Groundwater in Egypt plays an important role in the country＇s water budget. South Western desert represent an arid of desert biome within world＇s net-work of the biosphere reserves. In this study, the plant wild veg...Groundwater in Egypt plays an important role in the country＇s water budget. South Western desert represent an arid of desert biome within world＇s net-work of the biosphere reserves. In this study, the plant wild vegetation were surveyed in Abu Tartur mining area located in the Southern part of Western depending essentially on the seepage from water line tubes which supplies water demands at Abu Tartur. The vegetation-environment relationships in Abu Tartur are described. Data sets （42 species in 38 plots） beside the pip-line enriched from 13 wells were analyzed, using multivariate procedures, i.e., two-way indicator species analysis （TW1NSPAN）, detrended correspondence analysis （DCA） and detrended canonical correspondence analysis （CCA）, to produce a classification of plant communities in the studied areas and to examine the relationships of that plant communities to certain edaphic factors. Five plant communities were identified. Astragalus vogelii, Chenopodium murale, Citrullus colocynthis, Fagonia arabica, Farsetia aegyptia, Hyoscyamus muticus, Morettia philaeana, Cynodon dactylon, Trichodesma africana, Tarnarix nilotica, Senna italica, Schouwia purpurea, Salsola volkensii and Phragmites australis were common in the study area. Phytochemical survey for nitroprpionic compounds in some taxa belonging to Fabaceae family showed the absence of these toxic compounds by using GC/MS analysis. Also some phytochemical components ofAstragalus vogalii were extracted and identified by GC/MS spectra. A biological activity, in this regard was the screening of methanol extracts for some wild taxa of Abu Tartur against natural Tetranychus urticae as acricidal activity and the methanol extracts of some taxa give high mortality results, like Farsetia aegyptia （86.6%） and Fagonia arabica Burm. f. （70.0%）.展开更多
Benefiting from the rapid development of environmental DNA(eDNA)technologies,sedimentary DNA(sedDNA)emerges as a promising tool for monitoring plant compositions in remote regions.The Tibetan Plateau(TP),renowned for ...Benefiting from the rapid development of environmental DNA(eDNA)technologies,sedimentary DNA(sedDNA)emerges as a promising tool for monitoring plant compositions in remote regions.The Tibetan Plateau(TP),renowned for its harsh environment and numerous ponds and lakes,presents a potentially demanding region for the application of sedDNA on vegetation investigations.Here,we used the g and h universal primers for the P6 loop region of the chloroplast trn L(UAA)intron to amplify plant DNA in surface sediments from 59 ponds and small lakes on the southwestern TP.The applicability and limitations of using plant DNA metabarcoding for modern vegetation monitoring and palaeo-vegetation reconstructions have been assessed by comparing sedDNA,pollen,and vegetation survey data.Our results showed that plant DNA metabarcoding recorded 186 terrestrial taxa,of which 30.1%can be identified at the species level.The plant sedDNA approach can effectively disclose the dominant plant taxa(including Asteraceae,Cyperaceae and Poaceae)and significant vegetation assemblages in the vicinity of the investigated sites.The number of taxa and taxonomic resolution of plant sedDNA exceeded that of pollen analysis(75 taxa detected,5.3%can be identified at species level).Unlike pollen that retains a broad spectrum of regional plant signals(including Pinus and Artemisia),plant sedDNA mirrors very local plants,underscoring its utility in local vegetation monitoring and reconstructions.To conclude,plant DNA metabarcoding of(small)lake sediments warrant increased attention in the future for local vegetation monitoring and reconstructions on the TP.展开更多
Climate and grazing have a significant effect on vegetation structure and soil organic carbon(SOC)distribution,particularly in mountain ecosystems that are highly susceptible to climate change.However,we lack a system...Climate and grazing have a significant effect on vegetation structure and soil organic carbon(SOC)distribution,particularly in mountain ecosystems that are highly susceptible to climate change.However,we lack a systematic understanding of how vegetation structure reacts to long-term grazing disturbances,as well as the processes that influence SOC distribution.This study uses multiple sets of data spanning 20 years from a typical alpine grassland in the Qilian Mountains to investigate the effects of climate and grazing on various root-type grasses as well as the mechanisms that drive SOC distribution.We found that grazing increases the biomass of annual,biennial and perennial taproots while decreasing that of perennial rhizomes.We also found that various root-type grasses have different responses to climate and grazing.Multiple factors jointly control the variation of SOC content(SOCc),and the variation of SOC stock(SOCs)is mainly explained by the interaction between climate and grazing years.Climate and grazing can directly or indirectly affect SOCc through vegetation,and SOCs are mainly dominated by the direct effects of grazing years and grazing gradients.Grazing gradients and root-type grass biomass have a significant effect on SOC,with little effect from climate factors.Therefore,long-term grazing may affect the root-type grass and further affect SOC distribution through differences in nutrient acquisition ability and reproductive pathways.These findings provide important guidance for regulating soil carbon sequestration potential by varying the proportion of different root-type grass in the community via sowing,livestock configuration,or grazing time.展开更多
Roof greening is crucial for improving urban eco-environment, showing benefits, ecological y or social y, but it is so hard for investors in terms of capitals or promotion. The research introduced sponge-type composit...Roof greening is crucial for improving urban eco-environment, showing benefits, ecological y or social y, but it is so hard for investors in terms of capitals or promotion. The research introduced sponge-type composite vegetation carpet techniques and constructionprocess, making a breakthrough in greening form and having formulated a new one.展开更多
Saline wetlands are rare ecosystems in Saharan areas, which are important for conservation of many endemic and rare plant species. In this study, we investigated five saline wetland sites of the Oued Righ region, loca...Saline wetlands are rare ecosystems in Saharan areas, which are important for conservation of many endemic and rare plant species. In this study, we investigated five saline wetland sites of the Oued Righ region, located in the northeastern Algeria, to determine the environmental factors controlling the composition and distribution of plant communities. We established a total of 20 transects to measure the vegetation parameters （density and cover） and soil characteristics （electrical conductivity, moisture, pH, CaSO4, CaCO3, organic matter, Na＋, K＋, Mg2＋, Ca2＋, SO42 , CI-, NO3- and HCO3-）. A total of 17 plant species belonging to seven families were identified. The natural vegetation was composed of halophytic and hydro-halophytic plant communities, presented specially by the species of Amaranthaceae family. Soils in the studied wetlands were moist, gypsiferous, alkaline, salty to very salty with dominance of chloride and calcium. Results of the Canonical Correspondence Analysis （CCA） showed that community structure and species distribution patterns of vegetation were mainly dependent on soil characteristics, mainly being soil salinity （CaSO4, K＋, Ca2＋ and CI-） and moisture. The distribution of plant species was found to follow a specific zonal pattern. Halocnemum strobilaceum was observed to grow in highly salt-affected soils, thus being the more salt-tolerant species. Phragmites communis plants were widely distributed in the study area with a high density at the edges of accumulated water body. Juncus maritimus, Tamarix gallica and Saficornia fructicosa grew in soils that are partially or completely flooded in winter. Suaeda fructicosa, Traganum nudatum, Arthrocnemum glaucum, Aeluropus littoralis, Cressa cretica and Cynodon dactylon were distributed in salty and moist soils away from the open water body. Plants of Zygophyllum album, Limonastrirum guyonianum, Cornulaca monacantha, Cistanche tinctoria, Mollugo nudicaulis and Sonchus maritimus were found in soils with less salty and moisture. They constituted the outermost belt of vegetation in the studied wetlands. This study will provide a reference on introducing the salt-tolerant plant species as a fodder resource in saline habitats and regenerating the degraded saline wetlands.展开更多
文摘Groundwater in Egypt plays an important role in the country＇s water budget. South Western desert represent an arid of desert biome within world＇s net-work of the biosphere reserves. In this study, the plant wild vegetation were surveyed in Abu Tartur mining area located in the Southern part of Western depending essentially on the seepage from water line tubes which supplies water demands at Abu Tartur. The vegetation-environment relationships in Abu Tartur are described. Data sets （42 species in 38 plots） beside the pip-line enriched from 13 wells were analyzed, using multivariate procedures, i.e., two-way indicator species analysis （TW1NSPAN）, detrended correspondence analysis （DCA） and detrended canonical correspondence analysis （CCA）, to produce a classification of plant communities in the studied areas and to examine the relationships of that plant communities to certain edaphic factors. Five plant communities were identified. Astragalus vogelii, Chenopodium murale, Citrullus colocynthis, Fagonia arabica, Farsetia aegyptia, Hyoscyamus muticus, Morettia philaeana, Cynodon dactylon, Trichodesma africana, Tarnarix nilotica, Senna italica, Schouwia purpurea, Salsola volkensii and Phragmites australis were common in the study area. Phytochemical survey for nitroprpionic compounds in some taxa belonging to Fabaceae family showed the absence of these toxic compounds by using GC/MS analysis. Also some phytochemical components ofAstragalus vogalii were extracted and identified by GC/MS spectra. A biological activity, in this regard was the screening of methanol extracts for some wild taxa of Abu Tartur against natural Tetranychus urticae as acricidal activity and the methanol extracts of some taxa give high mortality results, like Farsetia aegyptia （86.6%） and Fagonia arabica Burm. f. （70.0%）.
基金supported by the National Natural Science Foundation of China(Grant Nos.42071107,42177433)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA2009000003)the Zhejiang Natural Science Foundation(Grant Nos.LY20D010002 and LY20D010003)。
文摘Benefiting from the rapid development of environmental DNA(eDNA)technologies,sedimentary DNA(sedDNA)emerges as a promising tool for monitoring plant compositions in remote regions.The Tibetan Plateau(TP),renowned for its harsh environment and numerous ponds and lakes,presents a potentially demanding region for the application of sedDNA on vegetation investigations.Here,we used the g and h universal primers for the P6 loop region of the chloroplast trn L(UAA)intron to amplify plant DNA in surface sediments from 59 ponds and small lakes on the southwestern TP.The applicability and limitations of using plant DNA metabarcoding for modern vegetation monitoring and palaeo-vegetation reconstructions have been assessed by comparing sedDNA,pollen,and vegetation survey data.Our results showed that plant DNA metabarcoding recorded 186 terrestrial taxa,of which 30.1%can be identified at the species level.The plant sedDNA approach can effectively disclose the dominant plant taxa(including Asteraceae,Cyperaceae and Poaceae)and significant vegetation assemblages in the vicinity of the investigated sites.The number of taxa and taxonomic resolution of plant sedDNA exceeded that of pollen analysis(75 taxa detected,5.3%can be identified at species level).Unlike pollen that retains a broad spectrum of regional plant signals(including Pinus and Artemisia),plant sedDNA mirrors very local plants,underscoring its utility in local vegetation monitoring and reconstructions.To conclude,plant DNA metabarcoding of(small)lake sediments warrant increased attention in the future for local vegetation monitoring and reconstructions on the TP.
基金funded by the China National Natural Science Foundation(32161143028)National Science and Technology Assistance(KY202002011)the Innovative Research Team of the Ministry of Education(IRT_17R50).
文摘Climate and grazing have a significant effect on vegetation structure and soil organic carbon(SOC)distribution,particularly in mountain ecosystems that are highly susceptible to climate change.However,we lack a systematic understanding of how vegetation structure reacts to long-term grazing disturbances,as well as the processes that influence SOC distribution.This study uses multiple sets of data spanning 20 years from a typical alpine grassland in the Qilian Mountains to investigate the effects of climate and grazing on various root-type grasses as well as the mechanisms that drive SOC distribution.We found that grazing increases the biomass of annual,biennial and perennial taproots while decreasing that of perennial rhizomes.We also found that various root-type grasses have different responses to climate and grazing.Multiple factors jointly control the variation of SOC content(SOCc),and the variation of SOC stock(SOCs)is mainly explained by the interaction between climate and grazing years.Climate and grazing can directly or indirectly affect SOCc through vegetation,and SOCs are mainly dominated by the direct effects of grazing years and grazing gradients.Grazing gradients and root-type grass biomass have a significant effect on SOC,with little effect from climate factors.Therefore,long-term grazing may affect the root-type grass and further affect SOC distribution through differences in nutrient acquisition ability and reproductive pathways.These findings provide important guidance for regulating soil carbon sequestration potential by varying the proportion of different root-type grass in the community via sowing,livestock configuration,or grazing time.
基金Supported by Guangdong Province Soft Science Research Program(2014B090903015)Guangdong Province Science&Technology Cooperation Program([2015]162)~~
文摘Roof greening is crucial for improving urban eco-environment, showing benefits, ecological y or social y, but it is so hard for investors in terms of capitals or promotion. The research introduced sponge-type composite vegetation carpet techniques and constructionprocess, making a breakthrough in greening form and having formulated a new one.
基金the Saharan Bio-resources Laboratory,Safeguarding and Valorization,Kasdi Merbah University of Ouargla,Algeria for providing support for this research
文摘Saline wetlands are rare ecosystems in Saharan areas, which are important for conservation of many endemic and rare plant species. In this study, we investigated five saline wetland sites of the Oued Righ region, located in the northeastern Algeria, to determine the environmental factors controlling the composition and distribution of plant communities. We established a total of 20 transects to measure the vegetation parameters （density and cover） and soil characteristics （electrical conductivity, moisture, pH, CaSO4, CaCO3, organic matter, Na＋, K＋, Mg2＋, Ca2＋, SO42 , CI-, NO3- and HCO3-）. A total of 17 plant species belonging to seven families were identified. The natural vegetation was composed of halophytic and hydro-halophytic plant communities, presented specially by the species of Amaranthaceae family. Soils in the studied wetlands were moist, gypsiferous, alkaline, salty to very salty with dominance of chloride and calcium. Results of the Canonical Correspondence Analysis （CCA） showed that community structure and species distribution patterns of vegetation were mainly dependent on soil characteristics, mainly being soil salinity （CaSO4, K＋, Ca2＋ and CI-） and moisture. The distribution of plant species was found to follow a specific zonal pattern. Halocnemum strobilaceum was observed to grow in highly salt-affected soils, thus being the more salt-tolerant species. Phragmites communis plants were widely distributed in the study area with a high density at the edges of accumulated water body. Juncus maritimus, Tamarix gallica and Saficornia fructicosa grew in soils that are partially or completely flooded in winter. Suaeda fructicosa, Traganum nudatum, Arthrocnemum glaucum, Aeluropus littoralis, Cressa cretica and Cynodon dactylon were distributed in salty and moist soils away from the open water body. Plants of Zygophyllum album, Limonastrirum guyonianum, Cornulaca monacantha, Cistanche tinctoria, Mollugo nudicaulis and Sonchus maritimus were found in soils with less salty and moisture. They constituted the outermost belt of vegetation in the studied wetlands. This study will provide a reference on introducing the salt-tolerant plant species as a fodder resource in saline habitats and regenerating the degraded saline wetlands.
