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... Both factors (increase in temperature and decrease in solar radiation) would reduce the panicle initiation, anthesis and maturity days altogether. The obtained results showed that a decrease in phenological days was accompanied by a reduction in rice yield [56]. This can be inferred that, when the duration of the crop growth period (phenological days) decreased, crops would not require water for those days that were eliminated from the growth period. ...
... This can be inferred that, when the duration of the crop growth period (phenological days) decreased, crops would not require water for those days that were eliminated from the growth period. The decrease in phenological days would also result in a shorter period for crop biomass accumulation and prevent proper growth, and thus will decrease the yield as well [56,57]. It can be also inferred that a significant decrease in rice phenology can influence the water demand and reduce the rice yield. ...
... It can also be seen that panicle initiation days increased for all the scenarios during 2020-2029; the growing degree days (GDD) for this stage was possibly not affected by an increase in temperature and solar radiation. Furthermore, all the growth stages (panicle initiation, anthesis and maturity) during each decade from 2020-2059 also validate the reasoning of an adverse impact of temperature and solar radiation on rice growth and development [56,65]. ...
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Climate change is a well-known phenomenon all over the globe. The influence of projected climate change on agricultural production, either positive or negative, can be assessed for various locations. The present study was conducted to investigate the impact of projected climate change on rice's production, water demand and phenology for the state of Bihar, India. Furthermore, this study assessed the irrigation water requirement to increase the rice production by 60%, for the existing current climate scenario and all the four IPCC climate change scenarios (RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5) by the 2050s (2050-2059). Various management practices were used as adaptation methods to analyze the requirement of irrigation water for a 60% increase in rice production. The climate data obtained from the four General Circulation Models (GCMs) (bcc_csm1.1, csiro_mk3_6_0, ipsl_cm5a_mr and miroc_miroc5) were used in the crop growth model, with the Decision Support System for Agrotechnology Transfer (DSSAT) used to simulate the rice yield, phenological days and water demand under all four climate change scenarios. The results obtained from the CERES-Rice model in the DSSAT, corresponding to all four GCMs, were ensembled together to obtain the overall change in yield, phenology and water demand for the 10 years from 2020 to 2059. We investigated several strategies: increasing the rice yield by 60% with current agronomic practice; increasing the yield by 60% with conservation agricultural practice; and increasing the rice yield by 30% with current agronomic practice as well as with conservation agricultural practices (assuming that the other 30% increase in yield would be achieved by reducing post-harvest losses by 30%). The average increase in precipitation between 2020 and 2059 was observed to be 5.23%, 13.96%, 9.30% and 9.29%, respectively, for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5. The decrease in yield during the 2050s, from the baseline period (1980-2004), was observed to be 2.94%, 3.87%, 4.02% and 5.84% for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, respectively. The irrigation requirement was predicted to increase by a range of 39% to 45% for a 60% increase in yield using the current agronomic practice in the current climate scenario by the 2050s, for all four climate change scenarios from the baseline period (1980-2004). We found that if we combine both conservation agriculture and removal of 30% of the post-harvest losses, the irrigation requirement would be reduced by 26% (45 to 19%), 20% (44 to 24%), 21% (43 to 22%), 22% (39 to 17%) and 20% (41 to 21%) with the current climate scenarios, namely, the RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5 conditions, respectively. This combination of conservation practices suggests that the irrigation water requirement can be reduced by a large percentage, even if we produce 60% more food under the projected climate change conditions.
... Around 35% of the world's olive oil is produced in Spain (1,251,300 t), the world's biggest producer (Consejo Oleícola Internacional, 2018), of which~75% is produced in Andalusia, its southernmost region (Ministerio de Agricultura, Pesca y Alimentación, 2018). Although olive productivity is at present partly controlled by irrigation (Palese et al., 2010), several previous studies have demonstrated that olive crops are greatly affected by weather variability (Osborne et al., 2001;Oteros et al., 2013), principally changes in precipitation and temperature (Galán et al., 2001(Galán et al., , 2005(Galán et al., , 2008Mancuso et al., 2002;Oteros et al., 2013) and responding to recent climate warming (Osborne et al., 2001;Galán et al., 2005). ...
... Around 35% of the world's olive oil is produced in Spain (1,251,300 t), the world's biggest producer (Consejo Oleícola Internacional, 2018), of which~75% is produced in Andalusia, its southernmost region (Ministerio de Agricultura, Pesca y Alimentación, 2018). Although olive productivity is at present partly controlled by irrigation (Palese et al., 2010), several previous studies have demonstrated that olive crops are greatly affected by weather variability (Osborne et al., 2001;Oteros et al., 2013), principally changes in precipitation and temperature (Galán et al., 2001(Galán et al., , 2005(Galán et al., , 2008Mancuso et al., 2002;Oteros et al., 2013) and responding to recent climate warming (Osborne et al., 2001;Galán et al., 2005). ...
... The impact of temperature variability is also a significant factor in olive oil production (Galán et al., 2005(Galán et al., , 2008Oteros et al., 2013). Previous studies on Olea response to long-term climate change demonstrated that this tree declines during dry and colder periods across the Mediterranean region (Martín-Puertas et al., 2009;Carrión et al., 2010;Pérez-Sanz et al., 2013). ...
... Other drivers reported in literature are genotypic diversity [13], latitude [14], topography [6,15,16] and rainfall [9,15]. However, it is worth noting that in a multi-environment trial [13], the genotype by environment interaction explained less than 10% of the observed variance in flowering dates, with genotypic diversity mostly affecting the quality of flowering. ...
... Other drivers reported in literature are genotypic diversity [13], latitude [14], topography [6,15,16] and rainfall [9,15]. However, it is worth noting that in a multi-environment trial [13], the genotype by environment interaction explained less than 10% of the observed variance in flowering dates, with genotypic diversity mostly affecting the quality of flowering. ...
... Our approach was based on two underlying principles: First, the use of data collected under heterogeneous environmental conditions and from different olive varieties to overcome many local peculiarities to scale up the work from field to large scale, and second, the exploration of all the possible phases to identify those in which the calibrations of DRs, including the base temperature, which is usually extracted from literature (e.g., [4,15,19]), were better performing. By applying these principles, our approach allowed us to minimize the residual variability from drivers other than temperature, as those attributable to genetic diversity, microclimate, the proximity of the meteorological stations, and farming practices. ...
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The calibration of a reliable phenological model for olive grown in areas characterized by great environmental heterogeneity, like Italy, where many varieties exist, is challenging and often suffers from a lack of observations, especially on budbreak. In this study, we used a database encompassing many phenological events from different olive varieties, years, and sites scattered all over Italy to identify the phases in which site-enlarged developmental rates can be well regressed against air temperature (Developmental Rate function, DR) by testing both linear and nonlinear functions. A K-fold cross-validation (KfCV) was carried out to evaluate the ability of DR functions to predict phenological development. The cross-validation showed that the phases ranging from budbreak (BBCH 01 and 07) to flowering (BBCH 61 and 65) and from the beginning of flowering (BBCH 51) to flowering can be simulated with high accuracy (r 2 = 0.93-0.96; RMSE = 3.9-6.6 days) with no appreciable difference among linear and nonlinear functions. Thus, the resulting DRs represent a simple yet reliable tool for regional phenological simulations for these phases in Italy, paving the way for a reverse modeling approach aimed at reconstructing the budbreak dates. By contrast, and despite a large number of phases explored, no appreciable results were obtained on other phases, suggesting possible interplays of different drivers that need to be further investigated .
... These authors showed that warmer temperature affected floral differentiation and led to a reduction in fruit set. These findings supported previous results suggesting earlier flowering dates as a consequence of faster completed development of flower structures (García-Mozo et al., 2010;Orlandi et al., 2010;Oteros et al., 2013;Aguilera et al., 2015). However, most of these studies were performed using a pollen-monitoring methodology that involved the capture of pollen emitted and dispersed into the atmosphere. ...
... The lack of chilling resulted in abnormal patterns of phenological stages and development of olive cultivars with advanced flowering date as observed during 2007, 2010 and 2014. These findings supported previous results suggesting earlier flowering dates of olive tree with warm conditions (García-Mozo et al., 2010;Orlandi et al., 2010;Oteros et al., 2013;Aguilera et al., 2015). However, most of these studies have been performed by using a pollen-monitoring methodology that cover large scale plantation regardless of used varieties. ...
Article
Climate changes are expected to have a great and negative impact on agriculture in Mediterranean region. In this region, olive industry plays a key role at regional and national level as in Tunisia. With expected increasing temperature, the impact of climate change on the phonological behavior of the olive cultivars was evaluated in the main production region in central Tunisia (34°56′08″N, 10°36′54″E) during 2005–2015.The relationships between the budburst and flowering dates and climatic variations were investigated for the main local (Chemlali, Chemchali, Oueslati and Chetoui) and foreign (Koroneiki and Arbequina) olive cultivars to state their adaptability to warm area climate. Chilling was computed as chill portions (CP) from October to budburst using Dynamic Model, whereas heat accumulation was quantified as growing degree hours (GDH) from budburst to the beginning of flowering. As a result, variable budburst and flowering dates of olive cultivars were obtained related to the climatic conditions occurring each year. ‘Chemlali’ and ‘Arbequina’ seemed to be the precocious cultivars with an average budburst date of DOY-71 (March-12), whereas ‘Chemchali’ and ‘Koroneiki’ were the most late with an average budburst dates of DOY-80 and DOY-81 (March21-22). The beginning of flowering occurred from DOY-93 (3-April) to DOY-126 (6-May), where ‘Chemchali’ seemed, also, to be the latest one. Winter chill impacted significantly olive flowering with a positive correlation between flowering date and chill accumulation. A tendency for advancing flowering of local and foreign olive cultivars occurred subsequent a lack of winter chill. Trends for increasing heat accumulation with increasing chilling were observed in exponential manner to achieve flowering of olive cultivars. Moreover, winter temperature, appeared to be one of the most important variables in determining flowering time of olive cultivars mainly when quarterly and monthly mean temperatures were considered. In conclusion, this investigation is the first database concerning olive cultivars originated from different geographical areas and grown in a warm area. It revealed that olive cultivars behaved differently with contrasting chilling and heat accumulations and in years with extreme climatic conditions. It will be more interesting to consider the important genetic diversity of olive tree to mitigate the harmful effect of increasing temperature in the future.
... The short-term predictive modelling in olive pollen is very complex and implies plenty of difficulties because (i) yearly flower production of olive trees depends on the environmental conditions during the current and previous year, as well as on the internal hormonal and biochemical balance of the plant ; and (ii) the variability associated to local features such as the topography or altitude on the succession of olive flowering characteristics (Aguilera and Ruiz Valenzuela 2012;Oteros et al. 2013;Rojo and Perez-Badia 2014). In addition, a strong variability among years and also in consecutive days in the maximum pollen concentration has been reported (Fernandez-Rodriguez et al. 2016a;Perez-Badia et al. 2013). ...
... The regional model using the pool dataset allows to generate more general forecasting models and hence represent better the overall olive crops in the Community of Madrid. Oteros et al. (2013) supported that local particularities could improve the predictions for particular locations, although the applicability of the model shrinks. ...
Article
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Air pollution in large cities produces numerous diseases and even millions of deaths annually according to the World Health Organization. Pollen exposure is related to allergic diseases, which makes its prediction a valuable tool to assess the risk level to aeroallergens. However, airborne pollen concentrations are difficult to predict due to the inherent complexity of the relationships among both biotic and environmental variables. In this work, a stochastic approach based on supervised machine learning algorithms was performed to forecast the daily Olea pollen concentrations in the Community of Madrid, central Spain, from 1993 to 2018. Firstly, individual Light Gradient Boosting Machine (LightGBM) and artificial neural network (ANN) models were applied to predict the day of the year (DOY) when the peak of the pollen season occurs, resulting the estimated average peak date 149.1 ± 9.3 and 150.1 ± 10.8 DOY for LightGBM and ANN, respectively, close to the observed value (148.8 ± 9.8). Secondly, the daily pollen concentrations during the entire pollen season have been calculated using an ensemble of two-step GAM followed by LightGBM and ANN. The results of the prediction of daily pollen concentrations showed a coefficient of determination (r2) above 0.75 (goodness of the model following cross-validation). The predictors included in the ensemble models were meteorological variables, phenological metrics, specific site-characteristics, and preceding pollen concentrations. The models are state-of-the-art in machine learning and their potential has been shown to be used and deployed to understand and to predict the pollen risk levels during the main olive pollen season.
... The reproductive stages were observed within a marked 50×50 cm square at 1.5 m height from the ground on the West side of each tree. As recommended by Oteros et al. (2013), the reproductive observations were repeated every 7 days from the last week of July until the first week of November (i.e., mid-winter to mid-spring) and documented with a photograph of each square. A square was divided into quarters, and each quarter was visually assigned a stage value (BBCH 50-69). ...
... Inflorescence bud opening (BBCH 53) is the first visually observed reproductive stage in olive. Under Mediterranean Basin conditions, several studies have shown earlier inflorescence development at lower altitudes (Rojo and Pérez-Badia, 2014) or for relatively warm locations or years (Elloumi et al., 2020;Oteros et al., 2013;Rojo and Pérez-Badia, 2015). In our study, a large range between the earliest and the latest C x L combinations was observed (approx. ...
Article
Detailed spring phenology studies are scarce in olive trees growing in non-Mediterranean climates despite crop expansion into new regions in the last few decades. Additionally, the vegetative phenology of olive trees has been little examined under any climate conditions. Thus, the aims of this study were to: (i) evaluate the timing of spring reproductive and vegetative phenological stages and their overlap for several olive cultivars growing under different air temperatures along a latitudinal gradient (29°–33° S) that included a range of altitudes (450–1,250 m asl) in western Argentina; and (ii) assess the potential relationships between the length (i.e., days) of some phenological phases and air temperature. All observations were performed during two growing seasons (2018–2019, 2019–2020). The temperature difference across the latitudinal-altitudinal gradient during the winter and early spring periods was between 4.2 and 6.0 °C. The separation of the first leaves (BBCH 11) most often occurred after inflorescence bud opening (BBCH 53) at warmer low latitude locations, but before BBCH 53 at cooler high latitude sites. A difference of 26 days in full flowering was found between extreme locations when considering both seasons. The variability of the reproductive stage dates was explained mostly by environmentally-related factors including location (71.7–95.2%) and season (0–18.1%) rather than by cultivar (2.8–6.6%). Nevertheless, cultivar responses did appear to depend on the climate conditions at different locations and growing seasons. The length of the inflorescence emergence phase (BBCH 53–60) decreased by 4.3 days/ °C as the mean air temperature during the phase increased. In contrast, the flowering phase length (BBCH 60–69) decreased with increasing mean air temperature during the phase up to 23 ºC, but increased above that temperature. These results should be useful for better timing of management practices and the development of phenological models that include non-Mediterranean environments.
... When an observer is presented with a group of individuals born at the same time, she may conclude that the individuals appear to be at somewhat different physiological stages, and continue to mature differently at any chronological age. For example, the onset of flowering in a grove may vary by several days [23] depending on the tree, or even vary by several weeks, depending on the species [24]. ...
... This equation is exact, and valid for both mobile and immobile cells, c.f. Eq. (23). Due to the last term, this equation is not closed. ...
Article
A model of physiological age, accompanied by non-linear diffusion in space, is studied analytically and numerically, and is shown to develop non-stationary traveling population waves. A window of intermediate growth rates is found where collective supercycles are formed from individual (stochastic) life cycles. Supercycle periods can be considerably different (larger or smaller) than the average longevities of contributing individuals, while the time-averaged spatial expansion rate has a local maximum in the supercycling mode. A method of adiabatic similarity solutions is used to derive dependencies of the solution parameters on source and sink inhomogeneities, and obtain closed coupled dynamic equations for the age structure, leading and trailing fronts. Analytical results are compared with numerically computed similarity and full solutions for several types of population waves. We discuss possible model applications to development of lichen thallus, multi-year patterns of agricultural crop yields and autocorrelation of locust swarming.
... Moreover, Tanasijevic et al. [74] found similar spatial expansion of the olive tree cultivation zone to the north, but this research does not include Bulgaria and Romania. Finally, Oteros et al. [75] found that the altitude plays a vital role in the phenological related climatic parameters of the olive trees. The findings of this study are corroborated to other research regarding olive cultivation in the same area. ...
... Moreover, Tanasijevic et al. [74] found similar spatial expansion of the olive tree cultivation zone to the north, but this research does not include Bulgaria and Romania. Finally, Oteros et al. [75] found that the altitude plays a vital role in the phenological related climatic parameters of the olive trees. ...
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Olive and vine cultivations are two of the most important crops in Europe, yielding high quality and value food products. The climate change over the Balkans may elevate the agroecological pressure for the established crops and shift their cultivations areas. One of the widely-used agroclimatic indices is the growing degree days (GDD) which accumulates the necessary thermal units for the selected crops. Despite the advances on the agroclimatic research, there are few available methods for spatiotemporal estimation of this useful index. So, this research is focused on the construction of simple and reliable equations for the calculation and projection of olive and vine cultivations’ GDD over the Balkans. The models’ input parameters are the time, the altitude, the distance from the seashore, and the latitude. Its assembly is made by the extracted spatial data, combined with the Agri4Cast dataset for the period of 1980 to 2018 incorporating the regional climate change trend. The results indicate that the most influential parameter is the time, followed by the latitude, for both cultivations. According to the projections, as quantified by GDD, a vast sprawl of olive and vine cultivation areas will have been formed to the northern parts of the studied area. To be more precise, the viticulture could expand spatially by 28.8% (of the Balkans area) by 2040, and by 15.1% to 2060, when the olive cultivations’ area could sprawl 23.9% by 2040 and 20.3% by 2060.
... Observations were made at the four azimuthal directions of each tree, every 3 days after the opening of the first flowers in the field. A simplified phenological scoring scale with five apparent scoring levels was developed after the ten levels proposed by Oteros et al. (2013). The macroscopical scoring levels are: ...
... (1) only swelled buds are observed, (2) open flowers are less than the swelled buds, (3) open flowers are more than the swelled buds (> 50% of the canopy, full flowering), (4) flowers appear a brown pistil and petals are falling, (5) first olive fruits observed (end of flowering, fruit set). Olive tree flowering was recorded on the day that at least 50% of the flowers were open (Oteros et al., 2013). ...
Article
Agricultural water demand in the Mediterranean region is expected to increase due to climate change. The application of deficit irrigation practices may improve the efficiency of water use in orchards, by accounting for changes in environmental conditions and in the tree growth. The main goal of this study was to improve our understanding on the effect of deficit irrigation on physiology, morphology, yield, and oil quality of ‘Koroneiki’ olive trees. The effect of two deficit irrigation treatments and three harvest dates on olive yield and oil quality were investigated in a 17-year old, low-density ‘Koroneiki’ orchard in Cyprus, during a high crop load year. For the sustained deficit irrigation (SDI) treatment 70% ETc was applied over the irrigated period, while the regulated deficit irrigation (RDI) consisted of 70% ETc during water-stress sensitive growth stages (shoot growth, flowering, bud initiation) and 35% ETc during water-stress tolerant growth stages (pit hardening, oil accumulation). Environmental conditions and volumetric soil water content of the 70-cm rootzone were monitored. A Kc of 0.37 was derived for the irrigated period from daily water balance computations, excluding rain days. No significant effects of the two irrigation treatments were found on morphology, physiology, fruit yield and oil quality. Midday stem water potential reached − 4 MPa in September as a result of increasing fruit load. Leaf conductance ranged between 65 and 228 mmol m⁻²s⁻¹, with highest values obtained under high soil water conditions and a vapour pressure deficit of 3.6 kPa. Yields were approximately 9 tons ha⁻¹ in both irrigation treatments while water productivity was 1.4 and 1.0 kg oil m⁻³ irrigation water in SDI and RDI, respectively. Maximum phenolic content was found in early December, reaching on average 202 mg kg⁻¹ oil in both irrigation treatments. Overall, irrigation water use in RDI was 32% less than in SDI, whereas oil quality was only affected by the harvest date.
... Some studies also point other factors closely related to temperature, like slope orientation or altitude, as relevant driver of flowering phenology e.g. (Oteros et al., 2013c) ...
Article
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Pollen respiratory allergies have been increasing in prevalence over the last two decades, partly as the result of the impact of climate change. For many allergenic trees, grass and weed species, increased pollen production and prolonged pollination period result in long-term increased abundance of pollen allergens in the atmosphere; earlier shifts of airborne pollen grains and prolonged exposure to respiratory allergens with important health effects on allergic individuals. The aim of this review paper was to investigate the impact of climate change and meteorological factors on pollen season indicators with a special focus on the main allergenic taxa worldwide. Main variables influencing flowering phenology such as location, climatic and meteorological parameters were identified, discussed and substantiated by published literature. Temperature, solar radiation, humidity, rainfall, wind speed and direction were identified among the most important meteorological parameters affecting the fluctuations of annual concentrations of allergenic airborne pollen grains. Although notable variations were observed according to allergenic species and studied geographical areas, temperature appeared to be the most important climatic parameter affecting flowering phenology and pollen season indicators, especially in tree species. Rising carbon dioxide levels also result in increased plant biomass, increased flowering intensity and pollen production in several tree, grass and weed allergenic species. In the light of this review, there is a growing body of evidence supporting the effect of climate change on the flowering phenology and pollen season indicators of a substantial number of allergenic ornamental and invasive plant species.
... Entretanto, a temperatura é ainda mais influente no que diz respeito às alterações fenológicas das espécies vegetais em um determinado local (HIDALGO-GAVEZ et al., 2018). Este elemento determina a taxa ou a velocidade da biossíntese e dos processos metabólicos vegetais (OTEROS et al., 2013). Diferentes pesquisas desenvolvidas ao redor do mundo indicam que a temperatura controla a resposta fenológica das espécies vegetais (FONTANA et al., 2018;RICHARDSON et al., 2018). ...
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Objetivou-se com este trabalho avaliar a fenologia em função da temperatura do ar e a qualidade de frutos de acessos de Physalis spp. visando sua potencial utilização em programas de melhoramento genético. O experimento foi conduzido na Universidade Federal da Fronteira Sul - campus Chapecó, SC. O delineamento experimental foi inteiramente casualizado, com 67 acessos de Physalis spp. Foram avaliados componenetes fenológicos em três períodos diferentes, observando o (1) número de dias decorridos desde a emissão do botão floral à antese, (2) dias decorridos da antese à fixação de frutos e (3) número de dias para a emissão de nós. Com os dados de temperatura do ar, foi calculada a soma térmica (GD) necessária para alcançar o início de cada evento fenológico. No que tange às variáveis produtivas, foram analisadas a massa de fruto com cálice (g), massa de fruto sem cálice (g), sólidos solúveis (°Brix) e o volume médio de fruto (cm3). Os dados fenológicos foram submetidos a análises descritivas enquanto que os dados produtivos, à Análise de Componentes Principais (PCA – Principal Components Analysis). O primeiro período de observação (06 a 30 de janeiro) resultou em menor número de dias necessários para o aparecimento de nós e para atingir a frutificação à partir da floração. A presença do cálice nos frutos aumentou sensivelmente a massa média do fruto em aproximadamente 0,45 g. A temperatura influencia o ciclo fenológico dos 67 acessos de Physalis os quais, por sua vez, se diferenciam no que diz respeito à qualidade de frutos.
... In areas with marked seasons, especially in regions that have dry seasons, such as the Mediterranean, evaporative demands vary considerably throughout the year and plants must constantly acclimatize: it is thus interesting in these cases to understand how plants transpire over a complete annual cycle [21]. The Eucalyptus genus stands out as one of the most widely planted exotic genera in tropical and Mediterranean climate regions and, together with Pinus, represents 98% of the world's forestry production [22,23]. ...
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Background and Objectives. Water stress is a major constraining factor of Eucalyptus plantations’ growth. Within a genetic improvement program, the selection of genotypes that improve drought resistance would help to improve productivity and to expand plantations. Leaf characteristics, among others, are important factors to consider when evaluating drought resistance evaluation, as well as the clone’s ability to modify leaf properties (e.g., stomatal density (d) and size, relative water content at the time of stomatal closure (RWCc), cuticular transpiration (Ec), specific leaf area (SLA)) according to growing conditions. Therefore, this study aimed at analyzing these properties in nursery plants of nine high-productivity Eucalyptus clones. Material and Methods: Five Eucalyptus globulus Labill. clones and four hybrids clones (Eucalyptus urophylla S.T. Blake Eucalyptus grandis W. Hill ex Maiden, 12€; Eucalyptus urograndis × E. globulus, HE; Eucalyptus dunnii Maiden–E. grandis E. globulus, HG; Eucalyptus saligna Sm. × Eucalyptus maidenii F. Muell., HI) were studied. Several parameters relating to the aforementioned leaf traits were evaluated for 2.5 years. Results: Significant differences in stomatal d and size, RWCc, Ec, and SLA among clones (p < 0.001) and according to the dates (p < 0.001) were obtained. Each clone varied seasonally the characteristics of its new developing leaves to acclimatize to the growth conditions. The pore opening surface potential (i.e., the stomatal d × size) did not affect transpiration rates with full open stomata, so the water transpired under these conditions might depend on other leaf factors. The clones HE, HG, and 12€ were the ones that differed the most from the drought resistant E. globulus control clone (C14). Those three clones showed lower leaf epidermis impermeability (HE, HG, 12€), higher SLA (12€, HG), and lower stomatal control under moderate water stress (HE, HG) not being, therefore, good candidates to be selected for drought resistance, at least for these measured traits. Conclusions: These parameters can be incorporated into genetic selection and breeding programs, especially Ec, SLA, RWCc, and stomatal control under moderate water stress.
... Bud formation, floral induction and rest take place in the first season. Inflorescences, flowering, and fruit growth and development take place in the second season and conclude at maturity (Oteros et al., 2013;Trentacoste et al., 2017); however, according to the region studied, flowering usually appears in the branches that are growing, but not in those that grew the previous year; that is why the biennial cycle does not occur; additionally, there is evidence that trees can have two or more flowerings and harvests, depending on the precipitation (García-Molano et al., 2012). ...
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The olive tree has expanded to several countries because of its easy adaptation to difficult edapho-climatic zones and high culinary and medicinal interest given the physicochemical composition of its fruit, including Argentina, Chile, Peru and Mexico, which have similar soil and climate conditions to the Mediterranean, where the phenological stages correspond to clearly distinct climatic seasons. However, in the Alto Ricaurte region in Boyaca, Colombia, olives do not set because of the tropical climate conditions. Because of these characteristics, the behavior of some trees, sown 4 to 30 years ago in this region, were evaluated. The tem-perature and precipitation were measured, and 20 branches were selected per tree, which were monitored from appearance until development; the polar and equatorial diameter of the fruits were measured until reaching maturation. A fruit and oil analysis was carried out with olives harvested in two maturation states in 2017. The temperature had a positive correlation with the phenological stages in a range of 11 to 29°C, which directly influenced the development of inflorescences and their performance. In the same year, there were two or more blooms with different intervals, where the same branch had inflorescences, flowers, freshly filled fruits and other mature fruits. As for the characteristics of the fruit and the oil, it was evident that the content of fatty acids was within the parameters required by the International Olive Council.
... On the other hand, a marked influence of environment conditions on olive flowering phenology has also been noted and reported by Orlandi et al. (2009), and suggested as an indicator of climate change (Osborne et al. 2000). Different environmental factors, as air temperature and water availability, have been reported to influence olive tree flowering phenology (Garcia-Mozo et al. 2015;Orlandi et al. 2009;Aybar et al. 2015;Oteros et al. 2013). With respect to flower quality, extreme environments such as high temperatures and water stress have been shown to negatively affect olive flower quality components such as pistil abortion (formation of imperfect, staminate flowers), ovary size, and ovule development Rapoport 2014;Benlloch-Gonzalez et al. 2018). ...
Article
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Flowering is one of the most critical processes in the reproductive phenology in fruit trees including olive. Under Mediterranean climate, olive flowering period normally occurs from early to late spring. Therefore, flowering time could be affected by environmental conditions such as water availability and temperature, thus influencing flower quality as well. Previous works have demonstrated the effect of genotype and environment on olive flowering, but those factors have never been compared in a single study nor their interaction evaluated. In the present work, we used a multi-environment trial established in four different agro-climatic conditions of Andalucía, Southern Spain, to test the genetic and environmental influences on flowering timing (flowering period, full bloom period, and full bloom date) and flower quality (flower number, perfect flower number and perfect flower percentage). Most of the variability found for flowering phenology parameters was due to environmental influence. On the contrary, for flowering quality parameters, most of the variability was of a genetic nature. In all cases, the genotype-environment interaction was significant. In this sense, the genotype by environment effects biplot model used to analyse the interaction showed that most of the genotypes evaluated have low stability for most of the parameters evaluated, except ‘Picual’ for flowering phenology parameters and ‘Koroneiki’ for quality. This emphasize the benefits of multi-environment trials on olive in order to select the best genotypes adapted to different environments and as a tool to face the future variability of environmental conditions caused by the climate-warming scenario. In conclusion, multi-environment trials allowed to efficiently quantify the effects of genetic and environmental factors and of their interaction on flowering phenology and on flower quality in olive.
... The results of this analysis show that the vegetation types in this region that are particular to Qiangtang Plateau (i.e., grasslands, barren lands, and desert) exhibit limited differences in spectra, image color, and texture which can easily result in confusions over their classification. The Qiangtang Plateau environment itself also exerts a significant impact on LC data classifications as the vegetation growing season here is mostly restricted to the summer and is much shorter than in low altitude areas (Oteros et al., 2013;. This means that it is difficult to monitor vegetation types outside of the short growing season and images within LC datasets may have been captured at different times of the year. ...
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We analyzed the spatial local accuracy of land cover (LC) datasets for the Qiang-tang Plateau, High Asia, incorporating 923 field sampling points and seven LC compilations including the International Geosphere Biosphere Programme Data and Information System (IGBPDIS), Global Land cover mapping at 30 m resolution (GlobeLand30), MODIS Land Cover Type product (MCD12Q1), Climate Change Initiative Land Cover (CCI-LC), Global Land Cover 2000 (GLC2000), University of Maryland (UMD), and GlobCover 2009 (Glob-Cover). We initially compared resultant similarities and differences in both area and spatial patterns and analyzed inherent relationships with data sources. We then applied a geographically weighted regression (GWR) approach to predict local accuracy variation. The results of this study reveal that distinct differences, even inverse time series trends, in LC data between CCI-LC and MCD12Q1 were present between 2001 and 2015, with the exception of category areal discordance between the seven datasets. We also show a series of evident discrepancies amongst the LC datasets sampled here in terms of spatial patterns, that is, high spatial congruence is mainly seen in the homogeneous southeastern region of the study area while a low degree of spatial congruence is widely distributed across heterogeneous northwestern and northeastern regions. The overall combined spatial accuracy of the seven LC datasets considered here is less than 70%, and the GlobeLand30 and CCI-LC datasets exhibit higher local accuracy than their counterparts, yielding maximum overall accuracy (OA) values of 77.39% and 61.43%, respectively. Finally, 5.63% of this area is characterized by both high assessment and accuracy (HH) values, mainly located in central and eastern regions of the Qiangtang Plateau, while most low accuracy regions are found in northern, northeastern, and western regions.
... It is often necessary to obtain the data with a time resolution bigger than that monitored. Downscaling of independent variables is necessary in areas like field phenology ( Oteros et al., 2013), meteorology ( Young et al., 1998) or even for pollen data ). Modelling is also necessary when we need to perform projections of conditions during unmonitored periods in the both directions: past and future (Graumlich, 1987;Radic et al., 2014). ...
... Additionally, experience has shown that other factors within the same orchard can alter the beginning of the flowering phase up to multiple days [10]. These factors are more difficult to model, such as the age and general condition of trees or the microlocation (e.g., facing the east or having a higher altitude). ...
Article
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The importance of monitoring and modelling the impact of climate change on crop phenology in a given ecosystem is ever-growing. For example, these procedures are useful when planning various processes that are important for plant protection. In order to proactively monitor the olive (Olea europaea)'s phenological response to changing environmental conditions, it is proposed to monitor the olive orchard with moving or stationary cameras, and to apply deep learning algorithms to track the timing of particular phenophases. The experiment conducted for this research showed that hardly perceivable transitions in phenophases can be accurately observed and detected, which is a presupposition for the effective implementation of integrated pest management (IPM). A number of different architectures and feature extraction approaches were compared. Ultimately, using a custom deep network and data augmentation technique during the deployment phase resulted in a fivefold cross-validation classification accuracy of 0.9720 ± 0.0057. This leads to the conclusion that a relatively simple custom network can prove to be the best solution for a specific problem, compared to more complex and very deep architectures.
... Partial least square (PLS) is a useful statistical tool to relate climatic factors with phenological events, which has showed a great environmental effect. This approach has been previously followed mainly to associate daily average temperature with phenological events related to flowering (Luedeling and Gassner, 2012;Luedeling et al., 2013;Oteros et al., 2013). This information may be critical to forecast the possible phenological behaviours caused by temperature variation (El Yaacoubi et al., 2014), particularly due to climate change. ...
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The pattern of olive oil accumulation is of paramount importance in olive because its influence in determining final oil yield and optimal harvesting date. In this work, we have evaluated the genetic and environment influence on the olive oil accumulation pattern. For that purpose, a set of cultivars and breeding selections planted in a multi-environment trial was evaluated in two consecutive harvest seasons. Significant effect of the environment, genotype and their interaction were observed for the maximum oil content reached and the rate of oil accumulation. On the contrary, the date of maximum oil content seems to depend only on the environment. The two breeding selections evaluated showed, in general, high stability and adaptability in oil accumulation parameters. Among the potential environmental factors that could affect oil accumulation, PLS analysis suggests that temperature could play a determinant environmental effect in the oil accumulation parameters tested in this study. These results underline the relevance of using multi-environment trials for adequate characterization of genotypes showing either good behaviour in variable environments or only under specific environmental conditions.
... Moreover, phenology can be considered as an evaluation tool for measuring viticulture aptitude as a function of climatic behavior for crop growth (Jones and Davis, 2000). Studying and modeling phenology is widespread for all cultivated species, such as pome fruits (Darbyshire et al., 2013), peaches (Miranda et al., 2013), olives (Aguilera et al., 2014;Oteros et al., 2013), apricots (Andreini et al., 2014), and pistachios (Zhang et al., 2015) as well as grapevines (Caffarra and Eccel, 2011;Fila et al., 2014;Ortega-Farías et al., 2002;Parker, 2012;Verdugo-Vásquez et al., 2017;Zapata et al., 2015). ...
Article
A study was carried out to develop and validate models that simulate grapevine phenology of the cultivars Cabernet Sauvignon, Merlot, Chardonnay and Sauvignon Blanc growing under Mediterranean climate conditions. In this study, phenology models were developed using a monomolecular equation, where the dependent and independent variables were the Eichhorn and Lorenz (1977) phenological (ELP) scale modified by Coombe (1995) and growing degree days (GDD), respectively. From the beginning of budburst to harvest, measurements of ELP and GDD were collected weekly from 49 commercial vineyards located in the Maule Region, Chile (between 34° 40′ and 36° 33′ south latitude, 72° 38′ and 70° 18′ west longitude). The results showed significant nonlinear correlations between the GDD and ELP scale, with values of R2 ranging between 0.95 and 0.98. Moreover, the validation indicated that the phenological models were able to predict the ELP scale with values of the root mean square error (RMSE), mean absolute error (MAE) and agreement index (dr) raging between 1.6–3.0, 1.3–2.5 and 88–89%, respectively. Major disagreements were observed near the harvest stage (ELP=40) which mainly depends on farm management.
... It is often necessary to obtain the data with a time resolution bigger than that monitored. Downscaling of independent variables is necessary in areas like field phenology (Oteros et al., 2013), meteorology (Young et al., 1998) or even for pollen data . Modelling is also necessary when we need to perform projections of conditions during unmonitored periods in the both directions: past and future (Graumlich, 1987;Radic et al., 2014). ...
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Background: Pollen is naturally emitted but it is also considered as an anthropogenic pollutant. Pollen concentrations are relevant for health, crop sciences and monitoring climate change, among others. Nevertheless, pollen is often insufficiently monitored resulting in a lack of data. Thus, modelling of pollen concentrations for unmonitored areas is necessary. The aim of this study was to develop an automatic system for calculating daily pollen concentrations at sites without explicit pollen monitoring. Method: We used data from 14 pollen taxa collected during 2015 at 26 stations distributed across Bavaria, Germany. The proposed system was based on the Kriging interpolation method to model pollen concentrations for unmonitored areas, in combination with regression of environmental parameters. The new method also took into account weather effects on daily pollen concentrations. Results: An automatic system was developed for calculating pollen concentrations at any location of the county. The results were displayed as daily pollen concentrations per m3 in maps of 1km2 resolution. The models are trained automatically for every day by using the pollen and weather inputs. Automatic inputs will increase the usability of the model. In 50% of the cases, Gaussian Kriging was selected as the optimal model. A R2 of 0.5 is reached in external validation without considering the effect of the weather. A R2 of 0.7 is reached after considering the effect of daily weather parameters. Conclusions: A fully automatic pollen network (ePIN) was built in Bavaria during 2018 that delivers data on-line without delay. The proposed method allows for a comparably small number of automatic devices per study area, but still providing information on pollen for any location in the study area.
... La fase fenológica del cultivo es la relación que existe entre las diferentes variables meteorológicas como temperatura, lluvia (necesidades hídricas del cultivo) y el desarrollo de un cultivo determinado (Oteros et al., 2013). ...
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Las oscilaciones atmosféricas de baja (OBF) (AMO, PDO, ONI) y alta frecuencia (OAF) (MJO) en Mesoamérica determinan el comportamiento de las precipitaciones y el viento. Se investigó la relación entre los dichos campos con estaciones de más de 70 años de datos en Mesoamérica y se relacionaron con la oscilación decadal del Pacífico (PDO) y la oscilación multidecadal del Atlántico (AMO), determinándose que tienen influencia determinante en Mesoamérica para generar cambios dentro de la variabilidad climática en períodos de años décadas. Cuando la AMO y PDO estuvieron en sus fases positivas (+) (negativas -) generaron períodos lluviosos (secos) en toda la región Pacífica (Caribe) de Mesoamérica. Además se utilizaron 410 estaciones pluviométricas para estudiar la MJO y se observó que las OAF influencian las lluvias en Mesoamérica modulando la corriente de Chorro de bajo nivel del Caribe (CLLJ). Cuando la MJO estuvo en fases 8, 1 y 2 (4, 5 y 6) generó más (menos) lluvias en la región del Pacífico Mesoamericano, igualmente sobre Colombia y Venezuela, siendo contrario el comportamiento en el Caribe centroamericano e influenciando especialmente por la orografía presente, tanto en los Andes como en Centroamérica. Se encontraron relaciones con las OBF y diversas actividades económicas como la pesca de camarón (Penaeus Vannamei y Xiphopenaeus riveti), donde durante los eventos en que la AMO tenía signo contrario a la PDO se tenían mayor (menores) probabilidad de que la cantidad de capturas de camarón en el Pacífico Costarricense fuera menor (mayor). Se determinó la influencia que tenían las OBF y el índice oceánico del Niño (ONI) con la pesca de camarón; se pudo encontrar que la PDO puede actuar como modulador del ONI, amplificándolo, y generando menor (mayor) pesca siendo significativos al 90% con la prueba exacta de Fisher. Por otro lado, los cultivos de arroz y frijol (Phaseollus vulgaris) presentaron mayores rendimientos en Costa Rica cuando la AMO y el ONI tenían signos contrarios. Regionalmente hubo variaciones importantes consecuencia de la cantidad de lluvias recibida en cada región. Los escenarios más sensibles a responder por las variaciones de las OBF fueron los secos, es decir cuando la configuración predominante generó menos lluvias la probabilidad de afectación de las
... La fase fenológica del cultivo es la relación que existe entre las diferentes variables meteorológicas como temperatura, lluvia (necesidades hídricas del cultivo) y el desarrollo de un cultivo determinado (Oteros et al., 2013). ...
... Therefore, the likely occurrence of high temperatures and/or water stress (due to normal or extreme events) during this period would have a strong impact on irrigation scheduling and olive oil production. However, the existing uncertainties about the impact of climate change on olive phenology (Osborne et al., 2000;De Melo-Abreu et al., 2004;Oteros et al., 2013) require the development of new phenological models able to simulate the crop's response under future climate conditions (Gabaldón-Leal et al., 2017). ...
Article
AdaptaOlive is a simplified physically-based model that has been developed to assess the behavior of olive under future climate conditions in Andalusia, southern Spain. The integration of different approaches based on experimental data from previous studies, combined with weather data from 11 climate models, is aimed at overcoming the high degree of uncertainty in the simulation of the response of agricultural systems under predicted climate conditions. The AdaptaOlive model was applied in a representative olive orchard in the Baeza area, one of the main producer zone in Spain, with the cultivar 'Picual'. Simulations for the end of the 21st century showed olive oil yield increases of 7.1 and 28.9% under rainfed and full irrigated conditions, respectively, while irrigation requirements decreased between 0.5 and 6.2% for full irrigation and regulated deficit irrigation, respectively. These effects were caused by the positive impact of the increase in atmospheric CO 2 that counterbalanced the negative impacts of the reduction in rainfall. The high degree of uncertainty associated with climate projections translated into a high range of yield and irrigation requirement projections, confirming the need for an ensemble of climate models in climate change impact assessment. The AdaptaOlive model also was applied for evaluating adaptation strategies related to cultivars, irrigation strategies and locations. The best performance was registered for cultivars with early flowering dates and regulated deficit irrigation. Thus, in the Baeza area full irrigation requirements were reduced by 12% and the yield in rainfed conditions increased by 7% compared with late flowering cultivars. Similarly, regulated deficit irrigation requirements and yield were reduced by 46% and 18%, respectively, compared with full irrigation. The results confirm the promise offered by these strategies as adaptation measures for managing an olive crop under semi-arid conditions in a changing climate.
... agricultural practices, crop rotation, etc.) and to evaluate crop-wheater reationships (e.g. forecasting pollen seasons, predicting cold damages on crops, etc.) (Justice et al. 1985;Chmielewski et al., 2004;Shimono, 2011;Oteros et al., 2013;2015). In recent decades, increasing attention is arising towards the impact that genetically modified (GM) crops may produce on environment and human health. ...
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In the framework of the LIFE + DEMETRA (LIFE08/NAT/IT/342) project, aimed at defining a methodology to monitor possible collateral effects of genetically modified (GM) crops on natural and semi-natural environments, a survey on plant biodiversity within the “Migliarino, San Rossore, Massaciuccoli” Regional Park - Tuscany (Italy) was carried out. Activities focused on: a) evaluating how phenological features may be influenced by different environments; b) detecting wild species subject to potential breeding with cultivated oilseed rape (Brassica napus L. var. oleifera D.C.); c) allowing a proper planning of crop plantation. Permanent plots were designed in six selected sites; phenological data were collected from March to October 2010 and then compared with meteorological data provided by three weather stations. Results showed that Sinapis arvensis L. and Cardamine hirsuta L. turned out to have a flowering period overlapping with B. napus var. oleifera. The phenological observations allowed the identification of three phenological groups. Some phenological variations between environments were highlighted, although it wasn’t possible to outline a clear relationship with the examined meteorological variables.
... Numerous researches point to temperature as the main meteorological factor involved in the regulation of the timing of the reproductive cycle of the olive tree [11,[53][54][55]; however, our results also showed a strong effect on olive yield. Moriondo et al. [56] reported a negative relationship between summer temperatures summer and olive production, coinciding with our results. ...
Article
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The effects of climate change on agricultural systems raise important uncertainties about the future productivity and suitability of crops, especially in areas suffering from intense environmental changes. Olive groves occupy Mediterranean areas characterized by seasonal temporary droughts, which cause this cultivation to be highly dependent on local microclimatic conditions. Olive crop production can be reliably estimated using pollen intensity metrics together with post-pollination environmental conditions. In this study, we applied this kind of statistics-based models to identify the most relevant meteorological variables during the post-pollination periods for olive fruit production. Olive pollen time-series for the period of 1999–2012 was analyzed in 16 Italian provinces. Minimum and maximum temperature during spring and summer (March–August) showed a negative relationship with olive production, while precipitation always showed a positive correlation. The increase in aridity conditions observed in areas of Italy during the summer represents an important risk of decreasing olive crop production. The effect of climate change on the olive production trend is not clear because of the interactions between human and environmental factors, although some areas might show an increase in productivity in the near future under different climate change scenarios. However, as more drastic changes in temperature or precipitation take place, the risk to olive production will be considerably greater.
... Small deviation was probably determined by local topography, such as elevation, which warrants further investigation. Oteros et al. [36] observed that altitude and percentage eastward slope were the most influential topographical factors affecting local olive tree phenology in southern Spain. Nevertheless, Copernicus' ERA5 data were proved to be a valid alternative to calculate GDD, confirming that phenological modeling based on application of meteorological stations and reanalysis products may be extended to olive tree areas sharing the same plant phenological phases. ...
Article
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Knowledge of phenological events and their variability can help to determine final yield, plan management approach, tackle climate change, and model crop development. THe timing of phenological stages and phases is known to be highly correlated with temperature which is therefore an essential component for building phenological models. Satellite data and, particularly, Copernicus’ ERA5 climate reanalysis data are easily available. Weather stations, on the other hand, provide scattered temperature data, with fragmentary spatial coverage and accessibility, as such being scarcely efficacious as unique source of information for the implementation of predictive models. However, as ERA5 reanalysis data are not real temperature measurements but reanalysis products, it is necessary to verify whether these data can be used as a replacement for weather station temperature measurements. The aims of this study were: (i) to assess the validity of ERA5 data as a substitute for weather station temperature measurements, (ii) to test different machine learning models for the prediction of phenological phases while using different sets of features, and (iii) to optimize the base temperature of olive tree phenological model. The predictive capability of machine learning models and the performance of different feature subsets were assessed when comparing the recorded temperature data, ERA5 data, and a simple growing degree day phenological model as benchmark. Data on olive tree phenology observation, which were collected in Tuscany for three years, provided the phenological phases to be used as target variables. The results show that ERA5 climate reanalysis data can be used for modelling phenological phases and that these models provide better predictions in comparison with the models trained with weather station temperature measurements.
... The threshold level was also reported to decrease towards the north ( Aguilera et al., 2013). Altitude is the topographical factor that most influences olive local phenology and the major weather factors are temperature, rainfall, and solar radiation, which control plant evapotranspiration ( Oteros et al., 2013Oteros et al., , 2014). Several studies used airborne pollen as a predictor variable for determining the potential sources of olive pollen emission, e.g. ...
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The paper presents the first modelling experiment of the European-scale olive pollen dispersion, analyses the quality of the predictions, and outlines the research needs. A 6-model strong ensemble of Copernicus Atmospheric Monitoring Service (CAMS) was run throughout the olive season of 2014, computing the olive pollen distribution. The simulations have been compared with observations in eight countries, which are members of the European Aeroallergen Network (EAN). Analysis was performed for individual models, the ensemble mean and median, and for a dynamically optimised combination of the ensemble members obtained via fusion of the model predictions with observations. The models, generally reproducing the olive season of 2014, showed noticeable deviations from both observations and each other. In particular, the season was reported to start too early by 8 days, but for some models the error mounted to almost 2 weeks. For the end of the season, the disagreement between the models and the observations varied from a nearly perfect match up to 2 weeks too late. A series of sensitivity studies carried out to understand the origin of the disagreements revealed the crucial role of ambient temperature and consistency of its representation by the meteorological models and heat-sum-based phenological model. In particular, a simple correction to the heat-sum threshold eliminated the shift of the start of the season but its validity in other years remains to be checked. The short-term features of the concentration time series were reproduced better, suggesting that the precipitation events and cold/warm spells, as well as the large-scale transport, were represented rather well. Ensemble averaging led to more robust results. The best skill scores were obtained with data fusion, which used the previous days' observations to identify the optimal weighting coefficients of the individual model forecasts. Such combinations were tested for the forecasting period up to 4 days and shown to remain nearly optimal throughout the whole period.
... First, cereals were the dominant crops in Greater Mesopotamia, whereas olive oil became widely exchanged over the second millennium BCE (Paulette, 2013: 102-103). Second, botanical evidence suggests that wheat and barley (olive) farming need a temperature ranging between 5 and 38 (higher than 4) degrees Celsius, suffers from water scarcity and requires an altitude between 0 and 3050 m (Serna-Saldivar, 2010; Oteros et al., 2013). ...
Article
The focus of archaeologists on reconstructing exchange and communication networks in the past resulted in the enormous improvement of methods for analyzing material flows and detecting trade routes. However, our understanding of the determinants of trade patterns over time and space is still limited. To help tackle this issue, we study through regression analysis the rich economic and institutional experience of Bronze Age Greater Meso-potamia. Our testable predictions originate from three main economic theories of trade expansion. First, because of trade costs, mutually beneficial exchanges are discouraged by distance and encouraged by the relative size of markets. Second, trade expands when more suitable farming conditions in neighboring polities allow consumption risk-sharing. Finally, trade develops when interlocking exchange circuits ease the canalization of goods from the outside by providing secure routes, a more certain resolution of legal disputes and credit provision. Ordinary Least Squares-OLS-estimates based on data on 44 major Mesopotamian polities observed for each half-century between 3050 and 1750 BCE are consistent with these predictions. Our approach provides a robust theory-based empirical strategy for integrating archaeological, environmental, and historical data and calls for a tighter interdisciplinary cooperation.
... the soil profile development and texture, which are usually synthesized by a land suitability index since they are inefficient in capturing historical farming productivity (Benati et al., 2022). To elaborate, the land suitability scores, as for instance the one developed by the Global Agro-Ecological Zones-i.e., GAEZ-project at a 5 arc-minute resolution for the entire globe, measure the ability of the soil to retain and supply nutrients and water to enable crops to maximally utilize climatic resources (Serna-Saldivar, 2010;Oteros et al., 2013) and combine information on present-day agro-edaphic conditions, such as soil water holding capacity, soil depth and textural class, and/or agro-climatic conditions-i.e., radiation and temperature-subsequent 1960. Since agro-edaphic conditions can reflect human intervention contemporaneous or consecutive to institutional formation, the extant literature has focused on the scores based only on agro-climatic conditions under low-input agriculture, which, therefore, should be independent from human decisions (Bentzen et al., 2016;Litina, 2016). ...
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We characterize the possible cooperation between nonelites and elites unable to commit to direct transfers. The elites can, however, incentivize investment by enacting a more inclusive political process, which entrusts the nonelites with the control over fiscal policies, and the nonelites can commit to cooperate via cultural accumulation. When the production conditions are adverse but not prohibitive, cooperative investments prevail only if the elites grant to the nonelites strong political rights to convince them that a sufficient part of the returns on joint investments will be shared via public good provision and the nonelites reciprocate by accumulating a level of culture assuring their participation despite the limited payoff. When, instead, the investment return is large, the elites might sustain cooperation even if they keep control over fiscal policies, and the nonelites accumulate the cultural level optimal absent commitment issues. Finally, the return on non-investment activities prevailing when cooperation in investment is unattainable raises the nonelites' outside option and, in turn, their cultural accumulation. These predictions are consistent with novel data on 44 major Mesopotamian polities observed for each half-century between 3050 and 1750 BCE. Conditional on polity and half-century fixed effects, the diffusion of interest-free loans of agricultural products and irrigation infrastructures is negatively and significantly related to a proxy of the farming return combining slope, temperature and rainfall, whereas the spread of formal merchant institutions is positively and significantly linked to the distance to the trade circuits. Moreover, cultural accumulation intensifies when the returns on non-investment "risk-sharing" activities is magnified by the avulsion of the great rivers. Our results remain robust to considering the inclusiveness of the political process, incidence of external and internal conflicts and extent of urbanization.
... Climate is one of the most important factors affecting the distribution of plants (Ma and Sun 2018;Ren et al. 2020). Climate change has been a relevant issue at the international level since the late 1980s (Pasqui and Giuseppe 2019) and clearly affects the distribution of plant species worldwide (Bosso et al. 2017;Zhang et al. 2018;Wang et al. 2019;Prevéy et al. 2020), including forest species (Bosso et al. 2017;Shirk et al. 2018), invasive species (Motloung et al. 2018; Katz and Zellmer 2018), rare species (Qin et al. 2017;Ma and Sun 2018), landscape plants (Zhang et al. 2018), fruit trees (Prevéy et al. 2020), and crops (Oteros et al. 2013;Gomes et al. 2020;Jayasinghe et al. 2020). Analyses of the effects of climate change on the potential distributions of plant species could provide basic references for species management and cultivation (Liu et al. 2017a;Gomes et al. 2020;Prevéy et al. 2020). ...
Article
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Climate change is significantly affecting the distribution of plants worldwide. Cyclocarya paliurus (Batal.) Iljinsk. (Juglandaceae), a rare deciduous tree, is a traditional nutraceutical tea owing to its health benefits and appealing flavor. In this study, climatic factors and soil physio-chemical factors were screened using MaxEnt modeling, and suitable habitat areas during three historical periods and under two climatic change scenarios were predicted based on 425 occurrence records. MaxEnt model performance was excellent, showing a high prediction ability, with an average area under curve value of 0.9786 ± 0.0025 and true skill statistic index of 0.9556. Eleven climatic factors, as well as four soil physio-chemical factors, were selected based on jackknife resampling. The habitat suitability simulation for three historical periods (last glacial maximum, mid-Holocene, and 1960–1990) showed that although the high-suitability area for C. paliurus decreased during the three periods, the combined intermediate- and high-suitability area increased. The analysis of the suitable habitat distributions under two global warming scenarios (RCP2.6 and RCP8.5) showed a decline in the suitable habitat area of C. paliurus in response to climatic warming. Our results provide basic references for the management of this species in nature.
... Estimation of GDDs to flowering and maximum rate of pit hardening were made for two "on" years, 2019 and 2021. Olive tree flowering observations were based on Oteros et al. [37] and were made twice weekly on the four azimuthal directions of 15 trees for each treatment. Flowering date was assumed when the average number of open flowers exceeded the number of swollen buds in the trees in each treatment. ...
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Climate change is affecting water resources in the Mediterranean region. In olive orchards, irrigation water use efficiency could be increased by accounting for trees’ alternate bearing behaviour and growth-stage sensitivity to drought. The main objective of this study is to examine olive tree phenology, morphology and physiology in “on” and “off” productive years for the improvement of irrigation scheduling. A regulated (RDI) and a sustained (SDI) deficit irrigation treatment were applied in a ‘Koroneiki’ olive orchard in Cyprus. Flowering occurred on 11 May 2019 and on 27 April 2021, which was caused by the lower temperatures in 2019. The Kc for the irrigation season, computed from daily water balance observations, was 0.37 in 2019 (38% canopy cover) and 0.41 in 2021 (62% canopy cover). Irrigation treatments did not significantly affect plant morphology and stem water potentials. In “on” years, shoot elongation ceased early in the season and stem water potential towards the end of September (−4.0 MPa) was lower than in the “off” year. Stem water potential recovery in the September of the “off” year indicated that irrigation could be less than 35% ETc in early fall. Water savings in RDI were 24–32% in “on” and 48% in “off” years relative to SDI, with no statistically significant effects on olive yields.
... Climate change, taking place also in the Mediterranean area, can lead to a reduction in water availability, an increase in temperatures and the need to use salty lands and water. Olive growing has expanded in recent decades outside the borders of the Mediterranean, reaching different continents, often affected by scarcity of water and nutritional resources and by phenomena of salinity of soils and irrigation water [57,58]. ...
Article
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Climate change, currently taking place worldwide and also in the Mediterranean area, is leading to a reduction in water availability and to groundwater salinization. Olive represents one of the most efficient tree crops to face these scenarios, thanks to its natural ability to tolerate moderate salinity and drought. In the present work, four olive cultivars (Koroneiki, Picual, Royal de Cazorla and Fadak86) were exposed to high salt stress conditions (200 mM of NaCl) in greenhouse, in order to evaluate their tolerance level and to identify key genes involved in salt stress response. Molecular and physiological parameters, as well as plant growth and leaves’ ions Na+ and K+ content were measured. Results of the physiological measurements showed Royal de Cazorla as the most tolerant cultivar, and Fadak86 and Picual as the most susceptible ones. Ten candidate genes were analyzed and their complete genomic, CDS and protein sequences were identified. The expression analysis of their transcripts through reverse transcriptase quantitative PCR (RT-qPCR) demonstrated that only OeNHX7, OeP5CS, OeRD19A and OePetD were upregulated in tolerant cultivars, thus suggesting their key role in the activation of a salt tolerance mechanism.
... These traits are sensitive to climatic variations and phenological parameters are widely used as bioindicators of climate change, especially in temperate climates (Schröder et al. 2014;Hamaoui-Laguel et al. 2015). Airborne pollen data are representative of large areas (Oteros et al. 2013;Rojo and Pérez-Badia 2014) and aerobiological studies have been used to quantify ongoing changes due to climate change at the regional scale (Makra et al. 2011;Smith et al. 2014;Lind et al. 2016). ...
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Climate change impacts on the structure and function of ecosystems will worsen public health issues like allergic diseases. Birch trees (Betula spp.) are important sources of aeroallergens in Central and Northern Europe. Birches are vulnerable to climate change as these trees are sensitive to increased temperatures and summer droughts. This study aims to examine the effect of climate change on airborne birch pollen concentrations in Central Europe using Bavaria in Southern Germany as a case study. Pollen data from 28 monitoring stations in Bavaria were used in this study, with time series of up 30 years long. An integrative approach was used to model airborne birch pollen concentrations taking into account drivers influencing birch tree abundance and birch pollen production and projections made according to different climate change and socio‐economic scenarios. Birch tree abundance is projected to decrease in parts of Bavaria at different rates, depending on the climate scenario, particularly in current centres of the species distribution. Climate change is expected to result in initial increases in pollen load but, due to the reduction in birch trees, the amount of airborne birch pollen will decrease at lower altitudes. Conversely, higher altitude areas will experience expansions in birch tree distribution and subsequent increases in airborne birch pollen in the future. Even considering restrictions for migration rates, increases in pollen load are likely in Southwestern areas, where positive trends have already been detected during the last three decades. Integrating models for the distribution and abundance of pollen sources and the drivers that control birch pollen production allowed us to model airborne birch pollen concentrations in the future. The magnitude of changes depends on location and climate change scenario.
... Soil moisture is needed for seed germination but precipitation during flowering and pollen dispersal can wash out pollen and lower counts. Water deficits have been shown to delay olive flowering 44 www.nature.com/scientificreports/ been shown to decrease pollen in Switzerland and the Mediterranean 46,47 . ...
Article
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Pollen and molds are environmental allergens that are affected by climate change. As pollen and molds exhibit geographical variations, we sought to understand the impact of climate change (temperature, carbon dioxide (CO2), precipitation, smoke exposure) on common pollen and molds in the San Francisco Bay Area, one of the largest urban areas in the United States. When using time-series regression models between 2002 and 2019, the annual average number of weeks with pollen concentrations higher than zero increased over time. For tree pollens, the average increase in this duration was 0.47 weeks and 0.51 weeks for mold spores. Associations between mold, pollen and meteorological data (e.g., precipitation, temperature, atmospheric CO2, and area covered by wildfire smoke) were analyzed using the autoregressive integrated moving average model. We found that peak concentrations of weed and tree pollens were positively associated with temperature (p < 0.05 at lag 0–1, 0–4, and 0–12 weeks) and precipitation (p < 0.05 at lag 0–4, 0–12, and 0–24 weeks) changes, respectively. We did not find clear associations between pollen concentrations and CO2 levels or wildfire smoke exposure. This study’s findings suggest that spore and pollen activities are related to changes in observed climate change variables.
... Soil moisture is needed for seed germination but precipitation during owering and pollen dispersal can wash out pollen and lower counts. Water de cits have been shown to delay olive owering [33,34]. Drought conditions have been shown to decrease pollen in Switzerland and the Mediterranean [35,36]. ...
Preprint
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Pollen and molds are environmental allergens that are affected by climate change. As pollen and molds exhibit geographical variations, we sought to understand the impact of climate change (temperature, carbon dioxide, precipitation, smoke exposure) on common pollen and molds in the San Francisco Bay Area, one of the largest urban areas in the United States. When using time-series regression models between 2002 and 2019, the annual average number of weeks with pollen concentrations higher than zero increased over time. For tree pollens, the average increase in this duration was 0.47 weeks and 0.51 weeks for mold spores. Associations between mold, pollen and meteorological data (e.g. precipitation, temperature, atmospheric carbon dioxide level, and area covered by wildfire smoke plumes) were analyzed using the autoregressive integrated moving average (ARIMA) model, which found that the peak concentrations of tree and grass pollens are associated with seasonal patterns of maximum temperature and precipitation. In addition, the peak concentrations of weed pollens are associated with seasonal temperature changes. We did not find clear associations of pollen and spore concentrations with carbon dioxide levels and wildfire smoke exposure. This study’s findings suggest that spore and pollen activities are related to changes in observed climate change variables.
... Cuticle thickness, ultrastructure, and chemical composition can vary dramatically in a species-, organ-and tissue-specific manner [2,11]. Thus, as they develop their leaves, plants can resort to specific morphological alterations to regulate their water losses, such as changes in the palisade parenchyma thickness [12] or the epidermis and cuticle water tightness [13], the latter being essential to control water losses, especially during drought periods, through cuticular transpiration [14,15]. ...
Article
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Plants are subjected to unregulated water loss from their surface by cuticular transpiration. Therefore, specific morphophysiological changes may occur during leaf development to eliminate water loss. This study aimed to examine the cuticular transpiration of 23 winter wheat genotypes and their wild-growing predecessors of the genus Aegilops, which were divided into three groups to demonstrate their diversity. The genotypes were sown in autumn and grown in regular field trials at the Research Institute of Plant Production in Piešťany, Slovakia. Cuticular transpiration and growth parameters were analyzed in the postanthesis growth stage. Gravimetric measurement of residual water loss was performed on detached leaves with a precisely measured leaf area. The lowest nonproductive transpiration values were observed in modern wheat genotypes, while higher cuticular transpiration was observed in a group of landraces. Aegilops species generally showed the highest cuticular transpiration with increased water loss, but the total water loss per plot was low due to the low leaf area of the wild wheat relatives. Some of the growth parameters showed a good correlation with cuticular transpiration (e.g., dry mass per plant), but direct relationships between leaf traits and cuticular transpiration were not observed. This study identified a high diversity in cuticular resistance to water loss in wheat and Aegilops accessions of different origins. The potential of identifying and exploiting genetic resources with favorable cuticular transpiration in crop breeding is discussed.
... First, cereals were the dominant crops in Greater Mesopotamia, whereas olive oil became widely exchanged over the second millennium BCE [Paulette, 2013: 102-103]. Second, botanical evidence suggests that wheat and barley (olive) farming need a temperature ranging between 5 and 38 (higher than 4) degrees Celsius, suffers from water scarcity and requires an altitude between 0 and 3050 m (Serna-Saldivar, 2010; Oteros et al., 2013). Third, considering the altitude is irrelevant in our sample since the maximum one is that of Kanesh, i.e., 1106 m. ...
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The focus of archaeologists on reconstructing exchange and communication networks in the past resulted in the enormous improvement of methods for analyzing material flows and detecting trade routes. However, our understanding of the determinants of trade patterns over time and space is still limited. To help tackle this issue, we study through regression analysis the rich economic and institutional experience of Bronze Age Greater Mesopotamia. Our testable predictions originate from three main economic theories of trade expansion. First, because of trade costs, mutually beneficial exchanges are discouraged by distance and encouraged by the relative size of markets. Second, trade expands when more suitable farming conditions in neighboring polities allow consumption risk-sharing. Finally, trade develops when interlocking exchange circuits ease the canalization of goods from the outside by providing secure routes, a more certain resolution of legal disputes and credit provision. Ordinary Least Squares—OLS—estimates based on data on 44 major Mesopotamian polities observed for each half-century between 3050 and 1750 BCE are consistent with these predictions. Our approach provides a robust theory-based empirical strategy for integrating archaeological, environmental, and historical data and calls for a tighter interdisciplinary cooperation.
... These traits are sensitive to climatic variations and phenological parameters are widely used as bioindicators of climate change, especially in temperate climates (Schröder et al. 2014;Hamaoui-Laguel et al. 2015). Airborne pollen data are representative of large areas (Oteros et al. 2013;Rojo and Pérez-Badia 2014) and aerobiological studies have been used to quantify ongoing changes due to climate change at the regional scale (Makra et al. 2011;Smith et al. 2014;Lind et al. 2016). ...
Article
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Climate change affects the reproductive life cycles of plants, including pollen production, which has consequences for allergic respiratory diseases. We examined climatic trends at eight locations in Bavaria, Southern Germany, with pollen time series of at least 10 years (up to 30 years in Munich). Climate change in Bavaria was characterized by a rise in temperature, but not during the winter. There is also a trend towards a more continental climate in Bavaria, which is significant in the Alps in the south of the territory. The influence of climate change depended on pollen type. Wind-pollinated arboreal species (e.g. Alnus, Betula and Cupressaceae/Taxaceae) showed advances in the start and end dates of pollen seasons and an increase in pollen load. These changes correlated negatively with late-winter (February) and spring temperatures (April). For herbaceous species, like Poaceae and Urticaceae, an earlier season was observed. Although precipitation is not a limiting factor in Southern Germany, water availability in the spring did influence the magnitude of grass pollen seasons. The effect of climatic change on the characteristics of pollen seasons was also more pronounced at higher altitudes, significant at > 800 m above sea level. Our results show that trends for start, end dates and intensity were similar at all locations, but only statistically significant at some. If we assume that earlier and more intense pollen seasons result in increases in prevalence and severity of allergic diseases, then the effect of climate change on public health in Bavaria may be significant.
... Entretanto, a temperatura é ainda mais influente no que diz respeito às alterações fenológicas das espécies vegetais em um determinado local (HIDALGO-GAVEZ et al., 2018). Este elemento determina a taxa ou a velocidade da biossíntese e dos processos metabólicos vegetais (OTEROS et al., 2013). Diferentes pesquisas desenvolvidas no mundo indicam que a temperatura controla a resposta fenológica das espécies vegetais (FONTANA et al., 2018). ...
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Olive is a long-living perennial species with a wide geographical distribution, showing a large genetic and phenotypic variation in its growing area. There is an urgent need to uncover how olive phenotypic traits and plasticity can change regardless of the genetic background. A two-year study was conducted, based on the analysis of fruit and oil traits of 113 cultivars from five germplasm collections established in Mediterranean Basin countries and Argentina. Fruit and oil traits plasticity, broad‐sense heritability and genotype by environment interaction were estimated. From variance and heritability analyses, it was shown that fruit fresh weight was mainly under genetic control, whereas oleic/(palmitic + linoleic) acids ratio was regulated by the environment and genotype by environment interaction had the major effect on oil content. Among the studied cultivars, different level of stability was observed, which allowed ranking the cultivars based on their plasticity for oil traits. High thermal amplitude, the difference of low and high year values of temperature, negatively affected the oil content and the oleic acid percentage. Information derived from this work will help to direct the selection of cultivars with the highest global fitness averaged over the environments rather than the highest fitness in each environment separately.
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Missing data is a common problem in scientific research. The availability of extensive environmental time series is usually laborious and difficult, and sometimes unexpected failures are not detected until samples are processed. Consequently, environmental databases frequently have some gaps with missing data in it. Applying an interpolation method before starting the data analysis can be a good solution in order to complete this missing information. Nevertheless, there are several different approaches whose accuracy should be considered and compared. In this study, data from 6 aerobiological sampling stations were used as an example of environmental data series to assess the accuracy of different interpolation methods. For that, observed daily pollen/spore concentration data series were randomly removed, interpolated by using different methods and then, compared with the observed data to measure the errors produced. Different periods, gap sizes, interpolation methods and bioaerosols were considered in order to check their influence in the interpolation accuracy. The moving mean interpolation method obtained the highest success rate as average. By using this method, a success rate of the 70% was obtained when the risk classes used in the alert systems of the pollen information platforms were taken into account. In general, errors were mostly greater when there were high oscillations in the concentrations of biotic particles during consecutive days. That is the reason why the pre-peak and peak periods showed the highest interpolation errors. The errors were also higher when gaps longer than 5 days were considered. So, for completing long periods of missing data, it would be advisable to test other methodological approaches. A new Variation Index based on the behaviour of the pollen/spore season (measurement of the variability of the concentrations every 2 consecutive days) was elaborated, which allows to estimate the potential error before the interpolation is applied.
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The different species of the genus Platanus, commonly known as plane trees, are widely grown as an ornamental species in Mediterranean cities over recent years. The pollen of these species is a major source of allergens. However, surprisingly little published research has addressed methods for predicting the allergy risk prompted by this pollen. In this work, we developed models for predicting airborne Platanus pollen concentrations constructed using data from central Spain. Predictions are very useful to alert citizens and give allergy patients advanced warning of expected high airborne pollen concentrations. The prediction models indicate that airborne Platanus pollen concentrations can be forecasted up to seven days (one week) in advance, using a method which combines the analysis of long-term aerobiological data (in this case, over the eleven-year study period), in order to detect seasonal trends within time-series, with the modelling of short-term fluctuations in airborne pollen concentrations prompted by daily changes in meteorological variables and pollen concentrations over the previous days. The meteorological variables studied were maximum and minimum temperature, rainfall and relative humidity. The results of the validation of prediction models yielded a coefficient of correlation between observed and predicted values of R = 0.7, indicating that these models predict most of the pollen peaks in the airborne pollen curve.
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Some parasitic plants are major pests in agriculture, but how this might be affected by climate change remains largely unknown. In this study, we assessed this for five generalist holoparasitic Cuscuta species (smoothseed alfalfa dodder ( Cuscuta approximata Bab.), alfalfa dodder ( Cuscuta europaea L.), soybean dodder ( Cuscuta chinensis C. Wright), Peruvian dodder ( Cuscuta australis R. Br.), Japanese dodder ( Cuscuta japonica Choisy)) and two of their main Leguminosae host crop species (soybean [ Glycine max (L.) Merr.] and alfalfa ( Medicago sativa L.)). For each of the five Cuscuta species and the two crop species, we ran MaxEnt models, using climatic and soil variables to predict their potential current distributions and potential future distributions for 2070. We ran species distribution models for all seven species for multiple climate-change scenarios, and tested for changes in the overlap of suitable ranges of each crop with the five parasites. We found that annual mean temperature and isothermality are the main bioclimatic factors determining the suitable habitats of the Cuscuta species and their hosts. For both host species, the marginally to optimally suitable area will increase by 2070 for all four RCP scenarios. For most of the Cuscuta species, the marginally to optimally suitable area will also increase. As the suitable area for both the hosts and the parasites will overall increase, Schoener’s D, indicating the relative overlap in suitable area, will change only marginally. However, the absolute area of potential niche overlap may increase up to six-fold by 2070. Overall, our results indicate that larger parts of the globe will become suitable for both host species, but that they could also suffer from Cuscuta parasitism in larger parts of their suitable ranges.
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Despite the relevance of strong political and property rights, we still lack a unified framework identifying their origins and interaction. In our model, the elite can elicit the citizens' cooperation in investment by granting a more inclusive political process, which allows them to select the tax rate and organize public good provision, and by punishing suspected shirking through the restriction of private rights. When the investment return is small, cooperation can only be attained under strong political and property rights and full taxation. When, instead, it is intermediate, the elite keeps control over fiscal policies and can implement partial taxation. When, finally, the investment return is large, the elite can also weaken the protection of private rights. Embracing the stick, however, is optimal only when production is sufficiently transparent, and, thus, punishment effectively disciplines a shirking citizen. These predictions are consistent with novel data on the division of the decision-making power, the strength of the private rights on land, the provision of public goods and the geographic conditions determining the expected return on farming and its opacity in a panel of 44 major Mesopotamian polities spanning each half-century between 3050 and 1750 BCE. Crucially, our estimates are quite similar when we also control for the trade potential, the severity of external and internal conflicts and the degree of urbanization.
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The concept of values has been extensively used as a proxy to investigate relationships between human-beings and their environment. Using a pragmatic epistemology, we investigated valuation processes at stake when farmers choose their management practices, focusing on soil biota valuations. We sought to determine to what extant values are situation-dependent and likely to evolve over time. We used five Focus Groups, in France, Germany, Romania, Spain and Sweden, where farmers described soil management situations and evaluated the outcomes of their practices. Soil management practices were reasoned according to local and current situations and not chosen ‘by principle’. Soils were mentioned in the assessment of practices outcomes rather than as a criterion for practices choices. Values appeared dynamic, influenced by social consensus on good practices and farming objectives. Implementing a new practice might develop knowledge that is further integrated in valuations, thereby reforming the references upon which farmers evaluate their practices. Overall, debating on what matters in agriculture in different regions before defining management measures or soil indicators might be necessary to design a sustainable European policy on soils.
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We study the possible cooperation between nonelites exerting an unobservable effort and elites unable to commit to direct transfers and, thus, always assure the nonelites’ participation. The elites can, however, incentivize investment by granting to the nonelites strong property rights to the input and a more inclusive political process, which entrusts them with control over fiscal policies. Adverse production conditions force the elites to enact strong nonelites’ political and property rights to convince them that a sufficient part of the returns on joint investments will be shared via public good provision. These reforms assure cooperation. When, instead, the expected investment return is large, the elites keep control over fiscal policies but refrain from weakening the nonelites’ property rights, while strengthening their own, if the production conditions are sufficiently opaque. Then, the expected cost of providing the extra public good guaranteeing the nonelites’ participation is too large. These predictions are consistent with novel data on 44 major Mesopotamian polities observed for each half-century from 3050 to 1750 BCE. While a lower growing season temperature favored a larger division of the decision-making power and stronger farmers’ use rights to land, only the latter are related to the diffusion of the very opaque viticulture. In addition, only the inclusiveness of the political process fostered the provision of public and ritual buildings as well as conscripted armies. Crucially, our results are robust to considering the trade potential, the severity of conflicts, and the degree of urbanization.
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Airborne pollen and meteorological-related variables have proved to be a good indicator of flowering, olive fruit production and to predict harvest of upcoming crop, thus enabling efficient management and marketing strategies. This study describes the first forecasting models of the olive fruit production based on pre-peak airborne annual pollen integral (APIn) from Olea europaea L. and meteorological data prior and during the flowering and ripening olive trees in Tétouan (NW of Morocco) over a period of 11 years (2008–2018). Aerobiological sampling was conducted using Burkard volumetric Hirst trap. The data were analyzed by multiple regression analysis. Several forecasting models developed were validated using data of 2018 (not included in the models) and compared with real olive crop data obtained from the Provincial Directions of Agriculture of Tétouan. The main factors influencing the final olive crop were the rainfall registered prior to flowering (March) and during fruit growing and minimum temperatures in July and June. The most accurate forecast models for the 2018 harvest showed the highest coefficient of determination (R² = 0.98; p < 000.1) and predicted the lowest RMSE between expected and observed data (452.80 and 398.75). The models developed provide efficient olive crop forecasting using independent variables which can be previously obtained. However, despite that the APIn is a reliable bio-indicator of regional crop yield forecasting in intensive farming areas it was not strongly representative in the regression equation probably due to the low airborne pollen concentrations recorded in Tétouan.
Thesis
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The thesis introduces forecasting of the temporal and geospatial patterns of pollen season in Europe (including influencing factors and daily concentration of pollen) through complex, multi-step transformation of data and parametric statistical analysis for model development and validation. Simulations were performed for several plant taxa at various (local, regional) spatial scales. The first part of the thesis develops a local flowering model for Riga. It is based on 12 years of observational data and aims at predicting the concentration of pollen in the air using the data from meteorological forecast. The model accuracy exceeds 80%. The second model is developed for regional-scale predictions of seasonal pollen index (SPI) – for the region covering Finland, Sweden, Lithuania, Latvia, Belarus, partly Russia and Norway. The SPI model is designed to be universally applicable to the entire region and has an accuracy of 65% in south-eastern part of the region up to 92% in the northern part of the region. The third part of the doctoral thesis describes an optimised ensemble built over simulations of six models for olive pollen over Europe in 2014. The optimization procedure included observations of previous days and was shown to noticeably improve the accuracy of the pollen forecasts generated by the individual models and simple ensembles (mean and median) built over their predictions. The result of doctoral thesis demonstrates the possibility to predict the amount of pollen in the air at different temporal and spatial scales using historical and forecasted meteorological information and past-time pollen counts. Forecasts are important for allergic people as well as for agricultural needs (potential crop production) and in phenological research. Practically applicable methodologies were constructed for the regional seasonal pollen index predictions, daily pollen forecasts in Riga, and European-scale ensemble fusion.
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The olive tree has expanded to several countries because of its easy adaptation to difficult edapho-climatic zones and high culinary and medicinal interest given the physicochemical composition of its fruit, including Argentina, Chile, Peru and Mexico, which have similar soil and climate conditions to the Mediterranean, where the phenological stages correspond to clearly distinct climatic seasons. However, in the Alto Ricaurte region in Boyaca, Colombia, olives do not set because of the tropical climate conditions. Because of these characteristics, the behavior of some trees, sown 4 to 30 years ago in this region, were evaluated. The temperature and precipitation were measured, and 20 branches were selected per tree, which were monitored from appearance until development; the polar and equatorial diameter of the fruits were measured until reaching maturation. A fruit and oil analysis was carried out with olives harvested in two maturation states in 2017. The temperature had a positive correlation with the phenological stages in a range of 11 to 29°C, which directly influenced the development of inflorescences and their performance. In the same year, there were two or more blooms with different intervals, where the same branch had inflorescences, flowers, freshly filled fruits and other mature fruits. As for the characteristics of the fruit and the oil, it was evident that the content of fatty acids was within the parameters required by the International Olive Council.
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The differentiation of olive floral buds during winter is strictly correlated with flowering in the spring and ultimately with fruit production in autumn and the determination of the time of flower bud induction is important for determining the possible causes of alternate bearing and for improving management practices to correct alternate bearing. The aim of this research was to study the time of flower bud differentiation and developmental steps in the 'Gemlik' olive cultivar in 2008 (offyear) and 2009 (on year). The sequence of initiation of the floral organs in each flower bud was sepals, stamens, petals, and gynoecium. There was no visible difference between the time of differentiation and the developmental stage of the floral organs with respect to the 'on' and 'off' years during the study.
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A mathematical model relating environmental temperatures to rest completion of 2 peach cultivars has been developed. The model equates temperatures to effective chill-units, such that, one can predict when rest will or has been completed with a high degree of accuracy.
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Experiments with olive ( Olea europaea L.) shoot explants were carried out to determine the influence of winter chilling on the release of axillary buds from dormancy. This investigation was designed to explore an alternative explanation for the confusing concept surrounding the role of chilling in olive floral induction. Leafy explants collected from 10 Nov. to 6 Mar. were grown in a greenhouse under mist at 13/24C (night/day) and in a growth chamber at 10/21C (night/day) to determine the end of dormancy. Growth of floral buds from leafy explants was first recorded from 5 Jan. samples. After that date the percentage of developing floral buds and rate of their development increased. Floral bud abscission, increase in bud fresh weight, and simultaneous decrease of relative bud dry weight were associated with growth initiation of floral buds. Manual defoliation of adult trees during the period of shoot explant collection indicated that leaves play a critical role in development once the floral buds had completed dormancy. Supplementary chilling of isolated shoots collected 20 Jan. demonstrated that 7.2C was sufficient to complete chilling requirements, while 12.5C allowed both the completion of chilling requirements and the proper temperature for subsequent floral bud growth. Winter chilling is required to release previously initiated floral buds from dormancy, and we question the previous concept that the role of chilling is to induce olive floral initiation.
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In Portugal, olive (Olea europaea L.) traditional groves of around 100 trees ha(-1) necessitate increasing pruning costs every year. As a result farmers tend to lengthen pruning intervals. With the purpose of studying an alternative to the expensive, labor-intensive manual pruning practice, field trials were established with three treatments: (i) manual pruning with a chain saw; (ii) mechanical pruning, performed by a tractor mounted circular disc-saws cutting bar; and (iii) mechanical pruning, as in the mechanical pruning treatment, followed by a manual pruning complement. Olive production and harvesting efficiency were evaluated every year for 8 yr. Olives were harvested with a trunk shaker, and the remaining nondetached fruits were collected manually. The pruning rate of mechanical pruning (487 trees h(-1)man(-1)) was substantially higher than the values of manual pruning and mechanical+manual pruning, which were the same (20 trees h(-1)man(-1)). Over the 8-yr period, mechanical pruning had an average yield of 36.4 kg tree(-1) yr(-1) which was significantly higher than the 30.1 kg tree(-1) yr(-1) of manual pruning and no significantly different from the 34.1 kg tree(-1) yr(-1) of mechanical+manual pruning. The shaker efficiency was significantly influenced by the year, ranging from 72 to 96%; no significant differences were found between treatments in terms of harvesting efficiency. Results indicate that after mechanical pruning trees can be kept for at least 8 yr without any significant loss in olive yield and no effect in harvesting efficiency, therefore reducing costs. Mechanical+manual pruning, performed in the same year, did not yield further improvement.
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In the last few years, many studies have used airborne pollen to record the flowering season of plants. However, the airborne pollen found in traps does not always originate from or reflect the flowering period of the taxa from the studied surroundings. This study compared aerobiological, melissopalynological and flowering phenological data obtained from olive trees. The results of the study suggest that pollen loads collected by honeybees can be used as an alternative method to airborne pollen to record the flowering phenological phases and to provide accurate results.
Article
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The present study implemented a regional phenological model that was derived through the growing season index and adapted to a widespread Mediterranean species, the olive (Olea europaea L.). This model considers not only individual phenological events, but also the main vegetative and reproductive phenological phases of the species, in an integrated biological approach. The regional model generally does not need to include specific meteorological variables calculated as weekly or monthly averages which could limit the extrapolation over large areas. The main climatic limitations of the olive cultivation areas in the south Mediterranean at latitudes around 10° (practically speaking, the geographical limits of the olive) are estimated here. This analysis uses information relating to local climatic changes over the last two decades (1990–1999, 2000–2009) to provide interpretations of the temperature, solar radiation rate, and evapotranspiration trends. This has allowed creation of a Mediterranean phenological model adapted to the olive, which presents the contemporary climate requirements during winter and the warm summer season. The climate analysis and comparisons of these two decades has allowed us to reveal a reduction in the index according to the minimum temperature, which has particular consequences in the northern monitoring areas. This phenomenon appears to present new positive scenarios for the future regarding a northward shift of olive cultivation areas, due to the potential enlargement of the growing season in winter. However, negative scenarios can also be foreseen in consideration of the failure to satisfy the minimum chilling requirements in the traditional southern cultivation areas of the olive.
Article
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The flowering characteristics of plant species of economic interest and the influence of climate on them are of great importance considering the implications for fruit setting and the final harvest: Olive is one of the typical species of the Mediterranean habitat. We have investigated the timing of olive full flowering during the anthesis period and flowering intensity over a period of 20 years (1990–2009), in three major cultivation areas of the Mediterranean basin: Italy, Spain and Tunisia. The importance of these characteristics from a bioclimatic point of view is considered. The biological behaviour was studied to determine its main relationships with temperature and water availability, considering also the different sub-periods and the bio-climatic variations during the study period. The flowering dates and pollen emissions show different behaviours for the Spanish monitoring area in comparison with the other two olive cultivation areas. In the Italian and Tunisian areas, the flowering period over the last decade has become earlier by about 5 and 7 days, respectively, in comparison to the previous decade. Moreover, pollen emissions have decreased in Perugia (Italy) and Zarzis (Tunisia) over the period of 2000–2009, while in Cordoba (Spain), they showed their highest values from 2005 to 2009. The climate analysis has shown an increase in temperature, which results in an increase in the growing degree days for the growth of the olive flower structures, particularly in the more northern areas monitored. Although the olive tree is a parsimonious water consumer that is well adapted to xeric conditions, the increase in the potential evapotranspiration index over the last decade in the Italian and Tunisian olive areas might create problems for olive groves without irrigation, with a negative influence on the flowering intensity. Overall, in all of these Mediterranean monitoring areas, the summer water deficit is an increasingly more important parameter in comparison to the winter parameters, which confirms that the winter period is not as limiting as the summer period for olive tree cultivation in these Mediterranean areas.
Article
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Phenological observations in olive tree (Olea europaea L.), on the first reproductive phase (budburst) and the winter chilling temperatures required for its onset, were analysed over a 4-year period (1998 - 2001). Research was carried out on two different cultivars growing in two Mediterranean olive-growing areas: 'Ascolana' in central Italy and 'Picudo' in southern Spain. The two main objectives of the study were: (1) to evaluate the different amounts of winter chilling, and their relationship with the budburst dates in outdoor olive plantations; and (2) to test the validity in the study areas of two chilling calculation methods, the Aron and the Utah method. Results show that for the Spanish cultivar the average chilling requirement of 997 h was approximately half of that recorded for the Italian cultivar (1848 h). Also, the year-to-year variability in chilling accumulation and the reproductive development date was observed to be higher in the Spanish area than in the Italian one, indicating a more consistent and predictable winter chilling response in the latter. As regards the validity of the methods, the Aron method seems to be more appropriate for use in warmer places, since it yielded better results in the Spanish site.
Article
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An aerobiological and phenological investigation on the olive tree was carried out during three years in two areas: Cordoba (Spain) and Perugia (Italy). In these countries, this species is economically important and those areas were chosen because of the long series of aeropalynological data (1982–1998) available, obtained by means of identical volumetric pollen traps. The aim of this study was to use phenological observations to prove the real contribution to the pollen curves in different cultivated areas. Results show that in Cordoba province (302.152 ha) the pollen curve is characterised by different peaks because of the pollination of different cultivated crops. In some cases, these crops are located far from the pollen trap (50 km) but pollen is transported thanks to favourable winds during the flowering period. In Perugia (750 ha) the pollen curve is characterised by only one peak; it is very concentrated because of the proximity of the investigated crops. The objective of this research was to obtain information on this species in order to elaborate statistical models aimed at forecasting the potential fruit production based on the amount of pollen released into the atmosphere.
Article
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The impact of climate change, and particularly of climate warming, is being tracked in many physical and biological systems. Plant phenology is seen as one of the most important bio-indicators, since trends can provide considerable temporal and spatial information regarding ongoing changes.Analyses performed at six sites in southern Spain from 1986 to the present have focused on vegetative and overall reproductive phenology in Olea europaea L., and Vitis vinifera L. and in various species of Quercus spp. and Poaceae. Early results suggest that trends in flowering patterns derived from field phenological observations were similar to trends in aerobiological data for most study species, and indicate a trend towards earlier foliation, flowering and fruit ripening. This advance is more evident in arboreal than in herbaceous species. Statistical analysis showed temperature increase was the major factor affecting earlier foliation, flowering and fruit ripening, as well as prompting delayed leaf fall. Herbaceous species were more affected than trees by changes in rainfall records.
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