本研究目的為探究六龜森林土壤與碳循環有關酵素活性之季節性變化及其與土壤性質之關係。結果顯示六龜森林土壤與碳循環有關的酵素活性：(1) 土壤β-配醣酶活性，在台灣杉人工林與天然闊葉林分別為1.20-3.06 (平均2.03 ± 0.79)及3.54-5.49 (平均4.18 ± 0.73) μmol p-nitrophenol g-1soil h-1，(2) 土壤β-胺基葡萄醣苷酶活性分別為1.50-1.86 (平均1.67 ± 0.13)及1.95 - 4.37 (平均3.00 ± 0.93) μmol p-nitrophenol g-1soil h-1，(3) 土壤纖維素酶活性分別為0.0945-0.332 (平均0.23 ± 0.08)及0.399-0.821 (平均0.62 ± 0.15) μmol glucose g-1soil 24 h-1。森林土壤有機碳總量和此三種土壤酵素活性均無顯著之季節性變化但均隨著土壤深度之增加而減少(p < 0.05)。簡單相關分析結果顯示：土壤β-配醣酶、β-胺基葡萄糖苷酶、纖維素酶活性彼此間且均與微生物生質碳、生質氮、全氮及有機碳間呈極顯著之正相關(p < 0.001)，土壤β-胺基葡萄糖苷酶、纖維素酶活性、生質碳、生質氮則均與土壤水分間呈顯著正相關(p < 0.05)。六龜森林土壤有機碳估計佔其森林碳匯池之比重：台灣杉人工林估計為61%，天然林闊葉林估計為47%。

A Taiwania plantation and a native hardwood forest, mainly Lauraceae and Fagaceae in Liu-Kuei, Taiwan were selected to examine the seasonal changes in the activities of soil enzymes related to the carbon cycle,
and the relationships between the soil enzyme activities and soil properties were also analyzed. The results showed that soil β-glucosidase activities in the Taiwania plantation and native hardwood forests were 1.20-3.06(average: 2.03 ± 0.79) and 3.54-5.49 (average: 4.18 ± 0.73) μmol p-nitrophenol g-1soil h-1, respectively; soilβ-glucosaminidase activities were 1.50-1.86 (average: 1.67 ± 0.13) and 1.95-4.37 (average: 3.00 ± 0.93) μmol p-nitrophenol g-1soil h-1, respectively; soil cellulase activities were 0.0945-0.332 (average: 0.24 ± 0.08) and 0.399-0.821 (average: 0.62 ± 0.15) μmol glucose g-1soil h-1, respectively. There was no significant seasonal change in the soil carbon content and the above soil enzyme activities, but all of them significantly decreased
while soil depth increased (p < 0.05). The results of simple regression analysis indicated that soil β-glucosidase,β-glucosaminidase, and cellulase activities significantly correlated with microbial biomass C, microbial biomass N, total nitrogen and soil organic carbon (p < 0.001). Soil β-glucosaminidase, cellulose activities,microbial biomass C and N significantly correlated with soil moisture (p < 0.05). The estimated percentages of the total soil organic carbon amounts to the forest carbon sinks were 61% and 47% for the Taiwania plantation and native hardwood forests in Liu-Kuei, Taiwan, respectively.