江西大岗山植被类型及其自然度与经营集约度的划分和评价*

１。采用样地法和点四分法在江西大岗山年珠、上村林场进行植被调查。主要植被类型有：栲楠常绿林、针阔混交林、竹阔混交林、杉木人工林、毛竹林、灌木林和山顶草地。该地区主要经营大面积杉木人工林和毛竹林，原地带性植被只剩下林相残破、零星分布的常绿阔叶林。２．提出自然度（植被与顶极群落的距离，分Ｖ级）与经营集约度（人工经营程度，共５等）对两林场进行了划分与双重评价。占人工林总面积３２．２６％的人工林经营良好，     

毛乌素沙地不同治理措施植被恢复效果分析

从群落数量结构与干物质生产方面对刘家窑头流域赵家塘不同治理措施下的植被恢复效果进行初步分析.结果表明林草复合措施植被恢复效果最好,灌木林地植被恢复优于乔木林地,杨树纯林地效果较差;草方格固沙能使植被迅速恢复;喷撒化学固沙剂对迎风坡植被恢复的效果较为显著.     

Incorporating forage grasses in riparian buffers for bioremediation of atrazine, isoxaflutole and nitrate in Missouri

Multi-species tree-shrub-grass riparian buffer systems have been recognized as one of the most cost-effective bioremediation approaches to alleviate nonpoint source agricultural pollution in heavily fertilized systems. However, highly concentrated herbicides in surface and subsurface water and shade cast by trees along the stream bank usually compromise the effectiveness of these systems. Greenhouse trials and field lysimeter studies were conducted to evaluate the tolerance of orchard grass (Dactylis glomerata), smooth bromegrass (Bromus inermis), tall fescue (Festuca arundinacea), timothy (Phleum pratense), and switchgrass (Panicum virgatum) ground covers to atrazine and Balance™ (isoxaflutole) plus their capacity to sequester and degrade these herbicides and their metabolites. Their ability to remove soil nitrate was also quantified. Concentrations of atrazine, Balance™ and their metabolites in the leachate, soil and plant samples were determined by solid phase extraction followed by high performance liquid or gas chromatographic analyses. Distribution of the herbicides and metabolites in the system was calculated using a mass balance approach. Herbicide bioremediation capacity of each lysimeter treatment was determined by the ratio of metabolites to parent herbicide plus metabolites. Bioremediation of nitrate was quantified by comparing nitrate reduction rates in grass treatments to the bare ground control. Based on this herbicide tolerance, bioremediation data and shade tolerance determined in a previous study, it was established that switch grass, tall fescue and smooth bromegrass are good candidates for incorporation into tree-shrub-grass riparian buffer systems designed for the bioremediation of atrazine, Balance™ and nitrate.     

沙化土地信息提取研究

采用LandsatETM 多时相影像,在地类光谱特征分析的基础上,用分层分离的方法,提取出沙化土地信息。以全国沙漠化普查地类划分标准中的植被覆盖度为确定沙化土地程度的依据,通过建立NDVI和实测植被覆盖度的回归模型,确定不同程度沙化土地对应的植被覆盖度与NDVI的对应关系,用NDVI阈值进行划分,得到沙化土地程度图。     

轿子山自然保护区植被类型及其保护价值评价

依据《云南植被》编目系统，将轿子山自然保护区的植被划分为7个植被型，9个植被亚型，16个群系，20个群落，并对各植被类型的保护价值进行了数量化评价，在此基础上对保护价值较高的急尖长苞冷杉林、野八角一乳状石栎林、杜鹃矮林、杜鹃灌丛和元江栲林、高山柏灌丛等6个主要植被类型进行了评价。     

The effect of multi-nutrient fertilization on understory vegetation nutrient concentrations in inland Northwest conifer stands

This study looked at the effects that multi-nutrient fertilization had on understory vegetation nutrient concentrations at four conifer forested locations in the inland Northwest. Multi-nutrient fertilization of conifer stands cannot only enhance the overstory species in the inland Northwest but also the understory vegetation. Determination of nutrient concentration response to fertilization treatments can provide managers the ability to better manipulate their forests for grazing and wildlife habitat. We grouped the understory vegetation into three general life forms: forbs, grasses and grass-likes, and shrubs. Multi-nutrient fertilization had little effect on nitrogen concentration across all life forms. Potassium and sulfur generally increased in concentration. Micronutrients as a whole showed less variability in response to multi-nutrient fertilization. Boron, copper, molybdenum, and zinc generally showed increases in concentrations across all life forms. We were able to conduct analyses on a selected number of understory vegetation species. Individual species showed variability in nutrient concentration response to multi-nutrient fertilization. Wildlife habitat and grazing quality were both increased and decreased following multi-nutrient fertilization. Increases in nutrient concentrations will provide more nutritious vegetation to these animals and vice versa for decreases in concentrations.     

三种不同植被恢复模式地上生物量及其营养元素含量研究

在广西忻城县喀斯特石山区对三种不同植被恢复模式 (任豆间种竹子模式、金银花模式、竹子模式 )地上部分生物量进行测定 .结果表明 :① 3种不同植被恢复模式的净生物量 ,显示出金银花(1 19t·hm-2 ·a-1) >竹子 (1 0 4t·hm-2 ·a-1) >任豆间种竹子 (1 0 1t·hm-2 ·a-1) ;②各种模式地上部分生物量的主要营养 (N ,P ,K)含量 ,显示出任豆间种竹子 (75 0 9kg·hm-2 ) >竹子 (33 4 0kg·hm-2 ) >金银花(2 2 95kg·hm-2 ) ;③各种模式地上部分生物量的主要营养含量的分配 ,均显示出N >K >P的规律。     

乌兰布和沙漠植被及其保护

乌兰布和沙漠降雨稀少,生态环境脆弱,有种子植物49科169属312种,以蒙古种、戈壁—蒙古种、戈壁种以及古地中海区系的荒漠成分占主导地位;自然植被为亚洲中部荒漠区与草原区的分界线,主要有梭梭、柠条、白刺和油蒿、沙冬青＋白刺＋油蒿、白刺＋红砂、白刺＋霸王＋油蒿、籽蒿＋沙竹、芦苇、白刺＋芨芨草等9类群丛。由于不合理的利用,草场植被逐年退化,正朝着极度荒漠化演变。对植被状况和平缓沙丘及半固定、半流动沙地等不同立地条件的草地,应因地制宜,造（林）封（育）飞（播）结合,开展综合治理,恢复植被,遏制沙漠化加重的趋势。     

杭州次生湿地中早园竹林的种子库特征

实验通过野外调查和萌发试验对杭州西溪湿地经济竹林的种子库特征进行研究。结果,经济竹林种子库中共出现14科26种植物,其中以十字花科、大戟科、玄参科、菊科和禾本科为主。种子库密度的垂直分布呈下降趋势。其种子库中有劣性杂草如一年蓬和蒲公英,并占有优势。竹林地10~15 cm土壤的板结和贫瘠是种子量稀少的主要原因,竹林大部分是在干扰和干旱生境下萌发的草本和灌木种子库,亦有永久种子库的贡献。     

乌海市平沟煤矸石山小地形土壤养分分析

文章以乌海市平沟煤矸石山上平台和边坡两种不同小地形上的土壤为研究对象,通过野外调查取样和室内分析化验,研究煤矸石山两种小地形对土壤养分的恢复情况。结果表明,土壤有机质、全N、碱解N含量在两种不同小地形上表现为边坡>平台,土壤P素、K素含量表现为平台>边坡,总体而言,边坡上土壤养分恢复效果比平台好。平台和边坡上土壤养分含量在不同土层深度中均表现为:0~20 cm层>20~40 cm层。通过参考土壤养分分级与丰缺度标准,目前土壤养分丰缺度主要呈现出缺或极缺状态。