Slow turnover and production of fungal hyphae during a Californian dry season

We used minirhizotrons to examine the production and turnover of fungal hyphae in situ during the dry season in a Californian grassland. Hyphae were produced relatively slowly throughout the season at rates that did not vary significantly over time, indicating that a portion of the fungal community was active even when soils were very dry. In addition, fungi displayed relatively long residence times, with half of the hyphae remaining in the soil for at least 145 days. Together, these results suggest that a contingent of active fungi may be capable of performing nutrient transformations when plants are otherwise dormant, while relatively long-lasting hyphae may immobilize nutrients for several months before turning over. (C) 2010 Elsevier Ltd. All rights reserved.