首页
登录
职称英语
During the last decade, Val Beasley of the University of Illinois College ha
During the last decade, Val Beasley of the University of Illinois College ha
游客
2024-10-17
0
管理
问题
During the last decade, Val Beasley of the University of Illinois College has led a team wanting to know why the world’s amphibian(两栖动物) populations have been decreasing or riddled with deformed limbs.
Evidence from his and other teams points to increasing numbers of common parasites as an important cause. However, the problems facing amphibian habitats really pose a distressing example of ecosystems out of balance because of human activity, according to Beasley, a professor of biosciences and executive director of Wildlife and Ecosystem Health. Beasley’s main collaborators, postdoctoral researcher Anna M. Schotthoefer and Rebecca A. Cole, a scientist with the National Wildlife Health Center in Madison, Wis. , say they agree.
A series of their research projects -— two published in 2003 and another that will appear as a book chapter this year — dramatically refine the data on parasitic activity and argue that physically and chemically induced changes of aquatic habitats are taking a toll.
"We have to be asking what human activities are contributing to imbalances in these ecosystems to set the stage for more severe infections, " Beasley said. "It’s becoming a serious question of how we can better manage landscapes, streams, wetlands, ponds and lakes. Frogs are among the first animals that young children see in a healthy wild place, but they are not finding them in the same numbers as in past years. "
Tadpoles (蝌蚪) of many species feed on algae converting the material into the protein, fat and other nutrients that are needed by other creatures higher in the food chain, Beasley said. Amphibians are clearly important players in ecosystem functioning, he added. "The frogs that develop from tadpoles subsequently eat up thousands of insects," he said, "The frogs themselves are also important prey for reptiles, birds and mammals."
In the study funded by Chicago Zoological Society, Beasley’s team noted that Midwest landowners hollow out their ponds so that deep water prevents the establishment of aquatic plants.
Such a practice allows for easier boating, swimming and fishing, but by eliminating aquatic plants, the habitat becomes structurally barren. Herbicide use also aggravates the problem and produces chemical changes. Plant-derived oxygen is reduced, and herbicides also may have direct toxic effects on tadpoles and other animals, Beasley said. The lack of vegetation may expose tadpoles to more parasites coming from the infected snails, because the tadpoles can’t hide or use the vegetation to brush off the parasites, Schotthoefer said.
So while the parasites seem to contribute to declines and deformation in frog populations,the challenge is to find management approaches that put balance back into amphibian ecosystems, Beasley said. [br] Which of the following statements might Rebecca A. Cole agree?
选项
A、Amphibian habitats are under threat of exotic species.
B、Human activities have done harm to amphibian habitats.
C、Parasites have invaded and destroyed amphibian habitats.
D、No one can explain why amphibian habitats have been destroyed.
答案
B
解析
第二段指出比斯利的观点:两栖动物栖息地面临的种种问题是因人类活动而造成生态系统失衡的一个惨痛例证。从这里可以推断出人类活动对两栖动物栖息地造成了破坏。接下来表丽贝卡·A·科尔对这种观点表示认同,可见[B]为答案。这里提到两栖动物栖息地面临的问题是由人类活动所致,并未提到外来物种,排除[A]项。根据第二段的内容可排除[C]和[D]项。
转载请注明原文地址:https://tihaiku.com/zcyy/3805574.html
相关试题推荐
IntheU.S.,collegesareeitherstate-supported,supportedbyreligiousorgan
Duringthelastdecade,ValBeasleyoftheUniversityofIllinoisCollegeha
Duringthelastdecade,ValBeasleyoftheUniversityofIllinoisCollegeha
Duringthelastdecade,ValBeasleyoftheUniversityofIllinoisCollegeha
Suicide,thenumber-twokillerofcollegestudent,claimsthelivesofappro
Suicide,thenumber-twokillerofcollegestudent,claimsthelivesofappro
Suicide,thenumber-twokillerofcollegestudent,claimsthelivesofappro
Nowadays,mostcollegesanduniversitiesencouragestudentsto[br][originalte
Doyouoftentravelonbusinesswithyour______?A、acquaintancesB、collegesC、lea
Thesetwoareasaresimilar______theybothhaveahighrainfallduringthisseas
随机试题
Howtoprotectyourcomputerfrombeingattackedbyavirus:Besureto
______IamIwillbethinkingofyou.A、WhereverB、WhenC、AsD、WhetherA本题考查的是由w
下列具有肝药酶抑制作用的药物中,所诱导的酶系类型最多的是A.胺碘酮 B.环丙沙
赵先生,男,45岁,汉族,某办公室职员,身高175cm,体重98kg,血压145
汉代的匡衡少年时没钱买蜡烛,就凿壁偷光,勤奋苦读。有一户人家有很多书。匡衡在这户
患者女,28岁。白血病化疗后,病情缓解。近日来发热,喉咙疼痛入院。查体:T39
我国《宪法》第13条规定:“公民的合法的私有财产不受侵犯。国家依照法律规定保护公
甲公司是ABC会计师事务所的常年审计客户,A注会计师负责申计甲公司2020年财务
(2020年真题)股票分割和股票股利的相同之处有()。A.不改变公司股票数
男,65岁。上腹痛半年,体重下降10kg,上消化道钡餐检查发现在胃小弯有一1.5
最新回复
(
0
)