Global effects of non-native tree species on multiple ecosystem services

Area of Science:

• Ecology
• Environmental Science
• Conservation Biology

Background:

• Non-native tree (NNT) species are globally introduced for ecosystem services like timber and erosion control.
• NNTs can also cause negative impacts, including increased fire risk and pollen allergenicity.
• A comprehensive global assessment of NNTs' ecosystem (dis)services is currently lacking.

Purpose of the Study:

• To conduct a global quantitative assessment of NNT effects on regulating (RES), provisioning (PES), and cultural ecosystem services (CES).
• To evaluate NNT impacts on pollen allergenicity as an ecosystem disservice (EDS).
• To understand the context dependency, synergies, and trade-offs of NNT effects on ecosystem services.

Main Methods:

• Compiled a global dataset of 1683 case studies from scientific literature, forestry reports, and social media.
• Included data from over 125 NNT species across 44 countries and seven biomes.
• Employed meta-analysis techniques to quantify NNT impacts on various ecosystem (dis)services.

Main Results:

• NNTs generally enhance regulating ecosystem services (e.g., climate regulation, soil fertility) but decrease provisioning services (e.g., timber provision).
• Effects on cultural services varied, increasing aesthetic values while decreasing scientific interest.
• NNT impacts were highly context-dependent, influenced by species traits, biome, and socio-economic factors, with observed synergies and trade-offs.

Conclusions:

• NNTs offer significant benefits to regulating ecosystem services but pose challenges for provisioning services.
• The diverse and context-specific impacts of NNTs necessitate tailored management strategies.
• Understanding these complex interactions is crucial for sustainable NNT implementation and ecosystem service provision.