首页
登录
职称英语
The forest from which Man takes his timber is the tallest and most impressiv
The forest from which Man takes his timber is the tallest and most impressiv
游客
2024-06-11
23
管理
问题
The forest from which Man takes his timber is the tallest and most impressive plant community on Earth. In terms of Man’s brief life it appears permanent and unchanging, save for the seasonal growth and fall of the leaves, but to forester it represents the climax of a long succession of events.
No wooded landscape we see today has been forest for all time. Plants have minimum requirements of temperature and moisture and, in ages past, virtually every part of Earth’s surface has at some time been either too dry or too cold for plants to survive. However, as soon as climatic conditions change in favour of plant life, a fascinating sequence of changes occurs, called a primary succession.
First to colonize the barren land are the lowly lichens, surviving on bare rock. Slowly, the acids preduced by these organisms crack the rock surface, plant debris accumulates, and mosses establish a shallow root-hold. Ferns may follow and, with short grasses and shrubs, gradually form a covering of plant life. Roots probe even deeper into the developing soil and eventually large shrubs give way to the first trees. These grow rapidly, cutting off sunlight from the smaller plants, and soon establish complete domination-closing their ranks and forming a climax community which may endure for thousands of years.
Yet even this community is not everlasting. Fire may destroy it outright and settlers may cut it down to gain land for pasture or cultivation. If the land is then abandoned, a secondary succession will take over, developing nmch faster on the more hospitable soil. Shrubs and trees are among the early invaders, their seeds carried by the wind, by birds and lodged in the coats of mammals.
For as long as it stands and thrives, the forest is a vast machine, storing energy and many elements essential for life. [br] Why is a "secondary succession" quicker?
选项
A、The ground is more suitable.
B、There is more space for new plants.
C、Birds and animals bring new seeds.
D、It is supported by the forest.
答案
A
解析
从第四段的中间,我们可以看出,根本的原因乃是土壤较为适宜。
转载请注明原文地址:https://tihaiku.com/zcyy/3629553.html
相关试题推荐
TheforestfromwhichMantakeshistimberisthetallestandmostimpressiv
TheforestfromwhichMantakeshistimberisthetallestandmostimpressiv
[originaltext]W:Haveyouevervisitedaredwoodforest?Irecentlyhadachanc
[originaltext]W:Haveyouevervisitedaredwoodforest?Irecentlyhadachanc
[originaltext]W:Haveyouevervisitedaredwoodforest?Irecentlyhadachanc
RainforestsTropicalrainforestsare
RainforestsTropicalrainforestsare
RainforestsTropicalrainforestsare
RainforestsTropicalrainforestsare
PassageOneAmazonrainforest,normallyoneoftheworld’swettestregi
随机试题
[originaltext]TheU.S.SpaceAgencyNASAsaysRussia’sorbitingMirspacest
Weallknowwhatanadvertisementis;it’s【B1】______messagethatannounce
股指期货近期与远期交割月份合约间的理论价差与()等有关。A、近月和远月合约之间的时间长短B、市场利率C、现货指数价格D、现货红利率A,B,C设
Walkingalongtheriver,heheardsomeone________forhelp.A、shoutingB、shoutC、s
建设项目管理的控制目标是指()。A:质量目标 B:收益目标 C:进度目标
下面关于人格权正确的是()A.人格权包括具体人格权和抽象人格权 B.抽象
2×19年1月1日,甲公司取得A公司25%的股权,实际支付款项6
某污水处理厂的设备安装工程由A安装公司承包施工,其土建工程由B建筑公司承包施工,
挖孔施工时相邻两桩孔不得同时开挖,宜()A.修改设计 B.避开雨季开挖
最新回复
(
0
)