scholarly journals Local-Scale Thermal History Influences Metabolic Response of Marine Invertebrates To Warming

2021 ◽  
Author(s):  
Racine E. Rangel ◽  
Cascade J.B. Sorte
Keyword(s):  
Climate Change ◽  
Metabolic Rate ◽  
Thermal History ◽  
Metabolic Response ◽  
Thermal Sensitivity ◽  
Hermit Crabs ◽  
Future Climate Change ◽  
Tide Pool ◽  
Time Periods ◽  
The Relationship

Abstract As climate change continues, anticipating species’ responses to rising temperatures, requires an understanding of the relationship between metabolic rate and thermal sensitivity, which itself may vary over space and time. We measured metabolic rates of three representative marine invertebrate species (hermit crabs Pagurus hirsutiusculus, periwinkle snails Littorina sitkana, and mussels Mytilus trossulus) and evaluated the relationship between thermal sensitivity (Q10) and thermal history. We tested the hypothesis that thermal history drives thermal sensitivity and quantified how this relationship differs over time (short-term to seasonal time scales) and between species. Organisms were collected from tide pools in Sitka, Alaska where we also recorded temperatures to characterize thermal history prior to metabolic rate assays. Using respirometry, we estimated mass-specific oxygen consumption (MO2) at ambient and increased temperatures for one individual per species per tide pool across three seasons. We evaluated relationships between thermal sensitivity and pool temperatures for time periods ranging from 1 day to 3 months prior to collection. For all species, thermal sensitivity was related to thermal history for the shorter time periods (1 day to 1 week). However, the direction of the relationships and most important thermal parameters (i.e., maximum, mean, or range) differed between species and seasons. We found that on average, P. hirsutiusculus and L. sitkana were more thermally sensitive than M. trossulus. These findings show that variability in thermal history over small spatial scales influences individuals’ metabolic response to warming and may be indicative of these species’ ability to acclimate to future climate change.

scholarly journals Impact of future climate change on water supply and irrigation demand in a small mediterranean catchment. Case study: Nebhana dam system, Tunisia

2019 ◽  
Vol 11 (4) ◽  
pp. 1724-1747 ◽  
Author(s):  
M. Allani ◽  
R. Mezzi ◽  
A. Zouabi ◽  
R. Béji ◽  
F. Joumade-Mansouri ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Supply ◽  
General Circulation ◽  
General Circulation Models ◽  
Future Climate ◽  
Annual Rainfall ◽  
Future Climate Change ◽  
Cycle Duration ◽  
Climate Change Scenarios ◽  
Time Periods

Abstract This study evaluates the impacts of climate change on water supply and demand of the Nebhana dam system. Future climate change scenarios were obtained from five general circulation models (GCMs) of CMIP5 under RCP 4.5 and 8.5 emission scenarios for the time periods, 2021–2040, 2041–2060 and 2061–2080. Statistical downscaling was applied using LARS-WG. The GR2M hydrological model was calibrated, validated and used as input to the WEAP model to assess future water availability. Expected crop growth cycle lengths were estimated using a growing degree days model. By means of the WEAP-MABIA method, projected crop and irrigation water requirements were estimated. Results show an average increase in annual ETo of 6.1% and a decrease in annual rainfall of 11.4%, leading to a 24% decrease in inflow. Also, crops' growing cycles will decrease from 5.4% for wheat to 31% for citrus trees. The same tendency is observed for ETc. Concerning irrigation requirement, variations are more moderated depending on RCPs and time periods, and is explained by rainfall and crop cycle duration variations. As for demand and supply, results currently show that supply does not meet the system demand. Climate change could worsen the situation unless better planning of water surface use is done.

In-stream wetland deposits, megadroughts, and cultural change in the northern Atacama Desert, Chile

2019 ◽  
Vol 91 (1) ◽  
pp. 63-80 ◽  
Author(s):  
Craig D. Tully ◽  
Jason A. Rech ◽  
T. Race Workman ◽  
Calogero M. Santoro ◽  
José M. Capriles ◽  
...  
Keyword(s):  
Climate Change ◽  
Cultural Change ◽  
Regional Climate ◽  
Atacama Desert ◽  
Regional Climate Change ◽  
Synoptic Climatology ◽  
Future Climate Change ◽  
San Salvador ◽  
Fluvial Terraces ◽  
The Relationship

AbstractA key concern regarding current and future climate change is the possibility of sustained droughts that can have profound impacts on societies. As such, multiple paleoclimatic proxies are needed to identify megadroughts, the synoptic climatology responsible for these droughts, and their impacts on past and future societies. In the hyperarid Atacama Desert of northern Chile, many streams are characterized by perennial flow and support dense in-stream wetlands. These streams possess sequences of wetland deposits as fluvial terraces that record past changes in the water table. We mapped and radiocarbon dated a well-preserved sequence of in-stream wetland deposits along a 4.3-km reach of the Río San Salvador in the Calama basin to determine the relationship between regional climate change and the incision of in-stream wetlands. The Río San Salvador supported dense wetlands from 11.1 to 9.8, 6.4 to 3.5, 2.8 to 1.3, and 1.0 to 0.5 ka and incised at the end of each of these intervals. Comparison with other in-stream wetland sequences in the Atacama Desert, and with regional paleoclimatic archives, indicates that in-stream wetlands responded similarly to climatic changes by incising during periods of extended drought at ~9.8, 3.5, 1.3, and 0.5 ka.

scholarly journals Adaptive evolution shapes the present-day distribution of the thermal sensitivity of population growth rate

2019 ◽  
Author(s):  
Dimitrios - Georgios Kontopoulos ◽  
Thomas P. Smith ◽  
Timothy G. Barraclough ◽  
Samraat Pawar
Keyword(s):  
Climate Change ◽  
Growth Rate ◽  
Adaptive Evolution ◽  
Thermal Performance ◽  
Population Growth Rate ◽  
Thermal Sensitivity ◽  
Rapid Evolution ◽  
Performance Curve ◽  
Thermal Performance Curve ◽  
The Relationship

AbstractDeveloping a thorough understanding of how ectotherm physiology adapts to different thermal environments is of crucial importance, especially in the face of global climate change. A key aspect of an organism’s thermal performance curve—the relationship between fitness-related trait performance and temperature—is its thermal sensitivity, i.e., the rate at which trait values increase with temperature within its typically-experienced thermal range. For a given trait, the distribution of thermal sensitivities across species, often quantified as “activation energy” values, is typically right-skewed. Currently, the mechanisms that generate this distribution are unclear, with considerable debate about the role of thermodynamic constraints vs adaptive evolution. Here, using a phylogenetic comparative approach, we study the evolution of the thermal sensitivity of population growth rate across phytoplankton (Cyanobacteria and eukaryotic microalgae) and prokaryotes (bacteria and archaea), two microbial groups that play a major role in the global carbon cycle. We find that thermal sensitivity across these groups is moderately phylogenetically heritable, and that its distribution is shaped by repeated evolutionary convergence throughout its parameter space. More precisely, we detect bursts of adaptive evolution in thermal sensitivity, increasing the amount of overlap among its distributions in different clades. We obtain qualitatively similar results from evolutionary analyses of the thermal sensitivities of two physiological rates underlying growth rate: net photosynthesis and respiration of plants. Furthermore, we find that these episodes of evolutionary convergence are consistent with two opposing forces: decrease in thermal sensitivity due to environmental fluctuations and increase due to adaptation to stable environments. Overall, our results indicate that adaptation can lead to large and relatively rapid shifts in thermal sensitivity, especially in microbes where rapid evolution can occur at short time scales. Thus, more attention needs to be paid to elucidating the implications of rapid evolution in organismal thermal sensitivity for ecosystem functioning.Author summaryChanges in environmental temperature influence the performance of biological traits (e.g., respiration rate) in ectotherms, with the relationship between trait performance and temperature (the “thermal performance curve”) being single-peaked. Understanding how thermal performance curves adapt to different environments is important for predicting how organisms will be impacted by climate change. One key aspect of the shape of these curves is the thermal sensitivity near temperatures typically experienced by the species. Whether and how thermal sensitivity responds to different environments is a topic of active debate. To shed light on this, here we perform an evolutionary analysis of the thermal sensitivity of three key traits of prokaryotes, phytoplankton, and plants. We show that thermal sensitivity does not evolve in a gradual manner, but can differ considerably even between closely related species. This suggests that thermal sensitivity undergoes rapid adaptive evolution, which is further supported by our finding that thermal sensitivity varies weakly with latitude. We conclude that variation in thermal sensitivity arises partly from adaptation to environmental factors and that this may need to be accounted for in ecophysiological models.

scholarly journals Radial Growth Response of Abies georgei to Climate at the Upper Timberlines in Central Hengduan Mountains, Southwestern China

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 606 ◽  
Author(s):  
Dingcai Yin ◽  
Derong Xu ◽  
Kun Tian ◽  
Derong Xiao ◽  
Weiguo Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Radial Growth ◽  
Future Climate Change ◽  
Hengduan Mountains ◽  
Growth Responses ◽  
Negative Effects ◽  
Climate Trend ◽  
Positive Effects ◽  
Monthly Total Precipitation ◽  
The Relationship

Climate change has an inevitable impact on tree radial growth, particularly at mountain timeberlines. To understand climate effects on conifer radial growth in the central Hengduan Mountains, and the potential impacts of future climate change on conifer forests, we studied the growth responses to climate variables in Abies georgei, the major tree species of conifer forest in the Hengduan Mountains. We collected tree ring samples from four sites near the timberlines and analyzed the relationship between principle components (PC#1) of four chronologies and climatic variables (monthly mean temperature and monthly total precipitation) by using response function analysis (RFA), redundancy analysis (RDA), and moving interval analysis (MIA). A. georgei growth was affected by both temperature (positive effects) and precipitation (negative effects). Specifically, the radial growth of A. georgei was significantly and positively correlated with current July (by 6.1%) and previous November temperature (by 17.3%) (detected by both RFA and RDA), while precipitation of current June (by 6.6%) and September (by 11.7%) inhibited tree growth (detected by RDA). More rapid warming in the most recent 20 years (1990–2010) clearly enhanced growth responses to July and November temperature, whereas the relationship was weakened for June and September precipitation, according to MIA. Under the climate trend of the study area, if the increasing temperature could offset the negative effects of excessive precipitation, A. georgei radial growth would likely benefit from warming.

scholarly journals Moderate levels of Eocene pCO2 indicated by Southern Hemisphere fossil plant stomata

Geology ◽  
2019 ◽  
Vol 47 (10) ◽  
pp. 914-918 ◽  
Author(s):  
Margret Steinthorsdottir ◽  
Vivi Vajda ◽  
Mike Pole ◽  
Guy Holdgate
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Climate Sensitivity ◽  
Climate Models ◽  
Future Climate Change ◽  
Fossil Plant ◽  
Time Intervals ◽  
Data Record ◽  
Climate Forcings ◽  
The Relationship

Abstract Reducing the uncertainty in predictions of future climate change is one of today’s greatest scientific challenges, with many significant problems unsolved, including the relationship between pCO2 and global temperature. To better constrain these forecasts, it is meaningful to study past time intervals of global warmth, such as the Eocene (56.0–33.9 Ma), serving as climatic analogues for the future. Here we reconstructed pCO2 using the stomatal densities of a large fossil Lauraceae (laurel) leaf database from ten sites across the Eocene of Australia and New Zealand. We show that mostly moderate pCO2 levels of ∼450–600 ppm prevailed throughout the Eocene, levels that are considerably lower than the pCO2 forcing currently needed to recreate Eocene temperatures in climate models. Our data record significantly lower pCO2 than inferred from marine isotopes, but concur with previously published Northern Hemisphere Eocene stomatal proxy pCO2. We argue that the now globally consistent stomatal proxy pCO2 record for the Eocene is robust and that climate sensitivity was elevated and/or that additional climate forcings operated more powerfully than previously assumed.

scholarly journals Radial Growth Response of Abies georgei to Climate at the Upper Timberlines in Central Hengduan Mountains, Southwestern China

2018 ◽  
Author(s):  
Dingcai Yin ◽  
Derong Xu ◽  
Kun Tian ◽  
Derong Xiao ◽  
Weiguo Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Radial Growth ◽  
Future Climate Change ◽  
Hengduan Mountains ◽  
Conifer Forest ◽  
Growth Responses ◽  
Negative Effects ◽  
Climate Trend ◽  
Positive Effects ◽  
The Relationship

Climate change has a inevitable impacts on tree radial growth, particularly at mountain timeberlines. To understand climate effects on conifer radial growth in the central Hengduan Mountains and potential impacts of future climate change on conifer forest, we studied growth responses to climate variables in Abies georgei, the major tree species of conifer forest in Hengduan Mountains. We collected tree ring samples from four sites near the timberlines and analyzed the relationship between principle components (PC#1) of four chronologies and climatic variables by using response function analysis (RFA), redundancy analysis (RDA) and moving interval analysis (MIA). A. georgei growth was affected by both temperature (positive effects) and precipitation (negative effects). Specifically, the radial growth of A. georgei was significantly and positively correlated with current July and previous November temperature (detected by both RFA and RDA), while precipitation of current June and September inhibited tree growth (detected by RDA). More rapid warming in recent 20 years (1990–2010) clearly enhanced growth responses to July and November temperature, whereas the relationship was weaken for June and September precipitation according to MIA. Under the climate trend of the study area, if the increasing temperature could offset the negative effects of excessive precipitation, A. georgei radial growth would likely benefit from warming, the dynamics of conifer forest should also consider indirect impacts of climate change.

scholarly journals From days to decades: numerical modeling of freshwater lens response to climate change stressors on small islands

2014 ◽  
Vol 11 (10) ◽  
pp. 11439-11487 ◽  
Author(s):  
S. Holding ◽  
D. M. Allen
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Spatial Scales ◽  
Future Climate Change ◽  
Small Islands ◽  
Freshwater Lens ◽  
Andros Island ◽  
Time Periods

Abstract. Freshwater lenses on small islands are vulnerable to many climate change related stressors, which can act over relatively long time periods, on the order of decades (e.g. sea level rise, changes in recharge), or short time periods, such as days (storm surge overwash). This study evaluates response of the freshwater lens on a small low-lying island to various stressors. To account for the varying temporal and spatial scales of the stressors, two different density-dependent flow and solute transport codes are used: SEAWAT and HydroGeoSphere. The study site is Andros Island in the Bahamas, which is characteristic of other low-lying carbonate islands in the Caribbean and South Pacific regions. In addition to projected sea level rise and reduced recharge under future climate change, Andros Island experienced a storm surge overwash event during Hurricane Francis in 2004, which contaminated the main wellfield. Simulations of reduced recharge result in up to 19% loss of freshwater lens volume, while sea level rise contributes up to 5% volume loss. The lens responds relatively quickly to these stressors, within 0.5 to 3 years. Simulations of the storm surge overwash indicate that the freshwater lens recovers over time; however, prompt remedial action can restore the lens to potable concentrations up to one month sooner.

Climate change and ticks: measuring impacts.

2021 ◽  
pp. 84-89
Author(s):  
Richard Wall ◽  
Saeed Alasmari
Keyword(s):  
Climate Change ◽  
Metabolic Rate ◽  
Disease Incidence ◽  
Rate Measurement ◽  
Tick Abundance ◽  
The Impact ◽  
The Relationship

Abstract This chapter focuses on the relationship between climate change and changes in tick abundance, phenology and disease incidence. It discusses evidences and limitations as well as novel tools (such as metabolic rate measurement) for detecting the impact of climate on ticks.

Hypoxic metabolic response of the golden-mantled ground squirrel

2001 ◽  
Vol 91 (2) ◽  
pp. 603-612 ◽  
Author(s):  
Renata C. H. Barros ◽  
Mary E. Zimmer ◽  
Luiz G. S. Branco ◽  
William K. Milsom
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Small Mammals ◽  
Ground Squirrel ◽  
Metabolic Response ◽  
Ground Squirrels ◽  
Metabolic Rates ◽  
The Relationship ◽  
Primary Strategy

We examined the magnitude of the hypoxic metabolic response in golden-mantled ground squirrels to determine whether the shift in thermoregulatory set point (Tset) and subsequent fall in body temperature (Tb) and metabolic rate observed in small mammals were greater in a species that routinely experiences hypoxic burrows and hibernates. We measured the effects of changing ambient temperature (Ta; 6–29°C) on metabolism (O2 consumption and CO2 production), Tb, ventilation, and heart rate in normoxia and hypoxia (7% O2). The magnitude of the hypoxia-induced falls in Tb and metabolism of the squirrels was larger than that of other rodents. Metabolic rate was not simply suppressed but was regulated to assist the initial fall in Tb and then acted to slow this fall and stabilize Tb at a new, lower level. When Ta was reduced during 7% O2, animals were able to maintain or elevate their metabolic rates, suggesting that O2 was not limiting. The slope of the relationship between temperature-corrected O2 consumption and Taextrapolated to a Tset in hypoxia equals the actual Tb. The data suggest that Tset was proportionately related to Ta in hypoxia and that there was a shift from increasing ventilation to increasing O2extraction as the primary strategy employed to meet increasing metabolic demands under hypoxia. The animals were neither hypothermic nor hypometabolic, as Tb and metabolic rate appeared to be tightly regulated at new but lower levels as a result of a coordinated hypoxic metabolic response.

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