The seasonal and spatial dynamics in the phytomacrofaunal communities of Lake Henley, Mastert : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Ecology at Massey Universityon

Abstract

Spatial and seasonal dynamics of macrophyte beds in Lake Henley, a shallow artificial lake in Masterton, were examined between June 1993 and June 1994. Observed fluctuations in macrophyte biomass were linked with changes in filamentous algae associated with the weed beds. Invertebrate communities associated with submerged macrophytes were also examined at multiple sites between June 1993 and June 1994. Overall community composition was related more to seasonal influences than differences between sites within the lake. However, species richness and abundance did differ spatially. Recommendations for the ongoing management of Lake Henley, including management of the macrophyte beds and the maintenance of water quality and quantity, are made with respect to the ecological characteristics of the lake. The influence of trophic status on macrophyte invertebrate communities was also explored with a survey conducted in May 1994 of 13 other lakes in the North Island. Nutrient enriched lakes were characterised by phytomacrofaunal communities with high abundance and higher numerical dominance, whereas nutrient poor lake phytomacrofaunal communities were characterised by lower abundances but higher diversity of some taxonomic groups, particularly insects.