荒漠草原生态恢复与重建：人工植被推动下水分介导的系统响应、生态阈值与互馈作用

荒漠草原(生态区)横贯我国西北地区东部,生态地位十分重要。近二十年来,通过封育禁牧、退耕还林(草),植被覆盖显著改善,但是生态系统质量和稳定性依然不高。由于长期将荒漠草原单纯视作草原的一部分,对其生态系统过渡性、脆弱性和复杂性本质特征认识不足,造成了荒漠草原生态学研究与区域生态建设实践之间不同程度的脱节。在分析荒漠草原生态区未来在我国生态安全格局中突出的但是被一定程度上忽视的地位的基础上,进一步归纳了荒漠草原生态系统的一般特征,指出了生态恢复与重建研究中存在的主要问题。进而以人工植被引入荒漠草原生态工程为案例,分析了人工植被驱动荒漠草原生态恢复与重建的过程与机制,归纳了“植被-水文-土壤”互馈作用驱动生态系统层级响应模式,并展望了今后的发展趋势与研究方向。     

南亚热带退化生态系统恢复和重建的生态学理论和应用

退化生态系统的恢复与重建是一项十分复杂的系统工程,其功能和动态过程涉及物质、能量、空间、时间和多样性等基本的生态变量。在南亚热带的气候生态因子中,既有光、温、水充裕的有利一面,也有秋旱、台风和暴雨等不利的因素,但总的来说,影响退化生态系统恢复的主导生态因子是土壤因子,如土壤肥力和土壤水份。极度退化的生态系统的恢复与重建,第一步就是控制水土流失,提高土壤肥力和土壤理化结构,这还需要工程措施和生物措施相结合．退化生态系统的植被的恢复与重建,最有效和最省力的是顺从生态系统的演替发展规律来进行,生态系统演替理论是指导退化生态系统重建的重要的理论基础．退化生态系统恢复与重建的优化结构的构建,依赖于对空间、生物、能量生态学原理的理解。种群密度制约、种群空间分布格局、边缘效应、生态位分化、食物链、生物多样性等原理均对生态系统结构的构建有指导意义．而生态系统的群体发展,则受物质定律的影响．     

三峡库区消涨带植被重建

重建三峡水库消涨带植被对于恢复消涨带功能、维持三峡工程安全和修复长江流域退化生态系统具有十分重要的意义.消涨带可分为自然消涨带和人工消涨带,自然消涨带及其植被是流域生态系统的组成部分,具有重要的生态、社会和经济价值.人为控制水位涨落而形成的人工消涨带很少有植被覆盖,属于退化的生态系统.三峡消涨带包括三峡自然消涨带和三峡水库消涨带,三峡工程的建设将淹没三峡自然消涨带及其植被并产生没有植被覆盖的三峡水库消涨带.作者认为开发利用三峡水库消涨带土地资源,发展库区经济将导致库区生态环境恶化、危及三峡工程安全且不利于长江流域生态系统的健康.解决三峡水库消涨带问题的关键是重建消涨带植被,并恢复其功能.该文从水利建设与环境保护的关系、三峡水库管理与库区景观建设的需要、消涨带功能恢复与流域生态系统康复和促进水库消涨带研究的深入阐述了开展三峡水库消涨带植被重建的必要性.     

消涨带及三峡水库消涨带植被重建

重建三峡水库消涨带植被对于恢复消涨带功能、维持三峡工程安全和修复长江流域退化生态系统具有十分重要的意义。消涨带可分为自然消涨带和人工消涨带,自然消涨带及其植被是流域生态系统的组成部分,具有重要的生态、社会和经济价值。人为控制水位涨落而形成的人工消涨带很少有植被覆盖,属于退化的生态系统。三峡消涨带包括三峡自然消涨带和三峡水库消涨带,三峡工程的建设将淹没三峡自然消涨带及其植被并产生没有植被覆盖的三峡水库消涨带。作者认为开发利用三峡水库消涨带土地资源,发展库区经济将导致库区生态环境恶化、危及三峡工程安全且不利于长江流域生态系统的健康。解决三峡水库消涨带问题的关键是重建消涨带植被,并恢复其功能。该文从水利建设与环境保护的关系、三峡水库管理与库区景观建设的需要、消涨带功能恢复与流域生态系统康复和促进水库消涨带研究的深入阐述了开展三峡水库消涨带植被重建的必要性。     

长江上游退化森林生态系统恢复与重建刍议

通过对国内外生态系统恢复与重建研究进展的综述,论述了我国长江上游森林生态系统退化的主要特征和森林生态系统退化的现状,分析了长江上游生态环境建设存在的主要问题,并提出相应对策。在此基础上,针对退化森林生态系统提出恢复和重建的基本思路和建议。     

利用人工围隔研究沉水植被恢复的生态效应

近几十年来,随着水体富营养化加剧和其它人类活动影响,一些湖泊,尤其是我国长江中下游地区浅水湖泊中,沉水植被锐减甚至消失。如武汉东湖,６０年代十分繁茂的沉水植被现已濒临灭绝。沉水植被作为主要初级生产者,在水生态系统中起着一定的作用。在退化湖泊生态系统重建与恢复中,重建沉水植被是关键性的步骤。本研究利用人工围隔,在富营养化水体中重建沉水植被,通过与近旁无沉水植被的湖区对照,从水体理化性质、浮游植物叶绿素ａ含量以及原生动物群落结构与多样性几个方面,研究沉水植被恢复的生态效应,以期为退化湖泊生态系统的重…     

半干旱黄土小流域不同恢复方式对生态系统多功能性的影响

在黄土高原大规模退耕还林（草）背景下,植被恢复对生态系统功能会产生极大影响。以往研究多为比较不同恢复方式或植被类型的单一生态系统功能,对生态系统多功能性的研究亟待加强。因此,基于甘肃定西龙滩流域3种恢复方式（天然荒草、自然恢复、人工恢复）6种植被类型（长芒草草地、赖草草地、苜蓿草地、柠条灌丛、油松林、山杏林）38个样地调查数据,选取与土壤养分储存与循环、水源涵养、初级生产力、多样性维持等相关的23个功能指标利用平均值法量化生态系统多功能性。研究结果显示,（1）除营养物转化与循环功能外,其余土壤相关的生态系统功能在不同恢复方式与植被类型间均具有显著性差异（P<0.05）。人工恢复植被的土壤肥力显著高于自然恢复植被;人工恢复植被中土壤肥力从高到低依次为柠条灌丛、苜蓿草地、山杏林、油松林。自然恢复植被的水源涵养功能显著高于人工恢复植被。（2）除植物生长策略外,其余植物相关的生态系统功能在不同恢复方式与植被类型间均具有显著性差异（P<0.05）。人工恢复植被中地上初级生产力从高到低依次为山杏林、油松林、柠条灌丛、苜蓿草地,并显著高于自然恢复植被。人工恢复植被中植物养分吸收能力从高到低依次为苜蓿草地、柠条灌丛、油松林、山杏林,并显著高于自然恢复植被。自然恢复植被的物种多样性显著高于人工恢复植被。（3）生态系统多功能性在不同恢复方式与植被类型间均具有显著性差异（P<0.05）。生态系统多功能性表现为人工恢复植被高于自然恢复植被,但人工恢复植被的水源涵养功能与物种多样性均低于自然恢复植被,不利于生态系统的可持续发展。研究认为,在植被恢复具体实践中,应针对不同的恢复目标,根据各植被类型的功能特征,制定因地制宜的植被恢复战略。     

岷江干旱河谷-山地森林交错带震后生态恢复的关键科学技术问题

作为典型的生态过渡区,岷江干旱河谷-山地森林交错带不仅是藏羌居民生活的重要区域,而且在抑制干旱河谷上延和延伸亚高山森林生态系统的功能等方面具有十分重要的作用。但这种脆弱生态系统极易受到人类活动干扰和自然灾害的损害,使其成为“5．12”汶川大地震中受损程度较高、灾后生态恢复与重建的重点区域之一。基于岷江干旱河谷-山地森林交错带受汶川大地震破坏的特点以及该区的生态重要性和本身的脆弱性,损毁生态系统的快速评估与生态重建规划、生产与生态双赢共建关键技术、震后残存植被保育、水源涵养地植被保护与恢复、震毁植被恢复与重建、耕地生产恢复与重建、边坡综合治理、低效薪炭林改良以及居民聚居点风景林营造等被认为是震后生态恢复的关键科学技术问题。震毁生态系统的生态恢复过程监测与评估、干旱河谷-山地森林交错带生态系统的脆弱性机制及生态学过程、震后生态系统对变化环境的响应与适应机制等可能是未来的重点研究领域。     

湖滨带退化生态系统的恢复与重建

湖滨带是水陆生态交错带的一种类型,在湖泊流域生态系统中发挥着重要作用,具有较高的生态、社会和经济价值.湖滨带的功能包括:缓冲带功能、保持生物多样性及生境保护功能、护岸功能和经济美学价值.湖滨带退化的原因主要是人为因素引起的生物群落结构的逆向演替及生态功能下降,退化湖滨带生态恢复与重建的理论基础是恢复生态学,其生态恢复技术可划分为三大类:湖滨带生境恢复与重建技术、湖滨带生物恢复与重建技术、湖滨带生态系统结构与功能恢复技术.云南洱海湖滨带近3年的生态恢复与重建试验的生态调查结果表明,试验区水生植被得到恢复,水质净化作用明显,藻类得到抑制,浮游动物的构成和数量发生变化,湖滨带湿地生态系统的生物多样性和稳定性增加.     

湿地生态单元定义及其在湿地恢复中的应用

生态单元的概念在生态系统的环境保护和生物保护中被广泛应用。通过阐述湿地生态单元的定义、内涵和外延,分析了湿地生态单元的特征,介绍了湿地生态系统的内部生态单元、湿地"外援"生态单元和人工重建湿地生态单元等在湿地恢复中的应用案例,并对湿地生态单元未来需要关注的研究方向进行了总结,以期为湿地保护与精细化管理提供理论基础和科学依据。     

Plant evolution can mediate negative effects from honey bees on wild pollinators

1. Pollinators are introduced to agroecosystems to provide pollination services. Introductions of managed pollinators often promote ecosystem services, but it remains largely unknown whether they also affect evolutionary mutualisms between wild pollinators and plants.
2. Here, we developed a model to assess effects of managed honey bees on mutualisms between plants and wild pollinators. Our model tracked how interactions among wild pollinators and honey bees affected pollinator and plant populations.
3. We show that when managed honey bees have a competitive advantage over wild pollinators, or a greater carrying capacity, the honey bees displace the wild pollinator. This leads to reduced plant density because plants benefit less by visits from honey bees than wild pollinators that coevolved with the plants.
4. As wild pollinators are displaced, plants evolve by increasing investment in traits that are attractive for honey bees but not wild pollinators. This evolutionary switch promotes wild pollinator displacement. However, higher mutualism investment costs by the plant to the honey bee can promote pollinator coexistence.
5. Our results show plant evolution can promote displacement of wild pollinators by managed honey bees, while limited plant evolution may lead to pollinator coexistence. More broadly, effects of honey bees on wild pollinators in agroecosystems, and effects on ecosystem services, may depend on the capacity of plant populations to evolve.

     

深圳的外来植物

通过对深圳外来植物调查 ,报道了深圳 1 0 2种外来植物 ,约占深圳植物种类总数的 1 0 % ;并对深圳 1 0种危害较大的外来入侵植物进行了简要介绍。通过对深圳外来植物区系的种类组成、原产地、生长型、生境和危害程度的分析 ,结果表明 :(1 )外来植物的入侵对深圳的自然生态系统的影响较小 ,对人工林或人为干扰严重的生态系统的影响较大 ;(2 )来自新大陆热带地区的外来植物对深圳容易入侵并造成较大危害 ;(3 )草本和藤本植物具有较强的入侵能力 ,高大乔木的入侵能力小 ,造成的危害程度也较小。     

中国天山野果林种子植物组成及资源状况分析

中国天山野果林种子植物共计60科237属435种,种类组成趋向于集中在少数科内,区系优势现象相当明显,反映出野果林自然环境的特殊性与区系的过渡性。在这些植物种类中有国家重点保护植物9种、中国珍稀濒危保护植物3种、自治区重点保护植物9种;林区野生植物资源非常丰富,统计结果表明：野生果树40种、食用植物30种、饲用植物以种、蜜源植物111种、观赏植物132种、香料植物如种、药用植物131种。文中对各类资源植物的特征进行了分析和讨论,并就野果林的保护及可持续利用提出建议。     

Native Mediterranean plants as potential food sources for natural enemies of insect pests in olive groves

The diversity of native non-crop (weed) vegetation in agricultural landscapes can provide arthropod natural enemies with food sources and shelter, thus improving natural pest control and reducing dependence on chemical pesticides. Moreover, native plants to a region are uniquely positioned to provide cultural ecosystem services such as wild food and wild medicinal plants, as well as aesthetics values. The Mediterranean Basin is one of the world’s richest places in terms of plant diversity. Olive cultivation is the basic tree cultivation in the Mediterranean and dominates its rural landscape. The olive grove ecosystem, whose flora presents a notable resemblance to the flora of Mediterranean type ecosystems, is home to a myriad of species of insects, spiders and other arthropods. This includes over one hundred phytophagous species, plus an uncounted number of entomophagous that help to reduce phytophagous populations. Here we present data on flowering plant species from the ground cover of olive groves, store information on characteristics of plant species namely physiognomic type and flowering period, geographic information and some statistical values on olive groves study area and records in the flora of visitor arthropods and cultural ecosystem services. The data include information on 36 olive groves, 100 flora species (taxa), of which 86 native in Portugal, 5 endemic to Iberian Peninsula and 4 endemic to Portugal Continental, and present also a summary of the records of visitor arthropods in these flora (i.e. 2 classes, 6 orders and 12 families).     

Plant management among the Nahua and the Mixtec in the Balsas River Basin,Mexico: An ethnobotanical approach to the study of plant domestication

Different forms of management of wild, weedy, and domesticated plants carried out by the Nahua and the Mixtec in the Balsas River Basin, Mexico, are described. Along with cultivation of domesticated plants, these forms of plant management include gathering from wild populations; in situtolerance of plant individuals during clearings of natural vegetation; in situenhancement and protection of particular plants among populations of some species; as well as sowing or planting of propagules and transplantation of complete individuals of weedy and wild plants in controlled ex situenvironments. Processes of artificial selection and possible routes of domestication occurring in these forms of plant management are discussed.     

Traditional agricultural gardens conserve wild plants and functional richness in arid South Sinai

Maintaining agricultural diversity is important for the conservation of rare species and for preserving underlying ecosystem processes on which smallholder farmers rely. The positive effects of crop diversity are well documented in tropical systems, but the conservation potential of arid agricultural systems is less clear. This study assesses the impact of three arid agroforestry systems on plant diversity and functional richness in South Sinai, Egypt: (1) mountain orchard gardens, (2) modern town gardens and (3) low desert date-palm gardens. We surveyed plants (cultivated and wild) within gardens and control plots of natural habitat and allocated each plant eight biological traits that are recognised as being linked with major ecosystem processes. Species diversity was quantified using three measures (Hill's numbers) and total species diversity was significantly higher within gardens than in the surrounding habitat at all three levels of diversity and across the three agroforestry systems. Species similarity was high between gardens and the surrounding habitat, and there was a strong overlap in the functional traits of wild plants and cultivated non-tree species. Despite the clear presence of trees within the gardens, the community weighted trait means (CWMs) showed that chamaephyte perennials were the dominant life-forms in both the gardens and the natural habitat. Functional richness differed between the three agroforestry systems, but was significantly higher within the gardens. Functional richness has been linked to increased productivity and CWMs showed that plants within the gardens were considerably taller than outside, suggesting higher biomass accumulation. These findings suggest that Bedouin agricultural practices are not having a negative effect on the flora of the region and that the continuation of these indigenous farming practices can actively benefit rare wild plants in the region. On a wider scale, this study supports the view that smallholder farms and homegardens can be valuable tools in conservation, preserving local species and maintaining ecosystem functioning.     

Pollinator sharing between mass-flowering oilseed rape and co-flowering wild plants: implications for wild plant pollination

Pollinating insects are not only important in wild plant pollination, but also in the production of a large number of crops. Oilseed rape production is increasing globally due to demands for biofuels which may have impacts on pollinating insects which visit the crop and on the pollination services delivered to co-flowering wild plants. In this study, we tested (1) the degree of pollinator sharing between oilseed rape and native wild plants in field margins and hedgerows and (2) the effects of oilseed rape on the quality of pollination service delivered to these wild plants. We found large overlap between flower visitors of wild plants and oilseed rape, but the composition of species overlap differed with respect to each wild plant species. Nearly all individual visitors caught on both the crop and foraging on wild species carried crop pollen, but more than half the insects also carried pollen from wild plants. However, very little oilseed rape pollen was deposited on wild plant stigmas. This shows that (1) oilseed rape overlaps in pollinator niche with most co-flowering wild plants, and (2) crop pollen deposition on wild plant stigmas is low which may indicate that it is unlikely to cause reductions in seed set of wild plants, although this was not measured here. Furthermore, wild plants in field margins and hedgerows are important sources of alternative forage for pollinating insects even when a crop is mass flowering, and we suggest maintenance and augmentation of field margins and hedgerows to provide alternative forage for pollinator conservation to continue provision of pollination services to both crops and wild plants.     

合肥市野生地被植物种类构成研究

在野外调查和统计分析的基础上,运用五点随机取样法对合肥市的野生地被资源进行了系统的调查,并根据调查结果,选取发生频率大于30%的野生地被植物作为统计分析的对象。运用Spss10.0软件,对综合值采用组间连接法进行聚类分析,找出合肥市不同类型的野生地被植物的常见种类,并分析其发生特点。结果表明:合肥市野生地被植物种类有119种,涉及43科,105属,其中菊科16种,禾本科10种,蓼科9种,十字花科8种。不同类型的野生地被植物种类构成主要有16种:冬春型野生地被植物4种,夏秋型野生地被植物5种,全光照型野生地被植物4种,蜀山森林生态系统型野生地被植物3种。     

Theoretical basis of the plant domestication

Summary Plant domestication is stimulated by economic demands. Crop plant formation is controlled primarily by natural selection in cultivation; artificial selection is only a useful addition. The ecotypical nature of the initial material has great bearing on the success of domestication. The weeds of a convergent group were well adapted to being cultivated; weeds of a divergent group can be domesticated only with difficulty. Wild plants in nature are extremely varied ecotypically: some can be domesticated easily, others with difficulty. Some wild plants and weeds can be cultivated without genetic change (naturalization), while a genetic transmutation is necessary for the domestication of others (acclimatization). New domesticated ecotypes can be produced: 1. as a result of reconstruction of the initial populations and new ecotype synthesis on the basis of individual genotypes; 2. by means of hybridization of wild or weed initial genotypes with cultivated ones; 3. by use of new mutations in cultivation and further plant breeding.     

Pollination by nocturnal Lepidoptera,and the effects of light pollution: a review

1. Moths (Lepidoptera) are the major nocturnal pollinators of flowers. However, their importance and contribution to the provision of pollination ecosystem services may have been under‐appreciated. Evidence was identified that moths are important pollinators of a diverse range of plant species in diverse ecosystems across the world. 2. Moth populations are known to be undergoing significant declines in several European countries. Among the potential drivers of this decline is increasing light pollution. The known and possible effects of artificial night lighting upon moths were reviewed, and suggest how artificial night lighting might in turn affect the provision of pollination by moths. The need for studies of the effects of artificial night lighting upon whole communities of moths was highlighted. 3. An ecological network approach is one valuable method to consider the effects of artificial night lighting upon the provision of pollination by moths, as it provides useful insights into ecosystem functioning and stability, and may help elucidate the indirect effects of artificial light upon communities of moths and the plants they pollinate. 4. It was concluded that nocturnal pollination is an ecosystem process that may potentially be disrupted by increasing light pollution, although the nature of this disruption remains to be tested.