4.2 Sustainability

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Do curso por National Research Tomsk State University

Ecology: from cells to Gaia

57 classificações

National Research Tomsk State University

Ecology: from cells to Gaia

57 classificações

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.

Na lição

Module 4. Population Ecology and Evolution

In this final module, we will explore the possibility of a new ecology by exploring the concept of sustainability, evaluating the human impacts on ecosystems and providing some solutions for nature conservation. Finally, we will see how to organise a citizen science event, called Bio-blitz, which can improve the scientific knowledge of our planet and, at the same time, rise the ecological awareness of citizens.

4.2 Sustainability5:19

Conheça os instrutores

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 seventeenth lesson of my course, ecology from south.

Today, we will talk about sustainability.

A resource used by human beings is defined as sustainable if it can be continued for

the foreseeable future.

The root of most environmental problems is the population problem,

a large human population that has been growing at a more than exponential rate.

Three groups of nations can be recognized,

those that passed through the demographic transition early, late or not yet.

Even if were possible instantaneously to bring about the transition in

all remaining countries of the world, the population problem will not be solved

partially because population grow as it's momentum.

The global carrying capacity for

human beings is variously estimated at between one and 1000 million, depending

mainly on what is deemed to constitute an acceptable standard of living.

Whenever a natural population is exploited by harvesting,

there is a risk of over-exploitation.

But harvesters also want to avoid under-exploitation

when potential consumers are deprived of resources.

The concept of the maximum sustainable yield,

MSY, has been a guiding principle in the exploitation of natural populations.

There are two simple ways of obtaining an MSY on a regular basis,

through a fixed portal or through a fixed effort.

Two limitations of the MSY approach are that it treats all individuals in

the population as identical and that it treats the environment as unvarying.

Improved harvesting strategies correct both these oversights.

Lack of knowledge of most fisheries around the world means that management is often

based on the precautionary principle, often in the absence of data.

Increasingly, animals and plants have been domesticated and

managed in a way that allowed much larger harvests, usually as mono-cultures.

But a high price may be paid to maintain this high rate of food production.

Monocultures offer ideal conditions for

the epidemic spread of disease and lead to widespread degradation of land.

In an ideal sustainable world,

new soil would be formed as fast as the old was lost.

But in most agricultural systems, this is not achieved.

When there is an overwhelming reliance on artificial fertilizers,

maintaining the organic matter capital of the soil tend to be neglected, and

this has declined worldwide.

Soil degradation can be slowed down by incorporating manual alternating

cultivation and fallow periods, or returning the land to grassy pasture.

In tropical regions, cultivation is more difficult because most of the nutrients

are in the biomass and not in the soil.

In other regions, instead, overgrazing and

excessive cultivation can lead to desertification and salinization.

Water is widely told to be the resource that future wars will be fought over.

On a global scale, agriculture is the largest consumer of fresh water.

And pumping fresh water from underground aquifers is the main cause of

loss of the agricultural land through salinization.

The aim of pest control is to reduce the pest population to its economic but

the so-called economic threshold may be of more immediate importance.

Pesticide makes the species harder than they target, and

may give rise to target faster solutions or secondary pest outbreaks.

Pests may also evolve pesticide resistance.

Biologists may also manipulate the natural enemies of pests in a way that

is called biological control via three forms of biological control.

That is incorporation, conservation, or inoculation, but

even biocontrol agents can have unwanted effects on nontarget species.

Integrated pest management, IPM, is a practical philosophy of pest management

that is ecologically based that uses all means of control where appropriate.

It relies heavily on natural mortality factors, and it calls for

specialist pest managers or advisors.

Evidence has been accumulating that the organic production as a sustainable

farming approach can yield economic returns too.

It is clear that very significant threats are posed to ecosystems around the world

by the increasing human population and

concomitant increases to agricultural development.

These are expected to have a particular damaging effect on biodiversity, because

most agricultural growth is predicted to occur in the species-rich tropics.

The production of coffee, chocolate, tea, palm oil, and

other tropical foods is considered one of the main causes of tropical deforestation.

So at the end of this lesson, I have some questions for you.

What is sustainability?

Then, is it possible to have sustainable population growth?

Next question, is it possible to have sustainable use of fossil fuels?

Or is it possible to have sustainable use of forest trees?

So, please try to answer this question, and see you in next lecture.

[MUSIC]

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