What constitutes the food chain in a typical, tropical terrestrial ecosystem? How do the animals and plants interact with each other and how is energy transferred and transformed from one level of the food chain to another? What is the difference between a food chain and a food web? Read the following article and find out answers to these questions. A link is provided for a more detailed description of a typical terrestrial ecosystem in the tropical regions.
Tropical terrestrial ecosystems are very productive ecosystems of the earth. It is blessed with a lot of sunlight all year round that drives sustained photosynthetic production. Animal diversity is very high in tropical regions primarily because of the likewise high diversity of plants that grow in almost any set of environmental conditions. The food web is complex, closely interconnected, and highly resilient to disturbances.
The Typical Tropical Terrestrial Ecosystem: An Illustration
The following figure illustrates the typical tropical ecosystem.
©2011 Patrick A. Regoniel
Photosynthesis by Plants
The terrestrial ecosystem is primarily driven by solar radiation from the sun. The heat energy captured by the plants is used in photosynthesis.
Photosynthesis is the process by which plants use the energy from sunlight, to produce food from two basic ingredients - carbon dioxide and water. Aside from the food produced through the photosynthetic process, oxygen is liberated by plants into the atmosphere.
The Role of Animals in the Ecosystem
Plants do not thrive alone in the ecosystem. Animals, particularly the grazers, consume part of the plant in order to survive. Grazers are also called herbivores or primary consumers.
In the typical terrestrial ecosystem above, the primary consumer is the grasshopper. The organic material ingested by the grazers serve as fuel to enable the animal to carry out its internal metabolic processes like digestion and respiration and routine activities. These routine activities include movement from one place to another, mating, among others.
As a result, not all of the energy is kept within the grazers but is released outside of their bodies as heat. Scientists estimate this heat loss at about ninety percent. When the grazers are consumed by animals in the next level of the food chain - the so-called secondary consumers, another 90% of the energy is lost as heat.
The sparrow in the typical terrestrial ecosystem in the figure above represents this group. The secondary consumer, again, becomes prey to the tertiary consumer represented by the snake in the above diagram. Another 90% of the energy is lost into the atmosphere as heat energy.
Food Chain and Food Web
The whole process of consumption or predation means that most of the energy is retained in the lower level of the food chain while the least energy remains in the uppermost level of the food chain. Herbivores, therefore, get most of the energy captured by plants.
When not consumed or preyed upon in the food chain, organisms eventually die of old age, disease or external forces of nature. The remaining dead, organic matter is acted upon by different kinds of microorganisms, shredders, or detritivores. These are generally referred to as the decomposers.
The decomposers include the bacteria, fungi, or invertebrates like millipedes. Decomposers reduce the organic matter into simpler forms forming the humus. The humus produced may be taken by the specific ecosystem where it is produced or transported as runoff to lower grounds - towards the other ecosystems.
The Real Ecosystem
The description given above is a simplistic explanation of the tropical terrestrial ecosystem. In reality, the terrestrial ecosystem is complex. The relationship between organisms is not just the simple, linear food chain but a network of prey-predator relationship. This is referred to as the food web, much like the intricate spider web.
The ecosystem concept illustrates how life on earth is wonderfully made. There is order in the apparent randomness people see in their environment. Man must therefore respect the very source of his survival.
For more information and pictures of animals and plants in a tropical ecosystem, you may read a photo-essay of Freshwater Ecosystem in Balsahan River, a typical freshwater ecosystem in the Philippines, a country located in the tropical zone.
© 15 May 2011 Patrick A. Regoniel Facts About the Tropical Terrestrial Ecosystem