Soil and litter macrofauna in shelterbelts and in adjacent croplands: changes in community structure after tree planting

Studies were carried out in the vicinity of Turew near Poznań (Western Poland) in the years 2003 and 2004 in three midfield shelterbelts of different age (150, 11, 6 years old) and along two transects across shelterbelt (6 and 11 years old) >ecotone> field at distance 15 and 50 m from the shelterbelt. The field located in deforested area was treated as the control. The studies were aimed at estimating the changes in community structure (composition, density, biomass) of soil and litter macrofauna, (mainly dipteran larvae), related to shelterbelt age both within shelterbelts as in adjoining fields. The results were compared to previous studies carried out in 1999-2000 in the same agricultural landscape. The density and biomass of soil and litter macrofauna were many times higher in shelterbelts (2824-870 ind. m[^-2] and 3782-521 mg.d.wt. m[^-2]) than in fields (483-53 ind. m[^-2] and 101-12 mg.d.wt. m[^-2]) and increased with the age of planted trees. The same was true for taxonomic richness. Ecotone zone of both transects was characterised by the greatest density and biomass of animals, mainly those of mobile epigeic animals, particularly the ants. The density and biomass values were declining in the field with the increasing distance from the shelterbelt. Across the transect of an older (10-11 years old) shelterbelt and adjacent field the density and biomass of studied animals were higher in all plots than across the younger (5-6 years old) one. It can be concluded, that the effect of the shelterbelt increases with age of planted trees. The results confirm the previous suggestions of the enhancement of the field macrofauna by forested strips. The highest similarity in taxonomic and dominance structure was found between the shelterbelts and their ecotones and they differed significantly from those in the field.