Leakage rates were determined from leaf cells loaded with rubidium and [(3)H]leucine. There was a differential response between leucine and rubidium leakage depending upon the species used. The rate of leucine leakage shows a small decline below 5 C for two altitudinal variants of Lycopersicon hirsutum Humb. and Bonpl., whereas Lycopersicon esculentum L. showed a marked increase below 5 C. Rubi...

Anurans are ectothermic animals very sensitive to temperature, mainly during the embryonic stage. In addition, environmental temperature decreases with altitude, and the amphibian fauna changes. Therefore, we studied the relationship between the embryonic thermal tolerances of twelve species of anurans and the temperatures of their microhabitat along an altitudinal gradient from 430 m to 2600 m...

Migratory species employ a variety of strategies to meet energetic demands of postbreeding molt. As such, at least a few species of western Neotropical migrants are known to undergo short-distance upslope movements to locations where adults molt body and flight feathers (altitudinal molt migration). Given inherent difficulties in measuring subtle movements of birds occurring in western mountain...

BACKGROUND AND AIMS Seed dormancy varies within species in response to climate, both in the long term (through ecotypes or clines) and in the short term (through the influence of the seed maturation environment). Disentangling both processes is crucial to understand plant adaptation to environmental changes. In this study, the local patterns of seed dormancy were investigated in a narrow endemi...

Nematode species are widely tolerant of environmental conditions and disperse passively. Therefore, the species richness distribution in this group might largely depend on the topological distribution of the habitats and main aerial and aquatic dispersal pathways connecting them. If so, the nematode species richness distributions may serve as null models for evaluating that of other groups more...

10 Altitudinal gradients represent short-range clines of environmental parameters like tem11 perature, radiation, seasonality and pathogen abundance, which allows to study the foot12 prints of natural selection in geographically close populations. We investigated phenotypic 13 variation for frost resistance and light response in five Arabidopsis thaliana populations rang14 ing from 580 to 2,350...