什么是食(shi)物鏈

生態(tai)(tai)系(xi)統中(zhong)貯存于(yu)有機物(wu)中(zhong)的(de)能量在生態(tai)(tai)系(xi)統中(zhong)層(ceng)層(ceng)傳導，通(tong)俗地講(jiang)，是各種生物(wu)通(tong)過(guo)一系(xi)列(lie)吃(chi)與(yu)被吃(chi)的(de)關系(xi)（捕食關系(xi)）彼此聯系(xi)起來(lai)的(de)序列(lie)，在生態(tai)(tai)學(xue)上被稱為食物(wu)鏈。

按照生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)與生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)之間的(de)(de)關系(xi)可將(jiang)食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)鏈(lian)(lian)分為(wei)捕(bu)食(shi)(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)鏈(lian)(lian)、腐食(shi)(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)鏈(lian)(lian)（碎食(shi)(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)鏈(lian)(lian)）和寄(ji)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)鏈(lian)(lian)。各種生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)以(yi)其獨特的(de)(de)方(fang)式(shi)(shi)獲得生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)存、生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)長、繁(fan)殖(zhi)所需的(de)(de)能(neng)量，生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)產者所固定的(de)(de)能(neng)量和物(wu)(wu)(wu)質通過一系(xi)列取食(shi)(shi)(shi)(shi)(shi)的(de)(de)關系(xi)在生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)間進行傳遞，如食(shi)(shi)(shi)(shi)(shi)草動(dong)物(wu)(wu)(wu)取食(shi)(shi)(shi)(shi)(shi)植(zhi)物(wu)(wu)(wu)，食(shi)(shi)(shi)(shi)(shi)肉動(dong)物(wu)(wu)(wu)捕(bu)食(shi)(shi)(shi)(shi)(shi)食(shi)(shi)(shi)(shi)(shi)草動(dong)物(wu)(wu)(wu)，這種不同生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)間通過食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)而形成的(de)(de)鏈(lian)(lian)鎖(suo)式(shi)(shi)單向聯系(xi)稱(cheng)為(wei)食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)鏈(lian)(lian)。一條完(wan)整的(de)(de)食(shi)(shi)(shi)(shi)(shi)物(wu)(wu)(wu)鏈(lian)(lian)是(shi)由生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)產者、消費者、共(gong)同構造的(de)(de)，源(yuan)頭(tou)開始(shi)于生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)產者光合(he)作用鎖(suo)定太(tai)陽能(neng)。

食物鏈的分類(lei)

食物鏈又稱為(wei)“營養鏈(lian)”。指生態系(xi)統中各種(zhong)生物(wu)(wu)以食物(wu)(wu)聯(lian)系(xi)起來的鏈(lian)鎖關系(xi)。例如

池塘中的藻類是水蚤的食物，水蚤又是魚類的食(shi)(shi)(shi)物，魚(yu)類又是(shi)人類和水(shui)(shui)鳥的食(shi)(shi)(shi)物。于是(shi)，池塘(tang)中的藻類、水(shui)(shui)蚤、魚(yu)便(bian)與人或水(shui)(shui)鳥之(zhi)間便(bian)形成了一種食(shi)(shi)(shi)物鏈(lian)。按照生(sheng)(sheng)物與生(sheng)(sheng)物之(zhi)間的關系可將(jiang)食(shi)(shi)(shi)物鏈(lian)分為捕食(shi)(shi)(shi)食(shi)(shi)(shi)物鏈(lian)、腐食(shi)(shi)(shi)食(shi)(shi)(shi)物鏈(lian)（碎食(shi)(shi)(shi)食(shi)(shi)(shi)物鏈(lian)）、和寄(ji)生(sheng)(sheng)食(shi)(shi)(shi)物鏈(lian)。

1、捕食性

如：青草→野兔→蛇→鷹。

禾谷類植物→昆蟲→青蛙→蛇。

大魚吃(chi)小魚，小魚吃(chi)蝦米，蝦米吃(chi)浮游(you)動物，浮游(you)動物吃(chi)綠(lv)藻。

2、碎食性

（腐食食物(wu)鏈）。指以零(ling)碎食物(wu)為基(ji)礎形成的食物(wu)鏈。如(ru)樹葉碎片及小藻類(lei)→蝦(xia)（蟹）→魚(yu)→食魚(yu)的(de)鳥類。

3、寄生性

以大(da)動(dong)物為基礎，小動(dong)物寄生到大(da)動(dong)物上形成的食(shi)物鏈。如哺乳(ru)類→跳(tiao)蚤→原(yuan)生(sheng)動物(wu)→細菌(jun)→過濾性病毒(du)。

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(wa)→蛇。青草(cao)→野(ye)兔→狐→狼。

2、寄生鏈： 寄(ji)生(sheng)鏈是指生(sheng)態系(xi)統中一些營(ying)寄(ji)生(sheng)生(sheng)活的生(sheng)物(wu)(wu)之間存在的營(ying)養關(guan)系(xi)。以(yi)活的動(dong)植物(wu)(wu)有(you)機(ji)體及大(da)型(xing)生(sheng)物(wu)(wu)為基礎，由(you)小型(xing)生(sheng)物(wu)(wu)寄(ji)生(sheng)到大(da)型(xing)生(sheng)物(wu)(wu)身上構成，如鹿→蚤(zao)(zao)→原生(sheng)動物→細菌→病毒。又如，鳥(niao)類(lei)→跳蚤(zao)(zao)→鼠疫細菌。

3、腐生(sheng)(sheng)鏈(lian)（碎食鏈(lian)）：腐生(sheng)(sheng)鏈(lian)指營腐生(sheng)(sheng)生(sheng)(sheng)活的(de)(de)生(sheng)(sheng)物(wu)通過分(fen)(fen)(fen)解(jie)作用(yong)在(zai)不同生(sheng)(sheng)物(wu)尸體(ti)的(de)(de)分(fen)(fen)(fen)解(jie)過程(cheng)中形成的(de)(de)相互聯系(xi)。是(shi)(shi)以死(si)亡(wang)的(de)(de)動(dong)植(zhi)物(wu)殘(can)體(ti)為基(ji)礎(chu)，從(cong)真菌、細菌和某些土(tu)壤動(dong)物(wu)開始的(de)(de)食物(wu)鏈(lian)，能(neng)量流動(dong)是(shi)(shi)由死(si)物(wu)向(xiang)小生(sheng)(sheng)物(wu)體(ti)再流向(xiang)大生(sheng)(sheng)物(wu)體(ti)。腐生(sheng)(sheng)鏈(lian)在(zai)生(sheng)(sheng)態(tai)系(xi)統(tong)中有著重(zhong)要的(de)(de)作用(yong)，它是(shi)(shi)生(sheng)(sheng)態(tai)系(xi)統(tong)的(de)(de)物(wu)質(zhi)循環不可缺少的(de)(de)部(bu)分(fen)(fen)(fen)。其(qi)特點是(shi)(shi)有分(fen)(fen)(fen)解(jie)者(zhe)參加。例如，死(si)亡(wang)的(de)(de)動(dong)植(zhi)物(wu)殘(can)體(ti)→跳蟲(chong)(chong)、螨類→食蟲(chong)(chong)昆蟲(chong)(chong)、蜘蛛(zhu)→食蟲(chong)(chong)鳥(niao)、小型哺乳動物。又如落葉→細菌→昆蟲(chong)(chong)→鳥(niao)。