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ons on nearby land. Freshwater habitats also provide homes for large numbers of species. 淡水生態(tài)系統(tǒng)的類型及其分布 淡水群落一般分為流水和靜水兩大群落類型。 組成我國淡水(湖泊、河流)植被的高等植物總數(shù)在 50種以上。 南方和北方有許多種類是共同的,但總的說來,南方的種類較 多,區(qū)系比較豐富。 如: 蓖葉眼子菜、線葉眼子菜、水竹葉、眼子菜、穿葉眼子菜、苦草、細葉水 毛茛、金魚藻、浮萍、紫萍、水蕨、水車前、滿江紅、菱 等等。 Rivers and Streams: FlowingWater Systems ? Many different conditions exist along the length of a river or stream. The nature of a flowingwater ecosystem changes greatly between its source (where it begins) and its mouth (where it empties into another body of water). ? Headwater streams (the small streams that are the sources of a river) are usually shallow, cold, swiftly flowing, and therefore highly oxygenated (溶解氧含量高 ). ? In contrast, rivers downstream from the headwaters are wider and deeper, cloudy (they contain suspended particulates), not as cold, slower flowing, and therefore less oxygenated. ? Along parts of a river or stream, groundwater (地下水 ) wells up through sediments on the bottom。 this local input of water moderates the water temperature so that summer temperatures are cooler and winter temperatures are warmer than in adjacent parts of the flowingwater ecosystem. 湍流 支流 河漫灘 三角洲 鹽沼 Lakes and Ponds 湖泊與池塘 StandingWater Ecosystems 靜水生態(tài)系統(tǒng) ? Standingwater ecosystems are characterized by zonation. A large lake has three zones: the littoral, limic and profundal zones.(濱岸帶、表水層帶和深水層帶 ) ? 濱岸帶、表水層帶和深水層帶 湖泊溫度分布 斜溫層 ? 淡水沼澤 Estuaries 河口 Where Fresh Water and Salt Water Meet 紅樹林:指生長在熱帶、亞熱帶低能海岸潮間帶上部,受周期性潮水浸淹,以紅樹植物為主體的常綠灌木或喬木組成的潮灘濕地木本生物群落。生長于陸地與海洋交界帶的灘涂淺灘,是陸地向海洋過度的特殊生態(tài)系。 Marine Ecosystems 海洋生態(tài)系統(tǒng) ? The Intertidal Zone(潮間帶) : Transition between Land and Ocean. ? The Benthic Environment(深海環(huán)境) : Sea grass Beds, Kelp (海草) Forests, and Coral Reefs ( 珊瑚礁 ) . ? The Neritic Province(淺海帶 ) : Shallow Waters close to Shore. ? The Oceanic Province(大洋帶) : Most of the Ocean ? The Impact of Human Activities 海洋生態(tài)系統(tǒng)的類型及其分布 海洋植物區(qū)系的地理分布也服從地帶性規(guī)律。 海洋生物 群落也像湖泊群落一樣分為若干帶: 1,潮間帶( intertidal)或沿岸帶( littoral zone) 2,淺海帶或亞沿岸帶( neritic 或 sublittoral zone) 3, 淺海帶以下沿大陸坡之上為半深海帶 4, 大洋帶( Pelagic zone) 透光層 遠洋環(huán)境 潮間帶 淺海帶 大洋帶 深海環(huán)境 深海區(qū) 超深海區(qū) 動植物的生物地理學地帶分布 海草 珊瑚礁是石珊瑚目的動物形成的一種結構。 在深海和淺海中均有珊瑚礁存在。它們是成千上萬的由碳酸鈣組成的珊瑚蟲的骨骼在數(shù)百年至數(shù)千年的生長過程中形成的。 珊瑚礁為許多動植物提供了生活環(huán)境,其中包括蠕蟲、軟體動物、海綿、棘皮動物和甲殼動物。此外珊瑚礁還是大洋帶的魚類的幼魚生長地。 珊瑚礁分布 邊礁、岸礁 環(huán)礁 堤礁 , 堡礁