Influence of land use and lithology on sources and ages of nutritional resources for stream macroinvertebrates: a multi-isotopic approach
Influence of land use and lithology on sources and ages of nutritional resources for stream macroinvertebrates: a multi-isotopic approach
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DOI：
10.1007/s00027-017-0542-3
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发表时间：
2017-06
期刊：
影响因子：
2.4
通讯作者：
Amber R. Bellamy;J. Bauer;A. Grottoli
中科院分区：
文献类型：
--
作者：
Amber R. Bellamy;J. Bauer;A. Grottoli
陆源碳（C）和有机物（OM）-通常具有显着的年龄-在许多溪流和河流中占主导地位，但很少有人知道它们对水生大型无脊椎动物消费者的潜在营养贡献。流域特征的影响（例如，土地利用和岩性）对水生消费者利用的C和OM的来源和年龄的影响也知之甚少。为了评估这些因素，大型无脊椎动物收集了6个源头流具有不同的流域岩性和土地利用的哈德逊-莫霍克河系统（纽约，美国）和分析天然δ 13 C，δ 15 N，δ 2 H，和δ 14 C。贝叶斯稳定同位素混合模型显示，本地初级生产占主导地位（62-92%）的生物量的所有功能摄食组（FFG）在所有网站，与外来来源的次要，但仍然显着（21-31%）的重要性。从低农业用地和高农业用地流域的溪流中收集的大型无脊椎动物估计分别同化0- 13%和4-31%的土壤来源的碳和有机质。富含页岩和缺乏页岩的大型无脊椎动物的δ 14 C值和表观年龄也存在显著差异（平均δ 14 C = −75和−34‰;等效δ 14 C年龄= 630和280年B. P.，分别）。列入14 C数据混合模型证实了本地初级生产的重要性，也表明间接岩性控制营养资源利用的影响流基质类型和潜在的保留外来C和OM。这项研究的结果进一步表明，本地与外来的贡献的相对大小的大型无脊椎动物取决于FFG，土地利用类型和岩性。
Terrestrially-derived carbon (C) and organic matter (OM)—often of significant age—dominate in many streams and rivers, yet little is known about their potential nutritional contributions to aquatic macroinvertebrate consumers. Impacts of watershed characteristics (e.g., land use and lithology) on the sources and ages of C and OM utilized by aquatic consumers are also poorly understood. To assess these factors, macroinvertebrates were collected from six headwater streams having different watershed lithologies and land uses in the Hudson-Mohawk River system (New York, USA) and analyzed for natural δ13C, δ15N, δ2H, and ∆14C. A Bayesian stable isotopic mixing model revealed that autochthonous primary production dominated (62–92%) the biomass of all functional feeding groups (FFGs) across all sites, with allochthonous sources being of secondary but still significant (21–31%) importance. Macroinvertebrates collected from streams in watersheds having low vs. high agricultural land use were estimated to assimilate 0–13 and 4–31% soil-derived C and OM, respectively. ∆14C values and apparent ages of macroinvertebrates from shale-rich and shale-poor sites were also significantly different (mean ∆14C = −75 and −34‰; equivalent14C ages = 630 and 280 years B.P., respectively). Inclusion of ∆14C data in mixing models confirmed the importance of autochthonous primary production, and also demonstrated indirect lithological control of nutritional resource utilization by influencing stream substrate type and potential retention of allochthonous C and OM. Findings from this study further showed that the relative magnitudes of autochthonous vs. allochthonous contributions to macroinvertebrates were dependent on FFG, land use type, and lithology.