 Water is usually only found deep inside holes at the bottom of blow @-@ out craters . Animals therefore get the moisture they need directly from their food . The black soil on and around cinder cones does not hold moisture for long , making it difficult for plants to establish themselves . Soil particles first develop from direct rock decomposition by lichens and typically collect in crevices in lava flows . Successively more complex plants then colonize the microhabitat created by the increasingly productive soil . 
