Wood anatomy of Cupressus and its relation to geographical distribution

The wood anatomy of 14 species of Cupressus was studied to determine whether there is a pattern of wood anatomical diversity between the species from the North and Central American (western) region and the Eurasian (eastern) region. Xanthocyparis vietnamensis and Chamaecyparis nootkatensis (syn. Xanthocyparis nootkatensis) were also studied to compare their wood anatomy, given their recent inclusion by some authors in Cupressus. The arrangement of the axial parenchyma, morphology of the transverse end walls of the axial parenchyma, presence of ray tracheids, typology of the end walls of the ray parenchyma cells and ray height support to some extent the division of Cupressus into two large groups: the American group (western region) and the Eurasian group (eastern region), as proposed in molecular phylogenetic studies. The wood anatomy of Chamaecyparis nootkatensis shares the presence of ray tracheids and the same ray typology with American Cupressus, and has the same ray height as Eurasian Cupressus. In contrast, Xanthocyparis vietnamensis shares the absence of ray tracheids and the same ray typology with Eurasian Cupressus, and has the same ray height as American Cupressus.

Septonema secedens. [Descriptions of Fungi and Bacteria].

A description is provided for Septonema secedens. Information on the host range (Betula pendula, B. alba [B. pubescens], Alnus sp., Ceanothus velutinus, Chamaecyparis nootkatensis, Cornus alba, Pinus sylvestris, Picea sp., Pseudotsuga menziesii and Rosa sp.), geographical distribution (Alaska and Idaho, USA; Kazakhstan; Czech Republic; Denmark; Germany; Netherlands; Russia; Switzerland; and UK), and dispersal and transmission of the pathogen is presented.

Chemical Composition, Antifungal and Antibacterial Activity of the Essential Oil of Chamaecyparis Nootkatensis from Spain

The chemical composition of the oil of Chamaecyparis nootkatensis (D. Don) Spach. has been analysed by gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GCMS). A total of 34 compounds were identified representing more than 90% of the total oil. The oil was richer in monoterpenes than in sesquiterpenes, the major constituents being limonene (53.2%), δ-3-carene (21.0%) and α-pinene (12.2%). The antibacterial and antifungal activities of the oil were also tested against Candida albicans, Bacillus subtilis, Enterobacter aerogenes, Enterococcus faecalis, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Salmonella sp. and Serratia marcescens. Only two of these, Bacillus subtilis and Candida albicans, were sensitive to the treatment, inhibition zones of 11 and 14 mm diameter being obtained, respectively. As far as we know, this is the first report of the antifungal and antibacterial activity of this species.

Survival and Growth of Planted Yellow-Cedar Seedlings and Rooted Cuttings (Stecklings) near Ketchikan, Alaska

The survival and growth of yellow-cedar (Chamaecyparis nootkatensis) seedlings and rooted cuttings (stecklings) were monitored for 6 years after planting at three sites near Ketchikan in southeast Alaska to determine whether stecklings could serve as a suitable planting stock. Survival for both seedlings and stecklings was >85% at the three sites. Survival, final diameter, and final height differed by site but not by the use or absence of Vexar as protection from browsing by Sitka black-tailed deer (Odocoileus hemionus sitkensis). Vexar produced a lower rate of browsing but contributed to form problems (especially leaving trees leaning and prostrate on the ground). Seedlings had significantly greater diameters than stecklings even though they experienced a higher rate of browsing at one site. Differences in diameter and height likely were due to genetic variation rather than seedling or steckling stock type. Stecklings appear to be a suitable source of planting stock; when used for large-scale reforestation efforts, genetic considerations are essential. Planting recommendations for maximizing yellow-cedar establishment during regeneration are given.

Twentieth-century warming and the dendroclimatology of declining yellow-cedar forests in southeastern Alaska

Decline of yellow-cedar ( Chamaecyparis nootkatensis ((D. Don) Spach) has occurred on 200 000 ha of temperate rainforests across southeastern Alaska. Because declining forests appeared soon after the Little Ice Age and are limited mostly to low elevations (whereas higher elevation forests remain healthy), recent studies have hypothesized a climatic mechanism involving early dehardening, reduced snowpack, and freezing injury. This hypothesis assumes that a specific suite of microclimatic conditions occurs during late winter and declining cedar populations across the region have responded similarly to these conditions. Based on the first geographically extensive tree ring chronologies constructed for southeastern Alaska, we tested these assumptions by investigating regional climatic trends and the growth responses of declining cedar populations to this climatic variation. Warming winter trends were observed for southeastern Alaska, resulting in potentially injurious conditions for yellow-cedar due to reduced snowfall and frequent occurrence of severe thaw–freeze events. Declining cedar forests shared a common regional chronology for which late-winter weather was the best predictor of annual growth of surviving trees. Overall, our findings verify the influence of elevational gradients of temperature and snow cover on exposure to climatic stressors, support the climatic hypothesis across large spatial and temporal scales, and suggest cedar decline may expand with continued warming.