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北方黑云杉林冠内空气CO_2浓度及其上方通量模拟



全 文 :北方黑云杉林冠内空气 CO2浓度
及其上方通量模拟
申双和 孙照渤
(南京信息工程大学气象灾害实验室 , 南京 , 210044)
陈镜明
(多伦多大学地理规划系 ,多伦多 , M5S 3G3)
摘  要
   考虑植物阴叶和阳叶对环境的反应 、植物叶片丛聚特性以及叶片氮素水平的垂直差异 , 建立了黑云杉林与大
气之间物质输送和能量交换的一维完全多层模式。模式中对阳叶和阴叶的叶面积指数借用 Chen J M 等提出的方
法 ,并经过修改以适用于多层模拟。叶水平的光合作用 c运用 Farq uhar方程并与 CO 2 传导方程联列获得。模式验
证的资料取自 BOREAS(Boreal Ecosy stem-fA tmosphere Study)研究计划中加拿大 Saskatchewan 的南试验区 ,属于温
带气候。通过对冠 o层上方的显热 、感热和 CO 2通量 、以及植物光合作用 、蒸腾作用和气孔传导等生理作用 t过程
的实测值进行了计算结果的验证 ,结果表明:计算的显热通量比实测值偏低 , 潜热通量则略高于实测值 ,而 CO 2 通
量只有在较高水平时偏高 , 3 个通量的计算值与实测值比较接近 , R 2 分别为 0.71 , 0.78 和 0.65 , 取得了较好的效
果。气孔导度 、光合作用和蒸腾作用的模拟结果表明 , 三者的实测与模拟值之间的 R2 分别达到 0.57 , 0.69 和
0.66 , 均通过 0.01 显著度检验 , 且无显著的系统偏差。因此 ,可以认为在多层模拟中充分考虑叶片不同受光状况 ,
不同氮素水平以及叶片丛聚特性的影响有助于更好地研究植被与大气的交换过程。
关键词:黑云杉 , CO2 通量 , 完全多层模式 ,二叶模型 , 叶片丛聚。
1 引 言
数十年来 ,对于生物与大气间的质量输送和能
量交换的研究已经取得长足进展 ,并提出许多不同
的模式[ 1 ~ 4] 。 这些 描述 土壤-植 被-大气 系 统
(SPAS)的输送模式其复杂性由简到繁 、适用范围由
小到大 、涉及的生物物理参数由少到多。通常可以
将这些模式分为两大类:一类属于大叶模式 ,另一类
属于多层模式。而在多层模式中有两种情况 ,一种
是只考虑太阳辐射环境和风速的垂直差异 ,而像气
温 、水汽压 、CO2浓度等其他因子则假设不随冠层深
度变化;另一种则充分考虑了这些因素的垂直差异 ,
从而试图能更加客观地表征冠层内实际的物理学和
生物学现象 ,它不仅能预报生物与大气间的物质与
能量交换 ,而且有助于理解控制这些交换的过程 。
后来发现 ,大叶模式和多层模式都存在着一种
缺陷 ,这就是没有将阳叶和阴叶区分开来 ,如 Sellars
等[ 1]最新版本的简明生物模式(SiB2)就是将冠层看
成一个大叶片 ,通过求解冠层顶部叶片能量平衡 、气
孔导度 、光合作用耦合方程 ,然后再标定到整个冠
层 。又如 Gu等[ 3]研制的冠层微气象学和质量输送
与能量交换的多层综合模式 ,谢正桐等[ 5] 研制的陆
气耦合模式 ,以及季劲钧等[ 6]研制的冠层传输多层
模式等均未区别叶片受光状况 ,将每一层作为一张
叶片处理。理论上来讲这些都是缺乏机理性的处理
方法[ 7] 。一方面阳叶与阴叶具有不同的光截取 ,因
而具有不同的温度和湿度 ,气孔的导度显然也就不
同 ,从而导致叶片光合作用用差异较大 ,而叶片光合
第 63卷第 6期
2 0 0 5 年1 2 月                
气 象 学 报
ACTA M ETEOROLOGICA SIN ICA
               Vol.63 , No.6
December 200 5
初稿时间:2004年 6月 30日;修改稿时间:2005年 1月 12日。
资助课题:国家自然科学基金项目(B29200)。
作者简介:申双和,男 , 1957年生 ,教授 ,博士生导师。主要从事农业气象 、生态环境气象研究。
970                      气  象  学  报                    63 卷 
971 6 期           申双和等:北方黑云杉林冠内空气 CO2 浓度及其上方通量模拟              
972                      气  象  学  报                    63 卷 
973 6 期           申双和等:北方黑云杉林冠内空气 CO2 浓度及其上方通量模拟              
974                      气  象  学  报                    63 卷 
975 6 期           申双和等:北方黑云杉林冠内空气 CO2 浓度及其上方通量模拟              
976                      气  象  学  报                    63 卷 
图 5 气孔导度 、光合作用和叶片蒸腾实测值与     
模拟结果比较(a.气孔导度 , b.光合作用 , c.蒸腾作用)     
Fig.5 Rela tionships between measured and estimated    
stomatal conductance(a), photosynthesis(b)
and transpiration(c)   
为 28 ,三者均通过0.01显著度检验。蒸腾的散布点
相对集中在 0.5 (mmol/(m2·s))以内 ,超过此值以
上的数据点只有 3个 ,因此 ,其模拟效果的可信性相
对来说稍差一些 。不过从图可以看出三者基本上没
有显著的系统偏差。
5 结论与讨论
本文研制的黑云杉林植被与大气之间物质输送
和能量交换模式具有较强的机理性 ,充分考虑了阴
叶和阳叶对环境的反应差异 ,同时考虑黑云杉树叶
丛聚的特性 ,通过对各通量及冠层内空气 CO2 浓
度 、叶片气孔导度 、光合作用和蒸腾作用的模拟值与
实测值比较 ,取得了较好的效果 。可以认为该模式
可进一步用于研究森林冠层内的物质输送特性。当
然在模式中由于没有考虑到林地苔藓类的光合 、呼
吸作用 ,因此会造成冠层下方 CO2 浓度估计值在夜
间偏低的情况 ,同时 ,苔藓类植物也会影响到地表蒸
发从而影响冠层热量平衡方程中的各个分量估算 。
因此 ,如何正确处理好这部分与大气的交换对更好
地研究整个冠层与大气的交换有着重要的意义 ,这
有待今后进一步更详细的工作 。
参考文献
[ 1]  Sellers P J , Randall D A , et al.A revised land surface parame-
terization(S iB2)f or atmospheric GCMs.Part I:model formula-
tion.J Climate , 1996 , 9:676-705
[ 2]  Baldocchi D D.A lagrangian random-w alk model for simulat ing
w ater vapor , CO 2 and sensible heat flux densit ies and scalar pro-
files over and wi thin a soybean canopy.Bound-Layer Meteo ,
1992 , 61:113-144
[ 3]  Gu L , et al.Micrometeorology , biophysical exchanges and NEE
decomoposition in a two-story boreal forest-development and test
of an integ rated model.Agricultural and Forest Meteorol, 1999 ,
94:123-148
[ 4]  吴红颜,申双和 , 徐为根.棉田 SPAS 水热传输的多层模式.
南京气象学院学报 , 2001 , 24(1):137~ 142
 Wu Hongyan , Shen Shuanghe , Xu Weigen.A multilayer model
for moisture and the1rmal transfer f rom cotton canopy.J Nan-
jing Inst Meteoro(in C hinese)2001 , 24(1):137-142
[ 5]  谢正桐 ,李家春 ,姚德良.考虑植被影响的陆气耦合模式.力
学学报 , 1998 , 30(3):267~ 276
 Xie Zhengtong , Li Jiachun.A land-ai r coupled model with vege-
tation impact.J M echanics(in Chinese), 1998 , 30(3):267-
276
[ 6]  季劲钧 ,胡玉春.一个植物冠层物理传输和生理生长过程的多
977 6 期           申双和等:北方黑云杉林冠内空气 CO2 浓度及其上方通量模拟              
层模式.气候与 环境研究 , 1999 , 4(2):152~ 164
 Ji Jinjun , Hu Yuchun.A multi layer model for physical transfer
and physiological grow th of plant canopy.Climatic and Envi ron-
men tal Res(in C hinese)1999 , 4(2):152-164
[ 7]  Norman J M.Scaling processes betw een leaf and canopy levelso.In:
Ehleringer J R, Field C B.Eds.Scaling Physiological Processes:
Leaf to Global.Londone:Academic Press, 1993.356 pp
[ 8]  Spit ters C J T.Separat ing the diffuse and di rect component of
global radiat ion and its implications for modeling canopy photo-
synthesis.Part I:Components of incoming radiat ion.Agricul-
tural and Forest Meteoro , 1986 , 38:225-237
[ 9]  Wang Y P , Leuning R.A tw o-leaf model for canopy conduc-
t ance , photosynthesis and partit ioning of avai lable energy I:
Model description and comparison wi th a mult i-layered model.
Agricultural and Forest Meteorol, 1998 , 91:89-111
[ 10]  Chen J M.Canopy architecture and remote sensing of the f rac-
t ion of photosy nthet ically active radiat ion in boreal conifer
stands.IEEE Trans Geosci Remote S ensing , 1996 , 34:1353-
1368
[ 11]  Farquhar G D , von Caemmerer S , Berry J A.A biochemical
model of photosynthetic CO 2 assimi lation in leaves of C3 species.
Planta , 1980 , 149:78-90
[ 12]  Chen J M , Liu J , Cihlar J , et al.Daily canopy photosynthesis
model tahrough temporal and spatial scaling for remote sensing
applicatiaons.Ecological Modelling , 1999 , 124:99-119
[ 13]  Montei th J L , Unsw orth M.Principles of Environm ental 
Physics.LondAon:Edw ard Arnol , 1980.241pp
[ 14]  Piters-Lidard C D , Zion M S , Wood E F.A soil-vegetat ion-at-
mosphere transfer scheme for modeling spatially variable w ater
and energy balance processes.J Geophys Res , 1997 , D4:4303
-4324
[ 15]  Leuning R.Modelling stomatal behaviour and photosynthesis of
Eucalyptzus Grandis.Aust J Plant Physiol , 1990 , 17:159-
175
[ 16]  Sellars P J , Mintz Y , Sud Y C , et al.A simple biosphere model
(SiB)f or use w ithin general circulat ion models.J Atmos Sci ,
1986 , 43:305-331
[ 17]  Collat z G J , Ball J T , Crivet C , et al.Physiological and envi ron-
men tal regulation of stomatal conductance , photosynthesis and
t ranspirat ion:a model that includes a laminar boundary layer.A-
gricultu ral Forest Meteoro , 1991 , 54:107-136
[ 18]  Sellers P J , Berry J A , Collatz G J , et al.Canopy reflectance ,
photosynt hesi s and t ranspi ration.III.A reanalysis using im-
proved leaf models and a new canopy integrat ion scheme.Re-
mote Sensing of Envi ronment , 1992 , 42:187-216
[ 19]  Bonan G B.Land-atmosphere CO2 exchange simulated by a land
surface process model coupled to an atmospheric general circula-
t ion model.J Geophys Res , 1995 , 100:2817-2831
[ 20]  Hirose T , Werger M J A.Maximising daily canopy photosyn-
thesis w ith res:pect to the leaf ni trogen allocation pat tern in the
canopy.Oecologia , 1987 , 72:520-526
[ 21]  de Pury D G G , Farquhar G D.Simple scaling of photosynthesis
f rom leaves to canopies withou t the errors of big-leaf models.
Plant Cell Envi r , 1997t , 20:537-557
[ 22]  Anten N P R , S chieving F , Werger M J A.Pat terns of light and
nit rogenddistribution in relation to canopy carbon gain in C3 and
C4 mono-and dicotyledonous species.Oecologia , 1995 , 101:504
-513
[ 23]  Waullschleger S D.Biochemical limi tat ions to carbon assimilation
in C3 apla , nts-a retrospective analysis of the A/Ci curves from
109 species.J Exp Botanyn , 1993 , 44:907-920
[ 24]  Jarvis P G , M orison J I L.S tomatal cont rol of t ranspiration and
photoksynthesis.In:Jarvi s P G , Mansfield T A III , Ed.Stom-
atal physiology.New York:Ceambridge University Press ,
1981.247-279
[ 25]  Running S W , Coughlan J C.A general model of forest ecosys-
tem processesmfor regional applications I.Hydrological balance ,
canopy gas exchange and primary Aproduction processes.Ecol
Model , 1998 , 42:125-154
[ 26]  Erbs D G , Klein S A , Duf fie J A.Estimai ton of diffuse radiation
f raction for hourly , daily and monthly-average global radiation.
Solar Energy , 1982 , 28:293-304
[ 27]  Black T A , C hen J M , Lee X , et al.Characteristics of short-
wave and longw ave irradiatnces under a Douglas-fir forest stand.
Can J Forest Res , 1991 , 12:1020-1028
[ 28]  Norman J M.Simulat ion of microclimates.In:Hat field J L ,
Thormason I J , Ed.Biometeorology in Integrated Pest Manage-
ment.New York:Academic Press , 1982.65-99
[ 29]  Chen B , Chen J M.A model for interpreting high-tow er CO 2
concent ratinon records for the surface carbon balance informa-
tion , A supplement to Eos , Transactiogns.American Geophysi-
cal Union , 2002 , 83:112
[ 30]  Spit ters C J T.Separating the dif fuse and direct component of
global raldiation and its implications for modeling canopy photo-
synthesis.Part II:Calculation of canopy photosyn thesis.Agri-
cultural and Forest Meteoro , 1986 , 38:231-242
[ 31]  Ross J.T he radiation regime and archi tecture of plant stands.
The Hagu e:Dr.W.Junk Publishers , 1981.391pp
[ 32]  Gu L , Shugart H H , Fuentes J D , et al.Micrometeorology , bio-
physical excthanges and NEE decomposit ion in a two-story boreal
forest-development and test of an integrated model.Agricultu ral
and Forest Meteoro , 1999 , 94:123-148
[ 33]  Jones H G.Plant M icroclimate:A Quantitative Approach to En-
vi ronmental pPlant Physiology.2nd ed.New York:Cambridge
University Press , 1992.428pp
[ 34]  Baldocchi D D , Harley P C.S caling carbon dioxide and water
vapor exchan.ge from leaf to canopy in a deciduous forest.II.
Model test ing and application.Plant Cell and Envi ron , 1995 ,
18:115-173
[ 35]  Kondu J , Xu J.A proper method for est imating sensible heat
flux above anhorizontal-homogeneous vegetation canopy using ra-
diometric surface observat ions.J Appl Meteoro , 1997 , 36:
978                      气  象  学  报                    63 卷 
1696-1711
[ 36]  左大康 ,周允华 ,项月琴等.地球表层辐射研究.北京:科学出
版社 , 1991.469pp
 Zuo Dakang , Zhou Yunhua , Xiang Yueqin , et al.S tudies on Radia-
tion i n the Epigeospher.Beijing:S cience Press , 1991.469 pp.
[ 37]  Monteith J L , Unsw orth M .Principles of Environmental
 Physics.rLondon:Edw ard Arnol , 1990.291pp
[ 38]  Lloyd J , Taylor J A.On the temperatu re dependence of soil res-
pi ration.Funct ional Ecology , 1994 , 8:315-323
MODELLINGOF AIR CO2 CONCENTRATION AND FLUX IN/ABOVE A BOREAL
BLACK SPRUCE STAND
Shen Shuanghe Sun Zhaobo
(Nanjing University of Information Sci Tech , Nanjing 210044)
Chen Jingming
(University of Toronto , Toronto , Canada M5S 3G3)
Abstract
A complete multilayer model of vegetation-atmosphere exchange has been developed for a boreal black
spruce stand , taking into account response of sunli t and shaded leaves to ambient condi tions respectively , leaf
clumping and nit rogen level in the leaves at dif ferent lay ers.The established model consists of one dimensional
air diffuse meteorological equation for transfer of w ater , heat , CO2 within and above the forest canopy , a two-
leaf submodel for leaf-air exchange , and an exponential function for distribution of ni trogen level in leaves w ith
height of canopy.Estimat ion of sunlit and shaded leaf area index w as borrow ed from Chen′s method , modified
for layer-by-layer by the authors of this paper.Photosynthesis at leaf level w as computed by combining Far-
quhar s equat ions and CO2 conductance equation.Soil temperature , moisture , and thermal and w ater fluxes be-
tween adjacent soil layers , obtained from ESES , were used for calculat ing exchanges of radiation , latent and
sensible heat betw een soil surface and its immediately overly ing canopy air.Data fo r model validation came from
a southern study area (53°59′N , 105°07′W)of BOREAS (Boreal Ecosystem-Atmosphere Study)located in
Saskatchew an , Canada and belog ing to temperate climat ic zone.The involved data , just covering main growing
season in 1994 , were sensible heat f lux , latent heat f lux , CO2 flux w hich w ere all measured by eddy correlat ion
method , and soil heat flux measured by thermal f low plate , CO2 concentration prof ile by LI 6262 IRGA , net ra-
diation and other regular meteo rological elements such as air temperature , humidity , wind speed , and air pres-
sure.Measurements of leaf photosynthesis , t ranspiration and stomata conductivity to CO2 were made by LI6200
portable photosynthesis system.The validation for physiological prog resses of the leaf stomata conductance , pho-
tosynthesis and transpiration shows that there w ere good ag reements and no marked systematic discrepancies be-
tween the measurements and the estimates.The flux modeling indicates that sensible heat fluxes were slightly
overestimated in comparison wi th observed ones , and betw een them a squared correlation coef ficient (R 2)
amounted to 0.71 but the difference f luctuated from time to time.In contrast to the sensible heat flux , est i-
mates of latent thermal flux were a lit tle low er than observed ones and R 2 reached 0.78.CO2 f lux simulation had
the lowest R
2
of 0.65 and slightly underestimated when it goes over 7 μmol/(m2·s).CO2 concentration w as of
the biggest R 2 of 0.90 although there w ere larger errors in the canopy air close to the forest f loor , rising f rom
omitting moss respi ration.Analysis of these f lux simulations leads to conclude that the complete multilayer model
of vegetation-atmosphereresented achieves good results and is helpful to better investigation into vegetation-atmo-
sphere exchange process because of it s well dealing w ith the leaf radiance absorption , ni trogen level and clump-
ing .
Key words:CO2 f lux , Complete multiplayer model , Tw o-leaf submodel , Leaf clumping , Black spruce.
979 6 期           申双和等:北方黑云杉林冠内空气 CO2 浓度及其上方通量模拟