Category Archives: Ecosystem Dynamics

This page includes educational materials on the dynamics of ecosystems in both the undergraduate and the graduate levels.

Ecosystem Management: Back to the Basics Approach

While browsing the literature you may have encountered the phrase “ecosystem management”. While this set of words may be commonly used, many find it vague and confusing at times. Here is a back to basics explanation to provide you a solid foundation for further study of this concept.

Ecosystem management, while discussed in literature or articles both online and offline, is a vaguely defined phrase that many students find confusing. Perhaps the main reason for its being is the continuing degradation that nature experiences with previous modes of natural resource management.

To simplify matters and to have a clearer view of ecosystem management, one approach is to break this concept down into manageable bits of information. If things become complicated, it is sensible to go back to the basics.

My approach then is to define ecosystem and management separately and draw out the principles and meanings from each of these basic definitions to eventually combine the two words “ecosystem” and “management” into the phrase “ecosystem management”.

What is an Ecosystem?

The definition of the ecosystem has been in the literature for long. Although there are many versions of what ecosystems are, the best definition I could surmise from the various literature, readings, and insightful thinking on the environment which I thought most appropriate is this:

An ecosystem is a set of interacting components working harmoniously together to acquire, produce and transfer energy to attain sustainability. 

The interacting components are the plants, non-living things and animals (humans included) within that ecosystem. These components work together in a harmonious manner such that the whole set composing the ecosystem is able to acquire, produce and transfer energy that makes the whole system run on the long term or simply make it sustainable.

The main source of that energy that drives the ecosystem is the sun. There is loss of energy in the process of transferring it from one source to another, i. e., from the sun as a major source of energy throughout the components of the ecosystem. The simplified ecosystem in Figure 1 below shows the interrelations.

the simplified ecosystem
Fig. 1. The simplified ecosystem showing the interacting components.

Notice that not all of the energy coming from the sun is efficiently transferred from one living component of the ecosystem to the other. This is illustrated by the red arrow oriented upwards. Heat as a form of energy is lost into the atmosphere.

Scientists estimate energy loss from each component at 10%. Why is this energy not wholly transferred to the next living component in the ecosystem? That’s mainly because some of it is used by the organism for its own purpose. What are these uses? Well, the organisms have to respire, reproduce, move from one place to another, feed, among other functions that will enable it to survive in its habitat.

Another important thing of the whole ecosystem thing is that without the sun the whole ecosystem would collapse. Plants as the basic components of the ecosystem will not be able to synthesize food and oxygen through the process of photosynthesis. This is why we need to maintain plants by whatever means as these components of the ecosystem lie at the very foundation of human existence. Simply put, plants produce life-giving oxygen without which man could not hope to survive in five minutes or so.

What is Management?

Management is defined differently according to the context by which it is being used. Management in the context of environmental management can be defined in the following manner:

Management is the process or act of getting the different components of a system working together to achieve a desired purpose.

This means, therefore, that management is a deliberate attempt to do something in such a way that a desired purpose is achieved. Whatever the outcome of the action depends on how well management was made.

At this point, it would be now easy to define what ecosystem management is.

What is Ecosystem Management?

Based on the previous discussion, the following definition of ecosystem management can thus be drawn:

Ecosystem management is the deliberate attempt to manipulate the set of interacting components in nature for man’s ultimate benefit.

Yes, the main purpose of ecosystem management is to make the whole management process beneficial to man as the end user and manager of that ecosystem. Thus, whatever man deliberately does to the ecosystem which is stable in itself will define the kind of ecosystem management that will prevail. The key actors of ecosystem management are scientists, policymakers, managers, and citizens tasked with ecosystem management (see extensive discussion by Grumbine, 2002).

The ultimate outcome of ecosystem management will entirely depend on how humans perceive the environment and how he perceives this will have to be handled to serve his needs. If the aim is to sustain the natural processes, then ecosystem management must ensure the least disturbance and maintenance of ecological integrity as much as possible.

Biodiversity Differences in Freshwater and Estuarine Ecosystems

There are very few references available on the biodiversity that can be found in freshwater and estuarine ecosystems of tropical countries. Students, therefore, are not able to appreciate the differences between these two ecosystems. Most of the published literature are descriptions of freshwater and estuarine ecosystems in temperate regions. Recognizing this gap, this article provides an overview of the two ecosystems and provides links to detailed descriptions of freshwater and estuarine ecosystems in Puerto Princesa, Palawan.

Why the Dearth of Literature on Freshwater and Estuarine Ecosystems?

Information on freshwater and estuarine ecosystems of tropical regions is lacking. It may be due to the lack of regard to the important role these ecosystems play in the life of people in communities or cities. It may also be due to the inability of educators in many tropical countries to develop and publish material which are in tune with their local settings.

Apparently, many of the teachers are still locked in their traditional modes of teaching. They are occupied with class work and traditional lecture sessions, limited by their four-cornered classrooms. Or probably, they have devoted themselves to economic activities to keep up with the ever-growing prices of goods and services.

Whatever the reason, the point is that many students in tropical countries learn from the books published by authors in other places which may not be relevant to their specific location. There should be a change in paradigm among teachers.

Recognizing this, I always take the opportunity to engage my environmental science and marine biology students in field work as I teach subjects that require them to go to the field and explore the environment. It may be a Dynamics of Ecosystems course or  the subject Research 01 where they need to familiarize themselves with actual research situations, i. e., in the field. I always attempt not to teach them but mentor them along the way.

Let them discover – so to speak.

Field Trip to Freshwater and Estuarine Ecosystems

There were two separate occasions of field work that I undertook with my students so they will get familiar with these ecosystems. These are

1) a trip to the freshwater ecosystem of Balsahan by graduate students enrolled in the Dynamics of Ecosystems course, and

2) a recent trip to the estuarine portion of Iwahig River.

Freshwater Ecosystem of Balsahan

We discovered a very diverse array of wildlife in the upper freshwater portion of Balsahan River. Among these is a species of Insulamon,  a crab endemic (or only found) to Palawan.

Insulamon sp., a freshwater crab endemic in Palawan.
Insulamon sp., a freshwater crab endemic to Palawan.

We did the survey in 2010 but then references on proper identification of the crab is not available so we were not able to identify it correctly. No taxonomist was also available for consultation at that time. What we lack in taxonomic skills we compensate by taking a photo of the crab for future reference. I posted a recent picture of the crab in my travel and wildlife website,, for comments but there were none.

Eventually, Dr. Hendrik Freitag, animal ecologist of Ateneo de Manila University, properly identified the crab as Insulamon palawanense in 2012. It was featured in the National Geographic Online Magazine. Dr. Freitag happened to visit Palawan State University and saw the picture in one of my online articles. He confirmed the crab indeed belongs to the same species he discovered.

Also, we saw a small, almost inconspicuous leaf frog, also an endemic species, hiding under the leaves along the riparian zone of Balsahan River. This is a funny looking frog with skin protruding like horns on its head.

A more detailed account of this trip and the diverse wildlife of Balsahan is published in another site. You may read it here.

Estuarine Ecosystem of Iwahig River

Estuarine ecosystems are also not well studied in the tropical regions especially in the unique Island of Palawan which has wildlife species in more affinity with nearby Borneo Island than the rest of the Philippines. Experts attribute this similarity to land bridges that connect mainland Palawan with Borneo.

Despite the itchy bites of the sandfly (local name: niknik), the marine biology students braved the waist deep waters near the mouth of Iwahig River. Many species of wildlife were photographed and then released back into the water. The mangroves growing in the estuarine portion of the river were likewise identified and photographed for reference.

Notable among the animals is another crab of purple color. Is it another Insulamon? We don’t know because no information on a crab with such appearance is available. Proper identification requires a considerable number of crabs, some measurements, and a whole lot of descriptions filled with jargon. The picture says it all anyway.

The whole trip lasted only for about two hours but a diverse collection of photographs on biodiversity of the estuarine ecosystem was obtained. This collection is better than any book published in printed format.

See all these biodiversity in the article I posted online for everybody. It is titled Tropical Ecosystem: Estuarine Biodiversity in Iwahig.

© 2012 October 27 P. A. Regoniel