Effects of fire disturbance on Larix gmelinii growth-climate relationship

Abstract

• The reduction in larch growth after the fire lasts for 3–5 years. • Fire disturbance can cause changes in the radial growth-climate relationship of trees before and after a fire. • Moisture plays a role in promoting tree growth after a fire. Wildfire is a widespread phenomenon on the earth that has affected most ecosystems and is responsible for enormous economic and environmental damage. The Greater Khingan Mountains, the south boundary of the boreal forest, are a fire-prone area. However, the effect of fire disturbance on tree growth in response to climate warming is unknown. To predict the future dynamics of boreal forests after fire disturbance and their feedback on climate change, we analyzed Larix gmelinii growth-climate relationships in burned areas at six sites. The result showed a significant decline in the growth of burned trees in all locations except CY1 during the fire years. There was a growth release 3–5 years after the fire disturbance. The result of growth-climate relationships found that the response of CY1 and GH burned and unburned trees to mean temperature changed from a positive to a negative correlation before and after the fire year. Changes in tree growth response to PDSI were significant for both burned and unburned trees, suggesting that this change in response is related to fire disturbance and influenced by climate warming and drying in recent decades. The resistance of larch to fire showed that in the three years before and after the fire year, there was a significant reduction in the growth of burned larch, except for CY1. Our findings suggested that burned and unburned larch respond differently to climate change. Wildfires change the relationship between the radial growth of trees and climate factors. It may also alter the structural composition and biodiversity of boreal forests.