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密度梯度对植物生物量分配格局的制约影响到混播草地在生态和生产上表现。2010年6—9月采用取代系列实验方法,在石羊河上游建立1年生人工混播草地,按燕麦(Avena sativa L.)与毛苕子(Vicia villosa Roth)的密度比例设置A(8:2)、B(6:4)、C(5:5)、D(4:6)和E(2:8)5个处理,研究了密度对燕麦与毛苕子生物量分配格局的影响。结果表明:混播草地中随着燕麦相对密度的减小和毛苕子相对密度的增大,燕麦根系生物量先减小后增大最后再减小的趋势与毛苕子相反,燕麦和毛苕子茎、叶生物量先减小后增大;随着牧草的生长,5种混播草地中燕麦和毛苕子茎生物量分配比例逐渐增加,叶、根生物量分配比例逐渐减少。密度制约下混播牧草资源分配策略发生的调整,证明了植物地上部分对光竞争的不对称性和地下部分对资源竞争的对称性,毛苕子攀援生长及其对燕麦茎秆的压力使植物茎秆生物量分配比例较高,实现了资源利用的最大化。
The restriction of density gradient on plant biomass distribution pattern affects the ecological and productive performance of mixed-sown grasslands. From June to September 2010, a series of artificial mixed grasslands were established in the upper reaches of Shiyang River using the substitution series of experimental methods. The density of Avena sativa L. and Vicia villosa Roth was set as A (8: 2) The effects of planting density on the biomass allocation pattern of oat and hazelnut were studied under the treatments of B (6: 4), C (5: 5), D (4: 6) and E (2: 8) The results showed that with the decrease of the relative density of oats and the relative density of the hairy ram in the mixed sowing grassland, the biomass of the oat first decreased, then increased and then decreased. In contrast with the hairy ramie, the biomass of stems and leaves First reduced and then increased; with the growth of forage grass, biomass allocation of oats and hairy ramie seedlings increased gradually in five mixed-sowing grasslands, and the proportion of leaf and root biomass decreased gradually. Density constraints under mixed grass forage resource allocation adjustment occurred to prove that the aerial part of the plant competition for the asymmetry of light and subsurface part of the competition for resources, hairy climbing growth and its pressure on the oat stem stalks organisms A higher proportion of the allocation of resources to achieve maximum utilization of resources.