Periodic Reporting for period 1 - INDEBT (Measuring and explaining the global debt of biotic homogenization in a changing world.)
Periodo di rendicontazione: 2022-10-01 al 2024-09-30
This project adresses the pressing issue of biotic homogenization (BH), a critical, yet under-researched aspect of the biodiversity crisis characterized by an increase in similarity between ecological communities across regions. This trend toward homogenization, largely driven by human activities such as habitat destruction, climate change, pollution, and species introductions, reduces the turnover of species composition between locations (β-diversity). Such changes threaten ecosystems' functionality, resilience, and capacity to provide essential services. While biodiversity loss has gained substantial attention globally, BH, as a consequence of ecological simplification, has remained insufficiently understood, particularly in terms of its spatial and temporal dynamics and the multi-scale effects of global change drivers.
This project addresses the urgent need to understand BH in a more comprehensive and integrative way, with the primary objective of creating a global, multi-taxa, and scale-dependent assessment of BH and identifying how its occurrence and intensity depend on specific global change drivers. This first objective aims to fill the significant knowledge gap regarding how BH is influenced by various factors such as climate change, land-use change, human population density, , each of which may act differently across spatial scales. By leveraging the BioTIME database, which compiles long-term biodiversity time-series data across various taxa and geographic locations, the project will analyze how β-diversity responds to these drivers over time and space. This large-scale, data-driven approach will provide unique insights into the spatially explicit patterns of BH, facilitating a more precise understanding of how and where specific global drivers contribute to the loss of ecological uniqueness among communities. Ultimately, this will help pinpoint the geographic and environmental contexts where conservation measures can be most effectively applied to mitigate further homogenization.
The second major objective is to introduce and quantify the concept of "homogenization debt," a novel framework analogous to the well-established extinction debt in biodiversity studies. Homogenization debt refers to the time-delayed impact of past environmental changes that are likely to result in increased community similarity in the future, even if current pressures are alleviated. By exploring this lag effect, the project will map out areas most vulnerable to future homogenization, enabling a forward-looking perspective on biodiversity loss. This assessment of homogenization debt will provide an empirical basis to guide policy decisions in prioritizing conservation efforts, especially in regions where delayed homogenization might otherwise go undetected.
This project addresses the urgent need to understand BH in a more comprehensive and integrative way, with the primary objective of creating a global, multi-taxa, and scale-dependent assessment of BH and identifying how its occurrence and intensity depend on specific global change drivers. This first objective aims to fill the significant knowledge gap regarding how BH is influenced by various factors such as climate change, land-use change, human population density, , each of which may act differently across spatial scales. By leveraging the BioTIME database, which compiles long-term biodiversity time-series data across various taxa and geographic locations, the project will analyze how β-diversity responds to these drivers over time and space. This large-scale, data-driven approach will provide unique insights into the spatially explicit patterns of BH, facilitating a more precise understanding of how and where specific global drivers contribute to the loss of ecological uniqueness among communities. Ultimately, this will help pinpoint the geographic and environmental contexts where conservation measures can be most effectively applied to mitigate further homogenization.
The second major objective is to introduce and quantify the concept of "homogenization debt," a novel framework analogous to the well-established extinction debt in biodiversity studies. Homogenization debt refers to the time-delayed impact of past environmental changes that are likely to result in increased community similarity in the future, even if current pressures are alleviated. By exploring this lag effect, the project will map out areas most vulnerable to future homogenization, enabling a forward-looking perspective on biodiversity loss. This assessment of homogenization debt will provide an empirical basis to guide policy decisions in prioritizing conservation efforts, especially in regions where delayed homogenization might otherwise go undetected.
From the start of the project, significant progress has been made in investigating biotic homogenization (BH) and its implications for biodiversity and conservation planning, with several key findings disseminated through published studies. The project has focused on understanding the spatial and temporal dynamics of biodiversity patterns and their responses to human-induced pressures. These include analyses of species distribution, trophic interactions, and ecological uniqueness across European terrestrial vertebrates, providing valuable insights into how BH manifests at various scales and within different ecological networks.
Dynamic Macroecological Patterns : a framework for undertanding diversity changes. A yet unpublished study from the project team has integrated macroecological theory with temporal and trait-based perspectives, enabling a refined analysis of biodiversity change attribution to human drivers. By examining species accumulation and beta diversity over time, the project has highlighted how changes in species distribution patterns reflect underlying human-driven pressures, offering a more nuanced perspective on BH and biodiversity dynamics.
Spatial Uniqueness of Trophic Networks: Another key output investigated the spatial uniqueness and functional redundancy of vertebrate trophic interactions across Europe, focusing on species assemblages and trophic roles. This study identified unique trophic networks particularly vulnerable to human activities and climate change, such as those in southern Europe (prone to human footprint) and the Arctic (affected by climate change). It underscored the importance of including interaction networks in conservation planning to preserve not only species but also the functional diversity that underpins ecosystem resilience(ssrn-4559390).
These findings have been disseminated through peer-reviewed articles, preprints and conference presentations, ensuring broad exposure to both academic and policy-making communities.
In terms of public dissemination of the project's findings, two notable outreach activities were conducted to engage broader audiences and stakeholders in biodiversity conservation. First, a presentation was made at the Fête de la Science, a major public science event, providing an opportunity to share insights from the project with the general public. Second, results were presented to the French Ligue pour la Protection des Oiseaux in Grenoble in Autumn 2023, targeting a conservation-focused audience.
Dynamic Macroecological Patterns : a framework for undertanding diversity changes. A yet unpublished study from the project team has integrated macroecological theory with temporal and trait-based perspectives, enabling a refined analysis of biodiversity change attribution to human drivers. By examining species accumulation and beta diversity over time, the project has highlighted how changes in species distribution patterns reflect underlying human-driven pressures, offering a more nuanced perspective on BH and biodiversity dynamics.
Spatial Uniqueness of Trophic Networks: Another key output investigated the spatial uniqueness and functional redundancy of vertebrate trophic interactions across Europe, focusing on species assemblages and trophic roles. This study identified unique trophic networks particularly vulnerable to human activities and climate change, such as those in southern Europe (prone to human footprint) and the Arctic (affected by climate change). It underscored the importance of including interaction networks in conservation planning to preserve not only species but also the functional diversity that underpins ecosystem resilience(ssrn-4559390).
These findings have been disseminated through peer-reviewed articles, preprints and conference presentations, ensuring broad exposure to both academic and policy-making communities.
In terms of public dissemination of the project's findings, two notable outreach activities were conducted to engage broader audiences and stakeholders in biodiversity conservation. First, a presentation was made at the Fête de la Science, a major public science event, providing an opportunity to share insights from the project with the general public. Second, results were presented to the French Ligue pour la Protection des Oiseaux in Grenoble in Autumn 2023, targeting a conservation-focused audience.
The INDEBT project has significantly advanced the understanding of biotic homogenization (BH), moving beyond the state of the art by integrating scale-dependent and multi-taxa approaches to assess the impacts of human-induced global changes. The innovative framework developed during the project combines macroecological theory with temporal and trait-based analyses to quantify and predict biodiversity responses to anthropogenic pressures. This framework has enabled a novel conceptualization of "homogenization debt," a delayed response of ecosystems to historical environmental changes, providing critical insights into biodiversity dynamics across spatial and temporal scales.
Key progress includes the assembly and integration of extensive biodiversity datasets, such as the enhanced - new version- BioTIME database, which facilitates large-scale biodiversity analyses. These advancements will allow for the first global-scale quantification of homogenization debt and the identification of biotic homogenization "hotspots," offering actionable data for conservation planning and policy development.
By the project's conclusion, expected results include a comprehensive mapping of BH and its drivers, the publication of a global map of homogenization debt across taxa, and the release of an analytical framework for exploring biodiversity changes. These outcomes will contribute to advancing biodiversity science, informing conservation strategies, and influencing environmental policies at both regional and global scales.
Key progress includes the assembly and integration of extensive biodiversity datasets, such as the enhanced - new version- BioTIME database, which facilitates large-scale biodiversity analyses. These advancements will allow for the first global-scale quantification of homogenization debt and the identification of biotic homogenization "hotspots," offering actionable data for conservation planning and policy development.
By the project's conclusion, expected results include a comprehensive mapping of BH and its drivers, the publication of a global map of homogenization debt across taxa, and the release of an analytical framework for exploring biodiversity changes. These outcomes will contribute to advancing biodiversity science, informing conservation strategies, and influencing environmental policies at both regional and global scales.