Semester

Fall

Date of Graduation

2010

Document Type

Dissertation

Degree Type

PhD

College

Davis College of Agriculture, Natural Resources and Design

Department

Wood Science and Technology

Committee Chair

James Rentch.

Abstract

Red spruce forests are a remnant ecosystem from the interglacial period of the Wisconsin glaciation and today are considered one of the most threatened forest ecosystems in the eastern United States. The extent of red spruce forests in West Virginia prior to exploitative logging which occurred from 1880--1920 is estimated at 190,000 ha, but today, these forests are estimated to occupy no more than 24,000 ha, resulting primarily from intense anthropogenic disturbances. With the extensive loss of presettlement habitat for red spruce in West Virginia, this species is a high priority for restoration, as these forests offer the unique habitat for the endangered Cheat Mountain salamander (Plethodon nettingi Green), and provide optimal habitat for the recently delisted Virginia northern flying squirrel (Glaucomys sabrinus fuscus Miller).;In the first portion of the study, a novel modeling technique, Maximum Entropy (Maxent) was used to model current red spruce forest habitat in West Virginia using 168 red spruce presence localities and 32 environmental and site-specific variables. For this analysis 283,000 ha were identified in 18 counties possessing suitable red spruce habitat in West Virginia. Variables considered important for all replicate model runs were maximum temperature of the warmest month (40.6%), minimum temperature of the coldest month (13.7%), slope percent (6.9%), mean temperature of the coldest quarter (6.5%), mean annual temperature (4.6%), and soil type (4.0%). The environmental and site-specific variables which contributed the most to overall model performance were also assessed further to examine the value or range of values in which red spruce habitat was likely to occur. For maximum temperature of the warmest month the threshold value identified was 25°C, where areas which had maximum summer temperature less than this value resulted in an increased probability of possessing suitable red spruce habitat. Additionally, for mean temperature of the coldest month, a threshold value was identified where all areas which possessed a mean winter monthly temperature less than -8.5°C resulted in increased probability of suitable habitat for red spruce to a peak of approximately -10.5°C.;In the second portion of the study, Maxent was used to model future distribution of red spruce habitat in West Virginia using 24 environmental and site-specific variables. Two climate change scenarios provided by the Intergovernmental Panel on Climate Change (IPCC) for three time periods (i.e., 2020, 2050, and 2080) were examined. Results for both model analyses indentified three variables which contributed significantly to model performance: mean temperature of the coldest quarter, elevation, and minimum temperature of the coldest month. When combined, these variables contributed more than 40% to model performance for both scenario models. Changes in suitable habitat area were also assessed for both model scenarios at each time period examined, with dramatic reductions identified. Approximately 6.2% of the land area in West Virginia was modeled to possess suitable red spruce habitat under current conditions. However, by the time period 2020, only 1.3% and 2.8% were identified for the aggressive and conservative climate change models, respectively. By the time period 2080, no suitable red spruce habitat was modeled using the aggressive climate change scenario with 53,866 ha identified using the conservative model, representing less than 1% of the land area in West Virginia.

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