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氮沉降和凋落物量的改变是全球变化影响森林生态系统的重要途径,然而二者的交互作用对土壤生态过程的影响仍知之甚少。本文研究氮添加(对照和添加10 gN·m~(-2)·a~(-1))和地表凋落物管理(对照、移除和加倍)对科尔沁沙地樟子松人工林干季(5月)和湿季(8月)土壤有效氮、基础呼吸和有效磷等的影响。结果表明:凋落物管理对土壤的影响在对照和氮添加样地中差异较大;在对照样地中,凋落物移除和加倍都显著提高了8月土壤呼吸,对有效磷和氮含量基本上无显著影响;在氮添加样地,凋落物移除与加倍均未影响土壤呼吸和有效磷含量,但显著降低有效氮含量;氮添加和凋落量变化的影响在湿季大于干季;单一的氮添加显著降低了8月的土壤有效磷含量和土壤呼吸,而凋落物量加倍减缓了氮沉降对土壤呼吸的抑制和磷限制性的加剧。
Changes in nitrogen deposition and litterfalls are important ways in which global changes affect forest ecosystems. However, the interactions between the two have little effect on soil ecological processes. In this paper, the effects of nitrogen addition (control and addition of 10 gN · m -2 · a -1) and surface litter management (control, removal and doubling) on the dry season of Pinus sylvestris var. Mongolica in Horqin sandy land May) and wet season (August) soil available nitrogen, basic respiration and available phosphorus and so on. The results showed that litter management affected the soil significantly differently in the control and nitrogen-added plots; in the control plots, litter removal and doubling significantly increased soil respiration in August, and the contents of available phosphorus and nitrogen No significant effect was observed in the nitrogen addition sites. Both litter removal and doubled litter removal did not affect soil respiration and available phosphorus content, but significantly decreased the available nitrogen content. The effects of nitrogen addition and litterfall change were greater in the wet season than in the dry season. The nitrogen addition significantly reduced soil available phosphorus and soil respiration in August, while doubling the amount of litter reduced the inhibition of nitrogen respiration on soil respiration and aggravated phosphorus restriction.