Conference Agenda

Acceleration of human activities over the past century might have caused a corresponding acceleration in the decline of abundance of species, but this has not been empirically assessed. Further, the temporal dynamics of abundance arises from a complex interaction between recruitment and loss of individuals, yet this interplay remains unexplored across large spatial scales. We address these gaps by examining temporal changes, acceleration, deceleration, and vital processes (i.e. recruitment and loss) across much of the North American avifauna from 1987 to 2021. We confirm the continent-wide decline of bird abundance, and pinpoint the regional hotspots of acceleration of this decline in the Mid-Atlantic region, Midwest, and California, matching broad spatial patterns of human activities. We further reveal that the increasing rate of loss is the primary process of acceleration of abundance decline in California and the Midwest, whereas a decrease in recruitment rate dominates in the Mid-Atlantic. Finally, we highlight a worrisome trend: 96% of bird species and 100% of families with increasing abundances are concurrently experiencing a decline in recruitment rate. Thus, we need conservation policies even for species that appear to be thriving. Simply preventing loss may not be enough, as we also need policies that enhance recruitment.

Human activities have altered the species composition of assemblages through introductions and extinctions, but it remains unclear how those changes can affect the different facets of biodiversity. Here we assessed the impact of changes in species composition on taxonomic, functional, and phylogenetic diversity across 281 bird assemblages worldwide. To provide a more nuanced understanding of functional diversity, we distinguished morphological from life-history traits. We showed that shifts in species composition could trigger a global decline in avian biodiversity due to the high number of potential extinctions. Moreover, these extinctions were not random but unique in terms of function and phylogeny at the regional level. Our findings demonstrated that non-native species cannot compensate for these losses, as they are both morphologically and phylogenetically close to the native fauna. In the context of the ongoing biodiversity crisis, such alterations in the functional and phylogenetic structure of bird assemblages could heighten ecosystem vulnerability.

Stored seeds of wild plant species serve as repositories of plant genetic diversity, and are valuable resources for evolutionary research, species conservation, and ecosystem restoration. However, long-term storage inevitably leads to the deterioration and loss of viability of the seed. While seed longevity is known to be species-specific, the significance of intraspecific variability in seed longevity, and how it varies across geographic ranges, remains unexplored. Here, we tested how seed longevity varies between and within species, and how it correlates with the climate in the source region. We focused on 42 common grassland species and 182 accessions from 23 regions across Europe. To simulate seed aging in storage, we exposed the seeds to artificial ageing conditions (60% relative humidity, temperature 45°C). The seed longevity strongly varied between species more than twenty-fold, increased with seed protein content, yet it did not depend on phylogeny. Within species, the seed longevity varied more than ten-fold between the accessions. It increased with the initial seed viability and mean annual temperature in the region of origin. Our results suggest that seed from warmer regions, especially those with high initial viability, survive longer in conservation seed banks.

In the face of increasing biodiversity threats, understanding the predictors of plant extinction risk is critical for conservation. Global assessments indicate over one-third of terrestrial plant species are rare, with regional extinctions outpacing documented global extinctions. Integrating national and regional Red Lists of vascular plants with plant trait data and phylogenies, we analyze patterns of regional plant extinctions globally, to discern the role of evolutionary and functional uniqueness in species' vulnerability. Specifically, we investigate whether phylogenetic marginality—species' evolutionary distinctiveness—correlates with their risk of regional and global extinction of vascular plants. Additionally, we examine if species that have gone extinct exhibit greater functional trait marginality, meaning they occupy more unique positions in the functional trait space compared to the broader species pool. This approach may prompt early conservation actions across countries, even before species are globally recognized as threatened, addressing the growing importance of extinction risk estimation for enhancing conservation initiatives amid escalating anthropogenic impact.

Endangered forest species often depend on slowly evolving structures of old-growth forests such as large-diameter trees and deadwood, or cautious or absent forest management. Small-scale private forests are particularly important in this regard, offering great structural diversity and varied landscapes shaped by the individual owners, and serve as refuges for forest biodiversity.

The Parcel Index of Conservation Attributes (PICA) is presented as a tool to quantify the value of individual small-scale private forest parcels in terms of crucial old-growth structures that are becoming rare in current forests. PICA values are defined by broadleaf tree volume, broadleaf deadwood, management intensity, biotope values (according to German federal law), and number of large-diameter trees.

The PICA components have been demonstrated to correlate with easily obtainable topographical data such as land use, plot geometry, and forest cover continuity. To aid nature conservation efforts in understanding the spatial distribution of valuable structures, we utilized machine learning algorithms to predict PICA values. We parameterized and evaluated different models using data collected from a field survey of 129 small-scale private forest parcels in the Lower Saxon Hills region. The models were then used to create a map of potential old-growth biodiversity hotspots.

Humans pose threats to numerous native species, while they also have introduced many species outside their native ranges, where some have become naturalized or even invasive. Most of the naturalized species are common at home, but some of them may actually be threatened. Naturalization of threatened species could be considered an accidental kind of ex-situ conservation, but with the potential to become invasive pose a conservation conflict. It remains, however, unknown how many threatened-but-naturalized species there are, what features they have, and in which regions they are native and naturalized. To address this, we combined databases on the global threat status and naturalization success of the world’s seed plants. We found that 231 threatened species have become naturalized elsewhere; most of them are trees or shrubs with economic uses such as provisioning of materials and landscaping. Europe received more threatened-but-naturalized species than expected, whereas Africa, which harbours the largest number, was under-represented. Australasia and Northern America were over-represented as donors of threatened species. Our study shows that some threatened plant species have managed to become naturalized outside their native range, although the number is relatively low. Future studies should test the potential conservation value of these naturalized populations.

Human induced climate change poses a threat to global biodiversity. Broad scale effects of climate change are often assessed on the basis of long-term changes in climatic conditions. However, the effect of increasing frequency and intensity of extreme weather events (EWE) due to climate change on biodiversity remains unclear. We introduce a general framework to investigate the effects of EWE on species. As a case study we train classical presence/absence models for 132 German bird species of conservation interest (species requiring assessment under the EU Bird Protection Areas guidelines) with monthly specific weather and remote sensing data over the time period of 1999 to 2022. The species-specific models predict the suitability through time from 1999 to 2022 for each month across Germany. With this approach, the suitability over all non-extreme months can be compared to the suitability in months with climatic extremes, to generate a measure of the impact of an extreme event on the distribution of a species. With this measure it is possible to identify geographic areas, species communities, taxonomic- and functional groups that may be vulnerable towards specific EWE.