Margalef's mandala and phytoplankton bloom strategies

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• 作者：Timothy Wyatt ^{twyatt@iim.csic.es" class="auth_mail}
• 关键词：Phytoplankton mandala ; Fitness ; Life-history strategies ; Population dynamics ; Red tides
• 刊名：Deep Sea Research Part II: Topical Studies in Oceanography
• 出版年：March, 2014
• 年：2014
• 卷：101
• 期：Complete
• 页码：32-49
• 全文大小：586 K

文摘

Margalef's mandala maps phytoplankton species into a phase space defined by turbulence (A) and nutrient concentrations (N_i); these are the hard axes. The permutations of high and low A and high and low N_i divide the space into four domains. Soft axes indicate some ecological dynamics. A main sequence shows the normal course of phytoplankton succession; the r-K axis of MacArthur and Wilson runs parallel to it. An alternative successional sequence leads to the low A-high N_i domain into which many red tide species are mapped. Astronomical and biological time are implicit. A mathematical transformation of the mandala (rotation) links it to the classical bloom models of Sverdrup (time) and Kierstead and Slobodkin (space).

Both rarity and the propensity to form red tides are considered to be species characters, meaning that maximum population abundance can be a target of natural selection. Equally, both the unpredictable appearance of bloom species and their short-lived appearances may be species characters. There may be a correlation too between these features and long-lived dormant stages in the life-cycle; then the vegetative planktonic phase is the 鈥榳eak link鈥?in the life-cycle. Red tides are thus due to species which have evolved suites of traits which result in specific demographic strategies.