Animals: bats, cave crickets, cave spiders, centipedes, millipedes, scorpions, beetles, cockroaches, moths, salamanders, frogs, snakes, snails, cave fish, crabs, shrimp, crayfish, microbes, and microorganisms.
Plants: mosses, ferns, and liverworts. Trees grow on top of caves and their roots grow into the caverns, feeding many animals and producing carbonic acids to weather away the limestone.
Rocks (limestone, sandstone, etc.), lakes, cool temperature, soil, darkness, minerals, stalactites, and stalagmites.
Carrying capacity is the largest number of individuals of one species that an environment can support. the four resources that every species needs to survive are food, water, shelter, and space.
The relationship between resources and the population of a certain species can be shown with cave rat snakes. If there are few cave rat snakes, there will be an abundance of resources for them including bats, cool (as in slightly cold) shelters, and water. If there was a sudden influx in the population of rat snakes, these resources would become fewer.
Below you can see the relationship between deer and wolf populations. By this you can see that this relationship between resources and the consumer doesn't just exist in caves, but in every environment. As one increases, the other decreases. You can compare the wolf line to the rat snakes and the deer to any resource the rat snake needs, such as bats, shelter, or water.
Limiting factors are any factors or conditions that limit the growth of a population in an ecosystem. Some examples would be starvation, diseases, parasites, accidents, hunting, weather, and predators.
In a cave, though, some of these can't happen because of the fact that caves are underground. Some limiting factors specific to a cave ecosystem would be diseases, parasites, predators, starvation, accidents, and possibly human interference. A strange limiting factor I found for troglobites, or organisms specifically adapted to live in complete darkness, is light. These creatures have evolved solely to live in caves to the point where they couldn't possibly live on the surface.
Anyways, back to the point. An example of how limiting factors affect the environment is seeing how a predator-prey relationship changes when a limiting factor happens in an environment. If, say, an ignorant human decides to make a natural habitat such as a cave a great tourist attraction, the unfortunate organisms living in that cave would be exposed to bright lights and loud noises. The bats in that habitat, with their great hearing and sensitive eyes, would probably immigrate deeper into the cave, leaving the cave crickets back in their original habitat without its main predator. This can lead to overpopulation, destroying most resources that the crickets need, creating fierce competition within the cave cricket species. The crickets would start dying in massive amounts because of the lack of sufficient resources, and the bats that immigrated deeper into the cave probably wouldn't have as much prey to feed on either, leading to competition and the starvation of the cave bats as well. Limiting factors can change the composition and resources within an ecosystem in huge ways if it's powerful enough.
The three different energy roles in every ecosystem are producers, consumers, and decomposers. They all play essential roles in an ecosystem, and are vital to each other for survival.
Producers are organic materials that provide their own food from non-living things, so an example would be plant materials washed down by floods. They convert sunlight into nutrients for themselves through photosynthesis. Of all the energy roles these organisms play the most important because they provide energy for all the organisms in an ecosystem.
Consumers are organisms that eat producers and other consumers. There are different kinds of consumers, consisting of primary, secondary, and tertiary consumers. Primary consumers feed on producers, secondary consumers feed on primary consumers, and tertiary consumers feed on secondary consumers. Some examples of consumers in a cave are bats, cave spiders, scorpions, and millipedes. They all get their energy from the organism that they eat, whether it be a producer or a consumer.
Decomposers are organisms that decompose dead organisms and turn them into nutrients for producers. Some examples would be earthworms and cave crickets. They get their energy from the dead organisms and when they digest them the dead organisms turn into nutrients. Decomposers link the transfer of energy from producers to consumers.
Food Chains vs Food Webs
Food chains and food webs show the flow of energy in an ecosystem. Food webs are more accurate though because they show multiple food chains and all the predators and prey of a specific organism. A food web for caves is shown below.
If any population was taken out of the food web, or the ecosystem, the whole balance in the ecosystem would be disrupted. Say, for example, you take the cave beetles out of the ecosystem, there would be an increase in the cricket and isopod populations because they wouldn't have as many predators if not one at all, and that would result in a decrease in cave bacteria and outside plant populations. Every organism is essential to the balance of an ecosystem.
Trophic Levels in Energy Pyramids
Energy pyramids are in the shape of a pyramid because the pyramid represents the amount of energy available in each trophic level. There is more energy at the bottom of the pyramid, where the producers are. There is less energy at the top, where the top carnivores are.
There is the most energy at the bottom because all the organisms at the bottom get their energy on their own. They use approximately 90% of the energy the receive to carry out the functions they need to live, so only 10% of the energy they receive is given to the primary producers that eat them. The primary producers also use up 90% of the energy they receive from the producers, as well as the secondary, tertiary, and every other consumer. Less and less energy is passed through the animals, so organisms at the top of energy pyramids must eat a lot to get the sufficient energy they need to survive. This is why there is less energy at the top.
The picture above shows the process of photosynthesis. Photosynthesis is how a plant gets nutrition. This process can be shown in the chemical equation below.
co2+h2o ---> c6h12o6+o2
Carbon dioxide, water, and light are needed for photosynthesis to occur. Carbon dioxide enters the leaf through its stomata, and comes from animals like us, water comes from the ground and through the roots of the plants, and light comes from the sun. If you were wondering, the arrow represents sunlight and it acts as and equal sign, showing that the substances on either side are equal. When all these things are combined in the leaf cells, photosynthesis occurs, and the carbon dioxide, water, and light are turned into oxygen and glucose. Glucose is a sugar that plants use for nutrition. The oxygen is sent out as waste from the plant so we can breathe it in and turn it into carbon dioxide again, and thus the cycle repeats itself.
Chloroplasts help make photosynthesis possible through a green substance called chlorophyll inside of them that collects sunlight. Photosynthesis occurs specifically in the chloroplast of the plant cell, but many other organelles help carry out the process of photosynthesis as well such as the cytoplasm and nucleus of the cell. Without these two other organelles photosynthesis wouldn't be possible, so the chloroplast can't take all the credit.
Some of you might be wondering at this point: Why is this guy talking about photosynthesis in a tackk about caves, where he specifically mentions there is no light? My reply: I have no idea. The only possible way this stuff relates to cave is the fact that floods bring green plants into caves.
Tropism is the bending or turning movement of an organism toward or away from an external stimulus, such as light, heat, or gravity. An example that would be found in a cave would be tree roots hanging down from the ceiling. The seed of the tree sent its roots down into the Earth to find water in response to gravity, the external stimulus in this case.
Here is a link to a video showing how plants respond to light. https://youtu.be/tLYOBi5gaVs?list=PL4o_UZqNTliIM0X5hhVGNisY1VcrpVOco
Tropisms such as these help a plant survive in its ecosystem. Pointing towards light helps the plant produce glucose through photosynthesis, and having the roots of a tree go down helps the tree find water to produce glucose as well. Without tropisms, the plant wouldn't be able to keep up with the world around it and probably die.
You might remember decomposers from the energy roles slide. These guys, like the producers, play an essential role in an ecosystem. Their job is to decompose dead materials such as dead animals and plants by eating them. When they excrete the dead materials, the once useless husks of life have become healthy nutrients for soil. Without these nutrients plants wouldn't be able to grow nearly as well and the energy circle in an ecosystem would stop once an organism died. Disease would also spread if the decomposers didn't break down the feces and dead bodies of organisms. Decomposers are the link that connects the energy circle between producers and consumers.
Some examples in a cave would be fungi, bacteria, earthworms, and cave crickets. Below are the things these organisms do.
Adaptations are the changes that a species makes to help survive in its environment. These are important because they can be the difference between life and death when it comes to the different limiting factors an environment contains. Adaptations are how a species keeps up with their environment. There are structural and behavioral adaptations. An adaptation is structural when it has to do with the physical body or appearance of a species. An adaptation is behavioral when it has to do with the behavior or actions of a species.
Some adaptations an animal would need in a cave ecosystem would be some way to be aware of your surroundings in the dark, a loss of skin pigment, sharp claws to catch prey, webbed fingers for swimming, wings for flying, extra legs to move faster, or anything that helps an animal move, find nutrients, or respond to threats.
Common adaptations for plants in a cave ecosystem are ways to get nutrients other than photosynthesis, the ability to latch onto other animals and become a parasite, the ability to grow on rocks and other hard surfaces, and anything that helps them acquire nutrients, be protected from consumers, or find water.
If an organism from a cave, say, a cave fish, was placed into a saltwater ocean randomly, that cave fish would die a miserable death. First of all, it hasn't evolved to live in an environment with salt and wouldn't know how to take the salt out of the water they're constantly inhaling. Secondly, unfamiliar predators and prey would make it impossible to distinguish what is safe or not. Thirdly, the cave fish wouldn't be able to see any of its surroundings by any means because it has evolved to live in a cave environment. Species have different adaptations for different environments, so you can't expect one set of adaptations to work for every ecosystem.
Natural selection is the process of adaptations developing in a species over time based on changes in the environment. Natural selection is how adaptations are created within a species. They also allow a species to survive and reproduce in a species.
An example of nature selecting a species in a cave ecosystem is the selection of the scorpion. Let's take a look at all the traits of a scorpion. Hard exoskeleton, 8 legs, giant pincers, and a huge stinger with venom at the end of its tail. They probably didn't start out in the world with all of these traits, but acquired them over the generations. The cycle of natural selection starts with the birth of a new batch of cute little creepy crawly arachnids. If a genetic mutation happens in the DNA of one of the little angels, they could have a new trait never before had by scorpions. For example, let's say that this special little snowflake with a genetic mutation randomly had a stinger at the end of his tail. This is a useful trait that allows a species to survive more easily, so he will retain it through his adulthood until he finds that special someone and reproduces. Because the mutation has helped the scorpion he will pass it down to his batch of newborns, and over many generations the whole scorpion species will eventually have a venomous, deadly stinger at the end of its tail. This happens to every species and makes it to where the species can keep up wth the environment, survive, and reproduce.