Predicting the effects of woodcutting and moose browsing on forest development in Gros Morne National Park, Newfoundland, Canada

2010 ◽  
Vol 86 (2) ◽  
pp. 178-192 ◽  
Author(s):  
Xinbiao Zhu ◽  
Charles P.-A. Bourque ◽  
Scott Taylor ◽  
Roger Cox ◽  
Carson Wentzell

Long-term scenario analysis was used to predict the effects of domestic harvesting and moose (Alces alces) browsing on forest growing stock, species composition, and age-class distribution for two groups of managed forest blocks dominated by balsam fir (Abies balsamea [L.] Mill.) in Gros Morne National Park (GMNP), western Newfoundland. Four scenarios were examined. The first scenario assumed no timber harvesting and light moose browsing. Transition rules applied to this scenario came from neighbouring industrial forests, where moose populations are regulated by hunting. The other test scenarios use GMNP-specific transition rules to address increased moose browsing in the park, where hunting has been prohibitedsince the park’s inception in 1973. One of the three tested scenarios was also given a “no timber harvest treatment” so that the effects of moose browsing on park forests may be quantified by comparison with the first scenario. The two remaining test scenarios were designed to address compound effects of timber harvesting and moose browsing within the park, each representingan alternative management sce- nario currently being implemented in GMNP. For both harvest scenarios, the overall achievable wood volume was found to be at least five orders of magnitude lower than growing stock, thus providing sufficient volume for the ongoing domestic wood- cutting program (1973-2060) in the park. The proposed levels of woodcutting were predicted to have little impact on forest growing stock and old-growth forest after 160 years of management, but not on maintaining white birch (Betula papyrifera Marsh.), which is already in low numbers. In contrast, moose browsing, although it was predicted to have little effect on age-class distribution, was estimated to cause a 12% to 32% reduction in growing stock over a 160-year planning horizon, depending on the scenario. This was characterized by a 47% to 50% reduction in growing stock of balsam fir and a 50% to 87% reduction in white birch, and a commensurate expansion in low-density black spruce (Picea mariana [Mill.] BSP) and grassland cover. Key words: balsam fir, black spruce, domestic harvest, grassland, scenario analysis, white birch

2021 ◽  
pp. 1-11
Author(s):  
Shannon White ◽  
Xinbiao Zhu ◽  
Fanrui Meng ◽  
Scott Taylor ◽  
Charles P.-A. Bourque

Moose (Alces alces L.) browsing in Gros Morne National Park has damaged its balsam fir (Abies balsamea (L.) Mill.)dominated forest. A forest estate model was used to evaluate (i) the impacts of moose browsing and woodcutting on forest succession and (ii) strategies of forest restoration through planting and moose population management. The simulation results show that under current heavy browsing pressure growing stock of balsam fir decreases by 38%, but the area of spruce (Picea mariana (Mill.) BSP and P. glauca (Moench) Voss) increases by 32% over a 100-year planning horizon, compared to that under light browsing scenario which is assumed to be similar to the forest outside the Park due to moose population management. Annual allowable cut (AAC) for the Park’s 19 400 ha domestic harvest area is estimated to be around 120 979 m3 in a light browsing scenario, 21% higher than the sustainable harvest level in a heavy browsing scenario. The model forecasts a 97% reforestation of the Park’s 7 194 ha disturbed area by planting in the heavy browsing scenario, leading to an increase in total forest growing stock by 22% and AAC by 12%. Integration of planting with moose population management could be a more efficient way of restoring forest under high browsing pressure in GMNP.


2021 ◽  
Vol 97 (3) ◽  
pp. 315-325
Author(s):  
Shannon White ◽  
Xinbiao Zhu ◽  
Fanrui Meng ◽  
Scott Taylor ◽  
Charles P.-A. Bourque

Moose (Alces alces L.) browsing in Gros Morne National Park has damaged its balsam fir (Abies balsamea (L.) Mill.)-dominated forest. A forest estate model was used to evaluate (i) the impacts of moose browsing and woodcutting on forest succession and (ii) strategies of forest restoration through planting and moose population management. The simulation results show that under current heavy browsing pressure growing stock of balsam fir decreases by 38%, but the area of spruce (Picea mariana (Mill.) BSP and P. glauca (Moench) Voss) increases by 32% over a 100-year planning horizon, compared to that under light browsing scenario which is assumed to be similar to the forest outside the Park due to moose population management. Annual allowable cut (AAC) for the Park’s 19 400 ha domestic harvest area is estimated to be around 120 979 m3 in a light browsing scenario, 21% higher than the sustainable harvest level in a heavy browsing scenario. The model forecasts a 97% reforestation of the Park’s 7 194 ha disturbed area by planting in the heavy browsing scenario, leading to an increase in total forest growing stock by 22% and AAC by 12%. Integration of planting with moose population management could be a more efficient way of restoring forest under high browsing pressure in GMNP.


1989 ◽  
Vol 19 (4) ◽  
pp. 524-526 ◽  
Author(s):  
I. D. Thompson ◽  
A. U. Mallik

We collected forest floor organic matter at two sites where exclosures had been established 12 years previously. The exclosures allowed examination of the effects of moose (Alcesalces) herbivory on the growth of balsam fir (Abiesbalsamea). The areas supported an understory with Kalmiaangustifolia, which has been shown to affect seedling growth of black spruce (Piceamariana). Balsam fir seedlings grown in the laboratory in soil from outside the exclosures showed a significant reduction in fresh weight of the primary root compared with plants grown in washed sand. Treatment soils also showed a previously known growth inhibition effect on roots of black spruce. Exclusion of moose browsing resulted in a higher density of balsam fir inside the exclosures, while Kalmia, which was not browsed, was more dense outside the exclosures. We postulate that moose browsing reduces the extent to which balsam fir shades Kalmia, and can result in a higher density of the latter species, with consequent inhibitory effects on regenerating coniferous species.


1999 ◽  
Vol 75 (6) ◽  
pp. 973-979 ◽  
Author(s):  
Robert Jobidon ◽  
Lise Charette ◽  
François Trottier

This study aimed at comparing manual and chemical release treatments in black spruce plantations within the balsam fir – white birch ecosystems located in the Lower-Saint-Lawrence and inland Gaspé région of Québec. Three experimental sites characterized by competition dominated by red raspberry (Rubus idaeus) were selected for the study. On each site, a completely randomized block design with seven repetitions was used. Each block was composed of four plots, each representing a vegetation treatment: a manual release, a manual release to be repeated two years later, a chemical release using Vision® (Monsanto Canada), and no treatment on a control plot. The effects of treatment on spruce growth were assessed 1, 2, and 5 years after treatment. The spruce seedlings benefited from the release treatments. After five years, spruce diameter was 25.2 to 42.9% superior, height was 12.5 to 24.8% superior and the mean volume index was 89.3 to 168.6% superior to seedlings on control plots. Moreover, growth profiles over time for the released and control seedlings were not parallel; the seedlings in the released plots showed a growth rate which was superior to that of the control plots, and differences in growth trajectories increased over time. For the three experimental sites, chemical release showed no significant advantage over manual release when assessed after five years of spruce growth variables. This result is attributed to a relatively poor vegetation regrowth after treatment. A manual release treatment was applied a second time on only one of the three sites. In this case, spruce demonstrated a significantly higher growth than on plots which were only manually released once. The survival rate was not significantly affected by either of the treatments except when seedlings suffered mechanical damage. This study supports the hypothesis whereby sites located within the balsam fir – white birch ecosystems for which vigor of competing vegetation is moderate, a manual release treatment produces similar results to a chemical release treatment in terms of black spruce growth in the ensuing years. Key words: black spruce, chemical release, competition, manual release, red raspberry, spruce plantations.


1993 ◽  
Vol 23 (7) ◽  
pp. 1388-1395 ◽  
Author(s):  
Ian D. Thompson ◽  
William J. Curran

A 1960 study from central Newfoundland suggested that moose (Alcesalces L.) would: (i) reduce the commercial value of second-growth forests of central Newfoundland by excessive damage to balsam fir (Abiesbalsamea (L.) Mill.); (ii) eliminate white birch (Betulapapyrifera Marsh.) from the forest canopy; (iii) alter conifer species composition; and (iv) reduce the carrying capacity of the area for moose. We resurveyed the original study areas in 1987. Our data suggest that moose have altered species composition in favour of white spruce (Piceaglauca (Moench) Voss) and black spruce (Piceamariana (Mill.) B.S.P.) on some sites and have reduced the mean height of balsam fir trees. White birch was generally absent from the canopy. However, contrary to the 1960 prediction, moose appear to have had a positive influence on forest growth by thinning most areas to stem densities comparable with those of precommercially thinned stands. Data from this study were compared with a general model of the influence of moose on balsam fir forests developed for Isle Royale, Michigan. Our data supported two predictions from Isle Royale: moose damage was highest at low balsam fir densities and at highest moose densities. Our results contradicted a third prediction, that height growth was greater in high density stands of saplings. Also, unlike at Isle Royale, despite heavy browsing pressure for extended periods, balsam fir will continue to dominate central Newfoundland forests.


1978 ◽  
Vol 8 (1) ◽  
pp. 116-120 ◽  
Author(s):  
B. B. Delaney ◽  
M. J. Cahill

A distinctive pattern of forest types has been observed on ribbed moraines of the Avalon Peninsula, Newfoundland. This previously unreported pattern is interesting in that the best forests occur on the exposed tops and the theoretically less favourable north slopes. On each moraine, the south slopes characteristically had an uncommercial forest of balsam fir (Abiesbalsamea (L.) (Mill.)) and black spruce (Piceamariana (Mill.) BSP.), the top and upper north slopes had a forest of white birch (Betulapapyrifera Marsh.) and balsam fir, and the lower north slope had a pure balsam fir forest. Site descriptions are provided for each forest type and the vegetation succession following fire is proposed.


1991 ◽  
Vol 8 (3) ◽  
pp. 126-128 ◽  
Author(s):  
David B. Roden ◽  
Gordon A. Surgeoner

Abstract Survival, development time, and pupal weights of larvae were determined for gypsy moth reared on foliage of red oak, sugar maple, white birch, trembling aspen, white spruce, black spruce, jack pine, and balsam fir. Mortality was >50% on sugar maple and balsam fir, 35% on jack pine, and ≤15% on the other species. Female larvae developed significantly faster on trembling aspen foliage (29 days at 21°C) than on that of other species. Larvae reared on foliage of trembling aspen, white birch, or a mixture of foliage of either species and that of other species produced larger pupae than did other foliage combinations. North. J. Appl. For. 8(3):126-128.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 248
Author(s):  
Tyler Searls ◽  
James Steenberg ◽  
Xinbiao Zhu ◽  
Charles P.-A. Bourque ◽  
Fan-Rui Meng

Models of forest growth and yield (G&Y) are a key component in long-term strategic forest management plans. Models leveraging the industry-standard “empirical” approach to G&Y are frequently underpinned by an assumption of historical consistency in climatic growing conditions. This assumption is problematic as forest managers look to obtain reliable growth predictions under the changing climate of the 21st century. Consequently, there is a pressing need for G&Y modelling approaches that can be more robustly applied under the influence of climate change. In this study we utilized an established forest gap model (JABOWA-3) to simulate G&Y between 2020 and 2100 under Representative Concentration Pathways (RCP) 2.6, 4.5, and 8.5 in the Canadian province of Newfoundland and Labrador (NL). Simulations were completed using the province’s permanent sample plot data and surface-fitted climatic datasets. Through model validation, we found simulated basal area (BA) aligned with observed BA for the major conifer species components of NL’s forests, including black spruce [Picea mariana (Mill.) Britton et al.] and balsam fir [Abies balsamea (L.) Mill]. Model validation was not as robust for the less abundant species components of NL (e.g., Acer rubrum L. 1753, Populus tremuloides Michx., and Picea glauca (Moench) Voss). Our simulations generally indicate that projected climatic changes may modestly increase black spruce and balsam fir productivity in the more northerly growing environments within NL. In contrast, we found productivity of these same species to only be maintained, and in some instances even decline, toward NL’s southerly extents. These generalizations are moderated by species, RCP, and geographic parameters. Growth modifiers were also prepared to render empirical G&Y projections more robust for use under periods of climate change.


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