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Previous attempts to quantify tree abundance at global scale have largely neglected the role of local competition in modulating the influence of climate and soils on tree density. Here, we evaluated whether mean tree size in the world’s natural forests alters the effect of global productivity on tree density. In doing so, we gathered a vast set of forest inventories including >3000 sampling plots from 23 well-conserved areas worldwide to encompass (as much as possible) the main forest biomes on Earth. We evidence that latitudinal productivity patterns of tree density become evident as large trees become dominant. Global estimates of tree abundance should, therefore, consider dependencies of latitudinal sources of variability on local biotic influences to avoid underestimating the number of trees on Earth and to properly evaluate the functional and social consequences.

Previous attempts to quantify tree abundance at global scale have largely neglected the role of local competition in modulating the influence of climate and soils on tree density. Here, we evaluated whether mean tree size in the world's natural forests alters the effect of global productivity on tree density. In doing so, we gathered a vast set of forest inventories including >3000 sampling plots from 23 well-conserved areas worldwide to encompass (as much as possible) the main forest biomes on Earth. We evidence that latitudinal productivity patterns of tree density become evident as large trees become dominant. Global estimates of tree abundance should, therefore, consider dependencies of latitudinal sources of variability on local biotic influences to avoid underestimating the number of trees on Earth and to properly evaluate the functional and social consequences.

Global patterns of regional (gamma) plant diversity are relatively well known, but whether these patterns hold for local communities, and the dependence on spatial grain, remain controversial. Using data on 170,272 georeferenced local plant assemblages, we created global maps of alpha diversity (local species richness) for vascular plants at three different spatial grains, for forests and non-forests. We show that alpha diversity is consistently high across grains in some regions (for example, Andean-Amazonian foothills), but regional 'scaling anomalies' (deviations from the positive correlation) exist elsewhere, particularly in Eurasian temperate forests with disproportionally higher fine-grained richness and many African tropical forests with disproportionally higher coarse-grained richness. The influence of different climatic, topographic and biogeographical variables on alpha diversity also varies across grains. Our multi-grain maps return a nuanced understanding of vascular plant biodiversity patterns that complements classic maps of biodiversity hotspots and will improve predictions of global change effects on biodiversity.

Previous attempts to quantify tree abundance at global scale have largely neglected the role of local competition in modulating the influence of climate and soils on tree density. Here, we evaluated whether mean tree size in the world’s natural forests alters the effect of global productivity on tree density. In doing so, we gathered a vast set of forest inventories including >3000 sampling plots from 23 well-conserved areas worldwide to encompass (as much as possible) the main forest biomes on Earth. We evidence that latitudinal productivity patterns of tree density become evident as large trees become dominant. Global estimates of tree abundance should, therefore, consider dependencies of latitudinal sources of variability on local biotic influences to avoid underestimating the number of trees on Earth and to properly evaluate the functional and social consequences.

Due to their large population sizes, synanthropic birds, including native and invasive species, can transmit pathogens to other vertebrates, and even humans. In particular, Newcastle disease virus (NDV) can cause lethal infections in a wide range of avian species as well as mild infections in humans and other non-avian hosts. In this study conducted in Barcelona, Spain, we assessed the seroprevalence of NDV in three synanthropic species comprising one native species (feral pigeon, Columba livia var. domestica; N = 16) and two invasive parrots (monk parakeet, Myiopsitta monachus, N = 50; and rose-ringed parakeet, Psittacula krameri, N = 23). These species are considered to have played important roles in the introduction and spread of NDV due to their high population densities, gregariousness, and prolonged viral shedding through faeces. We found a high seroprevalence of NDV in the feral pigeon (56%) and monk parakeet (38%) but a low seroprevalence in the rose-ringed parakeet (4%). These differences may be explained by the frequent interactions among feral pigeons and monk parakeets in their daily lives facilitating viral transmission from the former to the latter, because the feral pigeon is a well-known NDV reservoir. By contrast, the low seroprevalence of NDV in rose-ringed parakeets could be explained by its less frequent contacts with other urban bird species. The high seroprevalence of NDV in feral pigeons and monk parakeets provides new insights into the roles of novel interspecific relationships in the transmission and spread of NDV, and the risk of these synanthropic species as a source of NDV in urban environments. Finally, our findings highlight the need to monitor NDV in both native and non-native birds to prevent its spread to poultry, wildlife, and humans., Due to their large population sizes, synanthropic birds, including native and invasive species, can transmit pathogens to other vertebrates, and even humans. In particular, Newcastle disease virus (NDV) can cause lethal infections in a wide range of avian species as well as mild infections in humans and other non-avian hosts. In this study conducted in Barcelona, Spain, we assessed the seroprevalence of NDV in three synanthropic species comprising one native species (feral pigeon, Columba livia var. domestica; N = 16) and two invasive parrots (monk parakeet, Myiopsitta monachus, N = 50; and rose-ringed parakeet, Psittacula krameri, N = 23). These species are considered to have played important roles in the introduction and spread of NDV due to their high population densities, gregariousness, and prolonged viral shedding through faeces. We found a high seroprevalence of NDV in the feral pigeon (56%) and monk parakeet (38%) but a low seroprevalence in the rose-ringed parakeet (4%). These differences may be explained by the frequent interactions among feral pigeons and monk parakeets in their daily lives facilitating viral transmission from the former to the latter, because the feral pigeon is a well-known NDV reservoir. By contrast, the low seroprevalence of NDV in rose-ringed parakeets could be explained by its less frequent contacts with other urban bird species. The high seroprevalence of NDV in feral pigeons and monk parakeets provides new insights into the roles of novel interspecific relationships in the transmission and spread of NDV, and the risk of these synanthropic species as a source of NDV in urban environments. Finally, our findings highlight the need to monitor NDV in both native and non-native birds to prevent its spread to poultry, wildlife, and humans., Due to their large population sizes, synanthropic birds, including native and invasive species, can transmit pathogens to other vertebrates, and even humans. In particular, Newcastle disease virus (NDV) can cause lethal infections in a wide range of avian species as well as mild infections in humans and other non-avian hosts. In this study conducted in Barcelona, Spain, we assessed the seroprevalence of NDV in three synanthropic species comprising one native species (feral pigeon, Columba livia var. domestica; N = 16) and two invasive parrots (monk parakeet, Myiopsitta monachus, N = 50; and rose-ringed parakeet, Psittacula krameri, N = 23). These species are considered to have played important roles in the introduction and spread of NDV due to their high population densities, gregariousness, and prolonged viral shedding through faeces. We found a high seroprevalence of NDV in the feral pigeon (56%) and monk parakeet (38%) but a low seroprevalence in the rose-ringed parakeet (4%). These differences may be explained by the frequent interactions among feral pigeons and monk parakeets in their daily lives facilitating viral transmission from the former to the latter, because the feral pigeon is a well-known NDV reservoir. By contrast, the low seroprevalence of NDV in rose-ringed parakeets could be explained by its less frequent contacts with other urban bird species. The high seroprevalence of NDV in feral pigeons and monk parakeets provides new insights into the roles of novel interspecific relationships in the transmission and spread of NDV, and the risk of these synanthropic species as a source of NDV in urban environments. Finally, our findings highlight the need to monitor NDV in both native and non-native birds to prevent its spread to poultry, wildlife, and humans.

Little is known about how much continuous landscape transformation might affect the most vulnerable elements of biodiversity. In this study, we quantified changes in the normalized difference vegetation index (NDVI) over the past 35 years across locations with threatened plants and in Natura 2000 (N2000) protected areas, in an environmentally heterogeneous region of Southern Europe. First, we estimated the intensity and duration of NDVI gains and losses based on Landsat time series using the LandTrendr algorithm in Google Earth Engine. Then, we tested: 1) whether populations of threatened plants were located in more stable sites than non-threatened plants (i.e., lower NDVI changes); 2) whether NDVI changes around populations of threatened plants differed across habitats and inside/outside N2000 areas, and 3) whether lower NDVI changes occurred in N2000 areas than unprotected areas, thereby indicating their effectiveness at preserving biodiversity. Threatened plants tended to be concentrated in sites with less change irrespective of the habitat where they occurred and their location within protected areas. Occurrence in stable sites also reduced the risk associated with small-sized populations. N2000 areas were in line with the overall greening trend but they experienced less loss events than the unprotected areas, thereby supporting their role in slowing down human-induced land cover changes. Our approach demonstrates how long-term remote sensing monitoring can help to assess the effects of both slow processes and drastic landscape transformation events on priority plants in a comprehensive and rapid manner. This method can identify hidden patterns in extensive regions and guide effective conservation management.