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In the breeding process of agricultural crops, including sorghum, the use of multivariate statistics methods makes it possible to determine the correlation between morphometric traits, yield elements and biochemical parameters of grain in the model population, as well as to identify the load of hypothetical factors. The purpose of the current study was to identify the correlations between morphometric traits, yield elements and biochemical parameters of grain, which characterize the load of hypothetical factors in the model grain sorghum population. For practical breeding process, there have been analyzed 13 economically valuable traits in 27 grain sorghum varieties, developed by the FSBSI Russian Research and Project-technological Institute of sorghum and maize “Rossorgo”. There has been established a different variation degree of the traits of grain sorghum; a strong variation degree was established for such traits as ‘flag leaf area’, ‘the largest leaf area’, ‘panicle stem’, ‘productive tilling capacity’, ‘weight and number of grains per panicle’ (27.3–35.2%); a weak variation degree was established for such traits as ‘protein percentage’ and ‘starch content’ in grain (2.8–8.6%). The group with an average degree of variation includes the traits ‘plant height’ after 30 days of growing and at ripening period, ‘panicle length’, ‘1000-grain weight’, and ‘grain yield’ (10.1–15.6%). When analyzing the matrix of correlation coefficients, there were calculated the hypothetical factors with a contribution of more than 5% to the accumulated variance. There has been built a correlation pleiad, which made it possible to demonstrate mean (r = 0.51–0.68) and strong (r = 0.76–0.94) correlations. There have been considered six hypothetical factors reflecting the total contribution to the accumulated variance, Z-1 – 40.86%, Z-2 – 13.76%, Z-3 – 11.85%, Z-4 – 8.74%, Z- 5 – 6.69%, Z-6 – 5.99%. The first hypothetical factor is determined by such traits as ‘the largest leaf area’ and ‘flag leaf area’ (0.78–0.80), ‘weight and number of grains per panicle’ (0.84–0.91), ‘grain productivity’ (0.77) and ‘productive tillering capacity’ (- 0.78). The results obtained are used in breeding programs to develop grain sorghum varieties and hybrids adapted to the arid conditions of the Lower Volga region.

In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved sex differences in the degree of interindividual variation in energy expenditure. We found that, even when statistically comparing males and females of the same age, height, and body composition, there is much more variation in total, activity, and basal energy expenditure among males. However, with aging, variation in total energy expenditure decreases, and because this happens more rapidly in males, the magnitude of greater male variation, though still large, is attenuated in older age groups. Considerably greater male variation in both total and activity energy expenditure could be explained by greater male variation in levels of daily activity. The considerably greater male variation in basal energy expenditure is remarkable and may be explained, at least in part, by greater male variation in the size of energy-demanding organs. If energy expenditure is a trait that is of indirect interest to females when choosing a sexual partner, this would suggest that energy expenditure is under sexual selection. However, we present a novel energetics model demonstrating that it is also possible that females have been under stabilizing selection pressure for an intermediate basal energy expenditure to maximize energy available for reproduction. (C) 2022 The Author(s). Published by Elsevier Ltd.

Intraspecific diversity is a substantial part of biodiversity, yet little is known about its maintenance. Understanding mechanisms of intraspecific diversity shifts provides realistic detail about how phytoplankton communities evolve to new environmental conditions, a process especially important in times of climate change. Here, we aimed to identify factors that maintain genotype diversity and link the observed diversity change to measured phytoplankton morpho-functional traits Vmax and cell size of the species and genotypes. In an experimental setup, the two phytoplankton species Emiliania huxleyi and Chaetoceros affinis, each consisting of nine genotypes, were cultivated separately and together under different fluctuation and nutrient regimes. Their genotype composition was assessed after 49 and 91 days, and Shannon’s diversity index was calculated on the genotype level. We found that a higher intraspecific diversity can be maintained in the presence of a competitor, provided it has a substantial proportion to total biovolume. Both fluctuation and nutrient regime showed species-specific effects and especially structured genotype sorting of C. affinis. While we could relate species sorting with the measured traits, genotype diversity shifts could only be partly explained. The observed context dependency of genotype maintenance suggests that the evolutionary potential could be better understood, if studied in more natural settings including fluctuations and competition.

The aim of this study was to observe effects of the sowing date on the relationships among morphological properties of maize ears. The trial was set up in Zemun Polje in 2019 and encompassed five sowing dates with the initial one on April 1, and then on every 10 days until May 10 (S1, S2, S3, S4, S5). Three inbred lines (L1, L2, L3) were used as a material. During sowing, seeds were classified according to their size into small (6.5-8.4 mm), large (8.5-11 mm) and the primary seed fraction (6.5-11 mm). The parameters for the following morphological ear traits were determined under laboratory conditions: ear weight, ear length, ear thickness, cob weight and the grain yield. Obtained results indicated the significant contribution of all factors in expression of observed traits, as well as the significance of the interactions. The inbred L1 was the most stable genotype for the ear weight and the cob weight. The ear length and the ear thickness varied the least in all genotypes. The initial sowing dates (S1 and S2) were the most important for the ear weight. The third sowing date was the most important for the ear length (19.81cm) and the ear thickness (5.94cm). The highest cob weight was recorded in plants sown on the fifth sowing date (S5). The LSD tests showed that the differences in the morphological traits of ears of different sowing dates were significant between S5 and the remaining four sowing dates (p

Intraspecific trait variation (ITV) is common feature of natural communities and has gained increasing attention due to its significant ecological effects on community dynamics and ecosystem functioning. However, the estimation of ITV per se has yet to receive much attention, despite the need for accurate ITV estimation for trait-based ecological inferences. It remains unclear if, and to what extent, current estimations of ITV are biased. The most common method used to quantify ITV is the coefficient of variation (CV), which is dimensionless and can therefore be compared across traits, species, and studies. Here, we asked which CV estimator and data normalization method are optimal for quantifying ITV, and further identified the minimum sample size required for ±5% accuracy assuming a completely random sample scheme. To these ends, we compared the performance of four existing CV estimators, together with new simple composite estimators, across different data normalizations, and sample sizes using both a simulated and empirical trait datasets from local to regional scales. Our results consistently showed that the most commonly used ITV estimator (CV 1= σsample /μsample ), often underestimated ITV-in some cases by nearly 50%-and that underestimation varies largely among traits and species. The extent of this bias depends on the sample size, skewness and kurtosis of the trait value distribution. The bias in ITV can be substantially reduced by using log-transforming trait data and alternative CV estimators that take into consideration the above dependencies. We find that the CV4 estimator, also known as Bao's CV estimator, combined with log data normalization, exhibits the lowest bias and can reach ±5% accuracy with sample sizes greater than 20 for almost all examined traits and species. These results demonstrated that many previous ITV measurements may be substantially underestimated and, further, that these underestimations are not equal among species and traits even using the same sample size. These problems can be largely solved by log-transforming trait data first and then using the Bao's CV to quantify ITV. Together, our findings facilitate a more accurate understanding of ITV in community structures and dynamics, and may also benefit studies in other research areas that depend on accurate estimation of CV.

Some species intrinsically have a high invasiveness capacity, shown by high phenotypic plasticity and rapid growth, enabling a wide distribution across their native habitats and successful invasion in the introduced range. For such species, information from native habitats is critically important. An example is Glechoma hederacea, native to Eurasia but introduced and widespread in the USA. Our main objective was to investigate variation in traits of native G. hederacea populations across contrasting habitats: open, forest edge and understory. Vegetation was sampled and the ecophysiological and morphological traits were measured with accompanying environmental parameters. Results showed that in native habitats environmental conditions cover wide gradients of light and soil moisture. Plants had the highest cover in nutrient-rich, shaded habitats, representing the optimal habitat, indicating shade tolerance of G. hederacea. Plants from forest understory exhibited strong similarities in investigated traits to plants from the forest edge, even though this was a drier, sunnier habitat. Plants from open, sunny habitats experienced stress as indicated by the quantum efficiency of PSII and significantly higher sexual reproduction. Results show that G. hederacea is moderately tolerant simultaneously to shade and drought, a characteristic that has been reported for numerous invasive species, while at the same time it shares some characteristics with weedy plants.

Le specie aliene invasive (IAS) si stanno diffondendo a velocità sempre più elevata, con effetti molto negative a livello degli ecosistemi. Infatti, le IAS sono considerate una della maggiori cause della perdita di biodiversità e semplificazione degli habitat a livello globale. Di conseguenza, uno dei più grandi obiettivi in campo ecologico è quello di evidenziare le caratteristiche che ne favoriscono la diffusione. Quest’ ultime sono generalmente descritte dai ‘tratti funzionali’, definiti come caratteristiche morfologiche, fisiologiche o fenologiche, misurabili in un individuo dal livello cellulare sino a quello organismico. Lo scopo principale di questa Tesi è di evidenziare i tratti funzionali e meccanicistici (cioè tratti chiaramente associati a specifiche funzioni fisiologiche) alla base del processo di invasione. Nonostante il largo uso dei tratti funzionali, esistono ancora delle questioni parzialmente risolte riguardanti i metodi di misura. Nella prima parte di questa Tesi, ho quantificato la variabilità intraspecifica di due tratti modello, nell’ottica di definire un minimo e adeguato numero di repliche per misurare i tratti funzionali con una certa accuratezza e precisione (Studio 1). I tratti meccanicistici sono stati scarsamente utilizzati in campo ecologico, probabilmente perché la loro misura spesso richiede procedure difficili e molto lunghe. In questo senso, nello Studio 2 ho proposto un metodo semplificato per misurare il punto di perdita del turgore cellulare, un tratto meccanicistico direttamente associato alla resistenza all’aridità. Dopo aver cercato di trovare una risposta a domande di natura metodologica, ho concentrato le attività di ricerca su una delle più diffuse specie invasive, Ailanthus altissima (Aa). Nello Studio 3, ho confrontato tratti funzionali e meccanicistici di Aa e Fraxinus ornus (Fo) (che competono nelle stesse aree). La maggiore fitness associata ad Aa può essere legata alla sua bassa resistenza all’aridità, che è però controbilanciata da una alta efficienza di trasporto dell’acqua. In più, Aa ha mostrato una maggiore plasticità fenotipica di Fo in risposta a differenti condizioni di irraggiamento e nello studio 4 ho testato se questa sia una caratteristica presente anche nell’areale nativo di Aa (Cina). Tale studio dimostra che diverse modalità di aggiustamento del punto di perdita di turgore e una maggiore plasticità dei tratti legati ai costi di produzione delle foglie, possono essere alla base della maggiore fitness di Aa nel suo areale invasivo. Al fine di testare se i tratti descritti in Aa fossero condivisi da altre IAS, ho esteso l’analisi di tratti funzionali e meccanicistici su un più alto numero di specie (78 native e 15 IAS) sia erbacee che legnose (Studio 5). I risultati dimostrano che le IAS possiedono tratti che favoriscono una rapida crescita, indipendentemente dalla forma di crescita (erbacea o legnosa). Nello specifico, le IAS sembrano condividere una bassa resistenza all’aridità e una maggiore densità di venature fogliari, che influenzano i costi di produzione delle foglie e i tassi di crescita e di fotosintesi. Il coordinamento tra costi di produzione, livello di resistenza all’aridità e tratti legati alla fotosintesi può suggerire che la superiorità delle IAS possa dipendere da un maggiore capacità di accumulare biomassa pur con una simile o maggiore efficienza dell’uso dell’acqua. In conclusione, i tratti meccanicistici possono fornire nuove informazioni sui meccanismi alla base del processo di invasione delle IAS. Le nuove tecniche sviluppate per la loro misura potrebbero permettere di aumentare il numero di specie su cui misurare tratti meccanicistici riducendone i costi associati. La possibilità di generalizzare i pattern visti in questa Tesi ad una scala più ampia potrebbe infine portare alla definizione di un generale ‘Spettro di funzioni associate al processo di invasione’. The spread of alien invasive species (IAS) is occurring at unprecedented rates, causing strong impacts on ecosystems. Indeed, IAS are deemed one of the major causes of loss of biodiversity and habitat simplification worldwide. In this light, finding determinants of invasiveness has become an uprising research topic in plant ecology. Such features are generally described in terms of ‘functional traits’, i.e. morphological, physiological, or phenological characteristics which are measurable at the individual level from the cell to the whole-organism. The research activities described in this Thesis, aimed at highlighting which traits and associated functions might be at the basis on the invasion process, by measuring common functional traits as well as mechanistic traits (with clearer linkage to a physiological function) on a large number of species. Despite the large use of traits, there are still some critical issues to be solved in trait-based ecology. In the first part of this Thesis, I provided an analysis of the intraspecific variability of two model traits and I suggested a minimum and optimal sampling size to measure functional traits with a desired level of precision and accuracy (Study 1). Mechanistic traits have been seldom included in trait-based studies, because of difficult and time-expensive procedures for their measurement. In this light, in Study 2 I proposed a simplified framework for the measurement of leaf turgor loss point, a key mechanistic trait related to drought resistance. After addressing these methodological issues, in the second part of this Thesis I focused my research activities on Ailanthus altissima (Aa), which is one of the most invasive species in Europe. In Study 3, I compared functional and mechanistic traits of Aa Fraxinus ornus (competing Aa in the same areas). The superior fitness of Aa might be related to its lower resistance to drought stress, which was counterbalanced by higher water transport efficiency. I also detected larger phenotypic plasticity of Aa in response to light availability and I wondered whether this feature was also present in individuals growing in its native range (China). The comparison between individuals of Aa growing in its exotic vs native range (Study 4) suggested that novel features related to turgor loss adjustment and the higher plasticity in traits related to leaf-construction costs could increase Aa fitness in response to different environmental conditions in its invasive range. To test whether the features described for Aa were shared by other IAS, I analysed several functional and mechanistic traits related to resource acquisition, with special reference to water-use strategies, on a large number of herbaceous and woody species (78 native and 15 invasive species) (Study 5). Results showed that IAS were characterised by traits that favour fast-growth, independently of growth form or habitats features. IAS consistently shared lower drought resistance and denser venation network, which are mechanistic traits directly influencing leaf construction costs and photosynthetic and growth rates. The coordination between construction costs, drought resistance and photosynthesis-related traits, suggested that IAS outperform native species due to higher potential for carbon gain and biomass accumulation, while sharing similar or higher levels of water-use efficiency. In conclusion, mechanistic traits could provide novel insight in the mechanisms underlying plant invasion. Novel techniques recently developed could allow the measurement of such traits on a wide number of species with reduced cost. Widening the scale of the analyses provided in this Thesis might help in the definition of the ‘Spectrum of functions associated to plant invasion’.

There is unequivocal evidence that altered biodiversity, through changes in the expression and distribution of functional traits, can have large impacts on ecosystem properties. However, trait-based summaries of how organisms affect ecosystem properties often assume that traits show constancy within and between populations and that species contributions to ecosystem functioning are not overly affected by the presence of other species or variations in abiotic conditions. Here, we evaluate the validity of these assumptions using an experiment in which three geographically distinct populations of intertidal sediment-dwelling invertebrates are reciprocally substituted. We find that the mediation of macronutrient generation by these species can vary between different populations and show that changes in biotic and/or abiotic conditions can further modify functionally important aspects of the behaviour of individuals within a population. Our results demonstrate the importance of knowing how, when, and why traits are expressed and suggest that these dimensions of species functionality are not sufficiently well-constrained to facilitate the accurate projection of the functional consequences of change. Information regarding the ecological role of key species and assumptions about the form of species–environment interactions needs urgent refinement.

Supported by Portuguese Foundation for Science and Technology (FCT) through the Investigador FCT programme contract (M. Dolbeth, IF/00919/2015) and Decree-law 57/2016 contract (S. Leston), subsidised by the European Social Fund and Portuguese Ministry of Science, Technology and Higher Education (MCTES) through the Human Potential Operational Programme (POPH), and partially supported by the Strategic Funding (UID/Multi/04423/2019) awarded to CIIMAR. We also acknowledge the support of the MARS Network Travel Award for Young Scientists (D. Crespo) and the fellowship from project SmartBioR – Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate (D. Crespo, CENTRO-01-0145- FEDER-000018 co-funded by CENTRO2020/PORTUGAL2020/ FEDER); and the Coastal Biodiversity and Ecosystem Service Sustainability (CBESS) research programme (NE/J015644/1), funded by the U.K. Natural Environment Research Council (M. Solan, NE/ J015075/1). Changes in community structure concurrent with environmental forcing often form a precursor to changes in species diversity, and can have substantive consequences for ecosystem functioning. Here, we assess the effects of altered levels of evenness that are representative of different levels of eutrophication and changes in salinity associated with altered precipitation patterns, on the mediation of nutrient release by sediment-dwelling invertebrate communities. We find that an adjustment towards a more even distribution of species corresponds with an increase in sediment particle reworking that, in general, translates to increased levels of nutrient release. This response, however, is dependent on the functional role of each species in the community and is influenced by concomitant changes in salinity, especially when salinity extends beyond the range typically experienced by the community. Overall, our findings highlight the dynamic nature of species contributions to functioning and reinforce the importance of understanding when, and how, the mechanistic basis of species-environment interactions are modified as the influence of abiotic and biotic factors flex under periods of directional forcing. info:eu-repo/semantics/publishedVersion

Functional diversity is critical for ecosystem dynamics, stability and productivity. However, dynamic global vegetation models (DGVMs) which are increasingly used to simulate ecosystem functions under global change, condense functional diversity to plant functional types (PFTs) with constant parameters. Here, we develop an individual- and trait-based version of the DGVM LPJmL (Lund-Potsdam-Jena managed Land) called LPJmL- flexible individual traits (LPJmL-FIT) with flexible individual traits) which we apply to generate plant trait maps for the Amazon basin. LPJmL-FIT incorporates empirical ranges of five traits of tropical trees extracted from the TRY global plant trait database, namely specific leaf area (SLA), leaf longevity (LL), leaf nitrogen content (Narea), the maximum carboxylation rate of Rubisco per leaf area (inline image), and wood density (WD). To scale the individual growth performance of trees, the leaf traits are linked by trade-offs based on the leaf economics spectrum, whereas wood density is linked to tree mortality. No preselection of growth strategies is taking place, because individuals with unique trait combinations are uniformly distributed at tree establishment. We validate the modeled trait distributions by empirical trait data and the modeled biomass by a remote sensing product along a climatic gradient. Including trait variability and trade-offs successfully predicts natural trait distributions and achieves a more realistic representation of functional diversity at the local to regional scale. As sites of high climatic variability, the fringes of the Amazon promote trait divergence and the coexistence of multiple tree growth strategies, while lower plant trait diversity is found in the species-rich center of the region with relatively low climatic variability. LPJmL-FIT enables to test hypotheses on the effects of functional biodiversity on ecosystem functioning and to apply the DGVM to current challenges in ecosystem management from local to global scales, that is, deforestation and climate change effects.

The seeds of various plants were used as weights because their mass reputedly varies so little. Carob ( Ceratonia siliqua ), which has given its name to the carat, is particularly famous in this regard. But are carob seeds unusually constant in weight and, if not, how did the myth arise? The variability of seeds sampled from a collection of carob trees (CV=23%) was close to the average of 63 species reviewed from the literature (CV=25%). However, in a perception experiment observers could discriminate differences in carob seed weight of around 5% by eye demonstrating the potential for humans to greatly reduce natural variation. Interestingly, the variability of pre-metrication carat weight standards is also around 5% suggesting that human rather than natural selection gave rise to the carob myth.

Research Highlights: We investigated the variability of vessel diameter distributions within the liana growth form among liana individuals originating from a single site in Laussat, French Guiana. Background and Objectives: Lianas (woody vines) are key components of tropical forests. Lianas are believed to be strong competitors for water, thanks to their presumed efficient vascular systems. However, unlike tropical trees, lianas are overlooked in field data collection. As a result, lianas are often referred to as a homogeneous growth form while little is known about the hydraulic architecture variation among liana individuals. Materials and Methods: We measured several wood hydraulic and structural traits (e.g., basic specific gravity, vessel area, and vessel diameter distribution) of 22 liana individuals in a single sandy site in Laussat, French Guiana. We compared the liana variability of these wood traits and the correlations among them with an existing liana pantropical dataset and two published datasets of trees originating from different, but species-rich, tropical sites. Results: Liana vessel diameter distribution and density were heterogeneous among individuals: there were two orders of magnitude difference between the smallest (4 &micro, m) and the largest (494 &micro, m) vessel diameters, a 50-fold difference existed between extreme vessel densities ranging from 1.8 to 89.3 vessels mm&minus, 2, the mean vessel diameter varied between 26 &micro, m and 271 &micro, m, and the individual theoretical stem hydraulic conductivity estimates ranged between 28 and 1041 kg m&minus, 1 s&minus, 1 MPa&minus, 1. Basic specific gravity varied between 0.26 and 0.61. Consequently, liana wood trait variability, even within a small sample, was comparable in magnitude with tree surveys from other tropical sites and the pantropical liana dataset. Conclusions: This study illustrates that even controlling for site and soil type, liana traits are heterogeneous and cannot be considered as a homogeneous growth form. Our results show that the liana hydraulic architecture heterogeneity across and within sites warrants further investigation in order to categorize lianas into functional groups in the same way as trees