Climate warming and changes in Cyclotella sensu lato in the Laurentian Great Lakes

Limnology and Oceanography, Год журнала: 2016, Номер 62(2), С. 768 - 783

Опубликована: Дек. 2, 2016

Abstract We present the first evidence of biological change in all pelagic Laurentian Great Lakes associated with recent climatic warming. hypothesized that measured changes lake temperature, and resulting physical to water columns, were affecting diatom communities Lakes. A paleolimnological analysis 10 sediment cores collected from deep locations throughout basin indicates a (30–50 yr) reorganization community one characterized by elevated abundances several species group Cyclotella sensu lato , coinciding rising atmospheric temperatures. These increases are probable mechanistic result new regimes such as changing stratification depths longer ice‐free periods, possibly quality shifts. Efforts understand mechanisms these ongoing, but this compositional primary producers could have important implications food webs.

Язык: Английский

---

Late Quaternary vegetation and lake system dynamics in north-eastern Siberia: Implications for seasonal climate variability

Quaternary Science Reviews, Год журнала: 2015, Номер 147, С. 406 - 421

Опубликована: Сен. 3, 2015

Язык: Английский

---

Ice-cover is the principal driver of ecological change in High Arctic lakes and ponds

PLoS ONE, Год журнала: 2017, Номер 12(3), С. e0172989 - e0172989

Опубликована: Март 15, 2017

Recent climate change has been especially pronounced in the High Arctic, however, responses of aquatic biota, such as diatoms, can be modified by site-specific environmental characteristics. To assess if climate-mediated ice cover changes affect diatom response to climate, we used paleolimnological techniques examine shifts assemblages from ten Arctic lakes and ponds Ellesmere Island nearby Pim (Nunavut, Canada). The sites were divided a priori into four groups ("warm", "cool", "cold", "oasis") based on local elevation microclimatic differences that result differing lengths ice-free season, well about three decades personal observations. We characterized species shift Condition 1 (i.e. generally low diversity, predominantly epipelic epilithic assemblage) 2 typically more diverse ecologically complex assemblage with an increasing proportion epiphytic species). This was consistent pattern recorded across experienced warming. "warm" are amongst first lose their covers summer earliest highest magnitude changes. "cool" also exhibited 2, but, predicted, timing lagged sites. Meanwhile some "cold" sites, which until recently still retained raft summer, only this upper-most sediments. warmer "oasis" likely supported vegetation throughout records. Consequently, diatoms high-diversity, record. Our results support hypothesis length season is principal driver largely driven establishment new habitats, resulting increased diversity emergence novel growth forms species.

Язык: Английский

---

Abruptly and irreversibly changing Arctic freshwaters urgently require standardized monitoring

Journal of Applied Ecology, Год журнала: 2020, Номер 57(7), С. 1192 - 1198

Опубликована: Апрель 23, 2020

Abstract Arctic regions support a wide variety of freshwater ecosystems. These naturally oligotrophic and cold‐water streams, rivers, ponds lakes are currently being impacted by diverse range anthropogenic pressures, such as accelerated climate change, permafrost thaw, land‐use eutrophication, brownification the replacement northern biota with expansion more southern species. Multiple stressors rapidly changing systems aquatic habitats becoming suitable for species originating from southerly thereby threatening adapted to cold waters. The livelihoods Indigenous Peoples north will be altered when ecosystem services associated changes in biodiversity affected. Unfortunately, monitoring change freshwaters is inadequate, making it difficult, if not impossible, predict services. Synthesis applications . We propose three‐step approach better address facilitate rapid ecological that ecosystems experiencing result change. First, we should increase our efforts across all countries setting up network sites devoting effort broad‐scale baseline survey using standardized methods. Second, enhance modelling include both socio‐economic development. models help pinpoint species, geographical areas likely show abrupt response any changes. Third, interaction among scientists, policymakers different stakeholder groups. In particular, must involved leadership, planning execution assessment activities freshwaters. proposed approach, which critical detecting effects circumpolar region, has broader global coordination biomonitoring. Through routine monitoring, standardization methods, enhanced integrated scientific increased collaboration within sectors, effective management impacts on possible globally.

Язык: Английский

---

Perspectives for an integrated understanding of tropical and temperate high-mountain lakes

Journal of Limnology, Год журнала: 2016, Номер 75(s1)

Опубликована: Март 22, 2016

<p>High mountain lakes are extreme freshwater ecosystems and excellent sentinels of current global change. They likely among the most comparable across world. The largest contrast occurs between in temperate tropical areas. main difference arises from seasonal patterns heat exchange external loadings (carbon, phosphorus, metals). consequence is a water column structure based on temperature, lakes, oxygen, lakes. This essential implies that, one can expect more sustained productivity throughout year; higher nutrient internal loading mineralization organic matter; nitrification-denitrification potential related to oxyclines; metal mobilization due permanently reduced bottom layer. Quantifying linking these other biogeochemical pathways particular groups organisms agenda high-mountain limnology. intrinsic difficulties taxonomic study many inhabiting systems be now overcome with use molecular techniques. These techniques will not only provide much less ambiguous knowledge microscopic world, but also unveil new that difficult measure chemically solve biogeographical puzzles distribution some macroscopic organism, tracing relationship Daily variability vertical gradients tropics factors phytoplankton species turnover lakes; whereas seasonality driver communities. makes sense an integrated view ecosystem. A large part plankton biomass heterotrophic, mixotrophic prokaryotes compete for dissolved resources eukaryotic autotrophs. In fact, lake model applying investigation airshed sediments functional views. Additionally, districts as metacommunity units may reveal key differences limited (slow) dispersal. We propose limnological studies at high should adhere common general paradigm. which processes framed by airshed-to-sediment continuum concept district concept. solid understanding fundamental facilitate stronger contributions assessment impacts on-going change remote areas.</p>

Язык: Английский

---

Fifteen important questions in the spatial ecology of diatoms

Freshwater Biology, Год журнала: 2019, Номер 64(11), С. 2071 - 2083

Опубликована: Авг. 12, 2019

Abstract Recently, studies about the spatial distribution of microbial species and communities have increased substantially. Freshwater diatoms are used as one most popular model taxa in such macroecological studies, but exciting patterns ecology not been reviewed. Here, we identify 15 important questions freshwater diatom ecology, review major findings, suggest novel research avenues. We found that do support classical latitudinal diversity gradient, species–area relationship or Rapoport's rule. some, albeit inconsistent for an elevational Bergmann's rule niche conservation. Diatoms a positive interspecific abundance–occupancy like nearly all other taxa. With regards to metacommunity dynamics, typically structured by sorting, neutral dynamics mass effects also evident at large small scale, respectively. Taken together, this suggests follow some biogeographical similarly larger taxa, weaker than macro‐organisms. This may result because relatively strongly controlled local factors often exhibit efficient stochastic dispersal processes both scales. More is needed build more comprehensive view relationships gradients diversity, example. In future, well‐replicated field experiments, with intercontinental global coverage, trait‐based approaches, DNA ‐based identification would be fruitful avenues shed light into diatoms.

Язык: Английский

---

Nutrients and warming interact to force mountain lakes into unprecedented ecological states

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2020, Номер 287(1930), С. 20200304 - 20200304

Опубликована: Июль 8, 2020

While deposition of reactive nitrogen (N) in the twentieth century has been strongly linked to changes diatom assemblages high-elevation lakes, pronounced and contemporaneous other algal groups suggest additional drivers. We explored origin magnitude two mountain lakes from end Little Ice Age at ca 1850, 2010, using lake sediments. found dramatic community abundance composition. diatoms remain most abundant photosynthetic organisms, concentrations pigments decreased while representing chlorophytes increased 200-300% since 1950 total biomass more than doubled. Some began 1900 but shifts sedimentary proxies accelerated commensurate with many human-caused Earth System. In addition N deposition, aeolian dust may have contributed phosphorus. Strong increases summer air surface water temperatures 1983 direct indirect consequences for ecosystems. Such warming could directly enhanced nutrient use primary production. Indirect include leaching nutrients geologic cryosphere sources, particularly as glaciers ablate. we infer causal mechanisms, producer communities appear be without historical precedent are post-1950 acceleration global change.

Язык: Английский

---

Detecting climate‐related shifts in lakes: A review of the use of satellite Earth Observation

Limnology and Oceanography, Год журнала: 2024, Номер 69(4), С. 723 - 741

Опубликована: Март 11, 2024

Abstract Climate change exerts a profound impact on lakes, eliciting responses that range from gradual to abrupt transitions. When reaching critical tipping points, the established lake dynamics stand undergo substantial modifications, setting off chain reaction reverberates through entire ecosystem. This shift ripples into related ecosystem services and even influences well‐being of human communities. Despite importance shifts, we lack systematic overview their occurrence, mainly due data at global scale. We reviewed literature focusing climate‐related shifts assessed how satellite Earth Observation (EO) has contributed research topic, what can unlock this novel data. Our results show EO are used in only 9% studies although fraction increased since 2012. is most commonly assess surface extent, ice coverage, or phytoplankton phenology. These variables directly observable spatio‐temporal resolution satellites great advantage. But also be identified indirectly data, as example vertical mixing water, which described basis patterns. In all possible applications, expect increasing use future, including development early warning systems promise provide timely alerts regarding impending thus serving vanguard against alterations could ripple interconnected services.

Язык: Английский

---

Declines in ice cover are accompanied by light limitation responses and community change in freshwater diatoms

The ISME Journal, Год журнала: 2024, Номер 18(1)

Опубликована: Янв. 1, 2024

Abstract The rediscovery of diatom blooms embedded within and beneath the Lake Erie ice cover (2007–2012) ignited interest in psychrophilic adaptations winter limnology. Subsequent studies determined vital role plays ecophysiology as diatoms partition to underside ice, thereby fixing their location photic zone. Yet, climate change has led widespread decline across Great Lakes, with presenting a nearly “ice-free” state several recent winters. It been hypothesized that resultant turbid, isothermal water column induces light limitation amongst thus serves competitive disadvantage. To investigate this hypothesis, we conducted physiochemical metatranscriptomic survey spanned spatial, temporal, climatic gradients (2019–2020). Our results suggest ice-free conditions decreased planktonic bloom magnitude altered community composition. Diatoms increased expression various photosynthetic genes iron transporters, which suggests are attempting increase quantity photosystems light-harvesting components (a well-defined indicator limitation). We identified two gene families serve fitness turbid column: proton-pumping rhodopsins potential second means light-driven energy acquisition) fasciclins “raft” together buoyancy co-locate surface optimize acquisition). With large-scale changes already underway, our observations provide insight into how respond dynamic today shed on they will fare climatically tomorrow.

Язык: Английский

---

Underlying mechanisms governing on distribution and stratification of DOM during seasonal freeze-thaw cycles

The Science of The Total Environment, Год журнала: 2024, Номер 928, С. 172211 - 172211

Опубликована: Апрель 5, 2024

Язык: Английский

---