6.2 what roles do species play in a community?

Niches can be occupied by native and nonnative species
different ecological roles or niches that native, nonnative, indicator, keystone, and foundation species.
most introduced species of crops and animals are beneficial to us.
1957 wild African bees(killer bees)

villain壞人,惡棍
allergic過敏的
flee逃,逃走

Indicator species are biological smoke alarms
provide early warnings of harmful environmental change
trout species in water
birds
butterflies
amphibians

trout鱒魚
fragmentation分裂;破碎
introduction引進,傳入
vulnerable易受傷的
amphibian兩棲(類)的

Case study- why are amphibians vanishing?
amphibians- frogs, toads, and salamanders
indicator species
no single cause has been found to explain the amphibian declines
1.prolonged drought
2.pollution
3.viral, and fungal diseases
4.ultraviolet radiation
5.climate change(global warming)
6.overhunting
7.nonnative predators and competitors
如果多數兩棲類物種消失我們為何要關注？
1.environmental health is deterioration
2.improtant ecological roles (food chain)
3.genetic storehouse of pharmaceutical products

toad蟾蜍,癩蛤蟆
salamander蠑螈
tadpole蝌蚪
block阻擋,妨礙,阻止
permeable有滲透性的;可穿過的
readily很快地,立即
draining排出(液體)
prolonged特別長的
breeding生育,生殖;繁殖
viral病毒
fungal真菌的
embryo胚胎
parasite寄生蟲
deteriorating惡化
reptile爬蟲類
pharmaceutical製藥的
secretion分泌物
painkiller鎮痛劑
antibiotic抗生素
larvae幼蟲;幼體

Keystone species play important roles in communities
eliminating a keystone species may dramatically alter the sturcture and function of community.
critcial ecological roles
bees, butterflies, hummingbirds蜂鳥, bat, dung beetle
top predator keystone species(wolf, leopard, lion, alligator)
ecological services

science focus-why should we protect sharks?
370 shark species
feeding at the tops of food webs, remove injured and sick animals form the ocean.
人類對鯊魚得誤解
valuable fins 魚刺可治百病
high levels of toxic mercury
livers, meat, hides, and jaws
cancer, immune system
especially vulnerable to overfishing
least protected animals on earth
that sharks may not need us, but we and other species need them

keystone species關鍵物種
wedge-shape楔形物
archway拱門
teeming充滿的
dying垂死的
whale shark鯨鯊
basking shark姥鯊
megamouth shark巨口鯊
hack劈,砍
ingredient(烹調的)原料
fetch售得,賣得
dorsal背部的;背側的
mercury水銀,汞
liver肝臟
hide獸皮;皮革
deployed展開
immune免疫
aquarium水族館
outcry強烈的抗議
dung糞;糞肥
churn攪拌
aerate使通氣

Foundation species also play important ecological roles
shaping communities by creating and enhancing the habits in ways that benefit other species.
elephants
bat and bird
beraver

forage草料
antelope羚羊
regenerate重建;再生
beaver海狸,河狸
felling砍伐,砍倒
lodge巢穴