深圳市盐田区植被格局分析

运用景观生态学的方法 ,选取斑块形状指数、斑块形状破碎化指数、分维数、景观多样性指数、均匀度、相对丰富度、优势度等指标 ,对深圳盐田区的植被格局进行分析。结果显示 :在城乡发展过程中 ,盐田区植被景观保存较好 ,类型丰富 ;植被景观总体上呈现出符合其生境特征的规则分布 ;群落景观异质性较高 ,拥有南亚热带的沟谷雨林、山地常绿阔叶林、红树林等特色植被景观 ;沟谷雨林和季风常绿林是本区较脆弱的生态系统 ,应积极加以保护和发展     

Interpretation and Discrimination of Marshy Wetlands by Soil Factors in the Kuan-Tu Natural Park, Taiwan

This work investigated soil samples collected from Kuan–Tu wetlands, Taiwan. Factor analysis was performed to explain the impact of various soil factors on this marshy wetlands located in suburban Taipei. The results indicated that the latent factors were heavy metals, salinity, and soil organic matter. Canonical discriminant analysis was used to improve an existing vegetation classi–fication scheme by identifying the physical-chemical properties of sediment in Kaun–Tu wetlands, Taiwan. Predictive discriminant analysis was used to examine the ability of the models to predict class membership for unknown soil sample. Multivariate analysis of the spatial patterns of soil quality and vegetation types showed that different properties of soil grew different types of vegetation and absorbed contaminants differently. We can feasibly conserve a suitable habitat for wetland biology by processing these unstable predictor variables. The methodology and results provide useful information concerning the Kuan–Tu wetlands and may be applicable to other wetlands with similar properties that are experiencing similar environmental issues.     

Modeling and Measurement of Structural Changes at a Landscape Scale in Dryland Areas

We present a technique to quantify and model the intensity of structural changes produced by management of dry grazing lands at a landscape scale. The technique is illustrated with the analysis of digitized black–white (b/w) imagery and an application to the study of changes induced by grazing gradients. Structural changes in patchy vegetation canopies were studied in the Patagonian Monte (Chubut, Argentina) at two resolution scales by means of linear transects in the field (50 m) and others drawn on aerial b/w photographs (2–5 km) of grazed paddocks. Spatial series of plant cover values along transects in the field and on photographs were analyzed with standard techniques of spectral analyses, including auto-correlation spectra and Fourier transforms. In order to test the internal consistency of the techniques used, synthetic plant canopies with patches of varying cover and size were generated by means of a stochastic model of plant growth under different stocking rates or after varying periods of recovery. The behavior of the simulation model is consistent with the observed dynamics of plant canopies in semiarid environments. There is a consistent relation between the number and geometric properties of plant patches (patch number, patch size, patch connectivity) and the signal/noise ratios of the Fourier decomposition describing plant density data. Signal/noise ratios corresponding to plant cover data in paddocks with different grazing treatment are consistent with the assumptions derived from modeled canopies, as well as those estimated from optical density of b/w aerial photographs of paddocks. We tested the hypotheses that patch arrangements as quantified by the signal/noise ratios vary in accordance with grazing gradients in paddocks with a permanent corner-located watering point. The use of digitized b/w images allows inspecting permanent changes over time periods when other types of images were not yet available.     

A Gradient Study of 34 Elements in the Vicinity of a Copper-Nickel Smelter in the Kola Peninsula

Concentrations of 34 elements determined by ICP mass spectrometry were studied in surface soil and vegetation along a north–south gradient through the Pechenganickel smelter complex in Kola peninsula, northern Russia. Strong influence from the smelter was evident for Fe, Co, Ni, and Cu, mainly associated with dry deposition of large particles. Also for As, Se, Mo, Sb, Te, Bi, and Pb the smelter or associated sources appeared to be distinct contributors of contamination consisting presumably of smaller particles. Significant but less distinct effects leading to enhanced concentration levels were observed for P, S, V, Cr, Zn, and Tl. In the case of Mn, Rb, Sr, Cs, and Ba the concentrations in vegetation were generally lower near the source, which may be due to cation exchange with protons or heavy metal cations in the soil and subsequent leaching from the root zone. For Li, Be, B, Na, Mg, Al, Ca, Y, Cd, La, Th, and U no particular influence from the smelter complex was observed. Some characteristic differences observed in element concentrations in different plant species and between different years of Pinus sylvestris needles are discussed. The high concentrations observed for many trace elements in the humus horizon indicates that it acts as an active biogeochemical barrier against downward transport of these elements.     

陕西大柳塔煤矿复垦地植被群落与土壤因子的关系

以陕北风沙区大柳塔煤矿的复垦地为研究对象,通过样方调查与土壤采集,调查复垦地人工植被的种类与多样性,并运用典范对应分析(CCA)探讨了物种分布与土壤因子之间的关系。结果表明:(1)研究区内共发现植被11科20属21种。草本植被在区内占优势,其中豆科、菊科和藜科植被占种数的47.63%;草本植被以多年生为主,占调查种数的52.38%。(2)物种多样性测度表明,Simpon多样性指数、Shannon-Wiener指数与Pielou均匀度指数均是草地>灌丛>林地;Simpon优势度指数的变化则是林地>灌丛>草地,说明人工草地的物种多样性最高,其次为灌丛,林地最低。(3)CCA排序结果显示,土壤有机质和粗沙含量是制约研究区人工植被分布的主要因子。此外,土壤中0~20 cm粘粉粒含量影响草本植被的分布;而40~60cm的土壤含水量对乔、灌木的分布影响显著。     

柴河铅锌矿尾矿库复垦治理中不同覆土与植被措施的效益估算

以铁岭柴河铅锌矿尾矿库复垦治理为例,根据尾矿库“生态封闭”原理,选取表层覆土50cm种植紫穗槐（措施1）、设置土工布隔离后覆土30cm种植紫穗槐（措施2）和厚覆土150cm种植刺槐与紫穗槐（措施3）等3种不同覆土及植被措施,运用影子工程法、替代成本法、恢复费用法和生态价值法等方法,构建尾矿库覆土与植被措施的效益估算模型,估算各措施的深层淋滤污染扩散防治效益、地表径流侵蚀扩散防治效益和风蚀扩散防治效益.效益估算结果表明：措施1、措施2和措施3的深层淋滤污染扩散防治效益分别为2975.24,3449.56,3604.75万元/a;3种措施可在不同程度上减少表层覆土流失、下游河道淤积及水体重金属污染,产生的地表径流侵蚀扩散防治效益分别为1222.66,2585.71,2586.75万元/a;3种覆土及植被措施均可有效抑制重金属风蚀污染扩散,产生的风蚀扩散防治效益分别为1235.45,1235.45,1237.86万元/a. 3种覆土及植被措施在重金属污染防治方面的综合效益分别为5433.35,7270.72,7429.36万元/a. 深层淋滤污染扩散防治效益在综合效益中所占比重最大,尾矿库覆土及植被措施的选择应以控制雨水入渗淋滤为主,结合降雨、蒸发等气象因素和覆盖土壤特性等,考虑治理成本,合理确定覆土厚度以及设置隔离层的必要性.     

基于显微拉曼面扫的小尺寸微塑料检测方法

由于检测方法的限制,小尺寸（<50 μm）微塑料的检测研究较少.提出一种无须挑选、能够较为准确高效识别小尺寸微塑料的方法.筛选出2种合适的过滤膜作为分离和分析微塑料所用基底,使用显微拉曼光谱的面扫模式对5种常见的微塑料进行定性和定量检测.结果表明,该方法能够将最小粒径为1μm的小尺寸微塑料从滤膜背景上识别出来,并作伪彩色图直观显示微塑料的尺寸、形状和种类.以石英砂颗粒模拟环境样品中的杂质,该方法也可排除杂质的影响,准确定位微塑料.在3种浓度梯度下,不同粒径（5~50μm）的聚苯乙烯微塑料回收率为33.3%~79.0%.     

宝鸡市滨河路不同植被环境污染的磁学响应

为理解城市道路绿化带不同植被叶片附尘对污染的磁学响应,对宝鸡市滨河路不同类型的植被叶片进行系统的环境磁学实验分析.结果表明,植被叶片中磁性矿物含量相对较低,主要的载磁矿物为假单畴和多畴的亚铁磁性矿物,同时含有赤铁矿,灌木植被叶片的磁性矿物浓度与粒径均大于乔木,其中χ_lf值平均值为6.49×10^-8m³/kg,相比较校园清洁区的植被叶片,表现出较高的浓度.滨河路植被叶片的饱和等温剩磁（SIRM）和非磁滞剩磁磁化率（χ_ARM）的变化范围分别为（964~1226）×10^-6Am²/kg和（9.9~44.7）×10^-8m³/kg,同样也都远高于校园植被叶片（453~771）×10^-6Am²/kg和（6.8~15.1）×10^-8m³/kg,表明亚铁磁性矿物的相对含量较高.磁学参数表现出一定的空间变化规律,随着高度的增大,植被叶片含有的磁性矿物浓度和粒径逐渐递减.随着高度逐渐递减.同一高度内不同种类植被记录的环境污染各有差异,灌木植被紫金叶女贞的叶片样品中含有较高的磁性矿物浓度,指示其具有更好的滞尘和防治污染的能力.植被叶片的磁性矿物浓度在滨河路东段十字路口与西段路口呈现两个高值中心,指示两个污染相对较为严重的区域.     

滨岸带水华堆积与消散特征及其营养盐效应

为了解滨岸带植被、地形等地貌要素对蓝藻水华堆积及消散过程的影响,在太湖滨岸带设置不同形式的围格和植被实验区,通过逐日监测水体叶绿素a（Chl-a）的消长过程及同步营养盐变化,研究夏季蓝藻水华在湖泊滨岸带堆积与消散特征和营养盐效应.结果表明,滨岸带的地形地貌及植被状况对蓝藻水华的堆积程度及消散过程影响较大,软围隔营造的滨岸带静水环境,以及不同植被所形成的不同滞水区,显著加剧了蓝藻水华的局部堆积,从岸边挺水和浮叶植被区到开敞水域对照区,蓝藻水华的堆积程度依次递减;近岸挺水和浮叶植被区蓝藻水华堆积最严重,堆积时间最早,持续时间长;蓝藻水华堆积对营养盐等水质指标影响极大,堆积严重时该区域Chl-a含量达到了457.42μg/L,总氮（TN）达到11.04mg/L,总磷（TP）达到1.32mg/L;橡胶围格内浮叶植物区藻类堆积程度与近岸区类似,而浮叶植物与沉水植物混合区藻类堆积程度低于单一浮叶植物区;水体围隔能够加剧蓝藻水华的堆积,没有围隔的浮叶植物区藻类堆积程度最低.在蓝藻水华堆积过程中,蓝藻细胞仍在继续增殖,水体Chl-a仍会明显增加,而同期的水体营养盐的增幅小于Chl-a,甚至随着藻类生长消耗及生态系统的脱氮效应,溶解态氮磷下降明显.蓝藻水华消散过程中,TN、TP与Chl-a同步下降,但藻体中的氮磷释放到水中,导致堆积区的溶解态氮、磷有所增加,显示出明显的营养盐效应.本研究定量刻画了蓝藻水华局部堆积并快速致灾的地形地貌要素特点,揭示了蓝藻水华的水质与生态效应,为科学评估富营养化水体蓝藻水华的生态灾害风险提供科学依据.     

滨海湿地退化区鸟类刨坑觅食行为促进植被的恢复

鸟类是滨海湿地生态系统中非常重要的组成部分,也是能够通过自身行为影响非生物环境以及生物过程的生态系统工程师。了解鸟类在滨海湿地生态系统中的生态系统工程效应,对于开展滨海湿地的生态修复具有重要作用。通过野外调查研究由灰鹤（Grus grus）和斑嘴鸭（Anas poecilorhyncha）主导的滨海鸟类的刨坑觅食行为对植被退化区的地形以及土壤环境理化指标的影响,进而促进盐地碱蓬（Suaeda salsa）植被的恢复。结果表明：鸟类在植被退化区的刨坑觅食行为改变了退化区的微地形及土壤环境,使得土壤硬度和土壤盐度显著降低,而土壤含水率和土壤碳氮营养指标则显著高于未经鸟类影响的退化平坦区域;另外,鸟类活动改善的凹坑微地形环境能够显著提高盐地碱蓬的种子保留量、幼苗定植量和成株存活量,有效促进盐地碱蓬在植被退化区域的恢复。通过鸟类改变微地形进而促进植被恢复的启发,提出可以尝试人为模拟改造退化区的微地形环境,以通过人为干预的方式促进滨海湿地退化区的植被恢复,对滨海湿地的生态修复具有重要指导意义。