The phytoplankton communities of nine lakes, Waikato, New Zealand: a comparative study of floristics, seasonal dynamics and the influence of herbivory
type: CreativeWork
description: The structure and seasonal dynamics of the phytoplankton communities of nine shallow lakes located in relatively close proximity to one another within the Waikato Basin, and of similar age and origin, were studied for one year (July 1983 to July 1984); the lakes were Kainui, Mangahia, Mangakaware, Maratoto, Ngaroto, Rotokauri, Rotomanuka North and South, and Rotoroa. There was a broad range of physico-chemical regimes, a direct result of differing morphometries and quantities of allochthonous dissolved humic material from adjacent peatland and/or swamps, and varying degrees of exposure to wind. Community structure was markedly influenced by humic content, in terms of both α diversity and distribution of species within the major classes, with total numbers of species found per lake ranging from 113 to 210. Temporal patterns of community composition were directly related to specific mixing regimes and morphometry. Lakes which had minimal thermal stability throughout summer were dominated throughout the entire year by one or two algal classes, and it was shown statistically that the major phytoplankters were large, K- selected species (e.g., Botryococcus braunii and Microcystis aeruginosa). Unpredictable sequences of domination, one class replacing another after brief periods of importance, were recorded in lakes where ephemeral periods of summer stratification alternated with either equally short periods of holomixis or weakly developed stratification; the dominant species in these lakes were r- strategists such as Asterionella formosa, Acanthoceras zachariasi and Tetrastrum triangulare. Marked seasonal periodicity (including autogenic succession) occurred in Lake Rotomanuka North, the only warm monomictic lake within the series. Total α diversity (402 species) was higher than that of any other group of intensively studied New Zealand lakes, but compositional overlap at both generic and specific levels was low, with only 24 species being found in all nine lakes. Of th…
abstract: The structure and seasonal dynamics of the phytoplankton communities of nine shallow lakes located in relatively close proximity to one another within the Waikato Basin, and of similar age and origin, were studied for one year (July 1983 to July 1984); the lakes were Kainui, Mangahia, Mangakaware, Maratoto, Ngaroto, Rotokauri, Rotomanuka North and South, and Rotoroa. There was a broad range of physico-chemical regimes, a direct result of differing morphometries and quantities of allochthonous dissolved humic material from adjacent peatland and/or swamps, and varying degrees of exposure to wind. Community structure was markedly influenced by humic content, in terms of both α diversity and distribution of species within the major classes, with total numbers of species found per lake ranging from 113 to 210. Temporal patterns of community composition were directly related to specific mixing regimes and morphometry. Lakes which had minimal thermal stability throughout summer were dominated throughout the entire year by one or two algal classes, and it was shown statistically that the major phytoplankters were large, K- selected species (e.g., Botryococcus braunii and Microcystis aeruginosa). Unpredictable sequences of domination, one class replacing another after brief periods of importance, were recorded in lakes where ephemeral periods of summer stratification alternated with either equally short periods of holomixis or weakly developed stratification; the dominant species in these lakes were r- strategists such as Asterionella formosa, Acanthoceras zachariasi and Tetrastrum triangulare. Marked seasonal periodicity (including autogenic succession) occurred in Lake Rotomanuka North, the only warm monomictic lake within the series. Total α diversity (402 species) was higher than that of any other group of intensively studied New Zealand lakes, but compositional overlap at both generic and specific levels was low, with only 24 species being found in all nine lakes. Of th…
author: Etheredge, Margaret Kay
license: https://researchcommons.waikato.ac.nz/bitstreams/b15e8bb5-e1fe-456a-a7c6-883f9a975e73/download
date published: 1987
date modified: 2026-07-24T05:57:38Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato