scholarly journals Common species link global ecosystems to climate change

2016 ◽  
Author(s):  
Bjarte Hannisdal ◽  
Kristian A. Haaga ◽  
Trond Reitan ◽  
David Diego ◽  
Lee Hsiang Liow
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Planktonic Foraminifera ◽  
Species Abundance ◽  
Direct Interaction ◽  
Deep Ocean ◽  
Common Species ◽  
Global Changes ◽  
Ecosystem Structure ◽  
Widespread Species

Common species shape the world around us, and changes in their commonness signify large-scale shifts in ecosystem structure and function. Dominant taxa drive productivity and biogeochemical cycling, in direct interaction with abiotic components of the Earth system. However, our understanding of the dynamic response of ecosystems to global environmental changes in the past is limited by our ability to robustly estimate fossil taxonomic richness, and by our neglect of the importance of common species. To rectify this, we use observations of the most common and widespread species to track global changes in their distribution in the deep geological past. Our simple approach is robust to factors that bias richness estimators, including widely used sampling-standardization methods, which we show are highly sensitive to variability in the species-abundance distribution. Causal analyses of common species frequency in the deep-sea sedimentary record detect a lagged response in the ecological prominence of planktonic foraminifera to oceanographic changes captured by deep-ocean temperature records over the last 65 million years, encompassing one of Earth's major climate transitions. Our results demonstrate that common species can act as tracers of a past global ecosystem and its response to physical changes in Earth's dynamic history.

scholarly journals Common species link global ecosystems to climate change: dynamical evidence in the planktonic fossil record

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170722 ◽  
Author(s):  
Bjarte Hannisdal ◽  
Kristian Agasøster Haaga ◽  
Trond Reitan ◽  
David Diego ◽  
Lee Hsiang Liow
Keyword(s):  
Large Scale ◽  
Planktonic Foraminifera ◽  
Deep Ocean ◽  
Common Species ◽  
Ecosystem Structure ◽  
Environmental Forcing ◽  
Widespread Species ◽  
Quantitative Evidence ◽  
And Function

Common species shape the world around us, and changes in their commonness signify large-scale shifts in ecosystem structure and function. However, our understanding of long-term ecosystem response to environmental forcing in the deep past is centred on species richness, neglecting the disproportional impact of common species. Here, we use common and widespread species of planktonic foraminifera in deep-sea sediments to track changes in observed global occupancy (proportion of sampled sites at which a species is present and observed) through the turbulent climatic history of the last 65 Myr. Our approach is sensitive to relative changes in global abundance of the species set and robust to factors that bias richness estimators. Using three independent methods for detecting causality, we show that the observed global occupancy of planktonic foraminifera has been dynamically coupled to past oceanographic changes captured in deep-ocean temperature reconstructions. The causal inference does not imply a direct mechanism, but is consistent with an indirect, time-delayed causal linkage. Given the strong quantitative evidence that a dynamical coupling exists, we hypothesize that mixotrophy (symbiont hosting) may be an ecological factor linking the global abundance of planktonic foraminifera to long-term climate changes via the relative extent of oligotrophic oceans.

scholarly journals Evolution and extinction of Maastrichtian (Late Cretaceous) cephalopods from the López de Bertodano Formation, Seymour Island, Antarctica

2018 ◽  
Author(s):  
James Witts ◽  
Vanessa C. Bowman ◽  
Paul Wignall ◽  
J. Alistair Crame ◽  
Jane Francis ◽  
...  
Keyword(s):  
Sea Level ◽  
Environmental Changes ◽  
Planktonic Foraminifera ◽  
Seawater Temperature ◽  
Range Data ◽  
Widespread Species ◽  
Southern Latitude ◽  
The Family ◽  
Extinction Event ◽  
Seymour Island

One of the most expanded records to contain the final fortunes of ammonoid cephalopods is within the López de Bertodano Formation of Seymour Island, James Ross Basin, Antarctica. Located at ~65º South now, and during the Cretaceous, this sequence is the highest southern latitude onshore outcrop containing the Cretaceous–Paleogene (K–Pg) transition. We present comprehensive new biostratigraphic range data for 14 ammonite and one nautiloid species based on the collection of >700 macrofossils from high-resolution sampling of parallel sedimentary sections, dated Maastrichtian to earliest Danian in age, across southern Seymour Island. We find evidence for only a single, abrupt pulse of cephalopod extinction at the end of the Cretaceous when the final seven ammonite species disappeared, consistent with most evidence globally. In the lead up to the K–Pg extinction in the James Ross Basin, starting during the Campanian, ammonite diversity decreased overall, but the number of endemic taxa belonging to the family Kossmaticeratidae actually increased. This pattern continued into the Maastrichtian and may be facies controlled, linked to changes in sea level and seawater temperature. During the early Maastrichtian, ammonite diversity dropped significantly with only two species recorded from the basal López de Bertodano Formation on Seymour Island. The subsequent diversification of endemic taxa and reappearance of long-ranging, widespread species into the basin resulted in an increase in ammonite diversity and abundance during the mid-Maastrichtian. This was coincident with an apparent period of warming temperatures and sea level rise interpreted from palynology and sedimentology, perhaps reflecting a high latitude expression of the Mid-Maastrichtian Event. Late Maastrichtian diversity levels remained stable despite reported climatic and environmental variation. Ammonite diversity patterns during the Maastrichtian parallel those of microfossil species such as nannofossil and planktonic foraminifera, suggesting that dynamic climatic and environmental changes affected many planktonic and nektonic organisms during the latest Cretaceous. However, we suggest that these perturbations had a minimal effect on overall diversity prior to the catastrophic extinction event at the K–Pg boundary.

scholarly journals Covariation in population trends and demography reveals targets for conservation action

2021 ◽  
Vol 288 (1946) ◽  
pp. 20202955
Author(s):  
Catriona A. Morrison ◽  
Simon J. Butler ◽  
Robert A. Robinson ◽  
Jacquie A. Clark ◽  
Juan Arizaga ◽  
...  
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Local Population ◽  
Survival Rates ◽  
Population Trends ◽  
Population Declines ◽  
Conservation Action ◽  
Local Conditions ◽  
Widespread Species ◽  
Wide Range

Wildlife conservation policies directed at common and widespread, but declining, species are difficult to design and implement effectively, as multiple environmental changes are likely to contribute to population declines. Conservation actions ultimately aim to influence demographic rates, but targeting actions towards feasible improvements in these is challenging in widespread species with ranges that encompass a wide range of environmental conditions. Across Europe, sharp declines in the abundance of migratory landbirds have driven international calls for action, but actions that could feasibly contribute to population recovery have yet to be identified. Targeted actions to improve conditions on poor-quality sites could be an effective approach, but only if local conditions consistently influence local demography and hence population trends. Using long-term measures of abundance and demography of breeding birds at survey sites across Europe, we show that co-occurring species with differing migration behaviours have similar directions of local population trends and magnitudes of productivity, but not survival rates. Targeted actions to boost local productivity within Europe, alongside large-scale (non-targeted) environmental protection across non-breeding ranges, could therefore help address the urgent need to halt migrant landbird declines. Such demographic routes to recovery are likely to be increasingly needed to address global wildlife declines.

scholarly journals Demographic history and genomic response to environmental changes in a rapid radiation of wild rats

2021 ◽  
Author(s):  
Deyan Ge ◽  
Anderson Feijó ◽  
Zhixin Wen ◽  
Alexei V Abramov ◽  
Liang Lu ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Demographic History ◽  
Terrestrial Ecosystems ◽  
Tibet Plateau ◽  
Global Changes ◽  
Rapid Radiation ◽  
Protein Functions ◽  
Wild Rats ◽  
Qinghai Tibet Plateau ◽  
Genomic Response

Abstract For organisms to survive and prosper in a harsh environment, particularly under rapid climate change, poses tremendous challenges. Recent studies have highlighted the continued loss of megafauna in terrestrial ecosystems and the subsequent surge of small mammals, such as rodents, bats, lagomorphs, and insectivores. However, the ecological partitioning of these animals will likely lead to large variation in their responses to environmental change. In the present study, we investigated the evolutionary history and genetic adaptations of white-bellied rats (Niviventer Marshall, 1976), which are widespread in the natural terrestrial ecosystems in Asia but also known as important zoonotic pathogen vectors and transmitters. The southeastern Qinghai-Tibet Plateau (QHTP) was inferred as the origin center of this genus, with parallel diversification in temperate and tropical niches. Demographic history analyses from mitochondrial and nuclear sequences of Niviventer demonstrated population size increases and range expansion for species in Southeast Asia, and habitat generalists elsewhere. Unexpectedly, population increases were seen in N. eha, which inhabits the highest elevation among Niviventer species. Genome scans of nuclear exons revealed that among the congeneric species, N. eha has the largest number of positively selected genes. Protein functions of these genes are mainly related to olfaction, taste and tumor suppression. Extensive genetic modification presents a major strategy in response to global changes in these alpine species.

scholarly journals Impact of the municipal merger on watershed management: a study of Lake Kasumigaura, Japan

2021 ◽  
Author(s):  
Takeshi Mizunoya ◽  
Noriko Nozaki ◽  
Rajeev Kumar Singh
Keyword(s):  
Watershed Management ◽  
Large Scale ◽  
Environmental Changes ◽  
Water Environment ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Policy Implications ◽  
Pollution Reduction ◽  
Lake Kasumigaura ◽  
The Impact

AbstractIn the early 2000s, Japan instituted the Great Heisei Consolidation, a national strategy to promote large-scale municipal mergers. This study analyzes the impact that this strategy could have on watershed management. We select the Lake Kasumigaura Basin, the second largest lake in Japan, for the case study and construct a dynamic expanded input–output model to simulate the ecological system around the Lake, the socio-environmental changes over the period, and their mutual dependency for the period 2012–2020. In the model, we regulate and control the following water pollutants: total nitrogen, total phosphorus, and chemical oxygen demand. The results show that a trade-off between economic activity and the environment can be avoided within a specific range of pollution reduction, given that the prefectural government implements optimal water environment policies, assuming that other factors constraining economic growth exist. Additionally, municipal mergers are found to significantly reduce the budget required to improve the water environment, but merger budget efficiency varies nonlinearly with the reduction rate. Furthermore, despite the increase in financial efficiency from the merger, the efficiency of installing domestic wastewater treatment systems decreases drastically beyond a certain pollution reduction level and eventually reaches a limit. Further reductions require direct regulatory instruments in addition to economic policies, along with limiting the output of each industry. Most studies on municipal mergers apply a political, administrative, or financial perspective; few evaluate the quantitative impact of municipal mergers on the environment and environmental policy implications. This study addresses these gaps.

Ecological processes maintaining differential tree species distributions in an Australian subtropical rain forest: implications for models of species coexistence

2000 ◽  
Vol 16 (3) ◽  
pp. 387-415 ◽  
Author(s):  
Igor Debski ◽  
David F. R. P. Burslem ◽  
David Lamb
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Rain Forest ◽  
Large Scale ◽  
Species Coexistence ◽  
Common Species ◽  
Size Class ◽  
Differential Mortality ◽  
Mixed Composition ◽  
Large Scale Disturbance

All stems ≥ 1 cm dbh were measured, tagged, mapped and identified on a 1-ha plot of rain forest at Gambubal State Forest, south-east Queensland, Australia. The spatial patterns and size class distributions of 11 common tree species on the plot were assessed to search for mechanisms determining their distribution and abundance. The forest was species-poor in comparison to many lowland tropical forests and the common species are therefore present at relatively high densities. Despite this, only limited evidence was found for the operation of density-dependent processes at Gambubal. Daphnandra micrantha saplings were clumped towards randomly spaced adults, indicating a shift of distribution over time caused by differential mortality of saplings in these adult associated clumps. Ordination of the species composition in 25-m × 25-m subplots revealed vegetation gradients at that scale, which corresponded to slope across the plot. Adult basal area was dominated by a few large individuals of Sloanea woollsii but the comparative size class distributions and replacement probabilities of the 11 common species suggest that the forest will undergo a transition to a more mixed composition if current conditions persist. The current cohort of large S. woollsii individuals probably established after a large-scale disturbance event and the forest has not attained an equilibrium species composition.

scholarly journals Variability in larval gut pH regulation defines sensitivity to ocean acidification in six species of the Ambulacraria superphylum

2017 ◽  
Vol 284 (1864) ◽  
pp. 20171066 ◽  
Author(s):  
Marian Hu ◽  
Yung-Che Tseng ◽  
Yi-Hsien Su ◽  
Etienne Lein ◽  
Hae-Gyeong Lee ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Large Scale ◽  
Environmental Changes ◽  
Ph Regulation ◽  
Gastric Ph ◽  
Differential Sensitivity ◽  
Larval Stages ◽  
Regulatory Systems ◽  
Alkaline Conditions ◽  
Gut Ph

The unusual rate and extent of environmental changes due to human activities may exceed the capacity of marine organisms to deal with this phenomenon. The identification of physiological systems that set the tolerance limits and their potential for phenotypic buffering in the most vulnerable ontogenetic stages become increasingly important to make large-scale projections. Here, we demonstrate that the differential sensitivity of non-calcifying Ambulacraria (echinoderms and hemichordates) larvae towards simulated ocean acidification is dictated by the physiology of their digestive systems. Gastric pH regulation upon experimental ocean acidification was compared in six species of the superphylum Ambulacraria. We observed a strong correlation between sensitivity to ocean acidification and the ability to regulate gut pH. Surprisingly, species with tightly regulated gastric pH were more sensitive to ocean acidification. This study provides evidence that strict maintenance of highly alkaline conditions in the larval gut of Ambulacraria early life stages may dictate their sensitivity to decreases in seawater pH. These findings highlight the importance of identifying and understanding pH regulatory systems in marine larval stages that may contribute to substantial energetic challenges under near-future ocean acidification scenarios.

Barriers and levers for implementing sustainable Nature-Based Solutions in cities

2021 ◽  
Author(s):  
Chloé Duffaut ◽  
Nathalie Frascaria-Lacoste ◽  
Pierre-Antoine Versini
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Project Managers ◽  
Global Changes ◽  
Human Beings ◽  
Urban Context ◽  
Urban Plan ◽  
Education And Awareness ◽  
Awareness Raising ◽  
The City

<p>Hydro-meteorological risks are increasing and this could be due to global changes. These risks are particularly important in the urban context where most human beings live. Indeed, the impervious surfaces present in cities increase the risk of flooding, for example. Nature-Based Solutions can help to reduce these risks by creating permeable soils or storing water while promoting biodiversity. In this context, it is essential to understand what hinders the development and sustainability of these Nature-based Solutions in the city and what could help to deploy them on a large scale. For this purpose, various professionals working on Nature-Based Solutions in the city in France, were interviewed between 2020 and 2021, both in the academic and operational sectors, or even at the interface between the two: researchers in ecology or hydrology, IUCN (International Union for Conservation of Nature) project manager, project managers at the Regional Biodiversity Agency, director and natural environment manager of a watershed union, agro-economists engineer among others. They were asked what are the barriers and potential opportunities for Nature-Based Solutions implementation and sustainability in city. By analysing their answers, it emerges that the obstacles are more often cultural, political or financial than technical. The potential levers often mentioned are education and awareness-raising at all levels, especially for elected officials and the general public. Regulations such as the PLU (Local Urban Plan) and new funding for more natural spaces in the city also seem to be means of promoting Nature-based Solutions in urban areas. These interviews with diverse professionals directly involved in Nature-Based Solutions in cities allow to give real courses of action to be taken to democratize these Solutions throughout the French territory, or even internationally, and therefore ultimately reduce the risks of hydro-meteorology. This is one of the objectives of the French ANR project EVNATURB (Assessment of ecosystem performance of a renaturation of the urban environment), in which this study has been carried out.</p>

scholarly journals Assessing the Vulnerability of Marine Fisheries in China: Towards an Inter-Provincial Perspective

2018 ◽  
Vol 10 (11) ◽  
pp. 4302 ◽  
Author(s):  
Qi Chen ◽  
Weiteng Shen ◽  
Bing Yu
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Fisheries Management ◽  
Vocational Training ◽  
Large Scale ◽  
Environmental Changes ◽  
Marine Pollution ◽  
Marine Fisheries ◽  
Intergovernmental Panel ◽  
Adaptation Measures

China’s marine fisheries are undergoing large-scale environmental changes associated with climate change, marine pollution, and overfishing. The assessment of marine fisheries vulnerability has become extremely necessary for fisheries management and sustainable development. However, studies on China’s marine fisheries vulnerability remains sparse. This study aimed to provide an analysis of the inter-provincial level vulnerability of China’s marine fisheries under multiple disturbances. The vulnerability measure was composed of exposure, sensitivity, and adaptive capacity indicators specific to marine fisheries based on the Intergovernmental Panel on Climate Change (IPCC) definitions. Results showed that Liaoning, Hebei, Fujian, and Hainan provinces appeared to be the most vulnerable; Shanghai appeared to be less vulnerable among China’s 11 coastal provinces; and the key sources of vulnerability differed considerably among coastal regions. The high vulnerability regions could be divided into two different patterns according to the combination of exposure, sensitivity, and adaptive capacity, but they all had one thing in common: relatively low adaptive capacity. While some existing coercive measures to reduce dependence on fisheries were found to be helpful in China, the reality showed that appropriate adaptation measures such as improving fishermen’s education level and increasing vocational training may be helpful in enhancing the existing policy effectiveness.

scholarly journals Deglacial carbon cycle changes observed in a compilation of 127 benthic <i>δ</i><sup>13</sup>C time series (20–6 ka)

2018 ◽  
Vol 14 (8) ◽  
pp. 1229-1252 ◽  
Author(s):  
Carlye D. Peterson ◽  
Lorraine E. Lisiecki
Keyword(s):  
Time Series ◽  
Carbon Cycle ◽  
Carbon Storage ◽  
Large Scale ◽  
Deep Ocean ◽  
Atmospheric Co2 ◽  
Last Deglaciation ◽  
Terrestrial Biosphere ◽  
Spatial Coverage ◽  
Ocean Carbon

Abstract. We present a compilation of 127 time series δ13C records from Cibicides wuellerstorfi spanning the last deglaciation (20–6 ka) which is well-suited for reconstructing large-scale carbon cycle changes, especially for comparison with isotope-enabled carbon cycle models. The age models for the δ13C records are derived from regional planktic radiocarbon compilations (Stern and Lisiecki, 2014). The δ13C records were stacked in nine different regions and then combined using volume-weighted averages to create intermediate, deep, and global δ13C stacks. These benthic δ13C stacks are used to reconstruct changes in the size of the terrestrial biosphere and deep ocean carbon storage. The timing of change in global mean δ13C is interpreted to indicate terrestrial biosphere expansion from 19–6 ka. The δ13C gradient between the intermediate and deep ocean, which we interpret as a proxy for deep ocean carbon storage, matches the pattern of atmospheric CO2 change observed in ice core records. The presence of signals associated with the terrestrial biosphere and atmospheric CO2 indicates that the compiled δ13C records have sufficient spatial coverage and time resolution to accurately reconstruct large-scale carbon cycle changes during the glacial termination.

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