分类： 生物学 >> 生态学 提交时间： 2023-05-11 合作期刊: 《干旱区科学》
摘要：Soil faunas account for 23% of known animal species and play a crucial role in ecosystem processes such as mineralizing nutrients, regulating microbial community composition, forming soil aggregates, and enhancing primary productivity. However, due to global climate change, population density, community composition, and distribution patterns of soil fauna vary. Understanding the responses of soil fauna to major environmental change facilitate the conservation of biodiversity. Therefore, a review work of recent researches for analysing the effects of key environmental factors on soil fauna, such as warming, drought, food quality, and soil physical-chemical properties was studied. For most species, warming may exert a positive effect on their abundance and population development, however, it can inhibit the survival and reproduction of hibernating species. Drought leads to low soil porosity and water holding capacity, which reduces soil fauna population and changes their community composition. Drought also can reduce the coverage of flora and alter microclimate of the soil surface, which in turn indirectly reduces fauna abundance. Climate warming and elevated atmospheric carbon dioxide can reduce litter quality, which will force soil fauna to change their dietary choices (from higher-quality foods to poor quality foods) and reduce reproduction for survival. However, it is still predicted that enhanced species richness of plant (or litter) mixtures will positively affect soil fauna diversity. Habitat loss caused by the deterioration of soil physical-chemical property is primary factor affecting soil fauna. We mainly discuss the threats of increased salinity (a major factor in arid land) to soil fauna and their potential responses to anthropogenic disturbance in saline soils. The increase in soil salinity can override other factors that favour habitat specialists, leading to negative effects on soil fauna. Moreover, we find that more studies are needed to explore the responses of soil fauna in saline soils to human activities. And the relationship of important ecological processes with soil fauna density, community structure, and diversity needs to be redefined.
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： Three new coordination polymers, namely [Zn(FDA)(phen)(H2O)·H2O]n (1), [Cd(HFDA)(phen)2(NO3)] (2) and [Cd(FDA)(phen)]n (3) (H2FDA = 2,5-furandicarboxylic acid, phen = 1,10-phenanthroline) have been synthesized by the solvothermal method and characterized by elemental analysis, IR, powder X-ray diffraction, thermogravimetric analysis and X-ray single-crystal diffraction analysis. For 1, the neighboring Zn2+ ions are bridged by FDA2- as linkers to form one-dimensional (1D) chains, and phen ligands are as the terminal ligands. Furthermore, the 1D chains are packed into a three-dimensional (3D) supramolecular structure through hydrogen bonds and π-π interactions. For 2, the H2FDA ligand is partial deprotonation, which is a rare phenomenon among other coordination polymers based on H2FDA. Under the synergetic effect of phen ligands and the partial deprotonation of H2FDA, the structure of 2 is discrete. For 3, the Cd2+ ions are linked by two carboxylates of FDA2- ligand to give rise to 1D zig-zag chains, and phen ligands chelate the Cd2+ ions like 1. In addition, solid-state luminescent spectra of three coordination polymers were also studied at room temperature.
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