墾丁高位珊瑚礁自然保留區土壤之化育作用與分類

Pedogenesis and Classification of Soils in the Kenting Uplifted Coral Reef Nature Reserve, Southern Taiwan

許正一(Zeng-Yei Hseu) ； 王相華(Hsiang-Hua Wang) ； 伍淑惠(Shu-Hui Wu) ； 張英琇(Ing-Shou Chang)

《台灣林業科學》 19卷2期 (2004/06) Pp. 153-164

https://doi.org/10.7075/TJFS.200406.0153

摘要

墾丁高位珊瑚礁自然保留區為台灣唯一完整保留的高位珊瑚森林生態系，但未曾進行土壤化育作用方面之探討。本研究依地形在保留區內選取5個代表性土壤剖面，其中CR-l剖面位於保留區邊緣之珊瑚礁與砂頁岩母岩交界處，CR-2與CR-5位於保留區內之礁頂，而CR-3與CR-4則位於保留區內之礁底。研究結果發現礁底土壤厚度遠大於礁頂土壤，而pH值、有機碳及碳酸鈣含量則以礁頂土壤較高。所有土壤粘粒幾乎都超過30%，這是因為高溫多雨的環境使粘粒與游離鐵在剖面中明顯移動，而礁底土壤之粘聚層更可發現各種型式之定位排列良好的粘粒膜等微形態學之洗入作用證據。雖然礁頂土壤之碳酸鈣含量稍高於礁底土壤，但整體來說碳酸鈣自珊瑚礁母質溶解後，在土體中並無發生再沉澱作用。根據美國土壤分類系統(Soil Taxonomy)，5個剖面分類至亞類為CR-l：淺的簡育濕潤淋餘土；CR-2與CR-5：典型高鹽基淡色弱育土；CR-3與CR-4：典型厚育濕潤淋餘土。

關鍵字

高位珊瑚礁 ； 土壤化育 ； 粘粒 ； 游離鐵 ； 土壤分類

並列摘要

The Kenting Uplified Coral Reef Nature Reserve (KUCRNR) is the only forest ecosystem of uplifted coral reef area which is well protected in Taiwan. No study has been conducted on soil genesis of the KUCRNR. Based on the landscape position, 5 representative soil pedons were selected in this study in order to exploit the soil properties and pedogenesis. The CR-1 pedon was located at the margin between the parent rock of coral reef and sand-shale; the CR-2 and CR-5 pedons were at the top of the coral reef; and the CR-3 and CR-4 pedons were at the bottom of the coral reef From the results, soil depths at the bottom of the coral reef were much thicker than those at the top. However, the pH values and organic carbon and carbonate contents of soils at the top of the coral reef were higher than those at the bottom. High clay contents were found in all soils because of strong illuviation of clay. Furthermore, translocation of clay and free Fe within the soil was significant. However, illuviation of clay was identified by differently oriented clay coatings in the argillic horizons by micromorphology. Calcium carbonate is being dissolved from the coral reef, but it has not reprecipitated in the soil. Based on the Soil Taxonomy, Subgroups of the 5 pedons are Lithic Hapludalf for CR-1, Typic Eutrochrepts for CR-2 and CR-5 and Typic Paleudalfs for CR-3 and CR-4.

並列關鍵字

uplifted coral reef ； soil genesis ； clay ； free iron ； soil classification