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Accueil du site → Master → Chine → 2020 → Response of Soil Microbial Mineralization to the Desert Grassland-Shrubland State Anthropogenic Transition in the Eastern of Ningxia,China

Ningxia University (2020)

Response of Soil Microbial Mineralization to the Desert Grassland-Shrubland State Anthropogenic Transition in the Eastern of Ningxia,China

孙忠超;

Titre : Response of Soil Microbial Mineralization to the Desert Grassland-Shrubland State Anthropogenic Transition in the Eastern of Ningxia,China

Auteur : 孙忠超;

Grade : Master’s Theses 2020

Université : Ningxia University

Résumé
We selected a typical grassland-shrub mosaic formed by the anthropogenic introduction of shrub(Caragana Korshinskii)in the desert grassland of the eastern Ningxia as our research object,the four transition sites in the mosaic,i.e.,desert grassland(DG),grassland edge(GE),and shrubland edge(SE)and shrubland(SL)were selected based on the ecological boundary theory.We conducted the field investigation,in-situ mineralization under different rainfall gradients and indoor water(+40%,-40%)and litter(Agropyron mongolicum,Caragana korshinskii)addition experiments in laboratory to carry out research on.vegetation,soil microbes and their mineralization characteristics in the process of anthropogenic transitionn from desert grassland to shrubland,and aim to further explore the characteristics of variation in soil and vegetation with the anthropogenic vegetation transition from desert grassland to shrubland and the impact of vegetation change on soil microbial mineralization under global climate change,providing a theoretical basis and data for the restoration sustainability of desert grassland.The main results are as follows :(1)With the grassland-shrubland transition,there was no significant difference in richness,diversity and uniformity between the desert grassland and the two marginal sites,and these indexes of the shrubland was significantly lower than other sites(P<0.05),and was significantly lower 37.0%,42.4%,and 35.2%than that of the desert grassland and the two edge sites,respectively.The above-ground herbious biomass of grassland increased first and then decreased with the highest biomass at the grassland edge,while the shrub biomass showed a gradual increase and the highest shrub biomass was obtained in shrubland.(2)With the grassland-shrubland transition,the soil moisture in the 0-200 cm soil layer showed a decrease with the sites transition,i.,e the desert grassland>grassland edge>shrubland edge>shrubland.The seasonal dynamics of soil moisture at the desert grassland edge and grassland actively responded to rainfall changes,while Shrub edge and shrubland decreased with seasonal changes,resulting from the deep-seated water consumption was mainly supplemented in autumn

Mots clés : Desert grassland; Anthropogenic introduced shrub; Caragana korshinskii; soil microbial mineralization; Rainfall gradient; Litter addition;

Présentation (CNKI)

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