濒危珍稀植物七子花落叶的分解特性

The Decomposition Characteristics of Deblades of the Dangerous,Precious and Rare Plant Heptacodium miconioides

研究了亚热带地区濒危植物七子花落叶在不同网袋中的分解速率及其与土壤微生物和土壤环境因子的关系。结果表明:七子花落叶在不同网袋中的分解速率均呈单峰曲线变化。其中0 5cm网袋中的分解速率的峰值出现在9月份,分解速率达2 73mg·g-1d-1。0 2cm和0 1cm网袋中的分解速率的峰值出现在10月份,分解速率分别达3 61mg·g-1d-1和3 65mg·g-1d-1。七子花群落的土壤微生物和土壤净呼吸速率的旺盛期也发生在9～10月份。通径分析表明,在0 5cm的网袋中,七子花落叶分解的主要影响因素为土壤真菌、土壤净呼吸速率、土壤含水量。在0 2cm和0 1cm网袋中,主要影响因素为土壤温度、土壤净呼吸速率和放线菌的数量。各环境因素与土壤净呼吸速率之间的相互作用对七子花落叶分解速率产生的间接影响相对较大。

The results show that the decomposition rates of Heptacodium miconioides deblades in different net bags all assume unimodal curve change.The peak value of decomposition rate of the deblades in the net bag with the mesh diameter of 05 cm occurs in September,the decomposition rate reaches 273mg·g-1d-1.That of the deblades in the net bags with the mesh diameters of 02 cm and 01 cm occurs in Oct.,the de composition rates reach 361mg·g-1d-1 and 365mg·g-1d-1,respectively. The path analysis shows that in the net bag with mesh diameter of 05cm,the main influencing factors of Heptacodium miconioidesdeblade decomposition are the soil fungi,the soil net respiration rate and the soil water content.In the net bags with mesh diameters of 02 cm and 01 cm,those are the soil temperature,the soil net respiration rate and the ray fungi number. 