Research Summary: Forest Structure Diversity Depends on Age and Management
Study Title: “Diversity of forest structures important for biodiversity is determined by the combined effects of productivity, stand age, and management”
Authors: Aino Hamalainen, Kadri Runnel, Thomas Ranius, and Joachim Strengbom
Publication: Ambio, Springer Nature
Year Originally Published: 2024
On average, protected and unmanaged sites tend to be of lower productivity, reserving the high-productivity sites for human uses. This study demonstrates that high-productivity forests can support the richest array of biodiversity indicators and should not be overlooked in conservation efforts.
Outstanding Questions/Caveats: This study did identify some impacts that were likely the result of previous management in the protected areas, resulting from management that took place before they were protected. Because the typical form of forestry in Sweden is clear-cutting and replanting on 60- to 120-year rotations, the impacts measured there are likely to be somewhat different from those encountered in the northeastern United States, where most forestry practices already favor leaving some legacy trees behind. The primary forest types studied in the paper are also conifer-dominated (spruce and pine forests) whereas northeastern forests are more commonly dominated by broad-leaved species, such as beech, birch, maple, and oak. Thus the relative value of certain structural features that stood out as more important in this paper (i.e. standing and downed deciduous deadwood) may shift with forest composition.
Application to Northeast Wilderness Trust’s Work: As a forever-wild land trust, NEWT protects forests across the Northeast as Wildlands. Ensuring preservation of conservation land representative of the full suite of landscape conditions, from low productivity (steep, rocky, and high-elevation lands, for example) to high productivity (fertile forests of mid- to low-elevations and deep soils) is the best way to protect the full suite of forest structural features—and thus the broadest array of biodiversity. Ceasing management on these lands promotes the gradual accrual of critical forest structures.
NEWT also works closely with many allied organizations who protect managed forests across our region. This study provides valuable insight into how best to protect and promote the accrual of important structural complexity on these lands as well, including management actions like leaving some large trees and deadwood after logging.
Link to the Paper: https://link.springer.com/article/10.1007/s13280-023-01971-9
