Population and Community
An ecosystem is a system in which all the living organisms interact with all the nonliving components in an environment. The interaction between the biotic and abiotic components takes place through different nutrient cycles and energy flows. Ecosystems are affected by different internal factors like decomposition, evolution, shading, etc., and external factors like climate and the topography of an environment.
The main energy in an ecosystem is entered through the process of photosynthesis. The plants are then consumed by animals, which help in the decomposition of the organic matter and help out the nutrient cycles which convert nutrients into biomass that are used by the plants and other microbes.
Different Levels of an Ecosystem
The study that deals with abiotic and biotic components, their interactions, and different energy flows and nutrient cycles between them are known as ecology. The ecosystems can be studied at an exceedingly small scale and also on a very large scale. To make things easy, there exist levels of organisation of these ecosystems. These are known as the levels of ecological organisation that goes from the smallest level to the largest level- species, population, community, ecosystem, biomes, and biosphere.
Level 1 or the Species:
In level one, a group of individuals are genetically related to each other and can breed to produce offspring of their kind. This group of individuals is known as species. If an individual cannot produce an offspring that is genetically related to each other, that means, the individual does not belong to the same species, in biology, the latter or second part of any living organism’s name is its species name like for us Homo Sapiens, Sapiens is our species name.
Level 2 or the Population:
Organisms that belong to the same species may group and interact with each other in the same environment. Groups of the same species in an environment, in biological terms, are known as population, like the sapiens living together to form the human population in a place.
Level 3 or the Community:
Community is understood as the total population of living organisms, including groups of different species and not just the same. It accounts for the interaction between groups of living organisms belonging to different species groups in the same environment.
Level 4 or the Ecosystem:
This level is a system where all biotic (living component) factors in an environment interact with abiotic (non-living components) factors. In other words, all populations interact with abiotic components of the same environment. This level of ecological organisation is known as an ecosystem.
Level 5 or the Biome:
Biome is a biological word to denote a larger habitat. It is a much larger community of plants and animals of a distinct region. Flora and fauna of this distinct region complement each other and grow in a similar condition. A very fine example of one of the biomes in the world is the desert biome. In this biome, animals like camels and plants like cactus live and grow under the same hot and dry conditions.
Level 6 or the Biosphere:
Biosphere, also known as the ecosphere, is the largest level of ecological organization. It is used to describe the layer of earth sustaining life. It, in other words, is the total of various ecosystems together. It is the total part of the earth that sustains life and has the required conditions to breed life as well. It is this biosphere that is further divided into the atmosphere, lithosphere, and hydrosphere.
The Difference Between Species and Population
Species is a smaller scale of organization of individuals that are genetically similar or related to each other while the population is a larger scale of organization of groups of similar species.
The Difference Between Population and Community
Organisms that belong to the same species, form groups, and interact together in the same environment make the level of the population, whereas the total living population is in an environment in the community. The main population and community differences between the two are that the former has groups of the same species, while the latter has groups of different species, too, making it larger than the former.
All the living beings that belong to the same species are together called “Population”. For example, all the human beings belong to the species homo sapiens and they are considered to be the population of human beings which we measure through the census once every ten years. Community indicates different organisms living in a place and interacting with each other in an environment. To know more about the concepts related to ecosystem, species, environment and other concepts of biology, keep visiting Vedantu.
FAQs on Difference Between Species Population and Community
1. What is the fundamental difference between a species, a population, and a community in ecology?
The fundamental difference lies in the level of biological organisation. A species is the most basic unit, referring to a group of individual organisms that can interbreed to produce fertile offspring. A population is the next level up, consisting of all the individuals of a single species living in a specific geographical area. A community is a broader level, encompassing all the different populations of various species interacting within the same area.
2. How do species, population, and community fit into the larger ecological hierarchy?
These three terms represent the initial levels of the ecological hierarchy, which organises life from the individual to the global scale. The order is as follows:
- Species: A group of similar individuals (e.g., all Bengal tigers).
- Population: A group of one species in an area (e.g., all Bengal tigers in the Sundarbans).
- Community: All interacting populations in an area (e.g., tigers, deer, trees, and insects in the Sundarbans).
- Ecosystem: The community plus its non-living (abiotic) environment (e.g., the Sundarbans forest with its water, soil, and sunlight).
- Biome: A large region with a similar climate and types of communities (e.g., the tropical rainforest biome).
- Biosphere: All parts of Earth where life exists.
3. Can you provide a real-world example to illustrate the difference between a population and a community?
Certainly. Consider a pond ecosystem. The group of all Rohu fish (Labeo rohita) living in that pond constitutes a population. Similarly, all the lotus plants form another population, and all the frogs form a third population. The community of the pond would be the collection of all these populations interacting with each other—the Rohu fish, the lotus plants, the frogs, plus populations of algae, insects, and microorganisms living together in that same pond.
4. What are some key attributes of a population that an individual organism of a species does not have?
A population exhibits collective characteristics, known as population attributes, which are not applicable to an individual organism. These include:
- Population Density: The number of individuals per unit area or volume.
- Birth Rate (Natality): The rate at which new individuals are added to the population through reproduction.
- Death Rate (Mortality): The rate at which individuals are lost from the population.
- Age Distribution: The proportion of individuals in different age groups (pre-reproductive, reproductive, and post-reproductive).
- Sex Ratio: The ratio of males to females in the population.
5. How do interactions between different populations define the structure of a community?
The structure and characteristics of a community are largely defined by the network of interactions among its constituent populations. These interspecific interactions, such as predation (a predator eating prey), competition (organisms vying for the same limited resources), parasitism (one organism benefiting at another's expense), and mutualism (both organisms benefiting), determine the flow of energy, population sizes, and the overall species diversity within the community.
6. Why can't a single deer be considered a population?
A single deer cannot be considered a population because the term population, by definition, refers to a group of individuals of the same species living and interacting in a particular area. An individual organism is the basic unit of a species, but ecological properties like birth rate, death rate, and density can only be measured at the group or population level. Therefore, a single deer is an organism, while all the deer in a specific forest make up the population.
7. If a forest and a grassland are side-by-side, why are they considered different communities even if they share the same climate?
Even with a similar overall climate, a forest and a grassland represent different communities due to variations in their microhabitats and ecological niches. The dense tree canopy in the forest creates shady, humid conditions on the ground, favouring shade-tolerant plants and different animal species compared to the open, sunny, and often drier conditions of the grassland. These abiotic factors (like sunlight and soil moisture) lead to the establishment of distinct sets of interacting populations, thus forming two separate and unique communities.
