River birch (Betula nigra) is a state-threatened tree that grows at the wet edges of rivers and waterbodies. NH Heritage tracks this species and has published a separate fact sheet for it.

River birch is often used in landscaping. Since landscaped trees are often imported from other states, there is potential for “inappropriate” gene flow between natural and planted populations which could cause outbreeding depression and loss of genetic purity of natural populations. Planting them can also lead to confusion when trying to determine natural vs. planted populations.

(see also our separate fact sheet)

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