They are the zones or regions where organisms (animals, plants, etc) life and develop on the ground (soil) and air that surrounds a specific space of land. Living beings that inhabit the ecosystem supposedly find everything they need in order to survive in these places.
Depending on the abiotic factors of each ecosystem, there are different kinds of land habitats: deserts, prairies and forests.
Land ecosystems are part of larger ecosystems called biomes or ecological regions. These zones are delimited by altitude, climate, temperature and the level of precipitation. Ecological regions will be seen in depth in the next issues.
They are made up of plants and animals that live in water. These ecosystems are different in relation to the geographical region they are in (Antarctic, subantarctic, tropical and subtropical) and regarding their closeness to land (coastal ecosystems, oceanic and estuary).
Aquatic ecosystems (the same as land ecosystems) can vary wildly in size, form an ocean to a puddle of water. Likewise, there are salty and fresh water aquatic ecosystems.
Benthic organisms (which as a group are called benthos) inhabit the bottom of the sea, be it moving across adhered to the substrate or immersed in the sand or marine mud.
Pelagic organisms live freely in the water and are split into two groups: plankton and nekton. The tiny beings that have no active natatory organs and drift with the tide in superficial waters are called plankton. Vegetal plankton is known as phytoplankton and animal as zooplankton.
Nektons are the organisms capable of swimming and drifting freely through the water (fish, aquatic mammals, etc.).
In fresh water ecosystems (rivers, lakes, lagoons, etc.), relationships are established similar to marine ones, as there is also plankton and nekton.
In the case of rivers, it is known that differences are produced along its course (high, mid and low), as each stretch presents different flows, temperatures and depths. However, the existence of two superimposed communities has been determined, the ones at the bottom and the ones in free waters. Although these can change throughout the course of the river.
Variety of ecosystems
Land ecosystems as well as aquatic ones present a series of sceneries that have their own characteristics. Some of them are:
– Desert: it is a region whose main characteristics are lack of precipitation and high temperatures. However, despite these extreme conditions, numerous plants and animals live in deserts.
This way, plants have long roots (they help retain water) and also lose little water (perspiration), due to the fact that they transform their leaves into thorns and perform photosynthesis through the stems.
In the case of animals, we have some birds that can fly long distances in search of water and some land animals that have adapted their physiognomy to take the most advantage of the scarce water supply.
– Wetland: it is an area of flat lands that has shallow underground waters that rise to the surface at determined periods, forming lagoons and swamps, where certain species come to live. There are five kinds of wetland: marine, estuary, lacustrine, riverside and boggy.
– Mangrove: it is a group of semi-submerged trees that have been flooded with water with high levels of salinity, and due to this, they survive in coastal lands. The trees grow on long roots that elevate the trunks above the water level like stilts. In order to reproduce, they keep seeds in the branches until they are about to develop. When the tide goes down they fall, being able, in a few hours, to set roots and begin to grow before being back underwater.
– Coral reef: it is one of the planet’s richest aquatic ecosystems due to the great amount of species that inhabit them (fish, snails, coral and algae). The coral structure is made up of great colonies of coral, accumulations of sediments and calcareous sands. They are mainly found in tropical regions and there are two types of coral: hard and soft.
