The Earth is a wonder. Evolution itself is so amusing even after billion years of existence. Scientists have been discovering new things about our world, yet there is a lot to unravel. Plants and animals we see today existed before us. Plants were the first inhabitants of the Earth. When we speak of plants, do you think of only the tall poles with green leaves? Plants collectively mean any chlorophyll-containing organism. Hence, the words flora and fauna collectively define life on Earth. Flora indicates plants, and fauna indicates animals. What comes under flora, and what exactly defines fauna? Let’s find out more about the rich biodiversity of the Earth.
Flora vs Fauna
Flora and fauna are Latin words. Flora translates to “goddess of flower” and fauna to “ to derive or nurture”.
Flora interprets it as something related to flowers, or that bears flowers or flower-like structures. So, plants, algae and some fungi come under flora. Flora is a group of plants belonging to or native to a geographical region.
Fauna is a group of animals belonging to or native to a geographical region. So flora and fauna of the Amazon indicate all the plants and animal life of the Amazon forest.
Differences between flora and fauna in tabular form
|Meaning||Plant life in a particular region||Animal life in a particular region|
|Habit||Autotrophs and heterotrophs||Only heterotrophs|
|Movement||Stationary||Can move from one place to another|
|Subject of study||Studied in botany||Studied in zoology|
|Types||Horticulture flora, weed flora and native flora||Macro fauna, micro fauna, stygofauna, meiofauna.|
|Presence of cell wall||Present||Absent|
|Preparation of food||Can prepare their own food||Cannot prepare their own food|
What is flora?
The study of flora gives us extensive knowledge of plant kingdoms. We can learn about every plant and plant-related species, classification and niche.
Flora is often used to describe documenting plants from a specific area or historical period.
Plants are divided into floras based on their geography, also known as floristic region, climate, ecological factors, and era.
The floristic region might be ecosystems such as mountains and valleys, and the time could be either historic or current. They are further classified based on their specific habitats. Flora of a region differs from another. The flora of a desert would be different from the flora of a rainforest. Flora often indicates native species, but we do not exempt the newly introduced species. Native flora is plant species indigenous to a geographical region.
For example, the Brazil nut tree is a native flora to the Amazon rainforest.
Flora underwater accounts for all the marine and freshwater plant life from phytoplankton to floating plants. E.g. musk grass, water hyacinths, kelps, and purple corals.
Scientists also study fossil flora, which includes the study of extinct primitive plant life. It helps us know better about today’s flora based on evolution. E.g. An important fossil flora of India is the Gondwana flora that existed during the Jurassic Age.
The Mpofu fossil flora allows us to envision what the Earth would have been like when the biggest plants were no higher than our ankles and nearly no animals were roaming the land of the Earth. It helps us comprehend how our world evolved into the green home we know today.
Plants cultivated by humans are agricultural, horticultural, or garden flora. Horticultural Flora is a classification of plants grown for aesthetic purposes. Usually, these plants are cultivated for their aesthetic appeal in public and private gardens, landscaping, and indoor and outdoor living areas. Horticultural Flora is a diverse collection of flowers, shrubs, trees, and herbaceous plants that contribute significantly to the visual appeal of both natural and concrete settings. These plants are also frequently employed for their medicinal, nutritional, and economic significance.
Weed flora is a set of unwanted and undesirable plants. Yet, certain species that have historically retained in the weed flora may be valuable to other habitats. E.g. the weed Kariba has invaded the lake of Ossa, which was teeming with native and vulnerable species. Now, you can only see a large body of water covered by a green blanket. It has travelled through many countries from Brazil to Africa to Australia. The Bermuda grass, which was considered a weed, is now used in making golf courses and sports fields. These also support many herbivores.
Normal and transient flora are the two types of flora. Normal or resident flora is a permanent group of microbial flora living on any organism. The transient flora does not settle but tends to jump from one to another.
Trichodesmium is a phytoplankton that has the ability to absorb nitrogen gas and convert it into nitrogenous nutrients that will support its growth and make this organic form of nitrogen accessible to other phytoplankton for their own growth. Trichodesmium is a globally relevant and biogeochemically significant organism that significantly influences climate because it plays a critical function in delivering a limiting nutrient and removing CO2.
What is fauna?
Fauna accounts for all the animal life that exists or once existed in a geographical area. Faunistics is the study of animals that inhabit a particular region.
Types of fauna
These are believed to be rare and exist in microhabitats. These also include corals.
E.g. Komado dragon and okapi.
The name suggests cryo means cold. Cryofauna is animals that live in or near sub-temperature areas.
E.g. albatross, emperor penguins, polar bears and orcas.
Infauna lives at the bottom layer of a water body. These animals form deep burrows that go as deep as 3m long. Most extinct marine life belonged to infauna. Clams, worms and snails belong to this group.
Live in freshwater. Alligators, beavers and otters are examples of limnofauna.
Macrofauna is species classified by their size. They are often found in soft sediments, such as sand and mud, and occasionally gravel. Their size is defined by the mesh of a screen. The word macrofauna has evolved to refer to practically any bottom-living or bottom-associated animal which is between the size of 0.5 mm and 5 cm.
They frequently have brightly coloured bodies with pinks, reds, yellows, and even purple hues, as well as odd, one-of-a-kind patterns on their shells and exoskeletons.
E.g. Ladybug amphipod
The megafauna includes extinct and/or extant enormous or giant creatures from a location, habitat, or geological epoch.
E.g. African bush elephant and the Masai ostrich are the megafaunas of the African continent. Whales, great white sharks and squids are megafaunas of the pacific ocean.
According to their diet, megafaunal species can be divided into three groups: megaherbivores (like elephants), megacarnivores (like lions), and, less frequently, megaomnivores (like bears). The class of animals to which the megafauna belongs—mammals, birds, reptiles, amphibians, fish, and invertebrates—is another way to classify it.
For 180 million years, dinosaurs ruled the planet and got bigger. Tyrannosaurus Rex adults were 13 metres long and 6,000 kilogrammes in weight 66 million years ago. They were known as the King of the Lizards. Dinosaurs coexisted with mammals, but none were known to have been bigger than present badgers.
Following the extinction of the dinosaurs about 66 million years ago due to a catastrophic asteroid hit, lesser mammals grew in size to fill the ecological niche. Megaherbivores like proboscids and hornless rhinoceroses attained weights of 10,000 kilogrammes before plateauing in size around 40 million years ago.
The Würm glaciation, also known as the end of the last ice age, saw the extinction of many large ice age mammals, including woolly mammoths, in the Americas and northern Eurasia. This event is known as the Holocene extinction. The wave of extinctions has been linked to a number of theories, including human hunting, climate change, disease, extraterrestrial influence, and others.
Meiobenthos, aka meiofauna, are tiny benthic invertebrates that dwell in either saltwater or freshwater. The word meiofauna refers to a class of species that are larger than microfauna but smaller than macrofauna.
In 1942, Molly Mare initially used the term “meiobenthos.”There are just 35 animal phyla on Earth, hence meiofauna are probably the most varied group of creatures in the water. And tens of thousands of species. Meiofauna taxa have been promoted by researchers for being better environmental indicators for biomonitoring campaigns, which track environmental changes like pollution through time and place.
E.g. Water bear and gastrotrich
Mesofauna is creatures of moderate size. Members of the mesofauna include nematodes, mites, springtails, proturans, and pauropods.
The mesofauna has three different categories of feeders: micropredators, litter ingestors, and ecosystem engineers.
Micropredators manage the microbial population while eating microbial biomass. The micropredators consume during this process releases nutrients into the soil.
Leaf litter that has fallen from the trees and vegetation is consumed by litter ingestors. Both the physical structure and the chemical content of the soil are altered by these mesofauna.
Microfaunae are tiny creatures and organisms that have animal-like features. These are omnipresent. They live in water and soil.
These dwell in groundwater systems or aquifers, such as caves, fissures, and vugs. Based on their life cycle, these classify into stygophiles, stygoxenes, and stygobites.
Stygofauna are abundant in the Pilbara, and their evolution over millions of years demonstrates the durability and significance of groundwater in the Pilbara environment.
E.g. salamander cavefish and crayfish.
Troglofauna are little cave animals that have adapted to their dark environment. Subterranean fauna classifies into two types: troglofauna and stygofauna. Spiders, insects, myriapods, and other troglofaunal species are examples. Some troglofauna live entirely underground and cannot survive outside of caves. Among the adaptations and traits of troglofauna are heightened senses of hearing, touch, and smell.
Troglofauna lack eyes and have insufficient pigmentation. Troglofauna are primarily researched in caves, however alluvium is clearly a major habitat for them. They have also been gathered from calcrete beds in ancient valleys and iron ore deposits. As iron ore deposits weather, numerous vugs and voids form, which act as habitat for troglofauna.
Xenofauna includes the extraterrestrial life i.e. aliens. These occur outside the earth and do not have any proof of existence.
Birds are a group of warm-blooded vertebrates that belong to the class Aves. They are distinguished from other vertebrates by their feathers, toothless beaks, hard-shelled eggs, high metabolic rates, four chambered hearts, and robust yet lightweight skeletons.
Some bird species that live in watery habitats, especially seabirds and some waterbirds, have undergone further evolution to become swimmers.
The only species of dinosaurs still alive today are feathered theropod birds. Similarly, birds are classified as reptiles in modern terms, and crocodilians are their closest surviving cousins.
Fish are aquatic, craniate, gill-bearing animals without limbs. The hagfish, lampreys, cartilaginous, and bony fish that are alive today as well as other related extinct groups are included..
Soft-bodied chordates, which first appeared during the Cambrian epoch, are the earliest animals that may be categorised as fish.
Since most fish are ectothermic ("cold-blooded"), their body temperatures can shift in response to changes in the surrounding environment, although some of the larger, more energetic swimmers, including white sharks and tuna, can maintain a higher core temperature.
They can be found in almost all aquatic habitats, from the depths of the deepest oceans (where cusk-eels and snailfish can be found) to high mountain streams (where char and gudgeon, for example),
Main differences between flora and fauna in points
- Flora represents the plant life of a geographical region. Fauna represents animal life.
- Flora and Fauna describe the whole plant and animal kingdom respectively.
- Flora is classified based on topography, whereas fauna is classified based on evolution.
- Flora is stationary, whereas fauna is mobile.
- The study of plants is called botany, and the study of animals is called zoology.
- Flora includes autotrophs and heterotrophs. Fauna includes only heterotrophs.
- Flora is characterised by the presence of cell walls and fauna do not have a cell wall.
Flora and Fauna make up the Earth. We have learnt what distinguishes flora from fauna. Flora describes the plants, and fauna describes the animals. There are different types of flora and fauna. Yet, many other species are waiting to be discovered. Flora and fauna are very vital for the basic working of nature. Without one, the other can’t exist. One’s survival depends on the other. Flora covers minute phytoplankton to large trees. Fauna represents the microscopic fungi to macrofaunae like whales and elephants.