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USGS2017

Neonicotinoid insecticide removal by prairie strips in row-cropped watersheds with historical seed coating use

Neonicotinoids are a widely used class of insecticides that are commonly applied as seed coatings for agricultural crops. Such neonicotinoid use may pose a risk to non-target insects, including pollinators and natural enemies of crop pests, and ecosystems. This study assessed neonicotinoid residues in groundwater, surface runoff water, soil, and native plants adjacent to corn and soybean crop fields with a history of being planted with neonicotinoid-treated seeds from 2008-2013. Data from six sites with the same crop management history, three with and three without in-field prairie strips, were collected in 2015-2016, 2-3 years after neonicotinoid (clothianidin and imidacloprid) seed treatments were last used. Three of the six neonicotinoids analyzed were detected in at least one environmental matrix: the two applied as seed coatings on the fields (clothianidin and imidacloprid) and another widely used neonicotinoid (thiamethoxam). Sites with prairie strips generally had lower concentrations of neonicotinoids: groundwater and footslope soil neonicotinoid concentrations were significantly lower in the sites with prairie strips than those without; mean concentrations for groundwater were 11 and 20 ng/L (p = 0.048) and <1 and 6 ng/g (p = 0.0004) for soil, respectively. Surface runoff water concentrations were not significantly (p = 0.38) different for control sites (44 ng/L) or sites with prairie strips (140 ng/L). Consistent with the decreased inputs of neonicotinoids, concentrations tended to decrease over the sampling timeframe. Two sites recorded concentration increases, however, potentially due to disturbance of previous applications or influence from nearby fields where use of seed treatments continued. There were no detections (limit of detection: 1 ng/g) of neonicotinoids in the foliage or roots of plants comprising prairie strips, indicating a low likelihood of exposure to pollinators and other insects visiting these plants following the cessation of seed coating use. Offsite transport of neonicotinoids to aquatic systems through the groundwater and surface water were furthermore reduced with prairie strips. This study demonstrates the potential for prairie strips comprising 10% of an agricultural catchment to mitigate the non-target impacts of neonicotinoids.

Agriculture, Ecosystems and Environment↗

USGS2020

Reduced species richness of native bees in field margins associated with neonicotinoid concentrations in non-target soils

Native bees are in decline as many species are sensitive to habitat loss, climate change, and non-target exposure to synthetic pesticides. Recent laboratory and semi-field assessments of pesticide impacts on bees have focused on neonicotinoid insecticides. However, field studies evaluating influences of neonicotinoid seed treatments on native bee communities of North America are absent from the literature. On four Conservation Areas of Missouri, we sampled row-cropped (treated, n = 15) and reference (untreated, n = 9) agricultural fields, and their surrounding field margins for neonicotinoids in soil and non-target vegetation (i.e., native wildflowers). Wildflowers were further collected and screened for the presence of fungicides. Concurrently, we sampled native bees over three discrete time points throughout the agricultural growing season to assess potential impacts of seed treatment use on local bee populations over time. Neonicotinoids were detected in 87% to 100% of treated field soils and 22% to 56% of reference field soils. In adjacent field margin soils, quantifiable concentrations were measured near treated (53% to 93% detection) and untreated fields (33% to 56% detection). Fungicides were detected in < 40% of wildflowers, whereas neonicotinoids were rarely detected in field margin vegetation (< 7%). Neonicotinoid concentrations in margin soils were negatively associated with native bee richness ( β = −0.21, P < 0.05). Field margins with a combination of greater neonicotinoid concentrations in soil and fungicides in wildflowers also contained fewer wild bee species ( β = −0.21, P < 0.001). By comparison, bee abundance was positively influenced by the number of wildflower species in bloom with no apparent impact of pesticides. Results of this study indicate that neonicotinoids in soil are a potential route of exposure for pollinator communities, specifically ground-nesting species. Importantly, native bee richness in non-target field margins may be negatively affected by the use of neonicotinoid seed treatments in agroecosystems.

Missouri↗

USGS2021

The influence of floral resources and microclimate on pollinator visitation in an agro-ecosystem

As agriculture expands to meet the needs of a growing global population, natural ecosystems are threatened by deforestation and habitat fragmentation. Tropical agroforestry systems offer a sustainable alternative to traditional agriculture by providing food for production while also supporting biodiversity and ecosystem services. Previous studies have shown that these systems may even improve crop pollination, but the mechanisms of how these improvements occur are still poorly understood. Using coffee as a focal crop, we explored how microclimatic conditions affected nectar traits (sugar and caffeine concentration) important for pollinator visitation. We also studied how microclimate, floral traits, floral availability at the coffee plant level, availability of floral resources provided by other plant species in the agroecosystem (neighborhood floral availability), and the presence of other bees affected the amount of time bees spent foraging on coffee flowers and the proportion of coffee pollen carried on their bodies. We explored these factors using the two dominant coffee species farmed on Puerto Rico, Coffea canephora and C. arabica , under sun and shade management. We found that high nectar sugar concentration and temperature were important predictors of short floral visits (<15 seconds), while increased number of bees and open coffee flowers were important predictors of longer floral visits (16-180 seconds). High nectar caffeine concentration was an important predictor of longer visits on C. arabica flowers while the opposite was observed for C. canephora flowers. For both species, high coffee floral availability was the main predicting factor for the proportion of coffee pollen on the bees bodies. Surprisingly, neither neighborhood floral availability nor the type of coffee plantation (agroforest/shade or sun) were important predictors of bee visitation. These results suggest non-coffee flowering plants in coffee plantations were neither competitors nor facilitators of coffee plantes for pollinators. Additionally, most of the bees surveyed were carrying 80% pollen from one species ( C. arabica or C. canephora ), likely resulting in little heterospecific pollen deposition between Coffea and non-Coffea flowers. Shade trees in coffee plantations do not detract from pollinator visitation to coffee flowers, suggesting that the provision of multiple ecological and wildlife conservation benefits by shade trees is not in conflict with a growers ability to maximize the benefits of insect pollination on fruit production.

Adjuntas Lares,Las Marias, Maricao, Puerto Rico Ut↗

USGS2016

Assessing the evolution of soil moisture and vegetation conditions during the 2012 United States flash drought

This study examines the evolution of several model-based and satellite-derived drought metrics sensitive to soil moisture and vegetation conditions during the extreme flash drought event that impacted major agricultural areas across the central U.S. during 2012. Standardized anomalies from the remote sensing based Evaporative Stress Index (ESI) and Vegetation Drought Response Index (VegDRI) and soil moisture anomalies from the North American Land Data Assimilation System (NLDAS) are compared to the United States Drought Monitor (USDM), surface meteorological conditions, and crop and soil moisture data compiled by the National Agricultural Statistics Service (NASS). Overall, the results show that rapid decreases in the ESI and NLDAS anomalies often preceded drought intensification in the USDM by up to 6 wk depending on the region. Decreases in the ESI tended to occur up to several weeks before deteriorations were observed in the crop condition datasets. The NLDAS soil moisture anomalies were similar to those depicted in the NASS soil moisture datasets; however, some differences were noted in how each model responded to the changing drought conditions. The VegDRI anomalies tracked the evolution of the USDM drought depiction in regions with slow drought development, but lagged the USDM and other drought indicators when conditions were changing rapidly. Comparison to the crop condition datasets revealed that soybean conditions were most similar to ESI anomalies computed over short time periods (2–4 wk), whereas corn conditions were more closely related to longer-range (8–12 wk) ESI anomalies. Crop yield departures were consistent with the drought severity depicted by the ESI and to a lesser extent by the NLDAS and VegDRI datasets.

Agricultural and Forest Meteorology↗

USGS2022

Prairie wetlands as sources or sinks of nitrous oxide: Effects of land use and hydrology

National and global greenhouse gas (GHG) budgets are continually being refined as data become available. Primary sources of the potent GHG nitrous oxide (N 2 O) include agricultural soil management and burning of fossil fuels, but comprehensive N 2 O budgets also incorporate less prominent factors such as wetlands. Freshwater wetland GHG flux estimates, however, have high uncertainty, and wetlands have been identified as both sources and sinks. Here, we analyzed a regional database of >26,000 N 2 O chamber flux measurements sampled across >150 wetlands from the Prairie Pothole Region (PPR) in the Great Plains of North America. Our goal was to identify important land use and hydrologic drivers of N 2 O flux to help reduce uncertainty in N 2 O models, and to incorporate these drivers into an upscaled estimate of wetland N 2 O emissions from the U.S. portion of the PPR. Within individual wetlands, exposed soils with no standing water, such as along wetland edges, were hotspots that accounted for greater than 90% of wetland N 2 O emissions. In contrast wet (i.e., ponded) areas had minimal or negative N 2 O flux. N 2 O flux from wetlands nested within croplands (16.3–17.3 μg N 2 O m −2 hr −1 ) was, in some instances, nearly double that from wetlands within grasslands (9.2–14.4 μg N 2 O m −2 h −1 ). We estimated that seasonal N 2 O flux from PPR wetlands equated to roughly 0.2% (1.04 Tg CO 2 equivalents) of the U.S. N 2 O budget (c. 2019). Overall, even though PPR wetlands are a small net source of N 2 O to the atmosphere, their emissions are negligible relative to agricultural soil management. Policy and management to restore wetland hydrology and surrounding uplands from cropland to grasslands can reduce landscape N 2 O fluxes. Future activities focused on wetland N 2 O flux would benefit from inclusion of adjacent land use and hydrologic factors, as well as from incorporation of temporally dynamic ponded wetland areas.

Iowa, Minnesota, Montana, North Dakota, South Dako↗

USGS2023

Development of a benchmark eddy flux evapotranspiration dataset for evaluation of satellite-driven evapotranspiration models over the CONUS

A large sample of ground-based evapotranspiration (ET) measurements made in the United States, primarily from eddy covariance systems, were post-processed to produce a benchmark ET dataset. The dataset was produced primarily to support the intercomparison and evaluation of the OpenET satellite-based remote sensing ET (RSET) models and could also be used to evaluate ET data from other models and approaches. OpenET is a web-based service that makes field-delineated and pixel-level ET estimates from well-established RSET models readily available to water managers, agricultural producers, and the public. The benchmark dataset is composed of flux and meteorological data from a variety of providers covering native vegetation and agricultural settings. Flux footprint predictions were developed for each station and included static flux footprints developed based on average wind direction and speed, as well as dynamic hourly footprints that were generated with a physically based model of upwind source area. The two footprint prediction methods were rigorously compared to evaluate their relative spatial coverage. Data from all sources were post-processed in a consistent and reproducible manner including data handling, gap-filling, temporal aggregation, and energy balance closure correction. The resulting dataset included 243,048 daily and 5,284 monthly ET values from 194 stations, with all data falling between 1995 and 2021. We assessed average daily energy imbalance using 172 flux sites with a total of 193,021 days of data, finding that overall turbulent fluxes were understated by about 12% on average relative to available energy. Multiple linear regression analyses indicated that daily average latent energy flux may be typically understated slightly more than sensible heat flux. This dataset was developed to provide a consistent reference to support evaluation of RSET data being developed for a wide range of applications related to water accounting and water resources management at field to watershed scales.

continental United States↗

USGS2007

Eutrophication study at the Panjiakou-Daheiting Reservoir system, northern Hebei Province, People's Republic of China: Chlorophyll-a model and sources of phosphorus and nitrogen

Concentrations, loads, and sources of nitrate and total phosphorus were investigated at the Panjiakou and Daheiting Reservoir system in northern Hebei Province, People's Republic of China. The Luan He River is the primary source of water to these reservoirs, and the upstream watershed has a mix of land uses including agriculture, forest, and one large urban center. The reservoirs have a primary use for storage of drinking water and partially supply Tianjin City with its annual needs. Secondary uses include flood control and aqua culture (fish cages). The response of the reservoir system from phosphorus input, with respect to chlorophyll- a production from algae, was fitted to a model of normalized phosphorus loading that regresses the average summer-time chlorophyll- a concentration to the average annual phosphorus concentration of the reservoir. Comparison of the normalized phosphorus loading and chlorophyll- a response of this system to other reservoirs throughout the world indicate a level of eutrophication that will require up to an approximate 5–10-fold decrease in annual phosphorus load to bring the system to a more acceptable level of algal productivity. Isotopes of nitrogen and oxygen in dissolved nitrate were measured from the headwater streams and at various locations along the major rivers that provide the majority of water to these reservoirs. Those isotopic measurements indicate that the sources of nitrate change from natural background in the rivers to animal manure and septic waste upstream of the reservoir. Although the isotopic measurements suggest that animal and septic wastes are a primary source of nutrients, measurements of the molar ratio of nitrogen to phosphorus are more indicative of row-cropping practices. Options for reduction of nutrient loads include changing the management practices of the aqua culture, installation of new sewage treatment systems in the large urbanized area of the upper watershed, and agricultural management practices that would reduce the loading of nutrients and soil erosion from that land use.

Agricultural Water Management↗

USGS2004

An automated approach to mapping corn from Landsat imagery

Most land cover maps generated from Landsat imagery involve classification of a wide variety of land cover types, whereas some studies may only need spatial information on a single cover type. For example, we required a map of corn in order to estimate exposure to agricultural chemicals for an environmental epidemiology study. Traditional classification techniques, which require the collection and processing of costly ground reference data, were not feasible for our application because of the large number of images to be analyzed. We present a new method that has the potential to automate the classification of corn from Landsat satellite imagery, resulting in a more timely product for applications covering large geographical regions. Our approach uses readily available agricultural areal estimates to enable automation of the classification process resulting in a map identifying land cover as ‘highly likely corn,’ ‘likely corn’ or ‘unlikely corn.’ To demonstrate the feasibility of this approach, we produced a map consisting of the three corn likelihood classes using a Landsat image in south central Nebraska. Overall classification accuracy of the map was 92.2% when compared to ground reference data.

Computers and Electronics in Agriculture↗

USGS2000

Scaling up from field to region for wind erosion prediction using a field-scale wind erosion model and GIS

Factors that affect wind erosion such as surface vegetative and other cover, soil properties and surface roughness usually change spatially and temporally at the field-scale to produce important field-scale variations in wind erosion. Accurate estimation of wind erosion when scaling up from fields to regions, while maintaining meaningful field-scale process details, remains a challenge. The objectives of this study were to evaluate the feasibility of using a field-scale wind erosion model with a geographic information system (GIS) to scale up to regional levels and to quantify the differences in wind erosion estimates produced by different scales of soil mapping used as a data layer in the model. A GIS was used in combination with the revised wind erosion equation (RWEQ), a field-scale wind erosion model, to estimate wind erosion for two 50 km2 areas. Landsat Thematic Mapper satellite imagery from 1993 with 30 m resolution was used as a base map. The GIS database layers included land use, soils, and other features such as roads. The major land use was agricultural fields. Data on 1993 crop management for selected fields of each crop type were collected from local government agency offices and used to 'train' the computer to classify land areas by crop and type of irrigation (agroecosystem) using commercially available software. The land area of the agricultural land uses was overestimated by 6.5% in one region (Lubbock County, TX, USA) and underestimated by about 21% in an adjacent region (Terry County, TX, USA). The total estimated wind erosion potential for Terry County was about four times that estimated for adjacent Lubbock County. The difference in potential erosion among the counties was attributed to regional differences in surface soil texture. In a comparison of different soil map scales in Terry County, the generalised soil map had over 20% more of the land area and over 15% greater erosion potential in loamy sand soils than did the detailed soil map. As a result, the wind erosion potential determined using the generalised soil map Was about 26% greater than the erosion potential estimated by using the detailed soil map in Terry County. This study demonstrates the feasibility of scaling up from fields to regions to estimate wind erosion potential by coupling a field-scale wind erosion model with GIS and identifies possible sources of error with this approach.

Agriculture, Ecosystems and Environment↗

USGS2004

Developing index maps of water-harvest potential in Africa

The food security problem in Africa is tied to the small farmer, whose subsistence farming relies heavily on rain-fed agriculture. A dry spell lasting two to three weeks can cause a significant yield reduction. A small-scale irrigation scheme from small-capacity ponds can alleviate this problem. This solution would require a water harvest mechanism at a farm level. In this study, we looked at the feasibility of implementing such a water harvest mechanism in drought prone parts of Africa. A water balance study was conducted at different watershed levels. Runoff (watershed yield) was estimated using the SCS curve number technique and satellite derived rainfall estimates (RFE). Watersheds were delineated from the Africa-wide HYDRO-1K digital elevation model (DEM) data set in a GIS environment. Annual runoff volumes that can potentially be stored in a pond during storm events were estimated as the product of the watershed area and runoff excess estimated from the SCS Curve Number method. Estimates were made for seepage and net evaporation losses. A series of water harvest index maps were developed based on a combination of factors that took into account the availability of runoff, evaporation losses, population density, and the required watershed size needed to fill a small storage reservoir that can be used to alleviate water stress during a crop growing season. This study presents Africa-wide water-harvest index maps that could be used for conducting feasibility studies at a regional scale in assessing the relative differences in runoff potential between regions for the possibility of using ponds as a water management tool. ?? 2004 American Society of Agricultural Engineers.

Applied Engineering in Agriculture↗

USGS2003

Phytoplankton fuels Delta food web

Populations of certain fishes and invertebrates in the Sacramento-San Joaquin Delta have declined in abundance in recent decades and there is evidence that food supply is partly responsible. While many sources of organic matter in the Delta could be supporting fish populations indirectly through the food web (including aquatic vegetation and decaying organic matter from agricultural drainage), a careful accounting shows that phytoplankton is the dominant food source. Phytoplankton, communities of microscopic free-floating algae, are the most important food source on a Delta-wide scale when both food quantity and quality are taken into account. These microscopic algae have declined since the late 1960s. Fertilizer and pesticide runoff do not appear to be playing a direct role in long-term phytoplankton changes; rather, species invasions, increasing water transparency and fluctuations in water transport are responsible. Although the potential toxicity of herbicides and pesticides to plank- ton in the Delta is well documented, the ecological significance remains speculative. Nutrient inputs from agricultural runoff at current levels, in combination with increasing transparency, could result in harmful algal blooms.

California↗

USGS2005

Phosphorus component in AnnAGNPS

The USDA Annualized Agricultural Non-Point Source Pollution model (AnnAGNPS) has been developed to aid in evaluation of watershed response to agricultural management practices. Previous studies have demonstrated the capability of the model to simulate runoff and sediment, but not phosphorus (P). The main purpose of this article is to evaluate the performance of AnnAGNPS on P simulation using comparisons with measurements from the Deep Hollow watershed of the Mississippi Delta Management Systems Evaluation Area (MDMSEA) project. A sensitivity analysis was performed to identify input parameters whose impact is the greatest on P yields. Sensitivity analysis results indicate that the most sensitive variables of those selected are initial soil P contents, P application rate, and plant P uptake. AnnAGNPS simulations of dissolved P yield do not agree well with observed dissolved P yield (Nash-Sutcliffe coefficient of efficiency of 0.34, R2 of 0.51, and slope of 0.24); however, AnnAGNPS simulations of total P yield agree well with observed total P yield (Nash-Sutcliffe coefficient of efficiency of 0.85, R2 of 0.88, and slope of 0.83). The difference in dissolved P yield may be attributed to limitations in model simulation of P processes. Uncertainties in input parameter selections also affect the model's performance.

Transactions of the American Society of Agricultur↗

USGS2016

Basin scale controls on CO 2 and CH 4 emissions from the Upper Mississippi River

The Upper Mississippi River, engineered for river navigation in the 1930s, includes a series of low-head dams and navigation pools receiving elevated sediment and nutrient loads from the mostly agricultural basin. Using high-resolution, spatially resolved water quality sensor measurements along 1385 river kilometers, we show that primary productivity and organic matter accumulation affect river carbon dioxide and methane emissions to the atmosphere. Phytoplankton drive CO 2 to near or below atmospheric equilibrium during the growing season, while anaerobic carbon oxidation supports a large proportion of the CO 2 and CH 4 production. Reductions of suspended sediment load, absent of dramatic reductions in nutrients, will likely further reduce net CO 2 emissions from the river. Large river pools, like Lake Pepin, which removes the majority of upstream sediments, and large agricultural tributaries downstream that deliver significant quantities of sediments and nutrients, are likely to persist as major geographical drivers of greenhouse gas emissions.

Upper Mississippi River↗

USGS2016

Regional-scale controls on dissolved nitrous oxide in the Upper Mississippi River

The U.S. Corn Belt is one of the most intensive agricultural regions of the world and is drained by the Upper Mississippi River (UMR), which forms one of the largest drainage basins in the U.S. While the effects of agricultural nitrate (NO 3 - ) on water quality in the UMR have been well documented, its impact on the production of nitrous oxide (N 2 O) has not been reported. Using a novel equilibration technique, we present the largest data set of freshwater dissolved N 2 O concentrations (0.7 to 6 times saturation) and examine the controls on its variability over a 350 km reach of the UMR. Driven by a supersaturated water column, the UMR was an important atmospheric N 2 O source (+68 mg N 2 ONm -2 yr -1 ) that varies nonlinearly with the NO 3 - concentration. Our analyses indicated that a projected doubling of the NO 3 - concentration by 2050 would cause dissolved N 2 O concentrations and emissions to increase by about 40%.

Upper Mississippi River↗

USGS2010

Tools for assessing contaminated sediments in freshwater, estuarine, and marine ecosystems

Traditionally, concerns about the management of aquatic resources in aquatic ecosystems have focused primarily on water quality. As such, early water resource management efforts were often directed at assuring the potability of surface water or groundwater sources. Subsequently, the scope of these management initiatives expanded to include protection of instream (i.e., fish and aquatic life), agricultural, industrial, and recreational water uses. Although initiatives undertaken in the past 30 years have unquestionably improved water quality conditions, a growing body of evidence indicates that management efforts directed solely at the attainment of surface -water quality criteria may not provide an adequate basis for protecting the designated uses of aquatic ecosystems. In recent years, concerns about the health and vitality of aquatic ecosystems have begun to re -emerge in North America. One of the principal reasons for this is that many toxic and bioaccumulative chemicals, which are found in only trace amounts in water, can accumulate to elevated levels in sediments. Some of these pollutants, such as organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs), were released into the environment long ago. The use of many of these substances has been banned in North America for 30 years or more; nevertheless, these chemicals continue to persist in the environment. Other contaminants enter our waters every day from industrial and municipal discharges, urban and agricultural runoff, and atmospheric deposition from remote sources. Owing to their physical and chemical properties, many of these substances tend to accumulate in sediments. In addition to providing sinks for many chemicals, sediments can also serve as potential sources of pollutants to the water column when conditions change in the receiving water system (for example during periods of anoxia, after severe storms).

Book chapter↗

USGS2014

Spatial patterns of lacustrine fish assemblages in a catchment of the Mississippi Alluvial Valley

In the alluvial valley of the lower Mississippi River, floodplain lakes form isolated aquatic fragments that retain differing degrees of connectivity to neighbouring rivers. Within these floodplain lakes it was hypothesized that fish species composition, relative abundance, and biodiversity metrics would be shaped largely by aquatic connectivity within a catchment. Fish assemblages in 13 floodplain lakes (five on-channel; eight off-channel) were assessed with electrofishing in 2006–2012 in the Bear Creek catchment, Mississippi, USA. Bear Creek spans approximately 80 km before draining into the Yazoo River, a tributary of the Mississippi River. Fish assemblages in on-channel and off-channel lakes were different, and fish assemblages in on-channel lakes were as a group more homogeneous than off-channel lakes. Moreover, a longitudinal gradient in fish assemblages occurred in on-channel lakes. The observed patterns in fish assemblages are linked largely to differing intensities in connectivity among lakes within the catchment. Lakes with irregular connections have greater individuality, whereas lakes with continuous or chronic connection are more similar. The wide variation in connectivity could be a key to the distinctive biodiversity of catchments and the focus of fish conservation programmes. Off-channel floodplain lakes are among the first landscape elements to vanish as a consequence of agricultural development. These habitats tend to accumulate sediments at fast rates and are converted to agricultural land as soon as suitable drainage can be attained. Considering that off-channel lakes with limited connectivity contribute greatly to the heterogeneity of fish assemblages, such losses pose great concerns to conservation of biodiversity.

Mississippi↗

USGS2025

The future of biocontrol in the Anthropocene: A review of climate change impacts on biocontrol agents and their hosts

Biological control, the practice of using one species (biocontrol agent) to control the population of another (a host or prey species, hereafter target), can be a successful method to reduce pest species in agricultural and natural systems worldwide. Successful biocontrol agents often share a deep evolutionary history with their targets that results in high target specificity and synchronized phenology. However, with rapidly changing climatic conditions, users of biocontrol agents have questioned how climate change will affect both well-established and more recent biological control relationships. Using a meta-analysis of data collected from a systematic literature review, we evaluated the evidence for the impact of changing temperatures on the efficacy of biocontrol agents and corresponding responses in their targets. Overall, most studies of climate change impacts on biocontrol agents take place in the laboratory and focus on arthropod agents that are parasitoids. Results from our meta-analysis reveal that changes in temperature are projected to impact biocontrol agents and their targets similarly, with no overall significant changes to biocontrol agent or target performance. However, our results also show that temperature responses vary widely across study systems, as illustrated by case studies showing both positive, neutral, and negative effects of temperature on biocontrol agent efficacy, as well as variation in responses across the three core biological control measures of success: survival, reproduction, and efficacy. Our work highlights important knowledge gaps including how climate change will affect both biocontrol agents and their targets simultaneously. Additionally, we find that most current studies of climate impacts examined temperature relationships, predominantly of agricultural biocontrol agents. Increasing the breadth of studies is crucial for understanding the potential for climate change to affect the success of current and future biological control programs.

Ecological Applications↗

USGS2022

Wildlife associates of nine-banded armadillo (Dasypus novemcinctus) burrows in Arkansas

The Nine-banded Armadillo ( Dasypus novemcinctus ) is a widespread burrowing species with an expanding geographic range across the southeastern and midwestern United States. Armadillos dig numerous, large burrows within their home ranges and these burrows are likely used by a diverse suite of wildlife species as has been reported for other burrowing ecosystem engineers such as Gopher Tortoises ( Gopherus polyphemus ), Desert Tortoises ( Gopherus agassizi ), and Black-tailed Prairie Dogs ( Cynomys ludovicianus ). We used motion-triggered game cameras at 35 armadillo burrows in 4 ecoregions of Arkansas and documented 19 species of mammals, 4 species of reptile, 1 species of amphibian, and 40 species of bird interacting with burrows. Bobcat ( Lynx rufus ), Coyote ( Canis latrans ), Eastern Cottontail ( Sylvilagus floridanus ), Gray Fox ( Urocyon cinereoargenteus ), Gray Squirrel ( Sciurus carolinensis ), Northern Raccoon ( Procyon lotor ), Virginia Opossum ( Didelphis virginiana ), and unidentified rodents (mice and rats) were documented using burrows in all four ecoregions. We documented wildlife hunting, seeking shelter, rearing young in, and taking over and modifying armadillo burrows. The rate of use was highest in the Mississippi Alluvial Valley, a landscape dominated by agriculture, where natural refugia may be limited and rodents are abundant. Armadillo burrows are clearly visited and used by numerous wildlife species to fulfill various life stage requirements, and this list will likely expand if more attention is devoted to understanding the role of armadillos burrows. Armadillos are important ecosystem engineers, and their ecological role warrants more investigation and attention as opposed to only being viewed and managed as agricultural and garden pests.

Arkansas↗