| 51 | 生態系 | Ecosystem |
| 52 | 生態旅遊 | Ecotourism |
| 53 | 母樹林；選留木林分；特優母樹林 | elite stand；selected stand |
| 54 | 瀕臨絕種野生動物 | Endangered Species |
| 55 | 特有種 | Endemic species |
| 56 | 常綠針闊葉混合林 | evergreen conifer-broadleaf forest |
| 57 | 試驗地；試驗區；試區 | experimental site；experimental area |
| 58 | 成熟伐採；成熟的；可伐採的 | exploitable；mature |
| 59 | 因素分析 | factorial analysis |
| 60 | 指接 | finger joint |