豫东平原杨-农复合系统凋落物的数量、组成及其动态

Amount,composition and seasonal dynamics of litterfall in Poplar-Crop agroforestry ecosystems in Henan Eastern Plain

农林复合系统的凋落物既是维持植被系统和土壤系统养分循环的关键,也是维持农林复合系统结构和功能的重要因子。通过对豫东平原农区4年生、9年生和12年生3个不同林龄杨-农复合系统杨树凋落物的数量、组成及季节动态的研究来为深入研究农林复合系统对大气中CO2的调节作用以及碳循环机理提供参考数据。结果表明,4a杨-农复合系统年凋落物总量为11.18.thm-2;9a杨-农间作复合系统年凋落物总量为12.86 t.hm-2;12a杨-农复合系统年凋落物总量为13.75 t.hm-2。3个不同林龄的杨-农复合系统凋落物总量月变化模式较为相似,均在8月和11月份出现峰值,而以11月份数量最大。其季节变化模式则为秋季>冬季>夏季>春季。

Litterfall is a structurally and functionally important component of agroforestry ecosystems and plays an essential role in supplying organic matter and nutrient for the soil and sustaining nutrient cycle in vegetation-soil system. Amount, composition and seasonal dynamics of litterfall were investigated in the poplar-crop agroforestry systems with different years of poplar plantation （4, 9, and 12 years）in Henan Eastern Plain. The results showed that annual litterfall was 11.18, 12. 86 and 13.75 t·hm^-2 in the three years agroforestry systems, respectively, with a similar seasonal change pattern in the order autumn 〉 winter 〉 summer 〉 spring. Two monthly peaks of litterfall was found in August and in November in the three systems, respectively.. The present study provides important basis and scientific reference for further research on nutrient biogeochemical cycling, CO2 flux and carbon sequestration in agroforesty ecosystems.