The Rainforest Reserve of Tobago

The challenge is the preservation of Tobago's rainforest in the 2000's.

The main ridge rainforest in Tobago was set aside for protection in 1764, the earliest nature reserve in the world. The people and government are rightly proud of this history. Deforestation has come to a stand still. But the total rates of world tropical deforestation are difficult to estimate, but probably somewhere around 100,000 square kilometres (39,000 square miles) of rainforest are destroyed or seriously degraded every year. Some unique rainforests have been almost totally destroyed. Loss of biodiversity, and global warming (due to increased levels of carbon dioxide) became global issues surrounding rainforest destruction. These and logging are threatening our rainforest. Please help, during your visit, leave only your footprints and take only photographs and memories.

The Rainforest Reserve Road

This road runs through the mature virgin rainforest reserve from just south of Roxborough through to Bloody bay taking you past the entrance to Gilpin Trace. The Gilpin Trace. Bamboos - an import - of huge circumference towered hundreds of meters above. Spiny palms such as the 'gru-gru' and bromeliad-covered cycads or tree ferns formed the middle story, while a great profusion of bromeliads adorned the tree branches of the canopy high overhead. This is the most impressive area of rainforest in Tobago that can be accessed by car, with a dense canopy, many epiphytes, and more palms.

the imortel tree imported to provide shade for cocoa trees

Tobago's rainforest -

the northern part of the island boasts the oldest protected rainforest in the world. We owe this to Stephen Hales, a scientist who convinced plantation owners that if they went an cutting down the forest, they would destroy the balance of nature and reduce the island to a barren desert: remarkably, he did this in 1776.

leaf cutting ants

The term tropical rainforest was coined at the end of the 19th century by the famous German plant geographer, Alfred Schimper, who first called it Tropische Regenwald. This tropical rainforest is characterised by evergreen woody vegetation with a high and usually closed upper canopy 30 to 50 meters (100-165 feet) above ground level. Emergent trees protrude partly or entirely above the upper canopy. Woody climbers called lianas that can exceed 20 centimetres (8 inches) in diameter are often common and their tops can reach the upper canopy. These are seen on most of the hilly roads around Castara. Numerous seedlings and herbaceous plants dominate the ground layer and there is often a rich epiphyte community, such as orchids and bromeliads, that grows on the trunks and branches. The tropical rainforest is stratified in the sense of having layers. An understorey, a closed canopy, and emergents are almost always recognisable.

bromeliad

Biodiversity -

most of the world's rainforests are within 10° of the equator. Tropical rainforests contain most of our planet's biodiversity and there are probably still millions of insects that have not been scientifically recorded. The rainforest is also able to establish itself on the tropical mountain ridge of Tobago, hence montane rainforest. The equatorial rainforest is a broad-leaved evergreen formation found in the warm and moist areas of the tropics at low elevation. Overall, moisture is the main factor influencing the distribution of equatorial rainforest, though other factors, such as soils, can be important locally. More importantly, there is no pronounced dry season in Tobago that could result in severe moisture stress. Other than the upper canopy and emergents, there are also two or more forest layers, or strata, made up mostly of seedlings, shrubs, and trees. Vines and epiphytes attached to the trees are often abundant. As seen from the air the upper canopy is closed and little light reaches the forest floor.

Montane rainforests are especially abundant in the upper reaches of Tobago. Sometimes these are called cloud-forests, these clouds can be seen forming over the mountains that surround Castara.

heliconia

The mangrove -

the tropical coast at the southern end near the airport are bordered by intertidal forest communities consisting of plants highly adapted to periodic inundation, boggy soils, and saline conditions. These mangrove formations are not rainforests, but are mentioned here because they often fringe the latter at their coastal limits. Plant diversity is low in mangroves compared to rainforests because of the stressful conditions presented by salt or brackish water, and to some extent by tidal flooding. The greatest development of mangroves is found in brackish water areas.

The mangrove genera Avicennia (sometimes known as black mangrove) and Rhizophora (red mangrove) are widely spread.

Soil erosion -

Tobago's warm climate and copious precipitation can lead to strong weathering of the soils. Minerals are continuously leached (that is, dissolved by rain water) from the upper layers. Latosols are very poor in most minerals, although quartz, aluminium, and iron become concentrated because they are not heavily leached by rain water. Accelerated biological activity in the litter, along with high levels of precipitation, means that nutrients, unless somehow captured, will be leached away rather rapidly. Given the poor soils on which the rainforest grows, plants can capture nutrients by "withdrawing" them to stems before leaves fall, accumulating them from rain water in epiphytes and on trunks and, most importantly, taking them in the root zone before they are leached away. This is done with the help of nutrient-absorbing fungi that become integral parts of the rootmats. These symbiotic associations are called mycorrhizae; the fungi supply nutrients to the rainforest trees and these in turn furnish energy to the fungi.

buttress roots of the cotton tree

The different types of soil found in tropical regions lead to a mosaic of rainforest types. Tobago's tall, diverse rainforest with high biomass is found on the upland latosols. In the sandy areas, where podzolic soils dominate, stunted communities are found, and though tree species diversity is reduced, a better light environment allows a wealth of orchids, bromeliads, and other epiphytes to flourish. Plant life is dominated by angiosperms, or the flowering plants. The vast majority of species are woody. Somewhere between 80 and 200 woody species can be found in one hectare (2.5 acres) of the mature rainforest.

The greenery of seedlings, vines, epiphytes, and small trees will often obscures a clear-cut view of the rainforest's strata. Once conceptualised, however, it is usually possible to "see" the various layers. Altogether five strata can usually be identified. The highest consists of emergent trees that poke their crowns above the canopy. Emergent trees can be over 50 meters (165 feet) high. These are often magnificent trees, such as the Kapok cotton tree, whose horizontal branches can stretch 30-40 meters (100-130 feet) above the upper canopy.

The main canopy fills the spaces between the emergent trees and forms a continuous cover with them. Vines, epiphytes and lichens can grow profusely in the canopy as they claim their place in the sun. Below the upper canopy there is an amorphous layer of smaller trees that may be anywhere from about 10 to 30 meters (33 to 100 feet) in height. Many can be young individuals of the giant tree species in the neighbourhood; others have attained their full size. A shrub layer below this lower tree level can also have young individuals of canopy trees, but there are also a wide variety of mature woody individuals. Finally, the lower understorey consists of numerous seedlings and scattered herbaceous plants. Rarely is the ground layer so thick that a rainforest cannot be walked through, at least with a little help from a machete.

Millions of animal and plant species yet to be found -

Rainforests are the most diverse ecosystems on Earth because of the incredible numbers of animal species present. Most of this animal diversity is made up of insects, but many other invertebrate groups are also involved. A large rainforest region may have in excess of ten million animal species, though most of these have yet to be scientifically recorded. In contrast to temperate latitude forests, animal diversity in rainforests is heavily arboreal and always greater than that found living on the ground. Even some large vertebrates have evolved to spend most of their lives in the trees.

Rainforest trees are pollinated by insects and birds -

The high diversity of many animal groups, such as birds, can in large part be explained by the fact that various unique combinations of species tend to inhabit different layers of the rainforest. Life based in tropical trees has led to the evolution of several peculiar adaptations. Mutual interactions between plants and animals are characteristic of rainforests. Many animal groups, but especially insects and birds, pollinate rainforest trees, as wind is not an effective pollinator for most plant species in this relatively closed environment. The insects receive food from nectar and other substances, and in return pollinate the next flowers they visit. After fruit is formed, rainforest plants more often than not use animals to disperse their seeds. Birds and mammals are important dispersal agents in the rainforest. Some animal groups provide protection to a plant species and receive living quarters in return. Ants are the most common and abundant animals found in the Tobago Rainforest Reserve, and they have evolved to occupy all strata, from the understorey to the emergents. Many tropical plants have hollow structures in their stems or twigs that stinging or biting ants use as homes. Ants supply nutrients to the trees and also in many cases protect them from leaf and seed predators.

morphome butterfly

It is now generally accepted by scientists, though unfortunately not by many developers, that rainforests are of more potential value as a long-term sustainable resource when left more or less intact than when converted to pastures or other simplified habitats.

Tobago is doing its bit -

Rainforests have built up the largest standing biomass of any plant community on earth, and they have done this almost independently of soil conditions by evolving nutrient recycling. Managed rainforests can thus provide huge amounts of valuable timber, retain the naturally thin topsoil layers, regulate run-off, and stabilise local climate. The nursery at Louis d' Or near Roxborough and the Botanical Gardens at Scarborough are involved in such programmes.

Your future will depend upon the rainforest -

because rainforests contain our planet's greatest diversity of plants and animals, they also represent giant gene banks that are surely needed now and in the future for new drugs, foods, and other products. Medicinal substances already discovered in rainforests, such as diosgenin as an active agent in contraceptive pills, reserpin for cardiac problems, and curare used in heart and lung surgery, point to further and increased potential uses. Only a very small percentage of rainforest plants have thus far been assessed for potential chemical value. There are a large number of natural and human-induced factors that impact on rainforests. Hurricanes such as the one in 1963, forest fires, disease, landslides, and other natural factors are now of rather minimal influence compared to human deforestation, such as that caused by logging, road building, mining, and large-scale clearing for cattle pasture and other agricultural crops.

Ant large-scale clearing that may be allowed to take place in Tobago's rainforest areas would be of such an extent that hundreds of years would probably be needed for natural recovery to produce anything similar to the original vegetation. Some of the world's unique rainforests have been almost totally destroyed. Loss of biodiversity, and global warming (due to increased levels of carbon dioxide) became global issues surrounding rainforest destruction.

We want you to take pleasure when you visit the Rainforest Reserve -but it is yours to take care of. Please:

• DO NOT PICK PLANTS
• DO NOT LEAVE RUBBISH
• DO NOT DISTURB BIRDS

Also See:
Tobago Rainforest Tour
Eco Adventure In Trinidad and Tobago
Tobago Nature - Bird of Paradise Island, Birdwatching Locations in Tobago