Treesearch

Recruitment is the most sensitive plant life stage to environmental filters. Yet, most research linking functional traits to environmental filters has focused on adult plants with little known about early plant traits, their interactions with environmental filters, or their relation to species abundance. Likewise, how such relationships might vary between native and exotic species or influence plant invasion outcomes is unclear. We quantified regeneration traits for 12 native and 12 exotic (naturalized and invasive) forbs and evaluated trait relationships and their associations with...

Whitebark pine (Pinus albicaulis, PIAL) and foxtail pine (P. balfouriana, PIBA) are slow-growing, high-elevation, five-needled pines. Recently, PIAL has experienced significant mortality while PIBA has experienced minimal decline. PIBA exists in two disjunct southern (PIBAS) and northern (PIBAN) populations. Our study compared juvenile physiological and morphological traits between the two species (PIAL, PIBA) and foxtail populations (PIBAN, PIBAS) to investigate mechanisms underlying responses to environmental stressors in their high-elevation environments. We grew four-year-old PIAL and...

Boreal forest and Arctic tundra environments collectively hold the largest percentage of global terrestrial seasonal snow cover. Тhe in-situ snow measurement network is sparse and costly in these remote northern regions. Here, we complement existing snow depth monitoring in Arctic tundra and boreal forest by presenting an extensive (64°N-70°N) snow depth dataset and description of ground-based snow depth measurements collected during the NASA SnowEx Alaska intensive field campaign, March 7-16, 2023. We also report the accuracy of snow depth measurements in shallow boreal forest and Arctic...

Recent disasters showed major gaps in emergency alerting - the process of sending emergency information to communities rapidly - where people with limited-English proficiency (LEP) and auditory or visual (AV) disabilities experience issues receiving alerts in their preferred language or formats. In this paper, we review academic literature, agency reports, and news articles to synthesize barriers and develop best practices for inclusive alerting. The barriers identified include: (1) lack of capacity from agencies distributing alerts and warnings; (2) delay or lack of information in...

Climate change is altering precipitation regimes that control nitrogen (N) cycling in terrestrial ecosystems. In ecosystems exposed to frequent drought, N can accumulate in soils as they dry, stimulating the emission of both nitric oxide (NO; an air pollutant at high concentrations) and nitrous oxide (N2O; a powerful greenhouse gas) when the dry soils wet up. Because changes in both N availability and soil moisture can alter the capacity of nitrifying organisms such as ammonia-oxidizing bacteria (AOB) and archaea (AOA) to process N and emit N gases, predicting whether shifts in precipitatio...

During wildland fire spread both slope and wind act together to modify fire dynamics, commonly accelerating the rate of fire spread. To investigate this coupling effect, flow field measurements were conducted on stationary gaseous fires produced over a tilt table in a wind tunnel, with fireline intensities ranging from 41 to 123 kW/m. The angle of inclination (θ) and the wind speed (V) were varied from 0 to 30° and 0.30 to 1.27 m/s, respectively. The surface gas velocity of the fire at various downstream locations was measured using temperature-correlation velocimetry (TCV), which was...

Wildfires can lower soil carbon (C) stocks directly through combustion, but also indirectly during post-fire recovery if microbial C demands outpace photosynthetic C inputs. However, how much C is respired by soil microorganisms post-fire may depend on wildfire effects on particulate organic carbon (POC; mostly plant material accessible to microbes) and/or mineral-associated organic carbon (MAOC; considered C protected by minerals from decomposers), meaning assessment of wildfire impacts on these pools is necessary to predict microbial decomposition rates and, thus, the fate of soil C....

Euro-American settlement entailed comprehensive vegetation clearing and fire exclusion, with attendant decreases in fire-tolerant oak and pine tree species and open conditions throughout the southeastern and central eastern United States. While historical tree data are locked in individual land deeds for part of the eastern United States, two assessments during 1900–1909 provided historical tree composition in the southern Appalachian region, primarily in North Carolina. According to assessments during 1900–1909, fire-tolerant oaks and American chestnut (Castanea dentata) were the dominant...

Locational errors and sampling bias may produce unrepresentative species distribution models. To decompose the influence of errors, I modeled species distributions of 31 mammal species from georeferenced records and random samples from range maps, with potential sources of errors added or removed, using the random forests algorithm. Errors included the addition of (1) cities, (2) administrative centers, (3) records flagged as potential errors (e.g., outliers), and (4) urban records to range map samples; the removal of (5) flagged records and (6) urban records from georeferenced records;...

Rewilding is increasingly recognized as an impactful conservation strategy, but a key question remains: how do ecological systems respond to the return of species long absent from the landscape? Predicting these responses is challenging due to complex direct and indirect interactions, especially amid anthropogenic changes. The ongoing range expansion of grizzly bears (Ursus arctos) in western North America offers a unique opportunity to develop and test predictions about the effects of a large, generalist omnivore returning to its historic range. We developed a priori predictions that...