Pre-Colombian Jamaica: Caribbean Archeology and Ethnohistory

Environment, Fauna, and Flora / 49
central region, around the Cockpit country. Three- quarters of the island, including
the central mountainous region, is characterized by moderate rainfall,
> 1,270–2,540 mm (50–100 in) per year. The driest areas, with rainfall of
< 1,270 mm (50 in) per year, occur on the south coast, between Bull Bay and
Black River, and on the northwest coast, between Discovery Bay and Montego
Bay. Total rainfall for the island averages 1,960 mm (about 77 in) per year, with
a mean number of 123 rainy days. Such fluctuations as have occurred over the
period during which records have been kept are due to no more than random
factors (Gray 1990). The global figures conceal considerable variations over the
year. There are two peak rainy months, May and October, with average rainfall
totals of 239 mm (about 9 in) and 309 mm (about 12 in) respectively. The
driest month is March, with an average total of only 74 mm (about 3 in) each
year. Of course, there are exceptional events, notably the 37 hurricanes that
struck Jamaica between 1685 and 1974 (Clarke and Hodgkiss 1974). It is not
for nothing that the word is derived from the Taíno “huracan” (Senior 2003).
The combination of topography and climate means that Jamaica can be divided
into a number of natural habitats, granted that in the conditions of today
more than 75 percent of the land surface has been either cultivated or disturbed.
Those singled out by Downer and Sutton (1990:Figure 4) are as follows: (1)
wetlands. The largest such areas at the moment are the Negril and lower Black
River morasses. Here can be found lagoons and shallow estuaries, mangroves,
swamps, and swamp forests. (2) dry limestone forests. Remnants of these can
still be found at places along the coasts and inland, for example in the Dry Harbour
Mountains. No doubt in the past they were much more widespread. In
very parched areas, they are replaced by dry limestone scrub, as in the Hellshire
hills, and at Round Hill, the latter the site of a Pre- Columbian settlement.
(3) wet limestone forests. Most notably these include Dolphin Head, the Cockpit
country, and the John Crow mountains. (4) montane forests. These are essentially
confined to the upper reaches of the Port Royal and Blue mountains.
Sixty percent of the plant species in these areas are endemic.
Geology
Clearly, the topography of Jamaica is a direct reflection of the geological history
of the island. This has been well studied over many years (Donovan et al.
1995; Fincham 1997; Porter 1990; Porter et al. 1982; Robinson, in Donovan
and Jackson 1994; Zans et al. 1962). As Robinson reports, the stratigraphy of
the island is “simple in outline, but complex in detail.” (See Figure 8, a map