Tropical Forest Ecology 
 
Tropical forests are generically defined as "multi-storied, closed, broad-leaved forest vegetation with a continuous tree canopy of variable height and with characteristic diversity of species and life forms"."Tropical forests" are not one ecosystem. They encompass idyllic rainforest, cloud forest, dry forest, pine savanna, and much more.

Tropical rainforests are defined primarily by two factors:

 

1.    Located in the tropics.
2.    Amount of rainfall received (4-8m/yr) with little or no "seasonality", no dry or cold season of slower growth.


Tropical rainforests are the Earth's oldest living ecosystems. Fossil records show in Southeast Asia they have existed in their present form for 70 to 100 million years. Tropical rainforests are one of the most diverse, productive ecosystems in the world due to a combination of factors, including the stable environment, canopy structure, vertical stratification, habitat area and historical events.

 

Top Ten Forest Facts

 

1.    Tropical rainforests cover 2% of the Earth's land surface but they are home to two-thirds of all living species. Supporting an estimated 70% of terrestial plants, 30% of bird species & 90% of invertebrates.
2.    A typical four square mile patch of rainforest contains as many as 1,500 flowering plants species, 750 trees species, 125 mammal species, 400 birds species, 100 reptiles species, 60 amphibians species, and 150 butterflies species.
3.    One and a half acres of rainforest are lost every second, an area of rainforest the size of Belize is lost once a month.
4.    The U.S. National Cancer Institute has identified 3000 plants active against cancer cells. 70% of these are found in the rainforest. Twenty-five percent of the active ingredients in cancer-fighting drugs come from organisms found only in the rainforest.
5.    Experts estimate that we are losing 137 species every day due to rainforest deforestation, that's about 50,000 species a year.
6.    Over 20% of the world's oxygen is produced in the Amazon Rainforest.
7.    One tree in Peru was found to harbour forty-three different ant species - approximately the entire ant species in the British Isles.
8.    Estimates of global species diversity vary from 2 million to 100 million species, with a best estimate of somewhere near 10 million. Only 1.4 million have been named. More species are being discovered in the rainforests than anywhere else.
9.    Intact rainforests remove carbon dioxide, regulating local weather and global climate. The cutting and burning of rainforests contributes 25% of the world's global warming gasses.
10.    Half the total loss of rainforests has occurred this century, 25% in the last 20 years.

 
Why Conserve Tropical Forests?
 
Tropical Forests are of huge value to the biodiversity of the planet and hence to the existence of life on it.  They exists as home for people and animals as well as serving to regulate moisture and heat around the planet as part of the global weather systems.  The many values and functions of tropical forests may be described in terms of 'goods' and 'services' for the purpose of justifying its value to the sceptic. 

Benefits of goods and services are commonly assessed in terms of economic value, the monitary value of these banks of resources if they are expoited into the capitalist market economy.  This does not account for natural value of these incredible environments and their role in maintaining the balance of global climate for example.  However today, the modern world is increasingly recognising and acceptiong the importance of 'existence', the intrinsic and cultural values of the natural world.

 

Services

 

Climate Regulation

  • Rainforests are global heat and water pumps. Forests add to local humidity through transpiration, but above a rainforest the air is cooler so it is more likely to rain. Beneath the dense canopy humidity stays high and steady. The forests stay wet and evaporate vast quantities into the air above, forming clouds. Some falls again in the tropics but often clouds are carried great distances to fall as rain in the mid latitudes, often as far away as Europe and Australia.
  • Reducing forest cover reduces evaporation, more solar energy warms the earth's surface increasing air temperature. The hotter air over desert and grassland habitats, often replacing rainforests following logging or clearing, discourages cloud formation and deserts remain dry.
  • For more information visit: www.tropenbos.nl

 

Greenhouse Effect

  • Tropical forests have the best potential for greenhouse gas mitigation with the capacity to store carbon in their tissues as they grow. Reforestation of 3.9 million m2 (10 million km2) could sequester 100-150 billion metric tons of carbon dioxide over the next 50-100 years.
  • For more information visit: www.unep-wcmc.org

 

Watershed Protection

  • Forests help prevent drought and flooding by reataining water from tropical downpours and releasing it at a controlled rate. In a well-forested watershed, 95% of annual rainfall is trapped and released steadily, replenishing ground water and keeping streams flowing through dry seasons.
  • This constant supply of clean water is vital for sustaining an area's natural ecology. If large areas of watershed are deforested, catastrophic flooding can occur at huge environmental, economic and social costs. The Philippines is often affected by such events.
  • One of the most vital local functions fulfilled by forests is control of rainfall run-off to waterways.
  • For more information visit: www.tropenbos.nl

 

Soil Erosion Prevention

  • Linked to watershed protection is limiting sediment run-off, since forests anchor the soil with their roots. After heavy rains fall on deforested lands, run-off carries soil into local rivers increasing siltation, raising riverbeds, and leading to increased flooding. The increased sediment load is detrimental to river ecology, reducing light for photosynthesis, and smothering fish eggs.
  • On reaching the ocean, the water becomes cloudy causing regional declines in coral reefs.
  • For more information visit: www.tropenbos.nl 

 

Goods

 

Forest Resources: Timber

  • Forestry is important both to world economy, contributing 2% world GDP and 4% of GDP in developing countries, and comprising 3% international trade, and also to the local economies of many countries.
  • Timber is important at a local level, as a construction material in subsistence communities.
  • For more information visit: www.tropenbos.nl

 

Non-timber forest products (NTFPs - includes fibres, resins, plant and animal products)

  • An estimated 80% of the developing world relies on NTFPs. Although many are collected locally, some have been domesticated for large-scale production. In the international marketplace, NTFPs account for over US$1.1 billion in trade.
  • The projected economic value* of one hectare of forest in the Peruvian Amazon was US$6,820 per year if intact forest is sustainably harvested for fruits, latex and timber. But only US$1,000 if clear-cut for commercial timber (not sustainable) and US$148 if used as cattle pasture(*from Peters C.M., Gentry A.H., Mendelsohn R.O. (1989) Valuation of an Amazonian Rainforest. Nature Vol.339, pp 655-656).
  • For more information visit: www.tropenbos.nl

 

Food Source

  • An estimated 75,000 edible plants are found in rainforests but only 150 enter world commerce.
  • Rainforest Crops include rice, quinine, rubber, coffee, bananas, eggplants, lemons, oranges, tea, cacao, cashews, cassava, tapioca, peanuts, pineapples, guavas, brazil nuts, paw paws, avocadoes and many more.

 

Biological and Genetic Resource

  • Wild species have traits inadvertently bred out by selective breeding, thus domesticated plants and animals are more susceptible to pests and disease.
  • As such genes from wild plants are used to fortify modern varieties, and are likely to become increasingly important for this purpose.

 

Medicines

  • Rainforests are a vital source of medicines. Less than 1% of the world's tropical forest plants have been tested for pharmaceutical properties, yet at least 25% of all modern drugs came originally from rainforests, most first discovered and used by indigenous peoples.
  • Annual worldwide sales of plant-derived pharmaceuticals currently total $20 billion e.g. Morphine and Quinine. 70% of all plants known to have anti-tumour properties come from tropical rainforests.

 

Existence Values

 

Homeland for Forest Peoples

  • 500 million people live around tropical forests. Depending on the forests for products and services. For example, Rubber tappers are not indigenous to the forests of the Amazon but have learnt to live sustainably in the forest.
  • There are 150 million indigenous people who rely on the forests for their way of life. The forests meet their economic needs for food and shelter and form an integral part of their culture and spiritual traditions.
  •  For more information visit: www.cifor.cgiar.org

 

Non-material Values

  • The wonder and spiritual importance of the rainforests to all whom live in and around is profound. It is impossible to try to put a value on rainforests for all the riches they can and do offer.

 

Biodiversity

  • This situation has been likened by biologists Anne and Paul Ehrlich to "an aeroplane losing the rivets which keep it together. No one knows how many rivets the plane can lose before it falls apart."
  • For more information visit: www.iucn.org
How Are Tropical Forests threatened?

 

Extinction is a natural event and, from a geological perspective, routine. We now know that most species that have ever lived have gone extinct. The average rate over the past 200 million years is 1-2 species per million species present per year. The average duration of a species is 1-10 million years (based on the last 200 million years). There have also been several episodes of mass extinction. In the modern era, due to human actions, species and ecosystems are threatened with destruction to an extent rarely seen in the Earth's history. Industrial society has tended to see forests as free sources of valuable materials or as needless woods, occupying land and getting 'in the way' of development. As a result, threats to tropical forests exist at a range of scales: local - national - international.

 

Local Threats

 

An estimated 60% of tropical deforestation is caused by subsistence activities by people who use the rainforest's resources for their survival. Activities include:

  • Slash and Burn techniques for forest clearance. This is achieved by clearing shrubbery and forest trees, leaving areas to dry and then burning it. The land is planted with crops like bananas, palms, manioc, maize, or rice. After a year or two productivity of the soil declines, and transient farmers move on.
  • Wood gathered from forests is the major fuel in many countries.
  • Introduction of domesticated animals by local land users can devastate local wild animal populations.
  • Hunting to support subsistence agriculture is another major threat to wildlife at a local level.

 

National Threats

  • Government policies and politics affect all levels of development, from local initiatives to international relations. All of these affect the tropical forest ecosystem.
  • Governments encourage colonization of rainforest land. This land is seen as unproductive as it does not contribute to GNP. Tax incentives and building of large-scale infrastructure also drives colonisation.
  • Resettlement programmes are another method of colonising the rainforest frontier.
  • Increased levels of agriculture such as cash crops and cattle ranching put pressure on rainforest ecosystems due to land requirements.
  • Legal logging practises. For more information visit: The Rainforest Information Center

 

International Threats

 

Most threats on an international level are driven by economic forces.

  • Oil extraction. Like mining this process can devastate an area through the destruction of the forest, increased levels of infrastructure and workers, and pollution resulting from the oil extraction process.
  • Mining (strip and open cast mining are the two most destructive types). Apart from the simple destruction of the forest above and around the mine, the mining process releases harmful toxins, like mercury and cyanide into local waterways, polluting the waters and surrounding lands.
  • Cash crop agriculture has driven poorer people in to marginal land forcing many to cultivate forested areas.
  • Ranching. Increased demands for cheap meat products in developing countries have driven market forces in this area.
  • Logging. Continual demand for timber drives this destructive force. Short term logging concessions and the inability to control logging activities increase the rate of forest loss.
  • Trade in endangered species is a multi-million pound economy and is steadily increasing with Bushmeat being one of the most significant trade products.

Edward O Wilson, an eminent biologist, discusses the loss of biodiversity in the book The Diversity of Life. Here he highlights the gravity of the situation.

 

" The worst thing that can happen, will happen, is not energy depletion, economic collapse, limited nuclear war, or conquest by a totalitarian government. As terrible as these catastrophes would be for us, they can be repaired within a few generations. The one process ongoing in the 1980's that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats. This is the folly that our descendants are least likely to forgive us." The Diversity of Life

 

For more details on threats, see: World Rainforest Movement or The Rainforest Information Center

Forest Conservation Efforts:  
 
There are many theorised methods of forest conservation. However, the rate of deforestation is still increasing. New methodologies are being continually redefined in the hope that an effective result will be realised, but there is no 'one size fits all' solution. Different countries, regions and areas must use a combination of techniques to ensure forest conservation is a viable prospect. Some conventional approaches include:
 
The Tropical Forest Action Plan
 
  • The TFAP was launched by the Food and Agriculture Organization of the United Nations (FAO), the United Nations Development Programme (UNDP), the World Bank, and the World Resources Institute.
  • With a remit to look at major topics of tropical forest problems including; forestry and land use, forestry-based industrial development, fuel wood and energy, conservation of tropical forest ecosystems, and institutions.
  • For more information visit: www.odi.org.uk

 

The International Biodiversity Program

  • Designed to increase the global knowledge of biodiversity through data collection worldwide.
  • Aims to link organisations through data and idea sharing in order to assist conservation strategies.
  • Debt for Nature Schemes
  • Debt-for-nature swaps involve purchasing foreign debt, converting that debt into local currency and using the proceeds to fund conservation activities.
  • Proven to be successful in some areas although still remains highly controversial.

 

Sustained Yield Forestry

  • Aims to ensure long-term productivity of timber.
  • Under a rotation scheme the forest is segmented, whilst certain areas are harvested, others are being planted.
  • Selective Logging
  • Includes plantation schemes, decreasing levels of infrastructure, establishing buffer zones, only logging certain species over certain ages, directional tree felling and careful planning, these all contribute to reduce the impact of logging.

 

Ecotourism

  • Seen as a positive way for developing countries to bring in foreign revenue through non-extractive resource use.
  • Must be properly planned and have strict guidelines to ensure its long-term sustainability and success.
  • Parks and Reserves
  • Designation of areas where no extraction of natural resources takes place. However people that rely on the forest can loose or have their livelihoods diminished.
  • This practise must work in conjunction with alternative development schemes.
  • For more information visit: www.iucn.org

 

Species Action Plans

  • In many areas plans are implemented to protect either specific or a range of species by measures such as legal protection, translocation, captive breeding as well as physical protection within designated reserves.
  • For more information on conservation approaches visit The Rainforest Information Centre
 
Coral Cay's Contribution To Forest Conservation: 
 
The specific conservation aims on Coral Cay forest projects depend on a number of factors, including project partners and location. But Coral Cay effectively works to provide biodiversity information and local environmental capacity such that decision support tools (e.g. habitat maps) can be developed to aid local environmental management strategies, e.g. community-based reserve designation and management.

Coral Cay works across a range of spatial scales to achieve conservation objectives. Our forest conservation projects work at a local level, often with local communities, and engaging other local stakeholders through alternative livelihood provision and capacity building e.g. skills training, environmental awareness schemes. At a national level, we collaborate with NGOs and Government departments to ensure more effective adoption of conservation outputs. Finally at an international level, through our volunteer programme, and also promoting project work and outputs at internationals forums and relevant media to encourage greater support for work 'on the ground'.

 

Survey Methodologies

The terrestrial biodiversity survey work of CCC follows widely accepted and standard approaches using peer-reviewed methods. The survey work is normally composed of three major elements, which include:

  • Vegetation surveys and habitat mapping
  • Vertebrate surveys
  • Invertebrate surveys

 

Results of Coral Cay's efforts: 
 
Coral Cay conducts baseline surveys of natural resources for countries that have limited financial and technical resources to do the job themselves.

This information is then compiled and analysed to formulate recommendations for sustainable management and conservation which can only be developed by local stakeholders.

 

Baseline Data

 

Coral Cay surveys focus on faunal and floral biodiversity, and this baseline ecological information provides:

  • ecological data for habitat comparisons between monitoring sites. This includes assessing relative abundance and distribution of species in relation to habitat type.
  • information for comparison with scientific surveys in other rainforest environments.
  • records for national and International biodiversity databases and to compile full species inventories of the areas studied.
  • Provide baseline data on which future management guidelines can be developed.

 

Data Analysis

 

Ultimately, the empirical data generated will be integrated with other (environmental, social and economic) data sets using a Geographic Information System (GIS) in order to produce spatially referenced end user natural resource management tools.

 

What happens to the data?

 

The Coral Cay Data Highway flow diagram provides a graphic illustration of the 'inputs' and 'outputs' into data collection and analysis. Specifically for the forest projects, spatially referenced land cover data using digitised maps, aerial photographs and satellite images of the forest habitats is digitised into a GIS to create a base resource map for the forest area in question. Biodiversity distribution data gathered by Coral Cay volunteers is then overlaid onto this base map to classify the digitised features and produce detailed habitat and species distribution maps. The faunal and floral community composition data can then be extrapolated to classify other similar habitat areas within the same region of forest. Outputs from projects come in the form of resource assessment reports, conference papers, publications in peer reviewed journals, field guides and education materials.

 

Your Data

 

Every volunteer contributes valuable resource assessment data to a wider conservation process. Your data, in combination with that of others, contributes to the development of all outputs (as detailed above). Unfortunately it is not possible to compile reports regarding the data collected by individual volunteers but all your data is summarised in regular reports and other project outputs. Please be aware that the website is regularly updated and changed and may not feature all outputs produced at a particular expedition location. However, the CCC head office holds an extensive library of past reports, outputs, and other literature relating to the work of CCC, that we welcome you to consult. For further information, please contact the CCC science department science@coralcay.org