Etiology of canopy gaps in spruce–fir forests at Crawford Notch, New Hampshire

1988 ◽  
Vol 18 (11) ◽  
pp. 1463-1469 ◽  
Author(s):  
J. J. Worrall ◽  
T. C. Harrington
Keyword(s):  
Forest Canopy ◽  
Forest Type ◽  
Basal Area ◽  
Natural Disturbance ◽  
Ground Level ◽  
Canopy Gaps ◽  
Relative Importance ◽  
Conifer Forest ◽  
Canopy Trees ◽  
Spruce Beetle

Natural disturbance agents causing formation of canopy gaps were identified and quantified at five elevations (640, 765, 885, 1005, and 1130 m) in an old-growth spruce–fir forest. Actual and expanded gaps were measured to the inner edge of the crown or to the bole, respectively, of the live canopy trees at the gap margin. The percentage of forest canopy in gaps was lowest (6% for actual and 40% for expanded gap areas) at 1005 m elevation, near the upper limit of the spruce–fir phase, and highest (33% actual and 77% expanded) where the spruce–fir phase meets the mixed hardwood–conifer forest type at 765 m elevation. Mean gap size was smallest at the higher elevations. Expanded gap area was apportioned to tree species and disturbance agents according to basal area of affected trees in each gap. Twenty-two identified agents were involved in gap-phase mortality, and their relative importance varied strongly with elevation. Biotic diseases accounted for 66% of gap area at the lowest elevation (640 m) and only 7 and 15%, respectively, at the highest elevations (1005 and 1130 m). Root and butt rots were the most important group of biotic diseases at all elevations; their primary effect was to predispose trees to breakage of the stem near ground level. In contrast to biotic disease agents, chronic wind stress increased greatly in relative importance with elevation, accounting for 72% of gap area at 1130 m. The spruce beetle was an important disturbance agent at 640 and 765 m, where large, overmature red spruce trees had dominated the stand. Gap etiology appeared to be rarely restricted in time to a single event, and was often complex, with multiple agents occurring in the same gap and on the same tree.

Stand, species, and tree dynamics of an uneven-aged, mixed conifer forest type

1995 ◽  
Vol 25 (5) ◽  
pp. 803-812 ◽  
Author(s):  
John P. McTague ◽  
William F. Stansfield
Keyword(s):  
Tree Mortality ◽  
Forest Type ◽  
Species Abundance ◽  
Basal Area ◽  
Logistic Function ◽  
Conifer Forest ◽  
Individual Tree ◽  
Recovery Method ◽  
Parameter Recovery ◽  
Tree Survival

Stand-level equations are presented that project future merchantable tree survival, pole-tree basal area, and sawtimber basal area. Total basal area (excluding ingrowth) is the sum of the pole-tree and sawtimber components. Ratio equations are used for eight species (seven softwoods and one hardwood) to compute the change in species abundance and species basal area over time. Individual-tree mortality is predicted with a logistic function, while individual-tree diameter growth is predicted as a function of stand and individual-tree attributes. The individual-tree and species-level equations are adjusted so that tree frequency and basal area are consistent with the stand-level projection equations. Total ingrowth is computed with a stand-level projection equation and is distributed with a parameter recovery method using the uniform distribution. The presence or absence of ingrowth for a given species is determined with a discriminant function, while the proportion of total ingrowth allocated to a species is predicted with a logistic function.

Fire favours expansion of bamboo-dominated forests in the south-west Amazon

2010 ◽  
Vol 27 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Maira Smith ◽  
Bruce Walker Nelson
Keyword(s):  
Forest Fires ◽  
Basal Area ◽  
Natural Disturbance ◽  
Ground Level ◽  
Control Area ◽  
The South ◽  
South West ◽  
The Face ◽  
Woody Bamboos ◽  
Two Measures

Abstract:Forests dominated by semi-scandent woody bamboos of the genus Guadua cover about 165 000 km2 of the south-west Amazon. Because many woody bamboo species are favoured by disturbance some authors have inferred this landscape to be a consequence of indigenous or natural disturbance. As seen in satellite images, the rounded edges of some bamboo-dominated forests indicate expansion into surrounding forest. These edges are unrelated to topography and resemble the borders of ground fires in unlogged Amazon forests, suggesting that bamboo may have been favoured by past fires. We studied the recovery of Guadua sarcocarpa and its competitors in the face of simulated fire by cutting all plant stems at ground level in ten 100-m2 plots, compared with ten control plots, and by burning a 2500-m2 plot. In the clear-cuts, bamboos recovered more successfully than did palms and dicots, by two measures: biomass accumulated and per cent recovery of pre-disturbance biomass. Resprouted bamboo attained higher stem densities than in control sites at 11 mo. In the burn plot, bamboo basal area recovered to pre-burn levels after 2 y and approached that of an undisturbed control area after 3 y. Though other natural disturbances are relevant, we conclude that forest fires should favour the spread and dominance of Guadua species in the south-west Amazon.

Enlargement of canopy gaps associated with a fungal pathogen in Yosemite Valley, California

2000 ◽  
Vol 30 (10) ◽  
pp. 1501-1510 ◽  
Author(s):  
D M Rizzo ◽  
G W Slaughter ◽  
J R Parmeter, Jr.
Keyword(s):  
Contact Zone ◽  
Pinus Ponderosa ◽  
Tree Mortality ◽  
Host Density ◽  
Basal Area ◽  
Canopy Gaps ◽  
Heterobasidion Annosum ◽  
Conifer Forest ◽  
Yosemite Valley ◽  
Root Contact

The enlargement of 21 canopy gaps associated with the root pathogen Heterobasidion annosum (Fr.:Fr.) Bref. = Fomes annosus (Fr.) Karst.) in the mixed-conifer forest of Yosemite Valley was monitored between 1971 and 1998. Mean expanded gap area was 232 m2(range 38-802 m2) in 1971 and 1455 m2(range 150-4216 m2) in 1998. The pathogen is primarily spread among trees via root contacts; therefore, the spread and impact of H. annosum from the stump(s) where infection originated (gap makers) were characterized by describing the area of potential root contact as a variable-area plot. The potential root contact zone delineated the area that would be encompassed by mortality if all trees potentially in contact with the original gap makers had died. Of the 21 plots, the actual area of tree mortality exceeded the potential root contact zone in only two gaps. Enlargement rates around gap perimeters were uneven, ranging from 0 to 1.33 m/year. Incense-cedars (Calocedrus decurrens (Torr.) Florin) tended to die more slowly than ponderosa pines (Pinus ponderosa Dougl.), often 10-30 years after adjacent pines had died. Gap enlargement was not dependent on host density, basal area, or gap-maker diameter, and tended to stabilize over time, probably because of fungal competition in root wood and lack of sufficient suitable host material along gap margins.

scholarly journals Do Review Papers on Bird–Vegetation Relationships Provide Actionable Information to Forest Managers in the Eastern United States?

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 990
Author(s):  
Casey A. Lott ◽  
Michael E. Akresh ◽  
Bridgett E. Costanzo ◽  
Anthony W. D’Amato ◽  
Shengwu Duan ◽  
...  
Keyword(s):  
Forest Management ◽  
Information Needs ◽  
Online Survey ◽  
Forest Type ◽  
Grey Literature ◽  
Natural Disturbance ◽  
Eastern United States ◽  
Ecological Processes ◽  
Desired Future Conditions ◽  
Forest Managers

Forest management planning requires the specification of measurable objectives as desired future conditions at spatial extents ranging from stands to landscapes and temporal extents ranging from a single growing season to several centuries. Effective implementation of forest management requires understanding current conditions and constraints well enough to apply the appropriate silvicultural strategies to produce desired future conditions, often for multiple objectives, at varying spatial and temporal extents. We administered an online survey to forest managers in the eastern US to better understand how wildlife scientists could best provide information to help meet wildlife-related habitat objectives. We then examined more than 1000 review papers on bird–vegetation relationships in the eastern US compiled during a systematic review of the primary literature to see how well this evidence-base meets the information needs of forest managers. We identified two main areas where wildlife scientists could increase the relevance and applicability of their research. First, forest managers want descriptions of wildlife species–vegetation relationships using the operational metrics of forest management (forest type, tree species composition, basal area, tree density, stocking rates, etc.) summarized at the operational spatial units of forest management (stands, compartments, and forests). Second, forest managers want information about how to provide wildlife habitats for many different species with varied habitat needs across temporal extents related to the ecological processes of succession after harvest or natural disturbance (1–2 decades) or even longer periods of stand development. We provide examples of review papers that meet these information needs of forest managers and topic-specific bibliographies of additional review papers that may contain actionable information for foresters who wish to meet wildlife management objectives. We suggest that wildlife scientists become more familiar with the extensive grey literature on forest bird–vegetation relationships and forest management that is available in natural resource management agency reports. We also suggest that wildlife scientists could reconsider everything from the questions they ask, the metrics they report on, and the way they allocate samples in time and space, to provide more relevant and actionable information to forest managers.

Selection of forest canopy gaps by male Cerulean Warblers in West Virginia

2014 ◽  
Vol 126 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Kelly A. Perkins ◽  
Petra Bohall Wood
Keyword(s):  
West Virginia ◽  
Forest Canopy ◽  
Canopy Gaps ◽  
Cerulean Warblers ◽  
Selection Of

Root rot damage in naturally regenerated stands of spruce and balsam fir in Ontario

1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney
Keyword(s):  
Root Rot ◽  
Black Spruce ◽  
Basal Area ◽  
Ground Level ◽  
White Spruce ◽  
Balsam Fir ◽  
Tree Age ◽  
Stand Age ◽  
Root Decay ◽  
Forest Region

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.

Structure and Regeneration of Sal (Shorea robusta Gaertn. f.) Forests in Shiwalik Region of Kumaun Himalaya, India

2017 ◽  
Vol 40 (1) ◽  
pp. 1-8
Author(s):  
Bhawna Adhikari ◽  
◽  
Bhawana Kapkoti ◽  
Neelu Lodhiyal ◽  
L.S. Lodhiyal ◽  
...  
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Tree Canopy ◽  
Canopy Density ◽  
Kumaun Himalaya ◽  
Shorea Robusta ◽  
Canopy Trees ◽  
Dense Forest ◽  
Open Forest ◽  
Sal Forest

Present study was carried out to assess the structure and regeneration of Sal forests in Shiwalik region of Kumaun Himalaya. Vegetation analysis and tree canopy density was determined by using quadrat and densitometer, respectively. Density of seedlings, saplings and trees was 490-14067, 37-1233, and 273-863 ind.ha-1 respectively. The basal area was 0.12-5.44 m2 ha-1 reported for saplings and 25.4-77.6 m2 ha-1 for trees. Regeneration of Sal was found good in Sal mixed dense forest followed by Sal open forest and Sal dense forest, respectively. Regeneration of Sal was assisted by the presence of associated tree species as well as the sufficient sunlight availability on ground due to adequate opening of canopy trees in Sal forest. Thus it is concluded that the density of tree canopy, sunlight availability and also associated tree species impacted the regeneration of Sal in the region.

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