森林、草地和农田典型植被蒸散量的差异

利用中国生态系统研究网络(CERN)12个试验站1990—2003年的气象资料,基于大气-土壤-植被传输(SVAT)模型模拟植被的蒸散量,分析了不同气候条件下森林、草地、农田3种植被类型蒸散的变化规律.结果表明:多年平均蒸散量从高到低依次为热带森林、亚热带农田、温带森林、温带农田和草地;对农田生态系统而言,水稻的蒸散量最高,其次为小麦,玉米最低;3种生态系统月蒸散量峰值的年际变化差异显著,森林、草地的月蒸散量峰值年际变化较稳定,农田则较明显.

Differences of evapotranspiration on forest, grassland and farmland

By using the 1990-2003 meteorological data gathered from 12 ecosystem stations of Chinese Ecosystem Research Network, the evapotranspiration rates of forest, grassland and farmland were estimated by soil-vegetation-atmosphere transfer model, with their change patterns under different climate conditions investigated. The results showed that the mean annual evapotranspiration from high to low ranked as tropical forestland, subtropical farmland, temperate forestland, temperate farmland and grassland. For farmland, rice field had the highest annual evapotranspiration, followed by wheat field, and maize field. There was an obvious monthly variation of evapotranspiration on forestland, grassland and farmland, but the inter-annual amplitude of the variation was steadier on forestland and grassland than on farmland.