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opencc-zeroNov 2021View details →

Mercury accumulation in leaves of different plant types – the significance of tissue age and specific leaf area

Mercury, Hg, is one of the most problematic metals from an environmental perspective. To assess the problems caused by Hg in the environment it is crucial to understand the processes of Hg biogeochemistry, but the exchange of Hg between the atmosphere and vegetation is not sufficiently well characterised. We explored the mercury concentration, [Hg], in foliage from a diverse set of plant types, locations and sampling periods to study whether there is a continuous accumulation of Hg in leaves/needles over time. Measurements of [Hg] were made in deciduous and conifer trees in Gothenburg, Sweden (Botanical Garden and city area) as well as of evergreen trees in Rwanda. In addition, data for wheat from an ozone experiment conducted at Östad, Sweden, were included. Conifer data were quantitatively compared with literature data. In every case where older foliage was directly compared with younger, [Hg] was higher in older tissue. Covering the range of current year up to four-year old needles, there was no sign of Hg saturation in conifer needles with age. Thus, over time scales of approximately one month to several years, the Hg uptake in foliage from the atmosphere always dominated over Hg evasion. Rwandan broadleaved trees had generally older leaves due to lack of seasonal abscission and higher [Hg] than Swedish broadleaved trees. The significance of atmospheric Hg uptake in plants was shown in a wheat experiment where charcoal filtrated air lead to significantly lower leaf [Hg]. To search for general patterns, the accumulation rates of Hg in the diverse set of tree species in the Gothenburg area were related to the specific leaf area (SLA). Leaf area based [Hg] was strongly negatively and non-linearly correlated with SLA, while mass-based [Hg] had a somewhat weaker positive relationship with SLA (both relationships with p < 0.001). An elaborated understanding of the relationship behind [Hg] and SLA would support large-scale modelling of Hg uptake by vegetation and Hg circulation in general.

opencc-zeroNov 2021View details →

Life on a leaf: the development of spatial structure in epiphyll communities

1. The spatial structure of biotic communities can be shaped by niche-based or stochastic processes, and the importance of both can change through time. Niche-based processes include neighbour interactions, which can change in intensity and quality as communities develop in dependence of environmental conditions. Epiphylls, miniature communities of liverworts, lichens, algae and fungi on leaves, develop only in relatively moist forests, but their leaf-surface habitat is still characterised by moisture stress, especially in more exposed parts of the forest. As neighbours may alleviate moisture stress, we expected that in forest gaps (dryer, brighter) epiphyll communities would show more positive neighbour interactions, resulting in more clustered spatial patterns, than in closed forest, in accordance with the stress-gradient hypothesis. 2. To understand how the processes shaping epiphyll communities change through time and differ between gaps and closed forest, we examined the fine-scale spatial structure within and between epiphyll functional groups (algae, fungi, lichens, liverworts) during 12 months on 60 leaves across twelve sites in a tropical rainforest in Panama. We analysed changes in spatial positions and spatial associations within and between functional groups using spatial point pattern analysis based on repeated photography. 3. Epiphyll densities increased through time for most epiphyll functional groups. However, although epiphyll groups changed their positions through time, the general types of spatial patterns remained similar for most groups: only lichen patterns shifted from mostly random to mostly aggregated through time. We found only random and aggregated spatial patterns within groups, while among groups we additionally found segregated spatial associations, but no consistent temporal trend. Patterns did not differ between gaps and closed forest, thus not supporting the stress-gradient hypothesis. 4. Synthesis. Our results only weakly support the assumption that community-shaping processes change from neutral to niche-based as communities develop. We do provide empirical evidence that epiphyll communities are dynamic and exhibit different spatial association patterns within than among groups. This suggests different interactions and processes within than between groups. Experimental studies and monitoring of individual epiphyll patches are recommended to shed further light on what processes shape life on leaves.

opencc-zeroDec 2021View details →

Polyploidy promotes divergent evolution across the leaf economics spectrum and plant edaphic niche in the Dianthus broteri complex

<ol> <li>The evolution of the leaf economics spectrum (LES) is known to be constrained by genetic relatedness but also promoted at small geographic and phylogenetic scales. In those cases, we hypothesised that polyploidy would play a prominent role as an outstanding source of functional divergence and adaptive potential.</li> <li>We registered leaf-level nutrient, water and light economy related traits from the LES as well as edaphic properties in the four cytotypes of the autopolyploid Dianthus broteri complex (2×, 4×, 6× and 12×). We analysed the effect of ploidy level on the integration of the LES network, checked if concerted evolution occurred between LES and soil niche and tested the influence of phylogeny on the variables. Alternative evolutionary models for both sets of traits were compared.</li> <li> We found higher divergence of polyploids (especially 6× and 12×) compared to diploids in the LES and soil niche, but these traits are not coevolving. 6× and 12× showed opposite ecological strategies regarding resource use and higher uncoupling of the LES network. Early divergence of traits prevailed in both LES and edaphic niche (supported by better fitted evolutionary models with one optimum per cytotype), but post-polyploidization processes played an important role for the photochemical behaviour.</li> <li> Synthesis. Our results indicated shifts in ecological strategies across D. broteri cytotypes and suggested a powerful role of polyploidy in overcoming constraints for the evolution of plant functional traits. </li> </ol>

opencc-zeroJan 2022View details →

Leaf economics in a three‐dimensional environment: Testing leaf trait responses in vascular epiphytes to land use, climate, and tree zone

1. The study of functional traits offers predictive power for community ecology. Particularly in cases where individual species are difficult to study, known properties of trait spectra, such as the leaf economics spectrum (LES), and trait-environment relationships can provide crucial generalizable information that can contribute to forecasts of distributional shifts in response to the abiotic effects of climate and land use changes. 2. Vascular epiphytes have been proposed as indicators of environmental change, but we know little about the ecology of most species. Key functional trait assumptions are based on terrestrial plants; testing these in epiphytes verifies their universality and will inform applying functional traits in predicting epiphyte responses to climate and land use change. 3. In this study, we use functional traits from 37 vascular epiphyte species from forests and shade coffee farms at two sites in northern Nicaragua. We compare correlations among traits and intraspecific trait variances with those of terrestrial plants and among epiphyte taxonomic groups. We also test trait responses to environmental differences between sites and land use types, and within zones of the tree. 4. We find that epiphyte leaf traits fall toward the slower end of the LES, but with about one-third lower leaf nitrogen per change in specific leaf area (SLA) relative to terrestrial herbaceous plants. Bromeliads show less relationship between these traits than other epiphyte groups and also deviate in other trait interrelationships, suggesting unique leaf construction. 5. Trait-environment relationships varied most strongly along vertical gradients within trees, but some traits, including SLA and carbon isotope ratio, also responded to land use and site differences. 6. We present evidence that trait relationships established for terrestrial plants appear to translate to epiphytes, but identify some possible caveats. Strong trait response to vertical gradients within trees suggests that within-canopy shifts could provide resilience to climate and land use changes for some epiphyte species.

opencc-zeroJan 2022View details →

Leaf data of four families of broad-leaved plants

The data include two comma-delimited (csv) files and one word document. The data1.csv file saves the leaf raw data (including leaf lamina length, width, area, perimeter, fresh mass, and dry mass) from five groups of Phyllostachys edulis (Poaceae) differing in culm age. The bamboo plants grew in the Purple Mountain, Nanjing, China. The data2.csv file saves the leaf raw data (including leaf lamina length, width, area, perimeter, fresh mass, and dry mass) of 21 species from three families (nine Lauraceae species, six Fagaceae species and six Ulmaceae species) growing in Nanjing, China. Among the 21 species, we measured the data of leaf petiole fresh mass for the nine Lauraceae species. The word document (i.e., the metadata.docx file) is the metadata used to show the meanings of the column variables in each table.

opencc-by-4.0Jan 2022View details →

Videos:B. tabaci adult whiteflies emerging from pupae on a ToLCNDV-infected zucchini and tomato leaf,

Video S1: B. tabaci adult whitefly emerging from pupae on a ToLCNDV-infected zucchini leaf, Video S2: B. tabaci adult whitefly emerging from pupae on a ToLCNDV-infected tomato leaf.

opencc-zeroFeb 2022View details →

Climate-induced plasticity in leaf traits of riparian plants

Aim: Leaf inputs from riparian vegetation and its decomposition play a key role in energy and nutrients transfer in many stream ecosystems. Instream leaf-litter decomposition is mainly driven by leaf traits. Therefore, understanding and predicting leaf traits variation with current environmental changes and its putative effects on stream food webs is a critical challenge. Most studies have focused on the assumed higher interspecific leaf traits variability, with little research addressing an intraspecific perspective. Location: Andalusia, Spain Methods: We assessed the relative effects of climate and soil on the intraspecific variability in leaf traits of four common woody riparian species in permanent low-order Mediterranean streams along a wide aridity gradient. We used a space-for-time substitution approach to predict leaf traits changes and consequences for stream food webs in a future climate change scenario. Results: We found that climate had a major influence on intraspecific variability of leaf traits, but with opposite patterns depending on plant functional type. Results indicated that leaf quality—linked to palatability and decomposability—of Alnus glutinosa, Salix atrocinerea and Rubus ulmifolius (deciduous/semideciduous) will decrease with the forecasted aridification, whereas that of the evergreen Nerium oleander will increase. Main conclusions: Our findings suggest a decrease of intraspecific leaf-quality in riparian deciduous species with global warming in a relatively short term, which, in a longer term, may add to the forecasted dieback of deciduous species in riparian corridors of temperate climate zones. These forecasted changes have the potential to significantly impair ecosystem functioning of Mediterranean mountain streams currently under deciduous gallery forests.

opencc-zeroMar 2022View details →

FIG. 2. — Leafs hiding a in Ontogenetic systematic characterisation of an endemic frog Rhacophorus malabaricus Jerdon, 1870 (Anura: Rhacophoridae) from Western Ghats, Kerala, India

FIG. 2. — Leafs hiding a foam nest of Rhacophorus malabaricus Jerdon, 1870.

opencc-zeroMar 2022View details →

Data from: Exoskeleton ageing and its relation to longevity and fecundity in female Australian Leaf Insects (Phyllium monteithi)

Senescence is a decline in reproduction and survival rate with advancing age resulting from deterioration of somatic tissues and systems throughout the body. Age-related somatic changes (somatic ageing) have been studied extensively in vertebrates but are less well known in other animals, including insects. Since adult insects have very limited ability to repair their exoskeleton, somatic ageing could involve deterioration and discolouration of the cuticle. We investigated age-related changes in wing pigmentation and abdominal cuticle necrosis in females of the Australian leaf insect Phyllium monteithi. Adult females varied markedly in the extent and pattern of pigmentation on their bodies, and we found that pigment spots on the forewings increased in size with age in most individuals. As females aged, most individuals also exhibited increasing levels of abdominal cuticle necrosis, resulting in the loss of abdominal cuticle along the margin of the abdomen. Neither the extent of pigmentation nor cuticle loss were clearly associated with reduced fecundity or longevity in the protected laboratory environment, but it remains unknown whether these age-related changes have functional implications in the wild. Our results show that the P. monteithi exoskeleton undergoes complex changes with age, with potential implications for functional traits and fitness.

opencc-by-4.0Mar 2022View details →

Dataset from: Morphometric analyses of leaf shapes in four sympatric Medi-terranean oaks and hybrids in the Algerian Kabylie fores

Data correspond to the characterization of putative hybrids and oak species coexisting in a highly diversified oak forest in Algeria with four native oak species (Quercus suber, Q. ilex, Q. canariensis, and Q. afares). Sixteen plots, including 89 trees from the four native species and their putative hybrids were sampled. Leaves were scanned and their geometric morphometry analyzed by using 11 landmarks on the right side on their abaxial surface. Related paper: Akli, A.; Lorenzo, Z.; Alia, R.; Rahbi, K.; Torres, E. Morphometric analyses of leaf shapes in four sympatric Mediterranean oaks and hybrids in the Algerian Kabylie forest. Forests 2022, 13(4), 508  <a href="https://doi.org/10.3390/f13040508">https://doi.org/10.3390/f13040508</a>

opencc-by-4.0Apr 2022View details →

Fig. 2 in Data On The Reproductive Biology Of The Satanic Leaf-Tailed Gecko, Uroplatus Phantasticus (Squamata, Gekkonidae), At The Bion Terrarium Center As A Contribution To Ex Situ Offspring Programs

Fig. 2. Copulation process of U. phantasticus.

opencc-by-4.0Apr 2022View details →

Fig. 6. U in Data On The Reproductive Biology Of The Satanic Leaf-Tailed Gecko, Uroplatus Phantasticus (Squamata, Gekkonidae), At The Bion Terrarium Center As A Contribution To Ex Situ Offspring Programs

Fig. 6. U. phantasticus hatchlings; the one in the right corner has not molt yet.

opencc-by-4.0Mar 2022View details →

Anti-inflammatory and anti-bacterial potentials of mulberry leaf extract on oral microorganisms

This is supplementary files for main manuscript "Anti-inflammatory and anti-bacterial potentials of mulberry leaf extract on oral microorganisms"

opencc-zeroApr 2022View details →

Data recorded for leaf size, and leaf vein and areole measurements taken from nine Magnoliaceae species

Across species, the density of major veins in leaves scales inversely with leaf area. Yet, minor vein density manifests no clear relationship with respect to leaf are, despite having the potential to provide important insights into the trade-off between investments in leaf mechanical support, hydraulics, and light interception. To examine this phenomenon, between 120−380 mature leaves from each of nine Magnoliaceae species were sampled from Nanjing Forestry University campus and Nanjing Botanical Garden, Chinese Academy of Sciences, Nanjing, China in 2019 and 2020. The leaves were boiled, and the epidermal and mesophyll tissues were removed. The remaining leaf skeleton was stained to obtain a clear leaf venation network. The software LEAF GUI was used to obtain the data of leaf size, leaf vein and areole traits. The large sample size data render it possible to explore the scaling relationships between leaf size and each trait of leaf veins and areoles. This data set includes the information of leaf length, leaf width, leaf area, total vein length, total vein area, mean areole area per leaf, and the number of the areole sizes per leaf of the nine Magnoliaceae species.

opencc-zeroApr 2022View details →

Intra- and interspecific variability of specific leaf area mitigate the reduction of community stability in response to warming and nitrogen addition

Global environmental changes are reducing the diversity and affecting the functioning of natural ecosystems as well as their ability to reliably provide ecosystem functions and services to mankind. Many studies have shown that a greater plant diversity can stabilize community productivity against environmental fluctuations. However, most of these studies focused on plant species richness, thus overlooking the potential role of functional traits in stabilizing community productivity against environmental fluctuations. Whether and how functional trait mean and variability influence community stability in response to environmental changes and their relative contributions to community stability are largely unknown. Here, we used a 10-year experiment to investigate the role of species richness, as well as functional mean and intra- and interspecific variability of specific leaf area (SLA) of plants within- and among communities in driving community stability in response to nitrogen (N) addition and warming. We found that both N addition and warming reduced the temporal stability of community productivity by reducing species richness and its contribution to species asynchrony and species stability. In contrast, changes in the mean and variability of SLA in response to N addition and warming mitigated the reduction of community stability. Specifically, N addition reduced variation in SLA both by reducing interspecific differences in SLA within communities and differences in mean values of SLA among communities. Warming increased intraspecific differences in SLA among communities, leading to higher species stability that partly buffered the reduction of community stability. Our study demonstrates the role of trait mean and variability in mitigating the reduction of community stability in response to two pervasive global environmental changes. Gaining a deeper understanding of the processes linking global changes and the stability of our ecosystems requires integrating both trait mean values and trait variability.

Broad- and small-scale environmental gradients drive variation in chemical, but not morphological, leaf traits of vascular epiphytes

Variation in leaf functional traits along environmental gradients can reveal how vascular epiphytes respond to broad- and small-scale environmental gradients. Along elevational gradients, both temperature and precipitation likely play an important role as drivers of leaf trait variation, but these traits may also respond to small-scale changes in light, temperature, and humidity along the vertical environmental gradient within forest canopies. However, the relative importance of broad- and small-scale environmental gradients as drivers of variation in leaf functional traits of vascular epiphytes is poorly understood. Here, we examined variation in morphological and chemical leaf traits of 102 vascular epiphyte species spanning two environmental gradients along Cofre de Perote mountain in Mexico: i) a broad-scale environmental gradient approximated by elevation as well as by species' lower and upper elevational limits, and ii) small-scale environmental gradients using the relative height of attachment of an epiphyte on a host tree as a proxy for variation in environmental conditions within the forest canopy. We also assessed whether variation in morphological and chemical leaf traits along these gradients were consistent across photosynthetic pathways (CAM and C3). Broad- and small-scale environmental gradients explained more variation in chemical traits (marginal R2: 11-89%) than in morphological traits (marginal R2: 2-31%). For example, leaf carbon isotope signatures (δ13C), which reflects water-use efficiency, varied systematically across both environmental gradients, suggesting a decrease in water-use efficiency with increasing lower and upper elevational limits and an increase in water-use efficiency with relative height of attachment. The influence of lower and upper elevational limits on trait variation differed between photosynthetic pathways, except for leaf dry matter content and leaf nitrogen-to-phosphorus ratio. Contrary to our expectations, broad- and small-scale environmental gradients explained minimal variation in morphological leaf traits, suggesting that environmental conditions do not constrain morphological leaf trait values of vascular epiphytes. Our findings suggest that assessing multiple drivers of leaf trait variation among photosynthetic pathways is key for disentangling the mechanisms underlying responses of vascular epiphytes to environmental conditions.

Differential nutrient limitation and tree height control leaf physiology, supporting niche partitioning in tropical dipterocarp forests

Revealing the mechanisms of environmental niche partitioning within lowland tropical forests is important for understanding the drivers of current species distributions and potential vulnerability to environmental change. Tropical forest structure and species composition change across edaphic gradients in Borneo over short distances. However, our understanding of how edaphic conditions affect tree physiology and whether these relationships drive niche partitioning within Bornean forests remains incomplete. This study evaluated how leaf physiological function changes with nutrient availability across a fine-scale edaphic gradient and whether these relationships vary according to tree height. Furthermore, we tested whether intraspecific leaf trait variation allows generalist species to populate a wider range of environments. We measured leaf traits of 218 trees ranging in height from 4 to 66 m from 13 dipterocarp species within four tropical forest types (alluvial, mudstone, sandstone, kerangas) occurring along an < 5km edaphic gradient in North Borneo. The traits measured included saturating photosynthesis (Asat), maximum photosynthetic capacity (Vcmax), leaf dark respiration (Rleaf), leaf mass per area (LMA), leaf thickness, minimum stomatal conductance (gdark) and leaf nutrient concentrations (N, P, Ca, K, Mg). Across all species, leaf traits varied consistently in response to soil nutrient availability across forest types except Rleaf_mass, [Mg]leaf and [Ca]leaf. Changes in photosynthesis and respiration rates were related to different leaf nutrients across forest types, with greater nutrient-use efficiency in more nutrient-poor environments. Generalist species partially or fully compensated reductions in mass-based photosynthesis through increasing LMA in more nutrient-poor environments. Leaf traits also varied with tree height, except Vcmax_mass, but only in response to height-related modifications of leaf morphology (LMA and leaf thickness). These height-trait relationships did not vary across the edaphic gradient, except for Asat, [N]leaf, [P]leaf and [K]leaf. Our results highlight that modification of leaf physiological function and morphology act as important adaptations for Bornean dipterocarps in response to edaphic and vertical environmental gradients. Meanwhile, multiple nutrients appear to contribute to niche partitioning and could drive species distributions and high biodiversity within Bornean forest landscapes.

Leaf flammbility and volatiles of Ginkgo, Agathis, and Dicksonia

The Triassic-Jurassic Boundary marks the third largest mass extinction event in the Phanerozoic, characterised by a rise in CO2-concentrations from ~600 ppm to ~2100 – 2400ppm, coupled with a ~3.0 – 4.0°C temperature rise. This is hypothesized to have induced major floral turnover, altering vegetation structure, composition and leaf morphology, which in turn are hypothesized to have driven changes in wildfire. However, the effects of elevated CO2 on fuel properties, such as chemical composition of leaves, are also important in influencing fire behaviour, but yet have not been considered. We test this by selecting three Triassic analogue species grown experimentally in different atmospheric compositions, and analyse variations in leaf chemistry, and leaf level flammability. These data were used to inform a fire behaviour model. We find that all three species tested showed a reduction in their volatile component, leading to lower flammability. Accounting for these variations in a model, our results suggest that leaf intrinsic flammability has a measurable impact on modelled fire behaviour. If scaled up to ecosystem level, periods of elevated CO2 may therefore be capable of inducing both biochemical and morphological changes in fuel properties, and thus may be capable of influencing fire behaviour.

Scaling the leaf length-times-width equation to predict total leaf area of shoots

Background and Aims: An individual plant consists of different-sized shoots, each of which consists of different-sized leaves. To predict plant-level physiological responses from the responses of individual leaves, modelling this within-shoot leaf size variation is necessary. Within-plant leaf trait variation has been well investigated in canopy photosynthesis models but less so in plant allometry. Therefore, integration of these two different approaches is needed. Methods: We focused on an established leaf-level relationship that the area of an individual leaf lamina is proportional to the product of its length and width. The geometric interpretation of this equation is that different-sized leaf laminas from a single species share the same basic form. Based on this shared basic form, we synthesized a new length-times-width equation predicting total shoot leaf area from the collective dimensions of leaves that comprise a shoot. Furthermore, we showed that several previously established empirical relationships, including the allometric relationships between total shoot leaf area, maximum individual leaf length within the shoot and total leaf number of the shoot, can be unified under the same geometric argument. We tested the model predictions using five species, all of which have simple leaves, selected from diverse taxa (Magnoliids, monocots and eudicots) and from different growth forms (trees, erect herbs and rosette herbs). Key Results: For all five species, the length-times-width equation explained within-species variation of total leaf area of a shoot with high accuracy (R2 &gt; 0.994). These strong relationships existed despite leaf dimensions scaling very differently between species. We also found good support for all derived predictions from the model (R2 &gt; 0.85). Conclusions: Our model can be incorporated to improve previous models of allometry that do not consider within-shoot size variation of individual leaves, providing a cross-scale linkage between individual leaf-size variation and shoot-size variation.