你只把这一句话放这如何理解,这都是有上下文的,我给你找出来,就明白了。意思是:一块土地的外来干涉(disturbance)是如何影响着它被植物种类的拓殖(colonization)的。这外来干涉是指火烧,或者木头被伐掉等之类的外力干涉,使其它外来种子容易生存定居下来。答案是A:A.Disturbancereducesoreliminatescompetitionbyotherspecies.通过火灾和砍伐的外来干涉要么消除竞争对手要么降低其它物种竞争的强度,这样一个外来的种子就容易在这块区域殖民下来,并生存繁衍(colonization)。===PlantColonizationParagraph1Colonizationisonewayinwhichplantscanchangetheecologyofasite.Colonizationisaprocesswithtwocomponents:invasionandsurvival.Therateatwhichasiteiscolonizedbyplantsdependsonboththerateatwhichindividualorganisms(seeds,spores,immatureormatureindividuals)arriveatthesiteandtheirsuccessatbecomingestablishedandsurviving.Successincolonizationdependstoagreatextentontherebeingasiteavailableforcolonization-asafesitewheredisturbancebyfireorbycuttingdownoftreeshaseitherremovedcompetingspeciesorreducedlevelsofcompetitionandothernegativeinteractionstoalevelatwhichtheinvadingspeciescanbecomeestablished.Foragivenrateofinvasion,colonizationofamoist,fertilesiteislikelytobemuchmorerapidthanthatofadry,infertilesitebecauseofpoorsurvivalonthelatter.Afertile,plowedfieldisrapidlyinvadedbyalargevarietyofweeds,whereasaneighboringconstructionsitefromwhichthesoilhasbeencompactedorremovedtoexposeacoarse,infertileparentmaterialmayremainvirtuallyfreeofvegetationformanymonthsorevenyearsdespitereceivingthesameinputofseedsastheplowedfield.1.Accordingtoparagraph1,howdoesdisturbanceofasiteinfluenceitscolonizationbyaplantspecies?A.Disturbancereducesoreliminatescompetitionbyotherspecies.B.Disturbanceincreasesnegativeinteractionswithotherorganismsonthesite.C.Disturbancepreventsaplantspeciesfromcolonizinganewsite.D.Disturbancereducesthefertilityofasite.