Carrying capacity (K) is the maximum population size an environment can support indefinitely given available resources (food, water, shelter). In the logistic growth model, populations grow rapidly when small, slow as they near K, and level off at K. If a population exceeds K (overshoot), resource depletion can cause a severe dieback or population crash due to famine, disease, or conflict—density-dependent regulation. Carrying capacity can fluctuate with changing resources or disturbances, and resilience/recovery depends on ecosystem health. This is a key APES idea for Unit 3 (populations) and shows up on both multiple-choice and FRQ items where you might describe overshoot, dieback, or link K to logistic growth. For a clear topic review, see the Fiveable carrying-capacity study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and practice questions (https://library.fiveable.me/practice/ap-environmental-science).

Carrying capacity (K) is the maximum population size an ecosystem can support long-term given available resources. Populations grow toward K following a logistic growth curve; if they overshoot K (too many individuals), resources get depleted and density-dependent factors (competition, disease, starvation) increase, often causing a dieback or population crash—think St. Matthew Island reindeer. Carrying capacity can fluctuate with resource availability, season, or human impacts, so ecosystems may recover slowly depending on resilience. For the AP exam, know key terms (K, overshoot, dieback, density-dependent regulation, logistic model) and be ready to explain causes/effects of overshoot (famine, disease, conflict). Review the Topic 3.4 study guide on Fiveable for examples and practice (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and try practice questions for Unit 3 (https://library.fiveable.me/practice/ap-environmental-science).

If a population exceeds its carrying capacity (K), it’s called overshoot. The population uses more resources than the environment can replenish, causing resource depletion. Because food, water, or habitat become limited, density-dependent factors (like competition, disease, and predation) kick in and the population often suffers a dieback or population crash—sometimes severe or catastrophic. Classic patterns come from the logistic growth model: population grows, overshoots K, then falls back (or oscillates) until it stabilizes or collapses. Outcomes can include famine, increased disease, conflict, reduced reproductive success, and long recovery times if the ecosystem’s resilience is low (see the St. Matthew Island reindeer example in your CED keywords). For AP prep, know the terms overshoot, dieback, carrying capacity, and density-dependent regulation and how they show up on Unit 3 questions. For a quick review, check the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and practice problems (https://library.fiveable.me/practice/ap-environmental-science).

Overshoot happens when a population grows past its environment’s carrying capacity (K). After overshoot, resources (food, water, shelter) get depleted faster than they can renew, so individuals face starvation, weaker condition, and higher susceptibility to disease—that rapid dieback or population crash is the result. Density-dependent factors (competition, disease, predation, waste buildup) amplify mortality when density is high, so the population can fall sharply—sometimes catastrophically—below K before it stabilizes. Classic examples (e.g., St. Matthew Island reindeer) show how non-renewable or slowly renewing resources lead to overshoot and collapse. This idea ties directly to the logistic growth model and EKs in the CED (carrying capacity, overshoot, dieback). For a quick CED-aligned refresher and practice questions on carrying capacity, check the Topic 3 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and more Unit 3 resources (https://library.fiveable.me/ap-environmental-science/unit-3).

Carrying capacity (K) is the maximum number of individuals an environment can support long-term given available resources, space, and other limits. If a population goes past K, overshoot can happen, often followed by dieback (population crash) from resource depletion, disease, or famine—classic in the logistic growth model and AP CED keywords. Population growth rate is how fast the population size is changing over time (births − deaths ± migration). It’s often denoted r; when r > 0 the population grows, r = 0 it’s stable, r < 0 it declines. Put simply: carrying capacity is a limit (a ceiling), population growth rate is the speed and direction of change. Density-dependent regulation (like competition, disease) links the two—as N approaches K, growth rate typically slows. For more AP review, see the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) or the Unit 3 overview (https://library.fiveable.me/ap-environmental-science/unit-3). Practice questions are at (https://library.fiveable.me/practice/ap-environmental-science).

K (carrying capacity) is the maximum population size an ecosystem can support long-term given available resources (food, water, shelter). In models it’s the K in the logistic growth equation: population growth slows as N approaches K because density-dependent factors (competition, disease, predation) limit growth. If a population goes above K, overshoot occurs; resources get depleted and the population often suffers dieback or a population crash from famine, disease, or conflict—classic AP examples include St. Matthew Island reindeer and logistic vs. exponential (Malthusian) growth comparisons. For the AP exam, you should be able to: define K, explain overshoot and dieback, and connect density-dependent regulation to logistic curves (CED EK ERT-3.D.1 and ERT-3.E.1). For a quick review, see the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and practice problems at (https://library.fiveable.me/practice/ap-environmental-science).

When a population overshoots carrying capacity (K), it uses resources faster than the ecosystem can renew them. That overconsumption drains food, water, nesting sites, and other limiting resources—a process called resource depletion. Density-dependent factors then strengthen: competition for scarce resources raises stress, lowers reproduction, and increases spread of disease and famine. Those stresses can cause a dieback or population crash (classic example: St. Matthew Island reindeer). Overshoot also can trigger conflict (within or between species) and reduce ecosystem resilience, so recovery is slower and carrying capacity may drop. On the AP exam, link overshoot → resource depletion → density-dependent regulation → dieback (ERT-3.D and ERT-3.E). For a quick topic review, check the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and practice questions (https://library.fiveable.me/practice/ap-environmental-science).

Carrying capacity (K) is the maximum population an ecosystem can support long-term given resources and density-dependent limits. In models you usually use the logistic growth equation: dN/dt = rN(1 − N/K), where N = population size, r = intrinsic growth rate, and K = carrying capacity. Algebraically, when population growth rate (dN/dt) = 0, N = K—so K is the equilibrium population. Practically, you estimate K from data by finding the population size where growth levels off (logistic curve plateau) or by rearranging the equation using measured N and dN/dt to solve for K. Remember real ecosystems can overshoot K and suffer dieback (resource depletion, famine, disease), so K can fluctuate with resources and biotic resistance. For AP prep, know the logistic model, density-dependent regulation, overshoot/collapse examples, and practice problems on the topic (see the Topic 3.4 study guide: https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24). For more review, check Unit 3 or try practice questions (https://library.fiveable.me/ap-environmental-science/unit-3 and https://library.fiveable.me/practice/ap-environmental-science).

Overshoot happens when a population grows past the environment’s carrying capacity (K). After overshoot, resources (food, water, shelter) get depleted faster than they can renew, so per-capita resources fall. That increases density-dependent pressures (competition, starvation, spread of disease) and reduces reproduction and survival rates, causing a rapid dieback (population crash). The classic St. Matthew Island reindeer case shows how overshoot + limited resources led to catastrophic dieback. Dieback can be severe because time lags let the population exceed K before negative feedbacks (resource shortage, disease, conflict) kick in. On the APES exam, this is Topic 3.4 material—know K, overshoot, dieback, density-dependent regulation, and examples for MCQs and FRQs. For a concise review, check the Topic 3.4 study guide on Fiveable (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and practice questions (https://library.fiveable.me/practice/ap-environmental-science).

Overshoot happens a lot in nature and human history. Classic real-world examples: - St. Matthew Island reindeer: ~30 introduced in 1944 exploded to thousands by the 1960s, overshot food supply, then crashed to only a few dozen (a textbook overshoot → dieback case). - Easter Island: human population grew past the island’s ecological carrying capacity, leading to deforestation, resource depletion, and social collapse (historic example of overshoot and collapse). - Fisheries (e.g., Atlantic cod): intensive harvesting pushed populations below sustainable levels; stocks collapsed when reproductive capacity couldn’t recover—a form of human-driven overshoot and dieback. - Desert locust plagues or algal blooms: rapid population/resource use causes boom-and-bust cycles where resources deplete and populations crash. These illustrate EK ERT-3.D/E: overshoot (K exceeded) leads to resource depletion and density-dependent dieback or population crashes. For AP review, study the St. Matthew Island case and logistic growth/overshoot terms (see the Topic 3.4 study guide) (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24). For more Unit 3 review and practice, check the unit page (https://library.fiveable.me/ap-environmental-science/unit-3) and practice problems (https://library.fiveable.me/practice/ap-environmental-science).

Carrying capacity (K) is the max population an ecosystem can support long-term. If a population overshoots K, it uses up food, water, shelter and other resources faster than they’re replaced. That resource depletion causes famine (individuals don’t get enough calories/nutrients) and increases susceptibility to illness. Crowding and weakened bodies also make disease spread faster—these are density-dependent effects that drive dieback or a population crash (think St. Matthew Island reindeer). Famine and disease aren’t separate from carrying capacity—they’re the mechanisms by which overshoot leads to severe declines. On the APES exam, expect questions linking overshoot → resource depletion → famine/disease/dieback (Topic 3.4, EK ERT-3.D.1 and ERT-3.E.1). For a clear review and examples, check the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and try practice problems (https://library.fiveable.me/practice/ap-environmental-science).

When a population overshoots carrying capacity (K), several linked environmental impacts happen. First, resource depletion—food, water, and habitat—rises quickly, lowering per-capita resources. That often leads to dieback or a population crash (severe to catastrophic declines) driven by famine, disease, and conflict—classic density-dependent regulation. Overshoot can also degrade ecosystems: soil erosion, loss of plant cover, reduced biodiversity, and altered nutrient cycles make recovery slower and lower ecological carrying capacity. Populations and ecosystems may oscillate (overshoot and collapse) rather than return smoothly to logistic growth; resilience and recovery can be compromised. The St. Matthew Island reindeer case is a textbook example of overshoot → dieback. For AP exam prep, be ready to define K, describe overshoot and dieback, and connect causes (resource depletion, density-dependent factors) to outcomes. Review the Topic 3.4 study guide for examples and practice (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and more unit review (https://library.fiveable.me/ap-environmental-science/unit-3). For extra practice questions, see (https://library.fiveable.me/practice/ap-environmental-science).

Carrying capacity (K) sets the maximum prey population an ecosystem can support. If prey stays below K, predators and prey often show regular predator–prey oscillations: predator numbers lag behind prey numbers because predators depend on prey for food. If prey overshoots K, resource depletion can cause a sharp dieback (population crash) in the prey; predators then crash too from lack of food. Those density-dependent effects (competition, disease, starvation) tighten predator–prey coupling and can produce larger amplitude cycles or collapse. Carrying capacity can also fluctuate (seasonally or with habitat change), changing cycle timing and stability. For AP exam answers, link K, overshoot, dieback, and logistic growth to explain why predator numbers lag and why both populations can crash after overshoot (CED EK ERT-3.D.1, ERT-3.E.1). For a quick study refresher, check the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and practice questions (https://library.fiveable.me/practice/ap-environmental-science).

Carrying capacity (K) is the maximum population an ecosystem can support long-term with its available resources. Sustainability is about meeting present needs without compromising future ability to meet them—so a population at or below K is more likely to use resources sustainably. If a population overshoots K, resource depletion can occur and lead to dieback or a population crash (St. Matthew Island reindeer is a classic example). Logistic growth models show populations slowing as they approach K due to density-dependent regulation. For the AP exam, know those keywords (carrying capacity, overshoot, dieback, resource depletion, population crash) and be ready to explain ecological impacts and resilience/recovery. Want a focused review and practice problems on this? Check the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and more Unit 3 resources (https://library.fiveable.me/ap-environmental-science/unit-3).

Yes—carrying capacity (K) can change over time in the same ecosystem. K depends on available resources and conditions: if food, water, or habitat increase (succession, restoration, nutrient inputs) K goes up; if resources are depleted, pollution, drought, invasive species, or human land use reduce resources, K goes down. Populations can overshoot K and then suffer dieback (severe/population crash) because of resource depletion—classic in the St. Matthew Island reindeer case and in logistic growth models with density-dependent regulation. Seasonal variation and extremes (storms, fires) also make K fluctuate short-term; long-term shifts (climate change, habitat conversion) produce lasting changes. For APES, this topic links to overshoot, dieback, population crash, and resilience—so expect questions in Unit 3 about causes/effects and graph interpretation. Review the Topic 3.4 study guide (https://library.fiveable.me/ap-environmental-science/unit-3/carrying-capacity/study-guide/v2LtCnBGi4ceCTmPao24) and practice problems (https://library.fiveable.me/practice/ap-environmental-science).