保安林乃是為了發揮森林國土保安功能而劃設，以保障人民的生命財產安全，透過森林永久樣區之測設與定期複查，了解森林蓄積、生長與結構，以釐訂相關保育策略，確保保安林公益功能之發揮。本研究截至目前複查了170個樣區，所獲致之初步結論有三：第一，臺北市保安林之蓄積情形，幾乎都高於臺灣森林經營管理上所認定之「低劣林相的標準」，唯一落於該水準以下之樣區的週遭林分(四獸山)，可考慮施以林相改良之策略，以加強其水源涵養功能；第二，在前後期之林分生長變化上，臺北市保安林之生長情形，大致高於國有林林相變更之平均蓄積生長水準；第三，保安林之森林結構大致符合良好穩定平衡之狀態，指南宮地區之保安林宜增加取樣面積，以釐清其森林結構是否確屬於穩定平衡狀態。臺北市保安林永久樣區複查應持續
辦理，且應縮小複查之時間間隔至5年，以確實掌握林木枯死與晉級的情況，並觀察其是否有過熟與異常的現象。

The goal of protection forest is zoned for protecting land and soil, therefore the public welfare, and their living environment can be safequarded.Through setting up the permanent sample plots and periodic revision, to acquire forest growing stock, growth, and structure for preparing conservation strategy and providing protection and a variety of services for the pulbic. In this study, by revising 170 permanet sample plots at present three initial conclusions are made. Firstly,the growing stocks are almost above the level of stand conversion which considered as worse quality. The only special case are located in Se-Hso Mount forest, in which the stand conversion strategy are suggested for improving the function of water and soil conservation. Secondly, the average annual forest growth is also above the level of national forest conversion. Thirdly,the froest can meet the well stable or balanced structure.The forest around Zhi-Nan Temple should be added sampling size to make sure the
forest structure apparently. The permanent sample plots of Taipei protectionn forest is deserved to be revised, and the revision period should be shortened to 5 years for mornitoring the death and ingroth of trees among stands, and the forest over-mature or abnormality.