铁岭地区水土保持监测点规划与布局

水土保持监测是以水土流失及其防护措施为主要对象,对土壤侵蚀的发生、发展状况,环境影响及其防治效果的监测、分析与评价工作,是水土保持工作的基础和水土保持技术体系的重要组成部分.近年来,铁岭市尽管在水土保持方面做出了很大努力,取得了一定的成就,但随着社会经济的高速发展,开发建设项目大面积扰动土地,形成新的水土流失,出现一方治理,多方破坏的现象.该区水土流失状况呈现复杂化、多样化,水土流失现状依然不容乐观,成为制约地区社会经济发展的重要因素.重点阐述了铁岭地区的水土保持监测规划与布局,且在此基础上论述了水土保持监测规划与建设过程中存在的一系列问题,并提出相应的发展建议.     

Community and ecosystem consequences of giant knotweed (Polygonum sachalinense) invasion into riparian forests of western Washington, USA

The invasive, non-native herb, giant knotweed (Polygonum sachalinense), is becoming increasingly common in riparian corridors throughout North America and Europe. Despite its prevalence, there has been limited study of its ecological impacts. We investigated the effects of knotweed invasion on the abundance and diversity of forest understory plants, and the quantity and nutrient quality of leaf-litter inputs, in riparian forests in western Washington, USA. Among 39 sampling locations, knotweed stem density ranged from 0 to 8.8 m⁻². Richness and abundance (cover or density) of native herbs, shrubs, and juvenile trees (?3 m tall) were negatively correlated with knotweed density. Where knotweed was present (>5.3 stems m⁻²), litter mass of native species was reduced by 70%. Carbon:nitrogen ratio of knotweed litter was 52:1, a value 38-58% higher than that of native woody species (red alder [Alnus rubra] and willow [Salix spp.]). Resorption of foliar N prior to leaf drop was 76% in knotweed but only 5-33% among native woody species. By displacing native species and reducing nutrient quality of litter inputs, knotweed invasion has the potential to cause long-term changes in the structure and functioning of riparian forests and adjacent aquatic habitats.     

基于SLAF-seq技术的树莓SNP位点开发

为分析树莓群体的遗传进化关系,开发特异性SNP标记。选用23 个栽培种树莓以用SLAF-seq技术测序,从树莓全基因组范围开发SNP位点,以黑树莓基因组为参考基因组,通过生物信息学分析进行电子酶切预测,筛选特异长度的DNA片断,构建SLAF-seq 文库。通过高通量测序的方式获得海量序列标签,利用软件分析比对,获得多态性SLAF标签,进而开发大量特异性SNP位点。对照水稻的测序数据与参考基因组比对结果,双端比对效率为95.60%,酶切效率为93.52%,说明SLAF建库正常。通过测序共产生59.93 Mb的读长数据,测序质量值Q30 平均为95.07%,所有样品GC含量均值为39.16%,GC含量普遍不高,说明达到测序要求。本研究共获得425402 个SLAF标签,其中多态性的SLAF标签共有121610 个。获得749811 个有效单核苷酸多态(SNP),利用这些SNP分析了23 个树莓种质的群体结构与系统发生树。利用简化基因组测序技术SLAF-seq 可以高效地、低成本地开发出大量的可用于群体遗传结构分析的SNP标记。     

辽宁省PRRSVLN／0901株ORF5基因遗传变异分析及其抗原位点预测

根据已发表的PRRSVORF5基因序列设计引物,经RT-PCR对辽宁省PRRSVLN／0901株0RF5基因片段进行扩增、克隆及测序,结果得到长度为739bp的0RF5基因完整序列,与已知代表毒株进行核苷酸及其编码氨基酸同源性比对和系统进化树分析,LN／09010RF5基因序列与VR-2332株同源性达到88．6％,而与LV株,则相差甚远,仅为61．7％,表明PRRSVLN／0901病毒株为美洲型,与CBB-1-F3T、GD2007、JXA1、BJ0708等毒株同源性高达98．7％～99．5％,表明该病毒与2006年以来国内的多数流行变异株遗传关系相近。通过对PRRSVI,N／0901ORF5进行氨基酸疏水性及其编码蛋白跨膜区预测分析,表明该毒株ORF5具有多个抗原优势位点,与国内其他毒株既有共同位点又有区别位点,可以做为辽宁地区开发研制PRRS基因工程疫苗的重要蛋白基因。     

污染场地的环境管理现状分析

从污染场地的概念出发,综述了我国污染场地在法律、法规、标准体系的现状,指出了我国在这方面还很不完善。提出了应制定一部土壤污染防治法以及完善相关法规、标准体系,探讨了加速土壤污染相关的国家法律、法规、标准指南的官方批准、发布及其实施进程。     

山丘区铁路工程弃渣场分类及防护措施

针对山丘区铁路工程建设的实际情况,将弃渣场分为坡地型、沟道型、坑凹型等3类,并对不同类型弃渣场应采取的防护措施进行了分析和阐述,以期为山区铁路建设项目弃渣场的选址和防护措施的布设提供借鉴。     

基于SLAF-seq技术的古茶树SNP位点开发

为给古茶树遗传图谱构建、分子辅助育种和物种进化等研究提供参考,以48份贵州古茶树种质为研究对象,利用SLAF-seq技术,获取大量多态性SLAF标签,进而开发一批特异性强、稳定性高的单核苷酸多态性(SNP)位点。结果表明,利用猕猴桃参考基因组进行电子酶切预测,选择HaeIII酶进行酶切,得到237773个SLAF标签,其双端比对效率为91.40%,酶切效率为96.41%,说明SLAF建库正常。测序后各样品所获得的读长数为1279534~8460233,测序质量值Q30范围为92.61%~94.88%,均值为93.84%,测序获得的GC比例为43.52%~47.18%。共开发1656258个古茶树SLAF标签,样品的平均测序深度为24.21×,其中多态性SLAF标签有462897个,根据所获得的多态性SLAF标签来统计SNP位点信息,共得到2690638个群体SNP标记,根据完整度大于0.8且次要基因频率(MAF)大于0.05的标准进行过滤,得到283376个高一致性的群体SNP标记。     

典型复垦工业场地土壤垂直剖面重金属污染特征及潜在生态风险

[目的]揭示典型复垦工业场地中重金属元素污染特征及潜在生态风险,为此类工业复垦场地管理和治理提供科学依据。[方法]分析上海市33块典型复垦工业场地表层、中层和深层土壤中8项重金属(砷、镉、铬、铜、镍、铅、锌、汞)的含量,采用内梅罗指数法和潜在生态风险指数法对复垦工业场地土壤重金属污染进行生态风险评价。[结果]①复垦工业场地土壤中重金属整体风险可控,17个点位重金属含量超过风险筛选值,其中以表层土壤中Cu和Zn污染最为突出,最大超标倍数分别为3.24,3.73倍。下层土壤中重金属平均含量均低于上海市土壤背景值,部分点位存在一定的重金属累积;②复垦工业场地表层、中层和深层土壤重金属内梅罗综合污染指数分别为1.21,0.78,0.73,分别处于轻度污染、尚清洁和尚清洁水平,其中表层Cd和Zn污染最为突出;③除表层土壤Hg(中度)和Cd(中度)外,其余重金属元素均存在轻微生态风险,表层土壤潜在生态风险指数(RI)为107.22,总体潜在生态风险接近中等水平,中层及深层土壤处于轻微潜在生态风险水平。[结论]复垦工业场地土壤重金属存在一定程度的累积性污染,其中Cu,Cd,Hg和Zn污染较为突出,考虑到毒性响应因素,则Hg和Cd更应引起关注。     

Effects of stream map resolution on measures of riparian buffer distribution and nutrient retention potential

Riparian ecosystems are interfaces between aquatic and terrestrial environments recognized for their nutrient interception potential in agricultural landscapes. Stream network maps from a broad range of map resolutions have been employed in watershed studies of riparian areas. However, map resolution may affect important attributes of riparian buffers, such as the connectivity between source lands and small stream channels missing in coarse resolution maps. We sought to understand the influence of changing stream map resolution on measures of the river network, near-stream land cover, and riparian metrics. Our objectives were: (1) to evaluate the influence of stream map resolution on measures of the stream network, the character and extent of near-stream zones, and riparian metrics; (2) to compare patterns of variation among different physiographic provinces; and (3) to explore how predictions of nutrient retention potential might be affected by the resolution of a stream map. We found that using fine resolution stream maps significantly increased our estimates of stream order, drainage density, and the proportion of watershed area occurring near a stream. Increasing stream map resolution reduced the mean distance to source areas as well as mean buffer width and increased the frequency of buffer gaps. Measures of percent land cover within 100 m of streams were less sensitive to stream map resolution. Overall, increasing stream map resolution led to reduced estimates of nutrient retention potential in riparian buffers. In some watersheds, switching from a coarse resolution to a fine resolution stream map completely changed our perception of a stream network from well buffered to largely unbuffered. Because previous, broad-scale analyses of riparian buffers used coarse-resolution stream maps, those studies may have overestimated landscape-level buffer prevalence and effectiveness. We present a case study of three watersheds to demonstrate that interactions among stream map resolution and land cover patterns make a dramatic difference in the perceived ability of riparian buffers to ameliorate effects of agricultural activities across whole watersheds. Moreover, stream map resolution affects inferences about whether retention occurs in streams or riparian zones.     

Spatial patterns of plant invasiveness in a riparian corridor

Analysis of landscape-scale patterns of plant invasiveness can assist in interpreting spatial patterns of plant species richness. We investigated downstream variation in plant invasiveness in the riparian corridor of the free-flowing Vindel River in northern Sweden by introducing seeds of an alien species, Helianthus annuus, in 0.25 m² plots of natural vegetation from mountain headwaters to the coast and found a significant downstream pattern with middle reaches having the highest invasiveness. We related invasiveness to species richness, both on a reach scale (200-m long stretches of riverbank encompassing the experimental plots) and on the scale of experimental plots. We found no significant correlation between plant invasiveness and species richness, neither at the reach nor at the plot scale. The number of available soil substrates shows a significant positive quadratic relationship with location along the river and substrate fineness shows a near significant negative quadratic relationship with location along the river, with middle reaches having coarser substrates. Several studies have shown that plant species richness in riparian corridors often exhibits a quadratic pattern with highest species richness in the middle reaches of a river, similar to the pattern we found for invasiveness. Although species richness per se might not be a primary factor for invasibility, the same habitat conditions as those supporting plant species richness, can help in explaining large-scale patterns of plant invasion in riparian zones.