The cumulative effects of precipitation determine the occurrence of Tricholoma matsutake fruiting bodies

Abstract

Understanding the factors influencing mushroom occurrence is essential for advancing mushroom ecology and informing forest management practices. In this study, we hypothesized and demonstrated that the daily number of Tricholoma matsutake fruiting bodies is determined by the cumulative effect size of the antecedent precipitation index (API) up to the occurrence date. We employed a Bayesian approach with a state-space model for the analysis. Our results demonstrated a significant relationship between the number of fruiting bodies and API, with the cumulative effect size of API accurately predicting the number of fruiting bodies (R² = 0.89). Furthermore, the effect size on fruiting body number fluctuated daily, peaking 12 days before occurrence, and was 4.14 times that on the occurrence day and 19.98 times that 30 days prior at an API of 20 mm. These findings highlight the crucial role of precipitation in T. matsutake fruiting.