zonation
/zəʊˈneɪʃən/noun
mass noun
1- distribution in zones or regions of definite character成带; 分带; 分区, 区划：
quartz grains can exhibit zonation and rounding.
石英砂具有显示成带和变圆的特性。
1.1
- Ecology the distribution of plants or animals into specific zones according to such parameters as altitude or depth, each characterized by its dominant species【生态】（动, 植物）种群成带现象; （动, 植物）种群分布, 分区。