建瓯和武夷山米槠天然林凋落物量归还动态

林红莲 李爱萍 官惠玲 马红亮 高人

摘 要：为揭示中亚热带米槠天然林凋落数量、组分及季节动态特征。采用凋落叶直接收集法，于2013年开始对建瓯（主林层平均年龄200年）和武夷山（主林层平均年龄50年）两地的米槠天然林进行为期1年的月凋落物收集并测定其质量和各组分含量。结果表明：建瓯和武夷山米槠天然林年凋落物总量分别为9530.49、5590.18 kg·hm-2，建瓯年凋落量显著高于武夷山年均凋落量（P<0.05）;建瓯、武夷山米槠天然林年凋落物总量均呈现单峰模式，峰值分别出现在3月、4月;年凋落物的季节变化规律为春季>夏季>秋季>冬季;在凋落枝、叶、果、杂物等4个组成部分以凋落叶占比最大，占年凋落量的50.5%～67.2%，枝（13.1%～20.8%）和杂物（14.5%～17.8%）次之，果（1.9%～14.2%）最低;各组分凋落物季节变化均是春季和夏季高，秋冬季较低。

关键词：中亚热带;米槠天然林;凋落物;动态

中图分类号：S 723.1 文献标志码：A 文章编号：0253-2301（2021）01-0019-07

DOI：10.13651/j.cnki.fjnykj.2021.01.004

Abstract：The primary purpose of this study was to reveal the amount， composition and seasonal dynamic characteristics of litters in the natural forest of Castanopsis carlesii in the mid-subtropical zone. By using the method of directly collecting litters， the monthly litters of Castanopsis carlesii natural forests in Jian'ou （the average age of the main forest layer was 200 years） and Wuyi Mountain （the average age of the main forest layer was 50 years） have been collected for one year since 2013， and the quality of litters and the content of each component were measured. The results showed that the annual total amount of litters of Castanopsis carlesii natural forests in Jian′ou and Wuyi Mountain were 9530.49 kg·hm-2 and 5590.18 kg·hm-2， respectively， and the annual amount of litters in Jian′ou was significantly higher than that in Wuyi Mountain （P<0.05）. The annual total amount of litters of Castanopsis carlesii natural forests in Jian′ou and Wuyi Mountain showed a single peak model， and the peak value appeared in March and April， respectively. The seasonal change rule of the annual amount of litters was spring>summer>autumn>winter. Among the four components of branches， leaves， fruits and sundries， the litter leaves accounted for the largest proportion， accounting for 50.5%-67.2% of the annual amount of litters， followed by branches （13.1%-20.8%） and sundries （14.5%-17.8%）， and the fruits （1.9%-14.2%） were the lowest. The seasonal changes of each component of litters were all high in spring and summer， but low in autumn and winter.

Key words：Mid-subtropics; Natural forest of Castanopsis carlesii; Litter; Dynamics

森林凋落物（也稱枯落物）是指在森林生态系统中，由森林植物组分产生并归还到地表面所有有机物质的总称[1]。凋落物是植物与土壤之间养分循环连接的“纽带”，不仅是森林生态系统能量流动和养分循环关键环节，还对维持土壤肥力和补充土壤中有机质起着重要作用[2-4]。凋落物量是指单位时间内和单位面积上的林地地段上所有凋落物的总量，凋落量和组成能反映出植物各阶段生长发育过程中更新代谢情况，间接体现森林生态系统的初级生产力水平，是反映生态系统功能的重要指标[5-6]。因此，研究森林凋落物产量、组成、凋落节律变化对于深入了解森林生态系统的养分循环、结构和功能具有重要意义。

米槠Castanopsis carlesii为壳斗科栲属常绿阔叶乔木，它广泛分布于中亚热带地区海拔1300 m以下的山地丘陵。因我国亚……