Environmental Impact of Desert Dam Reservoir in Arid Habitat

Abstract

Background and Objective: Although desert dams create storage reservoirs that recharge ground water, irrigate desert agriculture and protect against flash floods, there is controversy about their effects on ecosystem. Work in this study was carried out to provide first environmental impact assessment of Wadi Jazan desert reservoir by studying its effects on soil and floristic composition. Materials and Methods: Soil analysis included studies of soil types and characteristics. Vegetation analysis included study of plant distribution, life forms, growth habits, carbon isotope discrimination, CO 2 fixation pathways, species drought and salt tolerance ranges. Results: Soil analysis revealed changes in soil type around reservoir from common sand-silt to clay and clay-loam types reflecting reservoir-induced changes in sedimentation patterns. Soil analysis also revealed increased soil electric conductivity and total dissolved solids in reservoir vicinity denoting increased soil salinity. High reservoir level during wet season enables water to cover vast areas with subsequent evaporation during long hot dry season resulting in salt accumulation and increased soil salinity. Vegetation analysis revealed prevalence of salt tolerant C3 species in saline soil in reservoir vicinity that was reversed with prevalence of C4 drought tolerant species as distance from reservoir increased. Presence of non-native aquatic and wetland species are due to recruitment facilitated by reservoir. Conclusion: Wadi Jazan desert reservoir modified sedimentation pattern, facilitated establishment of invasive aquatic plants and induced changes in regional floristic diversity and distribution.

Climate change and hydrological regime in arid lands: Impacts of dams on the plant diversity, vegetation structure and soil in Saudi Arabia

“…The dominance of annual herbs (39.74%) followed by perennial herbs (18.54%) was might be due to the availability of more moisture created by dams in those areas and secondly due to their short life cycle pattern that helps them to resist the instability of the ecosystem ( Alatar et al, 2012 , Gomaa, 2012 , Mahmoud et al, 2018 ). Our results are comparable with the study of Sayed et al, (2020) on the impact of Wadi Jizan desert reservoir which reported that the area around the reservoir harbored several plant species with different life forms and a prevalence of annuals and perennials herbs. Chorological analysis of the surveyed plants revealed the dominance of monoregional elements (57.623%), over the biregionals (27.81%) and pluriregionals, and the presence of the biregional and pluriregonal due to Saudi consider as a meeting point of Africa, South Europe and Asia ( Alatar et al, 2012 , Al-Sherif et al, 2013 , Osman et al, 2014 , Abdel Khalik et al, 2017 , Mahmoud et al, 2018 , Al-Yasi et al, 2019 , Al-Shehri et al, 2020 ).…”

“…Dam construction is one of the main strategies for storing and protecting runoff water for consumption and agricultural needs. Despite these socioeconomic roles, desert reservoirs fell into controversy because of their complex impact on desert ecosystems such as their influence over climate, ability to modify sedimentation patterns, facilitate the establishment of many plant species and last but not least their impact on regional floristic diversity ( Sayed et al, 2020 , Šulyová et al, 2021 ).…”

“…In Saudi Arabia, investigations to examine the influence of dams on flora and vegetation are scarce. Sayed et al, (2020) studied the impact of the Wadi Jizan dam reservoir on its immediate ecosystems and local floristic diversity and deduced that the dam altered the sedimentation pattern, aided in the establishment of invasive aquatic plants, and caused changes in regional floristic diversity and distribution. As a result, the main goal of this study is to evaluate the influence of dams on the vegetation composition, species diversity and soil of dam sites in various regions of Saudi Arabia.…”

Identification of Morphological and Physiochemical Characteristics, Flowering Periods, and Genetic Relationship of Citrus Species

“…Moreover, [7] also revealed that the genetic diversity and genetic relationships of 39 lime genotypes had been successfully evaluated through morphological analyses. In addition to morphological characterization, [8] reported that the differences among acid citrus accessions were obtained by observing leaf lamina and fruit shape. This study was supported by [9] who reported that morphological traits such as leaves and fruit could evaluate the difference in Citrus Grandi's genotypes.…”

“…ISSR marker mostly has been used in citrus species identification, because it could separate citrus species as well as varieties into proper clusters [8]. However, [12] revealed that the genetic similarities of the lemon group derived from morphological (75%) and molecular analyses (73%) were not different.…”