Laboratorio de Fotobiología, INIBIOMA (UNComahue-CONICET), Quintral 1250, R8400FRF, S. C de Bariloche, Río Negro, Argentina.
Laboratorio de Fotobiología, INIBIOMA (UNComahue-CONICET), Quintral 1250, R8400FRF, S. C de Bariloche, Río Negro, Argentina.
Sci Total Environ. 2015 Jul 15;521-522:280-92. doi: 10.1016/j.scitotenv.2015.03.102. Epub 2015 Apr 3.
Fluvial networks transport a substantial fraction of the terrestrial production, contributing to the global carbon cycle and being shaped by hydrologic, natural and anthropogenic factors. In this investigation, four Andean Patagonian oligotrophic streams connecting a forested catchment (~125km(2)) and draining to a double-basin large and deep lake (Lake Moreno complex, Northwestern Patagonia), were surveyed to analyze the dynamics of the allochthonous subsidy. The results of a 30month survey showed that the catchment supplies nutrients and dissolved organic matter (DOM) to the streams. The eruption of the Puyehue-Cordón Caulle at the beginning of the study overlapped with seasonal precipitation events. The largest terrestrial input was timed with precipitation which increased particulate materials, nutrients and DOM through enhanced runoff. Baseline suspended solids and nutrients were very low in all the streams (suspended solids: ~1mg/L; total nitrogen: ~0.02mg/L; total phosphorus: ~5μg/L), increasing several fold with runoff. Baseline dissolved organic carbon concentrations (DOC) ranged between 0.15 and 1mg/L peaking up to three-fold. Chromophoric and fluorescent analyses characterized the DOM as of large molecular weight and high aromaticity. Parallel factor modeling (PARAFAC) of DOM fluorescence matrices revealed three components of terrestrial origin, with certain degree of microbial processing: C1 and C2 (terrestrial humic-like compounds) and C3 (protein-like and pigment derived compounds). Seasonal changes in MOD quality represent different breakdown stages of the allochthonous DOM. Our survey allowed us to record and discuss the effects of the Puyehue-Cordón Caulle eruption, showing that due to the high slopes, high current and discharge of the streams the volcanic material was rapidly exported to the Moreno Lake complex. Overall, this survey underscores the magnitude and timing of the allochthonous input revealing the terrestrial subsidy to food webs in Patagonian freshwaters, which are among the most oligotrophic systems of the world.
河流网络输送了大量的陆地产物，促进了全球碳循环，并受到水文、自然和人为因素的影响。在这项研究中，我们调查了连接森林流域（约 125km²）并流入双盆地大型深湖（北巴塔哥尼亚莫雷诺湖复合体）的四条安第斯巴塔哥尼亚寡营养溪流，以分析异源补贴的动态。30 个月的调查结果表明，集水区向溪流供应养分和溶解有机物质（DOM）。研究开始时普耶韦-科登-卡勒火山的喷发与季节性降水事件重叠。最大的陆地输入与增加颗粒物质、养分和 DOM 的增强径流同步发生。所有溪流的悬浮固体和养分基线都非常低（悬浮固体：约 1mg/L；总氮：约 0.02mg/L；总磷：约 5μg/L），随着径流量的增加增加了数倍。基线溶解有机碳浓度（DOC）范围在 0.15 和 1mg/L 之间，峰值增加了三倍。色氨酸和荧光分析将 DOM 特征化为大分子量和高芳香度。DOM 荧光矩阵的平行因子模型（PARAFAC）揭示了三种具有一定微生物处理程度的陆地起源成分：C1 和 C2（陆地腐殖质样化合物）和 C3（蛋白质样和色素衍生化合物）。MOD 质量的季节性变化代表了异源 DOM 的不同分解阶段。我们的调查允许我们记录和讨论普耶韦-科登-卡勒火山喷发的影响，表明由于溪流的高坡度、高电流和流量，火山物质迅速被输送到莫雷诺湖复合体。总的来说，这项调查强调了异源输入的规模和时间，揭示了巴塔哥尼亚淡水食物网的陆地补贴，这是世界上最寡营养的系统之一。
