摘要
【目的】理解尾巨桉人工林土壤有机碳、全氮、全磷和全钾含量及其化学计量学特征随林龄(1、2、3、5、7年生)的变化,为研究尾巨桉人工林可持续发展提供理论基础。【方法】运用空间代时间的研究方法,选取立地条件相近的5个林龄的林分,在各林分内设置3块样地,采用5点法分层取样,测定土壤有机碳、全氮、全磷和全钾含量,并计算不同元素之间的计量比。【结果】尾巨桉人工林表层土壤(0~20 cm)的有机碳含量随着林龄增加而增加,但不同林龄表层土壤的全氮含量差异不显著。5年生林地全磷与全钾含量均低于或显著低于(P<0.05)其他各林龄;不同林龄林下土壤有机碳和全氮含量均随土层深度增加而下降,土壤全磷及全钾含量随土层深度变化未产生显著差异;随林龄增加,表层土壤碳氮比、碳磷比有增加趋势,土壤磷钾比、碳钾比、氮钾比随着林龄的增加呈现先降低后升高的变化趋势,不同林龄间土壤氮磷比未产生显著差异;相关分析表明:土壤有机碳与土壤全氮、全磷含量呈极显著正相关(P<0.01),土壤全氮、全磷及全钾含量间相关性均不显著(P>0.05)。【结论】研究区尾巨桉中幼龄期林下土壤碳氮循环速率较低,随林龄增加,土壤有机质矿化速率有所下降。5个林龄土壤磷元素含量较充足,氮元素成为主要限制因子。
[Purpose]The study explored the changes of soil organic C, total N, total P, total K and the stoichiometric characteristics of the Eucalyptus urophylla×E. grandis fast-growing forest with different ages(1, 2, 3, 5, 7 years) on the Leizhou Peninsula to provide theoretical basis for scientific management.[Method]Three sample plots were set in E. urophylla×E. grandis plantations with different ages. The five points sampling method was used for stratification and sampling. The concentration of carbon(C), nitrogen(N), phosphorus(P) and potassium(K) and the stoichiometric characteristics was analyzed in different plantations and soil depths.[Result]Soil C content(0~20 cm) increased signifcantly with the raising of stand age, while the total N content had minor differences. The total P and K content of 5-years old forest were lower or significantly lower(P<0.05) than other eucalyptus plantations. Soil organic C and total N in the five different plantations decreased with the increase of soil depth, the total P and total K content had smaller variability among the soil depth. The C/N and C/P had an increasing tendency with the increase of age while P/K, C/K and N/K decreased firstly, then increased in 5 and 7-years old; there was no significant difference in soil N/P among the different ages. Correlation analyses showed that: the soil organic C had significantly positive correlation with total N and total P(P<0.01). Correlations among soil total N, total P and total K were insignificant(P>0.05).[Conclusion]The circulation rate of the soil C, N of the E. urophylla×E. grandis in the middle and young age on the Leizhou Peninsula was comparatively slow. The mineralization rate of soil organic matter decreased with age increasing. Stands growth was limited by N.
引文
[1]ELSER J J,BRACKEN M E,CLELAND E E,et al.Global analysis of nitrogen and phosphorus limitation of primary producers in freshwater,marine and terrestrial ecosystems[J].Ecology Letters,2007,10(12):1135.DOI:10.1111/ele.2007.10.issue-12.
[2]贺金生,韩兴国.生态化学计量学:探索从个体到生态系统的统一化理论[J].植物生态学报,2010,34(1):2.DOI:10.3773/j.issn.1005-264x.2010.01.002.
[3]冼伟光,周丽,唐洪辉,等.不同林龄针阔混交林土壤生态化学计量特征[J].广东林业科技,2015,31(1):1.DOI:10 .3969/j.issn.1006-4427.2015.01.001.
[4]赵亚芳,徐福利,王渭玲,等.华北落叶松针叶碳、氮、磷含量及化学计量比的季节变化[J].植物营养与肥料学报,2015,21(5):1328.DOI:10.11674/zwyf.2015.0528.
[5]HAN W X,FANG J Y,GUO D L,et al.Leaf nitrogen and phosphorus stoichiometry across 753 terrestrial plant species in China[J].The New Phytologist,2005,168(2):377.DOI:10.1111/j.1469-8137.2005.01530.x.
[6]陈亚梅,刘洋,张健,等.巨桉混交林不同树种C、N、P化学计量特征[J].生态学杂志,2015,34(8):2096.
[7]王娜,程瑞梅,肖文发,等.三峡库区马尾松根和叶片的生态化学计量特征[J].林业科学研究,2016,29(4):536.DOI:10.3969/j.issn.1001-1498.2016.04.011.
[8]赵维俊,刘贤德,金铭,等.祁连山青海云杉林叶片-枯落物-土壤的碳氮磷生态化学计量特征[J].土壤学报,2016,53(2):477.
[9]曹娟,闫文德,项文化,等.湖南会同3个林龄杉木人工林土壤碳、氮、磷化学计量特征[J].林业科学,2015,51(7):1.DOI:10.11707/j.1001-7488.20150701.
[10]韩瑞芸,陈哲,杨世琦.秸秆还田对土壤氮磷及水土的影响研究[J].中国农学通报,2016,32(9):148.
[11]廖观荣,简明,钟继洪,等.桉树人工林生态系统养分循环与平衡研究Ⅴ.桉树林间种山毛豆对土壤肥力与林木生长的作用[J].生态环境,2003,12(4):443.DOI:10.3969/j.issn.1674-5906.2003.04.017.
[12]刘国粹,杜阿朋,陈少雄.桉树人工林养分循环研究成果分析[J].桉树科技,2013,30(3):60.DOI:10.3969/j.issn.1674-3172.2013.03.010.
[13]余雪标,白先权,徐大平,等.不同连栽代次桉树人工林的养分循环[J].热带作物学报,1999,20(3):60.
[14]陈少雄.桉树中大径材培育理论及关键技术研究[D].长沙:中南林业科技大学,2010.
[15]张治军,李慧,王志超,等.4个尾巨桉幼林林地土壤生态化学计量特征[J].桉树科技,2014,31(4):23.DOI:10.3969/j.issn.1674-3172.2014.04.005.
[16]张利丽,杜阿朋,刘国粹,等.不同整地方式尾巨桉林地土壤生态化学计量学特征[J].桉树科技,2015,32(3):28.DOI:10.3969/j.issn.1674-3172.2015.03.005.
[17]韩斐扬,周群英,陈少雄,等.2种桉树不同林龄生物量与能量的研究[J].林业科学研究,2010,23(5):690.
[18]孙楠.稻田改制对土壤理化性质的影响及其调控[D].北京:中国农业科学院,2007.
[19]邵梅香.南亚热带红椎与西南桦生态化学计量学特征研究[D].南宁:广西大学,2012.
[20]ZHOU G Y,LIU S G,LI Z,et al.Old-growth forests can accumulate carbon in soils[J].Science,2006,314(584):1417.DOI:10.1126/science.1130168.
[21]王春阳,周建斌,夏志敏,等.黄土高原区不同植物凋落物可溶性有机碳含量及其降解[J].应用生态学报,2010,21(12):3001.DOI:10.13227/j.hjkx.2011.04.006.
[22]樊后保,袁颖红,廖迎春,等.闽南山区连续年龄序列桉树人工林土壤养分动态[J].应用与环境生物学报,2009,15(6):756.
[23]庞圣江,张培,贾宏炎,等.桂西北不同森林类型土壤生态化学计量特征[J].中国农学通报,2015,31(1):17.
[24]JOBBAGY E G,ROBERT B J.The vertical di stribution of soil organic carbon and its relation to clmate and vegetation[J].Ecological Applications,2000,10(2):423.DOI:10.2307/2641104.
[25]WALKER T W,ADAMS A F R.Studies on soil organic matter:I[J].Soil Science,1959,87(1):10.DOI:10.1097/00010694-195901000-0001.
[26]刘兴诏,周国逸,张德强,等.南亚热带森林不同演替阶段植物与土壤中N、P的化学计量特征[J].植物生态学报,2010,34(1):64.DOI:10.3773/j.issn.1005-264x.2010.01.010.
[27]秦娟,孔海燕,刘华.马尾松不同林型土壤C、N、P、K的化学计量特征[J].西北农林科技大学学报(自然科学版),2016,44(2):68.
[28]高丽丽.西藏土壤有机质和氮磷钾状况及其影响因素分析[D].雅安:四川农业大学,2004.
[29]王维奇,曾从盛,钟春棋,等.人类干扰对闽江河口湿地土壤碳、氮、磷生态化学计量学特征的影响[J].环境科学,2010,31(10):2411.
[30]王绍强,于贵瑞.生态系统碳氮磷元素的生态化学计量学特征[J].生态学报,2008,28(8):3937.DOI:10.3321/j.issn:1000-0933.2008.08.054.
[31]CLEVELAND C C,DANIEL L.C:N:P stoichiometry in soil:is there a“redfield ratio”for the microbial biomass?[J].Biogeochemistry,2007,85(3):235.DOI:10.1007/s10533-007-9132-0.
[32]MAJDI H,OHRVIK J.Interactive effects of soil warming and fertilization on root production,mortality,and longevity in a Norway spruce stand in Northern Sweden[J].Global Change Biology,2004,10(2):182.DOI:10.1111/j.1529-8817.2003.00733.x.
[33]TIAN H Q,CHEN G S,ZHANG C,et al.S Hall.Pattern and variation of C:N:P ratios in China’s soils:a synthesis of observational data[J].Biogeochemistry,2010,98(1):139.DOI:10.1007/s10533-009-9382-0.
[34]贾宇,徐炳成,李凤民,等.半干旱黄土丘陵区苜蓿人工草地土壤磷素有效性及对生产力的响应[J].生态学报,2007,27(1):42.DOI:10.3321/j.issn:1000-0933.2007.01.005.
[35]MAKOI J,NDAKIDEMI P A.Selected soil enzymes:examples of their potential roles in the ecosystem[J].African Journal of Biotechnology,2008,7(3):181.DOI:10.5897/AJB07.590.
[36]TESSIER J T,RAYNAL D J.Use of nitrogen to phosphorus ratios in plant tissue as an indicator of nutrient limitation and nitrogen saturation[J].Journal of Applied Ecology,2003,40(3):523.DOI:10.1046/j.1365-2664.2003.00820.x.