Effects of Burn Severity and Environmental Conditions on Post-Fire Regeneration in Siberian Larch Forest

Thuan Chu,Xulin Guo,Kazuo Takeda

doi:10.3390/f8030076

Abstract

Post-fire forest regeneration is strongly influenced by abiotic and biotic heterogeneity in the pre- and post-fire environments, including fire regimes, species characteristics, landforms, hydrology, regional climate, and soil properties. Assessing these drivers is key to understanding the long-term effects of fire disturbances on forest succession. We evaluated multiple factors influencing patterns of variability in a post-fire boreal Larch (Larix sibirica) forest in Siberia. A time-series of remote sensing images was analyzed to estimate post-fire recovery as a response variable across the burned area in 1996. Our results suggested that burn severity and water content were primary controllers of both Larch forest recruitment and green vegetation cover as defined by the forest recovery index (FRI) and the fractional vegetation cover (FVC), respectively. We found a high rate of Larch forest recruitment in sites of moderate burn severity, while a more severe burn was the preferable condition for quick occupation by vegetation that included early seral communities of shrubs, grasses, conifers and broadleaf trees. Sites close to water and that received higher solar energy during the summer months showed a higher rate of both recovery types, defined by the FRI and FVC, dependent on burn severity. In addition to these factors, topographic variables and pre-fire condition were important predictors of post-fire forest patterns. These results have direct implications for the post-fire forest management in the Siberian boreal Larch region.

Highlights

Larix sibirica Ledeb. (Siberian Larch) is the dominant tree species covering approximately 80% of forests in the southern limit of the Siberian taiga of northern Mongolia
The higher values of pre‐fire Normalized Difference Vegetation Index (NDVI) than the area of significant decrease in the fractional vegetation cover (FVC) and forest recovery index (FRI) slope, 0.65 statistic showed that the area of significant increase in the post-fire FVC and FRI slope had higher and 0.46 respectively
This highlights the importance of the pre‐fire forest condition in the recovery values of pre-fire NDVI than the area of significant decrease in the FVC and FRI slope, 0.65 and 0.46 of the forest after fire disturbances in which healthier pre‐fire forest conditions determined by the respectively

Summary

Introduction

Larix sibirica Ledeb. (Siberian Larch) is the dominant tree species covering approximately 80% of forests in the southern limit of the Siberian taiga of northern Mongolia. (Siberian Larch) is the dominant tree species covering approximately 80% of forests in the southern limit of the Siberian taiga of northern Mongolia. This Larch forest in the taiga forest-steppe transition zone is vulnerable to climate change and fire disturbance [1,2]. Coupled with a growing demand for wood products and environmental services, increasing rates of natural disturbances such as fire and climate change has highlighted technical and scientific gaps in managing for the persistence of the Siberian Larch forest [3]. An improved understanding of the biogeochemical and biogeophysical properties and mechanisms that determine patterns in the post-disturbance Larch forest is a key step to manage the forest sustainably. Otoda et al [2] found that regeneration patterns

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