Quantifying the vertical diversification development stage of old-growth Douglas-fir to derive stage-specific targets for restoration silviculture

2021 ◽  
pp. 1-9
Author(s):  
Eric K. Zenner ◽  
JeriLynn E. Peck
Keyword(s):  
Development Stage ◽  
Douglas Fir ◽  
Diameter Distribution ◽  
Developmental Sequence ◽  
Old Growth ◽  
New Approach ◽  
Single Tree ◽  
Simple Index ◽  
Single Tree Selection ◽  
Oregon Cascades

Structural variability in natural Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests hinders restoration targets for the full old-growth developmental sequence. To guide stage-specific restoration, we present a new approach toward developing a simple index of the vertical diversification (VD) stage. VD-associated sub-stand structures were objectively identified by quantifying the size structures of live trees across a developmental sequence of 10 pristine stands in the Oregon Cascades, USA. Floating neighborhoods were used to delineate natural tree neighborhoods based on triangulated irregular networks in five concentric rings of ever-greater spatial extent (averaging 60–2060 m2). Diameter distributions summarized the most frequently encountered tree size structures among neighborhoods, with increasing deviation from the neutral multi-variate core. Of 18 observed diameter distribution types (DDTs), the core DDT characterized all-sized tree neighborhoods reflective of vertical diversification, which was most abundant in early old-growth (VD) stands and least abundant at the extremes of the sequence. VD declined in older stands, whose more distinct DDTs had peaks in larger trees and multiple size classes, likely reflecting horizontal diversification (HD). This new approach illustrates that structural restoration of VD stands could be facilitated by the single-tree selection method, while that of HD stands may be promoted with both single-tree and group selection as well as targeted release.

Effects of Single Tree Selection Harvests on Stand Structure, Species Composition, and Understory Tree Growth in a Sierra Mixed Conifer Forest

1990 ◽  
Vol 5 (2) ◽  
pp. 43-47 ◽  
Author(s):  
R. J. Lilieholm ◽  
L. S. Davis ◽  
R. C. Heald ◽  
S. P. Holmen
Keyword(s):  
Stand Structure ◽  
Diameter Distribution ◽  
Conifer Forest ◽  
Small Tree ◽  
Single Tree ◽  
Mixed Conifer Forest ◽  
Single Tree Selection ◽  
Shade Tolerant Species ◽  
Rates Of Growth ◽  
Understory Tree

Abstract After 20-28 years of single tree selection harvests in initially irregular even-aged stands, stand structure is approaching a target uneven-aged diameter distribution. Seedling stocking in managed stands is nearly three times greater than that of unmanaged stands. Although shade-tolerant species comprise the bulk of most size classes in both managed and unmanaged stands, selection harvests have resulted in adequate quantities of seedlings from all five conifer species, including pines. In managed stands, current small-tree stocking and rates of growth appear adequate to sustain single tree selection harvests over much of a 90-year growth simulation. Simulated peak growth rates of uneven-aged stands compare favorably with actual and anticipated yields from the forest's uneven- and even-aged stands. West. J. Appl. For. 5(2):43-47, April 1990.

scholarly journals Stand Structure and Composition in a Northern Hardwood Forest after 40 Years of Single-Tree Selection

2007 ◽  
Vol 24 (3) ◽  
pp. 197-202 ◽  
Author(s):  
Jonathan K. Neuendorff ◽  
Linda M. Nagel ◽  
Christopher R. Webster ◽  
Maria K. Janowiak
Keyword(s):  
Relative Density ◽  
Sugar Maple ◽  
Stand Structure ◽  
Forest Type ◽  
Diameter Distribution ◽  
Importance Value ◽  
Clear Trend ◽  
Single Tree ◽  
Single Tree Selection ◽  
Over Time

Abstract Uneven-aged northern hardwoods of the Great Lakes region are managed primarily through single-tree selection harvesting. We quantified species composition and stand structure after 40 years of single-tree selection in five stands as compared with three stands that were untreated for 40 years. Relative density and importance value of sugar maple significantly increased under single-tree selection, whereas relative density of yellow birch significantly decreased and eastern hemlock remained unchanged. Contemporary seedling and saplings layers were dominated by sugar maple regardless of treatment, but unmanaged stands contained more species. Diameter distribution varied over time and between unmanaged and managed stands. Increasing-q was the most common distribution shape in 2004, and there was no clear trend toward a negative exponential or rotated sigmoid distribution over time. Our results suggest that long-term single-tree selection may result in regeneration of fewer tree species commonly found in this forest type, with potential implications for future stand structure.

The effect of soil disturbance on growth and ectomycorrhizae of Douglas-fir and western hemlock seedlings: a greenhouse bioassay

1982 ◽  
Vol 12 (2) ◽  
pp. 343-353 ◽  
Author(s):  
M. Meyer Schoenberger ◽  
D. A. Perry
Keyword(s):  
Soil Disturbance ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Root Tips ◽  
Old Growth ◽  
Clear Cut ◽  
Old Growth Forest ◽  
Litter Leachate ◽  
Oregon Cascades ◽  
Tip Formation

In a greenhouse bioassay of soils from the central Oregon Cascades, Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings had the most total and ectomycorrhizal root tips when grown in soil from an unburned clear-cut and the least when grown in soil from (i) a 20-year-old plantation that had been clear-cut and burned in the late 1950's and (ii) one old-growth forest. Tip formation was intermediate in soil from a second old-growth forest, a recently burned clear-cut, and a 40-year-old natural burn. Root weights followed the same trend, but top weights did not differ among the various soils. Ectomycorrhizal and total root tips of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were lowest in soils from the plantation and recently burned clear-cut. Unlike Douglas-fir, western hemlock's tip production was not greater in the unburned clear-cut than in the old-growth forest soils. In this species, both top and root weights varied according to soil, with the largest seedlings produced in soil from the unburned clear-cut. With both species, there was a significant interaction between ectomycorrhizal type and soil type. Cenococcumgeophilum Fr. predominated on western hemlock and was reduced in soils from the burned clear-cut and plantation. In comparison with the mean for all soils, ectomycorrhizal types that predominated on Douglas-fir were enhanced in the unburned clear-cut soil and reduced in one old-growth soil, an effect apparently related to litter leachate.

Internal fungi in old-growth Douglas fir foliage

1977 ◽  
Vol 55 (6) ◽  
pp. 644-653 ◽  
Author(s):  
Mary E. Bernstein ◽  
George C. Carroll
Keyword(s):  
Transverse Section ◽  
Fungal Infections ◽  
Douglas Fir ◽  
Tree Canopy ◽  
Western Slope ◽  
Scanning Electron Micrographs ◽  
Old Growth ◽  
The Individual ◽  
Individual Trees ◽  
Oregon Cascades

Culture of surface-sterilized needles from a stand of old-growth Douglas fir trees on the western slope of the Oregon Cascades revealed the presence of latent fungal infections in all needles examined older than 3 years. Scanning electron micrographs of cut needle surfaces seen in transverse section showed occasional intercellular fungal hyphae in the needle parenchyma. Two species of fungi, Phyllosticta sp. and a suspected member of the Hemiphacidiaceae, appeared as the major colonizers of the needle blade; a third species, as yet unidentified, commonly grew out from the needle petiole. Endophytes were widespread in needles throughout the watershed regardless of the elevation and exposure of the individual trees sampled. Similarly, height of the needles in the tree canopy showed little correlation with the frequency of internal infections. Individual needles were cut into 10 segments before culture, and patterns of endophyte distribution within the needles were observed. The data are consistent with the hypothesis that needles are multiply infected during their 1st year. The initial rise in endophyte frequency occurs between November and March on 1st-year needles, a pattern suggesting waterborne spores as agents of infection. Both Phyllosticta and the hemiphacidiaceous fungus are known to produce gloeoid conidia, which are thought to be dispersed by rain. With increasing age, all needle segments become infected with endophytes.

Dynamics of the diameter distribution after selection cutting in uneven- and even-aged northern hardwood stands: a long-term evaluation

2019 ◽  
Vol 49 (12) ◽  
pp. 1525-1539 ◽  
Author(s):  
Sarita Bassil ◽  
Ralph D. Nyland ◽  
Christel C. Kern ◽  
Laura S. Kenefic
Keyword(s):  
Temporal Stability ◽  
Diameter Distribution ◽  
Weibull Function ◽  
Northern Hardwood ◽  
Selection Cutting ◽  
Single Tree ◽  
Second Growth ◽  
Single Tree Selection ◽  
Diameter Distributions

Selection cutting is defined as a tool for uneven-aged silviculture. Dependence on diameter distribution by forestry practitioners for identifying stand conditions has led to misuse of selection-like cuttings in even-aged northern hardwood stands. Our study used several long-term data sets to investigate the temporal stability in numbers of trees per diameter class in uneven-aged northern hardwood stands treated with single-tree selection and in 45-year-old second-growth stands treated with selection-like cuttings. We analyzed data from New York, Michigan, and Wisconsin to determine changes through time in number of trees across 2.5 cm diameter classes, shifts in the shape and scale of the three-parameter Weibull function used to describe the diameter distributions, and dynamics of associated stand attributes. Findings showed that single-tree selection cutting created and sustained stable diameter distributions and uniformity of conditions through consecutive entries in uneven-aged stands. By contrast, these characteristics varied through time in the second-growth stands that had been treated with selection-like cuttings. Analysis also showed that the Weibull shape and scale parameters for stands under selection system migrated towards those of the recommended target diameter distribution in the uneven-aged stands. These parameters diverged from the target with repeated use of selection-like cuttings in the second-growth even-aged stands.

Contrasting the temporal dynamics of stand structure in even- and uneven-sized Picea abies dominated stands

2011 ◽  
Vol 41 (2) ◽  
pp. 289-299 ◽  
Author(s):  
Eric K. Zenner ◽  
Erkki Lähde ◽  
Olavi Laiho
Keyword(s):  
Temporal Dynamics ◽  
Three Dimensional ◽  
Tree Size ◽  
Dimensional Structure ◽  
Diameter Distribution ◽  
Structural Development ◽  
Three Dimensional Structure ◽  
Single Tree ◽  
Single Tree Selection ◽  
The Impact

Although proposed as a means of increasing structural diversity in managed forests, the impact of single-tree selection on the temporal dynamics of three-dimensional structure has not been previously evaluated. Forest structural development in Picea-dominated stands was contrasted over 15 years in stem-mapped randomized plots in southern Finland that underwent either low thinning (creating the even-sized (ES) structure of a bell-shaped diameter distribution) or single-tree selection (maintaining the uneven-sized (UES) structure of a reverse-J-shaped distribution) through multiple harvest entries. Structure was quantified with nonspatial stand attributes (e.g., density) and indices that quantify spatially explicit relationships among neighboring trees (e.g., structural complexity index (SCI)). Over time, three-dimensional structure reflected differential tree growth and mortality, resulting in minor changes in tree composition, spatial pattern, and tree size differentiation and somewhat greater changes in the SCI. The third harvest entry simplified the forest structure in both structure types. However, structural metrics such as the variability of tree diameters, tree size differentiation, and the SCI recovered to preharvest levels within 2–4 years in UES plots, whereas no recovery was seen in the ES structure type. Single-tree selection was demonstrated to perpetuate the uneven-sized structure associated with natural nonpyrogenic Picea-dominated forests.

scholarly journals Preferences for Northern Hardwood Silviculture among Family Forest Owners in Michigan’s Upper Peninsula

2020 ◽  
Author(s):  
Alexander C Helman ◽  
Matthew C Kelly ◽  
Mark D Rouleau ◽  
Yvette L Dickinson
Keyword(s):  
Species Diversity ◽  
Hardwood Forests ◽  
Family Forest Owners ◽  
Forest Owners ◽  
Upper Peninsula ◽  
Northern Hardwood Forests ◽  
Family Forest ◽  
Northern Hardwood ◽  
Single Tree ◽  
Single Tree Selection

Abstract Managing northern hardwood forests using high-frequency, low-intensity regimes, such as single-tree selection, favors shade-tolerant species and can reduce tree species diversity. Management decisions among family forest owners (FFO) can collectively affect species and structural diversity within northern hardwood forests at regional scales. We surveyed FFOs in the Western Upper Peninsula of Michigan to understand likely future use of three silvicultural treatments—single-tree selection, shelterwood, and clearcut. Our results indicate that FFOs were most likely to implement single-tree selection and least likely to implement clearcut within the next 10 years. According to logistic regression, prior use of a treatment and perceived financial benefits significantly increased the odds for likely use for all three treatments. Having received professional forestry assistance increased likely use of single-tree selection but decreased likely use of shelterwood. We discuss these results within the context of species diversity among northern hardwood forests throughout the region.

Sign in / Sign up

Export Citation Format

Share Document