Ecoprovince-specific height-DBH modeling and height comparison of larix kaempferi in South Korea

Abstract

The diverse topography of South Korea directly influences forest ecosystems through regional growth environmental contrasts. This study developed height-DBH models classified by ecoprovince to analyze variations in tree height at a given DBH for L. kaempferi across five ecoprovinces in South Korea using data from the seventh National Forest Inventory (2016-2020). The height-DBH models were developed using four model types and evaluated using multiple validation metrics to determine the best-fitting model for each ecoprovinces. Vuong tests were conducted to assess whether the height-DBH relationships represented by the selected best-fitting models differ across ecoprovinces. The results revealed statistically significant differences between the Mountainous and Central hilly regions and the Southwestern hilly and Coastal regions, indicating that their height - DBH relationships are distinct. The Mountainous and Central hilly regions exhibited relatively greater heights at a given DBH, resulting in higher H/D ratios and slender tree forms. While these morphological characteristics may enhance the economic value of timber, they also imply reduced structural stability and greater vulnerability to wind damage such as windthrow. These findings highlight the importance of considering both economic and structural factors in regional forest management and demonstrate that ecoprovince-based height - DBH models can effectively support site-specific silvicultural planning in South Korea.