Biogeographic Changes Research Articles

Pleistocene Mammals from Pampean Region (Argentina). Biostratigraphic, Biogeographic, and Environmental Implications

The Pampean Region contains sedimentary sequences with abundant mammal fossil records, which constitute the chronological outline of the Plio–Pleistocene of South America. These classic localities have been used for more than a century to correlate with other South American regions. Throughout this time, a series of misinterpretations have appeared. To understand the stratigraphic significance of these localities and the geochronological situation of each unit referring to the Pleistocene, a critical historical study of the antecedents was carried out, evaluating the state of each unit. The biostratigraphic studies of the Pampean Region’s mammalian faunas improved the understanding of biogeographic changes taking into account the environmental fluctuations of the Pleistocene.

The future is now: marine aquaculture in the anthropocene

Abstract Aquaculture now produces more seafood than wild capture fisheries and this production is expected to at least double by 2050. Representing almost half of global production, marine aquaculture will contribute to sustainably feeding the growing humanity. However, climate change will undoubtedly challenge the future growth of marine aquaculture. Temperature and sea-level rise, shifts in precipitation, freshening from glacier melt, changing ocean productivity, and circulation patterns, increasing occurrence of extreme climatic events, eutrophication, and ocean acidification are all stressors that will influence marine aquaculture. The objective of this themed article set was to bring together contributions on the broad theme of the potential impacts, adaptation, and mitigation strategies of marine aquaculture to climate change. Here we present 14 papers covering a diverse set of approaches including experimentation, modelling, meta-analysis and review, and disciplines like biology, ecology, economics, and engineering. These articles focus on the impacts of climate change-related stressors on the aquaculture potential itself and on the resulting ecological interactions (e.g. parasitism and predation), on phenotypic plasticity and adaptation potential of species, and on measures to mitigate the effects of climate change on aquaculture and vice versa. Considering this, adaptation of the aquaculture sector relies on anticipating the biogeographical changes in the distribution of species, determining their potential for adaptation and selective breeding for resistance or tolerance to climate-induced stressors, and fostering ecosystem resilience by means of conservation, restoration, or remediation. By will or by force, aquaculture will contribute to the low carbon economy of tomorrow. Aquaculture must move towards a new paradigm where the carbon footprint and the analysis of the life cycle of products are at least as important as economic profitability.

世界自然遗产地陆生藻类物种多样性比较研究

藻类是真核生物进化、植物起源与进化、生物地理学研究的良好材料，研究藻类物种多样性对理解生命起源与早期进化，探明地球地质地貌演化有着非常重要的意义。以两世界自然遗产地施秉云台山白云岩喀斯特、赤水丹霞的陆生藻类为研究对象，通过G-F多样性指数、Jaccard相似性系数、Bray-Curtis矩阵比较分析了不同地质地貌的两世界自然遗产地陆生藻类的物种多样性及种组特征，结果如下：（1）两地陆生藻类丰富，均以蓝藻为优势，共有优势科为色球藻科Chroococcaceae、颤藻科Oscillatoriaceae，施秉云台山还具伪枝藻科Scytonemataceae、念珠藻科Nostocaceae优势，优势属为粘球藻属Gloeocapsa、色球藻属Chroococcus，赤水丹霞仅以粘球藻属Gloeocapsa为优势。（2）施秉云台山G-F多样性指数高于赤水丹霞。（3）两地陆生藻类泛热带成分明显，施秉云台山中国特有成分较赤水丹霞丰富；两地科、属、种相似性系数依次为：56.25%、44.05%、37.62%，科的相似性达到中度水平，与同纬度范围其它地区的Bray-Curtis矩阵聚类结果显示不同地质地貌的两地首先聚为一类。从陆生藻类多样性组成上，初步反映两世界自然遗产地的地质历史、地层岩性及地理位置的异同。;Algae have been regarded as very useful materials for the research of eukaryote evolution, plant origin and evolution, and biogeographic changes. Thus, their diversity profiles are essential in understanding life's origin and early evolutionary development and exploring the earth's geology and geomorphology structure. We studied the terrestrial algae of Shibing Yuntai Mountain (SYM) and Chishui Danxia (CD) in Guizhou, the two world natural heritage sites in China representing dolomite karst and danxia landforms, respectively. G-F diversity index, similarity index, and Bray Curtis were used to compare their species composition. The results indicate that:(1) the algae are abundant in both heritage sites, featured with dominant cyanobacteria species, especially the families of Chroococcaceae and Oscillatoriaceae. The SYM, however, is rich in Scytonemataceae and Nostocaceae, with more abundance of Gloeocapsa and Chroococcus, which is different from CD with abundant genus Gloeocapsa. (2) SYM's G-F diversity indices are greater than CD's. Thus, the species diversity of SYM is higher than that of CD. This phenomenon may be related to the factor that the alga-promoting effect of the dolomite soil and the alga-suppressing effect of the red layer soil containing rich Fe and Mn. The predominance of nitrogen-fixed cyanobacteria in Scytonemataceae and Nostocaceae reflects the dolomite karst's environmental characteristics:rich in calcium and magnesium but poor nutrition. The species of Gloeocapsa in CD are more abundant, which are related to the silicate minerals in sandstone, besides the dry and hot climate. (3) The algae analyzed in both sites have significantly tropical and subtropical compositions and are endemic to China, especially regarding SYM. The similarity coefficients of families, genera, and species between the two sites are 56.25%, 44.05%, and 37.62%. Family similarity reaches a moderate level. The Bray-Curtis results show that the two sites are clustered into the same category despite their different geological and geomorphological features. The shared similarity at family and genus levels of the algae implies that the two sites maybe have diverged from the same aquatic environments. However, the heterogeneity at the species level between the sites maybe have resulted from their different terrestrial geographic landscapes, which shaped the algae alternatively under natural selection and environmental adaptation principles. We find the characteristic algae that can prove the landform's development from different compositions of the existing algae at the two sites. Thus, this preliminary study integrally and systematically analyzes terrestrial algae's diversity, heterogeneity, and similarity, and geographic varieties in evolutionary development, stratigraphic lithology, and structure of the two heritage sites in China.

MORPHOLOGICAL CHANGES OF THE MOUTH OF THE SÃO MATEUS RIVER MOUTH, NORTH COAST OF ESPÍRITO SANTO, AND THE BIOGEOGRAPHICAL CONSEQUENCES TO THE MANGROVES

This paper is about the morphological and biogeographical changes in São Mateus River mouth in Espírito Santo State, southeast of Brazilian coast between 1970 and 2017. During this period the mangrove ecosystem had been disrupted by fluvial-marine processes that affect this part of coast causing several problems to the county of Conceição da Barra as well as to the navigation, to the fisherman and tourism. The evolution of this part of the coast shows that fluvial-marine processes and the precipitation along the basin of São Mateus River changed drastically in 1991 by increased precipitation along the watershed and, consequently, increasing the amount of water at the mouth modifying the estuarine features, which suffered erosion and deposition on the mangroves and restinga. On the other hand, these processes also led to the colonization of new areas by mangroves. These processes are being monitored by a research project which measures the damages over the mangroves and the replacement of another types of vegetation since 1995. This paper presents the changes in morphology in a systemic perspective integrating the vegetation and pluvial attributes in the basin of São Mateus River.

Biogeographic Changes in Forest Soil Microbial Communities of Offshore Islands—A Case Study of Remote Islands in Taiwan

Biogeographic separation has been an important cause of faunal and floral distribution; however, little is known about the differences in soil microbial communities across islands. In this study, we determined the structure of soil microbial communities by analyzing phospholipid fatty acid (PLFA) profiles and comparing enzymatic activities as well as soil physio-chemical properties across five subtropical granite-derived and two tropical volcanic (andesite-derived) islands in Taiwan. Among these islands, soil organic matter, pH, urease, and PLFA biomass were higher in the tropical andesite-derived than subtropical granite-derived islands. Principal component analysis of PLFAs separated these islands into three groups. The activities of soil enzymes such as phosphatase, β-glucosidase, and β-glucosaminidase were positively correlated with soil organic matter and total nitrogen. Redundancy analysis of microbial communities and environmental factors showed that soil parent materials and the climatic difference are critical factors affecting soil organic matter and pH, and consequently the microbial community structure.

A young age of subspecific divergence in the desert locust inferred by ABC random forest.

Dating population divergence within species from molecular data and relating such dating to climatic and biogeographic changes is not trivial. Yet it can help formulating evolutionary hypotheses regarding local adaptation and future responses to changing environments. Key issues include statistical selection of a demographic and historical scenario among a set of possible scenarios, and estimation of the parameter(s) of interest under the chosen scenario. Such inferences greatly benefit from (a) independent information on evolutionary rate and pattern at genetic markers; and (b) new statistical approaches, such as approximate Bayesian computation-random forest (ABC-RF), which provides reliable inference at a low computational cost and the possibility to measure prediction quality at the exact position of the observed data set. Here, we show full potential of the ABC-RF approach including prior knowledge on microsatellite genetic markers to decipher the evolutionary history of the African arid-adapted pest locust, Schistocerca gregaria, with support for a southern colonization of Africa, from a low number of founders of northern origin, dating back 2.6 Ky (90% CI: 0.9-6.6 Ky). We verify that this divergence time estimate accurately reflected true divergence time values by computing accuracy at a local posterior scale from simulated pseudo-observed data sets. The inferred divergence history is better explained by the peculiar biology of S. gregaria, which involves a density-dependent swarming phase with some exceptional spectacular migrations, rather than a continuous colonization resulting from the continental expansion of open vegetation habitats during more ancient Quaternary glacial climatic episodes.

Fuzzy sets allow gaging the extent and rate of species range shift due to climate change

The recent modification of species distribution ranges in response to a warmer climate has constituted a major and generalized biogeographic change. The main driver of the shift in distribution is the disequilibrium of the species ranges with their climatic favourability. Most species distribution modelling approaches assume equilibrium of the distribution with the environment, which hinders their applicability to the analysis of this change. Using fuzzy set theory we assessed the response to climate change of a historically African species, the Atlas Long-legged Buzzard. With this approach we were able to quantify that the Buzzard’s distribution is in a latitudinal disequilibrium of the species distribution with the current climate of 4 km, which is driving the species range northwards at a speed of around 1.3 km/year, i.e., it takes 3 years for the species to occupy new climatically favourable areas. This speed is expected to decelerate to 0.5 km/year in 2060–2080.

An ensemble high‐resolution projection of changes in the future habitat of American lobster and sea scallop in the Northeast US continental shelf

AbstractAimTo address the uncertainty associated with climate‐driven biogeographical changes in commercial fisheries species through an ensemble species distribution modelling (SDM) approach.LocationNortheast US Continental Shelf Large Marine Ecosystem (NEUS‐LME).MethodsWe combined an ensemble SDM platform (BIOMOD 2) and a high‐resolution global climate model (NOAA GFDL CM2.6) to quantify spatiotemporal changes in habitat of two commercially important species in the Northeast US Continental Shelf Large Marine Ecosystem (NEUS‐LME); American lobster (Homarus americanus); and sea scallop (Placopecten magellanicus). An ensemble SDM was calibrated using multi‐decadal fisheries‐independent surveys (1984–2016). Statistically weighted species‐specific ensemble SDM outputs were combined with 80 years of projected bottom temperature and salinity changes in response to a high greenhouse gas emissions scenario (an annual 1% increase in atmospheric CO2).ResultsStatistically significant changes (p < .05) in habitat suitability for both species were found over a large portion of the study area. Sea scallop undergoes a northward shift over the study period, while American lobster moves further offshore. The ensemble projections showed that several management zones were identified with increases and decreases in species‐specific habitat. Uncertainty due to variations in ensemble member models was also found in the direction of change within each management zone.Main conclusionsThis study provides ensemble estimates of climate‐driven changes and associated uncertainties in the biogeography of two economically important species in the United States. Projected climate change in the NEUS‐LME will pose management challenges, and our ensemble projections provide useful information for climate‐ready management of commercial fisheries.

Biological Oxygent Demand (BOD5) as Bio Indicator of Phytoplankton Diversity Index in The Mangrove Area of Kintap Estuary - South Kalimantan

Indonesia as a country that has the largest mangrove area in the world, of course contributes significantly to global climate change. It is known, the mangrove area is an area with abundant biodiversity. The existence of various industrial activities, such as oil palm plantations or special coal port operations make the mangrove area can receive negative impacts. Bio-indicators are living organisms such as plants, planktons, animals, and microbes, which are utilized to screen the health of the natural ecosystem in the environment. They are used for assessing environmental health and bio geographic changes taking place in the environment. The ability of microorganisms to reform the biodegradation process is an indicator of pollutants in the waters. In the process, microorganisms require or consume more dissolved oxygen (DO). So, the higher the concentration of BOD5, the concentration of dissolved oxygen (DO) in water is reduced. This research uses the grab sampling method, which is done 4 times in one year for water quality sampling (BOD5) and aquatic biota samples. The results of this research, showed a significant positive correlation regarding the concentration of BOD5 on biodiversity in mangrove areas. Thus, BOD5 concentration can also be used as an bio-indicator of the quality biodiversity of mangrove areas.

Biogeographic Patterns of Ectomycorrhizal Fungal Communities Associated With Castanopsis sieboldii Across the Japanese Archipelago.

Biogeographic patterns in ectomycorrhizal (ECM) fungal communities and their drivers have been elucidated, including effects of host tree species and abiotic (climatic and edaphic) conditions. At these geographic scales, genotypic diversity and composition of single host tree species change with spatial and environmental gradients, reflecting their historical dispersal events. However, whether the host genotypes can be associated with the biogeographic patterns of ECM communities remains unclear. We investigated the biogeographic pattern of ECM fungal community associated with the single host species Castanopsis sieboldii (Fagaceae), whose genotypic diversity and composition across the Japanese archipelago has already been evaluated. ECM communities were investigated in 12 mature Castanopsis-dominated forests covering almost the entire distribution range of C. sieboldii, and we quantified the effect of host genotypes on the biogeographic pattern of ECM fungal communities. Richness and community composition of ECM fungi changed with latitude and longitude; these biogeographic changes of ECM community were significantly correlated with host genotypic variables. Quantitative analyses showed a higher relative explanatory power of climatic and spatial variables than that of host genotypic variables for the biogeographic patterns in the ECM community. Our results suggest historical events of host dispersal can affect the biogeographic patterns of the ECM fungal community, while their explanation power was lower than that for climatic filtering and/or fungal dispersal.

An environmental (pre)history of European fishing: past and future archaeological contributions to sustainable fisheries.

This paper explores the past and potential contribution of archaeology to marine historical ecology. The primary focus is European fishing of marine and diadromous taxa, with global comparisons highlighting the wider applicability of archaeological approaches. The review illustrates how study of excavated fish bones, otoliths and shells can inform our understanding of: (a) changes in biogeography, including the previous distribution of lost species; (b) long-term fluctuations in the aquatic environment, including climate change; (c) the intensity of exploitation and other anthropogenic effects; (d) trade, commodification and globalisation. These issues are also relevant to inform fisheries conservation and management targets. Equally important, the long (pre)history of European fishing raises awareness of our ecological heritage debt, owed for centuries of wealth, sustenance and well-being, and for which we share collective responsibility. This debt represents both a loss and a reason for optimism, insofar as it is a reservoir of potential to be filled by careful stewardship of our rivers, lakes, seas and oceans.

Biogeographical zonation of rocky intertidal communities along the coast of Peru (3.5-13.5° S Southeast Pacific).

The biogeography of the Peruvian Eastern Pacific coast has been described based on oceanographic parameters and qualitative species occurrence data. This has generated disagreement about the limits and existence of different biogeographic units. In this study, the distribution of rocky-shore macrobenthic communities were recorded over 41 sites along the Peruvian coastline (3.5°S-13.5°S) and analyzed together with historic abiotic data in order to quantitatively evaluate the biogeographic zonation of rocky intertidal communities throughout the region and its relationship with environmental variables to propose an update bioregionalization. Clusters and non-metric multidimensional scaling were performed using Bray-Curtis dissimilarity matrices from abundance data to evaluate biogeographic patterns of dissimilarities of rocky-shore communities. Significant turnover of taxa among defined biogeographical units was tested using permutational multivariate dispersion. Relationships between of the biogeographical community’s structure and environmental factors were examined using Random Forest analysis on datasets available at Bio-Oracle and Jet Propulsion Laboratory—California Institute of Technology. Variation of community structure of 239 taxa depicted three biogeographical units along the region matching Panamic, transitional and Humboldt provinces. Beta diversity analysis indicated a significant turnover of taxa within the transitional unit. Random forest analysis showed a strong correlation between biogeographic units with phosphate, sea surface temperature, nitrate, dissolved oxygen, cloud fraction, and silicates. Our results set the putative limits of three biogeographic units for rocky-shore communities along the coast of Peru, providing base-line information for understanding further biogeographic changes on communities associated with the ongoing regional coastal cooling and impacts of El Niño events.

Thoughts on the Development of Physical Geography in the New Era

Physical geography is the basic discipline of geography and the cornerstone of comprehensive geography research. Based on the main research progress of physical geography, This paper considered the development direction of natural geography in the new era. Driven by global environmental change, physical geography and its sub-disciplines have gained new development in heritage. The research progress of physical geography in recent years mainly includes the integration and deepening of natural geographical processes, the integration of terrestrial surface systems, land-sea interactions and regional ecological environment management applications. The development of physical geography and its sub-disciplines needs to face the global environmental change and human needs, explore the application of new technologies and methods, conduct multi-factor and multi-process integration research, develop and improve geographic models, simulate and predict environmental change and sustainable development, and serve Major national needs and government decisions. In the process of development, it is urgent to pay attention to the following frontier areas and directions:(1) Geomorphology needs to focus on strengthening the relationship between geomorphology and global environmental change and human activities;(2) Biogeography needs to deepen the frontier fields such as attribute geography and global change biogeography. Exploring the spatial distribution of biogeography and human needs in the context of connection changes;(3) Hydrology needs to carry out comprehensive integration research of multi-element, multi-process and multi-scale, and develop emerging subject areas such as ecological hydrology, social hydrology and hydromorphology;(4) Physical Geography needs to be comprehensively introduced into climate change research’s role in the major international climate change research program, the climate change framework convention, etc;(5) Comprehensive physical geography needs to face the country’s major needs, focusing on the coupling of human and land systems In the areas of resource and environmental carrying capacity evaluation, ecological security pattern and ecological civilization construction, etc.;(6) Physical geography needs to deepen the coupling of natural and human elements and process research ‘establishing and developing complex system simulation model’ analysis and simulation change environment Nature, humanity Su coupling mechanism and the dynamic changes of land surface systems.

Evolutionary and biogeographical shifts in response to the Late Ordovician mass extinction

AbstractThe Late Ordovician mass extinction was an interval of high extinction with inferred low ecological selectivity, resulting in little change in community structure after the event. In contrast, the mass extinction may have fundamentally changed evolutionary dynamics in the surviving groups. We investigated the phylogenetic relationships among strophomenoid brachiopods, a diverse brachiopod superfamily that was a primary component of Ordovician ecosystems. Four Ordovician families/subfamilies sampled in the analysis (Rafinesquinidae, Strophomeninae, Glyptomenidae and Furcitellinae) were reconstructed as monophyletic groups, and the base of the strophomenoid clade that dominated the Silurian recovery was reconstructed as diversifying alongside these families during the Middle Ordovician. We time‐calibrated the phylogeny and used geographical occurrences to investigate biogeographical changes in the strophomenoids through time with the R package BiogeoBEARS. Our results indicate that extinction was higher in taxa whose ranges were constrained to tropical or subtropical regions. Furthermore, our results suggest important shifts in the diversification patterns of these brachiopods after the mass extinction. While most of the strophomenoid families survived the Late Ordovician event, ecologically abundant taxonomic groups during the Ordovician were either driven to extinction, reduced in diversity, or slowly died off during the Silurian. The new abundant strophomenoid taxa derived from one clade (consisting of Silurian–Devonian groups such as Douvillinidae, Strophodontidae and Amphistrophiidae) that diversified during the post‐extinction radiation. Our results suggest the selective diversification during the Silurian radiation, rather than selective extinction in the Late Ordovician, had a greater impact on the evolutionary history of strophomenoid brachiopods.

Comparing model parameterizations of the biophysical impacts of ocean acidification to identify limitations and uncertainties

Ocean acidification (OA) driven by anthropogenic CO2 emissions affects marine ecosystems, fisheries and aquaculture. Assessing the impacts of OA using projection models facilitates the development of future scenarios and potential solutions. Here, we explored various ways to incorporate OA impacts into a multi-stressor dynamic bioclimatic envelope model to project biogeographic changes of ten commercially exploited invertebrate species. We examine three dimensions of uncertainties in modelling biophysical OA effects: model structure, parameterization, and scenario uncertainty. Our results show that projected OA impacts are most sensitive to the choice of structural relationship between OA and biological responses, followed by the choice of climate change emission scenarios and parameterizations of the size of OA effects. Species generally showed negative effects to OA but sensitivity to the various sources of uncertainty were not consistent across or within species. For example, some species showed higher sensitivity to structural uncertainty and very low sensitivity to parameter uncertainty, while others showed greatest sensitivity to parameter uncertainty. This variability is largely due to geographic variability and difference in life history traits used to parameterize model simulations. Our model highlights the variability across the sources of uncertainty and contributes to the development of integrating OA impacts in species distribution models. We further stress the importance of defining the limitations and assumptions, as well as exploring the range of uncertainties associated with modelling OA impacts.

Long-term ecological data for conservation: Range change in the black-billed capercaillie (Tetrao urogalloides) in northeast China (1970s-2070s).

Long‐term ecological data can be an effective tool to help ecologists integrate future projections with historical contexts and provide unique insights into the long‐term dynamics of endangered species. However, hampered by data limitations, including incomplete and spatially biased data, relatively few studies have used multidecadal datasets or have examined changes in biogeography from a historical perspective. The black‐billed capercaillie (Tetrao urogalloides) is a large capercaillie (classified as Least Concern [LC] on the IUCN red list) that has undergone a dramatic decline in population during the late 20th century and is considered endangered. Its conservation status is pessimistic, and the species requires immediate protection. Therefore, we supplemented a historical dataset to identify changes in this bird's range and population in northeast China over the long term. The study area spanned Heilongjiang Province, Jilin Province, and the northeast corner of Inner Mongolia in northeast China. We integrated an ecological niche model (BIOMOD2) with long‐term ecological data on this species to estimate the magnitude of change in distribution over time. Our results revealed a 35.25% reduction in the current distribution of this species compared to their potential distribution in the 1970s. This decline is expected to continue under climate change. For example, the future range loss was estimated to be 38.79 ± 0.22% (8.64–90.19%), and the actual state could be worse, because the baseline range of the model was greater than the real range in the 2000s, showing a 12.39% overestimation. To overcome this poor outlook, a conservation strategy should be established in sensitive areas, including the southwestern Greater Khingan Mountains and northern Lesser Khingan Mountains. Actions that should be considered include field investigations, establishing a monitor network, designing ecological corridors, and cooperating with local inhabitants, governments, and conservation biologists to improve the conservation of the black‐billed capercaillie.

Predictions of response to temperature are contingent on model choice and data quality.

The equations used to account for the temperature dependence of biological processes, including growth and metabolic rates, are the foundations of our predictions of how global biogeochemistry and biogeography change in response to global climate change. We review and test the use of 12 equations used to model the temperature dependence of biological processes across the full range of their temperature response, including supra‐ and suboptimal temperatures. We focus on fitting these equations to thermal response curves for phytoplankton growth but also tested the equations on a variety of traits across a wide diversity of organisms. We found that many of the surveyed equations have comparable abilities to fit data and equally high requirements for data quality (number of test temperatures and range of response captured) but lead to different estimates of cardinal temperatures and of the biological rates at these temperatures. When these rate estimates are used for biogeographic predictions, differences between the estimates of even the best‐fitting models can exceed the global biological change predicted for a decade of global warming. As a result, studies of the biological response to global changes in temperature must make careful consideration of model selection and of the quality of the data used for parametrizing these models.

Climate-driven changes in functional biogeography of Arctic marine fish communities.

Climate change triggers poleward shifts in species distribution leading to changes in biogeography. In the marine environment, fish respond quickly to warming, causing community-wide reorganizations, which result in profound changes in ecosystem functioning. Functional biogeography provides a framework to address how ecosystem functioning may be affected by climate change over large spatial scales. However, there are few studies on functional biogeography in the marine environment, and none in the Arctic, where climate-driven changes are most rapid and extensive. We investigated the impact of climate warming on the functional biogeography of the Barents Sea, which is characterized by a sharp zoogeographic divide separating boreal from Arctic species. Our unique dataset covered 52 fish species, 15 functional traits, and 3,660 stations sampled during the recent warming period. We found that the functional traits characterizing Arctic fish communities, mainly composed of small-sized bottom-dwelling benthivores, are being rapidly replaced by traits of incoming boreal species, particularly the larger, longer lived, and more piscivorous species. The changes in functional traits detected in the Arctic can be predicted based on the characteristics of species expected to undergo quick poleward shifts in response to warming. These are the large, generalist, motile species, such as cod and haddock. We show how functional biogeography can provide important insights into the relationship between species composition, diversity, ecosystem functioning, and environmental drivers. This represents invaluable knowledge in a period when communities and ecosystems experience rapid climate-driven changes across biogeographical regions.

Biogeographic responses of the copepod Calanus glacialis to a changing Arctic marine environment.

Dramatic changes have occurred in the Arctic Ocean over the past few decades, especially in terms of sea ice loss and ocean warming. Those environmental changes may modify the planktonic ecosystem with changes from lower to upper trophic levels. This study aimed to understand how the biogeographic distribution of a crucial endemic copepod species, Calanus glacialis, may respond to both abiotic (ocean temperature) and biotic (phytoplankton prey) drivers. A copepod individual-based model coupled to an ice-ocean-biogeochemical model was utilized to simulate temperature- and food-dependent life cycle development of C.glacialis annually from 1980 to 2014. Over the 35-year study period, the northern boundaries of modeled diapausing C.glacialis expanded poleward and the annual success rates of C.glacialis individuals attaining diapause in a circumpolar transition zone increased substantially. Those patterns could be explained by a lengthening growth season (during which time food is ample) and shortening critical development time (the period from the first feeding stage N3 to the diapausing stage C4). The biogeographic changes were further linked to large-scale oceanic processes, particularly diminishing sea ice cover, upper ocean warming, and increasing and prolonging food availability, which could have potential consequences to the entire Arctic shelf/slope marine ecosystems.

Climate and environmental changes driving idiosyncratic shifts in the distribution of tropical and temperate worm reefs

An increasing number of studies have forecast the potential responses of marine life to future climate change. This study predicts how the distributional range of temperate and tropical worm reefs (WRs) might respond to climate and environmental changes (CECs). Compared with current distributions, the tested hypotheses were: (i) under a low CO2concentration and active atmospheric carbon capturing scenario (RCP2.6), both tropical and temperate WRs will maintain their current distributions and face only slight multi-directional biogeographic changes along the century; and (ii) under a high CO2concentration scenario (RCP8.5) WRs will shift toward higher latitudes, with marked changes for tropical species and slight changes for temperate species, specifically at the end of the 21st century. The hypotheses were tested using species distribution modelling, and exploratory statistical analyses were performed to tune model settings. Under scenario RCP2.6, in the middle of the century, areas of suitable habitat are predicted to slightly increase for the temperate WRs and conversely contract for tropical WRs. At the end of the century, multi-directional shifts without range retraction were predicted for both species, but tropical WRs showed major changes in their distribution. Under scenario RCP8.5 and throughout the century, multi-directional shifts increased the areas of suitable habitat for temperate WRs, whereas tropical WRs experienced shifts toward high latitudes and significant retraction at low latitudes. Results indicate that biogeographic range shifts are idiosyncratic for temperate and tropical WRs depending on the CECs scenarios considered.