草地学报

›› 1991, Vol. 1 ›› Issue (1): 156-162.DOI: 10.11733/j.issn.1007-0435.1991.01.019

• 研究论文 • 上一篇    下一篇

甘肃天祝高山线叶嵩草草地的第一性物质生产和能量效率:Ⅲ、草层的热值动态和光能转化率

胡自治1, 张映生1, 孙吉雄1, 徐长林1, 张自和2   

  1. 1. 甘肃农业大学, 兰州;
    2. 甘肃草原生态研究所, 兰州
  • 出版日期:1991-02-15 发布日期:2012-07-11

STUDIES ON MATTER PRODUCTION AND ENERGY EFFICIENCY IN TIANZHU ALPINE KOBRESIA CAPILLIFOLIA GRASSLAND:Ⅲ DYNAMICS OF CALORIFIC VALUES OF SWARO AND EFFICIENCY FOR SOLAR ENERGY UTILIZATION

Hu Zizhi1, Sun Jixiong1, Zhang Yinsheng1, Xu Changlin1, Zhang Zihe2   

  1. 1. Department of Grassland Science, Gansu Agricultural University, Gansu;
    2. Gansu Grassland Ecological Research Institute, Lanzhou
  • Online:1991-02-15 Published:2012-07-11

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摘要： 甘肃天祝金强河地区高山线叶嵩草草地6—10月绿色活体的平均热值为19186.03焦/克干物质,或20797.88焦/克有机物质。立枯物+凋落物(6—11月)、活根和死根(6—10月)的平均热值均低于绿色活体。草层的最大热量现存量,地上部分是在8月,地下部分是在6月,全草层(地上+地下部分)是在10月出现,分别为6920.53,93311.89和101444.09千焦/米2。地上、地下部分热量净积累分别为6314.85和16818.44千焦/米2·年,而全草层的热量净积累为14842.39千焦/米2·年。地下部分的热量现存量在各时期均远大于地上部分,它是草地生态系统中主要的热量库,对能量的流转和地上部分的生长具很大的调节作用,并且是草地耐牧性的物质基础。草地对太阳总辐射的光能转化率地上部分为0.110%,地下部分为0.303%,全草层为0.253%;地上部分对可见光生理辐射的转化率为0.224%,≥0℃—≤0℃生长季的光合效率为0.404%。

关键词: 高山, 线叶嵩草草地, 热值, 热量现存景, 光能转化率

Abstract: Calorific value and energy of sward and efficiency for solar energy utili-zation were determined during June to Noverber on Tianzhu alpine Kobresia capillifolia grassland.Outlinets of the results were as follows:1.The average calorific value of standing green was 19186.03j/g DM (20797.88 OM)and ranged from 13888.46 to 9466.47j/g DM (20500.10 to 21223.11 OM),it was higher than standing dead+litter,live roots or dead roots,while live rootshigherthan dead roots.There were some seasonal fluctuations of calorific values,the highest values of the standing green and standing dead+litter and lowest values of the live and dead roots were all in August.2.Maximum standing calorie of aboveground,underground and whole phyto-mass occurred on August 21,June 21 and October 23 and values of them was 6920.53,84968.62 and 937444.09kj/m2.yr.,respectively.Net calorie accumulation of aboveground and underground and whole sward was 6314.85,16818.44 and 14842.39 kj/m2.yr.,respectively.Becouse maximum standing calorie of both above ground and underground was not appearance in the same time,so net calorie ac-cumulation of whole sward was not sum of them.3.Conversion efficiency for solar total radiation utilization of aboveground,underground and whole sward was 0.110%,0.303% and 0.258%,respectively.Ef-ficiency of aboveground for physiological radiation of visible light was 0.224% and for photosynthetically available radiation during growth season was 0.404%. Maximum efficiency of aboveground for total radiation could reach to 0.464%occurred on July 20 to August 21.

Key words: alpine, Kobresia capillifolia grassland, calorific value, standing calorie, conversion efficiency for solar radiation.