and Barnes ...
A theoretical framework is proposed to explain how and where complex systems break up into agents... more A theoretical framework is proposed to explain how and where complex systems break up into agents or species. Splits lead to diversification and to abundance distributions which are similar to power functions on a rank-abundance representation and to lognormal functions on a frequency-abundance representation. The combined manifestation of power and lognormal functions is a polo distribution, a situation toward which
... tnc.org Jorge Cole1, jcole@tnc.org Mercedes Ibáñez1, mibanez@tnc.org Juan José Rodríguez1, jj... more ... tnc.org Jorge Cole1, jcole@tnc.org Mercedes Ibáñez1, mibanez@tnc.org Juan José Rodríguez1, jjrodriguez@tnc.org Stephan Halloy1, 2 ... TNC´s Amistad-Bocas del Toro Program identified important ecosystem and wildlife conservation targets, such as jaguars, tapirs, paramos ...
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