福州城市森林凋落物动态及其归还量

Litterfall Production and Return Dynamics of Subtropical Urban Forest in Fuzhou

2010年11月—2011年10月,通过对福建省福州市区江滨公园内番石榴、南洋杉和黄花槐3种人工林的凋落物动态及其归还量进行研究,结果表明:番石榴、南洋杉凋落物量在4月和9月出现凋落高峰,而黄花槐凋落物量在4月和8月出现凋落高峰;亚热带城市森林凋落高峰主要受降水量、气温和人为因子共同影响;黄花槐、番石榴和南洋杉年凋落物量分别为6 030.11±422.17、9 701.21±657.30和8 662.58±291.12 kg.hm-2.a-1,黄花槐、番石榴和南洋杉凋落物碳含量在40.9～41.5%,凋落物C归还量分别为2 466.31±175.20、4 026.00±270.81和3 568.98±119.07 kg.hm-2;树种和林分密度是各林分凋落物年归还量差异的主要原因,而单株凋落物年归还量主要受林分密度的影响.

An investigation was carried out to determine litterfall production and its seasonal dynamics in three artificial forests, including Psidium guajava Linn. （PSG）, Sophora xanthantha C. Y. Ma （SOX） and Agathis atropurpurea B. Hyland （AGA） from November 2010 to October 2011 in the Riv-erside Park of Fuzhou, Fujian province, China. Seasonal litterfall variations in PSG and AGA showed that there were two peaks in April and September, while for the SOX, the litterfall peaks occurred in April and August, and the seasonal dynamics and returned productions of litterfall in subtropical urban forest was mainly influenced by precipitation, temperature and human managements. The mean annual total litterfall production over one year of observations varied from 6 030. 11 ±422. 17 kg · hm^-2in the SOX to 9 701.21±657.30 kg · hm^-2 in the PSG. The carbon content ranged from 40. 9% to 41.5%. The annual carbon returned from litterfall in SOX, PSG and AGA were 2 466.31 ± 175.20 kg · hm^-2, 4 026.00 ＋270. 81 kg · hm^-2 and 3 568.98 ± 119.07 kg · hm^-2, respectively. This study demonstra-ted that the returned productions of litteffall in subtropical urban forest were different due to species and stand density, but the stand density also had deep effects on returned productions of litterfall at canopy scale.