Aeolian nutrient fluxes following wildfire in sagebrush steppe: Implications for soil carbon storage
Aeolian nutrient fluxes following wildfire in sagebrush steppe: Implications for soil carbon storage
复制标题
鼠尾草草原野火后的风沙养分通量：对土壤碳储存的影响
DOI：
10.5194/bg-8-3649-2011
复制
发表时间：
2011
期刊：
影响因子：
4.9
通讯作者：
N. Glenn
中科院分区：
文献类型：
--
作者：
N. Hasselquist;M. Germino;J. Sankey;L. Ingram;N. Glenn
在半干旱和干旱生态系统中，火灾后风沙输送的脉冲可能会基本影响营养物质的生物地球化学循环。我们的目标是在美国爱达荷州南部半干旱的鼠尾草草原生态系统的一场野火后发生的风沙输送的间歇性脉冲期间，阻止在跃变区发生的水平营养通量。我们还研究了营养盐通量的时间趋势如何受到侵蚀物质颗粒大小的变化以及与不同粒度类别相关的营养物质浓度的影响。在火烧后的最初几个月里，火烧区的总碳(C)和氮(N)通量分别高达235gCm1d1和19gNm1d1，而邻近的未烧失区的C和N通量几乎可以忽略不计。火后碳、氮通量的瞬变很大程度上归因于跃迁大小的颗粒的重新分布。火烧一年后，土壤表层全氮和有机碳浓度显著低于未火烧区。我们的结果表明，火灾后风沙输送的周期性脉冲如何影响土壤C和N的空间分布，这反过来又可能对土壤C的储存产生重要影响。这些发现表明，生态干扰可以加剧地貌过程，并突出了进一步研究的必要性，以更好地了解风沙输送在最近燃烧的景观中C和N的生物地球化学循环中所起的作用。
Pulses of aeolian transport following fire can pro- foundly affect the biogeochemical cycling of nutrients in semi-arid and arid ecosystems. Our objective was to deter- mine horizontal nutrient fluxes occurring in the saltation zone during an episodic pulse of aeolian transport that occurred following a wildfire in a semi-arid sagebrush steppe ecosys- tem in southern Idaho, USA. We also examined how tempo- ral trends in nutrient fluxes were affected by changes in par- ticle sizes of eroded mass as well as nutrient concentrations associated with different particle size classes. In the burned area, total carbon (C) and nitrogen (N) fluxes were as high as 235 g C m 1 d 1 and 19 g N m 1 d 1 during the first few months following fire, whereas C and N fluxes were negligi- ble in an adjacent unburned area throughout the study. Tem- poral variation in C and N fluxes following fire was largely attributable to the redistribution of saltation-sized particles. Total N and organic C concentrations in the soil surface were significantly lower in the burned relative to the unburned area one year after fire. Our results show how an episodic pulse of aeolian transport following fire can affect the spatial dis- tribution of soil C and N, which, in turn, can have important implications for soil C storage. These findings demonstrate how an ecological disturbance can exacerbate a geomorphic process and highlight the need for further research to bet- ter understand the role aeolian transport plays in the biogeo- chemical cycling of C and N in recently burned landscapes.