The earliest soil survey known for the area is the pioneering reconnaissance of the Canal Zone and its environs by Bennett (1926 & 1929).\u00a0 He mapped the whole of BCI as the Frijoles red clay, with a topographic subdivision for the central plateau.\u00a0\u00a0 He admitted that the separation of the moderately fertile red clays derived from intermediate lithologies in Panama was problematic.\u00a0 He noted that the clastic sedimentary formations contain much volcanic material and that their soils – the Gatun clays – are morphologically similar to the Frijoles clays, as are the Arraijan clays derived from calcareous sedimentaries.<\/p>\n
BCI is covered by a soil survey of the Canal area (Catapan, 1970) for the Comision de Reforma Agraria (CRA) of the Ministerio de Desarollo Agropecuaria (MIDA).\u00a0 The general map (1:100 000) shows the whole of BCI as \u2018Red Mountain Soils\u2019, where \u2018mountain\u2019 presumably means upland and non-alluvial rather than montane.\u00a0 BCI is also covered by 1:20 000 soils maps from the same study.\u00a0 These are held at the Comision\u2019s office in Santiago, and were made readily available by MIDA staff for inspection and copying.\u00a0 We have lodged hard copies of the Catapan 1:20 000 sheets covering BCI with STRI and the University of Potsdam.<\/p>\n
The Catapan maps appear to be based mainly on the interpretation of aerial photography of unknown scale and dating from the mid-1960\u2019s, with limited field checking. The mapping units are parametric compilations that incorporate: topsoil and subsoil diagnostic horizon designations according to the USDA Seventh Approximation (Soil Survey Staff, 1960); profile drainage; textual class; depth class; parent material group; slope gradient class; erosion class; stoniness class; and an evaluation of the land\u2019s potential capability using a system similar the eight class hierarchy then employed by USDA (Klingebiel & Montgomery, 1961). The Catapan mapping units are therefore of land\u00a0sensu lato<\/em>, rather than just soils.<\/p>\n The boundaries generally accord with our findings, and clearly separate the dipslope plateau from the more rugged Bohio scarp terrain, the sedimentary, and volcanic lowlands. Other similarities include the recognition of the subsoils on the Bohio scarplands as cambic, compared to the oxic subsoils elsewhere.\u00a0 Differences from our mapping and characterisation include their omission of smectitic mineralogy and impeded drainage on the Caimito marine facies, designation of the Bohio scarpland soils as having worse drainage than the rest of the island, and differentiation of umbric (dark) topsoils on the plateau compared with ochric (lighter coloured and less organic) topsoils elsewhere.<\/p>\n Although not primarily pedological, investigations in several disciplines have collected data that contribute to understanding of the soil cover of BCI.\u00a0 The soils interest was tangential and primary soils data were zero\/slight in many studies.<\/p>\n Those with more substantial soils data or discussions are summarised in Table 3.1. The list is incomplete and we welcome information on omissions and errors.<\/p>\n Study<\/strong><\/p>\n<\/th>\n Location on BCI<\/strong><\/p>\n<\/th>\n Data & findings relevant to soil cover<\/strong><\/p>\n<\/th>\n Notes<\/strong><\/p>\n<\/th>\n References<\/strong><\/p>\n<\/th>\n<\/tr>\n<\/thead>\n\n General physical environment<\/p>\n<\/td>\n Whole island<\/p>\n<\/td>\n Pits and augerings<\/p>\n<\/td>\n Some our soil classes are presaged in brief descriptions.\u00a0 Soil shallowness stressed.<\/p>\n<\/td>\n Dietrich et al.<\/em>, 1996; Phytosociology<\/p>\n<\/td>\n Whole island<\/p>\n<\/td>\n 13 plots identified as on Frijoles clay, 3 on gleys<\/p>\n<\/td>\n Tree spp distributions appear to be fairly indiscriminate with respect to soil type<\/p>\n<\/td>\n Knight, 1975<\/p>\n<\/td>\n<\/tr>\n Flora of BCI<\/p>\n<\/td>\n Whole island<\/p>\n<\/td>\n Identifies Frijoles clay, gleys & possible \u2018fragipan\u2019<\/p>\n<\/td>\n \u2018Fragipan\u2019 may refer to the pale swelling clays<\/p>\n<\/td>\n Croat, 1978<\/p>\n<\/td>\n<\/tr>\n Soil water potential in gaps & on slopes<\/p>\n<\/td>\n Andesite dipslope\/plateau & slopes<\/p>\n<\/td>\n Slope soils are better watered > plateau<\/p>\n<\/td>\n Possibly due to lateral inflows by throughflow from plateau upslope.<\/p>\n<\/td>\n Becker et al.<\/em>, 1988; Uptake of soil moisture in dry season<\/p>\n<\/td>\n \n<\/td>\n Available moisture depleted from surface down.\u00a0 Uptake by evergreens continues +\/- same through dry season & from deeper than deciduous.\u00a0 Soil moisture fairly constant below ca 1 m.<\/p>\n<\/td>\n \n<\/td>\n Jackson et al.,<\/em> 1995; Clay mineralogy of stream sediments<\/p>\n<\/td>\n Whole island<\/p>\n<\/td>\n Clays are mainly kaolinitic on andesite & Caimito volcanics; smectitic on Caimito marine sedimentary & Bohio.<\/p>\n<\/td>\n \n<\/td>\n Johnsson & Stallard, 1989<\/p>\n<\/td>\n<\/tr>\n Fine root biomass<\/p>\n<\/td>\n Gigante Peninsula (on mainland)<\/p>\n<\/td>\n Profile description & some analyses of red clay<\/p>\n<\/td>\n The study soil appears to be equivalent to Ava<\/u><\/p>\n<\/td>\n Cavalier, 1992<\/p>\n<\/td>\n<\/tr>\n Study<\/strong><\/p>\n<\/th>\n Location on BCI<\/strong><\/p>\n<\/th>\n Data & findings relevant to soil cover<\/strong><\/p>\n<\/th>\n Notes<\/strong><\/p>\n<\/th>\n References<\/strong><\/p>\n<\/th>\n<\/tr>\n Secondary phytochemical variation in Quararibea asterolepis<\/em><\/p>\n<\/td>\n \n<\/td>\n Distinction between Oxisols on andesite cap and Alfisols on slopes along southern Ava Trail<\/p>\n<\/td>\n Soils not significant factor in phytochemical variation<\/p>\n<\/td>\n Brenes-Arguedas & Coley, 2005<\/p>\n<\/td>\n<\/tr>\n Nutrient dynamics on three soil parent materials<\/p>\n<\/td>\n \n<\/td>\n Topsoil N, P & S at 15 m intervals along 200 m transects on andesite, Bohio & Caimito marine<\/p>\n<\/td>\n Some parent material differences for P, but very slight for N & S<\/p>\n<\/td>\n Yavitt, 2000; Yavitt & Wieder, 1988; Yavitt & Wright, 1996<\/p>\n<\/td>\n<\/tr>\n 5 years dry season irrigation experiment<\/p>\n<\/td>\n Caimito marine sedimentaries, Poacher\u2019s Peninsula<\/p>\n<\/td>\nOther pedospatial data<\/h2>\n
Previous data on soil cover of BCI<\/h3>\n
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\n \n \n \n \n \n \n \n \n \n \n \n
\nWindsor,<\/em> 1990<\/p>\n<\/td>\n<\/tr>\n\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n
\nDaws et al.<\/em>, 2002<\/p>\n<\/td>\n<\/tr>\n\n \n \n \n \n \n
\nMeinzer et al.,<\/em> 2004;
\nAndrade et al.<\/em>, 2005<\/p>\n<\/td>\n<\/tr>\n\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n