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Zhang Z.,CAS Institute of Zoology | Xu L.,CAS Institute of Zoology | Xu L.,University of Chinese Academy of Sciences | Guo C.,Sichuan University | And 2 more authors.
Integrative Zoology

The Yangtze vole (Microtus fortis Buechner, 1889) is a small herbivore species that inhabits lake beaches in the Dongting Lake region along the Yangtze River in Southern China. Its population shows strong oscillations during the wet season due to summer precipitation-induced immigration away from the lake into adjacent rice fields. The effect of El Niño-Southern Oscillation-driven precipitation on population abundance and growth of the vole species is not fully understood. We undertook an analysis of the combined data of 4 time series covering 1981-2006 from 4 different sites and a separate analysis on a single time series (1981-2006) from one site. Our results demonstrate that a dual effect of El Niño-Southern Oscillation-driven precipitation on the population abundance of voles is time-dependent: precipitation in the current year has a positive effect, whereas precipitation in the previous year has a negative effect. The dual effect of precipitation on vole population is well explained by the unique interactions among vole population, precipitation water level and the lake beach habitat around Dongting Lake. We found that drier than average weather of the previous year benefited voles because their breeding habitats, lake beaches, were exposed for long stretches of time. Wet weather was found to increase the number of voles inhabiting rice fields because as the water level of the lake rose they were forced from beaches into surrounding rice fields. Summer precipitation in the Dongting Lake region was found to be positively associated with the sea surface temperature (SST) of the eastern tropical Pacific Ocean of the previous year and winter SST and spring SST of the current year. Annual rates of increase in the vole population of the reconstructed time series are negatively associated with the vole abundance and autumn precipitation of the previous year and winter precipitation of the current years. These results suggest that both extrinsic and density-dependent intrinsic factors may affect population dynamics of the Yangtze voles. © 2010 ISZS, Blackwell Publishing and IOZ/CAS. Source

Qin H.,Zhejiang Agriculture And forestry University | Lu K.,Zhejiang Agriculture And forestry University | Strong P.J.,University of Queensland | Xu Q.,Zhejiang Agriculture And forestry University | And 4 more authors.
Applied Soil Ecology

Arbuscular mycorrhizal fungi (AMF) play key roles in plant growth, ecosystem sustainability and stability. However, it is still unclear how the soil, root AMF growth and community composition are affected by fertilizer application in subtropical wheat-rice rotation agro-ecosystems. We investigated the impact of different organic and/or inorganic fertilizers on AMF growth and community composition in a long-term experiment field in Zhejiang Province, east China. AMF biomass was determined using 16:1ω5 phospholipid fatty acids (PLFAs) and neutral lipid fatty acids (NLFAs) content. Soil and root AMF community compositions were determined by DGGE analysis, cloning, sequencing and phylogenetic analyses. The root colonization rate was not significantly affected by different fertilizer regimes. Manure amendment significantly enhanced both AMF hyphal (i.e., 16:1ω5 PLFA) and spore (i.e., 16:1ω5 NLFA) biomass content, while inorganic fertilizer only increased the AMF spore biomass. A total of 10 and 11 Glomeromycota phylotypes were detected in soil and root samples, respectively. Glomus was the dominant genus in both soil and root samples, while Acaulospora genus occurred in roots only. Although the different fertilizers altered soil AMF communities, the root AMF community structure was not significantly altered. Soil pH (. F=. 5.695, P<. 0.01) and available K (. F=. 4.888, P<. 0.01) contributed to both soil and root AMF community composition, while the C/P ratio (. F=. 3.893, P<. 0.01) only contributed to soil AMF community. The data suggests that high soil organic C content benefits AMF growth, while soil pH and available K concentration strongly influence AMF community. The root AMF community was much more resilient to the changes caused by long-term fertilizer application than the soil community. © 2015 Elsevier B.V. Source

Qin H.,Zhejiang Agriculture And forestry University | Wang H.,Zhejiang Agriculture And forestry University | Strong P.J.,University of Queensland | Li Y.,Zhejiang Agriculture And forestry University | And 2 more authors.
Soil Biology and Biochemistry

Although heavy winter mulch and high rate fertilizer application are commonly practiced in intensively managed bamboo (Phyllostachys praecox) plantations, little is known about the effects of these practices on soil microbial activities. Therefore a field study was conducted to investigate the long term intensive management on the development and composition of soil fungal communities. Fungal biomass (fungal phospholipid fatty acid marker), fungal DNA (18S rDNA real-time qPCR) and fungal community composition (culture-independent methods: DGGE, cloning and sequencing) were determined across a bamboo plantation that included seven stand age-classes (1, 4, 6, 8, 10, 12 and 20 years old). Although soil microbial PLFA biomass and fungal DNA abundance were unaffected during the first two years of intensive management, all increased significantly after three years of intensive management. The total microbial PLFA and bacterial PLFA increase linearly (P<0.001) with increasing stand age, while soil fungal PLFA and 18S gene abundance increase was best described using a quadratic equation (P<0.01). The fungal/bacterial ratio generally remained constant, but did increase for the 8 and 12 year stand soils. Sequencing of commonly-occurring bands revealed that the majority of the soil fungi were species of either Sordariomycetes or Chytridiomycetes. Cluster analysis by Ward's method revealed rapid short-term change in fungal communities that returned to its original composition within one to two years when the soils were not disturbed. This indicated a robust original fungal community that was resilient to transient perturbations resulting from intensive land management when allowed breaks from nutrient loading and soil disturbance. Redundancy analysis indicated that soil chemical characteristics, such as pH, Ntot and Corg, could account for 12.7%, 12.1% and 10.3% of the variance in soil fungal community composition, respectively. Stand age contributed to 12.6% of the variance of soil fungal community. © 2013 Elsevier Ltd. Source

Xiong X.-B.,Wuhan University | Xiong X.-B.,Hubei University | Liu W.-L.,Agricultural Technology Extension Center | Yuan X.-M.,Wuhan University | And 3 more authors.
Wuli Xuebao/Acta Physica Sinica

In this paper, SrZn2(PO4)2:Sn2+ (SZ2P:Sn2+), SrZn2(PO4)2:Mn2+ (SZ2P:Mn2+), SrZn2(PO4)2:Sn2+, and Mn2+(SZ2P:Sn2+, Mn2+) phosphors are prepared by high temperature solid state reaction. The X-ray diffraction patterns and photoluminescence spectra of the phosphors are investigated in detail. The emission spectrum of SZ2P:Sn2+ is a wide band peaking at 461 nm due to 3P1→1S0 transition of Sn2+, and overlaps effectively with the excitation spectrum of SZ2P:Mn2+, which shows that the absorption of SrZn2(PO4)2 host, and a series of peaks at 352, 373, 419, 431, and 466 nm, corresponding to 6A1(6S)→4E(4D), 6A1(6S)→4T2(4D), 6A1(6S)→[ 4A1(4G), 4E(4G)], 6A1(6S)→4T2(4G) and 6A1(6S)→4T1(4G) transition, respectively, are assigned to a wide band ranging from 200 nm to 300 nm. Therefore, luminescence intensity of Mn2+ is enhanced significantly by co-doping Sn2+ in SrZn2(PO4)2 host. According to the Dexter's energy transfer formula of multipolar interaction and Reisfeld's approximation, it is demonstrated that the energy transfer between Sn2+ and Mn2+ is due to the quadripole-quadripole interaction of the resonance transfer. The critical distance (Rc) of energy transfer is calculated to be about 1.78 nm. The tunable color is achieved by changing the doping concentrations of Sn2+ and Mn2+. The SZ2P:Sn2+, Mn2+ phosphor could emit strong blue-white light under the excitation of 254 nm ultraviolet (UV) light. The result shows that the SZ2P:Sn2+, Mn2+ is a promising phosphor for compact fluorescent lamp, and with the development of short wave UV semiconductor chip, this phosphor has potential applications in white light emitting diodes in the near future. © 2015 Chinese Physical Society. Source

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