The objective of the project is to test the theories of the structural
scaling in plants and to study their implications on sharing of
growth resources in pure and mixed stands of sun- and shade-adapted
boreal tree species (Picea abies, Pinus sylvestris, Betula pendula,
Acer saccharum, Betula alleghanienis, and Populus X wettsteinii).
The results will be used to explain growth dynamics of mixed species
tree communities. The growth resources considered are solar radiation
and soil fertility. The project combines work on three themes
in their respective working packages WP1, WP2 and WP3:
WP1 tests three theories of structural scaling (pipe model,
allometric scaling, and functional branch analysis) that explain
how attributes of organisms change with variation in their size
with measurements on the three-dimensional root-stem-shoot system
in these tree species. It further investigates how environmental
factors and species composition affect the scaling parameters.
These studies yield allocation patterns that can be utilized in
WP2 studies how the three-dimensional tree structure (represented
by scaling parameters) affects resource capture and competitive
resource sharing. This part is based on both experiments and modelling.
In WP3 two models LIGNUM
and ACROBAS that deal with resource capture and growth at tree
and stand level are modified on the basis of scaling parameters
and results of experiments. They are used to study the implications
of the interactions between above- and below-ground tree structure
and the sharing of resources on mixed-stand development.