Tropical forest degradation from selective logging, fire and edge effects is a major driver of carbon and biodiversity loss1–3, with annual rates comparable to those of deforestation4. However, its actual extent and long-term impacts remain uncertain at global tropical scale5. Here we quantify the magnitude and persistence of multiple types of degradation on forest structure by combining satellite remote sensing data on pantropical moist forest cover changes4 with estimates of canopy height and biomass from spaceborne6 light detection and ranging (LiDAR). We estimate that forest height decreases owing to selective logging and fire by 15% and 50%, respectively, with low rates of recovery even after 20 years. Agriculture and road expansion trigger a 20% to 30% reduction in canopy height and biomass at the forest edge, with persistent effects being measurable up to 1.5 km inside the forest. Edge effects encroach on 18% (approximately 206 Mha) of the remaining tropical moist forests, an area more than 200% larger than previously estimated7. Finally, degraded forests with more than 50% canopy loss are significantly more vulnerable to subsequent deforestation. Collectively, our findings call for greater efforts to prevent degradation and protect already degraded forests to meet the conservation pledges made at recent United Nations Climate Change and Biodiversity conferences.
Ensuring the persistence of biodiversity and ecosystem services represents a global challenge that need to be addressed with high urgency. Global priority areas can only be identified by means of an integrated prioritization approach that would not only preserve species numbers and ecosystem services, but also the evolutionary and functional components of diversity. In this study we combine global datasets on the distribution of mammals and birds with species traits and phylogenetic data and we identify conservation priorities for taxonomic, functional and phylogenetic diversity, as well as for three ecosystem services, including potential for carbon sequestration, pollination potential and groundwater recharge. We show that, when priority areas are identified based only on individual, e.g. functional diversity, or any combination of the three biodiversity components, these areas do not allow a sufficient protection of the three ecosystem services. However, an integrated approach whereby prioritization is based on all biodiversity components and ecosystem services would allow to identify areas that maximize protection of all ecosystem services with a minimal loss in biodiversity coverage. Our results highlight the need for an integrated conservation planning framework in order to optimally allocate resources and achieve the long-term preservation of the multiple dimensions of biodiversity and ecosystems services.
29 March 2023 in Communications Earth & Environment
The effectiveness of Protected Areas in conserving forest ecosystems has been examined at the continental scale using area-based habitat parameters, but knowledge of the three-dimensional structure of forest habitats is still lacking. Here, we assess the effectiveness of European Protected Areas in conserving the vertical structure of forests by analysing more than 30 million records from the Global Ecosystem Dynamics Investigation (GEDI), a spaceborne LiDAR (Light Detection And Ranging) mission. We compare a suite of indicators of the vertical structure of forests inside and outside nearly 10,000 protected areas. We find that European forests are on average 2 m taller and vertically more complex in protected areas than in nearby unprotected areas, albeit with some regional differences. At the same time, forests outside protected areas show greater variations in canopy height than inside, probably as a result of past and current forest management operations. Our findings highlight the positive imprint of environmental policies on forest structure across Europe and underscore how spaceborne LiDAR enables the large-scale monitoring of forest vertical structural attributes that are key to conservation and restoration policies.
25 July 2018 in Proceedings Of The Royal Society B-Biological Sciences
Trophic interactions play critical roles in structuring biotic communities. Understanding variation in trophic interactions among systems provides important insights into biodiversity maintenance and conservation. However, the relative importance of bottom-up versus top-down trophic processes for broad-scale patterns in biodiversity is poorly understood. Here, we used global datasets on species richness of vascular plants, mammals and breeding birds to evaluate the role of trophic interactions in shaping large-scale diversity patterns. Specifically, we used non-recursive structural equation models to test for top-down and bottom-up forcing of global species diversity patterns among plants and trophic guilds of mammals and birds (carnivores, invertivores and herbivores), while accounting for extrinsic environmental drivers. The results show that trophic linkages emerged as being more important to explaining species richness than extrinsic environmental drivers. In particular, there were strong, positive top-down interactions between mammal herbivores and plants, and moderate to strong bottom-up and/or top-down interactions between herbivores/invertivores and carnivores. Estimated trophic interactions for separate biogeographical regions were consistent with global patterns. Our findings demonstrate that, after accounting for environmental drivers, large-scale species richness patterns in plant and vertebrate taxa consistently support trophic interactions playing a major role in shaping global patterns in biodiversity. Furthermore, these results suggest that top-down forces often play strong complementary roles relative to bottom-up drivers in structuring biodiversity patterns across trophic levels. These findings underscore the importance of integrating trophic forcing mechanisms into studies of biodiversity patterns.
SUMMARY: Species distribution data are critical information sources when it comes to implementing the multiple Aichi Targets set by the international Convention on Biological Diversity. Although there have been international-scale efforts to aggregate distribution data, the magnitudes and locations of the gaps in biodiversity knowledge remain unclear. In this study, we use a large database, including over 200 000 species occurrence records, to identify knowledge gaps in biodiversity inventories for nine animal taxa in a Mediterranean biodiversity hotspot. Spatial modelling methods were employed to relate the completeness of inventories to population, road and protected area density. The completeness of faunistic inventories was correlated with the amount of protected areas, roads and population density. Despite more than 200 years of faunistic sampling, knowledge of the distributions of most animal taxa is still limited, especially for invertebrates. As the window of opportunity for achieving Aichi Targets 11 and 19 begins to close, means of filling such knowledge gaps are required. We argue that a combination of quantitative tools and citizen science data collection programmes may help inform conservation decisions.