Large-Scale Patterns of Turnover and Basal Area Change in Andean Forests

General patterns of forest dynamics and productivity in the Andes Mountains are poorly characterized. Here we present the first large-scale study of Andean forest dynamics using a set of 63 permanent forest plots assembled over the past two decades. In the North-Central Andes tree turnover (mortality and recruitment) and tree growth declined with increasing elevation and decreasing temperature. In addition, basal area increased in Lower Montane Moist Forests but did not change in Higher Montane Humid Forests. However, at higher elevations the lack of net basal area change and excess of mortality over recruitment suggests negative environmental impacts. In North-Western Argentina, forest dynamics appear to be influenced by land use history in addition to environmental variation. Taken together, our results indicate that combinations of abiotic and biotic factors that vary across elevation gradients are important determinants of tree turnover and productivity in the Andes. More extensive and longer-term monitoring and analyses of forest dynamics in permanent plots will be necessary to understand how demographic processes and woody biomass are responding to changing environmental conditions along elevation gradients through this century.     

Diversity and endemism of woody plant species in the Equatorial Pacific seasonally dry forests

The biodiversity hotspot of the Equatorial Pacific region in western Ecuador and northwestern Peru comprises the most extensive seasonally dry forest formations west of the Andes. Based on a recently assembled checklist of the woody plants occurring in this region, we analysed their geographical and altitudinal distribution patterns. The montane seasonally dry forest region (at an altitude between 1,000 and 1,100 m, and the smallest in terms of area) was outstanding in terms of total species richness and number of endemics. The extensive seasonally dry forest formations in the Ecuadorean and Peruvian lowlands and hills (i.e., forests below 500 m altitude) were comparatively much more species poor. It is remarkable though, that there were so many fewer collections in the Peruvian departments and Ecuadorean provinces with substantial mountainous areas, such as Cajamarca and Loja, respectively, indicating that these places have a potentially higher number of species. We estimate that some form of protected area (at country, state or private level) is currently conserving only 5% of the approximately 55,000 km² of remaining SDF in the region, and many of these areas protect vegetation at altitudes below 500 m altitude. In contrast, the more diverse seasonally dry forests in mountainous areas remain little protected.     

Cactus novelties from southern Ecuador

The epiphytic Rhipsalis riocampanensis from the upper montane rain forest of the Podocarpus National Park is described as a new species. A large columnar cactus previously known from N Peru, Browningia microsperma. is here recorded from the Loja province in southern Ecuador. It is the first time Browningia has been reported from Ecuador. Espostoa lanata ssp. roseiflora is described as a new subspecies based on a population in the Catamayo valley. It is suggested that Armatocereus rupicola is an older name for Armatocereus brevispinus.     

Mapping tree species vulnerability to multiple threats as a guide to restoration and conservation of tropical dry forests

Understanding the vulnerability of tree species to anthropogenic threats is important for the efficient planning of restoration and conservation efforts. We quantified and compared the effects of future climate change and four current threats (fire, habitat conversion, overgrazing and overexploitation) on the 50 most common tree species of the tropical dry forests of northwestern Peru and southern Ecuador. We used an ensemble modelling approach to predict species distribution ranges, employed freely accessible spatial datasets to map threat exposures, and developed a trait‐based scoring approach to estimate species‐specific sensitivities, using differentiated trait weights in accordance with their expected importance in determining species sensitivities to specific threats. Species‐specific vulnerability maps were constructed from the product of the exposure maps and the sensitivity estimates. We found that all 50 species face considerable threats, with an average of 46% of species’ distribution ranges displaying high or very high vulnerability to at least one of the five threats. Our results suggest that current levels of habitat conversion, overexploitation and overgrazing pose larger threats to most of the studied species than climate change. We present a spatially explicit planning strategy for species‐specific restoration and conservation actions, proposing management interventions to focus on (a) in situ conservation of tree populations and seed collection for tree planting activities in areas with low vulnerability to climate change and current threats; (b) ex situ conservation or translocation of populations in areas with high climate change vulnerability; and (c) active planting or assisted regeneration in areas under high current threat vulnerability but low climate change vulnerability, provided that interventions are in place to lower threat pressure. We provide an online, user‐friendly tool to visualize both the vulnerability maps and the maps indicating priority restoration and conservation actions.     

Opiate, cannabinoid, and eicosanoid signaling converges on common intracellular pathways nitric oxide coupling.

Scientific fields as they emerge initially appear to be unrelated to other projects even if they are in a similar area of interest. This is especially true in the case of opiate, cannabinoid, and eicosanoid signaling processes. In this limited speculative review, we attempt to examine aspects of their intracellular cascading signaling systems for their commonalities. We find intracellular calcium mobilization, nuclear factor kappa B involvement, adenylate cyclase activity, and, finally, constitutive nitric oxide release to be converging points for these signaling processes, occurring by separate and distinct receptor-mediated effector systems. Phosphokinase C, mitogen activated protein kinase, and cytosolic phospholipase A2 also represent points of common impact. In this regard, aspirin also appears to be involved in an aspect of this signaling convergence. We conclude that many of the physiological observations regarding the actions of these signaling molecules, for example, immunosuppression, neurotransmission, vasodilation, cellular adherence, and cytotoxicity, can now be understood by considering their converging biochemical cascades.