Published online by Cambridge University Press: 05 October 2012
Bryophytes are the most successful group of plants other than angiosperms in terms of their numbers of species, geographical distribution on all continents, and their habitat diversification. There are at least 10,000 species of mosses and over 6000 liverworts. All three groups of bryophytes, also including the hornworts, were the earliest green plants to move to the land; each group has had a very long evolutionary history, probably more than 400 million years. All three groups, derived from a green algal ancestor, evolved separately from one another and from vascular plants through this long period. Although the great diversity of tropical bryophytes is often cited, Rydin (2009) pointed out their important contribution to biodiversity in northern ecosystems: 7.5% of the world's bryophyte species are found in Sweden, whereas only 0.8% of vascular plant species are found there.
Bryophytes are unique among land plants in that their dominant stage is the haploid green gametophyte rather than the much shorter-lived diploid sporophyte. They differ from vascular plants in other ways as well, in aspects that make them excellent environmental monitors. They inhabit a very wide range of ecosystems, habitats, and specific microhabitats, including substrates on which vascular plants cannot live. Many species are able to live in nutrient-poor conditions, and are adapted to respond rapidly physiologically to intermittent periods favorable for photosynthesis.
Morphology and physiology
Bryophytes lack the roots, xylem, and phloem of vascular plants. The great majority are ectohydric, that is, without internal conducting tissues.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.