Latitudinal patterns and environmental drivers of taxonomic, functional, and phylogenetic diversity of woody plants in western Amazonian terra firme forests

Elucidating how environmental factors drive plant species distributions and how they affect latitudinal diversity gradients, remain essential questions in ecology and biogeography. In this study we aimed: 1) to investigate the relationships between all three diversity attributes, i.e., taxonomic diversity (TD), functional diversity (FD), and phylogenetic diversity (PD); 2) to quantify the latitudinal variation in these diversity attributes in western Amazonian terra firme forests; and 3) to understand how climatic and edaphic drivers contribute to explaining diversity patterns. We inventoried ca. 15,000 individuals from ca. 1,250 species, and obtained functional trait records for ca. 5,000 woody plant individuals in 50 plots of 0.1 ha located in five terra firme forest sites spread over a latitudinal gradient of 1200 km covering ca. 10°C in latitude in western Amazonia. We calculated all three diversity attributes using Hill numbers: q = 0 (richness), q = 1 (richness weighted by relative abundance), and q = 2 (richness weighted by dominance). Generalized linear mixed models were constructed for each diversity attribute to test the effects of different uncorrelated environmental predictors comprising the temperature seasonality, annual precipitation, soil pH and soil bulk density, as well as accounting for the effect of spatial autocorrelation, i.e., plots aggregated within sites. We confirmed that TD (q = 0, q = 1, and q = 2), FD (q = 0, q = 1, and q = 2), and PD (q = 0) increased monotonically towards the Equator following the latitudinal diversity gradient. The importance of rare species could explain the lack of a pattern for PD (q = 1 and q = 2). Temperature seasonality, which was highly correlated with latitude, and annual precipitation were the main environmental drivers of variations in TD, FD, and PD. All three diversity attributes increased with lower temperature seasonality, higher annual precipitation, and lower soil pH. We confirmed the existence of latitudinal diversity gradients for TD, FD, and PD in hyperdiverse Amazonian terra firme forests. Our results agree well with the predictions of the environmental filtering principle and the favourability hypothesis, even acting in a 10°C latitudinal range within tropical climate

Nota Científica: Hacia un Enfoque Biocultural en los Programas de Conservación de la Naturaleza

Se hace una revisión de los principales conceptos y lineamientos a considerar en la implementación de planes de monitoreo de la naturaleza y se da énfasis a la participación y la integración del conocimiento local como elementos claves en el monitoreo. Por último, se destaca la necesidad de un enfoque biocultural para asegurar acciones de conservación a futuro

Mapas y clasificación de vegetación en ecosistemas estacionales: un análisis cuantitativo de los bosques secos de Piura

We studied data from 65 0.1-hectare floristic inventories from the seasonal lowland vegetation in coastal Piura by using multivariate methods and analyses of floristic composition. We identified six vegetation groups, five of which greatly coincide with vegetation types already described 100 years ago by August Weberbauer. In contrast, we were not able to accurately identify any of the eight dry forest categories recently defined by the Proyecto Algarrobo for the study area using numerical methods. We conclude that the maps and data generated by Weberbauer are more accurate and better reveal the floristic relationships of the seasonally dry vegetation in Piura. Therefore, we suggest a more widespread use of the descriptions made by Weberbauer in the region, parallel to those of the Proyecto Algarrobo.Estudiamos datos de inventarios florísticos de 65 parcelas de 0,1 hectáreas de la vegetación estacional de las llanuras costeras de Piura usando métodos multivariados y análisis de composición florística. Identificamos seis grupos de vegetación, de los cuales cinco coinciden con tipos de vegetación descritos hace casi 100 años por Augusto Weberbauer. Por el contrario, de las ocho categorías de bosque seco definidas recientemente por el Proyecto Algarrobo para el área de estudio, ninguna pudo ser reconocida adecuadamente mediante métodos numéricos. Concluimos que los mapas y datos generados por Weberbauer resultan ser más exactos y revelan mejor las relaciones florísticas de la vegetación estacionalmente seca de Piura. Por lo tanto, sugerimos el uso más frecuente de las descripciones propuestas por Weberbauer para la región, paralelamente a los del Proyecto Algarrobo

Spatial patterns of above-ground structure, biomass and composition in a network of six Andean elevation transects

Background: The Amazon to Andes transition zone provides large expanses of relatively pristine forest wilderness across environmental gradients. Such elevational gradients are an excellent natural laboratory for establishing long-term interactions between forest ecosystems and environmental parameters, which is valuable for understanding ecosystem responses to environmental change. Aims: This study presents data on elevational trends of forest structure (biomass, basal area, height, stem density), species richness, and composition from six elevational transects in the Andes. Methods: We analysed the spatial patterns of forest structure, above-ground biomass and composition from 76 permanent plots, ranging from lowland Amazonian rain forest to high-elevation cloud forests in Ecuador, Peru, and Bolivia. Results: Forest above-ground woody biomass stocks ranged from 247 Mg ha −1 (Peru, 210 m) to 86 Mg ha −1 (Peru, 3450 m), with significantly decreasing trends of tree height and biomass and an increasing trend of stem density with increasing elevation. We observed an increase in forest richness at three taxonomic levels at mid-elevation, followed by a decrease in richness within the cloud immersion zone. Conclusions: The transects show an increase in stem density, a decline in tree height and above-ground coarse wood biomass and a hump-shaped trend in species richness with increasing elevation. These results suggest that environmental change could lead to significant shifts in the properties of these ecosystems over time