Abstract
摘要:土壤的空間變異可概括分為系統性與隨機性變異。系統性變異為由於地形地貌的變化與土壤生成因子間的交互作用所造成之土壤性質的改變,因此,地形土序(toposequence)的變化在土壤空間變異的研究上非常重要。土壤溶液是個移動相,為土壤中溶質重新分布的主因,並控制和反應出土壤剖面的生成化育的作用,在土壤生成化育的研究上,了解土壤溶液的組成(compositions)非常重要。本研究選擇陽明山國家公園之大屯山至其西北邊低地平原為研究區域,依90年度的研究結果,選擇1個典型的灰燼土、1個灰燼型的弱育土、1個典型的弱育土與1個典型的極育土,在不同的季節監測土壤水分與土壤溶液化學組成的變化。第二年度(91年度)主要的研究目的為(1)探討此地形土序中不同土壤類別之土壤溶液組成隨空間與時間的變動情形;(2)藉由不同類別土壤之土壤溶液組成分析,以了解此地形土序中典型灰燼土與典型極育土的化育作用,及了解灰燼土與極育土之過渡化育作用。研究結果發現:依據TDR現地量測的結果,灰燼土與極育土之土壤水分含量受東北季風的影響較大,而弱育土則因為土壤剖面所在之位置受到地形的屏障,減弱了東北季風對土壤水分含量的影響;在土
Abstract: The soil spatial variability generally included the systematic and random variability. Soil systematic variability is attributed to the change of soils located at the different geomorphic positions and their interaction between soil properties and soil formation factors. The soil variations of toposequence are very important to study the soil spatial variability. Soil solution is the mobile phase that controls the distribution of solutes within the soil system and also controls and reflects the pedogenic processes. It is very important to investigate the compositions of soil solution in the study of pedogeneic processes. The study area was selected from Tatung Mountain and their Northwestern area located in the Yangmingshan National Park. Based on the preliminary survey and analysis in the first year project (August, 2001 to July, 2002), one typic Andisol, one andic Inceptisol, one typic Inceptisol, and one typic Ultisol were selected to monitor the changes of soil moisture content and soil solution composition in the different seasons and diagnostic horizons. The objectives of this project are (1) to examine the spatial and temporal variability of soil solution compositions along this toposequence; (2) to recognize the pedogenesis of typic Andisol, typic Ultisol and the transition soils of Andisol and Ultisol based on the soil solution compositions. The results of this study suggest that the north-eastern monsoon greatly affect the soil moisture content of Andisol and Ultisol based on the results of TDR determined in-situ. Inceptisol was slightly affected by north-eastern monsoon because of the barrier of landscape in the study area. For the soil solution compositions, the depth distribution of different ions was similar within four soil pedons and the concentration of ions was higher in the surface soil and decreased gradually with soil depth. Most of the concentration of cations and anions was less than 200~250 μmol(+)/L and 100 μmol(+)/L, respectively. The higher concentration of Na and Cl (400~1000 μmol(+)/L and 400~800 μmol(+)/L, respectively) of this study area suggested that the soil was easily affected by the sea and it decreased with increasing the elevation and the distance far from the seashore. The concentrations of Fe, Al, and Si in soil solution were qualified as very low grade (Fe<20, Al<5, and Si<6 μmol(+)/L). The relationship analysis (r) of ions in soil solution also suggested that the source of Fe and Al of the soil solution in this study area probably come from the release of organic matter-bonded Fe and Al of soils. We need further studies to identify this proposal. The coefficient of variation (CV%) of soil moisture condition or the compositions of soil solution monitoring in the study area was higher in A horizon than B horizon. This result also indicated that the soil solution composition of A horizon was greatly affected by the soil environment. The concentration of Fe of soil solution could be regarded as one of the ind
Keyword(s)
地形土序
灰燼土
極育土
土壤溶液組成
土壤化育作用
空間與時間變異
Toposequence
Andisol
Ultisol
Soil solution composition
Pedogenesis
Spatial and temporal variability