Phenology of Mongolian Grasslands and Moisture Conditions
Phenology of Mongolian Grasslands and Moisture Conditions
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DOI：
10.2151/jmsj.85.359
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发表时间：
2007-06
影响因子：
3.1
通讯作者：
M. Shinoda;Shunsuke Ito;G. U. Nachinshonhor;D. Erdenetsetseg
中科院分区：
文献类型：
--
作者：
M. Shinoda;Shunsuke Ito;G. U. Nachinshonhor;D. Erdenetsetseg
利用蒙古草原独特的长期农业气象观测资料，研究了蒙古草原优势种针茅的物候(如羽化、抽穗、开花、成熟和衰老)与代表主要植被带的3个站点的水分条件之间的关系。结果表明，羽化日期与特定温度或有效积温无关，而与多数情况下羽化前5天内的降水有关。降雨量与出苗至抽穗天数呈显著正相关(r=0.93)，而向南典型草原区(Arvaikheer)也呈正相关(但不超过5%显著水平)。这种正相关很可能发生在布尔干，因为在干旱年份，针茅属植物。物候期往往比正常年份提前从营养生长阶段(即生物量增加)转换到生殖阶段(即种子生产)。这种转换的一个可能的触发因素是土壤湿度的降低，这与雨季的中断有关。
Unique long-term agro-meteorological measurements of Mongolian grasslands enabled us to investigate the relationship between the phenology of Stipa spp., one of the dominant perennial species (such as emergence, heading, flowering, maturity, and senescence), and moisture conditions for three stations representative of the major vegetation zones, during 1993 to 2002.The results showed that the emergence date relates neither to a specific temperature nor to an effective accumulative temperature, but to the presence of precipitation that occurs within five days prior to the emergence in most cases. For a northern-most wettest forest steppe region (Bulgan), the precipitation amount, and period of days from emergence to heading are significantly correlated (r = 0.93), while a southward typical steppe region (Arvaikheer) also exhibited a positive correlation (but not exceeding the 5% significance level). The positive correlation occurred at Bulgan most likely, because for drought years, Stipa spp. tended to switch a phenological stage from the vegetative growth (that is, a biomass increase), to reproductive phase (that is, seed production) earlier than for a normal year. One possible trigger for the switching is a decreased soil moisture, associated with a break of the rainy season.