scholarly journals On the modelling of tropical tree growth: the importance of intra-specific trait variation, non-linear functions and phenotypic integration

2020 ◽  
Author(s):  
Jie Yang ◽  
Xiaoyang Song ◽  
Min Cao ◽  
Xiaobao Deng ◽  
Wenfu Zhang ◽  
...  
Keyword(s):  
Tree Growth ◽  
Bayesian Models ◽  
Species Level ◽  
Linear Functions ◽  
Plant Performance ◽  
Growth Data ◽  
Growth And Survival ◽  
Individual Level ◽  
The Individual ◽  
Individual Trees

Abstract Background and Aims The composition and dynamics of plant communities arise from individual-level demographic outcomes, which are driven by interactions between phenotypes and the environment. Functional traits that can be measured across plants are frequently used to model plant growth and survival. Perhaps surprisingly, species average trait values are often used in these studies and, in some cases, these trait values come from other regions or averages calculated from global databases. This data aggregation potentially results in a large loss of valuable information that probably results in models of plant performance that are weak or even misleading. Methods We present individual-level trait and fine-scale growth data from >500 co-occurring individual trees from 20 species in a Chinese tropical rain forest. We construct Bayesian models of growth informed by theory and construct hierarchical Bayesian models that utilize both individual- and species-level trait data, and compare these models with models only using individual-level data. Key Results We show that trait–growth relationships measured at the individual level vary across species, are often weak using commonly measured traits and do not align with the results of analyses conducted at the species level. However, when we construct individual-level models of growth using leaf area ratio approximations and integrated phenotypes, we generated strong predictive models of tree growth. Conclusions Here, we have shown that individual-level models of tree growth that are built using integrative traits always outperform individual-level models of tree growth that use commonly measured traits. Furthermore, individual-level models, generally, do not support the findings of trait–growth relationships quantified at the species level. This indicates that aggregating trait and growth data to the species level results in poorer and probably misleading models of how traits are related to tree performance.

Biomass models for three species with different growth forms and geographic distribution in the Brazilian Atlantic forest

2021 ◽  
pp. 1-13
Author(s):  
Heitor Felippe Uller ◽  
Laio Zimermann Oliveira ◽  
Aline Renata Klitzke ◽  
Joberto Veloso de Freitas ◽  
Alexander Christian Vibrans
Keyword(s):  
Atlantic Forest ◽  
Geographic Distribution ◽  
Morphological Features ◽  
Brazilian Atlantic Forest ◽  
Growth Forms ◽  
Individual Level ◽  
Generic Models ◽  
The Individual ◽  
Species Specific ◽  
Individual Trees

Allometric models embedding independent variables such as diameter at breast height (d) and total height (h) are useful tools to predict the biomass of individual trees. Models for tropical forests are often constructed based on datasets composed of species with different morphological features and architectural models. It is reasonable to expect, however, that species-specific models may reduce uncertainties in biomass predictions, especially for palms, tree ferns, and trees with peculiar morphological features, such as stilt roots and hollow trunks. In this sense, three species with wide geographical distribution in the Brazilian Atlantic Forest were sampled, namely Euterpe edulis Mart., Cyathea delgadii Sternb., and Cecropia glaziovii Snethl., with the aim to (i) quantify their aboveground biomass (AGB), (ii) evaluate the AGB distribution in different plant compartments, (iii) fit species-specific models for predicting AGB at the individual level, and (iv) assess the performance of specific and generic models available in the literature to predict the AGB of individuals of these species. The compartment stem represented, on average, ∼74% of the total AGB of E. edulis individuals; in turn, the caudex compartment of C. delgadii represented, on average, ∼87% of the total AGB, while the trunk compartment of C. glaziovii represented, on average, ∼74%. Among the fitted models, the power model [Formula: see text] showed the best performance for E. edulis and C. delgadii. In turn, the asymptotic logistic model [Formula: see text], where dc is the diameter above the upper stilt root, presented the best performance for C. glaziovii. The variable h appeared as the most important predictor of AGB of E. edulis and C. delgadii; in contrast, the stem and caudex mean basic specific gravities were not suitable predictors. The fitted species-specific models outperformed the specific and generic models selected from the literature. They may, therefore, contribute to the reduction of uncertainties in AGB estimates. In addition, the results support evidence that specific models may be necessary for species with different growth forms and (or) peculiar morphological features, especially those with great abundance and wide geographic distribution.

scholarly journals How to predict tree death from inventory data — lessons from a systematic assessment of European tree mortality models

2017 ◽  
Vol 47 (7) ◽  
pp. 890-900 ◽  
Author(s):  
Lisa Hülsmann ◽  
Harald Bugmann ◽  
Peter Brang
Keyword(s):  
Tree Growth ◽  
Tree Mortality ◽  
Model Performance ◽  
High Temporal Resolution ◽  
Forest Reserves ◽  
Individual Level ◽  
Systematic Assessment ◽  
Influence Model ◽  
Mortality Models ◽  
The Individual

The future development of forest ecosystems depends critically on tree mortality. However, the suitability of empirical mortality algorithms for extrapolation in space or time remains untested. We systematically analyzed the performance of 46 inventory-based mortality models available from the literature using nearly 80 000 independent records from 54 strict forest reserves in Germany and Switzerland covering 11 species. Mortality rates were predicted with higher accuracy if covariates for tree growth and (or) competition at the individual level were included and if models were applied within the same ecological zone. In contrast, classification of dead vs. living trees was only improved by growth variables. Management intensity in the calibration stands, as well as the census interval and size of the calibration datasets, did not influence model performance. Consequently, future approaches should make use of tree growth and competition at the level of individual trees. Mortality algorithms for applications over a restricted spatial extent and under current climate should be calibrated based on datasets from the same region, even if they are small. To obtain models with wide applicability and enhanced climatic sensitivity, the spatial variability of mortality should be addressed explicitly by considering environmental influences using data of high temporal resolution covering large ecological gradients. Finally, such models need to be validated and documented thoroughly.

scholarly journals FuTRES: Functional Trait Resource for Environmental Studies

2019 ◽  
Vol 3 ◽  
Author(s):  
Meghan Balk ◽  
Ramona Walls ◽  
Robert Guralnick ◽  
Edward Davis ◽  
John Deck ◽  
...  
Keyword(s):  
Entire Range ◽  
Environmental Studies ◽  
Functional Trait ◽  
Species Level ◽  
Archaeological Sites ◽  
Logical Framework ◽  
Semantic Framework ◽  
Individual Level ◽  
Field Notes ◽  
The Individual

Functional traits are the features of organisms that directly interact with the environment. Studying change and variation in these traits across space, time, and taxonomy can inform how species have responded to environmental and climatic change, how communities are assembled, and other eco-evolutionary questions. Trait data are collected at the individual level; however, animal trait databases often report these data at the species level, undermining their value for researchers who want to look at variation within species and rendering trait data ambiguous when taxonomy is updated. Additionally, these data are often recorded in auxiliary fields, such as “field notes” or hidden in supplementary materials or published tables, making them difficult to recover by researchers. Furthermore, animal trait data from paleontological, zooarchaeological (from archaeological sites), and neontological specimens are typically curated in separate forums and formats that are not easily integrated to provide perspective across the entire range of time. We are developing a toolkit to overcome these challenges called FuTRES: Functional Trait Resource for Environmental Studies. We seek to make these data accessible, standardize trait descriptions across Vertebrata, and teach (future) scientists how to create FAIR (findable, accessible, interoperable, and reusable) trait datasets. To make data more FAIR, FuTRES employs ontologies, a logical framework for relating terms to search datasets and standardizing traits across datasets. FuTRES builds off existing ontologies and standards, such as UBERON for anatomical terms and PATO and OBA for trait terms, as well as create new terms that are general enough to be used for all vertebrates and multiple disciplines. This talk will showcase the semantic framework underpinning FuTRES, describe how we are linking diverse trait datasets to ontologies and, therefore, each other, and report the results of a preliminary analysis of integrated datasets.

scholarly journals The anatomy of a phenological mismatch: interacting consumer demand and resource characteristics determine the consequences of mismatching

2020 ◽  
Author(s):  
Luke R. Wilde ◽  
Josiah E. Simmons ◽  
Rose J. Swift ◽  
Nathan R. Senner
Keyword(s):  
Consumer Demand ◽  
Population Level ◽  
Climatic Conditions ◽  
Growth And Survival ◽  
Individual Level ◽  
Individual Fitness ◽  
Phenological Mismatch ◽  
Age Structured ◽  
Resource Characteristics ◽  
The Individual

AbstractClimate change has caused shifts in seasonally recurring biological events and the temporal decoupling of consumer-resource pairs – i.e., phenological mismatching. Despite the hypothetical risk mismatching poses to consumers, they do not invariably lead to individual- or population-level effects. This may stem from how mismatches are typically defined, e.g., an individual or population is ‘matched’ or ‘mismatched’ based on the degree of asynchrony with a resource pulse. However, because both resource availability and consumer demands change over time, this categorical definition can obscure within- or among-individual fitness effects. We therefore developed models to identify the effects of resource characteristics on individual- and population-level processes and determine how the strength of these effects change throughout a consumer’s life. We then measured the effects of resource characteristics on the growth, daily survival, and fledging rates of Hudsonian godwit (Limosa haemastica) chicks hatched near Beluga River, Alaska. At the individual-level, chick growth and survival improved following periods of higher invertebrate abundance but were increasingly dependent on the availability of larger prey as chicks aged. At the population level, seasonal fledging rates were best explained by a model including age-structured consumer demand. Our study suggests that modelling the effects of mismatching as a disrupted interaction between consumers and their resources provides a biological mechanism for how mismatching occurs and clarifies when it matters to individuals and populations. Given the variable responses to mismatching across consumer populations, such tools for predicting how populations may respond under future climatic conditions will be invaluable.

scholarly journals No simple answers for ecological immunology: relationships among immune indices at the individual level break down at the species level in waterfowl

2005 ◽  
Vol 273 (1588) ◽  
pp. 815-822 ◽  
Author(s):  
Kevin D Matson ◽  
Alan A Cohen ◽  
Kirk C Klasing ◽  
Robert E Ricklefs ◽  
Alexander Scheuerlein
Keyword(s):  
Species Level ◽  
Ecological Immunology ◽  
Individual Level ◽  
The Individual

scholarly journals Information-Theoretic Quantification of Dedifferentiation in the Aging of Motor and Executive Functions

2021 ◽  
Vol 13 ◽  
Author(s):  
Erik Chihhung Chang
Keyword(s):  
Executive Functions ◽  
Cognitive Aging ◽  
The Elderly ◽  
Young Group ◽  
Elderly Group ◽  
Linear Functions ◽  
Information Theoretic ◽  
Individual Level ◽  
Computational Load ◽  
The Individual

A central account of cognitive aging is the dedifferentiation among functions due to reduced processing resources. Previous reports contrasting trends of aging across cognitive domains mostly relied on transformed scores of heterogeneous measures. By quantifying the computational load with information entropy in tasks probing motor and executive functions, this study uncovered interaction among age, task, and load as well as associations among the parametric estimates of these factors at the individual level. Specifically, the linear functions between computational load and performance time differed significantly between motor and executive tasks in the young group but not in the elderly group and showed stronger associations for parameters within and between tasks in the elderly group than in the young group. These findings are in line with the dedifferentiation hypothesis of cognitive aging and provide a more principled approach in contrasting trends of cognitive aging across different domains from the information-theoretic perspective.

scholarly journals Topography and Traits Modulate Tree Performance and Drought Response in a Tropical Forest

2020 ◽  
Vol 3 ◽  
Author(s):  
Naomi B. Schwartz ◽  
Xiaohui Feng ◽  
Robert Muscarella ◽  
Nathan G. Swenson ◽  
María Natalia Umaña ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Functional Traits ◽  
Tree Growth ◽  
Drought Response ◽  
Species Variation ◽  
Individual Tree ◽  
Average Growth ◽  
Growth And Survival ◽  
Species Responses ◽  
Individual Trees

Predicting drought responses of individual trees in tropical forests remains challenging, in part because trees experience drought differently depending on their position in spatially heterogeneous environments. Specifically, topography and the competitive environment can influence the severity of water stress experienced by individual trees, leading to individual-level variation in drought impacts. A drought in 2015 in Puerto Rico provided the opportunity to assess how drought response varies with topography and neighborhood crowding in a tropical forest. In this study, we integrated 3 years of annual census data from the El Yunque Chronosequence plots with measurements of functional traits and LiDAR-derived metrics of microsite topography. We fit hierarchical Bayesian models to examine how drought, microtopography, and neighborhood crowding influence individual tree growth and survival, and the role functional traits play in mediating species’ responses to these drivers. We found that while growth was lower during the drought year, drought had no effect on survival, suggesting that these forests are fairly resilient to a single-year drought. However, growth response to drought, as well as average growth and survival, varied with topography: tree growth in valley-like microsites was more negatively affected by drought, and survival was lower on steeper slopes while growth was higher in valleys. Neighborhood crowding reduced growth and increased survival, but these effects did not vary between drought/non-drought years. Functional traits provided some insight into mechanisms by which drought and topography affected growth and survival. For example, trees with high specific leaf area grew more slowly on steeper slopes, and high wood density trees were less sensitive to drought. However, the relationships between functional traits and response to drought and topography were weak overall. Species sorting across microtopography may drive observed relationships between average performance, drought response, and topography. Our results suggest that understanding species’ responses to drought requires consideration of the microenvironments in which they grow. Complex interactions between regional climate, topography, and traits underlie individual and species variation in drought response.

Differential Effects of Competence and Morality on Self-Esteem at the Individual and the Collective Level

2020 ◽  
Vol 51 (3) ◽  
pp. 183-198
Author(s):  
Wiktor Soral ◽  
Mirosław Kofta
Keyword(s):  
Self Esteem ◽  
Differential Effects ◽  
Individual Level ◽  
The Subject ◽  
The Individual

Abstract. The importance of various trait dimensions explaining positive global self-esteem has been the subject of numerous studies. While some have provided support for the importance of agency, others have highlighted the importance of communion. This discrepancy can be explained, if one takes into account that people define and value their self both in individual and in collective terms. Two studies ( N = 367 and N = 263) examined the extent to which competence (an aspect of agency), morality, and sociability (the aspects of communion) promote high self-esteem at the individual and the collective level. In both studies, competence was the strongest predictor of self-esteem at the individual level, whereas morality was the strongest predictor of self-esteem at the collective level.

Metonymy in Dance: Ballet Bunheads Take a Cognitive Turn

2019 ◽  
Vol 37 (1) ◽  
pp. 18-34
Author(s):  
Edward C. Warburton
Keyword(s):  
Identity Formation ◽  
Cognitive Science ◽  
Artistic Development ◽  
Individual Level ◽  
Figures Of Speech ◽  
Self Image ◽  
Level I ◽  
Dance Educators ◽  
The Individual ◽  
Metaphor And Metonymy

This essay considers metonymy in dance from the perspective of cognitive science. My goal is to unpack the roles of metaphor and metonymy in dance thought and action: how do they arise, how are they understood, how are they to be explained, and in what ways do they determine a person's doing of dance? The premise of this essay is that language matters at the cultural level and can be determinative at the individual level. I contend that some figures of speech, especially metonymic labels like ‘bunhead’, can not only discourage but dehumanize young dancers, treating them not as subjects who dance but as objects to be danced. The use of metonymy to sort young dancers may undermine the development of healthy self-image, impede strong identity formation, and retard creative-artistic development. The paper concludes with a discussion of the influence of metonymy in dance and implications for dance educators.

Sign in / Sign up

Export Citation Format

Share Document