植被格局的分形模型：植被格局的分形特征

 目前植被格局研究存在一些问题,分形模型是解决这些问题的有力工具。选择从分枝到景观的各个等级层次上若干有代表性的研究实例进行介绍,给出了尺度、自相似性和分形维数在植被格局研究中的应用方法,说明了分形模型描述植被格局的实用性和优越性。在此基础上提出植被格局的分形机制,认为植被格局是具有自组织特征的分形体。最后对植被格局的分形模型进行了评价,提出研究中需要注意的若干问题以及未来的发展方向。     

萨吾尔山地植被概况

在和布克赛尔蒙古自治县农业资源调查与农业区划外业调查中,对全县的植被也做了初步调查,重点调查了山地植被。1980年至1984年区划工作中调查了我县境内的萨吾尔山、哈同(赛米斯台)山、铁布克山的植被。     

西双版纳森林植被研究

西双版纳是世界生物学多样性保护的关键和热点地区,倍受国际学术界的关注。笔者依据30多年来对西双版纳植被的调查,结合植物群落生态学与植物区系地理学研究,并参考世界类似热带植被的研究成果,对西双版纳植被的分类、物种组成、群落生态表现和植物区系特征等作了系统探讨,还进一步分析比较了其与世界类似热带森林植被的关系。结果显示,西双版纳的森林植被共包括32个较为典型的群系,且分属于7个主要的植被型,即热带雨林、热带季节性湿润林、热带季雨林、热带山地(低山)常绿阔叶林、热带棕榈林、暖热性针叶林和竹林。本文对西双版纳植被进行的全面记录和系统归纳,可为科学研究、生物多样性保护和自然保护区的管理提供参考。     

城市植被对空气负离子的影响

通过对厦门城市不同功能区空气负离子浓度的监测,分析空气负离子浓度与植被的关系及其日变化规律与气温和空气相对湿度之间的关系。结果表明:(1)城市功能区空气质量优劣顺序为:植物园、公园> 住宅小区> 商业街区> 海滩码头> 工业区> 广场,空气质量与植被丰富度有较强的正相关;(2)空气负离子浓度在日变化中呈现白天低、夜间高的特点,凌晨最高,中午最低,傍晚出现小波峰;(3)空气负离子浓度随气温的升高而降低,随空气湿度的升高而升高。     

Vegetation of the McDonald Islands, sub-Antarctic

The McDonald Islands (53°03^′S, 72°36^′E) are situated in the southern Indian Ocean, approximately 43 km west of Heard Island. These sub-Antarctic islands comprise McDonald Island itself, measuring ca.1 × 2 km, and two much smaller rocky outcrops, Flat Island and Meyer Rock. Five species of vascular plant occur on the islands. Only four species of moss were found, no hepatics, and eight species of lichen, together with algal and fungal species. Phanerogamic vegetation, comprising grassland and cushion-carpet herbfield, covers about one-third of the main island. Elsewhere, vegetation is absent or restricted to cryptogamic species. The distribution and occurrence of vegetation are strongly influenced by salt deposition, exposure to wind, substrate stability and biotic influences, particularly the very large assemblages of sea birds. The species-depauperate McDonald Islands are unique and have suffered negligible human impact. A management plan has been prepared; its implementation will be assisted by the information in this paper. The islands' protection will be further enhanced by an affirmative final decision on the current proposal for World Heritage Listing of Heard and the McDonald Islands. Received: 15 November 1996 / Accepted: 24 March 1997     

The Vegetation of Karachi

Summary The vegetation of Greater Karachi can be divided into three edaphic types.The coastal vegetation consists of three main associations. In the protected creeks facing the mouth of the rivers in shallow water is found mangrove vegetation consisting of mainly Avicennia alba Blume. In the muddy coastal swamps Arthroenemum indicum Moq is the main species. On the coastal sand dunes the main species consist of Suaeda monoica Forsk, Ipomaea pes-caprae Roth, Aerua pseudo-tomentosa Blatt and Hall, Calotropis procera Br. and Tamarix troupii, Hole.The vegetation of the calcarious rocks consists of mainly Commiphora mukul Engl., Grewia villosa Willd., Grewia tenax (Forsk) Boiss., Euphorbia caudicifolia Haines and Acacia senegal Willd.In the valleys between the hills where alluvium has been deposited over the basic rock by various rivers, the vegetation consists of Capparis decidua (Forsk) Edgew, Prosopis spicigera L. and Salvadora oleoides Dcne.

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Résumé La végétation de la région de Karachi peut être divisée en trois types trés différents au point de vue édaphique.La végétation littorale se compose de trois associations principales. Dans les criques protégées, en face des embouchures des fleuves, la végétation de la mangrove s'avance dans l'eau peu profonde. Elle consiste principalement d'Avicennia alba Blume. Dans les marais tourbeux du littoral, Arthrocnemum indicum Moq. occupe la première place. Sur les dunes littorales, les espèces principales sont Suaeda monoica Forsk, Ipomaea pes-caprae Roth., Aerua pseudo-tomentosa Blatt et Hall, Calotropis procera Br. et Tamarix troupii Hole.La végétation des rochers calcaires se compose principalement de Commiphora mukul Engl., Grewia villosa Willd., Grewia tenax (Forsk) Boiss., Euphorbia caudicifolia Haines et Acacia senegal Willd.Sur les alluvions des fleuves on note une végétation comprenant Capparis decidua (Forsk) Edgew, Prosopis spicigera L. et Salvadora oleoides Dcne.La végétation climax de la région est dominée par Salvadora oleoides Dcne et Prosopis spicigera L.

     

Vegetation und Landschaft

Ohne ZusammenfassungVortrag in der Sendereihe Unsere Erde des Österreichischen Rundfunks am 10-3-1969.