The components of an ecosystem

Classify the following elements of an ecosystem as biotic or abiotic: sunlight, an oak tree, air temperature, an earthworm, a rock, soil moisture, a mushroom, and wind.

From the following elements of a marine ecosystem, state which are biotic and which are abiotic: the water, an alga, the salinity, a dolphin, a rock on the seabed, and the light passing through the water.

An aquarium with fish, aquatic plants, a filter that oxygenates the water, and a lamp is a small artificial ecosystem. Identify its biotic and abiotic components and describe a relationship that occurs between them.

A woodpecker lives in a pine forest, where it excavates its nest in tree trunks and feeds on insect larvae living under the bark. State its habitat and describe its ecological niche.

Explain the difference between habitat and ecological niche using the example of a squirrel that lives in an oak wood and feeds on acorns.

Look at the diagram: two species of birds, A and B, live in the same holm oak tree. Bird A feeds on acorns in the canopy, and bird B feeds on insects living on the trunk. Do they share a habitat? Do they share an ecological niche? Justify your answers based on the diagram.

Grass, horses, vultures, and fungi live in a grassland. Classify each organism as a producer, a consumer, or a decomposer.

A temporary pond dries up every summer. Explain how this abiotic factor affects the living things in the pond and cite one adaptation that one of its plants might show.

In a natural park, the Iberian lynx and the red fox coexist in the same Mediterranean scrubland environment. The lynx hunts almost exclusively live rabbits by stalking among dense vegetation, whereas the fox consumes small rodents, carrion, fallen fruit, and insects in both dense and open areas. a) Identify, with reasoning, the habitat of both species and compare their ecological niches, indicating which is a specialist and which is a generalist. b) If an epidemic reduces the rabbit population by 90 %, predict what will happen to the population of each species and justify which one is more likely to survive based on the breadth of its ecological niche.

Define what an abiotic factor is and give three examples found in a marine ecosystem.

On the bare rocks of high mountains, only mosses and lichens grow. Identify two harsh abiotic factors of that environment and reason why these organisms are able to live there.

After clear-cutting a forest plot, it is recorded that the average soil temperature has increased by 7,5 °C and surface moisture has decreased by 40 % compared to the adjacent intact area. A technical report states that "these abiotic changes will only affect the felled trees, but not the rest of the living organisms in the soil". a) Refute the report's statement by explaining how the temperature change and desiccation directly affect decomposers (bacteria, fungi, and earthworms). b) Predict the cascading consequences that the loss of these decomposers will have on nutrient recycling and the forest's ability to regenerate naturally.