Site index and height growth curves for Douglas-fir (Pseudotsuga menziesii) (Mirb.) Franco in the Patagonian Andean Region of Rio Negro and Chubut, Argentina.

The aim of this paper was to establish Site Index and heitgh curves for Douglas-fir for the aplication in the Patagonian Andean region. There is no antecedence in the region. From stem analysis to 69 dominat trees, selected form 28 plots, into de area between Bariloche in the north (41°30' S, Rio Negro Province) and El Corcovado in the South (43° 30"S, Chubut Province), and between 500 to 1500 mm mean annual precipitation isohyet, as east and west limits, we prepared a data base with 1481 heigth-age register. For the construction of the growth heigth curve family we proceeded according with the methodology of the guide curve method and its later armonization, appiying no linnear method to the Schumacher Model. The site index curve were deduced from the heigth growth curve, the reference age is 20 years at breast heigth. The autovalidation was made and the function was constrasted with Bruce's heigth growth curve applied in the origen region. The distribution of the error prediction was very similar to those found in literature, and when we make the Bruce heigth growth curves constrats we find the same pattern in the range of age of the sample (<40 years), and 2% difference at the age of 65 years (out of the sample age).

Keywords: Pseudotsuga menziesii, Site Quality, height growth, Site Index, Patagonia.