Quantitative Ecology and the Woodland Ecosystem Concept
J . D . O V I N G T O N
The Nature Conservancy. monk'^ Wood Resenrch Station. St . Ives.
Huntingdonshire. England
I . Introduction ........................................................ 103
.............................................. 104
A . The Ecosystem Concept in Relation to Forest Research ................ 105
B . Terminology ...................................................... 107
111 . Organic Matter Dynamics .............................................. 107
A . LackofWeightData .............................................. 107
8 . Organic Matter in Woodland Ecosystems ............................ 108
C . OrganicMatter Production .......................................... 123
D . Organic Matter Turnover .......................................... 135
IV . Energy Dynamics .................................................... 139
A . Energy Fixation .................................................. 139
B . Energy Accumulation and Release .................................. 141
1'. Water Circulation .................................................... 143
A . Water Loss from Woodland Ecosystems .............................. 144
E$ Water Balance .................................................... 148
V I . Circulation of Chemical Elements ...................................... 150
A . Weights of Chemical Element8 in Woodland Ecosystems ................ 152
B . Removal of Chemical Elements by Harvesting of Tree Trunks ............ 153
6\ Nutrient Uptake. Retention and Release .............................. 153
Soil Changes ......................................................
175
E . Input ............................................................ 176
F . Output .......................................................... 180
G . Long-termBalanre ................................................ 181
VII . Conclusions .......................................................... 181
References .............................................................. 183
I1 . TheEcosystem Concept
/
I . INTRODUCTION
Trees. by virtue of their woody structure and longevity. normally
attain a great size. and the forest combination of trees. shrubs and
non-woody plants forms a multi-layered community frequently extending from the lowest soil depth t o about 30 m above ground level in temperate forests and 55 m in tropical rain forests (Richards. 1952) . Each
plant layer supports a variety of animad life. has its own characteristic
microclimate and is heterogeneous both vertically and horizontally . Of
all terrestrial communities. woodlands are probably the most complex
and massive. and not unexpectedly woodland ecologists have attempted
t o restrict their research t o whatever features they felt were of greatest
importance or could be recorded most readily .
I03
J . D . O V I N G T O N
The Nature Conservancy. monk'^ Wood Resenrch Station. St . Ives.
Huntingdonshire. England
I . Introduction ........................................................ 103
.............................................. 104
A . The Ecosystem Concept in Relation to Forest Research ................ 105
B . Terminology ...................................................... 107
111 . Organic Matter Dynamics .............................................. 107
A . LackofWeightData .............................................. 107
8 . Organic Matter in Woodland Ecosystems ............................ 108
C . OrganicMatter Production .......................................... 123
D . Organic Matter Turnover .......................................... 135
IV . Energy Dynamics .................................................... 139
A . Energy Fixation .................................................. 139
B . Energy Accumulation and Release .................................. 141
1'. Water Circulation .................................................... 143
A . Water Loss from Woodland Ecosystems .............................. 144
E$ Water Balance .................................................... 148
V I . Circulation of Chemical Elements ...................................... 150
A . Weights of Chemical Element8 in Woodland Ecosystems ................ 152
B . Removal of Chemical Elements by Harvesting of Tree Trunks ............ 153
6\ Nutrient Uptake. Retention and Release .............................. 153
Soil Changes ......................................................
175
E . Input ............................................................ 176
F . Output .......................................................... 180
G . Long-termBalanre ................................................ 181
VII . Conclusions .......................................................... 181
References .............................................................. 183
I1 . TheEcosystem Concept
/
I . INTRODUCTION
Trees. by virtue of their woody structure and longevity. normally
attain a great size. and the forest combination of trees. shrubs and
non-woody plants forms a multi-layered community frequently extending from the lowest soil depth t o about 30 m above ground level in temperate forests and 55 m in tropical rain forests (Richards. 1952) . Each
plant layer supports a variety of animad life. has its own characteristic
microclimate and is heterogeneous both vertically and horizontally . Of
all terrestrial communities. woodlands are probably the most complex
and massive. and not unexpectedly woodland ecologists have attempted
t o restrict their research t o whatever features they felt were of greatest
importance or could be recorded most readily .
I03