辽宁省老秃顶子不同林分类型土壤有机碳储量和碳氮垂直分布特征

以老秃顶子毛榛子灌丛、岳桦林、云冷杉与枫桦混交林、落叶阔叶林4种典型林分为对象,研究不同林分土壤有机碳质量分数和全氮质量分数的垂直分布特征及其与其它土壤基本属性(土壤m(碳)∶m(氮)、全磷质量分数、全钾质量分数、密度和p H值)的相关关系。结果表明:不同林分的土壤有机碳、全氮质量分数都随着剖面深度的增加有明显的降低,且不同土壤层次间呈现显著性差异。不同林分土壤有机碳和全氮质量分数平均值分别在23.45~46.98、1.42~2.91 g/kg,其中云冷杉、枫桦混交林的土壤有机碳和全氮质量分数最高,分别为46.98、2.91g/kg。各林分土壤m(碳)∶m(氮)平均值从大到小依次为岳桦林带、云冷杉与枫桦混交林、落叶阔叶林、毛榛子灌丛带;各林分0≤h50 cm土层土壤有机碳储量从大到小依次为云冷杉与枫桦混交林、毛榛子灌丛带、岳桦林带、落叶阔叶林带,分别为96.36、89.73、81.93和66.16 t/hm2。与土壤有机碳质量分数呈显著负相关的为土壤密度,呈极显著负相关的为土壤p H值,没有显著相关性的为土壤m(碳)∶m(氮)、全磷质量分数、全钾质量分数。

SoilO rganic Carbon Storage and Vertical Distribu tion of Carbon and Nitrogen under Di fferent Forest Types in the Laotudingzi Mountain of Liaoning

We estimated soil organic carbon ( SOC) storage and its vertical distribution under difference forest types, including Corylus mandshurica Maxim brushwood, Betula ermanii forest, Picea-Abies and Ribbed Birch mixed forest, deciduous broad-leaved forest in Laotudingzi Mountain of Liaoning Provence.The content of SOC and total nitrogen ( TN) decreased with increasing soil depth on all of the four soil profiles, and the content of SOC and TN showed significantly differences a-mong layers.The content of SOC and TN in Picea-Abies and Ribbed Birch mixed forest were the highest among the four for-est types (46.98 and2 .91 g/kg, respectively).The content of SOC and TN in four forest soils ranged from 23.45 to 46.98 g/kg and from 1.42 to 2.91 g/kg, respectively, in the descending order of Picea-Abies and Ribbed Birch mixed forest, Corylus mandshurica Maxim brushwood, Betula ermanii forest, and deciduous broad-leaved forest.The mean C/N was in the descending order of Betlu a ermain i forest (18.1) , Picea-Abies and Ribbed Birch mixed forest (16.2), deciduous broad-leaved forest (16.2), and Corylus mandshurica Maxim brushwood (16.1).The descending order of SOC storage of 0-50 cm soil layer was Picea-Abies and Ribbed Birch mixed forest (96.36 t/hm2), Corylus mandshurica Maxim brushwood (89. 73 t/hm2), Betula ermanii forest (81.93 t/hm2), and deciduous broad-leaved forest (66.16 t/hm2).Correlations analysis showed significantly positive correlations between SOC and TN, and highly negative correlation between pH, but no signifi-cant correlations between C/N, total phosphorus and total potassium.