TYPES OF ECOSYSTEMS AND THEIR CHARACTERISTICS - ENVIRONMENT - 2025

The types of ecosystems are the diversity of organisms present on the planet interacting with certain climatic conditions. An ecosystem is an area defined by a particular combination of abiotic (soil, water, climate) and biotic (living organisms) conditions.

Given the diversity of climates, soils, reliefs and life on Earth there are different types of ecosystems. The determining factors in the conformation of the planet's ecosystems are latitude, altitude and rainfall.

Types of ecosystems on the planet. Source: SirHenrry

Likewise, the height above sea level affects the temperature, while precipitation and other factors determine the availability of water.

Then, local factors such as the type of soil and the natural history of the place end up forming the mosaic of ecosystems on the planet. According to the system used, about 12 terrestrial and 4 aquatic biomes (set of ecosystems sharing common conditions of climate, fauna and flora) are recognized in the world.

On the other hand, the World Wide Fund for Nature (WWF, acronym in English) recognizes 14 terrestrial biomes, 12 freshwater and 5 marine. These in turn divided into some 1,500 ecoregions, each with different ecosystems, so their number on the planet is difficult to determine.

To simplify this diversity, we will address the main types of ecosystems grouping them based on large environmental units, climate, relief and vegetation.

Terrestrial ecosystems

- Tropical ecosystems

Humid rainforest

Rain forest. Source: German Robayo

The humid tropical forests are one of the most diverse ecosystems that exist, especially the lowland rainforests like those of the Amazon. In turn, there are diverse ecosystems of humid tropical forests, among them the flooded forest.

Within these, there are forests flooded with white waters and black waters, which depends on the type of river that generates the flood.

Similarly, there is a whole variety of lowland rainforest ecosystems, depending on the predominant species. For example, the morichal is a riparian forest dominated by the moriche palm (Mauritia flexuosa), which exists in the Venezuelan plains.

On the other hand, there are also humid mountain rainforests or cloudy forests, which develop between 800 and 3,000 meters above sea level. All humid tropical forests are characterized by their diverse strata of trees and abundant epiphytism and climbing.

An example of cloud forests are those of the Andes mountain range as the eastern yunga in Peru.

Dry rainforest

When the climate is bi-seasonal with a marked dry period, different types of dry forest ecosystems develop, such as deciduous and semi-deciduous forests.

In the first case, the insufficiency of water in the dry period is extreme and most of the species lose all their foliage. While in semi-deciduous forests there is more availability of water in the dry period, in some cases by groundwater.

In the semi-deciduous forests of tropical America, some species reach considerable heights (up to 40-50 m). Examples of this are the ceiba (Ceiba pentandra) or the mijao (Anacardium excelsum).

Scrub and thorn

In those more arid areas, forests do not develop, with thickets and thorn forests. These are formations dominated by large shrubs and small trees, many of them thorny.

In the American tropics, the presence of shrubby and arborescent cacti is common in these formations. One of the most common angiosperm families in these formations throughout the tropics is Leguminosae.

Bed sheets

Bed sheets. Source: Inti

These are ecosystems of plains, plateaus or areas of soft hills, warm and with a strong bi-seasonality. In these ecosystems grasses predominate, in some cases accompanied by scattered trees or palms.

Legume trees are quite abundant in both the African and American savannas. For example, the wooded savannas of Acacia spp. in Africa and the savannah tree savannas (Samanea saman) in America.

Large herbivores abound in the African savannas in very numerous herds such as the wildebeest (Connochaetes taurinus) and the zebra (Equus quagga). As well as large carnivores such as the lion (Panthera leo), the hyena (Crocuta crocuta) and the leopard (Panthera pardus).

High mountain grasslands

Above the tree line (3,400-4,000 meters above sea level) in the high mountains, ecosystems dominated by roseate grasses and small shrubs develop. Among these are the páramos and the puna, characterized by high solar radiation and low temperatures.

The páramos are ecosystems with higher humidity, while the puna is much drier. A characteristic genus of the páramos and endemic to the Colombian-Venezuelan Andes is Espeletia (Compositae), which groups together numerous species of herbs and shrubs.

Coastal grasslands

Various ecosystems dominated by grasses, subshrubs and small shrubs develop in coastal areas. The species that inhabit here are adapted to conditions of high salinity and strong winds.

Characteristic examples of this are the saladillo (Sporobolus virginicus) a grass and the beach purslane (Sesuvium portulacastrum) an aizoaceous.

Mangrove swamp

The mangrove is a transitional ecosystem between land and sea, dominated by tree species adapted to high salinity. For example, the red mangrove (Rhizophora mangle) is capable of living with its roots submerged in seawater.

This ecosystem is closely associated with marine ecosystems such as submerged grasslands and coral reefs.

Hot deserts

In the most arid areas deserts are formed, which are regions where the extreme limiting factor is humidity. Daytime temperatures can exceed 50ºC, while at night they can be close to zero degrees.

Vegetation and fauna are very scarce and highly adapted to conditions of water deficit. Among the characteristic animals of these ecosystems are the dromedary (Camelus dromedarius) and the camel (Camelus ferus), in Africa and Asia.

- Temperate ecosystems

Coniferous forest

These forests develop in the northernmost latitudes of the temperate zone or in mountainous areas. They are characterized by the dominance of gymnosperm species of the order Coniferae, especially pines (Pinus, Abies). As well as cypress and juniper trees (Juniperus, Cupressus) and cedars (Cedrus).

In some cases, very tall trees occur as in the Californian redwoods (Sequoia sempervirens) forests. This species can reach up to 115 m in height.

Mixed forest

This type of ecosystem is intermediate between the coniferous forest and the broadleaf forest. In turn, various types of mixed forest ecosystems are delimited, depending on the geographical location.

It is characterized by including both coniferous (Pinus, Abies, Juniperus) and broadleaf species. Among the latter are oak (Quercus robur), beech (Fagus sylvatica) and birch (Betula spp.).

In the southern hemisphere, gymnosperms typical of mixed forests belong to the Araucariaceae and Podocarpaceae families. In the case of the northern hemisphere, they are located in North America, in the United States and Canada as well as in Mexico, and also in Europe and Asia.

Deciduous forest

They are oak and holm oak forests, as well as alders and other species of angiosperms typical of the temperate zone. They are adapted to the temperate seasonal regime with spring, summer, autumn and winter.

Among the predominant tree genera are Quercus, Fagus, Betula, Castanea and Carpinus and in the deciduous forests of the southern hemisphere Quercus and Nothofagus predominate.

Mediterranean forest

They are forests that develop in a Mediterranean climate, which occurs in very defined areas of the planet. We find them only in the Mediterranean Sea basin, in California (USA), Chile, South Africa and Australia. It is a climate with mild and rainy winters and hot dry summers, with warm autumns and variable springs.

The plants have adapted to this hot and dry period, so they tend to be stunted and sclerophyllous (tough evergreen leaves). Among the common species in these ecosystems are oaks (Quercus robur), oaks (Quercus ilex) and cork oaks (Quercus suber).

Prairies

The meadows are herbaceous formations, with a predominance of grasses that develop on plains, plateaus or hilly areas in temperate regions. Although the structure of the vegetation makes them similar to savannas, they differ from them in climate and specific composition.

They include the North American and European grassland ecosystems, as well as the pampas (Argentina), the steppes (Eastern Europe and Asia) and the Velts (South Africa).

Coastal grasslands

As in the tropics, in the temperate zones diverse ecosystems develop in coastal plains. As in the tropics, herbs, subshrubs and shrubs adapted to high salinity predominate, although the floristic composition is different.

In these ecosystems there are species such as the grass Aleuropus littoralis in the Mediterranean.

- Arctic ecosystems

Taiga

Taiga. Source: peupleloup

It is the coniferous forest of the cold regions that forms an almost continuous band from North America to East Asia. It is a tall coniferous forest with a very sparse or absent understory, in some cases reduced to mosses and lichens.

The taiga is also not uniform and in it different ecosystems can be identified, for example the dark taiga and the light taiga. The first is made up of the typical leafy evergreen conifers (Pinus spp., Picea spp., Abies spp.) That form the boreal forest belt.

For its part, the clear taiga is located further north, bordering the tundra with species of Pinus and deciduous conifers (some species of Larix).

Tundra

Beyond the tree line marked by latitude, at the end of the taiga the tundra extends. It is an extensive plain dominated by mosses and lichens on a frozen soil substrate, permafrost.

Cold desert

Cold desert ecosystems are found in Antarctica and Greenland, with extensive ice-covered areas where plants and fauna are rare. The dominant animals are closely linked to the marine environment such as the polar bear, sea lions, seals, and others.

Freshwater ecosystems

- River ecosystems

All the ecosystems of rivers and streams that form the different basins of the planet are included. Of course, the diversity of these ecosystems is enormous, taking into account the large number of existing rivers.

Thus, in the course of the Amazon, which is the longest and mightiest river in the world, there are various ecosystems. This is due to the fact that the conditions of climate, temperature and composition of the water are not the same from its source to its mouth.

- Lake ecosystems

Lake Ontario (Canada). Source: Michael Gil

Lentic ecosystems include lakes, ponds and all those bodies of water confined to an area. The lakes are distributed throughout the planet and in dissimilar climates and only in Canada there are more than 30,000.

We find lakes both in tropical conditions, such as Lake Maracaibo in Venezuela, and in cold lands such as Lake Ontario in Canada. Also from sea level to considerable heights such as Lake Titicaca in the Andes between Peru and Bolivia (3,812 meters above sea level).

This implies that each lake or lagoon is a particular ecosystem with its associated flora, fauna and abiotic conditions.

Marine ecosystems

The marine environment covers about 361,132,000 km², with depths of up to 11,000 m and temperatures from 26 ºC to frozen areas. It includes superficial areas bathed by tropical sunlight to deep areas where the light cannot reach.

The world's oceans are fundamental to life, as they are part of a series of fundamental biogeochemical cycles. Among the most important we can mention the water cycle and the CO2 cycle, in addition the plankton of the oceans is the main producer of oxygen.

- Coasts and neritic or littoral zone

The coastal zone up to 10 m deep and the neritic zone (from 10 m to 200 m deep), include a great diversity of ecosystems. The determining factor here is the abundance of available solar radiation.

High productivity ecosystems such as coral reefs and submerged meadows of aquatic angiosperms develop in the tropics and subtropics.

Coral reefs

Coral reefs are the most productive ecosystems in the oceans and one of the most productive on the planet. They are made up of hundreds of thousands of organisms with calcareous exoskeletons that form shallow colonies and are poles of attraction for marine life.

Underwater meadows

Posidonia seagrass beds. Source: albert kok

Underwater meadows of angiosperm species develop in shallow marine areas of tropical and subtropical areas.

In the tropics, turtle grass (Thalassia testudinum) meadows are common, and in the Mediterranean we find Posidonia oceanica meadows.

- Pelagic or oceanic zone

In the open sea, important variations are established according to depth and latitude (which, among other things, influences the water temperature). In this area the ocean behaves like a large ecosystem, but different conditions are present on the seabed.

Sargasso Sea

It is a variable area of ​​about 3,500,000 km² where populations of sargassum algae (Sargassum spp.) Float. The currents determine a warm water system and allow the development of various marine organisms in the mass of algae.

Hydrothermal springs

Hydrothermal vents are found in the mid-ocean ridges of the Atlantic about 2,400 m deep. These high temperature water emissions happen thanks to volcanic activity.

The dissolved chemicals and the temperature generated allow the development of chemosynthetic archaea. These bacteria in turn form the basis of food chains that include large clams, tube worms, and other organisms.

References

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6. World Wild Life (Viewed Oct. 22, 2019). Taken from: worldwildlife.org/biomes