Communities
Key terms
Biomagnification 生物放大 Mutualism 互利共
作用
生
Commensalism 共栖
Niche 生态位
Competition 竞争
Predator 捕食者
Epiphyte 附生
Parasitism 寄生
External parasite 外部寄生 Symbiosis 共生
Chap 15 Community Interactions
Contents
15.1 Community, Habitat, and Niche 15.2 Kinds of Organism Interaction 15.3 The Cycling of Materials in
Ecosystems 15.4 The Impact of Human Actions on
Commensalism (共栖)
One organism benefits, the other is not affected
Epiphytic plants
Mutualism (互利共生)
Two species live in close association with one another, both benefit
Vector (带菌者):organism carrying a disease from one individual to another, bacterium Yersinia pestis 鼠疫杆菌
伯氏疏螺旋菌（Borrelia burgdorferi）
Lyme diseitat (栖息地): the kind of place, or part of an ecosystem, occupied by an organism
Niche (生态位): the specific functional role of an organism某一生物单元在生态系统中 的功能地位
Internal parasite 内部寄生 Habitat 栖息地 Host 宿主 Insecticide 杀虫剂
Transpiration 蒸腾 作用
Vector 带菌者 Pesticide 杀虫剂
15.1 Community, Habitat, and Niche
Two major ways
cheetah
chameleon
Individual that was killed was harmed, but Population benefits: predators help to
maintain feasible population size of prey Species benefits: predators act as selecting
Niche of an earthworm
Opossum with broad niche
Koala with narrow niche
Complete description of niche: Involves detailed inventory of influences, activities, and impacts Involves what the organism does and what is done to the organism
15.2 Kinds of organism interactions
Predation (捕食) Parasitism (寄生) Commensalism (共栖) Mutualism (互利共生) Competition (竞争)
Predation (捕食)
Occurs when one animal captures, kills, and eats another animal
Tapeworm 绦虫
Lamprey 七鳃鳗
Parasitism (寄生)
微甘菊 （Mikania micrantha Kumth）薇甘菊产 于热带美洲，多年生草质滕本植物，现广 泛分布于世界的热带地区，成为一种恶性 杂草。
Parasite
External parasite: live on the outside of their hosts, fleas — rat, dog Internal parasite: live inside the host Tapeworm—host
Prey (被捕食者): organism being killed, harmed Predator (捕食者): organism killing, benefits,
relatively larger than prey, and have specific adaptations in catching prey
parasites and vectors
Other interactions not fit neatly into the categories
Grass predators, or herbivore: cow — grass Some live on the host temporary Nest parasitism: cowbird and cuckoo
agents
Jumping spider
Parasitism (寄生)
One organism living in or on another living organism from which it derives nourishment
Parasite (寄生者) derives the benefit Host (宿主) was harmed
From the broad ecosystem point of view, look at general relationships among communities
Study the ecological relationships of certain species of organisms