Biomes

A biome represents communities of living things. And it's characterized by the predominant plant physiognomy in terrestrial biomes. Or by the physical environment in the case of aquatic biomes.

In the terrestrial environment, a biome represents a geographical area of uniform environment, characterized by climate, relief, soil, fauna, and, mainly, by vegetation formation, that is, by the physiognomy of the vegetation.

General patterns of the planet

The latitude influences the distribution of biomes on the planet. Earth regions located at the same latitude have similar climatic conditions have very close plant formations.

In addition to latitude, altitude also has a strong influence on the distribution of biomes. The increase in altitude causes a decrease in temperature and a modification in rainfall intensity. Thus, we can find biomes from colder regions and higher latitudes, such as tundra and taiga, in areas of higher altitudes present in the tropics and at the equator.

But despite the similarity in vegetation physiognomy, the species composition of a biome varies from one location to another.

Types of biomes:

-Tundra

The climate of the tundra is cold and dry, with low precipitation and little light throughout the year. In the Arctic tundra, rainfall varies between 200 mm and 600 mm, and in the Alpine tundra, it reaches up to 1 000 mm per year. Snow covers the ground for most of the winter, and the lower temperatures reach -22 °F. Summers are short, around three months, and temperatures reach a maximum of 50 °F.

The vegetation of the tundra is herbaceous, consisting of lichens, mosses, grasses, and small shrubs.

The strong winds, scarcity of water, and low temperatures are factors that prevent the presence of trees.

The fauna of the tundra consists of insects, birds, reindeer, musk ox, Arctic hare, Arctic fox, white bear, and Arctic wolf. Many birds migrate to the tundra in summer for nesting.

-Taiga

The taiga locates in the northern hemisphere in areas of Canada, the United States, Siberia, and mountainous regions. The climate of this biome is cold and dry, with severe winters, but short. In the taiga, average rainfall varies between 300 mm and 700 mm.

The vegetation of the taiga consists mainly of a homogeneous forest of conifers such as pines, sequoias, hemlock, and firs. The leaves of many pines are needle-shaped, protecting the plants from water loss and harsh cold. In addition to conifers, the taiga is home to diverse species of lichens, mosses, and herbaceous and shrubby angiosperms.

-Temperate Rainforest

The temperate forest locates itself in North America, Europe, Russia, China, Japan, Australia, and New Zealand. In these regions, the four seasons are well-defined, and the vegetation responds to climate change in a characteristic way.

The climate in this biome is temperate, with winter temperatures reaching 32°F. However, in the hot and humid summer, the maximum temperature is 95 °F.

The vegetation of the temperate forest is made up predominantly of deciduous trees that lose their leaves in the fall, reducing their metabolic activity during the harsh, dry winter. These plants produce new leaves during the hot, rainy summers. Characteristic trees are oaks, beeches, walnut trees, and maples.

-Rainforest

Tropical rainforest occurs in the equatorial and subequatorial regions of Central America, northern South America, eastern and western Africa, southern Asia, the Pacific Islands, and northeastern Australia, covering about 7% of the Earth's surface.

The climate is hot and humid, with relatively high and constant temperatures and abundant rainfall, with annual precipitation between 2,000 mm and 4,000 mm. The vegetation is hygrophilous.

This climate is favorable to the development of diverse species, providing this biome with the largest biodiversity on the planet.

The vegetation of the rainforest is stratified, formed by large, small-large trees, small trees, shrubs, and herbaceous plants that live on the living on the soil surface.

The warm, humid climate favors the growth of decomposer organisms, making essential nutrients available to be used by plants in photosynthesis. In the ground of these forests, the decomposition of organic matter forms a dark-colored fertile layer (called humus).

The soil has a biodiversity of worms, arthropods, fungi, and bacteria, maintained by the high amount of organic matter in the humus and by the humidity.

-Savanna

Savanna can be found in many places, such as South America, Europe, and Australia, although the best known is in Africa.

Rainfall in the savanna is seasonal, averaging 300 mm to 500 mm per year, and the dry season can last up to 9 months. Temperature is high throughout the year, averaging between 75 ºF and 84 ºF. And with more seasonal variation than in tropical rainforests.

The savanna vegetation consists of grasses, cactus, shrubs, and small trees. The trees and shrubs are scattered, often thorny, and have small leaves, characteristics related to relatively drier conditions.

The African savanna fauna is composed of various insects, herbivorous mammals, and birds.

-Camp

The camp occurs in flat tropical and temperate regions that receive an amount of rainfall intermediate between forests and deserts.  Grasslands exist in South America, North America, Europe, and Asia.

In this biome, winters are dry, and summers are wet. Annual rainfall is 300 mm to 1000 mm, and periodic droughts are common. Winters are cold, with an average temperature below 14 ºF, and summers are hot, with temperatures of 86 ºF.

The field vegetation consists of grasses and small shrubs.

The fauna consists of insects and mammals, such as rodents, prairie dogs, bison wolves, coyotes, and foxes.

-Desert

The desert occurs in ranges near the 30° latitude north and south, but also at other latitudes in the interior of continents, in regions of low humidity. There are deserts in Chile, Mexico, the United States, Africa, China, and Australia.

The climate is dry, the soil is arid, and annual precipitation is low and variable, usually less than 300 mm. 

In hot deserts, days can have temperatures above 104 °F, and nights can be cold. In cold deserts, on the other hand, there is less temperature variation throughout the day.

Desert vegetation is poor, low, and well dispersed. The few existing plants are xerophytic, i.e., adapted to the dry environment.

The fauna of the desert is made up of animals adapted to the scarcity of water. Among them are insects, arachnids, reptiles, birds, and mammals.