天目山柳杉的茎干液流特征

Stem sap flow of Cryptomeria fortunei in Mount Tianmu National Nature Reserve

利用Envis网络生态监测系统,对天目山柳杉Cryptomeria fortunei古树的茎干液流特征及环境因子的动态变化进行了监测,并对柳杉古树茎干液流速率的日变化、月变化进行分析。结果表明:柳杉古树茎干液流速率的日变化呈单峰或多峰曲线,并有明显的昼夜变化规律,茎干液流随环境因子的变化而波动。冬季的平均茎干液流速率在11月份最大,为56.7 mL.min-1,比2月份高22.9 mL.min-1。晴天茎干液流变化幅度较大,雨天茎干液流变化幅度较小。柳杉古树的茎干液流速率与环境因子之间经关联度分析得出:茎干液流速率与光合有效辐射关系最为密切,其次为气温和空气相对湿度。

The group of Cryptomeria fortunei trees in the Mount Tianmu Nature Reserve of Zhejiang Province fall into a decline. In order to find out their life activities, the diurnal and monthly variations of stem sap flow in old growth C. fortunei and environmental factors in the Mount Tianmu Nature Reserve were measured using the Environmental Information System （ENVIS） ecological environment monitoring network. Results showed that the daily change in stem sap flow velocity of declining Cryptomeria fortunei displayed single peak or multi-peaked curves with an obvious day and night rhythmic variation that fluctuated with environmental factors. For seasonal variation, the maximum average stem sap flow was 56.7 mL·min^-1 in November, which was 22.9 mL·min^-1 more than in February （33.8 mL·min^-1）. Also, the range of stem sap flow in the sunshine was greater than for a rainy day. The main environmental factors related to stem sap flow velocity were 1 ） photosynthetic active radiation（PAR）（r = 0.913） and 2） air temperature （r = 0.903） and relative humidity（r = 0.897）. [Ch, 5 fig. 1 tab. 26 ref.]