次生林與杉木人工林火後短期植被組成恢復與更新之比較

Comparison of Short-term Post-fire Vegetation Recovery and Regeneration in Secondary Forest and China Fir Plantation

2020年至2021年降雨明顯較低，臺灣發生多起火燒事件；惠蓀林場第三林班於2021年5月發生火燒，火燒區域主要為杜鵑嶺次生林至關刀山林道沿線杉木造林地。本研究欲探討火後植群回復情形，並評估火燒擾動對不同森林經營的影響，於次生林火燒與未燒區分別架設9樣區與5樣區，杉木人工林火燒區與未火燒區分別架設11樣區與5樣區。本研究共調查記錄68科146屬193種，以菊科、鳳尾蕨科及禾本科物種數較多。次生林及杉木人工林未火燒樣區共記錄57科91屬109種，其中易受害種（VU）3種；而火燒樣區共記錄58科110屬142種，包含易受害物種1種及瀕危物種（EN）1種。次生林未火燒區域與杉木人工林火燒前地被植群組成相近，地被物種組成以耐陰性物種為主，植群型區分為白背木薑子—芒萁型、玉山紫金牛—五節芒型。火後杉木人工林及次生林地被植群物種組成相似，均以先驅物種為優勢，植群型可區分為天臺烏藥—昭和草型、瓦氏鳳尾蕨—蘇鐵蕨型、貓腥草型。火後菊科、蕨類植物於火後大量萌發，歸化種物種數較未火燒地被植群多。火後短期演替的次生林、杉木人工林以先驅樹種為當地之喬木層優勢物種。

Extreme weather events, such as droughts and heat waves caused by climate change, have strengthened the intensity and frequency of wildfires, impacting forest ecosystems and making vegetation more vulnerable. A severe drought in Taiwan between 2020 and 2021 led to multiple wildfire events, including one in May 2021 at the third forest compartment of Huisun Forest Station. The wildfire impacted the secondary forests of Duzhuan Ridge and the China fir (Cunninghamia lanceolata) plantation along the Guandaoshan Forest Road. This study examined post-fire vegetation recovery and assess the impact of fire disturbances on different forest management practices. We established 30 sample plots, including 9 plots in the experimental group 5 in the control group for secondary forests, 11 in the experimental group, and 5 in the control group for China fir plantations. A total of 68 families, 146 genera, and 193 species were recorded, with Compositae, Pteridaceae, and Poaceae being the dominant families. The control groups recorded 57 families, 91 genera, and 109 species were recorded, including 3 vulnerable (VU) species, while the experimental groups recorded 58 families, 110 genera, and 142 species were, including 1 vulnerable (VU) and 1 endangered (EN) species. The ground cover vegetation in China fir plantations resembled the secondary forest without wildfire disturbance, composed of shade-tolerant species and classified as Ardisia cornudentata ssp. morrisonensis–Miscanthus floridulus type and the Litsea rotundifolia var. oblongifolia–Dicranopteris linearis type. The ground covers vegetation in both secondary forests and China fir plantation after wildfire composed of similar species, that classified into Lindera aggregata–Crassocephalum crepidioides type, Pteris wallichiana–Brainea insignis type, and Praxelis clematidea type. Pioneer species, especially Asteraceae and ferns, germinated after fire and dominated the post-fire vegetation, while the number of naturalized species was greater than in unburned area.