| environ. | biogeochemical cycle Movement of chemical elements in a circular pathway, from organisms to physical environment, back to organisms. The process is termed a nutrient cycle if the elements concerned are trace elements, which are essential to life. A biogeochemical cycle occurs when vegetation decomposes and minerals are incorporated naturally in the humus for future plant growth | 生物地理化学循环 (化学元素的运动循环，从生物到物理环境，回到生物。如果相关元素是微量元素，这个过程被称为一个养分循环，是生命的基础。一个生物地理化学循环发生在植被分解，矿物为未来植物生长被自然用于腐殖质。) |
