Bacterioplankton dispersal and biogeochemical function across Alaskan Arctic catchments
Bacterioplankton dispersal and biogeochemical function across Alaskan Arctic catchments
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阿拉斯加北极流域浮游细菌的扩散和生物地球化学功能
DOI：
10.1111/1462-2920.16259
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发表时间：
2022
影响因子：
5.1
通讯作者：
Bowden, William B.
中科院分区：
文献类型：
--
作者：
Lee, Raymond M.;Griffin, Natasha;Jones, Erin;Abbott, Benjamin W.;Frei, Rebecca J.;Bratsman, Samuel;Proteau, Mary;Errigo, Isabella M.;Shogren, Arial;Bowden, William B.
在北极集水区，浮游细菌通过土壤和溪流分散，两者都季节性地冻结和解冻/流动。为了表征这种分散及其对生态地球化学的潜在影响，我们收集了浮游细菌，并在融雪期间和植被衰老后，在高山，苔原和苔原为主的湖泊集水区的多个溪流中测量了溪流的物理化学。在所有集水区，在社区组成的差异与季节性解冻，然后附着状态（即自由浮动或沉积物相关），然后流秩序。浮游细菌的分类多样性和丰富度升高沉积物相关的馏分和高阶达到融雪。科Chthonomonadaceae，梨单胞菌科，和Xiphinematobacteraceae之间的季节差异很大，而Flavobacteriaceae和Microsillaceae之间的自由浮动和沉积物相关的馏分差异很大。物理化学数据表明，有高铁（Fe+）生产（高山流域）;铁+生产和氯（Cl−）去除（苔原流域）;和磷（SRP）去除和铵（NH 4+）生产（湖泊流域）。在苔原景观中，这些“热点”的Fe+生产和Cl−去除伴随着物种丰富度的变化，而SRP促进了先行群落。我们的研究结果表明，淡水增加了细菌从源头集水区到接收集水区的扩散，在那里浮游细菌-矿物关系稳定了自由流动河段的群落，但浮游细菌-营养关系稳定了那些被湖泊打断的群落。
In Arctic catchments, bacterioplankton are dispersed through soils and streams, both of which freeze and thaw/flow in phase, seasonally. To characterize this dispersal and its potential impact on biogeochemistry, we collected bacterioplankton and measured stream physicochemistry during snowmelt and after vegetation senescence across multiple stream orders in alpine, tundra, and tundra‐dominated‐by‐lakes catchments. In all catchments, differences in community composition were associated with seasonal thaw, then attachment status (i.e. free floating or sediment associated), and then stream order. Bacterioplankton taxonomic diversity and richness were elevated in sediment‐associated fractions and in higher‐order reaches during snowmelt. FamiliesChthonomonadaceae,Pyrinomonadaceae, andXiphinematobacteraceaewere abundantly different across seasons, whileFlavobacteriaceaeandMicroscillaceaewere abundantly different between free‐floating and sediment‐associated fractions. Physicochemical data suggested there was high iron (Fe+) production (alpine catchment); Fe+production and chloride (Cl−) removal (tundra catchment); and phosphorus (SRP) removal and ammonium (NH4+) production (lake catchment). In tundra landscapes, these ‘hot spots’ of Fe+production and Cl−removal accompanied shifts in species richness, while SRP promoted the antecedent community. Our findings suggest that freshet increases bacterial dispersal from headwater catchments to receiving catchments, where bacterioplankton‐mineral relations stabilized communities in free‐flowing reaches, but bacterioplankton‐nutrient relations stabilized those punctuated by lakes.