Diurnal, Seasonal, and Vertical Changes in Photosynthetic Rates in Cinamomum camphora Forests in Subtropical China

Author:

Li Zhiqiang12,Wu Qinxiang1,Peng Yuanying3ORCID,Lei Junjie1,Liu Shuguang12,Mao Can1,Liu Xin1,Wang Jun12,Yan Wende12,Chen Xiaoyong4ORCID

Affiliation:

1. College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China

2. National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Changsha 410004, China

3. College of Arts and Sciences, Lewis University, Romeoville, IL 60446, USA

4. College of Arts and Sciences, Governors State University, University Park, IL 60484, USA

Abstract

The increase in the global atmospheric CO2 concentration is expected to increase the productivity of forests, but the dynamic processes of such increased productivity in the forest canopy remain unclear. In this study, diurnal and seasonal variations and vertical changes in photosynthetic rates were investigated in Camphor tree (Cinnamomum camphora) forests in subtropical China. The effect of photosynthetically active radiation (PAR) and CO2 concentrations on photosynthetic rates were also examined in the studied forests. Results showed the diurnal patterns of photosynthesis exhibited two peaks on sunny days, but only one peak on cloudy days. The daily average photosynthetic rate on cloudy days was approximately 74% of that on sunny days. The photosynthetic rate decreased along the vertical forest canopy profile. If the photosynthetic rate in the upper canopy layer was 100%, the corresponding rates were 83% and 25% in the middle and lower canopy layers, respectively. The rates of dark respiration derived from the PAR response curve were 1.73, 1.25, and 1.0 µmol m−2 s−1 for the upper, middle, and lower canopy layers, respectively. The apparent quantum yield of photosynthesis was 0.0183, 0.0186, and 0.0327 µmol CO2 µmol−1 PAR for the upper, middle, and lower canopy, respectively. The initial slope of the photosynthetic response curve to CO2 was highest in the upper canopy and lowest in the lower canopy. The seasonal variation in photosynthetic rates exhibited a two-peaked pattern at all canopy positions, with the two peaks occurring in June and September. The stand biomass and biomass carbon storage were 144.7 t ha−1 and 71.6 t C ha−1 in the examined forests, respectively. The study provides a scientific reference for future research on accessing carbon sequestration and designing forest management practices, specifically in regulating canopy structure in subtropical regions.

Funder

National Key R&D Program of China

Joint Funds of the National Natural Science Foundation of China

Key Research and Development Program of Hunan Province

Publisher

MDPI AG

Reference58 articles.

1. The limits of forest carbon sequestration;Green;Science,2022

2. Use of US croplands for biofuels increases greenhouse gases through emissions from land-use change;Searchinger;Science,2008

3. Greenhouse effect: Greenhouse gases and their impact on global warming;Kweku;J. Sci. Res. Rep.,2018

4. Carbon allocation in forest ecosystems;Litton;Glob. Chang. Biol.,2007

5. A meta-analysis of 1,119 manipulative experiments on terrestrial carbon-cycling responses to global change;Song;Nat. Ecol. Evol.,2019

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3