同时存在的小浮游生物在海洋生产力梯度中经历了不同的相对放牧压力
Michael R Landry1, Michael R Stukel2, Karen E Selph3
1Scripps Institution of Oceanography, University of California at San Diego, San Diego, CA 92093.
概括
海洋的关键生产者 - - 皮科菲托浮游生物,由于选择性放牧而导致高产水域的下降,而不仅仅是大小. 这挑战了对微生物食物网动态和气候变化影响的传统观点.
科学领域:
- 海洋微生物生态学
- 海洋学 海洋学 海洋学
- 气候变化生物学
背景情况:
- 皮科菲托普朗克顿是开放海洋中占主导地位的初级生产者.
- 随着气候变化,它们的重要性正在增加.
- 它们的种群动态受微生物食物网相互作用的影响.
研究的目的:
- 测试假设,高生产率水域中皮科菲托普朗克顿丰富度的下降是由通过共享的捕食者传递给皮科菲托普朗克顿的异质型细菌 (HBAC) 的强化放牧驱动的.
- 了解放牧选择性在塑造微生物社区结构中的作用.
主要方法:
- 来自加利福尼亚现行生态系统 (CCE) 热带梯度的八次巡航的实验数据收集.
- 对皮科菲托浮游生物和细菌的丰富性,生长率和牧场死亡率的分析.
- 皮科菲托浮游生物 (Synechococcus - SYN) 和HBAC.之间的死亡率比较.
主要成果:
- 细菌的丰富性,生长和放牧死亡率随着初级生产的增加而增加.
- 皮科菲托普朗克顿的死亡率与细菌趋势有所不同.
- 与HBAC相比,SYN上的相对放牧率从低生产率到高生产率水域下降了12倍.
- 牧场的选择性,而不是规模,解释了死亡率比率的变化.
结论:
- 皮科菲托浮游生物的放牧压力是高度选择性的,这挑战了原生虫仅仅控制生物质的观点.
- 病毒可能不是唯一调节微生物多样性的"获胜者的杀手".
- 微生物食物网的复杂性和捕食者选择性对于理解应对气候变化的反应至关重要.
更多相关视频
相关概念视频
01:06Primary Production
23.6K
The total amount of energy acquired by primary producers in an ecosystem is called gross primary production (GPP). However, of this energy, producers use some for metabolic processes, and some is lost as heat, decreasing the amount of energy available to the next trophic level. The remaining usable amount of energy is called the net primary productivity (NPP). In terrestrial ecosystems, NPP is driven by climate, while light penetration and nutrient availability drive NPP in aquatic ecosystems.
23.6K
00:46Trophic Efficiency
20.6K
Trophic level transfer efficiency (TLTE) is a measure of the total energy transfer from one trophic level to the next. Due to extensive energy loss as metabolic heat, an average of only 10% of the original energy obtained is passed on to the next level. This pattern of energy loss severely limits the possible number of trophic levels in a food chain.
20.6K
01:27Diversity of Protists IV
22
Amoebozoa represent a diverse group of terrestrial and aquatic protists that utilize lobe-shaped pseudopodia for locomotion and feeding. This characteristic differentiates them from the Rhizaria, which possess threadlike pseudopodia. The primary classifications within Amoebozoa include gymnamoebas, entamoebas, and the plasmodial and cellular slime molds. Phylogenetic evidence indicates that Amoebozoa diverged from a lineage that ultimately gave rise to fungi and animals.Gymnamoebas and...
22
01:26Oxygenic Photosynthesis
19
Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate...
19
01:27Diversity of Protists II
22
Alveolates are a group of organisms recognized by the presence of alveoli, which are cytoplasmic sacs located beneath the cell membrane. While their function remains uncertain, alveoli may help regulate water balance by controlling how much water enters and leaves the cell. In dinoflagellates, these structures may serve as armor plates. There are three major types of alveolates: ciliates, which move using cilia; dinoflagellates, which use flagella for movement; and apicomplexans, which are...
22
01:27Diversity of Protists III
30
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
30