Deer Get By with a Little ELP From the Fiends
Extended leaf phenology, AKA ELP, is a trait many invasive plants share. In essence, it means they have earlier leaf emergence and/or later leaf drop than most native plants, and it’s considered to be one of the advantages that helps them thrive in many areas. For example, amur honeysuckle leaves start developing 2–3 weeks earlier than that of the many natives growing in the same habitats in parts of the east. Several nonnative woody species, like Japanese honeysuckle, and our friends buckthorn and barberry, extend their autumn growing season by about an extra month longer than compared with natives. This prolonged access to light and nutrients leads to increased growth.
The ELP of invasive plant species may also lead to increased deer populations, cranking-up pressures on native plant species. A study that looked into this theory examined the proportion of a deer’s diet comprised of amur honeysuckle. Researchers found that deer browsed honeysuckle during all growing months, but consumption was highest in early spring and late summer. Thus the honeysuckle, perhaps along with other ELP’s, provided enough food in the shoulder seasons to raise the deer population so that native species are hit harder during the non ELP periods.
Along with earthworms, deer and invasive plants are contributing to the increased lack of regeneration of native trees and understory plants, and to what some forest ecologists call “forest decline syndrome”. How to slow or prevent this trend from continuting into the future is a complicated task. However some success has been achieved in parks and other natural areas that have applied deer control methods and that have active invasive species pulling programs.
For More Information.
Stop by NETN’s webpage about the forest health monitoring program
. There you will find links to monitoring reports and briefs, journal articles, and in-depth details about how monitoring is accomplished in park forests.
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