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At least 1,189 records · Page 66Linked to original sources
USGS2025

Supporting dryland restoration success with applied ecological forecasting of seeding outcomes

Introduction Ecological restoration is increasingly used to sustain biodiversity and ecosystem services. In drylands of the western United States (US), post-disturbance restoration often involves seeding treatments to promote the recovery of native plant communities. Spatial and temporal variability in environmental conditions influences plant establishment and contributes to low restoration success in certain locations and years. Objectives Here, we discuss how forecasts for plant establishment can be developed and delivered to help land managers anticipate the impacts of near-term (months to years) environmental conditions on restoration. Methods We developed an ecological forecast system that predicts the outcome of restoration seeding by integrating weather forecasts, an ecosystem water balance model, and plant establishment models. Results In this article, we focus on a conceptual approach to developing, delivering, and applying ecological forecasts for restoration. We illustrate the potential of this approach by adapting existing ecological models to build an initial version of a decision support tool that delivers a species-specific ecological forecast for big sagebrush ( Artemisia tridentata ) establishment. Integrating ecological forecasts into plans for restoration seeding presents opportunities to anticipate and account for environmental variability. Conclusions Finally, we discuss how connecting research, forecast delivery, and management can maximize the impact of ecological forecasts on restoration success.

Idaho, Nevada↗
USGS2022

Coupling near-surface geomorphology with mangrove community diversity at the estuarine scale: A case study at Dongzhaigang Bay, China

Coastal wetlands are key features of the Earth’s surface and are characterized by a diverse array of coupled geomorphological and biological processes. However, the links between the distribution of biodiversity (e.g., species and structural diversity) and the formation of coastal geomorphology are not well understood on a landscape scale most useful to coastal zone managers. This study describes the relationship between select geomorphological and biological mangrove community features (i.e., species composition and functional root type) in a landscape-distributed coastal zone of Dongzhaigang Bay, Northeastern Hainan Island, China. A total of 11 mangrove species and five functional aerial root types were encountered, with the location of species by root types being controlled by the elevation of the soil surface. Plank roots, prop roots, and pneumatophores occupied the lowest intertidal elevations, while knee roots and fibrous roots of the mangrove fern, Acrostichum aureum , preferred the highest intertidal elevations. Surface sediment deposition in areas with mangroves was greater than deposition in non-mangrove forest zones, establishing an important biological mechanism for this large-area response as surface erosion/compaction was also more prominent within mangrove roots. Indeed, functional root type influenced the magnitude of deposition, erosion, and compaction, with knee roots and pneumatophores being more effective in promoting deposition and preventing surface erosion/compaction than prop roots. These results indicate a potential role for vegetation type (especially functional root type) to influence coastal geomorphological processes at large landscape scales. While soil surface elevation is correlated to the distribution of mangrove species and functional root types, a significant feedback exists between elevation change and the capacity of those root types to influence coastal geomorphological differentiation within sustainable intertidal elevations. An enhanced understanding of geomorphological development, mangrove species distribution, and functional root type may improve management to support nature-based solutions that adjust more effectively to sea-level rise through feedbacks.

Houpai, Sanjiang, Tashi↗
USGS2021

Climate change and expanding invasive species drive widespread declines of native trout in the northern Rocky Mountains, USA

Climate change and invasive species are major threats to native biodiversity, but few empirical studies have examined their combined effects at large spatial and temporal scales. Using 21,917 surveys collected over 30 years, we quantified the impacts of climate change on the past and future distributions of five interacting native and invasive trout species throughout the northern Rocky Mountains, USA. We found that the occupancy of native bull trout and cutthroat trout declined by 18 and 6%, respectively (1993–2018), and was predicted to decrease by an additional 39 and 16% by 2080. However, reasons for these occupancy reductions markedly differed among species: Climate-driven increases in water temperature and decreases in summer flow likely caused declines of bull trout, while climate-induced expansion of invasive species largely drove declines of cutthroat trout. Our results demonstrate that climate change can affect ecologically similar, co-occurring native species through distinct pathways, necessitating species-specific management actions.

Montana↗
USGS2002

Climate warming and disease risks for terrestrial and marine biota

Infectious diseases can cause rapid population declines or species extinctions. Many pathogens of terrestrial and marine taxa are sensitive to temperature, rainfall, and humidity, creating synergisms that could affect biodiversity. Climate warming can increase pathogen development and survival rates, disease transmission, and host susceptibility. Although most host-parasite systems are predicted to experience more frequent or severe disease impacts with warming, a subset of pathogens might decline with warming, releasing hosts from disease. Recently, changes in El Niño–Southern Oscillation events have had a detectable influence on marine and terrestrial pathogens, including coral diseases, oyster pathogens, crop pathogens, Rift Valley fever, and human cholera. To improve our ability to predict epidemics in wild populations, it will be necessary to separate the independent and interactive effects of multiple climate drivers on disease impact.

Science↗
USGS2010

The impact of conservation on the status of the world's vertebrates

Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.

Science↗
USGS2016

Consistent response of bird populations to climate change on two continents

Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends.

Science↗
USGS2017

Plant diversity increases with the strength of negative density dependence at the global scale

Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.

Science↗
USGS2018

Past and future global transformation of terrestrial ecosystems under climate change

Impacts of global climate change on terrestrial ecosystems are imperfectly constrained by ecosystem models and direct observations. Pervasive ecosystem transformations occurred in response to warming and associated climatic changes during the last glacial-to-interglacial transition, which was comparable in magnitude to warming projected for the next century under high-emission scenarios. We reviewed 594 published paleoecological records to examine compositional and structural changes in terrestrial vegetation since the last glacial period and to project the magnitudes of ecosystem transformations under alternative future emission scenarios. Our results indicate that terrestrial ecosystems are highly sensitive to temperature change and suggest that, without major reductions in greenhouse gas emissions to the atmosphere, terrestrial ecosystems worldwide are at risk of major transformation, with accompanying disruption of ecosystem services and impacts on biodiversity.

Science↗
USGS2018

Trout in hot water: A call for global action

Trout are one of the most culturally, economically, and ecologically important taxonomic groups of freshwater fishes worldwide (1). Native to all continents in the Northern Hemisphere, trout are a taxonomically diverse group of fishes belonging to 7 genera (Oncorhynchus, Salvelinus, Salmo, Hucho, Parahucho, Brachymystax, and Salvethymus) distributed across 52 countries. These coldwater specialists provide recreation and food to millions of people, and play important roles in ecosystem functioning and health (2). They are also extremely sensitive to human disturbances because they require cold, clean, complex, and connected habitats for survival and persistence (3) – all attributes that humans have substantially altered and degraded (4, 5). Despite their broad importance as societal icons and as indicators of biodiversity, many of the world’s trout species and lineages are endangered and some require immediate conservation efforts to reverse their precarious decline.

Science↗
USGS2021

Mapping out a future for ungulate migrations

Migration of ungulates (hooved mammals) is a fundamental ecological process that promotes abundant herds, whose effects cascade up and down terrestrial food webs. Migratory ungulates provide the prey base that maintains large carnivore and scavenger populations and underpins terrestrial biodiversity (fig. S1). When ungulates move in large aggregations, their hooves, feces, and urine create conditions that facilitate distinct biotic communities. The migrations of ungulates have sustained humans for thousands of years, forming tight cultural links among Indigenous people and local communities. Yet ungulate migrations are disappearing at an alarming rate ( 1 ). Efforts by wildlife managers and conservationists are thwarted by a singular challenge: Most ungulate migrations have never been mapped in sufficient detail to guide effective conservation. Without a strategic and collaborative effort, many of the world's great migrations will continue to be truncated, severed, or lost in the coming decades. Fortunately, a combination of animal tracking datasets, historical records, and local and Indigenous knowledge can form the basis for a global atlas of migrations, designed to support conservation action and policy at local, national, and international levels.

Science↗
USGS2024

Environmental and societal consequences of winter ice loss from lakes

More than half a billion people live near lakes that freeze over in the winter. However, lakes are rapidly losing winter ice cover in response to warming, and the rate of loss has accelerated over the past 25 years. Hampton et al . reviewed the state of seasonal ice cover on lakes and discuss some of the consequences of its disappearance. Ice loss will affect culture, economy, water quality, fisheries, and biodiversity, as well as weather and climate. —Jesse Smith

Science↗
USGS2026

Forest canopy decline under elevated CO2 during the Paleocene-Eocene Thermal Maximum

Uncertainty remains regarding the impact of rapid anthropogenic warming on forest ecosystem structure, biodiversity, and function. As an analog, we reconstruct forest canopy density and compositional change in Wyoming, USA, through the Paleocene-Eocene Thermal Maximum (PETM), an interval of abrupt carbon increase and warming ~56 million years ago. We develop a proxy to quantify leaf area index and assess shifts in floral composition using palynomorphs. Forest canopies opened abruptly at onset of PETM warming, landscape erosion increased, and vegetation shifted from broad-leaved angiosperm to fern- and palm-dominated ecosystems. When combined with regional data, these patterns suggest that continental-scale changes in plant communities cause landscape destabilization. These shifts also have implications for multimillennial-scale hydrologic and carbon cycle feedbacks in the climate system.

Wyoming↗
USGS2021

Carcass deposition to suppress invasive lake trout causes differential mortality of two common benthic invertebrates in Yellowstone Lake

Invasive species require management to mitigate their harmful effects on native biodiversity and ecosystem processes. However, such management can also have negative, unintended consequences on non-target taxa, ecosystem processes, and food web dynamics. In Yellowstone Lake, invasive lake trout ( Salvelinus namaycush ) have caused a decline in the native Yellowstone cutthroat trout ( Oncorhynchus clarkii bouvieri ) population. To suppress the invader, lake trout carcasses are deposited on the species’ spawning sites, causing embryo mortality by reducing dissolved oxygen as they decay. The non-target effects of carcass treatment are unknown, but benthic invertebrates may be sensitive to reductions in dissolved oxygen. Benthic invertebrate taxa have varying hypoxia tolerances; caddisflies ( Trichoptera , family Limnephilidae ) are hypoxia sensitive while amphipods Gammarus lacustris and Hyallela azteca are hypoxia tolerant. Both are widespread and abundant in Yellowstone Lake and comprise a large proportion of fish diets, so changes in their abundances could alter food web dynamics. We conducted an in situ experiment to determine if carcass deposition causes mortality in these two taxa of benthic invertebrates. The probability of mortality for caddisflies was 3.15 times higher in carcass treatments as compared to controls, while amphipod mortality did not change in response to carcass treatment. Amphipods, which contribute most significantly to fish diets, are unlikely to be reduced in response to carcass deposition, which is confined to a small fraction of the lake where lake trout spawn, limiting the possibility for lake-wide effects. We conclude that carcass deposition is unlikely to alter the availability of invertebrates as a food source for fish in Yellowstone Lake.

Wyoming↗
USGS2013

Frequent cross-species transmission of parvoviruses among diverse carnivore hosts

Although parvoviruses are commonly described in domestic carnivores, little is known about their biodiversity in nondomestic species. A phylogenetic analysis of VP2 gene sequences from puma, coyote, gray wolf, bobcat, raccoon, and striped skunk revealed two major groups related to either feline panleukopenia virus (“FPV-like”) or canine parvovirus (“CPV-like”). Cross-species transmission was commonplace, with multiple introductions into each host species but, with the exception of raccoons, relatively little evidence for onward transmission in nondomestic species.

Alabama, Arkansas, Arizona, Colorado, Connecticut,↗
USGS2018

Large hydromagmatic eruption related to Fernandina Volcano’s 1968 caldera collapse—Deposits, landforms, and ecosystem recovery

The hydromagmatic eruption that immediately preceded the 1968 caldera collapse of Fernandina Volcano, Galápagos, which had a volcano explosivity index (VEI) of 4, offers a case study of powerful eruptions where basaltic magma interacts with caldera-ponded water. The 4-d-long hydromagmatic eruption sequence records an early stage and a small fraction of the volume of magmatic withdrawal that led the caldera floor to lower 350 m over the next 10 d. Erupted tephra was lithic-rich. The small proportion of juvenile basaltic glass included blocky fragments, Pele’s tears, and Pele’s hair. Pyroclastic density currents swept across the western summit plateau 600–700 m above the vent and deposited dunes, cross-bedded and rubbly breccia deposits, imbricated lag blocks, and ash plasters, and toppled trees. Blocks ejected out of the caldera formed impact craters on the volcano’s flank >600 m higher and >1 km away. Ejected blocks are mostly basalt but include cumulate olivine gabbro. The vent area enlarged by 300 × 106 m3 during the eruption. A small adjacent fault-bounded block subsided after the eruption. Lake water and groundwater confined within the caldera by ring dikes were available to interact with hot rocks and magma. In our interpretation, this water helped to trigger and feed the eruption by interacting with rocks above a lowering magma column. Ecosystems recovered rapidly on the tephra. Eruptions have not diminished the island’s biodiversity despite Fernandina’s high rate of volcanic activity, including the massive resurfacing in 1968. Stratigraphic evidence suggests that the 1968 eruption may be only the latest in a series of explosive eruptions from the caldera.

Book chapter↗
USGS2023

Sentinel responses of Arctic freshwater systems to climate: linkages, evidence, and a roadmap for future research

While the sentinel nature of freshwater systems is now well recognized, widespread integration of freshwater processes and patterns into our understanding of broader climate-driven Arctic terrestrial ecosystem change has been slow. We review the current understanding across Arctic freshwater systems of key sentinel responses to climate, which are attributes of these systems with demonstrated and sensitive responses to climate forcing. These include ice regimes, temperature and thermal structure, river baseflow, lake area and water level, permafrost-derived dissolved ions and nutrients, carbon mobilization (dissolved organic carbon, greenhouse gases, and radiocarbon), dissolved oxygen concentrations, lake trophic state, various aquatic organisms and their traits, and invasive species. For each sentinel, our objectives are to clarify linkages to climate, describe key insights already gained, and provide suggestions for future research based on current knowledge gaps. We suggest that tracking key responses in Arctic freshwater systems will expand understanding of the breadth and depth of climate-driven Arctic ecosystem changes, provide early indicators of looming, broader changes across the landscape, and improve protection of freshwater biodiversity and resources.

Arctic Science↗
USGS2017

Measuring fish and their physical habitats: Versatile 2D and 3D video techniques with user-friendly software

Applications of video in fisheries research range from simple biodiversity surveys to three-dimensional (3D) measurement of complex swimming, schooling, feeding, and territorial behaviors. However, researchers lack a transparently developed, easy-to-use, general purpose tool for 3D video measurement and event logging. Thus, we developed a new measurement system, with freely available, user-friendly software, easily obtained hardware, and flexible underlying mathematical methods capable of high precision and accuracy. The software, VidSync, allows users to efficiently record, organize, and navigate complex 2D or 3D measurements of fish and their physical habitats. Laboratory tests showed submillimetre accuracy in length measurements of 50.8 mm targets at close range, with increasing errors (mostly <1%) at longer range and for longer targets. A field test on juvenile Chinook salmon ( Oncorhynchus tshawytscha ) feeding behavior in Alaska streams found that individuals within aggregations avoided the immediate proximity of their competitors, out to a distance of 1.0 to 2.9 body lengths. This system makes 3D video measurement a practical tool for laboratory and field studies of aquatic or terrestrial animal behavior and ecology.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2019

State-space analysis of power to detect regional brook trout population trends over time

Threats to aquatic biodiversity are expressed at broad spatial scales, but identifying regional trends in abundance is challenging owing to variable sampling designs, and temporal and spatial variation in abundance. We compiled a regional dataset of brook trout Salvelinus fontinalis counts across their southern range representing 326 sites from eight states between 1982-2014, and conducted a statistical power analysis using Bayesian state-space models to evaluate the ability to detect temporal trends by characterizing posterior distributions with three approaches. A combination of monitoring periods, number of sites and electrofishing passes, decline magnitude and different revisit patterns were tested. Power increased with monitoring periods and decline magnitude. Trends in adults were better detected than young-of-the-year fish, which showed greater inter-annual variation in abundance. The addition of weather covariates to account for the temporal variation increased power only slightly. Single- and three-pass electrofishing methods were similar in power. Finally, power was higher for sampling designs with more frequent revisits over the duration of the monitoring program. Our results provide guidance for broad-scale monitoring designs for temporal trend detection.

Canadian Journal of Fisheries and Aquatic Sciences↗