scholarly journals Predicting individual tree mortality in northern hardwood stands under uneven-aged management in southern Québec, Canada

2008 ◽  
Vol 65 (2) ◽  
pp. 205-205 ◽  
Author(s):  
Mathieu Fortin ◽  
Steve Bédard ◽  
Josianne DeBlois ◽  
Sébastien Meunier
Keyword(s):  
Tree Mortality ◽  
Individual Tree ◽  
Northern Hardwood

Variation in canopy gap formation among developmental stages of northern hardwood stands

1996 ◽  
Vol 26 (10) ◽  
pp. 1875-1892 ◽  
Author(s):  
Sally E. Dahir ◽  
Craig G. Lorimer
Keyword(s):  
Sugar Maple ◽  
Tree Mortality ◽  
Developmental Stages ◽  
Turnover Time ◽  
Gap Formation ◽  
Old Growth ◽  
Northern Hardwood ◽  
Hardwood Species ◽  
Shade Tolerant Species ◽  
Mature Stands

Trends in gap dynamics among pole, mature, and old-growth northern hardwood stands were investigated on eight sites in the Porcupine Mountains of western upper Michigan. Recent gaps (created between 1981 and 1992) were identified using permanent plot records of tree mortality, while older gaps (1940–1981) were identified using stand reconstruction techniques. Although canopy gaps were somewhat more numerous in pole and mature stands, gaps were <25% as large as those in old-growth stands because of smaller gap-maker size, and the proportion of stand area turned over in gaps was only about half as large. Gap makers in younger stands generally had mean relative diameters (ratio of gap-maker DBH to mean DBH of canopy trees) <1.0 and were disproportionately from minor species such as eastern hophornbeam (Ostryavirginiana (Mill.) K. Koch). Gap makers in old-growth stands had mean relative diameters >1.5 and were predominantly from the dominant canopy species. Even in old-growth forests, most gaps were small (mean 44 m2) and created by single trees. Based on the identity of the tallest gap tree in each gap, nearly all shade-tolerant and midtolerant species have been successful in capturing gaps, but gap capture rates for some species were significantly different from their relative density in the upper canopy. The tallest gap trees of shade-tolerant species were often formerly overtopped trees, averaging more than 60% of the mean canopy height and having mean ages of 65–149 years. Canopy turnover times, based on gap formation rates over a 50-year period, were estimated to average 128 years for old-growth stands dominated by sugar maple (Acersaccharum Marsh.) and 192 years for old-growth stands dominated by hemlock (Tsugacanadensis (L.) Carrière). While these estimates of turnover time are substantially shorter than maximum tree ages observed on these sites, they agree closely with independent data on mean canopy residence time for trees that die at the average gap-maker size of 51 cm DBH. The data support previous hypothetical explanations of the apparent discrepancy between canopy turnover times of <130 years for hardwood species and the frequent occurrence of trees exceeding 250 years of age.

Modeling individual tree mortality for white spruce in Alberta

2003 ◽  
Vol 163 (3) ◽  
pp. 209-222 ◽  
Author(s):  
Yuqing Yang ◽  
Stephen J Titus ◽  
Shongming Huang
Keyword(s):  
Tree Mortality ◽  
White Spruce ◽  
Individual Tree

scholarly journals An Individual-Tree Mortality Model for Complex Stands of Southeastern British Columbia

2005 ◽  
Vol 20 (2) ◽  
pp. 101-109 ◽  
Author(s):  
Hailemariam Temesgen ◽  
Stephen J. Mitchell
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Tree Mortality ◽  
Model Development ◽  
Mortality Rates ◽  
Average Deviation ◽  
Individual Tree ◽  
Permanent Sample Plots ◽  
Diameter Increment ◽  
Mortality Model

Abstract An individual-tree mortality model was developed for major tree species in complex stands (multi-cohort, multiaged, and mixed species) of southeastern British Columbia (BC), Canada. Data for 29,773 trees were obtained from permanent sample plots established in BC. Average annual diameter increment and mortality rates ranged from 0.08 to 0.17 cm/year and from 0.3 to 2.6%, respectively. Approximately 70% of the trees were used for model development and 30% for model evaluation. After evaluating the model, all 29,773 trees were used to fit the final model. A generalized logistic model was used to relate mortality to tree size, competition, and relative position of trees in a stand. The evaluation test demonstrated that the model appears to be well behaved and robust for the tree species considered in this study. For the eight tree species, the average deviation between observed and predicted annual mortality rates varied from −0.5 to 0.7% in the test data. West. J. Appl. For. 20(2):101–109.

A Biodegradable Formulation of MCH (3-Methylcyclohex-2-en-1-one) for Protecting Pseudotsuga menziesii from Dendroctonus pseudotsugae (Coleoptera: Curculionidae) Colonization

2020 ◽  
Vol 113 (4) ◽  
pp. 1858-1863 ◽  
Author(s):  
Gabriel G Foote ◽  
Christopher J Fettig ◽  
Darrell W Ross ◽  
Justin B Runyon ◽  
Tom W Coleman ◽  
...  
Keyword(s):  
New Mexico ◽  
Pseudotsuga Menziesii ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Individual Tree ◽  
Significant Difference ◽  
Antiaggregation Pheromone ◽  
Individual Trees

Abstract Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, trees and stands can be protected from Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (DFB)-caused mortality by application of synthetic formulations of the beetle’s antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH). A biodegradable formulation of MCH, SPLAT MCH, was developed and evaluated for protecting individual Douglas-fir trees and small stands from colonization and mortality by DFB. In an individual-tree experiment in Idaho, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of treated trees colonized and killed by DFB compared to untreated controls. SPLAT MCH was as effective as MCH bubble capsules for protecting individual trees. Both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB within 0.04-ha circular plots surrounding each treated tree compared to untreated controls. In 0.41 ha stands in New Mexico, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB compared to untreated controls, again with no differences observed between MCH treatments. In a similar stand level trial in Idaho, neither MCH treatment significantly reduced the proportion of trees colonized by DFB, and only MCH bubble capsules significantly reduced levels of tree mortality compared to untreated controls, but no significant difference was observed between SPLAT MCH and MCH bubble capsules. Overall, the results indicate that SPLAT MCH is as effective as MCH bubble capsules for protecting individual trees and small stands of Douglas-fir from DFB-caused mortality.

scholarly journals Diameter Growth in Even- and Uneven-Aged Northern Hardwoods in New Hampshire Under Partial Cutting

2004 ◽  
Vol 21 (3) ◽  
pp. 160-163 ◽  
Author(s):  
William B. Leak
Keyword(s):  
New Hampshire ◽  
Diameter Growth ◽  
Growth Responses ◽  
Partial Cutting ◽  
Individual Tree ◽  
Increment Core ◽  
Northern Hardwood ◽  
Important Concern ◽  
Understory Trees ◽  
Baseline Diameter

Abstract One important concern in the conversion of even-aged stands to an uneven-aged condition through individual-tree or small-group cutting is the growth response throughout the diameter-class distribution, especially of the understory trees. Increment-core sampling of an older, uneven-aged northern hardwood stand in New Hampshire under management for about 50 years established the baseline diameter-growth responses of the sapling, pole, and sawtimber strata. Growth responses of the poletimber and sawtimber in a 70-year-old even-aged stand were comparable to the uneven-aged stand after an initial partial cutting treatment; growth of the understory began approaching comparable rates after the second entry about 25 years after the first cut. North. J. Appl. For. 21(3):160–163.

Forty years of alternative management practices in second-growth, pole-size northern hardwoods. I. Tree quality deveSopment

1995 ◽  
Vol 25 (7) ◽  
pp. 1173-1179 ◽  
Author(s):  
Terry F. Strong ◽  
Gayne G. Erdmann ◽  
Jeffrey N. Niese
Keyword(s):  
Management Practices ◽  
Stand Structure ◽  
Control Treatment ◽  
Individual Tree ◽  
Northern Hardwood ◽  
Heavy Medium ◽  
Second Growth ◽  
Tree Quality ◽  
The Individual ◽  
Medium Selection

The effects of six cutting methods on tree quality were observed for 20 years in a northern hardwood stand in Wisconsin. Cutting treatments included an uncut control, three levels of individual tree selection (heavy, medium, and light), crop tree release, and diameter limit. Average annual diameter growth was least in the control treatment (0.13 in./year, 0.33 cm/year) and greatest in the heavy individual tree selection and diameter-limit cuts (0.18 in./year, 0.46 cm/year). Cull in trees in 1992 was significantly higher in the control and diameter-limit treatments. Changes in merchantable height (number of 16-ft (4.9-m) logs) over the period were not significantly different among treatments, but average merchantable heights were significantly greater in the individual tree selection treatments in 1992. Average tree grade increases were significantly better in the medium selection plots than in all other treatments except the crop tree release. Nearly a third of the sawlog-size trees in both the control and diameter-limit treatments were below sawlog grade, significantly more than in the other treatments. Only 2% of the trees in the heavy selection plots were below grade. Tree quality improved the most overall in the medium selection plots. Stand structure in this treatment also most closely matched that recommended by guides developed to sustain yield over long periods of cutting under uneven-aged management.

Consequences for ectomycorrhizal fungi of the selective loss or gain of pine across landscapes

Botany ◽  
2014 ◽  
Vol 92 (12) ◽  
pp. 855-865 ◽  
Author(s):  
Justine Karst ◽  
Morgan J. Randall ◽  
Catherine A. Gehring
Keyword(s):  
Community Composition ◽  
Tree Mortality ◽  
Ecosystem Processes ◽  
The Other ◽  
Fungal Communities ◽  
Individual Tree ◽  
Disturbance Regimes ◽  
Fungal Abundance ◽  
The Individual ◽  
And Shifts

Altered disturbance regimes and novel introductions are causing rapid shifts in the distribution of pines (Pinus L.). The functionally obligate symbiosis between pines and ectomycorrhizal (EM) fungi dictates that shifts in the distribution of one partner will affect the distribution of the other. In this review, we examine evidence for three hypotheses. (1) The loss of photosynthates through stress or tree mortality decreases the abundance of EM fungi and selects for less carbon-demanding species. (2) Pine introductions initiate establishment of novel EM fungal communities. (3) The extent of shifts in EM fungal abundance and community composition is mediated by surrounding vegetation. We find support for these hypotheses though changes in EM fungal abundance are variable and context-dependent. We posit that the consequences of shifts in EM fungal abundance and community composition extend beyond the individual tree to the landscape; these changes may affect population dynamics of both symbionts, ecosystem processes, and the conservation and evolution of fungi. In addition to conducting baseline surveys to assess the distribution of EM fungi, increasing our understanding of their function, morphology, propagation, and controls on host-specificity, and shifts would also assist in predicting the trajectory of ecosystems following the loss or gain of pine.

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