Abstract:
Among many ecological services provided by mangrove ecosystems, soil organic carbon (SOC) storages have recently received much attention owing to the increasing atmospheric partial pressure of dissolved CO2 (pCO2). Bacteria are fundamental to ecosystem functions and strongly influence the coupling of coastal carbon, nitrogen, and sulfur cycling in soils. The SOC storage and bacterial communities along a restored mangrove soil chronosequence in the Jiulong River Estuary were explored using the 16S rDNA sequencing technique. The results showed the SOC storage in the 100 cm soil profile was 103.31 ± 5.87 kg C m-2 and 93.10 ± 11.28 kg C m-2 for mangroves with afforestation ages of 36 and 60 years, respectively. The total nitrogen (TN) and total sulfur (TS) contents exhibited significant correlations with the SOC in the mangrove soils, but only TN and SOC showed significant correlation in tidal flat soils. Although the tidal flats and mangroves occupied the contiguous intertidal zone within several kilometers, the variations in the SOC storage along the restored mangrove soil chronosequence were notably higher. The Functional Annotation of Prokaryotic Taxa (FAPROTAX) database was used to annotate the metabolic functions of the bacteria in the soils. The annotation revealed that only four metabolic functions were enriched with a higher relative abundance of the corresponding bacteria, and these enriched functions were largely associated with sulfate reduction. In addition, the specifically critical bacterial taxa that were associated with the SOC accumulation and nutrient cycling, shaped the distinct metabolic functions, and consequently facilitated the SOC accumulation in the mangrove soils with various afforestation ages. The general homogenization of the microbial community and composition along the intertidal soil chronosequence was primarily driven by the reciprocating tidal flows and geographical contiguity.
摘要:
在红树林生态系统提供的许多生态服务中,由于溶解的CO2(pCO2)的大气分压增加,土壤有机碳(SOC)存储最近受到了广泛关注。细菌是生态系统功能的基础,并强烈影响沿海碳的耦合,氮,和土壤中的硫循环。使用16SrDNA测序技术探索了九龙江河口恢复的红树林土壤时间序列沿线的SOC存储和细菌群落。结果表明,造林年龄为36年和60年的红树林在100cm土壤剖面中的SOC储量为103.31±5.87kgCm-2和93.10±11.28kgCm-2,分别。在红树林土壤中,总氮(TN)和总硫(TS)含量与SOC显着相关。但在潮滩土壤中,只有TN和SOC表现出显著的相关性。尽管潮滩和红树林在几公里内占据了毗邻的潮间带,沿恢复的红树林土壤时间序列的SOC存储变化明显更高。原核分类群功能注释(FAPROTAX)数据库用于注释土壤中细菌的代谢功能。注释显示,只有四种代谢功能富集了相对丰度较高的相应细菌,这些丰富的功能在很大程度上与硫酸盐还原有关。此外,与SOC积累和养分循环相关的特别关键的细菌类群,塑造了独特的代谢功能,从而促进了不同造林年龄的红树林土壤中SOC的积累。沿潮间带土壤时间序列的微生物群落和组成的总体均匀化主要是由往复潮汐流和地理连续性驱动的。