岩溶石漠化不同修复林分的生物量和生产力及其动态变化

Biomass, Productivity and Their Dynamic Changes of Different Restoration Stands in Karst Rocky Desertification

关键词:  石漠化  纯林  混交林  生物量  定期平均净生产力  动态变化

Key words:  rocky desertification  pure plantation  mixed plantation  biomass  periodic mean net productivity  dynamic change

摘要:

为阐明岩溶石漠化不同修复林分的生物量和生产力特征及其动态变化规律，选择2011年营造的顶果木Acrocarpus fraxinifolius纯林(PAFP)、降香黄檀Dalbergia odorifera纯林(PDOP)和顶果木×降香黄檀混交林(MADP)为研究对象，设置固定监测样地，基于2013年、2015年、2019年和2021年的4次林分生物量测定，研究3种修复林分生物量、定期平均净生产力的特征及动态变化。结果表明：(1) 3种修复林分生物量均随年龄的增加而显著增加；不同林分、不同树种各器官生物量的变化规律类似，但不同器官生物量的变化规律有所不同。(2) 3种林分在2013-2021年的林分定期年平均净生产力以PDOP最高(8.68 t/hm²),PAFP最低(2.36 t/hm²)，MADP (5.09 t/hm²)介于两者之间；3种修复林分在2015-2019年、2019-2021年和2013-2021年的林分定期平均净生产力均存在显著差异,PDOP显著高于MADP和PAFP，MADP显著高于PAFP(P<0.05)；采用豆科固氮树种修复10 a的林分净生产力达到甚至超过了岩溶顶极、次顶极森林乔木层的净生产力，PAFP、MADP和PDOP在2019-2021年平均净生产力比2015-2019年分别提高53.65%、113.32%和38.36%，实现了岩溶石漠化生态系统生产力的快速修复和提升。(3) PAFP林分树叶的年平均净生产力非常低，仅为0.08 t/hm²，分别占PDOP (0.62 t/hm²)的12.90%和MADP (0.30 t/hm²)的26.67%,这是随着时间推移PAFP逐渐衰退的重要原因。

Abstract:

In order to clarify the characteristics of biomass and productivity and their dynamic change rules of different restoration stands in Karst rocky desertification, pure Acrocarpus fraxinifolius platation (PAFP), pure Dalbergia odorifera plantaion (PDOP) and mixed A.fraxinifolius×D.odorifera plantation (MADP) constructed in 2011 were selected as research objects.The fixed monitoring plots were set up to study the characteristics of biomass, periodic average net productivity and their dynamic changes of three kinds of restoration stands based on the four stand biomass measurements in 2013, 2015, 2019 and 2021.The results showed that the biomass of the three restoration stands had increased significantly with age.The biomass of organs in different stands and tree species changed similarly.However, the biomass variation of different organs was different.From 2013 to 2021, the periodic annual average net productivity was the highest (8.68 t/hm²) in PDOP, the lowest (2.36 t/hm²) in PAFP and MADP (5.09 t/hm²) was between the two.In 2015-2019, 2019-2021 and 2013-2021, there were significant differences in the periodic average net productivity of the three restoration stands.PDOP was significantly higher than MADP and PAFP, and MADP was significantly higher than PAFP.Our studies found that the net productivity of the restored Karst forest after 10 years restoration using legume nitrogen fixing tree species reached or even exceeded the net productivity of the Karst climax and sub-climax forests.The average net productivity of PAFP, MADP and PDOP in 2019-2021 increased by 53.65%, 113.32% and 38.36% respectively compared with 2015-2019, which indicated that the rapid restoration and improvement of ecosystem productivity in Karst rocky desertification were realized.The annual average net productivity of leaves in PAFP stands was very low, only 0.08 t/hm², accounting for 12.90% of PDOP (0.62 t/hm²) and 26.67% of MADP (0.30 t/hm²), which was an important reason for the gradual decline of PAFP over time.