Native American landscape modification in pre-settlement south-west Georgia

Fern, Rachel R.; Stober, Jonathan M.; Morris, Max A; Rutledge, Brandon T.

doi:10.1080/01433768.2020.1753983

Cited by 5 publications

(17 citation statements)

References 30 publications

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“…Results initially appear to challenge the findings of previous studies that tout the high importance of NAVs relative to environmental variables in predicting the distribution of trees favoured by Native Americans (Black et al, 2006; Fern et al, 2020; Tulowiecki & Larsen, 2015; Tulowiecki, Robertson, & Larsen, 2020). However, such differences can be attributed to differing geographic extents, resolutions of analysis and measures of taxon distributions.…”

Section: Discussioncontrasting

confidence: 88%

“…Models of relative abundance were developed for all 18 taxa, and two groups of taxa, using boosted regression trees (BRT). Also called gradient boosting machines, BRT is a machine‐learning technique used previously to discern Native American from environmental influences upon past forest composition (Fern et al, 2020; Tulowiecki & Larsen, 2015; Tulowiecki, Robertson, & Larsen, 2020). Capable of fitting complex nonlinear relationships between predictor variables and a response variable, the BRT technique creates a collection of regression trees whereby each tree is a term in the final model (Elith et al, 2008).…”

Section: Methodsmentioning

confidence: 99%

“…boosted regression trees, forest composition, forests, Native Americans, oak, tree species distributions tree locations (e.g. oak), but a strong predictor of fruit-producing tree locations, circa 1820 CE, along with soil and topographic variables (Fern et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

“…A study from southwest Georgia found that Native American village density was a modest predictor of mast‐producing tree locations (e.g. oak), but a strong predictor of fruit‐producing tree locations, circa 1820 CE, along with soil and topographic variables (Fern et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

“…We develop quantitative models using machine‐learning methods at a spatial resolution of 8 km to ascertain the effects of environmental variables alongside distance‐based proxies of Native American land use (circa 1500–1800 CE) on the geographic distribution of tree abundances (Table S2). Compared to previous studies that assessed possible Native American controls on vegetation across local extents (Black et al, 2006; Fern et al, 2020; Tulowiecki & Larsen, 2015; Tulowiecki, Robertson, & Larsen, 2020), we perform a regional‐extent analysis and explore relationships between Native American and tree taxon relative abundances estimated from historical land survey records (Paciorek et al, 2016). We assess the importance of Native American land use by examining whether (1) models trained with NAVs improve in predictive performance compared to models trained without NAVs, (2) NAVs are important according to variable importance measures and (3) model response curves show relationships between distance to settlement and tree taxa.…”

Section: Introductionmentioning

confidence: 99%

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Localized Native American impacts on past forest composition across a regional extent in north‐easternUnited States

Tulowiecki

Ranney

Keenan

et al. 2022

Journal of Biogeography

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Aim:Researchers have debated impacts of past Native American land use on forests including upon tree species composition in north-eastern United States (US), with estimates of impacts ranging from local to regional extent. This study examines tree relative abundances to assess whether Native Americans influenced geographic distributions prior to Euro-American settlement.Location: North-eastern United States (approx. 420,000 km 2 ).Taxon: Ash (Fraxinus spp.), basswood (Tilia americana), beech (Fagus grandifolia), birch (Betula spp.), cherry (Prunus spp.), chestnut (Castanea dentata), dogwood (Cornus spp.), elm (Ulmus spp.), fir (Abies balsamea), hemlock (Tsuga canadensis), hickory (Carya spp.), ironwood (Carpinus caroliniana and Ostrya virginiana), maple (Acer spp.), oak (Quercus spp.), pine (Pinus spp.), spruce (Picea spp.), tamarack (Larix laricina) and walnut (Juglans spp.), Methods:We used boosted regression trees to model abundance patterns and to assess the importance of distance-based proxies of Native American land use versus environmental variables. We trained models that included and excluded distance-based proxies. Abundance estimates from original land survey records (1650-1850 CE) were acquired for taxa at 8 km spatial resolution, and related to Native American settlement locations (1500-1800 CE) and 27 environmental variables.Results: When evaluated upon test data, regional-scale models of relative abundance that included distance-based proxies performed only slightly better than models that excluded them, with mean improvements in RMSE of 0.1 percentage points. Models suggest that Native American land use modestly altered the relative abundance of taxa locally, extending no more than 50 km from settlement. Models also suggest slight increases near settlement of a few percentage points in relative abundance for fire-tolerant and/or dietary taxa (e.g. oak, hickory and pine), and for early-successional taxa (e.g. ash). Main conclusions:Past Native American land use had no detectable effect on forest composition across a regional extent, but increased the abundance of fire-tolerant, shade-intolerant and nut-producing trees locally.

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Section: Discussioncontrasting

confidence: 88%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Localized Native American impacts on past forest composition across a regional extent in north‐easternUnited States

Tulowiecki

Ranney

Keenan

et al. 2022

Journal of Biogeography

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Native American geography shaped historical fire frequency in forests of eighteenth-century Pennsylvania, USA

Tulowiecki,

Hanberry,

Abrams

2023

Sci Rep

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Researchers have debated the relative importance of environmental versus Indigenous effects on past fire regimes in eastern North America. Tree-ring fire-scar records (FSRs) provide local-resolution physical evidence of past fire, but few studies have spatially correlated fire frequency from FSRs with environmental and anthropogenic variables. No study has compared FSR locations to Native American settlement features in the eastern United States. We assess whether FSRs in the eastern US are located near regions of past Native American settlement. We also assess relationships between distance to Native American settlement, environmental conditions, and fire frequency in central Pennsylvania (PA), US, using an “ensemble of small models” approach for low sample sizes. Regression models of fire frequency at 21 locations in central PA often selected distance-based proxies of Indigenous land use. Models with mean annual temperature and Native American variables as predictors explained > 70% of the variation in fire frequency. Alongside temperature and wind speed, “distance to nearest trail” and “mean distance to nearest town” were significant and important predictors. In 18th-century central PA, fires were more frequent near Indigenous trails and towns, and further south due to increasing temperature and pyrophilic vegetation. However, for the entire eastern US, FSRs are located far from past settlement, limiting their effectiveness in detecting fire patterns near population centers. Improving understanding of historical fire will require developing FSRs closer to past Native American settlement.

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Using witness trees as pyro-indicators to depict past fire environments across the eastern United States

Nowacki,

Thomas-Van Gundy

2024

fire ecol

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Understanding past fire environments is vitally important for applying silvicultural treatments, which often include prescribed burning to restore fire-dependent ecosystems. We have developed a novel method by which witness trees can be used as pyro-indicators to map past fire environments. The stepwise process first involves partitioning witness trees into two classes, pyrophobic and pyrophilic, based on their known ecophysiological traits. Pyrophilic percentages are then calculated at survey corners by dividing the number of pyrophilic trees by the total number of trees. Next, statistical spatial interpolation is applied to this point-based data set to produce a continuous response surface of pyrophilic percentages. The resultant maps capture gradients of fire importance across the pre-European-settlement landscape, which can be coupled with historic fire regime maps, thus providing additional information for better understanding and explaining past fire environments. We have applied this technique to various available witness-tree databases across the eastern United States. This paper serves as a compendium of our collective work to date.

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Native American landscape modification in pre-settlement south-west Georgia

Cited by 5 publications

References 30 publications

Localized Native American impacts on past forest composition across a regional extent in north‐easternUnited States

Localized Native American impacts on past forest composition across a regional extent in north‐easternUnited States

Native American geography shaped historical fire frequency in forests of eighteenth-century Pennsylvania, USA

Using witness trees as pyro-indicators to depict past fire environments across the eastern United States

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