开垦天然草地种植冰草和小麦对草地生产力和土壤碳储量的影响

Effects of Converting Native Grassland to Crested Wheatgrass and Wheat on Grassland Productivity and Soil Carbon Stock

[目的]为更加合理地利用和管理草地,保证草地可持续发展提供理论指导。[方法]选取代表性品种多年生牧草冰草和一年生作物小麦研究开垦天然草地对草地地上净初级生产力ANPP和草地土壤碳储量的影响 选取2个植被组成和土壤类型均不同的样地进行ANPP和土壤碳储量的对比研究。[结果]结果表明：ANPP和0~2×109、0~12×109g/hm2土壤碳储量显著受到样地和种植处理的影响（P〈0.05）。开垦天然草地种植冰草13/12年后,ADRI和Onefour样地的ANPP降低,而种植小麦使ANPP增加。开垦天然草地种植冰草13/12年土壤碳储量和对照相比无显著变化而种植小麦使土壤碳储量显著降低。ADRI样地3个处理的ANPP和土壤碳储量均显著高于Onefour样地的ANPP和土壤碳储量（P〈0.05）。加拿大混合普列里草地类型上,草地ANPP和土壤碳储量呈线性正相关关系（P〈0.0001）。[结论]加拿大混合普列里草地类型上,开垦天然草地种植冰草和小麦13或12年后使草地生产力发生明显变化。

[ Objective ] The research aimed to utilize and manage grassland more resonably and to provide theoretical guidance for the sustainable development of grassland. [ Method ] Two representitive forage types, prennial grass crested wheatgrass and annual crop wheat were chosed as cultivation treatments. Two sites （ ADRI and Onefour） were established in spring of 1993 and 1994 to investigate converting native grassland to crested wheatgrass and wheat on ANPP and soil carbon stock. [ Result]The results showed that, ANPP in 0 -2 × 10^9 and 0 - 12 ×10^9g/hm2 soil mass layers were significantly affected by sites and treatments （P 〈 0.05 ）. Converting native grassland to crested wheatgrass 13/12 years led lower ANPP while wheat led higher ANPP. Converting native grassland to crested wheatgrass 13/12 years had no effects on soil carbon stock （P 〉0.05） while wheat led lower soil carbon stock （P 〈0.05）. The ANPP of all treatments in ADRI site were all higher than those of Onefour site （ P 〈 0.05 ）. On Canadian Mixed Prairie, grassland ANPP had positive liner relation to soil organic carbon stock （ P 〈 0. 000 1 ）. [ Conclusion] Planting crested wheatgrass and wheat on Canadian Mixed Prairie for 13/12 years introduced grassland productivity changed significantly.