植物功能群去除对内蒙古典型草原羊草群落土壤碳、氮库的影响

2005—2007年，通过野外植物功能群去除试验，研究了内蒙古典型草原羊草群落植物多样性变化对土壤表层碳、氮库的影响.结果表明：典型草原生态系统表层土壤全碳、全氮含量年际变化较小(＜15%)，2005年的土壤全碳、全氮含量与2006、2007年无显著差异(P>0.05)，但2006年的土壤全碳、全氮含量显著高于2007年(P<0.05);无机氮含量年际变化较大，2006年铵态氮含量比2007年高80%，差异显著(P<0.05)，而硝态氮含量年变化不显著(P>0.05).去除植物功能群的数量和土壤硝态氮含量存在显著的线性正相关(P<0.05).说明植物物种多样性降低使土壤硝态氮含量增加，可能导致土壤氮的淋溶损失.

Effects of plant functional groups removal on the soil carbon, nitrogen pools in a Leymus chinensis community of typical steppe in Inner Mongolia.

A field plant functional groups (PFGs) removal experiment was conducted in 2005 〖KG-*2〗-〖KG-*7〗2007 to study the effects of plant diversity in a Le ymus chinensis community of typical steppe in Inner Mongolia on the topsoil (0〖KG-*2〗-〖KG-*7〗10 cm) carbon (C) and nitrogen (N) pools. In the three succ essive years, the topsoil total C and N contents had a slight change (<15%). They changed little in 2005, but were significantly higher in 2006 than i n 2007 (P<005). The topsoil NH4+-N content had a greater inter-annu al change, being 80% higher in 2006 than in 2007, while the NO3--N content had less significant change (P>005). There was a positive linear relation ship (P<005) between the number of removed PFGs and the content of soil NO3--N, which meant that the decrease of plant diversity increased so il NO3--N content, and consequently, led to a possible soil nitrogen loss through leaching.