盐城滨海湿地植被恢复原则与技术概述

盐城滨海湿地是江苏省重要的滩涂湿地,在珍稀动植物保护中发挥着重要的作用.由于滩涂湿地的过度开发利用,盐城滨海湿地正面临严重的破坏,生态功能逐渐退化.湿地植被恢复是退化湿地生态修复最重要的措施之一.该文基于盐城滨海湿地的退化现状和退化原因,提出了盐城滨海湿地植被恢复需遵循的生态学原则,包括:生态系统完整性、自然演替、优先...     

石臼湖湿地生态系统健康评价

湿地是地球上水陆相互作用形成的独特生态系统,对湿地生态系统健康评价,将为生态系统健康诊断和生态修复提供决策依据。充分考虑石臼湖湿地的实际情况,从湿地生态特征,功能整合性和社会经济环境等三方面共选取24项评价指标,建立评价指标体系;分别对石臼湖湿地的生态特征(湿地土壤、植被、水环境质量、生物多样性等)、生态功能(物质生产与生物多样性维持功能、水调节及水质净化功能等)进行了逐项具体分析与评价;然后运用模糊综合评价法及对数模型分别对石臼湖湿地生态系统健康状况进行了综合分析,并对两种评价方法进行了比较分析。最后,在评价分析的基础上,针对石臼湖湿地生态系统存在的问题提出了湿地恢复的对策及恢复方案。     

毛里湖国家湿地公园植被恢复原则与方式探讨

分析了毛里湖国家湿地公园的植物现状及问题,提出了植被恢复应遵循生态学原则、以自然为主、低碳可持续发展、统筹规划、分布实施、保护优先、科学修复、因地制宜、适地适树等原则,结合水源涵养林工程、退耕还林工程和湿地植被恢复工程,在实践中摸索和探讨植被恢复的方式,总结项目的经验和不足,为湿地公园植被恢复和发展提供借鉴和参考。     

溱湖湿地生态资源保护与开发对策研究

指出了溱湖湿地具有丰富的生态资源,是泰州姜堰重要的宝库,促进了泰州的经济发展。介绍了溱湖湿地的生态资源现状,分析了溱湖湿地发展所面临的危机,提出了溱湖湿地保护与开发的对策,为溱湖湿地可持续发展提供合理的建议。     

江苏省溱河湿地生态保护示范区建设的初步构想

通过对江苏溱河湿地的现状分析，对该地建立湿地保护示范区的指导思想、基本原则、建设目标和总体布局进行了探讨，提出江苏溱河湿地保护示范区应重点加强浅滩湿地生态林带、重点乌类栖息地生态林及鸟类繁育放养中心、糜鹿园及珍稀兽类繁育放养中心的建设，同时加慢环湖大堤及周边干道景观生态林带、出入湖河道两侧水土保持林带、滨湖地带森林公园建设，并要注重水生植被恢复与保护。     

杞麓湖国家湿地公园保护与恢复工程建设研究

为有效保护高原湖泊和湖泊生态系统,维系区域生态安全,保护生物多样性及栖息地,在杞麓湖国家湿地公园实施保护与恢复工程。文中阐述栖息地恢复、植被恢复和生态驳岸修复和水质恢复的工程设计和具体措施,保证湖水与湖滨带水体的连通性,增加水禽和鱼类栖息地类型,增加湿地物种组成和生物多样性,削减污染物入湖量,减少湖泊内源污染,改善湖泊水环境,逐步恢复湖泊生态系统,提升杞麓湖生态服务功能价值。     

论溱湖湿地生态系统的保护和恢复

湿地是人类最重要的环境资本之一,也是自然界富有生物多样性和较高生产力的生态系统。它不但具有丰富的资源,还具有环境调节功能和生态效益。湿地提供水资源、调节气候、涵养水源、均化洪水、降解污染物、维护生物多样性和为人类提供生产、生活资源方面都发挥了重要作用。一、溱湖湿地生态系统的现状。溱湖位于经济水平和文化水平相对发达的里下河地区,该地区地势平坦,水网密布,河湖星罗棋布。溱湖湿地占地面积为43.29km2,其中天然河湖湿地面积为10.68km2,人工湿地面积为32.61km2。溱湖湿地拥有多处滩涂,风光秀美,气候湿润,动植物资源丰富,…     

湿地生态恢复对策研究——以辽宁省朝阳市凉水河湿地生态恢复为例

以辽宁省朝阳市凉水河湿地生态恢复为例,在遵循湿地生态恢复地域性、生态学、最小风险性和最大效益、优先性原则前提下,着重从水体生态恢复、湿地植物生态恢复、生境栖息地生态恢复阐述了自然湿地生态恢复对策;从工艺流程、湿地基质和人工湿地植物选择分析阐述了人工湿地生态恢复对策。     

辽宁凌源青龙河国家湿地公园保护规划

遵循国家湿地公园"保护优先、科学恢复、合理利用、持续发展"的基本原则,以保护湿地资源、弘扬生态文明为目标,全面保护和恢复湿地生态系统、保护野生动植物及其栖息地,分析现状阐明规划目标及措施。     

大凌河不同空间尺度下河流湿地治理模式

本文介绍了大凌河自然概况,并从微观(植物群系-群落-生态系统构建)、中观(湿地公园生境恢复)以及宏观(大凌河流域)三种尺度研究分析湿地退化原因及过程。提出坚持自然恢复与人工修复相结合的方式对功能退化的河流湿地进行修复和综合整治,逐步恢复湿地生境,进而恢复湿地生态功能。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.