Widdringtonia schwarzii 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Pinopsida Pinales Cupressaceae

Scientific Name: Widdringtonia schwarzii (Marloth) Mast.
Common Name(s):
English Willowmore Cedar, Baviaans Cedar, Willowmore Cypress
Callitris schwarzii Marloth
Taxonomic Source(s): Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2013
Date Assessed: 2011-07-12
Assessor(s): Farjon, A.
Reviewer(s): Thomas, P. & Hilton-Taylor, C.
Contributor(s): Victor, J. & Van Wyk, A.E.
Widdringtonia schwarzii has a restricted distribution in the Baviaanskloof Wilderness Area. There is some uncertainty about its area of occupancy although it is considerably less than 500 km2. The number of locations is between 5 and 12 depending on the method used to determine them. The species was heavily exploited in the past for its durable timber that was used for house construction, but most logging probably took place more than 120 years ago (i.e. more than three generations ago). Its habitat has also been modified by the increased frequency of fires as a result of human activities in the area and the expansion of agricultural activities. Fires continue to have an impact on this species. The extent of past decline is difficult to quantify due to a lack of information about the extent of its past distribution. The most recent Red List of South African Plants (Raimondo et al. 2009) assessed this species as Near Threatened on the basis that it almost met the D2 criterion  for Vulnerable. Given the discovery of additional localities in the Kouga Mountains, it seems unlikely that any single threat would impact the whole area to drive this species very quickly to Critically Endangered or extinction. In this assessment the Near Threatened category is maintained but on the basis that it almost meets the criteria for listing as threatened under criteria B2ab(ii,iii,v) and possibly A2cd.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Endemic to the Eastern Cape Province of South Africa. It is recorded from the Kougaberg and Baviaanskloof mountains in the Willowmore District, where it grows in rocky ravines and canyons ['kloofs'] draining into the Baviaanskloof River and its tributaries. The extent of occurrence is estimated to be less than 1,200 km2, with a very small area of occupancy ranging from 7 km2 to 28 km2 depending on the method used to estimate it. It is known from 5-7 subpopulations. The number of locations is between 5 and 12.
Countries occurrence:
South Africa (Eastern Cape Province)
Additional data:
Estimated area of occupancy (AOO) - km2:7-28
Number of Locations:5-12
Lower elevation limit (metres):600
Upper elevation limit (metres):1200
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The global population is restricted to scattered trees and/or small stands in isolated localities (canyons) which form 5-7 subpopulations. The number of mature trees is not known. Some stands have been burnt in recent years but it is uncertain if this represents an overall decline due to lack of information about the total population size and recruitment success after fires.
Current Population Trend:Unknown
Additional data:
Continuing decline of mature individuals:Unknown
Population severely fragmented:Yes

Habitat and Ecology [top]

Habitat and Ecology:Widdringtonia schwarzii occurs in rocky ravines on steep slopes or cliffs ('krantzes') and in (dry) river beds of canyons between (600-)900-1,200 m a.s.l. Trees can attain large size in rocky streambeds of canyons, sheltered from 'veld fires', where they can form small groves. The surrounding vegetation is various types of fynbos (mostly restioid fynbos). The most reliable rainy seasons are spring and autumn as the area lies to the east of the main winter rainfall zone and west of the summer rainfall zone; the dry, hot summers are somewhat tempered by the sheltered micro-climate in deep, shady canyons, where deeper ground water remains available under stream beds.
Continuing decline in area, extent and/or quality of habitat:Unknown
Generation Length (years):40

Use and Trade [top]

Use and Trade: Willowmore Cedar was used in the past for construction timber of local farmsteads, for furniture making, fences and telegraph poles. Depletion of the resource to a few trees in inaccessible locations terminated this use and the remaining trees are now protected.

Threats [top]

Major Threat(s): Over-exploitation in the past has reduced the population to possibly a fraction of its former extent, but no data are available to help us accurately to estimate the level of decline due to this logging activity. Most of the logging is likely to have taken place more than 120 years ago (i.e. before the three generation time period required under the IUCN Red List Criteria). There would have been some logging in the 1900s but probably much reduced from that which occurred in the 1800s. At present, logging has ceased and now wildfires are the main threat, as this species is ill adapted to (frequent) fires. In 2008 wildfires affected stands in the Cedar Valley area; floods in 2010 also had an impact.

Conservation Actions [top]

Conservation Actions: In recent years, new localities have been found in remote upper parts of canyons in the Kouga Mountains, some of which harbour large trees. There is now much awareness of its conservation value and an active management programme (largely to prevent wildfires) is being implemented. Further cutting of trees is prohibited. Almost all subpopulations occur within the Baviaanskloof Wilderness Area. A limited amount of ex situ conservation has been undertaken in the form of seed collections and plants are grown in botanical gardens (e.g. Kirstenbosch National Botanical Garden in Cape Town). There is an active programme to control and eradicate any alien invasive plant species, but regular monitoring is required that no new infestations affect the area.

Citation: Farjon, A. 2013. Widdringtonia schwarzii. The IUCN Red List of Threatened Species 2013: e.T34147A2847889. . Downloaded on 20 June 2018.
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