Primary production of algae growing on natural and artificial aquatic plants: A study of interactions between epiphytes and their substrate1

Abstract

Epiphytes that grew on Poturnogeton richarclsonii were similar to those gron 1r1g on Inorphologically similar plastic plants in both biomass (as Chl a) and prinlar! production per unit area, over the growing seasons of 1976 and 1977. Alk* 1' d ine phosphatase nctivit! , nrl Indicator of P limitation, was always higher for epiphytes on artificial substrates, which suggests that real plants transfer a small amount of nutrient to their epiphytes. However, specific productioll of the epiphytes (production per unit of Chl) was not significantly different OII the two .\ub-strates. These similarities give little support to the hypothesized sy tnbiosis or cotllpetition between plant and epiphytes. The living plants appear to be a neutral \rll)\trate for dgal growth.

Distribution of the epiphytic organisms on Posidonia australis and P. sinuosa, two seagrasses with differing leaf morphology

“…These results confirm that, at least in the early stages of colonisation, seagrass leaves act as a 'neutral' substratum for the attachment of epiphytic organisms. The observations of Harlin (1973), Cattaneo & Kalff (1979. Horner (1987) and Lethbridge et al (1988), who compared epiphyte growth and distribution on natural and morphologically similar artificial substrata, support this finding.…”

“…Humm 1964, May et al 1978, Harlin 1980, Heijs 1985a), but much of this literature has concentrated on the taxonomy of these organisms, rather than the pattern of epiphyte distribution or the underlying causes for these patterns (e.g. Cattaneo & Kalff 1979, Horner 1987, Lethbridge et al 1988, Borowitzka et al 1990, Kendrick & Burt 1997.…”

“…The seagrass leaf is a n excellent habitat for epiphytic organisms, especially algae, for several reasons: (1) settlement at the apex of the leaves exposes epiphytic algae to higher light intensities and less sedimentation compared with those growing further down the leaf, and (2) the leaf's physical movement through the water also exposes the epiphytic algae to a much greater nutrient supply and washes away any inhibitory substances (Harlin 1975, Cattaneo & Kalff 1979, Keough 1986, Borowitzka & Lethbridge 1989. This paper compares the spatial and temporal distribution of epiphytic organisms on the leaves of the seagrasses Posidonia sinuosa and P. australis with related, but different, leaf morphologies and considers how abiotic factors, such as water flow and irradiance, and biotic factors, such as settlement, recruitment and growth habit, may affect the distribution of the epiphytic organisms observed.…”

Diatomáceas perifíticas em Potamogeton polygonus Cham. & Schltdl.: citações pioneiras para o estado do Paraná

“…Dentre os inúmeros substratos disponíveis para o estabelecimento da comunidade perifítica, as macrófitas aquáticas constituem o substrato natural com um dos maiores índices de abundância e riqueza de espécies de microorganismos. Algas encontram nessas plantas um local propício para seu desenvolvimento, sendo beneficiadas pelos compostos orgânicos e pelos nutrientes excretados pelas macrófitas, as quais de certa forma são protegidas dos organismos herbívoros pelo biofilme que se estabelece em sua superfície (Cattaneo & Kalff 1979). É muito provável que haja interações significativas entre as epífitas e as macrófitas aquáticas que lhes servem de suporte, e que essas trocas metabólicas afetem a composição específica das algas, a dinâmica populacional relacionada com a sucessão e a produtividade resultante (Wetzel 1983).…”

Epiphytic diatoms (Diatomeae) from Piraquara II urban reservoir, Paraná state

“…Stems of emergent macrophytes are suitable colonizable surfaces to epiphyton communities and are particularly able to transfer a small amount of nutrients to their epiphytes (Cattaneo & Kalff, 1979). As periphytic diatoms are sensitive to eutrophication, it is important to record the species that occured at present for comparision to the future assemblies, helping to understand the relationship between the species and the trophic level of aquatic system.…”