Plant diversity and grasses increase root biomass in a rainfall and grassland diversity manipulation
Plant diversity and grasses increase root biomass in a rainfall and grassland diversity manipulation
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DOI：
10.3389/fevo.2023.1259809
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发表时间：
2023-11
影响因子：
3
通讯作者：
L. Podzikowski;Megan M. Heffernan;James D. Bever
中科院分区：
文献类型：
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作者：
L. Podzikowski;Megan M. Heffernan;James D. Bever
植物生产力随多样性下降而丧失是众所周知的，其影响超过了包括干旱在内的其他全球变化驱动因素。这些模式最明显地是针对地上生产力而建立的，但与多样性相关的生产力增长是否在地下也得到了复制，人们仍然知之甚少。为了解决这一差距，我们于 2018 年建立了植物多样性操纵实验。这是对植物物种丰富度、群落组成以及降水的全面因子操纵。建立三年和五年后，从每个地块收集并合成两个散装土芯（20厘米深），并进行根部处理以确定作为根系作物的地下生物量。我们观察到丰富度与地上产量和地下生物量之间存在很强的正相关关系，从而产生了地上和地下多样性的正组合。从第三年到第五年，根茎作物增加了 1.4 倍。草群落产生更多的根系生物量（单一栽培平均为 463.9 ± 410.3g m−2），并且在这些群落中，丰富度和根系作物之间的关系程度最大。豆科植物群落产生的根最少（单一栽培平均 212.2 ± 155.1g m−2），地下直立作物不受多样性的影响。在低降水条件下，第三年的根部作物增加了 1.8 倍，而在第五年，我们观察到降水处理之间的根部作物相当。植物科是通过多样性观察到的地下生物量增加的强调节因素，与单一物种群落相比，单科草科和紫苑科在六个中产生的根直立作物高出 1.7 倍，在单科和多科群落中均观察到多样性与地上产量之间的关系。与单一栽培的平均根生物量相比，来自多个科的物种的多样化群落仅产生 1.3 倍的根系作物。我们令人惊讶地观察到，不同的单科群落可以产生超过不同多科群落产生的根直立作物的增加，这凸显了植物科内植物丰富度对于特定群落的重要性。这些模式对于理解多个全球变化驱动因素的相互作用具有潜在意义，因为降水和植物群落组成的变化确实会改变地上植物生产是否转化为地下生物量。
The loss of plant productivity with declining diversity is well established, exceeding other global change drivers including drought. These patterns are most clearly established for aboveground productivity, it remains poorly understood whether productivity increases associated with diversity are replicated belowground. To address this gap, we established a plant diversity-manipulation experiment in 2018. It is a full factorial manipulation of plant species richness and community composition, and precipitation. Three and five years post-establishment, two bulk soil cores (20cm depth) were collected and composited from each plot and were processed for roots to determine belowground biomass as root standing crop. We observed a strong positive relationship between richness and aboveground production and belowground biomass, generating positive combined above and belowground with diversity. Root standing crop increased 1.4-fold from years three to five. Grass communities produced more root biomass (monoculture mean 463.9 ± 410.3g m−2), and the magnitude of the relationship between richness and root standing crop was greatest within those communities. Legume communities produced the fewest roots (monoculture mean 212.2 ± 155.1g m−2), and belowground standing crop was not affected by diversity. Root standing crops in year three were 1.8 times higher under low precipitation conditions, while in year five we observed comparable root standing crops between precipitation treatments. Plant family was a strong mediator of increased belowground biomass observed with diversity, with single family grass and aster families generating 1.7 times greater root standing crops in six compared to single species communities, relationships between diversity and aboveground production were consistently observed in both single-family and multiple family communities. Diverse communities with species from multiple families generated only 1.3 times the root standing crop compared to monoculture average root biomass. We surprisingly observe diverse single family communities can generate increases in root standing crops that exceed those generated by diverse multiple family communities, highlighting the importance of plant richness within plant family for a given community. These patterns have potential implications for understanding the interactions of multiple global change drivers as changes in both precipitation and plant community composition do alter whether plant production aboveground is translated belowground biomass.