Summative LT 1.3 & 1.4 Study Guide

Flashcards created to help review concepts from the Summative LT 1.3 & 1.4 Study Guide.

What effect have humans had on the total potential NPP for the planet?

Humans reduce total NPP by using more land for housing, roads, etc., leaving less energy for ecosystems.

Explain why there are not many tigers in the world using the 2nd law of thermodynamics.

The 2nd law states energy loses quality; thus, there isn't enough quality energy to support many tigers as energy flows through trophic levels.

Compare and contrast photosynthesis and cellular respiration.

Photosynthesis converts solar energy into usable energy, while cellular respiration breaks down that usable energy for cellular functions.

What is the difference between a food chain and a food web?

A food chain shows one directional feeding patterns with one energy source per level, while a food web shows multiple directions and energy sources.

How do detritivores, scavengers, and decomposers play a role in the food web?

They help recycle nutrients by breaking down dead material, ensuring the ecosystem doesn't fill with dead matter.

Define abiotic and biotic components of an ecosystem and describe their limiting factors.

Abiotic: non-living factors (e.g., water), limiting survival; Biotic: living factors (e.g., other species), contributing to success.

How do density-dependent factors limit populations?

They affect populations based on size, e.g., disease or food availability increases competition in denser populations.

What is resource partitioning?

Resource partitioning is the division of resources by species to reduce competition, thus limiting density-dependent impacts.

Which has more influence in shaping an ecosystem - GPP or NPP?

NPP has more influence as it represents the energy available after respiration for organisms consuming plants.

If an ecosystem receives 10,000 kW of solar energy, how much will be captured by GPP? NPP?

GPP = 100 kW; NPP = 40 kW.

Why must predators in low NPP ecosystems cover huge ranges to survive?

Energy quality decreases through trophic levels, so predators need vast areas to find sufficient energy to survive.

What happens to an herbivore if solar energy is blocked?

If solar energy is insufficient, herbivores like rodents will struggle to survive, leading to population decline.

Discuss how a model can be both a closed and open system.

Closed system: matter cycles only among these organisms; Open system: solar energy enters, aiding producers.

Draw a pyramid of biomass assuming the producer level has 1600 kg.

Producer 1600 kg -> Primary consumer 160 kg -> Secondary consumer 16 kg -> Tertiary consumer 1.6 kg.

Why can you only burn a gallon of gasoline once?

Once burnt, the energy is transformed and quality is lost, aligning with thermodynamics laws.

Calculate the net primary productivity given GPP and respiration values.

Net primary productivity = GPP - respiration = 4.5 kgC/m2/year - 3.2 kgC/m2/year = 1.3 kgC/m2/year.