摘要
以黄土丘陵区沙棘(Hippophae rhamnoides)+油松(Pinus tabuliformis)、沙棘(H.rhamnoides)+刺槐(Robinia pseudoacacia)混交林(H_(r)P_(t)、H_(r)R_(p))及油松(P_(t))和刺槐(R_(p))纯林为对象,测定叶片、凋落物和0—100 cm土壤C、N、P含量及其化学计量比,探究混交造林对不同组分间养分协同变化规律的影响。结果表明:(1)相比P_(t),H_(r)P_(t)中油松叶片C、N、P含量(p<0.05)及N∶P(p>0.05)增加,C∶N和C∶P降低(p>0.05),表明H_(r)P_(t)有助于缓解N限制,加快其生长速率;相比R_(p),H_(r)R_(p)中刺槐叶片C、N含量及C∶P和N∶P降低,P含量及C∶N增加(p>0.05),表明H_(r)R_(p)增强刺槐对P的吸收,但降低其对C和N的固存;(2)相比P_(t),H_(r)P_(t)凋落物C、N、P含量及N∶P增加,C∶N和C∶P降低(p<0.05),表明H_(r)P_(t)有助于加快凋落物分解,促进养分归还;相比R_(p),H_(r)R_(p)凋落物C、N、P含量及其计量比均有所增加(p>0.05),表明H_(r)R_(p)对凋落物分解无显著作用;(3)相比P_(t)和R_(p),H_(r)P_(t)和H_(r)R_(p)土壤C、N、P含量增加,但C∶N和C∶P降低(p>0.05),表明H_(r)P_(t)和H_(r)R_(p)均有助于提高N和P利用效率,改善土壤养分状况;(4)叶片、凋落物化学计量指标间具有较强协同效应,且N、P相比C在不同组分间的相关性更明显。综上,相比H_(r)R_(p),H_(r)P_(t)更有助于改善养分限制因子供给,加快组分间养分转化。研究结果对于揭示黄土高原地区人工混交林生态系统养分供应潜力及合理制定营林规划具有重要意义。
Ecological stoichiometry focuses on the balance of chemical elements in ecological processes,in which the stoichiometric characteristics of carbon(C),nitrogen(N)and phosphorus(P)in different components are important features of ecosystem functions and processes.At present,it is not clear how the introduction of Hippophae rhamnoides(N-fixing)affects the nutrient cycling mechanism of ecosystem in N-fixing or non-N-fixing pure plantations.Therefore,two kinds of mixed forests(H.rhamnoides+Pinus tabuliformis,H_(r)P_(t);H.rhamnoides+Robinia pseudoacacia,H_(r)R_(p))and the pure forests of P.tabuliformis(P_(t))and R.pseudoacacia(R_(p))were selected.The C,N and P contents in leaf,litter and 0—100 cm soil layer were quantified,and the effects of mixed afforestation on the synergistic variation of nutrients among different components were explored.The results indicated that:(1)Compared with P_(t),the C,N,P contents(p<0.05)and the N∶P(p>0.05)increased,while C∶N and C∶P decreased(p>0.05)in the leaves of P.tabuliformis in H_(r)P_(t),indicating that H_(r)P_(t) was helpful to relieve the restriction of N and accelerate its growth rate.Meanwhile,compared with R_(p),the C,N,C∶P and N∶P decreased,while P and C∶N increased of R.pseudoacacia in H_(r)R_(p)(p>0.05),suggesting that H_(r)R_(p) might enhance the absorption of P by R.pseudoacacia,but the sequestration of C and N would be decreased.(2)The C,N,P contents and N∶P of the litters in H_(r)P_(t) were significantly higher than those of P_(t),and the C∶N and C∶P values were significantly lower than those of P_(t),indicating that H_(r)P_(t) was helpful to accelerate the decomposition rate of litter and promote nutrient return.Compared with R_(p),the C,N,P contents and their stoichiometric ratios of the litters in H_(r)R_(p) increased(p>0.05),suggesting that H_(r)R_(p) did not significantly promote the decomposition of litter.(3)Compared with P_(t) and R_(p),the soil C,N and P contents in H_(r)P_(t) and H_(r)R_(p) increased,but C∶N and C∶P decreased(p>0.05),in
作者
吴旭
牛耀彬
陈云明
董从国
乔雨宁
WU Xu;NIU Yaobin;CHEN Yunming;DONG Congguo;QIAO Yuning(College of Resources and Environment,Shanxi Agricultural University,Taigu,Shanxi 030801;Institute of Soil and Water Conservation,Northwest Agriculture and Forestry University,Yangling,Shaanxi 712100;State Key Laboratory of Soil Erosion and Dry Land Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences,Ministry of Water Resources,Yangling,Shaanxi 712100)
出处
《水土保持学报》
CSCD
北大核心
2021年第4期369-376,共8页
Journal of Soil and Water Conservation
基金
山西省高等学校科技创新项目(2020L0141,2020L0146)
山西农业大学科技创新基金(博士科研启动)项目(2020BQ38,2020BQ44)
山西省优秀博士来晋工作奖励项目(SXYBKY2020007)。
关键词
混交林
沙棘
油松
刺槐
黄土丘陵区
生态化学计量
mixed forest
Hippophae rhamnoides
Pinus tabuliformis
Robinia pseudoacacia
loess hilly region
ecological stoichiometry
