Carbon consequences of drought differ in forests that resprout

Area of Science:

• Ecology
• Climate Change Science
• Forestry

Background:

• Forest die-off events due to drought and heatwaves are increasing globally.
• These events impact forest carbon dynamics and storage capacity.
• Understanding these impacts is crucial for assessing forests' future mitigation potential.

Purpose of the Study:

• To quantify the effects of a severe drought/heatwave event on forest carbon dynamics.
• To assess the short-term recovery and carbon pool replenishment in a resprouting forest ecosystem.

Main Methods:

• Field measurements of live and dead standing carbon were conducted over two years in affected and unaffected forest plots.
• Stand measurements were taken five times post-drought/heatwave event.
• Analysis focused on changes in live and dead carbon pools and resprouting capacity.

Main Results:

• A significant loss of live standing carbon (49.3 t ha⁻¹) occurred post-event.
• The dead standing carbon pool significantly increased within six months.
• Rapid regrowth (82%-88%) of labile carbon pools was observed within 26 months, but net carbon changes were not substantial.
• 38% of surviving trees experienced partial mortality.

Conclusions:

• Resprouting forests exhibit resilience, rapidly replenishing some carbon pools.
• Dead carbon from die-offs may persist long-term due to slow decay rates.
• Climate change poses a threat, potentially turning resilient forests into carbon sources and impacting future fire regimes.