Trait shift history: Do grazing induced trait shifts in phytoplankton determine the sensitivity to nutrients and sinking? (Acronym: TraitHist)

性状转变历史：放牧引起的浮游植物性状转变是否决定了对营养物质和下沉的敏感性？

• 批准号: 257184792
• 负责人: Professor Dr. Ulrich Sommer
• 金额: --
• 依托单位: GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/257184792?language=en
• 关键词: Trait; shift; history; Do; grazing

It shall be tested whether shifts in phytoplankton size structure caused by zooplankton grazing determines the responsiveness of phytoplankton to nutrient depletion, nutrient enrichment and sinking. Phytoplankton from the Baltic Sea will be subject to zooplankton grazing in mesocosms. The effect of two types of zooplankton will be contrasted. Copepods which are expected to shift phytoplankton size distribution towards a dominance of smaller cell and the rotifer Brachionus plicatilis which is expected to shift the size distribution towards dominance of larger cells. After conditioning by grazing, phytoplankton communities from the copepod mesocosms, the Brachionus mesocosm and the control mesocosms will be subject to nutrient starvation and nutrient enrichment. Sinking rates will be measured at the end of the conditioning phase and in response to the nutrient treatments. The working hypotheses are:1) Copepod grazing will shift protist size distributions to a dominance of small cells.2) Brachionus grazing will shift protist size distributions to a dominance of large cells.3) Copepod-conditioned protist plankton willa) respond with faster growth to nutrient additions.b) better cope with prolonged nutrient shortage.c) be less vulnerable to sinking losses.4) Brachionus-conditioned protist plankton willa) sustain growth after nutrient addition for a longer period.b) initially maintain growth longer after the transition to nutrient shortage.c) be more vulnerable to sinking losses. 5) Sinking rates will also be influenced by nutritional state, as expressed by the C : limiting nutrient ratio in biomass.

应测试是否由浮游浮游生物引起的浮游植物大小结构的变化决定了浮游植物对养分耗竭，养分富集和下沉的反应。来自波罗的海的浮游植物将受到中浮游的浮游生物。两种类型的浮游动物的影响将形成鲜明对比。预计将浮游植物尺寸分布转移到较小的细胞和旋转膜的胸骨plicatilis的copepods，预计将大小分布转移到较大细胞的优势上。通过放牧调节后，来自CopePod中cos的浮游植物群落，腕杆菌中的中龙和对照中心将受到营养饥饿和养分富集的影响。下沉率将在调节阶段结束并响应养分治疗时测量。工作假设是：1）copepod放牧将把原生物的大小分布转移到小细胞的主导地位。2）Brachionus放牧会将原生物的大小分布转移到大细胞的优势上，3）3）copepod的protisted protist plankton willa willa willa）willa willa）willa）更快地加入了繁殖的繁殖物。培养基的生长浮游生物浮游生物的生长更长的时间。 5）下沉率也将受营养状态的影响，如C：限制生物量的养分比所表达的那样。