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USGS2017

Ad hoc instrumentation methods in ecological studies produce highly biased temperature measurements

In light of global climate change, ecological studies increasingly address effects of temperature on organisms and ecosystems. To measure air temperature at biologically relevant scales in the field, ecologists often use small, portable temperature sensors. Sensors must be shielded from solar radiation to provide accurate temperature measurements, but our review of 18 years of ecological literature indicates that shielding practices vary across studies (when reported at all), and that ecologists often invent and construct ad hoc radiation shields without testing their efficacy. We performed two field experiments to examine the accuracy of temperature observations from three commonly used portable data loggers (HOBO Pro, HOBO Pendant, and iButton hygrochron) housed in manufactured Gill shields or ad hoc, custom‐fabricated shields constructed from everyday materials such as plastic cups. We installed this sensor array (five replicates of 11 sensor‐shield combinations) at weather stations located in open and forested sites. HOBO Pro sensors with Gill shields were the most accurate devices, with a mean absolute error of 0.2°C relative to weather stations at each site. Error in ad hoc shield treatments ranged from 0.8 to 3.0°C, with the largest errors at the open site. We then deployed one replicate of each sensor‐shield combination at five sites that varied in the amount of urban impervious surface cover, which presents a further shielding challenge. Bias in sensors paired with ad hoc shields increased by up to 0.7°C for every 10% increase in impervious surface. Our results indicate that, due to variable shielding practices, the ecological literature likely includes highly biased temperature data that cannot be compared directly across studies. If left unaddressed, these errors will hinder efforts to predict biological responses to climate change. We call for greater standardization in how temperature data are recorded in the field, handled in analyses, and reported in publications.

Ecology and Evolution↗

USGS2020

Tracking fisheries through time: The American Fisheries Society as an historical lens

The historical context of current environment conditions offers vital guidance to North American fisheries professionals as they strive to develop effective management plans and policies. This retrospective includes understanding the remarkable historic fisheries resource and causative reasons for establishing their public fisheries agencies and the American Fisheries Society (Society). Through a review of primary historical documents and literature for North America, this paper identifies: factors contributing to the of founding of the Society and public fish commissions; shows how selected resource issues evolved; and documents how and why selected fisheries and aquatic habitat policies changed in response to those issues. Overexploitation, landscape-scale habitat alterations, mining, and dams were the causative agents for emergence of fisheries agencies and the Society, and these environmental factors remain relevant today. Beginning in the 1960s, after 100 years of inaction, North Americans grew tired of degraded waters and fisheries and forced policy changes that have directly and indirectly affected the fisheries we manage today. The historical events and resulting corrective legislation are taken for granted by those unaware that our Society has actively participated in developing policies to address these environmental harms. Further, the Society continues to play a vital role in identifying key issues, providing conduits for information to cope with impairments, and advocating for policies to conserve intact habitats and improve degraded systems. The struggles documented in this paper offer crucial lessons as we continue to be challenged by legacy resource issues and face emerging environmental stressors such as climate change as well as regression in long-standing environmental protection policies.

Fisheries Magazine↗

USGS2023

Compact or sprawling cities: Has the sparing-sharing framework yielded an ecological verdict?

Purpose of Review Global urban land area is growing faster than the urban population, raising concerns that sprawling, low-density development will reduce biodiversity and human wellbeing. The sparing-sharing framework, adapted from agroecology, provides one approach to assessing alternative urban growth patterns. It compares ecological outcomes in landscapes matched for total population and land area, but differing in configuration: land sparing (partitioned between densely urbanized and undeveloped areas) or land sharing (low-density development throughout). We reviewed the urban sparing-sharing literature since 2010 and recovered 15 studies conducted in 22 cities on four continents. Recent Findings Collectively, studies assessed effects of alternative development patterns on 296 species, 21 community metrics (such as species richness), and 26 indicators of ecosystem services or processes (such as carbon sequestration). Sparing was the best option for 51% of individual species; 43% of community metrics; and 27% of ecosystem service indicators. Summary Existing ecological research does not clearly favor one pattern or the other, and new approaches are needed to facilitate decision making and ecological insight. Specifically, future work could (1) explicitly evaluate optimized urban development patterns across multiple competing priorities (such as providing housing, delivering ecosystem services, and protecting priority species), (2) tackle issues of spatial scale and connectivity that are often ambiguous in sparing-sharing research, and (3) improve geographical representation. These advances can be made while preserving the key insight of the framework–that choices between alternative landscape configurations are only meaningful when those landscapes are matched for total area and the level of human needs met.

Current Landscape Ecology Reports↗

USGS1968

Fish furunculosis, 1952-1966

A review is made of the furunculosis literature based on a bibliography of papers published from 1952–1966. It is noted that furunculosis is still a serious problem. Rapid diagnostic procedures have been developed. New therapeutic drugs have been introduced for treatment of sulfa resistant strains of A. salmonicida. Genetic resistance to and oral immunization against furunculosis show promise but require further study.

Transactions of the American Fisheries Society↗

USGS2008

Mammal Inventory of the Mojave Network Parks-Death Valley and Joshua Tree National Parks, Lake Mead National Recreation Area, Manzanar National Historic Site, and Mojave National Preserve

This report describes the results of a mammal inventory study of National Park Service units in the Mojave Desert Network, including Death Valley National Park, Joshua Tree National Park, Lake Mead National Recreation Area, Manzanar National Historic Site, and Mojave National Preserve. Fieldwork for the inventory focused on small mammals, primarily rodents and bats. Fieldwork for terrestrial small mammals used trapping with Sherman and Tomahawk small- and medium-sized mammal traps, along with visual surveys for diurnal species. The majority of sampling for terrestrial small mammals was carried out in 2002 and 2003. Methods used in field surveys for bats included mist-netting at tanks and other water bodies, along with acoustic surveys using Anabat. Most of the bat survey work was conducted in 2003. Because of extremely dry conditions in the first two survey years (and associated low mammal numbers), we extended field sampling into 2004, following a relatively wet winter. In addition to field sampling, we also reviewed, evaluated, and summarized museum and literature records of mammal species for all of the Park units. We documented a total of 59 mammal species as present at Death Valley National Park, with an additional five species that we consider of probable occurrence. At Joshua Tree, we also documented 50 species, and an additional four 'probable' species. At Lake Mead National Recreation Area, 57 mammal species have been positively documented, with 10 additional probable species. Manzanar National Historic Site had not been previously surveyed. We documented 19 mammal species at Manzanar, with an additional 11 probable species. Mojave National Preserve had not had a comprehensive list previously, either. There are now a total of 50 mammal species documented at Mojave, with three additional probable species. Of these totals, 23 occurrences are new at individual park units (positively documented for the first time), with most of these being at Manzanar. Noteworthy additions include western mastiff bat at Joshua Tree, house mouse at a number of wildland sites at Lake Mead, and San Diego pocket mouse at Mojave National Preserve. There are also species that have been lost from the Mojave Network parks. We discuss remaining questions, including the possible occurrence of additional species at each park area (most of these are marginal species whose distributional range may or may not edge into the boundaries of the area). Taxonomic changes are also discussed, along with potential erroneous species records.

Open-File Report↗

USGS2023

Oil and gas reclamation—Operations, monitoring methods, and standards

This publication provides broad guidance for surface management of oil and gas development with a focus on promoting successful reclamation. Successful reclamation depends on sound best management practices, clear standards and expectations, defensible monitoring for effectiveness, and management of production facilities to minimize surface disturbance. This publication provides specific guidelines for surface management of oil and gas, including operations, standards, and monitoring. The development of this report was guided by existing Federal reclamation policy, a review of the scientific and other literature, as well as practical field experience. Expertise was pulled from multiple sources including Federal and State agencies, oil and gas contractors, and academia. The target audience for this report is primarily operators and contractors conducting oil and gas activities on U.S. Federal or Tribal lands and the surface management agencies responsible for guiding and enforcing these activities. The guidance on surface management presented here will also be useful for managing oil and gas activities on State and private lands and where private land occurs over Federal mineral estate (split estate).

Techniques and Methods↗

USGS2016

Ecology and conservation of Lesser Prairie-Chickens in sand shinnery oak prairies

Sand shinnery oak (Quercus havardii) prairies are unique ecosystems endemic to sandy soils of eastern New Mexico, northwestern Texas, and western Oklahoma; the historic and current distribution of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) overlaps these prairie systems. Lesser Prairie-Chicken populations in sand shinnery oak prairies of the Southern Great Plains have declined substantially since the late 1980s, most likely due to conversion of nesting and brood-rearing habitat to row-crop agriculture and extended periods of drought. In addition to threats universal throughout the species distribution, this population is susceptible to a changing climate in an area that is already representative of an extreme environment for ground-nesting birds. Recent studies of Lesser Prairie-Chicken ecology in sand shinnery oak prairies have expanded our knowledge on the ecology and management of the species, but a thorough review of the historic and current literature is lacking. In addition, current management guidelines exist for Lesser Prairie-Chickens in mixed grass and sand sagebrush prairies, but there are no comprehensive management guidelines for the species in sand shinnery oak prairies. This information is paramount given unique aspects of the vegetation community, relative ecosystem drivers, and environmental variation in sand shinnery oak prairie and the species’ current status as a proposed threatened species under the United States Endangered Species Act. Herein, we provide a thorough synthesis of literature pertaining to the life history, habitat requirements, habitat management, and population management for Lesser Prairie-Chickens in sand shinnery oak prairie, provide management guidelines and recommendations for the species in this ecoregion, and highlight current and future research needs. Within our objectives, we place emphasis on two recently completed long-term investigations into Lesser Prairie-Chicken ecology in sand shinnery oak prairie - a 10-year vegetation data set collected in Roosevelt County, New Mexico, 2001–2011 and a 6-year Lesser Prairie-Chicken data set collected in Roosevelt County, New Mexico and Cochran, Hockley, Terry, and Yoakum counties, Texas, 2006–2012.

Book chapter↗

USGS2017

Food web conceptual model

This chapter describes a general model of food webs within tidal wetlands and represents how physical features of the wetland affect the structure and function of the food web. This conceptual model focuses on how the food web provides support for (or may reduce support for) threatened fish species. This model is part of a suite of conceptual models designed to guide monitoring of restoration sites throughout the San Francisco Estuary (SFE), but particularly within the Sacramento-San Joaquin Delta (Delta) and Suisun Marsh. The conceptual models have been developed based on the Delta Regional Ecosystem Restoration Implementation Plan (DRERIP) models, and are designed to aid in the identification and evaluation of monitoring metrics for tidal wetland restoration projects. Many tidal restoration sites in the Delta are being constructed to comply with environmental regulatory requirements associated with the operation of the Central Valley Project and State Water Project. These include the Biological Opinions for Delta Smelt (Hypomesus transpacificus) and salmonids (U.S. Fish and Wildlife Service 2008; National Marine Fisheries Service 2009), and the Incidental Take Permit for Longfin Smelt (Spirinchus thaleichthyes) (California Department of Fish and Wildlife 2009). These regulatory requirements are based on the hypothesis that the decline of listed fish species is due in part to a decline in productivity of the food web (phytoplankton and zooplankton in particular) or alterations in the food web such that production is consumed by other species in the Estuary (Sommer et al. 2007; Baxter et al. 2010; Brown et al. 2016a). Intertidal wetlands and shallow subtidal habitat can be highly productive, so restoring areas of tidal wetlands may result in a net increase in productivity that will provide food web support for these fish species. However, other factors such as invasive bivalves that reduce phytoplankton and zooplankton biomass and invasive predatory fishes that may compete with or prey upon listed fishes can limit the utility of tidal wetlands for food web support (Lucas and Thompson 2012; Herbold et al. 2014). This model utilizes information from the previous DRERIP models for Delta food webs (Durand 2008) and tidal wetlands (Kneib et al. 2008), an updated DRERIP model (Durand 2015), and the State of BayDelta Science 2016 review of recent Delta food web literature (Brown et al. 2016a).

Interagency Ecological Program Technical Report↗

USGS2004

A summary of the scientific literature on the effects of fire on the concentration of nutrients in surface waters

This paper provides a detailed review of the chemical changes that occur in soil during a fire, the pathways by which nutrients are transferred from soil to surface-water bodies following a fire, and the temporal and spatial effects of fires on the concentration of nutrients in surface-water bodies during and following a fire that have been reported in the scientific literature. Thirty-nine papers from the scientific literature that represent studies that (1) were done in a variety of environments (savannas, grasslands, temperate forests, alpine forests, and so forth); (2) had a range of sampling frequency and duration, such as during and immediately following a fire (from the start of fire to 1 year later), short-term sampling (from end of fire to 3 years later), and long term-sampling (sampling for greater than 3 years following a fire); and (3) incorporated watersheds with various burn intensities, severities, and histories were reviewed and summarized. The review of the scientific literature has revealed that measurable effects of fires on streamwater quality are most likely to occur if the fire was severe enough to burn large amounts of organic matter, if windy conditions were present during the fire, if heavy rain occurred following the fire, and if the fire occurred in a watershed with steep slopes and soils with little cation-exchange capacity. Measurable effects of fires on lake- and reservoir-water quality are most likely to occur if, in addition to the factors listed for streams, the lake or reservoir is oligotrophic or mesotrophic and the residence time of water in the lake or reservoir is short relative to the length of time elevated concentrations of nutrients occur in runoff. Knowledge of whether a lake or reservoir is nitrogen or phosphorus limited is important because eutrophication of nitrogen-limited lakes may occur following a fire due to increasing nitrogen:phosphorus ratios caused by prolonged increases of nitrogen concentrations, especially nitrate.

Open-File Report↗

USGS2023

A research agenda for the science of actionable knowledge: Drawing from a review of the most misguided to the most enlightened claims in the science-policy interface literature

Linking science with action affords a prime opportunity to leverage greater societal impact from research and increase the use of evidence in decision-making. Success in these areas depends critically upon processes of producing and mobilizing knowledge, as well as supporting and making decisions. For decades, scholars have idealized and described these social processes in different ways, resulting in numerous assumptions that now variously guide engagements at the interface of science and society. We systematically catalog these assumptions based on prior research on the science-policy interface, and further distill them into a set of 26 claims. We then elicit expert perspectives (n = 16) about these claims to assess the extent to which they are accurate or merit further examination. Out of this process, we construct a research agenda to motivate future scientific research on actionable knowledge, prioritizing areas that experts identified as critical gaps in understanding of the science-society interface. The resulting agenda focuses on how to define success, support intermediaries, build trust, and evaluate the importance of consensus and its alternatives – all in the diverse contexts of science-society-decision-making interactions. We further raise questions about the centrality of knowledge in these interactions, discussing how a governance lens might be generative of efforts to support more equitable processes and outcomes. We offer these suggestions with hopes of furthering the science of actionable knowledge as a transdisciplinary area of inquiry.

Environmental Science & Policy↗

USGS2010

Restoration and revegetation associated with control of saltcedar and Russian olive: Chapter 7

Rationales for controlling or eliminating saltcedar and Russian olive from sites, river reaches, or entire streams include implicit or explicit assumptions that natural recovery or applied restoration of native plant communities will follow exotic plant removal (McDaniel and Taylor, 2003; Quimby and others, 2003). The vegetation that replaces saltcedar and Russian olive after treatment (“replacement vegetation”), with or without restoration actions, strongly influences the extent to which project objectives are successfully met. It is often assumed or implied that saltcedar and Russian olive removal alone is “restoration,” and many reports equate restoration success with areal extent of nonnative plants treated (for example, Duncan and others, 1993). However, removal of nonnative species alone does not generally constitute restoration. In this chapter, the term “restoration” refers to conversion of saltcedar- and Russian olive-dominated sites to a replacement vegetation type that achieves specific management goals and helps return parts of the system to a desired state. The degree to which a site is “restored” following removal of saltcedar or Russian olive typically depends upon a range of factors, such as (1) the site’s potential for restoration (such as extant soil conditions, site hydrology), (2) the direct and indirect effects of removal (for example, mechanical impacts to the site, effects of herbicides on nontarget vegetation), (3) the efficacy of restoration activities (for example, grading, reseeding, pole planting), and (4) the maintenance of processes that support native vegetation and prevent re-colonization by nonnative communities over the long term. This chapter summarizes and synthesizes the published literature on the topic of restoring native riparian vegetation following saltcedar and Russian olive control or removal. Most of the studies reviewed here are from saltcedar removal, revegetation, and river restoration projects in semiarid and arid parts of the Western United States. The paucity of literature on Russian olive prevents thorough evaluation of specific considerations for restoration following Russian olive removal; however, a few field studies are highlighted. Furthermore, the basic principles of restoration following vegetation removal and the considerations and lessons learned from saltcedar case studies are broadly applicable to sites across the Western United States. We begin with a brief discussion of planning and objective setting. Next, we discuss site factors and context, which are important to consider when selecting and prioritizing sites for restoration. We then review and synthesize the literature on restoration approaches and methods or combinations of methods to apply to particular sites. Throughout this chapter, we highlight what is known on the topics of restoring soils, vegetation, and site conditions following nonnative species removal, as well as future research needs.

Book chapter↗

USGS2019

Typha (cattail) invasion in North American wetlands: Biology, regional problems, impacts, ecosystem services, and management

Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural systems, but also is linked with a variety of ecosystem services such as bioremediation and provisioning of biomass, as well as an assortment of traditional cultural uses. Numerous physical, chemical, and hydrologic control methods are used to manage invasive Typha, but results are inconsistent and multiple methods and repeated treatments often are required. While this review focuses on invasive Typha in North America, the literature cited comes from research on Typha and other invasive species from around the world. As such, many of the underlying concepts in this review are relevant to invasive species in other wetland ecosystems worldwide.

Wetlands↗

USGS2023

60 years and beyond of Reviews of Geophysics

Reviews of Geophysics is an AGU journal, first established in February 1963. It is a hybrid open access invitation-only journal that publishes comprehensive review articles across various disciplines within the Earth and Space Sciences. The selection criteria are rigorous and many submissions are declined without review. The journal is the highest ranked in the fields of Geochemistry and Geophysics, with a high Journal Impact Factor (JIF 2021 = 24.9), which is indicative of its high visibility and influence within the scientific community. The journal's published review papers, beyond a mere summary of literature, provide crucial context for current work, and establish the framework for comprehensive understanding of research progress, challenges, and interconnections between different communities, so that research may be appreciated by a broad audience. We emphasize the importance of publishing studies that provide a comprehensive overview and synthesis of the current state of knowledge in a field, especially in the case of geophysics, where knowledge is rapidly developing, increasing and becoming more specialized.

Reviews of Geophysics↗

USGS2021

Review of the invasive Asian clam Corbicula spp. (Bivalvia: Cyrenidae) distribution in North America, 1924–2019

The bivalve Corbicula is one of the most successful aquatic mollusk invaders in the world. Since being introduced to North America from its native range in Asia, it has dispersed widely over a large portion of the continent from southern Canada to Panama. The first evidence of its introduction in the Western Hemisphere was discovered in 1924 in British Columbia, Canada. A review of distribution records from natural history museums, scientific literature, Federal and State agencies, universities, and oral and written communications with scientists has shown the continued dispersal of Corbicula in North America. Since the most recent comprehensive review of its distribution information through the mid-1980s, Corbicula has been found in an additional 2 Canadian Provinces, 10 U.S. States and Puerto Rico, 9 Mexican States, Cuba, and Panama. The known distribution in North America now includes 47 U.S. States, District of Columbia, Puerto Rico, 3 Canadian Provinces, 16 Mexican States, Cuba, and Panama. Corbicula has been found in three of the Laurentian Great Lakes (Erie, Michigan, Superior) primarily associated with industrial warmwater effluent refugia. Problems associated with Corbicula populations were widely realized not long after its arrival and included negative impacts to power generation, industrial water supply operations, and agricultural water conveyance. In natural settings, impacts on native mussels such as altering nutrient cycling, food webs, and sediment distribution dynamics have occurred. In past decades, control of established open water populations had not been a management priority. With a relatively recent interest in eradication of small, newly established populations, several attempts were made in the United States but were unsuccessful. Recent molecular genetic analyses provide evidence of multiple species and (or) genetically and morphologically distinguishable “forms” in North America. However, the number and identification of Corbicula species in North America remain unresolved. It appears likely that more than one species of Corbicula has been introduced into U.S. waters.

Scientific Investigations Report↗

USGS2021

Mercury exposure in mammalian mesopredators inhabiting a brackish marsh

Bioaccumulation of environmental contaminants in mammalian predators can serve as an indicator of ecosystem health. We examined mercury concentrations of raccoons ( Procyon lotor; n = 37 individuals) and striped skunks ( Mephitis mephitis ; n = 87 individuals) in Suisun Marsh, California, a large brackish marsh that is characterized by contiguous tracts of tidal marsh and seasonally impounded wetlands. Mean (standard error; range) total mercury concentrations in adult hair grown from 2015 to 2018 were 28.50 μg/g dw (3.05 μg/g dw; range: 4.46 – 81.01 μg/g dw) in raccoons and 4.85 μg/g dw (0.54 μg/g dw; range: 1.52 – 27.02 μg/g dw) in striped skunks. We reviewed mammalian hair mercury concentrations in the literature and raccoon mercury concentrations in Suisun Marsh were among the highest observed for wild mammals. Although striped skunk hair mercury concentrations were 83% lower than raccoons, they were higher than proposed background levels for mercury in mesopredator hair (1 – 5 μg/g). Hair mercury concentrations in skunks and raccoons were not related to animal size, but mercury concentrations were higher in skunks in poorer body condition. Large inter-annual differences in hair mercury concentrations suggest that methylmercury exposure to mammalian predators varied among years. Mercury concentrations of raccoon hair grown in 2017 were 2.7 times greater than hair grown in 2015, 1.7 times greater than hair grown in 2016, and 1.6 times greater than hair grown in 2018. Annual mean raccoon and skunk hair mercury concentrations increased with wetland habitat area. Furthermore, during 2017, raccoon hair mercury concentrations increased with the proportion of raccoon home ranges that was wetted habitat, as quantified using global positioning system (GPS) collars. The elevated mercury concentrations we observed in raccoons and skunks suggest that other wildlife at similar or higher trophic positions may also be exposed to elevated methylmercury bioaccumulation in brackish marshes.

California↗

USGS2018

Migratory coupling between predators and prey

Animal migrations act to couple ecosystems and are undertaken by some of the world’s most endangered taxa. Predators often exploit migrant prey, but the movements taken by these consumers are rarely studied or understood. We define such movements, where migrant prey induce large-scale movements of predators, as migratory coupling. Migratory coupling can have ecological consequences for the participating prey, predators and the communities they traverse across the landscape. We review examples of migratory coupling in the literature and provide hypotheses regarding conditions favourable for their occurrence. We also provide a framework for interactions induced by migratory coupling and demonstrate their potential community-level impacts by examining other forms of spatial shifts in predators. Migratory coupling integrates the fields of landscape, movement, food web and community ecologies, and represents an understudied frontier in ecology.

Nature Ecology & Evolution↗

USGS1993

How well can fishes prey on zebra mussels in eastern North America?

Literature on mollusk-eating fishes was reviewed to determine the potential for different species of fish to control zebra mussels in eastern North America. At least six species are potential predators of zebra mussels because they possess (1) both upper and lower pharyngeal teeth or (2) lower pharyngeal teeth and chewing pads located on the dorsal roof for crushing mollusk shells. Freshwater drum ( Aplodinotus grunniens ) and two centrarchids, redear sunfish ( Lepomis microlophus ) and pumpkinseed ( L. gibbosus ), possess both upper and lower pharyngeal teeth and are likely to consume more zebra mussels than fishes with only lower pharyngeal teeth. Only two catostomid species, copper and river redhorses ( Moxostoma hubbsi and M. carinatum ), have chewing pads that enable them to crush mollusks. The exotic omnivorous common carp ( Cyprinus carpio ), possessing lower teeth and a chewing pad, may prey on zebra mussels when aquatic insect larvae, its preferred food, become rare. Managing populations of drum, sunfishes and redhorses to reduce exploitation of large individuals and improve their habitats are suggested as means to intensify biological control of zebra mussels in eastern North America. Other Eurasian molluscivores, the roach ( Rutilus rutilus ) and the black carp ( Mylopharyngodon piceus ) should not be introduced into North America because research has shown repeatedly that an introduced biological controller usually does not forage for unwanted pests or reside only in preferred habitats of pests. Drum, sunfishes and redhorses should be preferred over these exotics as biological controllers of zebra mussels in North America because these native fishes will likely occupy newly established habitats of zebra mussels.

Fisheries↗

USGS2011

Effects of conservation practices on wetland ecosystem services in the Mississippi Alluvial Valley

Restoration of wetland ecosystems is an important priority for many state and federal agencies, as well as nongovernmental conservation organizations. The historic conversion of wetlands in the Mississippi Alluvial Valley (MAV) has resulted in large‐scale implementation of a variety of conservation practices designed to restore and enhance wetland ecosystem services. As a consequence, the effectiveness of multiple approaches in achieving desired conservation goals varies depending on site conditions, practices employed, and specific ecosystem services. We reviewed government agency programs and the scientific literature to evaluate the effects of conservation practices on wetlands in the MAV. There were 68 different conservation practices applied to a combined total of 1.27 million ha in the MAV between 2000 and 2006. These practices fell into two categories: Wetland Conservation Practices and Upland Conservation Practices. Sixteen different practices accounted for nearly 92% of the total area, and only three of these are directly related to wetlands: Wetland Wildlife Habitat Management, Wetland Restoration, and Riparian Forest Buffer. All three of these practices involve reforestation, primarily planting hard‐mast species such as Quercus sp. and Carya sp. These plantings are likely to develop into even‐aged stands of low tree diversity with little structural heterogeneity, which will impact future wildlife habitat. Since hydrology is a critical driver of wetland processes, the ability of a given conservation practice to restore wetland hydrology is a key determinant of how well it can restore ecosystem services. However, there is little to no follow‐up monitoring of projects, so it is difficult to know how much variability exists for any given practice or the efficacy of specific practices. Conservation practices that only plant trees without reconnecting the wetland to the hydrologic and nutrient fluxes in the watershed may restore some wildlife habitat but will do little for regulating services such as nitrogen retention. While conservation practices have overall beneficial effects on many ecosystem services in the MAV, the most effective are those with a direct link between the actions associated with a given practice and controls over ecosystem processes and services.

Arkansas, Kentucky, Louisiana, Mississippi, Missou↗