Riverine-Associated Swamps

_______Riverine-associated swamps of the Rio Bravo Conservation Area are found primarily along Booth's River, Irish Creek, and Rio Bravo. Annual fluctuation of the water level within these swamps is minimized by the slow and consistent flow rate of the drainages to which they are linked. Vegetation within the riverine-associated swamps is dominated by a rush-sedge community. Soils of these swamps are primarily peaty clays of moderate to high fertility status.

_______The prehistoric Maya are known to have developed riverine-associated swamps for agriculture in other areas of northern Belize such as along the New and Hondo Rivers (Bloom et al. 1985; Turner and Harrison 1983). Agricultural development of these swamps by the prehistoric Maya required the construction of drainage facilities such as canals and raised cultivation platforms. Drainage systems such as those built by the prehistoric Maya can be developed incrementally, and high returns to labor can be assured by the inherent suitability of the soils for agriculture when properly drained (Darch 1983; Miksicek 1985; Pohl and Miksicek 1985; Turner 1983b).

_______Archaeological surveys in areas immediately adjacent to Pulltrouser Swamp in northern Belize, a riverine-associated swamp with ancient Maya field systems next to the New River and north of Orange Walk Town, have documented ancient communities adjacent to the swamp and an overall settlement density for the vicinity averaging perhaps 26 structures per km2 (Turner and Harrison 1983:263). Thus, even where these zones are available, they support relatively low settlement densities. Riverine-associated swamps make up 8% of the Gallon Jug Region, equal to that of northern Belize, and represent a potentially important agricultural resource in the area. Not surprisingly, this resource is underrepresented in the Hills Subregion (4%), which is characterized by good drainage, but is more prevalent in the Lowlands Subregion (12%) and represents proportionately more of the area than found in northern Belize (see Figure 3).

Closed-Depression Seasonal Swamps

_______Closed-depression seasonal swamps are karstic depressions filled with deep deposits of impermeable clays. These seasonal swamps are not linked with river systems. During the rainy season, closed-depression seasonal swamps hold significant amounts of water but, during the dry season, they desiccate except for occasional sinkholes (see Cowgill and Hutchinson 1963; Lundell 1937; Siemens 1978). Even though these zones are seasonally inundated, the low marsh forest vegetation of these seasonal swamps is adapted to very low moisture requirements in order to survive the desiccation of the dry season. Soils of the closed-depression seasonal swamps are heavy clays with severe limitations to agricultural development related to both chemical and physical factors (see Fedick and Ford 1990; Pope and Dahlin 1989).

_______The exceedingly poor agricultural environment offered by the soils of the closed-depression seasonal swamps would have made even extensive cultivation by the prehistoric Maya a very risky, low-return endeavor. If developed for agriculture through drainage canals and raised platforms, the unfavorable nutrient, hydrologic, and mechanical soil environment of closed-depression seasonal swamps would produce substantially inferior returns to labor in comparison to similar systems developed in riverine-associated swamps. Whether or not closed-depression swamps were developed for agriculture by the prehistoric Maya is a matter of considerable debate among current researchers (Adams 1980, 1982; Adams et al. 1981; Dahlin 1979; Fedick and Ford 1990; Pope and Dahlin 1989; Puleston 1978; Sanders 1979; Turner and Harrison 1978; Wiseman 1983). This debate, however, is focused on the core area where closed-depression swamps make up over a quarter of the area (see Figure 3). In areas where these zones do not represent a large fraction of the area, they could not present a significant agricultural resource.

_______The relationship between prehistoric settlement and closed-depression seasonal swamps is in need of further investigation, although recent studies suggest that the prehistoric Maya generally avoided settling in areas adjacent to these types of swamps (Fedick and Ford 1990; Ford 1986). Closed-depression swamps are not a significant portion of the Gallon Jug Region (6%). Yet, this land resource is distributed in greater proportions in the Lowlands Subregion (8%) than in the Hills Subregion (4%), and its presence in close association with riverine-associated swamps is distinct from other areas of the central Maya lowlands.