摘要
以塔里木盆地柽柳(Tamarix)凋落物为研究对象,应用凋落袋法,揭示其在盐生(H1)和干旱(H2)生境中分解差异性及主要制约因子。结果表明:(1)经720 d分解,H1、H2生境中柽柳凋落物残留率分别为83.50%、53.73%,两种生境下凋落物残留率差异极显著(P<0.01)。(2)在H1、H2生境中,柽柳凋落物分解系数分别为0.082、0.320,分解50%所需时间分别为9.40、2.17 a,分解95%所需时间分别为40.62、9.36 a。(3)C元素在H1中富集-释放交替进行,在H2中为单一的富集-释放;N元素在H1中表现出累积-释放交替模式,在H2中表现出相反的变化趋势;P元素在0~360 d分解时间段均呈逐渐释放过程,而在第360~720 d,H1呈逐渐累积过程,H2呈累积-释放模式。木质素呈现逐渐释放模式,纤维素释放模式富集-释放交替进行。经720 d分解,C、N、P、木质素、纤维素残留率在两种生境中均存在极显著差异(P<0.01)。(4)微生境变化对凋落物分解制约因素并不相同,盐生生境下土壤Na^+含量是制约凋落物分解的主要因子,而干旱生境下残留量、土壤Mg^2+、凋落物全磷含量起主导作用。
Taking the litter of Tamarix in Tarim Basin as the research objects,litter-bag methods were applied to reveal the decomposition differences and main driving factors in halophytic habitats(H1)and arid habitats(H2).The results showed that:(1)Decomposed in H1 and H2 by 720 d,the litter residual rates of Tamarix were 83.50%and 53.73%respectively.The difference of residue decomposition was extremely significant(P<0.01)during the decomposing periods of day 0-720.(2)The decomposition coefficient were 0.082 and 0.320,the t0.5 values were 9.398 yrs and 2.166 yrs,and t0.95 values were 40.618 yrs and 9.362 yrs in H1,H2.(3)C elements were enriching-releasing alternately in H1,and a single enriching-releasing model in H2.N elements showed accumulating-releasing alternation pattern in H1,but opposite change trend in H2.P elements were gradually released during day 0-360 decomposition,while in day 360-720 the rule of P elements changed,H1 was gradually accumulating,and H2 was cumulating-releasing.Lignin showed gradually releasing pattern,and cellulose releasing pattern was enriched and released alternately.During the decomposing periods of the 720 d,C,N,P,lignin and cellulose residual rates were significant differences in different habitats(P<0.01).(4)Comprehensive analysis showed that the changes of microhabitat had different restriction factors on the decomposition of litter.Na^+content of the soil in saline habitat was the critical factor for restricting the decomposition of litter,while residual amount,Mg^2+content of the soil and total phosphorus content of litter in arid habitats had a combining role to litter decomposition.
作者
杨晶晶
吕瑞恒
梁继业
冯建菊
马国财
康佳鹏
Yang Jingjing;Lv Ruiheng;Liang Jiye;Feng Jianju;Ma Guocai;Kang Jiapeng(College of Life Sciences,Alar 843300,Xinjiang,China;Key Laboratory of Protection and Utilization of Biological Resource in Tarim Basin,Alar 843300,Xinjiang,China;College of Plant Science,Tarim University,Alar 843300,Xinjiang,China)
出处
《中国沙漠》
CSCD
北大核心
2020年第1期215-222,共8页
Journal of Desert Research
基金
国家自然科学基金项目(31360109)
国家基础资源调查专项(2017FY100200)
