Despite substantial progress in understanding global biodiversity loss, major taxonomic and geographic knowledge gaps remain. Decision makers often rely on expert judgement to fill knowledge gaps, but are rarely able to engage with sufficiently large and diverse groups of specialists. To improve understanding of the perspectives of thousands of biodiversity experts worldwide, we conducted a survey and asked experts to focus on the taxa and freshwater, terrestrial, or marine ecosystem with which they are most familiar. We found several points of overwhelming consensus (for instance, multiple drivers of biodiversity loss interact synergistically) and important demographic and geographic differences in specialists’ perspectives and estimates. Experts from groups that are underrepresented in biodiversity science, including women and those from the Global South, recommended different priorities for conservation solutions, with less emphasis on acquiring new protected areas, and provided higher estimates of biodiversity loss and its impacts. This may in part be because they disproportionately study the most highly threatened taxa and habitats. Front Ecol Environ 2022;

Synchronous dynamics (fluctuations that occur in unison) are universal phenomena with widespread implications for ecological stability. Synchronous dynamics can amplify the destabilizing effect of environmental variability on ecosystem functions such as productivity, whereas the inverse, compensatory dynamics, can stabilize function. Here we combine simulation and empirical analyses to elucidate mechanisms that underlie patterns of synchronous versus compensatory dynamics. In both simulated and empirical communities, we show that synchronous and compensatory dynamics are not mutually exclusive but instead can vary by timescale. Our simulations identify multiple mechanisms that can generate timescale‐specific patterns, including different environmental drivers, diverse life histories, dispersal, and non‐stationary dynamics. We find that traditional metrics for quantifying synchronous dynamics are often biased toward long‐term drivers and may miss the importance of short‐term drivers. Our findings indicate key mechanisms to consider when assessing synchronous versus compensatory dynamics and our approach provides a pathway for disentangling these dynamics in natural systems.

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The spatial synchrony of species richness and its relationship to ecosystem stability.

Some introduced species become invasive by releasing novel allelochemicals into the soil, directly harming nearby plants and soil microbes. Alliaria petiolata (garlic mustard) is an invasive plant, well known to excrete a suite of phytotoxic and antimicrobial allelochemicals, including allyl isothiocyanate (AITC) and benzyl isothiocyanate (BITC). While the effects of these chemicals on plant-mycorrhizae mutualisms are well documented, the effects on other plant-soil microbe interactions, such as the legume-rhizobia mutualism, have not yet been tested. Here, we performed laboratory and greenhouse experiments with both synthetic chemicals and leaf extracts to investigate the effects of allelochemicals in A.petiolata on a native leguminous plant, Amphicarpaea bracteata, and its rhizobia mutualists. We found that BITC reduced rhizobia growth rate in the lab, but had no effect on nodulation in the greenhouse when rhizobia were grown in the presence of plants. AITC did not directly harm either plants or rhizobia, though plants and rhizobia grown in the presence of AITC showed reduced nodulation, indicating that it disrupted the formation of the mutualism itself. We found no effects of A. petiolata allelochemical leaf extracts on plant performance or nodulation. Our data suggest that AITC causes mutualism disruption in this system by preventing the formation of nodules, which reduces plant growth and could threaten the long-term performance of rhizobia. Our study shows that the allelochemicals in A. petiolata disrupt the legume-rhizobia resource mutualism, adding another impact of these novel weapons in addition to their well-documented role in disrupting plant-mycorrhizae symbioses.