Leaf Dry Matter Research Articles

Climate and management changes over 40 years drove more stress‐tolerant and less ruderal weed communities in vineyards

AbstractSpontaneous plant communities have undergone considerable constraints due to human‐mediated changes. Understanding how plant communities are shifting in response to land management and climate changes is necessary to predict future ecosystem functioning and improve the resilience of managed ecosystems, such as agroecosystems. Using Mediterranean weed communities as models of managed plant communities in a climate change hotspot, we quantified the extent to which they have shifted from the 1980s to the 2020s in response to climate and management changes in vineyards. The weed communities of the same 40 vineyards in the Montpellier region were surveyed using the same protocol in spring, summer, and autumn, for two years, with a 40‐year interval (1978–1979 vs. 2020–2021). In four decades, the annual range of temperatures (i.e., the difference between the warmest month's and the coldest month's mean temperatures) increased by 1.2°C and the summer temperatures by 2°C. Weed management diversified over time with the adoption of mowing that replaced the chemical weeding of interrows. Chemical weeding is now mostly limited to the area under the row. Current weed communities were 41% more abundant, 24% more diverse, and with a less even distribution of abundance across species than the 1980s communities at the vineyard level. Modern communities were composed of more annual species (57% of annual species in the 1980s vs. 80% in the 2020s) with lower community‐weighted seed mass and were composed of fewer C4 species. They had higher community‐weighted specific leaf area, higher leaf dry matter content, and lower leaf area than the 1980s weed communities. At the community level, the onset of flowering was earlier and the duration of flowering was longer in the 2020s. Climate change induced more stress‐tolerant communities in the 2020s while the diversification of weed management practices favored less ruderal communities. This study shows that plant communities are shifting in response to climate change and that land management is a strong lever for action to model more diverse and eventually more desirable weed communities in the future.

Unraveling key environmental drivers of spatial variation in plant functional traits: Insights from Dacrydium pectinatum de Laub. in natural communities on Hainan Island, China

Accurate predictions of species distribution and coexistence in response to environmental changes depend on a thorough understanding of how functional traits relate to environmental conditions. However, there is still limited evidence regarding the sources of functional trait variation and the environmental mechanisms that regulate these traits in tropical forests. This study focuses on Dacrydium pectinatum de Laub., a crucial and endangered species native to the tropical mountain forests of Hainan Island, China. We gathered functional trait data from 68 permanent plots of D. pectinatum situated in three regions: Bawangling (163 tree species), Diaoluoshan (127 tree species), and Jianfengling (175 tree species). Nine functional traits were measured at the species level, and their variation patterns and sources were analyzed using linear mixed-effects models and variance decomposition methods. Our findings reveal that environmental pressures cause variations in trait relationships across different site conditions at the species level. Typically, inter-specific trait variation exceeds intra-specific variation, particularly for leaf area (LA) and specific leaf area (SLA). This indicates that trait variability is influenced by how species adapt to and balance specific environmental conditions. Site conditions significantly impact trait variation, especially for SLA, leaf dry matter content (LDMC), and wood density (WD). Additionally, intraspecific variation is notable for certain traits, reflecting individual responses to environmental heterogeneity. At the community level, eight out of nine traits exhibit significant changes in community-weighted mean (CWM) across various site conditions and environmental gradients. For instance, LA's CWM increases with soil fertility, whereas SLA, leaf nitrogen content (LNC), and leaf phosphorus content (LPC) show differences between site conditions. LDMC and WD decrease significantly in high-fertility environments, suggesting a transition from resource conservation to resource acquisition strategies within communities as soil fertility rises. Geographic variables play a crucial role in trait distributions across different community levels, with elevation and soil factors also contributing significantly to trait variation. Overall, our study provides direct evidence of how environmental filtering influences plant functional trait distributions and community assembly. Future research should explore the mechanisms driving these trait-environment relationships and their responses across various ecological contexts.

A functional trait-based assessment of urban street tree selection for Ethiopia

Urbanization in Ethiopia is rapidly reducing green space and biodiversity, and placing ecological stress on trees. Urban street trees (UST) can provide multiple ecosystem services, but need to cope with challenging street ecology and future climate risks. However, UST selection in Ethiopia is poor, and conventional trials and modern breeding are costly and time consuming to apply in Ethiopia. The main objective of the study was to identify potential UST species for two Ethiopian cities; Addis Ababa, and Arba Minch, by studying interspecific differences in functional traits. For the purpose, we created a database with list of 120 candidate UST gathered from multi-stakeholder workshop, literature review, and senior experts survey, and their ecological with their phenological and morphological features. Then we filtered 25 potential UST through framework analysis considering eco-morphological features of the trees. For the 25 species, we measured three types of plant functional traits: conservative traits (leaf mass per area and leaf dry matter content), acquisitive traits (leaf area, specific leaf area and leaf water content) and drought tolerance traits (leaf turgor pressure loss point, and leaf succulence index). Our results showed a strong trade-off between conservative and acquisitive traits, particularly between leaf dry matter content (LDMC) and specific leaf area (SLA) (r = −0.71), consistent with plant economic spectrum theory. Using PCA analysis, we identified three groups of potential USTs (Type I, II and III) that exhibit different adaptation strategies, consistent with Grime’s trait-based classification of universal plant adaptation strategies (CSR). Compared to species with high acquisitive traits (Type II and Type III), Type I species have high conservative and drought-tolerant traits shows better adaptation to harsh road environments, whereas Type II and Type III species may be more advantageous for urban parks and other resource-rich components of urban ecology. We also found significant variation in conservative, acquisitive and drought-tolerant traits among different species, indicating their different adaptation strategies. Our research advances the knowledge of plant adaptation in urban environments and provides a useful method for UST selection.

Coniferous Tree Species Identity and Leaf Aging Alter the Composition of Phyllosphere Communities Through Changes in Leaf Traits

Phyllosphere microorganisms are essential for plant growth and health. Although there are an increasing number of studies showing that the composition of phyllosphere communities varies among different plant species, it remains unclear whether and how their bacterial and fungal community composition predictably varies with plant traits and leaf age. In this study, we used high-throughput sequencing to explore the diversity and composition of phyllosphere communities in needles of different ages (originating from different cohorts) for three evergreen coniferous species (Pinus koraiensis, Picea koraiensis, and Abies nephrolepis). Our results indicated that Gammaproteobacteria (bacteria) and Dothideomycetes (fungi) were dominant in newly formed needles, whereas Actinobacteria (bacteria) and Eurotiomycetes (fungi) were dominant in perennial needles. Tree species identity and needle age were the main factors explaining the variations of the α diversity (species richness of phyllosphere communities) and β diversity (dissimilarity among phyllosphere communities). In particular, we found that leaf dry matter content, leaf mass per area, and total phosphorus content emerged as key predictors of composition and diversity of phyllosphere microbial communities, underscoring the major influence of tree species identity and needle age on phyllosphere communities through changes in plant functional traits. Finally, we found that the interaction between tree species identity and needle age also contributed significantly to explaining the diversity and composition of phyllosphere communities, probably because differences in plant functional traits or environmental conditions between new and perennial needles depend on tree growth rates and resource acquisition strategies. These findings provide new insights into the mechanisms of community assembly among different evergreen tree species and offer a better understanding of the interactions between plant traits and phyllosphere microorganisms during needle aging.

Understory plant biodiversity is inversely related to carbon storage in a high carbon ecosystem.

Given that terrestrial ecosystems globally are facing the loss of biodiversity from land use conversion, invasive species, and climate change, effective management requires a better understanding of the drivers and correlates of biodiversity. Increasingly, biodiversity is co-managed with aboveground carbon storage because high biodiversity in animal species is observed to correlate with high aboveground carbon storage. Most previous investigations into the relationship of biodiversity and carbon co-management do not focus on the biodiversity of the species rich plant kingdom, which may have tradeoffs with carbon storage. To examine the relationships of plant species richness with aboveground tree biomass carbon storage, we used a series of generalized linear models with understory plant species richness and diversity data from the USDA Forest Service Forest Inventory and Analysis dataset and high-resolution modeled carbon maps for the Tongass National Forest. Functional trait data from the TRY database was used to understand the potential mechanisms that drive the response of understory plants. Understory species richness and community weighted mean leaf dry matter content decreased along an increasing gradient of tree biomass carbon storage, but understory diversity, community weighted mean specific leaf area, and plant height at maturity did not. Leaf dry matter content had little variance at the community level. The decline of understory plant species richness but not diversity to increases in aboveground biomass carbon storage suggests that rare species are excluded in aboveground biomass carbon dense areas. These decreases in understory species richness reflect a tradeoff between the understory plant community and aboveground carbon storage. The mechanisms that are associated with observed plant communities along a gradient of biomass carbon storage in this forest suggest that slower-growing plant strategies are less effective in the presence of high biomass carbon dense trees in the overstory.

Influence of Iron and Zinc Biofortification on Growth and Yield of Drilled Rice (Oryza Sativa L.)

A field experiment was conducted during kharif 2022 and 2023 to study the effect of iron and zinc biofortification on the growth and yield of drilled rice (Oryza sativa L.) at Krushi Vigyan Kendra, Navsari Agricultural University, Dediapada, Gujarat. The experiment was laid out in a randomized block design with ten treatments. Based on pooled analysis, almost all the growth attributes (periodical plant height, number of tillers plant-1, leaf area, leaf area index and dry matter accumulation plant-1), yield attributes (productive tillers m-2, number of filled grains panicle-1, panicle length, weight of panicle and 1000 grain weight), grain yield (3035 kg ha-1) and straw yield (5336 kg ha-1) were recorded significantly higher under treatment T10 (soil ZnSO4 + FeSO4 each @ 25 kg ha-1 and foliar ZnSO4 + FeSO4 each @ 0.5% at 30 & 60 DAS). Based on the results, it concluded that for achieving higher growth and yield in drilled rice, the crop should be fertilized with soil ZnSO4 + FeSO4 each @ 25 kg ha-1 and foliar ZnSO4 + FeSO4 each @ 0.5% at 30 & 60 DAS along with RDF and soil ZnSO4 + FeSO4 each @ 25 kg ha-1 along with RDF.

Grass leaf structural and stomatal trait responses to climate gradients assessed over the 20th century and across the Great Plains, USA.

Abstract. Using herbarium specimens spanning 133 years and field-collected measurements, we assessed intraspecific trait (leaf structural and stomatal) variability from grass species in the Great Plains of North America. We focused on two widespread, closely related grasses from the tribe Paniceae: Dichanthelium oligosanthes subsp. scribnerianum (C3) and Panicum virgatum (C4). Thirty-one specimens per taxon were sampled from local herbaria from the years 1887 to 2013 to assess trait responses across time to changes in atmospheric [CO2] and growing season precipitation and temperature. In 2021 and 2022, the species were measured from eight grasslands sites to explore how traits vary spatially across natural continental precipitation and temperature gradients. Δ13C increased with atmospheric [CO2] for D. oligosanthes but decreased for P. virgatum, likely linked to increases in precipitation in the study region over the past century. Notably, this is the first record of decreasing Δ13C over time for a C4 species illustrating 13C linkages to climate. As atmospheric [CO2] increased, C:N increased and δ15N decreased for both species and %N decreased for D. oligosanthes. Across a large precipitation gradient, D. oligosanthes leaf traits were more responsive to changes in precipitation than those of P. virgatum. In contrast, only two traits of P. virgatum responded to increases in temperature across a gradient: specific leaf area (increase) and leaf dry matter content (decrease). The only shared significant trend between species was increased C:N with precipitation. Our work demonstrates that these closely related grass species with different photosynthetic pathways exhibited various trait responses across temporal and spatial scales, illustrating the key role of scale of inquiry for forecasting leaf trait responses to future environmental change.

The effect of industrial and urban dust pollution on the ecophysiology and leaf element concentration of Tilia cordata Mill.

The influences of airborne trace elements in urban dust on element concentrations and functional traits of Tilia cordata were examined. For the present study, the unwashed and washed leaves of T. cordata were collected to assess the concentration of metals in Katowice City, Poland, from sites of different traffic intensity and industry activity. The content of Al, Cd, Cr, Cu, Fe, Mn, Pb, Zn, C, and N was measured. Additionally, a number of functional traits such as photosynthetic pigment content, specific leaf area (SLA), leaf dry matter content (LDMC), and diseased areas of the leaves were determined to assess the impact of the polluters on the physiology of the trees and their resources acquisition strategy. We hypothesized that the photosynthetic pigments of T. cordata will decrease with the traffic and industry intensity, and the traits related to the resources acquisition and stress resistance will shift into a more conservative strategy.The Principal Component Analysis and the Inverse Distance Weighting (IDW) interpolation method helped to identify that the Fe, Zn, Al, and Cr were related mainly to traffic intensification and Pb to industrial activities. The results indicate that Katowice is considerably polluted by Zn (up to 189.6 and 260.2mgkg-1 in washed and unwashed leaves, respectively), Pb (up to 51.7 and 133.6mgkg-1), and Cd (up to 2.27 and 2.43mgkg-1) compared to other cities worldwide. Also, a reduction of approximately 27% in the photosynthetic pigments was observed at the high-traffic and industrial sites. The trees from the mainly affected areas with heavy traffic and industry tend to apply a conservative resources strategy with a decrement in SLA and an increment in LDMC. In contrast, the opposite trend was observed at the less affected sites (high SLA, low LDMC). The study showed that unfavourable urban conditions can trigger a plastic response on multiple levels. Knowledge of the possible paths of adaptation to urban conditions of different plant species is nowadays crucial to appropriate urban greenery planning.

Measuring standardized functional leaf traits of aquatic carnivorous plants – challenges and opportunities

Aquatic carnivorous plants (ACP) are an important component of humic nutrient-poor freshwater environments. However, these habitats are facing multiple impacts that ultimately lead to habitat degradation and declining ACP populations. Functional traits, particularly those within the leaf economics spectrum, are a valuable tool for studying plant adaptation strategies and plasticity. Given their unique morphological structure, ACP are essentially excluded from functional comparisons, which potentially limits our knowledge about the ecological roles of these species compared to non-carnivorous ones. In this study, we developed a protocol for measuring the leaf functional traits of ACP (leaf fresh and dry weight, leaf area, leaf dry matter content, specific leaf area, leaf pigment content, leaf phosphorus, nitrogen and carbon contents), and carnivory-related traits (number of traps and investment in carnivory). We measured 15 traits in seven ACP species (Aldrovanda vesiculosa, Utricularia australis, U. bremii, U. intermedia, U. ochroleuca, U. stygia, U. vulgaris), grown in the outdoor collection of aquatic and wetland plants of the Institute of Botany CAS at Třeboň, the Czech Republic. We used the functional traits of other macrophyte groups/species (lemnids, Nuphar lutea, Ceratophyllum demersum), collected with a similar methodology, to assess the comparability of ACP traits. We identified the “functional unit”, a modular structure, including one leaf node, plus an internode, which performs the function of a leaf in ACP, and selected its position along the stem to reflect species-specific growth rates. We collected 714 new trait records for the target ACP. Based on a multivariate trait space representation (PCA), ACP were distinct from the other macrophyte groups/species, which highlights these species’ structural and physiological peculiarities. Nonetheless, ACP entirely overlapped the comparison data along the first PCA axis, and most of the traits lay within the ranges observed for other macrophyte groups/species, which demonstrates the comparability of the ACP traits measured by the new protocol. Applying this protocol in ecological studies could shed light on the adaptations of ACP to environmental variability, with important conservation implications.

Pomegranate-Quinoa-Based Agroforestry System: An Innovative Strategy to Alleviate Salinity Effects and Enhance Land Use Efficiency in Salt-Affected Semiarid Regions.

Salinity is a major problem, impeding soil productivity, agricultural sustainability, and food security, particularly in dry regions. This study integrates quinoa, a facultative halophyte, into a pomegranate-based agroforestry with saline irrigation in northeast Morocco. We aim to explore this agroforestry model's potential in mitigating salinity's effects on quinoa's agronomic and biochemical traits and evaluate the land equivalent ratio (LER). Field experiments in 2020 and 2021 used a randomized block design with three replicates, including monocropping and agroforestry systems, two salinity levels (1.12 and 10.5 dS m-1), four quinoa genotypes (Titicaca, Puno, ICBA-Q4, ICBA-Q5), and a pomegranate control. Salinity significantly decreased total dry matter (40.5%), root dry matter (50.7%), leaf dry matter (39.2%), and root-to-shoot ratio (7.7%). The impact was more severe in monoculture than in agroforestry, reducing dry matter (47.6% vs. 30.7%), grain yield (46.3% vs. 26.1%), water productivity (47.5% vs. 23.9%), and total sugar (19.2% vs. 5.6%). LER averaged 1.86 to 2.21, indicating 86-121% higher productivity in agroforestry. LER averaged 1.85 at 1.12 dS m-1 and 2.18 at 10.5 dS m-1, reaching 2.21 with pomegranate-ICBA-Q5 combination. Quinoa-pomegranate agroforestry emerges as an innovative strategy, leveraging quinoa's salt resistance and agroforestry's potential to mitigate salinity impacts while enhancing land use efficiency.

Phenotypic plasticity of water-related traits reveals boundaries to the adaptive capacity of a dominant European grass species under increased drought

The intensification of droughts due to climate change is a global concern, and many plant species face increasing water deficits. Understanding the role of phenotypic plasticity in plant adaptation to these changing conditions is crucial. This research focuses on Bromopsis erecta, a dominant perennial grass in European and Mediterranean grasslands, to predict its potential adaptation to climate change. We assessed plants from shallow and deep soils (i.e., with contrasting water reserves) of a Mediterranean rangeland in southern France, and tested the effect of six years of experimentally increased summer drought compared to the ambient conditions on plant traits, survival and abundance. In both field and common garden experiments, we measured water-related traits, including static traits under non-limiting water conditions, and dynamic traits, such as rates of trait variation during drought. Trait plasticity was determined as a reaction norm to increasing soil water stress and was tested against changes in B. erecta abundance over the past decade, including the study period. Trait plasticity was detected only for leaf dry matter content (LDMC), revealing that the resource strategy of B. erecta became more conservative over less than a decade with higher LDMC and leaf thickness according to the plant economic spectrum. No plasticity was found for osmotic potential or specific leaf area. The variability of other traits was ascribed to the possible lagging effect of previous water stress and was associated more with soil depth than with previous summer drought intensity. The abundance decline of B. erecta, which dropped from 20 % to around 5 % in shallow soils, was not associated with the plasticity of LDMC but was positively correlated with variations in leaf base membrane damage, meaning unexpectedly, that plants exposed to the most severe summer drought also had the most sensitive leaf base membranes, a possible sign of maladaptive trait plasticity in the population. This key trait response reveals boundaries to the adaptive capacity of this perennial grass to survive pluri-annual drought.

Optimal phosphorus proportion increases cotton yields in low nitrogen environments by enhancing mid-upper canopy biomass and nitrogen utilization

To elucidate the physiological mechanism of optimal phosphorus (P) proportion under reduced nitrogen (N) environments on cotton yield, dry matter (DM) spatiotemporal distribution, and N utilization. A three-year experiment was conducted with reduced N (299 kg hm−2, N3), four proportions of P fertilizer (25:75 % at squaring and bloom-bolling stages (P1), 50 %:50 % (P2), 75 %:25 % (P3), 100 %:0 % (P4)), and a traditional N application (402.5 kg hm−2, N2) with P2 as control. Under the N3 treatment, the seed yield of P2 was 6.7–24.5 % higher than other P, and the yield of N3P2 was 1.6–2.6 % lower than N2P2. During the whole growth period, P2 demonstrated 12.4–46.9 % higher leaf and reproductive organs dry matter (LDM and RoDM) compared to other P, and primarily due to more mid-upper DM. Throughout the growth period, N3P2 maintained dominant LDM and exhibited RoDM 2.5 % higher at late-full bolling stage (LFB) compared to N2P2. Trends in leaf N content and reproductive organ N content were similar to DM, with N3P2 consistently maintaining higher levels. Regarding N metabolism activities, N3P2 displayed 8.5–16.1 % higher activity of nitrate reductase, 9.5–21.9 % higher activity of glutamine synthetase, and 7.5 %-15.6 % higher activity of glutamate synthase compared to other P across all growth stages, with no significant differences observed with N2P2. Moreover, N3P2 and N2P2 exhibited higher relative expression of NR, GS1, and ferredoxin-dependent glutamate synthase compared to other treatments. In Conclusion, at 25 % reduced N (N3), optimizing the proportion of P fertilizer (P2, 50 %:50 %) could lead to higher yields due to enhanced N re-utilization capabilities in the later growth stage and increased distribution of DM in leaves and reproductive organs, particularly in the middle and upper layers (especially the fruiting branches). The study findings hold significant theoretical implications for achieving sustainable and efficient production in drip-irrigated cotton fields under reduced N management.

Climate Influence on Leaf Appearance and Ligustroflavone and Rhoifolin Compounds of Turpinia arguta (Lindl.) Seem. from Different Chinese Habitats

The dry leaf of Turpinia arguta (Lindl.) Seem. is used in traditional Chinese medicine as a quick-acting product for sore throat and pharyngitis relief. Samples of T. arguta were collected from 40 different habitats mostly located in Jiangxi Province, and leaf appearance traits and dry matter yield were analyzed. HPLC was used to quantify ligustroflavone and rhoifolin, the pharmacological-quality markers for this species, according to the 2020 Edition of Chinese Pharmacopoeia. The correlations between leaf-measurable traits, ligustroflavone and rhoifolin contents, and climate factors were subsequently assessed using Pearson’s two-tailed correlation test and redundancy analysis. The highest dry matter yields were found in locations S(G-mt), Q(J-t), and A(X-t). Ligustroflavone and rhoifolin contents ranged from 0.023% to 1.336% and 0.008% to 0.962%, respectively; the highest levels of ligustroflavone and rhoifolin compounds were found in locations A(X-t) and Y(B-mt). Leaf morphology was influenced by the mean temperature of the warmest quarter, while leaf thickness was affected by the minimum temperature of the coldest month, precipitation seasonality, and solar radiation. Larger and thicker leaves predicted higher yields of ligustroflavone and rhoifolin compounds in T. arguta under Chinese southern conditions, such as those in Anyuan and Quannan counties. Our findings suggest that enhancing the mean diurnal temperature range and implementing appropriate shading during cultivation can enhance the ligustroflavone and rhoifolin compounds of T. arguta.

Closely related species differ in their traits, but competition induces high intra-specific variability.

Theories explaining community assembly assume that biotic and abiotic filters sort species into communities based on the values of their traits and are thus based on between-species trait variability (BTV). Nevertheless, these filters act on individuals rather than on species. Consequently, the selection is also influenced by intraspecific trait variability (ITV) and its drivers. These drivers may be abiotic (e.g., water availability) or biotic (e.g., competition). Although closely related species should have similar traits, many of them coexist. We investigated the relative magnitudes of BTV and ITV in coexisting closely related species and how their individual traits differ under different drivers of ITV. We manipulated conditions in a greenhouse pot experiment with four common Carex species, where individuals of each species originated from four source localities. Individuals were grown in factorial combinations of two moisture levels, with and without a competitor (grass species Holcus lanatus, a frequent competitor). We analyzed the variability of six morphological traits on individuals in the greenhouse and three morphological traits in the source localities. Species identity was the main determinant of differences in most traits. Competition exerted a greater effect than water availability. For leaf dry matter content (LDMC) and vegetative height, competition's effect even exceeded the variability among species. On the contrary, for specific leaf area (SLA) and clonal spread, the interspecific differences exceeded ITV induced by experimental treatments. SLA measured in the greenhouse closely correlated with values measured in field populations, while LDMC did not. The variability caused by source locality of ramets in the greenhouse was small, although sometimes significant. Closely related species differ in their traits, but for some traits, ITV can exceed BTV. We can expect that ITV can modify the processes of community assembly, particularly among coexisting closely related species.

Anatomical traits explain drought response of seedlings from wet tropical forests.

Water availability regulates plant community dynamics but the drought response of seedlings remains poorly known, despite their vulnerability, especially for the Asian tropics. In particular, discerning how functional traits of seedlings mediate drought response can aid generalizable predictions of tree responses to global environmental change. We assessed interspecific variation in drought response explained by above- and below-ground seedling traits. We conducted a dry-down experiment in the greenhouse using 16 tree species from the humid forests of Western Ghats in southern India, chosen to represent differences in affinity to conditions of high and low seasonal drought (seasonality affiliation). We compared survival, growth, and photosynthetic performance under drought and well-watered conditions and assessed the extent to which species' responses were explained by seasonality affiliation and 12 traits of root, stem and leaf. We found that the species from seasonally dry forest reduced photosynthetic rate in drought compared with well-watered conditions, but seasonality affiliation did not explain differences in growth and survival. Performance in drought vs well-watered conditions were best explained by anatomical traits of xylem, veins and stomata. Species with larger xylem reduced their growth and photosynthesis to tolerate desiccation. In drought, species with smaller stomata correlated with lower survival even though photosynthetic activity decreased by a larger extent with larger stomata. Overall, anatomical traits of xylem and stomata, directly related to water transport and gas-exchange, played a more prominent role than commonly used traits (e.g., specific leaf area, leaf dry matter content) in explaining species response to drought, and may offer a good proxy for physiological traits related to drought tolerance of seedlings.

Differential responses of community‐level functional traits to mid‐ and late‐season experimental drought in a temperate grassland

Abstract 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.

Leaf Functional Traits and Their Influencing Factors in Six Typical Vegetation Communities.

Leaf functional traits (LFTs) have become a popular topic in ecological research in recent years. Here, we measured eight LFTs, namely leaf area (LA), specific leaf area (SLA), leaf thickness (LT), leaf dry matter content (LDMC), leaf carbon content (LCC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), and leaf potassium content (LKC), in six typical vegetation communities (sclerophyllous evergreen broad-leaved forests, temperate evergreen coniferous forests, cold-temperate evergreen coniferous forests, alpine deciduous broad-leaved shrubs, alpine meadows, and alpine scree sparse vegetation) in the Chayu River Basin, southeastern Qinghai-Tibet Plateau. Our aim was to explore their relationships with evolutionary history and environmental factors by combining the RLQ and the fourth-corner method, and the method of testing phylogenetic signal. The results showed that (i) there were significant differences in the eight LFTs among the six vegetation communities; (ii) the K values of the eight LFTs were less than 1; and (iii) except for LCC, all other LFTs were more sensitive to environmental changes. Among these traits, LA was the most affected by the environmental factors, followed by LNC. It showed that the LFTs in the study were minimally influenced by phylogenetic development but significantly by environmental changes. This study further verified the ecological adaptability of plants to changes in environmental factors and provides a scientific basis for predicting the distribution and diffusion direction of plants under global change conditions.

Physiological traits, crop growth, and grain quality of quinoa in response to deficit irrigation and planting methods

Climate change has become a concern, emphasizing the need for the development of crops tolerant to drought. Therefore, this study is designed to explore the physiological characteristics of quinoa that enable it to thrive under drought and other extreme stress conditions by investigating the combined effects of irrigation water levels (100%, 75%, and 50% of quinoa's water requirements, WR as I1, I2 and I3) and different planting methods (basin, on-ridge, and in-furrow as P1, P2 and P3) on quinoa's physiological traits and gas exchange. Results showed that quinoa’s yield is lowest with on-ridge planting and highest in the in-furrow planting method. Notably, the seed protein concentrations in I2 and I3 did not significantly differ but they were 25% higher than those obtained in I1, which highlighted the possibility of using a more effective irrigation method without compromising the seed quality. On the other hand, protein yield (PY) was lowest in P2 (mean of I1 and I2 as 257 kg ha−1) and highest in P3 (mean of I1 and I2 as 394 kg ha−1, 53% higher). Interestingly, PY values were not significantly different in I1 and I2, but they were lower significantly in I3 by 28%, 27% and 20% in P1, P2, and P3, respectively. Essential plant characteristics including plant height, stem diameter, and panicle number were 6.1–16.7%, 6.4–24.5%, and 18.4–36.5% lower, respectively, in I2 and I3 than those in I1. The highest Leaf Area Index (LAI) value (5.34) was recorded in the in-furrow planting and I1, while the lowest value was observed in the on-ridge planting method and I3 (3.47). In I3, leaf temperature increased by an average of 2.5–3 oC, particularly during the anthesis stage. The results also showed that at a similar leaf water potential (LWP) higher yield and dry matter were obtained in the in-furrow planting compared to those obtained in the basin and on-ridge planting methods. The highest stomatal conductance (gs) value was observed within the in-furrow planting method and full irrigation (I1P3), while the lowest values were obtained in the on-ridge and 50%WR (I3P2). Finally, photosynthesis rate (An) reduction with diminishing LWP was mild, providing insights into quinoa’s adaptability to drought. In conclusion, considering the thorough evaluation of all the measured parameters, the study suggests using the in-furrow planting method with a 75%WR as the best approach for growing quinoa in arid and semi-arid regions to enhance production and resource efficiency.

Influence of Functional Traits of Dominant Species of Different Life Forms and Plant Communities on Ecological Stoichiometric Traits in Karst Landscapes.

Assessing the functional traits and ecological stoichiometric characteristics of dominant species across different life forms within plant communities in karst environments and investigating the inherent connection between them can provide insights into how species adjust their functional attributes in response to habitat heterogeneity. This approach offers a more comprehensive understanding of ecosystem processes and functions in contrast to examination of the taxonomic diversity of species. This study examines the relationship between the functional characteristics of dominant species in plant communities of various life forms in karst environments, focusing on deciduous leaf-soil ecological stoichiometry. The investigation relies on community science surveys, as well as the determination and calculation of plant functional traits and ecological stoichiometries, in plant communities of various life forms in Guizhou (a province of China). The findings of our study revealed considerable variability in the functional trait characteristics of dominant species across different plant-community life forms. Specifically, strong positive correlations were observed among plant height (PLH), leaf area (LA), leaf dry matter content (LDMC), and specific leaf area (SLA) in the dominant species. Additionally, our results indicated no significant differences in leaf ecological stoichiometry among different life forms. However, we did observe significant differences and strong positive correlations between soil N:P, withered material C:N, and apomictic C:P. Furthermore, our study found that plant height (PLH), leaf area (LA), and specific leaf area (SLA) were particularly sensitive to the ecological stoichiometry of soil and apomixis. The results of our study suggest that the functional traits of diverse plant-community life forms in karst regions are capable of adapting to environmental changes through various expressions and survival strategies. The development of various plant-community life forms in karst areas is particularly vulnerable to phosphorus limitation, and the potential for litter decomposition and soil nutrient mineralization is comparatively weaker. The functional traits of various plant-community life forms in karst regions exhibit greater sensitivity to both the soil's C:N ratio and the C:N ratio of apomictic material. Habitat variations may influence the ecological stoichiometric characteristics of the plant leaf-apomictic soil continuum.

Trade-Offs in Plant Functional Traits Driven by Soil Changes under Urban Hardened Surfaces

The large-scale surface hardening has changed the urban environment and affected the normal growth of urban plants. However, it is still unclear how the urban hardened surface affects the functional urban plant traits. To explore whether the urban hardened surface affects the ecological strategies of plants by changing the urban soil properties and reflecting them on the plant traits, we studied the physical and chemical properties and plant functional traits of three different types of hardened surface in Shandong Province, China. Our results showed that the physical and chemical properties (soil bulk density, soil total porosity, capillary porosity, non-capillary porosity, soil moisture content, pH, organic carbon, total nitrogen, total phosphorus, total potassium, available phosphorus, and available potassium) of urban soils showed obvious differences with the increase of hardening strength. In this case, the plant functional traits (branch diameter, branch length, leaf thickness, branch weight, internode length, leaf dry weight, leafing intensity, leaf area, specific leaf area, and leaf dry matter content) were also differentiated to varying degrees. Meanwhile, there was a strong correlation among plant functional traits. Nevertheless, hardened surfaces break the quantitative relationship among functional traits of urban trees. They do not affect their stable correlation: as the hardening intensity gradually increases, its correlation weakens. In addition, plant functional traits have a significant response mechanism to soil physicochemical properties. There was a transformation of plant resource utilization strategy by changing plant functional traits to adapt to the hardened environment. Urban trees exhibit strong and rapid resource-allocation strategies. They are mainly reflected in the reduction of branch diameter, branch weight, leaf dry matter content, leaf area, mass ratio of branches and leaves, and the improvement of leafing intensity and leaf thickness. Overall, there were tight connections among urban soil properties, plant branches, and leaves functional properties. This finding reveals that urban trees can change their functional traits and the plasticity of their trait combinations under the background of hardened urban surface expansion, which is conducive to survival and growth.