Nitrogen cycling genes abundance in soil and aboveground compartments of tropical peatland cloud forests and a wetland on Réunion Island

作者：Fahad Ali Kazmi, Ülo Mander, Reti Ranniku, Maarja Öpik, Kersti Püssa, Kaido Soosaar, Kuno Kasak, Mohit Masta, Claudine Ah‐Peng, Mikk Espenberg · 发表于：Scientific Reports · 年份：2025 · DOI：10.1038/s41598-025-12367-y · 被引用次数：3 · 研究领域：Peatlands and Wetlands Ecology、Soil and Water Nutrient Dynamics、Soil Carbon and Nitrogen Dynamics

Abstract Peatland cloud forests, characterized by high altitude and humidity, are among the least-studied tropical ecosystems despite their significance for endemism and the bioavailable nitrogen (N) that can be emitted as N 2 O. While research has mainly focused on soil, the above-ground microbial N cycle remains largely unexplored. We quantified microbial N cycling genes across ecosystem compartments (soil, canopy soil, tree stems, and leaves) in relation to N 2 O and N 2 fluxes and soil physicochemical properties in two peatland cloud forests and a wetland on Réunion Island. Complete denitrification minimized N 2 O emissions and increased N 2 fluxes in wetland soils. In cloud forest soils, archaeal nitrification primarily produced nitrate (NO 3 – ), while low pH potentially slowed denitrification, resulting in minimal N 2 O emissions. Soil N-fixers were more abundant in Erica reunionensis -dominated forests than in mixed forests. Tree stems varied between weak N 2 O sinks and sources, with fluxes unrelated to gene abundances in stems. High prokaryotic and fungal nirK gene abundance in forest canopy soil suggests potential for above-ground denitrification in wet conditions. nosZ -I genes found in forest canopy soil and leaves ( E. reunionensis , Alsophila glaucifolia , and Typha domingensis ) indicate that plants, including forest canopy, may play a significant role in the reduction of N 2 O.