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vegetation composition of Abu Tartur Mining Region （Western Desert, Egypt）： Biological and Phytochemical Survey of Some Studied Taxa

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Journal of Agricultural Science and Technology(A) 2016年第1期6卷 38-53页

作者： Maha Mohamed Abdelmonem El-Shamy Botany Department Faculty of Science Mansoura University Mansoura 35516 Egypt

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%）.

关键词： Abu Tartur vegetation composition aliphatic nitro-compounds Astragalus vogelii acaricidal activity.

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Application of plant DNA metabarcoding of lake sediments for monitoring vegetation compositions on the Tibetan Plateau

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Science China Earth Sciences 2024年第11期67卷 3594-3609页

作者： Kai WU Kai LI Weihan JIA Kathleen RSTOOF-LEICHSENRING Ulrike HERZSCHUH Jian NI Mengna LIAO Fang TIAN College of Life Sciences Zhejiang Normal UniversityJinhua 321004China Polar Terrestrial Environmental Systems Research Group Alfred Wegener Institute Helmholtz Centre for Polar and Marine ResearchPotsdam 14473Germany Institute of Environmental Science and Geography University of PotsdamPotsdam 14476Germany Institute of Biochemistry and Biology University of PotsdamPotsdam 14476Germany College of Resource Environment and Tourism Capital Normal UniversityBeijing 100048China

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.

关键词： Sedimentary DNA(sedDNA) Metabarcoding Pollen vegetation composition Tibetan Plateau

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Soil characteristics and plant distribution in saline wetlands of Oued Righ, northeastern Algeria

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Journal of Arid Land 2016年第6期8卷 948-959页

作者： Naima KOULL Abdelmadjid CHEHMA Division of Desertification Surveillance Scientific and Technical Research Center of Arid Areas Touggourt 30200 Algeria Saharan Bio-resources Laboratory Safeguarding and Valorization Kasdi Merbah University of Ouargla Ouargla 30000 Algeria

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 wit

关键词： saline wetlands soil properties vegetation composition Sahara Algeria

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vegetation Pattern in Northern Tibet in Relation to Environmental and Geo-spatial Factors

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Journal of Resources and Ecology 2018年第5期9卷 526-537页

作者： TIAN Li ZHANG Yangjian Claus HOLZAPFEL HUANG Ke CHEN Ning TAO Jian ZHU Juntao Lhasa Plateau Ecosystem Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences＋ Beijing 100101China Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Belling 100101＋ China Qianyanzhou Ecological Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101＋ China Department of Biological Sciences RutgersThe State University of New Jersey195 University AvenueNewark NJ 07102USA

Environmental and Geo-spatial factors have long been considered as crucial determinants of species composition and distributions. However,quantifying the relative contributions of these factors for the alpine ecosystems is lacking. The Tibetan Plateau has a unique ecological environment and vegetation types. Our objectives are to quantify the spatial distributions of plant communities on the Northern Tibetan Alpine grasslands and to explore the relationships between vegetation composition,Geo-spatial factors and environmental factors. We established 63 field plots along a 1200-km gradient on the Northern Tibetan Plateau Alpine Grassland and employed the two-way indicator species analysis（TWINSPAN） and the detrended canonical correspondence analysis（DCCA）. Fourteen communities of alpine grassland were identifiable along the transect and consisted of three vegetation types： Alpine meadow,Alpine steppe,and desert steppe. vegetation composition and spatial distribution appeared to be largely determined by mean annual precipitation and less influenced by temperature. A large fraction（73.5%） of the variation in vegetation distribution was explained by environmental variables along this transect,somewhat less by Geo-spatial factors（56.3%）. The environmental and Geo-spatial factors explained 29.6% and 12.3% of the total variation,respectively,while their interaction explained 43.9%. Our findings provide strong empirical evidence for explaining biological and environmental synergetic relationships in Northern Tibet.

关键词： alpine grasslands environmental interpretation spatial pattern Tibetan Plateau vegetation composition

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