Do phytoplankton communities evolve through a self-regulatory abundance-diversity relationship?
A small group of phytoplankton species that produce toxic or allelopathic chemicals has a significant effect on plankton dynamics in marine ecosystems. The species of non-toxic phytoplankton, which are large in number, are affected by the toxin-allelopathy of those species. By analysis of the abundance data of marine phytoplankton collected from the North-West coast of the Bay of Bengal, an empirical relationship between the abundance of the potential toxin-producing species and the species diversity of the non-toxic phytoplankton is formulated. A change-point analysis demonstrates that the diversity of non-toxic phytoplankton increases with the increase of toxic species up to a certain level. However, for a massive increase of the toxin-producing species the diversity of phytoplankton at species level reduces gradually. Following the results, a deterministic relationship between the abundance of toxic phytoplankton and the diversity of non-toxic phytoplankton is developed. The abundance-diversity relationship develops a unimodal pathway through which the abundance of toxic species regulates the diversity of phytoplankton. These results contribute to the current understanding of the coexistence and biodiversity of phytoplankton, the top-down vs. bottom-up debate, and to that of abundance-diversity relationship in marine ecosystems.
Roy
Shovonlal
S
School of Mathematics, The University of Manchester, Manchester M13 9PL, UK. shovon.roy@manchester.ac.uk
D044822:Biodiversity; D005075:Biological Evolution; D017753:Ecosystem; D019156:Indian Ocean; D008386:Marine Biology; D008387:Marine Toxins / Q000737:chemistry*; D008962:Models, Theoretical; D010839:Phytoplankton / Q000472:pathogenicity / Q000502:physiology*; D011157:Population Dynamics; D013045:Species Specificity; D013997:Time Factors
D008387:Marine Toxins