高寒混播草地优势草种生态位与种间竞争力分析

Niche and Interspecific Competitiveness of Dominant Herbage Cultivar in Alpine Mixture Artificial Grassland

为了探究高寒混播草地最优牧草配置,以上繁草‘同德’短芒披碱草(Elymus breviaristatus‘Tongde’,A),垂穗披碱草(Elymus nutans,B),‘同德’老芒麦(Elymus sibiricus‘Tongde’,D),‘青牧1号’老芒麦(Elymus sibiricus‘Qingmu No1’,E)、下繁草‘同德’小花碱茅(Puccinellia distans‘Tongde’,C),‘青海’草地早熟禾(Poa pratensis L.‘Qinghai’,F),‘青海’冷地早熟禾(Poa crymophila‘Qinghai’,G),‘青海’扁茎早熟禾(Poa pratensis var.anceps Gaud.‘Qinghai’,H)为试验材料,以种间竞争力(Competition ratio,CR)与相对产量总和(Relative yield total,RYT)为评价方法,测定牧草生物量。结果表明:下繁草竞争力小于上繁草;混播牧草数(Number of mixed herbage,NMH)为2时,B竞争力最强;NMH为3时,存在2种上繁草的组合RYT大于1;单播时C和A生态位宽度最大,混播后杂类草生态位宽度降低,D和E,C重叠度最高,A与F,G,H重叠度最低;高寒混播草地中优选牧草组合有B+E,B+D,E+H,A+C+D,B+C+D,建议慎选牧草组合为C+D,D+E,F+G,F+H,F+G+H。

In order to explore the alpine mixed grassland optimal variety configuration,Top grass Elymus breviaristatus‘Tongde’(A),Elymus nutans(B),Elymus sibiricus‘Tongde’(D),Elymus sibiricus‘Qingmu No1’(E),and Bottom grass Puccinellia distans‘Tongde’(C),Poa pratensis L.‘Qinghai’(F),Poa crymophila‘Qinghai’(G)and Poa pratensis var.anceps Gaud.‘Qinghai’(H)were used as materials.Competition ratio(CR)and Relative yield total(RYT)were used as evaluation method to determine the biomass of herbage.The results showed that:The competitiveness of the bottom grass was less than that of the top grass;When the Number of mixed herbage(NMH)was 2,B was the most competitive herbage.When NMH was 3,RYT of two top grass were greater than 1.The niche width of C and A were the largest in monoculture,but the niche width of weeds decreased after mixed sowing.The niche overlap of D,E,and C was the highest,and that of A with F,G,and H was the lowest.The combinations of B+E,B+D,E+H,A+C+D,B+C+D should preferred for alpine mixed grassland,and C+D,D+E,F+G,F+H,F+G+H should avoided.