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At least 1,117 records · Page 62Linked to original sources
USGS2018

Ecological resilience indicators for mangrove ecosystems

Mangrove ecosystems are coastal wetland ecosystems dominated by mangrove species that are typically found in the intertidal zone, characterized by frequently flooded saline soil conditions. The majority of the approximately 500,000 acres of mangrove ecosystem in the United States occurs in the NGoM, and almost all of that is in Florida, with over 90 percent in the four southern counties of Lee, Collier, Miami-Dade, and Monroe. Scattered stands and individuals occur north and westward into Louisiana and Texas (Osland et al., 2016). The three common mangrove species are: black mangrove (Avicennia germinans), white mangrove (Laguncularia racemosa), and red mangrove (Rhizophora mangle). The mangrove system described in this project includes Tidal Mangrove Shrubland and Tidal Mangrove Forest as classified in CMECS (FGDC, 2012). It is classified as Caribbean Fringe Mangrove (G004) in the USNVC (2016), with a variety of distinct associations, based on species dominance and ecological setting.

Book chapter↗
USGS2018

Ecological resilience indicators for salt marsh ecosystems

Salt marshes are coastal ecosystems within the intertidal zone, characterized by hypoxic, saline, soil conditions and low biodiversity. Low diversity arises from frequent disturbance and stressful conditions (i.e., high salinity and hypoxia), where vegetative reproduction and low competition result in mostly monotypic stands, with some differences in plant community influenced by flooding regime (described below). While there are several types of salt marshes in the Northern Gulf of Mexico (NGoM), ranging from low to high salt marshes and salt flats (Tiner, 2013), Spartina alterniflora–dominated salt marshes in the Coastal and Marine Ecological Classification Standard (CMECS) Low and Intermediate Salt Marsh Biotic Group (FGDC, 2012) are the most extensive and are the focus of this project. These salt marshes are classified as “Gulf Coast Cordgrass Salt Marsh” (CEGL004190; USNVC, 2016). Within the NGoM region, some salt marsh areas are dominated by other species such as Spartina patens and Juncus roemerianus, which both occupy higher elevations in high-precipitation zones (e.g., Louisiana, Alabama, Mississippi, and Florida). In lower precipitation regions (southern Texas), hypersaline conditions often develop yielding communities of succulent salt marsh plants (Batis and Salicornia spp.). In climatic zones with warmer winter temperatures, temperate salt marshes naturally transition to mangrove (generally in the southern Gulf of Mexico range) or, in areas with lower precipitation, to salt flats (generally in western part of the study area).

Gulf of Mexico↗
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↗
USGS2006

Ecological consequences of changing hydrological conditions in wetland forests of coastal Louisiana

Large-scale and localized alterations of processes affecting deltaic coastal wetlands have caused the complete loss of some coastal wetland forests and reduced the productivity and vigor of many areas in coastal Louisiana. This loss and degradation threatens ecosystem functions and the services they provide. This paper summarizes ecological relationships controlled by hydrological processes in coastal wetland forests of the Mississippi River delta and presents two case studies that illustrate the complexity of assessing hydrological control on swamp forest establishment and growth. Productivity of overstory trees has been affected by these changes, but the first case study illustrates that the relationship between flooding and growth may be site-specific. An important effect of increased flooding has been to reduce regeneration of swamp forest trees. The second case study is an outline of the kind of hydrological analysis required to assess probability of regeneration success.

Louisiana↗
USGS1992

Ecology of band-tailed pigeons in Oregon

The ecology of band-tailed pigeons ( Columba fasciata ) was investigated in western Oregon to assess the roles of survival and recruitment to population status and the relation of food, minerals, and diet to reproduction strategy. Band-tailed pigeons congregated at mineral deposits to consume minerals from mid-June to mid-September. Males generally arrived and departed between daylight and 1000 h and females between 0930 and 1200 h, the inverse of the nest attentive schedules for the sexes. The pigeons used one or several adjacent mineral sites throughout the summer and most returned to the same mineral site in subsequent years. Band-tailed pigeons were resident from April through September; migration apparently did not begin before late September. Three indirect sources of evidence indicated that fledging began in June, reached a peak in mid- August, and continued until late September. Second year (SY) band-tailed pigeons apparently began nesting later than and were about one-third as productive as adults. In Oregon, most of the adult population could fledge as many as two young over the 100-110-day nesting period, resulting in a maximum potential recruitment of 47-50% juveniles. We estimated that the fall population contained about 23% juveniles, 12% yearlings, and 65% adults. Mean annual survival of adults was 63.7%, but was year-specific. To maintain a stable population with the estimated survival rates required production near the biotic potential (40.8%). Conversely, a stable population could be attained with the estimated rate of recruitment (23%) and high but realistic rates of survival (adults, 83%; juveniles, 68%). Counts of band-tailed pigeons at mineral sites in Oregon indicated that the population had undergone two periods of modest increase (2.4-7.1% per year) and two periods of sharp decline (10.4-11.1% per year). In 1988 the population index was only 34% of the 1950-88 average. Harvest of band-tailed pigeons in the three Pacific Coast states averaged 414,000 from 1957 to 1983; about 55% of the harvest took place in California, 23% in Washington, and 22% in Oregon. In Oregon, about 65% of the harvest took place in the first 10 days of September and 40% was at mineral sites. Fewer juveniles were shot at mineral sites (13%) than at feeding areas (25%). Hunting at mineral sites was directed at experienced breeders and may be particularly detrimental to the population. However, the overall effect of hunting on abundance was not determined. Band-tailed pigeons fed extensively on elder ( Sambucus spp.) and cascara buckthorn ( Rhamnus purshiana ) berries while nesting. The emergence of Pacific red elder (S. callicarpa) berries in June provided the food resources necessary for initiation of reproduction in Oregon, and probably throughout the Northwest. Elder berries contain little calcium (0.06-0.12%), therefore, the pigeons in the Northwest may require a mineral supplement in their diet. Mineral sites may be the scarcest resource required for reproduction by band-tailed pigeons in the Northwest.

Oregon↗
USGS2017

Are nest boxes ecological traps for red-footed falcons Falco vespertinius at Naurzum

Nest box programs are frequently implemented for conservation of cavity-nesting birds, but their effectiveness is rarely evaluated in comparison to birds not using nest boxes. In the European Palearctic, Red-Footed Falcon ( Falco vespertinus ) populations are both of high conservation concern and are strongly associated with nest box programs in heavily managed landscapes. We used a 21-year monitoring dataset developed from monitoring 753 nesting attempts by Red-footed Falcons at the Naurzum Zapovednick to evaluate response of demographic parameters of Redfooted Falcons to environmental factors including use of nest boxes. Variations in lay date and in numbers of eggs were not well explained by any one model, but instead by combinations of models with terms for nest type, land cover type and degree of coloniality. In contrast, variation in both offspring loss and numbers of fledglings produced were fairly well explained by a single model including terms for nest type, land cover type, and an interaction between the two parameters (65% and 81% model weights respectively). Because, for other species, early lay dates are associated with individual fitness, this interaction highlighted a potential ecological trap where falcons using nest boxes on forest edges at Naurzum lay eggs earlier but suffer greater offspring loss and produce lower numbers of fledglings than do those in other nesting settings.

Kostanay Oblast↗
USGSDate not supplied

The ecology of Humboldt Bay, California, an estuarine profile

Synthesizes data on the ecological relationships and functions of the estuary, including information on physical aspects of the bay environment; describes the biotic communities and their relationships; provides management considerations in terms including environmental concerns; and identifies research and management information gaps. Portions of the bay are managed as a national wildlife refuge. Management issues for this ecosystem include loss of habitat and degradation of the environment by additional industrial development and nonpoint source pollution. -from Authors

California↗
USGS2020

Habitat suitability and ecological associations of two non-native ungulate species on the Hawaiian island of Lanai

The ability to effectively manage game species for specific conservation objectives is often limited by the scientific understanding of their distribution and abundance. This is especially true in Hawai‘i where introduced game mammals are poorly studied and have low value relative to native species in other states. We modeled the habitat suitability and ecological associations of European mouflon sheep (“mouflon”; Ovis musimon ) and axis deer ( Axis axis ) on the island of Lāna‘i using intensive aerial survey and environmental data that included climate, vegetation, and topographic variables. We conducted diagnostic tests on a suite of primarily categorical predictors and determined most were highly correlated. We therefore developed a suite of other spatial predictor layers with continuous variables. We tested several modeling approaches but settled on generalized linear models (GLM) and random GLMs because they could account for group size of animals and were based on curvilinear responses of each species to environmental variability. Both mammal species were habitat generalists showing little affinity to particular plant species or communities. Continuous predictors associated with plant productivity such as mean annual precipitation, normalized difference vegetation index (NDVI), and cloud cover were important explanatory factors in a GLM of axis deer and a random GLM of mouflon habitat suitability. The presence of axis deer was also an important explanatory predictor for mouflon distribution, but deer were not influenced by mouflon distribution, indicating asymmetrical competition. Consequently, mouflon were restricted to lower elevation arid and very dry slopes, whereas axis deer were more broadly distributed throughout other upland environments of the island, but avoided steep terrain. Findings indicate that removal of a substantial portion of the more abundant axis deer population may lead to an increase in abundance and distribution of mouflon without containment. Resulting spatial models of game mammal habitat suitability will be employed to inform land use prioritization analyses and to help resolve long-standing conflicts between native species conservation and sustained-yield hunting.

Hawai'i↗
USGS2020

Ecology of urban climates: The need for landscape biophysics in cities

In this chapter we will review and evaluate the climatic and ecological parallels between urbanization and climate change, with an emphasis on temperature and its effects on terrestrial ectotherms, a group of organisms thought to be particularly sensitive to climate change. We will summarize patterns of urban warming and how they relate to global climate change projections, then discuss the potential strengths and limitations of urban climates as a source of insight into biotic responses to climate change and highlight future research directions. Future work will benefit from explicit consideration of the mechanisms by which urbanization and urban warming drive ectotherms’ body temperatures and activity periods. Urban ecosystems may provide a valuable first approximation of the dramatic effects of warming on certain terrestrial systems, and continued advances in urban thermal biology will promote a mechanistic understanding of how organisms use, respond to, and adapt to the unique thermal landscapes of cities.

Book chapter↗
USGS2021

Cloud water interception in Hawai‘i: Developing capacity to characterize the spatial patterns and effects on water and ecological processes responses in Hawai‘i

Cloud-water interception (CWI) is the process by which fog or cloud water droplets are captured and accumulate on the leaves and branches of plants, some of which drips to the ground. Prior studies in Hawai'i indicate that CWI is highly variable and can contribute substantially to total precipitation. In this study, we monitored CWI and other processes at five mountain field sites on the Islands of Oʻahu, Maui, and Hawaiʻi to explore how CWI (1) varies with different climate and vegetation characteristics, (2) affects plant water use and growth, and (3) contributes to water resources. Results show that annual CWI varied from 158 to 910 mm, accounting for 3-34% of total water input at individual sites. This large variation was caused by differences in the quantity of cloud water, wind speed, and vegetation structure between sites. We developed a model to predict CWI using both climatic and forest canopy characteristics. On average, the model underestimated annual CWI by 18%, but reproduced the site differences relatively well. Plant water use decreased during periods of fog events mainly because of associated higher humidity. This new CWI model can be used to assess impacts of climate and land cover change on CWI and provide valuable information for resource management in Hawai‘i, which was not previously possible. At one field site, we explored the impacts of fog water on hydrological and ecological processes. Fog effects on native plant growth were indirect, primarily buffering effects of solar radiation. Removal of grass allowed natural regeneration of seedlings but did not alter soil moisture values. A soil data-collection program was initiated to help evaluate the role CWI has in providing moisture for plants, reducing wildfire risk within the fog zone, and contributing to groundwater recharge to aquifers that supply drinking water and groundwater discharge to streams.

Hawaii↗
USGS2021

Using structured decision making to incorporate ecological and social values into harvest decisions: Case studies of white-tailed deer and walleye

Harvest decisions for fish and wildlife populations often include conflicting ecological, economic, and social values. Using decision analysis, such as structured decision making and adaptive management, as a framework to aid decision makers in multi-objective decision making for setting harvest regulations can lead to a more transparent and resilient decision. The process includes opportunities for inclusion of stakeholders’ concerns, either through multi-party workshops or the use of social science techniques to elicit objectives (i.e., values) and predict consequences of management actions. The authors present two case studies of using decision analysis to determine stakeholders’ objectives, identify alternative harvest strategies, predict the consequences of these alternatives on all objectives, and analyze tradeoffs among objectives. A case study of white-tailed deer ( Odocoileus virginianus ) in New York State provides an example of combining predictive population modeling and implementation of survey instruments statewide to determine optimal region-specific harvest regulations. Harvest management of walleye ( Sander vitreus ) provides an example of the inclusion of commercial and recreational angler groups in a series of workshops to make decisions about harvest quotas for one of the world’s largest freshwater fisheries.

Book chapter↗
USGS2021

Identifying the ecological and management implications of mangrove migration in the northern Gulf of Mexico

Climate change is transforming ecosystems and affecting ecosystem goods and services. Along the Gulf of Mexico and Atlantic coasts of the southeastern United States, the frequency and intensity of extreme freeze events greatly influences whether coastal wetlands are dominated by freeze-sensitive woody plants (mangrove forests) or freeze-tolerant grass-like plants (salt marshes). In response to warming winters, mangroves have been expanding and displacing salt marshes at varying degrees of severity in parts of north Florida, Louisiana, and Texas. As winter warming accelerates, mangrove range expansion is expected to increasingly modify wetland ecosystem structure and function. Because there are differences in the ecological and societal benefits that salt marshes and mangroves provide, coastal environmental managers are challenged to anticipate effects of mangrove expansion on critical wetland ecosystem services, including those related to carbon sequestration, wildlife habitat, storm protection, erosion reduction, water purification, fisheries support, and recreation. This project produced information that is relevant to scientists and coastal resource managers working within the transition zone between mangrove forests and salt marshes. The two primary products are: (1) an investigation that leverages data and information from a community-curated data network called the Mangrove Migration Network to refine temperature thresholds for mangrove range expansion in a warming climate; and (2) a review article that examines current understanding of the effects of mangrove range expansion and displacement of salt marshes on wetland ecosystem services, including those related to carbon sequestration, wildlife habitat, storm protection, erosion reduction, water purification, fisheries support, and recreation.

Alabama, Florida, Louisiana, Mississippi, Texas↗
USGS1978

An evaluation of errors in mapping land use changes for the Central Atlantic Regional Ecological Test Site

Land use change maps prepared from high-resolution, high-altitude aerial photographs for the period 1970 to 1972 of the CARETS (Central Atlantic Regional Ecological Test Site) project were analyzed for accuracy. To test for errors of commission, all outlined areas (polygons) of land use change on five l:100000-scale maps were examined for accuracy. An estimate of the errors of omission was obtained by comparing the land use change polygons mapped for the Norfolk SMSA (Norfolk and Virginia Beach Standard Metropolitan Statistical Area) with the changes mapped in a more detailed study of the same area. The results of these studies showed that the largest number of errors was caused by misregistration of the land use change map to the 1970 land use map; however, only a very small percentage of the total land area of the land use change was affected by misregistration. In the Norfolk SMSA, which is an area of rapid urban growth, many of the land use changes had not been mapped. The conclusion is that quality control checks are necessary both during and after map compilation. The experience of the CARETS and other land use mapping experiments conducted in the early 1970's has resulted in the development of carefully designed quality-control procedures implemented in the nationwide mapping of land use and land cover currently being carried out by the U.S. Geological Survey.

Maryland, Virginia↗
USGS2024

A review of the ecology and conservation biology of Sali (Micronesian Starling, Aplonis opaca guami) on Guam

The accidental introduction of the Brown Treesnake (BTS, Boiga irregularis ) to Guam following World War II led to the extinction, extirpation, or severe decline of most of Guam’s native avifauna. One forest bird species that managed to persist is the cavity-nesting Såli (Micronesian Starling, Aplonis opaca guami ), a once-ubiquitous native omnivore whose current Guam distribution is restricted primarily to urbanized areas in the northern half of the island, with a second much smaller population on Cocos Island off southern Guam. Såli on Guam breed year-round and are habitat generalists with large home ranges. Besides arthropods and small vertebrates, they consume fruit from a wide range of native and introduced plant species and are key seed dispersers within the local ecosystem. Såli on Guam suffer extremely high post-fledging mortality due to predation by BTS and cats, leading to a population age structure strongly skewed towards adult birds. Other threats include habitat loss and degradation, extreme weather events, and sea level rise. Key management activities aimed at restoring this species include predator control, while non-native ungulate removal and vegetation management may be undertaken to support broader ecological recovery. This species account on Såli provides a review of the literature on this species, synthesizing information on habitat use, life history, and demographics to provide a biological foundation for future recovery efforts.

Micronesica↗
USGS2003

Wolves: Behavior, ecology, and conservation

Wolves are some of the world's most charismatic and controversial animals, capturing the imaginations of their friends and foes alike. Highly intelligent and adaptable, they hunt and play together in close-knit packs, sometimes roaming over hundreds of square miles in search of food. Once teetering on the brink of extinction across much of the United States and Europe, wolves have made a tremendous comeback in recent years, thanks to legal protection, changing human attitudes, and efforts to reintroduce them to suitable habitats in North America. As wolf populations have rebounded, scientific studies of them have also flourished. But there hasn't been a systematic, comprehensive overview of wolf biology since 1970. In Wolves , many of the world's leading wolf experts provide state-of-the-art coverage of just about everything you could want to know about these fascinating creatures. Individual chapters cover wolf social ecology, behavior, communication, feeding habits and hunting techniques, population dynamics, physiology and pathology, molecular genetics, evolution and taxonomy, interactions with nonhuman animals such as bears and coyotes, reintroduction, interactions with humans, and conservation and recovery efforts. The book discusses both gray and red wolves in detail and includes information about wolves around the world, from the United States and Canada to Italy, Romania, Saudi Arabia, Israel, India, and Mongolia. Wolves is also extensively illustrated with black and white photos, line drawings, maps, and fifty color plates.

Book↗
USGS1979

Ecological and physiological/toxicological effects of petroleum on aquatic birds: A summary of research activities FY76 through FY78

Oil and gas development and exploration in marine coastal areas and the Great Lakes will result in unavoidable spills of polluting oil. Although large oil spills may kill thousands of birds and stimulate much public concern, the bulk of oil that reaches aquatic environmentS released in the course of normal operations, with a total input into the world's oceans estimated at 6 million metric tons per year. The effects of sublethal low-level oil pollution may be more deleterious to bird populations over the long term than the spectacular bird kills resulting from oil spills. The physiological and ecological effects of oil on waterbirds were examined in a series of laboratory and field experiments, including studies of the effects of oiling on hatchability of eggs; the effects of an oil-contaminated diet on physiological condition, reproduction, and survival; and the accumulation of oil in body tissues. Chemical methodology was developed in support of these studies.

FWS/OBS↗
USGS2002

Landscape ecology of plague in the American southwest, September 19-20, 2000, Fort Collins, Colorado

During September 19-20, 2000, a workshop titled "Landscape Ecology of Plague in the American Southwest" was held in Fort Collins, Colorado. The workshop was funded by the U.S. Geological Survey (USGS)-Earth Surface Processes Team and sponsored by the USGS National Wildlife Health Center. Forty scientists and natural resource managers and administrators representing 8 federal agencies, 4 state agencies, 6 universities, and other local agencies and nongovernment organizations met to discuss historical and current status of plague in the United States, current activities in plague surveillance, research, and management in wildlife, and research and information needs relative to plague control and management. Eleven individual presentations on plague history, status, and trends; diagnostic technologies; epizootiological studies and observations; and control and management strategies and studies, followed by a panel discussion on the impact of plague on wildlife and ecosystems, led the way to extensive group discussions on important plague-related questions, issues and problems. Workshop attendees participated in identifying important research and information needs relevant to control and management of plague in wildlife, and in the process, established new cooperative and collaborative partnerships and enhanced existing relationships upon which future research and information needs can be met. The proceedings from this workshop are intended to be used by the natural resource managers and researchers from the various participating agencies, research facilities, as well as other stakeholders to aid in the development of future research and information programs and funding initiatives related to both zoonotic and sylvatic plague.

American Southwest↗
USGS2020

Population ecology and spatial synchrony in abundance within and among populations of valley oak (Quercus lobata) leaf gall wasps

What factors drive population variability through space and time? Here we assess patterns of abundance of seven species of gall wasps in three genera occurring on the leaves of valley oaks ( Quercus lobata ) at 10 sites throughout this species' statewide range in California, from 2000 to 2006. Our primary goals were to understand the factors driving variability in gall abundance and to assess the extent of spatial synchrony in gall wasp communities at both large and small geographic scales. On the large, statewide scale, there was significant site‐to‐site variation in gall abundance, driven in all cases primarily by differences in mean maximum seasonal temperatures, and lesser year‐to‐year variation. In contrast, on the small, local scale, differences were more pronounced from year to year than from tree to tree, and were to some extent correlated with differences in acorn production, suggesting an interaction with the reproductive effort of hosts. Significant spatial synchrony was detected, particularly at the statewide scale, but in no case did synchrony decline significantly with distance, despite sites being up to 741 km apart. Variation in spatial synchrony was correlated with a number of exogenous factors, including seasonal weather conditions, the acorn crop at the statewide scale and soil phosphorus availability at the local scale; however, most variation in spatial synchrony in our analyses remained unexplained.

California↗