DEVELOPMENT OF TREE SIZE DISTRIBUTIONS IN DOUGLAS-FIR FORESTS UNDER DIFFERING DISTURBANCE REGIMES

2005 ◽  
Vol 15 (2) ◽  
pp. 701-714 ◽  
Author(s):  
Eric K. Zenner
Keyword(s):  
Douglas Fir ◽  
Tree Size ◽  
Size Distributions ◽  
Disturbance Regimes

Bigleaf maple seedling establishment and early growth in Douglas-fir forests

1988 ◽  
Vol 18 (10) ◽  
pp. 1226-1233 ◽  
Author(s):  
Jeremy S. Fried ◽  
John C. Tappeiner II ◽  
David E. Hibbs
Keyword(s):  
Seed Predation ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Early Growth ◽  
Douglas Fir ◽  
Stand Development ◽  
Size Distributions ◽  
Canopy Density ◽  
Successful Establishment ◽  
Survival Of Seedlings

Survival, age and height distributions, and stocking of bigleaf maple (Acermacrophyllum Pursh) seedlings were studied in 1- to 250-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands in western Oregon to identify the stages in stand development in which bigleaf maple is most likely to establish successfully from seed. Maple seedling emergence averaged 30–40% where seeds were planted and protected from rodents but was typically <2% for unprotected seeds. Seedling survival after 2 years was highly dependent on canopy density, measured by percent sky. Average 1st-year survival of seedlings originating from planted, protected seeds was highest in clearcuts (1–2 years old, 36% survival, 56% sky) and pole-size stands (41–80 years old, 30% survival, 17% sky) with sparse understories and canopies. It was lowest in young stands with dense canopies (20–40 years old, 4% survival, 8% sky) and old stands (81–250 years old, 14% survival, 13% sky) with dense understories. Naturally regenerated populations of bigleaf maple seedlings, which occurred in aggregations (0.005–0.04 ha in area), were most abundant (up to 10 000/ha) in pole-size Douglas-fir stands. Although seedling size distributions within stands had a strongly inverse J shaped form, size distributions within aggregations appeared more normal (bell-shaped). Seedling age rarely exceeded 15 years. Seedlings grew slowly in the understory, often reaching only 25 cm in height after 8–10 years, and were intensively browsed by deer. Naturally regenerated seedlings were virtually absent from clearcuts, probably because of dense competing vegetation and lack of seed caused by poor dispersal and seed predation. The "window" for the most successful establishment of bigleaf maple seedlings appears to begin after canopy thinning and end before forbs and shrubs invade.

scholarly journals Distribution of Fine Roots of Ponderosa Pine and Douglas-Fir in a Central Idaho Forest

2008 ◽  
Vol 23 (4) ◽  
pp. 202-205 ◽  
Author(s):  
Gabriel Dumm ◽  
Lauren Fins ◽  
Russell T. Graham ◽  
Theresa B. Jain
Keyword(s):  
Ponderosa Pine ◽  
Root Distribution ◽  
Fine Roots ◽  
Fine Root ◽  
Douglas Fir ◽  
Tree Size ◽  
Soil Horizon ◽  
Soil Horizons ◽  
Fine Root Distribution ◽  
Root Content

Abstract This study describes soil horizon depth and fine root distribution in cores collected at two distances from the boles of Douglas-fir and ponderosa pine trees at a study site in a central Idaho forest. Concentration and content of fine roots extracted from soil cores were compared among species, soil horizons, tree size, and distance from bole. Approximately 80% of litter and humus samples contained no fine roots. The highest fine root content and concentrations of fine roots occurred in deep mineral soil for both species (1.24 g and 2.82 g/l for Douglas-fir and 0.98g and 2.24 g/l for ponderosa pine, respectively). No statistically significant differences were found in fine root content or concentration between species in any of the four soil horizons. Tree size was not a significant factor in fine root distribution in this study. Significant variables were horizon, distance from bole, and interactions among tree size, location of sample, and soil horizon. This study, which was part of a larger US Forest Service study to develop a predictive model of postfire tree mortality, provides baseline information that may be useful in predicting postfire damage to fine roots.

Comparing individual tree detection and the area-based statistical approach for the retrieval of forest stand characteristics using airborne laser scanning in Scots pine stands

2011 ◽  
Vol 41 (3) ◽  
pp. 583-598 ◽  
Author(s):  
Jussi Peuhkurinen ◽  
Lauri Mehtätalo ◽  
Matti Maltamo
Keyword(s):  
Laser Scanning ◽  
Statistical Approach ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Tree Size ◽  
Size Distributions ◽  
Individual Tree ◽  
Tree Detection ◽  
Airborne Laser ◽  
Number Of Stems

Airborne laser scanning based forest inventories employ two major methods: individual tree detection (ITD) and the area-based statistical approach (ABSA). ITD is based on the assumption that trees are of a certain form and can be delineated using airborne laser scanning techniques, whereas ABSA is an empirical method based on the relations between area-level forest attributes and laser echo height distributions. These two methods are compared here within the same test area in terms of their usefulness for estimating mean forest stand characteristics and tree size distributions. All evaluations were performed using leave-one-out cross validation. The average errors in volume and basal area did not differ significantly between the methods. ABSA resulted in overall better accuracies when estimating the diameter and height of the basal area median tree and the number of stems, whereas ITD produced significantly biased estimates for the number of stems and the mean tree size. Tree size distributions were estimated with slightly better accuracy using ABSA. More comprehensive investigations revealed that both methods were not able to estimate forest structure (tree size distribution and spatial distribution of tree locations), which in turn, affected the estimation accuracies.

Predicting average growth and size distributions of Douglas-fir saplings competing with sprout clumps of tanoak or Pacific madrone

New Forests ◽  
1991 ◽  
Vol 5 (2) ◽  
pp. 109-130 ◽  
Author(s):  
Timothy B. Harrington ◽  
John C. Tappeiner ◽  
Thomas F. Hughes
Keyword(s):  
Douglas Fir ◽  
Size Distributions ◽  
Average Growth ◽  
Pacific Madrone

Mortality and tree-size distributions in natural mixed-age forests

2007 ◽  
Vol 95 (1) ◽  
pp. 27-40 ◽  
Author(s):  
DAVID A. COOMES ◽  
ROBERT B. ALLEN
Keyword(s):  
Tree Size ◽  
Size Distributions ◽  
Mixed Age

scholarly journals On the Challenge of Fitting Tree Size Distributions in Ecology

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e58036 ◽  
Author(s):  
Franziska Taubert ◽  
Florian Hartig ◽  
Hans-Jürgen Dobner ◽  
Andreas Huth
Keyword(s):  
Tree Size ◽  
Size Distributions
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