Plant community composition influences fine root production and biomass allocation in perennial bioenergy cropping systems of the upper Midwest, USA
Plant community composition influences fine root production and biomass allocation in perennial bioenergy cropping systems of the upper Midwest, USA
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DOI：
10.1016/j.biombioe.2017.07.007
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发表时间：
2017-10
影响因子：
6
通讯作者：
Christine D. Sprunger;L. Oates;R. Jackson;G. Robertson
中科院分区：
文献类型：
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作者：
Christine D. Sprunger;L. Oates;R. Jackson;G. Robertson
细根在全球碳(C)循环中起着关键作用，因为土壤中大量的碳积累是细根生产和周转的结果。本研究探讨了植物群落组成和多样性对表层土壤细根产量的影响，以及6种不同组成和多样性的多年生作物系统中植物生物量分配给细根的影响。6个系统于2008年在美国中西部北部的一个高肥力和中等肥力地点建立，包括：柳枝稷（Panicum virgatum）、芒草（Miscanthus×giganteus）、杂交杨树（Populus nigra×P）。maxmowiczii ' NM6)、原生禾本科植物（andropogon gerardii、Elymus canadensis、P. virgatum、Schizachrium scoparium和sorghastrum nutans的5种组合）、早期演替系统，以及一个由25种已播草、豆科植物和草本植物组成的恢复草原。在三年的时间里（2011-2013），每年春天在这两个地点部署inggrowth核心；一半在季节中期提取，其余在深秋提取。在这两个地点，原生草地和恢复草原系统比其他种植系统在季中产生的细根多31-77%。芒萁和杂交杨树的细根产量最低。除柳枝稷在低肥力地外，混作种植制度将39-94%的能量分配给细根的生产。研究结果表明，与单一栽培相比，不同的生物燃料种植系统更有可能将地下的碳分配给细根，这可能对土壤碳封存产生影响。
Fine roots play a key role in the global carbon (C) cycle because much of the C accumulating in soil is the result of fine root production and turnover. Here we explore the effect of plant community composition and diversity on fine root production in surface soils and plant biomass allocation to fine roots in six perennial cropping systems differing in composition and diversity planted as biofuel feedstocks. The six systems were established in 2008 at both a high and a moderate fertility site located in the upper Midwest, USA and included: switchgrass (Panicum virgatum), miscanthus (Miscanthus×giganteus), hybrid poplar (Populus nigra×P. maximowiczii ‘NM6), native grasses (a five-species assemblage ofAndropogon gerardii, Elymus canadensis, P. virgatum, Schizachrium scoparium,andSorghastrum nutans), an early successional system, and a restored prairie with 25 sown grass, legume, and forb species. For three years (2011–2013) at both sites ingrowth cores were deployed each spring; half were extracted at mid-season and the rest in late fall. Native grasses and restored prairie systems produced 31–77% more fine roots by mid-season compared to the other cropping systems at both sites. Miscanthus and hybrid poplars tended to have the lowest fine root production. The polyculture cropping systems allocated 39–94% more energy to the production of fine roots, with the exception of switchgrass at the low fertility site. Findings demonstrate a greater potential for diverse biofuel cropping systems to allocate C belowground to fine roots as compared to monocultures, with potential implications for soil C sequestration.