scholarly journals Reconstructing paleoclimate and paleoecology using fossil leaves

2017 ◽  
Author(s):  
Daniel J. Peppe ◽  
Aly Baumgartner ◽  
Andrew G. Flynn ◽  
Benjamin Blonder
Keyword(s):  
Plant Traits ◽  
Terrestrial Ecosystems ◽  
Leaf Traits ◽  
Leaf Life Span ◽  
Computer Algorithms ◽  
Leaf Trait ◽  
Research Areas ◽  
Fossil Leaves ◽  
Leaf Economic Spectrum ◽  
The Relationship

Plants are strongly influenced by their surrounding environment, which makes them reliable indicators of climate and ecology. The relationship between climate, ecology, plant traits and the geographic distribution of plants based on their climatic tolerances have been used to develop plant-based proxies for reconstructing paleoclimate and paleoecology. These proxies are some of the most accurate and precise methods for reconstructing the climate and ecology of ancient terrestrial ecosystems and have been applied from the Cretaceous to the Quaternary. Despite their utility, the relationships between plant traits and climate that underlie these methods are confounded by other factors such as leaf life-span and phylogenetic history. Work focused on better understanding these confounding factors, incorporating the influence of phylogeny and leaf economic spectrum traits into proxies, expanding modern leaf trait-climate and ecology calibration datasets to additional biogeographic areas and climate regimes, and developing automated computer algorithms for measuring leaf traits are important growing research areas that will help considerably improve plant-based paleoclimate and paleoecological proxies.

scholarly journals Fossil Angiosperm Leaves: Paleobotany's Difficult Children Prove Themselves

2008 ◽  
Vol 14 ◽  
pp. 319-333 ◽  
Author(s):  
Peter Wilf
Keyword(s):  
Leaf Shape ◽  
Leaf Traits ◽  
Plant Ecology ◽  
Feeding Damage ◽  
Leaf Architecture ◽  
Research Areas ◽  
Fossil Leaves ◽  
Past Climate Change ◽  
Scientific Value ◽  
Time Extinction

The great bulk of the angiosperm fossil record consists of isolated fossil leaves that preserve abundant shape and venation (leaf architectural) information but are difficult to identify because they are not attached to other plant organs. Thus, poor taxonomic knowledge has tempered the tremendous potential of fossil leaves for constructing finely resolved records of biodiversity through time, extinction and recovery, past climate change and biotic response, paleoecology, and plant-animal associations. Moreover, paleoecological and paleoclimatic interpretations of fossil leaves are in great need of new approaches. Recent work is rapidly increasing the scientific value of fossil angiosperm leaves through advances in traditional paleobotanical reconstruction, phylogenetic understanding of both leaf architecture and the response of leaf shape to climate, quantitative plant ecology using measurable, correlatable leaf traits, and improved understanding of insect leaf-feeding damage. These emerging areas offer many novel opportunities to link paleoecology and neoecology. Increased collaboration across traditionally separate research areas is critical to continued success.

scholarly journals Phenology, seasonality and trait relationships in a New Zealand forest

2021 ◽  
Author(s):  
◽  
Sharada Paudel
Keyword(s):  
New Zealand ◽  
Leaf Traits ◽  
Leaf Longevity ◽  
Leaf Abscission ◽  
Future Research ◽  
Leaf Mass Per Area ◽  
Fruit Traits ◽  
Leaf Production ◽  
Leaf Economic Spectrum ◽  
The Relationship

<p>The phenologies of flowers, fruits and leaves can have profound implications for plant community structure and function. Despite this only a few studies have documented fruit and flower phenologies in New Zealand while there are even fewer studies on leaf production and abscission phenologies. To address this limitation, I measured phenological patterns in leaves, flowers and fruits in 12 common forest plant species in New Zealand over two years. All three phenologies showed significant and consistent seasonality with an increase in growth and reproduction around the onset of favourable climatic conditions; flowering peaked in early spring, leaf production peaked in mid-spring and fruit production peaked in mid-summer coincident with annual peaks in temperature and photoperiodicity. Leaf abscission, however, occurred in late autumn, coincident with the onset of less productive environmental conditions. I also investigated differences in leaf longevities and assessed how seasonal cycles in the timing of leaf production and leaf abscission times might interact with leaf mass per area (LMA) in determining leaf longevity. Leaf longevity was strongly associated with LMA but also with seasonal variation in climate. All 12 species produced leaves in spring and abscised leaves in autumn. Nevertheless, leaf longevity ranged from 6 months to 30 months among species, leading to several distinct leaf longevity categories (i.e. 6-7 months, 15-18 months and 27-30 months). Finally, I examined the relationship of leaf traits with flower and fruit traits and their relation to the global leaf economic spectrum (LES) that describes multivariate correlations between a combinations of key leaf traits. The results resonated with the patterns of leaf economic spectrum for New Zealand species and provided evidence for significant correlations between leaf and fruit traits, indicating that plants with long lived leaves and higher LMA produce fruits that take more time to develop, stay on the plant longer and have larger seed size. This study contributed to bridging the gap in our understanding of the relationship between vegetative and reproductive traits, it has increased our understanding of phenological patterns in New Zealand forests, and when viewed with earlier phenological studies, provides a first step towards understanding how New Zealand forest might respond to global climate change. In addition, the research illustrates how seasonality in climate can constrain the life times of leaves. In the context of global trait research culminating into the whole plant economics spectrum, this study provides clear evidence of leaf and fruit phenological and morphological trait associations. It helps to further our understanding of phenology, seasonality and plant trait relationships for some common tree species in New Zealand and presents some novel findings that provide a basis for future research.</p>

scholarly journals Leaf trait variability between and within subalpine grassland species differs depending on site conditions and herbivory

2019 ◽  
Vol 286 (1907) ◽  
pp. 20190429 ◽  
Author(s):  
Jennifer Firn ◽  
Huong Nguyen ◽  
Martin Schütz ◽  
Anita C. Risch
Keyword(s):  
Plant Traits ◽  
Intraspecific Variability ◽  
Leaf Traits ◽  
Nutrient Concentrations ◽  
Phosphorus Concentration ◽  
Geographical Differences ◽  
Leaf Trait ◽  
Interspecific Variability ◽  
Herbivore Exclusion ◽  
Trait Variability

Plant traits are commonly used to predict ecosystem-level processes, but the validity of such predictions is dependent on the assumption that trait variability between species is greater than trait variability within a species—the robustness assumption. Here, we compare leaf trait intraspecific and interspecific variability depending on geographical differences between sites and 5 years of experimental herbivore exclusion in two vegetation types of subalpine grasslands in Switzerland. Four leaf traits were measured from eight herbaceous species common to all 18 sites. Intraspecific trait variability differed significantly depending on site and herbivory. However, the amount and structure of variability depended on the trait measured and whether considering leaf traits separately or multiple leaf traits simultaneously. Leaf phosphorus concentration showed the highest intraspecific variability, while specific leaf area showed the highest interspecific variability and displayed intraspecific variability only in response to herbivore exclusion. Species identity based on multiple traits was not predictable. We find intraspecific variability is an essential consideration when using plant functional traits as a common currency not just species mean traits. This is particularly true for leaf nutrient concentrations, which showed high intraspecific variability in response to site differences and herbivore exclusion, a finding which suggests that the robustness assumption does not always hold.

scholarly journals Scaling of petiole anatomies, mechanics and vasculatures with leaf size in the widespread Neotropical pioneer tree species Cecropia obtusa Trécul (Urticaceae)

2020 ◽  
Vol 40 (2) ◽  
pp. 245-258 ◽  
Author(s):  
Sébastien Levionnois ◽  
Sabrina Coste ◽  
Eric Nicolini ◽  
Clément Stahl ◽  
Hélène Morel ◽  
...  
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Leaf Traits ◽  
Hydraulic Efficiency ◽  
Cross Sectional ◽  
Leaf Trait ◽  
Key Factor ◽  
Leaf Economic Spectrum ◽  
Geometrical Effect ◽  
Trait Variability

Abstract Although the leaf economic spectrum has deepened our understanding of leaf trait variability, little is known about how leaf traits scale with leaf area. This uncertainty has resulted in the assumption that leaf traits should vary by keeping the same pace of variation with increases in leaf area across the leaf size range. We evaluated the scaling of morphological, tissue-surface and vascular traits with overall leaf area, and the functional significance of such scaling. We examined 1,271 leaves for morphological traits, and 124 leaves for anatomical and hydraulic traits, from 38 trees of Cecropia obtusa Trécul (Urticaceae) in French Guiana. Cecropia is a Neotropical genus of pioneer trees that can exhibit large laminas (0.4 m2 for C. obtusa), with leaf size ranging by two orders of magnitude. We measured (i) tissue fractions within petioles and their second moment of area, (ii) theoretical xylem hydraulic efficiency of petioles and (iii) the extent of leaf vessel widening within the hydraulic path. We found that different scaling of morphological trait variability allows for optimisation of lamina display among larger leaves, especially the positive allometric relationship between lamina area and petiole cross-sectional area. Increasing the fraction of pith is a key factor that increases the geometrical effect of supportive tissues on mechanical rigidity and thereby increases carbon-use efficiency. We found that increasing xylem hydraulic efficiency with vessel size results in lower leaf lamina area: xylem ratios, which also results in potential carbon savings for large leaves. We found that the vessel widening is consistent with hydraulic optimisation models. Leaf size variability modifies scaling of leaf traits in this large-leaved species.

scholarly journals Phenology, seasonality and trait relationships in a New Zealand forest

2021 ◽  
Author(s):  
◽  
Sharada Paudel
Keyword(s):  
New Zealand ◽  
Leaf Traits ◽  
Leaf Longevity ◽  
Leaf Abscission ◽  
Future Research ◽  
Leaf Mass Per Area ◽  
Fruit Traits ◽  
Leaf Production ◽  
Leaf Economic Spectrum ◽  
The Relationship

<p>The phenologies of flowers, fruits and leaves can have profound implications for plant community structure and function. Despite this only a few studies have documented fruit and flower phenologies in New Zealand while there are even fewer studies on leaf production and abscission phenologies. To address this limitation, I measured phenological patterns in leaves, flowers and fruits in 12 common forest plant species in New Zealand over two years. All three phenologies showed significant and consistent seasonality with an increase in growth and reproduction around the onset of favourable climatic conditions; flowering peaked in early spring, leaf production peaked in mid-spring and fruit production peaked in mid-summer coincident with annual peaks in temperature and photoperiodicity. Leaf abscission, however, occurred in late autumn, coincident with the onset of less productive environmental conditions. I also investigated differences in leaf longevities and assessed how seasonal cycles in the timing of leaf production and leaf abscission times might interact with leaf mass per area (LMA) in determining leaf longevity. Leaf longevity was strongly associated with LMA but also with seasonal variation in climate. All 12 species produced leaves in spring and abscised leaves in autumn. Nevertheless, leaf longevity ranged from 6 months to 30 months among species, leading to several distinct leaf longevity categories (i.e. 6-7 months, 15-18 months and 27-30 months). Finally, I examined the relationship of leaf traits with flower and fruit traits and their relation to the global leaf economic spectrum (LES) that describes multivariate correlations between a combinations of key leaf traits. The results resonated with the patterns of leaf economic spectrum for New Zealand species and provided evidence for significant correlations between leaf and fruit traits, indicating that plants with long lived leaves and higher LMA produce fruits that take more time to develop, stay on the plant longer and have larger seed size. This study contributed to bridging the gap in our understanding of the relationship between vegetative and reproductive traits, it has increased our understanding of phenological patterns in New Zealand forests, and when viewed with earlier phenological studies, provides a first step towards understanding how New Zealand forest might respond to global climate change. In addition, the research illustrates how seasonality in climate can constrain the life times of leaves. In the context of global trait research culminating into the whole plant economics spectrum, this study provides clear evidence of leaf and fruit phenological and morphological trait associations. It helps to further our understanding of phenology, seasonality and plant trait relationships for some common tree species in New Zealand and presents some novel findings that provide a basis for future research.</p>

Exploring the Influences of Service Characteristics on Individuals’Use Intention of Mobile Health Services (Preprint)

2020 ◽  
Author(s):  
Fei Liu ◽  
Pengkun Wu ◽  
Xitong Guo
Keyword(s):  
Personal Information ◽  
New Technology ◽  
Information Service ◽  
Health Care Research ◽  
Privacy Concern ◽  
Service Adoption ◽  
Service Characteristics ◽  
Research Areas ◽  
New Information ◽  
The Relationship

BACKGROUND Service characteristic factors are verified as the determinants for influencing people’s use intention of mHealth. Exploration of the interactions among the service characteristics of users can play an important role in improving service adoption rate. mHealth service appears to be an emerging new technology that presents a new pattern of healthcare service; however, users have concerns that their personal information might be disclosed and used without permission. This concern hinders people’s adoption behavior of mHealth services. OBJECTIVE The objective of this study is to explore how service characteristics (service relevance and service accuracy) interact to influence individuals’ use intention of mHealth services. This study also investigates the moderating roles of innovativeness and privacy concern. METHODS To meet these objectives, six hypotheses thus developed were empirically validated using a survey to test the effects of service characteristics and personal traits on use intention of mHealth. RESULTS We confirm that service relevance and service accuracy positively and directly influence individuals’ use intention of mHealth services. In addition, innovativeness positively affects the relationship between service relevance and use intention. Privacy concern negatively influences the relationship between service relevance and use intention, but positively influences the relationship between service accuracy and use intention. CONCLUSIONS The present study provides new insights into the influencing factors of individuals’ usage behaviour toward mHealth services. Such insight could provide further understanding of how individuals adopt new information service or technologies, which contribute to both information system and health care research areas in a very promising way.

scholarly journals Relationships Among the Feeding Behaviors of a Mirid Bug on Cotton Leaves of Different Ages and Plant Biochemical Substances

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Haiyan Song ◽  
Zhaoke Dong ◽  
Lili Li ◽  
Zengbin Lu ◽  
Chao Li ◽  
...  
Keyword(s):  
Negative Impact ◽  
Leaf Age ◽  
Leaf Traits ◽  
Cotton Leaf ◽  
Young Plant ◽  
Feeding Behaviors ◽  
Probing Behavior ◽  
Negative Effect ◽  
Mirid Bug ◽  
The Relationship

Abstract Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) tends to feed on young plant tissues. To explore the relationship between stylet probing behaviors of adult A. lucorum and conditions of cotton leaves, we conducted an experiment using electropenetrography (EPG). Behaviors were recorded on four cotton varieties, in relation to thickness and biochemical traits of differently-aged leaves. Cotton leaf age had a significant effect on the probing behavior of A. lucorum but cotton variety did not. One-day-old leaves of A. lucorum received the highest mean number of stylet probes (penetrations) per insect, and longest mean durations per insect of combined stylet probing or its components, cell rupture and ingestion behaviors. All of the leaf traits (thickness and biochemical substances) were similar among these four cotton varieties. Leaf thickness had a significantly negative effect on the same four variables above. Gossypol and tannin also had a negative impact on combined probing duration. Redundancy analysis showed that the four EPG variables were closely related to nutrient substances (amino acids, sugar, and water) while they had the opposite relationship with plant defense substances (gossypol and tannin). On cotton in the seedling stages, A. lucorum fed more readily on the youngest, thinnest leaves in our no-choice EPG experiments. Nutrients and chemical resistance substances determined the probing duration of A. lucorum. Our findings can contribute to better understanding of patterns of feeding and host consumption by A. lucorum, ultimately improving cotton resistance to A. lucorum.

scholarly journals Dental functional traits of mammals resolve productivity in terrestrial ecosystems past and present

2012 ◽  
Vol 279 (1739) ◽  
pp. 2793-2799 ◽  
Author(s):  
Liping Liu ◽  
Kai Puolamäki ◽  
Jussi T. Eronen ◽  
Majid M. Ataabadi ◽  
Elina Hernesniemi ◽  
...  
Keyword(s):  
Net Primary Productivity ◽  
Terrestrial Ecosystems ◽  
Functional Trait ◽  
Geological Time ◽  
Crown Height ◽  
Short Term ◽  
Functional Interpretation ◽  
Terrestrial Mammals ◽  
Terrestrial Biomes ◽  
The Relationship

We have recently shown that rainfall, one of the main climatic determinants of terrestrial net primary productivity (NPP), can be robustly estimated from mean molar tooth crown height (hypsodonty) of mammalian herbivores. Here, we show that another functional trait of herbivore molar surfaces, longitudinal loph count, can be similarly used to extract reasonable estimates of rainfall but also of temperature, the other main climatic determinant of terrestrial NPP. Together, molar height and the number of longitudinal lophs explain 73 per cent of the global variation in terrestrial NPP today and resolve the main terrestrial biomes in bivariate space. We explain the functional interpretation of the relationships between dental function and climate variables in terms of long- and short-term demands. We also show how the spatially and temporally dense fossil record of terrestrial mammals can be used to investigate the relationship between biodiversity and productivity under changing climates in geological time. The placement of the fossil chronofaunas in biome space suggests that they most probably represent multiple palaeobiomes, at least some of which do not correspond directly to any biomes of today's world.

scholarly journals Linking hydraulic traits to tropical forest function in a size-structured and trait-driven model (TFS v.1-Hydro)

2016 ◽  
Vol 9 (11) ◽  
pp. 4227-4255 ◽  
Author(s):  
Bradley O. Christoffersen ◽  
Manuel Gloor ◽  
Sophie Fauset ◽  
Nikolaos M. Fyllas ◽  
David R. Galbraith ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Water Potential ◽  
Plant Traits ◽  
Coupled Model ◽  
Leaf Traits ◽  
Tree Size ◽  
Leaf Mass Per Area ◽  
Stem Water Potential ◽  
Plant Hydraulics ◽  
Individual Trees

Abstract. Forest ecosystem models based on heuristic water stress functions poorly predict tropical forest response to drought partly because they do not capture the diversity of hydraulic traits (including variation in tree size) observed in tropical forests. We developed a continuous porous media approach to modeling plant hydraulics in which all parameters of the constitutive equations are biologically interpretable and measurable plant hydraulic traits (e.g., turgor loss point πtlp, bulk elastic modulus ε, hydraulic capacitance Cft, xylem hydraulic conductivity ks,max, water potential at 50 % loss of conductivity for both xylem (P50,x) and stomata (P50,gs), and the leaf : sapwood area ratio Al : As). We embedded this plant hydraulics model within a trait forest simulator (TFS) that models light environments of individual trees and their upper boundary conditions (transpiration), as well as providing a means for parameterizing variation in hydraulic traits among individuals. We synthesized literature and existing databases to parameterize all hydraulic traits as a function of stem and leaf traits, including wood density (WD), leaf mass per area (LMA), and photosynthetic capacity (Amax), and evaluated the coupled model (called TFS v.1-Hydro) predictions, against observed diurnal and seasonal variability in stem and leaf water potential as well as stand-scaled sap flux. Our hydraulic trait synthesis revealed coordination among leaf and xylem hydraulic traits and statistically significant relationships of most hydraulic traits with more easily measured plant traits. Using the most informative empirical trait–trait relationships derived from this synthesis, TFS v.1-Hydro successfully captured individual variation in leaf and stem water potential due to increasing tree size and light environment, with model representation of hydraulic architecture and plant traits exerting primary and secondary controls, respectively, on the fidelity of model predictions. The plant hydraulics model made substantial improvements to simulations of total ecosystem transpiration. Remaining uncertainties and limitations of the trait paradigm for plant hydraulics modeling are highlighted.

Sign in / Sign up

Export Citation Format

Share Document