Freshwater Forum, Vol 28 (2010)

Benthic organic matter biomass and invertebrate community structure in five conifer plantation streams in the Peak District (Derbyshire, England)

Miira P. Riipinen, Michael Dobson


Invertebrate community structure and availability of organic matter was investigated in five streams lined with conifer trees. The streams differed in the dominant conifer tree species: a mixed spruce/pine, a pine, a spruce and two larch streams were compared. On two sampling occasions, five benthic samples were collected from each stream (one site per stream) in order to characterise the invertebrate community structure. An assessment of the main physical site characteristics was also carried out. Large differences between the sites were observed in both organic matter availability and invertebrate abundance and richness. The invertebrate communities of the sites were dominated by shredders and the overall invertebrate numbers correlated with organic matter availability. Both biomass of organic matter and invertebrates were significantly influenced by sampling date and site type. The spruce site, which had the widest channel, had the lowest biomass of both organic matter and invertebrates, whereas one of the larch sites had the highest of both. It is concluded that although the communities in the different types of conifer streams were somewhat different, it is likely that this is in response to a combination of physico-chemical variables and that retention of organic material is especially important. Implications for forestry management are discussed further.