全 文 ：Acta Botanica Sinica
植 物 学 报 2004, 46 (1): 35-45
Received 13 Dec. 2002 Accepted 5 Apr. 2003
Supported by the Knowledge Innovation Program of The Chinese Academy of Sciences (KSCX2-SW-107), the President Foundation of The
Chinese Academy of Sciences, DAAD-K.C.WONG Postdoctoral Fellowship and Cooperative Project of Chinese-Germany Ministries of
Agriculture.
* Author for correspondence.
http://www.chineseplantscience.com
Competition Strategies of Resources Between Stipa grandis and Cleistogenes
squarrosa. Ⅰ. Morphological Response of Shoot and Root on Sulfur Supply
WANG Yan-Fen1, WANG Shi-Ping1*, XING Xue-Rong1, CHEN Zuo-Zhong1, Ewald SCHNUG2, Silvia HANEKLAUS2
(1. Key Laboratory of Quantitative Vegetation Ecology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China;
2. Institute of Plant Nutrition and Soil Science of Federal Agricultural Research Center, Bundesallee 50,
D-38116 Braunschweig, Germany)
Abstract: Effects of nutrients (compounds of macro- and micro-elements) supply without sulfur (T1)
and with sulfur (T2) on the competition between Stipa grandis L. (C3) and Cleistogenes squarrosa L. (C4)
were examined using a replacement series design in a greenhouse experiment over a period of 80 d. Blank
treatment (nothing applied) (T0) was conducted simultaneously. It seems to be no inter-competition
between S. grandis and C. squarrosa in all treatments. There was also no intra-competition for S. grandis
in all treatments, and for C. squarrosa under T0 treatment because of low productivity. However, the
intra-competition of aboveground of C. squarrosa was significant when nutrients were supplied regardless
of sulfur (S) application. The interaction on dry weight of C. squarrosa per pot between S supply and
proportion of C. squarrosa was observed. Under the treatments of T1 and T2 the shoot growth of S. grandis
increased significantly compared with T0 treatment, but there was no significant difference between T1
and T2 treatments, indicating S had no effect on it. Root morphologies of S. grandis was not sensitive to
nutrients added. Nutrients supply (T1 and T2 treatments) not only increased significantly the shoot growth
of C. squarrosa, but also increased significantly its root growth. Sulfur increased significantly growth of the
shoot and root of C. squarrosa. Nutrients supply decreased significantly ratio of root to shoot dry matter
(RRS) of C. squarrosa regardless of S application, but the RRS of S. grandis was not affected by nutrients
applied. Sulfur also decreased significantly the RRS of C. squarrosa in 100% and 75% proportions of C.
squarrosa. The RRS of C. squarrosa was greater significantly in the 100% proportion than that in the 25%
proportion of C. squarrosa for all treatments. Therefore, photosynthesis is more allocated to root in
infertility soils than in fertility soils and the competition for nutrient resources stimulates root production.
The degree of leaf greenness of C. squarrosa in T1 treatment was less significantly than that in T0 and T2
treatments, and it was greater significantly in the 25% proportion than in the 100% proportion of C.
squarrosa under T1 and T2 treatments, indicating that nutrients supply increase chlorophyll content in
plant and may accentuate S deficiency or low plant productivity alleviate S deficiency.
Key words: Stipa grandis ; Cleistogenes squarrosa ; competition; morphology; sulfur (S) and other all
nutrients application
Stipa grandis is a C3, tall, dominant bunchgrass in
steppes of Euroasia Continent and Cleistogenes squarrosa
is a C4, short, dominant bunchgrass in degraded steppes of
the region. The productivity and biodiversity of S. grandis
communities are higher than that of C. squarrosa commu-
nities (Chen and Huang, 1988; Li, 1989; 1991; Wang et al.,
1998a; 1998b; 2001a; 2001b). However, the S. grandis com-
munity is usually succession into Artemisia frigida + C.
squarrosa community when overgrazing (Li, 1989; Wang et
al., 1998a). The degraded grassland ecosystems invaded
by highly competitive or disturbance-oriented plant spe-
cies demonstrate significant changes to community struc-
ture as well as changes in the size of resource pools and
overall resource availability (Robinson and Whalley, 1991).
To understand competitive mechanisms in any plant
community, it is important to consider that resource levels
are spatially and temporally heterogeneous and that numer-
ous physical and biotic processes limit the availability of
resources such as light, water, and nutrients (Tilman, 1988;
Lodge and Schipp, 1993; Dyer and Rice, 1999; Lodge, 2000).
In turn, the relative availability of aboveground and
belowground resources will influence the rate of plant growth
and the intensity of competitive relationships (Tilman, 1988;
Goldberg, 1990).
Sulfur (S) is a major plant nutrient and S deficiency has
been reported worldwide (Schnug, 1991; Ceccotti and
Acta Botanica Sinica植物学报 Vol.46 No.1 200436
Messick, 1995; Schnug and Haneklaus, 1998; Zhao et al.,
1999). S deficiency is often associated with grass domi-
nance (Gilbert and Shaw, 1981; Gilbert and Robson, 1984).
Despite this widespread occurrence of S deficiency in Nei
Mongol steppe (Wang et al., 1998b; 2001; 2002a; 2002b),
there were few comparative studies of the S nutrition of
pasture species in either monoculture or mixtures in the
region. Hence it is not possible to understand the marked
effect of S supply on the botanical composition of pastures.
The objective of this experiment was to determine the
competitive relationship between S. grandis and C.
squarrosa and the effect of nutrients application with S
and without S on them using a replacement series design in
greenhouse experiments. Inter-plant competition is influ-
enced by the interaction between plant morphology, nutri-
ents bio-availability and defoliation factors under natural
grassland (Hill and Gleeson, 1991). Their nutrients bio-avail-
ability will be explored in later papers in this series. Effects
of S and other nutrients supply on their growth and mor-
phologies are described in this paper.
1 Materials and Methods
1.1 Soil
A S-deficient top soil (0-20 cm) was collected in Au-
gust 2000 from the Nei Mongol Grassland Ecosystem Re-
search Station, The Chinese Academy of Sciences, which
is located at 43°26¢-44°08¢ N, 116°04¢-117°05¢ E and is
mostly more than 1 000 m above sea level (Wang et al.,
2001). The soil is a chestnut soil (Chinese classification)
and Calcic-orthic Aridisol in the U. S. soil taxonomy classi-
fication system, respectively. It is the dominant soil type in
the Nei Mongol Grasslands. The soil is a loamy sand and
the chemical composition of the soil is given in Table 1. The
soil had a water holding capacity (WHC) of 31.4%. Follow-
ing air drying at room temperature, the soil was screened
through a 2-mm sieve.
1.2 Pot experiment
The research was conducted in a greenhouse at the
Institute of Plant Nutrition and Soil Science, Federal Agri-
cultural Research Center (FAL), Braunschweig of Germany
during the growing season in 2001. The greenhouse condi-
tion was ambient with opening windows an average tem-
perature of day/night approximately 26/18 ℃ and the light/
dark time was 16/8 h each day.
The equivalent of 0.7 kg oven-dried soil was put into
1.4 L plastic pots (upper dimension 16 cm, down dimension
8 cm and height 11 cm), each with a saucer to prevent drain-
age losses of nutrients. Treatments consisted of two rates
of S addition: 0 and 28 mg S/pot (denoted as T1 and T2) and
each was three replications. S was applied as K2SO4. All
pots received a basal dressing of 140 mg N (NH4NO3), 70
mg P (KH2PO4), 35 mg Mg (MgCl2.6H2O), 7 mg Mn (MnCl2),
0.7 mg Cu (CuCl2.2H2O), 1.4 mg Zn (ZnCl2) and 0.7 mg B
(H3BO3). The disproportionate addition of K in different
treatments was balanced counter by the addition of pro-
portionate KCl to the pots. These were added to the soil as
solutions and mixed thoroughly. The soil moisture content
was raised to 70% of WHC by adding deionized water and
was maintained approximately at this level by frequently
weighing and adding deionized water during experiment.
At the same time, blank treatment (T0) without any nutri-
ents supply was designed with three replications.
Individual plant was planted in a replacement series in
the ratios shown in Table 2, at an overall density of 4 per
pot. Each species was planted in one of the 4 corners of the
square with 10 cm diagonals. All pots were arranged ran-
domly on trolley benches and the positions were rearranged
every fortnight.
1.3 Shoot morphology
The height of leaf canopy was measured to the tip of the
longest visible leaf, and the numbers of visible leaf and
tiller were counted at 10 d intervals after planting. The chlo-
rophyll content of the top leaf fully emerged for C. squarrosa
was determined using a hand-held chlorophyll meter
(Minolta SPAD 502) before harvesting. The plants were
harvested by cutting the shoots just above the soil surface
after 80 d of planting. Plants were weighed fresh weight
and dried at 60 ℃ for 48 h.
Table 1 Chemical characteristics of the basaltic soil used in the
study*
Soil characteristics Value
Clay content (<2 µm) 8.6%
pH (soil:water 1:5) 7.6
Organic C 8.0 g/kg
Total N 1.0 g/kg
Free CaCO3 0.5 g/kg
Ca(H2PO4)2-S 7.8 mg/kg
P2O5-CAL 2.2 mg/kg
Cu (0.43 mol/L HNO3) 0.9 mg/kg
Zn (0.43 mol/L HNO3) 1.1 mg/kg
Mn (DTPA) 4.2 mg/kg
Water holding capacity (WHC) 0.31
*Analyses were performed by laboratories of Institute of Plant Nu-
trition and Soil Science, Federal Agricultural Research Center (FAL),
Germany in Braunschweig.
Table 2 Densities (plants per pot) of the two species in a
replacement series
Stipa grandis 4 3 2 1 0
Cleistogenes squarrosa 0 1 2 3 4
Total 4 4 4 4 4
37WANG Yan-Fen et al.: Competition Strategies of Resources Between Stipa grandis and Cleistogenes squarrosa. Ⅰ.
1.4 Root morphology
Roots were removed by soaking the pots in a container
filled water and gently washing the soil from the roots. The
water in the container was screened through a 0.5 mm sieve
to avoid the loss of small roots. Roots were blotted dry and
weighed to determine root fresh weight. Root length was
measured using a modified line intersect method (Tennant,
1975). The mean root radius (R) was calculated from R =
√RFW/(L×π), where RFW is root fresh weight and L is
root length (Schenk, 1979). Root surface area (RSA) was
determined by multiplying the root length by the mean root
diameter andπ.
1.5 Statistics analysis
Analysis of variance and curve fitting were performed
using SPSS statistical software (SPSS, 1998). When signifi-
cant effects of S addition were detected, the one-way
ANOVA procedure within SPSS was used. When signifi-
cant of interactions between S addition and sampling date
were detected, the repeated measure method of the General
Linear Model procedure was used. LSD between means
were declared significant at P < 0.05.
2 Results
2.1 Effects of nutrients and the proportion of species on
their shoot morphologies
After 40 d of seedling emergence of S. grandis, leaf
canopy height (LCH), leaf number (LN) and tiller number
(TN) of T0 treatment were lower significantly than those of
T1 and T2 treatments, whereas there were no differences
significantly between T1 and T2 treatments (Figs. 1-3),
Fig.1. The influence of different treatments (T0, T1 and T2) on absolute height leaf canopy of S. grandis under 50 (a), 60 (b), 70 (c) and
80 (d) d after planting. T0, control (without any nutrients supplied); T1, all nutrients supplied without sulfur; T2, all nutrients supplied
with sulfur. The values of LSD0.05 were 3.59, 5.20, 2.63 and 5.17 in 50 d; 2.96, 6.42, 3.93, and 6.27 in 60 d; 3.24, 3.65, 2.91 and 5.63 in
70 d; and 3.10, 5.23, 3.30 and 6.39 in 80 d after planting, respectively. The bars are standard deviation.
Fig.2. The influence of different treatments (T0, T1 and T2) on leaves number of S. grandis under 50 (a), 60 (b), 70 (c) and 80 (d) d after
planting. T0, control (without any nutrients supplied); T1, all nutrients supplied without sulfur; T2, all nutrients supplied with sulfur.
The values of LSD0.05 were 1.42, 1.42, 0.81 and 1.76 in 50 d; 2.29, 1.73, 1.67 and 2.26 in 60 d; 2.17, 1.73, 1.67 and 2.26 in 70 d; and
1.74, 1.64, 2.36 and 2.65 in 80 d after planting, respectively. The bars are standard deviation.
Acta Botanica Sinica植物学报 Vol.46 No.1 200438
indicating that S did not markedly affect the growth and
development of individual S. grandis. However, after 20 d
of seedling emergence of C. squarrosa, not only LCH, LN
and TN of T0 treatment were lower significantly compared
with T1 and T2 treatments, but also S significant increased
LN and TN of C. squarrosa. The significant difference in
LN and TN between T1 and T2 treatments was observed
after 20 and 40 d of seedling emergence in the monoculture
of C. squarrosa, respectively, whereas significant differ-
ence in TN between T1 and T2 treatments existed 80 d of
seedling emergence for 25%-75% proportion of C.
squarrosa (Figs.4-6), indicating that S effect on LN and
TN of C. squarrosa varied with its proportion.
The effects of proportion of C. squarrosa on its LN and
TN were significant under T1 and T2 treatments at the last
two ten-days-experiments (Figs.5, 6), whereas LCH was not
affected by a replacement series for the whole experiment
period (Fig.4). For example, the LN of C. squarrosa in the
25% and 50% proportion of C. squarrosa increased by ap-
proximately 50% compared with in the 75% and 100% pro-
portions of C. squarrosa under T1 and T2 treatments (Fig.
5), and the similar results in TN were observed (Fig.6) at the
end of the experiment. Therefore, there was a significant
interaction effect in LN and TN between treatment, propor-
tion of C. squarrosa and sampling time (Table 3).
The significant difference of leaf chlorophyll content
was not observed between T0 and T2 treatments, whereas
it was lower significantly in T1 treatment than those in T0
and T2 treatments (Table 4), indicating that supply of other
nutrients may accentuate S deficiency or low plant produc-
tion alleviate S deficiency. Although there was no signifi-
cant difference between different proportions of C.
squarrosa in the chlorophyll content under T0 treatment, it
tends to increase with the decrease of proportion of C.
squarrosa. However, the leaves of plants grown in T1 and
T2 soils with 100% proportion (monoculture) of C.
squarrosa were significantly less green compared with those
of plants with 25% proportion (Table 4).
These results show that it is more sensitive to S defi-
ciency for C. squarrosa than for S. grandis. Intra-specific
competition of C. squarrosa is higher than inter-specific
competition between C. squarrosa and Stipa grandis. Ef-
fects of resource stress on the growth and development of
leaf and tiller emergence are heavier than that on the height
of C. squarrosa.
Fig.3. The influence of different treatments (T0, T1 and T2) on tillers number of S. grandis under 50 (a), 60 (b), 70 (c) and 80 (d) d after
planting. T0, control (without any nutrients supplied); T1, all nutrients supplied without sulfur; T2, all nutrients supplied with sulfur.
The values of LSD0.05 were 0.58, 0.86, 0.85, and 0.66 in 50 d; 0.51, 0.40, 0.79 and 0.66 in 60 d; 0.80, 0.20, 0.66 and 1.06 in 70 d; and
0.85, 0.92, 0.62 and 1.06 in 80 d after planting, respectively. The bars are standard deviation.
Table 3 Probabilities of the F test for the analysis of variance for
shoot variables
Leaf number Tiller number
Source Stipa Cleistogenes S. C.
grandis squarrosa grandis squarrosa
S (sulfur) 0.394 0.019 0.458 0.064
P (proportion) 0.031 0.028 0.076 0.006
D (d) 0.004 <0.001 0.001 0.001
S× P 0.944 0.073 0.808 0.359
S×D 0.414 0.006 0.006 0.009
P× D 0.835 0.002 0.159 0.010
S× P×D 0.911 0.044 0.545 0.289
39WANG Yan-Fen et al.: Competition Strategies of Resources Between Stipa grandis and Cleistogenes squarrosa. Ⅰ.
Fig.4. The influence of different treatments (T0, T1 and T2) on absolute height of C. squarrosa under 30 (a), 40 (b), 50 (c), 60 (d), 70
(e) and 80 (f) d after planting. T0, control (without any nutrients supplied); T1, all nutrients supplied without sulfur; T2, all nutrients
supplied with sulfur. The values of LSD0.05 were 1.73, 2.68, 3.11 and 4.01 in 30 d; 2.91, 2.69, 2.10 and 4.02 in 40 d; 1.52, 3.10, 2.76 and
3.43 in 50 d; 2.90, 3.36, 2.78 and 7.48 in 60 d; 4.32, 3.80, 3.19 and 5.67 in 70 d; and 4.33, 4.93, 4.08 and 7.59 d after planting, respectively.
The bars are standard deviation.
Fig.5. The influence of different treatments (T0, T1 and T2) on leaves number of C. squarrosa under 30 (a), 40 (b), 50 (c), 60 (d), 70
(e) and 80 (f) d after planting. T0, control (without any nutrients supplied); T1, all nutrients supplied without sulfur; T2, all nutrients
supplied with sulfur. The values of LSD0.05 were 0.92, 0.87, 1.87 and 1.41 in 30 d; 3.03, 0.94, 3.22 and 3.12 in 40 d; 1.15, 5.92, 11.56 and
7.45 in 50 d; 8.39, 3.46, 16.49 and 10.21 in 60 d; 9.95, 6.85, 13.74 and 5.90 in 70 d; and 8.07, 10.24, 15.90 and 8.09 d after planting,
respectively. The bars are standard deviation.
2.2 Effects of nutrients and the proportion of species on
their root morphyologies
The nutrients supplied (with and without S) increased
significantly number of germinal root, root radius and RSA
of C. squarrosa in all proportions compared with T0
treatment. Under the T1 and T2 treatments root length of C.
squarrosa and germinal root number and root radius of S.
grandis increased significantly in the proportions of 100%
and 75% of C. squarrosa and S. grandis compared with T0
treatment, respectively (Table 5). S application had no ef-
fect on root morphyologies.
There were no significant differences in all measured
root morphological characteristics of S. grandis in the dif-
ferent proportions of S. grandis of all treatments except in
the root radius between 100% and 25% proportion of S.
grandis under T2 treatment. The similar results were also
observed in all proportions of C. squarrosa except in the
number of germinal root between 100% and 25% of C.
Acta Botanica Sinica植物学报 Vol.46 No.1 200440
squarrosa under T1 and T2 treatments (Table 5).
2.3 Effects of nutrients and the proportion of species on
their biomass
The dry weight of shoot and root of individual S. grandis
and C. squarrosa in T0 treatment were lower significantly
than those of T1 and T2 treatments. S fertilizer did not affect
individual S. grandis biomass, whereas S increased signifi-
cantly individual C. squarrosa biomass for both shoot and
root (Table 6), indicating S is one of key limiting factors for
C. squarrosa production.
The dry weight of shoot and root of individual S. grandis
was not affected significantly by its different proportions
at each treatment of T0, T1 and T2 except the 50% propor-
tion at the T1 treatment (Table 6), indicating that the intra-
and inter-specific competition for S. grandis is small.
However, the dry weight of shoot per C. squarrosa in-
creased significantly with its proportion decrease, espe-
cially in the T1 and T2 treatments. It reached the maximum
at the 25% proportion of C. squarrosa for all treatments
Fig.6. The influence of different treatments (T0, T1 and T2) on tillers number of C. squarrosa under 30 (a), 40 (b), 50 (c), 60 (d), 70
(e) and 80 (f) d after planting. T0, control (without any nutrients supplied); T1, all nutrients supplied except sulfur; T2, all nutrients
supplied with sulfur. The values of LSD0.05 were 0.28, 0.40, 1.21 and 0.94 in 30 d; 0.47, 0.45, 0.47 and 0.81 in 40 d; 0.60, 1.53, 2.63 and
2.10 in 50 d; 1.41, 1.48, 2.85 and 2.58 in 60 d; 1.42, 2.12, 4.22 and 1.76 in 70 d; and 1.68, 2.41, 4.8 and 1.16 d after planting, respectively.
The bars are standard deviation.
Table 4 Influence of the replacement series of Stipa grandis/
Cleistogenes squarrosa on chlorophyll content (SPAD units) of
youngest emerged leaf of C. squarrosa under different nutrient
treatments (mean± SD)
Proportion
T 0 T 1 T 2 LSD0.05
(× 100)
100 27.7± 1.7 17.2± 0.6 26.3± 1.6 2.0
75 28.7± 2.6 20.4± 1.6 27.5± 1.9 2.9
50 28.6± 2.2 21.6± 4.1 28.9± 1.6 5.5
25 30.5± 4.0 24.7± 3.0 30.9± 3.0 4.8
LSD0.05 3.9 5.0 3.0
Abbreviations are the same as in Fig.1.
and was almost as 2 times as that of 100% proportion of C.
squarrosa, indicating intra-specific competition was sig-
nificant and interaction existed between S supply and pro-
portion of C. squarrosa (P < 0.05), but root dry weight per
C. squarrosa was not affected by its proportions for all
treatments (Table 6).
There were no significant difference in dry weight of
shoot, root and total (shoot + root) per pot between the
25%-75% proportion of S. grandis/C. squarrosa and mo-
noculture of S. grandis and C. squarrosa under T0 treatment,
indicating that there is no direct intra- and inter-competi-
tion for light and nutrients under infertility soil condition
because of low productivity (Fig.7). However, the dry
weight of shoot and total of C. squarrosa per pot increased
significantly with the increase of proportion of C. squarrosa
under T1 and T2 treatments. The root dry weight of monoc-
ulture of C. squarrosa per pot increased by 50% compared
with the monoculture of S. grandis in T2 treatment (Fig.7).
Interactions between S supply and proportion of C.
squarrosa were observed for dry weight of shoot, root and
total per pot, respectively (P < 0.05 and 0.01).
Although nutrients supplied (T1 and T2 treatments)
tended to decrease the ratio of root to shoot dry weight for
S. grandis compared with T0 treatment, there was no sig-
nificant difference (Table 7) between treatments and be-
tween the proportions of S. grandis. However, the ratio
decreased significantly by nutrients supplied for C.
squarrosa regardless of S. The influence of S application
on the ratio of root to shoot dry weight of C. squarrosa
veried with its proportions, S decreased significantly the
ratio in 100% and 75% proportions of C. squarrosa (Table
41WANG Yan-Fen et al.: Competition Strategies of Resources Between Stipa grandis and Cleistogenes squarrosa. Ⅰ.
7). At the 25% proportion of C. squarrosa, the ratio was
lower significantly than that of 100% proportion in all
treatments. These results show that photosynthesis is more
allocated to root in infertility soils than in fertility soils and
the competition for resources stimulates root production.
3 Discussion
Plants of both species in T0 treatment grew poorly re-
gardless of monoculture and mixtures and there were al-
most no significant difference between different propor-
tions of S. grandis / C. squarrosa (Figs.1-7; Table 6). Be-
cause the chemical analysis of the soil indicated that the
soil fertility was poor in all nutrients, especially macro-nu-
trients in N, P and S in this study (Table 1). At low
productivity, competition is small for soil nutrients (Hill,
1991). According to a definition of competition from
Table 5 Influence of the replacement series of Stipa grandis/Cleistogenes squarrosa on root morphologies individual plant under
different nutrient treatments (mean± SD)
Proportion Treatment LSD0.05 Treatment LSD0.05
(× 100) T 0 T 1 T 2 T 0 T 1 T2
Number of S. grandis germinal root per plant Number of C. squarrosa germinal root per plant
100 5.2± 0.7 11.0± 1.7 10.8± 1.6 3.5 6.5± 0.9 15.8± 1.3 21.3± 2.5 2.4
75 5.6± 1.2 10.4± 0.2 10.8± 1.8 1.8 6.0± 0.3 20.5± 1.6 24.4± 6.1 5.2
50 6.5± 0.9 8.3± 1.3 8.2± 1.6 1.8 5.7± 0.6 22.5± 5.1 28.2± 6.5 6.8
25 5.7± 0.6 9.9± 1.9 9.7± 2.1 4.4 6.3± 1.2 23.3± 4.9 32.3± 3.2 4.9
LSD0.05 ns ns ns 1.1 5.2 6.9
Average root radius of S. grandis (mm) Average root radius of C. squarrosa (mm)
100 0.42± 0.03 0.64± 0.21 0.72± 0.11 0.20 0.31± 0.03 0.61± 0.14 0.64± 0.10 0.14
75 0.43± 0.02 0.56± 0.01 0.59± 0.10 0.08 0.31± 0.03 0.67± 0.15 0.67± 0.13 0.16
50 0.46± 0.04 0.45± 0.08 0.51± 0.10 0.11 0.29± 0.03 0.60± 0.21 0.63± 0.09 0.19
25 0.42± 0.02 0.54± 0.13 0.49± 0.13 0.15 0.32± 0.01 0.58± 0.12 0.67± 0.09 0.12
LSD0.05 0.04 0.19 0.16 ns ns ns
Root length of S. grandis (cm) per plant Root length of C. squarrosa (cm) per plant
100 416± 167 426± 135 383± 136 ns 519± 158 1086± 148 925± 207 244
75 401± 63 417± 70 409± 81 ns 512± 270 1064± 116 993± 98 253
50 357± 67 305± 102 448± 89 ns 713± 246 1254± 507 1100± 583 661
25 458± 77 457± 162 515± 259 ns 551± 156 705± 125 894± 131 195
LSD0.05 ns ns ns ns ns ns
Root surface area of S. grandis (cm2) per plant Root surface area of C. squarrosa (cm2) per plant
100 110± 48 179± 91 155± 78 ns 103± 37 429± 148 373± 106 151
75 108± 20 147± 25 138± 32 ns 98± 43 442± 109 417± 46 103
50 102± 10 90± 45 145± 55 ns 127± 34 510± 201 446± 191 240
25 119± 15 162± 93 171± 123 ns 109± 28 261± 84 376± 82 99
LSD0.05 ns ns ns ns ns ns
Abbreviations are the same as in Fig.1.
Table 6 The dry weight (DW) of shoot and root of Stipa grandis and Cleistogenes squarrosa individual plant in replacement series
under different treatments (mg/plant) (mean±SD)
Proportion Shoot DW of S. grandis per plant LSD0.05 Root DW of S. grandis per plant LSD0.05
(× 100) T 0 T 1 T 2 T 0 T 1 T2
100 50± 16 139± 20 142± 65 57 50± 24 114± 28 103± 49 50
75 60± 24 129± 8 133± 55 50 51± 12 103± 12 103± 35 32
50 55± 9 67± 20 105± 34 33 55± 13 53± 13 87± 55 47
25 57± 15 115± 40 127± 46 58 57± 6 100± 27 80± 36 37
LSD0.05 24 52 80 7 9 20
Shoot DW of C. squarrosa per plant LSD0.05 Root DW of C. squarrosa per plant LSD0.05
T0 T 1 T 2 T 0 T 1 T2
100 60± 20 510± 90 1 150± 110 120 44± 17 126± 18 167± 21 27
75 70± 20 610± 20 1 350± 120 100 38± 12 132± 16 177± 32 31
50 70± 10 750± 30 1 670± 250 200 45± 10 163± 74 203± 81 43
25 140± 50 1050± 120 2 130± 310 280 30± 10 137± 40 193± 12 35
LSD0.05 60 110 300 ns ns ns
Abbreviations are the same as in Fig.1.
Acta Botanica Sinica植物学报 Vol.46 No.1 200442
Bullock (1998), it does not demonstrate competition be-
tween S. grandis and C. squarrosa in infertility soil. Grime
(1979) also suggested that the intensity of competition (i.e.
the degree of the reduction in performance due to
competition) will be lower in nutrient-poor habitats due to
lower productivity (Grime et al., 1988). However, intra-spe-
cific competition (density-dependent) of C. squarrosa seems
to be existence, maybe the species is more sensitive to
nutrients compared with S. grandis.
Applying soil nutrients increased growth and develop-
ment of both species, irrespective of nutrients with S or
without S. S increased significantly growth and develop-
ment for C. squarrosa, but not for S. grandis (Figs.1-7;
Tables 5-6). The dry weight of shoot of S. grandis and C.
squarrosa increased by 40%-150%, 700%-1 000% and
100%-200%, 1 500%-2 000% when nutrients were applied
without S and with S, respectively (Table 6).
Plant strategy theory of Grime et al. (1988) reveals trade-
offs among the plant traits adapted to the different envi-
ronmental types, for instance, the rapid uptake of resources
for rapid growth and the concomitant needs for high re-
source levels by competitors means that they are unable to
tolerate low resource levels, while their perenniality and tall
growth form gives them a low tolerance of disturbance.
However, C. squarrosa not only can survive with high den-
sity and small individual plant in the conditions of high
stress and high disturbance (natural degraded grasslands
of Nei Mongol steppe without any fertilizers supplied by
local people with overgrazing conditions) (Wang and Wang,
2001), but also grow rapidly and a large size in conditions
of low stress and low disturbance in this study. In contrast,
S. grandis can not survive when overgrazing (Wang et al.,
1998a) and its growth rate is lower than that of C. squarrosa
in low stress and low disturbance in this study. Therefore,
according to the theory of Grime et al. (1988), it has a diffi-
cult to explain why S. grandis is a dominant plant in fenced
grassland with low disturbance in Nei Mongol steppe be-
cause the shoot dry weight per C. squarrosa was as
Fig.7. The dry weight of shoot (SDW), root (RDW) and total of S. grandis/Cleistogenes squarrosa replacement experiments under
different treatments (T0, T1 and T2). T0, control (without any nutrients supplied); T1, all nutrients supplied without sulfur; T2, all
nutrients supplied with sulfur. The comparisons were only in the same items, such as SDW, RDW and total (SDW + RDW). Significant
difference (P < 0.05) in dry weight between replacement series treatments were indicated by different letters in sections of histograms.
The values of LSD0.05 between different treatments (T0, T1 and T2) under the same proportion of S. grandis (×100) were 0.23, 0.27,
0.45, 0.27 and 0.49 in T0; 0.20, 0.10, 0.16, 0.09 and 0.11 in T1; and 0.41, 0.30, 0.56, 0.26 and 0.52 in T2, respectively.
Table 7 Influence of the replacement series of Stipa grandis/Cleistogenes squarrosa on the ratio of root/shoot dry weight under
different nutrient treatments (mean± SD)
Proportion S. grandis
LSD0.05
C. squarrosa
LSD0.05
(× 100) T 0 T 1 T 2 T 0 T 1 T2
100 0.95± 0.23 0.82± 0.18 0.72± 0.12 ns 0.73± 0.11 0.26± 0.07 0.14± 0.01 0.11
75 0.91± 0.25 0.80± 0.10 0.79± 0.11 ns 0.58± 0.08 0.22± 0.02 0.13± 0.03 0.07
50 1.05± 0.44 0.82± 0.16 0.78± 0.22 ns 0.66± 0.25 0.22± 0.09 0.12± 0.05 0.22
25 0.94± 0.29 0.89± 0.24 0.67± 0.12 ns 0.26± 0.13 0.13± 0.04 0.09± 0.01 0.11
LSD0.05 ns ns ns 0.22 0.09 0.04
Abbreviations are the same as in Fig.1.
43WANG Yan-Fen et al.: Competition Strategies of Resources Between Stipa grandis and Cleistogenes squarrosa. Ⅰ.
2.5-fold as that of S. grandis when the proportion of S.
grandis is 75% without any nutrients supplied in this study
(Table 3). Maybe there are about 10-15 species coexist-
ence in the natural community of S. grandis, more competi-
tions exist and C. squarrosa may be suppressed by other
species, or S. grandis could be better for water competition
compared with C. squarrosa in semi-arid condition. On the
other hand, in a consistent with Tilman (1990), fertile habi-
tat (nutrients supplied in this study) with low disturbance
benefit a high allocation to stem (competition for light) and
high allocation to roots is favored in infertile habitats
(without any nutrients and S supplied in this study) (nutrient
competition) (Table 7). Therefore, for a perennial grass of S.
grandis, more accumulation of roots under infertile soil with
low disturbance may benefits competition for nutrients and
water resources in later years compared with a perennial
grass of C. squarrosa. Under undisturbed habitats, light is
the limiting resource, usually, S. grandis is a taller and a
more erect growth form compared with C. squarrosa, it can
capture light pre-emptively. Weiner (1990) suggested that
if two plants are competing, the taller should be able to
capture almost all the light and this disproportionate cap-
ture of resources should be termed asymmetric competition.
However, when competition is for a limiting soil nutrient,
even if one plant with a more developed root system or a
greater rate of uptake per unit root area captures more of
the nutrient, the partition of resources is proportionately
more equal (symmetric competition) (Weiner, 1990).
Therefore, toleration of low resource levels may be good
strategy for nutrient competition, but pre-emptive capture
of resources may be more effective for light competition.
References:
Bullock J M. 1998. Plant competition and population dynamics.
Hodgson J, Illius A W. The Ecology and Management of Graz-
ing Systems. Wallingford, UK: CAB International. 69-100.
Ceccotti S, Messick D L. 1995. Agronomic and economic value of
sulphur fertilizers relating to Chinese agriculture. Proceedings
of the International Workshop on Current and Future Plant
Nutrient Sulphur Requirements, Availability, and Commer-
cial Issues for China, Beijing, China. 44-56.
Chen Z-Z, Huang D-H . 1988. A measurement to underground
productivity and turnover value of Aneurolepidium chinense
and Stipa grandis grassland at the Xilin river valley in Inner
Mongolia. Inner Mongolia Grassland Ecosystem Research
Station. Grassland Ecosystem Research, Vol.2. Beijing: Sci-
ence Press. 132-138. (in Chinese with English abstract)
Dyer A R, Rice K. 1999. Effects of competition on resource
availability and growth of a California bunchgrass. Ecology,
80:2697－2710.
Gilbert M A, Shaw K A. 1981. Residual effects of sulfur fertiliz-
ers on cut swards of a Stylosanthes guianensis and native
grass pasture on a euchrozem soil in north Queensland. Aust J
Exp Agr Anim Husb, 21:334-342.
Gilbert M A, Robson A D. 1984. Studies on competition for
sulfur between subterranean clover and annual ryegrass.Ⅰ.
Effect of nitrogen and sulfur supply. Aust J Agr Res, 35:53-
64.
Goldberg D E. 1990. Components of resource competition in
plant communities. Grace J, Tilman D. Perspectives on Plant
Competition. California: Academic Press. 27-49.
Grime J P. 1979. Plant Strategies and Vegetation Processes.
Chichester: John Wiley and Sons.
Grime J P, Hodgson J G, Hunt R. 1988. Competitive Plant
Ecology. London: Unwin Hyman.
Hill M J, Gleeson A C. 1991. Competition between Clare and
Seaton Park, and Clare and Daliak subterranean clovers in
replacement series mixtures in the field. Aust J Agr Res, 42:
161-173.
Li Y H. 1989. Impact of grazing on Leymus chinensis steppe and
Stipa grandis steppe. Acta Oecol Appl, 10:31-46.
Li Y H. 1991. The current situation of steppe rangeland use in
Inner Mongolia: relations between rangeland structures with
grazing. The 4th international rangeland congress. Montpellier,
France, 340-345.
Lodge G M, Schipp A J. 1993. The domestication of the native
grasses Danthonia richardsonii Cashmore and Danthonia
linkii Kunth for agricultural use. Ⅱ. Agronomic and morpho-
logic variation. Aust J Agr Res, 44:79-88.
Lodge G M. 2000. Competition among seedlings of perennial
grasses, subterranean clover, white clover, and annual ryegrass
in replacement series mixtures. Aust J Agr Res，51:377-
383.
Robinson G G，Whalley R D B. 1991. Competition among
three agronomic types of the Eragrostis curvula (Schrad.)
Nees complex and three temperate pasture grasses on the
northern tablelands of New South Wales. Aust J Agr Res，
42:309-316.
Schnug E. 1991. Sulphur nutritional status of Europe crops and
consequences for agriculture. Sulphur Agr, 15:7-12.
Schenk M K, Barber S A. 1979. Root characteristics of corn
genotypes as related to P uptake. Agron J, 71:921-924.
Schnug E, Haneklaus S. 1998. Diagnosis of Sulphur Nutrition.
Schnug E. Sulphur in Agrosystems. Dordrecht, The
Netherlands: Kluwer Academic Publishers. 1-38.
SPSS Standard version. SPSS Inc. 1998.
Tilman D. 1988. Plant strategies and the dynamics and structure
of plant communities. Princeton: Princeton University Press.
Acta Botanica Sinica植物学报 Vol.46 No.1 200444
Tennant D. 1975. A test of a modified line intersect method of
estimating root length. J Ecol, 63:995-1001.
Tilman D. 1990. Constrains and trade offs: towards a predictive
theory of competition and succession. Oikos, 58:3-15.
Wang S-P,Li Y-H,Wang Y-F,Han Y-H. 1998a. The succession of
Artemisia frigida rangeland and multivariation analysis under
different stocking rates in Inner Mongolia. Acta Agrestia Sin,
6:299-305. (in Chinese with English abstract)
Wang S P, Wang Y F, Chen Z Z, Schnug E. 1998b. Effects of S
fertilization on forage yield and quality, and sheep perfor-
mance and wool quality in Inner Mongolia steppe. Schnug E,
Fotyma M. Codes of Good Fertilizer Practice and Balanced
Fertilization. Proceedings of 11th International Symposium
of International Scientific Centre of Fertilizers (CIEC).
Braunschweig, Germany. 264-274.
Wang S P, Wang Y F, Chen Z Z, Schnug E. 2001a. The influence
of different grazing systems on plant diversity of an Artemi-
sia frigida community in the Inner Mongolia steppe of China.
J Isselstein J, Spatz G, Hofmann M. Grassland Science in
Europe, Vol. 6. Duderstadt: Mecke Druck und Verlag. 123-
125.
Wang S-P,Li Y-H,Wang Y-F,Chen Z-H. 2001b. Influence of
Different Stocking Rates on Plant Diversity of Artemisia
frigida Community in Inner Mongolia Steppe. Acta Bot Sin,
43:89-96. (in Chinese with English abstract)
Wang S P, Wang Y F, Chen Z Z, Schnug E, Haneklaus S. 2001c.
Sulphur Content of Soils and Plants and its Requirement for
Ruminants in Inner Mongolia Steppe of China. Grass Forage
Sci, 56:418-422.
Wang S P, Wang Y F, Schnug E, Haneklaus S, Fleckenstein J.
2002a. Effects of Nitrogen and Sulphur Fertilization on Oats
Yield and Quality and Digestibility, Nitrogen and Sulphur
Metabolism by Sheep in the Inner Mongolia Steppes of China.
Nutr Cycl Agroecosys, 62:195-202.
Wang S-P , Wang Y-F , Cui X-Y, Chen Z-Z , Chi H-K , Schnug E,
Haneklaus S, Fleckenstein J. 2002b. Influence of sulphur
fertilizer on sulphur cycling and its implications on sulphur
fertilizer requirement of grazed pasture in warm seasonal
rangeland of Inner Mongolia steppe of China. Acta Bot Sin,
44:204-211.
Wang S-P,Wang Y-F. 2001. The Study on Over-compensation
Growth of Cleistogenes squarrosa Population in Inner
Mongolia Steppe. Acta Bot Sin,43:413-418. (in Chinese with
English abstract)
Weiner J. 1990. Asymmetric competition in plant populations.
Trends Ecol Evol, 5:360-364.
Zhao F J, Wood A P, McGrath S P. 1999. Effect of sulphur
nutrition on growth and nitrogen fixation of pea. Plant Soil,
212:209-219.
(Managing editor: HAN Ya-Qin)