Original article Depth distribution and composition of seed banks under different tree layers in a managed temperate forest ecosystem Sandrine Godefroid * , Shyam S. Phartyal 1 , Nico Koedam Department of General Botany and Nature Management (APNA), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium ARTICLE INFO Article history: Received 4 October 2004 Accepted 15 November 2005 Available online 27 January 2006 Keywords: Forest plantation Seed bank size Spatial pattern Ancient forest species Quercus robur Fagus sylvatica Pinus sylvestris ABSTRACT In the present work we examined the composition and distribution across three soil layers of the buried soil seed bank under three different overstory types (Fagus sylvatica, Quercus robur, Pinus sylvestris) and in logging areas in a 4383-ha forest in central Belgium. The objectives were: (1) to investigate whether species composition and species richness of soil seed banks are affected by different forest stands; (2) to examine how abundant are habitat-specific forest species in seed banks under different planted tree layers. The study was carried out in stands which are replicated, managed in the same way (even- aged high forest), and growing on the same soil type with the same land-use history. In the investigated area, the seed bank did show significant differences under oak, beech, pine and in logging areas, respectively in terms of size, composition and depth occur- rence. All species and layers taken together, the seed bank size ranked as follows: oak- wood > beechwood > logging area > pinewood. The same pattern was found for forest spe- cies. Seed numbers of Betula pendula, Calluna vulgaris, Dryopteris dilatata and Rubus fruticosus were significantly higher under the beech canopy. Carex remota, Impatiens parviflora and Lo- tus sp. showed a significantly denser seed bank in logging areas, while Digitalis purpurea seeds were significantly more abundant in soils under the oak canopy. The fact that the seed bank of an originally homogeneous forest varies under different planted stands highlights that a long period of canopy conversion can affect the composition and depth of buried seeds. © 2006 Elsevier SAS. All rights reserved. 1. Introduction Many European temperate forests are intensively managed and have been transformed into high-yielding monospecific plantations of either native or exotic species. Plantations even dominate in many European countries like Belgium, Denmark or United Kingdom (UNECE/FAO 2003). There is cur- rently ample evidence for the existence of an influence of ca- nopy structure and tree species composition on the growing conditions for herb and shrub species (e.g. Boncina, 2000). Management-related variables may explain more variation in understory vegetation than soil and microclimate vari- ables together (Aude and Lawesson, 1998). Influence of cano- py species on understory plants may be due to their effect on soil properties. More than 50 years ago, Ovington (1953) al- ready suggested that tree species influence soils differently. Trees can influence soil properties due to canopy intercep- tion of atmospheric deposition, weathering of soil minerals, nutrient output via water seepage or biomass removal (leaching), quality of litterfall, mineralization, stemflow, throughfall and root activity (Sydes and Grime, 1981a, ACTA OECOLOGICA 29 (2006) 283 – 292 * Corresponding author. Tel.: +32 2 629 3411; fax: +32 2 629 3413. E-mail address: sagodefr@vub.ac.be (S. Godefroid). 1 Present address: Forest Tree Seed Laboratory, Forest Research In- stitute, P.O. New Forest, Dehra Dun 248006, Uttaranchal State, India 1146-609X/$ - see front matter © 2006 Elsevier SAS. All rights reserved. doi:10.1016/j.actao.2005.11.005 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/actoec