Native
Native biota pose risks to forest health. Methods developed to assist and inform management decisions for risk assessment at the landscape scale have been diverse, ranging from simple empirical correlations to complex systems models. Assessment methods, however, share a common theme: they aim to quantify expected levels of attack and loss. Both insects and plants can introduce risk, and often act in concert. For example, increased overstory disturbance, whether from fire, insect defoliation, or other means of disturbance, selects for shade intolerant species with rapid rates of vegetative spread over slower growing, shade tolerant herbs and shrubs. The result is a low diversity but dense understory that can persist for long periods of time even if the canopy closes.
In this section, native biotic threats are examined through a review of bark beetle infestations and related assessment tools that have been developed as a result of these invasions. Additionally, a useful worldwide review of the formation of dense understory layers in forests, and resulting consequences and implications for forest dynamics, biodiversity, and succession is provided.
To further review the impact of native invasive species, consider reading the following Environmental Threats Case Studies:
- Methods to Assess Landscape-Scale Risk of Bark Beetle Infestation to Support Forest Management Decisions : The objective is to provide practitioners with suggestions on how to select appropriate methods for risk assessment of bark beetle infestations at the landscape scale in order to support their particular management decisions and to motivate researchers to refine novel risk assessment methods.
- The Formation of Dense Understory Layers in Forests Worldwide: Consequences and Implications for Forest Dynamics, Biodiversity, and Succession : Alterations to natural herbivore and disturbance regimes often allow a select suite of forest understory plant species to dramatically spread and form persistent, mono-dominant thickets.
Encyclopedia ID: p3282