Forest structure of managed patula pine in Ixtlan de Juarez, Oaxaca, Mexico

The diversity of arboreal species and the forest structure composition of Pinus patula Schl et Cham under different silvicultural conditions, in Ixtlan of Juarez, Oaxaca, Mexico was evaluated and compared. The information was registered only for trees over 7,5 cm of diameter breast height (dbh). The diversity was estimated through the Shannon Index (H'), the structural composition was defined through three characteristics, mingling species, spatial distribution and size differentiation, through the indices, Mingling by Godow (Mi), Contagion (Wi) and Dominance (Ui), respectively. The analysis was carried out comparing four silvicultural conditions called, pole stage, young stem, medium stem and old stem. The comparative results showed that greater diversity was presented in the medium stem and old stem forest. The major mingling degree was presented in the old stem condition. The tree distribution, in the four environments, presented a random distribution pattern and the dominance of Pinus patula is increasing while the condition develops.