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Maps in Action: Examples from NH Communities

The New Hampshire invasive plant prioritization map shows “hot spots” that are good places to start looking for invasive plants. Once you have an idea of what is present, the maps can also help you decide the most effective place to start tackling invasive plants. The following are examples from New Hampshire communities using real world mapping information.


Meredith: Keep “Hot Spots” For Invasive Plant Control Uninfested



There are three major “hot spots” for invasive plant control in Meredith. Starting to tackle invasive plants on the edge of these important areas will help keep them uninfested.

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A rapid assessment roadside survey was completed in Meredith in 2008. The town teamed with the NH Department of Agriculture’s Invasive Species Coordinator to collect invasive plant data visible while driving by in a car. It took just a week to record the location of over one thousand invasive plant populations.


The Priority Areas for Invasive Plant Management Map identifies three large “hot spots” for management, the interiors of which are without any known invasive populations. A good next step would be to try and explore these areas by foot to see if they really are free of invasive plants, or if there were just no populations visible from the road. If these “hot spots” truly are invasive free, then starting to manage the populations at their edge would be a good place to begin and would help keep these important areas invasive plant free.


Newmarket and Durham: Start Work in the Largest "Hot Spots"


Durham Newmarket

If there are several “hot spots” within your chosen study area, starting work in the largest is often a good idea.

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In 2005 and 2006, the NH Fish and Game Department and Great Bay National Estuarine Research Reserve staff teamed with conservation organizations and private land owners to map invasive plants throughout a 3,000 acre watershed that spans the border of Newmarket and Durham. They managed to survey 92 percent of the entire watershed and identified over 1,500 invasive plant populations. Deciding where to start management could quickly become overwhelming. Fortunately, the Priority Areas for Invasive Plant Management Maps can help decipher where to start work in a well thought out way, even in heavily impacted areas. In this example, there are several “hot spots” where invasive plant management would be particularly effective, but two of these are especially large so removal in these areas would be a good place to start.


Portsmouth: Keep Major Infestations From Spreading



If there are several “hot spots” within your chosen study area, starting work in the largest is often a good idea.

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In 2009, Portsmouth hired an ecological consulting company to complete an assessment of undeveloped properties within the city. Invasive plant information was collected using a simple data sheet and hand-held GPS. No information was recorded about the extent or density of any population.


Although darker areas on the Priority Areas for Invasive Plant Management Maps are usually the best starting point for management, in Portsmouth’s case it was found that one of the largest “hot spots” for management was heavily impacted with invasive plants. In this area the density of invasives is so great it is likely to be impossible to eradicate them throughout its extent. It would certainly take thousands of dollars and many years to make any significant impact. A clear strategy would be to focus on “spot fires” that prevent new populations from this major source spreading to surrounding areas.

Community hot spots


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