Seasonal kelp primary production at a rocky shore site: Integrating physiology and biochemistry into ecological modelling

岩石海岸的季节性海带初级生产：将生理学和生物化学纳入生态模型

• 批准号: 407670545
• 负责人: Professor Dr. Ulf Karsten, since 4/2019
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407670545?language=en
• 关键词: Seasonal; kelp; primary; production; rocky

Coastal hard bottom zones of temperate regions are dominated by dense underwater kelp forests as key primary producers, thereby generating high amounts of biomass and carbon, which represent a major trophic contribution to these marine ecosystems. Kelp forests provide three-dimensional, heterogeneously structured habitats, providing food and shelter for the associated rich marine flora and fauna. However, these underwater forests are under risk due to global warming as kelp needs low water temperatures. Surface waters in the North Sea around Helgoland have already warmed by more than 1°C since the 1960s and this trend is predicted to reach into the next century. Despite the ecological importance of kelps in coastal ecosystems, only very few data exist worldwide on standing biomass, distribution and crude primary production estimates. The study area Helgoland in the North Sea is an exceptional region with a reasonable database on kelp biomass, growth and vertical distribution. However, for an accurate calculation of kelp primary production, two main missing gaps remain: (1) the exact conversion of photosynthetic oxygen production into carbon fixation units and (2) the impact of increasing temperatures on seasonal kelp photosynthetic performance for a dynamic assessment of primary production. Both processes are not only unknown for kelps in the temperate region, but also for all other kelp communities worldwide. Therefore, the main goal of this project is to determine for the first time the seasonal changing primary production and carbon budget in these macroalgae. This will be achieved by using a combination of different approaches (O2- and 14C-method) as well as physiological and biochemical measurements of the actual carbon fixation with state-of-the-art methods such as chromatography and mass spectrometry. The impact of the forecasted global warming will be also investigated on the seasonal primary production rates. These results, together with the existing database on kelps around Helgoland, will be used to develop for the first time an ecological model for kelp primary production, i.e. a dynamic physiological box model. This will serve as a tool to simulate various global change scenarios and to identify biological sensitivities and possible thresholds. Such a broad approach has never been applied before to kelps worldwide and hence represents one of the key innovations of this proposal.

温带地区的沿海硬底带以密集的水下海藻林为主，是主要的初级生产者，从而产生大量的生物量和碳，对这些海洋生态系统的营养贡献很大。海带林提供了三维的、结构各异的生境，为相关的丰富海洋植物群和动物群提供了食物和庇护所。然而，由于全球变暖，这些水下森林正处于危险之中，因为海带需要低水温。自20世纪60年代以来，黑尔戈兰周围北海的表层沃茨已经升温超过1°C，预计这一趋势将持续到下一个世纪。尽管海带在沿海生态系统中具有重要的生态意义，但全世界关于现存生物量、分布和粗初级生产估计数的数据很少。研究区Helgoland在北海是一个特殊的区域与合理的数据库海带生物量，生长和垂直分布。然而，对于海带初级生产力的准确计算，仍然存在两个主要的缺失差距：（1）光合氧生产到碳固定单位的准确转换和（2）温度升高对季节性海带光合性能的影响，以动态评估初级生产力。这两个过程不仅是未知的海带在温带地区，但也为所有其他海带社区世界各地。因此，该项目的主要目标是首次确定这些大型藻类的季节性变化的初级生产和碳收支。这将通过使用不同方法（O2和14C方法）的组合以及使用最先进的方法（如色谱法和质谱法）对实际碳固定进行生理和生物化学测量来实现。还将调查预测的全球变暖对季节性初级生产率的影响。这些结果，连同现有的数据库在Helgoland周围的海带，将被用来开发首次海带初级生产的生态模型，即动态生理箱模型。这将作为模拟各种全球变化情景并确定生物敏感性和可能阈值的工具。这种广泛的方法以前从未应用于世界各地的海带，因此代表了本提案的关键创新之一。