uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/ab10b9d94a1bdad117e63e75706f662d Edward Faison David Foster https://orcid.org/0000-0003-1171-3762 Glenn Motzkin Researcher 2023 English

The "re-wilding" of ecosystems with extirpated large mammals has become a focus of recent scientific and conservation initiatives; however, it is unclear how proposed re-introductions will influence systems that are often vastly different from those that occurred before these animals were extirpated. Moose, the northeast’s largest Holocene browser, have recently expanded across southern New England’s temperate forest landscape after an absence of 200 years, realizing a natural re-wilding experiment. Moose have been well-studied throughout the boreal forest biome; however, because they are rare today in temperate forests, almost nothing is known of their ecology, behavior, or potential impacts to these ecosystems. This study investigated patterns of winter moose browse in order to: (1) gain insight into the likely influences of this herbivore on the vegetation patterns of the region; and (2) to identify the most important habitat features influencing moose winter foraging activity at a landscape and site scale. Two large forested watersheds in Central Massachusetts were sampled for moose browse, habitat features, and disturbances including forest harvesting and human activity. Chi-square and t-tests were used to identify browse species preferences of moose, and step-wise multiple regression was used to identify habitat variables that are strong predictors of browse intensity. Hardwoods and hemlock were favored over white pine, and browse intensity was significantly and positively related to forest harvesting, elevation, swamps, and distance to human settlement. The results from this study suggest that in the winter months, moose populations are concentrating in remote, elevated areas that are broken by swamps and have intensive forest harvests. In areas that support high moose densities, selective browsing, particularly in regenerating harvests, could promote less favored species like white pine at the expense of hardwoods and hemlock. The strong association between moose and forest harvesting indicates that recolonizing megafauna may interact with novel human conditions and disturbances to impact ecosystems differently than in the past. Nonetheless, habitat loss and climate change may ultimately preclude the long-term viability of moose and its impacts to this region.

browsing deer moose regeneration LTER controlled vocabulary populations LTER core area Harvard Forest HFR LTER USA HFR default

This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

Creative Commons Zero v1.0 Universal https://spdx.org/licenses/CC0-1.0.html CC0-1.0 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf115 Quabbin Reservoir, Ware River Watershed. Coordinates based on WGS84 datum. -72.35 -72.02 +42.42 +42.28 116 382 meter 2005 2005 genus Acer species rubrum red maple genus Alces species alces moose genus Betula species spp. birch genus Pinus species strobus white pine genus Quercus species spp. oak genus Tsuga species canadensis hemlock complete Information Manager Harvard Forest

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(978) 724-3302 hf-im@lists.fas.harvard.edu Harvard Forest

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(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu

Plots were established following a stratified random design by (1) forest type - four upland types: hemlock, white pine, mixed oak, and sugar maple-ash; and three wetland types: red maple swamp, conifer swamp, and terrace floodplain forest and (2) recent harvesting history (harvested vs. unharvested since 1984 for upland sites only). At least 10 sites were sampled for each forest type and harvesting stratum, which were identified on state forest type GIS layers, topographical maps, and a statewide forest harvesting database. In cases where field visits indicated that the vegetation and harvesting history of a site did not agree with the GIS layers, the site was sampled and assigned to the proper stratum. To ensure independence of plots, sample locations were separated by a minimum distance of 700 meters. A total of 156 sites met these sampling criteria and were divided between the two watersheds in approximate proportion to the relative forest area of each property.

Each study site consisted of two 100 m2 circular plots for sampling moose browse and tall shrub and tree density and composition. All trees greater than 2.5 cm DBH were recorded by species and DBH, and all tall shrubs greater than 1.8 meters high were recorded by species. In a nested 10 m2 circular subplot within each 100 m2 plot, all tree stems less than 2.5 cm DBH were recorded by species to determine seedling density and composition. The center of the two 100 m2 plots were 30 m apart, and data from the two plots were pooled for each site.

At each site, moose browse was assessed on trees and shrubs. To distinguish moose from deer foraging, browsing was assessed only above 1.8 m, the height limit for white-tailed deer foraging. Moose forage at all heights between 0-3 m, but feeding trials in Sweden showed that on greater than 80% of deciduous tree species they consume the most browse between 1.5 and 2.5 m. We assumed that recording browse above 1.8 would exclude most deer browse but still capture the predominant foraging activity of moose. In each 100m2 plot, all woody stems with live twigs between 1.8 and 3 meters were recorded by species and if browsed or not. Only twigs that were unequivocally browsed (torn or ragged stem) were recorded as "yes." Bark-stripped stems greater than 1.8 m high were also recorded as "browsed." Seedlings and saplings pulled or walked down and snapped along the major stem were also noted.

Harvard Forest

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(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu https://ror.org/059cpzx98 pointOfContact The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210. hf115-01-plot.csv plot data hf115-01-plot.csv 11145 8ad35b5bd33d5fc56027cecf5335fde4 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p11/hf115/hf115-01-plot.csv plot unique plot number unique plot number browse.index sum of proportion of browsed stems and total stems browsed/2 number 0.00000001 real NA missing value lat latitude meter 0.001 real NA missing value elev elevation in meters meter 1 whole NA missing value dist.h2o distance in meters from the plot to the nearest wetland or water body meter 1 whole NA missing value hilltop plot located on hilltop plot located on hilltop swamp plot located in a swamp as defined by saturated soils and wetland plant indicators plot located in a swamp as defined by saturated soils and wetland plant indicators wetland.forest plot located in a swamp or floodplain forest plot located in a swamp or floodplain forest tall.shrubs density of shrub stems over 1.8m high/200m² number 1 whole NA missing value dist.conifer distance in meters to the nearest patch of conifer forest cover meter 1 whole NA missing value hemlock.ba relative % of basal area of hemlock in the plot number 0.01 real NA missing value sugar.maple.ba relative % of basal area of sugar maple in the plot number 0.1 real NA missing value red.maple.ba relative % of basal area of red maple in the plot number 0.01 real NA missing value spruce.fir.ba relative % of basal area of spruce and fir combined in the plot number 0.01 real NA missing value oak.ba relative % of basal area of all oak species in the plot number 0.01 real NA missing value white.pine.ba relative % of basal area of white pine in the plot number 0.01 real NA missing value harvest.intensity amount of basal area removed from a harvested stand in m²/ha meterSquaredPerHectare 0.1 real NA missing value watershed watershed forest in which the plot was located 1 Ware River Forest 0 Quabbin Forest deer.density estimated number of deer/km² in the area the plot was located number 0.1 real NA missing value harvest harvest status of plot 1 the plot was located in a harvested area 0 the plot was located in an unharvested stand dist.dev distance in meters from the plot to the nearest developed area as defined by MassGIS. Distances greater than 1000m were assigned a value of 1000. meter 1 whole NA missing value 156 hf115-02-tree.csv tree data hf115-02-tree.csv 109973 23e6cafd103b616c5ae4b6de3537c140 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p11/hf115/hf115-02-tree.csv plot unique plot number unique plot number species tree species or genus name tree species or genus name dbh diameter at breast height in cm of tree (seedlings under 2.5 cm DBH assigned NA) centimeter 0.1 real NA missing value count number of stems number 1 whole NA missing value browsed browsed 0 unbrowsed at a height above 1.8m, under 3m 1 browsed at a height above 1.8m, under 3m NA no stems were within the available browse range (1.8-3m in height), or stem was not assessed because browsed/unbrowsed status was inconclusive stripped stripped 1 stem bark stripped above 1.8 m 0 stem not bark stripped above 1.8m broken broken 1 stem broken by moose 0 stem not broken by moose 3913 community short-term measurement