首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6篇
  免费   0篇
  国内免费   1篇
  2016年   1篇
  2014年   1篇
  2013年   1篇
  2011年   1篇
  2006年   1篇
  2003年   1篇
  1998年   1篇
排序方式: 共有7条查询结果,搜索用时 15 毫秒
1
1.
Role of the EXPO ’70 forest project in forest restoration in urban areas   总被引:1,自引:0,他引:1  
The forest-restoration project of EXPO ’70 Commemorative Park, Japan, is an epoch-making attempt to restore a nature-oriented forest park in an urban area in which large-scale land reclamation had occurred. The objective of this paper is to review the concept, planning, and design, and the outcome so far, and discuss current aspects of creating a core natural habitat in the city of Osaka. Innovative planning policy and design methods have been used for construction of the forest-restoration project of EXPO Park. Unexpected troubles have occurred, however. After approximately 10 years severe effects of poor drainage and soil compaction on the establishment of the forest have been revealed by intensive monitoring. Partial redevelopment and soil-amendment work has therefore been conducted. These improvements seemed to have resulted in “a self-sustaining forest”, the original objective of the planning policy. After approximately 25 years, however, a second intensive monitoring program has revealed that the status of nature restoration is generally favorable in quantity but not in structure of forest communities or biodiversity. The major issues identified are excessive tree density with a single foliage layer caused by the single generation of immature forest stand, and ecological isolation from the source of nature. The EXPO forest is currently in the “Second Generation” stage; this involves management, including artificial gap regeneration, and soil seed bank introduction, with careful monitoring. The project is expected to be an ideal example of a core habitat of nature-oriented forest in urban areas achieved by adaptive management.  相似文献   
2.
退化生态系统植被恢复的生理生态学研究进展   总被引:28,自引:4,他引:24  
赵平 《应用生态学报》2003,14(11):2031-2036
自然的力量和人类的干预导致局部性、区域性甚至全球性植物群落格局的变化。不管这种变化的原因是什么,变化的强度如何,生态系统常常通过自然演替能够恢复它们大部分的特征,亦可以通过人类的介入进行修复,退化生态系统恢复的实质是群落演替,是生态系统结构和功能从简单到复杂、从低级向高级演变的过程,植物生理生态特性研究可以解释退化生态系统植被恢复的一些宏观现象,并为植被恢复构建先锋群落提供可靠的科学依据,本文综述退化生态系统植被恢复的生理生态学研究的进展。  相似文献   
3.
Restoration of wetland and associated ecosystems is a major goal of land management agencies throughout the world. On the lower Colorado River, creation of riparian forests is planned to mitigate riparian habitat degradation by historic land-use conversions and river management. Current restoration practices use propagated plant stock. If direct seeding can be implemented, genetic and structural diversity could be enhanced at restoration sites even while reducing costs compared to vegetative propagation methods. A small-scale field study was implemented in Cibola, Arizona, to determine the effectiveness of direct seeding of Fremont cottonwood (Populus fremontii), Goodding's willow (Salix gooddingii), and coyote willow (S. exigua). For the first growing season, establishment of Fremont cottonwood averaged 7% of pure live seed rates for all treatments combined, whereas establishment of willows was less than 1%. Volunteer species were abundant, with grasses dominating cover and biomass after one growing season. Saltcedar (Tamarix ramosissima) established in abundance, but showed lower growth rates than Fremont cottonwood during the first growing season. Monitoring for three growing seasons indicated higher growth rates and survival of Fremont cottonwood compared to all volunteer species. Study results indicated that direct seeding of Fremont cottonwood is likely to be an efficient method for tree re-vegetation. Additional studies are required for willow species to determine if establishment from seed can be increased through enhanced weed control and elimination of Fremont cottonwood from the seed mix.  相似文献   
4.
Davies  Angus  Waite  Stephen 《Plant Ecology》1998,136(1):27-39
The relationships between the composition of the soil seed bank, the field layer vegetation, and the scrub canopy were investigated along a 69 m transect, grading from incipient woodland, through scrub, into intensively rabbit-grazed calcareous grassland. The results are used to assess the persistence of species associated with open calcareous grassland in the seed bank under developing scrub. Scrub age, composition and density, changed along the transect from the woodland to open grassland. A total of 35 forb and grass species were found in the field layer. The pattern evident in the scrub layer was also reflected in the herbaceous vegetation. The field layer in the most closed portion of the transect, where the scrub was oldest, was dominated by shade-tolerant species normally associated with woodland habitats. The abundance of these species decreased along the transect as the scrub age declined, and the field layer became increasingly dominated by species typical of open grassland. A total of 47 species germinated from the seed bank. Few species were recorded in the seed bank along the entire length of the transect. Overall, the seed bank was dominated by Hypericum perforatum and Centaurium erythraea, which accounted for 38.2% and 28.6% of emerging seedlings respectively. As with a number of similar studies, the composition of the seed bank had a low correspondence with the composition of the field layer vegetation. The results also emphasise that the composition of the seed bank can be viewed as an ecological palimpsest, with germinable seed of species from each stage of the old-field succession occurring in the soil. The seed bank is an important component in the re-vegetation of an area after disturbance such as scrub removal. This study supports the findings of previous research in showing that relatively few characteristic calcareous grassland species form persistent seed banks. The soil seed bank would therefore appear to be of limited value in the restoration of such grassland following scrub removal.  相似文献   
5.
采用空间序列代替时间序列的方法,对衡阳紫色土丘陵坡地不同过程中的不同土层、根际(Rhizosphere,R)与非根际(Non-rhizosphere,S)的土壤基础呼吸(Soil basal respiration,SBR)及代谢熵(Metabolic quotient,qCO2)的变化特征以及它们与土壤理化性质的关系进行研究。结果表明:(1)不同恢复阶段SBR与qCO2存在明显差异,从裸地(Ⅰ)、草本群落(Ⅱ)、灌木群落(Ⅲ)至乔木群落阶段(Ⅳ),SBR显著增强,qCO2显著减小,反映土地质量正在逐渐恢复;(2)不同恢复阶段SBR与qCO2存在垂直变化特征,从0~20cm、20~40cm至40~60cm土层, SBR显著减弱,qCO2显著增加;(3)从Ⅱ→Ⅳ,R与S变化明显,R与S的SBR均显著增强, R/S显著减小,表现出R>S的特点,R与S的qCO2的逐渐减小, R/S逐渐上升,也表现出R>S的特点,因此,创造更好的土壤条件有利于该区域植被恢复。  相似文献   
6.
为了解植被恢复对土壤活性有机碳库的影响,采用空间代替时间序列方法,对衡阳紫色土丘陵坡地植被恢复对土壤活性有机碳含量和分布进行研究。结果表明,土壤有机碳(SOC)、微生物量碳(MBC)、水溶性有机碳(DOC)、轻组有机碳(LFOC)和易氧化碳(ROC)含量均以乔灌阶段最高(P0.05),随土层加深显著减小(P0.05)。随恢复进程,MBC/SOC、DOC/SOC和ROC/SOC显著增加(P0.05);0~20 cm土层,LFOC/SOC随恢复显著增加(P0.05),而20~40 cm土层,LFOC/SOC的差异不明显(P0.05)。随土层加深,LFOC/SOC显著减小(P0.05),DOC/SOC、MBC/SOC和ROC/SOC逐渐增加(P0.05)。SOC、MBC、DOC、LFOC和ROC间存在极显著正相关关系(P0.01)。各类活性有机碳库与土壤含水量(SWC)、全氮(TN)、碱解氮(AN)和速效磷(AP)呈显著或极显著正相关关系(P0.05或P0.01),与土壤容重(BD)呈极显著负相关关系。因此,植被恢复在一定程度上可提高衡阳紫色土丘陵坡地土壤活性有机碳的形成和积累,增加土壤碳储量。  相似文献   
7.
土壤微生物在物质循环过程中具有重要作用且对环境变化敏感,是衡量土壤质量的重要指标.在恢复生态学研究中具有重要意义。为探究不同植被恢复模式对土壤理化性质和细菌群落的影响以及土壤细菌群落差异的原因,本研究以云南省昆阳磷矿为研究对象,运用PCR-DGGE技术和理化指标测定分析了三种植被恢复模式(芒草丛、旱冬瓜藏柏麻栎混交林、藏柏旱冬瓜混交林)下土壤细菌群落多样性、物种组成及土壤理化性质。结果表明:(1)植被恢复有助于改善土壤养分,不同植被恢复模式下土壤理化性质以及细菌群落多样性和物种组成均存在差异。(2)土壤细菌多样性与植被恢复模式之间具有显著相关性,但与土壤理化指标均无显著相关性。(3)土壤细菌群落物种组成与土壤碱解氮含量以及植被恢复模式间具有极显著相关性,与其他土壤理化指标间无显著相关性。本研究表明磷矿区不同植被恢复模式下土壤理化性质和细菌群落均具有差异,土壤细菌群落多样性差异的主要原因为植被恢复模式不同,物种组成差异的主要原因为土壤碱解氮含量不同,其次为植被恢复模式不同。  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号