Treesearch

Who are the groups stewarding the environment within local communities, where do they work, and who do they work with? The Stewardship Mapping and Assessment Project (STEW-MAP) survey has cataloged and mapped environmental stewardship groups in dozens of cities within the US and worldwide. The survey collects relational, network ties among respondents and their collaborators. In this study, we focus on the 2019 Baltimore, Maryland survey to better understand the relationships among environmental stewardship organizations across the city. We utilize exponential random graph models (ERGMs)...

Urban trees mitigate extreme heat through shading and evapotranspiration, but cooling effectiveness varies with tree traits, spatial configurations, and climate. This systematic mapping review synthesizes findings from 115 studies (2018 to 2024) using Reporting standards for Systematic Evidence Syntheses (ROSES) protocols. Studies were categorized based on geographic location, climate zone, and heat metric (e.g., land surface temperature or air temperature), highlighting a geographic skew toward North America and Asia and underrepresentation of arid and tropical zones. Findings show that...

In a field that is hyper-focused on efficiency and cost savings, environmental DNA (eDNA) sampling - or detecting fish and wildlife from traces of genetic material in the environment - has become the gold standard. Over the last decade, eDNA sampling has emerged as a powerful and cost-effective tool for national forests to obtain the data they need to make management decisions. Now, Forest Service scientists have created “biochips” that generate these high-value data even more efficiently, buoying the value of eDNA monitoring capacity far into the future.

Peatlands store about one third of global soil carbon despite occupying less than 5% of the land area. Recent estimates show that tropical peatlands store much more carbon than previously thought. There are considerable gaps in knowledge regarding the interannual variability of carbon budgets in tropical peatlands and the way that changing environmental conditions influence the carbon cycling in these ecosystems. We show that a palm swamp peatland in the Peruvian Amazon is sensitive to changes in environmental conditions and can flip from a large carbon sink to carbon neutral when there...

Fusiform rust, caused by the pathogen Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme, is the most important disease of loblolly pine (Pinus taeda L.) in the U.S., causing millions of dollars in damage each year. Using resistant genotypes has proven a successful strategy to limit the disease, but resistance selection still relies on visual inspection for symptoms, which can lead to misclassification due to human error and the presence of ‘escaped susceptibles’ (i.e., susceptible individuals with no visible symptoms due to either an extended asymptomatic phase of the disease...

Non-destructive tree phenotyping for resistance screening and early, presymptomatic disease detection figures prominently among the most important practical limitations inherent in forest health management. The need for point-of-care tools is particularly acute for managing diseases caused by non-native pathogens, often resulting in difficult-to-control biological invasions. One such case is represented by ash dieback in Europe, caused by Hymenoscyphus fraxineus, which has led Sweden to red-list its main host, European ash (Fraxinus excelsior). We evaluated the use of near-infrared (NIR)...

Common-pool resources (CPRs), including fisheries and the atmosphere, are critical for ecological, social, and economic sustainability but are easily overused. We use an agent-based model to investigate how social networks shape resource extraction outcomes. Networks with highly visible nodes can create a ‘‘majority illusion’’ in which most users believe high-intensity extraction is dominant, even if it is not. This misperception can push the entire population toward one of two possible states: an abundant, high-welfare resource or a depleted, low-welfare one. Aligning users’ environmental...

In the rapidly changing dynamics of urbanization, urban forests offer numerous benefits to city dwellers. However, the information available on these resources is often outdated or non-existent, leading in part to inequitable access to these benefits for the population. Access to equitable and just green spaces is a challenge for local governments, allowing the city’s inhabitants to enjoy a healthy environment. In this context, remote sensing serves as a powerful data source that enables the monitoring of the evolution and dynamics of cities over time, as well as changes in urban forests....

Tree species are often locally adapted to their environments, but the extent to which environmental adaptation contributes to incipient speciation is unclear. One of the rarest pines in the world, Torrey pine (Pinus torreyanaParry), persists naturally across one island and one mainland population in southern California. The two populations are morphologically and genetically differentiated but experience some connectivity, making it an ideal system for assessing the evolution of reproductive isolation. Previous work has found evidence of heterosis in F1 mainland-island hybrids, suggesting...

Crowd-sourced biodiversity data, such as those housed in the iNaturalist platform, are increasingly used to monitor species distributions. Such data represent unstructured biodiversity surveys that are generally comprised of incidental observations and do not report variation in sampling effort. These discrepancies may yield data that is incongruent with data from structured surveys. To assess whether mammalian iNaturalist data are reflective of data from traditional structured surveys, we calculated and compared measures of mammalian species richness and species pool similarity using data...