Towards an Understanding of Large-Scale Biodiversity Patterns on Land and in the Sea

This review presents a recent theory named ‘macroecological theory on the arrangement of life’ (METAL). This theory is based on the concept of the ecological niche and shows that the niche-environment (including climate) interaction is fundamental to explain many phenomena observed in nature from the individual to the community level (e.g., phenology, biogeographical shifts, and community arrangement and reorganisation, gradual or abrupt). The application of the theory in climate change biology as well as individual and species ecology has been presented elsewhere. In this review, I show how METAL explains why there are more species at low than high latitudes, why the peak of biodiversity is located at mid-latitudes in the oceanic domain and at the equator in the terrestrial domain, and finally why there are more terrestrial than marine species, despite the fact that biodiversity has emerged in the oceans. I postulate that the arrangement of planetary biodiversity is mathematically constrained, a constraint we previously called ‘the great chessboard of life’, which determines the maximum number of species that may colonise a given region or domain. This theory also makes it possible to reconstruct past biodiversity and understand how biodiversity could be reorganised in the context of anthropogenic climate change

North Atlantic pelagic biodiversity and hydro-meteorological variability

PARIS-BIUSJ-Thèses (751052125) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocPARIS-BIUSJ-Sci.Terre recherche (751052114) / SudocSudocFranceF

Conséquences des changements climatiques en milieu océanique

Climate change is unambiguous and its effects are clearly detected in all functional units of the Earth System. This paper presents analyses of sea surface temperature and show that climate change is affecting both biological and ecological systems of the world and most specifically the North Atlantic and its adjacent seas. Changes are seen from phytoplankton to zooplankton to fish and are modifying the dominance of species and the structure, the diversity and the functioning of marine ecosystems. Changes also range from biogeographical to phenological shifts and have involved in some regions of the Atlantic abrupt ecosystem shifts also called regime shifts. These alterations reflect the response of ecosystems to a warmer temperature regime. Mechanisms are complex because they are nonlinear exhibiting tipping points and varying in space and time. Sensitivity of organisms to temperature changes is high, implicating that a small modification in the temperature regime can have sustained ecosystem effects. It is urgent to develop monitoring systems, indicators and both statistical and mathematical tools to detect, better understand and anticipate the alterations of both biological and ecological systems that may be triggered by global climate change

Conséquences des changements climatiques en milieu océanique

Climate change is unambiguous and its effects are clearly detected in all functional units of the Earth System. This paper presents analyses of sea surface temperature and show that climate change is affecting both biological and ecological systems of the world and most specifically the North Atlantic and its adjacent seas. Changes are seen from phytoplankton to zooplankton to fish and are modifying the dominance of species and the structure, the diversity and the functioning of marine ecosystems. Changes also range from biogeographical to phenological shifts and have involved in some regions of the Atlantic abrupt ecosystem shifts also called regime shifts. These alterations reflect the response of ecosystems to a warmer temperature regime. Mechanisms are complex because they are nonlinear exhibiting tipping points and varying in space and time. Sensitivity of organisms to temperature changes is high, implicating that a small modification in the temperature regime can have sustained ecosystem effects. It is urgent to develop monitoring systems, indicators and both statistical and mathematical tools to detect, better understand and anticipate the alterations of both biological and ecological systems that may be triggered by global climate change

How Do Marine Pelagic Species Respond to Climate Change? Theories and Observations

International audienceIn this review, we show how climate affects species, communities, and ecosystems, and why many responses from the species to the biome level originate from the interaction between the species’ ecological niche and changes in the environmental regime in both space and time. We describe a theory that allows us to understand and predict how marine species react to climate-induced changes in ecological conditions, how communities form and are reconfigured, and so how biodiversity is arranged and may respond to climate change. Our study shows that the responses of species to climate change are therefore intelligible—that is, they have a strong deterministic component and can be predicted

Reliability of spatial and temporal patterns of <i>C. finmarchicus</i> inferred from the CPR survey

International audienceThe Continuous Plankton Recorder (CPR) survey has collected plankton since 1958 in the North Atlantic Ocean and its adjacent seas. Among all species recorded by the CPR, Calanus finmarchicus has probably been the most investigated species because of its ecological importance for the temperate and subpolar regions of the North Atlantic Ocean. However, abundances of C. finmarchicus assessed from the CPR survey have been rarely compared to more traditional sampling methodologies. In this study, we examine and compare spatial (surface and vertical) and temporal (diel and seasonal) patterns in the abundance of C. finmarchicus with another sampling technique in the gulf of Maine. Our results provide evidence that the CPR survey not only gives internally consistent time series of C. finmarchicus, but also an accurate representation of both spatial (surface and vertical) and temporal (diel and seasonal) patterns

Cod in a changing climate Match-mismatch and Threshold for the North Sea cod recruitment

Climatic changes are disrupting otherwise tight trophic interactions between predator and prey. Most of the earlier studies have primarily focused on the temporal dimension of the relationship in the framework of the match-mismatch hypothesis. Using a novel timeseries model explicitly quantifying both timing and the abundance component for predator-prey relationship, we show that timing and abundance of food affect the northsea cod (Gadus morhua) recruitment. The system shows a strong effect of matchmismatch; however, it does so in association with food abundance. The food abundance was shown to have a threshold effect on recruitment. This non-linear effect may explain the difficulties to reveal the mechanisms by which environment variability affects marine ecosystems. As such the quantification of the combined effect of abundance and timing of prey on predator dynamics will improve our ability to detect the effect of environmental changes on trophic interactions

Evidence for effects on the North Sea ecosystem due to varying oceanic inflow over the last 100 years

Oceanic inflow is estimated to contribute more than 90% of the nutrient input into the North Sea (NSTF, 1993). Variability in the volume, chemical properties, biological content and source of the inflowing water is thus likely to have a considerable effect on North Sea ecosystems. Changes seen in the plankton over the last 40 years, measured by the Continuous Plankton Recorder (CPR) survey, allow clear periods to be identified that appear to be associated with variability in inflow. Monthly estimates of inflow, outflow and netflow across a section between Orkney and Utsira in Norway, have been derived from runs of the NORWECOM model for two depth intervals: surface to 150m and >150m. A comparison is made between these modelled physical measurements and plankton results for the period 1958 to 1999. Distinguished plankton periods that appear to reflect changing inflow events are discussed in relation to hydrometeorological and fisheries variability and earlier plankton studies over approximately the last 100 years

Impact sur les systèmes biologiques aquatiques

National audienc

Impact sur les systèmes biologiques aquatiques

National audienc