Promoting function of seabuckthorn to increment of introduced foreign arbor trees in young growth period
Yan Xiaoling
(Xifeng Institute of Soil and Water Conservation, the Water Conservancy Commission of the Yellow River, Qingyang, Gansu 745000 China)
Abstract: For the behavior of introduced foreign arbor trees like Robinia pseudoacacia, Fraxinus velutina, Juglans nigra, mixed with Hippophae rhamnoides ssp sinensis, Lathyrus latifolius respectively, to form mixed types, the field test was carried out in the tableland and gully district of the Loess Plateau. The results showed that, the arbor trees of mixed types in young growth period have good increment including height, diameter compared with the pure stand, due to the nitrogen fixation from Hippophae rhamnoides ssp sinensis, Lathyrus latifolius, and the growth of seabuckthorn is higher in mixed stand than in pure stand itself. The suitable mixed types of arbor and shrub are useful both for the growth of arbor and shrub.
Key Words: Hippophae rhamnoides ssp sinensis; mixed types; increment; soil nutrient; tableland and gully district of the Loess Plateau
The Loess Plateau is the most severe soil lost place in the world, where the climate is dry, ecosystem is fragility, soil configuration is loosen, sandstorm is frequency, rainfall is high intensity and vegetation is sparse. Soil and water lost make the Loess Plateau gullies and steep slopes appear everywhere, disasters such as coast, dilapidation gravity collapse happen occasionally1。This region is short of arbor tree types that is used to recover the ecosystem. The efficient measure to prevent and cure soil and water lost is to introduced foreign arbor trees and make growth experiments2. Since the year of 1998, the introduced foreign arbor Hippophae rhamnoides ssp sinensis is more adaptability and grows rapidly, and it has the predominance to improve the environment[3]. Compound experimentation was made on the arbor trees, and many rehabilitation pattern and economic and eco-benefit were discussed. These made the base for the rehabilitation of the Loess Plateau.
1 The situation of examination
The examination area lies in the Qingyang, Gansu province on the tableland and gully district of the Loess Plateau, 35°44′N, 107°38′E,the altitude is1421.9m,the average precipitation is 561.5mm, and the precipitation between July and September occupied more than 60% of that of the entire annual. The annual evaporation is 1503.5mm; the annual average air temperature is, the extreme low air temperature is -22.6℃,the extreme high air temperature is 35.7℃,the average temperature of January is -5.6℃, the average temperature of July is 20.9℃;average sunlight time is 2449h, the total radiation is 548.5kJ/cm3,≥10℃ accumulated temperature is 2700~3300℃;length of frost free period is 162d;the soil is HeiLu soil.
-
Material and method
2.1 Experimentation material
Hippophae rhamnoides ssp sinensis is the native arbor tree, from the Ziwu mountain forest area. Robinia pseudoacacia、Fraxinus velutina、Juglans nigra、Lathyrus latifolius are introduced from the middle west of America in 1998—20004.
-
Experimentation design
Hippophae rhamnoides ssp sinensis is used as mixed arbor type and Lathyrus latifoliu as the mixture grass type, intercrop with Robinia pseudoacacia、Fraxinus velutina、Juglans nigra respectively. The 9 pattern is:
①Hippophae rhamnoides ssp sinensis(HRS);
②Robinia pseudoacacia (RP);
③Robinia pseudoacacia + Hippophae rhamnoides ssp sinensis (RP+HRS);
④Robinia pseudoacacia +Lathyrus latifoliu (RP+LL);
⑤Fraxinus velutina (FV);
⑥Fraxinus velutina + Hippophae rhamnoides ssp sinensis (FV+HRS);
⑦Fraxinus velutina + Lathyrus latifolius (FV+LL);
⑧Juglans nigra (JN);
⑨Juglans nigra + Lathyrus latifolius (JN+LL).
The tall, diameter, crest breadth and biomass was measured after stop growth every year. And after the fourth growing season, sampled on every pattern snake on 0~20、20~40、40~60cm, measure the 7 nutrient of the mixed soil samples.
3 Result and analysis
3.1 Behavior of introduced foreign arbor trees mixed with Hippophae rhamnoides ssp sinensis in the early year
The introduced foreign arbor tree like Hippophae rhamnoides ssp sinensis and Robinia pseudoacacia, Fraxinus velutina, Juglans nigra, growth in the nursery in the first year, and intercropped on the second year. The behavior of the 4 types is in the table 1.
Table 1 Hippophae rhamnoides ssp sinensis and the inter-cropped arbor types tree height
Tree age(a)
|
Plant name
|
Growth pattern
|
Tree height(cm)
|
Multiple of tree height of mixed forest to pure forest
|
1
|
RP
|
pure forest(seedling stage)
|
185.8
|
|
FV
|
pure forest(seedling stage)
|
52.3
|
|
JN
|
pure forest(seedling stage)
|
36.0
|
|
HRS
|
pure forest(seeding stage)
|
53.0
|
|
2
|
RP
|
pure forest
|
247.2
|
1.00
|
RP
|
RP+HRS
|
260.7
|
1.08
|
RP
|
RP+LL
|
240.8
|
0.97
|
HRS
|
pure forest
|
120.4
|
1.00
|
HRS
|
RP+HRS
|
137.0
|
1.14
|
FV
|
pure forest
|
73.7
|
1.00
|
FV
|
FV+HRS
|
91.3
|
1.24
|
FV
|
FV+LL
|
86.2
|
1.18
|
HRS
|
FV+HRS
|
119.2
|
0.99
|
JN
|
pure forest
|
36.00
|
1.00
|
JN
|
JN+LL
|
52.6
|
1.46
|
3
|
RP
|
pure forest
|
298.2
|
1.00
|
HRS
|
pure forest
|
239.6
|
1.00
|
RP
|
RP+HRS
|
339.5
|
1.14
|
RP
|
RP+LL
|
311.4
|
1.04
|
HRS
|
RP+HRS
|
245.5
|
1.03
|
FV
|
pure forest
|
140.9
|
1.00
|
FV
|
FV+HRS
|
172.5
|
1.22
|
HRS
|
FV+HRS
|
238.4
|
0.99
|
FV
|
V+LL
|
142.2
|
1.01
|
JN
|
pure forest
|
65.80
|
1.00
|
JN
|
JN+ LL
|
136.4
|
2.07
|
4
|
RP
|
pure forest
|
389.0
|
1.00
|
RP
|
RP+HRS
|
471.2
|
1.21
|
RP
|
RP+LL
|
478.5
|
1.23
|
HRS
|
pure forest
|
264.4
|
1.00
|
HRS
|
RP+HRS
|
283.5
|
1.07
|
FV
|
pure forest
|
194.5
|
1.00
|
FV
|
FV+HRS
|
225.7
|
1.16
|
FV
|
FV+LL
|
202.8
|
1.04
|
JN
|
pure forest
|
141.10
|
1.00
|
JN
|
JN+LL
|
200.80
|
1.42
|
Robinia pseudoacacia grows the most rapidly in the first year of Hippophae rhamnoides ssp sinensis, Robinia pseudoacacia , Fraxinus velutina, and Juglans nigra. Hippophae rhamnoides ssp sinensis and Fraxinus velutina secondly, the height is 52~53cm, Juglans nigra growth the most slowly, it’s height is 36cm.
In the second year, the different inter-corpping pattern was adopted, Robinia pseudoacacia +Lathyrus latifoliu tree height is the lower,the pure forest 97%,the rest like inter-cropped with Hippophae rhamnoides ssp sinensis and Robinia pseudoacacia, Fraxinus velutina, the tree height higher than pure forest 8%, 24% respectively. When Hippophae rhamnoides ssp sinensis and Robinia pseudoacacia was missed, the height is higher than pure forest 14%, and the height when mixed with Fraxinus velutina is simily(99%). Lathyrus latifolius was inter-cropped with Fraxinus velutina, Juglans nigra, the tree heigh is higher than pure forest 18%, 46% respectively. The effect is very marked. The effect of Hippophae rhamnoides ssp sinensis inter-cropping is better than Lathyrus latifolius.
On the third year, Hippophae rhamnoides ssp sinensis mixed with Robinia pseudoacacia, Fraxinus velutina, the tree height is higher than pure forest 14%, 22% respectively, Robinia pseudoacacia, Fraxinus velutina, Juglans nigra and Lathyrus latifolius mixed tree height is higher than pure forest by 4%, 1% and 107%. Hippophae rhamnoides ssp sinensis mixed effect is better than Lathyrus latifolius. Hippophae rhamnoides ssp sinensis, inter-cropped with Fraxinus velutina is better than mixed with Hippophae rhamnoides ssp sinensis, the former is higher than pure forest by 99%, Robinia pseudoacacia mixed with Hippophae rhamnoides ssp sinensis is higher than pure forest by 3%. The inter-cropping effects were showed, not only the main arbor height but also the shrub height was increased(Hippophae rhamnoides ssp sinensis).
In the fourth year, the height of Hippophae rhamnoides ssp sinensis mixed with Robinia pseudoacacia, Fraxinus velutina, is higher than pure forest by 21% and 16%, Robinia pseudoacacia, Fraxinus velutina, Juglans nigra and Lathyrus latifolius mixed, the height is higher than pure forest by 23%, 4% and 42%. The mixed effect of Hippophae rhamnoides ssp sinensis is better than Lathyrus latifolius.
The inter-cropping of plants, is help to its’ growth[5]. The arbor mixed with shrub and grass, it’s height is increased more rapidly than pure forest, and the mixed effect of Hippophae rhamnoides ssp sinensis is better than perennial bird’s foot.
From table1, diameter of Hippophae rhamnoides ssp sinensis(or Lathyrus latifolius) mixed with arbor, is better than pure forest. In the third year, diameter of Robinia pseudoacacia mixed type is bigger than pure forest by 14%~23%, Fraxinus velutina mixed type bigger than pure forest by 14%~17%, and Juglans nigra by 52%. In the fourth year, diameter of Robinia pseudoacacia mixed type is greater than pure forest by 7%~9%, Juglans nigra mixed type than pure forest by 23%. The conclusion show than the mixed type of arbor , shrub and grass is help to the arbor growth, and on the same time, Hippophae rhamnoides ssp sinensis grows better than before.
Table2 The diameter contrast of Hippophae rhamnoides ssp sinensis and inter-cropped arbor
Tree age(a)
|
Plant name
|
Growth pattern
|
Ground diameter
(cm)
|
Multiple of ground diameter of mixed forest to pure forest
|
DBH(cm)
|
Multiple of DBH of mixed forest to pure forest
|
1
|
RP
|
seeding stage
|
16.9
|
|
|
|
FV
|
seeding stage
|
7.8
|
|
|
|
JN
|
seeding stage
|
1.1
|
|
|
|
HRS
|
seeding stage
|
7.0
|
|
|
|
2
|
RP
|
pure forest
|
|
|
14.6
|
1.0
|
RP
|
RP+HRS
|
|
|
16.8
|
1.1
|
HRS
|
pure forest
|
22.8
|
1.0
|
10.0
|
1.0
|
HRS
|
RP+HRS
|
23.4
|
1.0
|
11.5
|
1.1
|
FV
|
pure forest
|
9.3
|
1.0
|
|
1.0
|
FV
|
FV+HRS
|
11.1
|
1.2
|
|
|
FV
|
FV+LL
|
10.0
|
1.1
|
|
|
HRS
|
FV+HRS
|
21.6
|
1.0
|
9.5
|
1.0
|
RP
|
RP+LL
|
|
|
14.0
|
0.9
|
JN
|
pure forest
|
11.0
|
1.0
|
|
|
JN
|
JN+LL
|
16.0
|
1.5
|
|
|
3
|
RP
|
pure forest
|
|
|
22.2
|
1.0
|
RP
|
RP+HRS
|
|
|
25.3
|
1.1
|
HRS
|
RP+HRS
|
30.2
|
1.0
|
18.3
|
1.1
|
RP
|
RP+LL
|
|
|
2.7
|
1.2
|
HRS
|
pure forest
|
29. 8
|
1.0
|
17.3
|
1.0
|
FV
|
FV+HRS
|
20.7
|
1.2
|
|
|
HRS
|
FV+HRS
|
29.5
|
1.0
|
16.4
|
1.0
|
FV
|
FV+LL
|
20.2
|
1.1
|
|
|
FV
|
pure forest
|
17.7
|
1.0
|
|
|
4
|
JN
|
pure forest
|
23.0
|
1.0
|
|
|
JN
|
JN+LN
|
35.0
|
1.5
|
|
|
RP
|
pure forest
|
|
|
44.0
|
1.0
|
RP
|
RP+HRS
|
|
|
47.0
|
1.1
|
RP
|
RP+L
|
|
|
4.8
|
1.1
|
HRS
|
pure forest
|
31.3
|
1.0
|
20.3
|
1.0
|
HRS
|
RP+HRS
|
33.2
|
1.1
|
21.5
|
1.1
|
JN
|
pure forest
|
43.0
|
1.0
|
|
|
JN
|
JN+LL
|
53.0
|
1.2
|
|
|
The mixed type of Hippophae rhamnoides ssp sinensis and arbor, not only speed the growth of Robinia pseudoacacia, Fraxinus velutina, but also spur the growth of accompany arbor. And every year, Hippophae rhamnoides ssp sinensis has a certain biomass, such as the mixed type in the third year, it’s biomass is 6.93kg/hm2, and the burgeon is good feed. Brushwood would be acquired about the fifth year, and provide the energy sources for the country [6].
Table 3 Height contrast of mixed types of Hippophae rhamnoides ssp sinensis
Plant name
|
First year
|
Second year
|
Third year
|
Mixed type
|
height
(cm)
|
biomass
(t/hm2)
|
height
(cm)
|
biomass
(t/hm2)
|
height
(cm)
|
biomass
(t/hm2)
|
HRS
|
137.00
|
1.94
|
239.60
|
3.78
|
283.50
|
6.93
|
Mixed with RP
|
LL
|
65.70
|
3.40
|
82.20
|
5.60
|
143.60
|
7.80
|
Mixed with RP
|
LL
|
49.00
|
3.15
|
140.00
|
7.50
|
139.00
|
7.75
|
Mixed with JN
|
3.2 Hippophae rhamnoides ssp sinensis accelerate the growth of arbor
The arrange in groups mainly lie on the balance of interspecific compete, interspedific association and plan clan. The homogeneity or heterogeneity plant would compete with each other when their demand is greater than the provide from the environment, and the greater the density, the more violence the compete, the more similitude of eco-behaviour, leave behaviour and eco-extent, the violence the compete. The sameness arbor types would use the finity resource high strengthly and the drastic compete7. Arrange in groups of arbor and grass in reason, forming the entironment of other plant, and using plant to improve the environment is the main measure to improve the man made forestry quality. Mixed Hippophae rhamnoides ssp sinensis with Lathyrus latifolius and Robinia pseudoacacia, Juglans nigra, using the legume bacteria of Hippophae rhamnoides ssp sinensis and azotobacteria of Lathyrus latifolius to increase the soil nitrogen, improve the soil properties, make a better growth of arbor. Soil nutrient of different growth types in the third year in talbe4.
Table4 Soil nutrient contrast of different mixed types
Growth pattern
|
Sample depth(cm)
|
Organic mater(%)
|
Total N(%)
|
Total P(%)
|
Total K(%)
|
hydrolyze nitrogen(mg/kg)
|
Available P(mg/kg)
|
Available K(mg/kg)
|
RP(pure forest)
|
0~20
|
1.53
|
0.053
|
0.09
|
1.82
|
25
|
36
|
170
|
20~40
|
0.90
|
0.041
|
0.07
|
1.76
|
10
|
10
|
120
|
40~60
|
0.84
|
0.037
|
0.07
|
1.82
|
6
|
9
|
130
|
RP+HRS
|
0~20
|
1.62
|
0.05
|
0.09
|
1.84
|
25
|
37
|
200
|
20~40
|
0.93
|
0.03
|
0.07
|
1.86
|
10
|
10
|
125
|
40~60
|
0.94
|
0.03
|
0.07
|
1.80
|
6
|
5
|
120
|
RP+LL
|
0~20
|
1.74
|
0.07
|
0.10
|
1.84
|
39
|
71
|
260
|
20~40
|
1.42
|
0.05
|
0.10
|
1.90
|
19
|
50
|
170
|
40~60
|
1.17
|
0.05
|
0.09
|
1.84
|
10
|
41
|
150
|
FV
|
0~20
|
1.54
|
0.06
|
0.09
|
1.96
|
52
|
40
|
290
|
20~40
|
1.13
|
0.05
|
0.08
|
1.94
|
34
|
49
|
220
|
40~40
|
1.16
|
0.05
|
0.08
|
1.95
|
37
|
12
|
185
|
FV+HRS
|
0~20
|
1.80
|
0.07
|
0.11
|
1.98
|
47
|
41
|
280
|
20~40
|
1.21
|
0.06
|
0.09
|
1.88
|
41
|
16
|
180
|
40~60
|
1.17
|
0.05
|
0.09
|
1.94
|
34
|
10
|
210
|
JN(pure forest)
|
0~20
|
1.55
|
0.06
|
0.09
|
1.78
|
33
|
63
|
180
|
20~40
|
1.15
|
0.04
|
0.08
|
1.86
|
18
|
23
|
130
|
40~60
|
1.02
|
0.05
|
0.07
|
1.85
|
6
|
7
|
135
|
JN+LL
|
0~20
|
1.77
|
0.06
|
0.09
|
1.87
|
46
|
63
|
245
|
20~40
|
1.15
|
0.05
|
0.08
|
1.86
|
26
|
22
|
150
|
40~60
|
1.21
|
0.05
|
0.09
|
1.84
|
27
|
13
|
160
|
The conclusion can be reached from the table4 after Robinia pseudoacacia, Juglans nigra and Fraxinus velutina inter-cropped, the 7 soil nutrient is increased than pure forest. In the Robinia pseudoacacia and Hippophae rhamnoides ssp sinensis mixed type, soil nutrient, except the phosphorus of 20~40, 40~60cm , the potassium of 40~60cm is lower than pure forest, the rest soil index is greater than Robinia pseudoacacia pure forest, Fraxinus velutina and Hippophae rhamnoides ssp sinensis mixed type. In the mixed type arbord, the soil hydrolyse nitrogen of 0~20cm, 20~40cm and 40~60cm, the soil hposphor and potassium is lower than Fraxinus velutina forest, the other index is greater than Fraxinus velutina.
There are many nodule in the root system of Hippophae rhamnoides ssp sinensis which can make nitrogen fixation direct from air. Hippophae rhamnoides ssp sinensis of 1hm2 can make nitrogen fixation 180kg every year, that is greater than the pea family plant much more. And Hippophae rhamnoides ssp sinensis branches and leaves is very think, the defoliate of Hippophae rhamnoides ssp sinensis of 4~5a is 5000多kg/hm2, it’s decompose can improve the soil fabric and soil fertility. The different quantity of recession of mixed types make the different soil nutrient, and the increase of soil nutrient and upper biomass is the reason why the mixed types grows better than pure forest.
4 Conclusion
Hippophae rhamnoides ssp sinensis, Lathyrus latifolius and Robinia pseudoacacia, Fraxinus velutina, Juglans nigra inter-cropped respectively, the superiority was exhibited. The mixed forest is more higher than the pure forest. On the fourth year, the tree height of the mixed type is increased by 7%~42%,diameter is increased by 6%~52%, at the same time, in the mixed forest, the growth index of Hippophae rhamnoides ssp sinensis is increased than Hippophae rhamnoides ssp sinensis pure forest. The reason of the mixed superiority is that Hippophae rhamnoides ssp sinensis has root fungus, Lathyrus latifolius has azotobacteria, and the soil nitrogen is increased, and the physicochemical property is improved, and the growth of arbor accelerated. The mixed types of arbor and bush, arbor and grass should be adopted in the rehabilitation project in West China.
This study was carried out with the instruction by Dr. Hu Jianzhong of Beijing forestry university, the author would like to thank him very much.
|