全 文 ：＊Co rrespondin g author , E-m ail:yn li@nw ipb.ac.cn
Received date:2006-04-30
Foundation item:Supported by the key p roject of k now ledge in-
novat ion p rog ram of CAS(No.KZCX1-SW-01-01A);State key basic
research and developm en t plan(No.2002CB412501);tw o joint Sino-
Japan ese p roject:“Research on the ef fects of carbon dynamics” and
“ global warming on temperate highland g rass land s”
Biography:Zhang Faw ei (1981- ), male , a postgraduate
student , major research field in alpine meadow ecology and glob al
change.
Article ID:1673-5021(2007)01-0006-07
Primary Study on Intensity of Surface Heating
Source and Biomass in an Alpine Kobresia Meadow
of the Qinghai-Tibetan Plateau
ZHANG Fa-wei1 , 2 , LI Hong-qin3 , LIU A n-hua1 , 2 , LI Ying-nian1 , ＊
(1.Northwest Institute o f Plateau B iology , CAS , X ining　 810001 , China;
2.Graduate School of the Chinese Academy of S ciences , Beij ing　100049 , China;
3.Academy o f Agro-Forestry , Qinghai University , Xining　810016 , China)
　　 Abstract:Based on the data measured by the eddy covariance me thod , the intensity of surface hea ting source and
ener gy balance , and aboveg round biomass and underg round biomass in an alpine meadow w ere analy zed in 2002.The
results show ed that the surface of alpine meadow w as heating r esource, and the there w as an evidently seasonal varia-
tion in hea ting intensity , aver age of intensity of surface hea ting source w as 88.5 W ·m -2 in 2002. The aboveg round
and underg round biomass also had a seasonal v ariation , re spectively. There w as positiv e co rrelation be tw een
aboveg round biomass and heating intensity , w hile complex rela tionship between unde rg round biomass and hea ting in-
tensity existed.I n the beg inning and end o f the g rowing sea son , po sitive co rrelation occur red , while at the middle of
the g rowing season , negativ e co r relation appeared.
Key words:Alpine K obresia meadow;Heating source intensity;Energy balance;Biomass
CLC number:S812　　　Document code:A
　　 The Qinghai-Tibetan Plateau , the roo f o f
the w o rld, has an important effect on A sian and
even global climate change. It has intensively re-
g ional solar radiation , sharp temperature varia-
tions , and imbalanced rainfall. Moreover , based
on intricate geog raphical situations , complicated e-
cosy stem pat terns are fo rmed[ 1].The Kobresia hu-
milis alpine meadow is the special vege tation in the
cold and humidity conditions , and covering 40%o f
the Qinghai-Tibetan Plateau.Because of g ood con-
ditions in animal husbandry , it supported the de-
velopment of the stock raising in the plateau re-
g ions o f the Qinghai province.It mainly distributes
in the sources of the Yellow River and Yang tse
Rive , and is also abundant in the Qilian
Mountains. U sing reasonably and protecting the
alpine meadow w ill have good ef fect on controlling
w ater and soi l le ssening , preventing soil deser ting ,
and the sustainable development o f indust ry and
ag riculture in our country[ 2]. Researching on the
heating surface intensity , soil heat energy balance ,
the variations of the biomass , and their relation-
ships wi ll not only provide informat ion on under-
standing the Plateau heating condi tions , but also
realize the relationship between biot ic and abiot ic
ecosy stems to know the law in energ y f lowing and
substance cycling[ 3].
The surface radiat ion has an impor tant ef fect
on the energ y t ransfo rming in the Soil -Plant -
Atmosphere-Community(SPAC)sy stems , and is
the element facto rs in forming micro climate , and
the foundat ion of the cumulat ing biomass. Only
understanding the pro cess o f the energy flow ing ,
and the principle of fo rming microclimate , can the
further study be carried out on the energy f low and
substance cycle in the alpine meadow ecosystem.
Since the first research on the Qinghai -Tibetan
Plateau meteorology in 1979 , a lo t of exciting results
have been acquired in the following studies
[ 4 , 5].A nd
then , many researches on hea ting energy balance
and surface heating intensi ty has been carried out
in the Qinghai-Tibetan Pla teau[ 6 ～ 10] , Li Guoping
repo rted that the surface w as a heat resource and
mean value w as 82.5 and 68.2 W · m-2 in the
—6—
第 29 卷　第 1 期　　　　　　　　　　中　国　草　地　学　报　　　　　　　　　　2007 年 1 月
　 Vol.29　No.1　 　　　　　　　　　Chinese Journal of G rassland　　　　　　　　　　Jan.2007 　
Gaize and Shiquan river regions o f the w est of the
Qinghai-Tibetan Plateau[ 8] , and based on the 14
years global so lar radiation data , Li Ren found that
global solar radiat ion flux density increased in the
last 20 century
[ 9].Because o f ce rtain facto rs limit-
ed , the research on heating intensity , biomass and
their relat ionship w as li t tle carried out and lit tle
discussed in alpine meadow [ 7 , 10].
Eddy covariance me thod is one of the tech-
nique of capturing the info rmation that substance
and energy exchange betw een the atmosphe re and
ecosy stem , and analyzing mutual interaction a-
mong the soil , biosphe re and atmosphere. Then ,
based on the da ta measured by eddy covariance
method and no rmal meteo rolog ical system as w ell
as the biomass in the g rowing season , the features
of the heating intensity , energy balance , and the
variation of the biomass (including aboveground
and underground)were discussed , and aimed at
understanding the dif fe rences in dist ribution o f the
heating balance components , and the function o f
the micro climate in eco sy stem , and providing mo re
informa tion for further study on substance f low ing
and energy cycling in the alpine meadow in the
Qinghai-Tibetan Plateau.
1　Materials and Methods
1.1　Site Description
The experiment w as carried out in the Haibei
Alpine Meadow Eco sy stem Research Stat ion , Chi-
nese Academy of Sciences(Haibei station , CAS)in
2002.The Haibei station , CAS , is loca ted atN37°
37′, E101°19′, in the no rtheast of the Qinghai-Ti-
betan Plateau , at an elevat ion of 3250m.The local
climate is long and co ld in w inter w hile shor t and
coo l in summer.The annual average ai r tempera-
ture is -1.7℃(acco rding meteo rological data f rom
1980 to 2000), January (the co ldest month)and
July (the w armest month)mean temperature are-
14.8℃ and 9.8℃, respectively ;Annual mean pre-
cipitation is about 580mm , 80% of rainfall i s f rom
May to September.T he grassland becomes green
about in early May and starts yellow a t early o f
Octobe r.T he soi l i s a clay loam , i ts ave rage thick-
ness is 65cm , which is classified as a M at Cry-gel-
ic[ 12].T he surface 0 ～ 10cm of soil i s abundant in
soil o rganic mat ter (SOM)(189.5 t · hm-2 , 0 ～
10cm), how ever , available nit rogen(N)which can
be absorbed by plant is poor.
The eddy covariance method observat ion tow-
er w as established in an alpine meadow , from 1km
in the nor thwest o f Haibei station.The re search
regions w as enough f lat and homogeneous and the
fetch w as more than 250m.The alpine meadow is
dominated by Kobresia humil is.The subdominants
include S tipa aliena , E lymus nutans , Festuca ovi-
na , Gent iana straminea , and Polygonum vivipa-
rum.The ave rage height o f vegetation in g rowing
season is about 30cm , and the peak leaf area index
is about 3.6 m-2 ·m-2[ 2 , 8 , 13].
1.2　Materials and Calculations
The data on heating balance and surface heating in-
tensity w as from the eddy covariance method system and
normal meteorological observation system.The eddy co-
variance measuring system , including open-path CO2 ,
and H2O concentrations analyzer at 2.2m (Li-7500 , Li-
Cor , USA), three-dimensional sonic anemometer
(CSAT 3 , CSI , USA)and photosynthetic photon flux
density (Li-190SB , Li-Cor , USA), was built on the
hand of the tower above ground 220cm and calculated
the latent heat flux , and sensible heat flux.The net ra-
diation flux , observed by the four instruments(CNR-1 ,
Kipp&Zonen , Netherlands), upw ards and downwards
long-wave and short-wave radiation meter.The soil heat
flux (HFT-3 , CSI , USA)was measured at the 2cm un-
der the soil surface.All data , including their mean , va-
riance , covariance values were calculated and recorded
with a data acquisition system (CR23X , CSI , USA)at
15 minute intervals.
The aboveground biomass and the underground bi-
omass were obtained by the Harvesting Method.In
the middle and end of every month(from May to Sep-
tember , be so-called the growing season), the plots was
selected in the topography flat and vegetation uniformity
regions. Then , six 50cm × 50cm plots for the
aboveground biomass was selected randomly , cut the
standing f rom the ground , and enclosed the paper bags
classified.Three 25cm×25cm subplots for underg round
biomass , where the aboveground has been gained al-
ready , the soil layers were taken out in 0 ～ 10cm , 0 ～
20cm and 20 ～ 40cm vertically with shovels and knives ,
the roots were picked out with sieves and enclosed in
—7—
ZHANG Fawei　LI Hongqin　LIU Anhua　LI Yingnian　　　Primary Study on Intensity of Surface Heating Source and Biomass in an Alpine KobresiaMeadow of Qinghai-Tibetan Plateau
cloth bags , washed cleanly and cased in the paper bags.
Finally , those bags w as drying in oven at the constant
temperature 65℃ and weighted by electronic balance ,
the weight unit was g·m-2.
The sensible heat flux and latent heat flux was cal-
culated by the principle of the eddy covariance.Accord-
ing to three-dimension wind speed , the mean value and
fluctuations of the temperature and humidity could be
calculated with following equation:
LE=Lρw′q′ (1)
H =ρCρw′q′ (2)
where the L is the w ater g asification latent
heat(2.5×106J ·kg-1), E is the vertical w ater va-
po r f lux (g · s-1), w is the vert ical w ind speed
(m · s-1), q is the relative humidi ty (g · g-1), ρis
the ai r density (kg ·m-3), Cρis the ai r special heat
in constant pressure(1004J ·kg-1 ·K-1), T is the
ai r temperature (K), ′is the symbo l of instanta-
neous f luctuations o f parameters and —repre-
sents the mean value of parameters in cer tain time.
The surface heating intensity w as the balance
between the ne t radiation and soil heat.In the con-
dit ions of energy clo sure , it also w as the sum of la-
tent heat and sensible heat. Because the energy
closure gap w as usual ly in eddy covariance sy stem
in the Fluxnet and w as up to 30% in some si tes[ 14] ,
the balance betw een net radia tion and soil heat w as
adopted to represent the surface heat ing intensity.
2　Results and Discussion
2.1　Seasonal Variation of the Soil Heating Bal-
ance and Intensity of Surface Heating Source
2.1.1　Net radiation flux(Rn)
According to the Fig.1-a , the net radiation flux
presented an obvious seasonal variation with one peak ,
Rn was maximal in July , daily mean value w as up to 250
W·m-2 , and minimum in December of the low est sun
angles , daily mean value was close to 0W ·m-2.More-
over , there were much more scatters in warming season
than cold season.The reasonable explanation was that
there w ere much more sunny days in cold season while
much more rainy days and great variations in cloud cover
in warm season.
Figure1　The varia tion of net radia tion (a), latent heat(b), sensible hea t(c)and soil heat flux (d)
in 2002 in the alpine meadow of the Qinghai-Tibe tan P lateau.
—8—
中国草地学报　2007年　第 29 卷　第 1 期
2.2.2　Latent heat flux
There w as a remarkable seasonal change in la-
tent heat f lux (Fig.1-b). In the g row ing season
wi th abundant rainfall and higher temperature , the
latent heat f lux increased and climbed to i ts climax
in the July , and daily mean value w as 120 W ·m-2.
Contrarily , in the non-g row ing season w ith thin
precipita tion and low er tempe rature , the t ranspira-
tion and evaporation decreased obviously and the
soil moisture content and air relative humidi ty w as
the low est.Then , the latent heat flux reduced and
w as m inimal in January , and i ts mean value w as a-
bout 0 W ·m-2.
2.2.3　Sensible heat flux
There w as much difference betw een the sea-
sonal variation of sensible heat f lux and that of net
radiation and latent f lux. Only a w eak seasonal
change appeared , and the simila r phenomenon w as
repo rted by Cai Xinan[ 15].There w ere tw o clima-
xes and valley s in the annual change of the sensible
heat f lux , and one climax occurred in Ma rch and
ano ther in October.The low est value w as in De-
cember and another lowe r value in July.This vari-
a tion w as correlated w ith the dist ribution of tem-
perature and precipitation , and the plant t ranspira-
tion and soi l evaporation in grow ing season. In
March , because of g razing in w inter and spring ,
the soil surface w as almost spared and the vegeta-
tion descended evidently.With the increase of to tal
sola r radiation , the soil received the heat easi ly ,
and the plant t ranspiration and soil ev aporat ion al-
ways w ere w eak. Then , the sensible heat f lux
dominated in the energy exchange between the soil
and the atmosphere.In July , in the periods of a-
bundant rainfall and intensive plant g row th , the
vegeta tion leaf area index w as lag er , and the most
energy absorbed by plants w as used in the plant
t ranspiration. Moreover , the soil w ater content
w as g reat and the most ene rgy absorbed by soil
w as used in the evaporation. Then , sensible heat
flux would be relatively low er in the July.After
September , because of lower temperature below 5℃,
most plants stopped growing and plant transpiration
and soil evaporation decreased evidently.The sensible
heat f lux increased slowly in the short periods , and
with the decrease of the air temperature , it started de-
scending and being clo se to 0 W ·m-2
2.2.4　Soil heat flux
Because o f the ef fect of plateau climate , the
soil surface accepted intensive so lar radiation and
its tempe ra ture increased quickly at the day time
whi le long-wave radiat ion had acutely coo ling
effect on soil at the night time , with the low soi l
hea t conductance , and the soil surface had great
temperature variat ion.Meanwhile , the plant ro ot
concentrated in the soil layer o f 0 ～ 20cm and had a
good ef fect in heat insulation.Then , the seasonal
variation range w as lit t le.A ccording to Fig.1-d ,
the soil heat f lux had obvious annual change , and
w as up to i t s climax (daily mean value w as 30
W ·m-2)in the end o f May while decreased g radu-
ally to it s minimum in the w inter.Meanwhi le , it
turned into posi tive value in the end o f February ,
which meant the soil gave the ene rg y out to the at-
mosphere;it turned into negative value in the mid-
dle of September , which meant the soil abso rbed
the energy from the atmosphere.T he absorbed en-
ergy w as about equal to the emit ted ene rg y and the
soil heat f lux w as close to zero , and that the mo re
t ime w as spent in the periods of negativ e value
than that of posi tive v alue by the soil heat flux
meant the more ability in absorbing heat in wa r-
ming season in the periods of soi l hea t balance.
Figure2　The annual va riation of surface heating source
intensity in 2002 in the a lpine meadow of the
Q inghai-T ibetan Plateau
—9—
ZHANG Fawei　LI Hongqin　LIU Anhua　LI Yingnian　　　Primary Study on Intensity of Surface Heating Source and Biomass in an Alpine KobresiaMeadow of Qinghai-Tibetan Plateau
2.2.5　Surface heating source intensity
The alpine meadow w as the heating sources
w ho le y ear , and the average heat ing source intensi-
ty w as 88.5 W · m-2 in the Qinghai-Tibetan Plat-
eau.The surface heating source field intensi ty w as
up to i ts maximum in July , which daily average
value w as 144.2 W · m-2 , and fell into it s mini-
mum in December , which daily average value w as
31.8 W ·m-2.As to heat ing up effect on the soil
surface , the alpine meadow w as a g reat heat
source s in summer , and i t w as also heat sources in
winter.Meanwhile , the heating source intensity
increase rate in the fi rst half of g row th season w as
(K=0.65 , R2 =0.52)was less than the decrease
rate in the later half o f g row th season (K =0.86 ,
R
2 =0.67).However , the air density in the Plat-
eau w as low er(0.9 kg ·m-3 , the one third o f that
in plain regions), the heating ef fect w as mo re than
one time in the plain regions at the same heating
source intensi ty.
2.2　The Variation of Aboveground and Un-
derground Biomass and Relationship Between
Them and Heating Source Intensity
F igure3　The g rowing-sea sonal variation o f aboveg round
biomass and underg round biomass in 2002 in a lpine
meadow of the Q inghai-T ibetan Pla teau
(unreasonable da ta only represented a declining
trend o f underg round biomass)
2.2.1　Aboveground biomass and underground bio-
mass
Fig.3 showed the t rend of seasonal change o f
aboveg round biomass. From beginning of June ,
w ith the following be tter conditions o f rainfall and
hea t , the plant pho to synthet ic intensi ty increased ,
the plant g rew fast so that the aboveg round bio-
mass enhanced evidently.A t the middle of Au-
gust , it reached maximum , about 414.2 g · m-2.
Along w ith the decline of temperature , photosyn-
thesis stopped and the aboveg round biomass de-
creased consequently.There w as much dif ference
in seasonal va riation between the underg round bio-
mass and aboveg round biomass.The change of it
w as characterized as “M ” sharp. In the end of
June , the fi rst climax appeared , w ith the rapid
plant g row th , the below g round biomass came into
the periods o f fast consumption , then , it turned a-
gain into another accumulat ive periods f rom the
end o f July to the end of g rowing season , and climbed
to the second climax , about 2122.7 g ·m-2.Because
of plant respirat ion and some underg round animals
consumption , the underw g round biomass declined
slow ly.
2.2.2　The relationship between the heating source
intensity and aboveground and underground biomass
In o rder to analyze the cor relat ion betw een the
hea ting source intensi ty and the biomass , the fo r-
mer w as averaged by fif teen days in the g rowing
season , which w as based on the intervals of ha r-
vest ing the aboveground biomass. The results
showed that there w as a positive correlation between the
heating source intensity and aboveground biomass.
However , there w as a lit t le difference betw een the
prophase (f rom June to August 15)and the ana-
phase (f rom August 15 to the October) of the
g row ing season.The explanation w as as the follow s:
In the prophase , because of the rapid increase of
aboveground biomass and heating source intensity , as
well as both similar increase rate , the liner slope was
0.12(R2 =0.96).In the anaphase , the plant photo-
synthesis ceased and their respiration maintained fo r a
long time , which made the aboveground biomass de-
cline.Meanwhile , the decrease rate (absolute slope=
55.0 , R2 =0.98)was less than the increase rate
(slope=87.4 , R2 =0.96)in the prophase.Moreover ,
the heating source intensity decreased rate in the ana-
phase was mo re than the increase rate in the prophase.
Consequently , the anaphase liner slope w as 0.26 (R2
=0.97), more than the prophase liner slope(Fig.4-a)
—10—
中国草地学报　2007年　第 29 卷　第 1 期
.Figure 4　The relationship betw een the surface hea ting source intensity and aboveg round biomass and
underg round biomass in 2002 in alpine meadow in the Q inghai-T ibetan Plateau
　　A s to the underg round biomass , there w as a
lit tle complicated co rrelation w ith heating source
intensi ty.At beginning (f rom June to July , it s
first climax)and end(f rom Septembe r 15 , it s sec-
ond climax , to October)of the g rowing season ,
there w as po sitive liner relationship w hile negative
relationship in the middle phase.At the beg ining
of grow ing season , the heating source intensity
w as in the rapid g row th pe riod and the plant pho-
to synthesis has already started , while the ai r tem-
perature w as low and sharp f luctuations , as w ell as
the soil didnt thaw enough , which made the plant
dif ficult to develop i ts aboveground po rtions , and
so the underg round biomass w as enhanced
[ 10] .
Therefo re was po sitive cor relation betw een under-
g round biomass and heating source intensity. In
the middle of g row ing season , with improvement
of the heat ing source intensi ty and wa ter condi-
tions , the plant g rew fast , whi le the energy ab-
sorbed by pho to synthe sis couldnt mee t the needs
of the plant g row th , which made the underground
biomass be consumed.In the periods of reproduc-
tive grow th , the ene rg y f rom photosynthesis w as
most expended by ef f lorescence and fruit and the
underwg round biomass couldnt cumulate , either.
With the preliminary decline of the heat ing source
intensity and end o f reproductive g row th , the nu-
t ritio n mat ter t ransferred from aboveg round to un-
derg round till the end of the middle phrase.So
the re w as negative cor relat ion betw een them. In
the end of the g rowing season , the heating source
intensity declined more and the photosynthesis
ceased , while the plant consumed the underg round
biomass due to respiration till the plant get into
dormancy (Fig.4-b).
3　Conclusions
In the observational periods , the alpine mead-
ow w as the heating sources , which appeared an ob-
vious seasonal variation , and i t mean value w as
88.5W · m-2. The net radiation f lux , latent heat
f lux and soi l heat f lux had an evident sing le-climax-
change while the sensible heat f lux presented a
w eak tw o-climaxes-variation.
There was distinct seasonal change in aboveg round
and underg round biomass , and the fo rmer w as single-
climax while the latter w asMsharp.In the pro-
phase and anaphase of grow ing season , there w as a
—11—
ZHANG Fawei　LI Hongqin　LIU Anhua　LI Yingnian　　　Primary Study on Intensity of Surface Heating Source and Biomass in an Alpine KobresiaMeadow of Qinghai-Tibetan Plateau
clearly po si tive liner co rrelation (R2 >0.97)be-
tw een the heating source intensi ty and
aboveg round biomass.As to the underg round bio-
mass , there w as a complicated co rrelat ion w ith
heating field , at beginning and end of the grow ing
season , there w as po sitive liner relationship w hile
negat ive relationship (R2 =0.71)in the middle
phase.
References:
[ 1] 　Zheng D , Zh ang Q S , Wu S H.Mountain g eoecology and su s-
tainable development of th e Tib etan Plateau [M ].Dordrecht ,
The Netherland:K luwer Acad emic Publ isher , 2000.
[ 2] 　Zhou Xingmin.Th e Kobresia meadow in Chin a [ M].Bei jing:
S cience Press , 2001.
[ 3] 　Li Yingnian.Th e study on radiation energy in growing season
in the Haibei alpine meadow[ J].Acta Ag rest ia S inica , 2001 ,
9(1):58-64(in Chines e wi th En glish abst ract).
[ 4] 　Ye Du zheng , Gao Y X.Th e Qingh ai-Tibetan Plateau meteorol-
ogy [ M].Beijing:S cience P ress , 1979.
[ 5] 　Zhang Jijia , Zhu B Z , Zhu F K , et al.T he ad vance of the
Qinghai-Tibetan Plateau m eteo rology [ M ] . Beijing:S cience
P ress , 1988(in Chines e wi th En glish abst ract).
[ 6] 　Bian Lingen , Lu L H , Dai C G , et al.The featu res of radia-
t ion balan ce components in the Qinghai-Tibetan Plateau in the
summer of 1998[ J] . Chinese Journal o f A tmospheric S ci-
ences , 2001 , 25(5):577-589 (in C hinese w ith Engli sh ab-
s t ract).
[ 7] 　Gu Song , Tang Y H , Cui X Y , et al. Energy exchan ge be-
tw een the atmosphere and a meadow ecosys tem on the Qing-
hai-Tibetan Plateau[ J] .A gr icultura l and Forest Meteorolo-
g y , 2005 , 129:175-185.
[ 8] 　Li Gu opin g , Duan Y T , Wu G f.The in tensi ty of s urface heat
source and su rface h eat balance on the Qingh ai-Xizang Plateau
[ J] . Scien tia Geograph ica S inica , 2003 , 23(1):13-18 (in
Chinese w ith Engli sh ab st ract).
[ 9] 　Li Ren , Ji G L , Yang W. Interan nual change of global s olar
radiat ion in Wu Daoliang region s[ J] . P lateau Meteorolog y ,
2005 , 24(2):173-177(in Chinese w ith Engli sh ab st ract).
[ 10] 　Li Yingnian , Wang Q X , Gong S , et al.Integrated monitoring of
the alpine meadow types and it s primary production[ J]. A cta
Geograph ica S inica , 2004 , 59(1):40-49(in Chinese w ith
Engli sh ab st ract).
[ 11] 　Yang Xiuhai , Liu J M.T he characteriz es of soil su rface heat-
ing b alance in summ er and w in ter in Gaize region s , Tibet[ J].
Tibetan S cience , 2002 , 106(2):48-54(in C hinese wi th Eng-
lish abst ract).
[ 12] 　Inst itute of soil science C A S.Chinese soil t ax onom y [ M].
Beijin g:S cience P ress , 2001.
[ 13] 　Li W , Zhou X.Ecosystem of Qingh ai-Tib etan plateau and
app roach for th eir sus tainable m anagem ent , series of s tu dies
on Qinghai-Tibetan Plateau [ M] . Guangzhou:Guangdong
S cience and Technolo gy P ress , 1998.
[ 14] 　Wilson K , Goldstein A , Falge E , et al.Energy b alance clo-
sure at Fluxn et si tes [ J].Agr icul tural and for est meteoro lo-
g y , 2002 , 113:223-243.
[ 15] 　Cai Xinan , Ren H , Peng S L , et al.T he h eating b alance of
the semi t ropical grassland in the Heshan [ J].A cta o f Tro pic
and S em itropic S inica , 1997 , 5(1):27-32(in Chinese w ith
Engli sh abs t ract).
青藏高原矮嵩草草甸地面热源强度与生物量的初步研究
张法伟1 , 2 , 李红琴3 , 刘安花1 , 2 , 李英年1
(1.中国科学院西北高原生物研究所 , 青海　西宁　810001;2.中国科学院
研究生院 ,北京　100049;3.青海大学农林科学院 , 青海　西宁　810016)
摘要:以涡度相关系统观测的数据为资料 ,对矮嵩草草甸 2002年的地面热源强度和地面热量平衡以及地上 、地下生物量
进行了研究。结果表明 ,在此观测期内 , 青藏高原矮嵩草草甸的地面均为热源 , 热源强度具有明显的季节变化 ,地面热源强度
的平均值为 88.5 W·m-2 ;地上 、地下生物量也呈现明显的季节变化 , 地上生物量与热源强度有正相关关系 , 而地下生物量与
热源强度则出现较复杂的关系 ,在生长季前期和后期表现为一定的正相关关系 ,在生长季中期则呈现为负相关关系。
关键词:矮嵩草草甸;热源强度;热量平衡;生物量
中图分类号:S812　　　文献标识码:A　　　文章编号:1673-5021(2007)01-0006-07
【责任编辑　刘天明】
—12—
中国草地学报　2007年　第 29 卷　第 1 期