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Summary Water use efficiency (WUE) represents the trade‐off between carbon assimilation and water loss in plants. It remains unclear how leaf stomatal and photosynthetic traits regulate the spatial variation of leaf WUE in different natural forest ecosystems. We investigated 43 broad‐leaf tree species spanning from cold‐temperate to tropical forests in China. We quantified leaf WUE using leaf δ13C and measured stomatal traits, photosynthetic traits as well as maximum stomatal conductance (Gwmax$$ {G}_{{\mathrm{w}}_{\mathrm{max}}} $$) and maximum carboxylation capacity (Vcmax$$ {V}_{{\mathrm{c}}_{\mathrm{max}}} $$). We found that leaves in cold‐temperate forests displayed ‘fast’ carbon economics, characterized by higher leaf nitrogen, Chl, specific leaf area, and Vcmax$$ {V}_{{\mathrm{c}}_{\mathrm{max}}} $$, as an adaptation to the shorter growing season. However, these leaves exhibited ‘slow’ hydraulic traits, with larger but fewer stomata and similar Gwmax$$ {G}_{{\mathrm{w}}_{\mathrm{max}}} $$, resulting in higher leaf WUE. By contrast, leaves in tropical forests had smaller and denser stomata, enabling swift response to heterogeneous light conditions. However, this stomatal configuration increased potential water loss, and coupled with their low photosynthetic capacity, led to lower WUE. Our findings contribute to understanding how plant photosynthetic and stomatal traits regulate carbon–water trade‐offs across climatic gradients, advancing our ability to predict the impacts of climate changes on forest carbon and water cycles. [ABSTRACT FROM AUTHOR]

Plant taxa and traits do not necessarily show synchronous responses to ecological disturbance. Based on the observation that taxonomically over‐diversified communities might be phenotypically redundant, we speculated that taxonomic and phenotypic community reassembly might be decoupled after fire in Mediterranean ecosystems.We applied a multi‐trait approach to describe plant community re‐assembly after fire across three 20‐year chronosequences based on 117 species and 23 traits, including whole‐plant, above‐ground and below‐ground traits. We quantified the post‐fire trajectories of different plant traits by analysing their community‐weighted means individually. We estimated the short‐ and long‐term phenotypic diversity of burned plots based on sets of traits. We also tested if trait and species turnover are decoupled across post‐fire trajectories. Finally, we calculated phenotypic redundancy, and assessed if above‐ and below‐ground traits have contrasted responses during post‐fire community reassembly.Individually, 16 out of 23 traits were affected by fire in the short term. Plant phenotypic diversity (stdMPD) decreased immediately after fire, driven by changes in whole‐ and above‐ground traits. Both whole‐ and above‐ground stdMPD in burned plots described positive trajectories across the chronosequences tending to converge with long‐unburned plots, whereas below‐ground stdMPD remained unaltered through time.Taxonomic and phenotypic beta diversity showed decoupled trajectories due to a larger species than trait replacement across time since fire. Finally, overall phenotypic redundancy of the studied plant communities described a regressive trajectory, similarly to above‐ground traits, whereas root traits kept a steady phenotypic redundancy through time.Synthesis. We provide evidence that above‐ and below‐ground traits describe different recovery trajectories after fire, with significant effects on the phenotypic redundancy of plant communities. Our results encourage the use of multi‐trait approaches to understand how the plant reassembly operates after disturbance, in order to refine ecological theory. This strategy might improve the efficacy of restoration programs through a functional approach to species selection. [ABSTRACT FROM AUTHOR]

Aim: Dispersal and environmental filtering processes affect plant species colonisation success on islands and can be identified by functional traits. However, the lack of synthesis about the different methodological approaches in functional ecology hampers generalisation of filtering processes across island systems. Location: Seventy islands of the Houtman Abrolhos archipelago, Western Australia. Major Taxa Studied: Angiosperms. Methods: We (i) apply a simple, conceptual framework based on the mean and variability of individual functional traits in plant assemblages to identify species filters on islands, (ii) illustrate how trait distributions of island assemblages change in relation to island area and their source pool, (iii) compare distributions of individual traits to multivariate functional diversity indices and trait spaces and (iv) provide guidelines to detect a signal of trait filtering in island floras. Results: The island assemblages showed evidence for selective filters operating on seed mass and marginally on leaf area but not on plant height. Mean and variability of seed mass differed to those of the source pool indicating selective forces operating between source pool and island assemblages, especially on smaller islands. Multivariate functional diversity indices and trait spaces failed to reveal filtering processes acting on the island assemblages and insights into the putative processes. Main Conclusions: Using the mean and variability of individual traits in plant assemblages provides direct information on the trait composition of island floras and the processes involved beyond what can be inferred from multivariate functional diversity indices or trait spaces. We used islands as their distinct boundaries and relatively simple sets of species provide good research models, but joint analyses of trait means and variability should also be applicable to understand filtering processes in isolates and habitat fragments on mainlands. [ABSTRACT FROM AUTHOR]

• The equations that use the product between L and W are the most suitable for predicting LA. • The linear and power models are the most suitable for estimating the leaf area of sweet potato cultivars;. • The proposed non-destructive method presents high accuracy for four sweet potato cultivars. Many researchers consider the leaf area the most critical parameter for plant growth and physiology studies. Using allometric equations is considered an effective and non-destructive method for estimating the leaf area of plants. The objectives of this study were to construct allometric equations to predict the leaf area of sweet potato cultivars as a function of leaf dimensions and to verify the effectiveness of the allometric equations constructed for each cultivar individually and for the grouped data. Two hundred fifty leaves of the sweet potato cultivars Beauregard, BRS Amélia, BRS Cuia, and Coquinho were collected, and then the length and width of each leaf were measured. Subsequently, the product between leaf length and width and the actual leaf area was calculated. Linear, linear without intercept, power, and exponential regression models were used to construct allometric equations to predict leaf area. The best equations were chosen according to the highest coefficients of determination and correlation, Willmott agreement index, and lowest Akaike information criterion and root mean square error. The equations obtained with the linear models without intercept and power using the length and width of the leaves were the most indicated for predicting the leaf area of sweet potato cultivars. [ABSTRACT FROM AUTHOR]

Fucoxanthin (FX) is a natural pigment that is found in brown seaweeds, diatoms, and other marine organisms. FX helps to improve the soil's physical and chemical properties. FX has been shown to have a positive impact on plant growth. The widespread usage and production of microplastics (MPs) products has resulted in a surge of plastic waste in the natural environment, posing a growing threat to plant growth. This study investigated the effects of Polystyrene MPs (PS) and FX on soil pH, electrical conductivity (EC), organic matter ;(OM), and available nutrients and maize (Zea mays L.) growth in a calcareous soil. Results showed PS led to a decline in soil pH, which negatively impacted maize growth. Higher levels of PS led to lower root and shoot dry weight, chlorophyll content, leaf area, and plant height. Increasing FX levels in the soil led to an increase in available nutrients, while decreasing EC and had a positive effect on maize growth factors, particularly under non-stress conditions. The positive effects of FX may be due to its antioxidant properties, ability to enhance photosynthesis, aid in nutrient absorption, and activate growth-related genes. FX mitigated the negative effects of PS on plant growth. The study highlights the potential of FX as a soil amendment to promote plant growth and mitigate the effects of environmental stressors on agriculture. [ABSTRACT FROM AUTHOR]

Background and Aims Leaf area (A) is a crucial indicator of the photosynthetic capacity of plants. The Montgomery equation (ME), which hypothesizes that A is proportional to the product of leaf length (L) and width (W), is a valid tool for non-destructively measuring A for many broadleaved plants. At present, the methods used to compute L and W for the ME can be broadly divided into two kinds: using computer recognition and measuring manually. However, the potential difference in the prediction accuracy using either method has not been thoroughly examined in previous studies. Methods In the present study, we measured 540 Alangium chinense leaves, 489 Liquidambar formosana leaves and 215 Liriodendron  ×  sinoamericanum leaves, utilizing computer recognition and manual measurement methods to determine L and W. The ME was used to fit the data determined by the two methods, and the goodness of fits were compared. The prediction errors of A were analysed by examining the correlations with two leaf symmetry indices (areal ratio of the left side to the right side, and standardized index for bilateral asymmetry), as well as the leaf shape complexity index (the leaf dissection index). Key Results The results indicate that there is a neglectable difference in the estimation of A between the two methods. This further validates that the ME is an effective method for estimating A in broadleaved tree species, including those with lobes. Additionally, leaf shape complexity significantly influenced the estimation of A. Conclusions These results show that the use of computer recognition and manual measurement in the field are both effective and feasible, although the influence of leaf shape complexity should be considered when applying the ME to estimate A in the future. [ABSTRACT FROM AUTHOR]

Background and Scope Plant functional traits are the result of natural selection to optimize carbon gain, leading to a broad spectrum of traits across environmental gradients. Among plant traits, leaf water storage capacity is paramount for plant drought resistance. We explored whether leaf-succulent taxa follow trait correlations similar to those of non-leaf-succulent taxa to evaluate whether both are similarly constrained by relationships between leaf water storage and climate. Methods We tested the relationships among three leaf traits related to water storage capacity and resource use strategies in 132 species comprising three primary leaf types: succulent, sclerophyllous, and leaves with rapid returns on water investment, referred to as fast return. Correlation coefficients among specific leaf area (SLA), water mass per unit of area (WMA), and saturated water content (SWC) were tested, along with relationships between leaf trait spectra and aridity determined from species occurrence records. Results Both SWC and WMA at a given SLA were ~10-fold higher in succulent leaves than in non-succulent leaves. While SWC actually increased with SLA in non-succulent leaves, no relationship was detected between SWC and SLA in succulent leaves, although WMA decreased with SLA in all leaf types. A principal component analysis (PCA) revealed that succulent taxa occupied a widely different mean trait space than either fast-return (P  < 0.0001) or sclerophyllous (P  < 0.0001) taxa along the first PCA axis, which explained 63 % of mean trait expression among species. However, aridity only explained 12 % of the variation in PCA1 values. This study is among the first to establish a structural leaf trait spectrum in succulent leaf taxa and quantify contrasts in leaf water storage among leaf types relative to specific leaf area. Conclusions Trait coordination in succulent leaf taxa may not follow patterns similar to those of widely studied non-succulent taxa. [ABSTRACT FROM AUTHOR]

Eucalyptus are trees sensitive to interference imposed by weeds mainly during the early growth phase. The repetitive use of herbicides with the same mechanism of action has led to the selection of resistant weeds, and Digitaria insularis stands out for its resistance to glyphosate. Due to its occurrence in eucalyptus plantations, knowledge regarding D. insularis interference in eucalyptus early growth is needed to develop management strategies. This study aimed to confirm D. insularis glyphosate-resistence; and also to evaluate the effect of densities and distances of glyphosate-resistant D. insularis, seeded and in regrowth, on the early growth of Eucalyptus urophylla × E. grandis (Clone AEC-144). Prior to eucalyptus' experiments, D. insularis glyphosate-resistance was confirmed through a dose–response curve experiment. After that, two experiments [one for weed's first growth (seeded) and other for second growth (regrowth)] were carried out in an open area, in 700 L pots, for 105 days after planting eucalyptus seedlings. The treatments consisted of increasing densities of D. insularis (0, 1, 2 and 3 plants m−2) planted at 10, 20 or 30 cm from the eucalyptus seedlings. Eucalyptus height, stem diameter, leaf area and dry matter were evaluated. The eucalyptus variables most sensitive to interference were leaf and stem dry matter, with reductions of 45% and 88.4%, respectively for weeds seeded and regrowth. Weed second growth (regrowth) interfered more aggressively in eucalyptus growth. The coexistence with D. insularis, regardless of density and distance, negatively interfered early tree growth. [ABSTRACT FROM AUTHOR]

Global warming may pose a threat to the productivity of grazed grasslands. In this study, we investigated changes in the warming response of aboveground regrowth with the repetition of simulated grazing in two Mongolian pasture species, Agropyron cristatum and Stipa krylovii. Plants were grown under warming or non-warming conditions and subjected to repeated clipping of aboveground parts three times at 4-week intervals. Aboveground parts collected at each clipping and whole plants harvested at the end of the experiment were dried and weighed. Specific leaf area (SLA) and the content of nitrogen (N) and crude fiber (CF) in leaves were measured to evaluate leaf morphology and pasture nutritional value. In both species, warming had little effect on regrowth when clipping was repeated one or two times. In A. cristatum, however, warming significantly diminished regrowth when clipping was repeated three times. Belowground biomass decreased with clipping–regrowth cycles only in A. cristatum, and the decline was enhanced by warming, implying that the depletion of belowground reserves contributed to the reduction of regrowth in this species. SLA and the N and CF contents were similar in the warming and non-warming treatments, indicating that warming had little effect on leaf morphology and pasture nutritive value in these Mongolian pasture species. Our results suggest that warming would likely have little effect on regrowth performance of grassland plants under lightly grazed conditions, but warming can decrease regrowth when grazing frequency is high, with the degree of decrease being species dependent. [ABSTRACT FROM AUTHOR]

In maize-soybean intercropping systems (ICS), the morphophysiological growth traits and grain yield of component crops (CC), especially of soybean suffer greatly, owing to the dominance of maize in acquiring growth resources and shading effect. Thus, a field trial was conducted entailing maize hybrids (H1= YH-1898 and H2= YH-5427) and defoliation treatments (R1= removal of top two leaves, R2= removal of top four leaves, R3= removal of top six leaves, and R4= no removal of leaves) for boosting soybean (cv. AARI-soybean) growth and yield in maize-soybean ICS. The response variables included plant height (PH), 1000 grains weight, grain yield (GY), and biological yield (BY) along with the physiological growth traits (leaf area index LAI, leaf area duration LAD, crop growth rate CGR, and net assimilation rate NAR) of CC. The H1 hybrid of maize outperformed the other hybrid by recording 8% and 9% higher PH and BY, respectively, while the H2 hybrid depicted 18% and 6% greater 1000 grain weight and GY, respectively, along with NAR. Additionally, R1H2 exhibited the maximum LAI, LAD, and CGR at 30, 60, 90, and 110 days after sowing (DAS). Contrastingly, soybean recorded 11% higher PH in intercropping with the H1 hybrid under R4 defoliation treatment along with significantly higher 1000 grains weight (13%), GY (57%), BY (10%), and NAR (157%). Moreover, soybean exhibited the maximum physiological growth in response to the R4H1 treatment combination. On the basis of the recorded findings, the H2R1 treatment combination could be recommended for boosting maize yield, whereas H1R4 or H1R3 could be adopted to bolster the growth and productivity of soybean intercrop, but at the cost of a significant reduction in maize yield. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Extreme precipitation events are becoming more intense and frequent due to climate change. This climatic shift is impacting the structure and dynamics of natural communities and the key ecosystem services they provide. Changes in species abundance under these conditions are thought to be mediated by functional traits, morpho‐physiological characteristics of an organism that impact its fitness. Future environmental conditions may, therefore, favour different traits to those in present‐day communities. After 6 years of manipulated precipitation levels, including drought (−50% of ambient precipitation), irrigation (+50% of ambient precipitation), and control (ambient precipitation), we measured five key functional traits (plant height, leaf dry matter content [LDMC], leaf thickness, specific leaf area [SLA], and leaf phosphorus concentration) in 586 individual vascular plants to study the effects of precipitation changes on community‐weighted functional traits. Additionally, we tested whether the precipitation change effects on the traits depend on the time of the growing season. As expected, reduced precipitation impacted community composition only for the late‐season timing, after the seasonal field mowing, but led to a significant change in all community‐level plant traits between season timings. Under drought, communities shifted towards shorter individuals with thicker but small leaves and lower phosphorous content. Overall, a combination of community reassembly and intraspecific variation contributed to community‐weighted differences between control and drought plots for plant height, SLA, and LDMC traits. Species turnover was the main driver of community‐weighted means (CWMs) shifts in all traits in the late‐season but SLA. Whereas all traits showed variations at the community level with drought, SLA and LDMC were the most responsive traits at the species level. Nevertheless, our results suggest underestimation of intraspecific variation due to sensitive species lower abundance under stress. No differences in CWMs of functional traits were observed between control and irrigated plots. Synthesis: Our findings suggest that functional trait composition of grassland communities may shift under climate change‐induced drought, depending on the growing season timings. Trait‐based attempts to predict ecosystem functioning must account for such temporal variation in community trait values. [ABSTRACT FROM AUTHOR]

This study employed two prevalent plastic products - straws and microfiber as microplastics (MPs) to elucidate their largely unexplored effects on soil's properties and the growth of the tomato plant (Solanum lycopersicum L.). For this experiment, a completely randomized design (CRD) was adopted where, straw - polypropylene (PP), microfiber - polyester (PES) + polyamide (PA), and their combinations (PP + PES + PA) were mixed with soil using different concentrations – 0% (control), 0.4%, 1%, and 2% (treatments) and kept for 45 days at room temperature. The findings demonstrated that incorporating 2% mixed MPs in soil significantly decreased bulk density and electrical conductivity 7.29% and 67.3%, respectively, while soil pH increased 17.84% in cultures containing 1% microfiber. Maximum water holding capacity (MWHC), soil organic carbon (SOC), and soil organic matter (SOM) showed varied responses based on MPs type and concentration. Specifically, MWHC increased 16.4% with 2% microfiber but declined 13.3% with 0.4% straw. The highest decreased (30.65%) in SOC and SOM were evident in cultures with 1% microfiber whereas increased 9.68% and 8.33% in cultures with 0.4% straw. In terms of the growth traits of S. lycopersicum, substantial reductions in plant height (56.37%), leaf number (54.37%), and girth diameter (56.43%) were observed in 2% straw containing cultures. Although no plant mortality was noted, the most pronounced reductions in leaf area (62.44%) and total plant biomass (68.16%) occurred in 2% microfiber cultures. Therefore, the ramifications of these findings may contribute to a deeper comprehension of the mechanisms and effects of MPs on soil properties and above-ground plant growth. [ABSTRACT FROM AUTHOR]

Large-scale multiplication of quality planting material is needed to meet the huge demand of planting material in fruit crops. Little information is available on the effect of fertigation on rootstock growth, budding success, and buddling growth in containerized citrus nursery. The present studies were undertaken to study the effect of eight fertigation treatments viz. control (N0P0), N60, N80, N100, N0P100, N60P100, N80P100, and N100P100 on the growth of rough lemon rootstock and subsequently budded three citrus varieties. Among the treatments, N60P100 significantly improved seedling height, diameter, leaf number, root growth, leaf area in rough lemon, Blood Red orange, Kinnow mandarin, and Daisy mandarin over the control. The stomatal conductance was higher with treatments N60, N80, N60P100, and N80P100. While higher photosynthetic rates were observed with N60P100 and N80P100, N60P100 also improved the budding success in Blood Red, Kinnow, and Daisy. Fertigation treatments increased the nutrient concentration in leaves of all the varieties. The principal component analysis revealed that plant height and diameter were positively correlated with root length, root diameter, root number, photosynthetic rate, stomatal conductance, and chlorophyll content in rough lemon. In all the varieties, the sprout length and diameter showed a positive correlation with leaf area, leaf number, root length, root diameter, fibrous root number, photosynthesis rate, stomatal conductance, and chlorophyll content. Among different treatments, N60P100 was the best treatment in improving the shoot growth, root growth, and physiological parameters of rough lemon rootstock. Besides, it also improved budding success and buddling growth in all three citrus varieties. [ABSTRACT FROM AUTHOR]

Various attributes are hypothesized to facilitate the dominance of an invasive species in non-native geographical and ecological regimes. To explore the characteristic invasive attributes of the family Asteraceae, a comparative study was conducted among nine species of this family, co-occurring in the western Himalayan region. Based on their nativity and invasion status, the species were categorized as "Invasive", "Naturalized", and "Native". Fifteen plant functional traits, strongly linked with invasion, were examined in the test species. The analyses revealed a strong dissimilarity between all the plant functional traits (except leaf carbon [Leaf C]) represented by "Invasive" and "Native" categories and most of the traits (except leaf area [LA], leaf nitrogen [Leaf N], Leaf C, and leaf carbon-nitrogen ratio [C: N]) represented by the "Naturalized" and "Native" categories. Similarly, "Invasive" and "Naturalized" categories also varied significantly for most of the traits (except Leaf N, Leaf C, capitula per m² population [Cm²], seeds per capitula [Scapitula], and seed mass). Invasive species are characterized by high LA, specific leaf area [SLA] and germination, and low C:N and leaf construction costs [LCC]. Most of the traits represented by native species justify their non-invasive behavior; whereas the naturalized species, despite having better size metrics (plant height), resource investment strategy (aboveground non-reproductive biomass [BNR], and aboveground reproductive biomass [BR]), and reproductive output (capitula per individual plant [Cplant], and seeds per individual plant [Splant]) failed to invade, which implies that the role of these functional aspects in imparting invasion potential to a species is not consistent in all the ecosystems and/or phylogenetic groups. Results of PCA revealed that trait divergence plays a more imperative role in invasion success than naturalization in the species of the family Asteraceae. The present study is intended to refine the pre-generalized invasion concepts associated with family Asteraceae to ensure more accurate identification of the potential invaders and better management of the existing ones. [ABSTRACT FROM AUTHOR]

This study examines the impact of canopy density, side wind speed, nozzle tilt angle, and droplet size on droplet penetration during plant protection spraying operations. Experiments conducted in citrus orchards evaluated how side wind speed and nozzle tilt angle influence droplet penetration across various canopy densities. A Phase Doppler Analyzer (PDA) was used to assess droplet size variations under different nozzle tilt angles and side wind speeds, yielding a multiple linear regression equation (R2 = 0.866) that links nozzle tilt angle and side wind speed with droplet size. Results showed that droplet size decreases with increasing nozzle tilt angle at a constant crosswind speed. Further experiments investigated the effects of droplet size and canopy leaf area density on droplet penetration, involving three canopy leaf area densities, four wind speeds, and six nozzle tilt angles. Droplet deposition and canopy coverage were measured under various spraying parameters, with conventional operations (0° nozzle tilt and orthogonal wind speeds) serving as controls. The study found that adjusting nozzle tilt angle and wind speed enhances droplet penetration in different canopy structures. Optimal parameters varied with leaf area density (LAD): an 18° tilt angle and 3 m/s wind speed for a LAD of 5.94 m3/m3, a 45° tilt angle and 2 m/s wind speed for a LAD of 8.47m2/m3, and a 36° tilt angle and 3 m/s wind speed for a LAD of 11.12m2/m3. At 1 m/s, droplet deposition followed a downward parabolic trend with changes in nozzle tilt angle, whereas at 2 m/s, deposition followed an upward parabolic trend. At a side wind speed of 3 m/s, droplet deposition remained unchanged with nozzle tilt angle but decreased with increasing canopy density. Nonlinear regression analysis indicated that leaf area density had a greater impact on deposition differences than droplet size, with droplet penetration decreasing as leaf area density increased. This study provides a reference for enhancing fog droplet penetration techniques in plant protection operations, offering practical guidelines for optimizing spraying conditions and improving pesticide use efficiency in different canopy structures. [ABSTRACT FROM AUTHOR]

Specific leaf area (SLA) and leaf dry matter content (LDMC) are key leaf functional traits often used to reflect plant resource utilization strategies and predict plant responses to environmental changes. In general, grassland plants at different elevations exhibit varying survival strategies. However, it remains unclear how grassland plants adapt to changes in elevation and their driving factors. To address this issue, we utilized SLA and LDMC data of grassland plants from 223 study sites at different elevations in China, along with climate and soil data, to investigate variations in resource utilization strategies of grassland plants along different elevational gradients and their dominant influencing factors employing linear mixed-effects models, variance partitioning method, piecewise Structural Equation Modeling, etc. The results show that with increasing elevation, SLA significantly decreases, and LDMC significantly increases (P < 0.001). This indicates different resource utilization strategies of grassland plants across elevation gradients, transitioning from a "faster investment-return" at lower elevations to a "slower investment-return" at higher elevations. Across different elevation gradients, climatic factors are the main factors affecting grassland plant resource utilization strategies, with soil nutrient factors also playing a nonnegligible coordinating role. Among these, mean annual precipitation and hottest month mean temperature are key climatic factors influencing SLA of grassland plants, explaining 28.94% and 23.88% of SLA variation, respectively. The key factors affecting LDMC of grassland plants are mainly hottest month mean temperature and soil phosphorus content, with relative importance of 24.24% and 20.27%, respectively. Additionally, the direct effect of elevation on grassland plant resource utilization strategies is greater than its indirect effect (through influencing climatic and soil nutrient factors). These findings emphasize the substantive impact of elevation on grassland plant resource utilization strategies and have important ecological value for grassland management and protection under global change. [ABSTRACT FROM AUTHOR]

AbstractForage legumes face simultaneous abiotic and biotic stresses, causing substantial yield losses. This study explores the combined impacts of drought and Phoma medicaginis infection on the growth and photosynthetic activity of Medicago truncatula contrasting lines TN6.18 and F83005.5. The tolerant TN6.18 line exhibits superior tolerance to combined drought and P. medicaginis infection, manifesting in minimal leaf area reduction, the highest number of healthy leaves, increased carotenoids content, a consistently high and stable photosynthesis rate, and enhanced performance of photosystems PSI and PSII. On the contrary, the sensitive F83005.5 line shows pronounced leaf chlorosis, particularly under drought stress, and decreased pigment levels under the combination of drought and P. medicaginis infection stresses (combined stress). Moreover, the drought-stressed F83005.5, experiences reduced hydration and photosynthetic performance, linked to diminished gas exchange and chlorophyll fluorescence parameters. Chlorophyll fluorescence revealed more severe PSI impairment than PSII under combined stress. In conclusion, understanding the Pm8 infection-drought interaction enhances insights into M. truncatula resistance mechanisms to the combination of these stresses. [ABSTRACT FROM AUTHOR]

Gibberellins (GAs), enzymes that play a significant role in plant growth and development, and their levels in plants could be regulated by gibberellin-oxidases (GAoxs). As important fruit trees and ornamental plants, the study of the mechanism of plant architecture formation of the Prunus genus is crucial. Here, 85 GAox genes were identified from P. mume, P. armeniaca, P. salicina, and P. persica, and they were classified into six subgroups. Conserved motif and gene structure analysis showed that GAoxs were conserved in the four Prunus species. Collinearity analysis revealed two fragment replication events of PmGAoxs in the P. mume genome. Promoter cis-elements analysis revealed 24 PmGAoxs contained hormone-responsive elements and development regulatory elements. The expression profile indicated that PmGAoxs have tissue expression specificity, and GA levels during the dormancy stage of flower buds were controlled by certain PmGAoxs. After being treated with IAA or GA3, the transcription level of PmGA2ox8 in stems was significantly increased and showed a differential expression level between upright and weeping stems. GUS activity driven by PmGA2ox8 promoter was detected in roots, stems, leaves, and flower organs of Arabidopsis. PmGA2ox8 overexpression in Arabidopsis leads to dwarfing phenotype, increased number of rosette leaves but decreased leaf area, and delayed flowering. Our results showed that GAoxs were conserved in Prunus species, and PmGA2ox8 played an essential role in regulating plant height. [ABSTRACT FROM AUTHOR]

Drought stress deteriorates agro-ecosystems and poses a significant threat to crop productivity and food security. Soil amended with biochar has been suggested to mitigate water stress, but there is limited knowledge about how biochar affects the physiology and vegetative growth of quinoa plants under soil water deficits. We grew three quinoa (Chenopodium quinoa Willd.) varieties, Titicaca (V1), Quipu (V2), and UAFQ7 (V3) in sandy loam soil without (B0) and with 2% woodchip biochar (B2) under drought conditions. The drought resulted in significant growth differences between the varieties. V3 performed vegetatively better, producing 46% more leaves, 28% more branches, and 25% more leaf area than the other two varieties. Conversely, V2 displayed significantly higher yield-contributing traits, with 16% increment in panicle length and 50% more subpanicles compared to the other varieties. Woodchip biochar application significantly enhanced the root development (i.e., root biomass, length, surface, and projected area) and plant growth (i.e., plant height, leaf area, and absolute growth rate). Biochar significantly enhanced root growth, especially fresh and dry weights, by 122% and 127%, respectively. However, biochar application may lead to a trade-off between vegetative growth and panicle development under drought stress as shown for V3 grown in soil with woodchip biochar. However, V3B2 produced longer roots and more biomass. Collectively, we suggest exploring the effects of woodchip biochar addition to the soil on the varietal physiological responses such as stomatal regulations and mechanisms behind the increased quinoa yield under water stress conditions. [ABSTRACT FROM AUTHOR]

Due of the potential of species to determine ecosystem properties, it is important to understand how species abundance influences community assembly. Using vegetation surveys on 35 dry grasslands in north-east Slovenia, we defined dominant (8) and subordinate (61) plant species. They were compared on 14 traits to test for differences in community-weighted mean (CWM) and functional diversity (FD). We found that dominants and subordinates differed strongly in their functional traits. Dominants showed higher leaf dry matter content and a more pronounced stress tolerance strategy and were all clonal with a large proportion of species with rhizomes and a rich bud bank, while other species showed a higher specific leaf area, a longer flowering period and more ruderals. For most traits, FD was higher in subordinates. Our results suggest that dominants drive community structure by limited susceptibility to non-competitive processes. Dominants may have positive effects on subordinates by mitigating environmental stressors. Subordinates are able to assemble together by being dissimilar and use different fine-scale niches that are engineered and homogenised by dominants. Our results show that there are fundamental differences in the relative importance of ecological processes between dominant and subordinate plants in species-rich grasslands, which is also important for their conservational management. [ABSTRACT FROM AUTHOR]

Background: Leaf nitrogen (N) and phosphorus (P) resorption is a fundamental adaptation strategy for plant nutrient conservation. However, the relative roles that environmental factors and plant functional traits play in regulating N and P resorption remain largely unclear, and little is known about the underlying mechanism of plant functional traits affecting nutrient resorption. Here, we measured leaf N and P resorption and 13 plant functional traits of leaf, petiole, and twig for 101 representative broad-leaved tree species in our target subtropical transitional forests. We integrated these multiple functional traits into the plant economics spectrum (PES). We further explored whether and how elevation-related environmental factors and these functional traits collectively control leaf N and P resorption. Results: We found that deciduous and evergreen trees exhibited highly diversified PES strategies, tending to be acquisitive and conservative, respectively. The effects of PES, rather than of environmental factors, dominated leaf N and P resorption patterns along the elevational gradient. Specifically, the photosynthesis and nutrient recourse utilization axis positively affected N and P resorption for both deciduous and evergreen trees, whereas the structural and functional investment axis positively affected leaf N and P resorption for evergreen species only. Specific leaf area and green leaf nutrient concentrations were the most influential traits driving leaf N and P resorption. Conclusions: Our study simultaneously elucidated the relative contributions of environmental factors and plant functional traits to leaf N and P resorption by including more representative tree species than previous studies, expanding our understanding beyond the relatively well-studied tropical and temperate forests. We highlight that prioritizing the fundamental role of traits related to leaf resource capture and defense contributes to the monitoring and modeling of leaf nutrient resorption. Therefore, we need to integrate PES effects on leaf nutrient resorption into the current nutrient cycling model framework to better advance our general understanding of the consequences of shifting tree species composition for nutrient cycles across diverse forests. [ABSTRACT FROM AUTHOR]

Cuscuta chinensis have a significant regulatory effect on plant growth, but the response mechanism of functional traits to the parasitism of C. chinensis and the trade-off relationship between traits and hyperspectral characteristics are not clear. We investigated the functional trait response and hyperspectral characteristics of Euonymus japonicus, the most common urban hedge plant in China, to the parasitism of C. chinensis. The results showed that the parasitism of C. chinensis led to the difference of leaf functional traits: the leaf thickness, stomatal density, and leaf dry matter content were significantly increased, whereas the leaf area, leaf weight, specific leaf area, chlorophyll content index, and leaf tissue density were significantly decreased. Notably, the parasitism of C. chinensis changed the spatial distribution pattern of stomata and promoted the stomata to be evenly distributed. Furthermore, the spectral reflectance of leaves treated with the parasitism of C. chinensis tended to increase. The parasitism of C. chinensis led to the "blue shift" of hyperspectral reflectance of leaves. There was a significant correlation between spectral parameters and leaf functional traits, and leaf biomass accounted for 83% of the variation in reflectance of the water stress band. In general, the parasitism of C. chinensis determines the strategic way of plant utilization of resources and affects the change of plant strategy by affecting the difference of traits. Urban plants were more inclined to invest resources in nutrient storage capacity at the expense of resources investment in photosynthetic capacity and defense mechanism. The plant ecological strategy changed from resource acquisition to resource conservation. This finding comes up with a new strategy that urban tree species can modify the plasticity of functional traits for survival and growth under the interference of parasitic plants. [ABSTRACT FROM AUTHOR]

Future changes in climate, together with rising atmospheric CO 2 ${\text{CO}}_{2}$, may reorganise the functional composition of ecosystems. Without long‐term historical data, predicting how traits will respond to environmental conditions—in particular, water availability—remains a challenge. While eco‐evolutionary optimality theory (EEO) can provide insight into how plants adapt to their environment, EEO approaches to date have been formulated on the assumption that plants maximise carbon gain, which omits the important role of tissue construction and size in determining growth rates and fitness. Here, we show how an expanded optimisation framework, focussed on individual growth rate, enables us to explain shifts in four key traits: leaf mass per area, sapwood area to leaf area ratio (Huber value), wood density and sapwood‐specific conductivity in response to soil moisture, atmospheric aridity, CO 2 ${\text{CO}}_{2}$ and light availability. In particular, we predict that as conditions become increasingly dry, height‐growth optimising traits shift from resource‐acquisitive strategies to resource‐conservative strategies, consistent with empirical responses across current environmental gradients of rainfall. These findings can explain both the shift in traits and turnover of species along existing environmental gradients and changing future conditions and highlight the importance of both carbon assimilation and tissue construction in shaping the functional composition of vegetation across climates. [ABSTRACT FROM AUTHOR]

Increased atmospheric nitrogen (N) deposition significantly disturbs ecosystem N cycle. Although foliar interception and uptake of N deposition can provide an important alternative N supply to forest ecosystems, the mechanisms regulating foliar N uptake from wet deposition are not fully understood. Here, we selected 19 woody species with a wide range of plant traits from different functional groups and conducted a 15N isotope labelling experiment through brushing 15NH4+ and 15NO3− solution on canopy leaves. Our findings demonstrate that leaves can directly absorb N from wet deposition within a few hours. The average leaf 15N recoveries were 10% and 28% under 15NH4+ and 15NO3− treatments across species, respectively, while twig N recoveries were only 1%–7% of leaf N recoveries. Differences in foliar N uptake efficiency among species were closely associated with leaf traits but were little influenced by meteorological conditions or soil nutrient status. Specifically, plants with higher leaf N concentration, larger specific leaf area and lower wax concentration exhibited higher leaf N recovery. Our results indicated that tree canopies could directly absorb N from atmospheric deposition. We highlight the critical role of leaf traits in determining canopy foliar N uptake, which may consequently influence plant competition under elevated N deposition. [ABSTRACT FROM AUTHOR]

Aerospace breeding is a breeding technique that utilizes a spacecraft to position plants in a space environment for mutagenesis, which is conducive to rapid mutagenesis for the screening of superior plant varieties. In this study, tea trees with aviation mutagenesis (TM) and those without aviation mutagenesis (CK) were selected as research subjects to analyze the effects of aviation mutagenesis on the growth, physiological properties, and hormone metabolism of tea trees, and to further screen the characteristic hormones and validate their functions. The results showed that the leaf length, leaf width, and leaf area of TM tea trees were significantly larger than those of CK. The growth indexes, the photosynthetic physiological indexes (i.e., chlorophyll content, intercellular CO2 concentration, stomatal conductance, transpiration rate, and photosynthetic rate), and the resistance physiological indexes (i.e., superoxide dismutase, peroxidase, catalase, and soluble sugar) were significantly higher in TM than in CK. Hormone metabolome analysis showed that four characteristic hormones distinguished CK from TM, namely, l-tryptophan, indole, salicylic acid, and salicylic acid 2-O-β-glucoside, all of which were significantly more abundant in TM than in CK. These four characteristic hormones were significantly and positively correlated with the growth indexes, tea yield, and the photosynthetic and resistance physiological indexes of tea trees. The leaf area, chlorophyll content, photosynthetic rate, and superoxide dismutase activity of tea tree seedlings after spraying with the four characteristic hormones were significantly increased, in which salicylic acid and salicylic acid 2-O-β-glucoside were more favorable to increase the leaf area and superoxide dismutase activity, while l-tryptophan and indole were more favorable to increase the leaf chlorophyll content and photosynthetic rate. It can be observed that aviation mutagenesis improves the accumulation of the characteristic hormones of tea trees, enhances their photosynthetic capacity, improves their resistance, promotes their growth, and then improves the tea yield. [ABSTRACT FROM AUTHOR]

Background: Drought is a significant abiotic stress that adversely affects plant growth, development, and metabolic processes, thereby reducing plant yield, quality, and production, and threatening global food security. In recent years, nanotechnology has emerged as a promising strategy to overcome the existing environmental challenges and has been tested on some plant species. But it is still awaiting investigation for grapevines. The aim of this study was to investigate the potential of selenium nanoparticles (Se-NPs) to modulate some morphological, physiological, and biochemical parameters in grapevine saplings (5 BB/Crimson Seedless, 41 B/Crimson Seedless, and 1103 P/Crimson Seedless) under drought stress conditions. Results: In the study, Se-NP solutions at different concentrations (0 (control), 1, 10, and 100 ppm) were applied by the spray method to wet the entire green surface of grapevine saplings grown under well-irrigated (90–100% field capacity) and drought stress (40–50% field capacity) conditions. Our results showed that 10 ppm Se-NP concentration had the most positive effect, 1 ppm concentration showed limited effects, and 100 ppm concentration led to toxic effects, especially when combined with drought conditions. Se-NP applications at 10 ppm concentration improved the growth parameters (leaf number, leaf area, root fresh and dry weight, shoot fresh and dry weight, etc.) and increased the SPAD index of grapevine saplings under both normal and drought conditions. Additionally, 10 ppm Se-NP applications improved the relative water content (RWC) and stomatal conductance values, proportional to the increases in protein content. On the other hand, under drought conditions, the drought index, leaf temperature, membrane damage index, hydrogen peroxide (H2O2) content, and malondialdehyde (MDA) levels significantly decreased as a result of 10 ppm Se-NP applications, showing an opposite trend. Furthermore, the levels of proline, total phenolics, and antioxidant enzymes (CAT, SOD, and APX) that rose significantly due to drought stress were reduced by 10 ppm Se-NP applications, which also helped to lessen the oxidative stress caused by the drought. Conclusion: The study concluded that foliar application of Se-NPs at 10 ppm significantly enhances drought tolerance in grapevine saplings by improving antioxidant defense, proline and protein accumulation, and overall growth, while lower concentrations are less effective and higher concentrations can cause phytotoxicity. These findings indicate that Se-NPs applications may hold promise not only for grapevines but also for mitigating drought stress effects and improving productivity in other economically important fruit species, warranting further exploration across diverse crop systems. [ABSTRACT FROM AUTHOR]

The presented maize experiment commenced in autumn 2022 at the Al-Hussainiya, Kerbala, Iraq. The experiment comprised two factors: the first included nitrogen (0, 150, and 300 kg N ha-1) and phosphorus (0, 50, and 100 kg P ha-1), and the second was the seaweed extract (2 and 4 ml L-1) used as a foliar application. The seaweed extracts (Algazone Mx30) were treatments applied in the main plots, while the subplots received mineral fertilizer combinations. A randomized complete block design (RCBD) consisted of a factorial arrangement and three replications to evaluate the maize cultivar ‘Maha’s’ response in clay loam soil. In most growth and yield parameters, applying nitrogen-phosphorous fertilizer combinations and the foliar application of seaweed extract (4 ml L-1) had a substantial effect. The interaction between the seaweed extract and nitrogen and phosphate fertilizers significantly improved leaf area, stem diameter, chlorophyll index in leaves, 500-grain weight, and biological and grain yields. The treatments with seaweed extract (4 ml L-1) and the combination of 150 N + 50 P performed better for leaf area (55.48 cm² plant-1), stem diameter (23.10 mm), chlorophyll index (48.54 SPAD), 500-grain weight (141.17 g), biological yield (357.56 g plant-1), and grain yield (201.46 g plant-1). [ABSTRACT FROM AUTHOR]

The latest study aimed to identify the effects of organic manure (sheep manure) with four concentrations (0, 5, 10, and 15 g seedling-1) and nano-zinc four levels (0, 1, 2, and 3 g L-1) on the growth of peach cultivar Hollywood seedlings. The experiment began in 2022 at private nurseries in Babylon province, Iraq. The nano-zinc application with three foliar sprays transpired at 30-day intervals. The experiment continued in a randomized complete block design (RCBD) with three replications. The addition of organic manure treatment (15 g seedling-1) excelled in traits of seedling length, stem diameter, number of leaves, chlorophyll content, shoot dry weight, leaves area, and zinc in the leaves, with highest averages of 62.03 cm, 8.08 mm, 51.20 leaf seedling-1, 43.8 SPAD, 57.35 g seedling-1, 1322.3 cm², and 56.40 mg kg-1, respectively, compared with the control treatment. The addition of nano-zinc (3 g L-1) was significantly superior in performance and excelled other treatments by revealing the highest values for the above growth traits, i.e., 60.45 cm, 7.83 mm, 50.90 leaves seedling-1, 42.35 SPAD, 54.85 g seedling-1, 1251.90 cm², and 53.63 mg kg-1, respectively. [ABSTRACT FROM AUTHOR]

Background: Nitrogen and phosphorus are amongst fundamental macronutrients, which are crucial for the growth and development of plant. Soils of dry land of central Rajasthan are deficit in nitrogen and phosphorus content which leads to lower productivity of kasuri methi. Therefore, adequate supply of nitrogen (foliar spray) and phosphorus could enhance productivity of kasuri methi. Methods: The experiment consisted of sixteen treatment combinations including four levels of phosphorus (control, 20, 40 and 60 kg/ha) and four levels of foliar application of nitrogen (control, 1.0, 1.5 and 2.0%). They were under taken in FRBD with three replications. Result: Growth parameters and yield of fresh and dried leaves of the crop increased almost linearly with increasing levels of phosphorus and foliar application of nitrogen. The result indicated that application of phosphorus 60 kg/ha and foliar nitrogen @ 2.0% to the kasuri methi crop significantly increased the plant height (cm) and leaf area per plant (cm² ) at each harvest, number of nodules per plant (58.17 and 53.33, respectively) and chlorophyll content (2.32 and 2.39 mg/100 g, respectively), fresh leaves yield (139.1 and 141.66 q/ha, respectively), dry leaves yield (20.01 and 22.38 q/ha, respectively), protein content in leaves (5.28 and 5.75%, respectively) and ascorbic acid in leaves (218.15 and 222.42 mg/100 g, respectively). [ABSTRACT FROM AUTHOR]

In the search for environmentally friendly options to manage plant pests and enhance productivity with fewer external inputs in agriculture, the screening of landraces has gained importance. The aims of this study were to characterize functional leaf traits in maize landraces, including morphological traits such as leaf toughness, thickness, specific leaf area (SLA), and number of trichomes, as well as physiological leaf traits such as photosynthesis, transpiration rate, and stomatal conductance. We aimed to determine the association of these traits with leaf damage caused by Spodoptera frugiperda across 24 maize landraces. Relationships of dependence among leaf traits and leaf damage were determined using principal component analysis, multiple regression analysis and sequential path analyses. All morphological leaf traits showed differences among maize landraces mainly at 20 and 30 days after emerge (DAE) whereas at 40 DAE the differences decreased. By the contrast, physiological leaf traits had high variation at 40 DAE among maize landraces. We found a negative dependency of principal component conformed by photosynthesis, transpiration rate, and stomatal conductance over leaf damage. Based on the level of leaf damage, we categorized maize landraces into two groups with low and high susceptibility. Surprisingly, we observed that in the former group, physiological leaf traits affected the number of trichomes, whereas in the latter group, they influenced leaf thickness. This finding highlights the necessity of detailed assessments of foliage properties to understand the impact of S. frugiperda infestations. Such an analytical approach is crucial in scientific research, providing deeper insights into the underlying mechanisms of interaction between the pest and its host plants. [ABSTRACT FROM AUTHOR]

Rarely do we observe competitive exclusion within plant communities, even though plants compete for a limited pool of resources. Thus, our understanding of the mechanisms sustaining plant biodiversity might be limited. In this study, we explore two common ecological strategies, species sorting and character displacement, that promote coexistence by reducing competition. We assess the degree to which woody plants may implement these two strategies to lower belowground competition for nutrients which occurs via nutritional (mostly mycorrhizal) mutualisms. First, we compile data on plant traits and the mycorrhizal association state of woody angiosperms using a global inventory of indigenous flora. Our analysis reveals that species in locations with high mycorrhizal diversity exhibit distinct mean values in leaf area and wood density based on their mycorrhizal type, indicating species sorting. Second, we reanalyse a large dataset on leaf area to demonstrate that in areas with high mycorrhizal diversity, trees maintain divergent leaf area values, showcasing character displacement. Character displacement among plants is considered rare, making our observation significant. In summary, our study uncovers a rare occurrence of character displacement and identifies a common mechanism employed by plants to alleviate competition, shedding light on the complexities of plant coexistence in diverse ecosystems. [ABSTRACT FROM AUTHOR]

An introduction to a novel habitat represents a challenge to plants because they likely would face new interactions and possibly different physical context. When plant populations arrive to a new region free from herbivores, we can expect an evolutionary change in their defense level, although this may be contingent on the type of defense, resistance or tolerance, and cost of defense. Here, we addressed questions on the evolution of tolerance to damage in non-native Spanish populations of Datura stramonium by means of two comparative greenhouse experiments. We found differences in seed production, specific leaf area, and biomass allocation to stems and roots between ranges. Compared to the Mexican native populations of this species, non-native populations produced less seeds despite damage and allocate more biomass to roots and less to stems, and had higher specific leaf area values. Plasticity to leaf damage was similar between populations and no difference in tolerance to damage between native and non-native populations was detected. Costs for tolerance were detected in both regions. Two plasticity traits of leaves were associated with tolerance and were similar between regions. These results suggest that tolerance remains beneficial to plants in the non-native region despite it incurs in fitness costs and that damage by herbivores is low in the non-native region. The study of the underlying traits of tolerance can improve our understanding on the evolution of tolerance in novel environments, free from plants' specialist herbivores. [ABSTRACT FROM AUTHOR]

Rodents can cause considerable changes in plant community composition. However, relationships between shifts in species dominance and plant functional traits caused by rodents have seldom been investigated, especially for belowground functional traits. In this study, a set of enclosures was constructed to analyze the effects of 10 years of Brandt's voles' activities on the defense strategies and dominant position changes of three gramineous plants (Leymus chinensis, Stipa krylovii, and Cleistogenes squarrosa) in Inner Mongolia. Here, we measured the dominance, biomass, and fourteen functional traits of three plants. The effects of Brandt's voles on dominance, biomass, and functional traits were analyzed, and then we explored the effect of functional traits on plant dominance by using the structural equation model. Results showed that long‐term feeding by Brandt's voles resulted in a significant decrease in the dominance of L. chinensis and S. krylovii, whereas C. squarrosa was positively affected. The belowground biomass of L. chinensis and S. krylovii was higher in the vole treatment, which showed that they were increasing their escape characteristics. The leaf thickness of L. chinensis and the leaf C:N ratio of S. krylovii significantly increased, while the specific leaf area of C. squarrosa significantly decreased. All three gramineous showed increased resistance traits in response to Brandt's voles, which positively affected their dominance. Tolerance‐related traits of S. krylovii significantly increased, with the increasing growth rate of root length contributing to enhancing its dominance. We highlight that selective feeding by rodents led to the selection of different defense strategies by three gramineous plants, and that changes in biomass allocation and functional traits in the different species affected plant dominance, driving changes in the plant communities. [ABSTRACT FROM AUTHOR]

The occurrence of black crust, a disease previously considered secondary, has become a cause for concern due to early leaf fall in rubber trees (Hevea brasiliensis). This study aimed to identify sources of resistance to black crust in 21 clones of rubber trees in a clonal garden. To achieve this, the disease severity was evaluated through eight assessments conducted over a 2‐year period. In each evaluation, 15 leaflets from three different parts of the plant (bottom, middle third and crown) were randomly collected, resulting in a total of 45 leaflets per plant. These leaflets were then taken to the laboratory, and the software Leaf Doctor was used to measure the percentage of leaf area exhibiting symptoms of black crust. The results were analysed using the Scott‐Knott test at a 5% probability level. The clones with the highest infected leaf area observed during the evaluations were IAC300, IAC418, IAC503, PB311 and RRIM600. Clone IAC511 did not show any symptoms of the disease in any of the evaluations. Clones IAC301, IAC411, IAC501, IAC507 and IRCA111 exhibited low percentages of affected leaf areas. Additionally, this study revealed the progression of the disease over the evaluation period. The infection initially starts on the youngest leaves (crown) in March and subsequently intensifies in the middle third of the plant, corresponding to the youngest leaf previously infected in the crown. Furthermore, environmental data collected in the experimental area over the 2‐year evaluation period indicated that the disease manifests with greater severity when the average temperatures fall below 25°C after periods of heavy rainfall, followed by dry periods with low relative humidity. The data presented in this study significantly contribute to the management of this disease in the field by identifying clones where the disease manifests with lower severity. [ABSTRACT FROM AUTHOR]

Summary: The coordinated interspecific variation in leaf traits and leaf lifespan is known as the leaf economic spectrum (LES). The limitation of CO2 diffusion to chloroplasts within the lamina is significant in C3 photosynthesis, resulting in a shortage of CO2 for Rubisco. Although Rubisco CO2/O2 specificity (SC/O) should be adaptively adjusted in response to the interspecific variation in CO2 concentrations [CO2] associated with Rubisco, SC/O variations across species along the LES remain unknown.We investigated the coordination among leaf traits, including SC/O, CO2 conductance, leaf protein content, and leaf mass area, across 23 woody C3 species coexisting on an oceanic island through phylogenetic correlation analyses.A high SC/O indicates a high CO2 specificity of Rubisco. SC/O was negatively correlated with [CO2] at Rubisco and total CO2 conductance within lamina, while it was positively correlated with leaf protein across species, regardless of phylogenetic constraint. A simulation analysis shows that the optimal SC/O for maximizing photosynthesis depends on both [CO2] at Rubisco sites and leaf protein per unit leaf area.SC/O is a key parameter along the LES axis and is crucial for maximizing photosynthesis across species and the adaptation of woody plants. [ABSTRACT FROM AUTHOR]

Although disturbance is considered a major driver of plant invasions across many systems, our understanding of the mechanisms by which disturbance mediates understorey invasions in natural forests is limited.We used a national natural forest inventory dataset spanning New Zealand's wide climatic and soil fertility gradients to disentangle disturbance‐mediated community characteristics driving abundance, species richness and functional composition of understorey plant invasions.Disturbance‐mediated declines in canopy tree abundance and increases in soil fertility and pH increased non‐native plant richness and cover relative to co‐occurring native plant assemblages. Cover of non‐native species also increased with proximity to anthropogenic land cover.Non‐native plant assemblages had higher community‐weighted mean (CWM) values for specific leaf area (SLA) but lower CWM values for height and woodiness relative to native assemblages irrespective of disturbance. However, greater nearby anthropogenic land cover drove increased woodiness in non‐native assemblages but decreased woodiness in co‐occurring native assemblages.Synthesis: Our study provides the first national‐scale evidence that canopy disturbance effects on soil properties increase both richness and abundance of non‐native plants in natural forest understories. We also revealed functional trait differences between native and non‐native assemblages (SLA in particular), which could alter fundamental forest ecosystem processes like litter decomposition and nutrient cycling. Finally, landscape‐scale anthropogenic impacts may exacerbate forest invasions by increasing non‐native abundance and favouring woody invaders, which may achieve dominance in future forest communities over the longer‐term. [ABSTRACT FROM AUTHOR]

Medicago sativa is a high-quality legume forage that is widely cultivated around the world. However, low phosphorus (LP) stress is one of the main limiting factors for its yield and quality. Currently, it is unclear how various alfalfa root types respond to LP stress. Thus, the creeping-rooted M. varia 'Gannong No. 4' (or GN), tap-rooted M. sativa 'Longdong' (or LD), and rhizomatous-rooted M. sativa 'Qingshui' (or QS) were selected to detect changes in growth, metabolites, phytohormones, and organic acids after 34 days of LP stress treatment (0.01 mmol·L−1 KH2PO4). We observed LP stress significantly inhibited plant growth, and 123, 73, and 42 considerably upregulated differential metabolites were categorized into 33, 26, and 20 metabolic pathways in GN, LD, and QS under LP stress, respectively. Amino acids, plant growth regulators, and organic acids are the main metabolites. After 34 d of LP treatment, the plant height, total surface area, leaf length, ground biomass, leaf width, total volume, leaf area, and ZT content of different root types of alfalfa significantly decreased, while the contents of malic acid, citric acid, oxalic acid, IAA, ABA, and GA3 significantly increased. The plant height, leaf length, leaf width, leaf area, total surface area, total volume, ground biomass, root biomass, the number of different metabolites, and the contents of malic, citric, and oxalic acid, and IAA of GN were significantly higher than those of QS and LD under LP stress. From this point of view, GN was more tolerant than LD and QS under the LP condition. [ABSTRACT FROM AUTHOR]

We tested an approach to estimate daily canopy net photosynthesis, A , based on estimates of transpiration, E , using measurements of sap flow and water-use efficiency, ω, by measuring δ13C in CO2 respired from shoots in the canopies of two conifers (Podocarpaceae) native to New Zealand. The trees were planted in adjacent 20-year-old stands with the same soil and environmental conditions. Leaf area index was lower for Dacrycarpus dacrydioides D.Don in Lamb (1.34 m2 m−2) than for Podocarpus totara G.Benn. ex D.Don var. totara (2.01 m2 m−2), but mean (± standard error) stem diameters were the same at 152 ± 21 mm for D. dacrydioides and 154 ± 25 mm for P. totara. Over a 28-day period, daily A (per unit ground area) ranged almost five-fold but there were no significant differences between species (mean 2.73 ± 1.02 gC m−2 day−1). This was attributable to higher daily values of E (2.63 ± 0.83 mm day−1) and lower ω (1.35 ± 0.53 gC kg H2O−1) for D. dacrydioides compared with lower E (1.82 ± 0.72 mm day−1) and higher ω (1.90 ± 0.77 gC kg H2O−1) for P. totara. We attributed this to higher nitrogen availability and nitrogen concentration per unit foliage area, N a, and greater exposure to irradiance in the D. dacrydioides canopy compared with P. totara. Our findings support earlier observations that D. dacrydioides is more adapted to sites with poor drainage. In contrast, the high retention of leaf area and maintaining low rates of transpiration by P. totara , resulting in higher water-use efficiency, is an adaptive response to survival in dry conditions. Our findings show that physiological adjustments for two species adapted to different environments led to similar canopy photosynthesis rates when the trees were grown in the same conditions. We demonstrated consistency between whole-tree and more intensive shoot-scale measurements, confirming that integrated approaches are appropriate for comparative estimates of carbon uptake in stands with different species. [ABSTRACT FROM AUTHOR]

Background and aims: Windblown sand movements, i.e., wind denudation and sand burial, pose a strong selective pressure on dune vegetation. Dune plants commonly receive repeated wind denudation or sand burial. Therefore, simultaneously examining the role of sand movement intensity and frequency in shaping dune vegetation is critical for dune biodiversity conservation and ecological restoration. However, studies of this nature are rare. Methods: We studied the integrated effects of sand movement intensity and frequency on the seedling performance of a dominant semi-shrub, Artemisia ordosica, in the Mu Us sandland. We subjected A. ordosica seedlings to a total intensity of 10 cm wind denudation or sand burial treatments conducted once, twice or four times. Key results: We found, given that the total intensity of sand movement remains the same, increasing frequency and decreasing intensity per time largely improved seedling survival. Furthermore, increasing frequency and decreasing intensity per time significantly alleviated the negative effects of wind denudation, although such alleviation effect was not detected for sand burial. Seedlings of A. ordosica increased specific leaf area, root length, and biomass allocation to root to adapt to wind denudation, while they developed adventitious roots to adapt to sand burial. Conclusions: Our results demonstrate that a single heavy sand movement is more detrimental than multiple light ones to the performance of A. ordosica seedlings. Our findings suggest that windproof measures to prevent severe sand movements is necessary to allow the establishment of A. ordosica during the dune restoration process. [ABSTRACT FROM AUTHOR]

Leaf wetness duration is a crucial factor in plant disease management. Current optical methods use standard RGB images to classify leaf wetness as a binary problem, i.e., wet or dry. Green leaves absorb red light, whereas water reflects it. Based on this difference, an experimental platform was built to semi-automatically measure droplet deposition on grape leaves while capturing red laser images using an RGB camera. The setup measured changes in leaf mass and area of scanned leaves to determine the water mass per leaf area as a measure of leaf wetness. A sprayer was used to apply water droplets to the leaves. As the amount of deposited water increased, the mean red channel intensity decreased, with more bright spots in the images. These bright spots were more distinguishable as droplets in the green channel. Segmented leaf area, mean red channel intensity, and the number of identified droplets were used as image features. A generalised additive model was employed to predict the leaf wetness value with extracted features. The R-squared value for the prediction of the validation dataset was 0.71. Image resolution and leaf orientation were identified as factors that influenced the model accuracy. The measurement method introduced in this study shows potential for accurately quantifying leaf wetness, and implies that in practice detecting leaf wetness can be integrated into a multi-classification problem, thereby broadening the potential applications of optical methods. • A novel non-contact optical method was developed to quantify leaf wetness. • The effect of water droplets on leaves on the images in visible light were analysed. • Factors influencing this method were identified for further development. • A semi-auto system was built to accurately measure the deposition on leaves. [ABSTRACT FROM AUTHOR]

We investigated the growth dynamics of hydroponic lettuce (Lactuca sativa) driven by the influence that potassium (K+) has on crop growth. This study aimed to determine whether increased K+ concentrations under different daily light integrals (DLIs) in a hydroponic system will boost growth of greenhouse lettuce. This study was conducted within a controlled glass greenhouse environment with varying DLIs achieved by integrating an adaptive lighting control system over a 16-hour photoperiod. We used three K+ treatments of 200, 400, or 600 mg·L-1 K+ and six DLI lighting treatments of 11.1, 12.9, 14.6, 15.9, 16.9, and 17 mol·m-2·d-1. We found that increasing K+ did not increase shoot dry weight, leaf area, or specific leaf area with increasing DLIs. Although K+ and DLI had an interacting effect on the root dry weight fraction, leaf chlorophyll content, and quantum yield of photosystem II, the K+ treatments did not increase or decrease with increasing DLIs. The influencing factor was DLI, which led to increases in shoot dry weight and leaf area, whereas a decrease in specific leaf area was observed with increasing DLIs. Ultimately, adding supplemental concentrations of K+ did not enhance lettuce growth, nor did these effects show any increase with increasing DLIs. [ABSTRACT FROM AUTHOR]

Health and quality of the root system are imperative to ensure the successful establishment of a citrus tree after transplant from the nursery into the field. Containerized citrus production in enclosed nurseries restricts root growth and can result in root circling and intertwining. This may hinder root expansion and result in root girdling after transplant, negatively affecting tree establishment and growth. The root structure of a transplanted citrus tree can also be affected by the container type used in the nursery. Containers with root-pruning properties like chemical pruning or air pruning reduce root circling and may produce superior root systems compared with regular, nonpruning containers. The aim of this study was to evaluate the effects of different nursery containers on root physiological and morphological traits and plant performance over 15 months of growth in the nursery. Three container types, chemical pruning containers, air-pruning containers, and standard nursery containers, were compared. The chemical pruning containers were standard citrus nursery containers with a mixture of copy hydroxide [Cu(OH)2] and copper carbonate (CuCO3) [10% copper (Cu)] applied to the inner wall. Pruning occurs upon contact of the roots with the Cu on the wall of the containers. The air-pruning containers were customsized Air-Pots in which pruning occurs on holes in the wall of the containers upon contact of the roots with the air. Two rootstocks, US-812 and US-942 (Citrus reticulata × Poncirus trifoliata), were included for comparison in the nongrafted stage and 12 months after grafting with 'Valencia' orange (Citrus sinensis). Chemical root pruning positively influenced tree height, shoot mass, leaf area, rootstock trunk diameter, and the nonfibrous root biomass. No differences among container types were observed for the fibrous root biomass, but chemical pruning produced more roots that were finer with a higher specific root length and a higher respiration rate. In contrast, air pruning produced more roots that were thicker compared with the other containers. Most of the leaf nutrients were lower in trees grown in the chemical pruning containers compared with the standard containers, except for Cu and zinc (Zn), which were highest in the former. Trees growing in air-pruning containers were not significantly different in growth from trees growing in standard containers. [ABSTRACT FROM AUTHOR]

The fundamental exchange of water for carbon lays the groundwork for understanding the interplay between carbon and water cycles in terrestrial ecosystems, providing valuable insights into global water and carbon balances and vegetation growth. Inherent water use efficiency (IWUE) was used as a study framework of the diurnal patterns and degree of coupling of carbon and water exchange to investigate the net ecosystem carbon exchange (NEE) responses of three water regime potato cropping systems [full-irrigation (FI), deficit-irrigation (DI), and rainfed (RF)] in Cundinamarca, Colombia. The eddy covariance method was used to determine CO2 and water fluxes, surface resistances, and the omega decoupling factor (Ω). Additionally, leaf area index (LAI), and specific leaf area (SLA) were assessed to determine the canopy influence on carbon and water exchange. The highest carbon sink activity (NEE = -311.96 ± 12.82 g C m−2) at FI, is primarily attributed to a larger canopy with high autotrophic activity and low internal resistance. This supported a highly coupled and synchronized exchange between evapotranspiration (ET) and gross primary production (GPP), as reflected in the highest IWUE (4.7 mg C kPa s−1 kg−1 H2O). In contrast, the lower sink capacity at DI (NEE = − 17.3 ± 4.6 g C m−2) and the net carbon source activity from RF (NEE = 187.21 ± 3.84 g C m−2) were related to a smaller leaf area available for water and carbon exchange, resulting in lower IWUE (2.3 and 1.01 mg C kPa s−1 kg−1 H2O, respectively) and a decoupled and desynchronized gas exchange caused by unbalanced restrictions on ET and GPP fluxes. These results provide new information on carbon–water interactions in potatoes and improve the understanding of carbon sequestration and drought effects on potato sink activity. [ABSTRACT FROM AUTHOR]

Water stress causes various plant morphological, physiological, and biochemical responses. Silicon application may reduce the water stress tolerance in plants by increasing the physiology parameters and the crop's vegetative growth. Hence, the study aims to evaluate the effect of water stress levels on Alternanthera sissoo, known as Brazilian spinach, and determine which silicon (Si) level is the best under water scarcity. The method implied measuring the water stress by different levels of water level applied to the plant which are 100 % (well-watered), 75 % (moderate water deficit), 50 % (high water deficit), and 25 % (severe water deficit). The variation of silicon concentrations is S0 (control), S1, S2 and S3 (0, 0.6, 0.9 and 1.2 %v/v) arranged in the Randomized Complete Block Design (RCBD) in the greenhouse. Growth, physiological, and biochemical parameters were analyzed during the experiment. The research findings showed that water stress results were statistically reduce the leaf area, leaf number root length, fresh weight, chlorophyll content, relative water content (RWC), and malondialdehyde (MDA). The root length, leaf area, and malondialdehyde (MDA) show the interaction between water stress level and silicon concentration. The study proposed that the Si nutrient management strategy has the potential to minimize the impacts of drought stress in Brazilian spinach. Regarding research findings, it was determined that the optimal water requirement for Alternanthera sissoo is 50 % of the water treatments, with a silicon concentration of 1.2 %v/v. This is essential for better water management of the plant. [ABSTRACT FROM AUTHOR]

To address the short lifetime of plasma‐activated water (PAW), this work reports on the application of ultralong‐lasting PAW for plant disease treatment. Compared with lettuce without ultralong‐lasting PAW treatment, the treated lettuce solution showed c. 1 log10 colony forming units mL−1 decrease in pathogens, as well as improvements in leaf area, leaf weight, root length, and root weight by 75%, 20%, 108.33%, and 150%, respectively. The leaf withering/root mortality rate of PAW‐treated plants was significantly lower than those of non‐PAW‐treated plants. Besides, disease defense‐related enzymes, such as catalase and β−1,3‐glucanase, were respectively enhanced by 112.5% and 5.13% in PAW‐treated lettuce, while the plant defense‐related genes were upregulated to respond to the pathogen's invasion. [ABSTRACT FROM AUTHOR]

Coupling solar-induced chlorophyll fluorescence (SIF) with gross primary productivity (GPP) for ecological function integration research presents numerous uncertainties, especially in ecologically fragile and climate-sensitive arid regions. Therefore, evaluating the suitability of SIF data for estimating GPP and the feasibility of improving its accuracy in the northern region of Xinjiang is of profound significance for revealing the spatial distribution patterns of GPP and the strong coupling relationship between GPP and SIF in arid regions, achieving the goal of "carbon neutrality" in arid regions. This study is based on multisource SIF satellite data and GPP observation data from sites in three typical ecosystems (cultivated and farmlands, pasture grasslands, and desert vegetation). Two precision improvement methods (canopy and linear) are used to couple multiple indicators to determine the suitability of multisource SIF data for GPP estimation and the operability of accuracy improvement methods in arid regions reveal the spatial characteristics of SIF (GPP). The results indicate the following. (1) The interannual variation of GPP shows an inverted "U" shape, with peaks values in June and July. The cultivated and farmland areas have the highest peak value among the sites (0.35 gC/m2/month). (2) The overall suitability ranking of multisource SIF satellite products for GPP estimation in arid regions is RTSIF > CSIF > SIF_OCO2_005 > GOSIF. RTSIF shows better suitability in the pasture grassland and cultivated and farmland areas (R2 values of 0.85 and 0.84, respectively). (3) The canopy method is suitable for areas with a high leaf area proportion (R2 improvement range: 0.05–0.06), while the linear method is applicable across different surface types (R2 improvement range: 0.01–0.13). However, the improvement effect of the linear method is relatively weaker in areas with high vegetation cover. (4) Combining land use data, the overall improvement of SIF (GPP) is approximately 0.11%, and the peak values of its are mainly distributed in the northern and southern slopes of the Tianshan Mountains, while the low values are primarily found in the Gurbantunggut Desert. The annual mean value of SIF (GPP) is about 0.13 mW/m2/nm/sr. This paper elucidates the applicability of SIF for GPP estimation and the feasibility of improving its accuracy, laying the theoretical foundation for the spatiotemporal coupling study of GPP and SIF in an arid region, and providing practical evidence for achieving carbon neutrality goals. [ABSTRACT FROM AUTHOR]

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Introduction: Salinity and droughts are severe abiotic stress factors that limit plant growth and development. However, the differences and similarities of non-structural carbohydrates (NSCs) responses patterns of trees under the two stress conditions remain unclear. Methods: We determined and compared the growth, physiology, and NSCs response patterns and tested the relationships between growth and NSCs concentrations (or pool size) of Eucommia ulmoides seedlings planted in field under drought and salt stress with different intensities and durations. Results and discussion: We found that drought and salt stress can inhibit the growth of E. ulmoides, and E. ulmoides tended to enhance its stress resistance by increasing proline concentration and leaf thickness or density but decreasing investment in belowground biomass in short-term stress. During short-term drought and salt stress, the aboveground organs showed different NSCs response characteristics, while belowground organs showed similar change characteristics: the starch (ST) and NSCs concentrations in the coarse roots decreased, while the ST and soluble sugar (SS) concentrations in the fine roots increased to enhance stress resistance and maintain water absorption function. As salt and drought stress prolonged, the belowground organs represented different NSCs response patterns: the concentrations of ST and SS in fine roots decreased as salt stress prolonged; while ST in fine roots could still be converted into SS to maintain water absorption as drought prolonged, resulting in an increase of SS and a decrease of ST. Significant positive relationships were found between growth and the SS and total NSCs concentrations in leaves and branches, however, no significant correlations were found between growth and below-ground organs. Moreover, relationships between growth and NSCs pool size across organs could be contrast. Conclusion: Our results provide important insights into the mechanisms of carbon balance and carbon starvation and the relationship between tree growth and carbon storage under stress, which were of great significance in guiding for the management of artificial forest ecosystem under the context of global change. [ABSTRACT FROM AUTHOR]