Dam builders and their works: Beaver influences on the structure and function of river corridor hydrology, geomorphology, biogeochemistry and ecosystems

Earth-Science Reviews, Journal Year: 2021, Volume and Issue: 218, P. 103623 - 103623

Published: May 5, 2021

Beavers (Castor fiber, Castor canadensis) are one of the most influential mammalian ecosystem engineers, heavily modifying river corridor hydrology, geomorphology, nutrient cycling, and ecosystems. As an agent disturbance, they achieve this first foremost through dam construction, which impounds flow increases extent open water, from all other landscape impacts follow. After a long period local regional eradication, beaver populations have been recovering expanding throughout Europe North America, as well introduced species in South prompting need to comprehensively review current state knowledge on how beavers influence structure function corridors. Here, we synthesize overall biogeochemistry, aquatic terrestrial Our key findings that complex dams can increase surface subsurface water storage, modify reach scale partitioning budgets, allow site specific flood attenuation, alter low evaporation, residence times, geomorphic heterogeneity, delay sediment transport, carbon, expand anaerobic conditions interfaces, downstream export dissolved organic carbon ammonium, decrease nitrate, lotic lentic habitat transitions primary production, induce 'reverse' succession riparian vegetation assemblages, complexity biodiversity scales. We then examine feedbacks overlaps between these changes caused by beavers, where longitudinal hydrologic connectivity create ponds wetlands, ecosystems, vertical hydraulic exchange gradients, biogeochemical cycling per unit stream length, while increased lateral will determine area wetland littoral zone habitats, assemblages. However, depends firstly hydro-geomorphic context, determines floodplain inundation, driver subsequent hydrologic, geomorphic, biogeochemical, dynamics. Secondly, it length time sustain disturbance at given site, is constrained top down (e.g. predation) bottom up competition) feedbacks, ultimately pathways following abandonment. This outsized processes also fundamentally distinct what occurs their absence. Current management restoration practices therefore re-examination order account for both positive negative, such potentially accommodate enhance engineering services provide. It hoped our synthesis holistic framework evaluating be used endeavor scientists managers into future continue numbers range.

Language: Английский

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Effects of Human Disturbance on Terrestrial Apex Predators

Diversity, Journal Year: 2021, Volume and Issue: 13(2), P. 68 - 68

Published: Feb. 9, 2021

The effects of human disturbance spread over virtually all ecosystems and ecological communities on Earth. In this review, we focus the terrestrial apex predators. We summarize their role in nature how they respond to different sources disturbance. Apex predators control prey smaller numerically via behavioral changes avoid predation risk, which turn can affect lower trophic levels. Crucially, reducing population numbers triggering responses are also that causes predators, may influence role. Some populations continue be at brink extinction, but others partially recovering former ranges, natural recolonization through reintroductions. Carnivore recovery is both good news for conservation a challenge management, particularly when occurs human-dominated landscapes. Therefore, conclude by discussing several management considerations that, adapted local contexts, favor predator functions nature.

Language: Английский

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Cats, foxes and fire: quantitative review reveals that invasive predator activity is most likely to increase shortly after fire

Fire Ecology, Journal Year: 2023, Volume and Issue: 19(1)

Published: April 13, 2023

Abstract Background Predators and fire shape ecosystems across the globe these two forces can interact to impact prey populations. This issue is particularly pertinent in Australia where there considerable scientific public interest post-fire impacts of invasive predators—the feral cat red fox. It remains unclear, though, whether increased fox activity response a general phenomenon, or responses are highly context-specific not generalisable. Results We reviewed analysed existing literature found that range positive (e.g., burnt areas), negative (decreased activity), neutral have been recorded different studies locations. Mixed effects modelling revealed were more likely when areas recently (shorter time since fire). The mean likelihood by cats decreased from 41% at 0 months 10% 100 post-fire, whereas probability for foxes 53 10%. suggests may be critical period immediately most vulnerable elevated predators, within which management interventions impactful. Conclusions Many our findings identified as potential cases either mechanistic apparent context dependency (variation patterns due observational ecological factors). provides pathway design future will enhance understanding predator fire, both globally. Conservation policy benefit additional research spanning greater events, along with comprehensive nuanced interpretation evidence.

Language: Английский

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Airborne environmental DNA captures terrestrial vertebrate diversity in nature

Molecular Ecology Resources, Journal Year: 2023, Volume and Issue: 24(1)

Published: July 27, 2023

The current biodiversity and climate crises highlight the need for efficient tools to monitor terrestrial ecosystems. Here, we provide evidence use of airborne eDNA analyses as a novel method detecting vertebrate communities in nature. Metabarcoding 143 samples collected during 3 days mixed forest Denmark yielded 64 bird, mammal, fish amphibian taxa, which detected 57 'wild' taxa represent over quarter around 210 vertebrates that occur overall area. We spatial movement temporal patterns influence weather conditions on detections. This study demonstrates high-resolution biomonitoring systems elucidates its potential guide global nature management conservation efforts ongoing crisis.

Language: Английский

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Impacts of beaver dams on riverscape burn severity during megafires in the Rocky Mountain region, western United States

Geological Society of America eBooks, Journal Year: 2024, Volume and Issue: unknown, P. 131 - 151

Published: Jan. 15, 2024

ABSTRACT Megafires, defined as fires with burn areas greater than 100,000 acres (404.7 km2), result partly from increasingly short wet seasons coupled consistently hotter, drier summers, and past forest management decisions. Historically rare, megafires have become common in recent years. In this study, we examined the impact of on riverscapes beaver dams to explore resilience these habitats. We investigated whether beaver-modified are more resistant impacts geomorphically similar lacking dams. Our analysis utilized remotely sensed field-collected data three Rocky Mountain region that burned 2020. results showed riparian (1537 dams, which occurred 658 out 13,933 valley bottom segments evaluated) had significantly reduced severity compared without or outside river corridor. Additionally, when were classified according their modeled dam capacities (a metric closely linked habitat quality), lower intensities those even within same theoretical capacity class. indicate a high degree manipulation by beavers significant resistance burning during megafires. This may also provide valuable secondary benefits postfire ecosystem health, water quality, biodiversity.

Language: Английский

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Patchy indirect effects of predation: predators contribute to landscape heterogeneity and ecosystem function via localized pathways

Oikos, Journal Year: 2023, Volume and Issue: 2023(10)

Published: Aug. 17, 2023

Predators are widely recognized for their irreplaceable roles in influencing the abundance and traits of lower trophic levels. also have shaping community interactions ecological processes via highly localized pathways (i.e. effects with well‐defined measurable spatio–temporal boundaries), irrespective influence on prey density or behavior. We synthesized empirical theoretical research describing how predators – particularly medium‐ large‐sized carnivores indirect confined to discrete landscape patches, we termed ‘patchy (PIEs) predation'. generate PIEs three main pathways: generating distributing carcasses, creating hotspots by concentrating nutrients derived from prey, killing ecosystem engineers that create patches. In each pathway, limited areas spatial temporal boundaries patches). Our synthesis reveals diverse complex ways indirectly affect other species ranging mediating scavenger parasite/disease transmission risk, altering biogeochemistry facilitating local biodiversity. provide basic guidelines these can be quantified at patch scales, discuss predator‐mediated patches ultimately contribute heterogeneity functioning. Whereas density‐ trait‐mediated predation generally occur through population‐scale changes, individual‐ patch‐level pathways. provides a more holistic view functional role ecosystems addressing patchy landscapes pathways, addition behavior

Language: Английский

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Feedback loops between 3D vegetation structure and ecological functions of animals

Ecology Letters, Journal Year: 2023, Volume and Issue: 26(9), P. 1597 - 1613

Published: July 7, 2023

Abstract Ecosystems function in a series of feedback loops that can change or maintain vegetation structure. Vegetation structure influences the ecological niche space available to animals, shaping many aspects behaviour and reproduction. In turn, animals perform functions shape However, most studies concerning three‐dimensional animal ecology consider only single direction this relationship. Here, we review these separate lines research integrate them into unified concept describes mechanism. We also show how remote sensing tracking technologies are now at global scale describe their consequences for ecosystem functioning. An improved understanding interact with is needed conserve ecosystems face major disruptions response climate land‐use change.

Language: Английский

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Relics of beavers past: time and population density drive scale‐dependent patterns of ecosystem engineering

Ecography, Journal Year: 2021, Volume and Issue: 2022(2)

Published: Dec. 28, 2021

Like many ecological processes, natural disturbances exhibit scale‐dependent dynamics that are largely a function of the magnitude, frequency and scale at which they assessed. Ecosystem engineers create patch‐scale affect yet we know little about how these effects across space or vary through time. Here, investigate patch by beavers Castor canadensis , ecosystem renowned for their pond‐creation behavior, processes We evaluated beaver population recovery influenced surface water in relation to density over 70 years multiple spatial scales (pond, watershed regional) northern Minnesota. Surface area was positively related scale; however, despite variation densities (and therefore area) scale, regional‐scale stable This stability appears have been driven asynchronous fluctuations among watersheds, combined with increasing importance abandoned ponds. Beavers initially created occupied larger ponds greater area, but time shifted towards occupying smaller As accumulated on landscape proportionally more stored within ponds, offset size Beaver engineering – density‐dependent mechanisms legacy from not only follows general patterns disturbance creating mosaic patches, organism‐created also generate scales. suggest restoring landscapes is viable method storage will ultimately help advance numerous conservation rewilding objectives. Our study demonstrates can be scale‐dependent, indicating researchers should evaluate impact diverse spatiotemporal fully understand functional roles ecosystems.

Language: Английский

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Intended and unintended consequences of wolf restoration to Yellowstone and Isle Royale National Parks

Conservation Science and Practice, Journal Year: 2021, Volume and Issue: 3(4)

Published: April 1, 2021

Abstract Wolves ( Canis lupus ), a once widely distributed species, were systematically removed from many temperate zone ecosystems due to conflicts with humans. A change in human attitudes and cultural norms has brought about recovery some suitable areas, yet reintroductions are still controversial. Two notable reintroduction areas the United States Yellowstone Isle Royale National Parks. Both proposals caused polarization debate. In opposition focused on outside park effects, mainly wolves killing livestock wild game also desired by hunters. At Royale, was mostly interventions into nature impairment of wilderness values contrary spirit 1964 Wilderness Act. locations had periods 20th century without presence dampening effect ungulate population fluctuations. Most outcomes at predicted as Environmental Impact Statement written beforehand correctly 78% 51 that examined. too recently reintroduced make similar comparisons, but we conclude intervention is not Act, nor author Howard Zahniser's vision, partially because wolf mitigation for actions. Also, intervening, or inaction, often perceived safer, would have more damaging impacts ecosystem functioning.

Language: Английский

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Logging, linear features, and human infrastructure shape the spatial dynamics of wolf predation on an ungulate neonate

Ecological Applications, Journal Year: 2023, Volume and Issue: 33(7)

Published: Aug. 21, 2023

Humans are increasingly recognized as important players in predator-prey dynamics by modifying landscapes. This trend has been well-documented for large mammal communities North American boreal forests: logging creates early seral forests that benefit ungulates such white-tailed deer (Odocoileus virginianus), while the combination of infrastructure development and resource extraction practices generate linear features allow predators wolves (Canis lupus) to travel forage more efficiently throughout landscape. Disturbances from recreational activities residential other major sources human activity ecosystems may further alter wolf-ungulate dynamics. Here, we evaluate influence several types anthropogenic landscape modifications (timber harvest, features, infrastructure) have on where how hunt ungulate neonates a southern forest ecosystem Minnesota, USA. We demonstrate each disturbance significantly influences wolf predation fawns (n = 427 kill sites). In contrast with "human shield hypothesis" posits prey use human-modified areas refuge, killed closer buildings than expected based spatial availability. Fawns were also within recently-logged expected. Concealment cover was higher at sites random sites, suggesting senses vision, probably olfaction, detect hidden fawns. Wolves showed strong selection hunting along hypothesize facilitated allowing among high-quality patches (recently logged areas, near buildings), increase encounter rates olfactory cues them These findings provide novel insight into strategies many ways alters neonate dynamics, which remained elusive due challenges locating small prey. Our research management conservation implications systems subjected pressures, particularly range overlap between expands appears be altering food web ecosystems.

Language: Английский

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