Topic Introduction

In this final topic, we look at the future of tropical forests. Over the past 100 years, tropical forests have been developed and converted to other forms of land use at an unprecedented rate. Figures published by the UN Food and Agriculture Organization indicate that we continue to lose forests, although the numbers that are published are frequently of questionable value.

The world’s attention was focused on the Amazon for a while, where major fires associated with the land clearance process achieved global news coverage. Headlines about the Amazon forest burning were widespread, but inaccurate. The majority of fires were on land where the trees had been felled earlier and left to dry out during the dry season. A few fires occurred within the forest itself, but these were rare in comparison to the number of fires on land where the forest cover had already been removed.

As in other parts of the world, the land clearance in the Amazon was for agriculture. There, the products being favoured were beef and soy, and there is an intimate and complex relationship between the two. In Southeast Asia, many forests have been cleared for oil palm plantations, and a few have been cleared for timber plantations.

Outcomes

By the end of this topic, you should be able to:

• Predict the effects of different types of disturbance on tropical forests
• Evaluate the relative importance of forest degradation and deforestation on the ecology of forests
• Compare the effects of logging with other forms of disturbance
• Assess the importance of invasive species as disturbance agents in pristine and modified forests

Topic Readings

Required Readings

• Ghazoul, J. and Sheil, D. 2010. Tropical Rain Forest Ecology, Diversity, and Conservation. Oxford, Oxford University Press, 516 pp. Chapter 16.

Optional Readings

• Ashton, P. 2014. On the forests of Tropical Asia. Lest the memory fade. London, UK: Kew Publishing. 670 pp. Chapter 9.
• Laurance, W.F. and Bierregaard, R.O. (eds.) Tropical forest remnants: Ecology, management, and conservation of fragmented communities. Chicago, Illinois, USA: University of Chicago Press.

Fundamental Concepts

PPT Presentations

This module contains one presentation:

5.2 A future for tropical forests.pptx Download 5.2 A future for tropical forests.pptx

Self-check Quiz (For certificate learning only)

After viewing topic presentations, take this self-check quiz to check your own progress. This quiz is designed to see how well you remember some of the issues presented in the topic. There are five questions, and each has a potential of 4 answers, only one of which is correct. When you are ready, click the link 'Self-check Quiz 5.2' to start taking the quiz.

Pre-readings and Discussion (For certificate learning only)

Once you have read Chapter 16 of Ghazoul, J. and Sheil, D. 2010. Tropical Rain Forest Ecology, Diversity, and Conservation, post one thought provoking question about the future of tropical forests, and answer/respond to at least one other student’s question on the discussion board Topic 5.2 Discussion.

Graded Assignments (For certificate learning only)

There is no graded assignment associated with this topic.

Topic Summary

In this topic, we have tried to present some thoughts about the future of tropical forests. Unfortunately, tropical forests continue to be a lost at an alarming rate, and many of the remaining ones are being degraded through multiple causes. Logging continues in many forests, and the effects of this are now quite well understood. Past management regimes have had much longer term effects that was anticipated at the time they were implemented, and forests appear to be a lot more sensitive that is often appreciated.

It is not just the mature trees that are sought after. A growing world population is resulting in the demand for protein, which in some tropical areas is supplied by "bushmeat". In other cases, wildlife is being captured and sold as pets, is being used as ornaments, or is being used in medicinal purposes. In some cases, the pressure on wildlife is so severe that the forests are referred to as "empty forests".

Further pressures are being placed on forests by deliberate and accidental species introductions. Lantana camara has now become a pervasive problem in many forests, displacing local species. Oceanic islands are particularly vulnerable to invasive species, as the Mascarene Islands have shown. The lowland forests of the Seychelles are now dominated by introduced species. In Hawai'i, the accidental introduction of mosquitoes has led to the collapse of the native avifauna as a result of avian malaria. Diseases can also spread into continental ecosystems, as shown by the spread of chytridiomycosis amongst frogs in many parts of the world. 

Countering many of these threats requires an understanding of the ecology of tropical forests. Unfortunately, there are still far too few tropical forest ecologists. Perhaps this course will inspire you to become one.

Topic Self-review (For self learning)

To review what you have learned in the topic, you are encouraged to use the following reflection questions as a study guide to do a self-review for the topic:

• Can you summarize the effects of different types of disturbance on tropical forests?
• What is the relative importance of forest degradation and deforestation to the ecology of forests?
• How does logging compare with other forms of disturbance?
• What is the importance of invasive species as disturbance agents in pristine and modified forests?