Past human influences on Amazonian forest: The marks of prehistoric human societies on tropical forests can still be detected today. Levis et al. performed a basin-wide comparison of plant distributions, archaeological sites, and environmental data. Plants domesticated by pre-Columbian peoples are much more likely to be dominant in Amazonian forests than other species. Furthermore, forests close to archaeological sites often have a higher abundance and richness of domesticated species. Thus, modern-day Amazonian tree communities across the basin remain largely structured by historical human use. Science , this issue p. 925

A large number of newly published and unpublished hectare plots in Amazonia and the Guiana Shield area allow an analysis of family composition and testing of hypotheses concerning alpha-diversity in the south American rain forest. Using data from 94 plots the family-level floristic patterns in wet tropical South America are described. To test diversity patterns, 268 plots are used in this large area. Contrary to a widely held belief, western Amazonian plots are not necessarily the most diverse. Several central Amazonian plots have equal or even higher tree diversity. Annual rainfall is not a good estimator for tree diversity in the Amazonia area and Guiana shield. Plots in the Guiana Shield area (and eastern Amazonia) usually have lower diversity than those in central or western Amazonia. It is argued that this is not because of low rainfall or low nutrient status of the soil but because of the small area of the relatively isolated rain forest area in eastern Amazonia and the Guiana Shield. The low diversity on nutrient-poor white sand soils in the Amazon basin is not necessarily due to their low nutrient status but is, at least partly, caused by their small extent and fragmented nature.

Analyses of forest loss and protected areas suggest that 36 to 57% of Amazonian tree flora may qualify as “globally threatened.”

Background: Wild orchids are illegally harvested and traded in Nepal for use in local traditional medicine, horticulture, and international trade. This study aims to: 1) identify the diversity of species of wild orchids in trade in Nepal; 2) study the chain of commercialization from collector to client and/or export; 3) map traditional knowledge and medicinal use of orchids; and 4) integrate the collected data to propose a more sustainable approach to orchid conservation in Nepal. Methods: Trade, species diversity, and traditional use of wild-harvested orchids were documented during field surveys of markets and through interviews. Trade volumes and approximate income were estimated based on surveys and current market prices. Orchid material samples were identified to species level using a combination of morphology and DNA barcoding. Results: Orchid trade is a long tradition, and illegal export to China, India and Hong Kong is rife. Estimates show that 9.4 tons of wild orchids were illegally traded from the study sites during 2008/2009. A total of 60 species of wild orchids were reported to be used in traditional medicinal practices to cure at least 38 different ailments, including energizers, aphrodisiacs and treatments of burnt skin, fractured or dislocated bones, headaches, fever and wounds. DNA barcoding successfully identified orchid material to species level that remained sterile after culturing. Conclusions: Collection of wild orchids was found to be widespread in Nepal, but illegal trade is threatening many species in the wild. Establishment of small-scale sustainable orchid breeding enterprises could be a valuable alternative for the production of medicinal orchids for local communities. Critically endangered species should be placed on CITES Appendix I to provide extra protection to those species. DNA barcoding is an effective method for species identification and monitoring of illegal cross-border trade.

Plants sustain human life. Understanding geographic patterns of the diversity of species used by people is thus essential for the sustainable management of plant resources. Here, we investigate the global distribution of 35,687 utilized plant species spanning 10 use categories (e.g., food, medicine, material). Our findings indicate general concordance between utilized and total plant diversity, supporting the potential for simultaneously conserving species diversity and its contributions to people. Although Indigenous lands across Mesoamerica, the Horn of Africa, and Southern Asia harbor a disproportionate diversity of utilized plants, the incidence of protected areas is negatively correlated with utilized species richness. Finding mechanisms to preserve areas containing concentrations of utilized plants and traditional knowledge must become a priority for the implementation of the Kunming-Montreal Global Biodiversity Framework.