胶莱盆地北部风尘堆积物光释光年代序列研究

山东省胶莱盆地的高岗部位存在大量的风尘堆积物,对其年代的研究一直存在较大的分歧.对胶莱盆地的潍坊前埠下风尘堆积剖面进行了系统的光释光年代测试,并与其以北16.9km的昌邑县徐林庄剖面的年代进行了对比,初步建立了胶莱盆地风尘堆积的光释光年代序列,研究表明该区风尘堆积主要是晚第四纪以来形成的堆积物.     

Shifts in microbial diversity through land use intensity as drivers of carbon mineralization in soil

Land use practices alter the biomass and structure of soil microbial communities. However, the impact of land management intensity on soil microbial diversity (i.e. richness and evenness) and consequences for functioning is still poorly understood. Here, we addressed this question by coupling molecular characterization of microbial diversity with measurements of carbon (C) mineralization in soils obtained from three locations across Europe, each representing a gradient of land management intensity under different soil and environmental conditions. Bacterial and fungal diversity were characterized by high throughput sequencing of ribosomal genes. Carbon cycling activities (i.e., mineralization of autochthonous soil organic matter, mineralization of allochthonous plant residues) were measured by quantifying ¹²C- and ¹³C-CO₂ release after soils had been amended, or not, with ¹³C-labelled wheat residues. Variation partitioning analysis was used to rank biological and physicochemical soil parameters according to their relative contribution to these activities. Across all three locations, microbial diversity was greatest at intermediate levels of land use intensity, indicating that optimal management of soil microbial diversity might not be achieved under the least intensive agriculture. Microbial richness was the best predictor of the C-cycling activities, with bacterial and fungal richness explaining 32.2 and 17% of the intensity of autochthonous soil organic matter mineralization; and fungal richness explaining 77% of the intensity of wheat residues mineralization. Altogether, our results provide evidence that there is scope for improvement in soil management to enhance microbial biodiversity and optimize C transformations mediated by microbial communities in soil.     

田面微地形对滴灌灌水均匀性的影响

首先分析了田面微地形对滴头实际工作压力的影响,田面越不平整,滴头实际工作压力与设计工作压力的差值越大,当田面局部高差大于滴头设计工作压力时,滴头流量等于零;然后提出了田面微地形产生的流量偏差率公式,并用泰勒级数展开;最后利用描述统计方法和独立样本T-检验的方法对余项进行分析,置信度为99%的余项取值区间为0.001￣0.002,说明余项能够被忽略,田面微地形产生的流量偏差率公式可以用简单的形式来表示。     

坡面侵蚀动力学及其相关参数的探讨

 从分析坡面水流形态动力学特性着手,对比土壤侵蚀临界坡度的研究;概述土壤侵蚀的机制,以及坡面水流中水流速度、泥沙含量和下垫面三者相互作用的关系。发现及时、准确和动态地测量水流速度和泥沙含量,是分析这些复杂关系的关键,它使定量研究坡面土壤侵蚀的机理成为可能。     

Effects of mycorrhizal inoculation of upland rice on uptake kinetics of arsenate and arsenite

We assessed the effect of mycorrhizal inoculation on short‐term uptake kinetics of arsenate and arsenite by excised roots of upland rice (Oryza sativa L. cv. Zhonghan 221). A concentration of 0.01–0.05 mM arsenic (As) differentially affected the influx rates of both arsenate and arsenite into rice roots non‐inoculated or inoculated with Glomus mosseae and G. versiforme. While V_max for arsenate uptake by non‐mycorrhizal roots was 1.02 µmol g^?1 fresh weight h^?1, it was reduced by a factor of 2.4 for mycorrhizal roots (about 0.42 µmol g^?1 fresh weight h^?1) in the high‐affinity uptake system. However, at high concentrations of 0.5–2.5 mM As only G. versiforme was able to reduce As influx. The results show that mycorrhizal effects on As uptake of upland rice are both concentration and species‐specific.     

有机肥与化肥配施下土壤氮组分变化与氮素利用率研究

本文通过盆栽试验,在等量化肥配施等量有机肥的情况下,研究有机-无机肥料配合施用对土壤氮素组成、小麦产量及氮素利用率的影响。结果表明,与单施化肥相比,有机肥与化肥配合施用不同程度地提高了土壤全氮、碱解氮、酸水解氮、非酸水解氮、微生物量氮、酸解铵态氮和氨基酸态氮含量,其中商品有机肥配施化肥处理的全氮、碱解氮、酸水解氮、非酸水解氮、微生物量氮和氨基酸态氮含量增加幅度最大,分别为8.33%、11.23%、7.17%、19.91%、23.53%和9.00%;化肥配施猪粪处理的酸解铵态氮含量增加幅度最大,为6.18%。猪粪、商品有机肥与化肥配合施用,投入总氮的当季利用率可以达到化肥处理的水平,相对而言,秸秆与化肥配合施用后对土壤有机氮各组分影响较小,氮素利用率较低,为23.95%。氮素利用率与土壤全氮、碱解氮、酸解氮、酸解铵态氮、氨基酸态氮、微生物量氮呈显著或极显著相关,非酸水解氮与氮素各组分以及氮素利用率均未达到显著相关水平。综上所述,不同有机肥与化肥配施虽然没有提高氮素利用率,但可改善土壤氮组分和土壤氮素养分状况。     

2000-2012年陕西省复种指数时空分布及潜力分析

利用MODIS数据,经过去云和Savitzky-Golay平滑处理,根据农作物生长曲线变化特征剔除干扰峰,结合陕西省土地利用数据、统计数据和气象数据,运用地统计趋势分析、年际变化分析和标准差的方法,获取陕西省2000-2012年复种指数时空分布及潜力分布.结果表明:陕西省复种指数地域差异显著,由北向南先增后减,呈现一定的纬度特征.复种指数年际变化也存在地域差异,与地貌类型和农业现代化水平密切相关.陕西省平均复种指数为160.32％,平均复种潜力为184.29％,陕南地区可挖掘潜力最大,其次是陕北地区和关中地区.研究结果可为陕西省农业政策制定及粮食估产提供依据.     

徐州山地森林生态质量评价研究

利用徐州山地森林标准地调查数据,从森林结构与功能和森林健康状况2个方面来构建森林生态质量评价指标体系,采用层次分析法、等级评分法、加权综合指数法来评价徐州山地森林生态质量状况。结果表明：无论是森林结构与功能还是健康状况,森林生态质量都是天然林好于混交林,混交林好于人工林;徐州山地森林生态质量等级好、中、差所占的比重大小悬殊,其中质量等级为差的所占比重最大,说明了徐州山地提高森林生态质量还有很大的潜力。     

六安市生态环境需水评价

近年生态环境需水成为区域（或流域）水资源及相关领域研究热点。依据生态环境需水的影响因素建立了包括1个目标层,4个准则层和22个指标的生态环境需水评价指标体系及其评价方法,并选择水资源优越的六安市为研究区,根据2008年统计资料,对其生态环境需水进行了综合评价,结果为优良级别,同时对影响生态环境需水的瓶颈因素进行了讨论。     

干旱和铅胁迫对刺槐和紫穗槐抗氧化酶活性的影响

通过盆栽实验,研究了铅胁迫和干旱胁迫对1 a生刺槐、紫穗槐及其紫穗槐平茬后萌条叶片抗氧化酶活性和丙二醛含量的影响。结果表明:高浓度(1 000~3 000 mg·kg-1)的铅处理能提高SOD活性,低浓度(300~500 mg·kg-1)的铅处理提高了POD活性;水分和铅胁迫共同作用,刺激了各树种叶片的酶活性。综合分析,紫穗槐的抗性优于刺槐,抗铅胁迫能力紫穗槐苗木>紫穗槐萌条>刺槐苗木。