摘要
为了解植物群落组成对森林土壤理化性质的影响,科学评价寒温带森林土壤养分供给水平。以大兴安岭寒温带白桦(B.platyphalla)林3种林下植被组成(兴安杜鹃-白桦(Rhododendron dauricum-Betula platyphalla)林、草类-白桦(Herba-Betula platyphalla)林、杜香-白桦(Ledum palustre-Betula platyphalla)林)为研究对象,利用聚类推进树和结构方程模型分析白桦林不同林下植被组成和不同土层土壤铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(-)-N)和有效磷(AP)的变化特征及影响因子。结果表明:5—10月份,0~20 cm土层,3种林下植被白桦林土壤NH_(4)^(+)-N和NO_(3)^(-)-N质量分数分别为4.14~21.66 mg·kg^(-1)、3.08~5.49 mg·kg^(-1),在8—9月份,3种林下植被白桦林土壤NH_(4)^(+)-N和NO_(3)^(-)-N质量分数较低;草类-白桦林土壤NH_(4)^(+)-N和NO_(3)^(-)N质量分数显著高于兴安杜鹃-白桦林(P<0.05),无机氮素中,NH_(4)^(+)-N比例为69%。5—10月份,0~20 cm土层土壤有效磷质量分数为7.57~55.21 mg·kg^(-1),土壤有效磷质量分数均在7、8月较低;草类-白桦林土壤有效磷质量分数显著低于兴安杜鹃-白桦林(P<0.05)。林下植被对白桦林土壤氮磷有效性有影响显著(P<0.05),草类-白桦林土壤氮有效性较高,兴安杜鹃-白桦林土壤磷有效性较高,杜香-白桦林土壤有效氮磷质量分数均处于中等水平。土壤含水率(SWC)和可溶性有机氮(SON)是影响3种林下植被白桦林土壤氮有效性的主要因素;土壤酸碱度(pH)是土壤磷有效性的主要影响因素。林下植被通过影响土壤pH值,间接影响土壤磷有效性;NH_(4)^(+)-N与有效磷呈显著负相关,NO_(3)^(-)-N与有效磷呈显著正相关。
In order to understand the impact of plant community composition on the physical and chemical properties of forest soil and scientifically evaluate the nutrient supply level of cold temperate forest soil.Taking three understory vegetation compositions in the cold temperate Betula platyphylla forests in the Great Khingan Mountains(Rhododendron dauricum-B.platyphylla forest,Herba-B.platyphylla forest,Ledum palustre-B.platyphylla forest)as the research objects,the change characteristics and influencing factors of soil ammonium nitrogen(NH_(4)^(+)-N),nitrate nitrogen(NO_(3)^(-)-N)and available phosphorus(AP)in different understory vegetation compositions of B.platyphylla forests and different soil layers were analyzed by using the clustering promotion tree and structural equation model.The results showed that from May to October,in the soil layer of 0-20 cm,the mass fractions of soil NH_(4)^(+)-N and NO_(3)^(-)-N in the three types of B.platyphylla forests with different understory vegetation were 4.14-21.66 mg·kg^(-1) and 3.08-5.49 mg·kg^(-1) respectively.From August to September,the mass fractions of soil NH_(4)^(+)-N and NO_(3)^(-)-N in the three types of B.platyphylla forests with different understory vegetation were relatively low.The mass fractions of soil NH_(4)^(+)-N and NO_(3)^(-)-N in the Herba-B.platyphylla forest were significantly higher than those in the R.dauricum-B.platyphylla forest(P<0.05).Among the inorganic nitrogen,the proportion of NH_(4)^(+)-N was 69%.From May to October,the mass fraction of soil available phosphorus in the soil layer of 0-20 cm was 7.57-55.21 mg·kg^(-1),and the mass fraction of soil available phosphorus was relatively low in July and August.The mass fraction of soil available phosphorus in the Herba-B.platyphylla forest was significantly lower than that in the R.dauricum-B.platyphylla forest(P<0.05).The understory vegetation had a significant impact on the availability of soil nitrogen and phosphorus in B.platyphylla forests(P<0.05).The soil nitrogen availability in the Herba-B.platyphylla forest was relatively high,the soil phosphorus availability in the R.dauricum-B.platyphylla forest was relatively high,and the mass fractions of available nitrogen and phosphorus in the soil of the L.palustre-B.platyphylla forest were at a medium level.Soil water content(SWC)and soluble organic nitrogen(SON)were the main factors affecting the soil nitrogen availability in the three types of B.platyphylla forests with different understory vegetation.Soil pH was the main factor affecting the soil phosphorus availability.The understory vegetation indirectly affected the soil phosphorus availability by influencing the soil pH value.There was a significant negative correlation between NH_(4)^(+)-N and available phosphorus,and a significant positive correlation between NO_(3)^(-)-N and available phosphorus.
作者
张明爽
蔡体久
满秀玲
高明磊
赵欢
Zhang Mingshuang;Cai Tijiu;Man Xiuling;Gao Minglei;Zhao Huan(Northeast Forestry University,Harbin 150040,P.R.China;Wudalianchi City Xinfa Town Agricultural Technology Extension Service Center)
出处
《东北林业大学学报》
北大核心
2025年第5期97-105,115,共10页
Journal of Northeast Forestry University
基金
国家重点研发计划(2021YFD2200405)。
关键词
白桦次生林
林下植被
无机氮
速效磷
Secondary Betula platyphylla forests
Understory vegetation
Inorganic nitrogen
Available phosphorus
