Battling Rong Huan Xuan

Evil Demon Trees were special creatures, something between a plant and a beast. They could form an inner core like beasts that was similar to a martial artist's Dantian; this was their source of power, known as tree heart. 

Since they counted as half-plants, Evil Demon Tree's tree heart was like spirit grasses, very easy to refine and thus even more precious.

Ling Han pursued them relentlessly, beating the Evil Demon Tree army into disarray. At last, seven Evil Demon Trees had their tree hearts dug out while the rest took the chance and escaped, disappearing without a trace. However, due to their quality of being half-plant, even if their tree hearts were gone, they wouldn't die. The tree heart would still slowly grow back after a thousand years.

Seven tree hearts should help him break through to the second layer of the Gushing Spring Tier, right?