Shrub Cover and Soil Moisture Affect Taxus baccata L. Regeneration at Its Southern Range.

The effect of key ecological and anthropic factors on the recruitment of the common yew (Taxus baccata L.) in Sardinia (Italy) has been analyzed. After bibliographic and cartographic research, followed by field surveys, we found 232 sites where yew grows in Sardinia (as opposed to 69 previously reported in the literature). Among them, we selected 40 sites, located in 14 different mountain chains, characterized by a number of individuals ranging from 11 to 836 adult yews with an average diameter at breast height (DBH) from 13 to 130 cm. By means of generalized linear modeling, we investigated and weighted the effect of ecological, structural, and anthropic factors on the amount of T. baccata recruitment. Our analyses showed that stand recruitment was positively correlated to shrub cover and soil moisture. In particular, shrub cover had a stronger effect, clearly showing that a thicker shrub layer, both bushy and/or spiny, corresponded to a higher number of yew seedlings and saplings. Secondarily, moister sites had a higher number of seedlings and saplings, showing that habitat suitability improved with higher humidity. On the contrary, recruitment was negatively correlated to browsing (both from livestock and wild animals). Our data confirm that the presence of a protective layer of shrubs is a crucial factor for seedling and sapling survival, mostly in relation to protection from summer drought and the browsing of large herbivores. Finally, guidelines for the conservation and restoration of T. baccata communities, referred to as the EU priority habitat 9580* (Mediterranean Taxus baccata woods), have been outlined.

Fatal Taxus baccata ingestion with perimortem serum taxine B quantification.

INTRODUCTION: Common yew (Taxus baccata) is a common decorative evergreen shrub with potentially fatal toxicity hallmarked by seizure, arrhythmia and cardiovascular collapse if ingested. Taxine B has been identified as one of the most cardiotoxic taxine alkaloids in Taxus spp, and another alkaloid, 3,5-dimethoxyphenol (3,5-DMP), is used as a marker of ingestion. We present a fatal case of ingestion of yew with perimortem serum and gastric taxine B, and 3,5-DMP concentrations. CASE PRESENTATION: A 22-year-old woman was brought to the emergency department (ED) from a nearby botanical garden after she was found apneic and pulseless after a witnessed generalized tonic clonic seizure. The patient was found to have a wide complex rhythm with persistent cardiovascular collapse and expired despite maximal supportive care in the ED. A baggie of plant material was found on the patient, identified as Taxus baccata. Perimortem serum and gastric samples were analyzed to quantify serum and gastric taxine B and 3,5-DMP concentrations. RESULTS: Perimortem serum showed a 3,5-DMP concentration of 86.9 ng/mL, and taxine B of 80.9 ug/mL. CONCLUSION: We report a perimortem serum and gastric taxine B and 3,5-DMP concentrations in a fatal case of T. baccata toxicity.

Microalgal biofilms on common yew needles in relation to anthropogenic air pollution in urban Prague, Czech Republic.

Excessive occurrence of microalgae on needles of gymnosperms was reported for the first time in the 1980s from the Scandinavian countries. Since then, it has been repeatedly encountered on needles from various European forest habitats. The abundance of these biofilms has been related to the climatic conditions, such as temperature and precipitation, as well as to the air pollution by nitrogen and sulfur oxides. Urban areas typically have relatively homogenous climates and profound variation in levels of air pollution. Therefore, variation in the occurrence of biofilms in localities within an urban area may be related to local anthropogenic air pollution. We investigated the abundance of biofilms occurring on needles of the common yew (Taxus baccata) in the city of Prague, Czech Republic. The biofilms were composed of algae, fungi and particulate matter. The cover area of the biofilms was marginally explained by a positive influence of short-term maximum atmospheric levels of nitrogen dioxide (NO2). The amounts of the microalgae were also positively influenced by short-term maximum NO2 levels. In addition, high atmospheric levels of particulate matter (PM10) were related to low abundance of algae. The microbial biofilms growing on widely cultivated conifers, such as the common yew, form one of the few commonly occurring natural communities in highly urbanized central areas of temperate European cities. Consequently, we propose that microscopic analysis of biofilms may be used as a rapid and cheap method to collect ecological data. Such data may be used in biomonitoring schemes illustrating the effects of anthropogenic air pollution on natural microcommunities in urban areas.