What Are Bioclimatic Zones?

Bioclimates and bioclimatic zones are concepts used in geography and climatology which help us to better understand how different types of climate affect our planet. They are descriptions and classifications based on a number of climate-related factors. Such factors include temperature, humidity, precipitation and other phenomena which influence the distribution of plant and animal life in a given geographical region.

Specifically, bioclimates are the sets of climatic conditions that determine the type of vegetation and animal life present in a region. These climatic conditions include aspects such as the average annual temperature, thermal amplitude, precipitation type, precipitation distribution, seasonal duration patterns and other climate-related factors.

Bioclimatic zones are geographical areas that share similar climatic characteristics. They are defined by the interaction of several climatic factors. These zones are divided mainly based on temperature and precipitation, which allows them to be classified into different types of climates. Such types of bioclimatic zones include the tropical, subtropical, temperate, cold and polar zones.

Within each bioclimatic zone, local variations may exist due to other factors. These include altitude, proximity to the sea, topography and the influence of ocean currents. For example, within the temperate climate zone, subtypes of bioclimatic zone include the Mediterranean climate, continental climate and oceanic climate. These each have their own distinctive climatic characteristics, even though they a part of a larger bioclimatic zone which is temperate.

Bioclimatic zones are divided into several main categories, each characterized by a specific set of climatic conditions. While there may be some variance or differing classifications, the main bioclimatic zones are the following:

• Tropical zones
• Subtropical zones
• Temperate zones
• Cold areas
• Polar zones

Below we detail the characteristics of each of the main bioclimatic zones of the planet Earth.

The tropics are areas located near the equator, specifically between the tropics of Cancer and Capricorn. Temperatures in these zones are high throughout the year. The difference between day and night temperatures is minimal, with relatively small seasonal variations. This creates a consistently hot and humid climate.

Precipitation is high in tropical zones and well distributed throughout the year. They are subject to frequent rains and, occasionally, intense storms. This constant humidity favors the development of lush and diverse vegetation, such as the different types of tropical rainforest that can develop. Rainforests are types of jungle ecosystems which are famous for their great biodiversity.

The favorable climatic conditions afford these regions to have the greatest biodiversity of anywhere on the planet. While these areas can be difficult for human settlements to thrive, the breadth of biodiversity in tropical climates have a worldwide impact. For example, they provide the lion's share of gas exchange on our planet which allows all other life to continue. Tropical biomes include rainforest, savannah and dry tropical forest, each with a unique variety of species adapted to their specific environment.

As in the tropics, the subtropics experience warm temperatures, but with greater seasonal variation. Summers are typically hot, while winters can be milder. They may also have some thermal fluctuations depending on location and local climatic influences.

The subtropics can experience a wide range of precipitation, from relatively dry regions to areas with more abundant rainfall. It is usually due to the influence of factors such as proximity to the ocean, ocean currents and local topography. The biomes we encounter include shrublands, deciduous forests, grasslands and semi-arid areas.

Learn about the difference between a biome and an ecosystem with our related guide.

One of the most distinctive characteristics of temperate zones is the presence of well-defined seasons. Summers are usually warm or moderate, while winters can be cold, with temperatures dropping to below freezing in many areas.

These areas experience moderate precipitation, with a relatively uniform distribution throughout the year. However, there may be significant variations in the amount of rainfall depending on geographic location and other local climatic factors.

They have a considerable daily and seasonal thermal amplitude. During summer, temperatures can be warm during the day and cool at night. In winter, temperatures can fluctuate between day and night, with lower highs and colder lows. The biomes present in temperate zones are varied and include mixed forests, deciduous forests, grasslands, steppes and shrublands, among others.

Learn about the difference between climate and weather with our related guide.

Cold and polar areas have extremely low temperatures, especially during the winter months. Temperatures can drop below 0 ºC/32 ºF for long periods of time, creating icy and freezing conditions.

In these regions, winters are usually prolonged with short days and long nights due to the tilt of the Earth's axis. During winter, sunlight is scarce and temperatures can reach extremely low levels. This results in the formation of permanent ice and snow.

Vegetation in cold and polar areas is adapted to harsh climatic conditions. In more northern regions, hardy trees such as pine and spruce predominate. These are often in the form of a taiga (boreal forest), a type of forest with coniferous trees.

In the regions closest to the poles, vegetation is sparse and consists of small and resistant plants such as lichens and mosses. In terms of fauna, you can find mammals such as the polar bear, arctic wolf and reindeer, as well as migratory birds that take advantage of the warmer seasons to reproduce and feed. However, this will depend on whether it is close to the North or South Pole.

In the polar regions, most of the ground is permanently frozen, something known scientifically as permafrost. In addition, these areas are covered by a layer of ice and snow for much of the year, helping to maintain cold temperatures and reflect sunlight.

Cold and polar areas are especially vulnerable to climate change. Rising temperatures are causing melting ice caps and loss of wildlife habitat, with significant impacts on local ecosystems and the global climate.

Now that you know what bioclimatic zones are, we recommend you read this article about the types of climate we can experience on our planet.

If you want to read similar articles to What Are Bioclimatic Zones?, we recommend you visit our Environment (other) category.