Invertebrate Colonization of Artificial Pondweeds of Differing Fractal Dimension

Abstract

Four pondweed designs were made, using fractal dimension as a measure of complexity to obtain some a priori control of the habitat architecture. Weed designs differed in complexity but total surface area of each of the shapes was the same. Recent theory suggests that abundance of invertebrate taxa and individuals will increase with increasing fractal complexity. Invertebrate colonization of the design was followed in two trials, firstly all four weed designs together in the same pond, secondly two of the designs in separate pools. In the first trial total numbers of individuals, total taxa and numbers of several species increased markedly with increased design complexity. in the second trial colonization of pools by the larvae of a Cyphon sp. (Coleoptera) was monitored in detail. Significantly higher numbers were found on the more complex weed design. Results generally support the hypothesis, though erratic colonization of pools was also important.