Grassland biodiversity restoration increases resistance of carbon fluxes to drought
Grassland biodiversity restoration increases resistance of carbon fluxes to drought
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DOI：
10.1111/1365-2664.13402
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发表时间：
2019-07-01
影响因子：
5.7
通讯作者：
Bardgett, Richard D.
中科院分区：
文献类型：
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作者：
Cole, Andrew J.;Griffiths, Robert I.;Bardgett, Richard D.
有证据表明，草原植物多样性的恢复不仅有利于生物多样性保护，还有利于生态系统服务的提供。虽然生物多样性 - 功能实验表明，植物多样性越高，植物生产力对极端气候的抵抗力就越强，但尚不清楚现实世界中草原恢复的管理措施是否同样能稳定生态系统对极端气候事件的反应。我们在英格兰北部进行了一项长期（23年）的田间实验，以验证旨在恢复生物多样性的管理措施能提高生态系统碳（C）通量对短期夏季干旱的抵抗力和恢复能力这一假设。通过测量在实验草地上模拟干旱时植物、土壤和微生物的反应来进行验证，在这些草地上，施肥和播撒种子的操作是为了提高植物物种多样性。停止施肥使植物物种丰富度略有增加。此外，停止施肥降低了植物总体生产力，并以草本植物和非禾本草本植物为代价促进了半寄生植物的生长。以生态系统呼吸来衡量的二氧化碳通量对干旱的抵抗力在未施肥的地块中更强，因为较低的植物生物量减少了水分需求，可能得益于半寄生植物比例的增加进一步降低了植物生物量。此外，豆科植物在干旱条件下增加，从而有助于植物生产力的整体抵抗力。无论恢复处理如何，土壤微生物碳和氮在重新湿润后的恢复都比土壤微生物群落组成的恢复更快，这表明土壤微生物群落对干旱具有较高的恢复力。综合与应用。这项研究表明，虽然草原多样性恢复管理提高了碳通量对干旱的抵抗力，但也降低了农业产量，这为土地管理者揭示了一种权衡。此外，通过长期恢复处理促进的豆科植物，可以通过增加生物量来帮助在干旱条件下维持植物群落的生产力。因此，草原管理策略不仅对生态系统过程有影响，而且对抵御极端天气事件的能力也有影响。
Evidence suggests that the restoration of plant diversity in grasslands not only brings benefits for biodiversity conservation, but also the delivery of ecosystem services. While biodiversity-function experiments show that greater plant diversity increases resistance of plant productivity to climate extremes, it is not known whether real-world management options for grassland restoration likewise stabilize ecosystem responses to extreme climate events. We used a long-term (23 year) field experiment in northern England to test the hypothesis that management aimed at biodiversity restoration increases the resistance and recovery of ecosystem carbon (C) fluxes to short-term summer drought. This was tested by measuring plant, soil and microbial responses to a simulated drought in experimental grassland plots where fertilizer application and seed addition have been managed to enhance plant species diversity. The cessation of fertilizer application brought about small increases in plant species richness. Additionally, cessation of fertilizer application reduced overall plant productivity and promoted hemi-parasitic plants at the expense of grasses and forbs. Resistance of CO2 fluxes to drought, measured as ecosystem respiration, was greater in non-fertilized plots, as lower plant biomass reduced water demand, likely aided by proportionally more hemi-parasitic plants further reducing plant biomass. Additionally, legumes increased under drought, thereby contributing to overall resistance of plant productivity. Recovery of soil microbial C and nitrogen was more rapid after rewetting than soil microbial community composition, irrespective of restoration treatment, suggesting high resilience of soil microbial communities to drought. Synthesis and applications. This study shows that while grassland diversity restoration management increases the resistance of carbon fluxes to drought, it also reduces agricultural yields, revealing a trade-off for land managers. Furthermore legumes, promoted through long-term restoration treatments, can help to maintain plant community productivity under drought by increasing their biomass. As such, grassland management strategies not only have consequences for ecosystem processes, but also the capacity to withstand extreme weather events.