Department of Soil and Water Conservation, CEBAS-CSIC, Murcia, Spain.
Department of Science and Agroforestry Technology and Genetics, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Albacete, Spain.
Glob Chang Biol. 2017 Oct;23(10):4185-4203. doi: 10.1111/gcb.13790. Epub 2017 Jul 6.
Climate change will affect semiarid ecosystems through severe droughts that increase the competition for resources in plant and microbial communities. In these habitats, adaptations to climate change may consist of thinning-that reduces competition for resources through a decrease in tree density and the promotion of plant survival. We deciphered the functional and phylogenetic responses of the microbial community to 6 years of drought induced by rainfall exclusion and how forest management affects its resistance to drought, in a semiarid forest ecosystem dominated by Pinus halepensis Mill. A multiOMIC approach was applied to reveal novel, community-based strategies in the face of climate change. The diversity and the composition of the total and active soil microbiome were evaluated by 16S rRNA gene (bacteria) and ITS (fungal) sequencing, and by metaproteomics. The microbial biomass was analyzed by phospholipid fatty acids (PLFAs), and the microbially mediated ecosystem multifunctionality was studied by the integration of soil enzyme activities related to the cycles of C, N, and P. The microbial biomass and ecosystem multifunctionality decreased in drought-plots, as a consequence of the lower soil moisture and poorer plant development, but this decrease was more notable in unthinned plots. The structure and diversity of the total bacterial community was unaffected by drought at phylum and order level, but did so at genus level, and was influenced by seasonality. However, the total fungal community and the active microbial community were more sensitive to drought and were related to ecosystem multifunctionality. Thinning in plots without drought increased the active diversity while the total diversity was not affected. Thinning promoted the resistance of ecosystem multifunctionality to drought through changes in the active microbial community. The integration of total and active microbiome analyses avoids misinterpretations of the links between the soil microbial community and climate change.
气候变化将通过加剧植物和微生物群落资源竞争的严重干旱影响半干旱生态系统。在这些栖息地中，适应气候变化的措施可能包括疏伐，通过降低树木密度和促进植物存活来减少资源竞争。我们通过排除降雨来引发干旱，对微生物群落的功能和系统发育响应进行了解读，以及森林管理如何影响其对干旱的抵抗力，研究地点为以 Pinus halepensis Mill. 为主的半干旱森林生态系统。采用多组学方法揭示了面对气候变化时基于群落的新策略。通过 16S rRNA 基因（细菌）和 ITS（真菌）测序以及宏蛋白质组学来评估总土壤和活性土壤微生物组的多样性和组成。通过磷脂脂肪酸（PLFA）分析微生物生物量，并通过整合与 C、N 和 P 循环相关的土壤酶活性来研究微生物介导的生态系统多功能性。由于土壤水分减少和植物发育不良，干旱样地中的微生物生物量和生态系统多功能性下降，但疏伐样地的下降更为显著。总细菌群落的结构和多样性在门和目水平上不受干旱影响，但在属水平上受到影响，且受季节性影响。然而，总真菌群落和活性微生物群落对干旱更为敏感，并与生态系统多功能性有关。干旱样地中的疏伐增加了活性多样性，而总多样性不受影响。疏伐通过改变活性微生物群落来提高生态系统多功能性对干旱的抵抗力。总微生物组和活性微生物组分析的整合避免了土壤微生物群落与气候变化之间联系的误解。
