Unit 2: Ecology & Biodiversity
| I. Introduction to Biodiversity (1,2,8,14,15,17) II. Ecosystem Services (2,29,59,65) III. Island
... [Show More] Biogeography (21) IV. Tolerance (17) | V. Natural Disruptions to Ecosystems (8,61,63) VI. Adaptations (15) VII. Ecological Succession (21,41)
| Textbook: Modules 1, 2, 8, 14, 15, 17, 21, 29, 41, 59, 61, 63, 65
| Vocabulary · Adaptation · Adaptive trait · Anthropogenic · Biodiversity · Cultural service · Disruption · Disturbance · Diversity index · Ecosystem · Ecosystem services · Environmental stress · Episodic | · Evolution · Generalist · Genetic diversity · Habitat diversity · Indicator species · Island biogeography · Keystone species · Limiting factors · Migration · Natural selection · Periodic · Pioneer species · Population bottleneck | · Primary succession · Provisioning service · Regulating service · Resilience · Resistance · Secondary succession · Specialist · Species diversity · Species evenness · Species richness · Supporting service · Tolerance
I. Introduction to Biodiversity
Biodiversity: the variety of life on earth
Three Scales of Biodiversity
1. __Genetic Diversity__: Genetic variation among individuals in a population (same species)
| What are examples of environmental stressors? (disturbance/disruption) - physical stress (natural disasters) - Wildfires - Pollution - Thermal Stress - Radiation - Biological (predation, competition, parasitism, and lack of mates)
| What would enable a population to bounce back more easily (have more resilience) after environmental stress/disturbance—high or low genetic diversity? Explain why, with an example.
__________________________________________________ :
A drastic and sudden reduction in the size of a population leads to a change in the gene pool
| What could cause bottlenecks?
2. Species Diversity : The number of species in a region or habitat (in a community or ecosystem)
(Review: What defines a species? A species can interbreed and produce viable offspring)
# identified and catalogued by scientists: 2 Million
# Estimate of actual total number on earth: 5-100 Million
Most common estimate: 10 Million
Most common animal: Nematode Worms
Most common organism: the bacterium Pelaqibacter ubique (1/3 of all single celled ocean organisms)
| The species diversity of a region is considered a critical environmental indicator. Why? (ex: Frogs)
| What would enable a community to show more resilience after environmental stress—high or low species diversity? Explain why, with an example.
3. Habitat/Ecosystem diversity: The variety of habitats that exist within a given region
| Generalist species: can live under a wide range of biotic/abiotic conditions Examples: wolves, deer, and raccoons | Specialist species: live under a very narrow range of conditions or feed on one or a very small group of species Examples: koala, panda, and salamander
| What impact would habitat loss have on these two categories of species? Specialist would be drastically effected by habitat loss, while generalist would survive Which group is in much more danger of extinction? Specialist
| Can you think of a reason why it might be advantageous to be a specialist?
| What impact would habitat loss have on animals with large or small territories?
Biodiversity Indices (plural of “index”): Measures of biodiversity that take into account both richness and evenness
· Species richness: # of total species
· Species evenness: Abundance of individuals within each species
Two useful indices: and
àSee Simpson’s Index worksheet and Quadrat Lab
II. Ecosystem Services
| Type of Ecosystem Service | What anthropogenic activities could affect these services negatively? | Consequences of these activities
| Ecological | Economic
| 1. Provisioning-goods that humans use directly | Deforestation, poaching/overhunting, over farming | Loss of biodiversity, | Supply and demand
| 2. Regulating-4 gigatons of carbon removed by ppk and plants nutrient/water cycle | Using fertilizer in the soil, pollution (acid rain), | Increase in greenhouse gases (degradation of the ozone layer), nutrient deficient soils due to fertilizers, algo bloom | Fishing industry is hurt, Florida has experienced an algo bloom, resulting in no swimmable water no tourism
| 3. Support-pollination, water filtration, natural pest control | Pesticides, exterminators, urban city runoff in the water filtration | Reduction in bee population less genetic variation in the ecosystem | Honey industry, tourism in areas where natural parks are
| 4. Cultural- (beauty) tourism, real estate, and recreation | Recreational activities, light pollution, poaching, vehicle emissions, mining, and drilling for oil, landfills | Coral bleaching, algo blooms |
III. Island Biogeography
Theory of Island Biogeography
Graph the data given below on the grid. Label axes, use correct units, and title the graph.
| Island area (ha) | # of bird species
What other term could be used for
| Considering the information displayed in the above graph, what is the relationship the Theory of Island Biogeography predicts between species richness and habitat size?
| A generalist species, like a city pigeon, rat, or raccoon would be likely to have narrow or broad ranges of tolerance? | Broad
| A specialist species, like a koala, would be likely to have a narrow or broad range of tolerance? | Narrow
| Consider an endangered tropical songbird from Indonesia and a city pigeon from San Francisco. How could you compare these two animals in terms of the Law of Tolerance? (Mention specific factors) The tropical songbird would have a harder time survive if the environmental factors drastically changed, while the pigeon would survive How does the Law of Tolerance relate to the reasons why some organisms become endangered and some don’t? the amount of tolerance that they can withstand in their specific environments
| Limiting factors: the environmental factor that is most often in short supply; even if all the other factors are optimum, it’s the one most likely to regulate population growth
| Fill in the Limiting Factors:
| Location | Limiting Factor
| Soil | Often nitrogen, phosphorus, or potassium- this is why NPK testing kits are used and why those nutrients are components of fertilizers
| The open ocean | Sometimes nitrogen, silica, or iron; sometimes dissolved oxygen
| Freshwater lakes and rivers | Often phosphorus
| Bays and estuaries | Salinity- level of salt in the water
| The fish tank | Air bubbles representing dissolved oxygen
| Desert plants | Water
| Small plants on the rainforest floor | Sunlight
V. Natural Disruptions to Ecosystems
| What are some natural disturbances that could impact ecosystems? Wildfires, tsunamis, earthquakes, volcanic eruptions
| Resistance: the ability to remain unchanged when being subjected to disturbance | Resilience: the ability and rate of an ecosystem to recover from a disturbance and to return to its pre-disturbed state
| Intermediate Disturbance Hypothesis:
Disturbances
A. Historical Changes in Climate
à See HHMI Computer Activity worksheet
https://www.biointeractive.org/sites/default/files/Paleoclimate-student-worksheet.pdf
B. Historical Changes in Sea Level
With your partner, note at least 5 interesting pieces of information you can interpret from these graphs. Make notations directly on the figure or written around it.
C. Habitat changes
| Natural Causes for Habitat Change:
| Come up with a fictional (but realistic) example of a population being forced to change their habitat due to a natural occurrence.
D. Wildlife migration
Watch videos, take notes in the following 2 columns
Amazing Animal Migrations by Land, Air, and Sea (2:13) https://www.youtube.com/watch?v=Mc3YIrs19fw
Animal Migration (1:20) https://www.youtube.com/watch?time_continue=1&v=zdUkJfW_xmY
| Which animals migrate? | What are some reasons for migration?
| We will be revisiting migration when we discuss the effects of climate change later on. Predict: How does climate change impact migrating animals?
| What makes modern-day change, with anthropogenic causes, different from all the previous natural change? _______________________ and _______________________
The theory of natural selection was developed by Charles Darwin and first presented in his book The Origin of Species, published in 1859. [Show Less]