Data from: Warming accelerates mangrove expansion and surface elevation gain in a subtropical wetland

Climatic warming can change how coastal wetland plants grow, thus altering their capacity to build land and keep pace with rising seas. As freeze events decline with climate change, mangroves expand their range to higher latitudes and displace salt marsh vegetation. Warmer air temperatures will likely alter above‐ and below‐ground plant dynamics as this dramatic coastal wetland biome shift proceeds, which in turn may result in changes in ecosystem function such as sediment building.
We used a large scale in situ warming experiment in a subtropical wetland to increase both marsh and mangrove ecosystem air temperatures. We assessed how 2 years of continuous warming influenced above‐ and below‐ground plant growth and surface elevation relative to sea level.
We found that chronic warming doubled plant height and accelerated the expansion of mangrove into salt marsh vegetation, as indicated by a sixfold greater increase in mangrove cover in warmed plots compared to ambient temperature plots and a corresponding loss in salt marsh cover. Surface elevation gain, a measure of soil‐building capacity, increased due to warming over a 2‐year period and these changes in surface elevation were driven by increased mangrove root production in warmed plots.
Synthesis. Our findings suggest that, in some coastal wetlands, warming can facilitate plant community changes from marsh to mangrove, with corresponding increases in growth that help coastal wetlands to keep pace with sea‐level rise.

气候变暖可改变滨海湿地（coastal wetland）植物的生长模式，进而改变其造陆及跟上海平面上升速率的能力。随着气候变化导致冻融事件减少，红树林（mangrove）的分布范围向高纬度扩张，并取代盐沼（salt marsh）植被。随着这一剧烈的滨海湿地生物群区（biome）转变过程推进，气温升高可能会改变植物的地上与地下动态，进而可能引发沉积物堆积（sediment building）等生态系统功能的变化。

我们在亚热带湿地中开展了大规模原位增温（in situ warming）实验，以提升盐沼与红树林生态系统的空气温度。我们评估了两年持续增温对植物地上、地下生长以及相对海平面的地表高程（surface elevation）的影响。

研究发现，长期增温使植物株高翻倍，并加速了红树林向盐沼植被的扩张：增温样地的红树林盖度较常温对照样地增长6倍，同时盐沼盖度出现相应下降。作为土壤构建能力的衡量指标，地表高程增益在两年增温周期中有所提升，而这种地表高程变化由增温样地中红树林根系生产力的提升所驱动。

综合讨论：本研究结果表明，在部分滨海湿地中，气候变暖可推动植物群落从盐沼向红树林转变，同时伴随植物生长的增强，助力滨海湿地跟上海平面上升的速率。