Evidence for a fungal loop in shrublands

Dryland communities may mitigate the loss of limited resources by exchanging nutrients through subterranean fungal connections, termed loops. In arid grasslands, loops can influence community composition and primary productivity, yet their ecological significance across dryland systems remains unexplored. We investigated functional role in nutrient translocation a North American shrubland ecosystem. traced movement 15N from moss-dominated biocrusts to dominant xeric shrub Larrea tridentata, 13C L. tridentata plots established situ Sonoran Desert. Measurements occurred at three time points spanning 1 week following simulated 2.5 mm rainfall event, distances up m tracer application. also used ITS sequencing investigate changes soils over 1-week period. discovered into foliage as well other spatially isolated biocrust patches, this did not occur until 4–6 days post-rainfall, when significantly higher δ15N was observed compared previous days. observe consistent patterns neighbouring shrubs or biocrusts, suggesting differential environmental drivers for carbon system. Fungal exhibited decrease alpha diversity on last day study, indicative delayed response concomitant with translocation. endophyte orders Pleosporales Pezizales dominated all plot soils, order more abundant enriched plots, that dark septate endophytic fungi were involved nitrogen The delay reflect rainfall-triggered rebuilding mycelial networks between members drought. Synthesis. Our results point fungal-mediated exchange pathways previously uninvestigated vegetation type, shrublands, where are translocated nearby shrubs. provide first evidence transfer be 6 rainfall, pulse-dynamic responses drylands, play