摘要
对休牧后的亚热带人工草地及长期禁牧草地牧草种群的构型及小格局的研究结果表明 ,随着放牧强度的增加 ,鸭茅、红三叶株丛宽度逐渐变小 .在对照及 6只羊·hm-2 、7 5只羊·hm-2 、10只羊·hm-2 轮牧草地上 ,鸭茅基径的峰值分别介于 6～ 8cm、2～ 4cm、0～ 2cm和 0～ 2cm之间 ;红三叶则介于 1～ 1 2cm、6～ 8cm、4～ 6cm和 2～ 4cm之间 ;鸭茅丛密度分别为 6 0、95 1、2 10 2和 16 0丛·m-2 ;单丛艹檗 数量分别为 11 9、11 2、7 3、6 9艹檗/丛 .与禁牧草地相比 ,放牧草地鸭茅单丛蘖的数量明显减少 ,而丛密度则明显增加 .白三叶节间长度因放牧强度增加而明显下降 ,为 1 5 1～ 2 0 4cm ,分枝角度则逐渐变大 ,介于 4 6 5～77 3°.鸭茅、白三叶及红三叶在小格局水平上其格局规模均以 1个样方 (2cm× 2cm)为主 ,并且随着放牧强度的提高 ,鸭茅、红三叶小格局规模进一步变小 .
This study was conducted on a 5-year artificial grassland in subtropical zone of South China.The main types of established artificial grassland there were Dactylis glomerata-Lolium prenne-Trifolium repens and D.glomerata-T.repens pastures. Four grazing intensities were designed,i.e.,CK(no grazing),G 1 (6 adult sheep·hm -2), G 2(7.5 adult sheep·hm -2) and G 3 (10 adult sheep·hm -2),and all the grazing plots were rotationally grazed. The architecture and small-scale pattern of grasses on the grazed and ungrazed grassland were discussed. After a period of 5-year grazing, the plant basal width and sward height of D. glomerata and T. pratense decreased gradually. In treatments CK,G 1,G 2 and G 3,the basal width of D. glomerata was 6～8,2～4,0～2 and 0～2 cm, and that of T. pratense was 1～1.2, 6～8, 4～6 and 2～4 cm, respectively. The tuft density of D. glomerata in treatments CK, G 1, G 2 and G 3 was 60, 95.1, 210.2 and 160 tufts·m -2, respectively. The tiller number per plant of D. glomerata decreased, while its tuft density increased significantly due to the increased grazing intensity. With the increase of grazing intensity, the internode length of T. repens decreased, while its branching angle increased. The average internode length in treatments CK, G 1, G 2 and G 3 was 2.04, 1.69, 1.64 and 1.51 cm, while the branching angle was 46.5, 65, 73 and 77.3°, respectively. The average leaf density of T. repens in treatments CK, G 1, G 2 and G 3 was 2.9, 13.0, 4.7 and 1.0·m -2, while the relevant stolon density was 19.9, 101, 142 and 82.6 m·m -2, respectively. Under moderate grazing intensity, both the leaf and stolon densities of T. repens increased. The main scale on small pattern of D. glomerata, T. repens and T. pratense was 2 cm×2 cm, which was further decreased under higher grazing intensity in the treatments of D. glomerata and T. pratense. Considering the heterogeneity of environmental resources, the change of the architecture and small-scale pattern could be regarded as an adaptation of grasses under grazing disturbance.
出处
《应用生态学报》
CAS
CSCD
2004年第12期2267-2271,共5页
Chinese Journal of Applied Ecology
基金
国家"九五"科技攻关资助项目 ( 960 160 2 0 2 )
关键词
人工草地
牧草
构型
小格局
Artificial grassland, Grass, Architecture, Small-scale pattern.
