| Autor: |
Casimiro Ordóñez-Prado, Melchor Rodríguez-Acosta, Juan Carlos Tamarit-Urias |
| Rok vydání: |
2020 |
| Předmět: |
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| Zdroj: |
ECORFAN Journal-Ecuador. :18-25 |
| ISSN: |
1390-9959 |
| DOI: |
10.35429/eje.2020.13.7.18.25 |
| Popis: |
Objective: Generate a density management guide (DMG) based on the Reineke density index for even-aged stands of Pinus montezumae in Puebla, Mexico. Methodology: Dasometric information from 90 sampling sites of the Forest Management Unit 2103 of the state of Puebla was processed. Each site was 1,000 m2, circularly, coming from natural stands in high density and competition; all growth conditions and age range were covered. The variables density per hectare (N) and quadratic diameter (Dq) were used to adjust the Reineke density-size model. The technique of linear ordinary least squares (OLS) was compared against that of stochastic frontier regression (SFR); the quality of the adjustments was assessed using statistical and graphic criteria. The self-thinning line was determined and a DMG was constructed defining four zones of Langsaeter growth. Contribution: The SFR technique in its semi-normal mode better defined the limit of the maximum boundary of the observed data. DMG is useful for prescribing thinnings as intermediate silvicultural treatments for stands of the species. The maximum density index for a reference Dq of 25 cm was 886 trees ha-1. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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