Journal of Biogeography, 26, 1115±1128 The land use history (1278±1990) of a mixed hardwood forest in western Belgium and its relationship with chemical soil characteristics K. Verheyen, B. Bossuyt, M. Hermy and G. Tack1 Laboratory for Forest, Nature and Landscape Research, Catholic University of Leuven, V. Decosterstraat 102, B±3000 Leuven and 1Ministerie van de Vlaamse Gemeenschap, Administratie voor Ruimtelijke Ordening en Huisvesting, Monumenten en landschappen, Gebr. Van Eyckstraat 2±6, B±9000 Gent, Belgium Abstract Aim During the last decades, an increasing number of studies have stressed the importance of historical human in¯uence on the ecology of forests and on the characteristics of forest soils. Therefore, the objectives of this study are (1) the quanti®cation of the land use history of Ename Wood from 1278 to 1990 and (2) to ®nd out whether the former land use of the forest has long-lasting effects on present-day chemical soil properties. Location The 62-ha present-day Ename Wood is situated in western Belgium and is the remainder of the 145-ha historical Ename Wood. Methods We disposed of eighteen land-use maps for the period between 1278 and 1990 which were digitized using a geographic information system (GIS). Transition between the different land uses and Shannon±Wiener diversity indices were calculated to quantify the history of changing land use. Mixed soil samples were taken in lots delimited on the basis of the historical data. Next, the soil properties were combined with the land-use variables using redundancy analysis and ANOVA. Results The quanti®cation of the land use changes showed that the present Ename Wood is the result of several forest regression and progression phases, with a complete clearance in the nineteenth century. Diversity in land use was maximal between the fourteenth and the sixteenth century due a variety of transitional forms between forest and pasture. A positive correlation between the duration of arable land use since the 19th century clearance and soil pH, calcium and phosphate content was observed and a negative correlation was found with the carbon content, the total nitrogen content and the C:N ratio. These correlations are probably caused by a combination of acidi®cation processes and the accumulation of organic matter under forest in combination with manuring practices in the twentieth century. Present-day forest lots which have been pastured for some time between 1278 and nineteenth-century clearance still had a signi®cantly lower pH and degree of base saturation, which is probably caused by the export of nutrient rich plant material at that time. Discussion and conclusions The results demonstrate that the developed methodology is successful and con®rm that historical land use, even in the distant past, can still in¯uence present-day soil characteristics. For this reason, long-term historical land use should always be considered in forest ecological research. Keywords Forest history, land use history, historical ecology, soil characteristics, GIS, redundancy analysis. 1999 Blackwell Science Ltd 1116 K. Verheyen et al. INTRODUCTION research as a case study for the large-scale historical ecological research of Flemish forests (Tack et al., 1993). This historical Some decades ago, ecologists in several European countries research has resulted in the reconstruction of eighteen land- started to recognize the importance of long-term human use maps of Ename Wood between 1278 and 1990 which disturbances in forests (Peterken, 1974; Rackham, 1980; Dubois, enabled us to assess the effects of this long-lasting land-use 1989; Pounds, 1990; Vos & Stortelder, 1992; Tack et al., history on the present-day forest. Therefore, the aim of this 1993; Willis, 1993; Fritzbùger, 1994; Ellenberg, 1995; Kirby & paper is: Watkins, 1998). These days, the extreme impact of land use history on both the ecology and present-day nature conservation • to quantify the land-use history changes of Ename Wood value of forests is widely accepted (Peterken, 1993, 1996). It from 1278 to 1990; has been proven that the historical human activity still has • to develop a methodology to relate these changes to profound effects on the present-day distribution of woodland ecological characteristics of the forest, in particular with species, the so-called `ancient woodland species' (e.g. Hermy present-day soil characteristics; and et al., 1993) and on present-day chemical forest soil properties • to determine whether the former land use, reconstructed such as pH, degree of base saturation, soil organic matter and back to 1278, has had long-lasting effects on present-day phosphate content (e.g. Froment & Tanghe, 1967; Goovaerts chemical soil properties of the forest. et al., 1990; Catt, 1994; Koerner et al., 1997; Wilson et al., 1997). While the data reported are speci®c to Ename Wood and In this respect, North American forests offer opportunities the soils it contains, it is believed that the forest is representative which are denied to European ecologists. The pre-settlement for many other forests in Belgium and elsewhere in temperate forests are still present as remnants, which enables scientists Europe. to make direct comparisons between these forests and the post- settlement ones (e.g. Foster, 1992a, 1992b; Orwig & Abrams, STUDY AREA 1994; Motzkin et al., 1996; and Matlack, 1997a, 1997b). Furthermore, since land-use changes have taken place relatively recently and have involved only one or two land-use changes Physical setting on each patch of land, effects can often be securely related to The present-day Ename Wood, which consists of two disjunct causes (Peterken, 1996). parts, occupies 62 ha in the province of Eastern Flanders, about In most of Europe however, it is much more complicated 25 km south of Ghent. It is the remainder of the 145-ha to assess the effects of former land use since almost no primary historical Ename Wood (Fig. 1). or old growth forest is left as a reference and the observed The annual precipitation is 775 mm and the mean annual effects of a particular land use history might be obscured by temperature 9.5°C. On average, the vegetation growing period the effects of an even earlier land use. Despite this drawback, lasts about 170 days. The forest itself is located on the eastern most of the research assessing the impact of historical land use side of the River Scheldt and the altitude ranges from 14 m to only covered relatively short time periods (Wilson et al., 1997) 62 m above sea level. The northern part (25%) lies on humic and early agricultural and forestry practices have been lumped alluvial and colluvial sediments. The remainder of the forest by ecologists into broad categories and discussed with little is situated on the relatively steep slopes of the river valley on regard to spatial precision (Foster, 1992b). This is all in sharp sandy±loam soils of Quarternary niveo-eolian origin with a contrast with the long-term and complex human disturbance clayey or stony sandy layer of Tertiary marine origin at variable in European forests. depth. Some soils are derived from this Tertiary material. Therefore, to assess the effects of former land use in Europe on present-day forest ecosystems, it is extremely important to reconstruct the land-use history in as detailed a manner as Biological setting possible and to maximize the temporal scale. This also Ename Wood used to be managed as a coppice with standards encompasses the development of a methodology to quantify for hundreds of years. However, during the last century the historical land-use changes and to relate these changes to forest was gradually transformed into a highwood: 32% of the present-day ecological data. area was planted with homogeneous Populus × canadensis The former county of Flanders (western Belgium and (Moench) (nomenclature follows De Langhe et al., 1988); 39% northern France) has been subjected to extreme human impact. of the area has a mixture of broadleaved trees of which Populus As early as the thirteenth century Flanders was, and still is, one × canadensis (Moench) is the dominant tree species and 29% of the most densely populated areas of Europe. Additionally, the of the area has a mixture of Fraxinus excelsior (L.) and Quercus former county of Flanders has an extensively documented robur (L.). Underneath the tree canopy a neglected coppice layer history. Therefore, this region offers unique opportunities to is still found, consisting mainly of Alnus glutinosa (Gaertn.), assess the long-lasting effects of historical land use. Within the Fraxinus excelsior (L)., Acer pseudoplatanus (L) and Corylus county, Ename Wood has been the subject of a detailed historical avellana (L.) (Verheyen & Vackier, 1997). The 75% of the forest which is situated on sandy±loam soils Correspondence: K. Verheyen, Fax: ++32 16 329760; e-mail: kris. belongs to the Endymio-Carpinetum forest plant community [email protected] (Noirfalize, 1984). This plant community is characterized by Blackwell Science Ltd 1999, Journal of Biogeography, 26, 1115±1128 Land use history of a mixed hardwood forest 1117 Figure 1 Map of the historical and the present-day Ename Wood and the location of the seventy-four lots used for the soil sampling. Hyacinthoides non-scripta (Chouard ex Rothm.). On the following the deforestation movement in the eleventh to alluvial and colluvial sediments (25%), the forest belongs to twelfth century. By 1300, forest covered only 9% of the the Pruno-Fraxinetum forest plant community (Oberdorfer, total area. However, some large forest areas remained 1953) with Filipendula ulmaria (Maxim.), Primula elatior (Hill), and they were connected by smaller forest patches and Cardamine pratensis ssp. picra (De Langhe et D'Hose) as many hedges. All forests were used intensively for differential species. pasturing, resulting in a variety of transitional forms between forest and pasture.