Transcript Document

Eco-physiological Relationships
Eco-physiological Relationships
Leaf area
Growth efficiency
Foliar nitrogen concentration
Nitrogen use efficiency
Preliminary nitrogen budgets
Projected Leaf Area Index
3
Waycross (Flatwoods)
2
1
0
Projected Leaf Area Index
6
3
2
10
12
B.F. Grant (Piedmont)
Control
Fertilize
Competition Control
Fert + CC
1
0
4
9
Stand Age
11
Current Annual Increment (m3 ha-1)
70
60
12 - Control
12 - Fert
12 - Comp Cont
12 - Fert + CC
10 - Control
10 - Fert
10 - Comp Cont
10 - Fert + CC
6 - Control
6 - Fert
6 - Comp Cont
6 - Fert + CC
Waycross (Flatwoods)
50
40
30
20
10
60
B.F. Grant (Piedmont)
11 - Control
11 - Fert
11 - Comp Cont
11 - Fert + CC
9 - Control
9 - Fert
9 - Comp Cont
9 - Fert + CC
4 - Control
4 - Fert
4 - Comp Cont
4 - Fert + CC
50
40
30
20
10
1
3
5
7
9
All-sided Leaf Area Index
11
BWPE = Bolewood Production Efficiency
(ft3 ac-1 projected LAI-1 year-1)
Waycross
B.F. Grant
Age
BWPE
Age
BWPE
6
277
4
480
10
226
9
220
12
189
11
203
1 m3 ha-1 = 14.3 ft3 ac-1
Waycross
B.F. Grant
Bolewood Prod. Eff.
(ft3 ac-1 proj. LAI-1 yr-1)
Bolewood Prod. Eff.
(ft3 ac-1 proj. LAI-1 yr-1)
Age
No Fert
Fert
Age
No Fert
Fert
6
249
306
4
586
374
10
224
229
9
231
209
12
197
181
11
207
197
1 m3 ha-1 = 14.3 ft3 ac-1
Bolewood Prod. Eff.
(ton of bolewood / ton leaf)
5
Waycross
4
3
2
No Fertilizer
Fertilizer
1
20
30
40
50
60
Average Tree Height (ft)
70
Bolewood Prod. Eff.
(m3 ha-1 LAI-1)
30
B.F. Grant
25
11 - Control
11 - Fert
11 - Comp Cont
11 - Fert + CC
9 - Control
9 - Fert
9 - Comp Cont
9 - Fert + CC
4 - Control
4 - Fert
4 - Comp Cont
4 - Fert + CC
20
15
10
5
0
0
10
20
30
40
50
Average Tree Height (ft)
60
8
Bolewood Prod. Eff.
(m3 ha-1 LAI-1)
B.F. Grant
11 - Control
11 - Fert
11 - Comp Cont
11 - Fert + CC
9 - Control
9 - Fert
9 - Comp Cont
9 - Fert + CC
4 - Control
4 - Fert
4 - Comp Cont
4 - Fert + CC
6
4
2
0
0
10
20
30
40
50
Average Tree Height (ft)
60
Nitrogen (percent)
2.0
1.8
1.6
Control Waycross
Fertilize
Competition Control
Fert + CC
(Flatwoods)
1.4
1.2
1.0
6
Nitrogen (percent)
2.0
10
12
B.F. Grant (Piedmont)
1.8
1.6
1.4
1.2
1.0
5
10
Stand Age
12
All-sided LAI
12
10
8
6
4
2
0
1.0
1.2
1.4
1.6
1.8
2.0
B.F. Grant (Piedmont)
10
All-sided LAI
12 - Control
12 - Fert
12 - Comp Cont
12 - Fert + CC
10 - Control
10 - Fert
10 - Comp Cont
10 - Fert + CC
6 - Control
6 - Fert
6 - Comp Cont
6 - Fert + CC
Waycross (Flatwoods)
12 - Control
12 - Fert
12 - Comp Cont
12 - Fert + CC
10 - Control
10 - Fert
10 - Comp Cont
10 - Fert + CC
6 -Control
6 - Fert
6 - Comp Cont
6 - Fert + CC
8
6
4
2
0
0.9
1.1
1.3
1.5
1.7
Nitrogen Concentration (percent)
1.9
Current Ann. Inc. (kg ha-1)
30000
Waycross (Flatwoods)
25000
12 - Control
12 - Fert
12 - Comp Cont
12 - Fert + CC
10 - Control
10 - Fert
10 - Comp Cont
10 - Fert + CC
6 - Control
6 - Fert
6 - Comp Cont
6 - Fert + CC
20000
15000
10000
5000
0
0
20 40 60 80 100 120 140 160 180 200
Dormant Season Nitrogen Content (kg ha-1)
Waycross
Nitrogen Use Efficiency
(ton ac-1 stem growth / ton ac-1 nitrogen
Age
No Fert
Fert
6
226
263
10
203
190
12
188
135
Dry Weight (tons acre )
-1
100
Waycross
wood
bark
branch
Leaf
80
60
40
20
0
0
2
4
6
8
10
12
14
C F H HF
C F H HF
C F H HF
6 -Year-old
10 -Year-old
12 -Year-old
16
1 ton acre-1 = 2245 kg ha-1
-1
Nitrogen (tons acre )
0.18
Waycross
0.16
Stem Wood
Stem Bark
Branch
Leaf
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0.00
0
2
4
6
8
10
12
14
C F H HF
C F H HF
C F H HF
6 -Year-old
10 -Year-old
12 -Year-old
16
1 ton acre-1 = 2245 kg ha-1
Conclusions
• Large positive effect of fertilization on leaf
area throughout stand development
• Decrease in growth efficiency with increasing
stand age
• Increase in growth efficiency with fertilization
when trees of equal size are compared
Conclusions cont’d
• Fertilization causes continued increase in
foliar nitrogen concentration with stand age
• Foliar nitrogen concentration and leaf area
correlated
• Trends in nitrogen use efficiency similar to
those for growth efficiency