The term flora is often used to cover all plants, fungi, and algae in a given environment, while fauna refers to the animals that live there. The scientific definition of flora and fauna is the plants and animals that live in a particular area or time. The difference between them stems from whether plants or animals are being discussed.
In botany, or the study of plants, flora actually has two distinct definitions. First, it can mean the plants of a given environment or period of time, as listed above, or it can refer to a book or such work that describes plants with the aim of identification. This first definition is the most common, and it refers specifically to those plant species that are indigenous to area or time. An indigenous species, whether plant or animal, is one that originated in an area and continues to grow and survive there without any interference by humans. The opposite of indigenous species are introduced ones.
Both flora and fauna have further classifications or subdivisions. Flora classifications depend on the region, climate, environment and period of the plants being described. The fauna subdivisions are based on mostly on where the animals live and their size.
There are many different flora regions across the planet. Some regions can be as large as entire continents or as small as a wetland or mountainous regions. Besides geographic areas, climate and time periods can group different plants into floras. Plants can also be grouped into native, agricultural and garden, and weed flora.
There are seven different subdivisions of fauna that are used, based on where the animals occur and their size. Infauna and epifauna are aquatic animals that live within or on the bottom of the ocean floor, respectively. Microfauna are microscopic in size, while meiofauna are slightly larger and live in both sale and fresh water soil environments. Macrofauna are tiny soil organisms, larger than meiofauna, but smaller than earthworms and nematodes, which are part of the mesofauna group. Megafauna are the large animals of the particular environment being discussed.
Both the flora and fauna of a region are studied separately and together by a number of different types of scientists. Botanists, or plant scientists, mainly study flora, while zoologists study fauna. Ecologists and those studying conservation look at both together, as the two groups are dependent on each other to survive.