湖南会同林区杉木人工林呼吸量测定

对杉木人工林的CO2排放动态和杉木各木质器官呼吸量进行了测定,结果表明,杉木树干呼吸的季节变化规律为3~7月份随着树木生长和气温的升高,树干呼吸呈上升的趋势,在7月份达年呼吸速率的最大值,CO2为0.376m g/(m3.m in)。8月至12月呈逐渐递减的趋势,在1~3月份树干呼吸基本上维持在一定数值上,并且杉木树干呼吸在杆材生长时期随着年龄的增大而减小;杉木树干呼吸的日变化规律为:一天中杉木树干呼吸基本上是随着温度升高而增大,随着温度降低而减小,中午前后出现午休现象。在杉木树干呼吸日变化曲线中出现两次高峰期,一次是在12:00~16:00时,另一高峰出现在24:00。根据测出的有关参数,用积分方法推导出杉木树干、树枝和树根的年呼吸量CO2分别为9.67t/(hm2.a)、2.21 t/(hm2.a)和2.12t/(hm2.a),结合叶片呼吸速率测定,计算出杉木林年呼吸量CO2为21.523 t/(hm2.a),其中,叶片年呼吸量CO2为7.523t/(hm2.a)。并初步确定杉木树干的维持呼吸占年呼吸的39.7%。

Respiration of chinese fir in plantations in Huitong,Hu'nan Province

Chinese fir(Cunninghamia lanceolata(Lamb.) Hook.) is a native and major commercial tree species in South China.Because of its high quality in timber and hence its high commercial value,Chinese fir has been widely planted in the subtropical area of China.The plantations of Chinese fir account for approximately one fourth of the total plantation forests in the area.In addition to its economic values,Chinese fir plantations are important to environmental protections in South China. Researches on the productivi...