Drought-induced changes in the phenology, productivity and diversity of Spanish fungi

Mushrooms are amongst the most important of non-timber forest products, with growing economic value in many rural areas of the Mediterranean region. At the same time, the effects of climate variability on fungal ecology and productivity are insufficiently understood, because the belowground life cycle of fungi is mediated in many different ways and observational field surveys at the community level are generally too short. Here, we assess records of 48, 348 mycorrhizal and saprotrophic fungal fruit bodies that were recorded at weekly intervals between 1995 and 2013 in Pinar Grande, the largest Spanish Scots pine forest. Autumnal fruiting was delayed by one week after 2004 compared with the period before, the mean annual number of sporocarps dropped from 2 880 to 2 045, and mean species richness declined from 55 to 51. Trends in the phenology and productivity of Boletus edulis and Lactarius spp., the most profitable edible species, were associated with decreasing Jul.–Sep. precipitation totals, whereas the mean fruit body weight of B. edulis significantly increased from 71 to 123 g (pre and post 2004). In tandem with declining Spanish tree growth and truffle harvest since the 1970s, this study reveals a strong dependency of drought-prone Iberian forest ecosystem productivity on hydroclimatic variability. In light of a predicted drier Mediterranean climate, our results further emphasize the importance of long and well-replicated field inventories at high spatiotemporal resolution for informing forest service and management strategies, as well as gastronomy and tourist industries.