Processing of pine (Pinus sylvestris) and birch (Betula pubescens) leaf material in a small river system in the northern Cairngorms, Scotland

Abstract

Processing rates, and macroinvertebrate colonisation, of pine needles and birch leaves were studied at eight sites on the river Nethy, a small river system in the Cairngorm region of north-eastern Scotland. Throughout this river system, processing rates were slow for pine (k values 0.0015-0.0034 day -1 ) and medium to fast for birch (k values 0.0085-0.0331 day -1 ). Plecopteran shredders dominated both pine and birch leaf packs during the early part of the experiment while chironomids were more important in the latter stages. It is suggested that the slow processing rate of pine needles could adversely affect the productivity of streams, particularly where needles provide the major allochthonous energy source and retentive features are limited. Forest managers should consider this when creating new pinewoods in treeless areas as it will take many years for the trees to reach a size at which they can effectively contribute retentive features, in the form of woody debris, to streams.

Seasonal variation of allochthonous and autochthonous energy inputs in an alpine stream

“…Coarse particulate organic matter (CPOM) collected in the Surber samples was hand-sorted and divided into two categories: larch (L. decidua) litter and other CPOM (grass fragments, leaf litter, and miscellaneous organic particles), to account for the different palatability of coniferous litter to macrobenthonic fauna (Campos and González, 2009;Collen et al, 2004). In the laboratory, larch litter and the other CPOM were air dried for 24 h, oven dried (105°C) for additional 24 h, and weighed with an electronic scale (accuracy±0.001 g).…”

Sericostoma vittatum (Trichoptera) Larvae Are Able to Use Pine Litter as an Energy Source

“…The need of long conditioning times to coniferous litter being an adequate substrate for detritivore colonization, feeding and growth is commonly cited in the literature (e.g., ALBA- RIÑO and BALSEIRO, 2002;COLLEN et al, 2004). In a laboratory experiment, ALBARIÑO and BALSEIRO (2001) found no growth (nor survival) of a detritivore stonefly fed on 15 days conditioned Pinus ponderosa needles.…”

Sustainability of UK forestry: contemporary issues for the protection of freshwaters, a conclusion

“…Perhaps most important of all, the overall energy subsidy provided in all forms from native riparian vegetation offers a means of enhancing secondary production in streams that would otherwise be unproductive for example those that are acidified or still recovering. Broadleaf energy inputs are more beneficial in this respect, not only in comparison with exotic conifers but also in comparison to the native Pinus sylvestris (Collen et al 2004).…”