天津大神堂海洋特别保护区生境修复初步评价

2012年4月、9月和2013年5月、9月份对渤海湾天津大神堂海洋特别保护区分别进行了大型底栖动物调查,用丰度/生物量比较曲线法分析了6个调查站位的大型底栖动物群落投礁前后受污染扰动的变化状况。结果表明,在调查期间保护区大型底栖动物群落表现出从最初的受到中等程度干扰→趋向于受到干扰→群落状况趋向正常,保护区生态状况已经大有好转,人工生态修复效果初显。     

5种光响应模型对小叶杨的适用性分析

采用Li-6400光合仪测定CO2400μmol·mol-1条件下小叶杨的光响应数据。分别采用直角双曲线修正模型、二次多项式模型、直角双曲线模型、非直角双曲线模型及指数模型对光响应曲线进行拟合,探讨5种模型对小叶杨的适用性。结果表明:直角双曲线、非直角双曲线及指数模型不能处理光抑制部分的光响应数据,且得到的最大净光合速率大于实测值,光饱和点远小于实测值;二次多项式虽能处理光抑制部分的光响应数据,但得到的光合参数有悖常识;直角双曲线修正模型不仅能处理光抑制部分的光响应数据,且拟合得到的各项光合参数均与实际相符,是拟合小叶杨光响应曲线的最适宜模型。     

洛伦茨曲线和基尼系数在林业上的应用

文章采用洛伦茨曲线和基尼系数的统计方法,对绥化市北林区一块样地的林木胸径分布情况进行统计分析,进而确定林木分化状况和分化程度,通过实践验证了洛伦次曲线和基尼系数的统计方法可正确反映林木分化程度,可用以正确指导和确定森林经营方案.     

Simulating bimodal tall fescue growth with a degree‐day‐based process‐oriented plant model

Plant growth simulation models have a temperature response function driving development, with a base temperature and an optimum temperature defined. Such models function well when plant development rate shows a continuous change throughout the growing season. This approach becomes more complex as it is extended to cool‐season perennial grasses with a dormant period and bimodal growth curves. The objective of this study was to develop such a bimodal growth model for tall fescue (Schedonorus arundinaceus (Schreb.) Dumort) in the Midwest USA based on multiyear measurement trials. Functions for bimodal growth were incorporated into the ALMANAC model and applied to tall fescue using published tall fescue yields for a variety of sites and soils. Fields of cultivars “Kentucky 31” and “BarOptima Plus E34” were divided into paddocks and sampled weekly for dry‐matter accumulation. These biomass estimates were used to derive weekly growth values by differences between sequential weekly samplings. The measured values were compared to a single tall fescue simulation each year on one soil. Using these results, the ALMANAC model was modified and tested against mean reported tall fescue yields for 11 sites, with one to three soils per site. When we introduced midsummer dormancy into ALMANAC, we assumed dormancy began on the longest day of the year and lasted until the photoperiod was 0.68 hr shorter than the longest. ALMANAC simulated previously reported tall fescue yields well across the range of sites. Thus, ALMANAC shows great promise to simulate bimodal growth in this common cool‐season grass.     

基于Shapley分解规则的中国农村经济益贫式增长研究

采用Lorenz曲线和Shapley贫困分解规则,对中国农村贫困规模进行测度和分解。研究表明,中国经济增长在弱绝对意义上益贫,而在相对和强绝对意义上非益贫。中国经济高速增长并不能自动缓解贫困,在今后发展中政府部门需更多地关注贫困、分配不平等和通货膨胀,让经济发展成果由全民共享。     

土壤水高矿化度对粉质黏土水力特性的影响

为获取高矿化度土壤水条件下的水力特征参数,并比较不同处理的影响,实验测定淡水、30、100及250g/L土壤水矿化度处理土样脱湿过程的水分特征曲线,并利用RETC软件进行模型参数拟合。结果表明,粉质黏土条件下,van Genuchten-Burdine模型可拟合各不同处理土壤水分特征曲线。各组实测曲线形态显示,在吸力较大阶段,当土壤水吸力增大到一定程度时含水率才发生变化,二者呈多值对应关系。TDS-30处理对应的残余体积含水率θr最大,α、n值最小,非饱和水力传导度K值衰减最快;中等大小孔隙的变化对非饱和水力传导度影响较为显著。研究成果可为深入开展矿化度潜水蒸发数值计算提供支持。     

九寨沟沉水杉叶藻的叶绿素荧光参数日变化研究

以来源于九寨沟芳草海、箭竹海和五花海3个湖泊的优势沉水植物杉叶藻(Hippuris vulgaris)为试材,利用Junior-PAM调制叶绿素荧光仪,在夏季对其快速光响应曲线和最大光化学效率(Fv/Fm)日变化动态进行测定,以揭示杉叶藻的光合特征及其与主要环境因子的关系。结果显示:3个湖泊光合有效辐射强度(PAR)日平均值之间无显著差异,五花海的水温(Tw)日平均值极显著高于芳草海和箭竹海。沉水杉叶藻的最大相对电子传递速率(r ETRmax)和半饱和光强(Ek)的日变化在箭竹海和五花海均呈双峰曲线,在芳草海呈单峰曲线;3个湖泊沉水杉叶藻光能利用效率一天中均呈早晚高、中午低的近"V"形曲线。五花海沉水杉叶藻的r ETRmax和Ek日平均值极显著高于箭竹海和芳草海,r ETRmax、Ek在箭竹海和芳草海之间无显著性差异,说明五花海沉水杉叶藻有更强的光合能力和对强光的耐受能力。3个湖泊沉水杉叶藻Fv/Fm日变化都呈"V"形曲线,五花海沉水杉叶藻Fv/Fm恢复速度大于芳草海和箭竹海。研究表明,不同的环境因子,特别是Tw,会导致沉水植物杉叶藻的叶绿素荧光参数在3个湖泊之间存在显著差异,即Tw是九寨沟沉水植物杉叶藻光合作用的主要影响因子,12℃为光合最适温度。     

生物炭及炭基氮肥对土壤持水性能影响的研究

为了探明生物炭及生物炭基氮肥对土壤水分特征的影响，笔者采用实验室土柱入渗、水分特征曲线法测定了混入不同量生物炭材料、生物炭基氮肥土样的水分入渗率、水分吸持力等有关数值。结果表明：随着生物炭材料、生物炭基氮肥混入量的增多，2种土壤垂直土柱水分入渗率均逐渐减小；在水势相同情况下，与对照相比，混入量越大，土壤可保持的水分越多，但这种增加效应是有限度的，超过一定混入量（80 t/hm2）反而会降低土壤持水量；不同生物炭基氮肥对同一土壤及同一生物炭基氮肥对不同质地土壤持水容量的影响均存在差异。因此，在田间实际应用中，生物炭基氮肥对土壤水分特征的影响取决于生物炭基肥料的性质或特征、施用量及土壤质地等因素。     

Intestinal absorption of forsythoside A in different compositions of Shuang-Huang-Lian

Shuang-Huang-Lian (SHL), a traditional Chinese formula containing Lonicerae japonicae flos (LJF), Scutellariae radix (SR) and Forsythiae fructus (FF), is commonly used to treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. Forsythoside A is one of the main active ingredients in Forsythiae fructus, a key herb in SHL. In the present study, effects of different compositions in SHL on the intestinal absorption of forsythoside A were investigated. The observations from in situ intestinal circulation model showed that A/%(h^− 1) of forsythoside A in FF + LSF, FF + SR and SHL were all reduced greatly compared with that in FF. However, in pharmacokinetics study, C_max and AUC_0 → 1440 of forsythoside A all increased and T_1/2 prolonged in SHL, FF + LJF and FF + SR compared with FF. The results indicated that the different compositions of SHL decreased absorption but increased bioavailability of forsythoside A, which may be related to its metabolism inhibited in intestine or liver.