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| Differences of environmental factors of different vegetation communities in erosion region of red soil in upper reaches of Lijiang river |
| Xiang Wusheng, La Xiankun, Lü Shihong, Ou Zulan, Lu Shuhua, Qin Jiake, Wang Xiaoying, Ye Wenpei |
| Guangxi Institute of Botany, Chinese Academy of Sciences, 541006, Cuilin, Guangxi, China |
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Abstract In order to provide scientific theoretic basis for vegetation restoration and rehabilitation in the eroded red soil region in the Lijiang basin, the differences of microclimatic environmental factors in the communities of primary vegetation types in the eroded red soil region in the upper reaches of Lijiang basin were compared and studied, and the variations of the main environmental factors in the process of vegetation degradation were also analyzed adopting method of time feature deduced by spatial feature. The results showed that the main microclimatic environmental factors have obvious changes in the process of vegetation degradation because of the degradation of vegetation community structure and species components, which is mainly showed in that. The vertical difference and time variation of light intensity in coniferous and broadleaf mixed forest and evergreen broadleaf forest were smaller than those in grass mass and shrub mass. Light intensity increased with height increasing. In above 150 cm, time variation of light intensity is obvious. The air temperature in coniferous and broadleaf mixed forest and evergreen broadleaf forest had 0-0. 5 ℃ of vertical differences and about 2 ℃ of time variations scale in the monitoring time, and the greater vertical difference and time variation of air temperature occurred in grass mass and shrub mass, and the greatest vertical variation scale was 6 ℃. The vertical variation of relative humidity in coniferous and broadleaf mixed forest and evergreen broadleaf forest was less obvious; whose variation scale was less than 5 % as well as that of soil inner temperature was less than 0.5 ℃. In contrast, those were greater in grass mass and shrub mass, and the greatest variation scale of relative humidity reached 25 % as well as the greatest scale of soil inner temperature reached 8 ℃. In general, the light intensity, the air temperature, the soil temperature and difference of our soil temperature increased continually in the process of vegetation degradation, while the air humidity decreased gradually, and their time and space fluctuant degrees were greater by greater.
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Received: 15 November 2004
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