Moss: Difference between revisions

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[[File:File.jpeg|200px|thumb|left|Sphagnum moss]]
{{Taxonomy
{{Taxonomy
| common_name = moss
| common_name = moss
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==Physical Characteristics==
==Physical Characteristics==
[[File:mossstructure.png|left|Basic moss structure.|thumb|150px|]]
===Structure===
Mosses (Bryophyta) are non-vascular plants in the broader parent group Bryophyta, which includes Liverworts and Hornworts (Raven et al. 2013). They are the most specious of the three divisions of bryophytes, with over 12,000 species worldwide (Crandall-Stotler and Bartholomew-Began 2007). Mosses are herbaceous photosynthetic plants that absorb water and nutrients through their leaf-like structures. They are non-vascular, as they lack lignified water- and nutrient-conducting tissue called xylem and phloem (Ligrone et al. 2000). Additionally, mosses lack true roots, instead, they have multicellular thread-like structures called rhizoids that anchor the plant to the substrate (Raven et al. 2013). Like other bryophytes, mosses are dominated by their haploid, gametophytic generation and reproduce using spores.


[[File:File.png|200px|thumb|left|Sphagnum moss]]


===Life Cycle===
[[File:Moss_3.png|Moss Life Cycle.|thumb|right|300px]]


==Structure==
: Like vascular plants, mosses exhibit alternating heteromorphic generations. The gametophyte generation is typically larger and independent, while the sporophyte generation is smaller and nutritionally dependent on the parent gametophyte(Cove et al. 2006). The life cycle begins when haploid spores are released from the capsule of the mature sporophyte and germinate into protonemata, and then later into male and female gametophytes. The gametophytes have either male (antheridia) or female (archegonia) reproductive organs (Reski 1998). Haploid sperm are released from the mature antheridia and swim in the water to the archegonia which house the non-motile egg. Fertilization occurs in the archegonium to produce a diploid zygote, which divides mitotically to form a young sporophyte. As the it matures, the archegonium enlarges to protect the sporophyte until maturation is reached. The mature sporophyte consists of the stalk and capsule (sporangium). Meiosis occurs within the sporangium, producing haploid spores which will be released to form the gametophytic generation (Raven et al. 2013).  
[[File:mossstructure.png|left|Basic moss structure.|thumb|150px|]]
: Mosses lack vascular tissue, which is what other plants use to transport water and nutrients from their roots to their leaves. Since they lack this tissue, their anatomy is dissimilar to more morphologically complex plants. Instead of roots, members of Bryophyta have rhizoids, which hold their vegetative structures onto the substrate that they are growing on. Without vascular tissue, water is transported from cell to cell by diffusion, which is why these plants are so small. The gametophyte is the non-reproductive vegetative structure that carries out photosynthesis. The sporophyte is the reproductive structure that is essential to the dispersal of spores [1].
 
==Life Cycle==
[[File:Moss_3.png|Moss Life Cycle.|thumb|center|600px]]
:Mosses have two parts to their life cycle. The first stage is the ''gametophyte'', the stage in which mosses will spend the majority of their life. When haploid spores germinate, they grow and mature, eventually developing male and female reproductive structures. The male structure is called the antheridia and produces sperm, while the female structure is called the archegonia and produces egg cells. The haploid sperm will swim through water to the archegonia (which releases a chemical signal to attract them), where the eggs will be fertilized and develop into diploid structures. This begins the ''sporophyte'' life stage. The sporophyte reproduces and via meiosis to create haploid spores, and the life cycle starts over again. Unlike seed bearing plants, water is essential in the reproduction of moss, which is why it must grow in moist environments [4].


==Environmental Role==
==Environmental Role==
: Mosses play an vital role in stabilizing [[soil]], reducing erosion, and reducing the risks of flooding by absorbing excess water. Their rhizoids can hold on to [[clay]], gravel, and sandy soil substrates. Along with absorbing moisture, mosses are an important carbon sink and could potentially play an important role in combating climate change. Additionally, mosses can filter other pollutants like excess sediment and salt used on roadways. Within the local environment mosses also have the ability to create humid microhabitats. [2] In some boreal and arctic ecosystems mosses are the primary plant type and are responsible for establishing soil layers, providing nutrients and habitats for new seeds to germinate, and providing areas for microinvertebrates to thrive [5].
:Mosses play an vital role in stabilizing [[soil]], reducing erosion, and reducing the risks of flooding by absorbing excess water. Their rhizoids can hold on to [[clay]], gravel, and sandy soil substrates. Along with absorbing moisture, mosses are an important carbon sink and could potentially play an important role in combating climate change. Additionally, mosses can filter other pollutants like excess sediment and salt used on roadways. Within the local environment mosses also have the ability to create humid microhabitats. [2] In some boreal and arctic ecosystems mosses are the primary plant type and are responsible for establishing soil layers, providing nutrients and habitats for new seeds to germinate, and providing areas for microinvertebrates to thrive [5].


==References==
==References==

Revision as of 03:40, 10 March 2023

Sphagnum moss


moss
Kingdom: Plantae
Phylum: Bryophyta

Physical Characteristics

Mossstructure.png

Structure

Mosses (Bryophyta) are non-vascular plants in the broader parent group Bryophyta, which includes Liverworts and Hornworts (Raven et al. 2013). They are the most specious of the three divisions of bryophytes, with over 12,000 species worldwide (Crandall-Stotler and Bartholomew-Began 2007). Mosses are herbaceous photosynthetic plants that absorb water and nutrients through their leaf-like structures. They are non-vascular, as they lack lignified water- and nutrient-conducting tissue called xylem and phloem (Ligrone et al. 2000). Additionally, mosses lack true roots, instead, they have multicellular thread-like structures called rhizoids that anchor the plant to the substrate (Raven et al. 2013). Like other bryophytes, mosses are dominated by their haploid, gametophytic generation and reproduce using spores.


Life Cycle

Moss Life Cycle.
Like vascular plants, mosses exhibit alternating heteromorphic generations. The gametophyte generation is typically larger and independent, while the sporophyte generation is smaller and nutritionally dependent on the parent gametophyte(Cove et al. 2006). The life cycle begins when haploid spores are released from the capsule of the mature sporophyte and germinate into protonemata, and then later into male and female gametophytes. The gametophytes have either male (antheridia) or female (archegonia) reproductive organs (Reski 1998). Haploid sperm are released from the mature antheridia and swim in the water to the archegonia which house the non-motile egg. Fertilization occurs in the archegonium to produce a diploid zygote, which divides mitotically to form a young sporophyte. As the it matures, the archegonium enlarges to protect the sporophyte until maturation is reached. The mature sporophyte consists of the stalk and capsule (sporangium). Meiosis occurs within the sporangium, producing haploid spores which will be released to form the gametophytic generation (Raven et al. 2013).

Environmental Role

Mosses play an vital role in stabilizing soil, reducing erosion, and reducing the risks of flooding by absorbing excess water. Their rhizoids can hold on to clay, gravel, and sandy soil substrates. Along with absorbing moisture, mosses are an important carbon sink and could potentially play an important role in combating climate change. Additionally, mosses can filter other pollutants like excess sediment and salt used on roadways. Within the local environment mosses also have the ability to create humid microhabitats. [2] In some boreal and arctic ecosystems mosses are the primary plant type and are responsible for establishing soil layers, providing nutrients and habitats for new seeds to germinate, and providing areas for microinvertebrates to thrive [5].

References

[1] Crandall-Stotler, B. J., and S. E. Bartholomew-Began. 2007. Morphology of Mosses (Phylum Bryophyta):3–13.
[2] Crooks, V. 2021, February 22. Bryophytes. Text, Smithsonian Tropical Research Institute. https://stri.si.edu/story/bryophytes.
[3] McHale, E. 2020, May 23. 7 interesting things about moss | Kew. https://www.kew.org/read-and-watch/moss.
[4] Carter, J. S. 2010, September 12. Mosses and Ferns. https://biologyclermont.info/wwwroot/courses/lab2/mosses%20intro.htm.
[5] Turetsky, M. R., B. Bond-Lamberty, E. Euskirchen, J. Talbot, S. Frolking, A. D. McGuire, and E.-S. Tuittila. 2012. The resilience and functional role of moss in boreal and arctic ecosystems. New Phytologist 196:49–67.