干旱区生态环境知识资源中心

Whereas the role of the photobiont within microlichen symbiosis is indisputable, the role of the mycobiont in the symbiosis is still questionable. Here we report a unique expansion of the endolithic lichen Caloplaca alociza on cobbles in the Negev Desert due to structural change induced by the mycobiont burrowing activity. By increasing the water-holding capacity of the rock it facilitates lichen expansion from the cobble margins (where they establish due to water capillary rise) to its sides. And thus, while rare at the cobble top, lichen expansion is taking place to the sides of the cobble albeit the fact that dew (the main water source) is significantly lower at the cobble sides than at its top.