Agriculture Reference
In-Depth Information
Fig. 4.4.1.
Bulk precipitation at the experimental site during the period December 1997-
November 1998.
Table 4.4.2.
Mean annual concentrations of dissolved organic carbon, nitrogen, phosphorus and
sulphur (DOC, DON, DOP and DOS) in bulk precipitation (BP), canopy throughfall (TF), forest floor
leachate (FF) and mineral soil porewater at 15, 30 and 90 cm depth in a European beech (Fagus
sylvaticaL.) forest with Lithic Rendolls during the period December 1997-November 1998. In
addition, the mean proportions of organic carbon and nutrients in the hydrophilic fraction (hiDOC,
hiDON, hiDOP and hiDOS) are given. Values in parentheses indicate the standard deviation.
DOC
(mg l
−
1
)
hiDOC
(%)
DON
(mg l
−
1
)
hiDON
(%)
DOP
(mg l
−
1
)
hiDOP
(%)
DOS
(mg l
−
1
)
hiDOS
(%)
Compartment
BP
3.73 (3.22)
nd
0.12 (0.05)
nd
0.01 (0.01)
nd
0.04 (0.02)
nd
TF
12.05 (10.19)
77
0.42 (0.11)
86
0.03 (0.02)
94
0.12 (0.06)
70
FF
30.26 (24.57)
68
1.32 (0.22)
80
0.09 (0.07)
97
0.31 (0.09)
92
15 cm
28.50 (23.33)
67
1.31 (0.24)
82
0.11 (0.09)
88
0.34 (0.11)
86
30 cm
25.69 (20.75)
67
1.30 (0.21)
83
0.13 (0.10)
92
0.34 (0.10)
89
90 cm
16.70 (14.04)
73
0.98 (0.20)
94
0.11 (0.09)
96
0.29 (0.10)
91
nd = Not determined.
(1991). The concentrations of DOC and organic nutrient forms were sig-
nificantly (
P
< 0.001) higher during the growing season (April-September
1998) than during winter 1997 and autumn 1998 (e.g. DOC and DOP;
Fig. 4.4.2).
The concentrations in the forest floor seepage water and the mineral
soil porewater peaked at heavy rain events during the first warmer weeks in
spring and after rain storms following drier periods in summer. In autumn
1998, the concentrations reached a more or less constant level clearly below
the concentrations during spring and summer. One reason for the constant
concentrations could be the large amount of rainfall during that time
resulting in permanent leaching of the forest floor material.
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