Keane Ben, Shuttleworth Emma L, Evans Martin G, Ritson Jonathan P, Harris Angela, Johnston Adam, Alderson Danielle M, Clay Gareth D
School of Environment, Education and Development, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK.
Department of Environment and Geography, University of York, York, YO10 5NG, UK.
Sci Rep. 2025 Jul 1;15(1):22167. doi: 10.1038/s41598-025-05348-8.
As the largest terrestrial carbon (C) store, peatlands are vital to meeting climate targets. Sphagnum, a genus of ca. 350 species, sustains many peatlands through its high water content and chemistry which inhibits decomposition and vascular plant proliferation. However, many peatlands face increased risk of drought due to climate change, and how Sphagnum will respond and recover from drought is unknown. We measured moisture content, CO and methane (CH) flux, and photosynthetic pigments in two species, S. palustre and S. squarrosum, over increasing drought (1-10 weeks) and recovery (1-10 weeks) periods. We identified biomass moisture thresholds of 12 g g (S. palustre) and 18 g g (S. squarrosum) below which irreversible damage occurred to photosynthesis. Due to higher moisture retention, and a lower moisture threshold, S. palustre withstood longer drought than S. squarrosum. These species-specific thresholds provide important insight for modelling peatland C sinks and for sustainable peatland restoration.
作为最大的陆地碳库，泥炭地对于实现气候目标至关重要。泥炭藓属约有350个物种，通过其高含水量和抑制分解及维管植物增殖的化学特性维持着许多泥炭地。然而，由于气候变化，许多泥炭地面临干旱风险增加的问题，而泥炭藓如何应对干旱并从干旱中恢复尚不清楚。我们在长达10周的干旱期和10周的恢复期内，测量了泥炭藓和粗叶泥炭藓这两个物种的含水量、一氧化碳和甲烷通量以及光合色素。我们确定了泥炭藓（含水量阈值为12克/克）和粗叶泥炭藓（含水量阈值为18克/克）的生物量水分阈值，低于该阈值光合作用会受到不可逆转的损害。由于更高的持水能力和更低的水分阈值，泥炭藓比粗叶泥炭藓能耐受更长时间的干旱。这些物种特异性阈值为泥炭地碳汇建模和可持续泥炭地恢复提供了重要见解。
