Carlos Alberto Arnillas

Aspergillus fumigatus is the leading cause of aspergillosis in immunocompromised individuals. Because A. fumigatus hyphae rapidly outgrow macrophages, they are generally thought to evade macrophage-mediated control once they exceed the size limits of phagocytosis, enabling invasive growth within host tissues. Here, we show that macrophages circumvent this limitation by capturing hyphal tips within persistent tubular phagocytic cups. Rather than resolving into complete phagosomes or disengaging from their targets, these long-lived open compartments maintain key features of phagocytic cups while progressively acquiring characteristics of maturing phagosomes. Their persistence sustains localized NOX2-dependent reactive oxygen species production, leading to hyphal-tip damage and restriction of fungal growth. Sustained PI(3,4)P2 signaling downstream of class I PI3K promotes prolonged NOX2 activity and is required for efficient hyphal restriction. Together, our findings reveal a previously unrecognized antifungal mechanism in which persistent phagocytic cups transform incomplete phagocytosis into sustained antimicrobial activity, extending macrophage control beyond the physical limits of engulfment.

Datasets describing the composition of biological communities across broad anthropogenic gradients are valuable resources for ecologists and conservation biologists, with applications ranging from testing theories of community assembly to guiding biodiversity management. But much of the most rigorously collected field survey datasets, particularly for vascular plant communities in urban environments, remain underutilized because they are not curated or publicly accessible. We compiled and standardized a large database of information on the composition of vascular plant communities from sites spanning urbanization gradients in 12 cities in northeastern North America. The database integrates 26 field studies conducted by researchers from 1987 to 2024, encompassing 746 sites of either forest ( n = 408 sites) or open habitat (e.g., meadow, prairie, vacant lot; n = 338 sites). Forest sites include canopy (overstorey) and ground (understorey) layers, while open habitats only include a ground layer. Field sites span a gradient of urbanization from rural to urban areas and are characterized as being minimally managed in situ at the time of surveys. Thus, the data are representative of spontaneous vegetation that was not seeded or planted. In total, the database contains records for 1296 taxa identified to the species level, including 322,101 presence/absence records and 23,805 abundance records, all geo‐referenced and accompanied by metadata on site area, sampling effort, site management, site history, and methodology, all of which varied by site. To ensure consistency across studies, taxonomic names were standardized according to the Database of Vascular Plants of Canada (VASCAN), and all measurements were summarized at the site level. Unlike presence‐only data commonly available from citizen science repositories, this database provides both presence/absence and abundance records collected through systematic surveys. As a result, it avoids many of the pitfalls associated with citizen science data such as opportunistic sampling, bias towards public/highly frequented sites, lack of a complete record of all species in a community, and misidentifications by nonexpert observers. It also enables analyses that would otherwise be difficult or impossible, such as studies of species abundance, community composition, rare taxa, and species of low desirability. Overall, this database offers a valuable resource for those interested in studying plant community dynamics and the impacts of urbanization and other anthropogenic gradients on biodiversity. The data are available for reuse under CC0 1.0 Universal licensing; however, we appreciate the citation of this data paper when reusing the dataset.

Aspergillus fumigatus is the leading cause of aspergillosis in immunocompromised individuals. Because A. fumigatus hyphae rapidly outgrow macrophages, they are generally thought to evade macrophage-mediated control once they exceed the size limits of phagocytosis, enabling invasive growth within host tissues. Here, we show that macrophages circumvent this limitation by capturing hyphal tips within persistent tubular phagocytic cups. Rather than resolving into complete phagosomes or disengaging from their targets, these long-lived open compartments maintain key features of phagocytic cups while progressively acquiring characteristics of maturing phagosomes. Their persistence sustains localized NOX2-dependent reactive oxygen species production, leading to hyphal-tip damage and restriction of fungal growth. Sustained PI(3,4)P2 signaling downstream of class I PI3K promotes prolonged NOX2 activity and is required for efficient hyphal restriction. Together, our findings reveal a previously unrecognized antifungal mechanism in which persistent phagocytic cups transform incomplete phagocytosis into sustained antimicrobial activity, extending macrophage control beyond the physical limits of engulfment.

Primary production underpins much of ecosystem functioning and is often limited by nutrient and water availability. Ongoing global increases in nutrient inputs and interannual precipitation variability are thus likely to impact primary production, with unclear consequences for interannual variability in plant biomass. We used data from 35 grasslands in the Nutrient Network coordinated fertilization experiment to test if nutrient addition alters the response of plant biomass to year‐to‐year variation in growing season precipitation, and whether the effects of nutrient addition vary with factors such as site aridity or plant community composition. Nutrient addition increased biomass (by an average of 46% across sites), rain‐use efficiency (by 48%), and the sensitivity of biomass to interannual variation in precipitation (i.e., larger increase in biomass in wet years; by 13%), but did not change the strength of the interannual precipitation‐biomass correlation. Both sensitivity and correlation strength were higher in more arid sites, regardless of nutrient addition. These results suggest that grassland ecosystem functioning may become more variable from year to year as nutrient enrichment increases biomass sensitivity to precipitation and precipitation becomes more variable.

Despite research and outreach efforts by ecologists and environmental scientists (EES), environmental crises continue to escalate. As a diverse group of concerned EES, we perceived a lack of clear guidance to articulate individual actions to improve sustainability. To address that gap, we propose ‘The Conguillío Statement on the values and responsibilities of ecologists’, a document summarizing values and responsibilities for EES in their different roles. Scientific and professional societies are fundamental institutions for the development and sharing of such guidelines across the many roles that EES take on. With the ongoing convergence of several crises, EES societies must take the lead to develop and disseminate contextualized and appropriate guidelines to their members. The ‘Conguillío Statement’ can stimulate that debate. We call on EES and their professional societies to take the lead on the effort to debate, adapt and adopt guidelines to inform EES practice towards a more sustainable future. Read the free Plain Language Summary for this article on the Journal blog.

The search for predictors of plant diversity has challenged scientists for decades. Here we identify intense photosynthetically active radiation (PAR) as a major factor constraining plant species richness in global grasslands. We show that the strength of the negative relationship between species richness and PAR increases with increasing elevation and that species richness is more strongly correlated with intense PAR than with UV-B radiation, climate variables, and atmospheric nitrogen deposition. In addition to species richness, plant biomass was also negatively correlated with PAR at higher elevations, indicating that intense PAR also constrains plant biomass in montane grasslands. Furthermore, we show that the decrease in plant species richness with increasing PAR is mainly caused by a decrease in species richness of forbs, sedges, and rushes. In contrast, species richness of grasses was only negatively correlated with PAR at high elevations, and species richness of legumes was not significantly correlated with PAR. Our results suggest that PAR constrains plant species richness in global grasslands and limits the extent to which plant species of specific functional groups can migrate uphill in response to climate warming.

Land cover data are commonly used to model the terrestrial carbon (C) sink, yet these data have wide margins of error that significantly alter estimates of global C storage. Here we demonstrate this data vulnerability in grasslands, which are critical to C cycling but whose estimated distribution has varied by >50 million km ² (3.5–42% of the Earth’s terrestrial surface). Comparing multiple high-resolution land cover products with expertly annotated grassland data from six continents, we show sources of mapping error and discuss C implications based on 2023 United Nations (UN) FAO estimates. Past misidentification arose from inconsistent definitions on grassland identity and classification flaws especially relating to woody plant cover. Correcting these errors adjusted grassland coverage to 22.8% of the terrestrial land base (30.1 million km ² ), elevating UN projections of soil C stocks to 155.02 Pg (0–30 cm depth). These findings underscore the challenges of biome mapping for ecosystem accounting and policy, when lacking field-validated remotely sensed data.

Indigenous Peoples are key knowledge holders and essential partners to confront global environmental crises, especially biodiversity loss. Many calls have been made to better integrate Indigenous Traditional Ecological Knowledge and Western ecological sciences. However, partnerships between these communities are complex due to power imbalances, distrust, different objectives, and injustices towards Indigenous Peoples. This raises the question of what meaningful engagement is, and for whom. These issues were discussed at a scientific workshop in Conguillío National Park, Chile. This initial encounter between ecologists and Mapuche elders, including a Machi (a Mapuche spiritual authority), has led to ongoing dialog and engagement. Responding to calls to listen deeply towards engagement with Indigenous Peoples in Western ecological sciences, we—the Machi and scientists—present our joint perspectives and reflections upon the process, drawing from Indigenous Knowledge and Western ecological sciences. Interweaving both lived experiences and scientific evidence, we document the environmental issues confronting the local Mapuche community caused by industrial developments in the territory. Our joint account highlights conflicts caused by non‐native tree plantations and the plans to construct a hydroelectric plant in the Truful–Truful watershed, which was opposed strongly by the local communities. Together with the industrial forestry plantations that cause land‐use change, the construction of this hydroelectric plant endangers biodiversity, including species of conservation significance, medicinal plants, and ultimately, the Mapuche way of life. Reflecting upon our collaboration and the process facilitated by Two‐Eyed Seeing, we illustrate that Indigenous voices and scientific evidence, together, can deepen our understanding of social‐ecological change in the territory and reveal opportunities for building trust and relationships. We highlight the importance of time, preparation for engagement, and advocating for change in knowledge partnerships in the ecological sciences. Learning from our collaboration, we call upon our communities to continue listening, engaging, and advocating for Indigenous representation in ecology.

The bidirectional relationship between plant species richness and community biomass is often variable and poorly resolved in natural grassland ecosystems^1–3, impeding progress in predicting impacts of environmental changes. In contrast, most biological communities have lognormal species abundance distributions (e.g., biomass, cover, number of individuals)^4–7, a general property that may provide predictive power for species richness and community biomass. Here, we demonstrate mathematical relationships between community characteristics and the abundance of dominant species arising from the lognormal distribution and test these predictions using observational and experimental data from 76 grassland sites across six continents. We find that community biomass provides little predictive ability for community richness, consistent with previous findings^3,8. In contrast, the relative abundance of dominant species quantitatively predicts species richness, whereas the absolute abundance of dominant species quantitatively predicts community biomass under both ambient and altered environmental conditions, as expected mathematically. These results are robust to the type of abundance measure used⁹. Simulated data further demonstrate the generality of these results. Our integrative framework, arising from a few dominant species and mathematical properties of species abundance distributions, fills a persistent gap in our ability to predict community richness and biomass under ambient and anthropogenically altered conditions^1,10.