Functionally distinct tree species support long-term productivity in extreme environments.

Area of Science:

• Ecology
• Forestry
• Biodiversity Research

Background:

• Functional diversity positively impacts ecosystem productivity, but the role of functionally distinct species remains unclear.
• Distinct species possess unique trait combinations, potentially influencing ecosystem functions uniquely.
• Understanding species' roles is vital for predicting ecosystem responses to biodiversity loss.

Purpose of the Study:

• To investigate the impact of functionally distinct species on ecosystem productivity.
• To assess how environmental conditions modulate the importance of distinct species.
• To evaluate the consequences of regional species loss on forest productivity.

Main Methods:

• Utilized a forest-gap model to simulate temperate forest successions across an environmental gradient.
• Conducted 10,560 simulations varying species composition (distinct vs. indistinct traits) and regional species pool size.
• Measured ecosystem productivity at the end of simulated successional trajectories.

Main Results:

• Long-term ecosystem productivity declined when distinct species were lost first, particularly under harsh environmental conditions.
• In milder environments, ecosystem productivity was more sensitive to the loss of ordinary species.
• Species functional distinctiveness, considering multiple trait dimensions, effectively captures species-specific impacts on productivity.

Conclusions:

• Species functional distinctiveness is a key factor in ecosystem productivity, especially under environmental stress.
• The importance of distinct species in sustaining ecosystem processes is highlighted, particularly in extreme environments.
• Conservation strategies should consider the role of functionally distinct species in maintaining ecosystem functions in a changing world.