惠蓀林場三種林分2001年枯落物及養分迴歸量研究

Study on the Litterfall and Recycling Amount of Nutrients of Three Stands in Hui-Sun Experimental Forest During 2001

以台灣中部惠蓀林場三種不同林分（天然林、杉木林、次生林）為對象，自2001 年1 月至2001年12月，調查每月枯落物量，包括落葉、枝條、繁殖體及其它，並分析養分的迴歸量。結果顯示全年枯落物總量以天然闊葉林5,508.3 kg ha-1 yr-1 為最高，次生闊葉林為3,664.1 kg ha-1 yr-1 次之，杉木人工林976.6 kg ha-1 yr-1 為最低。枯落物量在月份間有極顯著的差異，可區分為雙高峰期，一為3 月的生長季節，大量老葉被新葉取代而脫落，另一為6~7 月的颱風季節，因颱風侵襲而影響枯落物的總量及其成分比例。三種林分枯落物各成分中，皆以落葉量所佔比率為最高佔60.4~71.4 %、枝條枯佔12~16 %、繁殖體佔4.5~14.4 %、其他部份佔8.2~14.4 %。枯落物各養分迴歸量皆為天然闊葉林＞ 次生闊葉林＞ 杉木人工林。三種林分全年養分迴歸量為碳417.6~2,250.1 kg ha-1、氮11.9~85.3 kg ha-1、磷1.0~7.5 kg ha-1、鉀5.8~55.6 kg ha-1、鈣5.5~49.8 kg ha-1、鎂2.1~14.3 kg ha-1。 The monthly amount of litterfall and nutrient recycling amount of three different stands (natural hardwood stand, NS; China-fir plantation stand, CPS; and secondary hardwood stand, SS) in the Hui-Sun Experimental Forest were monitored from Jan. 2001 to Dec. 2001. The results showed that the annual total litterfall of NS (5,508.3 kg ha-1 yr-1) was the highest followed by SS (3,664.1 kg ha-1 yr-1), CPS (976.6 kg ha-1 yr-1) was the lowest. The amounts of litterfall varied significantly with month and indicated that litterfall showed two peaks during the study period. One was in growth season (March), and the other one was in typhoon season (June and July). The litterfall of which 60.4-71.4% was composed of leaf, 12-16% was branch, 4.5-14.4% was reproduction, and the remainder (8.2-14.4%) comprised other plant materials. The litterfall nutrient recycling amounts were NS＞SS＞CPS. Recycling amounts of these nutrients included 417.6-2,250.1 kg ha-1 C, 11.9-85.3 kg ha-1 N, 1.0-7.5 kg ha-1 P, 5.8-55.6 kg ha-1 K, 5.5- 49.8 kg ha-1 Ca and 2.1-14.3 kg ha-1 Mg, respectively.

The monthly amount of litterfall and nutrient recycling amount of three different stands (natural hardwood stand, NS; China-fir plantation stand, CPS; and secondary hardwood stand, SS) in the Hui-Sun Experimental Forest were monitored from Jan. 2001 to Dec. 2001. The results showed that the annual total litterfall of NS (5,508.3 kg ha-1 yr-1) was the highest followed by SS (3,664.1 kg ha-1 yr-1), CPS (976.6 kg ha-1 yr-1) was the lowest. The amounts of litterfall varied significantly with month and indicated that litterfall showed two peaks during the study period. One was in growth season (March), and the other one was in typhoon season (June and July). The litterfall of which 60.4-71.4% was composed of leaf, 12-16% was branch, 4.5-14.4% was reproduction, and the remainder (8.2-14.4%) comprised other plant materials. The litterfall nutrient recycling amounts were NS＞SS＞CPS. Recycling amounts of these nutrients included 417.6-2,250.1 kg ha-1 C, 11.9-85.3 kg ha-1 N, 1.0-7.5 kg ha-1 P, 5.8-55.6 kg ha-1 K, 5.5- 49.8 kg ha-1 Ca and 2.1-14.3 kg ha-1 Mg, respectively.