Moreno-Jiménez Eduardo, Ochoa-Hueso Raúl, Plaza César, Aceña-Heras Sara, Flagmeier Maren, Elouali Fatima Z, Ochoa Victoria, Gozalo Beatriz, Lázaro Roberto, Maestre Fernando T
Department of Agricultural and Food Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Department of Biology, IVAGRO, University of Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Campus del Rio San Pedro, 11510, Puerto Real, Cádiz, Spain.
Commun Biol. 2020 Jun 24;3(1):325. doi: 10.1038/s42003-020-1054-6.
The availability of metallic nutrients in dryland soils, many of which are essential for the metabolism of soil organisms and vascular plants, may be altered due to climate change-driven increases in aridity. Biocrusts, soil surface communities dominated by lichens, bryophytes and cyanobacteria, are ecosystem engineers known to exert critical functions in dryland ecosystems. However, their role in regulating metallic nutrient availability under climate change is uncertain. Here, we evaluated whether well-developed biocrusts modulate metallic nutrient availability in response to 7 years of experimental warming and rainfall reduction in a Mediterranean dryland located in southeastern Spain. We found increases in the availability of K, Mg, Zn and Na under warming and rainfall exclusion. However, the presence of a well-developed biocrust cover buffered these effects, most likely because its constituents can uptake significant quantities of available metallic nutrients. Our findings suggest that biocrusts, a biotic community prevalent in drylands, exert an important role in preserving and protecting metallic nutrients in dryland soils from leaching and erosion. Therefore, we highlight the need to protect them to mitigate undesired effects of soil degradation driven by climate change in this globally expanding biome.
旱地土壤中金属养分的有效性，其中许多对土壤生物和维管植物的新陈代谢至关重要，可能会因气候变化导致的干旱加剧而改变。生物结皮是由地衣、苔藓和蓝细菌主导的土壤表面群落，是已知在旱地生态系统中发挥关键作用的生态系统工程师。然而，它们在气候变化下调节金属养分有效性方面的作用尚不确定。在此，我们评估了发育良好的生物结皮是否会响应西班牙东南部地中海旱地7年的实验性增温和降雨减少来调节金属养分的有效性。我们发现，在增温和降雨减少的情况下，钾、镁、锌和钠的有效性增加。然而，发育良好的生物结皮覆盖层缓冲了这些影响，很可能是因为其组成部分能够吸收大量的有效金属养分。我们的研究结果表明，生物结皮作为旱地普遍存在的生物群落，在保护旱地土壤中的金属养分免受淋溶和侵蚀方面发挥着重要作用。因此，我们强调需要保护它们，以减轻这种全球范围不断扩大的生物群落中由气候变化驱动的土壤退化的不良影响。
