高寒小嵩草草甸种子库和种子雨动态分析

对小嵩草草甸种子库的大小和物种组成及与种子雨、地上植被的关系进行了初步研究 .结果表明 ,返青期和枯黄期小嵩草草甸种子库单位体积 (1.0m× 1.0m× 0 .1m)分别有种子nf=10 5 5 0粒和nk=13 815粒 ,分别由 2 2种和 2 4种植物组成 ,分属 9个科 .其中 ,莎草科、豆科和龙胆科占优势 ,禾本科所占比例较小 .每平方米种子雨nr=8436 .4粒 ,由2 5种植物组成 ,分属 10个科 ,莎草科和禾本科所占比例较大 .种子库和种子雨在物种组成上有一定的相似性 (r =0 .76 0 0 ,P <0 .0 1) ,二者共有 19个种 ,分别占种子库和种子雨物种总数的 82 .6 1%和 90 .48% .地上植被与种子库的相似性较小 ,地上植被中有 43.2 4%和 5 1.35 %的植物分别在返青期和枯黄期种子库中出现 ,6 0 %的植物出现于种子雨中 .在物种分布和优势度上 ,地上植被与种子雨间一致性较高 ,但它们与种子库间有一定的分歧 .从地上植被到返青期时的种子库 ,物种多样性降低了 1.6 1% ,从而说明种子库不仅是地上植被补充更新的源泉之一 ,而且是维持植物物种多样性的一种机制 .图 3参 13     

Recovery of Danish coastal dune vegetation after a wildfire

The initial recovery of vegetation after a wildfire in a coastal dune area in NW Jutland, Denmark, was studied over a 5-yr period by means of permanent plots representing various dune communities along a topographical gradient. The impact of the fire varied with the position of the plots. Fens and south-facing dunes were little affected while dune heath plots were severely affected including loss of the O-horizon. Post-fire conditions included presence of remaining soil organic matter, a soil seed bank and surviving below-ground plant parts. The soil surface remained stable during the study period. The initial five years of recovery comprised of an initial three-year recruitment phase during which cover and number of species increased and the quantitative species composition changed markedly, followed by two years of a declining rate of change. 38 species of vascular plants were recorded, 35 are regular components in dune, dune heath and heath fen and were recruited from the seed bank, from locally dispersed seeds and/or by sprouting from surviving vegetative parts. The remaining three species were ‘aliens’, dispersed from sources outside the area. Crustose lichens had an important role in the initial recovery by stabilizing the surface and probably inhibiting seed germination, whereas mosses mostly had a subordinate role. The seral position of the plots, as well as the expected time needed for full recovery of pre-fire vegetation, vary with topography and initial soil conditions. Five years after the fire the fen and the south-facing dune probably need less than a decade for full recovery. The remaining plots are judged to be relatively early seral; their full recovery into mature dry or moist dune heath vegetation and O-horizon is expected to need several centuries.     

葡萄酒副产品深度利用的研究进展

介绍了葡萄皮渣、葡萄籽、酒脚的深度利用途径：葡萄皮渣可用于酿酒、酿醋、提取色素和多酚、吸附重金属;葡萄籽可以提取葡萄籽油、葡萄籽蛋白和抗氧化物质;酒脚可以提取酒石酸盐。开展葡萄酒副产品的深度利用,不仅可以获得良好的经济效益,而且可有效减轻环保压力,获得巨大的社会效益。     

Seeds and rights: new approaches to post-war agricultural rehabilitation in Sierra Leone

Based on preliminary findings of ongoing 'action research' in the war zone in central Sierra Leone, this paper shows how more equitable seed distribution could contribute to fostering a culture of human rights as well as to agricultural rehabilitation. Assessment of seeds-and-toosl programmes in 19 villages found that aid agency targeting and distribution modalities channelled inputs through village committees which denied assistance to intended beneficiary groups. Such distribution inequalities constitute violations of fundamental human rights, exacerbate grievance and division and maintain the threat of social disorder. The benefits and disadvantages of an alternative, more inclusive, rights-based approach to seed distribution are discussed, and preliminary results from the pilot phase of CARE's Rights-based Approach to Food Security Project are presented. Under this project, village-level peace and rights days are held to allow villagers to debate the vulnerabilities that facilitated the war and to elaborate on local notions of human rights. In symbolising new beginnings, seed can be seen as a useful medium through which to debate a more inclusive--and ultimately less vulnerable--society.     

如何在红松母树林内实施计划烧除

林口林业局通过对红松母树林下的细小可燃物进行计划烧除实验,证明这种方法不但是预防森林火灾、保护红松母树林安全的有效措施,而且还可消除森林病害虫和增加林木生长量。     

浅析茶油加工企业环境污染防治对策

阐述了茶油加工工艺及生产流程,分析了茶油生产过程中的废水污染源、废气污染源、固废污染源和噪声污染源,结合国外内茶油生产加工和环保实践,针对性地提出了废水、废气、固废、噪声污染防治和资源化对策,分析了环境风险可信事故,并提出了环境风险防范措施,探讨了清洁生产合理化建议,为茶油生产企业的环境影响评价、工程治理和日常环境监管提供了依据。     

贵阳市近郊不同人为干扰迹地土壤种子库与地上植被的关系

采用种子萌发试验对贵阳市乌当区马背山喀斯特次生林不同干扰迹地(弃耕干扰、火烧干扰和碎石堆积干扰)土壤种子库与地上植被的关系进行研究,结果显示:弃耕地、火烧地和碎石堆积地的地面植被的物种数和生活型比土壤种子库丰富,土壤种子库中乔木种类缺乏,以菊科、禾本科和豆科植物等草本植物占优势。3种干扰迹地地上植被物种丰富度指数、均匀度指数均大于土壤种子库,弃耕地土壤种子库的生态优势度指数大于地上植被,而碎石堆积地则小于地上植被。3种干扰迹地土壤种子库与地表植被的物种相似性系数分别为0.4000、0.4274和0.3556,表明不同人为干扰方式对地表植被和土壤种子库的影响程度不同。     

元宝山冷杉濒危原因初探

元宝山冷杉是仅分布于广西融水县元宝山上的濒危树种。本文分析认为致使其濒危的主要原因是气候变迁,此外,种子发芽率低、群落环境以及人为活动影响也是导致其濒危的重要原因。建议在严格保护和管理现有生境的同时,开展人工辅助更新,并在生境相似的地方育苗造林。     

Adaptation of Nitraria sphaerocarpa to wind-blown sand environments at the edge of a desert oasis

This study addresses the adaptation of Nitraria sphaervcarpa to blown sand at the edge of a desert oasis with regard to the aspects of soil seed banks, seedlings, and population. Horizontally, the total number of seeds per unit area decreased from the shrub canopy center to intershrub areas, and most seeds were found under shrub canopies. Vertically, the highest proportion of seeds was found at depths of 5-10 cm. The emergence percentage, seedling mass, and seedling height, which were significantly affected by both burial depth and seed size, were highest at the optimal burial depth of 2 cm, and decreased with increasing burial depth in each seed size-class. Although seedling mass was usually greatest for large seeds and least for small seeds at each burial depth, little difference was observed in seedling height at shallow burial depths of 0-3 cm. The population shows a patchy and discontinuous distribution pattern. Population height increases with increasing sand depth. Also the density increases with increasing depth of sand in the desert; however, there is a steady decrease when the depth of sand is more than 100 cm. This result indicates that the depth of sand that is most suitable for the growth of Nitraria sphaervcarpa is 100 cm. The size of the population is significantly correlated with the sand depth, which increases with increasing depth in the desert.