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971.
Increasing drought decreases phosphorus availability in an evergreen Mediterranean forest 总被引:9,自引:2,他引:7
Mediterranean ecosystems are water-limited and frequently also nutrient-limited. We aimed to investigate the effects of increasing
drought, as predicted by GCM and eco-physiological models for the next decades, on the P cycle and P plant availability in
a Mediterranean forest. We conducted a field experiment in a mature evergreen oak forest, establishing four drought-treatment
plots and four control plots (150 m2 each). After three years, the runoff and rainfall exclusion reduced an overall 22% the soil moisture, and the runoff exclusion
alone reduced it 10%. The reduction of 22% in soil moisture produced a decrease of 40% of the accumulated aboveground plant
P content, above all because there was a smaller increase in aerial biomass. The plant leaf P content increased by 100 ± 40
mg m−2 in the control plots, whereas it decreased by 40 ± 40 mg m−2 in the drought plots. The soil Po-NaHCO3 (organic labile-P fraction) increased by 25% in consonance with the increase in litterfall, while the inorganic labile-P
fraction decreased in relation to the organic labile-P fraction up to 48%, indicating a decrease in microbial activity. Thus,
after just three years of slight drought, a clear trend towards an accumulation of P in the soil and towards a decrease of
P in the stand biomass was observed. The P accumulation in the soil in the drought plots was mainly in forms that were not
directly available to plants. These indirect effects of drought including the decrease in plant P availability, may become
a serious constraint for plant growth and therefore may have a serious effect on ecosystem performance. 相似文献
972.
Jose Luis Araus Shawn Carlisle Kefauver Omar Vergara‐Díaz Adrian Gracia‐Romero Fatima Zahra Rezzouk Joel Segarra Maria Luisa Buchaillot Melissa Chang‐Espino Thomas Vatter Rut Sanchez‐Bragado José Armando Fernandez‐Gallego Maria Dolores Serret Jordi Bort 《植物学报(英文版)》2022,64(2):592-618
High-throughput crop phenotyping, particularly under field conditions, is nowadays perceived as a key factor limiting crop genetic advance. Phenotyping not only facilitates conventional breeding, but it is necessary to fully exploit the capabilities of molecular breeding, and it can be exploited to predict breeding targets for the years ahead at the regional level through more advanced simulation models and decision support systems. In terms of phenotyping, it is necessary to determined which selection traits are relevant in each situation, and which phenotyping tools/methods are available to assess such traits. Remote sensing methodologies are currently the most popular approaches, even when lab-based analyses are still relevant in many circumstances. On top of that, data processing and automation, together with machine learning/deep learning are contributing to the wide range of applications for phenotyping. This review addresses spectral and red–green–blue sensing as the most popular remote sensing approaches, alongside stable isotope composition as an example of a lab-based tool, and root phenotyping, which represents one of the frontiers for field phenotyping. Further, we consider the two most promising forms of aerial platforms (unmanned aerial vehicle and satellites) and some of the emerging data-processing techniques. The review includes three Boxes that examine specific case studies. 相似文献
973.
974.
975.
Xavier Arnan Anna Escolà Anselm Rodrigo Jordi Bosch 《Botanical journal of the Linnean Society. Linnean Society of London》2014,175(3):395-408
Gynodioecy is a dimorphic breeding system in which female individuals coexist with hermaphroditic individuals in the same population. Females only contribute to the next generation via ovules, and many studies have shown that they are usually less attractive than hermaphrodites to pollinators. Several mechanisms have been proposed to explain how females manage to persist in populations despite these disadvantages. The ‘resource reallocation hypothesis’ (RRH) states that females channel resources not invested in pollen production and floral advertisement towards the production of more and/or larger seeds. We investigated pollination patterns and tested the RRH in a population of Thymus vulgaris. We measured flower display, flower size, nectar production, visitation rates, pollinator constancy and flower lifespan in the two morphs. In addition, we measured experimentally the effects of pollen and resource addition on female reproductive success (fruit set, seed set, seed weight) of the two morphs. Despite lower investment in floral advertisement, female individuals were no less attractive to pollinators than hermaphrodites on a per flower basis. Other measures of pollinator behaviour (number of flowers visited per plant, morph preference and morph constancy) also showed that pollinators did not discriminate against female flowers. In addition, stigma receptivity was longer in female flowers. Accordingly, and contrary to most studies on gynodioecious species, reproductive success of females was not pollen limited. Instead, seed production was pollen limited in hermaphrodites, suggesting low levels of cross‐pollination in hermaphrodites. Seed production was resource limited in hermaphrodites, but not in females, thus providing support for the RRH. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 395–408. 相似文献
976.
Karen B. Disante Jordi Cortina Alberto Vilagrosa David Fuentes Encarni I. Hernández Karin Ljung 《Physiologia plantarum》2014,150(3):412-424
Heavy metal contamination and drought are expected to increase in large areas worldwide. However, their combined effect on plant performance has been scantly analyzed. This study examines the effect of Zn supply at different water availabilities on morpho‐physiological traits of Quercus suber L. in order to analyze the combined effects of both stresses. Seedlings were treated with four levels of zinc from 3 to 150 µM and exposed to low watering (LW) or high watering (HW) frequency in hydroponic culture, using a growth chamber. Under both watering regimes, Zn concentration in leaves and roots increased with Zn increment in nutrient solution. Nevertheless, at the highest Zn doses, Zn tissue concentrations were almost twice in HW than in LW seedlings. Functional traits as leaf photosynthetic rate and root hydraulic conductivity, and morphological traits as root length and root biomass decreased significantly in response to Zn supply. Auxin levels increased with Zn concentrations, suggesting the involvement of this phytohormone in the seedling response to this element. LW seedlings exposed to 150 µM Zn showed higher root length and root biomass than HW seedlings exposed to the same Zn dose. Our results suggest that low water availability could mitigate Zn toxicity by limiting internal accumulation. Morphological traits involved in the response to both stresses probably contributed to this response. 相似文献
977.
Marc Yeste Efrén Estrada Elisabeth Pinart Sergi Bonet Jordi Miró Joan E. Rodríguez-Gil 《Cryobiology》2014
Reduced glutathione (GSH) improves boar sperm cryosurvival and fertilising ability when added to freezing extenders. Poor freezability ejaculates (PFE) are known to present lower resistance than good freezability ejaculates (GFE) to cryopreservation procedures. So far, no study has evaluated whether the ability of GSH to counteract the cryopreservation-induced injuries depends on ejaculate freezability (i.e. GFE vs. PFE). For this reason, thirty boar ejaculates were divided into three equal volume fractions and cryopreserved with or without GSH at a final concentration of either 2 or 5 mM in freezing media. Before and after freeze–thawing, sperm quality was evaluated through analysis of viability, motility, integrity of outer acrosome membrane, ROS levels, integrity of nucleoprotein structure, and DNA fragmentation. Ejaculates were classified into two groups (GFE or PFE) according to their post-thaw sperm motility and viability assessments in negative control (GSH 0 mM), after running cluster analyses. Values of each sperm parameter were then compared between treatments (GSH 0 mM, GSH 2 mM, GSH 5 mM) and freezability groups (GFE, PFE). In the case of GFE, GSH significantly improved boar sperm cryotolerance, without differences between 2 and 5 mM. In contrast, PFE freezability was significantly increased when supplemented with 5 mM GSH, but not when supplemented with 2 mM GSH. In conclusion, PFE need a higher concentration of GSH than GFE to improve their cryotolerance. 相似文献
978.
Rubén Rabaneda‐Bueno Sara Aguado Carmen Fernández‐Montraveta Jordi Moya‐Laraño 《Ethology : formerly Zeitschrift fur Tierpsychologie》2014,120(3):238-248
Animal personalities (e.g. consistent across‐context behavioural differences between individuals) can lead to differences in mate choice. However, evidence for this link remains limited. Pre‐mating sexual cannibalism can be a behavioural syndrome (i.e. a suboptimal personality) in which adaptive female aggression towards heterospecific prey spills over on non‐adaptive aggression towards courting males, independently of the female mating or feeding status (i.e. the ‘aggressive spillover hypothesis’, ASH). On the other hand, sexual cannibalism can also be a form of mate choice by which females selectively kill or mate with males depending on the male phenotype. We introduce the hypothesis that the most aggressive females in the population will not only attack males more frequently, but will be less likely to impose sexual selection on males through sexual cannibalism. Assuming that in a field common garden experiment in which females were fed ad libitum the rate of weight gain by a female may reflect her voracity or aggressiveness, we show that in the cannibalistic burrowing wolf spider Lycosa hispanica (formerly L. tarantula), voracity towards heterospecific prey predicts a female's tendency towards sexual cannibalism. Unmated females with higher weight gains were more cannibalistic and attacked males regardless of the male phenotype. On the other hand, females that were less voracious tended to be less cannibalistic, and when they did kill a male, they were selective, killing males in poorer condition and mating with those in better condition. Our results demonstrate that females with different phenotypes (growth rates) differently imposed selection on male condition, tentatively supporting the hypothesis that female aggression levels can spill over on sexual selection through sexual cannibalism. 相似文献
979.
Ana-Maria Hereş Jesús Julio Camarero Bernat C. López Jordi Martínez-Vilalta 《Trees - Structure and Function》2014,28(6):1737-1750
Key message
The retrospective analysis of wood anatomical features evidences how a long-term deterioration of hydraulic performance and carbon use portend drought-induced mortality in Scots pine.Abstract
Widespread episodes of drought-induced tree mortality are predicted to become more frequent as climate becomes warmer and drier. Nevertheless, growth trends and their links to changes in wood anatomy before tree dies are still poorly understood. Wood anatomical features provide valuable information that can be extracted to infer the mechanisms leading to tree death. In this study, we characterize drought-induced mortality affecting two Scots pine (Pinus sylvestris) sites (Prades and Arcalís) located in the North Eastern Iberian Peninsula. Co-occurring now-dead and living Scots pine trees were sampled and their wood anatomical features were measured and compared. We aimed to detect differences in anatomical features between living and dead trees, and to infer past physiological performances that might have determined their subsequent death or survival. Now-dead trees showed lower tracheid and resin duct production, and smaller radial lumen diameters than co-occurring living trees. At the more xeric Prades site, these anatomical differences were larger and chronic, i.e. were observed over the three studied decades, whilst they were less pronounced at the other, more mesic Arcalís site, where tree mortality episodes were more recent. This indicates that dead trees’ hydraulic conductivity was severely affected and that carbon investment in xylem formation and resin duct production was constrained prior to tree death. Our findings show that both hydraulic deterioration and low carbon allocation to xylem formation were associated to drought-induced mortality in Scots pine. Nevertheless, the temporal dynamics of these processes differed between populations as a function of site climatic conditions. 相似文献980.
Nancy Babio Estefanía Toledo Ramón Estruch Emilio Ros Miguel A. Martínez-González Olga Casta?er Mònica Bulló Dolores Corella Fernando Arós Enrique Gómez-Gracia Valentina Ruiz-Gutiérrez Miquel Fiol José Lapetra Rosa M. Lamuela-Raventos Lluís Serra-Majem Xavier Pintó Josep Basora José V. Sorlí Jordi Salas-Salvadó 《CMAJ》2014,186(17):E649-E657