scholarly journals Response of chironomid species (Diptera, Chironomidae) to water temperature: effects on species distribution in specific habitats

2013 ◽  
Vol 45 (2) ◽  
pp. 14 ◽  
Author(s):  
L. Marziali ◽  
B. Rossaro
Keyword(s):  
Water Temperature ◽  
Species Distribution ◽  
Freshwater Ecosystems ◽  
Maximum Temperature ◽  
Running Waters ◽  
Tolerance Limits ◽  
Thermal Habitat ◽  
Chironomid Species ◽  
The Impact ◽  
Lowland Lakes

The response of 443 chironomid species to water temperature was analyzed, with the aim of defining their thermal optimum, tolerance limits and thermal habitat. The database included 4442 samples mainly from Italian river catchments collected from the 1950s up to date. Thermal preferences were calculated separately for larval and pupal specimens and for different habitats: high altitude and lowland lakes in the Alpine ecoregion; lowland lakes in the Mediterranean ecoregion; heavily modified water bodies; kryal, krenal, rhithral and potamal in running waters. Optimum response was calculated as mean water temperature, weighted by species abundances; tolerance as weighted standard deviation; skewness and kurtosis as 3<sup>rd</sup> and 4<sup>th</sup> moment statistics. The responses were fitted to normal uni- or plurimodal Gaussian models. Cold stenothermal species showed: i) unimodal response, ii) tolerance for a narrow temperature range, iii) optima closed to their minimum temperature values, iv) leptokurtic response. Thermophilous species showed: i) optima at different temperature values, ii) wider tolerance, iii) optima near their maximum temperature values, iv) platikurtic response, often fitting a plurimodal model. As expected, lower optima values and narrower tolerance were obtained for kryal and krenal, than for rhithral, potamal and lakes. Thermal response curves were produced for each species and were discussed according to species distribution (<em>i.e. </em>altitudinal range in running water and water depth in lakes), voltinism and phylogeny. Thermal optimum and tolerance limits and the definition of the thermal habitat of species can help predicting the impact of global warming on freshwater ecosystems.

Climate change impact assessment of sub-alpine vegetation in national park using CMIP5 GCMs

2020 ◽  
Author(s):  
Jaeuk Kim ◽  
Huicheul Jung ◽  
Insang Yu ◽  
Sung-Hun Lee
Keyword(s):  
Climate Change ◽  
Impact Assessment ◽  
National Parks ◽  
Spatial Resolution ◽  
Species Distribution ◽  
Future Climate ◽  
Maximum Temperature ◽  
Alpine Vegetation ◽  
Distribution Method ◽  
The Impact

&lt;p&gt;In South Korea, national parks occupy the largest area among the protected areas designated to protect biodiversity and ecosystem. Among the 17 mountainous national parks, the vegetation in alpine and sub-alpine regions are very vulnerable to climate change. The objective of this study is to estimate the impact of climate change on sub-alpine vegetation considering uncertainties of future climate and the species distribution method. Observation data were gridded to 3 km spatial resolution from 1981 to 2010 using the Improved GIS-based Registry Model(IDW-IGISRM) based on the Inverse distance weighting(IDW). To reduce future uncertainty of climate change, future climate scenarios of RCP 4.5 and RCP 8.5 of CMIP5 GCM were utilized. In order to increase the spatial resolution of the GCM, Simple Quantile Mapping, one of the various bias correction and downscaling techniques, was applied. Bioclim DB, a bioclimatic variable considering temperature and moisture conditions, was established using monthly maximum temperature, minimum temperature and precipitation data among detailed GCM data. Impact assessment was held using Biomod2 of R package, for endangered sub-alpine vegetation in the National Forest Inventory(NFI). Verification of the species distribution models were carried out using AUC(Area Under the Curve) and TSS(True Skill Statistics). The result of this study is expected to be utilized for protected area management measures for biodiversity conservation in forests.&lt;/p&gt;&lt;p&gt;&amp;#8251; This work was supported by Korea Environment Industry &amp; Technology Institute(KEITI) through Climate Change Correspondence Program, funded by Korea Ministry of Environment(MOE)(2018001310004).&lt;/p&gt;

scholarly journals The Dynamic of Phytoplankton Community Structure in Face of Warming Climate in A Tropical Man-Made Lake

2017 ◽  
Vol 9 (1) ◽  
pp. 140 ◽  
Author(s):  
Sunardi Sunardi ◽  
Rina Febriani ◽  
Budi Irawan ◽  
Mutia Septi Saputri
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Water Temperature ◽  
Climate Warming ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Freshwater Ecosystems ◽  
Phytoplankton Community Structure ◽  
And Function ◽  
The Impact

<p>In freshwater ecosystems, water temperature plays as an environmental factor that regulates its structure and function. A research on the impacts of changes in temperature to the dynamics of the Phytoplankton community structure has been done. Data from nineteen-year period (1995 to 2013) were collected from Cirata Reservoir as an example of artificial tropical lake in Indonesia. The research aimed to determine the changes of water temperature as the impact of climate warming on the dynamics of phytoplankton community structure. Different measures such as species richness, diversity index, and abundance were measured in order to understand the changes of phytoplankton community structure. Trend analysis, linear regression, and correlation were applied to achieve our objective. The study revealed that changes in water temperature have affected the species richness, but not the diversity index and abundance of the phytoplankton. Bacilariophyceae and Cyanophyceae were found as two predominant phytoplankton classes in the lake with percentage of 48,45 and 41,43 respectively, assuming their capacity to adapt the new environment. This study suggests that climate warming implies changes of the freshwater ecosystems.</p>

scholarly journals River Temperature Evolution in Switzerland over the 21st Century

2021 ◽  
Author(s):  
Adrien Michel ◽  
Jannis Epting ◽  
Michael Lehning ◽  
Hendrik Huwald
Keyword(s):  
Climate Change ◽  
Water Temperature ◽  
Groundwater Recharge ◽  
Freshwater Ecosystems ◽  
Climate Change Scenarios ◽  
River Temperature ◽  
Impact Of Climate Change ◽  
Glacier Melt ◽  
Alpine Catchments ◽  
The Impact

&lt;p&gt;Climate change has and will have many impacts on natural and human systems, and many of these impacts are already well described in the literature. One impact of climate change that received less attention is the increase in river temperature, even though it is recognized as a key variable controlling the water quality of freshwater ecosystems. It influences both the metabolic activity of aquatic organisms and biochemical cycles. It is also a key variable for many industrial sectors, and favorable for the spreading of certain diseases affecting fish.&lt;/p&gt;&lt;p&gt;In a previous study (Michel et al., 2020) we showed a clear increase of +0.33 &amp;#177; 0.03 &amp;#176;C per decade in water temperature over the last four decades in Switzerland. Important differences between lowland and alpine catchment were identified. Indeed, the warming rate in alpine catchments is only half of that observed in lowlands rivers. This difference is attributed mainly to the contribution of cold water from snow and glacier melt in mountainous area during summer, mitigating the impact of air temperature warming.&lt;/p&gt;&lt;p&gt;As a follow up, the response of selected Swiss catchments in lowland and alpine regions to the future forcing is numerically assessed using the CH2018 climate change scenarios for Switzerland. This is done using a sequence of physics-based models. The CH2018 climate change scenarios have been extended to a new set of alpine meteorological stations and downscaled to hourly resolution (Michel et al., 2021).&lt;/p&gt;&lt;p&gt;The results show an increase in water temperature for any of the RCP (2.6, 4.5, and 8.5) scenarios and a strong impact of climate change on alpine catchments caused by changes in snowfall/melt, glacier melt, and surface albedo. Indeed, we see a rapid acceleration of the warming in alpine catchments which &amp;#8220;catch-up&amp;#8221; with the warming already observed in lowland catchments. This can lead to a warming of up to +7 &amp;#176;C by the end of the century in some alpine rivers with the RCP8.5 scenario. An important shift in the hydrological regime is also observed, particularly in high-altitude rivers.&lt;/p&gt;&lt;p&gt;As a result, river ecosystems will be severely impacted. In addition, the combined changes in water temperature and discharge have an important impact on the groundwater temperature annual cycle, as we discussed in Epting et al. (2021). Seasonal shifts in rivers water infiltration associated with increased groundwater recharge during high runoff periods could be an important factor affecting future groundwater temperatures.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;REFERENCES&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Epting, J., Michel, A., Affolter, A., &amp; Huggenberger, P.: Climate change effects on groundwater recharge and temperatures in Swiss alluvial aquifers, Journal of Hydrology X, 11, 100071, 2021, doi:10.1016/j.hydroa.2020.100071.&lt;/p&gt;&lt;p&gt;Michel, A., Brauchli, T., Lehning, M., Schaefli, B., &amp; Huwald, H.: Stream temperature and discharge evolution in Switzerland over the last 50 years: annual and seasonal behaviour, Hydrological and Earth System Science, 24, 115&amp;#8211;142, 2020, doi:10.5194/hess-24-115-2020.&lt;/p&gt;&lt;p&gt;Michel, A., Sharma, V., Lehning, M., &amp; Huwald, H.: Climate change scenarios at hourly time-step over Switzerland from an enhanced temporal downscaling approach, International Journal of Climatology, under review&lt;/p&gt;

scholarly journals Drought alters the biogeochemistry of boreal stream networks

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Lluís Gómez-Gener ◽  
Anna Lupon ◽  
Hjalmar Laudon ◽  
Ryan A. Sponseller
Keyword(s):  
Freshwater Ecosystems ◽  
Running Waters ◽  
Hypoxic Conditions ◽  
Boreal Streams ◽  
Northern Latitudes ◽  
Hydrological Extremes ◽  
Northern River ◽  
Poor Water Quality ◽  
And Shifts ◽  
The Impact

AbstractDrought is a global phenomenon, with widespread implications for freshwater ecosystems. While droughts receive much attention at lower latitudes, their effects on northern river networks remain unstudied. We combine a reach-scale manipulation experiment, observations during the extreme 2018 drought, and historical monitoring data to examine the impact of drought in northern boreal streams. Increased water residence time during drought promoted reductions in aerobic metabolism and increased concentrations of reduced solutes in both stream and hyporheic water. Likewise, data during the 2018 drought revealed widespread hypoxic conditions and shifts towards anaerobic metabolism, especially in headwaters. Finally, long-term data confirmed that past summer droughts have led to similar metabolic alterations. Our results highlight the potential for drought to promote biogeochemical shifts that trigger poor water quality conditions in boreal streams. Given projected increases in hydrological extremes at northern latitudes, the consequences of drought for the health of running waters warrant attention.

scholarly journals Comparison of Invasive Apple Snail (Pomacea canaliculata) Behaviors in Different Water Temperature Gradients

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1149
Author(s):  
Mi-Jung Bae ◽  
Eui-Jin Kim ◽  
Young-Seuk Park
Keyword(s):  
Water Temperature ◽  
Farming Systems ◽  
Freshwater Snail ◽  
Freshwater Ecosystems ◽  
Pomacea Canaliculata ◽  
Activity Levels ◽  
Self Organizing Map ◽  
Apple Snail ◽  
Temperature Changes ◽  
Organic Farming Systems

Pomacea canaliculata (known as invasive apple snail) is a freshwater snail native to South America that was introduced into many countries (including Asia and North America) as a food source or for organic farming systems. However, it has invaded freshwater ecosystems and become a serious agricultural pest in paddy fields. Water temperature is an important factor determining behavior and successful establishment in new areas. We examined the behavioral responses of P. canaliculata with water temperature changes from 25 °C to 30 °C, 20 °C, and 15 °C by quantifying changes in nine behaviors. At the acclimated temperature (25 °C), the mobility of P. canaliculata was low during the day, but high at night. Clinging behavior increased as the water temperature decreased from 25 °C to 20 °C or 15 °C. Conversely, ventilation and food consumption increased when the water temperature increased from 25 °C to 30 °C. A self-organizing map (an unsupervised artificial neural network) was used to classify the behavioral patterns into seven clusters at different water temperatures. These results suggest that the activity levels or certain behaviors of P. canaliculata vary with the water temperature conditions. Understanding the thermal biology of P. canaliculata may be crucial for managing this invasive snail.

scholarly journals Lagged recovery of fish spatial distributions following a cold-water perturbation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. D. Robertson ◽  
J. Gao ◽  
P. M. Regular ◽  
M. J. Morgan ◽  
F. Zhang
Keyword(s):  
Water Temperature ◽  
Species Distribution ◽  
Environmental Conditions ◽  
Cold Water ◽  
Heat Waves ◽  
Rapid Change ◽  
Nonlinear Effects ◽  
Spatial Distributions ◽  
Spatiotemporal Model ◽  
Yellowtail Flounder

AbstractAnomalous local temperature and extreme events (e.g. heat-waves) can cause rapid change and gradual recovery of local environmental conditions. However, few studies have tested whether species distribution can recover following returning environmental conditions. Here, we tested for change and recovery of the spatial distributions of two flatfish populations, American plaice (Hippoglossoides platessoides) and yellowtail flounder (Limanda ferruginea), in response to consecutive decreasing and increasing water temperature on the Grand Bank off Newfoundland, Canada from 1985 to 2018. Using a Vector Autoregressive Spatiotemporal model, we found the distributions of both species shifted southwards following a period when anomalous cold water covered the northern sections of the Grand Bank. After accounting for density-dependent effects, we observed that yellowtail flounder re-distributed northwards when water temperature returned and exceeded levels recorded before the cold period, while the spatial distribution of American plaice has not recovered. Our study demonstrates nonlinear effects of an environmental factor on species distribution, implying the possibility of irreversible (or hard-to-reverse) changes of species distribution following a rapid change and gradual recovery of environmental conditions.

scholarly journals Social media reveal ecoregional variation in how weather influences visitor behavior in U.S. National Park Service units

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily J. Wilkins ◽  
Peter D. Howe ◽  
Jordan W. Smith
Keyword(s):  
National Park ◽  
National Park Service ◽  
Spatial Behavior ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Daily Weather ◽  
Visitor Behavior ◽  
Park Service ◽  
The Impact

AbstractDaily weather affects total visitation to parks and protected areas, as well as visitors’ experiences. However, it is unknown if and how visitors change their spatial behavior within a park due to daily weather conditions. We investigated the impact of daily maximum temperature and precipitation on summer visitation patterns within 110 U.S. National Park Service units. We connected 489,061 geotagged Flickr photos to daily weather, as well as visitors’ elevation and distance to amenities (i.e., roads, waterbodies, parking areas, and buildings). We compared visitor behavior on cold, average, and hot days, and on days with precipitation compared to days without precipitation, across fourteen ecoregions within the continental U.S. Our results suggest daily weather impacts where visitors go within parks, and the effect of weather differs substantially by ecoregion. In most ecoregions, visitors stayed closer to infrastructure on rainy days. Temperature also affects visitors’ spatial behavior within parks, but there was not a consistent trend across ecoregions. Importantly, parks in some ecoregions contain more microclimates than others, which may allow visitors to adapt to unfavorable conditions. These findings suggest visitors’ spatial behavior in parks may change in the future due to the increasing frequency of hot summer days.

scholarly journals The impact of climate change in wheat and barley yields in the Iberian Peninsula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Virgílio A. Bento ◽  
Andreia F. S. Ribeiro ◽  
Ana Russo ◽  
Célia M. Gouveia ◽  
Rita M. Cardoso ◽  
...  
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Climate Model ◽  
Global Climate Models ◽  
Maximum Temperature ◽  
Historical Period ◽  
Early Winter ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Spring Maximum

AbstractThe impact of climate change on wheat and barley yields in two regions of the Iberian Peninsula is here examined. Regression models are developed by using EURO-CORDEX regional climate model (RCM) simulations, forced by ERA-Interim, with monthly maximum and minimum air temperatures and monthly accumulated precipitation as predictors. Additionally, RCM simulations forced by different global climate models for the historical period (1972–2000) and mid-of-century (2042–2070; under the two emission scenarios RCP4.5 and RCP8.5) are analysed. Results point to different regional responses of wheat and barley. In the southernmost regions, results indicate that the main yield driver is spring maximum temperature, while further north a larger dependence on spring precipitation and early winter maximum temperature is observed. Climate change seems to induce severe yield losses in the southern region, mainly due to an increase in spring maximum temperature. On the contrary, a yield increase is projected in the northern regions, with the main driver being early winter warming that stimulates earlier growth. These results warn on the need to implement sustainable agriculture policies, and on the necessity of regional adaptation strategies.

scholarly journals Analysis of the Accelerator-Driven System Fuel Assembly during the Steam Generator Tube Rupture Accident

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1818
Author(s):  
Di-Si Wang ◽  
Bo Liu ◽  
Sheng Yang ◽  
Bin Xi ◽  
Long Gu ◽  
...  
Keyword(s):  
Fuel Assembly ◽  
Steam Generator ◽  
Metal Flow ◽  
Maximum Temperature ◽  
Steam Generator Tube ◽  
Driven System ◽  
Fuel Assemblies ◽  
Accelerator Driven System ◽  
The Impact ◽  
Steam Bubble

China is developing an ADS (Accelerator-Driven System) research device named the China initiative accelerator-driven system (CiADS). When performing a safety analysis of this new proposed design, the core behavior during the steam generator tube rupture (SGTR) accident has to be investigated. The purpose of our research in this paper is to investigate the impact from different heating conditions and inlet steam contents on steam bubble and coolant temperature distributions in ADS fuel assemblies during a postulated SGTR accident by performing necessary computational fluid dynamics (CFD) simulations. In this research, the open source CFD calculation software OpenFOAM, together with the two-phase VOF (Volume of Fluid) model were used to simulate the steam bubble behavior in heavy liquid metal flow. The model was validated with experimental results published in the open literature. Based on our simulation results, it can be noticed that steam bubbles will accumulate at the periphery region of fuel assemblies, and the maximum temperature in fuel assembly will not overwhelm its working limit during the postulated SGTR accident when the steam content at assembly inlet is less than 15%.

scholarly journals Extreme Meteorological Events in a Coastal Lagoon Ecosystem: The Ria de Aveiro Lagoon (Portugal) Case Study

2021 ◽  
Vol 9 (7) ◽  
pp. 727
Author(s):  
José Fortes Lopes ◽  
Carina Lurdes Lopes ◽  
João Miguel Dias
Keyword(s):  
Water Temperature ◽  
Coastal Lagoon ◽  
Early Summer ◽  
Extreme Weather Events ◽  
Climate Change Scenarios ◽  
State Variables ◽  
Ria De Aveiro ◽  
Physical Conditions ◽  
Weather Events ◽  
The Impact

Extreme weather events (EWEs) represent meteorological hazards for coastal lagoon hydrodynamics, of which intensity and frequency are increasing over the last decades as a consequence of climate changes. The imbalances they generated should affect primarily vulnerable low-lying areas while potentially disturbing the physical balances (salt and water temperature) and, therefore, the ecosystem equilibrium. This study arises from the need to assess the impact of EWEs on the Ria de Aveiro, a lagoon situated in the Portuguese coastal area. Furthermore, it was considered that those events occur under the frame of a future sea-level rise, as predicted by several climate change scenarios. Two EWEs scenarios, a dry and an extremely wet early summer reflecting past situations and likely to occur in the future, were considered to assess the departure from the system baseline functioning. It was used as a biogeochemistry model that simulates the hydrodynamics, as well as the baseline physical and biogeochemistry state variables. The dry summer scenario, corresponding to a significant reduction in the river’s inflow, evidences a shift of the system to a situation under oceanic dominance characterized by colder and saltier water (~18 °C; 34 PSU) than the baseline while lowering the concentration of the nutrients and reducing the phytoplankton population to a low-level limit. Under a wet summer scenario, the lagoon shifted to a brackish and warmer situation (~21 °C, <15 PSU) in a time scale of some tidal periods, driven by the combining effect of the tidal transport and the river’s inflow. Phytoplankton patterns respond to variability on local and short-term scales that reflect physical conditions within the lagoon, inducing nutrient-supported growth. Overall, the results indicate that EWEs generate local and transient changes in physical conditions (namely salinity and water temperature) in response to the characteristic variability of the lagoon’s hydrodynamics associated with a tidal-dominated system. Therefore, in addition to the potential impact of changing physical conditions on the ecosystem, saline intrusion along the lagoon or the transfer of brackish water to the mouth of the system are the main consequences of EWEs, while the main biogeochemistry changes tend to remain moderate.

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