Effects of Forest Thinning on the Long-Term Runoff Changes of Coniferous Forest Plantation

Abstract

Forests and water are closely related to each other. Thus, forest management is crucial for the sustainable clean water supply. Forest thinning is one of the fundamental forest management practices, as it can change runoff by controlling the density of trees. In this study, the effect of forest thinning on long-term runoff changes was evaluated, based on the long-term rainfall-runoff data of a coniferous plantation forest catchment in Korea. From the double mass curve and Pettitt’s test, a statistically significant increase in runoff rates was identified. A simple linear regression model of the double mass curve can successfully quantify the net effect of forest thinning on the runoff increase. Furthermore, it was also confirmed that forest thinning does not significantly increase the risk of flooding. About ten years after forest thinning, crown closure rates of the coniferous plantation forest reached a level similar to the pre-thinning period, and runoff rates returned to the pre-thinning level, due to forest growth. As a result of this study, a proposed direction for Korea’s forest policy for water resource management is presented for the future.

An Analysis of Runoff Variation in a Small Basin in the Loess Plateau: Identifying the Variation Causes and Implications for Sustainable Water Management

“…Using this method and change-point analysis, runoff data were separated into the baseline period and the variation period. It was widely used to estimate the impact of human activities [21,[75][76][77][78]. In this study, by substituting the rainfall accumulation data in the post-mutation period into the equation of the rainfall-runoff double accumulation curve prior to the mutation, we obtained a set of runoff data that differed from the original post-mutation runoff data.…”

Evaluating changes in catchment‐scale evapotranspiration after 50% strip‐thinning in a headwater catchment

“…Thinning alters the hydrological components of the canopy and understory vegetation affecting runoff (e.g., Dung et al, 2012; Kuraji et al, 2019; Yang, 2019). Sun et al (2017) showed that evapotranspiration decreased by 21.4% after 50% strip‐thinning by plot scale measurements, while annual interception and transpiration decreased from 414.8 to 263.0 mm and from 441.0 to 272.1 mm, respectively.…”