Taxus contorta Griff.

Taxaceae

Taxus contorta is distributed from Afghanistan through the Himalayas to central Nepal where it is declining due to logging, agricultural expansion and especially exploitation for traditional and modern medicines. 

Distribution

Distributed in Afghanistan (Nuristan province and adjacent areas), Pakistan (NorthWest Frontier Province, the Federally Administered Tribal Area, North Punjab and Azad Kashmir, northwestern India (Himachal Pradesh, Jammu and Kashmir and Uttaranchal Pradesh) and in the northern districts of western and Central Nepal on the northern slopes of Annapurna-Manaslu range. It also occurs in the Jilong valley in Xizang, China.

Habitat and Ecology

In Afghanistan, T. contorta was originally recorded as a minor component of mid altitude coniferous forests 2400–2900 metres above sea-level (Freitag, 1972). In Pakistan, its distribution is also restricted to a relatively narrow altitudinal band (2000–3100m) in mixed coniferous forests (Cedrus deodara, Abies pindrow, Picea smithiana and Pinus wallichiana), usually on north facing slopes (Schikoff, 1996). Its altitudinal distribution appears to be moisture limited at lower altitudes and temperature limited at higher altitudes (Shafique, 2008). In northwestern India, it occurs in small scattered populations, usually along streams within coniferous forests and at lower altitudes than in Pakistan (1700–2600m), probably due to increased precipitation. In western and central Nepal (ca 83° 30’ E) T. contorta occurs in similar situations as in northwest India. In the Jilong Xian it occurs at altitudes of 2500–3100m above sea-level.

Human Uses

Its timber is used for house construction (roof shingles especially) and furniture as well as more specialised uses such as grave coverings and beehives. In Pakistan especially, the timber is also valued as fuel. In many areas, the foliage is a valuable source of fodder for livestock in winter and early spring. Bark, leaves and twigs have a range of traditional medicinal uses and are also used for the commercial production of Taxol, an anti-cancer drug.

Conservation Status

Global Status and Rationale

Endangered A2acd

Taxus contorta has undergone a recent, rangewide population decline of at least 50% but probably less than 80%. The causes of the decline are varied. In the western part of its range a suspected decline is inferred from the large scale logging of the conifer forests: in Afghanistan, up to 50% of the forests where it occurs have been destroyed or heavily logged (UNEP, 2003) over the last 30 years. In Pakistan, overexploitation for fuel, fodder and medicinal use has led to a significant decline. In the eastern part of its range, over exploitation for traditional and modern medicines are the principal drivers for its decline except within the Jilong valley in China.

Proposed National Status and Rationale - Afghanistan

Endangered A2cd
In Afghanistan, coniferous forests (its sole habitat) have declined by up to 50% over the last 25 years due to conflict and uncontrolled logging (Nasri et al., 1995; UNEP, 2003). Although there is no specific data for T. contorta, it is very likely that its subpopulations will have been significantly impacted. Consequently it has been provisionally assessed as Nationally endangered by the Afghanistan Wildlife Executive Committee (N. Kanderian pers.comm., March 2010)

Proposed National Status and Rationale - China

Critically Endangered B1ab(iii,iv)
In China this species was nationally assessed as Critically Endangered due to its restricted extent of occurrence and a decline in the area of occupancy (Wang & Xie, 2004). Prior to 2000, it was locally exploited for traditional medicine, fodder and firewood. Field visits within the last five years have found that, while it has a limited distribution, stands are healthy and show no evidence of continued exploitation or decline. The total population in this area numbers at least several hundred. Despite the absence of current decline, it should still be regarded as Critically Endangered due ti short period of time since exploitation ceased and long time needed for species such as T. contorta to recover..

Proposed National Status and Rationale - India

Critically Endangered A2cd
In NW India an estimated recent decline of up to 90% has occurred in the last 25 years, mainly due to harvesting for Taxol production. Adecline was already occurring due to increasing conversion of forests for agriculture, increased expoitation for tradiional medicines and as a source of firewood, timber and fodder.

Proposed National Status and Rationale - Nepal

Endangered A2cd
In Nepal Taxus populations are estimated to have undergone a recent decline of up to 80% due to harvesting for medicinal use. It is uncertain if Taxus contorta (western and central Nepal) has been impacted more the other two species that occur in central and eastern Nepal. Endangered may be an underestimate. In areas where Community Forestry organisations have control over forests more sustainable management practices have been introduced and the decline is slowing.

Proposed National Status and Rationale - Pakistan

Endangered A2cd
In Pakistan declines of almost 90% have been reported (Ahmed, 2004; Haq, 2011; Hussain, 2006; Mullikin, 2008). The main drivers for this decline are the conversion of forests for agriculture, over-collection for firewood and fodder (especially in winter and spring) and to a lesser extent collection for both traditional and modern medicinal use.

Conservation Actions

In Afghanistan the eastern conifer forests have been identified as important areas for conservation work as soon as possible. In Pakistan, T. contorta is known from a number of protected areas but these are under severe pressure from fuelwood collecting and other activities that are leading to forest degradation. In northwest India it was assessed as critically endangered at a regional level (Ved et al., 2003) and harvesting of wild trees has been banned. In Nepal Taxus 'wallichiana' has been nationally assessed as endangered and the government has imposed harvesting and exporting restrictions (Bhattari, 2004; Dhungana & Bhattarai, 2009). Plantations are being established and programmes are being developed to encourage its protection and cultivation in community forests as well as on private land. In China it is a First Class Protected Species which prohibits any exploitation. Taxus contorta is listed under CITES Appendix II.

A limited amount of research has been undertaken into the genetic variation of subpopulations in both Pakistan and northwest India (Mohapatra 2009, Shah et al. 2008). These indicate that while there is relatively low variation within each subpopulation, there are considerable differences between them. Wherever possible restoration programmes should use local provenances and ex-situ programmes should sample widely.