Competing droughts affect dust delivery to Sierra Nevada
Competing droughts affect dust delivery to Sierra Nevada
复制标题
DOI：
10.1016/j.aeolia.2019.100545
复制
发表时间：
2019-12-01
期刊：
影响因子：
3.3
通讯作者：
Aronson, E. L.
中科院分区：
文献类型：
--
作者：
Aarons, S. M.;Arvin, L. J.;Aronson, E. L.
矿物尘埃的产生和输送在季节、逐年以及冰期 - 间冰期时间尺度上都与气候密切相关。现代尘埃循环受土壤湿度影响，而土壤湿度部分取决于干旱持续时间和严重程度。因此，全球和区域干旱会加剧尘埃的产生和输送，通过尘埃对生态系统养分输送的影响，降低生态系统对干扰的脆弱性。在这项研究中，我们利用锶和钕同位素，并结合2015年采集的现代尘埃样本中的微量元素浓度，来量化区域和全球供应的尘埃在向山地生态系统输送养分方面的作用。研究地点位于美国内华达山脉南部的一个海拔样带上，样本涵盖了2014年（Aciego等人，2017年）和2015年（本研究）的旱季，当时该地区正经历一场历史性干旱。我们研究的目的是量化在养分有限的地点，尘埃循环对短期变化的时空变异性和敏感性。我们发现，在2015年旱季，亚洲源对位于该海拔样带上的地点的尘埃贡献率在10% - 40%之间，并且重要的是，与区域尘埃源相比，在夏季生长季其重要性有所增加。这些变化可能与2015年亚洲的长期干旱有关，这凸显了尘埃产生和输送对干旱的敏感性以及陆地生态系统中尘埃输送的遥相关。
The generation and transport of mineral dust is strongly related to climate on seasonal, year-to-year, and glacial-interglacial timescales. The modern dust cycle is influenced by soil moisture, which is partly a function of drought duration and severity. The production and transport of dust can therefore be amplified by global and regional droughts, thereby moderating ecosystem vulnerability to disturbance through the influence of dust on nutrient delivery to ecosystems. In this work, we use strontium and neodymium isotopes in combination with trace element concentrations in modern dust samples collected in 2015 to quantify the role of regionally versus globally supplied dust in nutrient delivery to a montane ecosystem. The study sites lie along an elevational transect in the southern Sierra Nevada, USA, with samples spanning the dry seasons of 2014 (Aciego et al., 2017) and 2015 (this study), when the region was experiencing a historic drought. The goal of our research was to quantify the spatial and temporal variability and sensitivity of the dust cycle to short term changes at nutrient-limited sites. We find that, during the dry season of 2015, Asian sources contributed between 10 and 40% of dust to sites located along this elevational transect, and importantly increased in importance during the summer growing season compared to regional dust sources. These changes are likely related to the prolonged drought in Asia in 2015, highlighting both the sensitivity of dust production and transport to drought and the teleconnections of dust transport in terrestrial ecosystems.