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Individual study: The effects of cutting and burning management of reed Phragmites australis beds on litter disappearance, Hickling Broad National Nature Reserve, Norfolk, England

Published source details

Cowie N.R., Sutherland W.J., Ditlhogo M.K.M. & James R. (1992) The effects of conservation management of reed beds. II. The flora and litter disappearance. Journal of Applied Ecology, 29, 277-284

Summary

Phragmites australis reed beds are valuable wildlife habitats and in the UK support some national rare fauna and flora. For conservation purposes reed beds may be managed by cutting, and in some areas reed is still harvested for thatching. Burning may also be used to arrest succession in reed beds, with periodic flooding also used as a management tool. Accumulation of reed litter and resultant raising and drying out of the ground surface is a problem in conservation management, cutting or burning, often in combination with periodic flooding, are management options. In this study, the effects of management on litter breakdown were determined by an experiment in which plots of reed were cut, burnt or left unmanaged.

Study site: The study was undertaken at Hundred Acre Marsh, Hickling Broad National Nature Reserve (National Grid ref: TG 434211), Norfolk, England.

Experimental design: A replicated experiment was undertaken in and area of 150 x 120 m, divided into 15, 30 x 40 m plots in a stand of reed. Strips around 2 m wide were cut around each. Treatments applied were:

i) cut – late March 1988 reeds cut and removed;

ii) burnt - late March 1988 reeds burnt against the wind (the burn was considered typical for reed beds);

iii) left unmanaged.


Litter disappearance: Old whole reed leaves were taken from standing stems in the unmanaged plots and on 1 November 1988 and air dried. Groups of leaves of known weight were placed in a little bag (10 x 10 cm, 0.02 mm nylon mesh or 4.5 mm polyester mesh) after soaking in distilled water for 24 h. Additional leaves were tied loosely to form bundles, soaked likewise. On 5 December 1988, two groups of four fine and four coarse litter bags and two leaf bundles were placed in each of the 15 plots and covered in litter. Half of the bag and leaf bundles were retrieved after 6 weeks, the rest after 26 weeks.

In the laboratory samples were cleaned, any invertebrates collected and the litter air-dried. Litter/soil samples (using a 22 cm diameter corer to 10 cm depth) were taken from around the leaf bundles, and invertebrates extracted. Leaf weight losses and the number of individuals of each invertebrate family were recorded for the sample types.

The rate of decomposition of reed leaf litter was determined by weight loss from litter bags and leaf bundles. Weight losses (Table 1, attached) were not significantly different between treatments. After 6 weeks weight loss was lowest in fine mesh then coarse mesh litter bags, and highest for leaf bundles, but after 26 weeks there was no significant difference between the three.

There was also no difference in associated soil invertebrates between treatments.
However, weight loss was inversely related to water depth in the plots and after 6 weeks correlated with the number of Oligochaetes (worms), Psychodid (dipteran fly) larvae and some Coleoptera (beetles).

Conclusions: Cutting and burning had no effect on the rate of litter breakdown and there was also no difference in associated soil invertebrates between treatments.


Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at:

http://links.jstor.org/sici?sici=0021-8901%281992%2929%3A2%3C277%3ATEOCMO%3E2.0.CO%3B2-8