BIOL 311 Species Interactions - Fall 2024 PDF

Announcements Ecology – (BIOL 311) Thursday: Species Interactions – pt 1 Ideas for the balance of the semester Read: Duarte and Maherali 2022 Tuesday: Species Interactions – pt 2 In-class quiz (Blackboard – bring your computers) Read: Wuster and Wuster 2023 T...

Announcements Ecology – (BIOL 311) Thursday: Species Interactions – pt 1 Ideas for the balance of the semester Read: Duarte and Maherali 2022 Tuesday: Species Interactions – pt 2 In-class quiz (Blackboard – bring your computers) Read: Wuster and Wuster 2023 Thursday: Biogeography Read Mendoza and Araujo 2022 Ecology in the News Climate change Landscape  Study Guide (you are responsible for the details) Concept: Competition can be direct or indirect, vary in its intensity, and occur between individuals of the same species or of different species Concept: “Competing” species are more likely to coexist if they use resources in “different” ways (there is a line here where this is no longer competition Concept: The outcome of competition can be altered by predation, the physical environment, and disturbance Concept: Predator populations can cycle with their prey populations Concept: Predation can affect prey distribution and  Study Guide (you are responsible for the details) Concept: Most carnivores have broad diets, whereas a majority of herbivores have relatively narrow diets Concept: Predation results in a wide range of capture and avoidance mechanisms Concept: In positive interactions, no species is harmed, and the benefits are greater than the costs for at least one of the species. Concept: Each partner in a mutualistic interaction acts in ways that serve its own ecological and evolutionary interests Concept: Positive interactions affect the abundances and distributions of populations as well as the  Study Guide Herbivory (you are responsible for the details) Allelopathy Case Study: Competition in Competition & plants that eat animals Resource Availability Case Study: lynx-hare Competitive Interspecific vs Coexistence Intraspecific Interactions Competitive Exclusion Tropic Interactions Resource (Niche) Competition Partitioning Fundamental & Realized Character Niche Displacement Direct & Indirect Predicting the Competition Outcome of Exploitation competition Competition Interference Competition Altering the outcome of competition  Study Guide Mycorrhizal fungi are (you are responsible for the ubiquitous details) Ectomycorrhiza Case Study: Ants & Fungi Arbuscular (endo) Reciprocal plant-herbivore mycorrhiza interactions Parasitism (that is not (compensation, induced defense, secondary symbiotic) compounds) Parasite (non-lethal) Effects of predation and & Parasitoids (lethal) herbivory on communities Camouflage Symbiosis Aposematic coloring Mutualism (+/+) Crypsis Commensalism (+/0) Mimicry Parasitism (+/-) Batesian Obligate and Facultative Müllerian Interspecific Interactions: The effects that individuals of different species have on one another in an ecological community. These interactions can be positive, negative, or neutral, and can be short-term or long-term Intraspecific Interactions: The interactions between individuals of the same species. They can be direct or indirect, and are important drivers of evolutionary changes, community assemblies, and distribution patterns Interspecific vs Intraspecific Interactions? Competition: a non-trophic interaction between individuals of two or more species in which all species are negatively affected by their shared use of a resource that limits their ability to grow, reproduce, or survive Interspecific: competition between individuals of different species Intraspecific: competition between individuals of the same species Competition in Plants that Eat Animals Mostly a Primary producer as that is where they get most of their energy Therefore, 1st level of the trophic pyramid Competition in Plants that Eat Animals Tend to grow in poor soils so it needs nutrients Shallow roots suggests it is a poor competitor Competition in Plants that Eat Animals No difference if exclude prey (insects) Look at within pairs Better growth if reduce competition (right pair vs left pair) And even better if reduce competition and have Competition is influenced by a number of factors Number and/or density of Competitors, Dominance, Age, Injury, Arrival Time, etc. Both types of competition may happen at the same time Interspecific – examples? Intraspecific – examples? What other species interactions do you see in the image? Occurs directly between individuals via aggression when the individuals interfere with foraging, survival, reproduction of others, or by preventing their physical establishment in a portion of the habitat. Individuals interact indirectly as they compete for common resources, like territory, prey or food. Simply put, the use of the resource by one individual will decrease the amount available for other individuals. Competition  Exploitation Interference Competition: competition: occurs occurs directly between when individuals individuals via aggression interact indirectly as when the individuals they compete for interfere with foraging, common resources, like survival, reproduction of territory, prey or food. others, or by directly Simply put, the use of preventing their physical the resource by one establishment in a portion Competition between/among similar species to distantly related species Elk are more likely to have a competitive foraging advantage over deer because Deer have a smaller relative stomach volume, so deer need higher quality, more digestible forage, whereas elk can use lower-quality forage, but need large amounts, Elk have a greater vertical reach than deer, allowing  Exploitation or Interference competition? Exploitation…eating similar foods How do plants compete?  Allelopathy Interference Competition (chemical warfare) Chemically-mediated competition between plants sometimes defined more broadly  It can prevent germination of its own seeds and that of others to reduce competition It can inhibit growth of nearby neighboring plants, reducing competition  Competition can be directional – one species (or individuals) harmed more than another Competition can be for more than 1 resource (e.g., light, space, water, nutrients, etc. Tall trees outcompete Small trees to compete short trees for for water and growing sunlight with little to space with impacts to no impact from short the larger trees trees  Competition between/among similar species to distantly related species Kangaroo rats and some species of ants eat seeds…Do they compete? Keep in mind…use of the resource determines if there is competition  Is there competition Yes & No No…smallest seeds for seeds? are not eaten by the K- K-Rats rats win What is present in the image? Predation Predator & Prey Trophic interactions Carnivory (Carnivore & Omnivore) Herbivory (Herbivore) Parasitism (Parasite & Parasitoids) Pathogens Carnivores tend to have broader dietary niche than many herbivore What about omnivores? Not absolutes…even specialists eat other items (intentional or accidental) Effects of Herbivory on Communities Reciprocal plant-herbivore interactions: Plants can respond to herbivory Triggering chemical production as a defense against herbivory Reciprocal plant-herbivore interactions: Plants can respond to herbivory Triggering growth and reproduction Effects of Predation on Communities  Effects of Predation on Communities  What do we know about Predator-Prey from previous lectures? Let’s identify as many as possible… X Population Size Draw a Predator- Prey Cycle Graph 0 Time Y Z  Let’s discuss this pattern A decrease in prey is What could trigger a followed by a decrease in decrease in prey? predators Other than the predation…  Let’s discuss this pattern What could Habitat resource degraded which trigger a decrease in could be followed by a reduced prey? carrying capacity (Not predation) Other density dependent factors (e.g., disease) Looking to the future…mid-semester status check What are some aspects of the class that we may want to keep, change, or drop? What can I do better to help you with learning the content and with conveying your knowledge? Discuss and anonymous written