Ecosystem effects of the world’s largest invasive animal

Ecology, Год журнала: 2020, Номер 101(5)

Опубликована: Янв. 29, 2020

Abstract The keystone roles of mega‐fauna in many terrestrial ecosystems have been lost to defaunation. Large predators and herbivores often play their native ranges, some established invasive populations new biogeographic regions. However, few empirical examples are available guide expectations about how affect novel environmental evolutionary contexts. We examined the impacts on aquatic an emerging population hippopotamus ( Hippopotamus amphibus ) that has growing Colombia over last 25 yr. Hippos Africa fertilize lakes rivers by grazing land excreting wastes water. Stable isotopes indicate sources contribute more carbon Colombian containing hippo populations, daily dissolved oxygen cycles suggest presence stimulates ecosystem metabolism. Phytoplankton communities were dominated cyanobacteria with hippos, bacteria, zooplankton, benthic invertebrate similar regardless presence. Our results hippos recapitulate role as engineers Colombia, importing organic matter nutrients detectable metabolism community structure early stages invasion. Ongoing range expansion may pose a threat water resources.

Язык: Английский

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Hippopotamus are distinct from domestic livestock in their resource subsidies to and effects on aquatic ecosystems

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2020, Номер 287(1926)

Опубликована: Апрель 29, 2020

In many regions of the world, populations large wildlife have been displaced by livestock, and this may change functioning aquatic ecosystems owing to significant differences in quantity quality their dung. We developed a model for estimating loading rates organic matter (dung) cattle comparison with estimated hippopotamus Mara River, Kenya. then conducted replicated mesocosm experiment measure ecosystem effects nutrient carbon inputs associated dung from livestock (cattle) versus (hippopotamus). Our shows that per capita input is lower than hippos, but total constitute portion herbivores numbers on landscape. Cattle transfers higher amounts limiting nutrients, major ions dissolved relative hippo dung, gross primary production microbial biomass were treatments treatments. results demonstrate different forms animal influence fundamentally ways when introduced into as terrestrially derived resource subsidy.

Язык: Английский

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The meta-gut: community coalescence of animal gut and environmental microbiomes

Scientific Reports, Год журнала: 2021, Номер 11(1)

Опубликована: Ноя. 30, 2021

Abstract All animals carry specialized microbiomes, and their gut microbiota are continuously released into the environment through excretion of waste. Here we propose meta-gut as a novel conceptual framework that addresses ability microbiome from an animal to function outside host alter biogeochemical processes mediated by microbes. We demonstrate this dynamic in hippopotamus (hippo) pools they inhabit. used natural field gradients experimental approaches examine fecal pool water microbial communities aquatic biogeochemistry across range hippo inputs. Sequencing using 16S RNA methods revealed community coalescence between microbiomes active received high inputs feces. The shared waters which excrete constitutes system could influence recipient ecosystems provide reservoir other hosts. dynamics may also occur where species congregate densities, particularly environments.

Язык: Английский

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Hippos ( Hippopotamus amphibius ): The animal silicon pump

Science Advances, Год журнала: 2019, Номер 5(5)

Опубликована: Май 1, 2019

Grazing hippos are key species in transfer of silicon from terrestrial grasses to lake diatoms.

Язык: Английский

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Drivers of water quality in Afromontane-savanna rivers

Frontiers in Environmental Science, Год журнала: 2022, Номер 10

Опубликована: Окт. 12, 2022

Although several studies have investigated the relationships between water quality in rivers and types of land use within their catchments, many aspects these remain unclear Afromontane-savanna rivers, especially interactions catchment use, seasonality stream size. catchments present a unique situation where headwater regions lowlands experienced more dramatic cover change, but mid-elevation remained rather natural. We examined influence seasonality, size, including interactions, on physico-chemistry, nutrients major ions Mara River Kenya, using data collected from 2010 to 2018 at >150 sampling sites Kenyan part river. developed generalized linear mixed models (GLMMs) explore (dry wet seasons), (forest, mixed, agriculture grasslands), size (stream orders 1–7), river quality. Water variables included physico-chemical measures (pH, dissolved oxygen [DO] concentration, temperature, electrical conductivity, total solids [TDS], turbidity, suspended [TSS] particulate organic matter [POM]), ( NH4+ , id="m2">O3− nitrogen [TDN], [TN], soluble reactive phosphorus [SRP], [TP] carbon), (Cl − F id="m3">SO42− Na + K Ca 2+ Mg Fe id="m4">HC

Язык: Английский

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Carrion ecology in inland aquatic ecosystems: a systematic review

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Год журнала: 2024, Номер 99(4), С. 1425 - 1443

Опубликована: Март 20, 2024

ABSTRACT Carrion ecology, i.e. the decomposition and recycling of dead animals, has traditionally been neglected as a key process in ecosystem functioning. Similarly, despite large threats that inland aquatic ecosystems (hereafter, ecosystems) face, scientific literature is still largely biased towards terrestrial ecosystems. However, there an increasing number studies on carrion ecology last two decades, highlighting their role nutrient recirculation disease control. Thus, global assessment ecological scavengers timely. Here, we systematically reviewed articles to describe current knowledge, identify research gaps, promote future will deepen our understanding this field. We found 206 relevant studies, which were highly North America, especially lotic ecosystems, covering short time periods, overlooking seasonality, crucial factor scavenging dynamics. Despite low scavenger assemblages, recorded 55 orders invertebrates from 179 families, with Diptera Coleoptera being most frequent orders. For vertebrates, 114 species 40 birds mammals common. Our results emphasise significance stabilising food webs facilitating cycling within Studies strongly effects carrion, particularly salmon carcasses America. The second common topic was foraging mostly evaluated through sporadic observations diet. Articles assessing assemblages scarce, only limited these consumption patterns, serve proxy for ecosystem. functions performed by diverse. main source cycling, appeared 52.4% ( N = 108) 46.1% 95) publications, respectively. Ecosystem associated also identified, water eutrophication pathogens (2.4%; 5 each). Regarding spanning all components 85), soil or column particular focus fish. Most positive (e.g. higher richness, abundance fitness; 84.7%; 72), while minority negative effects, changes community composition, even no effects. Enhancing roles amidst change, mainly water–land transport, due amount speed movement, control impact mitigation, predicted increase occurrence magnitude mortality events

Язык: Английский

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The Biology and Ecology of Streams and Rivers

Oxford University Press eBooks, Год журнала: 2023, Номер unknown

Опубликована: Май 30, 2023

Abstract A major textbook on running waters, promoting understanding of the nature rivers as ecosystems, and detailing biodiversity natural history their biota. The book takes a primarily biological approach to river ecology, dealing with scientific questions about but referring throughout possible applications approaches management. notion habitat templet refers suite environmental factors that face lotic organisms adaptations traits enable survival in such challenging environments. How does complex, patchy whole-river networks impinge population dynamics communities? Species interactions food web linkages determine flow energy material through communities lead ecosystem processes metabolism (the balance primary production community respiration) ecology nutrients. stresses systems ‘open’ exchanging materials land downstream systems. can be sustainable part capital which we all depend? In final chapter forward-looking view is progressively devoted applied questions. Biology Ecology Streams Rivers seeks provide knowledge necessary for their, our, future. We need appreciate ‘what do us’ reverse deterioration waters an increasingly thirsty, hungry changing world.

Язык: Английский

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A River of Bones: Wildebeest Skeletons Leave a Legacy of Mass Mortality in the Mara River, Kenya

Frontiers in Ecology and Evolution, Год журнала: 2020, Номер 8

Опубликована: Фев. 27, 2020

Animal carcasses can provide important resources for a suite of consumers, and bones may largely overlooked component this resource, as they contain large proportion the phosphorus (P) in carcass persist decades to millennia. We synthesized several datasets from our research Mara River, which annual mass drownings wildebeest (Connochaetes taurinus) contribute 2.2×105 kg per year, examine ecological role that bone could play river ecosystem prioritize questions on aquatic ecosystems general. measured stoichiometry used in-stream litterbags measure decomposition rate, both varied by type. Decomposition occurs two-stage process, with 15% being relatively labile decomposing 80-120 days remaining recalcitrant portion over >80 years, leading an estimated standing stock 5.1×106 river. mesocosm experiments leaching rates bones. Leachate fresh was order magnitude higher inorganic nitrogen (N) than P; however, aged leached much more P N, stimulated primary production. Biofilms growing had five times greater chlorophyll 2 organic matter those rocks, although algal composition not significantly different between two substrates. also differed biofilms rocks carbon (C) N stable isotope signature. Mixing models suggest account 19% macroinvertebrate 24% fish tissues even months after were present. In combination, these findings influence nutrient cycling, function, food webs potentially decadal time scales. Bones be other ecosystems, extirpations land mammals have led loss resource. Large animal unique via their slow release limiting nutrients.

Язык: Английский

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Livestock as vectors of organic matter and nutrient loading in aquatic ecosystems in African savannas

PLoS ONE, Год журнала: 2021, Номер 16(9), С. e0257076 - e0257076

Опубликована: Сен. 8, 2021

Populations of large wildlife have declined in many landscapes around the world, and been replaced or displaced by livestock. The consequences these changes on transfer organic matter (OM) nutrients from terrestrial to aquatic ecosystems are not well understood. We used behavioural data, excretion egestion rates C: N: P stoichiometry dung urine zebu cattle, develop a metabolism-based estimate loading OM (dung), C, N into Mara River, Kenya. also directly measured deposition cattle river during watering. Per head, excrete and/or egest 25.6 g dry (DM, 99.6 wet mass; metabolism) - 27.7 DM (direct input) OM, 16.0-21.8 5.9-9.6 N, 0.3-0.5 per day river. To replace an individual hippopotamus 100 individuals will be needed, but much less for different elements. In parts investigated sub-catchments were equivalent higher than that hippopotamus. patterns increased suspended materials as result livestock activity fit historical findings concentrations, dissolved carbon other variables agricultural areas River basin. Changing nutrient transport cycling having significant effects structure functioning both ecosystems.

Язык: Английский

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Alternative Biogeochemical States of River Pools Mediated by Hippo Use and Flow Variability

Ecosystems, Год журнала: 2020, Номер 24(2), С. 284 - 300

Опубликована: Июнь 8, 2020

Язык: Английский

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