土壤孔隙對於水分傳導與貯水能力評估非常重要，不同孔隙大小分布可以表示不同的水文現象。大孔隙率及粗孔隙率的大小影響水分入滲、移動及貯水能力，粗孔隙率亦是評估土壤涵養水源能力的指標。本研究目的為探討不同土地利用型態對於淺層土壤孔隙率特性之影響，藉由採集天然林、人工林及人工草地等三個不同土地利用型態之土壤樣品，進行土壤物理性質分析，評估土壤總體乾密度、比重與大、中、小、細及粗孔隙率大小。研究結果顯示不同土地利用型態之總體乾密度大小順序為天然林<人工林<人工草地；總孔隙率、大孔隙率與粗孔隙率大小順序為天然林>人工林>人工草地，且孔隙率會隨著土壤取樣深度增加而減少。將三個試驗區之總體乾密度與總孔隙率進行線性迴歸分析結果，均呈現高度顯著負相關。由變異數分析結果，天然林及人工林的總孔隙率和粗孔隙率均隨著取樣深度不同呈現顯著差異。土壤孔隙率與取樣深度間統計結果顯示，總、大、中、小、細及粗孔隙率在不同深度間皆呈現顯著差異。但是，在不同土地利用型態之間，除了細孔隙率不見顯著之外，其餘皆呈顯著差異。不同土地利用型態與取樣深度之交互關係顯示，粗孔隙率呈現顯著差異。從以上結果說明，不同土地利用型態會影響淺層土壤具有不同的物理特性。以大孔隙率及粗孔隙率評估水源涵養能力大小順序為天然林>人工林>人工草地，但評估單場降雨之土壤最大貯水容量時，仍需考慮集水區之降雨強度及水文現象。

Soil pore is important for water transport and assessment of water storage capacity. Different size and distribution of soil pore can represent different hydrological phenomena. Macroporosity and coarse porosity affect water infiltration, transportation and storage capacity. Coarse porosity are also assessment indicators for water storage capacity. The purpose of this study was to assess characteristics of surface soil porosity in different land-use types. Soil samples of three different land-use types (i.e. natural forest, plantation and artificial grass-covered land) were used to analyze the soil physical properties, which included dry bulk density, specific gravity and macroporosity, mesoporosity, miniporosity, microporosity and coarse porosity. The results showed that the trend of dry bulk density in different land-use types was: natural forest < plantation < artificial grass-covered land. The trend of total porosity, macroporosity, and coarse porosity was: natural forest > plantation > artificial grass-covered land. Soil sampling depth increased with decreasing value of porosity. Linear regression on dry bulk density and total porosity in each test zone showed a highly significant negative correlation. In the natural forests and plantations, difference in total porosity at different depths was due to macroporosity and coarse porosity at different depths. However, in artificial grass-covered land, difference in total porosity at different depths was due to microporosity at different depths. The relationships between total porosity and coarse porosity at different soil depths in the natural forests and plantations were significantly different by ANOVA. Soil porosity including total porosity, macroporosity, mesoporosity, miniporosity microporosity and coarse porosity was significantly different between soil depths. Soil porosity between the three different land-use types were significantly different, but it was not so for microporosity. The interaction between different land-use types and soil sampling depths were significantly different for coarse porosity. These results suggested that different land-use types indicated different soil physical characteristics. Assessment of water conservation capacity with macroporosity and coarse porosity showed the trend as follows: natural forest > plantation > artificial grass-covered land. However when considering maximum rainfall in a single field exceeding soil water storage capacity, water will be lost through surface runoff. Therefore, estimates of soil water conservation need to consider rainfall and hydrological observations of a catchment area in order to obtain correct results.