Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.

Amazonian Dark Earths (ADE) are the result of human modification of the Amazonian landscape since pre-Columbian times. ADE are characterized by increased soil fertility compared to natural soils. In the Amazonian forest, soil fertility influences understory herb and fern species composition. However, little research has been done to evaluate the effect of ADE on the composition of the understory community. We evaluated the effects of ADE and soil in 36 plots (150 m 9 4 m) established in a Bolivian moist forest (La Chonta). For each plot, we determined soil nutrients, and the composition, richness, and abundance of terrestrial fern, angiosperm herb, and understory palm species. We found that the presence of ADE created a gradient in soil nutrients and pH that affected the understory species composition especially of ferns and palms. Additionally, the higher nutrient concentration and more neutral soil pH on ADE soils caused a decrease of ferns species richness. We therefore conclude that the current composition of the understory community in this particular Bolivian forest is a reflection of past human modifications of the soil.

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Background and aims Amazonian Dark Earths (ADE) are ancient anthropogenic soils distributed in the Amazon basin. They are characterized by high nutrients such as phosphorus, calcium, potassium and nitrogen. We studied the effect of ADE on growth, morphology and physiology of 17 tree species from a Bolivian tropical moist forest. Methods We conducted a greenhouse experiment where seedlings were grown for 2-4 months on ADE and non-ADE. We evaluated soil nutrient concentrations, seedling growth, leaf and root functional traits, and leaf nutrient concentrations.

Las Comunicaciones Nacionales sobre Cambio Climático (CNCC) son un mecanismo para que los países informen sus avances en mitigación y adaptación, y constituyen uno de los elementos de base para la política sobre cambio climático a escala nacional. Colombia ha emitido tres CNCC. La tercera plantea un escenario que considera las proyecciones de diversos modelos incluidos en la quinta fase del Proyecto de Comparación de Modelos Acoplados (Coupled Model Intercomparison Project, CMIP), el cual se estima como el promedio de las proyecciones correspondientes a las cuatro trayectorias de concentración representativa (Representative Concentration Pathways,RCP) presentadas en el quinto reporte de evaluación del Panel Intergubernamental sobre Cambio Climático. Cada una de estas RCP representa una trayectoria de concentración de gases de efecto invernadero (GEI) para un escenario particular de crecimiento poblacional, económico y tecnológico que conduce a una posible trayectoria de evolución del sistema climático. En este estudio se comparan las proyecciones presentadas en la Tercera CNCC con las obtenidas directamente de los modelos empleados. Nuestros resultados demuestran que al utilizarse un promedio de RCP se pierden escenarios alternos que podrían ser importantes a la hora de considerar posibles futuros diferentes y anulan la utilidad de plantear diversas trayectorias de emisiones de GEI. Más aun, una comparación entre la Segunda y la Tercera CNCC muestra proyecciones de precipitación opuestas para diferentes regiones del país, lo cual es de particular importancia, pues el escenario de cambio climático planteado en la Tercera CNCC sirve de referencia para la toma de decisiones en materia de cambio climático a nivel nacional.

Understorey herbs form a diverse and understudied plant assemblage in tropical forests. Although several studies and research teams have long been dedicated to the study of this conspicuous vegetation component in Amazonia, no effort to unify the data has been undertaken to date. In contrast to trees and other life forms for which major data compilations already exist, a unified database dedicated to herbs is still lacking. Part of the problem is in defining what is a herb and how to effectively sample herb assemblages. In this article, we describe the database HERBase, an exhaustive compilation of published and unpublished data on herb inventories in Amazonia. We also describe the structure, functioning, and guidelines for data curation and integration in HERBase. We were able to compile information from 1381 plots from all six Amazonian geographic regions. Based on this dataset, we describe and discuss sampling and knowledge gaps, priority areas for new collections, and recommend sampling protocols to facilitate data integration in the future. This novel database provides a unique biodiversity data repository on understorey herbs that will enable new studies on community ecology and biogeography.

<p>Vegetation affects water balance partitioning via effects on incoming precipitation, local radiation balance and hydrological dynamics of soil. The extent of these effects is determined by plant functional traits. Commonly, the role of plant species on hydrological regulation has been assessed considering vegetation as homogeneous cover, even more, that approach underestimates the importance of species in this process. Nevertheless, in recent years, new focus has been placed on species study based on their functional traits and their roles in ecosystem functions as hydrological regulation. Still new tendencies are considering vegetation cover consisting of different species, each of them having different effects on hydrological regulation because they have different functional traits. In an 8-year old ecosystem restoration project established in Medellín (Colombia), we explored the relations between plant functional traits of 10 dominant species and ecohydrological processes that determine precipitation partitioning in the canopy via stemflow and throughfall. Here we show that functional traits describing tree crowns are significantly related with stemflow and throughfall. Our species exhibit differences in their functional traits and ecohydrological processes, forming a gradient of variation of ecohydrological processes and crown functional traits: from wide and less dense crowns in <em>Alnus acuminata</em> to smaller but more dense crowns in <em>Quercus humboldtii</em>, related with less throughfall temporal variability, and less stemflow temporal variability, respectively; the other species are placed along this gradient. This result suggests a complementary effect of species on the hydrological processes and consequently on the hydrological function, highlighting the importance of considering species diversity on hydrological regulation assessment. More specifically, our results emphasize the need to include information about the effects of species planted in ecological restoration projects over ecohydrological processes, via ecological criteria such as plant functional traits. This approach permits a more objective and complete study of hydrological regulation that brings key information for an adequate ecosystem management and restoration based on ecological roles of species that, through biological diversity, optimize ecosystem functions and services.</p>