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Biotic and Abiotic Factors

Biotic and Abiotic Factors

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To survive and have babies, living things must adjust to the conditions in their surroundings. Let's talk about two types of factors that affect life in an ecosystem: biotic and abiotic. Biotic factors are living things like plants and animals, while abiotic factors are non-living things like temperature and water. These factors can impact how different species adapt to their environment. To illustrate this, let's examine a desert ecosystem.

What Are Biotic and Abiotic Factors in an Ecosystem?

An ecosystem is a biological community composed of all living organisms (biotic factors) and their interaction with the physical environment (abiotic factors). The interaction between biotic and abiotic factors influences species adaptations to their specific environment.

What Is the Definition of Biotic and Abiotic Factors?

Let's talk about the two types of factors that impact an ecosystem: biotic and abiotic. Biotic factors are living things like animals, plants, and fungi. There are three main types of biotic factors: autotrophs, heterotrophs, and detritivores. Autotrophs, like plants and algae, produce their own food using sunlight or chemicals. Heterotrophs, like herbivores, carnivores, and omnivores, eat other organisms. Detritivores, such as earthworms and crabs, eat dead or decaying material to help recycle nutrients. Abiotic factors are non-living conditions like temperature, water, wind, light, and chemicals. These factors impact the ecosystem too. An ecosystem is a community of living things and their interactions with the environment.

How Do Biotic and Abiotic Factors Influence the Adaptation of Species?

Biotic and abiotic factors act as selection pressures that influence an organism's ability to survive and reproduce. This, in turn, can impact its evolutionary fitness. Selection pressures can either increase or decrease the likelihood of a certain trait appearing in a population. These pressures are external factors that impact an organism's chances of surviving in its environment. Evolutionary fitness is the term used to describe an organism's ability to survive and produce offspring.

How Do Biotic Factors Influence The Adaptation of Species?

Living organisms interact with each other in ways that affect their survival and reproduction. These interactions can be categorized into five main types of ecological relationships: competition, predation, commensalism, mutualism, and parasitism.

Competition occurs when organisms compete for resources such as food and territory. For example, plants may compete for sunlight, like in a rainforest where tall trees block out the sun and create a canopy. When an old-growth tree falls, plants in the layers below rush to maximize sun exposure. Some plants elongate their stems or leaves to avoid shade, while others tolerate shade.

Predation is when organisms consume other organisms for energy. For example, lions hunt zebras for food. Traits that help zebras escape or hide from lions, like speed and camouflage, increase their chances of survival. Lions have adapted to their prey's size and strength by hunting in groups and using tactics to corner their prey.

These relationships illustrate how living organisms interact and adapt to their environment to survive and reproduce.

 

Lions stalk their prey and hunt in groups
Lions stalk their prey and hunt in groups

Commensalism is when one organism benefits from the interaction while the other organism is unaffected. An example of this is the remora (family Echineidae), that have a flat disk-like structure that allows it to attach itself to sharks and other fishes, giving it access to a free ride and a free meal since it feeds on the leftovers of its host (Fig. 2).

 

A remora gets a free ride from a whale shark

Parasitism is when one organism benefits from the interaction while harming the other organism. For example, female brown-headed cowbirds (Molothrus ater) lay their eggs in the nests of other birds, including the savannah sparrow (Passerculus sandwichensis) (Fig. 3). Because the savannah sparrow cannot tell the fledglings apart, they take care of all of them, including those of the cowbirds. Cowbirds are much larger than the savannah sparrow, so they eat more food than the other fledglings.

The brown-headed cowbird fledgling is larger than the savannah sparrows fledglings
The brown-headed cowbird fledgling is larger than the savannah sparrows fledglings

Mutualism is a type of ecological relationship in which both organisms involved benefit from the interaction. An example of mutualism is the relationship between flowering plants and their pollinators. Most flowering plants are pollinated by animals like birds and insects. This interaction helps the plants to reproduce and diversify, while the pollinators get to eat pollen or nectar and use certain compounds to attract mates.

As a result of this relationship, flowering plants have adapted to attract pollinators by developing traits like pigments that give them bright colors that are attractive to certain pollinators, such as hummingbirds. In turn, pollinators like hummingbirds have adapted to the flowers in their ecosystem by developing different beak lengths and shapes that allow them to access the nectar and pollen of different types of flowers.

These adaptations and interactions between species illustrate the importance of mutualism in the survival and reproduction of different organisms in an ecosystem.

How Do Abiotic Factors Influence the Adaptation of Species?

Abiotic factors also play a major role in the ecosystem. Abiotic factors can limit or enhance the ability of organisms to survive and reproduce. Over time, organisms inherit adaptations that suit their environmental conditions.

Abiotic factors like wind and water can aid in dispersing pollen and seeds, helping plants reproduce. For example, the dipterocarp fruit (Fig. 4) has "wings" that allow it to use the wind draft to spread as far as possible.

 

Dipterocarp fruit. Dipterocarps (which literally translates to “two-winged fruits) are tall trees usually found in tropical rainforests
Dipterocarp fruit. Dipterocarps (which literally translates to “two-winged fruits) are tall trees usually found in tropical rainforests

Abiotic factors like temperature, salinity, and water pH can greatly affect marine life. Coral bleaching, for instance, occurs when the water temperature gets too high. Figure 5 shows how coral bleaching occurs due to factors such as increased temperatures, storm runoff and pollution, and high solar irradiance.

 

Coral and microscopic algae depend on each other for survival. When water temperatures get too high, the microscopic algae leave the coral tissue and the coral slowly dies

 

Biotic and abiotic factors are both essential components of an ecosystem, and their interactions play a crucial role in shaping the ecosystem's overall function and health. Both biotic and abiotic factors can impact the survival and success of species within the ecosystem. For example, a lack of water (an abiotic factor) can lead to the death of plants (a biotic factor), which can, in turn, impact the survival of animals (also biotic factors) that rely on those plants for food and habitat.

However, the main difference between biotic and abiotic factors is the nature of what they are made of. Biotic factors are living or once-living organisms within the ecosystem, while abiotic factors are non-living physical and chemical components, such as soil, air, water, and sunlight. Biotic factors have a direct impact on each other and can interact in complex ways, while abiotic factors are relatively stable and exist independently of biotic factors.

Another key difference between biotic and abiotic factors is that biotic factors depend on abiotic factors for their survival. Plants, animals, and fungi require specific abiotic factors, such as sunlight, water, and nutrients, to live and thrive. In contrast, abiotic factors do not depend on biotic factors for their existence or function.

Overall, while biotic and abiotic factors may seem very different, they are both critical components of an ecosystem and work together to shape the environment and the species within it.

Example of Biotic and Abiotic Factors in an Ecosystem

In a desert ecosystem, there are several biotic and abiotic factors that interact with each other to create a unique environment. One of the most significant abiotic factors in a desert ecosystem is water. The lack of rainfall in the desert makes it a scarce resource, and all the biotic factors in the ecosystem have to adapt to survive with very little water.

Plants like cacti have evolved to store water in their thick stems and spines, which also protect them from herbivores. In contrast, animals like camels have adapted to the lack of water by having the ability to store water in their humps and by being able to go without water for extended periods.

Temperature is another critical abiotic factor in a desert ecosystem. The hot and dry conditions of the desert can be challenging for many species, and animals and plants have adapted to survive in these conditions. For example, animals like lizards have evolved to burrow in the sand to avoid the intense heat of the sun, while plants like the Joshua tree have evolved to grow tall and thin to reduce their exposure to the sun's heat.

The sand in a desert ecosystem is also an essential abiotic factor that can impact the survival of species. Animals like camels have wide feet that help them walk on the sand, while snakes and lizards have developed scales that help them move across the sand without sinking. In contrast, plants like succulents have adapted to the sand by growing shallow roots that can absorb water quickly before it evaporates.

Biotic factors in a desert ecosystem include predators and prey, as well as competition for resources like water and food. For example, predators like coyotes and snakes hunt prey like rodents and insects, while herbivores like rabbits and deer compete for limited resources like plants and water.

In conclusion, the biotic and abiotic factors in a desert ecosystem are essential components that interact with each other in complex ways. The adaptations that species have developed to survive in this harsh environment are a testament to the resilience and ingenuity of nature.

 

Cacti have modified leaves called spines that conserve water and protect them from herbivores
Cacti have modified leaves called spines that conserve water and protect them from herbivores

Biotic and Abiotic Factors - Key takeaways An ecosystem is a biological community composed of all living organisms (biotic factors) and their interaction with the physical environment (abiotic factors).The interaction of organisms with biotic and abiotic factors can affect their survival and reproduction. Biotic factors (living organisms) interact with each other in ways that affect each other’s survival and reproduction. Interactions between biotic factors can be divided into five main types of ecological relationships, namely: Competition: when organisms compete for resources, such as food and territory. Predation: when organisms consume other organisms to obtain energy.  Commensalism: when one organism benefits from the interaction while the other organism is unaffected. Parasitism: when one organism benefits from the interaction while the other organism is harmed. Mutualism: when both organisms benefit from the interaction. Abiotic factors (non-living environmental conditions) can limit or enhance the ability of living organisms to survive and reproduce. Examples of abiotic factors are temperature, salinity, wind, and water.Biotic and abiotic factors are selection pressures: they increase or decrease the occurrence of a trait in a population of organisms at a given time. Organisms inherit adaptations that suit their environmental conditions, and over time, populations evolve with adaptations that are better suited to the biotic and abiotic factors in their ecosystem.

Biotic and Abiotic Factors

What are biotic and abiotic factors?

An ecosystem is a biological community composed of all living organisms (biotic factors) and their interaction with the physical environment (abiotic factors).

What is the difference between biotic and abiotic factors? 

In an ecosystem, biotic factors are living organisms while abiotic factors are non-living chemical and physical environmental conditions.

How are biotic and abiotic factors related?

Biotic and abiotic factors are components of an ecosystem: biotic factors are living things, while abiotic factors are non-living things. These factors interact and influence the adaptation of species. 

How do biotic and abiotic factors interact?

Biotic factors (living organisms) interact in ways that affect each other’s survival and reproduction. Interactions between biotic factors can be divided into five main types of ecological relationships: competition, predation, commensalism, mutualism, and parasitism. On the other hand, abiotic factors (non-living environmental conditions) can limit or enhance the ability of living organisms to survive and reproduce.

What biotic and abiotic factors influence adaptations of species?

Biotic factors (living organisms) interact with each other in ways that affect each other’s survival and reproduction. For instance, plants adapt to be able to compete with other plants over resources like sunlight and water. Abiotic factors (non-living environmental conditions) can limit or enhance the ability of organisms to survive and reproduce. For example, abiotic factors like wind and water can aid in the dispersal of pollen and seeds, helping plants reproduce.Over time, organisms inherit adaptations that suit their environmental conditions.

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