User:Danasabbah/Aquatic plant

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Aquatic plants live in small spaces, and it is one of the most productive plants. Therefore, marine plant systems have a massive effect on human society. These plants are usually grouped based on their size and their attachment modes. The most significant aquatic species consist of algae that can attach to non-living and living substrata.

There are many factors that affect plant respiration, photosynthesis, decay, and washout, such as: Light availability, water velocity, water temperature, phosphorus, nitrogen.

Distribution
The principal factor controlling the distribution of aquatic plants is the availability of water. However, other factors may also control their distribution including nutrient availability, disturbance from waves, grazing, and salinity. Some aquatic plants, especially macro-algae, are able to thrive in brackish, saline, and salt water.

Aquatic vascular plants are generally distributed widely. Climatic characteristics appear to have a minor effect on their distributions, besides determining significant disjunctions (temperate, tropical, subarctic). The dispersal must be regular enough to confirm the fast colonization of extensive areas following glacial retreat. However, dispersal restriction is still noticeable in areas isolated by geographic barriers. Aquatic vascular plants also deliver little taxonomic differentiation and lower within-species genetic variation.

Functions of macrophytes in aquatic system
Macrophytes have an essential role in wastewater treatment. It helps stabilize the bed's surface, provides the right conditions for the physical filtration, protects the vertical flow systems from clogging, protects from frost in the wintertime, and offers ample space for the attached microbial growth.

Macrophytes perform many ecosystem functions in aquatic ecosystems and provide services to human society. One of the important functions performed by macrophyte is uptake of dissolve nutrients (N and P) from water. Macrophytes are widely used in constructed wetlands around the world to remove excess N and P from polluted water.Beside direct nutrient uptake, macrophytes indirectly influence nutrient cycling, especially N cycling through influencing the denitrifying bacterial functional groups that are inhabiting on roots and shoots of macrophytes. Macrophytes promote the sedimentation of suspended solids by reducing the current velocities, impede erosion by stabilising soil surfaces. Macrophytes also provide spatial heterogeneity in otherwise unstructured water column. Habitat complexity provided by macrophytes tends to increase diversity and density of both fish and invertebrates.

The additional site-specific macrophytes' value provides wildlife habitat and makes treatment systems of wastewater aesthetically satisfactory.

Alien aquatic plant species
These species cause severe economic and ecological effects on the European freshwater ecosystems.

According to s study that was conducted in 2012, scientists reported a comprehensive overview of the alien aquatic plants with 46 European countries. The study results found 96 alien aquatic species from 30 from one European country. The aliens were primarily native to North America, Asia, and South America. The most spread alien plant in Europe was Elodea canadensis (Found in 41 European countries). Then, the second most distributed alien plant was Azolla filiculoides (25) in European countries. They were followed by Vallisneria spiralis which was reported in 22 countries.

The countries with the most alien aquatic plant species were France and Itlay. Scientists reported 34 species in the two countries. Followed by Germany with 27 species, and Belgium and Hungary with 26 species.

The European and Mediterranean Plant Protection Organization is trying to ban trading these plants because this is the most effective way to protect them from any risk.

Free-floating
Free-floating macrophytes are aquatic plants that are found suspended on water surface with their root not attached to substrate, sediment, or bottom of the water body. They are easily blown by air and provide breeding ground for mosquitoes. Example include Pistia spp. commonly called water lettuce, water cabbage or Nile cabbage.

Biologists found that free-floating plants have fewer zooplanktons than microcrustaceans, and microhabitat preferred submerged plants. The submerged and free-floating plants affect phytoplankton biomass, water chemistry, fish community structure, and zooplankton.