什么是食物鏈

生態(tai)系(xi)統中貯存(cun)于(yu)有機物中的(de)能(neng)量在(zai)生態(tai)系(xi)統中層(ceng)層(ceng)傳導，通俗地(di)講，是(shi)各(ge)種生物通過一系(xi)列(lie)吃與(yu)被(bei)吃的(de)關(guan)系(xi)（捕食(shi)關(guan)系(xi)）彼(bi)此聯系(xi)起(qi)來(lai)的(de)序(xu)列(lie)，在(zai)生態(tai)學上被(bei)稱為食(shi)物鏈。

按照生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)與生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)之間的(de)(de)關(guan)系(xi)(xi)可將食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)鏈(lian)(lian)分(fen)為捕食(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)鏈(lian)(lian)、腐食(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)鏈(lian)(lian)（碎食(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)鏈(lian)(lian)）和寄生(sheng)(sheng)(sheng)食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)鏈(lian)(lian)。各種生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)以其獨特的(de)(de)方式(shi)獲得(de)生(sheng)(sheng)(sheng)存、生(sheng)(sheng)(sheng)長、繁殖所(suo)需的(de)(de)能(neng)量(liang)，生(sheng)(sheng)(sheng)產(chan)者(zhe)(zhe)所(suo)固定(ding)的(de)(de)能(neng)量(liang)和物(wu)(wu)(wu)(wu)質通過一系(xi)(xi)列取(qu)(qu)食(shi)(shi)(shi)(shi)的(de)(de)關(guan)系(xi)(xi)在生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)間進行傳(chuan)遞，如食(shi)(shi)(shi)(shi)草動(dong)(dong)物(wu)(wu)(wu)(wu)取(qu)(qu)食(shi)(shi)(shi)(shi)植物(wu)(wu)(wu)(wu)，食(shi)(shi)(shi)(shi)肉動(dong)(dong)物(wu)(wu)(wu)(wu)捕食(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)草動(dong)(dong)物(wu)(wu)(wu)(wu)，這種不同生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)間通過食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)而形成的(de)(de)鏈(lian)(lian)鎖(suo)式(shi)單向(xiang)聯系(xi)(xi)稱為食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)鏈(lian)(lian)。一條完(wan)整的(de)(de)食(shi)(shi)(shi)(shi)物(wu)(wu)(wu)(wu)鏈(lian)(lian)是由(you)生(sheng)(sheng)(sheng)產(chan)者(zhe)(zhe)、消(xiao)費者(zhe)(zhe)、共同構造的(de)(de)，源頭開始于(yu)生(sheng)(sheng)(sheng)產(chan)者(zhe)(zhe)光(guang)合作用鎖(suo)定(ding)太陽能(neng)。

食物鏈(lian)的分(fen)類

食物鏈又稱為“營(ying)養鏈”。指(zhi)生態系統中各(ge)種生物以食(shi)物聯系起來的鏈鎖關系。例(li)如

池塘中的藻類是水蚤的食物，水蚤又是魚類的(de)食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)，魚(yu)類又是人類和水鳥的(de)食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)。于是，池塘(tang)中的(de)藻類、水蚤、魚(yu)便與(yu)人或水鳥之(zhi)間便形成了一種食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)鏈(lian)(lian)。按(an)照生物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)與(yu)生物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)之(zhi)間的(de)關系可將食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)鏈(lian)(lian)分為捕食(shi)(shi)(shi)食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)鏈(lian)(lian)、腐食(shi)(shi)(shi)食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)鏈(lian)(lian)（碎(sui)食(shi)(shi)(shi)食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)鏈(lian)(lian)）、和寄生食(shi)(shi)(shi)物(wu)(wu)(wu)(wu)(wu)(wu)(wu)(wu)鏈(lian)(lian)。

1、捕食性

如：青草→野兔→蛇→鷹。

禾(he)谷類(lei)植物→昆蟲→青(qing)蛙→蛇。

大(da)魚吃(chi)小(xiao)魚，小(xiao)魚吃(chi)蝦(xia)(xia)米，蝦(xia)(xia)米吃(chi)浮游動(dong)物，浮游動(dong)物吃(chi)綠藻。

2、碎食性

（腐(fu)食食物鏈(lian)）。指以零碎食物為基礎(chu)形(xing)成的食物鏈(lian)。如(ru)樹葉碎片及小(xiao)藻(zao)類→蝦（蟹）→魚→食魚的鳥類。

3、寄生性

以大動物(wu)為基礎，小動物(wu)寄生(sheng)到大動物(wu)上(shang)形成的食(shi)物(wu)鏈。如哺乳類→跳蚤→原生(sheng)動物→細菌→過濾(lv)性病毒。

食物鏈包括哪些類型

1、捕食鏈（牧食食物鏈）：捕食鏈是由生態系統中的生產者與消費者之間、消費者與消費者之間通過捕食與被捕食的關系形成的。能量通常由弱小生物流向強大的生物體內。它是生態系統中最重要的食物鏈形式。如植物→昆蟲→蛙→蛇(she)。青(qing)草→野兔→狐→狼。

2、寄生(sheng)鏈(lian)： 寄生(sheng)鏈是指生(sheng)態系統中一(yi)些營寄生(sheng)生(sheng)活(huo)的(de)生(sheng)物(wu)(wu)之(zhi)間(jian)存在的(de)營養關系。以活(huo)的(de)動植物(wu)(wu)有機體及大型(xing)生(sheng)物(wu)(wu)為基礎，由小型(xing)生(sheng)物(wu)(wu)寄生(sheng)到(dao)大型(xing)生(sheng)物(wu)(wu)身上構成，如鹿→蚤→原生動物→細菌→病毒。又如(ru)，鳥類(lei)→跳蚤→鼠疫(yi)細菌。

3、腐生(sheng)(sheng)(sheng)鏈(lian)(lian)(lian)（碎食鏈(lian)(lian)(lian)）：腐生(sheng)(sheng)(sheng)鏈(lian)(lian)(lian)指營腐生(sheng)(sheng)(sheng)生(sheng)(sheng)(sheng)活的(de)(de)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)通過分(fen)(fen)(fen)解作用(yong)在不(bu)同生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)尸體的(de)(de)分(fen)(fen)(fen)解過程(cheng)中形(xing)成的(de)(de)相互聯系(xi)。是(shi)以死亡的(de)(de)動(dong)(dong)(dong)植(zhi)物(wu)(wu)(wu)(wu)(wu)殘體為(wei)基礎，從真菌、細菌和(he)某些土壤動(dong)(dong)(dong)物(wu)(wu)(wu)(wu)(wu)開(kai)始的(de)(de)食物(wu)(wu)(wu)(wu)(wu)鏈(lian)(lian)(lian)，能量流動(dong)(dong)(dong)是(shi)由死物(wu)(wu)(wu)(wu)(wu)向(xiang)小生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)體再流向(xiang)大生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)體。腐生(sheng)(sheng)(sheng)鏈(lian)(lian)(lian)在生(sheng)(sheng)(sheng)態(tai)系(xi)統中有(you)著重要的(de)(de)作用(yong)，它是(shi)生(sheng)(sheng)(sheng)態(tai)系(xi)統的(de)(de)物(wu)(wu)(wu)(wu)(wu)質循環不(bu)可缺少的(de)(de)部分(fen)(fen)(fen)。其(qi)特點是(shi)有(you)分(fen)(fen)(fen)解者參加。例如，死亡的(de)(de)動(dong)(dong)(dong)植(zhi)物(wu)(wu)(wu)(wu)(wu)殘體→跳蟲(chong)(chong)(chong)、螨類(lei)→食蟲(chong)(chong)(chong)昆(kun)蟲(chong)(chong)(chong)、蜘蛛→食蟲(chong)(chong)(chong)鳥(niao)、小型哺乳動物。又如落葉→細菌→昆(kun)蟲(chong)(chong)(chong)→鳥(niao)。