Constraints to Ecosystem Development in High Arctic Polar Deserts

9300045布利斯这里概述的研究是1991年在加拿大德文郡贫瘠的高地高原上开始的一项研究的延续。本研究主要探讨土壤发育、隐花结皮和维管植物在极地沙漠形成中的相互作用。将继续对结壳和非结壳场地的宏观景观特征进行研究。 这项研究将扩大到包括石网和条纹的中尺度特征和这些特征在土壤风化过程中的作用，隐花植物结皮的建立和固氮，以及氮从结皮向土壤和维管植物的转移。将研究根系对寒冷、营养贫乏、霜冻扰动土壤的生理和生物力学适应，以及幼苗和成人的碳积累和水分关系的作用，因为这些方面涉及到极地沙漠广大地区维管植物的有限作用。年与年之间的巨大变化为这个高度压力的系统如何应对长期气候变化提供了线索。更好地了解广泛的，但很少了解极地沙漠系统对气候变化的反应将大大有助于在北极极地环境的全球变化的影响相关的计划目标。 ***

9300045 Bliss Research outlined here is a continuation of a study initiated in 1991 on the barren, upland plateau on Devon Island, Canada. This research focuses upon the interactive roles of soil development, and cryptogamic crust and vascular plant establishment and function in the formation of polar deserts. Research on the macroscale landscape features of crusted and non-crusted sites will continue. This study will be expanded to include the mesoscale features of stone nets and stripes and the role these features play in soil weathering processes, the establishment and nitrogen fixation of cryptogamic crusts, and the transfer of nitrogen from crusts to soils and vascular plants. The the physiological and biomechanical adaptations of root systems to cold, nutrient-poor, frosty disturbed soils, and the role of carbon accumulation and water rleations of seedlings and adults will be studied as these aspects relate to the limited role of vascular plants within vast areas of polar desert. The large year to year variability provides clues on how this highly stressful system may respond to longer term climate change. Better understanding the response to climate change of extensive, but little understood polar desert systems will contribute significantly to program goals related to the effect of global changes in the arctic polar environment. ***