摘要
为探讨水氮控制对荒漠草原优势植物无芒隐子草和冷蒿凋落物分解的影响,设置自然降雨(CK)、增雨30%(W)和减雨30%(R)3个水分处理以及0(N0)、30kg/hm^2·a(N30)、50kg/hm^2·a(N50)、100kg/hm^2·a(N100)4个氮素(NH_4NO_3)水平,开展水氮交互试验。结果表明:在21个月的分解过程中,无芒隐子草分解速率快于冷蒿。同一分解时间同水分处理,氮沉降促进两种凋落物的分解,CK-N和R-N处理,随施氮水平的增加促进作用先增强后减弱,于N50水平分解最快,分解50%所需时间为2.15a、2.45a和2.37a、2.69a,分解95%需要9.99a、11.37a和10.75a、12.24a;W-N处理,促进作用随施氮水平的增加而增强,于N100水平分解最快,分解50%所需时间为1.87a和2.23a,分解95%需要8.84a和10.30a。同一分解时间同氮素水平,增雨促进凋落物分解。相关分析表明:凋落物分解速率与初始全氮含量呈正相关,与初始全碳、纤维素、C/N、木质素、木质素/N和纤维素/N呈负相关。
To explore the effects of water and nitrogen manipulation on the litter decomposition of two dominant species,Cleistogenes songoricaand Artemisia frigidain a desert grassland,the water and nitrogen interaction test in three levels of water treatments：natural rainfall（CK）,increased rainfall of 30%（W）and reduced rainfall of 30%（R）and four levels of nitrogen（NH_4 NO_3）treatment：0（N0）,30 kg/hm^2·a（N30）,50 kg/hm^2·a（N50）and 100 kg/hm^2·a（N100）level was designed.The results showed that in 21 months of decomposition,the decomposition rate of Cleistogenes songorica was faster than Artemisia frigida.With the same decomposition time and water treatment,nitrogen deposition promoted the litter decomposition,whereas the promotion effect of Cleistogenes songorica and Artemisia frigida was increased first and then weakened with increasing the nitrogen application level under the treatments of CK-N and RN.In addition,the decomposition rate reached the maximum at N50 level.The required time for the decomposition of 50% was 2.15 a,2.45 a,2.37 aand 2.69 a,respectively,and the decomposition of 95%required 9.99 a,11.37 a,10.75 aand 12.24 a.Under W-N treatment,the promotion effect was enhanced with the increasing of nitrogen application level.The decomposition achieved the fastest rate at N100 level,and the decomposition time was 1.87 aand 2.23 afor 50% decomposition and 8.84 aand 10.30 afor 95% decomposition,respectively.With the same decomposition time and nitrogen level,the increase of rainfall promoted the litter decomposition.The correlation analysis showed that there were positive correlations between the litter decomposition rate and the initial total nitrogen content,and negative correlations with the initial total carbon,cellulose,C/N,lignin,lignin/N and cellulose/N.
作者
霍利霞
红梅
赵巴音那木拉
高海燕
叶贺
HUO Li-xia;HONG Mei;ZHAO Bayinnamula;GAO Hai-yan;YE He(College of Grassland,Resources and Environment,Inner Mongolia Agricultural University,Hohhot 010011,China;Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources,Hohhot 010011,China)
出处
《中国草地学报》
CSCD
北大核心
2018年第5期57-63,共7页
Chinese Journal of Grassland
基金
国家自然科学基金项目(31560156)
关键词
荒漠草原
凋落物分解
水分处理
氮素处理
初始化学含量
Desert grassland
Litter decomposition
Water treatment
Nitrogen treatment
Initialchemical content
