| Popis: |
A multi-species model of a deciduous forest is constructed that includes four species and three generic groups, based on one data set. Model equation coefficients are ob- tained using least squares, two-stage and three-stage least squares, and ridge regression statis- tical procedures. The resulting model equations are applied to a second data set and com- parisons made of the residual mean squares from both data sets. Six of seven comparisons indicate essential equality. The model is examined in the light of the existing forest and conclusions regarding forest stand trends are drawn. On the basis of the interrelations in the model and supporting evidence in the literature it is concluded that there is not a unidirectional trend in composition, but rather the possibility of many trends. Which trend is actually fol- lowed will depend on the state of the environmental variables and the extent of disturbance. |
Plný text