黄土台塬土壤持水特性及其变化规律研究

对陕西乾县枣子沟流域土壤持水性能、动态变化过程和特点,进行了连续5年(1986～1990)定位观测研究。结果表明,黄土台塬土壤优良的持水特性,是黄土旱塬优势生态条件和有较大增产潜力的原因之一。水分周年变化可分为2个阶段,3个时期,水分垂直分布可分为3个水分层类型。     

河口镇到龙门区间水土保持措施减沙水代价分析

水利水保措施的水沙效应评价方法是人们研究的热点之一。为了揭示水土保持和水利措施减少径流和泥沙综合特征的指标,提出了能明确反映水利、水保措施减少单位泥沙量时减少的径流量的减沙水代价(RRS)概念。RRS越大,减少单位泥沙同时减少的径流量越多,在措施减少相同径流量时,减少的泥沙量越小。对河口镇到龙门区间21条主要支流1970—1996年不同水利、水保措施的RRS分析表明,灌溉措施RRS远超出水保措施,梯田、造林、种草等坡面措施的RRS较为接近,坝地的RRS最小。随着流域输沙模数的增加,梯田、造林和种草等措施的RRS与坝地RRS差异变小。年均降水量与坝地RRS为显著负相关,而年均降水量与梯田、造林、种草的RRS显著正相关。     

启东与茅山茶区男性肝癌死亡率比较

用人群流行病学资料和血浆硒检测，比较了江苏省句容县茅山茶区与启东县非茶区男性肝癌死亡率与饮绿茶的关系。结果显示，饮茶率、饮茶量均较高的茅山，其男性肝癌死亡率明显低于启东，趋势性Ｘ２检验有极显著（Ｐ＜０．０１）的意义，但需在饮茶量相对较大时（＞３０ｇ／周）才有显著的保护作用，其ＲＲ值为０．１２。分别调整吸烟、饮酒因素的作用后，在茅山产茶区仍可看出常饮绿茶有显著降低肝癌死亡率的作用，趋势性Ｘ２值分别为８．８９（Ｐ＜０．０１）和５．４６（Ｐ＜０．０５），而在非产茶的启东，因饮茶量较少，绿茶的保护作用则不明显。此外，两地人群血浆抗癌成份硒水平的分析结果也表明，饮茶量大小与血浆硒成平行关系，以肝癌低发的句客人群平均血浆硒（１１．１μｇ／ｄ１）明显高于启东（５．７μｇ／ｄ１）。     

通道绿化林主要害虫及防治技术研究

对余姚市通道绿化林害虫的调查研究结果显示,重要绿化林带上的害虫共有318种,隶属于5目62科240属,其中有6种主要害虫：杨扇舟蛾、茶袋蛾、山东广翅蜡蝉、矩瘤蛎蚧、樟白轮盾蚧、红蜡蚧。防治强化预测预报集营林技术、生物与化学药剂的综合治理措施,能有效抑制通道绿化林虫害的发生。     

延河流域2013年7月连续暴雨下淤地坝毁坏情况调查与评价

[目的]查明2013年7月延河流域连续出现的5次范围广,历时长,量级大的强降雨条件下淤地坝的运行及毁坏情况。[方法]对延河流域3县区15个小流域45座淤地坝进行实地考察。[结果]被调查淤地坝中35座经受住了暴雨洪水的袭击。遭毁坏的10座淤地坝中9座为已淤满变为耕地的"闷葫芦"坝(一大件)及1座新建坝。而尚未淤满正在发挥作用的淤地坝以及新旧结合的坝系大多数都正常运行。[结论]延河流域该次淤地坝毁坏的直接原因是高强度和持续集中降雨造成的超标准暴雨洪水,同时淤地坝在建设、运行和管理方面也存在诸多问题。     

高速公路景观与绿化设计初探

为了把高速公路建成具有个性特色和良好生态的绿色生态走廊,从当前高速公路景观设计中存在的不足出发,对泰井高速公路景观设计的原则与内容进行分析,提出高速公路景观设计要注重生态恢复和路域景观特色构建,并提出一些相应的措施和手段。     

类菌原体引起的长春花变叶病

 长春花(Vinca rosea L.)是一种药用植物,可提取长春花碱;在南方也可作为门前宅旁绿化环境的花卉。长春花有开白花和开红花两个品种,都可发生变叶病害。     

尾叶桉育苗容器和基质的筛选试验

文章介绍了尾叶桉３种容器、２种基质和４种配比的育苗实验，分析比较了容器、基质及其不同配比对尾叶桉４个月生苗木和１．５年生幼林生长的影响，选出了比较理想的容器和基质及其配比。     

喷施生物先锋对麝香百合切花品质和叶绿素的影响

研究了生物先锋的喷施浓度对麝香百合花苞数、株高、叶长、叶宽及叶绿素含量的影响,试验结果表明,生物先锋能显著的改善麝香百合的切花品质和叶绿素的含量,所有处理中以先锋3/1000对切花品质和叶绿素的综合效应最佳.     

Changes in soil organic carbon and nutrient pools in aggregate-sized fractions along a chronosequence of wolfberry (Lycium barbarum L.) plantations in arid areas of Northwest China

Different land use and management actions can affect soil aggregates (SAs) and nutrient stocks, which are crucial for sustainable agriculture. The impacts of various chrono-sequences on the soil aggregate structure, soil organic carbon (SOC) and nutrients associated with aggregate fractions in wolfberry (Lycium barbarum L.) plantations are still not fully understood. This study examined the composition and stability of SAs, SOC, total nitrogen (TN), available phosphorus (AP) and exchangeable cations (K⁺, Na⁺, Ca²⁺ and Mg²⁺) in bulk soil and various aggregate-size fractions from five wolfberry plantations with varying ages (1, 4, 6, 10 and 13 years) and a corn field (0 years) in the arid region of northwest Ningxia in China. The results indicated that silt–clay (<53 μm) fractions were dominant in the soil, accounting for 51%–66%, under different plantation ages. The proportion of the macro-aggregates (>250 μm) increased significantly, by 40%–47%, over the 4 years of wolfberry plantation. Likewise, the soil aggregate stability was improved, and total exchangeable bases (TEB) along with numerous cations concentrations (K⁺, Na⁺, Ca²⁺ and Mg²⁺) in SAs were significantly reduced as the wolfberry plantings became older. Both concentrations of SOC and TN in the soil aggregates peaked in the 13th year. The silt–clay fractions stored a considerable amount of SOC and nutrients. However, short-term (under 6 years) cultivation of wolfberry reduced the stocks of SOC, TN and AP in the soil, while long-term (over 10 years) cultivation increased them, particularly in macro-aggregates. These findings indicated that long-term wolfberry farming had several advantages, such as enhancing soil structure, accumulating SOC and nutrients and ameliorating alkaline soils, especially after 10 years, in the arid northwest of China.