關刀溪森林生態系三種林分之土壤理化性質及土壤水化學成分

Physical and Chemical Properties of Soil and Chemical Components of Soil Water of Three Stands in Kuandaushi Forest Ecosystem

本研究的目的是探討關刀溪森林生態系內同一集水區所含三種林分，杉木林、次生林及天然林之土壤及土壤水（張力水、重力水）的性質及其差異，且就不同林分不同土層深度探討其變化。結果顯示此三種林分的土壤物理性質為杉木林屬緊密黏土質地，次生林屬小石礫多之疏鬆壤土質地而天然林為大石礫含量多之疏鬆黏土質地。三種林分土壤化學性質方面，天然林養分含量最高，陽離子交換能力也明顯較強，而土層愈深養分含量愈少；土壤pH值則以天然林最高，次生林次之，杉木林最低。在土壤水方面，三種林分張力水之導電度、各種無機離子濃度及凱氏氮皆高於重力水；而以天然闊葉林之營養鹽含量最高，次生闊葉林林次之，杉木人工林最低，此結果與不同林分之土壤化學性質相同。愈往下層土壤的張力水，其離子濃度逐漸下降，但pH值則有上升的現象。當一林分處於未經干擾且歧異度較高的情形下，不論土壤之物理結構或養分狀態皆顯現較理想的狀態。 The objectives of this study arc to compare the properties of soil and soil water (including tension and zero tension water) of three types of forests, a plantation (Cunninghamia lanceolata), a secondary hardwood, and a natural hardwood at Kuandaushi forest ecosystem in central Taiwan. The texture of soil of plantation is heavy clay, secondary hardwood is light loam, and natural hardwood is light loam soil. Jon concentrations and cation exchange capacity are higher in soil of natural hardwood than in secondary hardwood and in plantation. The ion concentrations decrease and pH increase with increasing soil depth. Soil pH is lower in plantation stand than in secondary hardwood and natural hardwood. Soil waters under tension are higher in conductivity and ion concentration than those of under zero-tension. Soils are better Structured and the fertility is higher under less disturbed natural forest than under secondary forest and plantation.

The objectives of this study arc to compare the properties of soil and soil water (including tension and zero tension water) of three types of forests, a plantation (Cunninghamia lanceolata), a secondary hardwood, and a natural hardwood at Kuandaushi forest ecosystem in central Taiwan. The texture of soil of plantation is heavy clay, secondary hardwood is light loam, and natural hardwood is light loam soil. Jon concentrations and cation exchange capacity are higher in soil of natural hardwood than in secondary hardwood and in plantation. The ion concentrations decrease and pH increase with increasing soil depth. Soil pH is lower in plantation stand than in secondary hardwood and natural hardwood. Soil waters under tension are higher in conductivity and ion concentration than those of under zero-tension. Soils are better Structured and the fertility is higher under less disturbed natural forest than under secondary forest and plantation.