The result showed that the grain yield fluctuation had stagevariation characteristics.
森林的过量采伐导致区域气候变化，进而引起粮食产量的变化。
2
Thus a method is proposed for comprehensive prevention with a deeply buried stagevariation cluster piles.
为此提出了采用深埋式变阶群桩进行综合防治的方法。
3
The Lithofacies paleogeography and the thickness variation of Maokouan Subseries and Wuchiapingian Stage in east part of South China are analyzed and some questions in dispute are discussed.