關刀溪森林生態系台灣二葉松與台灣五葉松在干擾地之天然更新

The natural regeneration of Pinus taiwanensis and Pinus morrisonicola following disturbances in Guandaushi forest ecosystem

1997年9月至1999年4月間在關刀溪森林生態系就台灣二葉松（Pinus taiwanensis Hay.）與台灣五葉松（Pinus morrisonicola Hay.）在干擾地之天然更新進行研究。台灣二葉松具輕度毯果延遲性，可保護種子；台灣五葉松不具毯果延遲性，種子成熟後毯果即開裂。干擾地松樹下種量受母樹數量的影響。更新苗的建立受有效種子量的影響，台灣二葉松有效種子量佔33.3%，台灣五葉松有效種子量佔75.0%。水分與植群競爭也影響更新苗的存活與成長。火燒之後一年台灣二葉松更新苗密度為0.74株/m2，火燒之後四年更新苗密度降為0.29株/m2。崩塌後約十年，台灣二葉松更新苗密度為0.09株/m2，台灣五葉松更新苗密度為0.18株/m2，多已具結實能力。崩塌地似較火燒地更適合建立松樹族群。 The natural regeneration of Pinus taiwanensis and P. morrisonicola following disturbances in Guandaushi forest were investigated from September 1997 to April 1999. Cone serotiny exists in P. taiwanensis for prolonging seed release. However, cones of P. morrisonicola were nonserotinous, and seeds released immediately after maturation. The seed fall at disturbed sites was controlled by the population of seed-banking trees. The seedling establishment was limited to the viable seeds that were 33.3% in P. taiwanensis and 75.0% in P. morrisonicola. The survival and development of seedlings were affected by soil water content and vegetation competition. Density of P. taiwanensis seedlings in burned sites declined from 0.74/m2 in the first year after fire to 0.29/m2 in the fourth year. Density of seedlings at the site ten years after landslide was 0.09/m2 for P. taiwanensis and 0.18/m2 for P. morrisonicola. The naturally regenerated seedlings already have reproductive ability. The establishment of pine seedlings at landslide site seems more successful than that at burned sites.

The natural regeneration of Pinus taiwanensis and P. morrisonicola following disturbances in Guandaushi forest were investigated from September 1997 to April 1999. Cone serotiny exists in P. taiwanensis for prolonging seed release. However, cones of P. morrisonicola were nonserotinous, and seeds released immediately after maturation. The seed fall at disturbed sites was controlled by the population of seed-banking trees. The seedling establishment was limited to the viable seeds that were 33.3% in P. taiwanensis and 75.0% in P. morrisonicola. The survival and development of seedlings were affected by soil water content and vegetation competition. Density of P. taiwanensis seedlings in burned sites declined from 0.74/m2 in the first year after fire to 0.29/m2 in the fourth year. Density of seedlings at the site ten years after landslide was 0.09/m2 for P. taiwanensis and 0.18/m2 for P. morrisonicola. The naturally regenerated seedlings already have reproductive ability. The establishment of pine seedlings at landslide site seems more successful than that at burned sites.