植穴控制体对盐渍土水分运移的影响

该研究旨在探讨以植穴控制体作为调控水分运移的基本单元,以提高盐渍土造林成效及土地使用价值。结合土柱微宇宙试验控制技术,选取植穴控制体（PHCB）的结构因子（木本植物、植穴袋材料、覆膜材料配比、填充材料配比及填料厚度）和环境因子（地下水矿化度、土壤质地、补水量）为影响因素,设计U12(12×43×34)的混合均匀试验。经回归分析筛选出PHCB最佳结构设计参数,建立植穴控制体结构因子和环境因子与含水率间关系的预测方程。分析结果显示：当每次补水量达到5.06 mm,土壤质地为轻黏土的环境条件下,木本植物选择紫叶李、植穴袋材料为麻布、PVA（polyvinyl alcohol）/VAE（vinyl acetate-ethylene copolymer emulsion）/蒙脱石的体积比按100︰20︰10配制成覆膜材料,秸秆、枯枝落叶和木屑以质量比1︰1︰2混合制成填料,可使植穴袋内的土壤含水率提高48.83%。而环境因子的地下水矿化度及结构因子填料厚度对植穴内水分运移的影响均不显著。PHCB可以有效调控盐渍土水分运移过程,是一种盐渍土生态修复方法。     

Vergleich zwischen Total- und königswasserextrahierbaren Elementgehalten in natürlichen Böden und Sedimenten

Comparison between total- and aqua regia extractable contents of elements in natural soils and sediments Total- and aqua regia extractable contents of 19 elements from 28 soil samples with widely varying composition of the ISE ring analytical program (INTERNATIONAL SOIL-ANALYTICAL EXCHANGE) of the year 1995 to 1997 have been taken to find out the comparability between the two fractions. The relations between the two fractions and pH, organic matter and clay content were considered by means of single and multiple regressions. The correlations between the total and aqua regia extractable contents of As, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, P, Pb and Zn are very close, whereas Al, Ba, K, Na and Sr are not or only weakly correlating. The multiple regressions show that the content of some aqua regia extractable elements and the proportion (in %) of the total contents is correlated with pH, organic matter and/or content of clay. In the same way the proportion of aqua regia extractable elements is closely related (except Fe and Hg) to the soil pH. Hereby the proportion of the aqua regia extractable content increases with increasing pH in the range 3,5—7,7. The determined equations are tested for As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn by using the values of certified reference material. The estimated aqua regia extractable contents are being compared with values of reference material. The average proportion of the calculated to the measured aqua regia contents of an element in percent are 99 for Zn, 98 for Co, Cu and Mn, 94 for Cd, 90 for Ni, 88 for Cr, 105 for Hg, 113 for As and 114 for Pb.     

Stand development of Norway spruce dominated subalpine forests of the Swiss Alps

In densely populated regions, forests can help protect communities and infrastructures from natural hazards such as avalanches and rockfall. To promote the protective function, substantial efforts are made to actively manage forest stands. In 2009 alone the Swiss government invested more than 60 million sfr for the maintenance of protection forests. However, to date there has been no comprehensive evaluation of how the structural development of actively managed stands differs from that of passively managed stands in the Alps. Over the past century the structure of Norway-spruce dominated subalpine forests of the Swiss Alps has been changing and it is not clear how these changes affect the potential protective function of these forests, as well as other forest functions such as wildlife habitat. Furthermore, it is not clear how stand dynamics and structural changes differ between stands that are actively managed and those that are passively managed, and thus to what degree active efforts of forest management are contributing to stands that actually have a greater protective function than passively managed forests.In this study, we analyzed the dynamics of subalpine forests using time series of forest inventory data and examined the influence of active vs. passive management, exposition, distance to treeline, elevation and slope steepness on stand structure and dynamics. We analyzed data from 395 plots in dense, subalpine, spruce-dominated forests in the Swiss Alps. Data were collected during three distinct periods (1983-1985, 1993-1995 and 2004-2006) as part of the Swiss National Forest Inventory (NFI). Using regression trees and multivariate statistics, we investigated which factors have the most important influence on tree growth and stand development.Overall, forest density increased significantly over the last 20 years and the predominance of dense forests increased at higher elevations. However, forest density has not increased in actively managed forests over the past 10 years. In passively managed stands, density was higher on south-facing slopes than on north-facing slopes. The volume and density of dead wood has increased over the last 20 years in both actively managed and passively managed forests. Active management over the last 20 years has maintained forest conditions that adequately maintain stands’ protection functions in the Swiss Alps. However, stand development, especially increasing density, in the passively managed stands of the Swiss Alps suggests that the majority of passively managed stands also provide adequate protective functions against rock and avalanche hazards without the high costs of active management.     

~(60)Coγ射线对双低甘蓝型油菜(Brassica napus L.)的辐射效应

用~(60)Coγ射线0、80、100、120、140、160krad的剂量辐射处理3个双低(低芥酸、低硫甙)甘蓝型油菜品种的干种子,从形态学、细胞学和生物化学3个方面研究了M_1代的剂量效应。结果表明,田间出苗率、成株率、产量、自交结果率、角果长度、每果粒数、自交结籽率和粗脂肪含量与剂量拟合曲线负相关,形态畸变率和染色体畸变率与剂量拟合曲线正相关,种子的芥酸和亚麻酸含量、菜饼的硫甙和蛋白质含量随着剂量的增加而呈不规则性变化。形态学效应、细胞学效应和生物化学效应之间关系密切,相关显著。3个品种的辐射敏感性顺序为中双2号>中双1号>中双3号。     

假眼小绿叶蝉种群活动高峰始盛期预测模型的研究

通过建立线性回归-时间序刊AR(p)组分预测模型,提出利用前一年气象因子资料,预测翌年茶园主要害虫假眼小绿叶蝉(Empoasca vitis)活动高峰始盛期的方法,从而提前了虫灾预测的发布时间。并将该方法应用于福建省福安茶区,对防治害虫、减少农药用量、优化茶园生态有较好效果。     

基于Logistic回归模型的新市区耕地数量变化景观立地要素驱动力分析

以保定市新市区为研究区域,采用统计学的研究方法进行单因素相关性分析,利用流失耕地与未流失耕地的累积概率曲线和不同范围内的流失耕地比例来分析耕地数量变化与自变量之间的相关性,以找出对耕地数量变化有贡献的因素。最后运用Logistic回归模型对耕地数量变化状况进行回归分析,定量化研究导致变化发生的景观立地要素驱动力因子,并对耕地变化的风险进行了预测分析。研究表明,耕地流失过程主要受到城镇、主要道路和主要河流三个景观立地要素的影响,离城镇用地和主要道路的距离越近,耕地流失的风险越高,而离主要河流越近,耕地流失的风险越低;利用回归结果进行耕地变化风险预测,能够模拟未来耕地数量和土壤质量变化情况,为耕地保护提供科学指导和依据。     

香蕉叶面积回归模型的建立

以粉蕉、红蕉、泰国蕉、大蕉等7个香蕉品种叶片为试材,应用数字图像处理技术精确测算叶面积,探讨叶长、叶宽及叶长×叶宽与实测叶面积之间的关系,并建立普适性应用模型。结果表明,7个香蕉品种的叶面积与叶长、叶宽的回归模型均达到极显著水平,可用于香蕉叶面积估算。进一步比较各模型的决定系数（R^2）和离回归平方和（Q）得知,以多项式方程和一元线性方程模拟计算的香蕉叶面积精确度更高,其中粉蕉、8818、巴西蕉建议使用拟合多项式方程来计算;红蕉、泰国蕉、皇帝蕉、大蕉建议使用拟合线性方程来计算。     

烤烟新品种云烟99及其亲本生长特性研究

为了解烤烟新品种云烟99生长特性,利用Logistic生长模型对云烟99的株高、叶片数、中部叶叶面积生长进行回归分析,并与其父本9147、母本云烟85做比较。结果表明:(1)云烟99及其亲本3个性状共9个Lo-gistic生长模型方程拟合程度均达极显著水平,能较真实地反映云烟99及其亲本的生长特性;(2)云烟99株高比亲本略高,叶片数与亲本相当,中部叶叶面积与父本相当、比母本大;(3)云烟99株高和叶片数的线性生长期与父本相当、比母本长,中部叶叶面积比亲本长;(4)云烟99的3个性状平均生长速率均介于双亲之间,但线性生长速率和最大生长速率存在差异。     

玉米新品种在秦巴高海拔山区的适应性分析

用产量增产百分数、差异显著性、变异系数法、回归系数法、高稳系数法和非参数度量法等多种分析方法 ,对 10个玉米新品种在高海拔山区 4个地点的适应性进行了系统聚类。结果表明 ,农大 10 8、农大 3138、陕资1号、成单 18号、97Q- 16 7和中单 32 1等 6个品种在高海拔山区表现出较高的生产潜力和较强的稳定性 ,具有良好的适应性     

基于遗传算法结合偏最小二乘的潮土碱解氮高光谱特征及含量估测

提取土壤碱解氮特征光谱是利用高光谱数据进行其含量估测的关键。对山东省典型潮土土壤样本测试高光谱并进行变换;采用遗传算法（GA）结合偏最小二乘法（PLS）,在筛选潮土碱解氮含量特征谱区的基础上,构建潮土碱解氮含量偏最小二乘（PLS）回归估测模型;优选最佳模型并与相关分析、逐步回归分析和单纯偏最小二乘回归分析的模型进行比较。结果表明：潮土碱解氮特征波段为449~469nm,988~1001nm,1065~1078nm,1716~1736nm,1912~1925nm,2213~2233nm,2262~2275nm;基于各输入光谱特征谱区构建的估测模型决定系数R²均较高,其中基于反射率一阶导数光谱筛选的特征谱区,构建的模型精度最高,数据点（147个）为原始全谱的7.17%,建模R²达到0.97,均方根误差RMSE为4.78mg/kg,验证R²为0.95,RMSE为5.49mg/kg,对潮土碱解氮含量具有较好的预测准确性;在光谱变换形式中,反射率的一阶导数表现最佳;方法比较显示采用遗传算法结合偏最小二乘（GA-PLS）获得较高预测精度的同时,可简化模型。说明遗传算法结合偏最小二乘法（GA-PLS）,可有效筛选土壤碱解氮的特征波段,减少模型参与变量,提高估测精度。