Content

Introduction
Readings
Fundamental Concepts
Self Check
Pre-readings and Discussion
Graded Assignment
Summary
Self Review

Topic Introduction

In this topic, we provide a brief introduction to the major environmental factors affecting tropical forest ecosystems. We start by looking at landforms, with a brief introduction to geomorphology. We then look at climate and how this affects the species within tropical forests. Water is obviously closely related to climate, and the next module we consider this critical environmental factor, without which there would be no life. In the final presentation in this topic, we look at tropical soils.

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

Describe the climate, hydrology, soils and landforms encountered in tropical forest environments.
Explain how these environmental factors influence the species composition of tropical forests.
Compare the importance of climate, water availability and soil type in influencing the structure and composition of tropical forests.
Interpret the importance of different environmental factors in the spatial distribution of forest types.
Combine the different environmental factors and describe their interactions.

Topic Readings

Required Readings

Ghazoul, J. and Sheil, D. 2010. Tropical Rain Forest Ecology, Diversity, and Conservation. Oxford, Oxford University press, 516 pp. Sections 9.1, 9.2 and 9.6.

Optional Readings

Corlett, R.T. 2009. The Ecology of Tropical East Asia. Oxford, UK: Oxford University Press. Sections 2.2, 2.3 and 2.4.

Landforms and Geomorphology

Gupta, A. 2011. Tropical Geomorphology. Cambridge, UK: Cambridge University Press.
Harvey, A. 2012. Introducing Geomorphology. A Guide to Landforms and Processes. Edinburgh and London, UK: Dunedin Press.
Thomas, M.F. 1994. Geomorphology in the Tropics. A Study of Weathering and Denudation in Low Latitudes. Chichester, UK: John Wiley & Sons.

Climate

Bellingham, P.J., Tanner, E.V.J. & Healey, J.R. 1995. Damage and responsiveness of Jamaican tree species after disturbance by a hurricane. Ecology 76, 2562-2580.
Boose, E.R., Foster, D.R. & Fluet, M. 1994. Hurricane impacts to tropical and temperate forest landscapes. Ecological Monographs 64, 369-432.
Brokaw, N.V.L. & Walker, L.R. 1991. Summary of the effects of Caribbean hurricanes on vegetation. Biotropica 23, 442-447.
Everham, E.M. & Brokaw, N.V.L. 1996. Forest damage and recovery from catastrophic wind. Botanical Review 62, 113-173.
Korner, C. 2009. Responses of humid tropical trees to rising CO₂. Annual Review of Ecology, Evolution and Systematics 40, 61-79.
Lugo, A.E., Applefield, M., Pool, D.J. and Mcdonald, R.B. 1983. The impact of hurricane David on the forests of Dominica. Canadian Journal of Forest Research 13, 201-211.
Lugo, A.E., Scatena, F.N. 1996. Background and catastrophic tree mortality in tropical moist, wet, rain forests. Biotropica 28, 585-599.
Prasad, V., Farooqui, V., Tripathi, S.K.M. et al. 2009. Evidence of Late Palaeocene – Early Eocene equatorial rain forest refugia in southern Western Ghats, India. Journal of Biosciences 34 (5), 777-797.
Tanner, E.V.J., Kapos, V. & Healey, J.R. 1991. Hurricane effects on forest ecosystems in the Caribbean. Biotropica 23, 513-521.
Turton, S.M. 1992. Understorey light environments in a north-east Australian rain forest before and after a tropical cyclone. Journal of Tropical Ecology 8, 241-252.

Hydrology

Bren, L. 2015. Forest Hydrology and Catchment Management. An Australian Perspective. Dordrecht, The Netherlands: Springer.
Chang, M. 2006. Forest Hydrology. An Introduction to Water and Forests. 2^nd edition. Boca Raton, Florida, USA: CRC Press.
Gunston, H. 1998. Field Hydrology in Tropical Countries: A Practical Introduction. Rugby, United Kingdom: Practical Action.

Soils

Ashraf, M.A., Othman, R, and Ishak, C.F. 2017. Soils of Malaysia. Boca Raton, Florida, USA: CRC Press.
Nambiar, S. and Brown, A.G. 1997. Management of Soil, Nutrients and Water in Tropical Plantation Forests. Canberra, Australia: Australian Centre for International Agricultural Research.
Proctor, J. (ed.) 1989. Mineral Nutrients in Tropical Forest and Savanna Ecosystems. Oxford, United Kingdom: Blackwell Scientific Publications.
Sanchez, P.A. 2019. Properties and Management of Soils in the Tropics. Cambridge, United Kingdom: Cambridge University Press.
Schulte, A. and Ruhiyat, D. 1997. Soils of Tropical Forest Ecosystems: Characteristics, Ecology and Management. Berlin, Germany: Springer.

Fundamental Concepts

PPT Presentations

2.1.1 Environment – Tropical Landforms.pptx

2.1.2 Environment - Tropical Forest Climates.pptx

2.1.3 Environment - Tropical Forest Hydrology.pptx

2.1.4 Environment - Tropical Forest Soils.pptx

Self-check Quiz

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 more important issues presented in the module. 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 2.1 to start taking the quiz.

Pre-readings and Discussion (For certification)

Once you have read Sections 9.1, 9.2 and 9.6 of Ghazoul, J. and Sheil, D. 2010. Tropical Rain Forest Ecology, Diversity, and Conservation, choose to post one thought provoking question about the physical environment of tropical forests, and remember to answer/respond to at least one other student’s question on the discussion board Online Discussion Module 2.

Graded Assignment (For certification)

Six Sentence Answer #2

You should by now be familiar with the Six Sentence Answer (6SA) format. If you are not, please refer to the course pages on graded assessments to see details of the 6SA exercise. You should not attempt to do this assessment until you have read and fully understood the requirements.

The Case

In Week 2, we presented the situation that you are a member of a major international forest consultancy firm that specializes in doing surveys of forests around the world. You have access to field teams and the latest surveying equipment, include LiDAR. Your company has taken on a contract with the UN-REDD (United Nations Collaborative Programme on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries) to survey the forests on a very large island in South-East Asia, and you have the full cooperation of the government.

By now, you have a produced a map of the island’s forests, and assessed the growing stock. Your field teams have done on-the-ground surveys to develop the allometric equations that you needed to produce estimates of the carbon stored in different types of forest on the island. You have found major differences, as you might expect, between the moist tropical forests on the west of the island and the dry forests in the rain shadow of the volcano on the east of the island.

Your CEO informs you that a review of the report that has been submitted to UN-REDD suggesting that the figures must be wrong, as they cannot believe that the trees in the most tropical forests on the island can be as small as your measurements suggest. They point out that the forests on the island of Borneo, located only a few hundred kilometres to the west, contain much larger trees. The CEO naturally is very upset by this review, and wonders whether you have made a serious mistake somewhere in your calculations. Please provide a plausible explanation for your results, using the 6SA format, and suggesting a respnse to the UN-REDD program.

Remember to follow the structure of the 6SA outlined in the section on graded assessments.

Formatting:

Double-space the text.
12-point font in New Times Roman or Calibri.
Put your name (Family or last name, followed by your first name), student number, the title “Topic 1.1 assignment”, and the date at the top of the first page.
Name the e-file: your Family or last name_your first name_ Topic 1.1_Assignment.doc (or .docx). Example: Innes_John_Topic 1.1_Assignment (or .docx).
Standard English usage, clear writing style.
All assignments should be submitted through Canvas before the deadline.

Topic Summary

In this topic, you are introduced to the major environmental factors that affect the structure and composition of tropical forests. Environmental factors affect forests in different ways, but also interact with each other, complicating their interpretation. Important aspects include temperature, humidity, moisture availability, soil chemistry and slope, but there are also many more subtle interactions, such as the importance of seasonal changes in cloud cover. Understanding these is critical to understanding tropical forest ecosystems.

Bear in mind that a critical part of forestry is being able to ‘read the landscape’. This is a skill that is best developed through experience, but it also requires a fundamental grounding in the different factors that affect forests. For example, you may be standing in a flat area of forest (which will admittedly make it very difficult to read the landscape). Is it flat because you are standing in a floodplain or because you are standing on the eroded remnants of an ancient landscape? Either would be expected to have very different soils and disturbance histories. Or you may be looking at the forests on the flanks of a mountain range. Why do they vary with altitude? What controls the differences? Are the differences consistent on either side of the mountain range? How old is the mountain range?

By the time you have completed this module, you should be in a better position to answer questions such as these.

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:

When did the current continents split apart, and was this before or after the evolution of most modern plants and animals?
Why do we find so many inselbergs in tropical regions?
How do tropical atmospheric circulation patterns affect the climates of tropical forests?
How important is interception and evaporation in forests?
What is the difference between clearwater and blackwater rivers?
What causes these differences?
Are tropical soils nutrient-deficient?
How does the nature of the soil affect its water-holding capacity?
How does soil type affect the vegetation growing at a site?

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