Andrew J Kerkhoff

Andrew J Kerkhoff
Kenyon College · Departments of Biology and Mathematics & Statistics

PhD

About

74
Publications
48,787
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8,353
Citations
Additional affiliations
January 2005 - present
Kenyon College
January 2004 - present
Kenyon College
July 2002 - July 2005
The University of Arizona

Publications

Publications (74)
Article
Full-text available
There is a clear demand for quantitative literacy in the life sciences, necessitating competent instructors in higher education. However, not all instructors are versed in data science skills or research-based teaching practices. We surveyed biological and environmental science instructors (n = 106) about the teaching of data science in higher educ...
Article
Full-text available
Significance We explore an extended view of the tropical conservatism hypothesis to account for two often-neglected components of climatic stress: drought and the combined effect of seasonal cold and drought—the latter being a common feature of extratropical dry environments. We show that evolutionary diversity of angiosperm assemblages in extratro...
Preprint
Full-text available
Estimating the distribution of phenotypes in populations and communities is central to many questions in ecology and evolutionary biology. These distributions can be characterized by their moments: the mean, variance, skewness, and kurtosis. Typically, these moments are calculated using a community-weighted approach (e.g. community-weighted mean) w...
Article
Life-history traits represent organisms' strategies to navigate the fitness trade-offs between survival and reproduction. Eric Charnov developed three dimensionless metrics to quantify fundamental life-history trade-offs. Lifetime reproductive effort (LRE), relative reproductive lifespan (RRL) and relative offspring size (ROS), together with body m...
Preprint
Full-text available
There is a clear and concrete need for greater quantitative literacy in the biological and environmental sciences. Data science training for students in higher education necessitates well-equipped and confident instructors across curricula. However, not all instructors are versed in data science skills or research-based teaching practices. Our stud...
Article
Full-text available
Aim: Tree crowns determine light interception, carbon and water exchange. Thus, understanding the factors causing tree crown allometry to vary at the tree and stand level matters greatly for the development of future vegetation modelling and for the calibration of remote sensing products. Nevertheless, we know little about large‐scale variation and...
Article
Full-text available
Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research sp...
Article
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The inverse relationship between size and abundance is a well‐documented pattern in forests, and the form of size–density relationships depends on the balance between growth and mortality rates in the community. Traditionally, studies of plant size distributions have focused on single‐species populations and forests, but here we examine diverse com...
Preprint
Full-text available
Life history traits represent organism's strategies to navigate the fitness trade-offs between survival and reproduction. Eric Charnov developed three dimensionless metrics to quantify fundamental life history trade-offs. Lifetime reproductive effort (LRE), relative reproductive lifespan (RRL), and relative offspring size (ROS), together with body...
Article
Full-text available
Much ecological research aims to explain how climate impacts biodiversity and ecosystem-level processes through functional traits that link environment with individual performance. However, the specific climatic drivers of functional diversity across space and time remain unclear due largely to limitations in the availability of paired trait and cl...
Article
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The concept of the biome has a long history dating back to Carl Ludwig Willdenow and Alexander von Humboldt. However, while the association between climate and the structure and diversity of vegetation has a long history, scientists have only recently begun to develop a more synthetic understanding of biomes based on the evolution of plant diversit...
Article
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Terrestrial net primary production (NPP) varies across global climate gradients, but the mechanisms through which climate drives this variation remain subject to debate. Specifically, it is debatable whether NPP is primarily influenced by ‘direct’ effects of climate on the kinetics of plant metabolism or ‘indirect’ effects of climate on plant size,...
Article
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Hutchinson's n-dimensional hypervolume concept underlies many applications in contemporary ecology and evolutionary biology. Estimating hypervolumes from sampled data has been an ongoing challenge due to conceptual and computational issues. 2.We present new algorithms for delineating the boundaries and probability density within n-dimensional hyper...
Poster
Full-text available
Multidimensional hypervolumes enable ecologists to visualize the functional trait space occupied by an ecological community. Previously, hypervolumes have been measured using a minimum convex hull, but convex hulls are exclusively determined by extreme points and they cannot account for possible holes in the trait space. A multivariate kernel densi...
Article
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Plant diversity, like that of most other taxonomic groups, peaks in the tropics, where climatic conditions are warm and wet, and it declines toward the temperate and polar zones as conditions become colder and drier, with more seasonally variable temperatures. Climate and evolutionary history are often considered competing explanations for the lati...
Article
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Variation in terrestrial net primary production (NPP) with climate is thought to originate from a direct influence of temperature and precipitation on plant metabolism. However, variation in NPP may also result from an indirect influence of climate via growing season length, plant age, stand biomass, and local adaptation. To identify the relative i...
Article
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Precise estimation of root biomass is important for understanding carbon stocks and dynamics in forests. Traditionally, biomass estimates are based on allometric scaling relationships between stem diameter and coarse root biomass calculated using linear regression (LR) on log-transformed data. Recently, it has been suggested that nonlinear regressi...
Article
Synthesis The tissue chemistry of plants can influence ecosystem processes including growth, herbivory, and decomposition. Our comparison of nitrogen and phosphorus in over 1700 autotroph taxa demonstrates that latitudinal trends in tissue chemistry are consistent across non-vascular and vascular species in freshwater, terrestrial, and marine ecosy...
Article
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The metabolic theory of ecology (MTE) predicts the effects of body size and temperature on metabolism through considerations of vascular distribution networks and biochemical kinetics. MTE has also been extended to characterise processes from cellular to global levels. MTE has generated both enthusiasm and controversy across a broad range of resear...
Article
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Aim In recent years evidence has accumulated that plant species are differentially sorted from regional assemblages into local assemblages along local-scale environmental gradients on the basis of their function and abiotic filtering. The favourability hypothesis in biogeography proposes that in climatically difficult regions abiotic filtering shou...
Article
Introduction to Ontogenetic ScalingAllometric Models of Ontogenetic GrowthCaveats and Conclusions Influences of Temperature and Stoichiometry
Article
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Metabolism, growth, and the assimilation of energy and materials are essential processes that are intricately related and depend heavily on animal size. However, models that relate the ontogenetic scaling of energy assimilation and metabolism to growth rely on assumptions that have yet to be rigorously tested. Based on detailed daily measurements o...
Article
Full-text available
Plant traits – the morphological, anatomical, physiological, biochemical and phenological characteristics of plants and their organs – determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services and provide a link from species richness to ecosystem functional diversity. T...
Conference Paper
Background/Question/Methods Large quantities of ecological and environmental data are increasingly available thanks to initiatives sponsoring the collection of large-scale data and efforts to increase the publication of already collected datasets. As a result, progress in ecology is increasingly limited by the speed at which we can organize and a...
Conference Paper
Background/Question/Methods Trait-based ecology has provided important insights into the mechanisms of how plant communities are assembled and structured. Many key functional traits have been found to vary between communities, but also within species at relatively small scales. However, intraspecific variability of functional traits is usually ta...
Article
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Biological stoichiometry theory considers the balance of multiple chemical elements in living systems, whereas metabolic scaling theory considers how size affects metabolic properties from cells to ecosystems. We review recent developments integrating biological stoichiometry and metabolic scaling theories in the context of plant ecology and global...
Conference Paper
Background/Question/Methods It is widely recognized that plant architecture is a core component underlying the plant phenotype. Indeed, the geometry of plant branching networks plays a major role in the metabolic scaling model proposed by West, Brown, and Enquist (WBE). In the WBE model, self-similar branching networks are fundamental in controllin...
Conference Paper
Background/Question/Methods Recent theory attempts to explain metabolic scaling based on the evolutionary optimization of the structure and function of resource supply networks and exchange surfaces. However, we know of no studies that have simultaneously examined the scaling of both metabolism and resource assimilation. We use the larvae of tobacc...
Article
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The study of elevational diversity gradients dates back to the foundation of biogeography. Although elevational patterns of plant and animal diversity have been studied for centuries, such patterns have not been reported for microorganisms and remain poorly understood. Here, in an effort to assess the generality of elevational diversity patterns, w...
Article
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Linking functional traits to plant growth is critical for scaling attributes of organisms to the dynamics of ecosystems 1,2 and for understanding how selection shapes integrated botanical phenotypes 3. However, a general mechanistic theory showing how traits specifically influence carbon and biomass flux within and across plants is needed. Building...
Article
Full-text available
Linking functional traits to plant growth is critical for scaling attributes of organisms to the dynamics of ecosystems and for understanding how selection shapes integrated botanical phenotypes. However, a general mechanistic theory showing how traits specifically influence carbon and biomass flux within and across plants is needed. Building on fo...
Data
Raw data for population sizes of the US, Switzerland, and the world (used in Figures 1 and figure 3). (1.10 MB XLS)
Article
Full-text available
Aim Relationships between range size and species richness are contentious, yet they are key to testing the various hypotheses that attempt to explain latitudinal diversity gradients. Our goal is to utilize the largest data set yet compiled for New World woody plant biogeography to describe and assess these relationships between species richness and...
Article
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Managing ecosystems for resilience—the capacity to maintain function in response to perturbation—is among the most pressing ecological and socioeconomic imperatives of our time. The variability of biological and ecological systems at multiple scales in time and space makes this task even more challenging, yet diverse ecological systems often displa...
Article
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Understanding how plant biomass is distributed between roots, stems, and leaves is central to many questions in life-history evolution, ecology, and ecosystem studies. Current ecological dogma states that patterns of biomass partitioning result from environmental differences. However, there are methodological issues associated with the role of plan...
Article
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Body size is perhaps the most fundamental property of an organism and is related to many biological traits, including abundance. The relationship between abundance and body size has been extensively studied in an attempt to quantify the form of the relationship and to understand the processes that generate it. However, progress has been impeded by...
Article
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The link between variation in species-specific plant traits, larger scale patterns of productivity, and other ecosystem processes is an important focus for global change research. Understanding such linkages requires synthesis of evolutionary, biogeograpahic, and biogeochemical approaches to ecological research. Recent observations reveal several a...
Article
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Reich et al. report that the whole-plant respiration rate, R, in seedlings scales linearly with plant mass, M, so that R=C(R)M(theta) when theta approximately 1, in which c(R) is the scaling normalization and theta is the scaling exponent. They also state that because nitrogen concentration (N) is correlated with c(R), variation in N is a better pr...
Article
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Urban areas and their voracious appetites are increasingly dominating the flows of energy and materials around the globe. Understanding the size distribution and dynamics of urban areas is vital if we are to manage their growth and mitigate their negative impacts on global ecosystems. For over 50 years, city size distributions have been assumed to...
Article
The mean-variance scaling relationship known as Taylor's power law has been well documented empirically over the past four decades but a general theoretical explanation for the phenomenon does not exist. Here we provide an explanation that relates empirical patterns of temporal mean-variance scaling to individual level reproductive behavior. Initia...
Article
Full-text available
Plant biomass and nutrient allocation explicitly links the evolved strategies of plant species to the material and energy cycles of ecosystems. Allocation of nitrogen (N) and phosphorus (P) is of particular interest because N and P play pivotal roles in many aspects of plant biology, and their availability frequently limits plant growth. Here we pr...
Article
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A principal challenge in ecology is to integrate physiological function (e.g. photosynthesis) across a collection of individuals (e.g. plants of different species) to understand the functioning of the entire ensemble (e.g. primary productivity). The control that organism size exerts over physiological and ecological function suggests that allometry...
Article
Aim While physical constraints influence terrestrial primary productivity, the extent to which geographical variation in productivity is influenced by physiological adaptations and changes in vegetation structure is unclear. Further, quantifying the effect of variability in species traits on ecosystems remains a critical research challenge. Here, w...
Article
We analyse the mean-variance scaling of reproductive output for a previously published forest model. The model relates individual reproductive effort and pollen limitation to the degree of synchrony in reproduction throughout a forest. We show that the exponent of Taylor's power law reflects the degree of synchrony of reproduction because it indica...
Article
Ecological stoichiometry, the study of the balance of energy and materials in living systems, may serve as a useful synthetic framework for evolutionary biology. Here, we review recent work that illustrates the power of a stoichiometric approach to evolution across multiple scales, and then point to important open questions that may chart the way f...
Article
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Population and community level processes must be at least partially determined by variation in the body sizes of constituent individuals, implying quantitative scaling relations can be extended to account for variation in those processes. Here we integrate allometric growth and life-history invariant theories, and use this approach to develop theor...
Article
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Masting is the synchronous, episodic production of large seed crops by perennial plant populations. Generally, hypotheses concerning the evolutionary origin and maintenance of masting entail economies of scale, where the benefit of large, synchronous reproductive events accrues by overcoming some environmental constraint, such as pollen limitation...
Article
1The pioneering work of Peter Eagleson has been proposed as a theoretical basis for ecohydrology. Central to the theory are three ‘ecological optimality hypotheses’ which represent ecologically important aspects of atmosphere–soil–vegetation interactions.2The model and its underlying assumptions have never been evaluated in an explicitly ecological...