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

Abstract

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.

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

“…2, 3, 4 and 5) and therefore likely altered vegetation patterns. Studies finding no relationship between past vegetation and Indigenous land use based solely on proximity to archaeological site locations 19 , 71 may be incorrect due to the omission of travel routes from analysis. Burning along travel corridors, and shifting corridors over centuries to millennia with changes in settlement patterns 72 , Indigenous peoples may have altered vegetation in most locations that were seasonally dry enough to ignite 16 .…”

“…They ignited low-intensity fires in forests, woodlands, and grasslands for purposes such as procuring food and easing travel 15 . Varying methodologies suggest that burning and related vegetation modifications occurred along travel corridors and within 10–50 km of towns 16 – 19 .…”

Natural forests for a safe climate: Enhancing ecosystem integrity, biodiversity and adaptive capacity for climate mitigation

“…Native people living in the Great Lakes and the Northeast practiced subsistence hunting, fishing, and plant gathering, as well as burning and small-scale farming. Their population was less than 1% of the current population and largely centered along the coast and in major river valleys, with localized and modest impacts across most of the region (Whitney, 1994;Lorimer and White, 2003;Milner and Chaplin, 2010;Oswald et al, 2020b;Frelich et al, 2021;Tulowiecki et al, 2022).…”

Forest-clearing to create early-successional habitats: Questionable benefits, significant costs

“…Native people living in the Great Lakes and the Northeast practiced subsistence hunting, fishing, and plant gathering, as well as burning and small-scale farming. Their population was less than 1% of the current population and largely centered along the coast and in major river valleys, with localized and modest impacts across most of the region (Whitney, 1994;Lorimer and White, 2003;Milner and Chaplin, 2010;Oswald et al, 2020b;Frelich et al, 2021;Tulowiecki et al, 2022).…”

“…Native burning and other subsistence practices, such as hunting, fishing, plant gathering, and small-scale farming had notable ecological impacts in the immediate vicinity of native encampments and settlements in the Northeast and Upper Great Lakes regions (Whitney, 1994;Lorimer and White, 2003;Oswald et al, 2020b;Frelich et al, 2021;Tulowiecki et al, 2022). However, modern land managers seem to be inappropriately misinterpreting a set of novel landscape conditions created by European land use over the last few centuries as having pre-European origins (Chilton, 2002;Oswald et al, 2020b;Cachat-Schilling, 2021).…”