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纯林土壤腐殖质含量及其构成是否会因枯落叶组成的单一性和单优群落环境的特殊性而发生分异变化是关系到森林可持续经营的关键问题.本文以内蒙半干旱低山区的6种典型纯林为研究对象,研究了不同树种纯林土壤腐殖质分异特征及其与其他生物化学性质的关系.结果表明:云杉和白桦林地土壤的腐殖质含量、缩合程度和稳定性均较高,其次为小叶杨和落叶松林地,再次为白榆林地,而油松林地土壤的腐殖质含量和缩合程度均最低、稳定性最差.土壤微生物生物量和磷酸酶活性与腐殖质各组分的积累及其稳定性存在相互促进作用;过氧化氢酶和脱氢酶活性则与土壤腐殖质存在相互抑制作用,且脱氢酶活性的提高可能破坏腐殖质的稳定性.速效N含量与腐殖质积累及其稳定性呈正相关,而全量Cu、Fe、Zn含量与腐殖质呈负相关,全Cu、Fe的增加可能会破坏腐殖质的稳定性.纯林环境及其枯落叶性质的特殊性是造成腐殖质分异的重要原因,混交改造或增加林下植被是改善土壤腐殖质构成的根本措施.
Whether pure forest soil humus content and composition will change due to the unity of litter composition and the uniqueness of single superior community environment is the key issue of sustainable forest management.Taking the 6 The results showed that the humus content, the degree of condensation and the stability of soils in spruce and birch were higher than those in the other two species , Followed by Populus simonii and Larix gmelinii, and once again the white-leaf forest, while the Pinus tabulaeformis soil had the lowest humus content and the lowest degree of condensation.The stability of the soil microbial biomass and phosphatase activity was negatively correlated with the accumulation of humus components And their stability promoted each other; catalase and dehydrogenase activity and soil humus mutual inhibitory effect, and increased dehydrogenase activity may undermine the stability of humus. Available N content and humus accumulation and stability While the content of total Cu, Fe and Zn was negatively correlated with humus, and the increase of Cu and Fe may destroy the stability of humus The peculiarities of the pure forest environment and its litter are the important reasons for the differentiation of the humus, and the mixed cultivation or the increase of the subsoil vegetation is the fundamental measure to improve the composition of the soil humus.