324
Isabel Serrasolses and V. Ramon Vallejo
400
Bumed-Ashbed
300
-G- .
+
NH4 -N
200
'V
N03 -100
----.- Mineral~
'Q
80
'V
""t:]--- 'V
400
300
200
100
0
:::::'0
80
til
01)
-- Z 60
Control 0-5
Clearcut 0-5
Burned 0-5
01)
::1.
'-"
I::
40
'1)
01)
0
20
b
Z
~
0
'W 'V'V 'V 'V 'V
'V
'V
'1)
.5
80
:E
60
Control 5-10
Clearcut 5-10
Burned 5-10
40
20
~
'V 'V "
""'t!O
'II'V 'V'V 'V
'V
W 'V'V 'V
'V
o 200 400 600 800
o 200 400 600 800
o 200 400 600 800
Days after the fire
Fig. 22.4. Mineral-N (nitrate and ammonium) over time in forest floor and mineral soil in control, cIearcut and burned plots. Mean of four bulk samples and standard deviation
nium predominated and showed the lowest increase registered (Fig. 22.4). The
increase in mineral N was observed for 1.5 years and then it decreased to the
pre-treatment values. The effect of dear-cutting in increasing N mineralization
has been widely observed (Vitousek 1981; Smethurst and Nambiar 1990).
Isabel Serrasolses and V. Ramon Vallejo
400
Bumed-Ashbed
300
-G- .
+
NH4 -N
200
'V
N03 -100
----.- Mineral~
'Q
80
'V
""t:]--- 'V
400
300
200
100
0
:::::'0
80
til
01)
-- Z 60
Control 0-5
Clearcut 0-5
Burned 0-5
01)
::1.
'-"
I::
40
'1)
01)
0
20
b
Z
~
0
'W 'V'V 'V 'V 'V
'V
'V
'1)
.5
80
:E
60
Control 5-10
Clearcut 5-10
Burned 5-10
40
20
~
'V 'V "
""'t!O
'II'V 'V'V 'V
'V
W 'V'V 'V
'V
o 200 400 600 800
o 200 400 600 800
o 200 400 600 800
Days after the fire
Fig. 22.4. Mineral-N (nitrate and ammonium) over time in forest floor and mineral soil in control, cIearcut and burned plots. Mean of four bulk samples and standard deviation
nium predominated and showed the lowest increase registered (Fig. 22.4). The
increase in mineral N was observed for 1.5 years and then it decreased to the
pre-treatment values. The effect of dear-cutting in increasing N mineralization
has been widely observed (Vitousek 1981; Smethurst and Nambiar 1990).