哀牢山中山湿性常绿阔叶林空心树木质残体呼吸作用初步研究

A Preliminary Research on Respiration of Woody Debris of Hollow-bearing Tree in the Montane Moist Evergreen Broad-leaved Forest of Ailao Mountains,Yunnan,China

对云南哀牢山中山湿性常绿阔叶林空心树木质残体雨季和干季的呼吸速率进行测定,并对木质残体呼吸速率与木质密度和含水量之间的相关关系进行比较,分析了呼吸速率对温度的敏感性。结果表明:树干表层木质残体雨季呼吸速率显著高于树干内层和洞内的(p<0.05),干季三个部位木质残体呼吸速率之间差异不显著(p>0.05)。含水量和呼吸速率存在季节差异,在树干表层和洞内雨季的含水量和呼吸速率显著高于干季的(p<0.05),而在树干内层季节差异不显著(p>0.05)。三个部位木质残体密度与呼吸速率在雨季显著负相关(p<0.01),三个部位的含水量和呼吸速率在雨季和干季都显著正相关(p<0.01);木质残体的温度系数(Q10)大小顺序为:洞内(2.08)>树干表层(2.01)>树干内层(1.73),树洞内部木质残体对温度响应最敏感。哀牢山地区干季空心树木质残体较低的含水量和全年温凉的气候条件可能成为该区中山湿性常绿阔叶林空心树木质残体分解重要的限制因子。

Hollow-beaing tree plays a key role at animal biodiversity of forest fauna in forest ecosystem. We measured the respiration rate of the woody debris of hollow-bearing tree during the rainy season and the dry season in the montane moist evergreen broad-leaved forest of Ailao Mountains, SW China. Furthermore the correlations among respiration rate, wood density and moisture were analyzed and temperature sensitivity of the respiration rate was simulated. The respiration rate of surface layer of trunk during rainy season was significantly higher that those of inner layer of trunk and hollow （p 〈0. 05 ） , but the difference of respiration rate during dry season was not significant for three positions （p 〉 0. 05 ）. The wood moisture and respiration rate of the surface layer, the inner layer and the hollow were higher during the rainy season than the dry season, and the difference was significant （p 〈 0. 01 ） for the surface layer and hollow, but not significant （p 〉 0. 05 ） for the inner layer. There was negative correlation between wood density and respiration rate, and the correlations for three different positions during rainy season were significant （p 〈 0. 01 ）. There was positive correlation between wood moisture and respiration rate for the three different positions during both rainy season and dry season. The temperature coefficient （ Q10 ） for three positions ranks as ： Hollow （2.08） 〉 Surface layer （2. 01 ） 〉 Inner layer （ 1.73 ） , which shows wood debris of hollow was the most sensitive to temperature. The results suggest： the low wood moisture during dry season and the cold climate during whole year were key limiting factors for the decomposition of woody debris of hollow-bearing tree in the montane moist evergreen broad-leaved forest of Ailao Mountains, SW China.