Abstracts |
Coarse wood provides important ecosystem structure and function such as water and
nutrient storage and critical habitat for the conservation of a variety of organisms, including
ectomycorrhizal (EM) fungi. The chemistry and EM communities were compared in coarse wood samples
collected from two advanced decay stages of logs in 12 paired young and old-growth stands in the
Oregon Cascade Range. Average total C and nonpolar extractives were higher in young stands (15-55
years) (mean = 53.38%, 95% CI of 52.48-54.27 and mean = 8.54%, 95% CI of 6.92-10.16,
respectively) compared with old-growth stands (200-500 years) (mean = 51.22%, 95% CI of
49.67-52.77 and mean = 6.75%, 95% CI of 5.88-7.62, respectively). Averages for total and
extractable P were higher in old-growth stands (mean = 0.03%, 95% CI of 0.02-0.04 and mean =
82.91, 95% CI of 52.24-113.57, respectively) compared with young stands (mean = 0.02%, 95% CI of
0.02-0.02 and mean = 56.17, 95% CI of 45.84-66.50, respectively). Average pH and total N were
highest in logs in the most advanced decay stage (mean = 4.17, 95% CI of 3.97-4.38 and mean =
0.35%, 95% CI of 0.29-0.40, respectively). No differences between log decay class or stand age
were detected for water-soluble extractives, hemicellulose plus cellulose (or acid-hydrolyzable
fraction), or acid-unhydrolyzable residue. Observed differences in average wood property values
between decay stages and between young and old-growth stands were small and, although
statistically significant, may not reflect an important difference in EM fungal habitat. EM
communities were similar between young and old-growth stands and between logs in decay classes 4
and 5. Results suggest that down wood in advanced decay stages provides similar habitat for EM
fungi in both old-growth and young, managed stands.
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