Treesearch

Land managers rely heavily on herbicides to mitigate exotic plant invasions but the nontarget effects of herbicides on treated plant, animal, and soil communities are often overlooked. Biological soil crusts (biocrusts) are important components of ecosystems yet the effects of different herbicides on biocrusts are rarely considered. We tested the impact of three widely used herbicides, indaziflam, imazapic, aminocyclopyrachlor, and chlorsulfuron, two of which were applied with or without a surfactant, on biocrusts dominated by mosses or lichens in intermountain grasslands. We found that...

The Paraclius arcuatus species-group is reviewed and includes the following seven species: P. angusticauda Van Duzee, 1933, P. angustipennis Van Duzee, 1929, P. arcuatus (Loew, 1861), P. brooksi sp. nov., P. elongatus Van Duzee, 1930, P. pumilio Loew, 1872, and P. xibun sp. nov. Paraclius angustipennis, P. arcuatus and P. pumilio are redescribed based on photographs of types and additional specimens. Paraclius femoratus Aldrich, 1901 is synonymized with P. arcuatus, syn. nov. and Paraclius magnicornis Van Duzee, 1927 is regarded as a junior synonym of P. pumilio, syn. nov. An identification...

Categorization of soil organic carbon (SOC) into different functional subpools according to their recalcitrance and protective mechanisms helps better understand ecosystems organic carbon (OC) dynamics, and various attempts have been made to explore the suitable experimental fractionation method for such purpose. However, most previous studies neglected the influences of environmental factors on the effectiveness of varying fractionation methods. Density fractionation has shown great promise in elucidating SOC immobilization mechanisms. Here, we compared three varying types of density...

This article is a Commentary on Marshall et al. (2023), 239: 2166-2179. Both eddy covariance (EC) and ground-based (biometric) estimates of carbon (C) stocks and fluxes are used to understand current stocks and fluxes of C, their future trajectories, and responses to changing climates. EC measures C fluxes by quantifying the covariance between fluctuations in vertical wind velocity and CO2 concentrations (Baldocchi, 2003). EC measurements are continuous over a large area (c. 0.5km2 ), nondestructive, use a more standardized methodology, and are made at hundreds of locations across different...

Visibility analyses, used in many disciplines, rely on viewshed algorithms that map locations visible to an observer based on a given surface model. Mapping continuous visibility over broad extents is uncommon due to extreme computational expense. This study introduces a novel method for spatially-exhaustive visibility mapping using airborne lidar and random forests that requires only a sparse sample of viewsheds. In 24 topographically and vegetatively diverse landscapes across the contiguous US, 1000 random point viewsheds were generated at four different observation radii (125 m, 250 m,...

Understanding interactions between environmental stress and genetic variation is crucial to predict the adaptive capacity of species to climate change. Leaf temperature is both a driver and a responsive indicator of plant physiological response to thermal stress, and methods to monitor it are needed. Foliar temperatures vary across leaf to canopy scales and are influenced by genetic factors, challenging efforts to map and model this critical variable. Thermal imagery collected using unoccupied aerial systems (UAS) offers an innovative way to measure thermal variation in plants across...

The past 100 years of empirical research in ecology have generated tremendous knowledge about the component interactions that structure ecological communities. Yet, we still lack the ability to reassemble these puzzle pieces to predict community responses to perturbations, a challenge that grows increasingly urgent given rapid global change. We summarize key advances in community ecology that have set the stage for modeling ecological systems and briefly review the evolution of ecological modeling efforts to identify critical hurdles to progress. We find that while Robert May demonstrated...

The 2019 Museum Fire burned in a mountainous region near the city of Flagstaff, AZ, USA. Due to the high risk of post-fire debris flows and flooding entering the city, we deployed a network of seismometers within the burn area and downstream drainages to examine the efficacy of seismic monitoring for post-fire flows. Seismic instruments were deployed during the 2019, 2020, and 2021 monsoon seasons following the fire and recorded several debris flow and flood events, as well as signals associated with rainfall, lightning and wind. Signal power, frequency content, and wave polarization were...

Although wolves are wide-ranging generalist carnivores throughout their life cycle, during the pup-rearing season wolf activity is focused on natal den sites where pup survival depends upon pack members provisioning food. Because prey availability is influenced by habitat quality within the home range, we investigated the relative importance of prey species for adults and pups and further examined the relationship between habitat characteristics, wolf diet, and litter size on Prince of Wales Island (POW) in Southeast Alaska. During 2012-2020, we detected 13 active den sites within the home...

Selenium (Se) contamination of public lands and water is a result of irrigated agriculture and mining activities in areas rich in Se geologic deposits. Pariette Draw is part of the northern Colorado Plateau and is an area of concern for Se contamination in the Pariette Wetlands. Pariette Wetlands, a wetland built in the 1970s to provide wildlife habitat, is distinguished by its arid climate and a short growing season of hot dry summers followed by cold winters with several months below freezing. An understanding of how Se is mobilized and removed within the wetland will provide management...