Insights From a New 1-ha Permanent Forest Plot Reveal Differences Between Habitat Type and Similarities Between Forest Type in the Southwestern Amazon.

The southwestern Amazon is a biodiversity hotspot home to some of the oldest permanent forest dynamics plots in the basin. Despite the region's abundance of plots, we still know relatively little about how tree diversity and composition change across the region's precipitation gradient, between habitat types, and how disturbed and managed forests compare to protected, old-growth forests since the majority of forest plots are located in protected forests. In this study, we first described a new 1-ha permanent forest dynamics plot at the confluence of agricultural land and managed Brazil nut forest.

Functional composition of the Amazonian tree flora and forests.

Plants cope with the environment by displaying large phenotypic variation. Two spectra of global plant form and function have been identified: a size spectrum from small to tall species with increasing stem tissue density, leaf size, and seed mass; a leaf economics spectrum reflecting slow to fast returns on investments in leaf nutrients and carbon. When species assemble to communities it is assumed that these spectra are filtered by the environment to produce community level functional composition.

Hotter Temperatures Reduce the Diversity and Alter the Composition of Woody Plants in an Amazonian Forest.

Rapid warming and high temperatures are an immediate threat to global ecosystems, but the threat may be especially pronounced in the tropics. Although low-latitude tree species are widely predicted to be vulnerable to warming, information about how tropical tree diversity and community composition respond to elevated temperatures remains sparse. Here, we study long-term responses of tree diversity and composition to increased soil and air temperatures at the Boiling River-an exceptional and unique "natural warming experiment" in the central Peruvian Amazon.

Refuting the hypothesis of Centinelan extinction at its place of origin.

Scientists' limited understanding of tropical plant communities obscures the true extent of species loss caused by habitat destruction. The Centinelan extinction hypothesis posits an extreme but widely referenced scenario wherein forest clearing causes the immediate extinction of species known only from a single geographic location. It remains unclear, however, whether the disappearance of such microendemics reflects their global extinction or insufficient collection effort at larger scales.

The biogeography of the Amazonian tree flora.

We describe the geographical variation in tree species composition across Amazonian forests and show how environmental conditions are associated with species turnover. Our analyses are based on 2023 forest inventory plots (1 ha) that provide abundance data for a total of 5188 tree species. Within-plot species composition reflected both local environmental conditions (especially soil nutrients and hydrology) and geographical regions.

Leaf thermal safety margins decline at hotter temperatures in a natural warming 'experiment' in the Amazon.

The threat of rising global temperatures may be especially pronounced for low-latitude, lowland plant species that have evolved under stable climatic conditions. However, little is known about how these species may acclimate to elevated temperatures. Here, we leveraged a strong, steep thermal gradient along a natural geothermal river to assess the ability of woody plants in the Amazon to acclimate to elevated air temperatures.

Rediscovery of L.E.Skog & L.P.Kvist (Gesneriaceae) at multiple sites in western Ecuador.

We report the rediscovery of the Critically Endangered cloud forest herb , not seen since 1985. In 2019 and 2021, was recorded at five sites in the western foothills of the Ecuadorian Andes, 4-25 km from the type locality at the celebrated Centinela ridge. We describe the species' distribution, abundance, habitat and conservation status and offer recommendations for further research and conservation efforts focused on and the small, disjunct forest remnants it occupies.