''Widdringtonia wallichii'', Clanwilliam cedar or Clanwilliam cypress, previously ''Widdringtonia cedarbergensis'' is a species of ''

Widdringtonia ''Widdringtonia'' is a genus of coniferous trees in the Cupressaceae (Cupressaceae, cypress family). The name was Austrian botanist Stephan Endlicher's way of honouring an early expert on the coniferous forests of Spain, Capt. Samuel Edward Widdr ...

'' native to

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

, where it is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the Cederberg Mountains northeast of

Cape Town Cape Town is the legislature, legislative capital city, capital of South Africa. It is the country's oldest city and the seat of the Parliament of South Africa. Cape Town is the country's List of municipalities in South Africa, second-largest ...

Western Cape Province The Western Cape ( ; , ) is a province of South Africa, situated on the south-western coast of the country. It is the fourth largest of the nine provinces with an area of , and the third most populous, with an estimated 7 million inhabi ...

. Due to harsh weather conditions, like limited rainfall and frequent wildfires, growth is limited. Ring width almost correlates with rainfall due to such harsh environmental conditions It is threatened by

habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

Farjon, A. (2005). ''Monograph of Cupressaceae and ''Sciadopitys. Royal Botanic Gardens, Kew. and protected in South Africa under the National Forest Act (Act 84) of 1998. It is a small

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

growing to 5–7 m (rarely to 20 m) tall. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are scale-like, 1.5 mm long and 1 mm broad on small shoots, up to 15 mm long on strong-growing shoots, and arranged in opposite decussate pairs. The

cones In geometry, a cone is a three-dimensional figure that tapers smoothly from a flat base (typically a circle) to a point not contained in the base, called the ''apex'' or '' vertex''. A cone is formed by a set of line segments, half-lines, ...

are globose to rectangular, 2–3 cm long, with four scales.

Chemical constituents

''W. wallichii'' is used in a cedarwood oil with multiple uses such as in Texas, it used as feedstock and in Virginia it is used for cosmetics like perfumes, aftershave lotions, and soaps. Cedarwood oil is also used in home remedies. The

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...

derived from leaves contains

terpinen-4-ol Terpinen-4-ol is an isomer of terpineol with the chemical formula C10H18O. A primary constituent of tea tree oil, it is obtained as an extract from the leaves, branches, and bark of '' Melaleuca alternifolia'' Cheel. Despite considerable basic and ...

(36.0%),

sabinene Sabinene is a natural bicyclic monoterpene with the molecular formula C10H16. It is isolated from the essential oils of a variety of plants including Marjoram, holm oak (''Quercus ilex'') and Norway spruce (''Picea abies''). It has a strained ...

(19.2%),

γ-terpinene The terpinenes are a group of isomeric hydrocarbons that are classified as monoterpenes. They each have the same molecular formula and carbon framework, but they differ in the position of carbon-carbon double bonds. α-Terpinene has been isolate ...

(10.4%), α-terpinene (5.5%) and

myrcene Myrcene, or β-myrcene, is a terpene, monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from ''Myrcia'', from which it gets its name. It is an intermediate in the production of several frag ...

(5.5%). The wood oil contains thujopsene (47.1%),

α-cedrol Cedrol is a sesquiterpene alcohol found in the essential oil of conifers (cedar oil), especially in the genera ''Cupressus'' (cypress) and ''Juniperus'' (juniper). It has also been identified in '' Origanum onites'', a plant related to oregano. Its ...

(10.7%), widdrol (8.5%) and cuparene (4.0%).

Conservation of species

''W. wallichii'' is an endangered species facing population decline. Reasons for such declines are habitat loss and inbreeding within populations. Habitat loss due to harsh environmental conditions. Wildfires occur in the area causing ''W. wallichii'' mature trees to die frequently. ''W. wallichii'' growth rate is slower compared to their counterparts which is a factor in population decline of the species. Genetically, there are some hypotheses on why ''W. wallichii'' is not as fire resistant as some of the other within the genus and one of them is heavy logging. Heavy logging the current population is subjected to causes a fragmentation within the structure and heavy selection within the leftover mature trees within the population structure. Another hypothesis is that current selection for the mature trees is poorly adapted to fire intensive environments causing lack of genetic variation within the gene pool and heavy selection for those traits occurs. Upon further observations, it is not the mature trees themselves that are not fire resistant but their seed recruitment and lack of. Inbreeding within the population of ''W. wallichii'' due to self pollination because of lack of movement of pollen which further fragments the population. Seed dispersal is difficult which limits the success of fertilization in ''W. wallichii''. The seeds are left under the canopy of mature trees and waiting for the winds and runoff water. Other modes of dispersal like small animals are not likely to assist in the process of larger seeds. There is no dormancy period of the seeds after dispersal which leaves them vulnerable and sometimes unviable.

Methods of conservation

One of the methods of population growth and conservation of ''W. wallichii'' is use of fire. Using calculated levels of fire during natural seed release which occurs in late summer and beginning autumn will assist in reduction of litter affecting seed dispersal. Litter during these periods inhibits the success of seed dispersal by blocking the seeds' movements of the winds and access to the runoff water. Their regeneration due to lack of seed dispersal from the blockage of litter and otherwise stated is inhibited as well. Another method is replantation of seedlings in newly burned areas of ''W. wallichii''. Replanting seedlings in newly burned areas suggests when closely monitored and provided necessary components such as shade, soil, and competition from surrounding seedlings, they are successful in regrowth than seedlings planted prior. Also using pre heated seeds in previously burnt areas from wildfires increases success of growth.

References

* {{Taxonbar, from=Q17275235 Afromontane flora wallichii Trees of South Africa Protected trees of South Africa Endangered plants Taxonomy articles created by Polbot Taxobox binomials not recognized by IUCN Taxa named by Élie-Abel Carrière