The importance of large-diameter trees to the creation of snag and deadwood biomass

Ecological Processes

Table 1 Total snagfall, pieces of wood (from the main stem), wood volume, and wood biomass in the Wind River Forest Dynamics Plot. Trees 1 ≤ DBH < 10 cm were not mapped and were assumed to have fallen as a single piece. Pieces with unknown dates reflect top pieces of still-living trees that were comprehensively sampled beginning in 2017. “Pre Estab.” indicates deadwood on the ground at plot establishment in 2010–2011

	Diameter class	Year										Total
	Diameter class	Pre Estab.	2012	2013	2014	2015	2016	2017	2018	2019	Unkn. Date	Total
Newly fallen trees and snags^a	1 cm ≤ DBH < 10 cm	17	4	51	39	59	120	283	602	377	0	1552
	10 cm ≤ DBH < 60 cm	3211	27	57	25	35	79	137	114	77	0	3762
	≥60 cm DBH	483	3	9	7	4	14	12	8	6	0	546
New pieces of deadwood^b	1 cm ≤ DBH < 10 cm	27	4	51	39	59	121	283	602	384	11	1581
	10 cm ≤ DBH < 60 cm	3887	39	66	40	53	132	168	131	98	509	5123
	≥60 cm DBH	594	6	21	14	5	79	15	14	10	420	1178
Volume (m³)	1 cm ≤ DBH < 10 cm	0.80	0.02	0.14	0.12	0.19	0.45	0.65	1.54	1.19	2.44	7.54
	10 cm ≤ DBH < 60 cm	2111.23	10.07	23.57	11.98	27.84	48.15	77.92	37.31	20.19	185.11	2553.37
	≥60 cm DBH	1955.00	44.73	62.70	89.89	13.50	217.91	117.22	74.05	73.60	676.94	3325.54
Biomass (Mg)	1 cm ≤ DBH < 10 cm	0.35	0.01	0.06	0.04	0.06	0.19	0.28	0.75	0.65	0.01	2.40
	10 cm ≤ DBH < 60 cm	1010.05	4.53	10.09	6.56	6.73	20.40	34.81	17.45	13.57	60.54	1184.73
	≥60 cm DBH	959.14	15.70	29.60	43.91	6.16	140.63	53.76	34.54	34.61	299.17	1617.22

^aTrees and snags that fell with the remaining stump <1.37 m tall (including 44 subsequently measured <10 cm diameter)
^bExplicitly mapped pieces of wood ≥10 cm diameter and ≥1 m long and non-mapped pieces of wood from trees 1 ≤ DBH < 10 cm, with those smaller trees assumed to have fallen as one piece (see the “Materials and methods” section). These reflect the number of pieces into which trees and snags fell, as well as fallen pieces of standing trees