Date of Award

Spring 5-2025

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Ecology and Environmental Sciences

First Committee Advisor

Sabrina Morano

Second Committee Member

Adam Daigneault

Third Committee Member

Erin Simons-Legaard

Abstract

The future of Maine’s forests and the habitat they provide for wildlife is uncertain in the face of many climatic, social, economic, and political influencing factors. Historically, forest management in Maine has prioritized conventional forestry aims such as timber production and commercial harvesting. However, evolving market demands, policy shifts, changing land ownerships, and climate projections are prompting a shift toward more complex and multi-faceted management objectives. Changes in management objectives can alter the forested landscape and impact the diverse ecosystem services provided by Maine’s forests. The three key services we focused on for this research were wildlife habitat, timber production, and carbon sequestration and storage. To assess the implications of these changes, we used an integrated modeling framework to examine how socio-economic and political drivers of forest management decisions may impact future wildlife habitat conditions in Maine's commercial forestlands. We focused on moose (Alces alces) and white-tailed deer (Odocoileus virginianus) as culturally and economically important focal species, while evaluating trade-offs and synergies among habitat provision, timber production, and carbon storage under alternative forest management strategies.

Chapter 1 assessed the impacts of seven forest management practices, ranging from not harvesting to intensive clearcuts, under three climate scenarios on key habitat components for moose and deer. Forest composition and age structure were simulated using LANDIS-II, a widely used landscape-scale forest ecosystem model, and then translated into projected habitat conditions through ArcGIS-based spatial analysis. Clearcut with natural regeneration produced the greatest gains in moose forage habitat area, increasing by more than 300% relative to current baseline levels by 2100. For deer wintering habitat, both no-harvest set-asides and continuous cover practices produced similarly strong outcomes, each increasing deer habitat area by over 250% compared to baseline. Conversely, continuous cover and no-harvest practices virtually eliminated moose forage habitat by 2100, while clearcutting significantly reduced deer wintering habitat. Partial harvest—the dominant practice currently used in Maine—also showed important limitations, leading to a 99% decline in moose forage habitat by 2100 and providing only modest gains for deer wintering habitat relative to no-harvest and continuous cover practices. These results highlight the potential unintended consequences of Maine’s shift from historical clearcutting toward partial harvest management following the Forest Practices Act. Climate impacts were secondary to management influences, though they became more pronounced later in the century. Overall, the chapter highlighted strong trade-offs between species habitat needs, emphasizing the challenge of simultaneously managing for young and mature forest conditions.

Chapter 2 built upon these findings by exploring ecosystem service (e.g., wildlife habitat, timber production, and carbon sequestration and storage) trade-offs associated with prioritizing big game habitat through a scenario analysis using the Maine Integrated Forest System Model. We evaluated 17 scenarios that varied by maximization objective (moose or deer habitat component), harvest target (low, medium, high, or unconstrained), and management area constraint (current or no constraints). Results showed that, under a single scenario, seven of the ten tracked ecosystem services could improve relative to the baseline reference case without reducing harvest levels. Improvements included increased moose and deer habitat area, enhanced rates of carbon sequestration, and higher net revenues, achieved by shifting management away from business-as-usual practices toward greater use of clearcutting with natural regeneration alongside expanded set-aside areas. Moose-focused optimization produced broader ecosystem service benefits compared to deer-focused strategies, highlighting its potential as a foundation for multi-objective management. Our results also demonstrated that multiple management strategies can achieve the same level of timber output to meet production goals. However, management area constraints appeared to be the biggest limiting factor overall. No scenario simultaneously increased all services, reinforcing the need for tailored strategies to balance competing objectives.

Together, these findings suggest that prioritizing wildlife habitat in Maine’s commercial forests can be compatible with sustaining other key ecosystem services when management actions are strategically planned and spatially tailored across the landscape. By using predictive modeling to evaluate trade-offs, this study provides valuable insights for adaptive forest management and conservation planning. The results also underscore the potential role of nature-based solutions in advancing biodiversity, carbon, and forest industry goals while supporting culturally and economically important wildlife species.

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