Spatial abundance patterns across species' ranges have attracted intense attention in macroecology and biogeography. One key hypothesis has been that abundance declines with geographical distance from the range centre, but tests of this idea have shown that the effect may occur indeed only in a minority of cases. We explore an alternative hypothesis: that species' abundances decline with distance from the centroid of the species' habitable conditions in environmental space (the ecological niche). We demonstrate consistent negative abundance -ecological distance relationships across all 11 species analysed (turtles to wolves), and that relationships in environmental space are consistently stronger than relationships in geographical space.

Understanding the long-term dynamics of urban vegetation is essential in determining trends in the provision of key resources for biodiversity and ecosystem services and improving their management. Such studies are, however, extremely scarce due to the lack of suitable historical data. We use repeat historical photographs from the 1900s, 1950s, and 2010 to assess general trends in the quantity and size distributions of the tree stock in urban Sheffield and resultant aboveground carbon storage. Total tree numbers declined by a third from the 1900s to the 1950s, but increased by approximately 50% from the 1900s–2010, and by 100% from the 1950s–2010. Aboveground carbon storage in urban tree stocks had doubled by 2010 from the levels present in the 1900s and 1950s. The initial decrease occurred at a time when national and regional tree stocks were static and are likely to be driven by rebuilding following bombing of the urban area during the Second World War and by urban expansion. In 2010, trees greater than 10 m in height comprised just 8% of those present. The increases in total tree numbers are thus largely driven by smaller trees and are likely to be associated with urban tree planting programmes. Changes in tree stocks were not constant across the urban area but varied with the current intensity of urbanization. Increases from 1900 to 2010 in total tree stocks, and smaller sized trees, tended to be greatest in the most intensely urbanized areas. In contrast, the increases in the largest trees were more marked in areas with the most green space. These findings emphasize the importance of preserving larger fragments of urban green space to protect the oldest and largest trees that contribute disproportionately to carbon storage and other ecosystem services. Maintaining positive trends in urban tree stocks and associated ecosystem service provision will require continued investment in urban tree planting programmes in combination with additional measures, such as revisions to tree preservation orders, to increase the retention of such trees as they mature.

Introduction: Climate change represents a problem that generates long-term impacts and is considered a threat to the conservation of many species. Objective: To evaluate the impact of climate change on the distribution areas of 10 trees species characteristic of cloud forests in the state of Oaxaca. Materials and methods: The impact was evaluated for two-time horizons (2050 and 2080) and two emission scenarios (RCP 4.5 and 8.5) under the Had GEM2-ES general atmospheric circulation model. Current and future distribution was modeled with MaxEnt. The distribution of Carpinus tropicalis, Juglans pyriformis, Liquidambar styraciflua, Litsea glaucescens, Magnolia dealbata, Magnolia schiedeana, Ostrya virginiana, Symplocos coccinea, Zinowiewia concinna and Taxus globosa were obtained from the herbarium specimen review. Results and discussion: In RCP 4.5, J. pyriformis, L. styraciflua, L. glaucescens and S. coccinea increased (2.8 % to 20.5 %) their area of distribution. In this scenario, the rest of the species reduced their area by up to 30 % compared to the current distribution. In RCP 8.5-2050, J. pyriformis and O. virginiana had a gain of more than 5 %. All species showed a reduction greater than 10 % under the RCP 8.5-2080 scenario. The models showed area under the curve greater than 0.8 and partial ROC (Receiver Operating Characteristic) greater than 1.7. Conclusions: Understanding the response of 10 species to climate change will serve as a basis for proposing conservation and monitoring plans, since nine of them are in some category of risk.