鹽鹼灘

鹽鹼灘，又稱鹽沼，是沿海潮間帶和陸地間的一種生態系統，海水或鹹水有規律地湧入流出地帶。這一地帶主要生長鹽土植物。Adam, P (1990). Saltmarsh Ecology. Cambridge University Press. New York.Woodroffe, CD (2002). Coasts: form, process and evolution. Cambridge University Press. New York.這些植物是陸生植物且耐鹽鹼。在水域食物鏈及海陸營養交換中鹽鹼灘扮演著重要的地位，此外次地帶也為一些陸地生物的生存提供了支持。同時它起著海岸保護的作用。

鹽鹼灘常出現在溫帶和極地的海岸線上，Allen, JRL, Pye, K (1992). Saltmarshes: morphodynamics, conservation, and engineering significance. Cambridge University Press. Cambridge, UK.有穩固、形成和淹沒三種狀態。通常鹽鹼灘有河流帶來的沉積物形成的砂基或泥基，Chapman, V. J. (1974). Salt marshes and salt deserts of the world. Phyllis Claire Chapman, Germany.且處於障壁島、路堤、河口等有遮蔽之處。熱帶和亞熱帶因有紅樹林而不易形成鹽鹼灘，因為後者的生態是以草本植物為主導的。Adam, P (1990). Saltmarsh Ecology. Cambridge University Press. New York.

大多數鹽鹼灘的地勢和海拔都很低，因為地帶空曠，所以常有大量人口聚集。Bromberg-Gedan, K., Silliman, B. R., and Bertness, M. D. (2009). Centuries of human driven change in salt marsh ecosystems, Annual Review of Marine Science, 1: 117-141.根據實際地貌的差異，鹽鹼灘又可分為三角洲、開闊海岸、海灣和溺灣等等。歐洲等河流眾多之處常見有三角洲鹽鹼灘。Woodroffe, CD (2002). Coasts: form, process and evolution. Cambridge University Press. New York.Te Ara - The Encyclopedia of New Zealand (2005-2010). Plants of the Estuary . Retrieved 15 March 2010

成因

潮灘隨著沉積物不斷堆積而升高，漸漸可以生長植物，Pethick, J. (1984). An introduction to coastal geomorphology. Edward Arnold, London.隨著先鋒種繁殖體的到達，此地生態開始改善。河流帶來懸浮泥沙，藍綠藻可以固著沉積物，Ginsburg, R. N., and Lowenstam, H. A. (1958). The influence of marine bottom communities on the depositional environment of sediments. The Journal of Geology, 66: (3), 310-318.加上新生的植物，Bird, E. (2008). Coastal geomorphology: an introduction. John Wiley & Sons Ltd, West Sussex, England.更使得堤岸愈來愈穩固。Aspden, R. J., Vardy, S. and Paterson, D. M. (2004). Salt marsh microbial ecology: microbes, benthic mats and sediment movement. In Fagherazzi, S., Marani, M. and Blum, L. K. (Eds), The Ecogeomorphology of Tidal Marshes (pp. 115-136). American Geophysical Union, Washington, DC.

潮汐與植被帶
沿海鹽鹼地與普通土地最大的區別在於其每日都有潮汐沖刷，造成該地持續積水。這對鹽鹼地的營養積累有著重要積極影響。除去這些低沼澤外，高沼澤因為地勢較高可以減少潮汐沖刷的影響，因而鹽度較低。實際上鹽鹼灘的鹽度依據氣候時間的不同也會發生變化，例如下雨可以減少鹽度而蒸發則使其增加。因此根據生理適應能力的不同，該地帶會形成不同的小環境。一般來說地勢較低處的植被耐鹽鹼度較高，也可以承受水的浸泡。Bertness, MD, Ewanchuk, PJ, Silliman, BR (2002). Anthropogenic modification of New England salt marsh landscapes. Proceedings of the National Academy of Sciences 99(3): 1395-1398.Rand, TA (2000). Seed Dispersal, Habitat Suitability and the Distribution of Halophytes across a Salt Marsh Tidal Gradient. Journal of Ecology 88(4): 608-621.

參考文獻

外部連結

Friends of Famosa Slough
Geography resource for schools
Johnson, CY (2006). Cause sought as marshes turn into barren flats. The Boston Globe.
Marine Nature Study Area operated by the Town of Hempstead: Dept. of Conservation & Waterways, located in Oceanside, New York, USA
New England Sudden Wetland Dieback
Salt Marsh Nature Center located in the Marine Park section of Brooklyn, New York, USA

Category:土壤
Category:湿地
Category:生態區域
Category:海岸地理學