3.1 Fundamental ecological processes

Loading...

From the course by National Research Tomsk State University

Ecology: from cells to Gaia

48 ratings

National Research Tomsk State University

Ecology: from cells to Gaia

48 ratings

This course presents the principles of evolution and ecology for citizens and students interested in studying biology and environmental sciences. It discusses major ideas and results. Recent advances have energised these fields with evidence that has implications beyond their boundaries: ideas, mechanisms, and processes that should form part of the toolkit of all biologists and educated citizens. Major topics covered by the course include fundamental principles of ecology, how organisms interact with each other and their environment, evolutionary processes, population dynamics, communities, energy flow and ecosystems, human influences on ecosystems, and the integration and scaling of ecological processes through systems ecology. This course will also review major ecological concepts, identify the techniques used by ecologists, provide an overview of local and global environmental issues, and examine individual, group and governmental activities important for protecting natural ecosystems. The course has been designed to provide information, to direct the student toward pertinent literature, to identify problems and issues, to utilise research methodology for the study of ecology and evolution, and to consider appropriate solutions and analytical techniques. Needed Learner Background: general biology and a good understanding of English. This course has the following expectations and results: 1) covers the theoretical and practical issues involved in ecology and evolution, 2) conducting surveys and inventories in ecology, 3) analyzing the information gathered, 4) and applying their analysis to ecological and conservation problems.

From the lesson

Module 3. Energy in Ecological Systems

In this module, we will discuss some fundamental ecological processes, such as those must be present in any Gaian planet. We will consider the Gaian effects of parasites and predators, biodiversity and hypercycles and we will see how these processes regulates our planet. Finally, we will consider the global ecological role of biomass, photosynthesis and carbon sequestration.

3.1 Fundamental ecological processes5:12

Meet the Instructors

Roberto Cazzolla Gatti
Ph.D., Associate Professor in Ecology and Biodiversity
Biological Diversity and Ecology Laboratory, Bio-Clim-Land Centre of Excellence, Biological Institute

[MUSIC]

Hi learners.

Welcome to the 11th lecture of my course, Ecology From Cells to Gaia.

Today we will talk about fundamental ecological processes.

We can classify ecological entities in an interactical manner.

From genes to individuals, populations, species, communities, ecosystems and

finally, to the biosphere.

The basic question to develop a planetolary ecology is for

any planet with carbon based life, which persists over geological time scales,

what is the fundamental set of ecological processes that must be present?

In 2001, Norman Peace has outlined a number of reasons for

thinking that any life in the universe will be based on organic chemistry.

One of the most widely discussed possibility about the origin of life

is the colonization or recolonization of the Earth from Mars via microbes

transported in meteorites originating from planetary surfaces.

An interesting variation of this idea is that during a large asteroid impact on

Earth, microorganisms could be ejected into the space inside rocks

which later fall back onto the new sterile Earth, so reseeding our planet.

Any process which tends to increase the survival of life on a planet

is said to have a positive Gaian effect, while one that decreases the chances

of survival has a negative Gaian effect at this base.

Gaia theroy, proposed by James Lovelock and co-developed by the microbiologist

Lee Margulis in 1970s suggests that organisms interact with their inorganic

surroundings on earth to form a symbiotic self regulating complex system that

helps to maintain and perpetuate the condition for life on the planet.

This theory explains how the biosphere and

evolution of life beings influence the stability of all salinity,

global temperature, oxygen in the atmosphere, a liquid hydropshere and

other environmental conditions that affect the habitability of Earth.

The second law of thermodynamics states that heat flows

from a hotter to a colder body so that entropy is greater, or

at least not lower, after any given process has taken place.

In 1995, Margulis and

Sargon described organisms as island of water in an ocean of cows.

To survive, all organisms must acquire energy from their environment.

In so doing, produce waste products which they release back into their surroundings.

Indeed, this is so

fundamental that it could be considered the basic concept of ecology.

Lanton, in 2004, described Gaia as a type of planetary scale open thermodynamic

system with abundant life supported by a flux of free energy from a nearby star.

If transport on some planets may be organized to produce entropy at

the maximum possible rate.

The universal requirement for

increased entropy from the second law of thermodynamics is responsible for

the general circulation of the atmosphere on Earth, and other similar planets.

So organisms maintain their highly ordered state by taking in free energy from

the environment, and as usual, these energies cannot be 100% efficient,

releasing waste product back into the environment.

So planetary ecology can work because of diversity.

As Tyler in 1998, has written, a monocultural planet is,

therefore, a thought experiment with no place in reality.

In any successful ecological system, it is necessary for material and

waste products to be recycled to make them available for use.

Any ecological system that produced an product which couldn't be broken

down would, on the geological time scale, be in trouble.

I provide you an example of recycling.

White-rot fungi, break down both lignin and cellulose.

Their food source is the cellulose only.

However, they need to break down the lignin enzymatically to get it.

Consuming organ is not evolved, this could have proved problematic for

abundant life on Earth.

With increasing amounts of resources and organic deposit and unavailable to life.

So one species waste product can be a resource for another species.

An ecological system needs organisms from at least two major guilds,

autotroph and decomposers, which really is a material from waste products,

including dead autotrophs.

As such, any ecological system, which has survived for a geological period

of time on a planet, must consist of at least two types of organism.

So at the end of this lesson, I have a question for you.

What is the importance of other major guilds, such as predators and

parasites, in the equilibrium of ecological system in a Gaian perspective?

Try to formulate an answer, and we will analyze this process in the next lesson.

See you next time, bye.

[MUSIC]

Explore our Catalog

Join for free and get personalized recommendations, updates and offers.

Coursera provides universal access to the world’s best education, partnering with top universities and organizations to offer courses online.

© 2018 Coursera Inc. All rights reserved.

Download on the App Store

Get it on Google Play