Ecology of Iranian Forest

Introduction and objective: Quercus castaneifolia C.A. May is one of the most valuable species of Hyrcanian forest ecosystems in terms of an environmental and economic aspects. The aim of this study was to assess the effects of multicultural mixing patterns on the quantitative characteristics and soil properties in Q. castaneifolia stands in the natural habitat, which can provide useful information in the sustainable management close to the nature of future afforestation with this species.

Material and methods: Three stands of Q. castaneifolia; i) pure stand (at least 90% Q. castaneifolia), ii) Querco-Parroteum with Acer (ca. 50% Q. castaneifolia) and iii) Acero-Parroteum with Quercus (less than 20% Q. castaneifolia) with four replications were selected to investigate some silvicultural and soil characteristics in the Sorkhdary forest management plan in Golestan province. For this study, in each of the studied stands, a 150×200-meter sampling network was implemented using a random-systematic method and 15 circular sampling samples of 1000 square meters were collected (a total of 45 circular sampling plots in all stands).

Results: The results showed that the average trees number, in three pure Quercus stand, 50% and 20% Q. castaneifolia mixed stands were 274, 289 and 252 ha-1 and the calculated mean stands volume were 442.27, 394.87 and 371.65 m3ha-1, respectively. In pure Quercus stands had trees mostly the diameter breath height (DBH) >35 cm and in 20% Q. castaneifolia mixed stand had most trees DBH< 35 cm. The highest total tree height was measured in the DBH >55 cm in Q. castaneifolia pure stands. The highest soil pH was measured in Quercus pure stands (6.6) and the lowest values were measured in 20% Q. castaneifolia mixed stands (5.99). Moreover, the highest soil organic matter and nitrogen contents were measured in Q castaneifolia pure stands (6.90% and 0.85%) and the lowest values were measured in 20% mixed Q. castaneifolia stands (4.15% and 0.40%). In terms of phosphorus and potassium contents, both pure and mixed 50% Q. castaneifolia stands showed higher values in compare to mixed 20% Q castaneifolia stands.

Conclusion: Consequently, the higher intensity of Q. castaneifolia in stands enhanced quantitative stand growth and improved chemical properties of soil such as organic matter, nitrogen, potassium and phosphorus content.