山东海岸沙生植被的特点和生态评价

山东海岸分布着特殊意义的海岸沙生植被,其特点为群落类型单纯,组成种类结构简单,具有显著的镶嵌性。植物有很强的抗旱、耐瘠、耐热、耐盐能力,群落自然演替缓慢。本文对该岸区沙生植被的恢复、发展和防止生态平衡失调等问题进行了生态评价,并从植物生态学角度提出海岸开发设想。     

古尔班通古特沙漠南缘中段梭梭群落初步研究

前言梭梭（Haoxylonammodendron）在准噶尔盆地广为分布。盆地范围较大，各区自然环境有所差异，这一差异对生长在不同地段的梭梭群落的影响，目前还缺深入了解，我们对古尔班通古特沙漠南线中段进行了考察。现就该地的梭梭群落作一讨论，以分析环境差异对梭梭群落分布的影响。1自然条件及植被概况古尔班通古特沙漠南线中段位于中部天山北麓古老冲积平原上，北为连绵的沙漠，南临灌溉绿洲。由于上游截水灌溉，原有的老龙河早已断流，尾问湖车道海子，白家海子等都已干涸，目前该地大大的地表径流，除水库外办大较大的水体。该地的地理位置…     

古尔班通古特沙漠公路扰动带植被恢复研究

古尔班通古特沙漠区域伴随多条沙漠公路的修筑，公路沿线形成了生态扰动带（包括施工扰动带和运营扰动带）。它使地表空气流场改变、地表覆被剥离、风沙源出现、地表径流过程受阻、地表水分重分配以及生境隔离。野外考察和样品分析表明，扰动带的植被恢复取决于消面稳定性、降水的地表分配、时间、地下水位、种源和风场等因素，并初步总结出如下规律：①草方格内部表面沙层的有机质随时间逐渐增多；②草方格固沙措施加速了植被恢复的速度；③迎风坡自然覆沙，种子易于着床和萌发；④路肩上形成长营养期的中生植物，边坡形成旱生植物，路边优动带内的植被恢复情况因水分条件而变化；⑤植被恢复与时间成正比，演替过程为：短命植物、三芒草→蒿类→梭梭或白梭梭。最后提出改进草方格沙障的材料、增加土壤的有机质含量、使用干水、适时播种等恢复措施。     

城市群的生态研究方向:城市群落学解析

城市群落是若干城市在共同的生境条件下通过竞争、共生等生态行为所形成,并与环境相互作用的城市群体,是具有协同进化、演替等生态功能的有机体.运用群落生态学的理论、方法对群落中城市种群间的关系、城市群落的结构特征及城市群落演替等方面进行研究,试图探求促进城市群落持续发展的规律.首先界定城市群落、城市群落学等相关概念,构建城市群落学理论框架;其次对比分析了生物群落与城市群落的特征和生态功能上的相似性和差异性;最后阐述了有关城市群落的种群组成、种间关联、群落结构及群落演替的研究内容,并提出了相应的城市群落研究方法.从生态学角度来看城市问题,借鉴群落生态学的原理和研究方法来认识城市群的发展,是"回归自然"的城市发展观点,有利于促进城市群落功能的发挥,推动城市群落向特定的方向演替.     

新疆阿勒泰地区土地“三化”分析

土地沼泽化、盐渍化和沙漠化是干旱区土地退化的主要表现形式之一，职权勒泰地区土地“三化”具有发展快、危害严重等特点。“三代”形成与地质、地貌、气候、水源和植被等自然因素有关，更受盲目开垦、用水不当、破坏植被等人为因素影响，存在由荒草地→耕地→盐渍地→沼泽地演替等6种过程，宜采取规划土地，合理利用；稳定耕地面积，切勿盲目开垦，因地制宜，发展种植业；完善渠系、灌排配套；井灌井排，降低地下水位；改革灌溉方式，节约用水；保护荒漠植被，营造防风林带；加强“三化”动态监测及防治研究等措施，以保障开的土地永续利用与区域可持续发展。     

基于Landsat／TM和ETM＋的理塘草地沙化趋势及其驱动力分析

文章利用1989、1994、2000和2005年的4期Landsat／TM，ETM＋遥感影像，在几何校正、辐射定标、大气校正的基础上计算了归一化植被指数（NDVI），建立最小二乘法线性回归方程对多时相NDVI进行同化处理，基于二分模型提取植被覆盖度并转换成荒漠化指数（DI），对理塘县城附近约103．1km2范围的分类研究结果表明：（1）分为无沙化、轻度、中度、重度和严重沙化5级，其中2005年中度、重度和严重沙化面积分别为2．562km2、2．925km2和1．576km2；中度沙化比1989年减少9．69％，重度和严重沙化分别增多35．79％和161．8％；（2）2005年中度以上沙化面积比1989年增加1．470km2，增加了26．3％，年增加率为1．47％；（3）沙化面积呈前期小、中期大幅增加、后期增加减缓的总体趋势；（4）降水量和风速因子的变化趋势有利于缓解沙化，气温变化趋势没有反映出对沙化的促进作用。人类活动是造成沙化趋于恶化的主要因素；（5）沙化增加趋势与同类研究结果一致。     

基于分形理论的陕西省城镇体系规模与空间结构研究

应用分形理论对陕西省城镇体系进行了规模和空间结构研究。通过分析其规模结构探讨了目前该省的城镇体系特点，再应用关联维数分析了陕西省城镇体系的空间结构。其结论为：陕西城镇体系分布符合分形特征；首位分布明显；城镇规模等级体系结构不平衡；空间分布较集中，主要集中在以西安为中心的关中城市群；城镇体系结构受自然条件影响显著，导致陕北和陕南经济落后于关中。针对上述分析，提出陕西省未来的发展建议．力口快完善城镇道路体系，提高通达能力；继续推进“一线两带”建设；陕北以资源深加工为主体，做大做强煤炭、电力、油气和化工四大产业，积极发展现代农业和红色旅游；打造秦巴山区城市圈（带）和经济带．以实现关中、陕北、陕南相百但讲与其同学犀．     

流沙河流域不同生态恢复程度下植物群落特征研究

根据野外调查的数据分析，对流沙河流域干旱河谷不同生态恢复程度下的群落特征进行了研究。调查样方中分布的植物共33科61属66种。在林地中，共有植物24科41属45种。但是不同恢复程度中的物种组成有显著差异：Ⅰ级恢复程度中有11科17属17种，Ⅱ级恢复程度中有13科21属21种，Ⅲ级恢复程度中有18科27属31种；主要物种为松科、蔷薇科、马桑科、禾本科、菊科植物；物种丰富度依次为Ⅲ级〉Ⅱ级〉Ⅰ级；生物量的变化特点为对照（0．31t／hm^2）〈Ⅰ级（5．66t／hm^2）〈Ⅱ级（200．29t／hm^2）〈Ⅲ组（307．06t／hm^2）。在园地中，共有植物19科37属37种；物种丰富度变化不明显，梨树始终在样方中占主导；生物量的变化：Ⅲ级（217．67t／hm^2）〉Ⅱ级（72．60t／hm^2）〉Ⅰ级（39．71t／hm^2）〉对照（0．21t／hm^2）;果树产量变化Ⅰ组（31t／hm^2）〈Ⅱ组（54t／hm^2）〈Ⅲ级（195t／hm^2）。     

新疆荒漠区土壤微生物与土壤环境关系的初步探讨

对不同季节沙湾荒漠区内农田区和非农田区两大生态环境中9种土壤类型进行的土壤微生物特征、土壤理化性质、植被群落及生物量等调查与监测的基础上，通过对比、分析得出：土壤微生物总数随土壤肥力的增高而增高；随地面植物生物量的增大而增大；土壤PH植与总盐分在一定范围内制约着微生物的数量及组成；在众多因素中人为因素影响最大。整个地区土壤微生物总数为农田区咱然荒漠区）撂荒地；在自然荒漠区为南部低山丘陵荒漠化草场区>中部冲洪积平原绿洲荒漠区＞北部准噶尔盆地荒漠及古尔班通古特沙漠区；9种土壤类型按微生物总数排序为：灌耕灰漠土）灌耕棕钙土）山地棕钙土）灰漠上）龟裂土识沙土）盐土）灌木林立）碱化灰漠土。     

一种高效复合絮凝剂对多种废水的处理效果

用聚合氯化铝（PAC）和聚丙烯酰胺（PAM）复配成复合絮凝剂（PAC＋PAM）应用于污染河水、生活污水、工业废水和餐饮废水等6种废水的处理，结果表明。PAC、PAM、PAC＋PAM对污染河水的CODc。SS、浊度有显著降低作用，PAC＋PAM的净水效果明显优于PAC和PAM；PAC＋PAM对6种废水中COD的去除率为81．5％～90．4％，平均84．6％。对SS的去除率为81．9％～96．5％，平均88．9％，对浊度的去除率为91．3％-98．0％，平均95．1％；处理后悬浮物基本被絮凝沉降，水体变得较清澈透明，异味或臭味消除。说明本PAC＋PAM复合絮凝剂对各种废水均有良好的净水效果，具有重要的应用价值。     

铜陵铜矿尾矿的不良特性对植被重建的影响与治理对策

铜矿尾矿库是人为造成的类似沙漠化的景观,它占用土地并带来严重的环境问题,而植被重建是恢复矿区生态系统的主要措施。本文分析了铜陵铜矿尾矿的不良特性对植被重建的影响,提出了相应的治理对策     

Dynamic floodplain vegetation model development for the Kootenai River, USA

The Kootenai River floodplain in Idaho, USA, is nearly disconnected from its main channel due to levee construction and the operation of Libby Dam since 1972. The decreases in flood frequency and magnitude combined with the river modification have changed the physical processes and the dynamics of floodplain vegetation. This research describes the concept, methodologies and simulated results of the rule-based dynamic floodplain vegetation model "CASiMiR-vegetation" that is used to simulate the effect of hydrological alteration on vegetation dynamics. The vegetation dynamics are simulated based on existing theory but adapted to observed field data on the Kootenai River. The model simulates the changing vegetation patterns on an annual basis from an initial condition based on spatially distributed physical parameters such as shear stress, flood duration and height-over-base flow level. The model was calibrated and the robustness of the model was analyzed. The hydrodynamic (HD) models were used to simulate relevant physical processes representing historic, pre-dam, and post-dam conditions from different representative hydrographs. The general concept of the vegetation model is that a vegetation community will be recycled if the magnitude of a relevant physical parameter is greater than the threshold value for specific vegetation; otherwise, succession will take place toward maturation stage. The overall accuracy and agreement Kappa between simulated and field observed maps were low considering individual vegetation types in both calibration and validation areas. Overall accuracy (42% and 58%) and agreement between maps (0.18 and 0.27) increased notably when individual vegetation types were merged into vegetation phases in both calibration and validation areas, respectively. The area balance approach was used to analyze the proportion of area occupied by different vegetation phases in the simulated and observed map. The result showed the impact of the river modification and hydrological alteration on the floodplain vegetation. The spatially distributed vegetation model developed in this study is a step forward in modeling riparian vegetation succession and can be used for operational loss assessment, and river and floodplain restoration projects.     

昆仑山木孜塔格峰北坡藏羚繁殖地的自然植被

通过对阿尔金山国家级自然保护区内藏羚产羔繁殖期的野外考察,研究了昆仑山木孜塔峰北坡藏羚繁殖地的自然植被及其分布,从繁殖地的自然生态特征按摩了藏羚与其繁殖期栖息生之间的关系。结果表明,藏羚对产羔繁殖地的选择不是基于植被条件,而是选择更加安全的区域作为其产羔繁殖地。     

Germinable Soil Seed Banks and the Restoration Potential of Abandoned Cropland on the Chinese Hilly-Gullied Loess Plateau

Poor vegetation cover is generally considered to be a major factor causing soil erosion on the Loess Plateau in China. It has been argued that tree planting restoration is ineffective, and natural re-vegetation is an alternative ecological solution for restoring abandoned cropland and controlling soil erosion. The aims of this study were to investigate the characteristics of soil seed banks and to assess the natural restoration potential of abandoned cropland in the hilly-gullied Loess Plateau. The soil seed bank was identified by the germination method with the soil samples, which were collected at four sampling times (April, August, and October 2005 and August 2006) from 12 plots abandoned 3–30 years prior to sampling. The seed bank densities of all of the samples in the 0–10 cm soil layer varied from 1,067 ± 225 to 14,967 ± 1,606 seeds m⁻². Fifty-one species (24 annual and 27 perennial species) belonging to 18 families were identified, and 39% of these species belonged to the families Compositae and Gramineae. The pioneer species Artemisia scoparia dominated the seed bank, with an average seed density of 3,722 seeds m⁻², and accounted for 74.4% of the seeds in the bank. The local dominant species (such as Lespedeza davurica, Artemisia gmelinii, Bothriochloa ischaemun and Stipa bungeana) of the later succession stages also existed at densities varying from 17 to 1, 383 seeds m⁻². The combination of soil seed bank characteristics, reproductive traits of the species, the specific landscape conditions indicates that the potential to restoring the abandoned croplands in the hilly-gullied Loess Plateau via natural re-vegetation could be substantial.     

Predicting Opportunities for Greening and Patterns of Vegetation on Private Urban Lands

This paper examines predictors of vegetative cover on private lands in Baltimore, Maryland. Using high-resolution spatial data, we generated two measures: “possible stewardship,” which is the proportion of private land that does not have built structures on it and hence has the possibility of supporting vegetation, and “realized stewardship,” which is the proportion of possible stewardship land upon which vegetation is growing. These measures were calculated at the parcel level and averaged by US Census block group. Realized stewardship was further defined by proportion of tree canopy and grass. Expenditures on yard supplies and services, available by block group, were used to help understand where vegetation condition appears to be the result of current activity, past legacies, or abandonment. PRIZM™ market segmentation data were tested as categorical predictors of possible and realized stewardship and yard expenditures. PRIZM™ segmentations are hierarchically clustered into 5, 15, and 62 categories, which correspond to population density, social stratification (income and education), and lifestyle clusters, respectively. We found that PRIZM 15 best predicted variation in possible stewardship and PRIZM 62 best predicted variation in realized stewardship. These results were further analyzed by regressing each dependent variable against a set of continuous variables reflective of each of the three PRIZM groupings. Housing age, vacancy, and population density were found to be critical determinants of both stewardship metrics. A number of lifestyle factors, such as average family size, marriage rates, and percentage of single-family detached homes, were strongly related to realized stewardship. The percentage of African Americans by block group was positively related to realized stewardship but negatively related to yard expenditures.     

雅玛里克山植被类型及物种多样性的特征

采用典型样地法对雅玛里克山进行了植被调查，结果表明，该区的植物群落类型有14种；植物种类有223种植物．分属37科147属，植物生活型有9类；短命和类短命植物获得一定发育，旱生类型的植物占绝对优势，一年生植物占有一定比例等。     

Use of a Wetland Index to Evaluate Changes in Riparian Vegetation After Livestock Exclusion 1

Abstract: A method was developed to characterize ecological integrity of riparian sites based on the abundance of hydric species. This wetland index can be calculated with species data, or with community type data as performed here. Classified riparian community types were used to describe vegetation at 14 livestock exclosures and adjacent grazed areas. Community type wetland index values were generated and used to calculate site wetland index values. It was hypothesized that removal of livestock would result in higher wetland index values because of release from herbivory and decreased physical disturbance of vegetation, streambanks, and soil. The wetland index for exclosures was about 12% higher than grazed sites; differences were statistically significant (p < 0.01) based on paired t‐tests. The increase in hydric vegetation after livestock exclusion may have contributed to the greater bank stability (p = 0.002) and smaller width‐to‐depth ratio (p = 0.005) in exclosures. Challenges were encountered in using community types to describe and compare site vegetation, which could be avoided with species data collection. The wetland index can be a tool to monitor sites over time, compare sites with similar environments, or compare sites for which environmental differences can be accounted.     

Structure and diversity of Erica ciliaris and Erica tetralix heathlands at different successional stages after cutting

In NW Europe, it is known that cutting is a useful tool for managers with regard to decisions about the conservation and management of wet heathlands. Nevertheless it is rarely described quantitatively in the international literature. In Spain, knowledge about this is scarce or lacking. In this study, twenty communities were selected in Galicia (NW Spain) that would represent from one to four stages of vegetation development after cutting. Two 5?×?5?m plots were established for each stage to characterise the vegetation on the basis of its species composition, frequency values, vertical structure and linear cover features. The Diversity Shannon index was calculated and multivariate analyses were performed. As succession advanced, notable changes were produced in the cover of dominant species, Erica ciliaris and Ulex gallii in the first stages and Erica tetralix and Genista berberidea in mature ones. Also, the species richness decreased because of the reduced number of herbs species in the mature stages and, finally, the cover values are indicators of the degree of vegetation development, together with the other parameters of height, overlayering or diversity. Cutting is a useful tool for management of heathlands because the existence of vegetation units belonging to different succession stages increases the internal diversity of communities. On the other hand, the vertical and horizontal structure reflects the formidable resilience of the vegetation community to this practice. This study offers a global vision of the dynamics of wet heathlands after cutting, with very useful ecological information that can be used by the people responsible for their management.     

合理开发坡地资源--以江西省吉水县为例

本文通过对江西省吉水县坡地资源现状、特点的分析,从未利用坡地、利用不充分坡地、利用不合理坡地３方面对吉水县坡地资源进行了潜力分析,并提出了开发利用坡地资源的途径