Institute of Wetland Research, Chinese Academy of Forestry, Beijing, 100091, China.
Beijing Key Laboratory of Wetland Services and Restoration, Beijing, 100091, China.
Sci Rep. 2019 Sep 25;9(1):13813. doi: 10.1038/s41598-019-50161-9.
Plant litter is an important component in wetland ecosystems, and the role of plant litter decomposition is considered to be important for wetland ecosystem functions and services. However, the consequences of litter inputs have seldom been experimentally tested in real ecosystems such as constructed wetlands (CWs). The enriched nutrients in CWs might weaken the role of litter inputs on soil carbon and nitrogen cycling. Here, we conducted a two-month field experiment to examine the effects of litter inputs on the soils in CWs. Our results showed that litter inputs significantly affected soil microbial (bacterial and fungi) diversities and properties (soil total nitrogen and nitrogen isotopes), and litter species with higher stoichiometry ratios, i.e. C/N, C/P and N/P led to higher microbial diversities. However, litter species had no or weak effects on microbial activities (CO and CH flux) or on the relative abundance of microbial communities, indicating that other environmental factors in such a CW might have stronger effects on those factors than litter inputs. These results highlighted the importance of submerged plant litter in nutrient-rich wetland ecosystems and provide potential tools for managers to improve the ecosystem functions and/or services via altering microbial diversities.
植物凋落物是湿地生态系统的重要组成部分，植物凋落物分解被认为对湿地生态系统功能和服务很重要。然而，在人工湿地（CWs）等实际生态系统中，很少有实验来检验凋落物输入的后果。CWs 中丰富的养分可能会削弱凋落物输入对土壤碳氮循环的作用。在这里，我们进行了为期两个月的野外实验，以检验凋落物输入对 CW 土壤的影响。我们的结果表明，凋落物输入显著影响了土壤微生物（细菌和真菌）的多样性和性质（土壤总氮和氮同位素），而具有更高化学计量比（即 C/N、C/P 和 N/P）的凋落物物种导致更高的微生物多样性。然而，凋落物物种对微生物活性（CO 和 CH 通量）或微生物群落的相对丰度没有或只有微弱的影响，这表明 CW 中的其他环境因素对这些因素的影响可能比凋落物输入更强。这些结果强调了富营养化湿地生态系统中淹没植物凋落物的重要性，并为管理者提供了通过改变微生物多样性来改善生态系统功能和/或服务的潜在工具。
