Table Summary statistics including minimum and maximum values, median, and median absolute deviation (MAD) of nickel (Ni), manganese (Mn), and Cobalt (Co) concentrations (ppm) in surface and subsurface soils measured by field-portable XRF (FpXRF) across three survey periods.

Survey period	Sites (n)	Area (km²)	Surface												Subsurface†
			Ni (ppm)				Mn (ppm)				Co (ppm)				Ni (ppm)				Mn (ppm)				Co (ppm)
			min	max	median	MAD	min	max	median	MAD	min	max	median	MAD	min	max	median	MAD	min	max	median	MAD	min	max	median	MAD
Pre-fire (2023)	97	0.4	52	246	109	47	228	2193	713	315	72	298	183	59	52	232	116	43	324	2378	834	303	59	214	107	43
Post-fire#1 2025*	135	5.6	52	3702	441	517	386	7119	1488	783	40	1604	309	296	50	303	93	44	264	2119	926	435	40	218	91	49
Post-fire#2 2025^	64	5.6	52	339	100	49	45	3207	871	551	8	833	107	68	1	329	100	49	45	3207	871	551	8	265	97	56

Values represent minimum, maximum, and mean concentrations for each metal.
†Subsurface measurements are from a few mm below the surface; *Post-fire#1 survey conducted Jan 21–Feb 12; ^Post-fire#2: Feb 18–Mar 27 (surface samples were measured in triplicate during Post-fire#2).

Quick links

Search