楓香人工林凋落物量及其N，P化學(xué)計(jì)量季節(jié)動(dòng)態(tài)特征

陳嬋+王光軍++朱凡等

摘 要 為了探索凋落物量及其N，P化學(xué)計(jì)量隨著季節(jié)變化所呈現(xiàn)的規(guī)律性和相關(guān)關(guān)系，以湖南楓香（Liquidamba formosana Hance）人工林兩年的凋落物為研究對(duì)象，開(kāi)展凋落物量、各組分產(chǎn)量及其N，P質(zhì)量分?jǐn)?shù)和質(zhì)量比生態(tài)化學(xué)計(jì)量特征的研究.結(jié)果表明：2012和2013年凋落物總量無(wú)顯著差異性，分別為5 085.9±657.6 kg·hm-2和4 935.7±609.7 kg·hm-2.各組分凋落量從大到小排序?yàn)椋喝~、枝、花果、碎屑.葉的N，P質(zhì)量分?jǐn)?shù)之間，葉的w（P）與m（N）∶m（P）之間，枝的w（P）與m（N）∶m（P）之間以及碎屑的w（P）與m（N）∶m（P）之間均存在一定的相關(guān)性（P<001）.楓香人工林凋落物及各組分產(chǎn)量及N，P質(zhì)量分?jǐn)?shù)和生態(tài)化學(xué)計(jì)量均存在顯著的季節(jié)動(dòng)態(tài)，表明季節(jié)變化對(duì)其均產(chǎn)生了一定的影響.而楓香林凋落物的N，P質(zhì)量比值逐漸增加，表明P元素對(duì)該生態(tài)系統(tǒng)起到了限制作用.

關(guān)鍵詞 楓香；凋落物；氮磷質(zhì)量比；生態(tài)化學(xué)計(jì)量特征；季節(jié)動(dòng)態(tài)

中圖分類號(hào) Q14文獻(xiàn)標(biāo)識(shí)碼 A文章編號(hào) 10002537（2016）02001607

Seasonal Dynamic of Litter Production and Its N and P Ecological

Stoichiometry in Liquidamba Formosana Plantation in Hunan， China

CHEN Chan1，2， WANG GuangJun1，2*， ZHU Fan1，2， ZHAO Yue1，2， LIANG XiaoCui1，2

（1. College of Life Science and Technology， Central South University of Forestry and Technology， Changsha 410004， China；

2. National Engineering Lab for Applied Technology of Forestry and Ecology in South China， Changsha 410004 China）

Abstract In order to explore the regularity and correlation of litter production and its N and P ecological stoichiometry with seasonal changes， we took the object of Liquidamba formosana Hance plantation in Hunan as an example to investigate the production of litter and its components， and ecological stoichiometry characteristics of nitrogen（N）， phosphorus（P） and the N and P ratio in each component. The results showed that there was no significant defference of litter biomass in the year of 2012 and 2013， which were found to be 5 085.9±657.6 kg·hm-2 and 4 935.7±609.7 kg·hm-2 ， respectively. The order of components production is the following： leaf>branch>flower>fragment. Reasonable correlations were discovered between N and P elements in leaf， between P and the N and P ratio in leaf， between the P content with the N and P ratio in branch， and between P and N and P element ratio in fragment. There exists significant seasonal dynamics of litter and components production， N and P content and ecological stoichiometry in each component of Liquidamba formosana plantations. Seasonal changes should have had an impact on these features. The N and P ratio in litter components was gradually increasing， suggesting that the P element is the limiting factor to this ecosystem.

Key words Liquidamba formosana； litter fall； N and P ratio； ecological stoichiometry； seasonal dynamic

凋落物層是森林生態(tài)系統(tǒng)能量轉(zhuǎn)換和物質(zhì)循環(huán)的重要場(chǎng)所，凋落物分解后形成森林表層土壤的腐殖質(zhì)和有機(jī)質(zhì)[1].因此，森林凋落物在維持土壤肥力、維持森林生態(tài)系統(tǒng)穩(wěn)定性以及確保森林生態(tài)系統(tǒng)物質(zhì)循環(huán)和能量循環(huán)正常運(yùn)轉(zhuǎn)方面具有重要的作用[23].凋落物的N，P質(zhì)量比制約著凋落物的養(yǎng)分循環(huán)和分解，其變化特征可以反映N，P養(yǎng)分的限制作用[46].由于人工林的多樣性低，生態(tài)穩(wěn)定性差，對(duì)土壤肥力的消耗遠(yuǎn)遠(yuǎn)大于天然林，因此，近年來(lái)國(guó)內(nèi)外越來(lái)越關(guān)注對(duì)人工林凋落物生物量、組成、營(yíng)養(yǎng)元素含量及分解速率等方面的研究.鄭路等[7]研究了從熱帶到亞熱帶和溫帶林凋落物現(xiàn)存量及養(yǎng)分特征.楊會(huì)俠等[8]和葛曉改等[9]對(duì)馬尾松人工林年凋落物量與養(yǎng)分歸還動(dòng)態(tài)的研究發(fā)現(xiàn)，凋落物對(duì)維持馬尾松人工林林地養(yǎng)分具有……