追蹤火燒存活木的年輪得知，環山地區的臺灣二葉松（Pinus taiwanensis Hayata）森林在近廿年間至少曾發生3次林火。最近一次火燒發生於1995年12月，不具萌蘗能力的臺灣二葉松平均致死率為73.1﹪；闊葉樹大多由地際再萌蘗，僅1.6﹪死亡。火燒後的上木組成隨火燒強度及原植群類型而不同；地被雖隨上木組成及海拔高而有些許差異，然皆以高山芒（Miscanthus transimorrisonensis Hayata）及巒大蕨（Pteridium aquilinum(L.) Kuhn subsp. Wightianum (Wall.) Shieh）最為優勢，其中巒大蕨具明顯的季節性消長。火燒後臺灣二葉松之天然下種量，可能與種子來源有關；幼苗的萌發及死亡與月降水量、微環境等有關。本區若長期不再發生火燒，海拔較低的地區，臺灣二葉松終將被殼斗科及樟科等闊葉樹所取代；海拔較高的地區，可能演替為針闊葉樹混交林。唯未來人為干擾可能更為頻繁，火燒週期或將縮短，而使本區停留草生地景觀。

　　　　　Based on dendrochronological studies of fire-scarred trees, there were at least 3 fires at Taiwan red pine (Pinus taiwanensis) forest in Fansan area during the past 20 years. 73.1% of Taiwan red pine were completely killed by the last fire in December of 1995. Most hardwoods, however, sprouted from the base. Only 1.6% were completely killed. The postfire canopy composition was related to fire intensity and original vegetation type. After burning, Miscanthus transmorrisonensis and Pteridium aquilinum subsp. wightiamim were dominant ground cover, but Pteridium aquilinum subsp. wightianum showed seasonal fluctuation. Postfire regeneration of Taiwan red pine was related to seed source. The germination and mortality of Taiwan red pine seedlings were related to microenvironment and monthly rainfall. If there is no more fire in this area, the vegetation will succeed to hardwood forest at lower elevation or to hardwood-conifer mixed forest at higher elevation. However, more frequent fires are probably inevitable. Thus all this area may eventually change to grasslands.