3-5-1-3~3-5-2-1

In natural ecosystems, most consumers feed on more than one type of consumer.Because of this, organisms in most ecosystems form a complex network of interconnected food chains called a food web(Figure 3-15). Trophic levels can be assigned in food webs just as in food chains. Food chains and webs show how producers, consumers, and decomposers are connected to one another as energy flows through trophic levels on an ecosystem.
在自然的生態系統中,大部分的消費者以超過一種以上的消費者為食.因為這樣,生物在大部分的生態系統形成一個以食物鏈互相連接構成的網狀系統而這個系統就是食物網(圖3-15).營養階層可以被分配在食物網裡就像分配在食物鏈裡那樣.食物鏈和食物網顯示生產著,消費者,和分解者在生態系統中經由營養階層當能量流動是如何互相連接
Usable energy Decreases with Each Link in a Food Chain or Web
可利用的能量在食物鏈或食物網中減少

Each trophic level in a food chain or web contains a certain amount of biomass, the dry weight of all organic matter contained in its organisms. In a food chain or web, chemical energy stored in biomass is transferred from one trophic lever to another.
每一個營養階層在食物鏈或食物網中容納一個某種程度的生物量,包含在生物體中所有有機物質的乾重.在一個食物鏈或食物網中,化學能量貯存在生物量中從一個營養階層轉變成另一個營養階層.