Feedbacks and interlinks between the biosphere, the hydrosphere and the geosphere shape habitats and life patterns on Earth's surface. The spaces within soil and rocks create a rich and complex environment supporting a wide array of life forms. Water, an essential element of life, is by far the most influential resource shaping biodiversity at scales ranging from micrometers (microbial life on soil grains) to megameters (vegetation patterns at watershed scale and across geographical regions). Mechanistic understanding of the suite of processes and conditions that promote and maintain ecosystem diversity remains rudimentary. The microbial diversity found in soil alone represents "an immense and unexplored frontier in science of astronomical dimensions and of astonishing complexity" (Curtis and Sloan, 2004). The session is open to contributions related to the interaction and feedback mechanism between life and geological environments throughout geological history. We encourage also those who discuss the interaction of humans with geological environments. We solicit contributions concerning interactions and feedbacks between biodiversity (community and species diversity and functional diversity) and hydro-geological patterns and earth dynamics (e.g. natural radioactivity, earthquakes, neotectonic faults) at all space and time scales. We encourage presentations addressing questions pertaining to effects of perturbations and changes in diversity on hydrological and biogeochemical cycles at local and global scales; how to quantify hydrologically-mediated interactions that contribute to diverse ecosystems; patterns in resource availability shaping ecological function. We invite experimental and modeling work, and studies derived from new observational capabilities (methods and networks) aimed at quantifying links between hydrological processes and biological diversity of ecosystems.