Treesearch

Insect outbreaks affect forest structure and function and represent a major category of forest disturbance globally. However, the resulting impacts on evapotranspiration (ET), and especially hydrological partitioning between the abiotic (evaporation) and biotic (transpiration) components of total ET, are not well constrained. As a result, we combined remote sensing, eddy covariance, and hydrological modeling approaches to determine the effects of bark beetle outbreak on ET and its partitioning at multiple scales throughout the Southern Rocky Mountain Ecoregion (SRME), USA. At the eddy...

Polyomaviruses are oncogenic viruses that are generally thought to have co-evolved with their hosts. While primate and rodent polyomaviruses are increasingly well-studied, less is known about polyomaviruses that infect other mammals. In an effort to gain insight into polyomaviruses associated with carnivores, we surveyed fecal samples collected in the USA from bobcats (Lynx rufus), pumas (Puma concolor), Canada lynxes (Lynx canadensis), and grizzly bears (Ursus arctos). Using a viral metagenomic approach, we identified six novel polyomavirus genomes. Surprisingly, four of the six genomes...

Bark beetle (Dendroctonus spp.) epidemics generate snags, providing nesting and foraging opportunities for woodpeckers and other disturbance-associated wildlife. Forest managers need to know how long snags persist to include wildlife habitat conservation in their objectives, but published studies of snag persistence following disturbance under-represent beetle-killed forest. We analyzed snag persistence rates in relation to environmental covariates following a mountain pine beetle (Dendroctonus ponderosae) epidemic in the Elkhorn Mountains (Montana, U.S.A.) over a 6-year study period...

Particulate matter (PM) is a major primary pollutant emitted during wildland fires that has the potential to pose significant health risks to individuals/communities who live and work in areas impacted by smoke events. Limiting exposure is the principle measure available to mitigate health impacts of smoke and therefore the accurate determination of ambient PM concentrations during wildland fire events is critical to protecting public health. However, monitoring air pollutants in smoke impacted environments has proven challenging in that measurement interferences or sampling conditions can...

1. Species-rich forests can produce litter of varying carbon (C) and nitrogen (N) composition (i.e. quality), which can affect decomposition and play a central role in long-term soil organic carbon (SOC) accumulation. However, how differences in litter quality affect SOC decomposition and formation remains unclear over the full litter decomposition trajectory.2. We followed the in situ complete decomposition of added 13C-labelled high-( low C:N) and low-quality (high C:N) leaf-litter and its effect on particulate organic matter (POM) and mineral-associated organic matter (MAOM) fractions...

Western North America has been experiencing persistent drought exacerbated by climate change for over two decades. This extreme climate event is a clear threat to native plant communities. Artemisia tridentata is a keystone shrub species in western North America and is threatened by climate change, urbanization, and wildfire. A drought Genotype x Environment (G x E) experiment was conducted to assess phenotypic plasticity and differential gene expression in A. tridentata. The G x E experiment was performed on diploid A. tridentata seedlings from two populations (one from Idaho, USA and one...

Wildfires usually increase the hydrological and erosive response of forest areas, carrying high environmental, human, cultural, and financial on- and off-site effects. Post-fire soil erosion control measures have been proven effective at mitigating such responses, especially at the slope scale, but there is a knowledge gap as to how costeffective these treatments are.In this work, we review the effectiveness of post-fire soil erosion mitigation treatments at reducing erosion rates over the first post-fire year and provide their application costs. This allowed assessing the treatments’...

We have developed a version of the Continuous Change Detection and Classification algorithm within the Google Earth Engine environment. It has been used with 20 years of Landsat data (1999-2019) to produce a new, publicly available global dataset of pre-computed time series break points and harmonic coefficients. We present results from regional use cases demonstrating classification and change detection with this new dataset and compare them to other temporal compositing techniques. Our results demonstrate that gains in overall accuracy using CCDC may be small on a yearly basis, but they...

Current and past climatic changes can shift plant climatic niches, which may cause spatial overlap or separation between related taxa. The former often leads to hybridization and introgression, which may generate novel variation and influence the adaptive capacity of plants. An additional mechanism facilitating adaptations to novel environments and an important evolutionary driver in plants is polyploidy as the result of whole genome duplication. Artemisia tridentata (big sagebrush) is a landscape-dominating foundational shrub in the western United States which occupies distinct ecological...

Placing traits into novel evolutionary contexts may profoundly alter their functional roles. Here, we investigated whether the elaiosome, a lipid-rich appendage located on seeds, retained its role as a seed dispersal trait promoting mutualisms with insectivorous ants following human-mediated introduction of the elaiosome-bearing Carduus nutans into the Argentinean Caldenal. This system is located within the Neotropical region, an alleged myrmecochory cold spot. Specifically, we first tested the assumption that the elaiosome mediates the interaction between C. nutans and the native ant...