Abstract

MARTINEZ-SALVADOR, Martín; VALDEZ-CEPEDA, Ricardo David  and  POMPA GARCIA, Marín. Influence of physical variables in the yield of Pinus arizonica and Pinus engelmannii in the south of Chihuahua, México. Madera bosques [online]. 2013, vol.19, n.3, pp.35-49. ISSN 2448-7597.

In the south of Chihuahua Mexico, site index (IS) models were used in order to identify the influence of soil, climate and topography variables on P. arizonica and P engelmannii growth. The IS models were fitted by using the Schumacher equation and the guide curve with information from stems analysis. Additionally a systematic sampling method was carried out on 400 m² field plots. Dominant tree height and age, and physical variables of the sites were measured. Site index models were adjusted with tree height and age data for both species. With site index models the productivity of each sampled plot was identified. An analysis of canonical discriminate was carried on in order to identify multivariate differences in the productivity levels, and an analysis of variance was conducted to detect differences per each variable studied. Site index models accuracy were statistically significant with a pseudo r² > 0,9. The ADC showed differences in the levels of productivity, where slope, vertical dissection, soil deep and temperatures were the most important variables. According to the analysis of variance (α ≤ 0,05), the values for places whit highest productivity, and those variables which have more influence over the growth of both species are: soil depth > 43 cm, slope lower than 12° ± 8°, average of minimum temperature of 8 °C ± 3 °C, maximum temperatures < 18 °C ± 3 °C. These values could be highly useful to build spatial models of productivity in the northwest of Mexican forest.

Keywords : Station quality; growth; site index; physical variables.

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