我国农牧交错带资源环境现状与可持续发展对策

阐述了我国东部农区与西部牧区之间生态过渡带———农牧交错带独特资源与环境特征 ,指出该区应打破系统的封闭性 ,引进负熵促进系统从无序向有序、从低级向高级演化 ,调整农业产业结构 ,使农牧业系统良性耦合 ,实现资源优化配置 ,积极扩大对内对外开放 ,获取外源能量流、物质流、价值流和信息流 ,开拓新的经济增长点和就业渠道     

采取综合配套措施,积极防治人为破坏

采取综合配套措施,包括广泛宣传《条例》、《细则》,增强广大人民群众的法制观念;严肃查处典型案例,巩固扩大治理成果;采取果断有力措施,开展毀林开荒大检查,充分利用行政手段,明确和完善具体政策;加强队伍建设,建立乡规民约;建立健全水土保持机构,协调各个方面共同防治人为破坏,近5年来,基本上煞住了人为破坏的歪风。     

试论开发治理水土流失山区的方略

我国山区约占国土总面积的70%,自然资源十分丰富。治理和开发山区在国家经济建设中处于重要战略地他,应与重点开发沿海发达地区统筹兼顾,发挥各自优势,互相支援,互相促进,协调发展。山区水土流失严重,是山区贫困的根源,是山区开发的主要障碍。水土保持是防治水土流失,保护和合理利用山区水土资源,改善生态环境,减少自然灾害,发展多种商品经济,脱贫致富的战略措施;是山区交通、工矿等基本建设的根本保证和开发山区的基础。治理开发山区总的方向是:预防为主,治管结合,全面规划,综合治理,以发展多种经营为主,同时不放松粮食生产,尽快脱贫致富;还要把观念和职能,转到以预防为主,治管结合的轨道上来,加强以监督管理和法制来防治新的水土流失。同时还要依靠政策、科学和投入,特别要建立健全全国各级水土保持机构体系,以强化水土保持和山区开发,为我国社会主义现代化建设做出更大贡献。     

京津沙源区草场沙退化综合整治模式探讨

为尽快落实中央政府关于做好京津周边地区防沙治沙工作,遏制土地继续沙化和沙漠蔓延扩展,加大草原沙化、退化治理力度,减轻风沙对京津周边地区危害的战略布署,开展浑善达克沙地草场沙化、退化综合整治技术试验示范研究,旨在全面了解浑善达克沙地草场沙化、退化形成演化规律,探索解决畜草矛盾的途径和草原生态环境综合整治及水-草-畜持续发展的模式,研究开发和引进一批草场沙化、退化综合整治和水草资源合理利用的技术,并通过治理工程将各种技术组装集成示范推广,使新模式实体化,从而为我国草场防沙、治沙生态保护及区域群众脱贫致富提供决策依据和技术支撑.     

腐殖酸和溶液的pH对Na和Ca土壤粘土分散的影响

Dispersed soil clays have a negative impact on soil structure and contribute to soil erosion and contaminant movement.In this study,two typical soils from the south of China were chosen for investigating roles of pH and humic acid(HA) on dispersion of soil clays.Critical flocculation concentration (CFC) of the soil clay suspension was determined by using light transmission at a wavelength of 600 nm.The results indicated that effects of pH and HA on dispersion of the soil clays were closely related to the type of the major minerals makin up the soil and to the valence of the exchangeable cations as well.At four rates of pH(4,6,8and 10),the CFC for the Na-yellow-brown soil treated with H2O2 was increased from 0.32 to 0.56,6.0 to 14.0,10.0 to 24.6 and 26.0 to 52.0mmol L^-1 NaCl,respectively when Na-HA was added at the rate of from 0 to 40mgL^-1,With the same Na-HA addition and three pH(6,8and 10)treatments,the CFC for the Na-red soil was incresed from 0.5 to 20.0,1.0 to 40.0 and 6.0 to 141.0mmol L^-1 NaCl,respectively.Obviously,pH and HA has greater effects on clay dispersion of the red soil(dominated by 1:1 minerals and oxides) than on that of the yellow-brown soil(dominated by 2:1minerals).However,at three rates of pH(6,8and 10) and with the addition of Ca-HA from 0 to 40mg L^-1,the CFC of the Ca-yellow-brown soil and Ca-red soil treated with H2O2 was increased from 0.55 to 0.81,0.75 to 1.28,0.55 to 1.45and 0.038 to 0.266.0.25 to 0.62,0.7to 1.6mmol CaCl2 L^-1,respectively.So,Na-soil claye are more sensitive to pH and HA than Ca-soil clays.     

论西部地区生态环境的治理

长期的滥垦、滥采、滥收、滥伐和滥用水资源使西地区的生态环境产生了干旱缺水、植被稀少、水土流失、土地荒漠化、土壤盐渍化及酸化、生物多样性减少、沙尘暴加剧等问题；生态环境平衡被打破，环境变得极其脆样。生态环境的治理是西部大开发中的一项长期、复杂而又艰巨的基础性工程，中央政府和西部地区要有持续奋占百态防护林带、研制木材的替代技术、强化对饮食、医药、皮革等产业的管理、发展生态农业等措施来加强对西部生态环境的治理，为西部经济的起飞创造一个良好的基础。     

考虑非一致性的黄土高原区旱涝复合事件的演变特征及其动态变化

受气候变化和人类活动的双重影响,传统水文序列的一致性假设受到破坏,在考虑非一致性的条件下探究相邻季节间旱涝复合事件的动态变化及主导因子,对区域的粮食安全与旱涝灾害防御意义重大。为探究非一致性条件下旱涝复合事件的动态演变特征及其主导因子,该研究以黄土高原为研究对象,基于广义可加模型拟合单季节标准化降水指数的边缘分布,构建二维Copula模型分析旱涝复合事件（中、重和极端情景下）的发生概率,并利用变量投影重要性准则探究复合事件动态变化的主导因子。结果表明：1）1982-2015年间正常转旱、旱转正常、正常转涝和涝转正常事件分布广泛且发生频次较高（高于22次）;2）春-夏内蒙古持续干旱、夏-秋青海持续干旱、秋-冬宁夏持续干旱、冬-春山西持续干旱、夏-秋陕西持续洪涝、夏-秋甘肃持续洪涝事件的发生概率较大;3）春-夏由旱转涝、夏-秋持续洪涝、秋-冬由涝转旱、秋-冬持续干旱和冬-春季持续干旱事件的发生概率显著上升,对该区域社会经济与生态将产生不利影响;4）复合事件发生概率动态变化的主导因素为北极涛动指数和太阳黑子指数。研究成果将为黄土高原地区旱涝复合事件的精准防御提供科技支撑。     

甘洛县的泥石流类型和防范措施

甘洛县泥石流类型主要属暴雨泥石流。按状态分为沟谷型泥石流和山坡型泥石流,按组成物质分为泥石流和泥流,按流体性质分为稀性泥石流、粘性泥石流和过渡性泥石流。防范措施有:1、修筑拦砂坝等,达到局部治理;2、回避泥石流;3、疏通沟道,加固工程,提高安全系数。     

CHANGES IN THE PHYSICAL AND CHEMICAL PROPERTIES OF A MINERAL TOPSOIL UNDER THE INFLUENCE OF PEAT DEBRIS

Changes are reported of particle size distribution, organic carbon and nitrogen values, cation exchange capacity and exchangeable cation populations, and in iron and aluminium patterns as a result of adding varying rates of acid peat debris to a mineral topsoil. Up to 3 cm of peat had beneficial effects on soil chemical and physical properties but 5 to 8 cm was sufficient to cause considerable acidification, release of Fe and other ions from primary minerals and the development of an iron seam (or pan) which contains up to 7 per cent free iron. Greater thickness of peat (up to 30 cm) caused soil reaction to drop to pH 4 or less and produced so much humic acids as to inhibit iron precipitation and to facilitate its removal from the profiles. The effects of soil moisture on the pattern of peat humification in the deeper additions (20–30 cm) are also outlined.     

基于PSR-CPM模型的市域土地生态安全评价

以PSR模型为基础,构建目标层、准则、因素层和指标层4级评价体系,运用突变级数法（CPM）对2005—2014年晋城市土地生态安全水平进行了评价。结果表明:2005—2008年,晋城市土地生态安全水平呈上升趋势,达到临界安全状态;2008—2009年,土地生态安全呈下降趋势,降低到较不安全水平;2009—2013年,土地生态安全水平呈上升趋势,并稳定在较安全水平;2013—2014年土地生态安全水平略有下降趋势,再次降低到较不安全状态。2005—2008年的变化主要是晋城市开展造林工程和产业结构改革的结果;2008—2009年的变化主要是受经济危机和旱灾的影响;2009—2013年的变化主要是由于经济、粮食产量的恢复和工业污染得到有效控制;2013—2014年的变化主要是经济发展减缓和人口增长所造成的。针对主要限制因素,晋城市今后应更加注重产业结构转型,控制工业污染排放和增加农业灌溉设施这三个方面的工作。     

温州蜜柑叶片黄化果园土壤及叶片的养分含量特征

弄清叶片黄化柑橘园土壤与叶片的养分含量特征,为改善柑橘园营养状况,提高柑橘产量和品质提供理论与技术支撑。通过对黄化和无黄化温州蜜柑园土壤、叶片的养分含量进行分析,研究影响温州蜜柑叶片黄化的关键因子。结果表明,温州蜜柑叶片的钙、镁、硼含量与SPAD值呈显著或极显著正相关,叶片黄化是由叶片中钙、镁、硼含量不足所造成的,属于综合缺素型,同时叶片中钾、铁、锰含量较高,叶片对钙、镁、硼的吸收与对钾、铁、锰的吸收之间存在相互拮抗的关系;土壤酸化是叶片黄化的主要驱动因子,pH值较低一方面降低了土壤中钙、镁、硼的有效性,另一方面,土壤中较高的铁、锰含量抑制了柑橘对钙、镁、硼的吸收,最终导致叶片因缺钙、缺镁、缺硼而出现黄化。喷施含钙、镁、硼的叶面肥料,防止土壤酸化是改善温州蜜柑叶片黄化的有效措施。     

Sorption of Sulfonamides and Tetracyclines to Montmorillonite Clay

The current study investigated the sorption of sulfadimethoxine (SMT), sulfamethoxazole (SMX), tetracycline (TET), and oxytetracycline (OTC) to Na-rich montmorillonite clay in synthetic effluent (SE) and field wastewater effluent (FE). Both SMT and SMX showed a low sorption capacity and are therefore likely to be highly mobile in the environment, while the sorption of TET to clay in environmental pH range (6.5–7.5) showed similarly high adsorption capacity. Differences in sorption capacities of TET and OTC to SE or FE were attributed to the various concentrations of divalent cations in the effluents. In addition, differences in sorption of OTC or TET to SE were attributed to their different molecular structure. Moreover, the adsorption of TET in SE and FE showed linear adsorption isotherms and fitted to Freundlich model. Further experiments showed that addition of humic acid or SE to TET sorbed to clay did not enhance or suppress the sorption of TET to clay.     

退耕还林(草)对北洛河上游水沙变化的影响

为探究黄土高原地区退耕还林（草）政策的水沙响应问题,以植被恢复较好的北洛河上游为研究区域,根据其控制站吴起水文站1971—2010年4—10月实测水沙资料,定量分析降水量、径流量和输沙量三个水文要素的变化趋势和发生突变的年份。结果表明:1971—2010年,降水量并未发生显著的趋势性变化,径流量和输沙量呈显著减小趋势;综合四种突变点检验方法结果,并结合水土保持措施资料,确定径流量和输沙量的突变年份为2002年;利用双累积曲线定量分析降水和以退耕还林（草）为主的人类活动对径流量与输沙量的影响,相对于1971—2002年,2003—2010年降水和人类活动对径流量的影响程度分别为70.8%和29.2%,对输沙量的影响程度分别为34.0%和66.0%。植被的减沙作用明显大于减水作用,以退耕还林（草）为主的人类活动是北洛河上游流域泥沙减少的主要驱动力。     

Durum Wheat Genotypic Variation of Yield and Nitrogen use Efficiency and Its Components Under Different Water and Nitrogen Regimes in the Mediterranean Region

Farmers in dry areas of the Mediterranean region are reluctant to apply nitrogen (N) fertilizer to rainfed wheat because of frequent drought. So, it is desirable to select varieties with high nitrogen use efficiency (NUE). The objectives of this study, conducted in 2009/10 and 2010/11 in Syria, were to study the response of genotypes of durum wheat to low and high N applications and to evaluate the contribution of N uptake efficiency and utilization efficiency to NUE under rainfed and supplemental irrigation conditions. Under the rainfed regime, grain yield decreased significantly in year 1 and year 2 when applying N fertilizer at a high rate. The early maturing genotypes gave the highest average yields under rainfed and irrigated regimes. High N fertilizer rate decreased significantly NUE from 36.1 to 24.3 in year 1 and 37.0 to 5.8 in year 2. Under irrigation, NUE fell from 84.6 to 67.1 in year 1 and from 117.7 to 33.3 in year 2. The contribution of N uptake efficiency and utilization efficiency to NUE varied from one year to another. In year 1, the contribution of N utilization efficiency was more important at all nitrogen levels; while the opposite was observed in year 2 when more N was applied. The fractions of the genotype sum of squares, respectively, for N uptake efficiency and utilization efficiency were in average 0.15 and 0.78 in year 1 and 0.75 and 0.25 in year 2. From this study we conclude that high N levels in the soil exacerbate the effect of water stress on productivity and NUE of wheat. Early maturing new genotypes tend to be better adapted and to use nitrogen more efficiently under limited water conditions. N utilization efficiency contributes more to NUE under high N availability than N uptake efficiency and vice-versa.     

Materials for sustained and controlled release of nutrients and molecules to support plant growth

Controlled release fertilizers (CRFs) are a branch of materials that are designed to improve the soil release kinetics of chemical fertilizers to address problems stemming losses from runoff or other factors. Current CRFs are used but only in a limited market due to relatively high costs and doubts about their abilities to result in higher yields and increased profitability for agricultural businesses. New technologies are emerging that promise to improve the efficacy of CRFs to add additional functionality and reduce cost to make CRFs a more viable alternative to traditional chemical fertilizer treatment. CRFs that offer ways of reducing air and water pollution from fertilizer treatments, improving the ability of plants to access required nutrients, improving water retention to increase drought resistance, and reducing the amount of fertilizer needed to provide maximum crop yields are under development. A wide variety of different strategies are being considered to tackle this problem, and each approach offers different advantages and drawbacks. Agricultural industries will soon be forced to move toward more efficient and sustainable practices to respond to increasing fertilizer cost and desire for sustainable growing practices. CRFs have the potential to solve many problems in agriculture and help enable this shift while maintaining profitability.     

黄河源头区水土流失及草业综合治理探讨

黄河源头区属高寒半干旱气候区 ,地带性植被为高寒草甸。由于自然条件恶劣和超载过牧、沙金开采等 ,致使水土流失日益严重 ,草业在该区水土流失治理中的地位和作用独特 ,具有不可替代性。具体对策是 :草原牧区禁止超载过牧 ;沙化严重的地区进行封育改良 ;陡坡地退耕 ,缓坡地实行草、粮带状间作 ;加强对工矿和城镇建设的管理     

On the prediction of acid precipitation events and their effects on fishes

It is possible to predict acid rain events and melts of acid snow some 12 to 24 hr in advance, including estimation of the magnitude and duration of such events. This is sufficient notice to permit monitoring of stream chemistry and fish plasma and muscle ions before acid stress, and to continue this monitoring throughout and after specific events. Such a program has been in place for 2 yr in waters tributary to the Milford Bay Trout Hatchery, Ontario. During one snow melt in February 1984 surface waters showed a decline to pH 4 and associated negative ANC. Rainbow trout held in such water lost plasma Na and Cl rapidly and died within 28 hr. The hatchery water supply, consisting of a mixture of spring and surface water, showed a decline in alkalinity from 300 to 30 μeq.L^?1, and a pH change from 6.6 to 5.4, during snow melt. Total A1 concentration increased from 42 to 222 μg.L^?1 during snow melt with the “reactive” component increasing from 17 to 112 μg.L^?1. Rainbow trout held in this water did not show physiological stress. More rapid run-off of melt water could be expected to exhaust all of the alkalinity in the hatchery water supply permitting the pH to decline and A1 concentration to rise to levels lethal to the hatchery stock of rainbow trout.     

基于生产生活可达性的农村居民点整治分区及模式

农村居民点整治应满足农户生产生活的需求,提高农村居民点的生产生活可达性。该文从生产生活可达性切入,以农村居民点生产生活可达性作为整治分区和采取何种整治模式的依据,从生产可达性和生活可达性两方面出发构建生产生活可达性评价指标体系,采用空间可达性测度方法和指标综合评判法计算得到农村居民点(斑块)生产生活可达性,将其分为I、II、III、IV 4个等级,分别对应发展区、优化区、引导区和拆迁区。根据整治分区并结合实际情况,划分了城镇化发展模式、城乡统筹发展模式、综合优化模式、辐射引导模式、增减挂钩模式和生态搬迁模式等6种整治模式,并对整治思路和具体做法做了探讨。该研究尝试将生产生活可达性评价结果应用于农村居民点整治,对有序整治农村居民点和改善提高农村人居环境有指导意义。     

生物炭不同施用方式对水盐调控及小麦苗期生长的影响

为研究生物炭不同应用模式对盐碱土水盐调控及小麦苗期生长的影响。通过室内桶栽模拟试验，生物炭以2种物理状态(粉状和杆状)、3个添加量(1%,3%和5%质量百分比)分别作为覆盖和添加物，以不添加生物炭的处理作为对照。结果表明：“干播湿出”条件下，FF(粉状覆盖)、GF(杆状覆盖)处理小麦出苗率分别为对照(CK)的7.33～9.00,3.00～3.33倍；FH(粉状混合)、GH(杆状混合)处理的出苗率较CK分别提高66.67%～166.67%,33.00%～367.00%。FF、GF处理的株高大幅提高，较CK分别提高21.52%～34.55%,24.54%～40.48%;FH、GH处理的株高小幅提高，较CK分别提高-1.35%～12.22%,3.76%～8.59%。不同应用模式的灌后含水率差异明显，FF处理的表层土壤较CK提高0.31%～15.58%;而GF处理的表层土壤含水率较CK下降0.40%～7.65%;FH、GH处理的土壤含水率较CK分别提高7.33%～18.61%,1.33%～18.38%;蒸发后FF、GF处理的含水率较CK分别提高4.34%～45.38%,27.08%～53.22...     

Nowhere to run and nowhere to hide: Response of endemic Mt. Graham red squirrels to catastrophic forest damage

A consequence of isolation is increased susceptibility to catastrophe. Insect damage to fragmented and isolated forests has the potential to serve as a catastrophic force; such damage has increased worldwide due to climate change and fire suppression policies. We examined the response of endangered endemic Mt. Graham red squirrels to catastrophic insect damage due to moths, beetles, and introduced aphids. Insects changed the forest environment significantly for the endemic squirrel by reducing basal area and stem densities of live stems, while increasing number and basal area of standing dead stems. Availability of two major foods, fungi and tree seeds, declined in insect-damaged forests relative to trends in undamaged forests. Numbers of Mt. Graham red squirrels declined precipitously in insect-damaged forests suggesting a catastrophe. Conservation options are limited in such situations. Forest-insect induced catastrophes are likely to become more common in the near future as forest health declines due to past management tactics and climate change. Prudent conservation measures include the anticipation of insect outbreaks and effective forest treatments to decrease likelihood of such catastrophes to species of precarious conservation status, while avoiding abrupt changes to critical habitat.