【摘要】 为认识四川盆地西缘亚热带典型阔叶混交林的凋落物产量模式与养分动态特征,通过直接收集法收集凋落物,对四川盆地西缘乡土珍贵树种峨眉含笑-喜树混交林凋落物产量、碳氮磷含量及归还量月动态进行了为期1年(2016)的观测和分析.结果显示:混交林中叶的年凋落物总量为2 853.36 kg/hm~2,其中含笑1 644.82 kg/hm~2,喜树1208.54 kg/hm~2.两种林木凋落叶产量季节动态明显,含笑凋落叶量最大值在出现4月(476.03 kg/hm~2),最小值出现在9月(43.73 kg/hm~2);而喜树最大值和最小值分别出现在11月(534.41 kg/hm~2)和6月(21.58 kg/hm~2).含笑和喜树凋落叶中碳氮磷含量在夏季相对较高.含笑凋落叶碳氮磷归还量高峰均在4月和11月;喜树凋落叶碳氮磷归还高峰均在11月.混交林凋落叶的碳氮磷年总归还量分别为1 186.11、38.78、1.76 kg/hm~2.总之,该区域混交林凋落物产量月动态模式主要受控于林木生物学特性,且凋落物碳氮磷含量和归还量存在明显季节性变化;结果可为区域生态系统相似混交林的保护和恢复提供理论依据.(图5表1参29)更多还原

【Abstract】 This study aims to determine the leaf litterfall production patterns of native tree species and the dynamic characteristics of carbon(C), nitrogen(N), and phosphorus(P), to provide data support for regional ecosystem protection and restoration. Fresh leaf litter of Michelia wilsonii and Camptotheca acuminata mixed forest was collected by litter traps every month in 2016. The concentrations of C, N, and P in the fresh litter were determined, and their return fluxes were calculated accordingly. The annual litterfall was 2 853.4 kg/hm~2 in this mixed forest, with 1 644.8 kg/hm~2 and 1 208.5 kg/hm~2 for M. wilsonii and C. acuminate,respectively. There were significant seasonal variations in leaf litterfall. The maximum litterfall for M. wilsonii was measured in April(476.0 kg/hm~2) and the minimum in September(43.7 kg/hm~2). The maximum and minimum value for C. acuminate were recorded in November(534.4 kg/hm~2) and June(21.6 kg/hm~2), respectively. The content of C, N, and P in both tree species was relatively large in summer. The two peaks of C, N, and P return flux for M. wilsonii were observed in April and November, with a maximum value in November. The total annual C, N, and P flux within fresh leaf litter of the mixed forest were 1 186.1 kg/hm~2,38.8 kg/hm~2 and 1.8 kg/hm~2, respectively. Leaf litterfall and C, N, and P return fluxes of tree species are dominantly controlled by biological traits. In addition, there are obvious seasonal changes of C, N, and P content and return flux of litterfall, which can provide theoretical basis for the protection and restoration for similar mixed forests in regional ecosystems.更多还原