Natural disturbance and gap phase dynamics in southern Appalachian spruce–fir forests

1985 ◽  
Vol 15 (1) ◽  
pp. 233-240 ◽  
Author(s):  
Peter S. White ◽  
Mark D. MacKenzie ◽  
Richard T. Busing
Keyword(s):  
Species Interactions ◽  
Community Organization ◽  
Natural Disturbance ◽  
Canopy Gaps ◽  
Old Growth ◽  
Capture Process ◽  
Canopy Density ◽  
Great Smoky Mountains ◽  
Phase Dynamics ◽  
Smoky Mountains

Spatially small canopy gaps dominated the natural disturbance regime of old-growth spruce–fir forests in the Great Smoky Mountains, North Carolina and Tennessee. New gaps ≤200 m2 in size were formed with a frequency of 0.006 to 0.009/year and the 1- to 10-year age class of these gaps covered an estimated 6 to 17% of the study area (depending on calculation method). Sixty canopy gaps sampled on a 7-ha intensive study site ranged in size from 15 to 150 m2. Although tree replacement patterns in these gaps were unpredictable from gap size and age, the gap event was important in species interactions. The three canopy dominants, Abiesfraseri (Pursh) Poir., Picearubens Sarg., and Betulalutea Michx.f., had unique suites of life history traits. Abies reached high understory densities, but had the highest canopy turnover rate of the three species. Betula was scarce in the understory, but had a crown expansion rate in gaps eight times that of the two conifers. Picea was the longest lived species and appeared to have the best survivorship. Tree replacement models based on advanced regeneration led to the prediction that Abies canopy density would increase and Betula canopy density would decrease, while models based on gap inventories led to opposite conclusions. Data from direct observation of the gap capture process supported the hypothesis that this old-growth stand was near compositional equilibrium and underscored the importance of disturbance effects in community organization.

Biomass and production of southern Appalachian cove forests reexamined

1993 ◽  
Vol 23 (4) ◽  
pp. 760-765 ◽  
Author(s):  
R.T. Busing ◽  
E.E.C. Clebsch ◽  
P.S. White
Keyword(s):  
Temperate Forest ◽  
Deciduous Forest ◽  
Net Primary Production ◽  
Coniferous Forest ◽  
Biomass Accumulation ◽  
Temperate Deciduous Forest ◽  
Old Growth ◽  
Great Smoky Mountains ◽  
Smoky Mountains ◽  
Cove Forests

Aboveground biomass and aboveground net primary production (ANPP) were determined for leaf, branch, and bole compartments of cove forests in the Great Smoky Mountains, Tennessee. The sample plots included young stands (42-63 years following agricultural abandonment) and old stands with no history of logging or catastrophic fire. Tree species, diameter at breast height (DBH), and 10-year radial growth increment data were collected on plots of 0.4–1.0 ha. Biomass was estimated with species-specific allometric equations for the Great Smoky Mountains and eastern Tennessee. ANPP was estimated using diameter growth measurements to determine biomass accumulation over the preceding 10-year interval. Biomass estimates for the predominantly deciduous old-growth stands ranged from 326 to 394 Mg•ha−1 on plots ≥ 0.4 ha. These were consistently greater than the corresponding estimates of 216–277 Mg•ha−1 for young stands. The old Tsuga-dominated stands had the highest biomass estimates of 415–471 Mg•ha−1 for 1.0-ha plots. Annual ANPP estimates were high (11.7–13.1 Mg•ha−1) among the young stands. These stands had particularly high bolewood production. ANPP of the old-growth plots ≥ 0.4 ha ranged from 6.3 to 8.6 Mg•ha−1•year−1 for the deciduous stands and 8.0–10.1 Mg•ha−1•year−1 for the coniferous–deciduous stands. Previous biomass estimates for primeval cove forests were well above temperate forest means of 300–350 Mg•ha−1. Our estimates based on larger plots were lower than previous estimates of 500–610 Mg•ha−1, but they still exceeded temperate forest means. Our deciduous values were 26–94 Mg•ha−1 above the temperate deciduous forest mean of 300 Mg•ha−1, and our Tsuga–deciduous values were 65–121 Mg•ha−1 above the temperate coniferous forest mean of 350 Mg•ha−1.

Gradient analysis of old spruce – fir forests of the Great Smoky Mountains circa 1935

1993 ◽  
Vol 71 (7) ◽  
pp. 951-958 ◽  
Author(s):  
R.T. Busing ◽  
P.S. White ◽  
M.D. MacKenzie
Keyword(s):  
Solar Radiation ◽  
Gradient Analysis ◽  
Deciduous Forest ◽  
Basal Area ◽  
Slope Aspect ◽  
Old Growth ◽  
Abies Fraseri ◽  
Great Smoky Mountains ◽  
Old Growth Forest ◽  
Smoky Mountains

The response of old-growth spruce – fir vegetation to environmental gradients was investigated using 1930s plot data from the Great Smoky Mountains. Gradients related to forest composition and position of the ecotone with the deciduous forest were identified using canonical correspondence analysis (CCA) and their role in vegetation response to climate change was considered. The data were subsequently stratified into three elevation classes and ordinated separately using CCA to identify gradients at various elevations. The effect of elevation on tree stratum composition and structure was profound. Secondary gradients influencing the tree stratum included slope aspect, potential solar radiation, and topographic position. Abies fraseri basal area and density were high above 1800 m elevation. Comparable basal area levels of Picea rubens were attained at elevations ranging from 1400 to 1900 m. Total stand basal area and density increased with elevation. The importance of topographic position increased with elevation, while that of slope aspect and potential solar radiation decreased. Presumably, the increasing incidence of cloud cover with elevation diminished the effect of slope aspect and potential solar radiation at higher elevations. The transition from deciduous forest occurred in the 1300 – 1600 m elevation range. A substantial proportion (24%) of plots had mixed composition (30 – 70% spruce – fir by basal area), suggesting that the ecotone is not abrupt in old-growth forest. Environmental variables other than elevation did not have a strong effect on ecotone position. Attempts to infer long-term ecotone dynamics along the elevation gradient based on species size-class data were inconclusive. Key words: Abies fraseri, gradient analysis, Great Smoky Mountains, old-growth forest, Picea rubens, spruce – fir forest.

Using Spatial Modeling to Improve Wetland Inventories in Great Smoky Mountains National Park

2019 ◽  
Vol 39 (4) ◽  
pp. 482
Author(s):  
Alix A. Pfennigwerth ◽  
Joshua Albritton ◽  
Troy Evans
Keyword(s):  
Spatial Modeling ◽  
National Park ◽  
Great Smoky Mountains ◽  
Smoky Mountains
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