Production and turnover of mycorrhizal soil mycelium relate to variation in drought conditions in Mediterranean Pinus pinaster, Pinus sylvestris and Quercus ilex forests.
In forests, ectomycorrhizal mycelium is pivotal for driving soil carbon and nutrient cycles, but how ectomycorrhizal mycelial dynamics vary in ecosystems with drought periods is unknown. We quantified the production and turnover of mycorrhizal mycelium in Mediterranean Pinus pinaster, Pinus sylvestris and Quercus ilex forests and related the estimates to standardised precipitation index (SPI), to study how mycelial dynamics relates to tree species and drought-moisture conditions. Production and turnover of mycelium was estimated between July and February, by quantifying the fungal biomass (ergosterol) in ingrowth mesh bags and using statistical modelling. SPI for time scales of 1-3 months was calculated from precipitation records and precipitation data over the study period. Forests dominated by Pinus trees displayed higher biomass but were seasonally more variable, as opposed to Q. ilex forests where the mycelial biomass remained lower and stable over the season. Production and turnover, respectively, varied between 1.4-5.9 kg ha-1  d-1 and 7.2-9.9 times yr-1 over the different forest types and were positively correlated with 2-month and 3-month SPI over the study period. Our results demonstrated that mycorrhizal mycelial biomass varied with season and tree species and we speculate that production and turnover are related to physiology and plant host performance during drought.
['Hagenbo|Andreas|A|0000-0002-4192-0511', 'Piñuela|Yasmine|Y|0000-0002-1150-7160', 'Castaño|Carles|C|0000-0002-2403-7006', 'Martínez de Aragón|Juan|J|0000-0001-5663-2080', 'de-Miguel|Sergio|S|0000-0002-9738-0657', 'Alday|Josu G|JG|0000-0001-7510-8655', 'Bonet|José Antonio|JA|0000-0003-2209-9374']
D055864:Droughts D017753:Ecosystem D065928:Forests D025282:Mycelium D038821:Mycorrhizae D028223:Pinus D041605:Pinus sylvestris D029963:Quercus D012987:Soil D014197:Trees
production turnover drought precipitation fungal biomass ectomycorrhiza extramatrical mycelium extraradical mycelium