Frequency of sprout-origin trees in pre-European settlement forests of the southern Appalachian Mountains

We hypothesized that tree form, recorded in historical public land surveys, would provide a valuable proxy record of regeneration patterns during early-European settlement of North America’s eastern deciduous forest. To test this hypothesis, we tallied stem form from witness trees used in land survey records in the southern Appalachian Mountains from 13 counties spanning four physiographic provinces: Piedmont, Blue Ridge, Ridge and Valley, and Cumberland Plateau. A total of 3% of witness trees used in the land surveys were of sprout origin. American basswood (Tilia americana L.) exhibited the highest proportion of sprout-origin trees at 12%. Other overstory species with a high proportion of sprout-origin trees were hickory (Carya sp.), red maple (Acer rubrum L.), and sycamore (Platanus occidentalis L.), all with 6% of stems being from sprout origin. Blue Ridge had significantly more sprout-origin trees compared with the other three physiographic provinces. Forests in the southern Appalachian Mountains during the pre-European settlement period had a suite of disturbances that controlled their growth and regeneration; however, most of these disturbances did not result in large-scale tree mortality, and therefore, sprouts were not an important source of regeneration.

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Investigation of Atmospheric Rivers Impacting the Pigeon River Basin of the Southern Appalachian Mountains

Weather and Forecasting ◽

10.1175/waf-d-17-0060.1 ◽

2018 ◽

Vol 33 (1) ◽

pp. 283-299 ◽

Cited By ~ 8

Author(s):

Douglas K. Miller ◽

David Hotz ◽

Jessica Winton ◽

Lukas Stewart

Keyword(s):

North Carolina ◽

River Basin ◽

Large Scale ◽

Large Fraction ◽

Appalachian Mountains ◽

Warm Season ◽

Atmospheric Rivers ◽

Southern Appalachian Mountains ◽

Low Level ◽

Southern Appalachian

Abstract Rainfall observations in the Pigeon River basin of the southern Appalachian Mountains over a 5-yr period (2009–14) are examined to investigate the synoptic patterns responsible for downstream flooding events as observed near Knoxville, Tennessee, and Asheville, North Carolina. The study is designed to address the hypothesis that atmospheric rivers (ARs) are primarily responsible for the highest accumulation periods observed by the gauge network and that these periods correspond to events having a societal hazard (flooding). The upper 2.5% (extreme) and middle 33% (normal) rainfall events flagged using the gauge network observations showed that half of the heaviest rainfall cases were associated with an AR. Of those extreme events having an AR influence, over 73% had a societal hazard defined as minor-to-major flooding at the USGS river gauge located in Newport, Tennessee, or flooding observations for locations near the Tennessee and North Carolina border reported in the Storm Data publication. Composites of extreme AR-influenced events revealed a synoptic pattern consisting of a highly amplified slow-moving positively tilted trough, suggestive of the anticyclonic Rossby wave breaking scenario that sometimes precedes hydrological events of high impact. Composites of extreme non-AR events indicated a large-scale weather pattern typical of a warm season scenario in which an anomalous low-level cyclone, cut off far from the primary upper-tropospheric jet, was located in the southeastern United States. AR events without a societal hazard represented a large fraction (75%–88%) of all ARs detected during the study period. Synoptic-scale weather patterns of these events were fast moving and had weak low-level atmospheric dynamics.

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Pleistocene Glaciation in the Blue Ridge Province, Southern Appalachian Mountains, North Carolina

Science ◽

10.1126/science.181.4100.651 ◽

1973 ◽

Vol 181 (4100) ◽

pp. 651-653

Author(s):

J. O. Berkland ◽

L. A. Raymond

Keyword(s):

North Carolina ◽

Appalachian Mountains ◽

Pleistocene Glaciation ◽

Blue Ridge ◽

Southern Appalachian Mountains ◽

Southern Appalachian ◽

Blue Ridge Province

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A Study of Two Impactful Heavy Rainfall Events in the Southern Appalachian Mountains During Early 2020, Part II; Regional Overview, Rainfall Evolution, and Satellite QPE Utility

Remote Sensing ◽

10.3390/rs13132500 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2500

Author(s):

Douglas Miller ◽

Malarvizhi Arulraj ◽

Ralph Ferraro ◽

Christopher Grassotti ◽

Bob Kuligowski ◽

...

Keyword(s):

Heavy Rainfall ◽

Large Scale ◽

Appalachian Mountains ◽

Heavy Rainfall Event ◽

Atmospheric Conditions ◽

Rainfall Events ◽

Southern Appalachian Mountains ◽

Atmospheric River ◽

Southern Appalachian ◽

Heavy Rainfall Events

Two heavy rainfall events occurring in early 2020 brought flooding, flash flooding, strong winds, and tornadoes to the southern Appalachian Mountains. Part I of the study examined large-scale atmospheric contributions to the atmospheric river-influenced events and subsequent societal impacts. Contrary to expectations based on previous work in this region, the event having a lower event accumulation and shorter duration resulted in a greater number of triggered landslides and prolonged downstream flooding outside of the mountains. One purpose of this study (Part II) is to examine the local atmospheric conditions contributing to the rather unusual surface response to the shorter duration heavy rainfall event of 12–13 April 2020. A second purpose of this study is to investigate the utility of several spaced-based QPE and vertical atmospheric profile methods in illuminating some of the atmospheric conditions unique to the April event. The embedded mesoscale convective elements in the warm sector of the April event were larger and of longer duration than of the other event in February 2020, leading to sustained periods of convective rain rates. The environment of the April event was convectively unstable, and the resulting available potential energy was sustained by relatively dry airstreams at the 700 hPa level, continuously overriding the moist air stream at low levels attributed to an atmospheric river.

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A Study of Two Impactful Heavy Rainfall Events in the Southern Appalachian Mountains during Early 2020, Part I; Societal Impacts, Synoptic Overview, and Historical Context

Remote Sensing ◽

10.3390/rs13132452 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2452

Author(s):

Douglas Miller ◽

John Forsythe ◽

Sheldon Kusselson ◽

William Straka III ◽

Jifu Yin ◽

...

Keyword(s):

Heavy Rainfall ◽

Large Scale ◽

Appalachian Mountains ◽

Environmental Stability ◽

Antecedent Soil Moisture ◽

Rainfall Events ◽

Southern Appalachian Mountains ◽

Low Level ◽

Southern Appalachian ◽

Heavy Rainfall Events

Two heavy rainfall events occurring in early 2020 brought flooding, flash flooding, strong winds and tornadoes to the southern Appalachian Mountains. The atmospheric river-influenced events qualified as extreme (top 2.5%) rain events in the archives of two research-grade rain gauge networks located in two different river basins. The earlier event of 5–7 February 2020 was an event of longer duration that caused significant flooding in close proximity to the mountains and had the higher total accumulation observed by the two gauge networks, compared to the later event of 12–13 April 2020. However, its associated downstream flooding response and number of landslides (two) were muted compared to the April event (21). The purpose of this study is to understand differences in the surface response of the two events, primarily by examining the large-scale weather pattern and available space-based observations. Both storms were preceded by anticyclonic Rossby wave breaking events that led to a highly amplified 500 hPa wave during the February storm (a broad continent-wide 500 hPa cyclone during the April storm) in which the accompanying low-level cyclone moved slowly (rapidly). Model analyses and space-based water vapor observations of the two events indicated a deep sub-tropical moisture source during the February storm (converging sub-tropical low-level moisture streams and a dry mid-tropospheric layer during the April storm). Systematic differences of environmental stability were reflected in differences of storm-averaged rain rate intensity, with large-scale atmospheric structures favoring higher intensities during the April storm. Space-based observations of post-storm surface conditions suggested antecedent soil moisture conditioned by rainfall of the February event made the widespread triggering of landslides possible during the higher intensity rains of the April event, a period exceeding the 30 day lag explored in Miller et al. (2019).

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