scholarly journals Marine phytoplankton functional types exhibit diverse responses to thermal change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
S. I. Anderson ◽  
A. D. Barton ◽  
S. Clayton ◽  
S. Dutkiewicz ◽  
T. A. Rynearson
Keyword(s):  
Growth Rates ◽  
Thermal Response ◽  
Marine Phytoplankton ◽  
Future Climate Change ◽  
Change Scenario ◽  
Functional Responses ◽  
Thermal Change ◽  
Functional Types ◽  
Thermal Growth ◽  
Marine Productivity

AbstractMarine phytoplankton generate half of global primary production, making them essential to ecosystem functioning and biogeochemical cycling. Though phytoplankton are phylogenetically diverse, studies rarely designate unique thermal traits to different taxa, resulting in coarse representations of phytoplankton thermal responses. Here we assessed phytoplankton functional responses to temperature using empirically derived thermal growth rates from four principal contributors to marine productivity: diatoms, dinoflagellates, cyanobacteria, and coccolithophores. Using modeled sea surface temperatures for 1950–1970 and 2080–2100, we explored potential alterations to each group’s growth rates and geographical distribution under a future climate change scenario. Contrary to the commonly applied Eppley formulation, our data suggest phytoplankton functional types may be characterized by different temperature coefficients (Q10), growth maxima thermal dependencies, and thermal ranges which would drive dissimilar responses to each degree of temperature change. These differences, when applied in response to global simulations of future temperature, result in taxon-specific projections of growth and geographic distribution, with low-latitude coccolithophores facing considerable decreases and cyanobacteria substantial increases in growth rates. These results suggest that the singular effect of changing temperature may alter phytoplankton global community structure, owing to the significant variability in thermal response between phytoplankton functional types.

scholarly journals Resilience to temperature and pH changes in a future climate change scenario in six strains of the polar diatom <i>Fragilariopsis cylindrus</i>

2015 ◽  
Vol 12 (14) ◽  
pp. 4235-4244 ◽  
Author(s):  
M. Pančić ◽  
P. J. Hansen ◽  
A. Tammilehto ◽  
N. Lundholm
Keyword(s):  
Climate Change ◽  
Growth Rates ◽  
Significant Interaction ◽  
Elevated Temperatures ◽  
Future Climate Change ◽  
Change Scenario ◽  
Ph Tolerance ◽  
Increased Temperature ◽  
Fragilariopsis Cylindrus ◽  
Negative Effect

Abstract. The effects of ocean acidification and increased temperature on physiology of six strains of the polar diatom Fragilariopsis cylindrus from Greenland were investigated. Experiments were performed under manipulated pH levels (8.0, 7.7, 7.4, and 7.1) and different temperatures (1, 5, and 8 °C) to simulate changes from present to plausible future levels. Each of the 12 scenarios was run for 7 days, and a significant interaction between temperature and pH on growth was detected. By combining increased temperature and acidification, the two factors counterbalanced each other, and therefore no effect on the growth rates was found. However, the growth rates increased with elevated temperatures by ~ 20–50 % depending on the strain. In addition, a general negative effect of increasing acidification on growth was observed. At pH 7.7 and 7.4, the growth response varied considerably among strains. However, a more uniform response was detected at pH 7.1 with most of the strains exhibiting reduced growth rates by 20–37 % compared to pH 8.0. It should be emphasized that a significant interaction between temperature and pH was found, meaning that the combination of the two parameters affected growth differently than when considering one at a time. Based on these results, we anticipate that the polar diatom F. cylindrus will be unaffected by changes in temperature and pH within the range expected by the end of the century. In each simulated scenario, the variation in growth rates among the strains was larger than the variation observed due to the whole range of changes in either pH or temperature. Climate change may therefore not affect the species as such, but may lead to changes in the population structure of the species, with the strains exhibiting high phenotypic plasticity, in terms of temperature and pH tolerance towards future conditions, dominating the population.

scholarly journals Resilience to temperature and pH changes in a future climate change scenario in six strains of the polar diatom <i>Fragilariopsis cylindrus</i>

2015 ◽  
Vol 12 (6) ◽  
pp. 4627-4654 ◽  
Author(s):  
M. Pančić ◽  
P. J. Hansen ◽  
A. Tammilehto ◽  
N. Lundholm
Keyword(s):  
Climate Change ◽  
Growth Rates ◽  
Significant Interaction ◽  
Elevated Temperatures ◽  
Future Climate Change ◽  
Change Scenario ◽  
Ph Tolerance ◽  
Increased Temperature ◽  
Fragilariopsis Cylindrus ◽  
Negative Effect

Abstract. The effects of ocean acidification and increased temperature on physiology of six strains of the polar diatom Fragilariopsis cylindrus from Greenland were investigated. Experiments were performed under manipulated pH levels (8.0, 7.7, 7.4, and 7.1) and different temperatures (1, 5 and 8 °C) to simulate changes from present to plausible future levels. Each of the 12 scenarios was run for 7 days, and a significant interaction between temperature and pH on growth was detected. By combining increased temperature and acidification, the two factors counterbalanced each other, and therefore no effect on the growth rates was found. However, the growth rates increased with elevated temperatures by ∼20–50% depending on the strain. In addition, a general negative effect of increasing acidification on growth was observed. At pH 7.7 and 7.4, the growth response varied considerably among strains. However, a more uniform response was detected at pH 7.1 with most of the strains exhibiting reduced growth rates by 20–37% compared to pH 8.0. It should be emphasized that a significant interaction between temperature and pH was found, meaning that the combination of the two parameters affected growth differently than when considering one at a time. Based on these results, we anticipate that the polar diatom F. cylindrus will be unaffected by changes in temperature and pH within the range expected by the end of the century. In each simulated scenario, the variation in growth rates among the strains was larger than the variation observed due to the whole range of changes in either pH or temperature. Climate change may therefore not affect the species as such, but may lead to changes in the population structure of the species, with the strains exhibiting high phenotypic plasticity, in terms of temperature and pH tolerance towards future conditions, dominating the population.

scholarly journals Continental vs. Global Niche-Based Modelling of Freshwater Species’ Distributions: How Big Are the Differences in the Estimated Climate Change Effects?

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 816
Author(s):  
Danijela Markovic ◽  
Jörg Freyhof ◽  
Oskar Kärcher
Keyword(s):  
Climate Change ◽  
Thermal Properties ◽  
Safety Margin ◽  
Thermal Response ◽  
Future Climate Change ◽  
Freshwater Species ◽  
Response Curves ◽  
Preferred Temperature ◽  
Continental Scale ◽  
Management Actions

Thermal response curves that depict the probability of occurrence along a thermal gradient are used to derive various species’ thermal properties and abilities to cope with warming. However, different thermal responses can be expected for different portions of a species range. We focus on differences in thermal response curves (TRCs) and thermal niche requirements for four freshwater fishes (Coregonus sardinella, Pungitius pungitius, Rutilus rutilus, Salvelinus alpinus) native to Europe at (1) the global and (2) European continental scale. European ranges captured only a portion of the global thermal range with major differences in the minimum (Tmin), maximum (Tmax) and average temperature (Tav) of the respective distributions. Further investigations of the model-derived preferred temperature (Tpref), warming tolerance (WT = Tmax − Tpref), safety margin (SM = Tpref − Tav) and the future climatic impact showed substantially differing results. All considered thermal properties either were under- or overestimated at the European level. Our results highlight that, although continental analyses have an impressive spatial extent, they might deliver misleading estimates of species thermal niches and future climate change impacts, if they do not cover the full species ranges. Studies and management actions should therefore favor whole global range distribution data for analyzing species responses to environmental gradients.

scholarly journals An Assessment of Recent and Future Temperature Change over the Sichuan Basin, China, Using CMIP5 Climate Models

2017 ◽  
Vol 30 (17) ◽  
pp. 6701-6722 ◽  
Author(s):  
Daniel Bannister ◽  
Michael Herzog ◽  
Hans-F. Graf ◽  
J. Scott Hosking ◽  
C. Alan Short
Keyword(s):  
Climate Change ◽  
Sichuan Basin ◽  
Climate Models ◽  
Distribution Functions ◽  
Future Climate ◽  
First Century ◽  
Future Climate Change ◽  
Change Scenario ◽  
The Sichuan Basin ◽  
Twenty First Century

The Sichuan basin is one of the most densely populated regions of China, making the area particularly vulnerable to the adverse impacts associated with future climate change. As such, climate models are important for understanding regional and local impacts of climate change and variability, like heat stress and drought. In this study, climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are validated over the Sichuan basin by evaluating how well each model can capture the phase, amplitude, and variability of the regionally observed mean, maximum, and minimum temperature between 1979 and 2005. The results reveal that the majority of the models do not capture the basic spatial pattern and observed means, trends, and probability distribution functions. In particular, mean and minimum temperatures are underestimated, especially during the winter, resulting in biases exceeding −3°C. Models that reasonably represent the complex basin topography are found to generally have lower biases overall. The five most skillful climate models with respect to the regional climate of the Sichuan basin are selected to explore twenty-first-century temperature projections for the region. Under the CMIP5 high-emission future climate change scenario, representative concentration pathway 8.5 (RCP8.5), the temperatures are projected to increase by approximately 4°C (with an average warming rate of +0.72°C decade−1), with the greatest warming located over the central plains of the Sichuan basin, by 2100. Moreover, the frequency of extreme months (where mean temperature exceeds 28°C) is shown to increase in the twenty-first century at a faster rate compared to the twentieth century.

scholarly journals Highly variable iron content modulates iceberg-ocean fertilisation and potential carbon export

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Mark J. Hopwood ◽  
Dustin Carroll ◽  
Juan Höfer ◽  
Eric P. Achterberg ◽  
Lorenz Meire ◽  
...  
Keyword(s):  
Global Analysis ◽  
Marine Phytoplankton ◽  
Climate Feedback ◽  
Carbon Export ◽  
Sediment Distribution ◽  
Fertilization Effect ◽  
Polar Oceans ◽  
Marine Productivity ◽  
Iron Delivery ◽  
Potential Carbon

AbstractMarine phytoplankton growth at high latitudes is extensively limited by iron availability. Icebergs are a vector transporting the bioessential micronutrient iron into polar oceans. Therefore, increasing iceberg fluxes due to global warming have the potential to increase marine productivity and carbon export, creating a negative climate feedback. However, the magnitude of the iceberg iron flux, the subsequent fertilization effect and the resultant carbon export have not been quantified. Using a global analysis of iceberg samples, we reveal that iceberg iron concentrations vary over 6 orders of magnitude. Our results demonstrate that, whilst icebergs are the largest source of iron to the polar oceans, the heterogeneous iron distribution within ice moderates iron delivery to offshore waters and likely also affects the subsequent ocean iron enrichment. Future marine productivity may therefore be not only sensitive to increasing total iceberg fluxes, but also to changing iceberg properties, internal sediment distribution and melt dynamics.

Predicting Climate-Driven Habitat Shifting of the near Threatened Satyr Tragopan (Tragopan Satyra; Galliformes) in the Himalayas

2018 ◽  
Vol 11 (4) ◽  
pp. 221-230 ◽  
Author(s):  
Bijoy Chhetri ◽  
Hemant K. Badola ◽  
Sudip Barat
Keyword(s):  
Climate Change ◽  
Climate Change Scenario ◽  
Azimuth Angle ◽  
Future Climate Change ◽  
Slope Aspect ◽  
Change Scenario ◽  
Bioclimatic Variables ◽  
The Future ◽  
Present Distribution ◽  
Community Assemblages

Current rates of climatic change will affect the structure and function of community assemblages on Earth. In recent decades, advances in modelling techniques have illuminated the potential effects of various climatic scenarios on biodiversity hotspots, including community assemblages in the Himalayas. These techniques have been used to test the effects of representative concentration pathways (RCPs) AR5-2050, based on future greenhouse gas emission trajectories of climate change scenario/year combinations, on pheasants. Current bioclimatic variables, Miroc-esm, Hadgem2-AO and Gfdl-cm3, in future climate change scenario models, were used to predict the future distribution and the gain/loss of future habitat area, within the Himalayas, of the pheasant, Satyr Tragopon (Tragopan satyra). The results indicate that future climatic conditions may significantly affect the future distribution of Satyr Tragopon and the effectiveness of protective areas (PAs). Using the python based GIS toolkit, SDM projection, regions of high risk under climate change scenarios were identified. To predict the present distribution of the species, environment parameters of bioclimatic variables, red reflectance, blue reflectance, solar azimuth angle, altitude, slope, aspect, NDVI, EVI, VI, and LCLU were used. The forest cover (NDVI) and the canopy cover (EVI), and variables affecting forest structure, namely altitude, slope, solar azimuth angle and Bio7, were the primary factors dictating the present distribution of T. satyra. The predicted trend of habitat shifting of T. satyra in the Himalayas to higher altitudes and latitudes will gradually become more prominent with climate warming.

Potential changes in monthly fire risk in the eastern Canadian boreal forest under future climate change

2009 ◽  
Vol 39 (12) ◽  
pp. 2369-2380 ◽  
Author(s):  
Héloïse Le Goff ◽  
Mike D. Flannigan ◽  
Yves Bergeron
Keyword(s):  
Climate Change ◽  
Forest Fires ◽  
Fire Risk ◽  
Weather Conditions ◽  
Future Climate ◽  
Fire Season ◽  
Future Climate Change ◽  
Change Scenario ◽  
Fire Weather Index ◽  
Fire Activity

The main objective of this paper is to evaluate whether future climate change would trigger an increase in the fire activity of the Waswanipi area, central Quebec. First, we used regression analyses to model the historical (1973–2002) link between weather conditions and fire activity. Then, we calculated Fire Weather Index system components using 1961–2100 daily weather variables from the Canadian Regional Climate Model for the A2 climate change scenario. We tested linear trends in 1961–2100 fire activity and calculated rates of change in fire activity between 1975–2005, 2030–2060, and 2070–2100. Our results suggest that the August fire risk would double (+110%) for 2100, while the May fire risk would slightly decrease (–20%), moving the fire season peak later in the season. Future climate change would trigger weather conditions more favourable to forest fires and a slight increase in regional fire activity (+7%). While considering this long-term increase, interannual variations of fire activity remain a major challenge for the development of sustainable forest management.

scholarly journals Amplified Arctic warming by phytoplankton under greenhouse warming

2015 ◽  
Vol 112 (19) ◽  
pp. 5921-5926 ◽  
Author(s):  
Jong-Yeon Park ◽  
Jong-Seong Kug ◽  
Jürgen Bader ◽  
Rebecca Rolph ◽  
Minho Kwon
Keyword(s):  
Ecosystem Model ◽  
Future Climate ◽  
Marine Phytoplankton ◽  
The Arctic ◽  
Future Climate Change ◽  
Greenhouse Warming ◽  
Climate Projections ◽  
Arctic Warming ◽  
Marine Ecosystem Model ◽  
The Future

Phytoplankton have attracted increasing attention in climate science due to their impacts on climate systems. A new generation of climate models can now provide estimates of future climate change, considering the biological feedbacks through the development of the coupled physical–ecosystem model. Here we present the geophysical impact of phytoplankton, which is often overlooked in future climate projections. A suite of future warming experiments using a fully coupled ocean−atmosphere model that interacts with a marine ecosystem model reveals that the future phytoplankton change influenced by greenhouse warming can amplify Arctic surface warming considerably. The warming-induced sea ice melting and the corresponding increase in shortwave radiation penetrating into the ocean both result in a longer phytoplankton growing season in the Arctic. In turn, the increase in Arctic phytoplankton warms the ocean surface layer through direct biological heating, triggering additional positive feedbacks in the Arctic, and consequently intensifying the Arctic warming further. Our results establish the presence of marine phytoplankton as an important potential driver of the future Arctic climate changes.

scholarly journals Using species distribution models to infer potential climate change-induced range shifts of freshwater fish in south-eastern Australia

2011 ◽  
Vol 62 (9) ◽  
pp. 1043 ◽  
Author(s):  
Nick Bond ◽  
Jim Thomson ◽  
Paul Reich ◽  
Janet Stein
Keyword(s):  
Climate Change ◽  
Freshwater Fish ◽  
Species Distribution ◽  
Climate Change Scenario ◽  
Species Distribution Models ◽  
Range Shifts ◽  
Future Climate Change ◽  
Change Scenario ◽  
Climate Change Scenarios ◽  
Distribution Models

There are few quantitative predictions for the impacts of climate change on freshwater fish in Australia. We developed species distribution models (SDMs) linking historical fish distributions for 43 species from Victorian streams to a suite of hydro-climatic and catchment predictors, and applied these models to explore predicted range shifts under future climate-change scenarios. Here, we present summary results for the 43 species, together with a more detailed analysis for a subset of species with distinct distributions in relation to temperature and hydrology. Range shifts increased from the lower to upper climate-change scenarios, with most species predicted to undergo some degree of range shift. Changes in total occupancy ranged from –38% to +63% under the lower climate-change scenario to –47% to +182% under the upper climate-change scenario. We do, however, caution that range expansions are more putative than range contractions, because the effects of barriers, limited dispersal and potential life-history factors are likely to exclude some areas from being colonised. As well as potentially informing more mechanistic modelling approaches, quantitative predictions such as these should be seen as representing hypotheses to be tested and discussed, and should be valuable for informing long-term strategies to protect aquatic biota.

scholarly journals Impacts of Stratospheric Sulfate Geoengineering on Global Solar Photovoltaic and Concentrating Solar Power Resource

2017 ◽  
Vol 56 (5) ◽  
pp. 1483-1497 ◽  
Author(s):  
Christopher J. Smith ◽  
Julia A. Crook ◽  
Rolf Crook ◽  
Lawrence S. Jackson ◽  
Scott M. Osprey ◽  
...  
Keyword(s):  
Solar Power ◽  
Climate Model ◽  
Diffuse Radiation ◽  
Lower Atmosphere ◽  
Energy Output ◽  
Future Climate Change ◽  
Change Scenario ◽  
Solar Photovoltaic ◽  
Concentrating Solar Power ◽  
Direct Radiation

AbstractIn recent years, the idea of geoengineering, artificially modifying the climate to reduce global temperatures, has received increasing attention because of the lack of progress in reducing global greenhouse gas emissions. Stratospheric sulfate injection (SSI) is a geoengineering method proposed to reduce planetary warming by reflecting a proportion of solar radiation back into space that would otherwise warm the surface and lower atmosphere. The authors analyze results from the Met Office Hadley Centre Global Environment Model, version 2, Carbon Cycle Stratosphere (HadGEM2-CCS) climate model with stratospheric emissions of 10 Tg yr−1 of SO2, designed to offset global temperature rise by around 1°C. A reduction in concentrating solar power output of 5.9% on average over land is shown under SSI relative to a baseline future climate change scenario (RCP4.5) caused by a decrease in direct radiation. Solar photovoltaic energy is generally less affected as it can use diffuse radiation, which increases under SSI, at the expense of direct radiation. The results from HadGEM2-CCS are compared with the Goddard Earth Observing System Chemistry–Climate Model (GEOSCCM) from the Geoengineering Model Intercomparison Project (GeoMIP), with 5 Tg yr−1 emission of SO2. In many regions, the differences predicted in solar energy output between the SSI and RCP4.5 simulations are robust, as the sign of the changes for both HadGEM2-CCS and GEOSCCM agree. Furthermore, the sign of the total and direct annual mean radiation changes evaluated by HadGEM2-CCS agrees with the sign of the multimodel mean changes of an ensemble of GeoMIP models over the majority of the world.

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