Aestivation provides flexible mechanisms for survival of stream drying in a larval trichopteran (Leptoceridae)

2012 ◽  
Vol 63 (9) ◽  
pp. 821 ◽  
Author(s):  
S. Wickson ◽  
E. T. Chester ◽  
B. J. Robson

Some freshwater species aestivate to resist drying; however, little is known about factors affecting post-aestivation survival. Climate change prolongs drying and may make short bursts of flow more frequent in southern Australian streams, thereby affecting aestivation success. The tolerance of larval Lectrides varians (Mosley) to drying was tested by inducing aestivation in dry or moist sediment and then re-immersing larvae and measuring survival and activity. Survival did not differ between individuals that were continually immersed (78%) or aestivating on moist sediment (70.5%) after 16 weeks. Survival was significantly lower on dry sediment (29.3%). Furthermore, some larvae showed delayed responses to re-immersion; 65% of individuals showed activity within 4.5 h, whereas over 30% of larvae did not become active until 72 h after re-immersion. L. varians can survive extended periods (112 days) without surface water, showing a bimodal response to re-immersion that increases the likelihood of population persistence by enabling some larvae to remain aestivating during short-lived bursts of stream flow. L. varians populations will therefore be more robust to prolonged stream drying and short-lived flow events than are some other insect taxa, although as the duration of aestivation increases larval survivorship decreases, suggesting that there are limits to the flexibility of aestivation traits.


Hydrology ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 70
Author(s):  
Gopal Chandra Saha ◽  
Michael Quinn

This study assessed how hydraulic fracturing (HF) (water withdrawals from nearby river water source) and its associated activities (construction of well pads) would affect surface water and groundwater in 2021–2036 under changing climate (RCP4.5 and RCP8.5 scenarios of the CanESM2) in a shale gas and oil play area (23,984.9 km2) of northwestern Alberta, Canada. An integrated hydrologic model (MIKE-SHE and MIKE-11 models), and a cumulative effects landscape simulator (ALCES) were used for this assessment. The simulation results show an increase in stream flow and groundwater discharge in 2021–2036 under both RCP4.5 and RCP8.5 scenarios with respect to those under the base modeling period (2000–2012). This occurs because of the increased precipitation and temperature predicted in the study area under both RCP4.5 and RCP8.5 scenarios. The results found that HF has very small (less than 1%) subtractive impacts on stream flow in 2021–2036 because of the large size of the study area, although groundwater discharge would increase minimally (less than 1%) due to the increase in the gradient between groundwater and surface water systems. The simulation results also found that the construction of well pads related to HF have very small (less than 1%) additive impacts on stream flow and groundwater discharge due to the non-significant changes in land use. The obtained results from this study provide valuable information for effective long-term water resources decision making in terms of seasonal and annual water extractions from the river, and allocation of water to the oil and gas industries for HF in the study area to meet future energy demand considering future climate change.



2014 ◽  
Vol 5 (3) ◽  
pp. 391-407 ◽  
Author(s):  
Alireza Gohari ◽  
Ali Bozorgi ◽  
Kaveh Madani ◽  
Jeffrey Elledge ◽  
Ronny Berndtsson

Optimal reservoir operation changes and adaptation strategies for the Zayandeh-Rud River Basin's surface water supply system are examined for a changing climate during the 2015–2044 period. On average, the monthly temperature in the basin is expected to increase by 0.46–0.76 °C and annual precipitation is expected to decrease by 14–38% with climate change, resulting in a reduction of the Zayandeh-Rud's peak stream flow and the amplitude of its seasonal range. Snowfall decrease in winter months will generally lead to an 8–43% reduction in annual stream flow under climate change. A reservoir operation model is developed and optimal reservoir operation strategies are identified for adaptation of the basin's surface water supply to climate change in the face of the increasing water demand. Results indicate that the reservoir drawdown season starts 2 months earlier under climate change. Smaller storage levels and greater water releases must occur to meet the increasing water demand. The optimized water release can provide sufficient water for non-agricultural water demand, but agriculture will experience more severe water shortage under a changing climate. Having the highest vulnerability, the agricultural sector should be the main focus of regional management plans to address the current water challenge and more severe water shortages under climate change.



Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 816
Author(s):  
Danijela Markovic ◽  
Jörg Freyhof ◽  
Oskar Kärcher

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.



Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1109
Author(s):  
Nobuaki Kimura ◽  
Kei Ishida ◽  
Daichi Baba

Long-term climate change may strongly affect the aquatic environment in mid-latitude water resources. In particular, it can be demonstrated that temporal variations in surface water temperature in a reservoir have strong responses to air temperature. We adopted deep neural networks (DNNs) to understand the long-term relationships between air temperature and surface water temperature, because DNNs can easily deal with nonlinear data, including uncertainties, that are obtained in complicated climate and aquatic systems. In general, DNNs cannot appropriately predict unexperienced data (i.e., out-of-range training data), such as future water temperature. To improve this limitation, our idea is to introduce a transfer learning (TL) approach. The observed data were used to train a DNN-based model. Continuous data (i.e., air temperature) ranging over 150 years to pre-training to climate change, which were obtained from climate models and include a downscaling model, were used to predict past and future surface water temperatures in the reservoir. The results showed that the DNN-based model with the TL approach was able to approximately predict based on the difference between past and future air temperatures. The model suggested that the occurrences in the highest water temperature increased, and the occurrences in the lowest water temperature decreased in the future predictions.



Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 371
Author(s):  
Kevin Pello ◽  
Cedric Okinda ◽  
Aijun Liu ◽  
Tim Njagi

The environmental effects of climate change have significantly decreased agricultural productivity. Agroforestry technologies have been applied as a solution to promote sustainable agricultural systems. This study evaluates the factors influencing the adoption of agroforestry technology in Kenya. A multistage sampling technique was employed to collect data from 239 households in West Pokot County, Kenya. A Probit model and K-means algorithm were used to analyze the factors affecting farmers’ agroforestry technology adoption decisions based on the sampled households’ socio-economic, demographic, and farm characteristics. The study found that the total yield for maize crop, farm size, extension frequency, off-farm income, access to training, access to credit, access to transport facilities, group membership, access to market, gender, distance to nearest trading center, and household education level had significant effects on the adoption of agroforestry technologies. The findings of this study are important in informing policy formulation and implementation that promotes agroforestry technologies adoption.



Author(s):  
Sadegh Abedi ◽  
Mehrnaz Moeenian

Abstract Sustainable economic growth and identifying factors affecting it are among the important issues which have always received attention from researchers of different countries. Accordingly, one of the factors affecting economic growth, which has received attention from researchers in the developed countries over recent years, is the issue of environmental technologies that enter the economic cycle of other countries after being patented through technology transfer. The current research investigated the role of the environment-related patents and the effects of the patented technological innovations compatible with climate change mitigation on the economic growth and development in the Middle East countries within a specific time period. The required data were gathered from the valid global databases, including Organization for Economic Co-operation and Development and World Bank and have been analyzed using multi-linear regression methods and econometric models with Eviews 10 software. The obtained results with 95% confidence level show that the environmental patents (β = 0.02) and environment management (β = 0.04) and technologies related to the climate change mitigation (β = 0.02) have a significant positive impact on the sustainable economic development and growth rate in the studied countries. Such a study helps innovators and policymakers in policy decisions related to sustainable development programs from the perspective of environmentally friendly technologies by demonstrating the role of patents in three important environmental areas, namely environmental management, water-related adaptation and climate change mitigation, as one of the factors influencing sustainable economic growth.



Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 987
Author(s):  
Mana Raj Rai ◽  
Amnat Chidthaisong ◽  
Chaiwat Ekkawatpanit ◽  
Pariwate Varnakovida

The Himalayas, especially the Everest region, are highly sensitive to climate change. Although there are research works on this region related to cryospheric work, the ecological understandings of the alpine zone and climate impacts are limited. This study aimed to assess the changes in surface water including glacier lake and streamflow and the spatial and temporal changes in alpine vegetation and examine their relationships with climatic factors (temperature and precipitation) during 1995–2019 in the Everest region and the Dudh Koshi river basin. In this study, Landsat time-series data, European Commission’s Joint Research Center (JRC) surface water data, ECMWF Reanalysis 5th Generation (ERA5) reanalysis temperature data, and meteorological station data were used. It was found that the glacial lake area and volume are expanding at the rates of 0.0676 and 0.0198 km3/year, respectively; the average annual streamflow is decreasing at the rate of 2.73 m3/s/year. Similarly, the alpine vegetation greening as indicated by normalized difference vegetation index (NDVI) is increasing at the rate of 0.00352 units/year. On the other hand, the annual mean temperature shows an increasing trend of 0.0329 °C/year, and the annual precipitation also shows a significant negative monotonic trend. It was also found that annual NDVI is significantly correlated with annual temperature. Likewise, the glacial lake area expansion is strongly correlated with annual minimum temperature and annual precipitation. Overall, we found a significant alteration in the alpine ecosystem of the Everest region that could impact on the water–energy–food nexus of the Dudh Koshi river basin.



2018 ◽  
Vol 10 (12) ◽  
pp. 4712 ◽  
Author(s):  
Jinjia Wu ◽  
Jiansheng Qu ◽  
Hengji Li ◽  
Li Xu ◽  
Hongfen Zhang ◽  
...  

The theme of global sustainable development has changed from environmental management to climate governance, and relevant policies on climate governance urgently need to be implemented by the public. The public understanding of climate change has become the prerequisite and basis for implementing various climate change policies. In order to explore the affected factors of climate change perception among Chinese residents, this study was conducted across 31 provinces and regions of China through field household surveys and interviews. Combined with the residents’ perception of climate change with the possible affected factors, the related factors affecting Chinese residents’ perception of climate change were explored. The results show that the perceptive level of climate change of Chinese residents is related to the education level and the household size of residents. Improving public awareness of climate change risk in the context of climate change through multiple channels will also help to improve residents’ awareness of climate change. On the premise of improving the level of national education, improving education on climate change in school education and raising awareness of climate change risk among dependents will help to improve the level of Chinese residents’ awareness of climate change, which could be instrumental in promoting public participation in climate change mitigation and adaptation actions.



2011 ◽  
Vol 113 (3-4) ◽  
pp. 1025-1048 ◽  
Author(s):  
Torben O. Sonnenborg ◽  
Klaus Hinsby ◽  
Lieke van Roosmalen ◽  
Simon Stisen


Climate ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 92
Author(s):  
Tewodros R. Godebo ◽  
Marc A. Jeuland ◽  
Christopher J. Paul ◽  
Dagnachew L. Belachew ◽  
Peter G. McCornick

This work aims to assess water quality for irrigated agriculture, alongside perceptions and adaptations of farmers to climate change in the Main Ethiopian Rift (MER). Climate change is expected to cause a rise in temperature and variability in rainfall in the region, reducing surface water availability and raising dependence on groundwater. The study data come from surveys with 147 farmers living in the Ziway–Shala basin and water quality assessments of 162 samples from groundwater wells and surface water. Most groundwater samples were found to be unsuitable for long term agricultural use due to their high salinity and sodium adsorption ratio, which has implications for soil permeability, as well as elevated bicarbonate, boron and residual sodium carbonate concentrations. The survey data indicate that water sufficiency is a major concern for farmers that leads to frequent crop failures, especially due to erratic and insufficient rainfall. An important adaptation mechanism for farmers is the use of improved crop varieties, but major barriers to adaptation include a lack of access to irrigation water, credit or savings, appropriate seeds, and knowledge or information on weather and climate conditions. Local (development) agents are identified as vital to enhancing farmers’ knowledge of risks and solutions, and extension programs must therefore continue to promote resilience and adaptation in the area. Unfortunately, much of the MER groundwater that could be used to cope with declining viability of rainfed agriculture and surface water availability, is poor in quality. The use of saline groundwater could jeopardize the agricultural sector, and most notably commercial horticulture and floriculture activities. This study highlights the complex nexus of water quality and sufficiency challenges facing the agriculture sector in the region, and should help decision-makers to design feasible strategies for enhancing adaptation and food security.



Sign in / Sign up

Export Citation Format

Share Document