黄河源区“黑土型”退化草地人工群落组分配置技术研究

Studies on Allocate Skills of Artificial Community of "Black Soil Type" Degraded Grassland in the Yellow River Source Region

在黄河源区的"黑土型"退化草地上,以6种多年生禾本科牧草的不同混播处理(A-垂穗披碱草;B-垂穗披碱草+冷地早熟禾;C-垂穗披碱草+冷地早熟禾+中华羊茅;D-垂穗披碱草+冷地早熟禾+中华羊茅+波伐早熟禾;E-垂穗披碱草+冷地早熟禾+中华羊茅+波伐早熟禾+西北羊茅;F-垂穗披碱草+冷地早熟禾+中华羊茅+波伐早熟禾+西北羊茅+短芒老芒麦)进行了连续3 a的群落学试验研究。结果表明,不同混播群落的牧草产量差异极显著(P<0.01),建植的当年,混播群落牧草产量、草层高度和群落盖度等指标主要受垂穗披碱草和短芒老芒麦等高禾草控制;垂穗披碱草单播群落牧草产量显著高于混播群落(P<0.01),第2年各群落生长趋势与建植当年基本一致,但混播群落的生长优势已开始显现。第3年,6种牧草混播处理的牧草产量显著高于单播群落(P<0.01)。不同高、矮禾草的合理配置可有效地优化人工植被的群落结构,遏制单一种建植的快速退化现象,几种多年生禾本科牧草的合理混播配置可能是"黑土型"退化草地进行人工建植恢复的关键技术,是一项快速稳定恢复"黑土型"退化草地植被的重要措施。

Three-years observation for Different mixture combinations of six perennial grasses（A. Elymus nutans , B. Elymus nutans ＋ Poa crymophila , C. Elymus nutans ＋ Poa crymophila ＋ Festuca sinensis ,D. Elyrnus nutans ＋ Poa crymophila ＋ Festuca sinensis ＋ Festuca ryloviana , E. Elymus nutans ＋ Poa crymophila ＋ Festuca sinensis ＋ Festuca ryloviana ＋ Poa poiphagorum, F. El ymus nutans ＋ Poa crymophila ＋ Festuca sinensis ＋ Festuca ryloviana ＋ Poa poiphagorum ＋ Elymus breviaristatus） in ＂Black Soil Type＂degraded grassland of Maqing country, the Yellow River source region was reported in this paper. The result showed that the difference of forage yields among the different mixture communities were very significant. In the planting year, all change of the indexes as forage yield, community height and community coverage were controlled mainly by Elymus nutans and Elymus breviaristatus, forage yield of Elymus nutans were significantly higher in pure culture than in mixture community, growth trend in the second year was in agreement with that in the planting year, while the dominancy of mixture community started to appear. In the third year, forage yield was significantly higher in mixture than in pure culture. Biomass distribution of different sward with different forage composition had become the stable pyramid structure. So, rationally allocating different peren- nial grasses in mixture sowing was the key technology in establishing artificial vegetation for ＂Black Soil Type＂ degraded grassland in the Yangtze River and Yellow River source region, reasonable collo- cation of different tall and low grass varieties optimized effectively community structure, kept single tame pasture from degradation, and was a vital measure to restore ＂Black Soil Type＂ degraded grassland quickly and stably.