Sustainable Ecosystems

What is a sustainable ecosystem? Sustainability: the ability to meet the needs of today without compromising the needs of future generations

Sustainable ecosystems… Support organisms (living things) and can continue to do so in the future. Are biodiverse – have many species of organisms living in them.

Biodiversity and Sustainability The biodiversity of an ecosystem contributes to the sustainability of that ecosystem. Higher/more biodiversity = more sustainable Lower/less biodiversity = less sustainable High biodiversity in an ecosystem means that there is a great variety of genes and species in that ecosystem. SPEAKER’S NOTES: How does an ecosystem become sustainable? By having a lot of biodiversity. The biodiversity of an ecosystem contributes to the sustainability of that ecosystem. The higher the biodiversity of an ecosystem, the more sustainable it is. Conversely, lower biodiversity equals less sustainability. Why is this? The higher biodiversity in an ecosystem means that there is a greater variety of genes and species in that ecosystem.

Sustainable ecosystems provide to organisms… a continual food source clean water sufficient space a suitable habitat other living organisms to interact with

Sustainability Strongly linked to ecosystem health. The more sustainable an ecosystem is, the healthier able to “deal” with external stress better (i.e. limiting factors). SPEAKER’S NOTES: Sustainability is an indicator of ecosystem health. The more sustainable an ecosystem is, the healthier it is because it is able to deal with external stress better. What is “external stress” on an ecosystem? (have students respond) [Answer: limiting factors.] What are some examples of limiting factors? (have students respond) [Possible answers] Human activities and natural disasters such as deforestation, tornadoes, floods, pollution, etc.

Brainstorm! What threats are there to the sustainability of an ecosystem? Disease, limited resources (water, space, food, sunlight, etc.), human disturbance (pollution, destruction of habitat), catastrophic events (hurricane, wildfire, climate change),natural changes in environment, invasive species (An example in central Texas are the ashe juniper trees, commonly called cedar trees. These trees were once naturally controlled by fire but human settlement has reduced the natural fire cycle. Cedar trees suck more water from the ground inhibiting the growth of other species.)

What would cause an ecosystem to be unsustainable? Pollution, lack of space, lack of food, lack of water, low biodiversity… What would happen to organisms in an unsustainable ecosystem?  EXTINCTION (the permanent disappearance of a species of organism)

Case of Easter Island read case study

EXAMPLE OF SUSTAINABLE USE OF A NATURAL RESOURCE A fish stock with a standing population of 1million adults, 100 000 new adults per year, and natural mortality of 50 000 adults per year If the fishery is controlled at a catch of less than 50 000 fish per year, the fishery should be indefinitely sustainable (unless other factors such as drought or disease, intervene).

Are our present lifestyles sustainable? A. Yes B. To some extent C. Probably not D. No Defend your answer!! Write A paragraph with your thoughts

WORLD SCIENTISTS’ WARNING TO HUMANITY (1992) from102 Nobel laureates and1600 other scientists We are on a collision course with the regenerative capabilities of the ecosphere. Human society may be unable to sustain life as we know it. Fundamental changes are urgent.