FLICKR, GORDON ROBERTSONPlant-soil feedback is the idea that as plants grow in soil, they change the soil, and that the soil in turn affects their growth. When the soil surrounding a given plant promotes the growth of conspecific plants, plant-soil feedback is positive. But when the soil discourages the growth of conspecific plants, the feedback is negative. In independent studies published in Science today (January 12), researchers examined how mycorrhizal fungi—which live in and around plant roots and help plants gather nutrients—affect plant population diversity.
Both groups used greenhouse experiments to model plant-soil feedback, examining plants with different microbial symbioses and nutrient-gathering strategies. François Teste of the University of Western Australia and IMASL-CONICET/UNSL in San Luis, Argentina, and colleagues used their resulting data to predict how plant-soil feedback relationships might affect plant diversity in the long run. Meantime, Jonathan Bennett of the University of British Columbia, Canada, and colleagues tested their greenhouse study findings in the field.
“The take-home message is that these below-ground mechanisms—which, in general, we call the plant-soil feedback mechanism—[are] important in driving local plant diversity,” Teste told The Scientist.
“We knew before . . . that there is a range in direction in strength of feedback,” ecologist Justine Karst of the University of Alberta in Canada, ...
