This morning the class walked with Tom Lee through College woods exploring invasive and/or nonnative plant materials. He gave us valuable information about various plants. It feels good to learn about plant material found in the New Hampshire area, and how this material effects the area surrounding it. There aer 2,500 vascular plants in New Hampshire. Fifty of these are not native, and only about a 30 of these are invasive. Interestingly, invasives tend to form in patches and the only way to successfully control them is through chemicals. Tom briefly discussed the use of Early Detection Rapid Response (EDRR) in controlling invasives before they become out of control.
There are no clear answers about nonnatives. Some have become invasive and may be detrimental to the area; where as, others do not seem to have had a significant negative impact upon the environment. Their offspring do not cultivate within a natural area. Why wouldn't they? Invasives seem to have found disturbed areas where they can gain some ground, only to intrude even more. Others such as the multiflora rose is invasive, but may be an important species for endangered Northeastern rabbit habitat.
There are three theories why invasives may have gained control easier here than in their homeland:
1. Enemy Release Hypothesis: fewer enemies in new land; therefore, more vigour
2. Natural Resistance Hypothesis: more competition from natives in homeland
3. Disturbed Hypothesis: Why won't our native plants move into disturbed areas as quickly as nonnatives? Why are nonnatives more vigorous?
Below are photos of plants Tom introduced us to and a brief description:
Asian Bittersweet: Nonnative, invasive, strangler, grows more vigorously than natives, perennial
Reed Canary Grass: European genotype, not distinguishable from native genotype through observation, invading floodplains
Multiflora Rose: stipular at base is lacerated, one of most aggressive invasives, displaces native vegetation, makes marvelous thickets (habitat for rabbit and birds), rose hips good food for birds and nectar for bee pollen, from Asia
Burning Bush: corky wings on twig, leaves finely toothed, elliptical, opposite, able to reproduce in shade, spreads vegetatively, banned by state for use in landscaping
Norway Maple: blockier leaf than Sugar Maple, all 5 leaf lobes are large, break stem to find milky sap, bark with patterning or latticing on it, shade tolerant
This tree has the potential for pushing sugar maple from its habitat, which would have a signficant impact on the economy of New Hampshire. Sugar maple provides income for making maple syrup, wood for furniture, and splendid fall color (tourism). On the other hand, the Norway maple is a second rate tree: requires more sap to make syrup, wood weaker, and fall color ugly yellow.
Japanese Barberry: used for hedges, shade tolerant, thorny, shrubby
Glossy Buckthorn: most common invader on seacoast, veins never reach edge (like Dogwood), branches form an "S" shape, alternate leaves, oval, no teeth
Kim presented her lesson today on Wessels' chapter focused on overgrazing. I enjoyed her lesson because it used visuals and really made you think about how the environment might change.
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