摘要
采用OTC模拟增温实验,研究了川西北亚高山草甸植物群落结构及生物量对温度升高的响应。由于开顶式生长室(OTC)的增温作用,在整个生长季内,地温(15cm)、地表温度和气温(30cm)的平均值在OTC内比对照样地分别高0.28、0.46℃和1.4℃,OTC内土壤相对含水量也明显减少,低于对照样地5.49%。受增温及土壤含水量减少的影响,1年后,植物群落结构及生物量生产发生了显著的改变。植物群落优势种和组成结构发生改变。OTC内禾草的盖度(19.21%)及生物量(44.07g/m2),均显著大于对照样地(8.04%和18.1g/m2),而杂类草的盖度(72.8%)及生物量(210.54g/m2)均显著小于对照样地(83.5%和244.9g/m2)。OTC内的地上鲜体生物量(265.17g/m2)和地下0～30cm的根系生物量(1603.84g/m2)与对照样地(分别为272.63g/m2和1826.77g/m2)相比较,都出现了不同程度的减少。根系在土壤不同层中的分配比例明显改变,OTC内0～10cm土层的生物量分配比例增加,而20～30cm土层的生物量分配比例则明显减少。
From 2006 to 2007, a total number of 5 open top chamber （OTC） experiments were carried out in the subalpine meadow of northwestern Sichuan province, and the effects of the OTCs on temperature, soil water content, and plant biomass and community structure were examined. In the growing season, the mean soil temperatures at depth of 15cm and of ground surface and the air temperature at 30cm above ground were enhanced by 0.28℃ , 0.46℃ and 1.4℃ by the OTC facility, respectively. However, soil water content in OTC was 5.49% lower than that in the control ones. With the warming and drying effect, plant biomass and community structure of the subalpine meadow changed significantly. The grass coverage （19.21%） and biomass （44.07g/m^2） in the OTC were significantly higher than those in the control （8.04% and 18. 1g/m^2, respectively）, while the forbs coverage （72.8%） and biomass（210.54g/m^2）in OTC were significantly lower than those in the control （83.5% and 244.9 g/m^2, respectively）. Above- and below-ground plant fresh biomass were 265.17g/m^2 and 1603.84 g/m^2 in OTC, respectively, significantly lower than those in the control （272.63g/m^2 and 1826.77g/m^2, respectively）. The distribution pattern of root biomass was also significantly changed by the OTCs. The proportion of root biomass increased at the depth of 0 -10cm soil layer but decreased at the depth of 20 -30cm soil layer, relative to those of the control.
出处
《生态学报》
CAS
CSCD
北大核心
2008年第11期5286-5293,共8页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(40671181
90511008)
国家"十一五"科技支撑计划资助项目(2006BAC01A11
2006BAC01A15)
四川省青年基金资助项目(03ZQ026-043)~~
关键词
川西北
亚高山草甸
开顶式生长室
增温
群落结构
生物量
Northwestern Sichuan
sub-alpine meadow
open top chamber
temperature enhancement
community structure
biomass
