珍贵树种多树种混交林的凋落物现存量及持水性能

Litter standing crop and its water-holding capacity of the mixed forest of rare tree multi-species

【目的】探讨南方珍贵树种多树种随机混交栽培的可行机制,为广西营造珍贵树种优良经营模式提供理论依据。【方法】采用样地调查和室内分析相结合的方法,分析6年生珍贵树种多树种混交林、格木+柚木、格木纯林和降香黄檀纯林4种林分类型的凋落物储量、养分特征及持水性能等生态特征。【结果】凋落物单位面积现存量为:格木+柚木混交林(4550.4 kg/ha)>多树种混交林(3984.9 kg/ha)>降香黄檀纯林(2198.1 kg/ha)>格木纯林(1862.4 kg/ha);多树种混交林凋落物层C/N为20.98∶1,半分解层凋落物储量占凋落物储量的49.34%,养分分解速率高于其他林分类型,且全量N、P、K养分归还总量最高,为66.67 kg/ha。多树种混交林凋落物自然含水率(量)、最高持水率(量)及有效拦蓄总量各项指标均高于格木+柚木混交林和对照纯林。【结论】6年生珍贵树种多树种混交林凋落物现存量不具明显优势,但养分分解速率较快,凋落物N、P、K养分归还总量及持水性能均高于格木+柚木混交林和对照纯林,南方珍贵树种多树种混交模式具有可行性。

[Objective]A feasible mechanism for randomly mixed way of rare tree multi- species in southern China was explored to provide preliminary theoretical references for creating excellent managing modes for rare tree multi- species in Guangxi. [ Method ] By adopting the combination of sample plot survey and indoor analysis method, the under- growth litter reserves, nutrient and water-holding capacity of 6-year mixed forest of multi species, Erythrophloeum fordii and Teetona grandis mixed forest, Erythrophloeum fordii pure forest and Dalbergia odorifera pure forest were studied. [Result]The results indicated that litter standing crop was Erythrophloeum fordii and Tectona grandis mixed forest （4550.4 kg/ha ） 〉mixed forest of multi species （ 3984.9 kg/ha） 〉 Dalbergia odorifera （2198.1 kg/ha ）and Erythrophloeum fordii （1862.4 kg/ha）pure forest. C/N of mixed forest of multi-species was 20.98：1, meanwhile the proportion of F layer was 49.34%. Moreover the total nutrient of NPK （66.67 kg/ha）was higher than any other stand. Index of natural mois- ture content （capacity）, maximum water holding rate （capacity）and modified interception of litter all showed that mixed forest of multi-species was the highest. [ Conclusion ]Litter standing crop of 6-year-old mixed forest of rare tree multi- species has no obvious advantages, however the nutrient decomposition rate is faster. Total nutrient return and water- holding capacity of litter shows that mixed forest of rare tree multi-specie is higher than Erythrophloeum fordii ＋ Tec- tona grandis mixed forest and pure forests.