Taxus baccata in Morocco: a tree in regression in its southern extreme

Abstract

Abstract:The knowledge on chorology of species is basic for biogeographic and ecological studies and for conservation actions. The data on the chorology of Taxus baccata in Morocco have not been studied. The bibliographic resources, herbarium material, unpublished data of several botanists and the authors' field notes have been reviewed. Two yew populations on Jbel Lakrâa in the Rif and near Bekrit in the Middle Atlas were measured to verify demographic structure and health conditions. The Maxent model of predicted habitat based on bioclimatic variables was used to evaluate the potential geographic range of T. baccata. The species occurs in the mountain areas of northern Morocco: in the Rif, the Middle and High Atlas, at altitudes between (500) 1200 and 2000 (2350) m. In the High Atlas, it reaches its southernmost locations within the geographic range. The populations represented by the highest number of individuals are found in the Western Rif and Middle Atlas, while from the High Atlas only single, isolated individuals are known. The yew occurred preferably in forests of Cedrus atlantica, Abies maroccana, groves of Betula fontqueri, Ilex aquifolium and Prunus lusitanica and in riparian forests located in narrow gorges. Seedlings were observed only at single localities. The population of T. baccata in the Rif presented a good health condition with successful regeneration, while the population in the Middle Atlas was in a much worse state, where only 4-8 m high yews were observed, without natural regeneration. The Maxent model of predicted habitat, based on bioclimatic variables, suggests that T. baccata could occur today in much broader mountainous areas in Morocco, especially in the Rif and Middle Atlas. However, the progressive decline of this species in Morocco indicates the significant importance of other factors on yew distribution, including microsite conditions and human pressure. Taxus baccata in Morocco is in regression at most of its localities and should be treated as a vulnerable species. Measures to ensure the yew's conservation are needed, especially at its southernmost localities in the High Atlas.

Past, present, and future geographic range of an oro-Mediterranean Tertiary relict: The juniperus drupacea case study

“…The effect of mist in the mountains may be comparable to the beneficial influence of mistiness on the northern slopes of the Rif Mountains in northern Africa on the occurrence of Abies marocana Trab. (Esteban et al 2010) and Taxus baccata L. (Romo et al 2017). However, both of these species are more susceptible to a lack of humidity than J. drupacea.…”

“…Similar studies were conducted with Juniperus excelsa M. Bieb. in the central part of Turkey (Özkan et al 2015), Q. coccifera L. in the Levantine countries (Al-Qaddi et al 2017), and Taxus baccata L. in Morocco (Romo et al 2017). A potential impact of climate changes beginning in the Pliocene through modern times up to the end of the twenty-first century within the entire area of distribution was verified only for laurel and cedar.…”

Seed Dormancy Breaking of an Endangered Medicinal Tree Species (Taxus Baccata L.) Using Embryo Culture

“…Taxus species, belonging to the family Taxaceae, are small trees or shrubs valued for their medicinal properties (Hao et al, 2015;Romo et al, 2017). There are seven closely related species worldwide (Gegechkori, 2018), including Taxus baccata L., which is the only representative in Algeria.…”

“…T. baccata L. is a valuable medicinal plant, especially for its taxol (Paclitaxel) content, and an important chemo-therapeutic agent for treating several types of cancer as well as AIDS-related Kaposi's sarcoma (Osuna-Torres et al, 2015). Besides, this species is also valued for its hardwood, which is used for musical instruments and furniture making (Lanker et al, 2010;Romo et al, 2017).…”

Spatial genetic structure and diversity of natural populations of Aesculus hippocastanum L. in Greece

“…425 km along the Balkan Peninsula, implying the possibility of abrupt environmental gradients. Similar to other Tertiary relicts, the species requires humid conditions [13, 50, 51], and shows some habitat specialization [52]. According to Tsiroukis [53], 62% of natural populations are located in ravines with constantly flowing water and 11% with temporary water.…”