Rainforest Booklet Final Version

THE TROPICAL RAINFOREST

OF

TOBAGO:

The Main Ridge

"Did also in pursuance of your said Instructions remove to Your Majesty a tract of Wood Land lying in the interior and most hilly parts of this island for the purpose of attracting

frequent Showers of Rain upon which the Fertility of Lands in these Climates doth entirely depend.

William Young

Assented to by his Honour the Commander in Chief this

Thirteenth day of April One Thousand Seven Hundred and Seventy Six."

The Tropical Rainforest of Tobago: The Main Ridge

Graham Wellfare and Hema Singh

Environment Tobago

A project by Environment Tobago

in collaboration with

BP Trinidad and Tobago

Acknowledgements

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This circumstances under which this book came to be, are indeed unique. Graham Wellfare, a visiting volunteer from London , wrote the initial version of this book in 2002-2003. The wealth of information contained within its pages remained quietly seated at Environment Tobago until 2008 when it re-emerged. It is now updated, re-edited and new information have been added which includes burning issues such as Global Warming and Climate Change. There is a glossary, facts and activities all relating to rainforests.

The thorough research done by Graham is commendable and we would like to acknowledge his efforts and thank him for leaving with us this invaluable tool which will be used to raise awareness and communicate the value of Tobago’s Main Ridge Rainforest.

Special thanks to Mrs. Patricia Turpin, President of Environment Tobago for her insight and vision for this project and the time she volunteered to edit this book.

Thank you to the Board of Directors of Environment Tobago for acknowledging that this project is worth pursuing.

Thank you to Mrs. Claudette Allard, Chief Education Coordinator, the Division of Education, Youth Affairs and Sport, Tobago House of Assembly for providing the Foreword, and from inception, pledging the Division’s full support for this book and recognizing the crucial role it will play in achieving conservation and protection of our Rainforest.

To the Management and Staff of BP Trinidad and Tobago LLC, thank you for making this project possible. Your demonstration of, and commitment to Corporate Social Responsibility is clear. Thanks to your dedicated staff for reviewing this book and making valuable input which resulted in this final product.

Photo Credits: Photographs by Graham Wellfare, Hema Singh, Bertrand Bhikarry

Cover Photograph: The Main Ridge Forest Reserve, Tobago

Research and Script Preparation: Graham Wellfare and Hema Singh

Editing: Patricia Turpin and Hema Singh

Layout and Drafting: Hema Singh and Patricia Turpin

Copyright © 2009 by Environment Tobago. Information contained in this book may be reproduced only for educational purposes and due credit must be given to Environment Tobago.

Table of Contents

Foreword…………………………………………………………. ……iv

Preface…………………………………………………………………..v

Chapter 1: What is a rainforest?................................................................1

Chapter 2: Where are rainforests found?...................................................3

Chapter 3: The Structure of Tobago’s Rainforest……………………….4

Chapter 4: The History of Tobago’s Rainforest………………………...8

Chapter 5: Why are rainforests so important?.........................................11

Functions and Services provided by Tobago’s Rainforest

Chapter 6: Biodiversity- The key to the rain forest survival…………..15

Chapter 7: Relationships in the Rainforest……………………………..19

Chapter 8: Plant Life on Trees…………………………………………22

Chapter 9: Nutrient Recycling in the Rainforest……………………….24

Chapter 10: Threats To Our Rainforest………………………………...26

Chapter 11: Climate Change and Our Rainforests……………………..29

Closing Thoughts………………………………………………………31

Appendix………………………………………………………………32

Glossary………………………………………………………………..33

References……………………………………………………………..35

Facts…………………………………………………………………...36

Activities………………………………………………………………37

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Foreword

iv

There are some things that define us in this small island of Tobago and one of them is our rain forest. This is part of our heritage, legally protected from human degradation and passed on from generation to generation since 1776, with each generation holding it in trust and passing it on, hopefully in prime condition to the next one.

This is indeed an awesome responsibility and is no more the responsibility of the Division of Agriculture, Marine Resources and the Environment or of Environment Tobago than it is yours and mine. We all have to feel ownership of it and take care of it in the same way as we take care of any other personal possession that we treasure.

But before we can take care of it appropriately, we need to understand it and feel pride in it as the national treasure that it is. It is in this area of educating the public about our rain forest that Environment Tobago has stepped forward in collaboration with BPTT and taken on the educating of people as their responsibility. They have indeed done a marvelous job and are to be commended.

This book will be useful to students and teachers in schools and other institutions. It will be useful to persons interested in the natural history of Tobago and the region as well as to the visitor to Tobago. It is well set out and extremely reader friendly with numerous illustrations and reading it will provide a pleasurable experience for all.

Mrs. Claudette Allard

Chief Education Coordinator

Division of Education, Youth Affairs and Sport,

Tobago House of Assembly

Preface

v

The first time I reviewed a draft of this book “Tropical Rainforest of Tobago-the Main Ridge”- the potential for addressing information gaps and changing the mindset of our citizens to conservation and stewardship was made starkly obvious. Finally, the book has been completed, with thanks to its authors. The importance of this book cannot be underestimated.

This Ecosystem- the oldest “reserve” in the western hemisphere- having been so declared in 1765; is just a small part of the Rainforests world-wide situated north and south of the Equator in a narrow belt. Most of them are under threat from one source or another. In T&T, our forests have disappeared at a rate of 0.8% per year and between 1990- 2000, 2% have been removed.

Tobago’s Main Ridge forest reserve is 3956 hectares in size. It houses a vast variety of biodiversity; it is ecologically healthy, biologically diverse and contributes to our well-being. It provides watershed protection, soil protection, erosion control, landscape beauty, disaster risk reduction, carbon sequestration, climate regulation, water for all of our uses- domestic and commercial, and recreational and eco-tourism services.

Yet, we have threats to this wonder of nature from, forest fires (man-made), Illegal logging, quarrying, squatting, invasive alien species (bamboo), unsustainable extraction of plants and animals and climate change impacts.

Despite these threats, we offer this book as a way of drawing attention to the environmental issues affecting the rain forests locally, nationally and globally. A greater awareness of the links between this forest and our well-being will be fostered, and our population will learn to steward and support its growth in a sustainable manner, taking ownership of this, our greatest natural treasure.

Mrs. Patricia Turpin

President

Environment TOBAGO

Chapter 1Chapter 1Chapter 1Chapter 1 What is a Rainforest?What is a Rainforest?What is a Rainforest?What is a Rainforest? A rainforest is “a tree covered area in warmer regions of the world where rainfall averages over 200 cm per year, allowing for year round growth” The Green Encyclopedia.

This rather brief, dull description of a rainforest doesn’t do justice to these wondrous places.

When you think of what a rainforest is what comes to mind? Heat, humidity, noise, smells, danger, beauty, trees, rain,

biodiversity, deforestation, birds, snakes…..the list is almost endless. This is truly what a rainforest is.

This booklet gives you an introduction to the wonders of the rainforest and why they are so important to our future. By

focusing on Tobago’s unique forest reserve this complexity begins to unravel.

Rainforests are not just about trees and wildlife, they perform many functions essential to the earth’s and our own well being. However, they are still threatened, with repercussions that continue to be disastrous for everyone. Perhaps if the world looked to Tobago and its rainforest reserve the true value of this natural resource can be realised.

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When is a rain forest not a rain forest?When is a rain forest not a rain forest?When is a rain forest not a rain forest?When is a rain forest not a rain forest?

Other forests exist within the tropics that do not receive enough rainfall to be considered true rainforests. There is generally a dry season that limits growth and causes some trees to shed their leaves. These are known as ‘monsoon forests’, ‘seasonal evergreen forests or ‘deciduous seasonal forests’. While they perform many of the functions of the rainforest they do not have the diversity of life.

The forested areas outside of the reserve in Tobago are generally seasonal evergreen forests while Little Tobago is covered with deciduous seasonal forest.

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Photo: H. Singh

Photo: H. Singh

Rainforests are found in 3 main areas of the world: South East Asia, Central Africa and Central and South America. Existing in a narrow band North and South of the equator and occupying less than 1% of the earth’s surface, they have the greatest concentration of wildlife of any ecosystem.

The map below indicates where rainforests are naturally found but much of this has been lost, particularly in South East Asia. Huge tracts still exist in Amazonia and central Africa but even these are constantly under threat.

You might ask yourself why a small place like Tobago has a rainforest when it is not in any of these regions. Even more remarkable is how this rainforest is still standing when all around the world deforestation is so rampant? This is a story of plate tectonics and of a man who had the vision, over 200 years ago.

Chapter 2Chapter 2Chapter 2Chapter 2 Where Are Rainforests Found?Where Are Rainforests Found?Where Are Rainforests Found?Where Are Rainforests Found?

Map Showing Major Rainforests of the World

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Depending on its history and location, rainforests typically have 4 layers:

The emergent layer where the giants of the forest occur. Trees here can grow in excess of 50m.

The canopy layer this is the area in which the majority of trees exist as well as most of the wildlife as this is where sunlight is most abundant.

The under story layer is the section in which tree ferns, palms and slow growing trees predominate due to their ability to grow in low levels of light.

The ground layer is the section in which non woody plants and tree seedlings occur. Little light penetrates here so growth is sparse.

This rainforest structure is relatively stable as there is little light for seedlings to take hold. This is known as a climax community. However as soon as a large tree falls, light becomes available on the forest floor. Almost immediately this space is filled by herbaceous plants and climbers. Through the jumble of fallen old growth, pioneer trees make their way toward the sunlight. In turn, these trees provide shelter for the emergent trees to grow, and eventually fill the gap.

Chapter 3Chapter 3Chapter 3Chapter 3 The Structure of Tobago’s RainforestThe Structure of Tobago’s RainforestThe Structure of Tobago’s RainforestThe Structure of Tobago’s Rainforest

Pioneer Trees

Because competition for light is so intense pioneer trees have to be quick growing to prevent themselves from being smothered by other plants. To achieve this they often have large leaves and lightweight or hollow trunks, both of which maximize photosynthesis for growth. They also have slippery trunks and often enlist the help of ants to avoid other plants taking hold. Pioneer trees provide perfect sheltered conditions for canopy or emergent trees to grow below them and although they may only last 30-40 years, they play a vital role in the rainforest structure.

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Layers In A Rainforest

Emergent Layer

Canopy Layer

Understory Layer

Forest Floor Layer

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The rainforest on the main ridge has been classified as lower montane rainforest.

This occurs above 250m, where there are no emergent trees because of exposure to wind. The canopy reaches a height of approximately 30m. Hurricane Flora has had a great effect on the structure of the forest, leaving most of the trees no older than 40 years. However, there are pockets of older trees that escaped the full force of the storm.

The most common canopy tree is the rosewood, while a typical understory tree is the palm or mountain cabbage.

You will also find the tree fern here, the only living descendent of a family of trees that died out 290 million years ago.

The ground layer is not typical for a rainforest. as more light has been available since the hurricane to allow plants to grow.

A common ground plant is the “coconut-like” Cyclanthaceae.

The cecropia peltata or bois canot is one of the most common pioneer trees in the reserve.

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The Effect of Hurricane Flora: Near the entrance to the Gilpin trail, the structure of the rainforest can easily be seen. The slender trees and lush ground vegetation indicate that forest growth is new. The sheer force of the wind combined with the enormous volume of rainfall had a disastrous effect at the time. Forty years later the forest once again looks healthy. Fast-forward a couple of hundred years and the canopy trees will return while the ground vegetation will diminish.

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Tobago’s rainforest is unique in the Caribbean for two reasons. Firstly, Tobago used to be connected to South America and so has much of its flora and fauna. Secondly, the Main Ridge Rainforest has been legally protected since 1776, making it the oldest protected forest reserve in the western hemisphere.

Plate Tectonics Plate tectonics, or the movement of the earth’s crust, causes continents to move and mountains to form. Between 225 and 65 million years ago, land that eventually became Trinidad and Tobago, was much further west than it is today. This land was periodically connected to mainland South America, through sea levels falling, allowing for migration of plants and animals. Sea levels rose and Tobago became an island about 11,000 years ago. Tobago is believed to have been connected to Venezuela as there are some species that exist here and Northern Venezuela but not in Trinidad.

Protection For millions of years the rainforest here was undisturbed except for the odd natural disaster and some small scale hunting by the Caribs and Arawaks. In the 18th century the British arrived. This was the era of the sugar trade in Europe. Settlers arrived with land grants from the crown and began to replace the natural forest with sugarcane. At the same time, an English scientist Stephen Hales, was researching the circulation of sap in trees and the relationship between these green plants and the atmosphere. Results of his research displayed the intimate relationship between trees and rainfall. If you cut down trees rainfall will decrease.

A friend of Hales, Soame Jenyns, an MP in England, understood the enormity of this discovery and the importance of having it protected by law, what is now known as the Main Ridge Forest Reserve.

He suffered strong opposition as many other MP’s were plantation owners and viewed the forest as timber. Jenyns explained to them that if

Chapter 4Chapter 4Chapter 4Chapter 4 The History of Tobago’s RainforestThe History of Tobago’s RainforestThe History of Tobago’s RainforestThe History of Tobago’s Rainforest

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the forest was cut down then Tobago would be turned into a desert and their crops would fail.

After 11 years of persuasion, an act was finally passed on 13th April, 1776 to protect the forest forever.

This story is remarkable and it constitutes what many consider to be the world’s first environmental act. But it is also a tragedy, this knowledge has been known for two centuries but deforestation still continues apace worldwide.

Hurricane Flora

In 1963, hurricane flora swept through Tobago devastating 75% of the forest. Many of the birds and animals starved as a result -their food supply had suddenly vanished. But we should not think this was a tragedy, hurricanes are natural events that cleanse forests of disease. In the 40 years since hurricane Flora, the rainforest has begun to grow back, so when you visit the reserve what you see is totally natural. Something very rare indeed for such a small place.

Map Showing Main Ridge Forest

Tobago’s Main Ridge Forest

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10

“Storms can cause extensive damage in the rainforest through tree falls. When a canopy or emergent tree falls, dozens of other neighboring trees, attached by lianas, are brought down with it. Surveying the forest following a storm can reveal numerous tree falls, light gaps, and fallen matter including epiphytes and branches. However, a healthy forest can recover from moderate storm damage in a matter of months or years. The "light gaps" are quickly colonized and soon filled by canopy trees, while the fallen matter is decomposed and reabsorbed back in to the system.”

http://rainforests.mongabay.com/0802.htm

Chapter 5Chapter 5Chapter 5 Why Are Rainforests So Important?Why Are Rainforests So Important?Why Are Rainforests So Important?

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RAINMAKER:

Trees create rain through ‘evapotranspiration’. Water that the tree does not use is transpired through its leaves, evaporating in the heat of the sun. This will condense to form clouds and eventually fall as rain.

BIODIVERSITY:

Rainforests account for a large proportion of the worlds flora and fauna (as much as 50% according to some scientists) yet much of it is still unrecorded. Locally this diversity can be utilized by harvesting the forest for food, timber, medicines and many other useful products. If harvested in a sustainable manner these products could also be traded internationally.

CARBON SINK:

Through Photosynthesis the carbon from carbon dioxide in the atmosphere is fixed or “sequestered” into the plants and trees. This helps to alleviate global warming.

WATERCATCHMENT:

Rainforests act like a sponge soaking up excess rainwater and allowing it to percolate slowly through the soil, enabling streams and rivers to run constantly throughout the year. This provides dependable, good quality water for millions of people in the tropics.

CONTROL OF SOIL EROSION:

The trees in a rainforest break the impact of heavy rain with its leaves and roots. A drop of rain can take as long as 40 minutes to reach the forest floor!

ALBEDO EFFECT:

Surface albedo or the ‘shininess’ of the land surface is a basic factor in controlling climate. Rainforests have thick, green vegetation which absorbs much of the suns energy limiting the amount of heat reflected back into the atmosphere and so controlling global warming.

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Two hundred years ago Tobago’s rainforest was protected for its rain creating properties. Since then the many other functions it provides have been realized. Today, the forest Reserve is considered vital for the islands’ livelihood.

Without it the water supply would be disrupted, crops would fail and coral reefs would die. Once again, remember that this is a service provided FREE by the forest. To replace or repair damage caused by deforestation would be enormous.

Water Supply

The rainforest provides rain and is the watershed for a large part of the island. It provides year round, clean household water for most of the eastern part of the island.

A study done on the Courland catchment area (which provides most of the western half of the island but is outside the forest reserve) suggests that due to deforestation and poor agricultural practices. Water supply has become less predictable and more costly in this area. Run off has increased in the wet season and water flow has decreased in the dry season. Soil in the water, ‘turbidity’, causes pumping stations to malfunction and costly chemicals are used to reduce the effect. Water shortages could become commonplace in the dry season unless action is taken like re-forestation of the hills in this area.

Coral reef protection

By controlling soil erosion and allowing year round clear water to flow into the sea. The rainforest protects many of Tobago’s reefs in the east. The beautiful reefs at Speyside, Englishman's Bay and Castara are all dependent on this service. Deforestation would result in increased turbidity and a change in the salinity of the sea due to flood/drought regimes in the rivers. Both could have a disastrous effect on the reefs. In turn the fishing and tourist industries, which are dependent on the reefs, would decline.

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Photo: B. Bhikarry

Diagram Illustrating the Benefits of a Healthy

Rainforest

Tourism

Tourism is Tobago’s second largest employer and its biggest money earner. The rainforest plays a key role in attracting visitors to this island with its beautiful vistas, stunning wildlife and easy access. Many guides are employed to show visitors these delights. Without it a large sector of the industry would be lost.

Timber

The reserve is too small and inaccessible to provide a timber industry in Tobago. If timber is to be extracted it should be outside the reserve in conjunction with agriculture.

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Biodiversity within a rainforest can be viewed on 2 levels: SPECIES diversity-the number of different species and GENETIC diversity - the differences within a species. Of all the earth’s ecosystems rainforests are the most diverse and productive. Although they cover only 6% of the land surface they contain over half the estimated 5-10 million plants and animals.

Awesome statistics abound. A hectare of rainforest in Brazil can contain 500 different species of trees. On one of these trees 400 unique species might be found. The value of this abundance cannot be over emphasised both for its aesthetic value and for the services it can provide to people. It is these products of the forests- the medicines the food and the chemicals that is one of the keys to their survival.

Genetic Diversity- The differences that occur within a species are vital to its long-term survival. These differences allow for adaptation to environmental changes – not every individual or population has the genetic make up to survive change. Habitat destruction decreases the gene pool and so decreases the chances of a species survival.

Why are rainforests biologically rich?

1. The tropics, where rainforests exist, have escaped the devastating effects of ice ages leaving them to evolve undisturbed for millions of years.

2. Most plants here are pollinated by animals and birds (as there is little wind). The relationship between animals and plants can effect the evolution of both creating new species in the process.

3. Rainforests are perfect breeding grounds for pests, viruses, bacteria and fungi. If only a few species were to evolve these would be quickly targeted and die off.

Chapter 6Chapter 6Chapter 6Chapter 6 BiodiversityBiodiversityBiodiversityBiodiversity–––– The Key To Rainforest SurvivalThe Key To Rainforest SurvivalThe Key To Rainforest SurvivalThe Key To Rainforest Survival

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Biodiversity in TobagoBiodiversity in TobagoBiodiversity in TobagoBiodiversity in Tobago

For such a small island Tobago is fortunate to have a very rich flora and fauna. This is because it was once joined to the South American continent and so has remnants of the life from the rainforest there. Although many of the larger animals have been ‘extirpated’ (become locally extinct) it still holds an impressive array of life. Tobago is less rich than its big sister Trinidad but it does have 15 birds, 4 frogs, 1 snake and 1 lizard that Trinidad does not have.

Tobago’s Flora and Fauna

Tobago’s rainforest remains poorly recorded except for birds and larger animals. No comprehensive records exist for insects or smaller animals. The last major survey of trees was in 1943, before the hurricane and plant records are rare.

It is difficult to specify the number of birds that live in the rainforest on such a small island, as there is a large overlap of habitats. Approximately 100 species of bird can be seen of which the following live exclusively in the reserve.

White tailed sabre-wing hummingbird

Golden olive woodpecker

Collared trogon

Great black hawk

Striped breasted spine tail

SPECIAL TO TOBAGO

Blue backed manekin Cocrico White tailed sabre-wing hummingbird Red snake or Tobago false coral

OTHER ANIMALS

21 snakes

5 large mammals

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Using BiodiversityUsing BiodiversityUsing BiodiversityUsing Biodiversity

Although it is the beauty and bounty of the rainforests that attract us to them in the first place, it maybe the wealth of the forest products derived from this diversity that could hold the key to their survival.

The diversity of life in rainforests means that there are more types of plants to use in industry, more types of fruits and crops that can be grown for food and more types of plants that can be utilised for their medicinal purposes. Below are just a few examples of what has been discovered in the rainforests.

All this sounds great but the issue is complicated by the manner in which these products are exploited and by the political consequences of some discoveries. For example logging has to be carried out in a sustainable manner so as not to compromise forest regeneration; property rights need to be addressed for all countries where rainforest products generate an income and are a part of community livelihood.

Industry: The sap of the Amazonian copaiba when poured straight into a fuel tank can power a truck. It is almost identical to diesel.

Agriculture: The dazzling array of fruits and crops from the rainforest offer varieties of food, that maybe resistant to pests and diseases that affect modern crops.

Medicine: 70 % of all plants that have been identified as having anti- cancer properties are exclusive to the rainforest. Only 1%of plants have been examined! The rosy periwinkle found in Madagascar gives a 99% chance of recovery from leukemia

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Tobago’s Medicinal CabinetTobago’s Medicinal CabinetTobago’s Medicinal CabinetTobago’s Medicinal Cabinet

Tobago’s rainforest is no different; there are a wealth of plants used locally for medicinal purposes. However the rainforest plants are poorly documented - much of the knowledge has been passed down through generations by word of mouth. A report does exist that lists plants that need to be researched for their chemical compounds.

This touches on an important issue. Knowledge like this is invaluable but unless it is written down it could become lost as the culture moves toward a more western dependency of synthetic medicines.

Some rainforest plants recommended for further research

The instantly recognizable dead cecropia leaf can be boiled and used as a tea for hypertension and diarrhea

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Chapter 7Chapter 7Chapter 7Chapter 7 Relationships in the RainforestRelationships in the RainforestRelationships in the RainforestRelationships in the Rainforest

Rainforest ecology is complex. Scientists have barely scratched the surface of understanding the rainforest's ecological complexities.

Relationships occur between plants, between plants and animals and between plants and fungi. This is what makes the rainforest work. But it also makes it vulnerable. By interfering in these processes, particularly through deforestation, vital links in the ecology can be broken, leaving the future of the forest in doubt.

The relationship between organisms is called SYMBIOSIS. Three types of symbiotic relationships occur in rainforests: Mutualism, Commensalism and Parasitism. These relationships can be mutually beneficial, benign or destructive. The following pages give examples of all three.

Diagram Showing Types of Relationships Found In Rainforests

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An agouti breaks open a

Brazil nut pod with its

powerful jaws.

The agouti and the Brazil nut: The bertholletia tree in the Amazon region produces a nut whose protective pod is so tough only one animal can crack it, the agouti. By producing more nuts than an agouti can eat in one meal the nuts become dispersed by the rodent who buries them for a later date. Ultimately, some nuts are forgotten and are left to grow into another tree. Remove the agouti and the berthollet ia t ree will disappear.

Mutualism

(Good for you, good for me)

Commensalism

(Good for me, doesn’t bother you)

Flower mites which feed on pollen hitchhike from one flower to a fresher one by climbing into the nasal passages of hummingbirds and disembarking when carried to another flower.

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Parasitism (Good for me, bad for you)

The leafcutter ant parasitic fly lays its eggs on the backs of leaf-cutter ants in this way target the porters which carry leaves. The larvae burrow into the ant’s body after hatching and feed on it until it dies.

Fast Facts

Type: Bug

Diet: Omnivore

Average Lifespan in the wild: several

weeks to several years

Size: 0.08 to 1 inch (2 to 25mm)

Did you know? Ants can lift and carry more than 3 times their weight!

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Chapter 8Chapter 8Chapter 8Chapter 8 Plant Life on TreesPlant Life on TreesPlant Life on TreesPlant Life on Trees

One of the remarkable aspects of the rainforest is the variety of plant life that lives on the trees. This is another form of rainforest relationships.

As so little light gets to the forest floor, plants have had to adapt to survive using alternative areas within the forest that provide more exposure to sunlight. This could be on the leaves of trees, the trunks or even on the plants already using trees as their home.

These plants: lianas (vines or climbers), epiphytes and stranglers play a vital role in the structure of the rainforest.

Epiphytes

Epiphytes are a truly remarkable group of plants. Orchids, ferns and bromeliads are just a few examples of floor plants that can live on trees. They have adapted to use every available inch on a tree. A tree in a pristine rainforest is often unrecognizable because it can be covered by these plants.

Epiphytes use trees only for support, this relationship is fairly benign, all their nutrients come from falling matter-leaves, dead insects or dust. Orchids and ferns trap this amongst their roots where over time a fine soil is formed.

Bromeliads also retain a reservoir of water at the base of their leaves. When matter falls here, a rich nutritious soup is created.

Stranglers

Stranglers are another remarkable group of plants. They are found only in rainforests and whereas epiphytes do not harm trees stranglers will eventually kill their host.

Starting life off as an innocent epiphyte a strangler will often take hold on a branch of a tree. As time goes by roots are sent down to the nutrients in the soil below. As the roots grow thicker, they gradually join up around the host tree and starve it of its nutrients and sunlight (“strangler” might be a misnomer). Slowly the original tree dies and rots away leaving a hollow, lattice tree in its place. This is a parasitic relationship.

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Vines or climbers

These plants, known as lianas, use the trunk of a tree to reach up toward the light. As they grow aerial roots are sent down to reach the nutrients in the soil. These cables that seem to descend from the sky can grow to be as thick as a mans thigh. Again this is a relatively benign relationship leaving the host tree unharmed.

A small bromeliad beginning its life on a branch.

Above: A strangler tree (the parrot apple in Tobago) takes a grip on its host

Left: A common sight in the forest reserve a cheese plant moves up a trunk to the light.

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Photo: B. Bhikarry

Chapter 9Chapter 9Chapter 9Chapter 9 Nutrient Recycling in RainforestsNutrient Recycling in RainforestsNutrient Recycling in RainforestsNutrient Recycling in Rainforests

We have discovered that rainforests are home to more species of plants than anywhere else so surely the soils must be fantastically nutritious. WRONG! Rainforest soils are surprisingly poor in nutrients. How can this be?

Firstly rainforest soils are typically very old. The rains over the last millennium have stripped the soils of its soluble nutrients. Secondly, the nutrients in dead organic matter such as leaves, wood and animals are very quickly broken down and reabsorbed by the plants. The nutrients are locked up within the plants. This rapid breakdown occurs because of the humidity and presence of bacteria, fungi and certain types of animals (mainly ants and termites). For example a leaf will take about 6 weeks to decompose in a rainforest while it takes up to a year in a temperate forest. All this leaves a very thin, typically 2-4 cm layer of fertile soil. For this reason the roots of trees are very shallow, tapping into the nutrients at the ground surface with the help of fungal threads.

Because trees are very shallow rooted they develop ‘buttresses’ to stabilize themselves.

TERMITES AND ANTS

These incredible creatures represent a crucial element in the rainforest ecology. Studies have shown that these tiny creatures can make up a quarter of all animal mass here. Termites are the principal recycler of nutrients from dead wood. Ants are the principal recycler of dead animals of a similar size.

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MORE ABOUT LEAFCUTTER ANTS

This family of ants, known locally as bachacs, is one of the most recognizable animals in the rainforest. Generally viewed as pests (especially in agriculture) they are in fact one of the principal agents in recycling nutrients in the forest. Leafcutters have been practicing agriculture for millions of years and live almost entirely on a fungus they produce from fresh leaves. The waste from this process is incredibly nutritious and is quickly absorbed by plants and trees. In fact the nutrients would probably go back to the very plants that provided the fresh leaves in the first place.

On The Trail of Leafcutter Ants

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Chapter 10Chapter 10Chapter 10Chapter 10 Threats To RainforestsThreats To RainforestsThreats To RainforestsThreats To Rainforests

Despite a widespread knowledge of the importance of rainforests they are still under severe threat. Huge areas are being lost due to deforestation and their integrity is being compromised by over hunting. In addition the silent threat of climate change could well be their ultimate downfall.

Deforestation

The principal causes of deforestation are:

Agriculture

Conversion of forests to agriculture accounts for over 60% of deforestation. Vast areas are cut, burnt and used for crops or livestock. Rainforest soils have been shown to be invariably poor for this type of practice. Often it is poor farmers of these regions that are forced to farm these areas. Within a few years the fertility is gone and the farmers have little choice but to clear new areas, only to repeat the cycle.

Logging

Again vast areas are destroyed by the effects of logging. This has been particularly severe in South East Asia where only a small percentage of the original forest remains. Logging not only often precedes conversion to agriculture; it also opens up areas to be farmed because of the roads built to transport the timber.

Deforestation is also being carried out for house building, new roads, mining and oil exploitation. Huge areas are also flooded through the construction of dams.

Bulldozers are used to help clear forests. They compact the soil, reducing the ability of the forest to regenerate even further.

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Hunting

Hunting for wildmeat has occurred in rainforests for as long as people have lived there. It is still a vital source of protein to many people in Amazonia and Central Africa. Population sizes in rainforests have generally been small enough for this to have little impact on the ecology of the forest. However, problems arise when hunting extends to providing for a wider appetite, either in cities or in other countries. This over exploitation of animals can have a subtle but important effect , particularly to the biodiversity. Remember everything is linked- if you lose one species you might loose others dependent on it. The forest could still be standing but the variety of life would be diminished. Hunting for the pet trade, furs and traditional medicines also play a part in species depletion.

Why animals are huntedWhy animals are huntedWhy animals are huntedWhy animals are hunted

• Caiman- Skins meat, oil

• Snakes- Skins

• Otters-Skins

• Primates-Medical science

• Birds- Plumes, pets

• Deer- Skins, meat

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Deforestation and Quarrying currently occurring in Tobago

Photo: H. Singh

Hunting in Tobago’s Rainforest

Tobago’s rainforest is well protected for its trees but all is not well for its larger animals. People have hunted here since they first stepped ashore many thousands of years ago. But over the last four centuries Tobago’s larger animals, or ‘game’, have been decimated.

Why has this happened? It is the age-old thinking of “limitless supply” people still believe they can hunt indefinitely without repercussions. Wrong! At the current rate the animals will join the others (shown on page 32) that have already disappeared. Although there is a hunting season this is largely ignored and rarely enforced.

A moratorium on hunting in the reserve needs to be imposed so a proper scientific survey can be done. From this, new stricter laws can be implemented while giving the animals a chance to recover. Ideally hunting should be illegal in the reserve. This will then provide a supply of animals to the forest outside this area where hunting can be controlled.

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Climate Change

The silent threat of climate change could hold the ultimate fate for the rainforest. The loss of forest cover will radically alter the surrounding climate by reducing rainfall and changing the albedo effect. Add to this the enormous amounts of carbon dioxide released through the burning of the forest and you have a recipe for disaster. However, as there are so many factors involved scientists are not certain what the eventual outcome will be. For example, is there a point in time where there is not enough forest to produce the rain it needs to sustain itself?

Chapter 11Chapter 11Chapter 11Chapter 11 Climate Change and Our RainforestsClimate Change and Our RainforestsClimate Change and Our RainforestsClimate Change and Our Rainforests

The Greenhouse Effect Solar radiation enters the earth’s atmosphere. Some of this radiation is absorbed by the ocean and other living things. About one third of the solar radiation is reflected back into outer space. However, gases such as carbon dioxide, methane and water vapour trap radiation and warms the earth. This heating of the earth or the greenhouse effect is a natural phenomenon and makes life possible. By warming the earth to just the right temperature living things are able to flourish.

Global Warming

Studies have shown that over the years, the average global temperature has risen and that this is as a result of increasing levels of carbon dioxide released into the atmosphere. This increased global temperature or heating up of the earth is known as Global Warming.

Climate Change This heating up of the earth causes changes in global weather patterns. Known climate can therefore become unpredictable and result in the following:

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Weather– related deaths

Increased Infectious diseases

Increased Respiratory illnesses

Lower crop yields

Changes in water supply and quality

Erosion of beaches

Loss of habitat and species

Forest composition

Geographic range of forests

Forest health ad productivity

Climate change is one of the biggest challenges facing our world today. Between 20 to 25% of carbon dioxide emissions come from deforestation and land use changes. Forests play a critical role in regulating the carbon dioxide in the atmosphere. Through the process of photosynthesis, forests utilize large quantities of this green house gas to make food, thereby reducing the amount in the atmosphere. By removing forests, the gas remains in the atmosphere and further, when we burn the trees, we release even more carbon dioxide into the environment!

It is imperative that we save what is left of our rainforests.

Here are some of things you can do:

Educate yourself & others

Plant trees

Reduce and Reuse paper

Reduce use of plastic and gasoline

Facts about the benefits provided by planting one tree:

Absorbs over one tonne of harmful greenhouse gases over its lifetime (US EPA)

Produces enough oxygen for 4 people every day (Tree Canada Foundation)

Provides the equivalent cooling effect of ten room-size air conditioners operating 20 hours a day (US Department of Agriculture)

Provides an estimated US $273 (about TT$1638) of environmental benefits in every year of its life (American Forests)

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Closing ThoughtsClosing ThoughtsClosing ThoughtsClosing Thoughts

Rainforests are awe inspiring places. Full of beauty, they provide the earth and its people with the essence of life, not just aesthetically but practically too. But there lurks a dark cloud over their future that possibly threatens us all.

Tobago offers a small antidote to this with its forest reserve, providing the world with a wonderful example of what can be achieved. However, it is a small place and most rainforests are huge in comparison- their protection is difficult and their future looks bleak. Ultimately their fate depends on whether their true value can be recognised, by everyone, from the poor farmer to the people in power.

Undeniably this comes down to money and the question:

“ are rainforests worth more standing than they are cut down? ”

We hope that we have proved that they are.

Perhaps all that is needed is a change in attitude, to realise that everything in life, like the rainforests, is connected. Plan for the long term. Think sustainably. Everyone would benefit not just a few. Unfortunately, changing attitudes and behaviours still remain the hardest task of all.

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Photo: B. Bhikarry

AppendixAppendixAppendixAppendix

Other Animals

Wild pig Raccoon

GOING, GOING……Animals that still survive in the rainforest.Animals that still survive in the rainforest.Animals that still survive in the rainforest.Animals that still survive in the rainforest.

GONEGONEGONEGONE……. but not forgotten. ……. but not forgotten. ……. but not forgotten. ……. but not forgotten. Animals that have become extinct in Tobago

Iguana

Armadillo

Agouti

Ocelot

Red Brocket Deer

Blue & Yellow Macaw Maned Wolf

Otter

Muskrat

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GlossaryGlossaryGlossaryGlossary

Annual ring - The growth layer of 1 year, as viewed on the cross section of a stem, branch, or root.

Biological control - Control of plants, diseases, and animal pests by the use of natural enemies. Bole - The main trunk of a tree. Browse - Small bushes, sprouts, herbaceous plants, small trees, etc., that wildlife feed on. Burn, controlled - Any burning that a landowner starts intentionally to accomplish a particular purpose, and over which he or she exercises some surveillance or control. Burn, prescribed - The application of fire to land under conditions of weather, soil moisture, and time of day, that will accomplish specific silvicultural, wildlife, grazing, or fire hazard reduction purposes.

Canopy - A collective term for the layer formed by the crowns of the taller trees in a forest. The canopy is the highest layer of the forest--the intertwined branches of mature trees that shade and protect lower forest layers and provide a habitat for insects, birds and small mammals.

Crotch - The fork of a tree or branch. Crown - The branches and foliage of a tree. Deciduous - Term applied to trees (commonly broadleaf) that drop all their leaves sometime during the year.

Dendrology - The identification and systematic classification of trees and shrubs.

Habitat -The environment in which the plant or animal lives.

Field layer - The field layer is the first layer of growth on the forest floor--a soft carpet of mosses, ferns, wildflowers, grasses and other low plants. It is a habitat for many insects, mammals, reptiles and amphibians.

Latitude - distance north or south from the earth's equator measured through 90 degrees

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GlossaryGlossaryGlossaryGlossary

Litter layer - The litter layer is the floor of the forest, where decaying plant matter and fungi undergo the transformation into soil. Bacteria, insects and worms in the litter help break down the plant matter.

Old growth - A forest that has never been changed by management or harvesting. This term is misapplied by many to describe any forest that appears to be old. Individual trees in this type of forest are usually over 200 years old, and there are large standing and fallen dead trees throughout the stand.

Photosynthesis-is a process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Riparian zone -That area adjacent to rivers and streams identified by vegetation, wildlife, and other qualities unique to these locations.

Sapling - A young tree of small diameter

Silviculture - The art and science of producing and tending a forest; the theory and practice of controlling forest establishment, composition, growth, and quality of forests to achieve the objectives of management. Snag - A standing, dead tree or a standing section of the stem of a tree broken off at the height of 20 ft or more. If less than 20 ft, it is properly termed a "stub.

Soil layer - The soil layer is the foundation of the forest, supporting and providing moisture and nutrients to plant and tree roots. It consists of decomposed plant matter and inorganic material, such as rocks, minerals and clay. Timber - A term loosely applied to forest stands or their products; often applied to wood in forms suitable for heavy construction (houses, ships, bridges).

Understory - The understory is made up of bushes, shrubs, woody plants and young trees reaching up to the forest canopy; it provides a habitat for birds and insects.

Virgin forest - A mature or over mature forest essentially uninfluenced by human activity.

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ReferencesReferencesReferencesReferences Books and Journals

1.Trinidad and Tobago report to FAO on plant genetic resources 1996. 2.Rainforest Action Network Factsheet no.10 3.Rainforest Action Network Fact sheet no.1 4. Tobago the forgotten island. The Naturalist 4,7. 1983. Dave Hardy 5.WASA and Thames Water International- Design of a Watershed Programme for Courland Catchment Tobago. 6. EMA- State of the Environment Report 1996. 7.Treatment and Cures with Local Herbs – Albetina Pavy 8 A Guide to the Convention on Biological Diversity- IUCN 9.In Search of Nature – Edward Wilson 10.Native Trees of Trinidad and Tobago – Victor Quesnel & T. Fareell. 11. The Snakes of Trinidad and Tobago – Hans E Boos 12. Wild Plants of the Eastern Caribbean – Sean Carrington 13. Neotropical Rainforest Mammals – Loise H. Emmons 14. Natures Services – Gretchen C Daily 15. An Introduction to Ecology – John Cloudsley-Thompson 16. The Private Life of Plants – David Attenborough 17. Birds of Trinidad and Tobago – Richard Ffrench 18. An Introduction to Conservation Biology- RB Primark 19. Medicinal Plants of Trinidad and Tobago – Commonwealth Secretatiat 20. The Empty Forest – Kent H. Redford, Bioscience Vol. 42. 1992

Websites www.freestockphotos.com www.gimp-savy.com www.sjs.sd83.bc.ca/lib/sd83/imagelib.htm www.Freefoto.com www.pic4learning.com www.ecuadorphotos.tripod.com www.zoonet.org http://idahoptv.org/dialogue4kids/season8/forestsdesertswetlands/glossary.cfm#forest http://www.enchantedlearning.com/subjects/rainforest/Where.shtmlhttp://www.enchantedlearning.com/subjects/rainforest/radiobuttonquiz/radio_button_quiz1.shtml http://www.enchantedlearning.com/subjects/rainforest/label/labelstrata.shtml http://www.srl.caltech.edu/personnel/krubal/rainforest/Edit560s6/www/facts.html http://www.srl.caltech.edu/personnel/krubal/rainforest/Edit560s6/www/whlayers.html http://www.playmasmontreal.com/images/Before%20the%20Destruction.ppt#272,12,Slide 12 http://www.saverfn.org/lessonssymb.html http://www.google.tt/imgres?imgurl=http://s.ngm.com/2007/01/hummingbirds/img/hummingbird-flower-615.jpg&imgrefurl=http://ngm.nationalgeographic.com/ngm/0701/feature4/ http://www.wildernessproject.org/members_join_nativetrees.php?gclid=CI-Hns6o4ZgCFQVhnAodwleMdw

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FactsFactsFactsFacts

• The area of a rainforest the size of a football field is being destroyed per second.

• The trees of a tropical rainforest are so densely packed that rain falling on the canopy can take as long as ten minutes to reach the ground.

• Giant bamboo plants can grow up to 9 inches per day

• Some rainforest monkeys are omnivores, eating both plants and animals

• Bats are essential for the pollination of many tropical foodstuffs such as bananas and mangoes

• I out of 4 ingredients in our medicines come from rainforest plants

• About 2000 trees per minute are cut down in rainforests!

Help Save Our Rainforests! Be a Part of the Solution!

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1. The very tallest trees in a rainforest are called emergents

Yes No

2. Are rainforests important to the environment?

Yes No

3. The upper parts of the trees in a rainforest are called the canopy

Yes No

4. Rainforests supply food, medicine, oxygen, and clean water.

True False

5. Does it ever freeze in a tropical rainforest?

Yes No

6. Rainforests get over 100 feet of rain each year.

True False

7. The understory, the area between the leaves and the ground, is usually:

Shady and Cool OR Bright and Hhot

8. Are tropical rainforests always found near the equator of the Earth?

Yes No

9. How many species of insects live in rainforests?

Millions OR hundreds

10. Do the largest animals live on the forest floor?

Yes No

Activity 1Activity 1Activity 1Activity 1

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Tropical Rainforest Strata: Label Me!

Read the definitions, then label the strata (layers) of the tropical rainforest diagram below.

canopy - the upper parts of most of the trees (about 65 to 130 feet or 20 to 40 m tall). This leafy environment is full of life: insects, arachnids, many birds, some mammals, etc.

emergents - the tops of the tallest trees, which are much higher than the average trees (the canopy).

forest floor - the ground - it is teeming with animal life, especially insects and arachnids, plus large animals (like anacondas and jaguars).

understory - a dark, cool environment that is under the leaves but over the ground. Most of the understory of a rainforest has so little light that plant growth is limited. There are short, leafy, mostly non-flowering shrubs, small trees, ferns, and vines (lianas) that have adapted to filtered light and poor soil.

Activity 2Activity 2Activity 2Activity 2

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The Blue Morpho Butterfly (Morpho menelaus) is an iridescent blue butterfly that lives in rainforests of South and Central America, including Brazil, Costa Rica, and Venezuela and Tobago.

Anatomy: The Blue Morpho Butterfly is a species of neotropical butterfly that has brilliant blue wings (the females are are not as brilliantly colored as the males and have a brown edge with white spots surrounding the iridescent blue area). The undersides (visible when the butterfly is resting) are brown with bronze-colored eyespots. The Blue Morpho has a wingspan of about 6 inches (15 cm). Adults drink the juices of rotting fruit using their straw-like proboscis.

The caterpillar of the Blue Morpho is red-brown with bright patches of lime-green on the back, and it eats the plant Erythroxylum pilchrum nocturnally (at night).

Activity 3Activity 3Activity 3Activity 3

39

Rainforest

Activity 4Activity 4Activity 4Activity 4

Rainforest Anagram

tugnnhi

odueiudsc

gadneednre

ixecttn

gtrduho

Unscramble the words below

Answers: Hunting, Deciduous, Endangered, Extinct, Drought

Rainforests Are Beautiful...Help

Protect Them

Activity 5Activity 5Activity 5Activity 5

Colour the Beautiful Orchid Below Feel Free to Use Your Imagination!

Popular around the globe for their beauty and variety, orchids are the largest family of plants in the entire world. There are 25,000-30,000 different species of orchid, at least 10,000 of which can be found in the tropics. Orchid species can differ greatly from one another, with extreme variations in size, weight and color.

www.rainforest-alliance.org

Activity 6Activity 6Activity 6Activity 6

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