Burdick D M, Mendelssohn I A
Laboratory for Wetland Soils and Sediments, Department of Marine Sciences, Center for Wetland Resources, Louisiana State University, 70803-7511, Baton Rouge, LA, USA.
Oecologia. 1987 Dec;74(3):321-329. doi: 10.1007/BF00378924.
Soil waterlogging responses were examined in three Spartina patens populations along a steep flooding gradient in coastal Louisiana. Root anatomy and physiological indicators of anaerobic metabolism were examined to identify and compare flooding responses in dune, swale and marsh populations, while soil physicochemical factors were measured to characterize the three habitats. Soil waterlogging increased along the gradient from dune to marsh habitats and was accompanied by increases in root porosity (aerenchyma). Aerenchyma in marsh roots was apparently insufficient to provide enough oxygen for aerobic respiratory demand, as indicated by high root alcohol dehydrogenase activities and low energy charge ratios. Patterns of root metabolic indicators suggest that dune and swale roots generally respired aerobically, while anaerobic metabolism was important in marsh roots. However, in each population, relatively greater soil waterloging was accompanied by differences in enzyme activities leading to malate accumulation. In dune and swale roots under these circumstances, depressed adenylate energy charge ratios may have been the result of an absence of increased ethanol fermentation. These trends suggest that: 1) Aerenchyma formation was an important, albeit incomplete, long-term adaptation to the prevalent degree of soil waterlogging. 2) All populations adjusted root metabolism in response to a relative (short-term) increase in soil waterlogging.
在路易斯安那州沿海一条陡峭的水淹梯度带上的三个互花米草种群中，研究了土壤渍水响应。对根的解剖结构和厌氧代谢的生理指标进行了检测，以识别和比较沙丘、洼地和沼泽种群的水淹响应，同时测定了土壤理化因子以表征这三种生境。从沙丘到沼泽生境，沿着梯度土壤渍水增加，同时根孔隙度（通气组织）也增加。沼泽根中的通气组织显然不足以满足有氧呼吸需求提供足够的氧气，高根乙醇脱氢酶活性和低能荷比表明了这一点。根代谢指标的模式表明，沙丘和洼地的根一般进行有氧呼吸，而厌氧代谢在沼泽根中很重要。然而，在每个种群中，相对较高的土壤渍水伴随着导致苹果酸积累的酶活性差异。在这种情况下，沙丘和洼地根中腺苷酸能荷比降低可能是乙醇发酵未增加的结果。这些趋势表明：1）通气组织的形成是对普遍的土壤渍水程度的一种重要的（尽管不完整）长期适应。2）所有种群都响应土壤渍水的相对（短期）增加而调整根代谢。
