Modelling the effects of changes in solar radiation on gross primary production in subtropical evergreen needle-leaf plantations

doi:10.3724/SP.J.1258.2014.00019

Abstract

Abstract:

Aims Solar radiation is the energy source of terrestrial ecosystem carbon and water cycles. Observation shows that solar radiation has experienced noticeable variations in recent decades and significantly impacted on plant photosynthesis. Our objective was to investigate the impacts of changes in solar radiation on gross primary production (GPP) at the Qianyanzhou eddy tower site in subtropical forest in China.
Methods We first established the relationship between diffuse radiation fraction and clearness index based on the observed solar radiation and diffuse radiation data. Then, a two-leaf ecological process model, the Boreal Ecosystem Productivity Simulator (BEPS), was used to simulate the impacts of different changes in solar radiation on shaded GPP, sunlit GPP, and canopy GPP in the typical subtropical evergreen needle-leaf plantations.
Important findings Results showed that the effects of changes in solar radiation on shaded leaves predominantly determined the changes in the canopy photosynthesis as the shaded leaves contributed 67% to the total GPP. The impacts of changes in solar radiation on GPP varied inter-annually due to variations in the intensity and distribution of solar radiation from year to year. The GPP during 2003-2005 reached maximum when the solar radiation changed by -5.44%, -1.83%, and 6.26% in each year, respectively. Increased solar radiation enhanced the GPP during May and June, but reduced the GPP from July through September. The shaded leaves responded to changes in radiation differently in different seasons, and the sunlit and shaded leaves had different responses in the same season. Consequently, there were patterns of apparent offset in the total GPP and reduced sensitivity to changes in solar radiation on an annual basis. The changes in solar radiation had the smallest impact on GPP when the clearness index was at 0.43.

Key words: diffuse radiation, direct radiation, gross primary production, shaded leaf, sunlit leaf

LI Deng-Qiu, ZHOU Yan-Lian, JU Wei-Min, WANG Hui-Min, LIU Yi-Bo, WU Xiao-Cui. Modelling the effects of changes in solar radiation on gross primary production in subtropical evergreen needle-leaf plantations[J]. Chin J Plant Ecol, 2014, 38(3): 219-230.

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URL: https://www.plant-ecology.com/EN/10.3724/SP.J.1258.2014.00019

https://www.plant-ecology.com/EN/Y2014/V38/I3/219

Figures/Tables 10

Fig. 1 Seasonal variations in the clearness index and solar radiation in the Qianyanzhou plantation ecosystem from 2003 to 2005. A, B and C are 2003, 2004 and 2005, respectively. The bar represents the percentage of predefined intervals of clearness index (<0.25, 0.25-0.50, ≥0.50) in each month; the open circle represents the monthly average solar radiation.

Table 1 Comparisons between gross primary production (GPP) simulated by the BEPS model and observed at the Qianyanzhou eddy tower site during 2003-2005

年 Year	观测总初级生产力 Observed GPP (g C·m^-2·a^-1)	模拟总初级生产力 Simulated GPP (g C·m^-2·a^-1)	阴叶总初级生产力 GPP in shaded leaves (g C·m^-2·a^-1)	决定系数 Determination coefficient	平均偏差 Mean bias error	均方根误差 Error of mean square root
2003	1 650	1 695	1 138	0.85	0.12	1.01
2004	1 730	1 767	1 174	0.89	0.10	0.83
2005	1 609	1 718	1 157	0.87	0.30	1.02
2003-2005	1 663	1 727	1 156	0.86	0.13	0.94

Fig. 2 Scatterplot between diffuse radiation fraction and clearness index (circle), along with the fitted regression curve (solid line). R0, solar radiation at the top of the atmosphere; Rd, diffuse radiation; Rs, solar radiation.

Fig. 3 Changes in solar radiation (Rs), direct radiation (Rb), and diffuse radiation (Rd) with clearness index (Rs/R0) when solar radiation at the top of the atmosphere (R0) is equal to 40 MJ·m-2·d-1.

Fig. 4 Variations in the photosynthetically active radiation (APAR) (A) and gross primary production (GPP) (B) with changes in solar radiation for shaded and sunlit leaves. ΔAPARsh, ΔAPARsun, ΔGPPsh and ΔGPPsun are the difference (in percentage) of APAR absorbed by the shaded leaves, APAR absorbed by the sunlit leaves, GPP in the shaded leaves, and GPP in the sunlit leaves. 2003SH, 2004SH and 2005SH represent shaded leaves in 2003-2005, respectively; 2003SUN, 2004SUN and 2005SUN represent sunlit leaves in 2003-2005, respectively.

Fig. 5 Relationships between gross primary production (GPP) and changes in solar radiation in 2003, 2004, and 2005, respectively. x, changes in solar radiation; y, annual GPP.

Fig. 6 Impacts of changes in solar radiation on monthly gross primary production (GPP) during 2003-2005. A, B and C are the canopy GPP in 2003, 2004, and 2005, respectively. D, E and F are GPP of the shaded leaves in 2003, 2004, and 2005, respectively. G, H and I are GPP in the sunlit leaves in 2003, 2004, and 2005, respectively. ΔGPP, ΔGPPsh and ΔGPPsun are the differences in the canopy GPP, GPP in the shaded leaves, and GPP in the sunlit leaves, respectively.

Fig. 7 Impacts of changes in solar radiation on canopy gross primary production (GPP), GPP in the shaded leaves (GPPsh), and GPP in the sunlit leaves (GPPsun) in different clearness index intervals. A, B and C are the differences in the percentage for canopy GPP, GPP in the shaded leaves, and GPP in the sunlit leaves, respectively. D, E and F are the differences in canopy GPP, GPP in the shaded leaves, and GPP in the sunlit leaves, respectively.

Table 2 Distribution of clearness index over different periods during 2003-2005

年份 Year	平均晴空指数 Mean clearness index			晴空指数≤0.43 Clearness index ≤0.43
年份 Year	1-12月 January to December	4-6月 April to June	7-9月 July to September	1-12月 January to December	4-6月 April to June	7-9月 July to September
2003	0.39 (0.21)	0.35 (0.18)	0.51 (0.16)	45%	55%	23%
2004	0.38 (0.20)	0.38 (0.19)	0.47 (0.16)	50%	53%	35%
2005	0.33 (0.21)	0.34 (0.18)	0.45 (0.18)	60%	60%	38%
平均值 Mean	0.37 (0.21)	0.36 (0.18)	0.48 (0.17)	52%	56%	32%

Appendix table 1 The key parameters used in the BEPS model in simulating gross primary production (GPP) of the Qianyanzhou ecosystem

参数描述 Parameter description	参数值 Parameter value	来源 Source
比叶面积 Specific leaf area (m²·kg^-1 C)	15	Li et al., 2007
聚集度指数 Clumping index	0.60	He et al., 2013
冠层消光系数 Canopy extinction coefficient	-0.5	Chen & Cihlar, 1996
最大冠层导度 Maximum canopy conductance (mm·s^-1)	1.6	Running & Coughlan, 1988
最大羧化速率 Maximum carboxylation rate (μmol CO₂·m^-2·s^-1)	20	Ju et al., 2010
最大叶氮含量 Maximum leaf nitrogen concentration (%)	1.5	Bonan, 1995
最大叶肉导度 Maximum mesophyll conductance (CO₂ m·s^-1)	8.0e-04	Liu, 2013
光合最低温度 Minimum temperature for photosynthesis (℃)	0	Liu, 2013
光合最适温度 Optimum temperature for photosynthesis (℃)	28	Wen et al., 2010
光合最高温度 Maximum temperature for photosynthesis (℃)	37	Liu, 2013
冠层对降雨的截留系数 Precipitation intercept rate (m·LAI^-1·d^-1)	0.001	Liu, 2013
气孔关闭时的叶水势 Leaf water potential at stomatal closure (MPa)	-2.1	Wang et al., 1991
气孔开放时的叶水势 Leaf water potential at stomatal opening (MPa)	-1.0	Wang et al., 1991
光补偿点 Light compensation point (kJ·m^-2·d^-1)	432	Liu, 2013

References 51

[1]	Alpert P, Kishcha P, Kaufman YJ, Schwarzbard R (2005). Global dimming or local dimming? Effect of urbanization on sunlight availability. Geophysical Research Letters, 32, L17802, doi: 10.1029/2005GL023320.
[2]	Boland J, Scott L, Luther M (2001). Modelling the diffuse fraction of global solar radiation on a horizontal surface. Environmetrics, 12, 103-116.
[3]	Bonan GB (1995). Sensitivity of a GCM simulation to inclusion of inland water surfaces. Journal of Climate, 8, 2691-2704.
[4]	Che H, Shi G, Zhang X, Arimoto R, Zhao J, Xu L, Wang B, Chen Z (2005). Analysis of 40 years of solar radiation data from China, 1961-2000. Geophysical Research Letters, 32, L06803, doi: 10.1029/2004GL022322.
[5]	Chen JM, Cihlar J (1996). Retrieving leaf area index of boreal conifer forests using Landsat TM images. Remote Sensing of Environment, 55, 153-162.
[6]	Chen JM, Liu J, Cihlar J, Goulden M (1999). Daily canopy photosynthesis model through temporal and spatial scaling for remote sensing applications. Ecological Modelling, 124, 99-119.
[7]	Chen JM, Mo G, Pisek J, Liu J, Deng F, Ishizawa M, Chan D (2012). Effects of foliage clumping on the estimation of global terrestrial gross primary productivity. Global Biogeochemical Cycles,, 26, GB1019, doi: 10.1029/2010GB-003996.
[8]	Chen X, Chen J, An S, Ju W (2007). Effects of topography on simulated net primary productivity at landscape scale. Journal of Environmental Management, 85, 585-596.
[9]	Erbs D, Klein S, Duffie J (1982). Estimation of the diffuse radiation fraction for hourly, daily and monthly-average global radiation. Solar Energy, 28, 293-302.
[10]	Fang JY, Chen AP, Peng CH, Zhao SQ, Ci LJ (2001). Changes in forest biomass carbon storage in China between 1949 and 1998. Science, 292, 2320-2322.
[11]	Feng X, Liu G, Chen JM, Chen M, Liu J, Ju WM, Sun R, Zhou W (2007). Net primary productivity of China’s terrestrial ecosystems from a process model driven by remote sensing. Journal of Environmental Management, 85, 563-573.
[12]	Gu LH, Baldocchi D, Verma SB, Black TA, Vesala T, Falge EM, Dowty PR (2002). Advantages of diffuse radiation for terrestrial ecosystem productivity. Journal of Geophysical Research, 107, 4050, doi: 10.1029/2001JD001242.
[13]	Gu LH, Baldocchi DD, Wofsy SC, Munger JW, Michalsky JJ, Urbanski SP, Boden TA (2003). Response of a deciduous forest to the Mount Pinatubo eruption: enhanced photosynthesis. Science, 299, 2035-2038.
[14]	Gu LH, Fuentes JD, Shugart HH, Staebler RM, Black TA (1999). Responses of net ecosystem exchanges of carbon dioxide to changes in cloudiness: results from two North American deciduous forests. Journal of Geophysical Research, 104, 31421-31434.
[15]	He HL, Zhang L, Li JH, Zhou YC, Ren XL, Yu GR (2012). E-Science system for carbon budget integration research of Chinese terrestrial ecosystem. Advances in Earth Science, 27, 246-254. (in Chinese with English abstract)
	[ 何洪林, 张黎, 黎建辉, 周园春, 任小丽, 于贵瑞 (2012). 中国陆地生态系统碳收支集成研究的e-Science系统构建, 地球科学进展, 27, 246-254.]
[16]	He MZ, Ju WM, Zhou YL, Chen JM, He HL, Wang SQ, Wang HM, Guan DX, Yan JH, Li YN, Hao YB, Zhao FH (2013). Development of a two-leaf light use efficiency model for improving the calculation of terrestrial gross primary productivity. Agricultural and Forest Meteorology, 173, 28-39.
[17]	He XZ, Zhou T, Jia GS, Zhang ZY, Li XJ, Zhao C, Feng SH (2011). Modeled effects of changes in the amount and diffuse fraction of PAR on forest GPP. Journal of Natural Resources, 26, 619-633. (in Chinese with English abstract)
	[ 何学兆, 周涛, 贾根锁, 张自银, 李秀娟, 赵超, 冯胜辉 (2011). 光合有效辐射总量及其散射辐射比例变化对森林GPP影响的模拟. 自然资源学报, 7, 619-633.]
[18]	Ju W, Wang S, Yu G, Zhou Y, Wang H (2010). Modeling the impact of drought on canopy carbon and water fluxes for a subtropical evergreen coniferous plantation in southern China through parameter optimization using an ensemble Kalman filter. Biogeosciences, 7, 845-857.
[19]	Knohl A, Baldocchi DD (2008). Effects of diffuse radiation on canopy gas exchange processes in a forest ecosystem. Journal of Geophysical Research, 113, doi: 10.1029/2007 JG000663.
[20]	Lauret P, Boland J, Ridley B (2010). Derivation of a solar diffuse fraction model in a Bayesian framework. Case Studies in Business, Industry and Government Statistics, 3, 108-122.
[21]	Li XR, Liu QJ, Cai Z, Ma ZQ (2007). Specific leaf area and leaf area index of conifer plantations in Qianyanzhou Station of subtropical China. Journal of Plant Ecology (Chinese Version), 31, 93-101. (in Chinese with English abstract)
	[ 李轩然, 刘琪璟, 蔡哲, 马泽清 (2007). 千烟洲针叶林的比叶面积及叶面积指数. 植物生态学报, 31, 93-101.]
[22]	Liang F, Xia XA (2005). Long-term trends in solar radiation and the associated climatic factors over China for 1961-2000. Annales Geophysicae, 23, 2425-2432.
[23]	Liu BY, Jordan RC (1960). The interrelationship and characteristic distribution of direct, diffuse and total solar radiation. Solar Energy, 4(3), 1-19.
[24]	Liu YB (2013). The Spatial and Temporal Variations of Water Use Efficiency in China’s Terrestrial Ecosystems Simulated Using Remote Sensing and a Process-based Model. PhD dissertation, Nanjing University, Nanjing. 123. (in Chinese)
	[ 柳艺博 (2013). 基于遥感和过程模型的中国陆地生态系统水分利用效率时空变化特征研究. 博士学位论文, 南京大学, 南京. 123.]
[25]	Liu YB, Ju WM, Chen JM, Zhu GL, Xing BL, Zhu JF, He MZ (2012). Spatial and temporal variations of forest LAI in China during 2000-2010. Chinese Science Bulletin, 57, 2846-2856.
[26]	Liu YF, Yu GR, Wen XF, Wang YH, Song X, Li J, Sun XM, Yang FT, Chen YR, Liu QJ (2006). Seasonal dynamics of CO₂ fluxes from subtropical plantation coniferous ecosystem. Science in China Series D: Earth Science, 49, 99-109. (in Chinese)
	[ 刘允芬, 于贵瑞, 温学发, 王迎红, 宋霞, 李菊, 孙晓敏, 杨风亭, 陈永瑞, 刘琪璟 (2006). 千烟洲中亚热带人工林生态系统CO₂通量的季节变异特征. 中国科学D辑, 36 99-109.]
[27]	Lloyd J, Taylor J (1994). On the temperature dependence of soil respiration. Functional Ecology, 8, 315-323. DOI URL
[28]	Mercado LM, Bellouin N, Sitch S, Boucher O, Huntingford C, Wild M, Cox PM (2009). Impact of changes in diffuse radiation on the global land carbon sink. Nature, 458, 1014-1017.
[29]	Pan YD, Birdsey RA, Fang JY, Houghton R, Kauppi PE, Kurz WA, Phillips OL, Shvidenko A, Lewis SL, Canadell JG, Ciais P, Jackson RB, Pacala SW, McGuire AD, Piao SL, Rautiainen A, Sitch S, Hayes D (2011). A large and persistent carbon sink in the world’s forests. Science, 333, 988-993.
[30]	Reindl D, Beckman W, Duffie JA (1990). Diffuse fraction correlations. Solar Energy, 45, 1-7.
[31]	Ren XL, He HL, Zhang L, Zhou L, Yu GR, Fan JW (2013). Spatiotemporal variability analysis of diffuse radiation in China during 1981-2010. Annales Geophysicae, 31, 277-289.
[32]	Roderick ML, Farquhar GD, Berry SL, lan Noble R (2001). On the direct effect of clouds and atmospheric particles on the productivity and structure of vegetation. Oecologia, 129, 21-30.
[33]	Running SW, Coughlan JC (1988). A general model of forest ecosystem processes for regional applications I. Hydrologic balance, canopy gas exchange and primary production processes. Ecological Modelling, 42, 125-154.
[34]	Shao ZY, Zhou T, Shi PJ, Gong DY (2009). Spatial-temporal characteristics of the influence atmospheric pollutant on surface solar radiation changes for Chinese key cities. Plateau Meteorology, 28, 1105-1114. (in Chinese with English abstract)
	[ 邵振艳, 周涛, 史培军, 龚道溢 (2009). 大气污染对中国重点城市地面总辐射影响的时空特征高原气象,, 28, 1105-1114.]
[35]	Sinclair T, Murphy C, Knoerr K (1976). Development and evaluation of simplified models for simulating canopy photosynthesis and transpiration. Journal of Applied Ecology, 13, 813-829. DOI URL
[36]	Sprintsin M, Chen JM, Desai A, Gough CM (2012). Evaluation of leaf-to-canopy up scaling methodologies against carbon flux data in North America. Journal of Geophysical Research, 117, doi: 10.1029/2010JG001407.
[37]	Stanhill G, Cohen S (2001). Global dimming: a review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences. Agricultural and Forest Meteorology, 107, 255-278.
[38]	Sun JS, Zhou GS (2010). Review of advances in measurements and effects of diffuse radiation on terrestrial ecosystem productivity. Chinese Journal of Plant Ecology, 34, 452-461. (in Chinese with English abstract)
	[ 孙敬松, 周广胜 (2010). 散射辐射测量及其对陆地生态系统生产力影响的研究进展. 植物生态学报, 34, 452-461.]
[39]	Wang P, Sun R, Hu J, Zhu Q, Zhou Y, Li L, Chen JM (2007). Measurements and simulation of forest leaf area index and net primary productivity in Northern China. Journal of Environmental Management, 85, 607-615.
[40]	Wang SQ, Zhou L, Chen JM, Ju WM, Feng XF, Wu WX (2011). Relationships between net primary productivity and stand age for several forest types and their influence on China’s carbon balance. Journal of Environmental Management, 92, 1651-1662.
[41]	Wang SS, Gao RF, Wu GM (1991). Plant Physiology2nd edn. China Forestry Publishing House, Beijing. Beijing. (in Chinese)
	[ 王沙生, 高荣孚, 吴贯明 (1991). 植物生理学. 第二版. 中国林业出版社, 北京.]
[42]	Wang YP, Leuning R (1998). A two-leaf model for canopy conductance, photosynthesis and partitioning of available energy I: model description and comparison with a multi-layered model. Agricultural and Forest Meteorology, 91, 89-111. DOI URL
[43]	Weiss A, Norman J (1985). Partitioning solar radiation into direct and diffuse, visible and near-infrared components. Agricultural and Forest Meteorology, 34, 205-213. DOI URL
[44]	Wen XF, Wang HM, Wang JL, Yu GR, Sun XM (2010). Ecosystem carbon exchanges of a subtropical evergreen coniferous plantation subjected to seasonal drought, 2003-2007. Biogeosciences, 7, 357-369. DOI URL
[45]	Wild M, Gilgen H, Roesch A, Ohmura A, Long CN, Dutton EG, Forgan B, Kallis A, Russak V, Tsvetkov A (2005). From dimming to brightening: decadal changes in solar radiation at earth’s surface. Science, 308, 847-850. DOI URL
[46]	Xu C, Liu M, An S, Chen JM, Yan P (2007). Assessing the impact of urbanization on regional net primary productivity in Jiangyin County, China. Journal of Environmental Management, 85, 597-606. DOI URL
[47]	Xuan SL, Shi CL, Jin ZQ, Cao HX, Wei XF, Wang JJ (2012). Variation of solar radiation over the middle and lower reaches of the Yangtze River and its influence on photosynthetically active radiation. Jiangsu Journal of Agriculture Science, 28, 1444-1450. (in Chinese with English abstract)
	[ 宣守丽, 石春林, 金之庆, 曹宏鑫, 魏秀芳, 王晶晶 (2012). 长江中下游地区太阳辐射变化及其对光合有效辐射的影响. 江苏农业学报, 28, 1444-1450.]
[48]	Yu GR, Song X, Wang QF, Liu YF, Guan DX, Yan JF, Sun XM, Zhang LM, Wen XF (2008). Water-use efficiency of forest ecosystems in eastern China and its relations to climatic variables. New Phytologist, 177, 927-937.
[49]	Yu GR, Wen XF, Li QK, Zhang LM, Ren CY, Liu YF, Guan DX (2004). Seasonal patterns and environmental control of ecosystem respiration in subtropical and temperate forests in China. Science in China Series D, 34(A02), 84-94. (in Chinese)
	[ 于贵瑞, 温学发, 李庆康, 张雷明, 任传友, 刘允芬, 关德新 (2004). 中国亚热带和温带典型森林生态系统呼吸的季节模式及环境响应特征. 中国科学D辑, 34(A02) 84-94.]
[50]	Zhang WJ, Wang HM, Yang FT, Yi YH, Wen XF, Sun XM, Yu GR, Wang YD, Ning JC (2011). Underestimated effects of low temperature during early growing season on carbon sequestration of a subtropical coniferous plantation. Biogeosciences, 8, 1667-1678.
[51]	Zhou Y, Zhu Q, Chen JM, Wang YQ, Liu J, Sun R, Tang S (2007). Observation and simulation of net primary productivity in Qilian Mountain, western China. Journal of Environmental Management, 85, 574-584.