Mosses in Battersea Park

What are mosses?

  • Mosses are believed to be the most ancient form of plant, having evolved from algae. They are one of the first colonisers of bare ground
  • Unlike flowering plants, mosses have no roots. The leafy parts, known as gametophytes, trap energy from light and convert it into food.
  • Mosses are less colourful than flowering plants, but they are fascinating when they are looked at closely. Many mosses have capsules on top of stalks, known as sphorophytes. The gametophytes and sporophytes come in many, many different shapes and sizes.
  • Many mosses can survive desiccation, sometimes for months or even years, and can return to life within a few hours of rehydration.
  • There are around 1,100 species of moss in the British Isles, and around 12,000 species in the world.

 

 

Where do mosses grow?

  • Forests and trees
  • Rocks
  • Roofs and walls
  • Cemeteries
  • Roads
  • Streams
  • Mountains
  • Deserts
  • Polar regions

 

 

Life cycle

"Like all land plants (embryophytes), bryophytes have life cycles with alternation of generations. In each cycle, a haploid gametophyte, each of whose cells contains a fixed number of unpaired chromosomes, alternates with a diploid sporophyte, whose cells contain two sets of paired chromosomes. Gametophytes produce haploid sperm and eggs which fuse to form diploid zygotes that grow into sporophytes. Sporophytes produce haploid spores by meiosis, that grow into gametophytes."

(from https://en.wikipedia.org/wiki/Bryophyte#Life_cycle )

 

 

Life cycle - alternative version

  • Mosses can reproduce in more ways than one:
    • (1) Sexual reproduction:
      • Sperm from a male part of the moss uses water to reach an egg produced by a female part, and fertilises the egg. Tiny insects such as springtails may also help to disperse the sperm.
      • After fertilisation, a stalk grows up from the egg and a capsule forms on top of the shoot. This is the sphorophyte. The stalk is known as the seta.
      • Eventually the capsule releases spores from an opening at the tip, known as the peristome. Like seeds, the spores spread and germinate.
      • Peristome teeth help disperse spores by regulating the release of spores. When conditions are dry, the peristome teeth close, protecting the spores. When conditions are moist, the teeth open, allowing the spores to be released into the environment, where they can be carried by the wind or water to new locations for germination.

 

 

Life cycle - alternative version

  • (2) Mosses can also reproduce asexually:

    • Some mosses have have small, asexual reproductive structures called gemmae. These are tiny, multicellular structures containing cells capable of developing into new moss plants. When conditions are favorable, gemma cups release the gemmae.
    • The gemmae are dispersed by raindrops or other disturbances, facilitating their spread to new habitats. Once they land in suitable conditions, the gemmae can germinate and grow into new moss plants, allowing for rapid colonization of new areas.
    • Asexual reproduction can also occur when a fragment breaks off from a gametophyte and develops into a new moss in a new location. Each fragment is capable of developing into a genetic clone of the parent moss.
    • Fragments can be spread on the feet of animals - an example is Silvery Bryum (Bryum argenteum) growing in the cracks between paving slabs. Another means of dispersal is to put moss into a blender with something like buttermilk, yoghurt or egg white, and to spread the blended mixture by hand.

 

 

Contribution to ecosystems

  • Mosses can help to retain moisture in the soil, preventing erosion and providing a stable environment for other plants to grow.
  • The leaves and shoots are constructed in a way which can retain moisture, especially when mosses form a dense cushion or mat. Seeds caught up in the shoots can germinate.
  • Mosses absorb carbon dioxide from the atmosphere during photosynthesis, helping to mitigate climate change by locking carbon away in their tissues.
  • Mosses provide habitat and shelter for various micro-organisms, insects, and small animals, contributing to overall ecosystem diversity. In our park you can see moss below roofs where birds have tossed them to the ground.
  • Mosses filter and purify water by absorbing pollutants and trapping sediments, improving water quality in streams and wetlands.
  • Some species can fix nitrogen from the atmosphere, making it available to other plants and enriching the soil.
  • Mosses are sensitive to changes in environmental conditions such as air pollution and moisture levels, making them valuable indicators of ecosystem health and environmental quality.

 

 

Find out more

Acknowledgments

  • British Bryological Society website and Field Guide
  • Inaturalist - www.inaturalist.org
  • Expert moss identifiers on Inaturalist, including George Greiff (georgeg) and Stefan Gey (tayloria)
  • Photos taken with a Samsung Galaxy S22 smartphone and a Juision microscope
  • ChatGPT 3.5, for providing information and writing some of the code used to display these pictures
  • My very patient dog              
             

 

 

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