摘要
基于三峡消落带夏汛期水淹特征,设置两种水分处理[无水淹对照组(CK)和水淹组(F)],采用分解袋法,对三峡库区消落带3种具有典型代表性的一年生草本植物狼杷草(Bidens tripartita)、稗(Echinochloa crus-galli)和水蓼(Polygonum hydropiper)地上枯落物干质量损失率和养分释放特征进行研究。结果表明:1)3种一年生草本枯落物的初始化学组成及其化学计量比差异显著(P<0.05),干质量损失率和元素释放率与初始N、P、K含量及N/P比值显著正相关,而与初始C、木质素含量以及木质素/N和C/N比值显著负相关;2)水淹加速了3种植物枯落物的干质量损失率和元素释放速率,对N、P、K释放率的影响最大;3)除对照组的P元素释放速率和水淹组的K元素释放率外,狼杷草和稗的干质量损失率和元素释放率均显著高于水蓼(P<0.05)。这表明狼杷草和稗对三峡库区的水体和底泥的营养状态具有较大影响,其枯落物的快速分解可能造成水体和底泥N、P含量升高,而水蓼对其的影响较小。因此,建议优先考虑对狼杷草和稗在夏汛期前适时回收、刈割,从而减少其对库区水体及底泥的养分释放。
The effects of flooding on the ground litter decomposition and nutrient release of three dominant annual herbaceous plants(Bidens tripartita,Echinochloa crus-galli,and Polygonum hydropiper)from a water-level fluctuation zone were investigated using the litter-bag method.The control group(CK)and water flooding group(F)were designed according to the characteristics of flooding in the Three Gorges Reservoir Area(TGRA)during summer.The results revealed the following:1)The initial contents and ratios of elements in the three herbaceous litters were different(P<0.05).The initial nitrogen(N),phosphorus(P),and potassium(K)contents and ratios of the litters were positively correlated with the dry mass loss rates and element release rates,and negatively correlated with the initial carbon(C)and lignin contents and lignin/N and C/N ratios.2)Flooding accelerated the dry mass loss rates and element release rates of the three herbaceous litters,having the greatest influence on the rates of N,P,and K release.3)Except for the rate of P release by the CK group and of K release by the F group,the dry mass loss rates and element release rates of B.tripartita and E.crus-galli were higher than those of P.hydropiper(P<0.05).This indicates that B.tripartita and E.crus-galli may have great influence on the nutritional status of the water and sediments in the TGRA,and the rapid decomposition of their litter may lead to increases in the N and P contents,whereas P.hydropiper has little effect in this regard.Therefore,it is suggested that priority should be given to the timely recovery and mowing of B.tripartita and E.crus-galli before the summer flood season in order to reduce the release of nutrients to the water and sediments.
作者
谢婷婷
李丽娟
刘明辉
陈雪梅
陈春桦
杨治华
李昌晓
XIE Tingting;LI Lijuan;LIU Minghui;CHEN Xuemei;CHEN Chunhua;YANG Zhihua;LI Changxiao(Key Laboratory of Eco-environment in the Three Gorges Reservoir Region of Education/Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region/State Cultivation Base of Eco-agriculture for Southwest Mountainous Land/College of Life Science,Southwest University,Chongqing 400715,China)
出处
《草业科学》
CAS
CSCD
2020年第2期226-236,共11页
Pratacultural Science
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
水淹
枯落物
干质量损失率
元素释放率
flooding
litter
dry mass loss rates
element release rates
