Evaluation of a tree classification system in relation to mortality risk in Québec northern hardwoods

2008 ◽  
Vol 84 (6) ◽  
pp. 886-899 ◽  
Author(s):  
François Guillemette ◽  
Steve Bédard ◽  
Mathieu Fortin

A tree classification system was developed in the 1980s as part of a guide for tree-marking in the rehabilitation of unevenaged northern hardwood stands in Québec. It differentiates trees that are at high and low risk of mortality, trees with sawlog potential and cull trees. The risk class was assessed based on the presence of major crown and bole defects. The main objective of the present study was to evaluate this system with respect to its capacity to predict the probability of tree mortality. The variables used to classify the trees were observed in 88 experimental plots (0.5 ha) established between 1983 and 1999. Tree-level mortality probabilities were modelled for sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.) and yellow birch (Betula alleghaniensis Britt.) to test the significance of the classification variables. The presence of decay, fungus or canker, wounds, uprooting, the death of at least 30% of the crown or of the roots, and the product class had significant (p < 0.05) effects on mortality probabilities for at least one of the 3 species studied. In the main, the results supported the tree classification system. However, this system could be modified to differentiate not only trees with a high or low mortality risk, but also to identify some very high-risk trees. Key words: northern hardwood, mortality, defect, quality, classification, selection cutting, partial cut, sugar maple, American beech, yellow birch, uneven-aged, tree-marking

2011 ◽  
Vol 41 (4) ◽  
pp. 881-891 ◽  
Author(s):  
Farrah R. Fatemi ◽  
Ruth D. Yanai ◽  
Steven P. Hamburg ◽  
Matthew A. Vadeboncoeur ◽  
Mary A. Arthur ◽  
...  

Estimates of aboveground biomass and nutrient stocks are commonly derived using equations that describe tree dimensional relationships. Despite the widespread use of this approach, there is little information about whether equations specific to stand age are necessary for accurate biomass predictions. We developed equations for small trees (2–12 cm diameter) of six species in four young northern hardwood stands. We then compared our equations with equations used frequently in the literature that were developed in mature stands (Whittaker et al. 1974. Ecol. Monogr. 44: 233–252). Our equations for yellow birch ( Betula alleghaniensis Britt.) predicted 11%–120% greater stem wood for individual trees compared with the equations from Whittaker et al. and, on average, 50% greater aboveground yellow birch biomass in the four stands that we studied. Differences were less pronounced for sugar maple ( Acer saccharum Marsh.) and American beech ( Fagus grandifolia Ehrh.); our equations predicted, on average, 9% greater aboveground stand biomass for sugar maple and 3% lower biomass for American beech compared with Whittaker et al. Our results suggest that stand age may be an important factor influencing the aboveground allometry and biomass of small yellow birch trees in these developing northern hardwood stands.


2013 ◽  
Vol 89 (04) ◽  
pp. 512-524 ◽  
Author(s):  
Martin Béland ◽  
Bruno Chicoine

We examined applicability of various partial cutting systems in order to regenerate tolerant hardwood stands dominated by sugar maple (Acer saccarhum), American beech (Fagus grandifolia) and yellow birch (Betula alleghaniensis) on northern New Brunswick J.D. Irving Ltd. freehold land. Sampling of 1065 one-m2 plots in 31 stands managed by selection cutting, shelterwood method and strip or patch cutting and in six control stands allowed a 15-year retrospective study of natural regeneration in stands of low residual densities and with minimal soil disturbance and no control of competing vegetation. Beech regeneration was most abundant in the patch cuts, yellow birch in shelterwood stands and sugar maple in the selection system areas. Results suggest that initial stand conditions influence the composition of the regeneration more than the prescribed treatment. At the stand scale (a few hectares), sugar maple recruitment was positively influenced by its proportion in the initial stand, and negatively by the cover of herbs and shrubs. Yellow birch regeneration was mainly affected by shrub competition. At the plot (1 m2) scale, mineral soil and decayed wood substrates and ground-level transmitted light were determinant factors for yellow birch regeneration. Beech-dominated stands were likely to regenerate to beech. A dense beech sucker understory was promoted in harvested patches. Areas with dense understory of American beech, shrubs, or herbs require site preparation to reduce interference either before or at the time of partial cutting. Shelterwood seed cutting and selection cutting should leave a residual of 12 m2/ha and 17 m2/ha respectively in seed trees uniformly distributed.


2004 ◽  
Vol 21 (3) ◽  
pp. 117-122 ◽  
Author(s):  
Ralph D. Nyland ◽  
David G. Ray ◽  
Ruth D. Yanai

Abstract Knowledge of the relative rates of height growth among species is necessary for predicting developmental patterns in even-aged northern hardwood stands. To quantify these relationships, we used stem analysis to reconstruct early height growth patterns of dominant and codominant sugar maple (Acer saccharum Marsh.), yellow birch (Betula alleghaniensis Britton), white ash (Fraxinus americana L.), and America beech (Fagus grandifolia Ehrh.) trees. We used three stands (aged 19, 24, and 29 years) established by shelterwood method cutting preceded by an understory herbicide treatment. We analyzed 10 trees of each species per stand. Height growth was similar across stands, allowing us to develop a single equation for each species. Our data show that yellow birch had the most rapid height growth up to approximately age 10. Both sugar maple and white ash grew more rapidly than yellow birch beyond that point. Beech consistently grew the slowest. White ash had a linear rate of height growth over the 29-year period, while the other species declined in their growth rates. By age 29, the heights of main canopy trees ranged from 38 ft for beech to 51 ft for white ash. Both yellow birch and sugar maple averaged 46 ft tall at that time. By age 29, the base of the live crown had reached 17, 20, 21, and 26 ft for beech, sugar maple, yellow birch, and white ash, respectively. Live–crown ratios of upper-canopy trees did not differ appreciably among species and remained at approximately 40% for the ages evaluated. These results suggest that eliminating advance regeneration changes the outcome of competition to favor species other than beech. North. J. Appl. For. 21(3):117–122.


1999 ◽  
Vol 29 (3) ◽  
pp. 339-346 ◽  
Author(s):  
M A Arthur ◽  
T G Siccama ◽  
R D Yanai

Improving estimates of the nutrient content of boles in forest ecosystems requires more information on how the chemistry of wood varies with characteristics of the tree and site. We examined Ca and Mg concentrations in wood at the Hubbard Brook Experimental Forest. Species examined were the dominant tree species of the northern hardwood forest and the spruce-fir forest. The concentrations of Ca and Mg, respectively, in lightwood of these species, mass weighted by elevation, were 661 and 145 µg/g for sugar maple (Acer saccharum Marsh.), 664 and 140 µg/g for American beech (Fagus grandifolia Ehrh.), 515 and 93 µg/g for yellow birch (Betula alleghaniensis Britt.), 525 and 70 µg/g for red spruce (Picea rubens Sarg.), 555 and 118 µg/g for balsam fir (Abies balsamea (L.) Mill.), and 393 and 101 µg/g for white birch (Betula papyrifera Marsh.). There were significant patterns in Ca and Mg concentrations with wood age. The size of the tree was not an important source of variation. Beech showed significantly greater concentrations of both Ca (30%) and Mg (33%) in trees growing in moist sites relative to drier sites; sugar maple and yellow birch were less sensitive to mesotopography. In addition to species differences in lightwood chemistry, Ca and Mg concentrations in wood decreased with increasing elevation, coinciding with a pattern of decreasing Ca and Mg in the forest floor. Differences in Ca and Mg concentration in lightwood accounted for by elevation ranged from 12 to 23% for Ca and 16 to 30% for Mg for the three northern hardwood species. At the ecosystem scale, the magnitude of the elevational effect on lightwood chemistry, weighted by species, amounts to 18% of lightwood Ca in the watershed and 24% of lightwood Mg but only 2% of aboveground biomass Ca and 7% of aboveground Mg.


Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 588 ◽  
Author(s):  
Edouard Moreau ◽  
Steve Bédard ◽  
Guillaume Moreau ◽  
David Pothier

Many northern hardwood stands include several low-vigor trees as a result of past management. To restore these degraded stands, partial cuts are applied with partly validated tree classification systems that are based upon apparent stem defects. We sampled 214 sugar maple (Acer saccharum Marsh.) and 84 yellow birch (Betula alleghaniensis Britt.) trees from six sites covering the northern hardwood forest zone of the Province of Quebec, Canada. We evaluated their vigor with a four-class system, and quantified the growth efficiency index and several indices that were based solely upon radial growth. The growth efficiency index increased non-significantly with increasing tree vigor class. The five-year basal area increment (BAI-1-5) was significantly different between the lowest and highest tree vigor classes. Yet, temporal changes in BAI-1-5 helped classify correctly only 16% of high-vigor trees that became poorly vigorous 8–10 years later. Overall, these results suggest that the tree classification system is weakly related to actual tree vigor and its application likely generates few significant gains in future stand vigor. Modifying and simplifying the tree vigor system must be considered to facilitate the tree marking process that is required to improve the vigor of degraded stands.


2016 ◽  
Vol 46 (1) ◽  
pp. 114-121 ◽  
Author(s):  
Jean-Bastien Lambert ◽  
Aitor Ameztegui ◽  
Sylvain Delagrange ◽  
Christian Messier

Small-seeded tree species such as yellow birch (YB, Betula alleghaniensis Britt.) require deadwood or mineral soil for their establishment. Although much research has been done comparing YB germination on leaf litter vs. exposed mineral soil, less is known about deadwood as a seedbed and how different seedbeds affect YB early growth along light availability and size gradients. We examine how three common seedbeds (deadwood, moss cover on deadwood, and mineral soil) affected establishment and growth, biomass partitioning, and morphological traits of YB juveniles growing in the understory of temperate mixed deciduous and coniferous forests in southern Quebec. A total of 274 YB were sampled in four sugar maple (Acer saccharum Marsh.) dominated northern hardwood stands where selective cuts had been applied 6 and 15 years prior to sampling. Over 75% of the YB found on deadwood were on material of birch and conifer origin, although these species made less than 40% of the basal area. YB juveniles growing on deadwood showed traits that improve survival in shade such as reduced height growth for tall plants, higher efficiency in resource capture, and multilayered crowns. Our results demonstrate the importance of deadwood of birch and conifer origin in maintaining an abundant, natural, spatially well-distributed, and multistoried regeneration of YB.


Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 742 ◽  
Author(s):  
Simon Bilodeau-Gauthier ◽  
Steve Bédard ◽  
François Guillemette

Multi-cohort forest management in northern hardwood stands may well be the best way to successfully regenerate tree species of intermediate shade tolerance, such as yellow birch (Betula alleghaniensis Britt.). The creation of large enough gaps in the canopy favors increased light availability within the opening, while soil scarification provides suitable germination seedbeds. Evidence of these methods’ success nonetheless remains mostly the purview of experimental studies rather than operational tests. In Quebec, Canada, the multi-cohort methods promoted include group selection cutting and patch cutting. The present study tested their implementation at an operational scale and over a large territory in both hardwood-dominated and mixedwood stands. We assessed their efficacy in promoting natural regeneration of commercial hardwood trees, notably yellow birch and sugar maple (Acer saccharum Marsh.). We conducted regeneration surveys at 2, 5, 10, and 15 years after harvest. Overall, group selection and patch cuttings were successful in regenerating the target species. Yellow birch, for instance, showed a mean stocking around 60% and a mean sapling density around 3400 stems ha−1 after 15 years. We compared several variables for measuring regeneration in early years, and found that the relative abundance, the stocking based on one stem per sampling unit, and the mean maximum height were good predictors of the relative presence of yellow birch and sugar maple in 15-year-old canopy openings. Using smaller sampling units (6.25 m2 rather than 25 m2) and waiting until year 5 may be more useful for making such predictions. In addition, there was an important turnover in vertical dominance in these openings. Non-commercial woody competitors were frequently dominant in early years but were often replaced by commercial hardwoods, notably yellow birch. We propose certain thresholds for assessing the success of post-harvest regeneration and for evaluating the need for a cleaning treatment.


1996 ◽  
Vol 26 (10) ◽  
pp. 1875-1892 ◽  
Author(s):  
Sally E. Dahir ◽  
Craig G. Lorimer

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.


2007 ◽  
Vol 24 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Jodi A. Forrester ◽  
Kimberly K. Bohn

Abstract Forest management in northern hardwoods benefits from the use of site preparation treatments when the amount of American beech (Fagus grandifolia Ehrh.) and fern species in the understory interferes with regeneration of more desirable species, e.g., sugar maple (Acer saccharum Marshall). We assessed the cover and diversity of herbaceous and woody species in the ground layer of three Adirondack northern hardwood stands before and 3 years after a mechanical site preparation that removed all trees less than 14 cm with a brush saw. The treatment significantly increased the cover of all species cumulatively, with herbaceous, shrub, and arborescent species increasing significantly more in treated plots than in untreated plots. Sugar maple cover increased more in treated plots than in untreated plots, although American beech did as well. Species richness increased significantly more in treated plots than in untreated plots, but differences in diversity and evenness were not significantly different because of treatment after 3 years. Multivariate analysis indicated only minor changes in the plant community composition. Results show that mechanical site preparation techniques are a viable option for promoting abundance and maintaining diversity of the ground-layer vegetation in northern hardwood forests.


2008 ◽  
Vol 38 (3) ◽  
pp. 488-497 ◽  
Author(s):  
Marie-Lou Lefrançois ◽  
Marilou Beaudet ◽  
Christian Messier

Crown openness (CO) of mature trees influences light transmission within the forest canopy. However, in modeling, this variable is often considered constant within species, and its potential regional variability is ignored. The objective of this study was to evaluate if CO values of yellow birch ( Betula alleghaniensis Britt.), sugar maple ( Acer saccharum Marsh.), and eastern hemlock ( Tsuga canadensis (L.) Carrière) vary according to the following factors: (i) species, (ii) regional actual evapotranspiration (AET), (iii) tree size (i.e., diameter at breast height, DBH), and (iv) angle of transmission from zenith. To achieve this, CO was evaluated for 136 yellow birches, 109 sugar maples, and 68 hemlocks from different regions of western Quebec, southern Ontario, and northern Michigan. Results showed that all of the studied factors affected CO. While dominant trees can intercept light laterally as well as vertically, smaller trees are more efficient at intercepting light vertically. Increasing AET is associated with more open crowns. Given its importance in light transmission in the understory, a better understanding of how CO varies between individuals, species, and regions is needed.


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