NUÑEZ martin Andres
Fungal endophytes associated with roots of nurse cushion species have positive effects on native and invasive beneficiary plants in an alpine ecosystem.
MOLINA-MONTENEGRO, M. A., OSES, R., TORRES-DÍAZ, C., ATALA, C., NUÑEZ M. A. & ARMAS, C.
PERSPECTIVES IN PLANT ECOLOGY EVOLUTION AND SYSTEMATICS
Año: 2015 vol. 17 p. 218 - 226
Facilitation has been proposed to be a fundamental mechanism for plant coexistence, being particularlyimportant in highly stressful environments such as alpine environments. In this type of environment,species called ?cushion plants? can ameliorate the stressful conditions, acting as nurses for other plants.Ofthe several mechanisms proposed in the positive-interactions framework, plant?microorganism interactionmay be one of the most common, but least documented. Here we show that the presence ofendophytes isolated from the roots of cushion plants Laretia acaulis can play a fundamental role in theestablishment, performance and survival of both native and exotic plant seedlings that are known to befacilitated by the cushion species.To test this, we measured survival and growth of two native and one invasive species at 3200 m in theAndes of Central Chile. Plants were grown inside artificial cushions filled with native soil, with or withoutsterilization, and with or withoutfungal endophytic inoculation to evaluate the role of fungal endophyteson survival and growth. In addition, we conducted a second experiment in a greenhouse with the invasivespecies to evaluate the effect of fungal endophytic infection/association on plant ecophysiologicalperformance, dry biomass and seed output.Overall, our results showed a strong positive effect of fungal endophytes on the survival and growthof both native and invasive species. Moreover, maximum quantum efficiency (Fv/Fm), biomass accumulationand seed production were enhanced in the invasive species when soils were inoculated withendophytes. Thus, facilitation by root endophytic fungi on native and invasive alpine plants could determinesurvival and establishment in this harsh environment.Several studies have shown that direct facilitation by cushion plants in alpine environments improvesthe performance and fitness of both native and exotic plants. Our results suggest that there are indirecteffects, mediated by microorganism associations that may also help to explain the successful establishmentof native and invasive species in these environments. If indirect plant?plant facilitation throughroot fungal endophytes proves to be a widespread phenomenon in alpine ecosystems, it could be a keycomponent in the structuring of plant communities in those stressful environments.