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White spruce (Picea glauca (Moench) Voss) cone crops were measured from 1986 to 2011 in the Kluane region of southwestern Yukon to test the hypothesis that the size of cone crops could be predicted from spring and summer temperature and rainfall of years t, t - 1, and t - 2. We counted cones in the top 3 m of an average of 700 white spruce trees each year spread over 3-14 sites along 210 km of the Alaska Highway and the Haines Highway. We tested the conventional explanation for white spruce cone crops that implicates summer temperatures and rainfall in years t and t - 1 and rejected it, since it explained very little of the variation in our 26 years of data. We used exploratory data analysis with robust multiple regressions coupled with Akaike's information criterion corrected (AICc) analysis to determine the best statistical model to predict the size of cone crops. We could statistically explain 54% of the variation in cone crops from July and August temperatures of years t - 1 and t - 2 and May precipitation of year t - 2. There was no indication of a periodicity in cone crops, and years of large cone crops were synchronous over the Kluane region with few exceptions. This is the first quantitative model developed for the prediction of white spruce cone crops in the Canadian boreal forest and has the surprising result that weather conditions 2 years prior to the cone crop are the most significant predictors. Key words: white spruce cone production, Yukon, climate, Kluane, Picea glauca. Les auteurs ont emis l'hypothese a savoir si l'on peut predire l'importance de la production des cones chez l'epinette blanche (Picea glauca (Moench) Voss) a partir des temperatures du printemps et de l'automne et des precipitations des annees t, t - 1, et t - 2. Pour verifier l'hypothese, ils ont mesure la production des cones de 1986 a 2011 dans la region de Kluane dans le sud-ouest du Yukon. Chaque annee, ils ont compte les cones dans les 3 m superieurs d'une moyenne de 700 tiges d'epinettes blanches dispersees dans 3-14 sites sur une longueur de 210 km le long des autoroutes de l'Alaska et Haines. Ils ont verifie l' explication conventionnelle pour la production des cones chez l' epinette blanche impliquant les temperatures estivales et les precipitations des annees t et t - 1, et l'ont rejetee puisqu'elle explique tres peu de la variation dans leurs donnees de 26 annees. Ils ont utilise l' analyse exploratoire des donnees avec des regressions multiples robustes couplees avec l' analyse du critere d' information d'Akaike corrige (AICc) pour determiner le meilleur modele statistique permettant de predire la production de cones. Ils ont pu ainsi expliquer 54 % de la variation de la production des cones a partir des temperatures de juillet et aout des annees t - 1et t - 2 et la precipitation de mai de l'annee t - 2. Il n'y a aucune indication de periodicite dans la production des cones, et les annees de forte production sont synchrones sur l'ensemble de la region de Kluane avec quelques exceptions. Il s'agit du premier modele quantitatif developpe pour la prediction des productions de cones chez l'epinette blanche dans la foret boreale canadienne avec le resultat surprenant que les conditions climatiques 2 ans avant l' annee de production constituent les meilleurs predicteurs. Mots-cles : production de cones de l'epinette blanche, Yukon, climat, Kluane, Picea glauca. [Traduit par la Redaction], Introduction Cone crops of white spruce (Picea glauca (Moench) Voss) in the boreal forest region vary dramatically from year to year. A combination of climatic events are usually put forward [...]

A species is expected to occur where the prevailing biotic and abiotic conditions fall within its fundamental niche. Geographic range limits should, therefore, occur when the survival and fitness of individuals along ecological gradients is reduced to the point at which populations are no longer self-sustaining. Abrupt limits to a species' distribution are expected to reflect abrupt changes in the ecological conditions that cause sharp declines in fitness across the limit. We investigated the correlation between geographic variation in environment and fitness across the abrupt northern range limit of a coastal dune plant, Camissoniopsis cheiranthifolia (Onagraceae). In each of 64 plots distributed across five sites along a 200-km transect spanning the species' northern range limit (four within the range plus one beyond the limit), we measured plant community composition as a proxy for variation in biotic and abiotic environmental factors and lifetime fitness of genetically standardized experimental populations of C. cheiranthifolia. There was substantial variation in plant community composition among plots and sites across the range limit, and fitness of experimental plants covaried strongly with the first principal component of plant community composition. However, we did not detect an abrupt shift in plant community or the expected decline in fitness across the range limit. In fact, fitness and recruitment increased toward the limit and were relatively high beyond the limit. This suggests that habitat beyond the range did not occur outside of the species' fundamental niche. These results challenge niche-based explanations for range limits and suggest that hypotheses involving the finer-scale distribution of habitat patches or constraints on dispersal warrant more serious consideration. Key words: Camissoniopsis cheiranthifolia; coastal dunes; demography; fitness; geographic ranges; Pacific coast; plant community structure; range limits; seedling recruitment; transplant experiment.

Knowledge of target environments in breeding programs is important to better direct the development of germplasm. The objectives of this study were to identify associations among barley (Hordeum vulgare L.) growing environments to identify mega-environments to select the best locations to breed barley. Twenty-seven years of grain yield data from the International Barley Yield Trial (IBYT) conducted by the ICARDA-CIMMYT Barley Breeding Program, consisting of 750 grain yield trials of two replications representing 235 locations in 75 countries, were analyzed using pattern analysis to group sites across years that represent similar selection environments. The shifted multiplicative model (SHMM) was employed to group sites within each year. Environments clustered into three main groups and squared Euclidean distances were used to identify a representative location within each cluster. Group 1 locations were characterized as being cool with intermediate precipitation; Group 2 locations were warmer and drier; and Group 3 sites were generally cool and had the highest average precipitation. The respective representative key locations for each of the three groups were Leida, Spain; Boulifa, Tunisia; and Setif, Algeria. All three key locations are located in the Northern Hemisphere between 36[degrees] and 41[degrees] latitude. The results of this study show that the global adaptation of barley is possible and can be improved by breeding and selection for adaptation within the three main mega-environments identified.

Fungi and protists make up an ecological group, trichomycetes, that inhabit the guts of invertebrates, mostly aquatic insects. Trichomycetes are reported herein from arthropods collected in lotic habitats (fast flowing streams) and lentic environments (ponds, ditches, seeps, and lakes) from 11 sites in Algonquin Park and 6 other sites in Ontario, Canada. Thirty-two trichomycete species were recovered, including 7 new species: Legeriomyces algonquinensis, Legeriosimilis leptocerci, Legeriosimilis whitneyi, and Paramoebidium umbonatum are described from mayfly nymphs (Ephemeroptera); Pennella digitata and Glotzia incilis from black fly and midge larvae (Diptera), respectively; and Arundinula opeongoensis from a crayfish (Crustacea). Legeriomyces rarus Lichtw. & M.C. Williams and Stachylina penetralis Lichtw. are new North American records, and seven species are documented for the first time in Canada. More common and widely distributed trichomycete species such as Harpella melusinae Leger & Duboscq and Smittium culicis Manier, were also recovered. Most previous studies on trichomycetes have been done primarily in lotic environments but clearly lentic systems (e.g., ponds and lakes) harbour diverse arthropod communities and further exploration of these habitats will continue to increase our knowledge of trichomycete diversity. Key words: Amoebidiales, Eccrinales, Harpellales, insect fungal endobionts, symbiotic protista. Les champignons et les protistes comportent un groupe ecologique, les trichomycetes, qui habitent les intestins de la plupart des insectes aquatiques. Les auteurs rapportent des ttrichomycetes provenant d'arthropodes vivants dans des habitats lotiques (cours d'eau rapides) et des environnements lentiques (etangs, fosses, suintement et lacs) recoltes sur 11 sites dans le parc Algonquin et six autres sites en Ontario, au Canada. On a trouve 33 especes de trichomycetes, incluant sept nouvelles especes pour l'Amerique du Nord: Lageriomyces algonquinensis, Lageriosimilis leptocerci, Lageriosimilis whitneyi et Paramoebidium umbonatum, decrits a partir de nymphes d'ephemeres (Ephemeroptera); Pennella digitata et Glotzia incilis a partir de mouches noires et de brulots (Diptera) respectivement; et Arundinula opeongoensis a partir d'un ecrevisse (Crustacea). Le Lageriomyces rarus Lichtw. & M. C. Williams et le Stachylina penetralis Lichtw. Sept especes sont repertoriees pour la premiere fois au Canada. On a egalement retrouve des especes de trichomycetes communes et largement distribuees, comme l'Harpella melusinae Leger & Duboscq et le Smittum culicis Manier. La plupart des etudes antecedentes sur les trichomycetes ont ete conduites surtout en environnements lotiques, mais il est clair que les systemes lentiques (etangs et lacs) comportent diverses communautes d'arthropodes et que d'autres explorations de ces habitats vont permettre d'augmenter notre connaissance de la diversite des trichomycetes. Mots-cles : Amaoebidiales, Eccrinales, Harpellales, champignons endosymbiontes des insectes, protistes symbiotiques. [Traduit par la Redaction], Introduction Canada has a wide variety of freshwater aquatic habitats such as lakes, ponds, swamps, rivers, and streams, making up extensive watersheds. Information on Canada's immense hydrologic diversity is available [...]

Spaciinodum collinsonii, a Triassic sphenophyte from the central Transantarctic Mountains, Antarctica, is reinterpreted based on new material in order to clarify discrepancies from previous work and to detail the development and ecology of the Spaciinodum plant. Vegetative stems have alternating nodes and internodes, nodes distinguished by a solid diaphragm of tissue, internodes by the presence of vallecular (cortical) and carinal canals, and a hollow pith. Whorls of branches arise immediately above the nodes, alternating with the leaves of the subjacent nodes. Branches develop in the cortex and are anatomically similar to the stems. While Spaciinodum is similar to extant Equisetum, it is distinctive in that its large vallecular canals form a complete ring within the cortex and are separated only by thin fimbrils of tissue. The majority of specimens of Spaciinodum are now believed to be dormant buds with condensed nodes and internodes, with progressively longer internodal regions more basally. More apical portions of buds have cellular internodes because the areas where the canals will form have not yet ruptured from elongation. The abundance of buds and the absence of elongated stems in the permineralized peat deposit suggest that Spaciinodum underwent dormancy during the dark Antarctic winters. Key words: Antarctica; dormancy; Equisetophyte; Triassic; Spaciinodum; stem bud.

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 [...]

A central goal of comparative plant ecology is to understand how functional traits vary among species and to what extent this variation has adaptive value. Here we evaluate relationships between four functional traits (seed volume, specific leaf area, wood density, and adult stature) and two demographic attributes (diameter growth and tree mortality) for large trees of 240 tree species from five Neotropical forests. We evaluate how these key functional traits are related to survival and growth and whether similar relationships between traits and demography hold across different tropical forests. There was a tendency for a trade-off between growth and survival across rain forest tree species. Wood density, seed volume, and adult stature were significant predictors of growth and/or mortality. Both growth and mortality rates declined with an increase in wood density. This is consistent with greater construction costs and greater resistance to stem damage for denser wood. Growth and mortality rates also declined as seed volume increased. This is consistent with an adaptive syndrome in which species tolerant of low resource availability (in this case shade-tolerant species) have large seeds to establish successfully and low inherent growth and mortality rates. Growth increased and mortality decreased with an increase in adult stature, because taller species have a greater access to light and longer life spans. Specific leaf area was, surprisingly, only modestly informative for the performance of large trees and had ambiguous relationships with growth and survival. Single traits accounted for 9-55% of the interspecific variation in growth and mortality rates at individual sites. Significant correlations with demographic rates tended to be similar across forests and for phylogenetically independent contrasts as well as for cross-species analyses that treated each species as an independent observation. In combination, the morphological traits explained 41% of the variation in growth rate and 54% of the variation in mortality rate, with wood density being the best predictor of growth and mortality. Relationships between functional traits and demographic rates were statistically similar across a wide range of Neotropical forests. The consistency of these results strongly suggests that tropical rain forest species face similar trade-offs in different sites and converge on similar sets of solutions. Key words: demography; functional ecology; height; life-history theory; seed mass; shade tolerance; species coexistence; specific leaf area; trees; tropical rain forest; wood density.

Selection of winter wheat (Triticum aestivum L.) genotypes requires testing programs with complementary locations that sample environments of interest with minimal duplication. The goal of the current study was to improve prediction of genotype performance in the highly variable environments of the central Great Plains in the United States by estimating the contributions of genotype, location, and year to wheat yield variability and identifying subgroups of test locations that minimize crossover genotype-by-environment interaction. Variance components were estimated from Kansas wheat performance data from 17 locations from 1982 to 2002. Annual data sets balanced for genotypes and environments were used to generate genotype, genotype-by-environment biplots that could objectively separate locations into groups with the same top-yielding genotype. Location, year, and their interaction introduced the greatest proportion of the variability in wheat performance test yields. Frequency of common grouping during the 21-year period was used to construct six groups of test locations representing unique target environments. Evaluation of the six groups using results from two subsequent years revealed that they generally agreed with location groups observed in the previous 21 years. Smaller regional genotype-by-environment variance component estimates compared with statewide estimates further confirmed the effectiveness of the pro posed six regions for reducing genotype-by-environment interaction.

Factors affecting survival and recruitment of 3531 individually mapped seedlings of Myristicaceae were examined over three years in a highly diverse neotropical rain forest, at spatial scales of 1-9 m and 25 ha. We found convincing evidence of a community compensatory trend (CCT) in seedling survival (i.e., more abundant species had higher seedling mortality at the 25-ha scale), which suggests that density-dependent mortality may contribute to the spatial dynamics of seedling recruitment. Unlike previous studies, we demonstrate that the CCT was not caused by differences in microhabitat preferences or life history strategy among the study species. In local neighborhood analyses, the spatial autocorrelation of seedling survival was important at small spatial scales (1-5 m) but decayed rapidly with increasing distance. Relative seedling height had the greatest effect on seedling survival. Conspecific seedling density had a more negative effect on survival than heterospecific seedling density and was stronger and extended farther in rare species than in common species. Taken together, the CCT and neighborhood analyses suggest that seedling mortality is coupled more strongly to the landscape-scale abundance of conspecific large trees in common species and the local density of conspecific seedlings in rare species. We conclude that negative density dependence could promote species coexistence in this rain forest community but that the scale dependence of interactions differs between rare and common species. Key words: autologistic regression: community compensatory trend (CCT); Ecuador; Myristicaceae; seedling; spatial autocorrelation; species coexistence; tropical forest; Yasuni.