Abstract: Biodiversity is decreasing dramatically with ecological environment deteriorating and human predatory utilization. It has been a critical issue how to protect and study the biodiversity. Hemarthria Compressa is a quality gramineous forage, which is planted in tropical and sub-tropical areas as an excellent grass resource for stockbreeding. In present study, the population component number, distribution, and biomass structure of the cultivated Hemarthria compressa mowing grassland in the different growth period were analyzed. Results show that different curved shapes are seen in the charts among the different parameters. The tiller number of population emerges in an ‘S’ shape during the phenophase. In the early regrowth period and flowering period, the number of secondary tiller is larger than that of the first. When the plant height reaches 50 cm, the number of first tiller which determines the forage yield could ascend to a peak of 3640 tiller/m². During the booting stage when the plant height is about 80 cm, the number of first tiller drops to 2840 tiller/m². Meanwhile, the leaf number of each tiller and of the population are both in an ‘S’ shape shown in the chart. The leaf area of each tiller shows a ‘厂’ shape in the chart, while the leaf area of population gives a typical double ‘S’ shape. In addition, the leaf biomass of each tiller and of the population show an ‘n’ and a double ‘S’ shape, respectively. The number of stem is approximately the same as that of the tiller, though the stem biomass of each tiller and of the population are not shown in an ‘S’ shape synchronously. The aboveground biomass of population is of an ‘S’ shape during the phenophase, while the quality of forage deceases linearly. The changes of the component structure and of the number of population reflect the growth stage and the development condition of the population, which decide the distribution of biomass and the econo-mic outputs. Therefore, scientific and reasonable use and management of the cultivated grassland, based on the growth rhythm of the population, is a key project in the future.

Key words: Hemarthria Compressa, Cultivated population, Component, Biomass, Forage

摘要： 测定扁穗牛鞭草(Hemarthria compressa)人工割草地不同生长时期种群构件数量与分布、生物量结构变化,结果表明:在生育期内种群分蘖数呈现双“S”形变化,在再生初期与开花期二级分蘖数量大于一级分蘖,决定产量的一级分蘖在株高50cm时,数量达最大值3640蘖/cm,到孕穗期(株高约80cm)降为2840蘖/cm;单蘖与叶片数均呈双“S”形变化;单蘖叶面积呈“厂”形变化,而叶面积呈现出典型的双“S”形变化;单蘖和叶片生物量分别呈“n”和双“S”形变化;茎的数量与分蘖数变化一致,单蘖和茎生物量并非同步呈双“S”形变化;地上生物量在生育期内呈“S”形变化;牧草质量呈“直线”形下降。

关键词: 扁穗牛鞭草, 人工种群, 构件, 生物量, 牧草