The Dynamic Studies On Grassland Vegetation Types And Characteristic In Etuokeqian Banner

The paper investaged 173 plots in 93×104hm2grassland of Etuokeqian Banner from 2003 to 2008 and according to classifying principle and standard of China grassland type, we analysised the dynamic characteristic of grassland types. The main results were as follows:1. According to classifying principle and standard of China grassland type, grassland of Etuokeqian Banner was classified warm-temperature grassland type, warm-temperature desert grassland type, warm-temperature grassland desert type, lowland meadow type.And the type was classified 9 sub-types,25 patterns. The warm-temperature grassland type had the maximum area, about 443838.86 hm2; The warm-temperature grassland desert type was the minimum area, about 101546.26 hm2.The plain-hill desert grassland sub-types had the most grassland patterns(12).2. The yield,cover and height had a similar change among years and had a consistent change with precipitation in different grassland patterns. In warm-temperature grassland type, Artemisia ordosica Krasch, Fringed Sagebrush, Thymus serphyllum grassland pattern and Artemisia ordosica Krasch, Periploca sepium,Broadleaved herb grassland pattern had the maximum yield among years.In warm-temperature desert grassland type, Chinese ephedra,Artemisia ordosica Krasch, Broadleaved herb grassland pattern had the maximum yield among years.In warm-temperature grassland desert type, Kalidium foliatum, Reaumuria trigyna, Broadleaved herb grassland pattern had the maximum yield; In lowland meadow type, Phragmites communis, Calamagrostis pseudophragmites, Broadleaved herb grassland pattern had the maximum yield. In different grassland types, the yield of desert grassland sub-type had the maximum change,about 39.04%;low wetland meadow sub-type and warm-tempertaure grassland desert had the middle change,about 36.32%,36.95%;plain-hill desert grassland sub-type,desert grassland sub-type and plain-hill grassland sub-type had the minimum change,about 32.63%,32.58%,32.7%。In different grassland patterns,the maximum change of yield was Artemisia ordosica Krasch, Chinese ephedra grassland pattern;the minimum change was Chinese ephedra, Broadleaved herb grassland pattern.3. The yield,cover and height had different change among seasons in different grassland patterns,but the whole summer and autumn had higher yield,cover and height than winter and spring.And the cover and height had significant change among seasons, autumn>summer>winter>spring. In different grassland types,the maximum change of yield was low wetland meadow sub-type,about32.57%;the middle change were plain-hill grassland sub-type and desert grassland sub-type,about 31.89%,31.14%;the minimum change were plain-hill desert grassland sub-type,desert grassland sub-type and warm-tempertaure grassland desert, about28.60%,28.51%,28.65%. In different grassland patterns,the maximum change of yield was Puccinellia distans, Broadleaved herb grassland pattern,about 36.41%;the minimum change were Caragana Korshinskii, Broadleaved herb grassland pattern,about 16.84%.4. The yield, cover and height had different change among months in different grassland patterns.From January to December, the change of the yield,cover and height was"S"pattern,the lowest was March or Aperl;the highest was August or September. In different grassland types among months,the maximum change of yield was low wetland meadow sub-type ,about 33.11%;the minimum change was plain-hill grassland sub-type,about 22.45%. In different grassland patterns among months,the maximum change of yield were Kalidium foliatum, Reaumuria trigyna, Broadleaved herb grassland pattern,Squarrose agriophyllum, annual grassland pattern and Puccinellia distans, Broadleaved herb grassland pattern,about 36.41%,35.89%,35.79%;the minimum change were Artemisia ordosica Krasch, Fringed Sagebrush, Thymus serphyllum grassland pattern and Phragmites communis, Calamagrostis pseudophragmites,Broadleaved herb grassland pattern,about 26.39%,26.82%.