首页
登录
职称英语
Eight thousand years ago, forests covered more than 23 million square miles,
Eight thousand years ago, forests covered more than 23 million square miles,
游客
2025-01-15
16
管理
问题
Eight thousand years ago, forests covered more than 23 million square miles, or about 40 percent of Earth’s land surface. Today, almost half of those forests have fallen to the ax, the chain saw, the matchstick, or the bulldozer.
A map unveiled in March by the Washington-based World Resources Institute not only shows the locations of former forests, but also assesses the condition of today’s forests worldwide. Institute researchers developed the map with the help of the World Conservation Monitoring Center, the World Wildlife Fund, and 90 forest experts from a variety of universities, government organizations, and environmental groups.
Only one-fifth of the remaining forests are still "frontier forests", defined as a relatively undisturbed natural forests large enough to support all of their native species. Frontier forests offer a number of benefits: They generate and maintain biodiversity, protect watersheds, prevent flooding and soil erosion, and stabilize climate.
Many large areas that have traditionally been classified as forest land don’t qualify as "frontier" because of human influences such as fire suppression and a patchwork of logging. "There’s surprisingly little intact forest left," says research associate Dirk Bryant, the principal author of the report that accompanies the new map.
In the report, Bryant, Daniel Nielsen, and Laura Tangley divide the world into four groups: 76 countries that have lost all of their frontier forest; 11 nations that are "on the edge"; 28 countries with "not much time"; and only eight—including Canada, Russia, and Brazil—that still have a "great opportunity" to keep most of their original forest. The United States is among the nations said to be mining out of time: In the lower 48 states, says Bryant, "only 1 percent of the forest that was once there as frontier forest qualifies today."
Logging poses the biggest single threat to remaining frontier forests. "Our results suggest that 70 percent of frontier forests under threat are threatened by logging," says Bryant. The practice of cutting timber also creates roads that cause erosion and open the forest to hunting, mining, firewood gathering, and land clearing for farms.
What can protect frontier forests? The researchers recommend combining preservation with sustainable land use practices such as tourism and selective timber extraction. It’s possible to restore frontiers," says Bryant, "but the cost and time required to do so would suggest that the smart approach is to husband the remaining frontier forest before it’s gone. [br] What is the main idea of the passage?
选项
A、The present situation of frontier forest on Earth.
B、The history of ecology.
C、The forest map in the past.
D、Beautiful forests in different parts of the world.
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3913589.html
相关试题推荐
WelearnedthatColumbushasdiscoveredAmericain1492.A、haddiscoveredB、disco
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
OfalltheemployedworkersintheUnitedStates,12.5millionarepartofa
随机试题
Readthememoandnotebelow.Completetheclaimform.Writewordorphrase(in
[originaltext]W:OK,John,youweresayingthatyoutaughtwritinginAmerica,
Chinesegovernmentencouragepeopletodrinkmilkandhopethat______.[br]The
下表为a、b两组不同土的颗粒组成成分及击实试验结果,请回答下列问题:(3)土的击
关于牙冠形态的生理意义,说法错误的是A.牙冠邻面突度可分散咬合压力 B.牙冠外
上市公司的下列事项,必须经股东大会特别决议通过的有( )。 Ⅰ.发行公司债券
按执行价格和标的资产市场价格关系分类,期权可分为()。A.看涨期权和看跌期权
下列选项中不属于患者道德义务的是()A.保持和恢复健康 B.接受医学生的
茵陈保肝作用的有效成分是A.茵陈烯酮B.β-蒎烯C.6,7-二甲氧基香豆素D.茵
根据《医疗废物管理条例》,医疗废物集中贮存、处置设施选址应当远离( )。A.交
最新回复
(
0
)