Ecological systems

This slideshow defines ecology and ecological systems.

1. Ecological Systems

2. Ecosystems & Ecology Ecology is the scientific study of relationships in the natural world. Ecosystems are integrated systems that energy flows into and out of. Ecosystems consist of living and nonliving parts and processes

3. An “ecological map” of the Mojave Desert highlighting geologic formations, land use, and vegetation cover.

4. Ecosystems & Ecology Physiological ecology: relationships between organisms and their physical environments Population ecology: relationships between organisms of the same species

5. Ecosystems & Ecology Community ecology: relationships between different species Ecosystem ecology: relationships between organisms and the fluxes of matter and energy through biological systems

6. Ecosystems & Ecology The water, carbon, nitrogen, and phosphorus cycles are the most important cycles to ecosystem health The water cycle is central to the functioning of land ecosystems changes that affect it can have significant impacts on land ecosystems

7. Ecosystems & Ecology Human activities generate roughly 7 billion tons of carbon per year 4 billion tons is sequestered by ocean and land ecosystems 3 billion tons remain in the atmosphere

8. Ecosystems & Ecology The most important factors regulating ecosystems are: Temperature ranges Moisture availability Light availability Nutrient availability: n itrogen and phosphorus are two of the most essential mineral nutrients across all ecosystems; they limit growth if not sufficiently available They determine what types of life are likely to flourish where

9. Ecosystems & Ecology The latitudinal biodiversity gradient : tropical areas generally have more plant and animal biodiversity (the total number of species present) than high latitudes a stable, predictable environment over time is believed to to produce the largest numbers of species this is true for marine, freshwater, and terrestrial ecosystems in both hemispheres

10. Ecosystems & Ecology Latitudinal biodiversity among vertebrates: highest concentration of diversity is in equatorial regions and declines polewards .

11. Ecosystems & Ecology Regulating Ecosystem Functions “Bottom-up” resource availability: the availability of energy and nutrients influences the activity at higher trophic levels Keystone species: so named because they are vital to an entire ecosystem; they occupy an ecological niche that influences many other species

12. Ecosystems & Ecology Niche: “the intersection of all of the ranges of tolerance under which an organism can live” As ecosystems (like a clear-cut forest) come back, they become more diverse and complex: the number of species increases niches become narrower with increased competition Understanding succession helps us identify conditions that can bring an ecosystem back into its natural state

13. The above photo is from https://www2.nau.edu/lrm22/lessons/ r_and_k_selection / r_and_k.html K-selected r-selected Succession (showing r and K-selected species as well)

14. Ecosystems & Ecology Carrying capacity: the maximum number that the environment can support r-selected organisms (for reproduction ): capable of rapid growth in favorable conditions; typically considered pests K-selected organisms (for carrying capacity—i.e. approaching it ): larger, grow more slowly, have fewer offspring and spend more time parenting them K-selected species are more prone to extinction than r-selected species

15. Regardless of the Earth’s carrying capacity, humans are using resources 50% faster than they are being replenished ( Earth Overshoot Day ) Ecosystems & Ecology

16. (photo: http:// populationgrowth.org )

17. Ecosystems & Ecology Trophic Levels and Energy Transfer Only 10% of net energy production at one trophic level is passed on to the next level This is due to respiration, growth and reproduction, defecation, and nonpredatory death An example of a (rare) trophic cascade “ Wolf Reintroduction Changes Ecosystem in Yellowstone ” See the full documentary: Wolves of Yellowstone

18. Ecosystems & Ecology Trophic Levels (cont.) Bioaccumulation : the collection of contaminants in animal tissues as contaminants move up the food web “ Biomagnification …” “ Ecosystem Ecology …”