Establishment and dynamics of the balsam fir seedling bank in old forests of northeastern Quebec

2003 ◽  
Vol 33 (4) ◽  
pp. 597-603 ◽  
Author(s):  
Sylvain Parent ◽  
Marie-Josée Simard ◽  
Hubert Morin ◽  
Christian Messier
Keyword(s):  
Adventitious Roots ◽  
Seedling Recruitment ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Disturbance Regime ◽  
Hylocomium Splendens ◽  
Substrate Type ◽  
Age Classes ◽  
Estimation Errors ◽  
Seedling Bank

This study examines balsam fir (Abies balsamea (L.) Mill.) recruitment in old fir stands. Studying the regeneration of these stands is essential to understand the regeneration dynamic of the species in the absence of stand-destroying disturbances. The objectives were (1) to obtain substrate–seedling associations for different age-classes and according to the presence or absence of adventitious roots; (2) to evaluate the contribution of the seed rain to seedling recruitment; (3) to re-examine age structures using the most appropriate method that minimizes estimation errors due to the presence of adventitious roots. A total of 90 quadrats (1 m2) were established along transects. In each quadrat, subtrates were characterized (type and topography) and their area was estimated. All balsam fir seedlings (<50 cm tall) present in the quadrats were located, harvested whole (root and shoot), and described (age, height, presence of adventitious roots, etc). Fir seedlings were strongly associated with woody mounds covered with thin mats of mixed mosses and Pleurozium shreberi (Bird.) Mitt. but negatively associated with flat topography particularly dominated by Hylocomium splendens (Hedw.) B.S.G. The presence of adventitious root is related to seedling age more than substrate type or topography. The age structure is in agreement with seed production and disturbance regime.

Missing growth rings at the trunk base in suppressed balsam fir saplings

2002 ◽  
Vol 32 (10) ◽  
pp. 1776-1783 ◽  
Author(s):  
Sylvain Parent ◽  
Hubert Morin ◽  
Christian Messier
Keyword(s):  
Radial Growth ◽  
Adventitious Roots ◽  
Abies Balsamea ◽  
Dry Mass ◽  
Balsam Fir ◽  
Leaf Biomass ◽  
Growth Rings ◽  
Terminal Bud ◽  
Below Ground ◽  
Age Estimates

Numerous researchers have suggested a causal relationship between low leaf biomass in suppressed trees and the lack of radial growth at the base of the trunk. The objective of this study was to verify this relationship with suppressed balsam fir (Abies balsamea (L.) Mill.) saplings found growing in an old-growth fir stand. A total of 29 saplings varying in height from 67 to 183 cm were uprooted. All saplings had adventitious roots. All terminal bud scars (TBS) found between the apex of the terminal leader and the trunk base (first adventitious root) as well as those found below ground were localized, and rings were counted between TBS along the aboveground trunk. Various morphological traits and the ratio of photosynthetic tissue dry mass (P, needles) to non-photosynthetic tissue dry mass (nP, aboveground stem) were used as an indicator of tree vigour. Between 3 and 33 rings counted along the aboveground trunk were missing at the trunk base. The number of missing rings at the base of the trunk was correlated with total height (r = 0.41), height growth (r = –0.51), radial growth (r = –0.44), the P/nP ratio (r = –0.73), and the proportion of live crown (r = –0.62). Moreover, from 2 to 35 additional rings, missing at the trunk base, were found in the belowground section of trunk and these missing rings were associated with the adventitious roots phenomenon. In conclusion, suppressed firs had missing rings at the base of the trunk. When all of the missing rings were added to the number of rings counted at the base of the trunk, age estimates provided a different temporal pattern of recruitment compared with that obtained by solely counting rings at the base of the trunk. Stem analysis on the entire trunk is the best aging method for suppressed balsam fir saplings.

Balsam fir and white spruce seedling recruitment in response to understory release, seedbed type, and litter exclusion in trembling aspen stands

2005 ◽  
Vol 35 (3) ◽  
pp. 667-673 ◽  
Author(s):  
G. Geoff Wang ◽  
Kevin J Kemball
Keyword(s):  
Forest Floor ◽  
Seedling Recruitment ◽  
Mineral Soil ◽  
Abies Balsamea ◽  
White Spruce ◽  
Balsam Fir ◽  
Trembling Aspen ◽  
Light Competition ◽  
Seedling Mortality ◽  
Undisturbed Forest

Experimental seeding of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) was implemented in three mature trembling aspen (Populus tremuloides Michx.) stands in southeastern Manitoba to test (i) the effect of vegetation (light) competition and seedbed type (undisturbed forest floor, exposed mineral soil, and rotten logs) on seedling recruitment over the first 2 years and (ii) the effect of broadleaf litter exclusion on seedling mortality during the first winter. The study indicated that, with adequate seed supply, seedbed type was the most important factor limiting seedling recruitment, especially the recruitment of white spruce, in trembling aspen stands. Seedling recruitment on the best and the worst seedbeds differed by 1.8 times for balsam fir but by 19 times for white spruce. Significant differences in soil moisture and temperature were found between seedbed types. Broadleaf litter exclusion also facilitated the recruitment of balsam fir and white spruce, but only on undisturbed forest floor. Vegetation (light) competition, however, did not limit seedling recruitment. On the contrary, the presence of understory vegetation benefited seedling recruitment on rotten logs. Compared with white spruce, balsam fir is better adapted to regenerate in trembling aspen stands. Balsam fir was about 4, 12, and 36 times better than white spruce when regenerating on exposed mineral soil, rotten log, and undisturbed forest floor, respectively.

Effects of adventitious roots on age determination in Balsam fir (Abies balsamea) regeneration

2000 ◽  
Vol 30 (3) ◽  
pp. 513-518 ◽  
Author(s):  
Sylvain Parent ◽  
Hubert Morin ◽  
Christian Messier
Keyword(s):  
Adventitious Roots ◽  
Age Determination ◽  
Abies Balsamea ◽  
Balsam Fir

Early seedling demography in balsam fir seedling banks

1999 ◽  
Vol 29 (10) ◽  
pp. 1502-1509 ◽  
Author(s):  
Robin Duchesneau ◽  
Hubert Morin
Keyword(s):  
Seed Dispersal ◽  
Abies Balsamea ◽  
Ecological Factors ◽  
Balsam Fir ◽  
Permanent Plots ◽  
Seedling Mortality ◽  
Dispersal Pattern ◽  
Seedling Demography ◽  
Seedling Bank ◽  
Early Establishment

Following the 1995 mast year, we conducted detailed seedling demography surveys to characterize some ecological factors affecting germination and early establishment in understory balsam fir (Abies balsamea (L.) Mill.) seedling banks and verify if recruitment from a cohort can potentially renew the balsam fir seedling bank. Twenty-five seed traps paired with 32 demography subplots were located in each of four permanent plots and regularly monitored over a 2-year period. Spatial patterns of newly emerged seedlings generally corresponded to those found for seed dispersal. However, at the end of the monitoring period, the spatial pattern of surviving seedlings was independent of the seed dispersal pattern. Seedbed types and understory light environments were the main factors explaining seedling mortality. Sphagnum mosses and decaying wood were the most favorable seedbeds for early establishment. The 0- to 25-cm seedling populations grew in size because of the addition of new recruits. If, in the years to come, mortality rates of the 1995 cohorts were similar to those of already established 0- to 25-cm seedlings, mast years of seed production, at least during endemic periods, would be crucial for recruitment and renewal of balsam fir seedling banks.

Reply - Effects of adventitious roots on age determination in balsam fir regeneration

2002 ◽  
Vol 32 (7) ◽  
pp. 1296-1300 ◽  
Author(s):  
Sylvain Parent ◽  
Hubert Morin
Keyword(s):  
Boreal Forests ◽  
Adventitious Roots ◽  
Age Determination ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Careful Examination ◽  
Growth Rings ◽  
Reverse Taper ◽  
Closed Canopy

In many Canadian boreal forests, balsam fir (Abies balsamea (L.) Mill.) seedlings established under closed canopy generally develop adventitious roots. Adventitious roots induce the formation of a reverse taper, i.e., a reduction of the diameter and of the number of growth rings towards the true collar (hypocotyl region). Consequently, ring count at any level of the trunk underestimates the true age of firs, and we recommend a reassessment of balsam fir dynamics inferred from studies based on ages estimated by ring count. Recently, Kneeshaw and Claveau (D.D. Kneeshaw and Y. Claveau. 2001. Can. J. For. Res. 31: 1292-1295) presented data from a subsample of fir seedlings to demonstrate that ring count is an accurate aging technique for most fir regeneration. A careful examination of the methodology, data, and samples presented suggests that true collars were not precisely located. We also present data collected on seedlings sampled in the same study area as Kneeshaw and Claveau. Most of the seedlings (57 of 60 seedlings, <50 cm in height) had adventitious roots, and ring count was not an appropriate aging method. According to our study, Kneeshaw and Claveau either did not locate the true collar or presented atypical balsam fir seedlings.

Chronologie de la croissance chez des semis de sapin baumier (Abies balsamea (L.) Mill.) après une coupe à blanc avec protection de la régénération

2002 ◽  
Vol 78 (6) ◽  
pp. 876-885 ◽  
Author(s):  
Sylvain Parent ◽  
Jean-Claude Ruel
Keyword(s):  
Abies Balsamea ◽  
Ring Width ◽  
Complete Removal ◽  
Moisture Stress ◽  
Height Growth ◽  
Balsam Fir ◽  
White Birch ◽  
Strong Response ◽  
Seedling Bank ◽  
Wide Range

The method of harvesting with protection of the advanced regeneration consists of a complete removal of the main canopy to release a seedling bank established under the overstory shade. After harvesting, seedlings acclimated to understory conditions could suffer from moisture stress, especially the small, juvenile seedlings (less than six years). The objective of the study is to determine the capacity of understory-acclimated balsam fir seedlings to respond positively and immediately to release. The response to release was studied in two seedling populations belonging to two distinct climatic regions of Quebec, the Western and the Eastern sections of the balsam fir-white birch ecological domain. Results show that the response patterns were similar in both populations. Response to release occurred in two steps. One year after harvesting, basal ring width was on the average five times larger than prior to harvesting (p > 0.001). Height growth only became significantly higher the second year after release (p < 0.001). On average, juveniles showed higher height growth rates (height growth/height) than older seedlings. This rate was negatively correlated to seedling height at harvesting (r = -0,68, p < 0.001). Our study clearly shows that balsam fir seedlings can respond immediately and positively to large openings. The strong response of juvenile seedlings to release indicates that these can contribute significantly to the future stand. The geographic and climatic differences between the two stands under study suggest that these observations apply to a wide range of balsam fir stands. Key words: advance growth, balsam fir, release

Substrate type and the distribution of sugar maple at its elevational limit in the White Mountains, New Hampshire

1998 ◽  
Vol 28 (3) ◽  
pp. 494-498 ◽  
Author(s):  
Jason D Demers ◽  
Thomas D Lee ◽  
James P Barrett
Keyword(s):  
New Hampshire ◽  
Tree Species ◽  
Sugar Maple ◽  
Abies Balsamea ◽  
Red Spruce ◽  
Balsam Fir ◽  
Betula Alleghaniensis ◽  
Range Limit ◽  
Substrate Type ◽  
Yellow Birch

The relationships between tree species distribution and substrate characteristics were examined at the upper elevational limit of sugar maple (Acer saccharum Marsh.) in the White Mountain National Forest, New Hampshire. Four tree species were studied: sugar maple, balsam fir (Abies balsamea (L.) Mill.), red spruce (Picea rubens Sarg.), and yellow birch (Betula alleghaniensis Britton). At 51 individual trees (>=2.5 cm diameter at breast height) of each species, "substrate type" was described based on the parent material, soil horizons, depth and texture of the B and C horizons, nature of surface boulders, and the depth to and type of impermeable layer. Substrate type was significantly (p < 0.001) associated with tree species. Sugar maple was relatively more frequent on deep fine and compact tills, less frequent on washed or shallow till, and absent on shallow, organic, or grus (weathered granite) substrates. Red spruce, balsam fir, and yellow birch were less sensitive to substrate type. Red spruce and yellow birch were most frequent on organic material or grus over rock. Balsam fir most frequently occurred on washed till. As the frequency of substrates favorable to sugar maple declined with elevation, it is possible that the upper elevational range limit of this species is influenced by substrate availability.

Effects of adventitious roots on age determination in Balsam fir (Abies balsamea) regeneration

2000 ◽  
Vol 30 (3) ◽  
pp. 513-518 ◽  
Author(s):  
Sylvain Parent ◽  
Hubert Morin ◽  
Christian Messier
Keyword(s):  
Adventitious Roots ◽  
Age Determination ◽  
Abies Balsamea ◽  
Annual Growth ◽  
Balsam Fir ◽  
Growth Rings ◽  
Annual Growth Rings ◽  
Terminal Bud ◽  
Closed Forest ◽  
Reverse Taper

The age structure of balsam fir (Abies balsamea (L.) Mill.) regeneration is frequently used to investigate boreal forest dynamics of North America. Tree ages are usually estimated by counting annual growth rings at the shoot-root interface located above or close to the root system. Inaccurately locating the shoot-root interface could lead to imprecise age determination. In this study, balsam fir seedlings (<2 m height) were harvested in whole from closed forest stands located in the province of Quebec, Canada. Seedling age was determined by (i) counting the number of annual growth rings at the presumed shoot-root interface, and (ii) counting all terminal bud scars from the apex to the base of the hypocotyl (true collar). For all seedlings with adventitious roots, the number of terminal bud scars on the entire trunk was higher than the number of growth rings at the shoot-root interface. The formation of adventitious roots on the belowground trunk was accompanied by a reverse taper phenomenon, i.e., the number of annual growth rings decreased from the presumed shoot-root interface to the true collar. Counting annual growth rings at any level on the trunk of balsam fir seedlings that form adventitious root systems would not be reliable, underestimation's exceeding 20 years are possible and the resulting age structures could lead to erroneous interpretations of regeneration dynamics.

Balsam fir (Abies balsamea) establishment dynamics during a spruce budworm (Choristoneura fumiferana) outbreak: an evaluation of the impact of aging techniques

2001 ◽  
Vol 31 (3) ◽  
pp. 373-376 ◽  
Author(s):  
Sylvain Parent ◽  
Hubert Morin ◽  
Christian Messier
Keyword(s):  
Conventional Method ◽  
Seedling Recruitment ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Adult Mortality ◽  
Balsam Fir ◽  
Tree Age ◽  
Terminal Bud ◽  
The Impact

The effects of recurrent spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks on balsam fir (Abies balsamea (L.) Mill.) mortality have been extensively studied in Canada. Most studies report substantial seedling recruitment of balsam fir during outbreaks when reproductive trees are dying. According to previous research, this contradiction could be due to inaccuracies in the conventional aging method. Counting the maximum number of growth rings found at the tree base would significantly underestimate tree age. Counting terminal bud scars found on the entire trunk, including buried stem, would give a more accurate tree age. In this study, we compare recruitment dynamics obtained for aging seedlings in two balsam fir populations (about 500 km apart) using (i) the conventional method and (ii) bud scar counts. For both populations, the conventional method shows substantial recruitment during adult mortality, while the second aging technique reveals reduced recruitment during the epidemic phase of the spruce budworm outbreak.

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