Forest invasive species
A severe threat to the forest sector worldwide is invasive species, defined as “Species that are non-native to a particular ecosystem and whose introduction and spread cause, or are likely to cause, socio-cultural, economic, or environmental harm, or harm to human health.” (FAO).
In the absence of their natural enemies, these invasive species can thrive in new environments, displacing native species and disrupting entire ecosystems.
Some invasive species, however, are intentionally introduced for economic, environmental, or social purposes. Intentional introduction, particularly in the case of ornamental plants and animals, can lead to significant problems when such species escape their intended environment and harm native ecosystems.
This is particularly concerning in the forest sector: non-native tree species are often used in agroforestry and commercial forestry and to combat desertification. Many such species are valued for their adaptability to diverse sites, their rapid growth and the multiple uses of their products. In some cases, however, such species have become invasive outside their intended environment and are serious ecological threats. It is vital to ensure that such species serve their intended purpose and do not negatively impact native ecosystems.
Globally, there is limited comprehensive information about invasive species and their impact on the forest sector. Sharing information is crucial for planning and implementing effective strategies to manage invasive species.
Resources
Scientific review of the impact of climate change on plant pests
Climate change represents an unprecedented challenge to the world’s biosphere and to the global community. It also represents a unique challenge for plant health. Human activities and increased market globalization, coupled with rising temperatures, has led to a situation that is favourable to pest movement and establishment.
Biological invasions, driven by human actions, involve the intentional or unintentional introduction of species, which alter ecosystems and facilitate invasions.
Key contributors to introduction and spread:
Economics and trade:
- Open economies and trade routes increase vulnerability to biological invasions.
Climate change and atmospheric changes:
- Climate change creates favorable conditions for invasive species, altering ecosystems and disrupting natural successional patterns.
- Increased concentrations of greenhouse gases affect invasive species success, influencing plant dynamics and ecosystem composition.
Learn more with FAO’s recent “Scientific review of the impact of climate change on plant pests”.
Conflict:
- Conflict and civil unrest disrupt the implementation of biosecurity measures in forestry, facilitating invasive species introduction.
- Displacement during conflict can act as a dispersal mechanism, with military transport introducing invasive species.
Regulatory regimes:
- Countries lacking effective regulations and resources are more vulnerable to invasions.
Tourism:
- International tourism intensifies invasive species risks, as travelers transport living organisms or contaminated materials.
Activities in the forest sector can contribute to the introduction and spread of invasive species through certain utilization practices. Additionally, the intentional introduction of live plant or seed materials for commercial forestry and agroforestry, without applying the necessary phytosanitary measures, can also create pathways for invasive species to spread.
Economic:
- Invasive species can directly impact production efficiency, affecting both natural and planted forests.
- Economic consequences include potential trade restrictions, control costs, and losses in conservation values and ecosystem services.
Ecological and environmental:
- Invasive species can alter the genetic makeup of community structures in forest ecosystems, especially within native forests, and disrupt ecosystem processes.
- Impacts extend to genes, species, habitats, and ecosystems, leading to fragmentation, destruction, and alteration.
Social and health:
- Local communities may experience a loss of food, fuel sources and traditional medicines due to impacts on native biodiversity.
- Forest workers and residents may face increased exposure to invasive species, potentially carrying infectious diseases.
Socio-economic and environmental benefits:
- Planted forests, often composed of non-native species, contribute to timber, fiber, fuelwood, and non-wood forest products.
- Non-native tree species aid in combating desertification, protecting soil and water, and enhancing biodiversity.
Management:
- Careful management of introduced species is essential to prevent them from becoming invasive.
- Examples include some Conifers and Eucalyptus species, Australian Acacia species, Prosopis juliflora among others.