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Ecology 3
Question | Answer |
---|---|
What kind of species is intraspecific competition dealing with? | Between members of the same species |
When do we see intraspecific competition? | When there are limited resources |
Interference: What are direct interactions? | Contests over resources |
Are direct interactions costly? Why or why not? | Yes - Takes time, energy, and can result in injury |
How are direct interactions with Cnidarians costly for the cnidarian? | They sting. It is costly because once they use one, they can not use it again. |
Resource Competition: What basis do indirectly competing organisms go by? | First come first serve |
Do indirectly competing individuals use resources separately or simultaneously? | Simultaneously (Exploitation) |
What is exploitation? | When one species partakes in consumption of a limited resource and makes it unavailable to another. (One gains energy at the expense of another) |
Exploitation deals with how ______ resources are being used _______ _______. | Quickly, over time |
Which spatial distribution of food is more beneficial when it comes to defense: uniform or clumped? | Clumped |
Which form of competition occurs when food is uniformly distributed, creating low contest potential? | Exploitative Competition |
Which form of competition occurs when food has a clumped distribution, creating a high contest potential? | Interference Competition |
What does the resource matching rule do? | Matches the number of competitors to the amount of resources |
What is "ideal" for ideal free distribution? | All individuals can accurately asses resource amount |
What is "free" for ideal free distribution? | Animals can move freely from one patch to another |
Tests of Ideal Free Distribution (IFD) - Sticklebacks. Explain this experiment. | Before feeding, fish distributed randomly. One side, 5 daphnea dropped, the other side 1 daphnea dropped. If 6 fish, 5 go to one side, 1 go to the other side. |
What kind of species is interspecific competition dealing with? | Between members of different species |
For IFD, when is there Nash Equilibrium? | When the two are equal |
When there is interspecific competion, there is a _____ to both species. | Cost |
What is the fundamental niche? | Biotic and abiotic conditions that predict where a species may live (Where it SHOULD live) |
What is the realized niche? | Where a species ACTUALLY lives |
Which niche, fundamental or realized, do we use with scientific data? | Realized niche |
What is a classic example of resource partitioning? | Warblers in a tree. Can have different species at different heights who each eat a different kind of food. (See also: anoles, algal species) |
What does the Competitive Exclusion principle state? | two species competing for the same resource cannot coexist at constant population values. |
When testing for competitive exclusion, what do you do to determine if one species would "win" | Remove one of the species. See if the other species takes over the previously owned space. |
Joseph Connel: Barnacle example: What happened to Chthalamus when Balanus was removed? | Cthalamus spread: It was being confined to the upper rocks because of balanus |
In terms of niches, what does competitive exclusion show? | The realized niche is smaller than the fundamental niche. |
With ecological models, if you hold some variables constant and manipulate other variables, what can you predict? | You can predict how species/individuals will be affected (To be able to form a hypothesis) |
With ecological models, what can you do after you have formed a hypothesis and collected data? | You can compare the actual data to a model to 'fit' it, and then you can make adjustments |
Modeling competion: What do you see if: INTRAspecific > INTERspecific? | Both species will exist |
Modeling competion: What do you see if: INTERspecific > INTRAspecific? | One will drive the other to extinction |
Explain the Competition Experiment dealing with the rodent granivores | Different rodents who ate different things were used. Placed in exclusion plots. They removed different species to see what would happen. |
In the Competition Experiment dealing with rodent granivores, what happens to the pocket mice and grasshopper mice if you remove the kangaroo rats? | The pocket mice increase, the grasshopper mice stayed constant |
In the Competition Experiment dealing with rodent granivores, what was concluded? | Kangaroo rats, under normal conditions, outcompete pocket mice. (Similar to the barnacle experiment) |
Character displacement: What does niche divergence do? | Reduces competition |
What is an area of allopatry? | Where one species can exist alone |
What is an area of sympatry? | Where two species exist together |
Two species will be more dissimilar in areas of _____ than areas of _____. | Sympatry, Allopatry |
Why would two species be more dissimilar in areas of sympatry than areas of allopatry? | Helps to avoid and minimize competion |
What is a classic example of character displacement? | Darwin's Finches. (Result of foraging competition) |
What kind of competition is a result of the character displacement with Rhinoceros Beetles? | Sexual competition |
In areas of allopatry, what do two different species of rhinoceros beetles look like? | They are about the same size. |
In areas of sympatry, what do two different species of rhinoceros beetles look like? | One species is much smaller than the other species. |
What are four different kinds of exploitation? | Predation, Herbivory, Parasitism, and Parasitoids |
What do parasitoids do to another species? (2) | They invade another species and eventually kill it. It may alter the host's behavior. |
Why would a parasitoid potentially alter the host's behavior? | To benefit the reproduction of the parasitoid. |
What is one example of something that a parasitoid can alter in terms of behavior of the host? | Movement patterns (Ex: make it move to water, climb upwards, or stay still) |
Why would a parasitoid want to alter what plant the host chooses? | It can affect the host plant choice so foraging behavior will benefit the parasitoid. |
Parasitoids can use viruses - what is an example? | Bracovirus |
Where can parasitoids pack viruses? | in ovaries |
What can the viruses that parasitoids carry cause? | Brain swelling (It affects body guarding behavior) |
What kind of individuals will parasitoids generally not infect? | Those who are not sexually mature |
What is a sex-linked example of the effects of parasitoidism? | Wasps lay eggs on male crickets (who sing) Mutant males can't sing so won't get parasitized, but natural selection favors males who call |
What does a bracovirus do? | It alters the behavior of the parasitoid host |
The ____ directs the population of the predator. | Prey |
What are three things the Lotka Volterra equations show? | How populations oscillate together, how the prey peaks first and then the predator, and other environmental factors |
Lotka Volterra: What does the x axis represent? | Prey isocline |
Lotka Volterra: What does the y axis represent? | Predator isocline |
What is handling time? | The time it takes to capture, manipulate, and process food |
What is Refugia? | Areas (situations) whereby animals gain some protections from being exploited |
What is immigration? | The movement of new individuals into a population |
What do cicadas seek refuge in? | Numbers. Even if all of the predators are eating, they can't eat them all. |
What is masting? | It is in plants and it is a time where all individuals fruit together to avoid seed predation |
What "natural disaster" can be required for refugia? | Fire. It can be required for germination and cause a mass germination after |
How does size help animals with refugia? | Larger animals are safer from predators. |
What happens with the coevolution between two species? | Each adapts to changes in the other |
What are mutualisms? | Interactions between individuals of different species that benefits both individuals |
What are the two categories that mutualisms can be? | Falcultative or obligate |
What is an example of a three way mutualism? | Lichen! (Algae + yeast + fungus) |
What are two different histories of mutualisms through endosymbiosis? | Mitochondria and chloroplasts |
When should mutualisms evolve? | When the fitness of individuals that engage in mutualism is greater than individuals that don't |
What are three different organisms that share mutualisms with plants? | Pollinators, bacteria, fungi |
What is a rhizosphere? | An area around a root that is inhabited by a unique population of microorganisms |
What percent of species have mycorrhizal associations? | 90 |
What inorganic nutrient is tropical limited by? | Phosphorous |
What inorganic nutrient is temperate limited by? | Nitrogen |
Mutualism between plant and mycorrhizal fungi: What benefit does the plant get? | It is able to obtain more inorganic nutrients |
Mutualism between plant and mycorrhizal fungi: What benefit does the fungi get? | It obtains sugars |
Where is Arbuscular mycorrhizal fungi (AMF) found? | Inside plant cells (Endo) |
Where is Ectomycorrhizal fungi (EM) found? | Outside of roots. |
For ectomycorrhizal fungi, what does more hyphae equal? | More absorption |
What is the mycorrhizosphere? | It is the area around the mycorrhizal fungi where nutrients are released |
What is increased near the mycorrhizosphere? | Microbial population and activity |
Mycorrhizal Fungi: What do you see with rich soils? | More shoot, less root. More energy on reproduction. |
Mycorrhizal Fungi: What do you see with poor soils? | Less shoot, more root. More associations. |
What is AMF's role in ecological restoration? | It increases host establishment and increases soil quality (Nitrogen and aeration) |
Explain the Acacia-Ant symbiosis | Tree has thorns that ants libe in. Tree has nectaries for food that ants eat. Ants protect the tree from herbivores. ALSO caterpillars - secrete a sugary substance for ants to eat so they can feed on the tree. |
Coral Mutualisms: Corals and Crustaceans: What does the crustacean do? | Protect the coral from sea stars. Stimulate mucus flow. |
Coral Mutualisms: Corals and Crustaceans: What does the coral provide? | Lipid rich mucus that the crustaceans feed on. |
Coral Mutualisms: Corals and Crustaceans: What if the corals does now have mucus present? | Unwanted things will grow on the coral in the absence of mucus such as algae and tunicates |
What does a community consist of? | All the species that interact with one another in a given area. |
What three things does community structure describe? | The number of species, the relative abundance of species, and the kinds of species (both taxonomically and functionally) |
What does a guild consist of? | Organisms that all obtain their energy in a similar manner |
What are some examples of guilds? | herbicovres, granivores, filter feeders, etc |
What would you NOT have a guild of? | Producers |
What is a life form? | It is a grouping of organisms based on their plant growth and development. |
What are four examples of life forms? | Grasses, shrubs, trees, and forbs |
What do life forms indicate? (4) | soil depth, nutrient levels, moisture availability, animals in the area |
Guilds and life forms DO NOT reflect _____ _____, only _____ _____. | evolutionary history, energy transfers |
What can diatom life forms and ecological guilds be used for? | to assess pesticide contamination in rivers |
How are diatoms grouped and separated? | By size and shape |
What is an indicator species? | They are sensitive to environmental change. |
What are stalked diatoms sensitive to? | They are more sensitive to pesticides and herbicides than motile diatoms |
What do mucus tubule diatoms do when pesticides are present? | They can live with the toxins present while the stalked ones will die |
For most species abundance, what kind of distribution do you expect to see? | Log normal distribution (looks like a bell shaped curve) |
What do food webs impact? | Abundance |
What do food webs show? | Feeding interactions in a community |
What is interaction strength? | The effect of one species on the abundance of another species |
How do you test to see the strength of an interaction? Ex: lynx and a hare | Take away the lynx to see the effect. If the hare population booms, then it was a strong interaction. You remove the interactor. |
What does a bottom-up control influence? | physical or chemical properties on primary production such as temperature and nutrients |
What is a bottom up control in terms of trophic levels? | Primary production influences other trophic levels. Moves from the bottom up. Literally. |
What is a top down control in terms of trophic levels? | It is the influence of consumers on an ecosystem which affects other trophic levels. Moves from the top down. Literally. |
What are top-down controls also known as? | The trophic cascades hypothesis. It shows the effects of predators on prey, often showing tertiary consumers. |
How do you detect the effects of secondary consumers on an ecosystem? | Remove the secondary consumers. |
What happens if primary producers decrease? | It is bad for the community and causes a decrease in diversity |
What is biomass? | The total mass of all living species in an area. |
What is compensatory growth? | There is increased growth rates with a reduction in respiration and self shading. The plant uses the energy for growth instead of producing sugars. |
What does intermediate levels of grazing cause? | Most compensatory growth |
A keystone species is like the critical piece in an arch. What happens if you remove it? | The arch collapses. |
What kind of biodiversity does a kelp forest have? (low, moderate, high) | High |
Community: Urchins, Sea Otters, and Kelp: What do sea otters do? | Generate heat. They have a fast metabolism so they eat a lot. They can eat urchins. |
Community: Urchins, Sea Otters, and Kelp: What do the Urchins do? | They feed on dead stuff and plants. They love kelp and destroy kelp forests quickly by either eating the whole kelp or weakening the bases |
Community: Urchins, Sea Otters, and Kelp: What happens to the urchin, kelp, and biodiversity when sea otters ARE present? | Urchins decrease, Kelp increases, overall biodiversity increases. |
Community: Urchins, Sea Otters, and Kelp: Who is the keystone species in this example? | You can argue either Otter or Kelp as the keystone species |
What are two examples of keystone species? | Gopher tortoise, Ficus trees. |
What happens if you remove any top predator? | The top-down cascade effect and it also prevents competitive exclusion |
When we see an increase in top predators, what else do we see? | An increase in species richness. |
What is an invasive species? | An introduced species that is non-native that has a negative effect on native species. |
What is a disturbance? | A sudden change in an abiotic factor that causes a change in the community. |
What is ecological succession? | A change in a biological community over time. |
What is primary succession? | The creation of new substrate. |
Who is the first species on the scene during primary succession? | Pioneer species |
What are two examples of areas where primary succession occurs? | The sides of volcanoes and glaciers retreating |
What do pioneer species NOT need to survive? | soil |
What is an example of an awesome pioneer species? | Lichens! |
How are lichens an awesome pioneer species? | They secrete acids to break down the rock and substrate to get nutrients. |
What happens when a lichen, a pioneer species, dies? | Organic matter will be added to the rock. |
What is an example of a species that participates in primary succession? | Mosses |
Primary succession: What role do mosses play? | They can grow in little soil and as they die they add organic matter to the soil so that flowering plants can grow. |
Primary Succession: What is an intermediate community dominated by? | Shrubs |
What is another name for a climax community? | Mature community |
What makes a community mature? | It has a stable group of plants and animals. It is the end result of succession (but not really because communities are always changing) |
Community stages: What happens in the pioneer stage? | Small plants grow in cracks. There is water and minerals. |
Community stages: Primary Succession:What are two examples of plants you would see in the pioneer stage? | Moss and grass |
Community stages: What happens to the soil in the intermediate stage? | The soil layer builds up |
Community stages: Primary Succession:What are two examples of plants you would see in the intermediate stage? | Small shrubs and trees |
Community stages: What do you see in the climax stage? | Trees grow taller. They block out the light, thereby thinning the understory. |
Life history traits: What are two types of plants? | Early and Late Successional |
Life History Traits: What happens to the seeds of early successional plants? | They are well dispersed by wind, birds, and bats. |
Life History Traits: What is early successional enhanced by? | Light |
Life History Traits: What kind of seeds do early successional plants have? | Many small seeds |
Life History traits: What happens to the seeds of late successional plants? | They are poorly dispersed and end up close to the parent plant. They are moved by either gravity or mammals. |
Do all plants stay early or late successional? | Evolutionarily speaking, it pays for them to switch strategies over time. |
Is succession clear cut? | No! It depends on disturbances and interactions |
Interactions: What happened with facilitation in our game? (Early vs late) | Late won and moved forward, while early moved back |
Interactions: What happened with inhibition(competition) in our game? (Early vs Late) | Late won and moved forward while early stayed in place. |
Interactions: What happened with tolerance in our game? (Early vs Late) | Both early and late stayed put. |
What is an example of an event that causes secondary succession? | A fire |
Community Stages: Secondary succession (Temperate deciduous forest) : What are some examples of what you would see in the primary stage? | crabgrass, horseweed, aster, ragweed |
Community Stages: Secondary succession (Temperate deciduous forest) : What are some examples of what you would see in the intermediate stage? | pines, shrubs, young deciduous |
Community Stages: Secondary succession (Temperate deciduous forest) : What are some examples of what you would see in the climax stage? | Oaks and Hickories |
What does FIT stand for? | Facilitation, Inhibition, Tolerance |
What are the three models of succession? | Facilitation model, inhibition model, tolerance model. |
What happens in the Facilitation model? | Some initial species are able to colonize and modify the environment, which makes it no longer suitable for themselves. This allows a new suite of species to appear. |
Facilitation model: What happens in rocky intertidal communities between the red and green algae? | Green algae first came and modified the area so that the red could come and colonize. Green algae facilitated red algae which facilitated surf grass. |
Facilitation model: What happens in rocky intertidal communities if red algae is removed? | Brown algae comes in and invades (kelp) It does not allow the recruitment of surf grass. |
What happens in the tolerance model? | There is initial colonization by many species (pioneer) that modify the environment, having little to no effect on other species. Later colonizers eventually eliminate earlier species. |
What happens in the inhibition model? | Early occupants modify the environment and make it less suitable for late arrivals. Other species can only invade if the area is disturbed by events such as fires and landslides. |
What do you need to know about the three mechanisms of succession? | What are they and what do they predict |
What happened with the inhibition model when they experimentally removed algae? | Early colonists inhibit recruitment, so when the intermediate community species was removed, it was recolonized by pioneer species rather than new species. |
What happens to species richness with community age? | It increases rapidly and then levels off |
What are pioneer species limited by? | Nitrogen. They get it from nitrogen fixing bacteria and soil |
What are intermediate and climax communities limited by? | Phosphorous. It is trapped in the bedrock and not easily in the soil, so when lichen is on a rock it uses acids and frees up phosphorous. |
What happens when phosphorous is freed up in an intermediate or climax community? | It is doing well and vegetation increases while nutrient losses decrease. |
What nutrients are the community staged limited by and in what order? | Early on they are limited by Nitrogen, and later on they are limited by Phosphorous. |
What is species richness? | The number of species in a community? |
What is species evenness? | The relative abundance of species |
How is species evenness shown? | As a proportion. Ex: 2 green / 10 total = 1/5 |
what happens to species evenness if an invasive species comes in? | It is bad! |
Species richness can be the same while the evenness is different: True or false? | True! |
What is species diversity? | It is a combination of evenness and richness |
What is the value range for species diversity? | 0 - 1.0 (1 being good evenness) |
What do rank abundance curves do? | Rank species from most abundant to least abundant. Less fluctuation = more even |
Rank abundance curves: The more even the line is, the more____ the community. | Diverse |
When is there greater evenness in rank abundance curves? | When the slope approaches zero. |
What does the Shannon Wiener Index measure? | The species diversity based on the proportion of each species in a community. |
What is the general equation (simplified) for Shannon Wiener Index? | H' = The sum of: (ln pi)pi |
What is the minimum and maximum value for the Shannon Wiener Index? | Minimum value is 0, there is no upper limit |
The higher the Shannon Wiener Index (H') the higher the ________ and _______. | Richness and evenness. |
What are three factors that affect species diversity? | Environmental Heterogeneity, Nutrient Availability, and Environmental Equilibrium and Disturbance. ***KNOW: how these topics affect species diversity |
What happens when the Community and Ecosystem reach Stability? | Because there is stability, it does not change because there is no disturbance. |
Key Concept: Communities tend to be more stable when there is higher ____ _____. | Species diversity |
What is the insurance hypothesis? | As the number of species increases, the probability of overcoming disturbances increases. (As diversity increases, stability increases) |
What is resistance? | The ability to maintain structure or function in face of a potential disturbance. |
What is resilience? | The ability to return to a previous state after a disturbance. |
How is there a trade off between resilience and stability? | With a high resilience, it is like two hills. It is not as stable, but if it changes it can easily go back. With a low resilience, it is like two mountains, although it is more stable, if it changes it is NOT easy to return. |
What were the three extra credit topics? *Reminder so that you pay extra attention to them* | Acacia trees and ants, Parasitoids, Interspecific vs Intraspecific |
Hey guys! (Aka select few that I sent this to) | I hope you all do well on your ecology exam tomorrow :) I hope this helped! |