本研究採取臺大實驗林管理處清水溝營林區鳳凰有機茶園（茶樹齡4年、11年及45年，代號分別為ORG-4, ORG-11, and ORG-45）及毗鄰慣行茶園（代號為 CON-8）之土壤進行分析，以了解慣行茶園和由慣行轉型有機茶園之土壤性質及土壤微生物多樣性。研究結果顯示， 所有茶園中， 土壤pH、總氮、有效性磷無顯著差異。三個有機茶園之總體密度介於1.12-1.15 Mg m⁻³之間，無顯著差異，而慣行茶園之總體密度為 0.87±0.09 Mg m⁻³，顯著低於所有有機茶園。ORG-4和ORG-11之土壤有機質分別為19.22和33.5 g kg⁻¹; 陽離子交換容量分別為20.81和19.22 cmol⁽⁺⁾ kg⁻¹，顯著低於ORG-45 (62.2 g kg⁻¹和 31.57 cmol⁽⁺⁾ kg⁻¹) 和CON-8 (51.8 g kg⁻¹和28.38 cmol⁽⁺⁾ kg⁻¹)，且兩有機茶園土壤性質主成分分析之結果相似度最高。但在土壤微生物組成方面，CON-8 和 ORG-4 最為相似，而非ORG-4和ORG-11，顯示土壤理化性質與管理方式可能並非影響土壤微生物菌相的唯一原因。而在有機茶園中，也可觀察到細菌多樣性指數 (H) 與優勢度指數 (S) 隨樹齡增加的結果。

In this study, we invested effects of farm management on soil Abstract properties and soil bacterial diversity in an organic plantation with different plant ages (4, 11, and 45 years, designated as ORG-4, ORG-11, and ORG-45, respectively) in the Chingshueigou tract of the Experimental Forest, National Taiwan University, and an adjacent private conventional tea plantation (designated as CON-8, both in Nantou County). Results showed that soil pH, total nitrogen, and available phosphorus did not significantly differ among the sites. Bulk density (BD) for all organic samples was 1.12–1.15 Mg m⁻³, and BD in CON-8 was 0.87 ± 0.09 Mg m⁻³, significantly lower. Soil organic matter (SOM) in ORG-4 and ORG-11 was 19.22 and 33.5 g kg⁻¹, and cation exchange capacity (CEC) was 20.81 and 19.22 cmol⁽⁺⁾ kg-1, respectively. SOM and CEC were significantly lower in ORG-45 (62.2 g kg⁻¹ and 31.57 cmol⁽⁺⁾ kg⁻¹) and CON-8 (51.8 g kg⁻¹ and 28.38 cmol⁽⁺⁾ kg⁻¹). Results from principal component analysis also indicated that ORG-4 and ORG-11 were more closely resembled each other than the other samples. However, considering soil microbial communities, the most similar one was CON-8 and ORG-4, not ORG-4 and ORG-11, indicating that soil properties and management may not be the only factor contributing to the composition of soil microbial communities. In the organic plantation, results also showed an increase of bacterial diversity and dominance indices with plant age.