森林破坏,植被减少为什么会导致沙漠气候

1

首先土壤表面的植被 有助于截留雨水是雨水渗透到地下 另外植被固定土壤表皮防止被雨水冲走
森林破坏以后固定土壤表皮的植被没有的,雨水得不到固定 大部分雨水形成地表径流 地表径流过大容易产生洪涝 ,地表径流过大也不利于雨水下渗补充地下水
反正森林破坏就必定导致一系列的生态灾难

B 

小题1:C
小题2:A


小题1:漫画反映的主题是植被破坏导致区域涵养水源的能力下降，气候变干，土地沙化更加严重。
小题2:图中反映了植被破坏会引起降水减少，土地沙化，环境恶化等问题，体现了区域的整体性特点，即“牵一发而动全身”。

通过改变地面状况，影响局部地区气候．如人工造林、修建水库和灌溉工程，可以使当地气温的变化趋于缓和．如果任意砍伐森林，则可能使当地气候恶化．近50年来，人类在生产、生活过程中排放的二氧化碳等温室气体急剧增加，使全球气温升高，旱涝等灾害频繁．排放出的氯氟化合物破坏高空的臭氧层，导致地面太阳紫外线辐射增强，进而危及人类的健康．在人口密度大、工业集中的城市，往往中心城区的气温比郊区高，风速比郊区小，上升气流显著，雾和低云增多．
故选：D．

答案A
森林的光合作用能够吸收二氧化碳.

植被破环——>水土流失——>泥沙囤积——>导致黄河、长江下游泥沙剧增——最后,易发洪水

The World Wildlife Fund (WWF) defines biodiversity as "the wealth of life on Earth, the millions of plants, animals, and micro-organisms, the gens they contain and the intricate ecosystems they build into the living enviroment." Rainforest are one of the most biologically diverse regions of the world. Over a millions species of plants and animals are known to live in the forests and millions more are not classified. The unique enviroment of the rainforest allows for such biodiversity to exist.
The process of deforestation in various geographical regions is destroying this unique enviroment. Consequently, many animals and plants that live in the rainforests face the specter of extinction. The extinction of the plants and animals leads to diminished gene pool. The lack of biodiversity and a reduced planetary gene pool could have many unforeseen ramifications, some of which could be fatal to the future of humanity. In addition, there are ethical, aesthetic and philosophical question regarding mankind's responsibility for other life. This issue concerns more industrialized countries in the North more than it concerns lesser developed countries in the South. This is especially true in developing countries such as Brazil. I will elaborate on that later.
Another isssue that probably concerns the North more that the South is the advancement of humanity. As the planetary gene pool continues to diminish, there are less oppertunities for advancements in many fields. In particular, medicine may benefit from the cultivation of certain plants that grow only in rainforests. The medicines that come from them could cure cancer, AIDS, or other terminal deseases. Of course, that claim can easily be dismissed as speculative, given that there is little or no evidence to support it. However, it is too early to dismiss the possibility. Furthermore, if the rainforests are completely destroyed, the oppertunity to explore that possibility would be lost forever. The effect that would have on future generations is incalculable. Preserving the rainforest would leave many oppertunities in medicine and many other fields open for future generations to explore and further advance humanity.
There is at least on issue that would concern both North and South equally. That is preservation and is compatibility with forest use and management. Different people have different uses of rainforests. Indigenous people who live in the forests, as well as the non-indigenous people who live in the forests, the forest is their home, source of food, shelter, nourishment, recreation, culture, and livelihood. The forest provides the materials for thier homes, wood for their fires, the fish, the edible plants, and many more neccessities as well as amenities. Some of the non-indigenous people sell some of the forest resources for money. They do not exploit the forest because they sell commodities in limited numbers to preserve the forest resources for the future. This ensures that they can continue to make thier livelihoods by selling products from the forest.