Variation in wood density across South American tropical forests.

Wood density is a critical control on tree biomass, so poor understanding of its spatial variation can lead to large and systematic errors in forest biomass estimates and carbon maps. The need to understand how and why wood density varies is especially critical in tropical America where forests have exceptional species diversity and spatial turnover in composition. As tree identity and forest composition are challenging to estimate remotely, ground surveys are essential to know the wood density of trees, whether measured directly or inferred from their identity.

Tropical forests in the Americas are changing too slowly to track climate change.

Understanding the capacity of forests to adapt to climate change is of pivotal importance for conservation science, yet this is still widely unknown. This knowledge gap is particularly acute in high-biodiversity tropical forests. Here, we examined how tropical forests of the Americas have shifted community trait composition in recent decades as a response to changes in climate.

Nitro-fatty acids-mediated nitroalkylation modulates fine-tuning catalase antioxidant function during salinity stress in plants.

Nitro-fatty acids (NO-FAs) are novel molecules resulting from the interaction of unsaturated fatty acids and nitric oxide (NO) or NO-related molecules. In plants, it has recently been described that NO-FAs trigger a powerful antioxidant and defense response against stressful situations, the induction of the heat-shock response (HSR), and they exert their signaling function mainly through a reversible post-translational modification called nitroalkylation. Catalase (CAT) is a key antioxidant enzyme for the control of the hydrogen peroxide (HO) levels generated by environmental oxidative stress.

Planar Tetracoordinate Oxygen Atoms.

Planar tetracoordinate oxygen (ptO) atoms are rare, with only a few examples confirmed to date. This study systematically investigates 515 potential structures, formulated as OXY , where n+m=4, q ranging from +2 to -2, and following the 18-valence electron rule. High-level ab initio calculations identified 35 global minima containing a ptO atom, predominantly stabilized by Group 13 elements.

Large range sizes link fast life histories with high species richness across wet tropical tree floras.

Understanding how the traits of lineages are related to diversification is key for elucidating the origin of variation in species richness. Here, we test whether traits are related to species richness among lineages of trees from all major biogeographical settings of the lowland wet tropics. We explore whether variation in mortality rate, breeding system and maximum diameter are related to species richness, either directly or via associations with range size, among 463 genera that contain wet tropical forest trees.