Soil properties of lowland savannas of Belize

ARTICLE ABSTRACT A fresh approach is presented to address the increasingly urgent need for alternative land management strategies in savannas. We illustrate how fine-scale information of soil characteristics, can be used to enable a more precise delimitation of sites suitable for different forms of land stewardship, including agro-pastoral activities, forestry, biodiversity and tourism. By collating data from previous soil surveys, and augmenting this with targeted new surveys, we produce the first national data set of soil properties for the lowland savannas of Belize. Most of these soils are typical of savanna soils worldwide, i.e. acidic (mean surface pH=5.7), nutrient-poor (mean surface TEB=3.4cmol/kg) and coarse textured (mean surface clay=13.0%). Nevertheless there is a marked spatial variability across the country in these soil properties. Some soils exhibit unusually high subsurface clay fractions (max=73%), whilst other sites have exceptionally high pH in lower horizons (max=8.4). Cluster analysis is used to group sites with similar soil properties. Across 79 sites there is a clear division between soils with high clay percentages and those with coarser textures. These are sub-divided into five groups based on further differences in parent material, chemical properties and site characteristics. Mapping the locations of these groups enables more specific land use recommendations to be made. This ability to make targeted land use recommendations from fine scale soil information represents an advance over the previous national land use policy, where all savanna lands were considered unsuitable for agriculture. This approach could be applied to marginal savannas worldwide. DATA SET DESCRIPTION To create a national savanna soils data set for Belize we sought an approach applicable internationally in other countries which also have limited resources for conducting extensive soil surveys. Firstly, savanna data from pre-existing surveys were collated (Jenkins et al., 1976; King et al., 1986; Furley and Ratter, 1989; King et al., 1989; King et al., 1992; Furley et al., 2001). This dataset was reduced and simplified to establish a subset of soil properties that were comparable across all the sites. New surveys and laboratory analysis of soil samples were conducted to increase coverage in areas where the existing data were sparse or non-existent (Stuart et al., 2012). Combining the historical data with the new surveys produced a total of 88 sites across the country. NB In an associated research article, we analyse and describe properties at 79 of these sites in lowland savanna areas, as we exclude 9 sites (highlighted in yellow) which were are located in saline environments.