Northern Forest Futures Project

Biodiversity

[photo:] a frog

Conservation of Biological Diversity

People enjoy a variety of ecosystem services, or benefits, from forests, including water purification, recreation, income from tourism, timber products, and the cultural and economic benefits from hunting, fishing, and gathering (Shvidenko et al. 2005). Across the Northern United States, growing human populations will place increased service demands on forests for the foreseeable future. The type, magnitude, and stability of future services from northern forests will depend in part on the level of biological diversity in those forests.


Key Findings

Present Day

  • Forests cover 174 million acres in the North, or 41 percent of the total land area.
  • Current tree species richness by State ranges from 49 species sampled in Rhode Island to 99 species sampled in West Virginia, with 160 tree species recorded regionwide.
  • Northern forests provide habitat for more than 363 terrestrial vertebrate species, with richness varying among habitat classes and wildlife taxa; the highest level of richness is associated with birds, and with forests of open-canopy structure and hardwood dominance.
  • With one exception—amphibians in closed-canopy hardwoods—most forest wildlife species also frequent one or more nonforest habitats.

Projected 2010 to 2060

  • Forest area is projected to decrease slightly across the North, with the rate ranging from 3.5 to 6.4 percent and with losses concentrated around existing urban and suburban areas.
  • Under all scenarios, area is projected to decrease for four forest-type groups (aspen-birch, elm-ash-cottonwood, oak-hickory, and spruce-fir) and increase for one group (maple-beech-birch); white-red-jack pine, which is projected to increase under current rates of biomass utilization, would decrease under high biomass-utilization scenarios.
  • Under all scenarios, the forest area in the large diameter size class is projected to increase by 3.5 to 5.7 percent and the medium diameter size class is projected to decrease; the small diameter size class is projected to decrease under scenarios that assume no increase in biomass harvesting for energy, but increase or remain stable under high biomass utilization scenarios.
  • Closed-canopy habitat classes are projected to gain acreage whereas open-canopy habitat classes are projected to lose acreage; intensive biomass harvesting rates for bioenergy are projected to result in losses for closed-canopy classes and to a lesser degree for open-canopy classes.
  • Increasing fragmentation and parcellation are expected to reduce high-density core forests within large patches and the average size of family forest landholdings in every State; these changes would decrease the ecological services and socioeconomic benefits of core forests and diminish the ability to manage large patches of forest.
  • Overall tree species richness is projected to decline through 2060; projected reductions in early successional habitats such as oak-hickory could have a large effect on tree species richness in such ecosystems.

From Future Forests of the Northern United States, NRS-GTR-151, 2016.

Maps and Figures

Forest land area estimates under baseline conditions (2010) and
projections (2020 to 2060) under greenhouse gas emission storylines A1B,
A2, and B2 (IPCC 2007) for the North
Forest land area estimates under baseline conditions (2010) and projections (2020 to 2060) under greenhouse gas emission storylines A1B, A2, and B2 (IPCC 2007) for the North

For additional detail, see Criterion 1: Conservation of Biological Diversity in the Future Forests of the Northern United States.