scholarly journals Key biological responses over two generations of the sea urchin Echinometra sp. A under future ocean conditions

2020 ◽  
Vol 637 ◽  
pp. 87-101 ◽  
Author(s):  
S Uthicke ◽  
F Patel ◽  
S Karelitz ◽  
HM Luter ◽  
NS Webster ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Urchin ◽  
Gonad Development ◽  
Climate Change Scenarios ◽  
Ammonium Excretion ◽  
Short Term ◽  
Final Size ◽  
Treatment Conditions ◽  
Significant Difference ◽  
Excretion Rates

Few studies have investigated the effects of ocean warming and acidification on marine benthic organisms over ecologically relevant time scales. We used an environmentally controlled coral reef mesocosm system to assess growth and physiological responses of the sea urchin species Echinometra sp. A over 2 generations. Each mesocosm was controlled for temperature and pCO2 over 29 mo under 3 climate change scenarios (present day and predicted states in 2050 and 2100 under RCP 8.5). The system maintained treatment conditions including annual temperature cycles and a daily variation in pCO2. Over 20 mo, adult Echinometra exhibited no significant difference in size and weight among the treatments. Growth rates and respiration rates did not differ significantly among treatments. Urchins from the 2100 treatment had elevated ammonium excretion rates and reduced O2:N ratios, suggesting a change in catabolism. We detected no difference in spawning index scores or oocyte size after 20 mo in the treatments, suggesting that gonad development was not impaired by variations in pCO2 and temperature reflecting anticipated climate change scenarios. Larvae produced from experimentally exposed adults were successfully settled from all treatments and raised for 5 mo inside the mesocosm. The final size of these juveniles exhibited no significant difference among treatments. Overall, we demonstrated that the mesocosm system provided a near natural environment for this urchin species. Climate change and ocean acidification did not affect the benthic life stages investigated here. Importantly, in previous short-term (weeks to months) experiments, this species exhibited reductions in growth and gonad development, highlighting the potential for short-term experiments with non-acclimated animals to yield contrasting, possibly erroneous results.

scholarly journals The role of glacier dynamics and threshold definition in the characterisation of future streamflow droughts in glacierised catchments

2017 ◽  
Author(s):  
Marit Van Tiel ◽  
Adriaan J. Teuling ◽  
Niko Wanders ◽  
Marc J. P. Vis ◽  
Kerstin Stahl ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Scales ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Glacier Area ◽  
Short Term ◽  
Drought Characteristics ◽  
Wide Range ◽  
Glacier Dynamics ◽  
The Future

Abstract. Glaciers are essential hydrological reservoirs, storing and releasing water at various time scales. Short-term variability in glacier melt is one of the causes of streamflow droughts, defined as below normal water availabilities. Streamflow droughts in glacierised catchments have a wide range of interlinked causing factors related to precipitation and temperature on short and long time scales. Climate change affects glacier storage capacity, with resulting consequences for discharge regimes and drought. Future projections of streamflow drought in glacierised basins can, however, strongly depend on the modelling strategies and analysis approaches applied. Here, we examine the effect of different approaches, concerning the glacier modelling and the drought threshold, on the characterisation of streamflow droughts in glacierised catchments. Streamflow is simulated with the HBV-light model for two case study catchments, the Nigardsbreen catchment in Norway and the Wolverine catchment in Alaska, and two future climate change scenarios (RCP4.5 and RCP8.5). Two types of glacier modelling are applied, a constant and dynamical glacier area conceptualisation. Streamflow droughts are identified with the variable threshold level method and their characteristics are compared between two periods, a historical (1975–2004) and future (2071–2100) period. Two existing threshold approaches to define future droughts are employed, (1) the threshold from the historical period and (2) a transient threshold approach, whereby the threshold adapts every year in the future to the changing regimes. Results show that drought characteristics differ among the combinations of glacier area modelling and thresholds. The historical threshold combined with a dynamical glacier area projects extreme increases in drought severity in the future, caused by the regime shift due to a reduction in glacier area. The historical threshold combined with a constant glacier area results in a drastic decrease of the number of droughts. The drought characteristics between future and historic periods are more similar when the transient threshold is used, for both glacier dynamics conceptualisations. With the transient threshold causing factors of future droughts, can be analysed. This study revealed the different effects of methodological choices on future streamflow drought projections and it highlights how the options can be used to analyse different aspects of future droughts: the transient threshold for analysing future drought processes, the historical threshold to assess changes between periods, the constant glacier area to analyse the effect of short term climate variability on droughts and the dynamical glacier area to model realistic future discharges under climate change.

scholarly journals Potential Distribution of Blumea Balsamifera in China Using MaxEnt and The Ex-Situ Conservation Based on its Effective Components and Fresh Leaf Yield

2021 ◽  
Author(s):  
Lingliang Guan ◽  
YuXia Yang ◽  
Pan Jiang ◽  
Qiuyu Mou ◽  
Yunsha Gou ◽  
...  
Keyword(s):  
Climate Change ◽  
Ex Situ ◽  
Distribution Area ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Total Flavonoids ◽  
Fresh Leaf ◽  
Significant Difference ◽  
Leaf Yield ◽  
Suitable Habitats

Abstract Blumea balsamifera is a famous Chinese Minority Medicine, which has a long history in Miao, Li, Zhuang and other minority areas. In recent years, due to the influence of natural and human factors, the distribution area of B. balsamifera resources has a decreasing trend. Therefore, it is very important to analyze the suitability of B. balsamifera in China. Following three climate change scenarios (SSP1-2.6, SSP2-4.5 and SSP5-8.5) under 2050s and 2070s, geographic information technology (GIS) and maximum entropy model (MaxEnt) were used to simulate the ecological suitability of B. balsamifera. The contents of L-borneol and total flavonoids of B. balsamifera in different populations were determined by gas chromatography (GC) and ultraviolet spectrophotometry (UV). The results showed that the key environmental variables affecting the distribution of B. balsamifera were mean temperature of coldest quarter (6.18-26.57 ℃), precipitation of driest quarter (22.46-169.7 mm), annual precipitation (518.36-1845.29 mm) and temperature seasonality (291.31-878.87). Under current climate situation, the highly suitable habitat was mainly located western Guangxi, southern Yunnan, most of Hainan, southwestern Guizhou, southwestern Guangdong, southeastern Fujian and western Taiwan, with a total area of 24.1×104 km2. The areas of the moderately and poorly suitable habitats were 27.57×104 km2 and 42.43×104 km2, respectively. Under the future climate change scenarios, the areas of the highly, moderately, and poorly suitable habitats of B. balsamifera showed a significant increasing trend, the geometric center of the total suitable habitats of B. balsamifera would move to the northeast. In recent years, the planting area of B. balsamifera has been reduced on a large scale in Guizhou, and its ex situ protection is imperative. By comparison, the content of L-borneol, total flavonoids and fresh leaf yield had no significant difference between Guizhou and Hainan (P > 0.05), which indicated that Hainan one of the best choice for ex-situ protection of B. balsamifera.

Anomalous fractional clearance of negatively charged Ficoll relative to uncharged Ficoll

2003 ◽  
Vol 285 (6) ◽  
pp. F1118-F1124 ◽  
Author(s):  
Marco A. M. Guimarães ◽  
Julijana Nikolovski ◽  
Lynette M. Pratt ◽  
Kerryn Greive ◽  
Wayne D. Comper
Keyword(s):  
Steady State ◽  
Plasma Proteins ◽  
Capillary Wall ◽  
Short Term ◽  
Charge Selectivity ◽  
Significant Difference ◽  
Fractional Clearance ◽  
Excretion Rates ◽  
Approach To Steady State

Recent studies, using low-temperature perfusion of rat kidneys, have claimed the existence of renal charge selectivity simply on the basis of the differential excretion rates of uncharged Ficoll and charged proteins. To test for the existence of charge selectivity in vivo, we examined the clearance of negatively charged Ficoll compared with uncharged Ficoll. A short-term approach to steady state was used to study the fractional clearances. Relative clearances were also examined using an osmotic pump technique where the tracers reach a steady-state value in conscious rats after 7 days. Carboxymethyl Ficoll was stable during filtration and renal passage, was not taken up by the kidneys, and did not bind to plasma proteins. There was no significant difference in the fractional clearance of molecules with radius of 36 Å for Ficoll (fractional clearance = 0.048 ± 0.038, n = 5) and negatively charged carboxymethyl Ficoll (fractional clearance = 0.028 ± 0.019, n = 5). For molecules with radii greater than 36 Å, carboxymethyl Ficoll had facilitated clearance with respect to uncharged Ficoll [for example, at a radius of 60 Å fractional clearance for Ficoll = 0.0012 ± 0.0005 ( n = 5), whereas that for carboxymethyl Ficoll = 0.015 ± 0.005 ( n = 5)]. Renal function was not compromised by carboxymethyl Ficoll as uncharged Ficoll in urine exhibited similar hydrodynamic size profiles when studied in the presence of excess unlabeled carboxymethyl Ficoll. The facilitated clearance of negatively charged Ficoll with respect to uncharged Ficoll reveals a property of the capillary wall, which has been previously observed with other nonproteinaceous polyanions. This study demonstrates that the glomerular capillary wall is not charge selective in the form of excluding negatively charged Ficoll. However, the charge properties of the capillary wall may influence the facilitated transport of charged Ficoll compared with uncharged Ficoll.

scholarly journals Temperature, but not pH, compromises sea urchin fertilization and early development under near-future climate change scenarios

2009 ◽  
Vol 276 (1663) ◽  
pp. 1883-1888 ◽  
Author(s):  
Maria Byrne ◽  
Melanie Ho ◽  
Paulina Selvakumaraswamy ◽  
Hong D. Nguyen ◽  
Symon A. Dworjanyn ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Urchin ◽  
Ocean Warming ◽  
Future Climate ◽  
Interactive Effects ◽  
Future Climate Change ◽  
Marine Biota ◽  
Climate Change Scenarios ◽  
Eastern Australia ◽  
Near Future

Global warming is causing ocean warming and acidification. The distribution of Heliocidaris erythrogramma coincides with the eastern Australia climate change hot spot, where disproportionate warming makes marine biota particularly vulnerable to climate change. In keeping with near-future climate change scenarios, we determined the interactive effects of warming and acidification on fertilization and development of this echinoid. Experimental treatments (20–26°C, pH 7.6–8.2) were tested in all combinations for the ‘business-as-usual’ scenario, with 20°C/pH 8.2 being ambient. Percentage of fertilization was high (>89%) across all treatments. There was no difference in percentage of normal development in any pH treatment. In elevated temperature conditions, +4°C reduced cleavage by 40 per cent and +6°C by a further 20 per cent. Normal gastrulation fell below 4 per cent at +6°C. At 26°C, development was impaired. As the first study of interactive effects of temperature and pH on sea urchin development, we confirm the thermotolerance and pH resilience of fertilization and embryogenesis within predicted climate change scenarios, with negative effects at upper limits of ocean warming. Our findings place single stressor studies in context and emphasize the need for experiments that address ocean warming and acidification concurrently. Although ocean acidification research has focused on impaired calcification, embryos may not reach the skeletogenic stage in a warm ocean.

scholarly journals Different patterns of climate change scenarios for short-term and multi-day precipitation extremes in the Mediterranean

2012 ◽  
Vol 98-99 ◽  
pp. 63-72 ◽  
Author(s):  
Jan Kyselý ◽  
Santiago Beguería ◽  
Romana Beranová ◽  
Ladislav Gaál ◽  
Juan Ignacio López-Moreno
Keyword(s):  
Climate Change ◽  
Precipitation Extremes ◽  
Climate Change Scenarios ◽  
Short Term ◽  
The Mediterranean

Feeding, respiration, and excretion by the tropical sea urchin Tripneustes gratilla (Echinodermata: Echinoidea) from the Philippines

2002 ◽  
Vol 82 (2) ◽  
pp. 299-302 ◽  
Author(s):  
Danilo T. Dy ◽  
Frederick A. Uy ◽  
Christine M. Coralles
Keyword(s):  
Feeding Rate ◽  
Regression Coefficient ◽  
Kappaphycus Alvarezii ◽  
The Philippines ◽  
Ammonium Excretion ◽  
Thalassia Hemprichii ◽  
Significant Difference ◽  
Tripneustes Gratilla ◽  
Excretion Rates ◽  
Tropical Sea

The rates of ingestion, egestion, ammonium excretion, and CO2 respiration of Tripneustes gratilla (Echinodermata: Echinoidea) from a shallow water embayment at eastern Mactan Island, central Philippines were examined. There was no significant difference in weight-specific feeding rate with the three macrophytes (Sargassum polycystum, Thalassia hemprichii, and Kappaphycus alvarezii). The power function equation, M=KWb fitted well with the weight-specific egestion rates ((r2=0·93), weight-specific CO2 respiration rates (r2=0·92) and ammonium excretion rates (r2=0·86). Weight-specific egestion rates, CO2 respiration and ammonium excretion were indirectly proportional to body weight. For weight-specific egestion rate (in μg DW faeces/g DW urchin-h), the regression coefficient, b and constant, K were −2·31±0·68 (mean±SE) (P=0·02) and 6359·55±5394·31 (P=0·29), respectively. The b and K for CO2 respiration were −1·28±0·48 (P=0·04) and 39·72±10·59 (P=0·01), respectively. For ammonium excretion, the b and K were −1·03±0·46 (P=0·11) and 262·51±56·89 (P=0·02), respectively.

scholarly journals Evaluating the Impact of Climate Change on Paddy Water Balance Using APEX-Paddy Model

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 852 ◽  
Author(s):  
Mohammad Kamruzzaman ◽  
Syewoon Hwang ◽  
Soon-Kun Choi ◽  
Jaepil Cho ◽  
Inhong Song ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Balance ◽  
Maximum Temperature ◽  
Climate Change Scenarios ◽  
Climate Scenarios ◽  
Water Balance Components ◽  
Impact Of Climate Change ◽  
Paddy Water ◽  
Significant Difference ◽  
The Impact

This research aims to assess the impact of climate change on water balance components in irrigated paddy cultivation. The APEX-Paddy model, which is the modified version of the APEX (Agricultural Policy/Environmental eXtender) model for paddy ecosystems, was used to evaluate the paddy water balance components considering future climate scenarios. The bias-corrected future projections of climate data from 29 GCMs (General Circulation Models) were applied to the APEX-Paddy model simulation. The study area (Jeonju station) forecasts generally show increasing patterns in rainfall, maximum temperature, and minimum temperature with a rate of up to 23%, 27%, and 45%, respectively. The hydrological simulations suggest over-proportional runoff–rainfall and under-proportional percolation and deep-percolation–rainfall relationships for the modeled climate scenarios. Climate change scenarios showed that the evapotranspiration amount was estimated to decrease compared to the baseline period (1976–2005). The evaporation was likely to increase by 0.12%, 2.21%, and 7.81% during the 2010s, 2040s, and 2070s, respectively under Representative Concentration Pathway (RCP)8.5, due to the increase in temperature. The change in evaporation was more pronounced in RCP8.5 than the RCP4.5 scenario. The transpiration is expected to reduce by 2.30% and 12.62% by the end of the century (the 2070s) under RCP4.5 and RCP8.5, respectively, due to increased CO2 concentration. The irrigation water demand is generally expected to increase over time in the future under both climate scenarios. Compared to the baseline, the most significant change is expected to increase in the 2040s by 3.21% under RCP8.5, while the lowest increase was found by 0.36% in 2010s under RCP4.5. The increment of irrigation does not show a significant difference; the rate of increase in the irrigation was found to be greater RCP8.5 than RCP4.5 except in the 2070s. The findings of this study can play a significant role as the basis for evaluating the vulnerability of rice production concerning water management against climate change.

scholarly journals Stochastic Flood Risk Assessment under Climate Change Scenarios for Toronto, Canada Using CAPRA

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 227
Author(s):  
Daniela Rincón ◽  
Juan Felipe Velandia ◽  
Ioannis Tsanis ◽  
Usman T. Khan
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Flood Risk ◽  
Numerical Models ◽  
Social Impacts ◽  
Climate Change Scenarios ◽  
Flood Risk Assessment ◽  
Short Term ◽  
Modeling Approach

Amongst all natural disasters, floods have the greatest economic and social impacts worldwide, and their frequency is expected to increase due to climate change. Therefore, improved flood risk assessment is important for implementing flood mitigation measures in urban areas. The increasing need for quantifying the impacts of flooding have resulted in the development of methods for flood risk assessment. The aim of this study was to quantify flood risk under climate change scenarios in the Rockcliffe area within the Humber River watershed in Toronto, Canada, by using the Comprehensive Approach to Probabilistic Risk Assessment (CAPRA) method. CAPRA is a platform for stochastic disaster risk assessment that allows for the characterization of uncertainty in the underlying numerical models. The risk was obtained by integrating the (i) flood hazard, which considered future rainfall based on the Representative Concentration Pathways (RCPs 2.6, 4.5, 6.0, and 8.5) for three time periods (short-term: 2020–2049, medium-term: 2040–2069, and long-term: 2070–2099); (ii) exposed assets within a flood-prone region; (iii) vulnerability functions, which quantified the damage to an asset at different hazard levels. The results revealed that rainfall intensities are likely to increase during the 21st century in the study area, leading to an increase in flood hazards, higher economic costs, and social impacts for the majority of the scenarios. The highest impacts were found for the climate scenario RCP 8.5 for the long-term period and the lowest for RCP 4.5 for the short-term period. The results from this modeling approach can be used for planning purposes in a floodplain management study. The modeling approach identifies critical areas that need to be protected to mitigate future flood risks. Higher resolution climate change and field data are needed to obtain detailed results required for a final design that will mitigate these risks.

scholarly journals Os Impactos das Alterações Climáticas na Cana-de-Açúcar Cultivada em Sistema de Sequeiro na Região Nordeste do Brasil (The Impacts of the Climate Changes on Sugar Cane Cultivated in Rainfed Systems in Northeastern of Brazil)

2012 ◽  
Vol 5 (1) ◽  
pp. 170 ◽  
Author(s):  
Sonaly Duarte Oliveira ◽  
Vicente de Paulo Rodrigues Da Silva ◽  
Carlos Antônio Costa Dos Santos ◽  
Madson Tavares Silva ◽  
Edicarlos Pereira De Sousa
Keyword(s):  
Climate Change ◽  
Sugar Cane ◽  
Climate Changes ◽  
Potential Evapotranspiration ◽  
Saccharum Officinarum ◽  
Rainfall Time Series ◽  
Climate Change Scenarios ◽  
Significant Difference ◽  
Agricultural Zoning ◽  
Agricultural Areas

Os impactos das alterações climáticas sobre o zoneamento agrícola de risco climático do cultivo da cana-de-açúcar (Saccharum officinarum L.) na região Nordeste do Brasil (NEB) são analisados neste estudo. Foram utilizadas as séries históricas de precipitação pluvial com no mínimo 30 anos de dados diários, bem como o coeficiente de cultivo, a evapotranspiração potencial e a duração do ciclo da cultura. Adotou-se como critério de corte para o Índice de Satisfação das Necessidades de Água para a cultura (ISNA), o valor 0,65. Os cenários utilizados de alterações climáticas foram sem aumento na temperatura do ar e com aumentos de 1,5, 3 e 5ºC associados às variações na precipitação de ± 10, 25 e 40%. Os cenários de mudanças climáticas analisados indicam redução considerável nas áreas agricultáveis favoráveis ao cultivo da cana-de-açúcar no NEB, afetando assim, as áreas de produção da cultura. Existe diferença relevante entre os cenários sem aumento na temperatura do ar e os três cenários de aquecimento global. Palavras-chave: Mudanças climáticas, zoneamento agrícola, evapotranspiração, precipitação pluvial.  The Impacts of the Climate Changes on Sugar Cane Cultivated in Rainfed Systems in Northeastern of Brazil  ABSTRACTThe impacts of climate change on agricultural zoning of climate risk of sugar cane (Saccharum officinarum L.) in northeastern region of Brazil (NEB, in portuguese) are analyzed in this study. It was used daily rainfall time series with at least 30 year as well as crop coefficients, potential evapotranspiration and length of crop cycle. It was adopted as criterion the value threshold of 0,65 for Water Requirements satisfaction index (WRSI). The scenarios used of climate change were no increase in air temperature and increases of 1.5, 3.0 and 5.0ºC associated to changes in rainfall of ± 10, 25 and 40%. The analyzed climate change scenarios indicate a significant reducing in agricultural areas favorable to the cane sugar cultivation in the NEB, and therefore affecting the agricultural areas of sugar cane. There is a significant difference between the scenarios with no increase in temperature and three scenarios of global warming.   Key words: Climate changes, agricultural zoning, evapotranspiration, precipitation.

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