Understory vegetation patterns and environmental conditions in the spruce-fir forests of Mt. Moosilauke, New Hampshire

Harty, Melissa
Peter Palmiotto, PhD
Department of Environmental Studies
This study examined the understory vegetation of the spruce-fir forests of Mr. Moosilauke, in Warren and Benton, NH. Species composition, cover and diversity were assessed at 833m, 985m, and 1136m on both the east and west aspects of the mountain. Spring and summer samples were taken to capture phonological differences in species composition. Environmental factors including litter depth, canopy cover, and balsam fir regeneration were measured in each plot, and elevation, aspect, and soil type were controlled for, to determine if these factors influenced vegetation patterns. Elevation played an important role in both understory cover and species richness, which decreased with elevation increase. However, mean understory cover was further influenced by the two soil types (spodosols and histosols) occurring along the elevation gradient. Both herb and fern species cover was significantly greater on spodosols compared to histosols. Yet, the cover of fern and herb species was not significantly different among spodosls at 833m and 985m, or among histosols at 985m and 1136m. Tree species cover in the understory was not significantly affected by this soil type. All spring ephemeral and shrub species encountered occurred on spodosols. Understory diversity and richness was further influenced by spring canopy cover, moss as a substrate, and cover by balsam fir regeneration. Higher species diversity was found in plots with less spring canopy cover and the lowest diversity and richness was encountered in plots with a greater percent cover of moss and dense balsam fir regeneration. This study commenced to understand the factors influencing understory vegetation patterns and may be used with past and future data collected from the permanent plots on Mt. Moosilauke to gain further insight into long-term, spatial and temporal trends in understory diversity.

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