Mountains play important ecological roles. They contain the majority for the world's forests, which are habitats for much of the planet's terrestrial biodiversity. They often are habitats for endemic species found nowhere esle on earth. They also serve as sanctuaries for animal species driven from lowland areas.
Mountains also help regulate the earth's climate.Mountaintops covered with ice and snow affect climate by reflecting solar radiation back into space. This helps cool the earth and offset global warming. However, many of the world's mountain glaciers are melting mostly because of global warmming. As the earth gets warmer, mountaintop glaciers and other land-based glaciers could melt and help raise sea levels.
Finally,mountains play a critical role in the hydrologic cycle by serving as major storehouses of water. In the warmer weather of spring and summer, much of their snow and ice melts and is released to streams for use by wildlife and by humans for drinking and irrigating crops. Despite their ecological,economic,and cultueal importance, the fate oh mountain ecosystems has not been a high priority of governments or for many environmental organizations.
山扮演了重要的生態角色，它包含了世界上大多數的森林也提供了地球上陸生生物多樣性的棲息地，山也常被發現地方性的種類，也提供在低窪地區的陸生生物避難所。
山也幫助調節地球氣候，山頂上覆蓋的冰和雪會反射太陽輻射，有幫助冷卻地球的溫室效應，許多的高山冰河融化是因為全球的暖化，而地球的暖化會幫助海平面的上升。
最後，山也扮演水文循環必須的角色是水的重要寶庫，在溫暖的季節像春天和夏天山頂上的冰和雪融化釋放到河裡提供野生生物和人引用及灌溉作物，它對生態、經濟、文化都很重要，所以政府和環境組織應該要優先保護山這個的生態系。
2009年1月9日 星期五
15週 (2) 5-2 p.89
Temperate deciduous forests grow in areas with moderate average temperatures that change significantly with the season. These areas have long, warm summers, clod but not too severe winters, and abundant precipitation, often spread fairly evenly throughout the year.
This biome is dominated by a few species of broadteaf aeciauous trees such as oak, hickory, maple, poplar, and beech. They survive cold winters by dropping their leaves in the fall and becoming dormant through the winter. Each spring they grow new leaves whose colors change in the fall into an array of reds and golds before the leaves drop.
溫和落葉林生長於平均氣溫適中且四季分明的地區，這些地區非常廣、溫暖、和冷，但卻不包含嚴冬和一整年平均分布的豐富降雪。
而這生物社會控制於一些少數特殊的闊葉菸草落葉樹，像橡木、山胡桃木、楓樹、楊木、山毛櫸，他們活下於冬天是靠落下他們的葉子在秋天的時候且休眠渡過冬天，到春天時他們就會長出新的葉子，而這些樹木在秋天時葉子會轉變成深紅色或金色在他們落下葉子以前。
This biome is dominated by a few species of broadteaf aeciauous trees such as oak, hickory, maple, poplar, and beech. They survive cold winters by dropping their leaves in the fall and becoming dormant through the winter. Each spring they grow new leaves whose colors change in the fall into an array of reds and golds before the leaves drop.
溫和落葉林生長於平均氣溫適中且四季分明的地區，這些地區非常廣、溫暖、和冷，但卻不包含嚴冬和一整年平均分布的豐富降雪。
而這生物社會控制於一些少數特殊的闊葉菸草落葉樹，像橡木、山胡桃木、楓樹、楊木、山毛櫸，他們活下於冬天是靠落下他們的葉子在秋天的時候且休眠渡過冬天，到春天時他們就會長出新的葉子，而這些樹木在秋天時葉子會轉變成深紅色或金色在他們落下葉子以前。
14週 (1) 5-2 p.84~p.86
Many of the world's natual temperate grasslands have disappeared because their fertile soils are useful for growing crops and grazing cattle.
Cold grasslands, or arctic tunara, lie south of the arctic polar ice cap.During most of the year, these treeless plains are bitterly cold, swept by frigid winds, and covered with ice and snow.Winters are long and dark, and scant precipitation falls mostly as snow.
Under the snow, this biome is carpeted with a thick, spongy mat of low-growing plants, primarily grasses, mosses, lichens, and dwarf shrubs.Trees or tall plants cannot survive in the cold and windy tundra because they would lose too much of their heat.Most of the annual growth of the tundra's plants occurs during the 5-to 8-week summer, when the sun shines almost around the clock.Figure 3 on p.S50 in Supplement 11 shows some components and food-wed interactions in an arctic tundra ecosystem.
世界上有許多的溫和草原消失掉，因為這些肥沃的土壤常被我們用來種植作物和放養牲口。
冰原、北極寒帶草原和北極南部的冰冠，這些無樹木的草原長年寒冷、吹著強烈冷風和覆蓋著冰雪，冬天時為永夜且缺乏降雨，主要為降雪。
在雪下，這生物群系覆蓋著厚實如海棉狀草蓆的低等植物，主要為草、青苔、地衣和矮小的灌木，像樹和一些高的植物不能存活在這寒冷多風的苔原因為他們會遺失掉他們所需的熱量，許多的一年生苔原植物他們得生長期間發生在5-8星期的夏天，當太陽日以繼夜的照射時。在補充P.S50 中有北極苔原生態系統的組成和食物網的互動。
Cold grasslands, or arctic tunara, lie south of the arctic polar ice cap.During most of the year, these treeless plains are bitterly cold, swept by frigid winds, and covered with ice and snow.Winters are long and dark, and scant precipitation falls mostly as snow.
Under the snow, this biome is carpeted with a thick, spongy mat of low-growing plants, primarily grasses, mosses, lichens, and dwarf shrubs.Trees or tall plants cannot survive in the cold and windy tundra because they would lose too much of their heat.Most of the annual growth of the tundra's plants occurs during the 5-to 8-week summer, when the sun shines almost around the clock.Figure 3 on p.S50 in Supplement 11 shows some components and food-wed interactions in an arctic tundra ecosystem.
世界上有許多的溫和草原消失掉，因為這些肥沃的土壤常被我們用來種植作物和放養牲口。
冰原、北極寒帶草原和北極南部的冰冠，這些無樹木的草原長年寒冷、吹著強烈冷風和覆蓋著冰雪，冬天時為永夜且缺乏降雨，主要為降雪。
在雪下，這生物群系覆蓋著厚實如海棉狀草蓆的低等植物，主要為草、青苔、地衣和矮小的灌木，像樹和一些高的植物不能存活在這寒冷多風的苔原因為他們會遺失掉他們所需的熱量，許多的一年生苔原植物他們得生長期間發生在5-8星期的夏天，當太陽日以繼夜的照射時。在補充P.S50 中有北極苔原生態系統的組成和食物網的互動。
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