摘要
为探究三峡消落带泥沙淤积条件下一年生草本枯落物的分解及养分变化特征,通过模拟实验,采用分解袋法,研究不同泥沙埋深对4种一年生草本分解及养分动态的影响。所选择的三峡消落带4种一年生优势草本植物包括马唐(Digitaria sanguinalis)、稗(Echinochloa crusgali)、狼杷草(Bidens tripartita)、苍耳(Xanthium sibiricum),设置了无掩埋(0 cm)、中度掩埋(5 cm)和深度掩埋(10 cm)3个泥沙掩埋深度,试验周期为180 d。结果表明:(1)在整个实验期间,4种一年生草本枯落物的分解速率均呈现先快后慢的特点,与0 cm泥沙埋深处理相比,5、10 cm埋深下4种一年生草本枯落物的分解速率均显著降低;(2)在分解结束时,4种一年生草本枯落物C含量变化不大,P元素处于释放状态,而在泥沙掩埋下N元素处于富集状态;(3)除马唐和稗枯落物的P含量变化外,4种一年生草本枯落物C、N、P含量均表现为0 cm掩埋处理显著低于5、10 cm处理组;相反,4种一年生草本枯落物K含量则表现为0 cm掩埋处理显著高于5、10 cm处理组。研究表明消落带大量泥沙淤积抑制枯落物的分解和C、N、P元素释放,有利于降低对三峡库区水体富营养化及营养物质悬浮的贡献率,一定程度上,对库区水质保护有正面效应。
To explore traits related to litter decomposition and the nutrient change of annual herbaceous species under the condition of sediment deposition in the Three Gorges Reservoir.The effects of different sediment depths on ground litter decomposition and nutrient dynamic characteristics of four annual dominant herbaceous species(Digitaria sanguinalis,Echinochloa crusgali,Bidens tripartita,and Xanthium sibiricum)in the water-level fluctuation zone of the Three Gorges Reservoir were investigated using the litter-bag method.Three sediment depths included no burial(0 cm),moderate burial(5 cm)and deep burial(10 cm),were treated with an experimental period of 180 days.The results showed that:(1)During the experiment period,the decomposition rate of litters of four annual herbaceous species was fast at first and then slow.Compared with 0 cm sediment depth treatment,the decomposition rate significantly decreased in 5 cm and 10 cm.(2)When the decomposition ended,the carbon(C)content of four annual herbaceous species litters remained stable,the phosphorus(P)element was released,while the nitrogen(N)was enriched under sediment burial.(3)Except for changes in phosphorus content of D.sanguinalis and E.crusgali litter,the content of carbon,nitrogen and phosphorus of four annual herb litter in 0 cm was significantly lower than that in 5 cm and 10 cm treatment groups.On the contrary,the potassium(K)content of four annual herbs species litters in 0 cm was significantly higher than that in 5 cm and 10 cm treatment group.The results revealed that a large amount of sediment deposition in the water-level fluctuation zone inhibited the decomposition and C,N,and P release of the litter,which is beneficial to reduce the contribution of litter decomposition to water eutrophication and nutrient suspension in the Three Gorges Reservoir,and to a certain extent,has a positive effect on water quality protection.
作者
谢婷婷
刘明辉
袁中勋
张松林
李昌晓
XIE Tingting;LIU Minghui;YUAN Zhongxun;ZHANG Songlin;LI Changxiao(Key Laboratory of Eco-environment in the Three Geservoir Region of Education,Chongqing Key Laboratory of Plant Ecology and Reources Research in the Three Gorges Region,School of Life Science,Southwest University,Chongqing 400715,China;State Cultivation Base of Eco-agriculture for Southwest Mountainous Land,Chongqing 400715,China)
出处
《生态学报》
CAS
CSCD
北大核心
2020年第21期7755-7766,共12页
Acta Ecologica Sinica
基金
重庆市建设科技项目(城科字2019第1-4-2)
重庆市科技兴林首席专家团队项目(TD2019-2)
中央林业改革发展资金科技推广示范项目(渝林科推2017-12)
国家国际科技合作专项(2015DFA90900)。
关键词
三峡消落带
一年生草本
泥沙掩埋深度
分解速率
养分含量
water-level fluctuation zone of the Three Gorges Reservoir
annual herbaceous
sediment burial depth
decomposition rate
nutrient contents
