Successful range-expanding plants experience less above-ground and below-ground enemy impact

Area of Science:

• Ecology
• Evolutionary Biology
• Plant Science

Background:

• Species are shifting ranges to higher latitudes and altitudes due to climate change.
• Understanding factors influencing range-expanding species' success in new habitats is crucial.

Purpose of the Study:

• To investigate the defense mechanisms of range-expanding plant species against herbivores and soil pathogens compared to native species.
• To assess the role of enemy control in the success of species expanding their ranges.

Main Methods:

• Fifteen plant species, including range-expanders and natives, were grown with and without locusts (shoot herbivores) and aphids.
• Biomass reduction by herbivores was measured.
• Pathogenic effects in the root-zone soil were assessed.

Main Results:

• Range-expanding plants exhibited better defense against shoot herbivores (locusts) and root pathogens than native species.
• Locusts performed worse on range-expanding species, reducing their biomass less than native species.
• Aphids showed no significant difference in performance between range-expanding and native plants.

Conclusions:

• Range-expanding plant species possess enhanced defenses against common enemies, potentially facilitating their establishment in new environments.
• Reduced enemy control may contribute to the success of species shifting ranges due to climate warming.
• These findings suggest that successful range expanders could pose a greater invasion risk in novel habitats.