Adding complex trophic interactions to a size-spectral plankton model: Emergent diversity patterns and limits on predictability
Adding complex trophic interactions to a size-spectral plankton model: Emergent diversity patterns and limits on predictability
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DOI：
10.1016/j.ecolmodel.2011.05.018
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发表时间：
2011-08-10
影响因子：
3.1
通讯作者：
Banas, Neil S.
中科院分区：
文献类型：
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作者：
Banas, Neil S.
提出了一种新的NPZ（营养-浮游植物-浮游动物）模式，该模式在机械上简单，但浮游植物（1-20 μ m）和小型浮游动物（2.1-460 μ m）各有40个尺寸级，以详细解决一个层次的营养相互作用。一般的，经验异速生长的关系被用来parameterized最佳猎物的大小和大小的选择性为每个食草动物类，很少这样做。这种复杂的捕食者-猎物联系和现实的猎物偏好的包含产生了一个浮游植物多样性与全球海洋观测一致的新兴模式的系统，即，多样性（以香农均匀度衡量）和生物量之间呈抛物线关系。它还产生了显着的长期时间演变，在何种程度上可以从务实的意义上强迫预测的社区对养分强迫的反应的地方限制。当一个简单的营养供应的年度循环重复了很多年，短暂的波动高达两个因素在春季开花的幅度持续10-20年之前，一个稳定的季节性生物量周期是实现。当营养供应的年周期的振幅是一个随机的年际调制，这些长寿命的瞬态添加显着的噪音，100年的年平均营养供应和年平均生物量之间的相关性。这种噪声是20%的总年际方差在模型的基本情况下，范围从0%到40%，这取决于放牧大小的选择性。在一般情况下，开花时间尺度的不可预测性是阻尼时，食物网的复杂性增加，使食草动物的选择性降低，而年际尺度上的不可预测性表现出相反的模式，增加食物网的复杂性增加到一个高的阈值，过去的社区结构和生物量的时间演变都突然简化。这些结果提出了一种新的策略，合奏生态系统预测和不确定性估计，类似于常见的方法在流通和气候建模，其中内部变异（捕食者-猎物的相互作用在生物的情况下，涡流和气候系统振荡的物理情况下）的解决和量化，而不是抑制。(C)2011 Elsevier B. V.保留所有权利。
A new model in the NPZ (nutrient-phytoplankton-zooplankton) style is presented, mechanistically simple but with 40 size classes each of phytoplankton (1-20 mu m) and small zooplankton (2.1-460 mu m), in order to resolve one level of trophic interactions in detail. General, empirical allometric relationships are used to parameterize both the optimal prey size and size selectivity for each grazer class, as is rarely done. This inclusion of complex predator-prey linkages and realistic prey preferences yields a system with an emergent pattern of phytoplankton diversity consistent with global ocean observations, i.e., a parabolic relationship between diversity (as measured by the Shannon evenness) and biomass. It also yields significant long-term time evolution, which places limits on the extent to which the community response to nutrient forcing can be predicted from forcing in a pragmatic sense. When a simple annual cycle in nutrient supply is repeated exactly for many years, transient fluctuations up to a factor of two in spring bloom magnitude persist for 10-20 years before a stable seasonal biomass cycle is achieved. When the amplitude of the nutrient-supply annual cycle is given a random interannual modulation, these long-lived transients add significant noise to a 100-year correlation between annual-mean nutrient supply and annual-mean biomass. This noise is 20% of total interannual variance in the model base case, and ranges from 0% to 40% depending on the grazer size selectivity. In general, unpredictability on the bloom timescale is damped when food-web complexity is increased by making grazers less selective, while unpredictability on the interannual scale shows the opposite pattern, increasing with increasing food-web complexity up to a high threshhold, past which community structure and biomass time evolution both suddenly simplify. These results suggests a new strategy for ensemble ecosystem forecasting and uncertainty estimation, analogous to methods common in circulation and climate modeling, in which internal variability (predator-prey interactions in the biological case; eddies and climate-system oscillations in the physical case) are resolved and quantified, rather than suppressed. (C) 2011 Elsevier B.V. All rights reserved.