松嫩草原碱化草地角碱蓬群落水分生态的研究

 本文采用自行设汁的蒸散仪和加拿大Campbe 11科学仪器公司生产的自动气象设备测定了松嫩草原碱化草地角碱蓬群落的蒸散、蒸腾量、太阳辐射及空气温度等环境因子。分析结果表明生长季的睛天条件下,角碱蓬群落的蒸散、蒸腾速率的日进程均为单峰曲线,且各月份间差异很大。群落蒸腾速率与太阳辐射强度、空气温度、相对湿度、风速等环境因子紧密相关,其中与太阳辐射强度呈极显著正相关关系。生长季降雨量和土壤含水量在角碱蓬群落水分循环与平衡的过程中起重要调节作用。1992年6～8月的生长季中,角碱蓬群落总的水分亏缺较少(6.3mm),但各月份间差异很大,其中6月份水分亏缺最高(30.1mm)。     

大针茅草原蝗虫的群落结构和能流研究

大针茅草原蝗虫的常见种类有１１种,其中７种属蝗亚科。毛足棒角蝗短星翅蝗和鼓翅皱膝蝗狭翅雏蝗分别构成蝗虫早、中、晚期的优势种类蝗虫九落的物 丰富度及多样性指数在蝗虫的性中期较高。蝗虫的次级生产力为５．１８ｋＪ／ｍ＾２．ａ,是地上净初级生产国物０．１８％。通过整个蝗虫群落的能流为１６．８４ｋＪ／ｍ＾２．ａ不同的蝗虫各 在生态秕有流中具有不同的贡献;其中毛尼中棒角蝗天整个蝗虫 能流中直着十分重要的作用,     

东北羊草草原综合生态因子对微生物生长的作用──IRM模型的研究

本文从分解者亚系统水平研究了东北羊草草原土壤中微生物生长的季节变化．多种生态因子的季节变化及环境因子对微生物的综合作用规律。微生物总数,总生物量和总呼吸强度的季节动态呈单峰上凸式曲线变化,８月份有明显的高峰值出现,它们分别为：２６８９．０×１０￣４个／ｇ·干土、２５．４１×１０￣（０３）ｇ／ｇ·干土、０．８９５２×１０￣（－３）ｇＣＯ＿２／ｇ·干土·ｄ。土壤生态因子的季节变化与土壤微生物呈现不同程度的正相关和负相关。同时利用ＩＲＭ的模型─—探讨了生态因子对微生物生长的综合作用规律：生态因子对微生物生长的综合作用指数ｒ＿ｎ在整个生长季节中为０．００３１８－０．１１１５,其中７－９月份ｒ＿ｎ较大,对出生物生长的限制作用较小,微生物生长较快,５、６和１０月份ｒ＿ｎ较小,对微生物生长限制作用较大,微生物生长较慢。     

南方红豆杉叶精油化学成分的研究

采用水蒸汽蒸馏法提取南方红豆杉叶的精油,通过色谱－质谱－计算机联用技术分析了精油的化学成分。从中初步鉴定出２６个化合物,占精油总量的９６％,主要成分是：棕榈酸（３５．６６％）,９－十六碳烯酸９－十六碳稀酯（１１．２８％）,３－辛醇（４．４７％）,１－苯－１,２－丙二酮（４．３％）,Ｎ－苯基－１－萘胺（３．５７％）,１,２－苯二羧酸（２－甲基丙基）二酯（３．５７％）,６,１０－二甲基－５,９－十一双     

青海高原中华双腔吸虫等四种双腔吸虫成熟尾蚴的扫描电镜比较观察

青海高原中华双腔吸虫,矛形双腔吸虫等四种双腔吸虫尾蚴经扫描电镜比较观察显示它们体表具有明显的差别。中华双腔吸虫尾蚴体部末部表皮呈具间隔的纵嵴,矛形双腔吸虫尾蚴在此部位呈如同玉米棒的玉米珠粒,未定名的“B”型和“D”型尾蚴,前者呈海棉状,后者介于矛形双腔和中华双腔的形态之间。这四种尾蚴的口吸盘、腹吸盘及体两侧表皮上,具有触毛及乳突的情况亦不相同。     

Effect of topsoil storage on microbial activity,primary production and decomposition potential

Summary The effects of disturbing (cultivating) and stockpiling prairie grassland topsoil on microbial activity, microbial biomass C, plant production and decomposition potentials were studied by measuring CO₂ efflux from unamended and glucose amended soil in the laboratory and by conducting a pot and litter bag study in the greenhouse. Stockpiling appeared to have very little effect on soil respiratory activity, but did reduce the microbial biomass C levels. Throughout the 3 year study the microbial biomass C in the surface soil of the stockpile was less than that in the undisturbed soil, while the biomass C in soil at the bottom of the stockpile was at no time significantly different from that in the undisturbed soil. The reduction in microbial biomass C in the surface soil immediately after stockpiling was attributed to a decrease in the soil organic C levels caused by a slight dilution of the topsoil with subsurface mineral soil, and the exposure of the stockpile surface to extreme environmental conditions. Soils from all depths of the stockpile responded more slowly to the addition of glucose than soil from the undisturbed and cultivated treatments even when no differences in biomass were detected between the undisturbed and stockpiled soils. It is postulated that the rapidity with which the soil microbial biomass responds to glucose additions may be a sensitive indicator of stress on the soil biological components. The reduction in biomass after storage for 1 year had no adverse effects on the decomposition or primary production potential of the stored soil. Rather, shoot production by fall rye was stimulated in the stored topsoil, presumably a result of better N nutrition.     

Fluctuations in a coastal dune grassland due to fluctuations in rainfall: Experimental evidence

Experiments with rainfall on a dune grassland near Oostvoorne, the Netherlands with Festuco-Galietum as the main syntaxon are described. Both increase in rain through additional watering and decrease in rain through catchment are presented to plots belonging to the xerosere and the mesosere. Clear changes in the floristic composition are the result, even after only two years. Typical Festuco-Galietum species are promoted by high rainfall, species of open habitat such as Corynephorus canescens are promoted by drought. The results are discussed against the background of long term permanent plot observations in the area and a relation with rabbit grazing intensity is supposed.Nomenclature of vascular plants follows Heukels-van Ooststroom (1975) Flora van Nederland 18 ed., Woiters-Noordhoff, Groningen; Nomenclature of syntaxa follows Westhoff & den Held (1969). Plantengemeenschappen in Nederland, Thieme, Zutphen.Field work in 1978 was carried out with Frans Bongers and Marc de Lyon, in 1979 with Marc de Lyon, Picter Meeuwissen and Guiljo van Nuland, all then MSc. students at the Division of Geobotany. Their help and the advice of Dr. Peter van der Aart, Institute of Ecological Research, Oostvoorne, are acknowledged.     

猕猴桃品种‘金桃’采收指标与果实软熟品质相关性研究

分别对河南省27个果园的中华猕猴桃（Actinidia chinensis Planch.）品种‘金桃’果实的5项采收生理指标及果实软熟时的8项品质性状进行测定,采用主成分分析法对果实软熟时的品质指标进行综合评分,并对果实的采收生理指标、果实软熟品质指标及综合分值间进行相关性分析。结果显示,采收时的生理指标（干物质、色度角、硬度和可溶性固形物）均与果实软熟品质综合分值间呈极显著相关,其中干物质相关系数最高,为0.437。干物质与体现果实软熟品质的关键指标（可溶性固形物、总糖和糖酸比）均呈极显著性相关。研究结果表明‘金桃’果实采收时,干物质含量是果实软熟时品质的重要评价指标,而可溶性固形物和色度角是评判采收期的辅助指标。     

黄连体细胞胚胎发生及植株再生

黄连(Coptis chinensis F.)是我国著名常用中药,具有清热燥湿,凉血解毒的功用。长期以来由于过量的采挖,造成野生资源亏缺。在人工栽培中,由于黄连种子小,休眠期长,出苗不整齐,生长缓慢,要6—7年才能收获,因而限制了黄连的生产。对黄连的研究,过去主要集中于黄连的有效成份分析及药物学方面。近年来日本T. Furuya等开展了应用黄连细胞大量培