Fuel dynamics after a bark beetle outbreak impacts experimental fuel treatments

Fire Ecology

Table 5 Summary of fuel load and crown fire potential differences by treatment at the Fire and Fire Surrogate Study. Fuel and crown fire potential attributes: FWD = fine woody debris load, CWD = coarse woody debris loading, LD = litter and duff loading, CF = canopy fuel loading, CBH = canopy base height, CBD = canopy bulk density, PT = probability of torching, CI = crowing index

Treatment	2002 to 2016 change^a
Treatment	FWD	CWD	LD	CF	CBH	CBD	PT	CI
Control	↑	↑	↓	↓			↑
Burn-only	↑	↑	↑	↓		↓	↑
Thin-only	↓		↓	↑	↓	↑		↓
Thin+Burn			↑	↑
	Beetle outbreak impact (vs. Control)^b
	FWD	CWD	LD	CF	CBH	CBD	PT	CI
Control
Burn-only
Thin-only	←→	←→		→←		→←	←→	→←
Thin+Burn	←→	←→		→←		→←	←→
	2016 Tukey-Kramer rank^c
	FWD	CWD	LD	CF	CBH	CBD	PT	CI
Control	B	B		B	A	C	B	A
Burn-only	AB	B		AB	B	BC	B	A
Thin-only	AB	A		AB	AB	AB	AB	A
Thin+Burn	A	A		A	C	A	A	B

^aStatistically significant differences (α = 0.10) between 2002 and 2016 values. ↑ = values increased, ↓ = values decreased, blank = no change
^bStatistically significant effect (α = 0.10) of beetle outbreak on treatment effect over control. ← → = treatment and control differences inflated, → ← = treatment and Control differences diminished, blank = no effect
^cStatistically significant pairwise differences (α = 0.05) at 2016 measurement. Shared letters indicate no difference. A = lowest value, blank = no difference