台灣南部泥岩惡地形土壤之化育作用與分類

Genesis and Classification of the Soils on the Mudstone Bad-landscape in the Southern Taiwan

許正一(Zeng-Yei Hseu) ； 賴美君(Mei-Chun Lai) ； 林盈成(Yin-Chen Lin) ； 駱佩如(Pei-Ru Lo)

《土壤與環境》 5卷4期 (2002/12) Pp. 323-329

https://doi.org/10.30058/SE.200212.0007

摘要

台灣泥岩惡地形土壤主要分佈在西南及東部地區，面積約1,000 km2。泥岩土壤因膠結作用較差，容易造成土壤沖蝕且植物不易生長。目前國內尚欠缺有關泥岩土壤育作用與分類之探討，因此本研究在高雄縣田寮鄉一古亭坑層土壤地形序列，上，選擇山頂（summit）、背坡（backslope）及趾坡（footslope）之土壤剖面，探討其形態特徵與理化性質，建立泥岩土壤之化育作用模式，並以美國土壤新分類系統（Soil Taxonomy）分類泥岩土壤，以期提供生態環境保育及植生復育之參考。結果顯示，三個剖面之B層土壤粘粒含量均在40%以上，但僅符合變育層（cambic horizon）之要求。三個剖面之土壤構造皆以強而大尺寸的角塊狀構造為主，且非常緊密，總體密度極高，但仍可發現大小不同的植根與生物孔洞。所有化育層之EC值均大於2.0 dS/m，且鈉含量高於一般土壤。以土壤形態與化育作用之觀點來看，本研究之剖面確已化育形成A及B層，不應只視為母質，而是一種土壤。山頂與背坡剖面可分類為粘質的混合型礦物炎熱的典型簡育暫乾弱育土的混合型礦物炎熱的典型簡育暫乾弱育土（Clayey, mixed, hyperthermic, Typic Haplustepts），而趾坡剖面則因粘粒含量較少而分類為壤質的混合型礦物炎熱的典型簡育暫乾弱育土（Loamy, mixed, hyperthermic, Typic Haplustepts）。

關鍵字

泥岩 ； 惡地形 ； 化育作用 ； 土壤分類

並列摘要

The soils of mudstone bad-land in Taiwan are mainly distributed in the south-western and eastern regions with about 1,000 km2. The mudstone soils are characterized by poor cementation, high erosibility and constrained planting. Less studies were conducted in the genesis and classification of the mudstone soils. Three soil pedons on the summit, backslope and footslope were selected in this study along a mudstone toposequence at Tien-Liao, Kaohsing, south-western Taiwan. The objectives are (i) to study the morphological characteristics and properties, (ii) to interpret the genetic processes, and (iii) to classify the mudstone that the clay contents were more than 40% in the Bhorizons of the summit and backslope pedons. They only met the requirement of cambic horizon. Strong and large angular blocky structures were found in all three pedons. The soils with high bulk density were very firm, but firm, but some roots and biopores were found. Electrical conductivity (EC) values in all the horizions with high content of exchangeable Na were more than 2 dS/m. Based on morphology and genesis, clear A and B horizons were identified. Therefore, the study profiles are truly soils, not parent materials. The pedons on the summit and backslope are classified as Clayey, mixed, hyperthermic, Typic Haplustepts, and the pedon on the footslope as Loamy, mixed, hyperthermic, Typic Haplustepts.

並列關鍵字

mudstone ； bad-land ； genesis ； soil classification