中文摘要：

本文研究了不含有5-圈和K4的平面图的森林分解问题。利用权转移法,证明了任意不含有5-圈和K4的平面图能分解成三个森林,且其中有一个森林的最大度不超过2,这一结果推广了文献[2,3]中的结论。

英文摘要：

In this paper, we consider the forest decomposition of planar graphs without 5-cycles or K4. By the rules of discharging, we prove that every planar graph without 5-cycles or K4 can be decomposed into three forests with one whose maximum degree is at most 2, which generalizes the results in [2, 3].