首页
登录
职称英语
Plant and Animal Life of the Pacific IslandsP1: The Pacific Islands region cove
Plant and Animal Life of the Pacific IslandsP1: The Pacific Islands region cove
游客
2024-01-03
51
管理
问题
Plant and Animal Life of the Pacific Islands
P1: The Pacific Islands region covers 32 million square kilometers and is one of the richest, most complex terrestrial and marine ecosystems on Earth. Some islands that used to be parts of continents still carry some small plant and animal remnants of their earlier biota, providing clear examples of evolution and interesting patterns of colonization, adaptation, and speciation. Cn the contrary, some other islands arose due to volcanic activity or reef growth, which usually subside over time due to erosion and changing sea levels. When islands emerge, they undergo the process of ecological succession as species colonize the island. Only those species with ways of spreading to these islands were able to undertake the long journeys, and the various factors at play resulted in diverse combinations of new "colonists" on the islands. One estimate is that the distribution of plants was 75 percent due to being transported by birds, 23 percent by floating, and 2 percent by wind.
P2: Four major factors account for the fact that the plants and animals on Oceanic islands largely migrate from west to east. The size and fertility of the territory of certain islands is the first determining factor. That is, the larger the islands are, the wider the range of species they are able to support. Second, the further east the islands are, generally the less the diversity of species found there, largely because the eastern islands tended to be smaller, more scattered, and remote, as evidenced by the easterly decline in species diversity of birds and coral fish. It is estimated that there were over 550 species of birds in New Guinea, 127 in the Solomon Islands, 54 in Fiji, and 17 in the Society Islands. From the west across the Pacific, the Bismarck Archipelago and the Solomon Islands have more than 90 families of shore fish , Fiji has 50 families, and the Society Islands have 30. Third, the latitude of the islands also influenced the biotic mix, as those islands in relatively cooler latitudes, notably New Zealand, were unsuited to supporting some of the tropical plants with which Pacific islands are generally associated.
P3: The fourth factor that has influenced species distribution and the shaping of Pacific ecosystems was wind. There are strong prevailing winds throughout the Pacific Ocean, which has been known for centuries due to scientific development. Those in the northern hemisphere are called "North-easterlies", while their counterparts of the southern hemisphere are known as "south-easterlies." Further south, beginning from approximately thirty degrees south, the winds are mostly from the west. Therefore, on nearly every single island of large scale exists an ecological difference between its windward and leeward sides. Apart from the wind action itself on plants and soils, wind has a major effect on rain distribution. The Big Island of Hawaii offers a prime example; one can leave Kona on the leeward side in brilliant sunshine and drive across to the windward side where the city of Hilo is blanketed in mist and rain.
P4: The long geological isolation of the Pacific islands and their particular climatic conditions have combined to create a unique and spectacular ecosystem. New species cannot immigrate via land, and instead must arrive via air, water, or wind. As a result, organisms with high dispersal capabilities, such as plants and birds, are much more common on islands than are poorly dispersing taxa like mammals. Since immigration of predators and competitors is limited, many species of flightless and ground-nesting birds are able to persist in these new niches. This results in a high occurrence of endemism, where species are unique to a localized area. Besides, endemism is often the result of adaptive radiation, when a single species colonizes an area and rapidly diversifies to fill all of the available niches. These endemic species derived form adaptive radiation are often small in number, unused to serious predation, limited in range, and therefore vulnerable to disruption.
P1: The Pacific Islands region covers 32 million square kilometers and is one of the richest, most complex terrestrial and marine ecosystems on Earth. ■ Some islands that used to be parts of continents still carry some small plant and animal remnants of their earlier biota, providing clear examples of evolution and interesting patterns of colonization, adaptation, and speciation. ■ On the contrary, some other islands arose due to volcanic activity or reef growth, which usually subside over time due to erosion and changing sea levels. ■ When islands emerge, they undergo the process of ecological succession as species colonize the island. ■ Only those species with ways of spreading to these islands were able to undertake the long journeys, and the various factors at play resulted in diverse combinations of new "colonists" on the islands. One estimate is that the distribution of plants was 75 percent due to being transported by birds, 23 percent by floating, and 2 percent by wind. [br] The passage supports which of the following statements about species on volcanic islands?
选项
A、Volcanic island species are unlike the species found in other Pacific Ocean locations.
B、Volcanic islands lack the diversity of species found elsewhere in the Pacific.
C、Volcanic island species are all transplants from distant locations and exist in combinations not found elsewhere.
D、Volcanic island species differ from those on other islands in that animal species show greater diversity than plant species do.
答案
A
解析
【事实信息题】文中提到其他岛屿上仍存有大陆上留下的物种,而火山岛屿上只有远方传播来的物种。
转载请注明原文地址:https://tihaiku.com/zcyy/3328805.html
相关试题推荐
Somesubsistenceactivitiessuchashuntinglargeanimalsornettingfishrequir
______landandmoneyenabledconstructionoftheUnionPacificrailroadtobegi
Mostgeologistsbelieve______fromtheremainsoftinymarineplantsandanimal
TheEdiacarafossilformation,whichcontainstheoldestknownanimalfossil
SpeculationontheoriginofthesePacificislandersbeganassoonasoutsid
ContrarytotheargumentsofsomethatmuchofthePacificwassettledbyPo
SpeculationontheoriginofthesePacificislandersbeganassoonasoutsid
SpeculationontheoriginofthesePacificislandersbeganassoonasoutsid
Thistypeoflearning,however,iscalledconditioning.Theanimalsimplyle
Thesubjectsofthepaintingsaremostlyanimals.Thepaintingsrestonbare
随机试题
《纸盒包装设计》一课,设计合理的教学重点是() A.知识与技能
甲公司相关财务数据列示如下: 甲公司所应选择的财务战略是()。 A.回购
共用题干 ClimateChangePosesMajorRisksf
在基建工程可研初设审查环节,()kV及以下变电站基建工程可研初设审查由地
在青年期,我们通过与同伴的来往,表露各自的喜、怒、哀、乐,促进情感交流,使自己能
治疗久泻久痢之寒热虚实错杂证,宜首选A.芍药汤 B.葛根芩连汤 C.乌梅丸
股票基金的投资风险包括()。A:系统性风险 B:非系统性风险 C:管理运作风
单件小批生产类型企业编制生产作业计划时,宜采用( )。A.在制品定额法 B.
根据《建设工程质量管理条例》,在正常使用条件下,装修工程的最低保修期限为( )。
急性心肌梗死24小时内伴发急性左心功能不全的处理,下列哪项不适宜A.应用吗啡
最新回复
(
0
)