Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Succession, Biodiversity and Invasive Species
Transcript of Succession, Biodiversity and Invasive Species
Disturbances Happen! Deal with it!
Kinds of Succession
Climax Communities and Biodiversity
Forest Fires cause Disturbances
Effects of Disturbances
Disturbances have direct and indirect effects on an ecosystem.
Like what? Examples?
The resulting changes can be reversible and in many cases are part of the natural life cycle of plants.
Some species are highly adapted to disturbances! They love them (and depend on them)!
Jack Pine is an example of a pioneer species.
Pioneer Species: Species which establish themselves early in a disturbed area.
Pioneer species modify the environment by creating soils and adding nutrients when they die and decay.
Like a moss!
Primary Succession!Where no man (or woman or plant) has gone before!
Primary Succession: Communities that arise from lifeless areas.
Mount St. Helens
Secondary Succession: A process that reduces an already established ecosystem (e.g. a forest) to a smaller population of species, followed by recovery over time.
We already discussed unused fields... What else?
Climax Communities: A group of species who have reached a steady state. Ratio and diversity of species does not change over time.
Succession Promotes Biodiversity!
Are there more species early in the succession process or later? Remember, spruce dominates the later climax forests in Northern Ontario...
What happens when there is no biodiversity?
Ecological Disturbance: A temporary change in average environmental conditions that causes a pronounced change in an ecosystem.
So does logging, especially clear cutting!
Jack Pines are adapted to forest fires, which occur naturally every 60 to 200 years in the forests around Thunder Bay
Mosses and lichens establish themselves easily in moist areas where there is little competition, due to disturbances
The big difference is... Soil ALREADY exists!
The end of succession or part of the process?
Sudbury and Mining: A great example of human caused succession
Locally, a spruce-tamarack forest with a low mossy cover, defines climax communities in Northern Ontario
Biodiversity: The variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable.
Do you think a pathogen or predator would like a monoculture?
Hint: We do!
Threats to Biodiversity
People are the biggest threat, there are many ways in which we threaten the diversity of species...
Monoculture!!! Our dependence on wheat is bad news!
"Save me from over-exploitation!"
-- American Ginseng
Question! Is planting trees, after logging disturbances, a good solution to the loss of biodiversity caused by these disturbances?
Invasive Species: Introduced species which negatively affect the diversity of species in a region over time.
A local example... Dogwood Anthracnose!
Caused by a fungal infection, not currently present in the area but there is high potential!
After a few years, that disease could end up like... Garlic Mustard!
Highly prevalent in Southern Ontario and just south of Thunder Bay, in Minnesota!!
Worse case scenario...
To prevent the spread of rabbits, an invasive species in Australia, the government built 3,256 km or fencing in the West of the country, between 1901 and 1907.
It didn't work... huge amounts of money were wasted and the spread of rabbits was not stopped... Now Australia has one of the most intensive biological import restrictions in the world. Probably an easier solution...
Why is prevention better than management after the fact?