What is a potential risk of using pesticides excessively in forestry?

Using pesticides excessively in forestry can lead to the development of pest resistance. This occurs when pests are repeatedly exposed to a particular pesticide, allowing certain individuals that have or develop resistant traits to survive and reproduce. Over time, this can result in a population of pests that no longer respond to that pesticide, making it ineffective for pest control. Consequently, increased applications may lead to a cycle of needing even stronger or more toxic chemicals, further complicating pest management efforts. This phenomenon not only challenges the sustainability of pest control methods but can also have significant ecological impacts, as resistant pests may disrupt local ecosystems and affect non-target species. In contrast, the other options mentioned, such as increased crop yield, improved soil health, and enhancements in local ecosystems, are generally not direct outcomes of excessive pesticide use, as they often suffer from negative consequences associated with pesticide applications.