Ecological synthesis

The overall goal of the Core Project Synthesis is to realise synergy within and beyond the Exploratories via synthesis service and by research tackling the guiding questions of the project. We do this by using two elements:

• Promoting and fostering synthesis activities by individuals or groups of individuals in the Exploratories through running a statistical help desk, teaching synthesis techniques, offering workshops, and creating and curating synthesis datasets.
• Developing and supporting a synthesis programme to coordinate and support working groups composed of Explorers and international scientists.

Promoting and catalysing synthesis within the Exploratories

In addition to developing exemplary synthesis using state-of-art methods, we promote and catalyse synthesis activities by other core and contributing projects using the following tools:

• Promoting and facilitating new synthesis proposals by encouraging Explorers to address synthesis questions, pointing out knowledge gaps and synergy options, and giving practical advice on how to initiate and write a synthesis proposal.
• Organising courses, covering topics and tools around synthesis research, by taking into account the needs of Explorers.
• Harmonising synthesis datasets by assembling data from numerous research projects which are essential for synthesis analyses. On this front, we collaborate with the BExIS team and the data owners to create and update synthesis datasets.
• Offering a statistical help-desk in the form of individual meetings and group workshops.

Synthesis Team Program

We organise and support a Synthesis Program with up to six targeted Synthesis Teams, connecting Explorers with international researchers and projects on topics such as:

• Towards a unified land-use theory
• Extending the land-use gradients: forests, grasslands and arable fields
• Ecological stability
• Climate change responses
• Land use experiments
• Social ecology of land use in changing climate
• Response of multi-trophic food webs to land use intensity

In the previous phases of the Biodiversity Exploratories, the Core Project Synthesis has facilitated synthesis in the Exploratories, resulting in 84 synthesis proposals (as of May 2026, Fig. 2). Over the years, we have organised several courses on scientific writing, data management, as well as on statistical and ecological topics such as community assembly or functional traits. We have supported many Explorers, particularly early-career researchers (masters and PhD students), via our helpdesk service. Finally, we have assembled synthesis datasets on biodiversity and ecosystem functions in forests and grasslands, which are used in the majority of synthesis proposals.

We have generated knowledge on the main guiding questions of the Exploratories and enriched them with new dimensions. We have found that land-use intensification decreases the diversity of multiple groups (Allan et al. 2014), changes their interrelationships (Manning et al. 2015) and homogenises communities (Gossner et al. 2016) in grasslands, and that the picture in forests is much more complex because of the multidimensionality of forest management (Penone et al. 2019). We have found that rare species and functional diversity are important for functioning (Allan et al. 2015, Soliveres et al. 2016) and that biodiversity at multiple trophic levels drives multifunctionality in grasslands and forests (Soliveres et al. 2016b, Felipe-Lucia et al. 2020). Ultimately, grassland management and forest features are key to ecosystem functioning (Allan et al. 2015, Felipe-Lucia et al. 2018). In addition to plot-level management and environmental conditions, recent works have emphasised the role of landscape composition and configuration for local biodiversity (Seibold et al. 2019, Le Provost et al. 2021) and the supply of cultural and regulating services (Le Provost et al. 2023), and provided a novel analytical framework for ecosystem services upscaling to landscape scales (Boesing et al. 2026).

Recent work has also highlighted land-use impacts on other biodiversity facets beyond taxonomic diversity. We have shown that land-use intensification drives a synchronised replacement of “slow traits” by “fast traits” related to resource acquisition across taxonomic groups in grasslands (Neyret et al. 2024). Also, Heidrich et al. (2023) found that functional and phylogenetic diversity increases with forest structural heterogeneity for beetles, spiders, birds and bats. Moreover, we have demonstrated that functional traits mediate the effect of land use on drivers of community stability both within and across trophic levels in grasslands and forests (Sperandii et al. 2025).

Another persistent gap in the Exploratories is related to temporal biodiversity dynamics and how it mirrors spatial dynamics under land-use intensification. Neuenkamp et al. (2025) showed that temporal trends in biodiversity under land-use intensification follow similar directions but are much weaker compared to spatial trends, likely due to the smaller variation in land use over time and lag in responses. This suggests that the prevailing space-for-time replacement approach in the Exploratories is useful but may overestimate intensification effects.

The relevance of the Exploratories’ approach has also been supported through comparison with two of the largest and longest-running grassland biodiversity experiments: the Jena Experiment in Germany and BioDIV in the USA. This collaboration showed that biodiversity–ecosystem functioning patterns observed in experimental plots are broadly congruent with those found in the observational plots of the Exploratories (Jochum et al. 2020). Novel experiments have also been established to elucidate mechanisms behind biodiversity changes and potential management and restoration strategies. For example, the Seed Addition and Disturbance Experiment (SADE) resulted in a synthesis work showing that increasing plant species richness by seeding has only marginal effects on ecosystem functioning (Freitag et al. 2023).

Current synthesis efforts are expanding these perspectives further. We recently demonstrated that winner–loser dynamics under land-use intensification vary strongly across taxa, trophic groups, and ecosystems (Pinho et al., submitted), moving beyond prevailing community-level approaches that ignore species-level dynamics. In parallel, the Core Project Synthesis is developing long-term, bias-corrected climate reconstructions to support the integration of anthropogenic climate change (particularly extreme climate events) into the Exploratories’ guiding questions (Benedetti et al., in prep.). These efforts provide the basis for understanding how different forms of climate extremes, and their interactions with land-use intensity, reshape ecosystems over time. Additionally, we are developing a quantitative framework to reinterpret the grazing component of land-use intensity within disturbance theory, disentangling grazing duration and livestock density to better understand how different perturbation regimes shape biodiversity and ecosystem processes in grasslands (Reji Chacko et al., in prep.).

With the kick-off of the most recent phase, we have already organised two workshops to kick off Synthesis Teams. We will continue to support the Biodiversity Exploratories with tools and knowledge to catalyse scientific synthesis within and beyond the consortium.