Ecosystem Dynamics, Limiting Factors, and Sustainability

Ecosystem Interactions and SNC1W Foundation - This document explores the fundamental interactions within an ecosystem involving various organisms such as the Kookaburra, Rabbit, Wedged Tailed Eagle, Mouse, Grass, Snake, and Grasshopper. - These organisms demonstrate complex interactions that define the dynamics of their specific habitat. # Population Dynamics and Limiting Factors - Population Definition: A population is a group of members from the same species that live in the same area. - Population Variability: The size of a population is constantly changing due to various Limiting Factors. - Limiting Factors Definition: These are factors that limit the growth, distribution, or amount of a population in an ecosystem. # Categorization of Limiting Factors - Abiotic Limiting Factors: - Available Resources: water, food, space, and soil. - Climate: temperature and weather changes. - Natural Disturbances: storms, droughts, and fires. - Human Disturbances: construction, deforestation, and logging. - Biotic Limiting Factors: - Competition among organisms. - Predation. - Cooperation and Symbiosis. - Presence of disease-causing organisms. # Biotic Limiting Factors: Competition - Competition Definition: The interaction between two or more organisms for the same resource in a given habitat. - Types of Competition: - Intraspecific: Occurs between members of the same species. Example: Male sheep competing to determine who will mate and produce offspring. - Interspecific: Occurs between different species competing for the same resources. Example: Raccoons and ravens both feeding on eggs from the same nest of a bird. - Resource Targets: Organisms can compete for food, shelter, space/territory, light, and mates. - Ecological Niches: For similar species to live together in the same area, they must have slightly different niches. Example: Many different species of bird may feed on the same spruce budworm, but each species feeds in a different part of the spruce tree. # Biotic Limiting Factors: Predation and Disease - Predation Definition: When one organism eats another organism to obtain food. - Prey Adaptations for Survival: - Physical Attributes: speed, mimicry, and camouflage. - Physical Defenses: quills and bad taste. - Chemical Defenses: odor and ink spray. - Disease-Causing Organisms: Biotic factors that limit populations include bacteria, fungi, and parasites. # Biotic Limiting Factors: Cooperation - Cooperation Definition: Occurs between the same type of organism or species that live together to help each other. - Examples of Cooperative Behavior: - Sharing food and childcare responsibilities. - Grooming each other and taking care of the sick. - Hunting in packs and providing collective protection. # Symbiotic Relationships - Symbiosis Definition: Occurs between two different species where one lives in, on, or near a member of another species. - Types of Symbiosis: - Parasitism: Benefits one species and harms the other. Relationship notation: $(+)$ and $(-)$. - Commensalism: Benefits one species with no effect on the other. Relationship notation: $(+)$ and $(0)$. - Mutualism: Both species benefit from the interaction. Relationship notation: $(+)$ and $(+)$. # Carrying Capacity and Sustainability - Carrying Capacity Definition: The maximum number of individuals an ecosystem can support without reducing its ability to support future generations of the same species. - Population Dynamics: Populations typically overshoot the carrying capacity before it is fully reached. - Environmental impact: If a population exceeds the carrying capacity for a long period, it usually harms its environment. - Sustainability Rule: For an ecosystem to be sustainable, no single population in the community can exceed its carrying capacity by very much or for very long. - Goal of Sustainability: To meet the needs of the present generation without affecting the ability of future generations to meet their needs. # Case Study: Predator-Prey Relationships (Hare and Lynx) - Cycle Mechanics: - As the number of hares increases, the lynx can capture hares more easily. - Because lynx are well-fed, they can have more offspring, leading to an increase in the lynx population. - The increase in lynx population eventually causes a decrease in the hare population because more are being eaten. - As the hare population (food supply) decreases, the lynx population also decreases. - With fewer lynx, the hare population begins to recover, and the cycle repeats. # Predator-Prey Simulation and Study Tasks - Simulation Resource: Interactions between predators, prey, herbivores, carnivores, and omnivores in a forest ecosystem can be explored at: https://www.learner.org/wp-content/interactive/envsci/ecology/ecology.html - Simulation Objective: Run the model until Day $100$ to observe population changes. Consider if two plant species can survive together and why. - Homework Requirements: - Complete the Symbiotic Worksheet Page. - Finish the Predator-Prey Simulation. - Complete the Carrying Capacity Worksheet. - Continue creating study flashcards.