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USGS2011

The human dimension of fire regimes on Earth

Humans and their ancestors are unique in being a fire‐making species, but ‘natural’ (i.e. independent of humans) fires have an ancient, geological history on Earth. Natural fires have influenced biological evolution and global biogeochemical cycles, making fire integral to the functioning of some biomes. Globally, debate rages about the impact on ecosystems of prehistoric human‐set fires, with views ranging from catastrophic to negligible. Understanding of the diversity of human fire regimes on Earth in the past, present and future remains rudimentary. It remains uncertain how humans have caused a departure from ‘natural’ background levels that vary with climate change. Available evidence shows that modern humans can increase or decrease background levels of natural fire activity by clearing forests, promoting grazing, dispersing plants, altering ignition patterns and actively suppressing fires, thereby causing substantial ecosystem changes and loss of biodiversity. Some of these contemporary fire regimes cause substantial economic disruptions owing to the destruction of infrastructure, degradation of ecosystem services, loss of life, and smoke‐related health effects. These episodic disasters help frame negative public attitudes towards landscape fires, despite the need for burning to sustain some ecosystems. Greenhouse gas‐induced warming and changes in the hydrological cycle may increase the occurrence of large, severe fires, with potentially significant feedbacks to the Earth system. Improved understanding of human fire regimes demands: (1) better data on past and current human influences on fire regimes to enable global comparative analyses, (2) a greater understanding of different cultural traditions of landscape burning and their positive and negative social, economic and ecological effects, and (3) more realistic representations of anthropogenic fire in global vegetation and climate change models. We provide an historical framework to promote understanding of the development and diversification of fire regimes, covering the pre‐human period, human domestication of fire, and the subsequent transition from subsistence agriculture to industrial economies. All of these phases still occur on Earth, providing opportunities for comparative research.

Journal of Biogeography↗

USGS2004

Assessing biodiversity in Nuevo Leon, Mexico: Are nature reserves the answer?

The Mexican state of Nuevo Leon, located in the northeastern portion of the country, currently has 26 state and three federal nature reserves covering approximately 4.5% of its land area. These reserves were established for a variety of reasons not necessarily related to conservation purposes. In 2000 in response to a growing concern about the lack of organized conservation reserve planning to protect the important biological and physical features of Mexico, the Mexican Commission for Knowledge and Use of Biodiversity proposed 12 new terrestrial reserves for Nuevo Leon. The new reserves, if established, would increase the proportion of protected lands in the state to almost 24% of the state's land area. We compiled a Geographic Information System (GIS) analysis using digital thematic maps of physical and ecological features to examine how well the existing and proposed reserves incorporated the major biological and physical features of the state. The existing reserves are located primarily in regions with elevations > 1,000-1,500 m, on less productive soils, and are dominated by pine and oak forest cover types. As a result, the state's dominant biotic region - low elevation coastal plain with xeric scrub vegetation - is disproportionately under represented in the current reserve system. The new reserves would expand the protection of biophysical resources throughout the state. However, the inclusion of important resources in the low elevation coastal lands would still be limited.

Nuevo Leon↗

USGS2023

Assessing contaminants of emerging concern in the Great Lakes Ecosystem: A decade of method development and practical application

Assessing the ecological risk of contaminants in the field typically involves consideration of a complex mixture of compounds which may or may not be detected via instrumental analyses. Further, there are insufficient data to predict the potential biological effects of many detected compounds, leading to their being characterized as contaminants of emerging concern (CECs). Over the past several years, advances in chemistry, toxicology, and bioinformatics have resulted in a variety of concepts and tools that can enhance the pragmatic assessment of the ecological risk of CECs. The present Focus article describes a 10+- year multiagency effort supported through the U.S. Great Lakes Restoration Initiative to assess the occurrence and implications of CECs in the North American Great Lakes. State-of-the-science methods and models were used to evaluate more than 700 sites in about approximately 200 tributaries across lakes Ontario, Erie, Huron, Michigan, and Superior, sometimes on multiple occasions. Studies featured measurement of up to 500 different target analytes in different environmental matrices, coupled with evaluation of biological effects in resident species, animals from in situ and laboratory exposures, and in vitro systems. Experimental taxa included birds, fish, and a variety of invertebrates, and measured endpoints ranged from molecular to apical responses. Data were integrated and evaluated using a diversity of curated knowledgebases and models with the goal of producing actionable insights for risk assessors and managers charged with evaluating and mitigating the effects of CECs in the Great Lakes. This overview is based on research and data captured in approximately about 90 peer-reviewed journal articles and reports, including approximately about 30 appearing in a virtual issue comprised of highlighted papers published in Environmental Toxicology and Chemistry or Integrated Environmental Assessment and Management . Environ Toxicol Chem 2023;42:2506–2518. © 2023 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Environmental Toxicology and Chemistry↗

USGS2008

Mapping the information landscape: Discerning peaks and valleys for ecological monitoring

We investigate previously unreported phenomena that have a potentially significant impact on the design of surveillance monitoring programs for ecological systems. Ecological monitoring practitioners have long recognized that different species are differentially informative of a system's dynamics, as codified in the well-known concepts of indicator or keystone species. Using a novel combination of analysis techniques from nonlinear dynamics, we describe marked variation among spatial sites in information content with respect to system dynamics in the entire region. We first observed these phenomena in a spatially extended predator-prey model, but we observed strikingly similar features in verified water-level data from a NOAA/NOS Great Lakes monitoring program. We suggest that these features may be widespread and the design of surveillance monitoring programs should reflect knowledge of their existence.

Journal of Biological Physics↗

USGS2025

Invasive wild pig movement and space use in a mixed-use forest landscape, South Carolina

Invasive wild pigs ( Sus scrofa ) pose considerable ecological and economic challenges across their introduced range, and understanding their spatial ecology is critical for management. This research and accompanying dataset represents adult wild pig movement in South Carolina, United States based on 16 individuals collared in 2023-2024. Using hourly GPS collar data for 6 males and 5 females, we calculated autocorrelated kernel density estimates (AKDEs) and monthly kernel density estimates (KDEs) to characterize space use. Individual pigs had an average hourly step length of 83 m and average net displacement of 930 m. On average, pigs used 2.32 km 2 monthly, while they used 2.95 km 2 over their entire tracked period (mean = 111 days). This work aims to support management actions and future research on invasive wild pigs.

South Carolina↗

USGS2002

Carboniferous Psammichnites: Systematic re-evaluation, taphonomy and autecology

The ichnogenus Psammichnites Torell 1870 includes a wide variety of predominantly horizontal, sinuous to looped, backfilled traces, characterized by a distinctive median dorsal structure. Though commonly preserved in full relief on upper bedding surfaces, some ichnospecies of Psammichnites may be preserved in negative hyporelief. Psammichnites records the feeding activities of a subsurface animal using a siphon-like device. Several ichnogenera reflect this general behavioral pattern, including Plagiogmus Roedel 1929 and the Carboniferous ichnogenera Olivellites Fenton and Fenton 1937a and Aulichnites Fenton and Fenton 1937b. Based on analysis of specimens from the United States, Spain, and the United Kingdom, three Carboniferous ichnospecies of Psammichnites are reviewed in this paper: P. plummeri (Fenton and Fenton, 1937a), P. grumula (Romano and Meléndez 1979), and P. implexus (Rindsberg 1994). Psammichnites plummeri is the most common Carboniferous ichnospecies and is characterized by a relatively straight, continuous dorsal ridge/groove, fine transverse ridges, larger size range, and non-looping geometric pattern. It represents a grazing trace of deposit feeders. Psammichnites grumula differs from the other ichnospecies of Psammichnites by having median dorsal holes or protruding mounds. The presence of mounds or holes in P. grumula suggests a siphon that was regularly connected to the sediment-water interface. This ichnospecies is interpreted as produced by a deposit feeder using the siphon for respiration or as a device for a chemosymbiotic strategy. Psammichnites implexus is characterized by its consistently smaller size range, subtle backfill structure, and tendency to scribble. Although displaying similarities with Dictyodora scotica , P. implexus is a very shallow-tier, grazing trace. Changes in behavioral pattern, preservational style, and bedform morphology suggest a complex interplay of ecological and taphonomic controls in Carboniferous tidal-flat Psammichnites . A first distributional pattern consists of guided meandering specimens preserved in ripple troughs, probably reflecting food-searching of buried organic matter concentrated in troughs. A second is recorded by concentration of Psammichnites on ripple crests and slopes. In some cases, the course is almost straight to slightly sinuous and closely follows topographic highs, suggesting a direct control of bedform morphology on trace pattern. Occurrences of Carboniferous Psammichnites most likely represent an opportunistic strategy in marginal-marine settings. Analysis of Carboniferous Psammichnites indicates the presence of a siphon-like device in the producer and reestablishes the possibility of a molluscan tracemaker.

Ichnos: An International Journal for Plant and Ani↗

USGS2016

Climate change implications for tropical islands: Interpolating and interpreting statistically downscaled GCM projections for management and planning

The potential ecological and economic effects of climate change for tropical islands were studied using output from 12 statistically downscaled general circulation models (GCMs) taking Puerto Rico as a test case. Two model selection/model averaging strategies were used: the average of all available GCMs and the average of the models that are able to reproduce the observed large-scale dynamics that control precipitation over the Caribbean. Five island-wide and multidecadal averages of daily precipitation and temperature were estimated by way of a climatology-informed interpolation of the site-specific downscaled climate model output. Annual cooling degree-days (CDD) were calculated as a proxy index for air-conditioning energy demand, and two measures of annual no-rainfall days were used as drought indices. Holdridge life zone classification was used to map the possible ecological effects of climate change. Precipitation is predicted to decline in both model ensembles, but the decrease was more severe in the “regionally consistent” models. The precipitation declines cause gradual and linear increases in drought intensity and extremes. The warming from the 1960–90 period to the 2071–99 period was 4.6°–9°C depending on the global emission scenarios and location. This warming may cause increases in CDD, and consequently increasing energy demands. Life zones may shift from wetter to drier zones with the possibility of losing most, if not all, of the subtropical rain forests and extinction risks to rain forest specialists or obligates.

Puerto Rico↗

USGS2019

Reduced soil macropores and forest cover reduce warm-season baseflow below ecological thresholds in the upper Delaware River Basin

We examined the impacts of changes in land cover and soil conditions on the flow regime of the upper Delaware River Basin using the Water Availability Tool for Environmental Resources (WATER). We simulated flows for two periods, circa 1600 and 1940, at three sites using the same temperature and precipitation conditions: the East Branch (EB), West Branch (WB), and mainstem Delaware River at Callicoon, NY. The 1600 period represented pristine forest and soils. The 1940 period included reduced forest cover, increased agriculture, and degraded soils with reduced soil macropore fractions. A model-sensitivity test examined the impact of soil macropore and land cover change separately. We assessed changes in flow regimes between the 1600 and 1940 periods using a variety of flow statistics, including established ecological limits of hydrologic alteration (ELOHA) thresholds. Reduced forest soil macropore fraction significantly reduced summer and fall base flows. The 1940 period had significantly lower Q50 flows (50% exceedance) than the 1600 period, as well as summer and fall Q90 and Q75-90 flows below the ELOHA thresholds. The 1- to 7-day minimum flows were also lower for the 1940 period, by 17% on the mainstem. 1940 flows were 6% more likely than the 1600 period to fall below the low-flow threshold for federally endangered dwarf wedgemussel (Alasmidonta heterodon) habitat. In contrast, the 1940 period had higher flows than the 1600 period from late fall to early winter.

New York, Pennsylvania↗

USGS1979

Exploitation of marine mammals: r-selection of K-strategists?

The importance of marine mammals as predators to the organization of marine communities is poorly known, although in several structurally analogous systems the ecological and evolutionary roles of predators are known to be of considerable importance. Occupation of the marine environment by mammals probably carried physiological constraints for single-young pregnancies thereby limiting all species to low intrinsic rates of population increase. As such, species subjected to high mortality rates from predation or other natural disturbances became extinct; those that survived probably were largely resource limited. In view of this scenario it is suggested that stable populations of marine mammals can be maintained at high levels without being manipulated in most communities. Exploitation probably constitutes a rather dramatic environmental change to marine mammals consequently subjecting them to selective forces fundamentally different from many of those under the influence of which they evolved.

Journal of the Fisheries Research Board of Canada↗

USGS2018

Applying recreation ecology science to sustainably manage camping impacts: A classification of camping management strategies

Wilderness and other protected natural areas such as national forests, parks, and refuges are managed to provide high-quality recreational opportunities while preserving natural resource conditions. In managing recreation visitation, land managers could allow visitors to create their own infrastructure of trails and campsites, or they could choose to apply an impact management strategy to provide an infrastructure that includes sustainably designed trails and campsites. Recreation ecology studies have repeatedly demonstrated that informal “visitor-created” trails and campsites are generally not sustainably designed or located (Cole 1981, 1982a, 2013; Marion 2016; Wimpey and Marion 2011). For example, informal trails frequently occur in flat terrain where trail widening and muddiness can be chronic problems, or are fall-aligned (perpendicular to contour lines) in sloping terrain, where they are considerably more vulnerable to soil loss and widening (Marion et al. 2016; Marion and Wimpey 2017). Similarly, visitors are highly attracted to flat terrain near water for camping, where they frequently create substantial numbers of large and unnecessary campsites at densities that threaten visitor solitude, experiential qualities, and natural resources.

International Journal of Wilderness↗

USGS2017

Conservation status of an imperiled crayfish, Faxonius marchandi Hobbs, 1948 (Decapoda: Cambaridae)

We summarize the distribution, ecology, threats, and conservation status of Faxonius marchandi ( Hobbs, 1948 ), the Mammoth Spring crayfish, a limited-range endemic species to the Spring River drainage of Missouri and Arkansas, USA. The species is known from 51 locations on lower-order perennial and intermittent streams in only the eastern portion of the drainage. Faxonius marchandi is found in larger rocky substrates in shallower, slower-velocity habitats of well-buffered, mineral-rich streams. The invading alien crayfish Faxonius neglectus chaenodactylus ( Williams, 1952 ) is the most likely threat to F . marchandi . These compiled data should serve as a baseline for future comparison, and facilitate discussion about future management, conservation, and research efforts.

Arkansas, Missouri↗

USGS2026

Gerrard strain Rainbow Trout are not piscivorous in a shallow, polymictic reservoir

Objective Georgetown Lake (Montana, USA) is renowned for its multispecies salmonid fishery. Although many anglers target kokanee Oncorhynchus nerka in Georgetown Lake, the body length of kokanee has typically been considered unsatisfactory. To reduce the density of kokanee and increase the average size, Montana Fish, Wildlife & Parks began stocking the piscivorous Gerrard strain of Rainbow Trout O. mykiss (hereafter “Gerrard”) in 2015 to consume kokanee. In 2020, preliminary evidence suggested that the average length of kokanee greater than 200 mm increased by almost 40 mm. Methods To assess the efficacy of biocontrol through the introduction of a piscivore to predate on kokanee, we examined the diet composition of all potential predators (three strains of Rainbow Trout and Brook Trout Salvelinus fontinalis ) to determine the amount of predation on kokanee and to understand the feeding ecology of all potential predators. Results There was little evidence of piscivory in any predator and no evidence of Gerrards consuming kokanee. Gerrards exhibited a generalist feeding strategy, and there was dietary overlap and no difference in trophic position among Gerrards and other predators. Conclusions From a biological-control perspective, there is no benefit in continuing to stock Gerrards to reduce kokanee densities in Georgetown Lake. These findings underscore the challenge of predicting predator–prey relationships, as diet plasticity can lead to unexpected dynamics based on resource availability and habitat structure within aquatic ecosystems, highlighting the importance of evaluating management interventions, such as biocontrols, in different ecosystems.

Montana↗

USGS2023

Learning from arid and urban aquatic ecosystems to inform more sustainable and resilient futures

The hydrology and aquatic ecology of arid environments has long been understudied relative to temperate regions. Yet spatially and temporally intermittent and ephemeral waters characterized by flashy hydrographs typify arid regions that comprise a substantial proportion of the Earth. Additionally, drought, intense storms, and human modification of landscapes increasingly affect many temperate regions, resulting in hydrologic regimes more similar to aridlands. Here we review the contributions of Dr. Nancy Grimm to aridland hydrology and ecology, and applications of these insights to urban ecosystems and resilience of social-ecological-technological systems. Grimm catalyzed study of nitrogen cycling in streams and characterized feedbacks between surface water-groundwater exchange, nitrogen transformations, and aquatic biota. In aridlands, outcomes of these interactions depend on short- and long-term variation in the hydrologic regime. Grimm and colleagues applied hydrological and biogeochemical insights gained from study of aridland streams to urban ecosystems, integrating engineering, social and behavioral sciences, and geography. These studies evolved from characterizing the spatial heterogeneity of urban systems (i.e., watersheds, novel aquatic systems) and its influence on nutrient dynamics to an approach that evaluated human decision-making as a driver of disturbance regimes and changes in ecosystem function. Finally, Grimm and colleagues have applied principles of urban ecology to look toward the future of cities, considering scenarios of sustainable and resilient futures. We identify cross-cutting themes and approaches that have motivated discoveries across Grimm’s multi-decadal career, including spatial and temporal heterogeneity, hydrologic connectivity and regime, disturbance, systems thinking, and resilience. Finally, we emphasize Grimm’s broad contributions to science via support of long-term research, dedication to mentoring, and extensive collaborations that facilitated transdisciplinary research.

Journal of Hydrology↗

USGS2002

The Protected Areas Visitor Impact Management (PAVIM) framework: A simplified process for making management decisions

Ecotourism and protected area visitation in Central and South America have resulted in ecological impacts, which some protected areas managers have addressed by employing visitor impact management frameworks. In this paper, we propose the Protected Area Visitor Impact Management (PAVIM) framework as an alternative to carrying capacity and other frameworks such as Limits of Acceptable Change. We use a set of evaluation criteria to compare the relative positive and negative attributes of carrying capacity, other decision-making frameworks and the new framework, within the context of their actual and potential use in Central and South America. Positive attributes of PAVIM include simplicity, flexibility, cost effectiveness, timeliness and incorporating input from stakeholders and local residents. Negative attributes include diminished objectivity and cultural sensitivity issues. Further research and application of PAVIM are recommended.

Journal of Sustainable Tourism↗

USGS2019

Life-history variation of two inland salmonids revealed through otolith microchemistry analysis

Increasingly, otolith microchemistry analysis is used as a tool to trace fish migrations, especially migrations of diadromous fishes. Yet, few studies have used otolith microchemistry to trace migrations in small inland watersheds, leaving major knowledge gaps in our understanding of inland fish spatial ecology. Here, we evaluate the use of tributary habitat for spawning and describe and compare fluvial brown trout ( Salmo trutta ) and rainbow trout ( Oncorhynchus mykiss ) natal origin distribution, time spent in natal streams, and spawning site fidelity. 63% of rainbow trout and 57% of brown trout migrated after hatching. Brown trout showed greater variation in time spent in natal tributaries, suggesting that individuals are temporally distributing risk among offspring. By contrast, rainbow trout showed greater variation in natal origin, suggesting that individuals are spatially distributing risk among offspring. Our results indicate there is high inter- and intraspecific migration variation in inland salmonid populations, which may be linked to access to a mosaic of spawning and rearing habitat types.

Colorado, Wyoming↗

USGS2021

Campfire Conversations at the 2020 annual meeting: Insights & lessons learned from “cuss-and-discuss” rather than “chalk-and-talk”

• The 2020 SRM Annual Meeting piloted “Campfire Conversation,” round-table discussions styled after the World Café approach. • The event attracted 280 attendees and enabled multidirectional knowledge exchange (i.e., “cuss and discuss”), rather than one-way “chalk-and-talk.” Attendees participated in three 20-minute facilitated round-table discussions around three topics they selected from a menu of 13 timely rangeland issues. • Change was a common theme for many Campfire Conversations, including social, climatic, ecological, management, and policy changes. • Participants highlighted a desire for SRM to grow as an organization by enhancing members’ opportunities and resources for multidirectional knowledge exchange among students, scientists, practitioners, and policy-makers; cross-generational mentorship; cross-disciplinary training; diverse ways of knowing; and greater inclusivity and connection to the SRM. • A post-event analysis of the Campfire Conversation event revealed valuable lessons for organizing successful World Café-style sessions at future SRM meetings, including virtual meetings.

The Rangelands Journal↗

USGS1996

Movement patterns of wintering lesser scaup in Grand Calumet River - Indiana Harbor Canal, Indiana

Lesser scaup ( Aythya affinis ) winter in the Grand Calumet River—Indiana Harbor Canal (GCR-IHC) drainage into southern Lake Michigan, a polluted oasis in the highly urban and industrial corridor of northern Illinois and Indiana. The GCR-IHC is an important wintering area for lesser scaup in northwestern Indiana, especially after Lake Michigan freezes, because of the lack of other wildlife habitat in the area. We investigated the feeding and movement patterns of these wintering lesser scaup to better understand the ecological significance of this area to wintering waterfowl and to interpret contaminant levels in these lesser scaup. We implanted radio transmitters in 20 individuals in January 1994 and tracked them until early March 1994. Four lesser scaup disappeared and four died within the first 2 weeks after implantation; 12 lesser scaup remained in the GCR-IHC for the next 6–7 weeks. Individual radio-marked scaup (n = 12) were located in the GCR-IHC on an average of 62.2% (extreme values = 25–87%) of the searches. No radio-marked lesser scaup were located outside the GCR-IHC. Lesser scaup were feeding during 23% of the radio fixes.

Journal of Great Lakes Research↗

USGS2015

Final project memorandum: sea-level rise modeling handbook: resource guide for resource managers, engineers, and scientists

Coastal wetlands of the Southeastern United States are undergoing retreat and migration from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. Much of the literature describing potential sea-level rise projections and modeling predictions are found in peer-reviewed academic journals or government technical reports largely suited to reading by other Ph.D. scientists who are more familiar or engaged in the climate change debate. Various sea-level rise and coastal wetland models have been developed and applied of different designs and scales of spatial and temporal complexity for predicting habitat and environmental change that have not heretofore been synthesized to aid natural resource managers of their utility and limitations. Training sessions were conducted with Federal land managers with U.S. Fish and Wildlife Service, National Park Service, and NOAA National Estuarine Research Reserves as well as state partners and nongovernmental organizations across the northern Gulf Coast from Florida to Texas to educate and to evaluate user needs and understanding of concepts, data, and modeling tools for projecting sea-level rise and its impact on coastal habitats and wildlife. As a result, this handbook was constructed from these training and feedback sessions with coastal managers and biologists of published decision-support tools and simulation models for sea-level rise and climate change assessments. A simplified tabular context was developed listing the various kinds of decision-support tools and ecological models along with criteria to distinguish the source, scale, and quality of information input and geographic data sets, physical and biological constraints and relationships, datum characteristics of water and land elevation components, utility options for setting sea-level rise and climate change scenarios, and ease or difficulty of storing, displaying, or interpreting model output. The handbook is designed to be a primer to understanding sea-level rise and a practical synthesis of the current state of knowledge and modeling tools as a resource guide for DOl land management needs and facilitating Landscape Conservation Cooperative (LCC) research and conservation initiatives.

Conference Paper↗