Stand dynamics modulate water cycling and mortality risk in droughted tropical forest

da Costa A.C.L., Rowland L., Oliveira R.S., Oliveira A.A.R., Binks O.J., Salmon Y., Vasconcelos S.S., Junior J.A.S., Ferreira L.V., Poyatos R., Mencuccini M., Meir P. (2017) Stand dynamics modulate water cycling and mortality risk in droughted tropical forest. Global Change Biology. : 0-0.
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Doi: 10.1111/gcb.13851

Resum:

Transpiration from the Amazon rainforest generates an essential water source at a global and local scale. However, changes in rainforest function with climate change can disrupt this process, causing significant reductions in precipitation across Amazonia, and potentially at a global scale. We report the only study of forest transpiration following a long-term (>10 year) experimental drought treatment in Amazonian forest. After 15 years of receiving half the normal rainfall, drought-related tree mortality caused total forest transpiration to decrease by 30%. However, the surviving droughted trees maintained or increased transpiration because of reduced competition for water and increased light availability, which is consistent with increased growth rates. Consequently, the amount of water supplied as rainfall reaching the soil and directly recycled as transpiration increased to 100%. This value was 25% greater than for adjacent nondroughted forest. If these drought conditions were accompanied by a modest increase in temperature (e.g., 1.5°C), water demand would exceed supply, making the forest more prone to increased tree mortality. © 2017 John Wiley & Sons Ltd.

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Early-life foraging: Behavioral responses of newly fledged albatrosses to environmental conditions

de Grissac S., Bartumeus F., Cox S.L., Weimerskirch H. (2017) Early-life foraging: Behavioral responses of newly fledged albatrosses to environmental conditions. Ecology and Evolution. 7: 6766-6778.
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Doi: 10.1002/ece3.3210

Resum:

In order to survive and later recruit into a population, juvenile animals need to acquire resources through the use of innate and/or learnt behaviors in an environment new to them. For far-ranging marine species, such as the wandering albatross Diomedea exulans, this is particularly challenging as individuals need to be able to rapidly adapt and optimize their movement strategies in response to the highly dynamic and heterogeneous nature of their open-ocean pelagic habitats. Critical to this is the development and flexibility of dispersal and exploratory behaviors. Here, we examine the movements of eight juvenile wandering albatrosses, tracked using GPS/Argos satellite transmitters for eight months following fledging, and compare these to the trajectories of 17 adults to assess differences and similarities in behavioral strategies through time. Behavioral clustering algorithms (Expectation Maximization binary Clustering) were combined with multinomial regression analyses to investigate changes in behavioral mode probabilities over time, and how these may be influenced by variations in day duration and in biophysical oceanographic conditions. We found that juveniles appeared to quickly acquire the same large-scale behavioral strategies as those employed by adults, although generally more time was spent resting at night. Moreover, individuals were able to detect and exploit specific oceanographic features in a manner similar to that observed in adults. Together, the results of this study suggest that while shortly after fledging juvenile wandering albatrosses are able to employ similar foraging strategies to those observed in adults, additional skills need to be acquired during the immature period before the efficiency of these behaviors matches that of adults. © 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

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Nematode distributions as spatial null models for macroinvertebrate species richness across environmental gradients: A case from mountain lakes

de Mendoza, G., Traunspurger, W., Palomo, A., Catalan, J. (2017) Nematode distributions as spatial null models for macroinvertebrate species richness across environmental gradients: A case from mountain lakes. Ecology and Evolution. : 0-0.
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Doi: 10.1002/ece3.2842

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