三峡消落带落羽杉人工幼林叶片分解及磷释放特征  

Foliar decomposition and phosphorus release in a Taxodium distichum young forest stand rehabilitated in the hydro-fluctuation belt of the Three Gorges Reservoir

作　　者：宋虹 袁中勋 任庆水 杨文航 王朝英[1,2,3] 李昌晓[1,2,3] SONG Hong;YUAN Zhongxun;REN Qingshui;YANG Wenhang;WANG Chaoying;LI Changxiao(Key Laboratory of Eco environment in the Three Gorges Reservoir Region of the Ministry of Education,Chongqing 400715,China;Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region,Chongqing 400715,China;School of Life Sciences,Southwest University,Chongqing 400715,China)

机构地区：[1]三峡库区生态环境教育部重点实验室,重庆400715 [2]重庆市三峡库区植物生态与资源重点实验室,重庆400715 [3]西南大学生命科学学院,重庆400715

出　　处：《生态学报》2019年第21期8100-8110,共11页Acta Ecologica Sinica

基　　金：重庆市林业重点科技攻关项目(渝林科研2016-8,2019-16);国家科技部国际合作专项(2015DFA90900);中央财政林业科技推广示范项目(渝林科推2014-10)

摘　　要：为探究三峡消落带人工重建植被落羽杉(Taxodium distichum)幼林叶片在不同水文条件下的分解特征及其对土壤 水体磷的贡献潜力,本实验在控制条件下,模拟三峡库区消落带土壤水分变化设置了常规生长水分条件(CK)、轻度干旱水分胁迫(T1)、潮湿(T2)、2 cm水淹(T3)、10 cm水淹(T4)5个不同处理,研究落羽杉叶片分解及磷释放特征。研究结果表明:(1)在整个试验期间(90 d),T3、T4两个水淹处理的叶片失重率分别达51%(T3)和55%(T4),显著高于CK、T1、T2三个未水淹处理;(2)未分解残留叶片中的全磷含量在CK、T1、T2三个未水淹的处理组呈现增加趋势,而水淹处理(T3、T4)呈减少趋势;(3)土壤全磷含量在试验过程中呈现波动性变化特征,但至试验结束时,各处理中土壤全磷含量与CK相比均无显著差异;(4)T3、T4处理中叶片添加显著增加了上覆水体中总磷含量,试验过程中呈现出在分解初期迅速上升,在分解10 d时达到峰值,之后逐渐降低并趋于稳定,但试验结束时仍显著较高,分别是对应无叶片组的17.15倍(T3)和5.81倍(T4)。这些结果说明水淹通过促进落羽杉叶片的分解从而增加上覆水体中磷的含量,因此有必要在水淹前对消落带的落羽杉幼林叶片进行适时采收,以尽可能减少其对库区水体的磷负荷。To explore traits related to leaf decomposition and the potential contribution of the phosphorus of the leaves of Taxodium distichum to the soil-water system in the fluctuation zone of the Three Gorges Reservoir,an indoor experiment was conducted upon simulation of the water change of the hydro fluctuation belt in the reservoir.Five different kinds of water treatments were applied to investigate leaf decomposition processes of T.distichum and phosphorus release characteristics.Five water treatments included normal growth water condition(CK),light drought water stress(T1),water saturation(T2),2 cm flooding(T3),and 10 cm flooding(T4).The results showed that:1)During the entire experiment period(90 d),the rate of leaf weight loss of the two flooding groups reached 51%(T3)and 55%(T4),which were significantly higher than that of the three unflooded treatment groups of CK,T1,and T2;2)The total phosphorus content in leaves increased in the CK,T1,and T2 treatment groups,but decreased in the flooding treatments(T3 and T4);3)The total phosphorus content of the soil showed fluctuation characteristics during the experiment period,but at the end of experiment there was no significant difference in soil total phosphorus content between the treatment groups and the CK group;4)During the experiment period,total phosphorus content of the overlying water of the T3 and T4 treatment groups with addition of leaves increased significantly compared with that of the respective treatment groups without addition of leaves and showed a rapid increase in the initial decomposition rate followed by a gradual decrease and finally a stable state.The peak value of leaf decomposition was observed on the 10th day,after which leaf decomposition decreased.However,at end of the experiment the total phosphorus content of T3 and T4 treatment groups with addition of leaves was still significantly higher than that of the respective treatment groups without addition of leaves,reaching 17.15(T3)and 5.81(T4)times higher,respectively.These results indicated

关 键 词：消落带 土壤水分变化 落羽杉叶片 磷 三峡库区 

分 类 号：S71[农业科学—林学]