A Study of Water Stress on Olive Growing Under the Effect of Climate Change in South East of Tunisia

2017 ◽  
pp. 1-16
Author(s):  
A. Hachani ◽  
Mohamed Ouessar ◽  
A. Zerrim
Keyword(s):  
Climate Change ◽  
Water Stress

scholarly journals Impacts of Climate Change Interacting Abiotic Factors on Growth, aflD and aflR Gene Expression and Aflatoxin B1 Production by Aspergillus flavus Strains In Vitro and on Pistachio Nuts

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 385
Author(s):  
Alaa Baazeem ◽  
Alicia Rodriguez ◽  
Angel Medina ◽  
Naresh Magan
Keyword(s):  
Climate Change ◽  
Gene Expression ◽  
Water Stress ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Abiotic Factors ◽  
Pistachio Nuts ◽  
Significant Difference ◽  
Spoilage Fungi

Pistachio nuts are an important economic tree nut crop which is used directly or processed for many food-related activities. They can become colonized by mycotoxigenic spoilage fungi, especially Aspergillus flavus, mainly resulting in contamination with aflatoxins (AFs), especially aflatoxin B1 (AFB1). The prevailing climate in which these crops are grown changes as temperature and atmospheric CO2 levels increase, and episodes of extreme wet/dry cycles occur due to human industrial activity. The objectives of this study were to evaluate the effect of interacting Climate Change (CC)-related abiotic factors of temperature (35 vs. 37 °C), CO2 (400 vs. 1000 ppm), and water stress (0.98–0.93 water activity, aw) on (a) growth (b) aflD and aflR biosynthetic gene expression and (c) AFB1 production by two strains A. flavus (AB3, AB10) in vitro on milled pistachio-based media and when colonizing layers of shelled raw pistachio nuts. The A. flavus strains were resilient in terms of growth on pistachio-based media and the colonisation of pistachio nuts with no significant difference when exposed to the interacting three-way climate-related abiotic factors. However, in vitro studies showed that AFB1 production was significantly stimulated (p < 0.05), especially when exposed to 1000 ppm CO2 at 0.98–0.95 aw and 35 °C, and sometimes in the 37 °C treatment group at 0.98 aw. The relative expression of the structural aflD gene involved in AFB1 biosynthesis was decreased or only slightly increased, relative to the control conditions at elevated CO, regardless of the aw level examined. For the regulatory aflR gene expression, there was a significant (p < 0.05) increase in 1000 ppm CO2 and 37 °C for both strains, especially at 0.95 aw. The in situ colonization of pistachio nuts resulted in a significant (p < 0.05) stimulation of AFB1 production at 35 °C and 1000 ppm CO2 for both strains, especially at 0.98 aw. At 37 °C, AFB1 production was either decreased, in strain AB3, or remained similar, as in strain AB10, when exposed to 1000 ppm CO2. This suggests that CC factors may have a differential effect, depending on the interacting conditions of temperature, exposure to CO2 and the level of water stress on AFB1 production.

scholarly journals Applications of Satellite Remote Sensing to Water Governance and the Mitigation of Climate Change Effects

2020 ◽  
Author(s):  
Ilham Ali ◽  
Jay Famiglietti ◽  
Jonathan McLelland
Keyword(s):  
Climate Change ◽  
Water Management ◽  
Remote Sensing ◽  
Water Stress ◽  
Satellite Remote Sensing ◽  
Water Governance ◽  
Remote Sensing Data ◽  
Sensing Data ◽  
Climate Change Effects ◽  
Water Issues

Water stress in both surface and groundwater supplies is an increasing environmental and sustainable management issue. According to the UN Environment Program, at current depletion rates almost half of the world's population will suffer severe water stress by 2030. This is further exacerbated by climate change effects which are altering the hydrologic cycle. Understanding climate change implications is critical to planning for water management scenarios as situations such as rising sea levels, increasing severity of storms, prolonged drought in many regions, ocean acidification, and flooding due to snowmelt and heavy precipitation continue. Today, major efforts towards equitable water management and governance are needed. This study adopts the broad, holistic lenses of sustainable development and water diplomacy, acknowledging both the complex and transboundary nature of water issues, to assess the benefits of a “science to policy” approach in water governance. Such negotiations and frameworks are predicated on the availability of timely and uniform data to bolster water management plans, which can be provided by earth-observing satellite missions. In recent decades, significant advances in satellite remote sensing technology have provided unprecedented data of the Earth’s water systems, including information on changes in groundwater storage, mass loss of snow caps, evaporation of surface water reservoirs, and variations in precipitation patterns. In this study, specific remote sensing missions are surveyed (i.e. NASA LANDSAT, GRACE, SMAP, CYGNSS, and SWOT) to understand the breadth of data available for water uses and the implications of these advances for water management. Results indicate historical precedent where remote sensing data and technologies have been successfully integrated to achieve more sustainable water management policy and law, such as in the passage of the California Sustainable Groundwater Management Act of 2014. In addition, many opportunities exist in current transboundary and interstate water conflicts (for example, the Nile Basin and the Tri-State Water Wars between Alabama, Georgia, and Florida) to integrate satellite-remote-sensed water data as a means of “joint-fact finding” and basis for further negotiations. The authors argue that expansion of access to satellite remote sensing data of water for the general public, stakeholders, and policy makers would have a significant impact on the development of science-oriented water governance measures and increase awareness of water issues by significant amounts. Barriers to entry exist in accessing many satellite datasets because of prerequisite knowledge and expertise in the domain. More user-friendly platforms need to be developed in order to maximize the utility of present satellite data. Furthermore, sustainable co-operations should be formed to employ satellite remote sensing data on a regional scale to preempt problems in water supply, quantity, and quality.

scholarly journals Improving Water Productivity in Rice – A Response to Climate Change and Water Stress in Pakistan

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Arjumand Nizami ◽  
Muhammad Zulfiqar ◽  
Jawad Ali ◽  
Naushad Khan ◽  
Imran Sheikh
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Water Productivity

scholarly journals Assessing the Impact of Drought Stress and Soil Cultivation in Chardonnay and Xynisteri Grape Cultivars

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 670 ◽  
Author(s):  
Antonios Chrysargyris ◽  
Panayiota Xylia ◽  
Vassilis Litskas ◽  
Menelaos Stavrinides ◽  
Lisa Heyman ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Water Content ◽  
Agricultural Sector ◽  
Grape Juice ◽  
Titratable Acidity ◽  
Anthocyanin Content ◽  
Total Anthocyanin ◽  
Mediterranean Areas ◽  
The Impact

Cyprus has a long tradition in grape cultivation and wine making and grapevine is important for the sustainability of the agricultural sector, like in other Mediterranean areas. Water scarcity, which is projected to increase due to climate change, could negatively affect the sector. In this research, the effects of irrigation and tillage treatments on various aspects of vine growth and product quality (e.g., yield, physiology and quality attributes), were studied in Chardonnay and Xynisteri cultivars grown in clay soils in Cyprus. Regarding soil properties and water content, N and K were more abundant in the soil than P and through the growing period irrigation tended to increase electrical conductivity (EC) in the soil. Soil water content (volumetric) was 22%–27.5% and 13%–16%, when irrigation was applied or not, respectively. Vegetative soil cover occupied 50%–55% of the surface and contained species typically present in Mediterranean farms (e.g., Poaceae, Fabaceae and Brassicaceae). Tillage increased yield in Xynisteri (4–5 kg plant−1) but negatively affected other parameters such as chlorophyll levels (in Xynisteri). In combination with irrigation, tillage increased antioxidant activity in Chardonnay (assessed by FRAP and DPPH), at harvest. Total phenolics at harvest were higher in the grape juice of Xynisteri, compared to Chardonnay (30–40 and 20–25 mg GA g−1 fresh weight, respectively). Irrigation influenced phytohormone levels in the two cultivars. ABA increased in non-irrigated Xynisteri, reflecting an increased capacity to react towards water stress. Water stress is considered to increase polyphenols in grapes, but in the case of Xynisteri it seems that irrigation water is required to obtain better quality grapes as without irrigation volumetric water content (VWC) is close to the permanent wilting point. Titratable acidity and total tannins decreased in Chardonnay, when tillage and irrigation were applied. In addition, tillage and irrigation tended to elevate the pH of the grape juice. Tillage and irrigation on the other hand, had no effect on the levels of ascorbic acid and total anthocyanin content. The results of this research may help to select management strategies that support the adaptation of viticulture to climate change in Cyprus and other Mediterranean areas.

scholarly journals Human and Climate Effects on the Hamoun Wetlands

2019 ◽  
Vol 11 (3) ◽  
pp. 609-622 ◽  
Author(s):  
Saeideh Maleki ◽  
Saeid Soltani Koupaei ◽  
Alireza Soffianian ◽  
Sassan Saatchi ◽  
Saeid Pourmanafi ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Time Series ◽  
Water Stress ◽  
Rural Areas ◽  
Human Activities ◽  
Large Scale ◽  
Upstream Region ◽  
Ecosystem Recovery ◽  
Climate Effects

Abstract Negative impacts of climate change on ecosystems have been increasing, and both the intensification and the mitigation of these impacts are strongly linked with human activities. Management and reduction of human-induced disturbances on ecosystems can mitigate the effects of climate change and enhance the ecosystem recovery process. Here, we investigate coupled human and climate effects on the wetland ecosystem of the lower Helmand basin from 1977 to 2014. Using time series climate-variable data and land-use changes from Landsat time series imagery, we compared changes in ecosystem status between the upstream and downstream regions. Results show that despite a strong and prolonged drought in the region, the upstream region of the lower Helmand basin remained dominated by agriculture, causing severe water stress on the Hamoun wetlands downstream. The loss of available water in wetlands was followed by large-scale land abandonment in rural areas, migration to the cities, and increasing unemployment and economic hardship. Our results suggest that unsustainable land-use policies in the upstream region, combined with synergistic effects of human activities and climate in lower Helmand basin, have exacerbated the effects of water stress on local inhabitants in the downstream region.

Evaluating climate change induced water stress: A case study of the Lower Cape Fear basin, NC

2013 ◽  
Vol 40 ◽  
pp. 115-128 ◽  
Author(s):  
Michael T. Griffin ◽  
Burrell E. Montz ◽  
Jennifer S. Arrigo
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Cape Fear

Using Dynamic Adaptive Policy Pathways and hydrological modelling to co-create water resource adaptation policies for climate change: a practical example for southern Portugal

2020 ◽  
Author(s):  
João Pedro Nunes ◽  
Luís Filipe Dias ◽  
Bruno A. Aparício ◽  
Inês Morais ◽  
Ana Lúcia Fonseca ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Water Resources ◽  
Hydrological Modelling ◽  
Future Scenarios ◽  
Local Policy ◽  
Policy Makers ◽  
Implementation Phase ◽  
Adaptive Policy ◽  
Southern Portugal

&lt;p&gt;Mediterranean agricultural systems often rely on irrigation, which can cause conflicts with domestic water demand due to limited water resources. Climate change could enhance these conflicts by bringing a drier climate, lowering water availability, while increasing irrigation demands, therefore creating a need for timely adaptation actions. However, the creation of adaptation plans requires the integration of local policy-makers and stakeholders, both to ensure that the plans are adjusted to local physical and social conditions, and to secure investment in the implementation phase. As many are not technical experts in water resources, this integration requires innovative methodologies to ensure that knowledge gained from advanced hydrological methods can be effectively transmitted for use.&lt;/p&gt;&lt;p&gt;These issues were addressed in the climate change adaptation plan for water resources in the Algarve region (southern Portugal), which was co-created between hydrologists and local stakeholders and policy-makers under project CLIMAAA, by using the Dynamic Adaptive Policy Pathways (DAAP) approach to synthetize the results from hydrological modelling of future scenarios.&lt;/p&gt;&lt;p&gt;Future scenarios were simulated from the present until 2100 using a hydrological model, with multiple realizations of climate scenarios RCP4.5and RCP8.5. The results show an increase in water stress conditions, mainly in the RCP8.5 scenario. Future scenarios and potential adaptation measures were discussed with the local policy-makers (regional and municipal water managers) and water users (water utilities, farmer associations). An agreed-upon set of measures was then simulated with the model to assess their effectiveness for adaptation. These results were used to design a DAAP specifically for the water sector in the Algarve.&lt;/p&gt;&lt;p&gt;Policy-makers were then presented with the DAPP, combined with a cost assessment, and selected the most suitable and politically reliable adaptation pathway until 2100. They did not consider socially desirable to decrease irrigation use, and showed a strong preference for measures such as promoting efficient water use and water retention landscapes, which are distributed and incremental, to measures such as wastewater recycling which require a large investment. However, they did consider desalination as a last resort despite the high investment, to be applied in case other measures fail to maintain water stress below an acceptable threshold. In the end, an adaptation plan for water resources was co-created between policy-makers and researchers which strongly reflected local desires and preferences, while ensuring that its effectiveness was assessed with the best available tools; this plan is now in in the review and implementation stage.&lt;/p&gt;

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