or another<br /> Flight p Flight c Flight e Lifestyle , Center osearche Flight t Free a Flight l Flight , Center osearchp Flight t Flight n Lifestyle  searchp Trimmingsexystrippedmomanddaughter csearche Trimmingsexystrippedmomanddaughter  searcha Flight  searcho Center   Lifestyle no Flight nsearche<img src="http://www.extravaganzi.com/wp-content/uploads/2010/08/Bugatti-Veyron-16.4-Super-Sport-23.jpg"/><br />one another because of the stochastic nature of gap<br />colonization,allowing species-rich communities to persist,<br />In a late successional community such as a forest,gaps<br />undergo a mini-succession resulting in a mosaic of patches<br />at different stages of succession.<br />Patch dynamics<br />建设者控制<br />群落<br />在有些群落中，所有的物种似乎都移殖的不错，彼此<br />在竞争上不分优劣。斑块移殖只是个别现象而已。有<br />些珊瑚礁鱼群落就是如此，由于没有哪一个物种比任<br />何其他物种更喜欢移殖，所以多样性高。在英国的<br />Chalk草地群落中就存在着相似的情况。<br />相关主题 演 替（见 R1）<br />In some communities it seems that all species are equally<br />good colonizers and are equally matched competitively,<br />Here patch colonization is a matter of chance alone,This is<br />the situation in some reef fish communities,Diversity is<br />high because on one species is more likely to colonize than<br />any other,A similar situation exists in chalk grassland<br />communities England.<br />Founder-<br />controlled<br />communities<br />Related topics Succession (R1)<br />S1 生态系统格局<br />要 点<br />植被与气候 地球植被被明显地分为许多区域或形式，这些区域或<br />形式在很大程度上反映了气候条件。这种分布是由于<br />植物对温度和水分适应的结果。事实上，第一张气候<br />图和标准的 Koppen气候分类是建立在植被图基础之上<br />的。 Koppen绘制的大的植物分区是我们现在所说的生<br />物群系（ Biome）。生物群系表达的是世界上主要的群<br />落类型的划分。生物群系由动植物种类明显的结合以<br />及具有大致相同生活型（ life form）的植被如杂草或落<br />叶树组成。<br />The vegetation of the earth is divided into distinct blocks or<br />formations which broadly reflect climatic conditions,This<br />pattern arises as a result of the adaptation of plant form to<br />temperature and water availabilty,The first climate map and<br />the standard Koppen classification of climate were,in fact,<br />based on vegetation maps,The great plane formations mapped<br />by Koppen are what we now call biomes,Biomes represent the<br />divisions of the major community types of the world,<br />consisting of distinctive combinations of plant and animal<br />species and characterized by an approximately uniform life<br />form of vegetation,such as grass or deciduous trees.<br />Key Notes<br />Vegetation and<br />climate<br />S1 EOSYSTEM PATTERNS<br />群落交错区 在局域和地区范围内，当物种个体沿着环境梯度变化<br />的时候，群落也发生了变化。物种、群落和生物群系<br />的边界是不明显的和非突然断开的。而是模糊的和逐<br />渐的。沿着生态交错区（ ecotone），生物群系彼此融<br />合。在这个连续体上植被图勾画出的边界指出了一个<br />生物群系大概从哪结束，另一个从哪开始。<br />On the local and regional scale communities vary as the<br />individual species respond to environmental gradients,The<br />boundaries of individual species,communities and biomes<br />are not distinct and abrupt,but blurred and gradual,<br />Superimposes boundaries on this continuum,indicating<br />approximately where coe biome ends and another begins.<br />Ecotones<br />温度和分布 霜冻的危害也许是限制植物分布的最重要的单一因素。<br />在一些情况下，物种分布的限制很可能与阻止物种生<br />存的致死温度相关的。在物种的分布限制与等温线之<br />间找出密切的对应关系是很普通的事情。朗基耶尔<br />（ Raunkiaer）的生活型分类就是建立在植物的分生组<br />织对霜冻适应脆弱性的基础之上的。<br />Damage by frost is probably the single most important<br />factor limiting plant distribution,In some cases it is<br />possible to relate to relate the distributional limits of a<br />species to a lethal temperature which precludes survival,<br />It is common to find a close correspondence between the<br />distributional limits of a species and an isotherm,<br />Raunkiaer‘s classification of life forms is based on the<br />vulnerability of plant meristems to frost.<br />Temperature and<br />distribution<br />相关主题 适应（见 B1） 群落、结构和稳定（见 Q1）<br />应付环境变异（见 B2） 草地（见 S2）<br />太阳辐射与气候（见 C1） 冻原（见 S3）<br />微气候（见 C2） 森林（见 S4）<br />温度与物种分布（见 E3）荒漠、半荒漠和灌丛（见 S5）<br />太阳辐射与植物（见 F1）<br />Related topics Adaptation (B1) community,The structure and stability (Q1)<br />Coping with environmental variation (B2) stability (S2)<br />Solar radiation and climate (C1) Tundra (S3)<br />Microclimate (C2) Forests (S4)<br />Temperature and species Deserts,semi-deserts and<br />distribution (E3) shrubland (S5)<br />Solar radiation and plants (F1)<br />S2 草 地<br />要 点<br />基本区域 草地存在于降雨介于荒漠和森林之间的区域。依据温<br />度的不同，草地有两种主要的类型：热带草地（萨旺<br />纳 Savannah）和温带草地（欧亚草原 Steppe、北美草原<br />Prairie和南美草原 Pampas）。草地在北美洲、北欧和非<br />洲占据着广大的区域，与气候不适合荒漠或森林发育<br />的荒漠或森林混生在一起。<br />Grasslands occur where rainfall is intermediate between that of<br />deserts and forests,There are two major types of grassland<br />depending on the temperature,tropical grassland (savannah),<br />and temperate grassland (steppe,prairie and pampas),<br />Grasslands occupy vast areas in North America,northern<br />Europe and Africa,blending into desert or forest where the<br />climate is unsuitable.<br />Key Notes<br />Primary regions<br />S2 GRASSLANDS<br />气候与土壤 热带草地在湿季可以得到 1200mm（ 60英寸）以上的雨<br />水，但是在持续的旱季却一滴雨都没有。较低的土壤<br />湿度可以阻止营养物循环和减少营养物的获得性。温<br />带草地每年得到的降水在 250和 600mm（ 10~30英寸）<br />之间。气候是大陆性气候，即夏季炎热而冬季寒冷。<br />草地土壤具有大量的有机物质并且是非常肥沃的，它<br />们非常适宜如玉米和小麦等农作物的耕作。<br />Tropical grasslands may receive up to 1200 mm (60<br />inches) of rain in the wet season,but none during the<br />prolonged dry season,Low soil moisture impedes nutrient<br />cycling and reduces nutrient availability,Temperate<br />grasslands have between 250 and 600 mm (10-30 inches)<br />of rainfall per annum,The climate is continental with hot<br />summers and cold winters,Grassland soils receive a large<br />amount of organic matter and are very rich,making them<br />well suited to the growing of arable crops such as corn<br />and wheat.<br />Climate and soils<br />主要植被 草地具有很高的初级生产力和相对低的生物量。管理<br />的草地被用来作为农田和牧场。草地群落是以禾草类<br />为优势，但是常常也包含一些树木，如金合欢树，它<br />是非洲萨旺纳群落的特点。温带草地包括阔叶的多年<br />生植物，这些多年生植物要么在较早的季节开花，要<br />么在禾死亡之后开化。<br />草地动物 非洲萨旺纳草原养活了大量的食草和食叶动物种群。<br />这些食草动物反过来又养活了数目庞大的哺乳类食肉<br />动物。植被结构的单一性、树木的稀少和短的生长季<br />节限制了鸟类和两栖类的多样性。<br />Grasslands have a high primary productivity and<br />relatively low biomass,Managed grasslands are used for<br />crops and for rangeland,Grassland communities are<br />dominated by grass species but frequently include trees,<br />such as the acacia which is characteristic of the African<br />savannah,Temperate grasslands include broad-leaved<br />perennials which either flower early in the season or after<br />grasses have died down.<br />Major vegetation<br />The African savannah supports large populations of<br />grazing and browsing animals,These herbivores in turn<br />support large numbers of mammalian carnivores,The<br />uniformity of the vegetation structure,the absence of<br />trees and the short growing season limit the diversity of<br />birds and amphibians.<br />Grassland<br />animals<br />环境关系 强烈的放牧管理的草地能够导致草地群落的破坏、土<br />壤侵蚀和沙漠化。最初的温带草地动物区系，由于猎<br />杀和草地转变为农耕地及牧场，已经几乎灭绝了。大<br />的食草动物、洞穴动物和捕食者现在在自然状况下要<br />么灭绝了，要么就是十分稀少。为了满足兽群的迁移<br />性行为，热带草地中的国家公园必须很大，或者必须<br />有适合生境的走廊相连接。<br />相关主题 土壤形成特性和分类（见 G3） 生态系统格局（见 S1）<br />保育对策（见 V2） 初级和次级生产力（见 P2）<br />Intensive grazing of managed grasslands can lead to the<br />destruction of grassland communities,soil erosion and<br />desertification,The original temperate grassland fauna has<br />been almost extinguished by hunting and the conversion of<br />grasslands to arable cultivation and rangelands,Large<br />herbivores,burrowing animals and predators are now<br />either extinct in the wild or rare,In order to accommodate<br />the migratory behavior of herds,national parks in tropical<br />grasslands must be very large,or be connected by<br />corridors of suitable habitat.<br />Environmental<br />concerns<br />Related topics Soil formation,properties and Ecosystem patterns (S1)<br />classification (G3) Conservation strategies (V2)<br />Primary and secondary production (P2)<br />S3 冻 原<br />要 点<br />基本区域 北极冻原 （ arctic tundra）在北部的北冰洋和极地冰盖<br />与南部的针叶树森林之间，形成了一个环绕极地的带。<br />但是，较小的，生态学上相似的这种区域在高山的林<br />线以上也有分布，称之为 高山冻原 （ alpine tundra）<br />The arctic tundra forms a circumpolar band between the<br />Arctic Ocean and the polar ice caps to the north and the<br />coniferous forests to the south,Smaller,but ecologically<br />similar regions found above the tree line on high mountains<br />are called alpine tundra.<br />Key Notes<br />Primary regions<br />S3 TUNDRA<br />气候与土壤 在一年的大多数时间里，温度都是在植物生长所需要<br />的温度以下。降水量较低（通常每年少于 250mm）而<br />且主要以降雪的形式出现。在地面以下的一定深度，<br />存在着永远不化的永冻层（ permafrost）。较低的生产<br />力和有限的微生物活动导致了土层很薄。<br />主要植被 冻原具有很低的生产力，但是却具有很高的物种丰富<br />性。植被是由很矮的垫状和形成小丘状的植物组成。<br />夏季日照很长并伴有较高的温度，这样使植物的初级<br />生产力，在一年的这一时期要比冬季高一个数量级。<br />The temperature falls below that required for plant growth<br />of most of the year,Precipitation is low (usually less than<br />250 mm) and occurs mainly as snow,Below a certain depth<br />the ground remains permanently frozen forming permafrost,<br />The low productivity and limited microbial activity result<br />in thin soils.<br />Climate and soils<br />Tundra has a low productivity,but a high species richness,<br />The vegetation consists of low-growing mat-and<br />hummock-forming plants,The long day length during the<br />summer,combined with higher temperatures,allows<br />primary productivity at this time of the year to be an order<br />of magnitude higher than in the winter.<br />Major