Which of the following is NOT a threat to North American forests?

Organic farming is not considered a threat to North American forests because it promotes sustainable agricultural practices that can enhance biodiversity and soil health. Instead of depleting resources or damaging ecosystems through harmful chemicals or unsustainable practices, organic farming aims to coexist with the environment. It encourages practices like crop rotation, natural pest control, and composting, which can even contribute positively to surrounding ecosystems, including forests. This is quite different from activities like logging, the introduction of non-native species, or uncontrolled wildfires, which can lead to significant environmental degradation and loss of forest areas.