In depositional intertidal coastal systems, primary production is dominated by benthic microalgae (microphytobenthos) inhabiting the mudflats. This benthic productivity is supporting secondary production and supplying important services to humans including food provisioning. Increased frequencies of extreme events in weather (such as heatwaves, storm surges and cloudbursts) are expected to strongly impact the spatiotemporal dynamics of the microphytobenthos and subsequently their contribution to coastal food webs. Within north-western Europe, the years 2018 and 2019 were characterized by record-breaking summer temperatures and accompanying droughts. Field-calibrated satellite data (Sentinel 2) were used to quantify the seasonal dynamics of microphytobenthos biomass and production at an unprecedented spatial and temporal resolution during these years. We demonstrate that the Normalized Difference Vegetation Index (NDVI) should be used with caution in depositional coastal intertidal systems, because it may reflect import of remains of allochthonous pelagic productivity rather than local benthic biomass. We show that the reduction in summer biomass of the benthic microalgae cannot be explained by grazing but was most probably due to the high temperatures. The fivefold increase in salinity from January to September 2018, resulting from reduced river run-off during this exceptionally dry year, cannot have been without consequences for the vitality of the microphytobenthos community and its resistance to wind stress and cloud bursts. Comparison to historical information revealed that primary productivity of microphytobenthos may vary at least fivefold due to variations in environmental conditions. Therefore, ongoing changes in environmental conditions and especially extreme events because of climate change will not only lead to changes in spatiotemporal patterns of benthic primary production but also to changes in biodiversity of life under water and ecosystem services including food supply. Satellite MPB data allows for adequate choices in selecting coastal biodiversity conservation and coastal food supply.

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利用光谱信息评估沿海沉积系统中微底栖动物的生物量和初级生产

在潮间带沉积的沿海系统中，初级生产以居住在滩涂中的底栖微藻（微藻类底栖藻类）为主。这种底层生产力正在支持次级生产并向人类提供重要服务，包括粮食供应。预计天气中极端事件（例如热浪，风暴潮和暴风雨）的发生频率增加，将强烈影响微型底栖动物的时空动态，进而影响其对沿海食物网的贡献。在西北欧，2018年和2019年的特征是创纪录的夏季温度和随之而来的干旱。在这些年中，使用现场校准的卫星数据（前哨2）以前所未有的时空分辨率对微底栖生物量和产量的季节动态进行了量化。我们证明，在沉积的沿海潮间带系统中应谨慎使用归一化植被指数（NDVI），因为它可能反映了异地中上层生产力残留的进口，而不是局部底栖生物量的进口。我们表明，底栖微藻夏季生物量的减少无法通过放牧来解释，但最有可能是由于高温所致。2018年1月至2018年9月，盐分增加了五倍，这是由于在这一异常干旱的一年中河流径流减少了，不会对微底栖动物群落的活力及其对风压和云爆的抵抗力产生任何后果。与历史资料的比较表明，由于环境条件的变化，微底栖动物的初级生产力可能至少变化五倍。因此，由于气候变化造成的环境条件的不断变化，特别是极端事件的变化，不仅会导致底栖初级生产的时空格局发生变化，而且还会导致水和生态系统服务（包括粮食供应）下生物多样性的变化。MPB卫星数据可为选择沿海生物多样性保护和沿海食品供应提供足够的选择。与历史资料的比较表明，由于环境条件的变化，微底栖动物的初级生产力可能至少变化五倍。因此，由于气候变化造成的环境条件的不断变化，特别是极端事件的变化，不仅会导致底栖初级生产的时空格局发生变化，而且还会导致水和生态系统服务（包括粮食供应）下生物多样性的变化。MPB卫星数据可为选择沿海生物多样性保护和沿海食品供应提供足够的选择。与历史资料的比较表明，由于环境条件的变化，微底栖动物的初级生产力可能至少变化五倍。因此，由于气候变化造成的环境条件的不断变化，特别是极端事件的变化，不仅会导致底栖初级生产的时空格局发生变化，而且还会导致水和生态系统服务（包括粮食供应）下生物多样性的变化。MPB卫星数据可为选择沿海生物多样性保护和沿海食品供应提供足够的选择。持续不断的环境条件变化，尤其是由于气候变化而导致的极端事件，不仅会导致底栖初级生产的时空格局发生变化，而且还会导致水和生态系统服务（包括粮食供应）下生物多样性的变化。MPB卫星数据可为选择沿海生物多样性保护和沿海食品供应提供足够的选择。持续不断的环境条件变化，尤其是由于气候变化而导致的极端事件，不仅会导致底栖初级生产的时空格局发生变化，而且还会导致水和生态系统服务（包括粮食供应）下生物多样性的变化。MPB卫星数据可为选择沿海生物多样性保护和沿海食品供应提供足够的选择。