Plankton size diversity in UK coastal waters: observations and modelling

细胞大小被认为是浮游生物生态学中的“主性状”，因为它最好地概括了生物体提供关键生态系统功能的能力，如养分吸收、能量转移、碳输出和初级生产速率[1,2,3]。单个浮游生物的体积一般都很小，因此它们对生态系统的贡献是它们数量总和的结果。在这里，我们的目标是了解浮游生物群落的大小多样性如何影响其整体生态系统功能，以及驱动浮游生物群落结构变化的因素。这可以通过构建描述浮游生物群落动态的大小结构生态系统模型，并利用英国海岸附近三个浮游生物观测站（普利茅斯、斯通黑文和Ewe湖）的长期时间序列数据来实现。特别令人感兴趣的是浮游生物大小多样性与生态系统功能的关系。浮游生物群落中大小结构的重要性得到了这样一个事实的支持，即平均细胞大小与海洋中浮游生物群落的一般行为有关。平均细胞大小较小的浮游植物群落通常出现在营养枯竭的水域[4]，由于来自更高营养水平的强烈放牧压力，能量保留在接近表面的地方。相反，较大的浮游植物群落没有受到如此强烈的放牧压力，较大的细胞可以沉入深海。通过这个过程，碳在一个被称为生物泵的过程中被从大气中输送出去。同样，已有的一些研究表明，浮游生物的大小多样性与浮游生物群落的能量转移有关[6]，但是，这项工作的范围有限，因为它只是对相关变量的观察。通过采用机制建模方法，我们可以更好地理解大小多样性如何以及为什么影响浮游生物群落的能量转移、碳输出和初级生产Kiorboe， T. & Hirst， A. Am。Nat. 183.4 (2014), b[2] Litchman， E. & Klausmeier， A. Annu。启生态。另一个星球。系统39.1 (2008),b[3] Litchman， E.等。[j] .浮游生物学报。35.3 (2013),[3].]科学。rep 5.1 (2015), [5] Maranón， E. Ann。科学通报，2015,(1),[10]。皇家社会程序B 283.1824 （2016）

Cell size is regarded as a 'master trait' in plankton ecology as it best summarises an organism's ability to provide key ecosystem functions, such as nutrient absorption, energy transfer, carbon export, and primary production rates [1,2,3]. Individual plankton organisms are generally microscopic in size, and so their ecosystem contributions are a result of their combined abundance. Here, we aim to understand how the size diversity of plankton communities affects their overall ecosystem functioning, and what drives changes in plankton community structure. This can be achieved through the construction of size-structured ecosystem models describing plankton community dynamics, and utilising long-term time series data from three plankton observatories around the UK coast (Plymouth, Stonehaven, and Loch Ewe).Of particular interest is the relationship plankton size diversity has with ecosystem functioning. The importance of size structure in a plankton community is supported by the fact that mean cell size is associated with the general behaviours of a plankton assemblage in the ocean. Phytoplankton communities with a small mean cell size often occur in nutrient-depleted waters [4], with energy retained near the surface due to intense grazing pressure from higher trophic levels. Conversely, communities of larger phytoplankton are not under such intense grazing pressure, and larger cells can sink to the deep ocean [5]. Through this process, carbon is transported away from the atmosphere in a process known as the biological pump. Similarly, some existing work has shown that plankton size diversity is associated energy transfer in plankton communities [6], however, the scope of this work is limited as it is simply an observation of correlated variables. By taking a mechanistic modelling approach we can better understand how and why size diversity impacts energy transfer, carbon export and primary production in plankton communities.[1] Kiorboe, T. & Hirst, A. Am. Nat. 183.4 (2014), [2] Litchman, E. & Klausmeier, A. Annu. Rev. Ecol. Evol. Syst. 39.1 (2008), [3] Litchman, E. et al. J. Plankton Res. 35.3 (2013), [4] Acevedo-Trejos, E. et al. Sci. Rep. 5.1 (2015), [5] Maranón, E. Ann. Rev. Mar. Sci. 7.1 (2015), [6] Garcia-Comas, C. et al. Proc. Royal Soc. B 283.1824 (2016)