定義： Arenosols are sandy soils, including both soils developed in residual sands after in situ weathering of usually quartz-rich sediments or rock, and soils developed in recently deposited sands such as dunes in deserts and beach lands.
定義： A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)
定義： An organism that feeds on mud or sand and shows little discrimination in the size or type of particles eaten. The sediment is ingested and any digestible organic material is assimilated as it passes through the alimentary canal.
