Saturday 25 May
Endangered Species of the Week: Kakapo - the World's Favourite Species!

What’s the World’s Favourite Species?
Find out here.| Kingdom | Plantae |
| Phylum | Tracheophyta |
| Class | Coniferopsida |
| Order | Coniferales |
| Family | Taxodiaceae |
| Genus | Sequoiadendron (1) |
The giant sequoia is world-renowned as the largest living thing on the planet, and these majestic trees continue to inspire wonder. Although not the tallest trees, their sheer volume, with the possible exception of colonial organisms such as corals, make giant sequoias the largest living things on earth (3). Also known as 'big tree' in California, the giant sequoia lives up to its name, reaching up to 95 meters in height and 11 meters in diameter (2). The massive, tapering trunk is a characteristic reddish-brown colour; the bark is extremely thick, sometimes up to 60 centimetres, and deeply furrowed (4). In mature trees the first half of the trunk is clear of branches, they form a rounded crown towards the top with individual branches sweeping downward with upturned ends (3). The small, scale-like leaves are green and spirally arranged (4). Both male and female cones are carried on the same tree; female cones are up to 7.5 centimetres long and four centimetres wide, composed of spirally arranged scales. They are reddish-brown when mature and contain numerous, flattened, winged seeds (4).
TopGiant sequoias take around 20 years to reach maturity and start bearing cones, and the oldest known individuals are over 3,000 years old (2). Pollination occurs between December and May and cones develop during the spring and summer months (4). Seeds are only released as the cones dry out, shrinking and thus revealing gaps from which the seeds can fall; the process is therefore dependent on particular conditions and cones can lay dormant for many years (5). Each cone contains roughly 230 seeds and each tree will have around 11,000 cones at any one time; these tiny winged seeds are dispersed away from their parent tree by the wind, insects and rodents (2). The germination of seeds is, however, also dependent on particular conditions and these tiny, thin seeds require highly favourable soils with no overlying vegetation into which they can bury easily (4). As with other long-lived trees, fire seems to pay an important role in the life of a giant sequoia. A relatively high frequency of low intensity fires helps to rid the area of competitors whilst providing rich soils for the germination of seedlings. The heat generated by fires also helps to dry out the cones and open them. Mature trees are fairly indestructible; the loosely packed fibres in the thick bark are very poor conductors of fire (3).
TopThe giant sequoia is found on the western slopes of the Sierra Nevada mountain range, California, United States (4). Today the range is much more discontinuous than it once was, and the species is restricted to around 75 distinct groves (2).
TopInhabits mixed conifer woodlands, which are dominated by the California white fir (Abies concolor var. lowiana) (2). Found in protected areas where there are deep, moist soils, at altitudes between 1,100 and 1,500 metres above sea level (4).
TopClassified as Vulnerable (VU) on the IUCN Red List 2007 (1).
TopGiant sequoia forests were massively logged from the time they were first discovered in the mid 1800s until the 1950s (1). The resistant nature of the wood made it a favourable timber and it was used to make a wide variety of items from fence posts to patio furniture (2). Roughly 34 percent of the original range of the giant sequoia was lost to timber extraction (4). Ironically, a further threat to sequoia groves came from fire prevention strategies imposed by forest managers; this strategy prevented sequoias from regenerating successfully, whist allowing competitor species to proliferate (4).
TopThe giant sequoia is now recognised as a national treasure and as much as 90 percent of the population is protected (1). The best-known groves are found in Yosemite, Sequoia and Kings Canyon National Parks (3); attracting tourists from far and wide to view these magnificent trees. The National Parks Service now practices controlled burning as part of its management strategy, although further research is needed into the natural cycle of disturbance in order to better understand these processes (4). Giant sequoias have a vital role within the Sierra Nevada ecosystem and their majesty has also provided an aesthetic and cultural role within society; thus making their future survival extremely important (6).
TopFor further information on the giant sequoia see:
Authenticated (20/03/03) by Dr Alijos Farjon, Royal Botanic Gardens, Kew.
http://www.kew.org
More »Related species
Image credit
© David Kjaer / naturepl.com
Nature Picture Library
5a Great George Street
Bristol
BS1 5RR
United Kingdom
Tel: +44 (0) 117 911 4675
Fax: +44 (0) 117 911 4699
info@naturepl.com
http://www.naturepl.com
Link to this photo
Embed this ARKive thumbnail link by copying and pasting the code below.
Terms of Use - The displayed thumbnail may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.
Read more about
MyARKive
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material 
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.