Climatic controls on phosphorus concentrations in The Loch, Loch Vale Watershed, Rocky Mountain National Park, Colorado, USA since the last glacial maximum
Climatic controls on phosphorus concentrations in The Loch, Loch Vale Watershed, Rocky Mountain National Park, Colorado, USA since the last glacial maximum
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DOI：
10.1017/qua.2022.19
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发表时间：
2022-05
影响因子：
2.3
通讯作者：
J. Price;David W. Szymanski;Krista E. H. Slemmons;Mackenzie Eskey;Edward Johnson;S. Bricker
中科院分区：
文献类型：
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作者：
J. Price;David W. Szymanski;Krista E. H. Slemmons;Mackenzie Eskey;Edward Johnson;S. Bricker
摘要美国科罗拉多的高山-亚高山洛赫维尔流域（LVW）具有较高的P5+向地表沃茨的自然通量。对于1992-2018年，P5+浓度（[P5+]）高于检测限的溪流样本数量最多，出现在2008年，对应于最高的冻裂强度（FCI）。因此，相对寒冷的冬季和温暖的夏季，相对较低的年平均温度部分影响流[P5+]。沉积物岩心采集自LVW的出口湖洛赫。铁、铝和锰氧化物结合磷（吸附和自生磷酸盐; NP）可作为古湖泊[P5+]的替代测量。最高的NP在核心发生在寒冷和干燥的Allerød interstade。NP浓度最低的核心发生在气候非常潮湿的时期，在晚更新世和早全新世。因此，[P5+]在相对寒冷的冬季最高，随后是相对温暖的夏季，年平均温度相对较低，降雨量和/或冰冻圈融化相对较少。目前，LVW正在经历永久冰冻圈的变暖和融化，自2008年以来FCI迅速下降。这有可能大大减少LVW地表水生态系统中的[P5+]，降低生物生产力，增强磷限制，并增加生态系统对风成P5+的依赖。
Abstract The alpine–subalpine Loch Vale watershed (LVW) of Colorado, USA, has relatively high natural lithogenic P5+ fluxes to surface waters. For 1992–2018, the largest number of stream samples with P5+ concentrations ([P5+]) above detection limits occurred in 2008, corresponding with the highest frost-cracking intensity (FCI). Therefore, relatively cold winters and warm summers with a comparatively low mean annual temperature partly influence stream [P5+]. Sediment cores were collected from The Loch, an outlet lake of the LVW. Iron-, Al-, and Mn-oxide-bound phosphorus (adsorbed and authigenic phosphates; NP) serves as a proxy measurement for paleolake [P5+]. The highest NP in the core occurred during the cold and dry Allerød interstade. The lowest NP concentrations in the core occurred during climatically very wet periods in the Late Pleistocene and Early Holocene. Therefore, [P5+] are highest with relatively cold winters followed by relatively warm summers, relatively low mean annual temperatures, and relatively little rainfall and/or cryospheric melting. Currently the LVW is experiencing warming and melting of the permanent cryosphere with a rapidly declining FCI since 2008. This has the potential to dramatically decrease [P5+] in surface water ecosystems of the LVW, reducing biological productivity, enhancing P-limitation, and increasing ecosystem reliance on aeolian P5+.