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Herb

Unit 2 - Ecosystems & Ecology

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Globe Showing Europe Africa

Unit 1 - Foundations Of Environmental Systems & Societies

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Flexed Biceps

Unit 3 - Biodiversity & Conservation

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Writing Hand

Unit 4 -Water & Aquatic Food Production Systems & Societies

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Deciduous Tree

Unit 5 - Soil Systems & Terrestrial Food Production Systems & Societies

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Cloud

Unit 6 - Atmospheric Systems & Societies

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Thermometer

Unit 7 - Climate Change & Energy Production

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Briefcase

Unit 8 - Human Systems & Resource Use

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Bar-Chart

Internal Assessment

🎈 Did you know: Populations can grow in two different ways - exponentially and logistically! Like, seriously, they have these cool curves to represent their growth patterns!

This is like being on a roller coaster that only goes up. The population increases rapidly and continuously. Picture a J on its side; that&#39;s what the growth chart looks like (figure 2.1.11 (a)). This growth kicks off slowly because of limiting factors but then shoots up when those limiting factors are defeated!

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Limiting factors: Things that can curb the population growth. For plants, it&#39;s light, nutrients, water, CO2, and temperature. For animals, it&#39;s food, mates, and water.

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Positive feedback: Once limiting factors are overcome, the population begins to grow faster because there are more individuals to reproduce.

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Real-world example: Consider bacteria. If we give them a suitable environment (temperature, food), they reproduce like crazy!

This one&#39;s like a roller coaster with a massive loop in the middle. The growth is slow at first, then super fast, and then it slows down again, leading to a plateau. The slowing down happens because new limiting factors pop up.

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New Limiting factors: They include limited food, increased predation, disease, accumulation of wastes, and competition. These factors may be density-dependent, which means they become more significant as the population grows.

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Carrying Capacity: This is the maximum number of individuals that an environment can support. In an S-Curve, populations hit a wall - their carrying capacity - and then bob up and down around this number because of seasonal changes or changes in resource availability, etc.

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Real-world example: Take a deer population. When food is plentiful, their numbers increase, but when winter arrives, food becomes scarce, and numbers decrease, stabilizing over time.

This is the &quot;J-curve gone wrong&quot; scenario. The population grows super fast, but then a sudden drop in the population occurs - a population crash - due to limiting factors like seasonal climate change, disease, or overexploited food resources.

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Real-world example: Ever heard about the reindeer on St. Matthew Island? The population skyrocketed from 29 to 6000 because of abundant food, but then crashed to less than 50 because they depleted their food source. Talk about a dinner party gone wrong!

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🔍 Important Note: Population growth is not a one-size-fits-all! It&#39;s super complex and depends on many different factors, both environmental and species-specific. This makes the study of population growth very exciting, and sometimes unpredictable, like your favorite cliffhanger TV show!

Population Dynamics: Curves & Crashes

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Standard Level

Environmental Systems & Societies SL

Unit 2 - Ecosystems & Ecology

Population Dynamics: Curves & Crashes

Table of content

Exponential growth (j-curve)

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Unit 2 - Ecosystems & Ecology

Population Dynamics: Curves & Crashes

Table of content

Exponential growth (j-curve)

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