Early Lake Ontogeny Following Neoglacial Ice Recession at Glacier Bay, Alaska

明尼苏达大学的丹尼尔·恩斯特罗姆博士和赫伯特·赖特博士提议对阿拉斯加冰川湾10000年前冰川衰退后的湖泊生态进行研究。这项调查将探索湖泊发育的最早阶段，与120年来的冰川消融时间序列上的植被和土壤的初级演替有关。重点将放在水化学、初级生产力和浮游植物组成的变化，以及流域地质和水文在调节从流域到湖泊的物质流动方面的影响。早期湖泊个体发育的问题将通过两种互补的研究策略来解决。(1)将比较已知年龄的湖泊和初级集水区演替的不同阶段的湖沼学条件，以及(2)来自这些相同趋势的沉积物岩心在个别地点的pH、碱度和藻类组成。将检验关于冰后早期土地/水相互作用的几个假设，包括(A)集水区土壤的逐渐淋溶使湖泊随着时间的推移变得更加酸性，(B)不同地点之间的水文和地质差异控制着湖泊变化的速度和方向，(C)与早期土壤形成相关的营养通量增加导致湖泊生产力的初步增加，(4)泥炭生长和区域沼泽化阻碍了土壤内部排水，导致地表水营养不良。这项工作对古岩溶学以及古生态学和一般生态学的学生都有很高的兴趣。如果把它放在当前对全球气候变化及其对生态系统和人造系统的影响的关注和关注的背景下，它就会变得更加重要。湖泊如何发展和稳定也是研究当代湖泊如何受到酸化干扰并从酸化中恢复的人感兴趣的。调查人员和他们的机构因在这一领域的工作而闻名于世。

Drs. Daniel Engstrom and Herbert Wright of the University of Minnesota propose a study of lake ecology following the glacial recession of 10,000 years ago in Glacier Bay, Alaska. This investigation will explore the earliest stages of lake development in relation to primary succession in vegetation and soils along a 120-year deglaciation chronosequence. Emphasis will be placed on changes in water chemistry, primary production and phytoplankton composition, and the influence of catchment geology and hydrology in regulating material flow from watershed to lake. The problem of early lake ontogeny will be attacked with two complementary research strategies. (1) Limnological conditions will be compared among lakes of known age and in different stages of primary catchment succession, and (2) sediment cores from these same trends in pH, alkalinity, and algal composition at individual sites. Several hypotheses concerning early postglacial land/water interactions will be tested, including (a) the progressive leaching of catchment soils makes lakes more acidic over time, (b) hydrologic and geologic differences among sites act to control the rates and direction of limnological change, (c) increased nutrient flux associated with early soil formation result in an initial increase in lake productivity, and (4) peat growth and regional paludification impede internal soil drainage and cause the dystrophication of surface waters. This work has high interests for students of paleolimnology in particular and paleoecology and ecology in general. It gains in significance when placed in context of current interests and concerns about global climatic change and its influence on ecosystems and man-made systems. How lakes develop and stabilize is also of interest to those studying how contemporary lakes are disturbed by and recover from acidification. The investigators and their institution are world renowed for their work in this area.