黄土高原油松与其他树种枯落叶混合分解对土壤性质的影响

EFFECTS OF DECOMPOSITION OF LEAF LITTERS FROM PINUS TABULAEFORMIS AND OTHER TREES ON SOIL PROPERTIES IN THE LOESS PLATEAU

通过油松及其他10个树种枯落叶单独和混合分解试验,探讨了油松与其他树种枯落叶混合分解对土壤性质的影响及在对土壤性质影响中是否存在相互促进或抑制作用。结果表明:11种枯落叶单独分解均明显提高了土壤脲酶、脱氢酶、磷酸酶活性和有机质、碱解氮含量,但在对土壤速效磷含量和CEC的影响中存在较大差异。油松分别与侧柏、小叶杨、刺槐和白榆枯落叶混合分解对土壤微生物总量的影响存在明显的相互促进作用;油松与沙棘枯落叶混合分解对土壤磷酸酶活性的影响存在相互促进作用,而与侧柏、白桦和白榆枯落叶混合分解对土壤磷酸酶活性的影响存在相互抑制作用;油松与大部分树种枯落叶混合分解对土壤速效钾的影响存在相互促进作用,而对土壤速效磷的影响存在相互抑制作用;油松分别与小叶杨、沙棘、紫穗槐枯落叶混合分解对土壤有机质的影响存在相互促进作用。就土壤性质总体而言,油松与沙棘、刺槐、小叶杨和紫穗槐枯落叶成对混合分解对土壤性质综合表现为相互促进,而与侧柏、辽东栎、白桦、落叶松和柠条枯落叶成对混合分解对土壤性质综合表现为相互抑制。

An indoor experiment was carried out of having leaf litters from Pinus tabulaeformis and from other 10 spe- cies of trees decomposed,separately or mixedly to explore effects of the decomposition on soil properties and any synergic or offsetting actions between the two in mixture. It was found that decomposition of the leaf litters separately significantly increased the activities of soil enzymes, like urease, dehydrogenase and phosphatase, and contents of organic matter and available N,but varied sharply in the effect on available P and CEC in the soil. The decomposition of leaf litter from P. tabulaeformis mixed with that from Platycladus orientalis, Populus simonii, Robinia pseudoacacia, or Ulmus pumila, sepa- rately showed obvious synergic effects on total soil microbe. In decomposition,its mixture with that from Hippophae rham- noides affected activity of the soil enzyme of phosphatase, synergically,but its mixture with the leaf letter from P. orientalis, Betula platyphylla or U. pumila, separately, did reversely. Its mixture with leaf litters from most of the trees, separately, showed a synergic effect on soil available K content, but,reversely on soil available P content. Its mixture with that from P. simonii,H, rhamrtoides or Amorpha fruticosa, separately, displayed a synergic effect on soil organic matter content. In terms of soil properties as a whole in their effects, its mixture with leaf litter from H. rhamnoides, R. pseudoacacia, P. simonii or A. fruticosa , separately , all acted synergically, whereas its mixture with that from P. orientalis , Quercus liao- tungensis, B. platyphyUa, Larix principis-rupprechtii, or Caragana microphylla, separately, did reversely.