做青环境调控方式对乌龙茶品质影响的试验研究   总被引：7，自引：2，他引：7  

金心怡  陈济斌  王秀萍  吉克温  苏益平 《农业工程学报》2003,19(6):215-218

为了降低乌龙茶人工做青环境的投资成本和能耗，改善做青环境空气质量，对恒温恒风和恒温无风两种做青环境进行试验比较，通过在线测定做青环境指标及青叶若干生理指标，探明做青环境调控方式对叶层空气参数、青叶生理生化变化以及毛茶品质的影响。结果表明，恒温恒风调控方式能有效降低叶层空气的相对湿度，改善空气质量，增大青叶的气孔导度、失水速率及呼吸速率，提高毛茶的水浸出物和游离氨基酸含量，毛茶品质较优。春茶乌龙茶做青环境调控参数宜为：温度22～25℃，相对湿度70%～80%，做青前期叶层平均风速0.2 m/s。  相似文献   

Threat syndromes and conservation of the Australian flora   总被引：1，自引：0，他引：1  

M.A. Burgman  D. Keith  D. Widyatmoko 《Biological conservation》2007,134(1):73-82

The status of the Australian flora was reviewed by compiling published information on all critically endangered and endangered species listed federally in 2004. Threatening processes were categorised and their contributions to past, present and future declines were assessed. The information was cross-referenced against State agency information and field knowledge. Land clearance for agriculture (grazing and cropping) and urbanization have been the primary causes of range contractions and habitat loss in the past, responsible for the current status of the majority of threatened Australian plants. In the future, land clearance will remain important but new issues are emerging. Many species are now at risk from demographic and environmental uncertainty alone. Threats growing in importance include disease, salinity, invasive species and changed disturbance regimes. Many species are subject to common, landscape-level threats. A key issue to emerge from our analysis is that most species are threatened by a number of interacting factors - threat syndromes. Several future risks may be mitigated effectively by simple, low-cost changes in policy, such as more stringent controls on land clearance, strategic fire management, and firmer control on the importation of plant species. Other factors will require greater effort and new strategies to mitigate, including social and legal initiatives in urban landscapes and broad strategies for pathogens, climate change and other landscape-level processes.  相似文献   

Evaluation of Ornithogalum genebank accessions for some characteristics of importance for breeding cut flowers or pot plants     

G.M. Littlejohn  L.M. Blomerus 《Genetic Resources and Crop Evolution》1997,44(3):227-234

The South African Ornithogalum L. species are divided into three subgenera; Aspasia, Urophyllon and Osmyne. The species of horticultural importance, such as O. thyrsoides, are found in the subgenus Aspasia, and all have pure coloured flowers ranging from white to yellow to deep orange. Accessions numbering 299 were collected and grown under comparative conditions. Characteristics of use in discriminating superior parents for hybridization were measured, such as: leaf position and colour; stem length; shape, size and density of the inflorescence; size, shape and colour of the flower; the presence of visual virus symptoms and the reaction of leaf cuttings to tissue culture propagation. The aim was to quantify the variation according to the characteristics deemed of importance for selecting genotypes for cut or pot flower breeding. Variation for each of the traits measured was observed in each of the species. The evaluation of the Ornithogalum improved the process of selecting accessions as parents in hybridization by providing an indication of the variation present in the natural populations. Thus specific accessions could be selected to combine either at interspecific or intraspecific level to breed for distinct types.  相似文献   

贵州省开阳茶园土壤养分状况与肥力质量评价   总被引：10，自引：0，他引：10  

任艳芳  何俊瑜  张艳超  刘冬  王艳玲  陈会 《土壤》2016,48(4):668-674

为明确贵州省开阳县茶园土壤养分状况,为优质茶叶生产提供参考,对贵州省开阳县茶园土壤进行了调查,分析了158个土壤样品的养分含量及养分间的相关性,并采用主成分分析法和模糊数学隶属度函数模型,通过计算土壤肥力综合指标值(IFI)对土壤养分状况进行综合评价。结果表明:贵州省开阳茶园土壤p H偏酸,有机质、全氮和碱解氮含量较为丰富;但全磷、速效磷、全钾和速效钾含量缺乏所占比例较大,分别仅有16.46%、14.56%、20.89%和12.66%的土壤样品达到优质高产茶园标准。开阳茶园土壤IFI值平均为0.59,属于中等以上土壤肥力茶园所占的比例为61.40%,茶园土壤肥力质量总体水平属于良好,但土壤偏酸,速效磷和速效钾的含量相对偏低,应重点改酸和增施磷钾肥。  相似文献   

稻秸覆盖对有机茶园土壤生态环境影响的研究   总被引：12，自引：1，他引：12  

汪汇海  沙丽清  杨效东 《中国生态农业学报》2006,14(4):65-67

对多年稻秸覆盖下有机茶园土壤生态环境的研究表明,稻秸覆盖能改善土壤养分状况,稻秸覆盖处理0～40cm土层中,有机质、全N、全P和速效性N、P、K的平均含量均比对照相应土层高,分别是对照处理的2.00倍、1.87倍、1.66倍、1.91倍、1.91倍、2.56倍;稻秸覆盖能增加土壤微生物主要类群数量,0～40cm土层中,覆盖处理的真菌和细菌分别是对照的3.54倍和4.46倍;稻秸覆盖能增加干季土壤含水量,稻秸覆盖处理的0～10cm、10～20cm和0～30cm各土层的土壤含水量分别比对照相应土层提高了26.24%、13.92%和12.38%;稻秸覆盖能改善土壤动物总数状况,稻秸覆盖处理的0～40cm土层中,土壤动物个体总数是对照处理的1.87倍。因此,稻秸覆盖值得在有机茶园中大力推广。  相似文献   

Consequences of the spatial configuration of resources for the distribution and dynamics of the endangered Parnassius apollo butterfly     

Marianne S. Fred  Robert B. O’Hara 《Biological conservation》2006,130(2):183-192

Based on several years of data from two populations of the endangered Apollo butterfly (Parnassius apollo, L. 1758), we study how the amount and spatial location of patches of larval (host-plant) and adult (nectar plant) resources affects the distribution of females and their larval offspring in the following year. In the coastal population (nectar-plant and host-plant patches spatially segregated), females moved frequently between patches to aggregate on larger host-plant patches close to nectar-plant patches. In the archipelago population (where nectar-plants and host-plants co-occur), the abundance of females increased with higher proximity to other host-plant patches and with more nectar-plants on the patch. Next year’s larval abundance correlated with the abundance of females in the previous season in both populations. A model of the population dynamics in the two populations in relation to the spatial configuration of nectar and host-plant patches showed that the spatial configuration of larval and adult resources had population-dynamical consequences. In many organisms, different life-history stages use different resources. Incorporation of information on the location and abundance of adult resources can provide additional insight for the suitability of a particular landscape in harbouring a population.  相似文献   

覆盖与间作对亚热带丘陵区茶园土壤微生物量的影响   总被引：12，自引：0，他引：12  

沈程文  肖润林  徐华勤  夏艳君  任全  黄瑶 《水土保持学报》2006,20(3):141-144

在亚热带丘陵区红壤幼龄茶园经过4年稻草覆盖及间作三叶草田间小区试验，对土壤剖面分析结果表明．稻草覆盖及间作三叶草均能明显增加土壤表层有机C、碱解N、有效P．增加土壤微生物量C、N、P。剖面中土壤有机C、微生物量C、全N、碱解N、土壤微生物量N、全P、有效P、微生物量P随深度的增加而递减。稻草覆盖影响到40cm土层左右，阃作白三叶草影响到20cm左右。0～20cm土层微生物量C／有机CT2〉T3〉T1，3个处理微生物量N／全N在1．02～2．74之间，微生物量P和全P比值在2．27～13．1之间。亚热带丘陵区红壤幼龄茶园土壤微生物量碳与土壤有机碳C、碱解N、微生物量N、有效P、微生物量P具有极显著的正相关关系（P〈0．01），与全N、全P呈显著的正相关关系（P〈0．05）。  相似文献   

酶处理对绿茶浸提液成分及膜过滤通量影响的研究   总被引：6，自引：0，他引：6  

郑宝东  曾绍校 《农业工程学报》2003,19(6):212-214

为解决绿茶饮料生产中出现的沉淀问题，研究了酶处理对绿茶浸提液成分及膜通量的影响。结果表明双酶水解后绿茶汁的膜过滤通量比未经过酶处理的茶汁提高21%～40%；粘度下降6%～13%，氨基态氮增加11%～41%，而茶多酚、咖啡碱等成分变化不大。并且双酶混合酶解处理后的绿茶浸提液经过超滤能有效解决绿茶饮料“冷后浑”的现象。  相似文献   

Lakeshore diversity and rarity relationships along interacting disturbance gradients: catchment area, wave action and depth     

Paul A MorrisNicholas M Hill  Edward G ReekieHeather L Hewlin 《Biological conservation》2002,106(1):79-90

Diversity patterns of riparian plant communities have been associated with disturbance. Populations of a diversity of Atlantic Coastal Plain plants occur as disjuncts on shores of large catchment area lakes in Nova Scotia. These lakeshore communities contain rare plants with local, national and global rankings. The populations of rare plants are dynamic and their management requires an understanding of the relationship between disturbance and the survival of rare plants. This present study measured (overwinter wooden dowel removal) and observed disturbance along gradients of catchment area (CA), exposure and depth. In three separate experiments ranging from the landscape to the lake, to the single shoreline level, disturbance was linked to lake CA, exposure and depth, respectively. At all scales, disturbance was positively associated with the presence of rare species. The pattern of rare species richness over the river system was complex; at the within-lake level, the frequency of rare species per site was greatest in the intermediate CA lake while the pool of rare species was greatest in the largest CA lake. The findings focus field efforts on wide, exposed shorelines of large CA lakes where new rare plants continue to be discovered. In addition, the discrepancy between highest frequency of rare plants on intermediate CA lakes and highest species pools of rarities on large CA lakes, reinforces the need for larger protected area systems for the most naturally disturbed ecosystems which often support populations having a high turnover rate but a low site to site frequency.  相似文献   

Aspects of phytoremediation of organic pollutants   总被引：1，自引：0，他引：1  

Stefan Trapp  Ulrich Karlson 《Journal of Soils and Sediments》2001,1(1):37-43

Phytoremediation is a quite novel technique to clean polluted soils using plants. In theory, phytoremediation methods are cheap, are accepted by the public and, compared to physical or chemical approaches, are ecologically advantageous. Until today, however, there are only a few examples of successful applications. One reason is that the processes involved are complex, and a full clean up may require many years. Plants affect the water balance of a site, they change redox potential and pH, and stimulate microbial activity of the soil. These indirect influences may accelerate degradation in the root zone or reduce leaching of compounds to groundwater. Compounds taken up into plants may be metabolised, accumulated, or volatilised into air. Based on these processes, several phytoremediation methods have been developed: Phytoextraction, rhizofiltra-tion, phytostabilisation, rhizo and phytodegradation, pump and tree, land farming, phytovolatilisation, hydraulic control and more. Already in use are plants (and here willow, poplar and grass) for the degradation of petroleum products, aromatic hydrocarbons (BTEX), chlorinated solvents, explosives and cyanides. However, phytotoxicity and pollutant mass balances were rarely documented. Often, the success of the projects was not controlled, and only estimates can be made about the applicability and the potential of phytoremediation. This lack of experience about possibilities and limitations seems to be a hindrance for a broader use of these techniques.  相似文献