Leaf Tissue Density Research Articles

Effects of different soil and water conservation measures on plant functional traits in the Loess Plateau.

Soil and water conservation measures (SWCM) have wide-ranging effects on vegetation and soil, and their effects on the ecosystem are multifaceted, with complex mechanisms. While numerous studies have focused on the impact of such measures on soil, the improvement of plant functional traits is a major factor in the ecological recovery of the Loess Plateau. This survey extensively investigated no measure plots, vegetation measure plots, and engineering measure plots in the Loess Plateau. The impact of SWCM on plant functional traits was investigated using structural equation modeling. We examined six plant functional traits-leaf dry weight (LD), specific leaf area (SLA), leaf tissue density (LTD), leaf total phosphorus (LTP), leaf total nitrogen (LTN), and leaf volume (LV)-correlated with resource acquisition and allocation. In 122 plots, we explored the effects of measures, soil, diversity, and community structure on the weighted average of plant functional traits. The findings showed substantial positive correlations between LD and SLA, LD and LV, SLA and LV, SLA and LTP, and LTP and LTN. LTD has a substantial negative correlation with LD, LTD with SLA, and LTD with LV. SWCM limits diversity, and the mechanisms by which it affects plant functional traits vary. In the structural equation model (SEM) of vegetation measures, improving community structure enhances plant functional traits, but soil factors have the greatest influence on plant functional traits in SEM engineering measures. Plant functional trait differences on the Loess Plateau result are due to differential plant responses to diverse soil properties and community structure. Vegetation measures enhance the chemical properties of plant functional traits, while engineering measures improve physical properties. The study provides a theoretical foundation for vegetation restoration and management following the implementation of diverse SWCM.

Variations in the leaf economics spectrum, anatomical, ultrastructural, and stomatal traits of five tree species in the urban-rural air pollution environment

Rapid urbanization has contributed to global increases in air pollution derived from urban areas. Unlike natural forests, urban forests are exposed to higher concentrations of airborne pollutants due to the strong urban-suburban-rural pollutant emission gradients. However, there remains a pressing lack of available information pertaining to the urban air pollution-related effects on the leaf economics spectrum, anatomical, ultrastructural, and stomatal traits of tree species along an urban-rural gradient. Here, the degree to which urban air pollution impacts the adaption of greening tree species and associated service functions was assessed by sampling five common tree species (Acer pictum, Fraxinus chinensis, Koelreuteria paniculata, Salix babylonica, Sophora japonica) along urban-rural-natural forests in the Beijing metropolitan region of China. These analyses revealed a significant reduction in leaf mass per unit area (–13.4 %), leaf thickness (–16.7 %), and stomatal area (–27.5 %) with increasing proximity to areas of greater air pollution that coincide with significant increases in leaf tissue density (+12.6 %), leaf nitrogen content (+10.1 %), relative chlorophyll content (+2.7 %), and stomatal density (+11.9 %). Higher air pollution levels were associated with organelle changes including gradual disintegration of chloroplasts, larger intercellular spaces and apparent starch and plastoglobuli deposition. Air pollution was conducive to the strengthening of the trade-off potential and adaptation strategies of trees in urban ecosystems, which are associated with trees with a rapid investment return strategy associated with thick leaves and strong photosynthetic capacity. These results provide strong empirical evidence of the profound air pollution-induced changes in leaf functional traits and adaption ability of urban forest tree species.

Leaf functional traits of Daphniphyllum macropodum across different altitudes in Mao’er Mountain in Southern China

Investigating functional traits among mountain species with differing altitude requirements is integral to effective conservation practices. Our study aims to investigate the structural and chemical characteristics of Daphniphyllum macropodum leaves at three altitudes (1100 m, 1300 m, and 1500 m) across southern China to provide insight into changes in leaf functional traits (LFT) as well as plant adaptations in response to changing environmental conditions. Leaf structural characteristics include leaf thickness (LT), leaf area (LA), specific leaf area (SLA), and leaf tissue density (LD), respectively, while chemical properties include carbon-nitrogen-phosphorus (C:N:P) contents and ratios, such as C/N, C/P, and N/P. Our findings demonstrated the significant effect of altitude on both structural (LT, SLA, LD) and chemical aspects (N, C/N, N/P) of LFT. In particular, leaves at 1100 and 1300 m differed greatly, with 1300 m having lower SLA values than 1100 m. Observable trends included an initial increase followed by a decline as the altitude rose. Notable among them were the LT, LD, N, and N/P values at both locations. Traits at 1300 m were significantly higher than at 1100 m; SLA and C/N values displayed an inverse trend, with their lowest values occurring at 1300 m. Furthermore, this research demonstrated various degrees of variation among LFT, with structural traits exhibiting greater fluctuation than chemical traits. Robust correlations were observed among certain traits, such as LT, LD, and SLA. Furthermore, the interdependency relationships between N and C/N, as well as P and C/P, demonstrated interconnectedness. Redundancy analysis indicated that soil factors, specifically P content, exerted the strongest impact on LFT. At 1100 m, D. macropodum employed acquisition strategies; however, at 1300 m, conservation strategies emerged, showing a shift from acquisition strategies at lower altitudes to conservative strategies at higher ones.

Seedling development of Schizolobium parahyba var. amazonicum inoculated with Rhizoglomus clarum in different doses of phosphorus

This work aimed to evaluate the growth and phosphorus uptake of Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby (pinho-cuiabano) seedlings inoculated with Rhizoglomus clarum (T.H.Nicolson & N.C.Schenck) Sieverd., G.A.Silva & Oehl at different doses of phosphorus. The treatments consisted of five levels of phosphorus (0, 25, 50, 100 and 200 mg dm-³) and inoculation or not with R. clarum. After 45 days of seedling inoculation, we analyzed: height, root fresh and dry matter, shoot fresh and dry matter, number of leaves, survival, stem diameter, root volume, Dickson quality index, mycorrhizal colonization, relative water content, leaf tissue density, phosphorus content, efficiency of phosphorus uptake and efficiency of phosphorus utilization. Inoculation with R. clarum and the lowest doses of phosphorus resulted in lower seedling mortality rates. R. clarum did not increase the phosphorus content, efficiency of phosphorus uptake, efficiency of phosphorus utilization, relative water content and the Dickson quality index of the seedlings, but it was efficient in increasing the shoot fresh and dry matter as well as leaf tissue density. Inoculation with R. clarum and phosphate fertilization had a significant joint effect on seedling height and root fresh matter. Thus, it can be concluded that R. clarum may represent an important sustainable technology for the production of pinho-cuiabano seedlings, increasing seedling growth, even at low levels of phosphate fertilization.

Plant Leaf Functional Adaptions along Urban-Rural Gradients of Jinhua City.

Environmental changes induced by urbanization may significantly alter plant survival strategies, thereby introducing uncertainties in their ability to withstand extreme heat. This study, centered on Jinhua City, distinguished urban, suburban, and rural areas to represent the various intensities of urbanization. It examined the leaf function properties of evergreen and deciduous trees common in these regions, focusing on leaf and branch characteristics. Employing an analysis of variance (ANOVA), principal component analysis (PCA), and path analysis (PA) of the plant functional traits and the climatic factors of each region, this study assessed the impact of urbanization on plant survival strategies. By tracking changes in plant functional traits from June to August, it explored the capacity of plants to acclimate to urban-warming-related heat stress across different urbanization gradients. The findings revealed that leaf thickness (LT) and stomatal size (SS) initially decreased and then increased, whereas specific leaf area (SLA) and leaf tissue density (LTD) first rose and then declined, from rural to urban regions. From June to August, branch wood density (WD), chlorophyll (Chl) content, LTD, and leaf dry matter content (LDMC) increased, whereas SLA and leaf water content (LWC) diminished, in all regions. PCA suggested that there was no significant change in the resource allocation strategy of plants (p > 0.05), with drought tolerance significantly reduced in the suburbs on the gradient of urbanization (p < 0.05). During the summer, with high temperature, plants were predominantly biased towards slow-return, conservative strategies, particularly among evergreen species. Compared to precipitation, PA revealed a significant urban warming effect. During summer, temperature was the main factor influencing resource investment strategy and drought resistance, with a notably stronger impact on the former. The high temperature in summer promoted a conservative survival strategy in plants, and the urbanization effect increased their tolerance to high temperatures.

Functional Segregation of Resource Utilization Strategies between Invasive and Native Plants and Invasion Mechanisms in the Water Level Fluctuation Zone: A Case Study of Pengxi River in Three Gorges Reservoir, China

The ecosystem of the water level fluctuation (WLF) zone of the Three Gorges Reservoir (TGR) is highly vulnerable and sensitive due to its unique cyclical flooding and drought conditions. The ecological impact of biological invasion in this area is particularly severe, making it crucial to study the differences in resource utilization strategies between invasive plants (IPs) and native plants (NPs) using functional traits to explore the mechanisms of invasion. We selected the WLF zone of Pengxi River in the TGR area and conducted a multi-scale study along the elevation gradient. The results reveal that at the regional scale, IPs have a larger height and specific leaf area, smaller leaf tissue density, and specific root length compared to NPs, showing a preference for enhancing aboveground resource acquisition over leaf defense capabilities. They allocate more tissue construction resources to their roots to withstand environmental pressures, which may be the key to their successful intrusion, highlighting the role of niche differentiation. On the community scale, the H and SLA of IPs and NPs are positively correlated with elevation, while the LTD of IPs shows a negative correlation. At elevations of 175 m and below, IP and NP exhibit functional convergence, while above 175 m, functional divergence was observed. This indicates that although the different resource utilization strategies are crucial for successful IP invasion, the environmental filtering from periodic floods and drought pressures play a significant role in community assembly in the WLF zone, allowing IP to integrate into habitats with similar functional characteristics already inhabited by NP and establish their own communities.

Impact of abandonment on leaf morphology traits and nutrient utilization strategies of dominant tree seedlings in Moso bamboo forests

The restoration of ecological functions in abandoned Moso bamboo forests facilitates positive succession in evergreen vegetation. Nevertheless, there is a limited understanding regarding the leaf functional traits and nutrient utilization strategies of understory vegetation after abandonment. This study investigated the impact of abandonment duration (9 and 21 years) on leaf morphological traits, soluble sugars characteristics, carbon (C), nitrogen (N), phosphorus (P), and their ratios in dominant tree seedlings (Lithocarpus brevicaudatus and Schima superba) within Moso bamboo forests. Leaf sizes increased significantly with prolonged abandonment in both species, accompanied by a consistent decrease in leaf thickness and leaf tissue density. These morphological indices were more pronounced in L. brevicaudatus compared to S. superba (P < 0.05), and they showed a positive correlation with tree sizes. Moreover, leaf soluble sugars, C, and C: N: P ratios of both tree species decreased over duration abandonment, while N and P contents increased. Specifically, L. brevicaudatus exhibited elevated levels of fructose, glucose, N, and P, whereas S. superba displayed higher sucrose, C, and C: N: P ratios. Our findings reveal that both species, with extended abandonment, enlarged their leaf area and improved carbon utilization, facilitating adaptation to competitive resource habitats. Particularly, L. brevicaudatus exhibited a propensity to augment leaf sizes, as well as N, and P contents, suggesting a strategy to enhance carbon assimilation through additional N and P nutrient supplementation. Conversely, S. superba primarily focused on bolstering carbohydrate reserves, indicating that moderate thinning or pruning of bamboo forests could boost sunlight penetration, along with the appropriate nutrient supplementation. These insights significantly contribute to the scientific understanding necessary for the classification and management of mixed stands in abandoned bamboo forests.

Using the response–effect trait framework to disentangle the effects of environmental change on the ecosystem services

Abstract Functional traits play a vital role in mediating the responses of ecosystem services to environmental changes and in predicting the functioning of the ecosystem. However, the connection between functional traits and ecosystem services has become increasingly intricate due to climate change and human activities for degraded ecosystems. To investigate this relationship, we selected 27 sampling sites in the Yanhe River Basin of the Chinese Loess Plateau, each containing two types of vegetation ecosystems: natural vegetation and artificial vegetation ecosystems. At each sampling site, we measured ecosystem services and calculated the composition index of community traits. We established a response–effect trait framework that included environmental factors such as climate, elevation and human activities. Our results showed that leaf tissue density (LTD) was the overlapping response and effect trait when responding to climate change. LTD is positively correlated with mean annual temperature and negatively correlated with supporting services. Under the influence of human activities, leaf nitrogen content and leaf dry matter content were carriers of environmental change. Comparing the two vegetation ecosystems, the relationship between functional traits and ecosystem services showed divergent patterns, indicating that human activities increased the uncertainty of the relationship between functional traits and ecosystem services. Trait-based ecology holds promise for enhancing predictions of ecosystem services responses to environmental changes. However, the predictive ability is influenced by the complexity of environmental changes. In conclusion, our study highlights the importance of understanding the complex connection between functional traits and ecosystem services in response to climate changes and human activities.

Idiosyncrasy and predictability in intraspecific trait–climate relationships of grasses

AbstractMany plant species can exhibit remarkable variation in leaf characteristics, depending on their abiotic and biotic environment. Environmental changes therefore have the potential to alter leaf traits, which in turn scale up to influence ecosystem processes including net primary productivity, susceptibility to fire, and palatability to herbivores. It is not well understood how consistent trait–environment relationships are among species, across sites and over time. This presents a fundamental challenge for functional ecology, because no study can measure all relevant species in all places at all times. Thus, understanding the limits of transferability is critical. We collected leaf trait measurements on 13 species of grass (family: Poaceae) across 11 sites and five years (n = 3091 individuals). Sites were arrayed along a spatial precipitation gradient in coastal northern California (annual precipitation of 590–1350 mm) with substantial interannual precipitation variability (from 60% below the 30‐year average to 100% above average). Temporal and spatial linear relationships between precipitation and specific leaf area (SLA) appear at first idiosyncratic, with each species sometimes displaying positive and sometimes negative responses. However, this variation arises from sampling different portions of an underlying hump‐shaped relationship, which was shared across most species. This hump‐shaped relationship was driven primarily by changes in leaf tissue density. These results suggest the potential for transferability among species, as well as between space and time, as long as the gradients are sufficiently long to capture the nonlinear response. Future work could explore the physiological basis of the nonlinear SLA response, including the possibility that distinct physiological mechanisms are operating at the two extremes of the gradient.

Nutrients from spawning salmon influence leaf area, tissue density, and nitrogen-15 in riparian plant leaves.

Nutrient subsidies have significant impacts on ecosystems by connecting disjunct habitats, often through long-distance animal migrations. Salmon migrations on the North Pacific coasts provide these kinds of nutrient subsidies from senescent fish at the end of their life cycle, which can have significant ecological effects on terrestrial species. This can include impacts on individuals, populations, and communities, where shifts in community composition towards plant species that indicate nitrogen-rich soils have been documented. We investigated the effects of variation in salmon spawning density on the leaf traits of four common riparian plant species on the central coast of British Columbia, Canada. We found that all plant species had higher foliar salmon-derived nitrogen on streams with a higher spawning density. Three of the four species had larger leaves, and one species also had higher leaf mass per area on streams with more salmon. However, we found no differences in leaf greenness or foliar percent nitrogen among our study streams. These results demonstrate that nutrient subsidies from spawning salmon can have significant impacts on the ecology, morphology, and physiology of riparian plants, which lends support to a mechanism by which certain plants are more common on productive salmon streams.

Plant life history strategies vary in subtropical forests with different disturbance histories: an assessment of biodiversity, biomass, and functional traits.

Disturbance alters environmental conditions in forests. Plants growing in forests with different disturbance histories in diverse environments may adopt varying life history strategies, but few studies focus on this effect. This study comprehensively investigated plant biodiversity, biomass, and functional traits in subtropical forests with two different disturbance histories in east China to explore differences in life history strategies. Biodiversity was slightly higher in disturbed compared to conserved forests. Significantly higher biomass was measured in conserved relative to disturbed evergreen broadleaved forests (P < 0.05). In conserved forests, leaf tissue density (LTD) was significantly higher and leaf thickness (LT), leaf dry matter content (LDMC), twig tissue density (TTD), twig dry matter content (TDMC), bark tissue density (BTD) and dry matter content (BDMC), and stem tissue density (STD) and dry matter content (SDMC) were significantly lower than in disturbed forests (P < 0.05). In terms of associated plant biodiversity, biomass, and functional traits, conserved forests adopted a resource acquisition strategy, reducing biodiversity and developing multiple functional traits such as high leaf area and specific leaf area and low LT, LDMC, TTD, TDMC, BTD, BDMC, STD, and SDMC to support a high biomass accumulation rate. Disturbed forests adopted a resource conservation strategy, enhancing biodiversity and developing converse trait combinations to lower the rate of biomass accumulation. A comprehensive investigation of plant biodiversity, biomass, and functional traits and subsequent assessment of plant life history strategies in conserved and disturbed forests will aid investigations of regional biodiversity and carbon reserves, contribute data to the TRY and Chinese plant trait databases, and improve ecological management and restoration efforts in east China.

Parasitism by Cuscuta chinensis is associated with changes in leaf functional traits and hyperspectral characteristics of Eunymus japonicas.

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.

Patterns in leaf traits of woody species and their environmental determinants in a humid karstic forest in southwest China

IntroductionLeaf functional traits constitute a crucial component of plant functionality, providing insights into plants’ adaptability to the environment and their regulatory capacity in complex habitats. The response of leaf traits to environmental factors at the community level has garnered significant attention. Nevertheless, an examination of the environmental factors determining the spatial distribution of leaf traits in the karst region of southwest China remains absent.MethodsIn this study, we established a 25 ha plot within a karst forest and collected leaf samples from 144 woody species. We measured 14 leaf traits, including leaf area (LA), leaf thicknes (LT), specific leaf area (SLA), leaf length to width ratio (LW), leaf tissue density (LTD), leaf carbon concentration (LC), leaf nitrogen concentration (LN), and leaf phosphorus concentration (LP), leaf potassium concentration (LK), leaf calcium concentration (LCa), leaf magnesium Concentration (LMg), leaf carbon to nitrogen ratio (C/N), leaf carbon to phosphorus ratio (C/P), and leaf nitrogen to phosphorus ratio (N/P), to investigate the spatial distribution of community-level leaf traits and the response of the leaf trait community-weighted mean (CWM) to topographic, soil, and spatial factors.ResultsResults showed that the CWM of leaf traits display different spatial patterns, first, the highest CWM values for LT, LTD, C/N, and C/P at hilltops, second, the highest CWM values for LA, SLA, LW, LC, LN, LP, and LK at depressions, and third, the highest CWM values for LCa, LMg, and N/P at slopes. The correlation analysis showed that topographic factors were more correlated with leaf trait CWM than soil factors, with elevation and slope being the strongest correlations. RDA analysis showed that topographic factors explained higher percentage of leaf trait CWM than soil factors, with the highest percentage of 19.96% being explained by elevation among topographic factors. Variance Partitioning Analysis showed that the spatial distribution of leaf traits is predominantly influenced by the combined effects of topography and spatial factors (37%-47% explained), followed by purely spatial factors (24%-36% explained).DiscussionThe results could improve our understanding of community functional traits and their influencing factors in the karst region, which will contribute to a deeper understanding of the mechanisms that shape plant communities.

A comprehensive model for predicting the development of defense system of Capparis spinosa L.: a novel approach to assess the physiological indices

Capparisspinosa L. (caper) is a halophytic plant that grows in semi-arid or arid environments. The current study used an integrated experimental and computational approach to investigate the network of inter-correlated effective variables on the activity of antioxidant enzymes, proline, and photosynthetic pigments in stressed caper. To investigate the possible relationships among intercorrelated variables and understand the possible mechanisms, predictive regression modelling, principal component analysis (PCA), Pearson's correlation, and path analysis were implemented. PCA successfully discerned different salt ratio- and drought-specific effects in data in the current study, and treatments with higher growth indices are easily recognizable. Different salt ratios did not have a significant effect on the activity of four antioxidant enzymes, proline and photosynthesis pigments content of caper. While at the mean level, the activity of four antioxidant enzymes of SOD, POD, CAT, and APX significantly increased under drought stress by 54.0%, 71.2%, 79.4%, and 117.6%, respectively, compared to 100% FC. The drought stress also significantly increased the content of carotemoid (29.3%) and proline (by 117.7%). Predictive equation models with highly significant R2 were developed for the estimation of antioxidant enzyme activity and proline content (> 0.94) as well as pigments (> 0.58) were developed. Path analysis studies revealed that proline is the most important regressor in four antioxidant enzyme activities, while leaf tissue density was the most effective variable in the case of chlorophylls. Furthermore, the network of intercorrelated variables demonstrated a close relationship between caper's antioxidant defence system, pigments, and morphological parameters under stress conditions. The findings of this study will be a useful guide to caper producers as well as plant ecophysiological researchers.

Variations and driving factors of leaf functional traits in the dominant desert plant species along an environmental gradient in the drylands of China

Leaf functional traits (LFTs) of desert plants are responsive, adaptable and highly plastic to their environment. However, the macroscale variation in LFTs and driving factors underlying this variation remain unclear, especially for desert plants. Here, we measured eight LFTs, including leaf carbon concentration (LCC), leaf nitrogen concentration (LNC), leaf phosphorus concentration (LPC), specific leaf area (SLA), leaf dry matter content (LDMC), leaf mass per area (LMA), leaf thickness (LTH) and leaf tissue density (LTD) across 114 sites along environmental gradient in the drylands of China and in Guazhou Common Garden and evaluated the effect of environment and phylogeny on the LFTs. We noted that for all species, the mean values of LCC, LNC, LPC, SLA, LDMC, LMA, LTH and LTD were 384.62 mg g−1, 19.91 mg g−1, 1.12 mg g−1, 79.62 cm2 g−1, 0.74 g g−1, 237.39 g m−2, 0.38 mm and 0.91 g cm−3, respectively. LFTs exhibited significant geographical variations and the LNC, LMA and LTH in the plants of Guazhou Common Garden were significantly higher than the field sites in the drylands of China. LDMC and LTD of plants in Guazhou Common Garden were, however, considerably lower than those in the drylands of China. LCC, LPC, LTH and LTD differed significantly among different plant lifeforms, while LNC, SLA, LDMC and LMA didn't show significant variations. We found that the environmental variables explained higher spatial variations (3.6–66.3 %) in LFTs than the phylogeny (1.8–54.2 %). The LCC significantly increased, while LDMC and LTD decreased with increased temperature and reduced precipitation. LPC, LDMC, LMA, and LTD significantly increased, while SLA and LTH decreased with increased aridity. However, leaf elements were not significantly correlated with soil nutrients. The mean annual precipitation was a key factor controlling variations in LFTs at the macroscale in the drylands of China. These findings will provide new insights to better understand the response of LFTs and plants adaptation along environmental gradient in drylands, and will serve as a reference for studying biogeographic patterns of leaf traits.

Differential impact of liana colonization on the leaf functional traits of co-occurring deciduous and evergreen trees in a tropical dry scrub forest

The present study was carried out to analyze the leaf functional traits of co-occurring evergreen and deciduous tree species in a tropical dry scrub forest. This study also intended to check whether the species with contrasting leaf habits differ in their leaf trait plasticity, responding to the canopy infestation by lianas. A total of 11 leaf functional traits were studied for eight tree species with contrasting leaf habits (evergreen and deciduous) and liana-colonization status (with or without liana). In the liana-free environment (L–), evergreen trees had significantly higher leaf tissue density (LTD) and total chlorophyll (CHLt) than the deciduous species. Whereas the deciduous trees had higher specific leaf area (SLA) and mass-based leaf nitrogen concentration (Nmass). The leaf trait-pair relationship in the present study agreed with the well-established global trait-pair relationships (leaf thickness (LT) vs. SLA, Nmass vs. LT, SLA vs. Nmass, and LDMC vs. SLA). There was a significant difference between L+ and L– individuals in leaf area (LA), petiole length (PL), SLA, LDMC, and CHLt in the deciduous species. On the other hand, evergreen species showed marked differences across LT, SLA, LTD, Nmass, and chlorophyll components between L+ and L– individuals of the same species. The results revealed the differential impact of liana colonization on the host trees with contrasting leaf habits. The deciduous species with the acquisitive strategy can have a competitive advantage over evergreen species in the exposed environments (L–), whereas evergreen species with shade-tolerant properties were better acclimated to the shaded environments (L+). Therefore, liana colonization can significantly impact the C-fixation strategies of the host trees by altering their light environment and further, the magnitude of such impact may vary among species of different leaf habits. The result also indicated the patterns of convergence and divergence in some of the leaf functional traits between evergreen and deciduous species explaining the patterns of species co-existence.

Should more individuals be sampled when measuring functional traits of tree species in habitat-heterogeneous karst forests?

When measuring plant functional traits across geomorphologies, 5–10 healthy individuals of a plant species are commonly sampled. However, whether more individuals should be sampled in habitat-heterogeneous karst vegetation remains unknown. In this study, two dominant tree species (Clausena dunniana and Platycarya strobilacea) in karst evergreen and broadleaved mixed forests in Southwestern China were selected. On the basis of a large quantity of individuals of the two species grown in different peak clumps and slope positions, variations of 10 morphological traits in the two species were statistically analyzed. The suggested sampling number of individuals, which could mostly represent the common trait characteristics, was further explored. All traits showed significant differences between the two species (p &amp;lt; 0.05). The traits of P. strobilacea displayed larger intraspecific variations than those of C. dunniana, except for twig dry matter content. The bark thickness (BT), leaf area (LA), and specific leaf area (SLA) of C. dunniana and the BT, SLA, LA, leaf tissue density, and bark tissue density of P. strobilacea presented large intraspecific variations. Most traits exhibited significant differences between peak clumps and/or among slope positions (p &amp;lt; 0.05). Random sampling analysis indicated that the suggested sampling numbers of individuals for the 10 traits are 6–23 in C. dunniana and 9–29 in P. strobilacea. The common accepted sample size in normal geomorphologies is not sufficiently large in most cases. Larger sample sizes are recommended for traits, such as SLA, BT, and LA, with larger intraspecific variations. Therefore, under sufficient labor, material, and time, more individuals should be sampled when measuring plant functional traits in habitat-heterogeneous karst vegetation.

Strategic differentiation of subcommunities composed of evergreen and deciduous woody species associated with leaf functional traits in the subtropical mixed forest

The joint assembly of evergreen and deciduous tree species, typical karst vegetation of evergreen and deciduous broad-leaved mixed forests through respective subcommunities, play an important role in maintaining biodiversity in subtropical karst regions, and leaf functional traits can strategically specify plant resource utilization. However, it is unclear how these assembled subcommunities of evergreen and deciduous species maintain differentiation strategies. This study surveyed 53 forest plots of 20 m × 20 m dividing 212 adjacent lattices in a typical karst forest. Leaf traits of woody plants were measured regarding the specific leaf area (SLA), leaf dry matter content (LDMC), leaf tissue density (ltd), and leaf C, N, and P contents. The differences between deciduous and evergreen subcommunities were compared using the community-weighted means (CWM). The SLA and LDMC of the deciduous subcommunity were greater than the evergreen subcommunity; meanwhile, the leaf C, C/N and C/P ratios of the evergreen subcommunity were significantly higher than those of the deciduous subcommunity. However, the leaf N, P and N/P ratios of the deciduous subcommunity were significantly enhanced than the evergreen subcommunity. Moreover, both subcommunities showed significant negative correlations between SLA, leaf N and ltd, LDMC, signifying a trade-off of leaf-economic trait in deciduous and evergreen subcommunities. Furthermore, principal component analysis (PCA) on leaf functional traits specified the strategic differentiation mainly located at the side of the resource acquisition with high SLA and leaf N content for the deciduous subcommunity and situated at the side of the resource conservation with high LDMC and ltd for the evergreen subcommunity. In conclusion, the trade-off correlated with leaf functional trait differentiation suggested a resource acquisition strategy for the deciduous subcommunity and a resource conservation strategy for the evergreen subcommunity in the subtropical climate-dominating mixed forest of karst ecosystem.

Coordinated variation in root and leaf functional traits of Hippophae rhamnoides treated at different stump heights in feldspathic sandstone areas of Inner Mongolia.

This study was aimed to clarify the effects of stumping on root and leaf traits as well as the tradeoffs and synergies of decaying Hippophae rhamnoides in feldspathic sandstone areas, and to select the optimal stump height that contributed to the recovery and growth of H. rhamnoides. variations and coordination between leaf traits and fine root traits of H. rhamnoides were studied at different stump heights (0, 10, 15, 20cm, and no stumping) in feldspathic sandstone areas. All functional traits of the leaves and roots, except the leaf C content (LC) and the fine root C content (FRC), were significantly different among different stump heights. The total variation coefficient was the largest in the specific leaf area (SLA), which is therefore the most sensitive trait. Compared to non-stumping, SLA, leaf N content (LN), specific root length (SRL) and fine root N content (FRN) all improved significantly at stump height of 15cm, but leaf tissue density (LTD), leaf dry matter content (LDMC), leaf carbon to nitrogen ratio (LC : LN), fine root tissue density (FRTD), fine root dry matter content (FRDMC) and fine root carbon to nitrogen ratio (FRC : FRN) all decreased significantly. The leaf traits of H. rhamnoides at different stump heights follow the leaf economic spectrum, and the fine roots show a similar trait syndrome to the leaves. SLA and LN are positively correlated with SRL and FRN and negatively with FRTD and FRC : FRN. LDMC and LC : LN are positively correlated with FRTD and FRC : FRN, and negatively correlated SRL and RN. The stumped H. rhamnoides changes to the 'rapid investment-return type' resource trade-offs strategy, and the growth rate is maximized at the stump height of 15cm. Our findings are critical to the prevention and control of vegetation recovery and soil erosion in feldspathic sandstone areas.

杉木叶片、细根功能性状对毛竹扩张及伐除的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 杉木叶片、细根功能性状对毛竹扩张及伐除的响应 DOI: 10.5846/stxb202108262394 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31770680,32171786);浙江省自然科学基金项目(LY14C160010);暨阳"533英才计划"项目 Responses of leaf and fine root functional traits of Cunninghamia lanceolata to Phyllostachys edulis expansion and removal Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:功能性状能够反映植物对不同环境的适应策略。毛竹扩张与外来植物入侵相似,常引起原有植物生存环境的改变,而原有植物功能性状对毛竹扩张及伐除的响应机制尚不清楚。选取毛竹-杉木混交林和去竹杉木林为研究对象,以杉木纯林为对照,比较分析杉木比叶面积、叶干物质含量、叶组织密度等叶功能性状以及比根长、细根生物量、细根根长密度等细根功能性状的变化以及其间的相关关系。结果表明:(1)与杉木纯林相比,混交林中杉木的叶相对含水量以及叶干物质含量分别减少了5.07%、0.032 g/g,叶组织密度以及比叶面积分别增加了0.005 g/cm3、10.33 cm2/g;而去竹杉木林中,杉木比叶面积、叶相对含水量减少,叶干物质含量和叶组织密度则呈上升趋势。(2)与杉木纯林相比,混交林中杉木细根生物量、细根体积密度以及细根根长密度都不断下降,而杉木细根比根长在0-20 cm土深处显著增加(P<0.05);而去竹杉木林中杉木细根比根长、细根根长密度和细根生物量则显著降低(P<0.05),细根体积密度在20-30 cm土深处有所增加。(3)杉木纯林中杉木细根功能性状间相关性较为紧密,混交林及去竹杉木林中杉木叶片功能性状间相关性较高。研究表明,杉木可通过比叶面积、叶组织密度以及细根比根长等功能性状的调整及性状关联,以适应毛竹扩张或去除毛竹后引起的空间、资源竞争的变化。研究结果有利于更好地理解杉木叶片、细根对不同生境的响应特征及生态适应策略,可为毛竹林合理经营与扩张调控提供科学依据。 Abstract:Functional traits can reflect the adaptation strategies of plants to different environments. The expansion of Phyllostachys edulis is similar to the invasion of alien plants, which often causes changes in the living environment of native plants. However, the response mechanism of the functional traits of native plant functional traits to the expansion and removal of Phyllostachys edulis is still unclear. The mixed forest of moso bamboo and Chinese fir and Chinese fir forest after bamboo removal were selected as the research objects, and the pure Chinese fir forest was used as the control. The changes of leaf functional traits, such as specific leaf area, dry matter content and tissue density, as well as fine root functional traits, like specific root length, fine root biomass and fine root length density, and their correlation were measured and analyzed. The results show that: (1) Compared with the pure Chinese fir forest, the leaf relative water content and leaf dry matter content of Chinese fir in mixed forest decreased by 5.07% and 0.032 g/g respectively. However, the leaf tissue density and specific leaf area in mixed forest increased by 0.005 g/cm3 and 10.33 cm2/g respectively. Compared with the pure Chinese fir forest, the specific leaf area and leaf relative water content of Chinese fir forest after bamboo removal decreased, while the leaf dry matter content and leaf tissue density increased. (2) Compared with the pure Chinese fir forest, the fine root biomass, fine root volume density and fine root length density of Cunninghamia lanceolata decreased continuously in mixed forest, but the ratio of fine root to root length increased significantly in 0-20 cm soil depth (P<0.05). Compared with the pure Chinese fir forest, fine root length, fine root length density and fine root biomass decreased significantly in Chinese fir forest after bamboo removal (P<0.05), while fine root volume density increased in soil depth of 20-30 cm. (3) The correlation between fine root functional traits of Cunninghamia lanceolata in pure forest was close, and the correlation between leaf functional traits in Chinese fir forest after bamboo removal and mixed forest was high. These results suggest that Cunninghamia lanceolata can adapt to the changes of space and resource competition caused by bamboo expansion or removal by adjusting and correlating the functional traits such as specific leaf area, leaf tissue density and fine root to root length. The results will help to better understand the response characteristics of leaves and fine roots of Cunninghamia lanceolata to different habitats and ecological adaptation strategies, and provide scientific basis for rational management and expansion regulation of bamboo forest. 参考文献 相似文献 引证文献