| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4376681 | Ecological Modelling | 2011 | 10 Pages |
Toona ciliata Roem. (Australian red cedar) requires a nurse-tree overstory to prevent damage from drought and irradiation in some regions of north-eastern Argentina. T. ciliata was planted in the understory of Pinus taeda L. (625 stems/ha), Pinus elliottii Engelm. × Pinus caribaea Morelet (625 stems/ha), and Grevillea robusta A. Cunn. (833 stems/ha) nurse trees, which were thinned to 0, 25, 50, 75 and 100% of the initial densities. We measured initial T. ciliata mortality and growth as well as Leaf Area Index (LAI) based on light transmission. T. ciliata soil water availability and its effect on early growth and mortality were examined by modelling drought stress using the two-dimensional forest hydrology model ForWaDy. Simulated patterns in T. ciliata water stress for the different overstory treatments were consistent with observed patterns of mortality. Early mortality was lowest with a G. robusta overstory, with corresponding lowest drought stress values and high modelled soil water contents in the top soil layer in intermediate and high overstory densities. Mortality was highest with a P. elliottii × P. caribaea overstory in treatments with the highest modelled drought stress values in the most open treatments. The model supported our field observations by indicating that water stress was an important limitation to T. ciliata survival and growth on our study sites. The linkage between T. ciliata establishment success, early growth and soil water availability as indicated by ForWaDy, leads us to conclude that the model is a suitable stand management tool for guiding establishment of T. ciliata plantations.
► Toona ciliata requires nurse-trees to prevent damage from drought and irradiation in Argentina. ► Planting T. ciliata in the understory of pine and Grevillea introduces competition for water. ► With ForWaDy we examined T.ciliata soil water availability effects on early growth and mortality. ► T. ciliata drought stress was lowest under G. robusta, and highest under P. elliottii × P. caribaea. ► ForWaDy is a suitable stand management tool for guiding establishment of T. ciliata plantations.
