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In the Rocky Mountain Forest District of British Columbia, a dramatic series of fires occurred during 2003, setting the stage for an abundant morel crop in the following year. During 2004, the abundance of post-fire morels (Morchella spp.) was measured and the plant community associated with morel production was characterized. Morel production averaged 6473 [+ or -] 2721 morels* [ha.sup.-1] in five burnt forests that were surveyed. Production ranged from 1702* [ha.sup.-1] at Plumbob Mountain to a significantly higher 16827* [ha.sup.-1] in the Kootenay National Park, where the highest level of duff consumption (71%) was also observed. Several plant species had high importance in morel habitat, and were also associated with above-average morel abundance: Chamerion angustifolium (L.) Holub, Arnica cordifolia Hook., Erythronium grandiflorum Pursh, Spiraea betulifolia Pallas subsp. lucida (Dougl. ex Greene) Taylor and MacBryde, Menziesia ferruginea Sm., Rosa acicularis Lindl. subsp. sayi (Schwein.) W.H. Lewis, Pinus contorta Dougl. ex Loud. var. latifolia Engelm., Abies lasiocarpa (Hook.) Nutt., and Picea glauca (Moench) Voss x engelmannii (Torr. & Gray ex Hook.) Brayshaw. Compositae and Vaccinium spp. were important species when considered as groups. Grass species, including Calamagrostis rubescens Buckl., were more proximate to morel-free plots. The characteristics of morel habitats observed in this study may be useful in future management of the resource, through conservation of habitat, management of prescribed burning, and postponement of salvage logging in potentially highly productive areas. Key words: Morchella, indicators, fire, mushroom. Le District forestier des montagnes Rocheuses, en Colombie canadienne, a connu en 2003 de spectaculaires incendies de foret, preparant les sites pour une abondante recolte de morilles l'annee suivante. En 2004, les auteurs ont mesure l'abondance de morilles (Morchella spp.) post incendie et ont caracterise la communaute vegetale associee. La production moyenne de morilles a atteint 6473 [+ or -] 2721 morilles* [ha.sup.-1] dans les cinq forets brulees observees. La production allait de 1702* [ha.sup.-1] in Plumbob Mountain a une quantite significativement plus elevee de 16827* [ha.sup.-1] dans le Parc national de Kootnay, ou la litiere a le plus fortement brule (71 %). On a observe plusieurs especes de plantes d'importance dans l'habitat des morilles egalement associees avec une abondance au-dessus de la moyenne des sporophores: Chamerion angustifolium (L.) Holub, Arnica cordifolia Hook., Erythronium grandiflorum Pursh, Spirea betulifolia Pallas subsp. lucida (Dougl. ex Greene) Taylor and MacBryde, Menziesia ferruginea Sm., Rosa acicularis Lindl. subsp. sayi (Schwein.) W.H. Lewis, Pinus contorta Dougl. ex Loud. var. latifolia Engelm., Abies lasiocarpa (Hook.) Nutt., and Picea glauca (Moench) Voss xengelmannii (Torr. & Gray ex Hook.) Brayshaw. Les composees et les Vaccinium spp. occupent une place importante comme groupes. Les graminees, incluant le Calamagrostis rubescens, se retrouvent plutot a proximite des parcelles sans morille. Les caracteristiques des habitats de la morille, observees dans cette etude, pourraient etre utiles pour l'amenagement de la ressource, en assurant la conservation de l'habitat, l'utilisation du brulage controle, et la remise a plus tard de la recolte sur les surfaces a fort potentiel de production. Mots-cles : Morchella, indicateurs, feu, champignon. [Traduit par la Redaction], Introduction After a large forest fire, the emergence of phoenicoid mushrooms signals the renewal of forest life, as well as the almost certain arrival of morel pickers. Cooked morels (Morchella [...]

Quantitative real-time PCR is used for examining the abundance of nifH, nirS, and nirK gene fragments involved in nitrogen (N) fixation and denitrification in thinned second-growth Douglas-fir (Pseudotsuga menziesii subsp. menziesii {Mirb.] Franco) forest soil. The studies have shown no clear influence of tree thinning on nifH, nirS and nirK, whereas soil organic matter, total carbon and N have affected N-cycling gene abundance.

We investigated the N-utilizing bacterial community in anoxic brackish groundwater of the low and intermediate level nuclear waste repository cave in Olkiluoto, Finland, at 100m depth using 15N-based stable isotope probing (SIP) and enrichment with 14/15N-ammonium or 14/15N-nitrate complemented with methane. Twenty-eight days of incubation at 12℃ increased the concentration of bacterial 16S rRNA and nitrate reductase (narG) gene copies in the substrate amended microcosms simultaneously with a radical drop in the overall bacterial diversity and OTU richness. Hydrogenophaga/Malikia were enriched in all substrate amended microcosms and Methylobacter in the ammonium and ammonium+methane supplemented microcosms. Sulfuricurvum was especially abundant in the nitrate+methane treatment and the unamended incubation control. Membrane-bound nitrate reductase genes (narG) from Polarimonas sp. were detected in the original groundwater, while Burkholderia, Methylibium, and Pseudomonas narG genes were enriched due to substrate supplements. Identified amoA genes belonged to Nitrosomonas sp. 15N-SIP revealed that Burkholderiales and Rhizobiales clades belonging to the minority groups in the original groundwater used 15N from ammonium and nitrate as N source indicating an important ecological function of these bacteria, despite their low number, in the groundwater N cycle in Olkiluoto bedrock system. [ABSTRACT FROM AUTHOR]

Atmospheric concentrations of carbon dioxide (CO2) have significantly increased over the past century and are expected to continue rising in the future. While elevated levels of CO2 will likely result in higher crop yields, weed growth is also highly likely to increase, which could increase the incidence of herbicide resistant biotypes. An experiment was conducted in 2012 to determine the effects of an elevated CO2 environment on glyphosate and halosulfuron efficacy for postemergence control of purple and yellow nutsedge (Cyperus rotundus L. and C. esculentus L.). Both species of nutsedge where grown in 3.0-L containers under either ambient or elevated (ambient + 200µmol mol-1)CO2 in open-top field chambers and treated with either 0.5x,1.0x,or 1.5x of the manufacturer's labeled rate of halosulfuron, glyphosate, or a tank mix of the two herbicides. The growth of both nutsedge species responded positively to elevated CO2, purple nutsedge had increased shoot and root dry weights and yellow nutsedge had increased shoot, root, and tuber dry weights and counts. Few treatment differences were observed among the herbicides at any of the rates tested. At 3 weeks following herbicide application, both purple and yellow nutsedge were adequately controlled by both herbicides and combinations at all rates tested, regardless of CO2 concentration. Based on this study, it is likely that predicted future CO2 levels will have little impact on the efficacy of single applications of halosulfuron or glyphosate for control of purple and yellow nutsedge at the growth stages described here, although scenarios demanding more persistent control efforts remain a question. [ABSTRACT FROM AUTHOR]

A response from the authors of an article on the role of extreme climatic change in assisted migration in forestry (forestry AM), that was published in a previous issue, is presented.