發(fā)布時(shí)間：2018-08-11 15:04

【摘要】：川西亞高山森林群落土壤氮循環(huán)對(duì)全球氣候變化非常敏感。采用室內(nèi)培養(yǎng)法,研究川西3個(gè)森林群落(天然針葉林、云杉人工林和樺木次生林)土壤有機(jī)層和礦質(zhì)土壤層無(wú)機(jī)氮含量在兩個(gè)培養(yǎng)溫度(20℃和10℃)下4周內(nèi)動(dòng)態(tài)變化。結(jié)果表明:培養(yǎng)4周后,在20℃培養(yǎng)條件下天然針葉林、云杉人工林和樺木次生林硝態(tài)氮含量比在10℃培養(yǎng)條件下分別高出104.32%、52.11%和25.57%;而銨態(tài)氮含量?jī)H高出10.18%、24.06%和44.82%。有機(jī)層土壤氨化速率、硝化速率和凈氮礦化速率大多表現(xiàn)為20℃顯著高于10℃;相反,溫度對(duì)礦質(zhì)土壤層氮轉(zhuǎn)化速率影響大多不顯著。此外,天然林土壤凈氨化速率、硝化速率和凈氮礦化速率均高于樺木次生林和云杉人工林。實(shí)驗(yàn)期間,3個(gè)森林群落土壤凈硝化速率20℃比10℃高79.03%—128.89%,而凈氨化速率僅高37.81%—63.33%。綜上所述,溫度變化對(duì)川西亞高山森林土壤氮礦化具有顯著影響,而溫度效應(yīng)因森林類型、土壤層次和氮形態(tài)而不同。與礦質(zhì)土壤層相比,土壤有機(jī)層氮礦化對(duì)溫度變化更為敏感。
[Abstract]:The soil nitrogen cycle of the alpine forest community in western Sichuan is very sensitive to global climate change. The contents of inorganic nitrogen in soil organic layer and mineral soil layer of three forest communities (natural coniferous forest, Picea spruce plantation and secondary birch forest) in western Sichuan were studied under two culture temperatures (20 鈩，

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