Implementation of a long-term vegetation monitoring program at Apostle Islands National Lakeshore

Sanders, Suzanne; Grochowski, Jessica

We initiated a long-term vegetation monitoring program at Apostle Islands National Lakeshore (APIS) in summer 2011. The goals of this monitoring program are to detect forest change and to draw inferences about forest health so that management recommendations can be provided to the park. We established 48 plots at APIS, distributed among five forest types. In the hemlock-hardwoods forest type, sugar maple, yellow birch, and hemlock were all abundant and regenerating, although it is not clear whether the structure of this forest type is converging on that observed in old growth hemlock-hardwood forests in the region. The bigtooth aspen-paper birch type is succeeding toward a mid-successional sere. Currently, red maple dominates; it is not clear whether this is transitioning toward a hemlock-hardwood type or possibly to the balsam fir cover type. Mountain maple-black ash forests are are also succeeding toward a mid-successional sere, although the successional trajectory is not clear. Currently, these plots are dominated by mountain maple, which does not attain large diameters or great height, and by black ash. The latter species is expected to be eliminated from the park due to the impending arrival of the emerald ash borer (EAB). Eastern white cedar forest is common throughout the islands and is a climax type. Like cedar, the balsam fir forests are fairly stable and, barring massive disturbance, will not likely transition to other types in the coming decades. Preventing the introductions of invasive species, particularly buckthorn and exotic honeysuckles, is especially important to maintaining the health of the Park’s forests. This is especially relevent in black ash-alder swamps where only two species dominate. The loss of black ash due to EAB could reduce the stability of these habitats, allowing invasives to more easily establish a foothold. It is highly recommended that ash seed is collected within the park for deposit with the USDA National Plant Germplasm System. This could preserve locally adapted genotypes for future reintroduction after effective EAB control measures are developed. This would also allow researchers to test for possible resistance. These plots at Apostle Islands National Lakeshore will be revisited in 2017. Comparisons of change can be made at that time.

Implementation of a long-term vegetation monitoring program at Apostle Islands National Lakeshore

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