Per Dinerstein et al's classification (1995), the biotope belongs to the Central American Atlantic moist forest ecoregion category. The heterogeneous vegetation of the area is typical of inundated zones and is represented by several families that have adapted to the many aquatic environments. Lands prone to flooding account for more than 50% of the protected area (FUNDAECO/CECON, 2001). The most abundant habitats are lowland flood forest, highland forest and mangrove forest (Pérez et al., 2001). Plant groups associated with the many bodies of water are evident in the area. One important part of the biotope is under heavy human pressure, and grasslands and agricultural lands slowly creep upon the forest. Illegal human invasions of the area are abundant.
Lowland Flooded Forest
This type of forest thrives in grounds prone to periodical flooding, in marshes that locals call "swampos", generally around rivers and close to the lagoons in the southern area of the biotope. It is a medium-height forest, with trees between 15 and 20 m and rare individuals that project beyond the average canopy. The canopy is mostly sparse, which promotes a thick and complex understory of palm trees. The prevalent tree species, chew stick (Symphonia globulifera), Santa María (Calophyllum brasiliense) and water chestnut (Pachira aquatica) (CONAP, sf), mix with the corozo palm (Orbignya cohune) and Cyclanthus sp understory.
Detail of the lowland forest dosel (photo © PW-Guatemala)
It thrives in grounds not prone to flooding, generally in the central and eastern areas of the biotope. It develops in slopes or flat grounds, which apparently varies the flower composition (CONAP, sf). It is a well-developed and exuberant forest, with high trees and the occasional individual that projects beyond the canopy. Treetops are dense and at least three forest strata are evident: the highest up to 30m; intermediate, between 18 and 20 m, and the inferior, between 12 and 15 m. Although flat grounds are not prone to flooding, the slower drainage surely determines the presence of species that belong to flooded grounds, such as the water chestnut (Pachira aquatica) and chew stick (Symphonia globulifera). The understory abounds with ferns such as Pterocarpus officinalis. Some species, as Pouteria sp. and the tourist tree (Bursera simaruba), grow in slopes, which drain easily and faster, and are seldom found in rocky soils.
Mangrove forest, riparian and aquatic associations
There are different riparian and aquatic associations in the biotope. One of the more resilient communities is the mangrove forest, which is distributed almost exclusively in the southern part of the protected area. The canopy is very homogeneous, often of low height and does not grow beyond 5-8 meters, although some individuals protrude many meters above the average canopy. The mangrove (Rhizophora mangle) is the dominant species, although chew stick (Symphonia globulifera), Santa María (Calophyllum brasiliense) and water chestnut (Pachira aquatica) are also present (CONAP, sf). In some riparian places, there are well-established shrub formations of Chrysobalanus icaco (Pérez et al., 2001), which are as tall as or slightly shorter than the mangrove. The dragon blood tree (Pterocarpus officinalis) thrives in small isolated patches. Associations of Nymphaea ampla, Cabomba paleaformis, Ceratophyllum demersum, Utricularia sp. are evident in water communities, whereas Vallisneria americana and Potamogeton illinoensis are found in other places (Pérez et al., 2001).
Although some research has been carried out in the area, a few updated studies show the biodiversity status of Chocón Machacas. Among the very scant information available on the presence of major felines, Balas and Polisar (2001) report occasional sightings of jaguars (Panthera onca) in the area. Updated studies of the area report 130 bird, 31 mammal, 31 reptiles and amphibian, and 82 fish species. Preliminary studies indicate that the biotope might harbor an important diversity of the total Guatemalan aquatic flora. Among the prevalent fauna, one of the most important is the manatee (Trichechus manatus), although area inventories indicate that they are not particularly abundant (PNUMA, 1995). The neotropical otter (Lutra longicaudis) is one of the most common species. The crocodile (Crocodylus acutus) has become extinct (CECON, sf) due to illegal hunting.
The biotope's fauna includes several birds, such as the king vulture (Sarcoramphus papa) and the orange-breasted falcon (Falco deiroleucus), which are included in CONAP's Red List. The neotropical otter (Lutra longicaudis) is mentioned in CITES' Appendix I, and three turtles, the Tabasco mud turtle (Kinosternon acutum), the Mexican giant musk turtle (Staurotypus triporcatus) and the slider turtle (Trachemys scripta), as well as the manatee (Trichechus manatus), appear in IUCN's (1) Red List (2003).
1 The three turtles as LR and the manatee as VU