Search results for "Clima"
showing 10 items of 6069 documents
Predicting shifting sustainability trade-offs in marine finfish aquaculture under climate change
2018
Defining sustainability goals is a crucial but difficult task because it often involves the quantification of multiple interrelated and sometimes conflicting components. This complexity may be exacerbated by climate change, which will increase environmental vulnerability in aquaculture and potentially compromise the ability to meet the needs of a growing human population. Here, we developed an approach to inform sustainable aquaculture by quantifying spatio-temporal shifts in critical trade-offs between environmental costs and benefits using the time to reach the commercial size as a possible proxy of economic implications of aquaculture under climate change. Our results indicate that optim…
Seasonal and ontogenetic shifts in the diet of Arctic charr Salvelinus alpinus in a subarctic lake.
2010
Seasonal and ontogenetic shifts in the diet of Arctic charr Salvelinus alpinus were studied in a deep, ultra-oligotrophic lake in subarctic Finland from both stomach contents and the stable carbon (delta(13)C) and nitrogen (delta(15)N) isotope compositions of muscle and liver tissues. Both diet and isotope results indicated that the S. alpinus population relied mainly on littoral benthic energy sources. The strong littoral reliance appeared largely independent of season or fish size, although the data lacked small (total length, L(T),130 mm) and young (3 years) S. alpinus. Liver isotope values of intermediate-sized S. alpinus (200-350 mm), however, suggested exploitation of the increase in …
The antagonistic effect of UV radiation on warming or nitrate enrichment depends on ecotypes of freshwater macroalgae (Charophytes).
2019
Increases in ultraviolet radiation (UVR), a negative global change factor, affect aquatic primary producers. This effect is expected to be modulated by other global change factors, and to be different for populations adapted to different environments. A common garden experimental approach using freshwater green macroalgae, the cosmopolitan charophyte species Chara hispida and C. vulgaris, allowed us to test whether the beneficial increases in water temperature (T) and nitrate concentration (N) mitigate negative UVR effects. Also, whether these interactions would be not only species-specific but also according to the origin of the population; therefore, two populations of each species were u…
Seasonal fluctuations in leaf phenolic composition under UV manipulations reflect contrasting strategies of alder and birch trees
2010
Seasonal variation in leaf phenolic composition may be important for acclimation of plants to seasonal changes in their biotic and abiotic environment. For a realistic assessment of how plants respond to solar UV-B (280-315 nm) and UV-A (315-400 nm) radiation, seasonal variation in both environment and plant responses needs to be taken into account. This also has implications for studies concerning stratospheric ozone depletion and resulting increased UV-B radiation, as other environmental variables and/or plant phenology could interact with UV radiation. To elucidate this, we established a field experiment using plastic films attenuating different parts of the solar UV spectrum. The concen…
Global functional variation in alpine vegetation
2021
International audience; Questions. What are the functional trade-offs of vascular plant species in global alpine ecosystems? How is functional variation related to vegetation zones, climatic groups and biogeographic realms? What is the relative contribution of macroclimate and evolutionary history in shaping the functional variation of alpine plant communities? Location. Global. Methods. We compiled a data set of alpine vegetation with 5,532 geo-referenced plots, 1,933 species and six plant functional traits. We used principal component analysis to quantify functional trade-offs among species and trait probability density to assess the functional dissimilarity of alpine vegetation in differ…
Do plant-based biogeographical regions shape aphyllophoroid fungal communities in Europe?
2018
Aim: Aphyllophoroid fungi are associated with plants, either using plants as a resource (as parasites or decomposers) or as symbionts (as mycorrhizal partners). In spite of their strong association with plants, it is unknown how much plant distributions determine their biogeographical patterns compared with environmental factors such as climate and human land use. In this study, our aims are to (1) describe the spatial diversity patterns of aphyllophoroid fungi in Europe and (2) identify the factors shaping these patterns. Location: Europe, as well as the adjacent Subarctic to Arctic islands (Greenland, Faroe Islands, Iceland, Svalbard), Palestine and the south-east coast of the Caspian Sea…
Scale- and taxon-dependent patterns of plant diversity in steppes of Khakassia, South Siberia (Russia)
2016
The drivers of plant richness at fine spatial scales in steppe ecosystems are still not sufficiently understood. Our main research questions were: (i) How rich in plant species are the natural steppes of Southern Siberia compared to natural and semi-natural grasslands in other regions of the Palaearctic? (ii) What are the main environmental drivers of the diversity patterns in these steppes? (iii) What are the diversity-environment relationships and do they vary between spatial scales and among different taxonomic groups? We sampled the steppe vegetation (vascular plants, bryophytes and lichens) in Khakassia (Russia) with 39 nested-plot series (0.0001-100-m(2) plot size) and 54 additional 1…
Increasing water temperature and disease risks in aquatic systems: Climate change increases the risk of some, but not all, diseases
2010
Global warming may impose severe risks for aquatic animal health if increasing water temperature leads to an increase in the incidence of parasitic diseases. Essentially, this could take place through a temperature-driven effect on the epidemiology of the disease. For example, higher temperature may boost the rate of disease spread through positive effects on parasite fitness in a weakened host. Increased temperature may also lengthen the transmission season leading to higher total prevalence of infection and more widespread epidemics. However, to date, general understanding of these relationships is limited due to scarcity of long-term empirical data. Here, we present one of the first long…
Influence of Riverine Input on Norwegian Coastal Systems
2020
Coastal ecosystems are of high ecological and socioeconomic importance and are strongly influenced by processes from land, sea, and human activities. In this study, we present physical, chemical, and biological observations over two consecutive years from three study regions along the Norwegian coast that represent a broad latitudinal gradient in catchment and oceanographic conditions (∼59–69°N): outer Oslofjord/southern Norway, Runde/western Norway, and Malangen/northern Norway. The observations included river monitoring, coastal monitoring, and sensor-equipped ships of opportunity (“FerryBox”). The riverine discharge and transports were an order of magnitude higher, and the spatiotemporal…
Satellite survey of seasonal trophic status and occasional anoxic 'malaigue' crises in the Thau lagoon using MERIS images
2011
International audience; The Thau lagoon, located in southern France, suffers episodically from anoxic crises locally known as 'malaigue'. Such crises mostly occur under warm conditions, low winds leading to a strong eutrophication of the lagoon. The development of a sulphur bacterium sometimes gives locally to the waters a 'milky turquoise' appearance and leads to shellfish mortality. One of the indicators of the eutrophication status of the lagoon can be surveyed by the chlorophyll product provided by remote sensing images such as Medium Resolution Imaging Spectrometer (MERIS). In this paper we compare chl2 (or algal2) estimations provided by MERIS level 2 products and the ground measureme…