Central America
Map 1 shows the distribution of 13 forest types in the Central America region. There are two types of non-tropical forest in Mexico, and the rest of the forest types are tropical. Much of the tropical forest in Mexico is montane, except the forests on the Yucatán peninsula. Due to the different origins of the datasets for each country, forest types do not always match on both sides of a national border. Quite a bit of disturbed natural forest is shown for Guatemala but not in its neighbouring countries: this is due to the absence of a "disturbed" category in the classifications used in the source datasets from those coutries. The needleleaf forests of Honduras are distinctly shown, and the freshwater swamp forests of Nicaragua. The Pacific side of the countries south of Mexico is much less forested than the Atlantic side, and the opposite is true for Mexico itself, except in the very south. There are also more dry forest categories along the Pacific coast than the Atlantic.
There are 10 Ecological Zones included in this region (Map 2). Much of Mexico is in the premontane dry zone, and much of the rest of the countries is in the premontane moist zone.
Mexico has by far the greatest amount of forested area in the region (Table 1, Fig. 2). Guatemala, Honduras, Nicaragua and Panama all had forest cover figures more than twice that for Belize, Costa Rica, or El Salvador. Apart from El Salvador, Mexico had the lowest percentage of forest protected, by quite a significant margin (Fig. 2). Excluding these two countries the other nations in Central America had between 19 and 43% of their forests protected, the highest being both Belize and Costa Rica. These are quite high figures for forest protection, and raise the question of the effectiveness of the laws that define the protection. FAO's forest change rate for Central America is -0.52%, a figure that includes Mexico but excludes Belize (FAO, 1995). This is much higher than the global average which is listed as -0.2%.
Of the 13 forest types in the region lowland evergreen broadleaf rain forest covered the greatest area and thorn forest the least (Fig. 2, Table 2). Together the lower and upper montane forests in the region made up more than the lowland evergreen broadleaf rain forest, but the protection was low: 5.1% for lower and 8.6% for upper. The semi-evergreen moist broadleaf forest had the highest percentage protection (Fig. 2, 51%). This forest was found in the study to occur exclusively in Belize, but this was due to the re-classification of national datasets into the classification used for this project, and does not reflect a forest type endemic to Belize. Further work to smooth the different national classifications, particularly in cross-border forest areas, will be required to render the dataset truly reflective of forest type differences. Non-tropical sclerophyllous dry forest and tropical mixed needleleaf/broadleaf forest were the least protected categories. Most of these occurred in Mexico, but the latter type occurred in Belize and El Salvador as well. Freshwater swamp forest occurred in Belize, Guatemala and Nicaragua, and was protected in each country, although most of the protection was in Guatemala (Table 2), giving an overall figure of 25% . Belize, Honduras and Nicaragua had tropical needleleaf forest, and in all countries it was protected. However, the overall protection was low, 7.8%.
Premontane dry and premontane moist were the two zones with the greatest forest cover in the region (Fig. 3). There were nine forest types in the former, all of which had some protection except the disturbed natural forest category (Table 3). Two other types had very low protection, tropical mixed needleleaf/broadleaf forest and non-tropical sclerophyllous dry forest (Table 3). The latter type was only protected in two of the zones it occurred in (and there only minimally), so the variants in the unprotected zones should be investigated with regard to extending protected areas to include these. In the premontane moist zone all forest types represented had some protection except the sclerophyllous dry forests. However the former had very little protection (2.6%, Fig. 3). Lowland evergreen broadleaf rain forest and non-tropical mixed needleleaf/broadleaf forest occurred in all zones except two (Table 3). All other forest types were represented in fewer ecological zones. One forest type was confined to two ecological zones: thorn forest. This only occurred in Mexico (Table 2, Map 1), and was only protected in one of the zones: the unprotected variant in the lowland arid/desertic zone may be quite different from that in the zone with protection, and should be investigated further.
In an attempt to impartially indicate natural, undisturbed forest variants which may be under the most immediate threat of destruction, a list was drawn up that pinpointed those under 100 km2 in extent with none protected. These are variants of relatively limited extent and which do not even have any legal protection; possibly much less actual protection. Some of these forest variants may indeed be truly rare and unprotected types, others are clearly fragments of forest at the end of their ranges, as for example certain types of dry forest should not normally occur in moist ecological zones, or vice versa. An in-depth analysis of these forest variants is outside the scope of this study. There were 4 of the 59 variants in Central America that met these criteria, and these are listed below (T=tropical forest type, N=non-tropical forest type):
The drier ecological zones, in general, supported less forest cover (Table 4), although the montane dry zone was 66% forested, which was an exception. This was a relatively small non-tropical zone (Map 2). The percentage of the ecological zone that was covered by protected forest was 0% for three zones and less than 5% for a further four zones.