Suchergebnisse

10 páginas.-- 4 tablas.-- 60 referencias.-- Supporting InformationAdditional Supporting Information may be found in the online version of this article ; 1. Understanding the proximate factors that govern the widespread mast-seeding process is a question of considerable interest that remains poorly understood. The identity and effect of these factors may vary among coexisting species that differ in leaf habit, potentially resulting in temporally asynchronous patterns of seed production. 2. In this study, we aim to identify the proximate causes of mast-seeding using two oak species with contrasting leaf habit that coexist in southern Spain, the deciduous Quercus canariensis and the evergreen Q. suber. Simultaneously, we review the literature on environmental drivers of mast-seeding in Mediterranean oaks, distinguishing between evergreen and deciduous species. 3. Our results indicate that Mediterranean oaks are primarily sensitive to weather, mast-seeding being strongly correlated with water availability and air temperature, mainly in the spring and summer. 4. The two study oak species were affected by weather in quite different ways, most likely because of different abiotic requirements as well as contrasting functional strategies of resource use and biomass allocation. Specifically, annual seed production in Q. canariensis was more severely limited by drought than in Q. suber, but responded positively to warmer spring temperatures. 5. Q. canariensis showed a large interannual variability, whereas Q. suber exhibited much more constant seed production. These two species also exhibited a very low level of synchrony in their temporal patterns of seed crop size, most likely due to phenological differences in the processes of flowering and seed maturation. 6. Synthesis. Our results indicate that weather plays a crucial role as a proximate driver of mastseeding in Mediterranean oaks. We hypothesize that the current abundance of co-occurring species that differ in leaf habit could be altered under future climate change scenarios. The decline of seed production with drier conditions will be potentially greater in deciduous species, particularly those inhabiting wetter sites. Alternatively, the expected warmer temperatures could negatively affect evergreen species as a consequence of their more conservative strategy of biomass allocation. Our findings suggest that understanding how species with different functional or phenological attributes adjust their reproductive abilities to weather may enable us to infer the effects of ongoing environmental changes on population recruitment and dynamics. ; We thank the "Consejería de Medio Ambiente" (Andalusian Government) and the technical staff of Los Alcornocales Natural Park, for the facilities and support to carry out our fieldwork. We are very grateful to María Amían, Ana Pozuelos, Rocío Sánchez and other undergraduate students for field assistance. This study was supported by a postdoctoral contract of the Andalusian Government to IMPR, by the Spanish MEC projects Heteromed (REN2002- 4041-C02-02), Dinamed (CGL2005-5830-C03-01) and Interbos (CGL2008-04503-C03-01), and by the Andalusian Anasinque-PE2010-RNM-5782 project. WDK was supported by the National Science Foundation (grant DEB-0816691). ; Peer reviewed

13 páginas.-- 2 figuras.-- 7 tablas.-- 47 referencias.-- Additional supporting information may be found in the online version of this article at http://onlinelibrary.wiley.com/doi/10.1002/ecy.1490/suppinfo.-- Koenig_et_al ; Although the functional basis of variable and synchronous seed production (masting behavior) has been extensively investigated, only recently has attention been focused on the proximate mechanisms driving this phenomenon. We analyzed the relationship between weather and acorn production in 15 species of oaks (genus Quercus) from three geographic regions on two continents, with the goals of determining the extent to which similar sets of weather factors affect masting behavior across species and to explore the ecological basis for the similarities detected. Lag-1 temporal autocorrelations were predominantly negative, supporting the hypothesis that stored resources play a role in masting behavior across this genus, and we were able to determine environmental variables correlating with acorn production in all but one of the species. Standard weather variables outperformed "differential-cue" variables based on the difference between successive years in a majority of species, which is consistent with the hypothesis that weather is linked directly to the proximate mechanism driving seed production and that masting in these species is likely to be sensitive to climate change. Based on the correlations between weather variables and acorn production, cluster analysis failed to generate any obvious groups of species corresponding to phylogeny or life-history. Discriminant function analyses, however, were able to identify the phylogenetic section to which the species belonged and, controlling for phylogeny, the length of time species required to mature acorns, whether they were evergreen or deciduous, and, to a lesser extent, the geographic region to which they are endemic. These results indicate that similar proximate mechanisms are driving acorn production in these species of oaks, that the environmental factors driving seed production in oaks are to some extent phylogenetically conserved, and that the shared mechanisms driving acorn production result in some degree of synchrony among coexisting species in a way that potentially enhances predator satiation, at least when they have acorns requiring the same length of time to mature. ; This study was supported by National Science Foundation grant DEB- 1256394; Andalusian projects Anasinque- PE2010- RNM- 5782, P07- RNM02688, and P10- AGR6501; Spanish MEC projects Heteromed REN2002- 4041- C02- 02, Dinamed CGL2005- 5830- C03- 01, and Interbos CGL2008- 04503- C03- 01; a postdoctoral contract of the Andalusian Government (to IMPR); and a post-doctoral contract of the Operative Program of the European Social Fund (to MDC). ; Peer reviewed

A shuffle. Do you experience the following? Cigarette smoke and white cheddar popcorn. It's all in my pretty little head. Crinkling paper bedsheets. Excess. A woman who swallowed a fly, leaves and steel. A polka-dot collar. Blink... Side effects are a misnomer. An artist's manifesto. Non-linear. I want to be disjointed, unformed, messy, hurting, mad. Madness is both personal and political. Through an autoethnographic series of performative poetry and prose, Loose Leaf intends to evoke encounters with some of the affects, experiences, and politics of madness and psychiatrization. It works to offer both an embodied and theoretical engagement with one form of mad performance, and to compel readers to perform a form of mad reading.

The objective of this work was to model and identify the best models for estimating the leaf area, determined by digital photos, of buckwheat (Fagopyrum esculentum Moench) of the cultivars IPR91-Baili and IPR92-Altar, as a function of length (L), width (W) or length x width product (LW) of the leaf blade. Ten uniformity trials (blank experiments) were carried out, five with IPR91-Baili cultivar and five with IPR92-Altar cultivar. The trials were performed on five sowing dates. In each trial and cultivar, expanded leaves were collected at random from the lower, middle and upper segments of the plants, totaling 1,815 leaves. In these 1,815 leaves, L and W were measured and the LW of the leaf blade was calculated, which were used as independent variables in the model. The leaf area of each leaf was determined using the digital photo method (Y), which was used as a dependent variable of the model. For each sowing date, cultivar and thirds of the plant, 80% of the leaves (1,452 leaves) were randomly separated for the generation of the models and 20% of the leaves (363 leaves) for the validation of the models of leaf area estimation as a function of linear dimensions. For buckwheat, IPR91-Baili and IPR92-Altar cultivars, the quadratic model (Ŷ = 0.5217 + 0.6581LW + 0.0004LW2, R2 = 0.9590), power model (Ŷ = 0.6809LW1.0037, R2 = 0.9587), linear model (Ŷ = 0.0653 + 0.6892LW, R2 = 0.9587) and linear model without intercept (Ŷ = 0.6907LW, R2 = 0.9587) are indicated for the estimation of leaf area determined by digital photos (Y) based on the LW of the leaf blade (x), and, preferably, the linear model without intercept can be used, due to its greater simplicity.

Resumé Nous avons tous besoin d'habiter un « foyer », témoin et support de notre histoire et de notre identité.