Rp. Griffiths et Ak. Swanson, Forest soil characteristics in a chronosequence of harvested Douglas-fir forests, CAN J FORES, 31(11), 2001, pp. 1871-1879
Citations number
72
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
This study was designed to measure the microbiological and chemical charact
eristics of forest soils in a chronosequence of harvested Douglas-fir (Pseu
sotsuga menziesii (Mirb.) Franco) stands in different climatic settings. Mi
neral soil samples were collected along transects running from old-growth (
OG) forests into harvested stands of ages 5, 15, and 40 years (5YS, 15YS, a
nd 40YS, respectively) in the H.J. Andrews Experimental Forest in the centr
al Oregon Cascade Mountains. We took litter depth measurements and cores to
test for the presence of mycorrhizal mats at each sampling location. Denit
rification potential was significantly lower in OG than in 5YS, and litter
depth, forest floor respiration rate, and concentration of ectomycorrhizal
mats were significantly greater in OG than in 5YS. Values were intermediate
in 15YS and similar to those measured in OG in 40YS. No significant stand-
age differences occurred in soil organic matter, soil moisture, pH, mineral
izable N, laboratory soil respiration rate, or extractable ammonium. Sample
variability was generally lowest in OG forests and highest in 5YS, and no
consistent autocorrelations were observed for any of the variables at lags
of 5 m or greater. We found no second-level interactions between stand age
and location in ANOVA analyses, suggesting that, within the limits of this
study, climate did not influence soil response to disturbance and subsequen
t recovery; however, several soil properties were affected by site location
and, therefore, climate.