Michael Luke Mccormack

• PhD
• Researcher at Morton Arboretum

Root hairs play an important role in the acquisition of soil resources by increasing the absorptive surface area. Yet, key factors driving the variation of root hair traits across different species along biogeographic gradients are still poorly quantified, limiting our understanding of the functional relevance of root hairs. We measured root hair l...

Exploring why species of different plant growth forms can coexist in the same forest is critical for understanding the long-term community stability, but poorly studied on this from root ecological strategies. The aim of this study was to explore the variation of root functional traits among different growth forms and their distribution patterns in...

Nutrient acquisition, conservation and recycling are three mechanisms for plants to meet their nutritional requirements. However, how nutrient recycling relates to other mechanisms remains unknown. Here, we hypothesize that nutrient resorption processes are coordinated with plant nutrient‐acquisition strategies. We measured leaf and root nutrient r...

Understanding the functions and coordination of plant traits is critical for predicting how diverse species respond to climate change. According to hydraulic and economic theories, leaves and roots-key organs for resource acquisition-are expected to function in coordination, such that species with faster resource utilization would possess leaf and...

Purpose of Review To synthesize new information regarding the environmental sensitivity and impact of climate change on leaf-, wood-, phloem- and root phenology of deciduous forests of the temperate (and boreal) zone, comprising overstory and understory, and both woody and herbaceous species. Recent Findings The environmental sensitivity and impac...

Understanding the functions and coordination of plant traits is critical for predicting how diverse species respond to climate change. According to hydraulic and economic theories, leaves and roots—key organs for resource acquisition—are expected to function in coordination, such that species with faster resource utilization would possess leaf and...

Background Urban trees provide many environmental benefits but often face challenging growing conditions like waterlogged soils. How tree root systems respond to waterlogging impacts tree performance and survival, yet this has received little attention. Our goal was to identify how the roots of temperate urban tree species respond and recover to wa...

Root exudation and nutrient uptake have profound impacts on soil biogeochemistry, yet quantification of these fluxes in mature trees is rare. We measured exudation and nitrogen (N) uptake rates of 11 tree species - gymnosperms and angiosperms associating with arbuscular mycorrhizal (AM) or ectomycorrhizal (EcM) fungi – at the Morton Arboretum, USA,...

Quantifying nitrogen uptake rates across different forest types is critical for a range of ecological questions, including the parameterization of global climate change models. However, few measurements of forest nitrogen uptake rates are available due to the intensive labor required to collect in situ data. Here, we seek to optimize data collectio...

Gymnosperms encompass a diverse group of mostly woody plants with high ecological and economic value, yet little is known about the scope and organization of fine‐root trait diversity among gymnosperms due to the undersampling of most gymnosperm families and the dominance of angiosperm groups in recent syntheses. New and existing data were compiled...

Fine root lifespan is a critical trait associated with contrasting root strategies of resource acquisition and protection. Yet, its position within the multidimensional “root economics space” synthesizing global root economics strategies is largely uncertain, and it is rarely represented in frameworks integrating plant trait variations. Here, we co...

Tree roots form symbioses with soil microbes to acquire nutrients, but the relationships between root nutrient acquisition strategies and microbial community composition remain poorly understood. Here, we measured root traits and root-associated fungal and bacterial guilds in 336 trees of 52 species from a subtropical forest. We found a fungal grad...

Tree roots form symbioses with soil microbes to acquire nutrients, but the relationships between root nutrient acquisition strategies and microbial community composition remain poorly understood. Here, we measured root traits and root-associated fungal and bacterial guilds in 336 trees of 52 species from a subtropical forest. We found a fungal grad...

Tree roots form symbioses with soil microbes to enhance nutrient acquisition. Roots with different nutrient acquisition strategies may therefore host microbial communities with distinct functions. To investigate these relationships, we measured root traits and root-associated fungal and bacterial guilds in 336 trees of 52 species from a subtropical...

1. Root respiration is essential for nutrient acquisition. The respiration rate of absorptive roots theoretically relates to the economics of carbon‐nutrient exchange, but its empirical role remains largely unexplored in the trait space defining nutrient uptake strategies. 2. Here, we measured the respiration rates of the distal, non‐woody, absorpt...

Projecting the dynamics and functioning of the biosphere requires a holistic consideration of whole‐ecosystem processes. However, biases toward leaf, canopy, and soil modeling since the 1970s have constantly left fine‐root systems being rudimentarily treated. As accelerated empirical advances in the last two decades establish clearly functional dif...

Mycorrhizas are widespread below‐ground symbioses formed between plant roots and soil fungi. This plant–fungal partnership impacts terrestrial ecosystems by mediating plant performance and biogeochemical processes. The influence of mycorrhizas on plant and ecosystem functioning is ultimately driven by the biological processes that regulate plant–my...

Projecting the functioning of the biosphere requires a holistic consideration of whole-ecosystem processes. Although improving leaf and canopy processes has been the focus of ecosystem model development since the 1970s, the arbitrary homogenization of fine-root systems into a single pool is at odds with observations. This discrepancy has increased...

paragraph Recent studies of plant fine roots have greatly advanced our understanding of their geometric properties and symbiotic relationships, but knowledge of how these roots are spatially distributed across the soil matrix lags far behind. An improved understanding of broad-scale variability in root vertical distribution is critical for understa...

Convergent patterns in morphological and genetic traits of mycorrhizas have been well-documented and reflect common selection forces that define mycorrhizas. However, generalizable patterns of mycorrhiza-associated chemical alterations, which are immediately linked to plant and fungal strategies for successful symbiosis, have yet to be emerged. Com...

In the context of a recent massive increase in research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on generating cutting‐edge, meaningful and integrated knowledge. Consideration of the below‐ground components in plant and ecosystem studies has been consistently calle...

Fine‐root branching, vertical distribution and morphology together with root growth rate are key dimensions that determine root strategies for belowground resource acquisition. However, few studies have addressed these traits together with coordinated measures of root growth rates, limiting generalizations about how these root traits coordinate amo...

Ecological theory is built on trade-offs, where trait differences among species evolved as adaptations to different environments. Trade-offs are often assumed to be bidirectional, where opposite ends of a gradient in trait values confer advantages in different environments. However, unidirectional benefits could be widespread if extreme trait value...

Plant trait variation drives plant function, community composition and ecosystem processes. However, our current understanding of trait variation disproportionately relies on aboveground observations. Here we integrate root traits into the global framework of plant form and function. We developed and tested an overarching conceptual framework that...

Aims Rock fragments are widespread in soil profiles. Despite direct effects of rock fragment content (RFC) on vegetation and soil properties, how plants respond to variations in RFC remains poorly understood. In this work, we investigated responses of two contrasting xerophytic species to varying RFC. Methods Root biomass allocation, vertical dist...

Harsh environmental conditions affect both leaf structure and root traits. However, shoot growth in high‐latitude systems is predominately under photoperiod control while root growth may occur for as long as thermal conditions are favorable. The different sensitivities of these organs may alter functional relationships above‐ and belowground along...

Whether and how warming alters functional traits of absorptive plant roots remains to be answered across the globe. Tackling this question is crucial to better understanding terrestrial responses to climate change as fine‐root traits drive many ecosystem processes. We carried out a detailed synthesis of fine‐root trait responses to experimental war...

The effects of plants on the biosphere, atmosphere and geosphere are key determinants of terrestrial ecosystem functioning. However, despite substantial progress made regarding plant belowground components, we are still only beginning to explore the complex relationships between root traits and functions. Drawing on the literature in plant physiolo...

Motivation Trait data are fundamental to the quantitative description of plant form and function. Although root traits capture key dimensions related to plant responses to changing environmental conditions and effects on ecosystem processes, they have rarely been included in large‐scale comparative studies and global models. For instance, root trai...

Aims Vertical fine-root distribution determines the potential for acquisition of resources throughout soil profiles; yet, variation among forest types and changes in vertical distribution with environments are poorly understood. We examined vertical root distributions of different forest communities to determine how belowground strategies shift acr...

In the context of a recent massive increase into research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on producing cutting edge, meaningful and integrated knowledge. Consideration of the belowground components in plant and ecosystem studies has been consistently calle...

Fine roots mediate below‐ground resource acquisition, yet understanding of how fine‐root functional traits vary along environmental gradients, within branching orders and across phylogenetic scales remains limited. Morphological and architectural fine‐root traits were measured on individual root orders of 20 oak species (genus Quercus) from diverge...

Plant economics run on carbon and nutrients instead of money. Leaf strategies aboveground span an economic spectrum from “live fast and die young” to “slow and steady,” but the economy defined by root strategies belowground remains unclear. Here, we take a holistic view of the belowground economy and show that root-mycorrhizal collaboration can sho...

Motivation Trait data are fundamental to quantitatively describe plant form and function. Although root traits capture key dimensions related to plant responses to changing environmental conditions and effects on ecosystem processes, they have rarely been included in large-scale comparative studies and global models. For instance, root traits remai...

Root systems show a tremendous diversity both between and within species, suggesting a large variability in plant functioning and effects on ecosystem properties and processes. In recent decades, developments in many areas of root research have brought considerable advances in our understanding of root traits and their contribution to plant and eco...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress t...

Plant economics run on carbon and nutrients instead of money. Leaf strategies aboveground span an economic spectrum from ‘live fast and die young’ to ‘slow and steady’, but the economy defined by root strategies belowground remains unclear. Here we take a holistic view of the belowground economy, and show that root-mycorrhizal collaboration can sho...

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...

Key functions of fine roots are often related to their morphological traits, yet little is known about the patterns and controls on fine-root morphological traits in the tropical forest biome. In this study, we consolidated data on key root morphological traits to describe patterns of root trait variation among different tropical regions and examin...

Vegetation impacts on ecosystem functioning are mediated by mycorrhizas, plant–fungal associations formed by most plant species. Ecosystems dominated by distinct mycorrhizal types differ strongly in their biogeochemistry. Quantitative analyses of mycorrhizal impacts on ecosystem functioning are hindered by the scarcity of information on mycorrhizal...

Since their emergence onto land, terrestrial plants have developed diverse strategies to acquire soil resources. However, we lack a framework that adequately captures how these strategies vary among species. Observations from around the world now allow us to quantify the variation observed in commonly-measured fine-root traits but it is unclear how...

Variation in resource acquisition strategies enables plants to adapt to different environments and may partly determine their responses to climate change. However, little is known about how belowground plant traits vary across climate and soil gradients. Focusing on interior Douglas-fir (Pseudotsuga menziesii var. glauca) in western Canada, we test...

We thank reader Joseph Craine for pointing out three inadvertent errors in this Letter. First, 4 of the 71 divergence dates extracted from ref. ¹ of this Amendment and used in Fig. 1b of the original Letter were overestimated. The correct values are 45 million years ago (Ma) for Apocynaceae, 51 Ma for Anacardiaceae, 40 Ma for Primulaceae, and 53 Ma...

Synthesising trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Despite the well-recognised importance of traits for addressing ecological and evolutionary questions, trait-based approaches still struggle with several basic data requirements to deliver openly accessible, reproducible, and tr...

Fine root decomposition constitutes a critical yet poorly understood flux of carbon and nutrients in terrestrial ecosystems. Here, we present the first large‐scale synthesis of species trait effects on the early stages of fine root decomposition at both global and local scales. Based on decomposition rates for 279 plant species across 105 studies a...

Despite the importance of fine roots for the acquisition of soil resources such as nitrogen and water, the study of linkages between traits and both population and community dynamics remains focused on aboveground traits. We address this gap by investigating associations between belowground traits and metrics of species dynamics. Our analysis inclu...

Understanding the effects of global change in terrestrial communities requires an understanding of how limiting resources interact with plant traits to affect productivity. Here, we focus on nitrogen and ask whether plant community nitrogen uptake rate is determined (a) by nitrogen availability alone or (b) by the product of nitrogen availability a...

Aim Rising air temperature and changing precipitation patterns already strongly influence forest ecosystems, yet large‐scale patterns of belowground root trait variation and their underlying drivers are poorly understood. Here, we investigated general patterns of root tip adjustments within fine‐root systems and the potential ecological implication...

Version 2 of the Fine-Root Ecology Database is bigger, better, and free to download and use.

Background and aims: Root mechanical traits, including tensile strength (Tr), tensile strain (εr) and modulus of elasticity (Er), are key functional traits that help characterize plant anchorage and the physical contribution of vegetation to landslides and erosion. The variability in these traits is high among tree fine roots and is poorly underst...

Plant roots mediate the impacts of environmental change on ecosystems, yet knowledge of root responses to environmental change is limited because few experiments evaluate multiple environmental factors and their interactions. Inferences about root functions are also limited because root length dynamics are rarely measured. Using a 5‐year experiment...

This corrects the article DOI: 10.1038/nature25783.

Background: Roots play a pivotal role in defining plant ecological success and mediating terrestrial ecosystem functioning. However, roots are difficult to study as they are hidden in the soil matrix and express a plurality of forms and functions: nutrient acquisition, anchorage, nutrient and water transport. Scope: In this special issue, we gather...

The distribution of mycorrhizal associations across biomes parallels a distinct gradient of soil carbon (C) and nitrogen (N) stocks, raising the question of how mycorrhizal traits relate to ecosystem properties. Arbuscular mycorrhizal ( AM ) and ectomycorrhizal ( EM ) hosts and fungi employ contrasting strategies for N acquisition, which may manife...

Plant roots have greatly diversified in form and function since the emergence of the first land plants1,2, but the global organization of functional traits in roots remains poorly understood3,4. Here we analyse a global dataset of 10 functionally important root traits in metabolically active first-order roots, collected from 369 species distributed...

Functional traits and their variation mediate plant species coexistence and spatial distribution. Yet, how patterns of variation in belowground traits influence resource acquisition across species and plant communities remains obscure. To characterize diverse belowground strategies in relation to species coexistence and abundance, we assessed four...

Background and aims Fine-root traits mediate the capacity of plants to acquire soil resources in different environments. This study aimed to examine the changes of fine-root traits when roots proliferate into the litter layer vs. mineral soils, and to determine fine-root trait plasticity of these roots in response to nitrogen (N) addition. Methods...

Ectomycorrhizal fungi are important in many forest ecosystems, yet their production dynamics and responses to environmental changes are poorly understood. Cenococcum geophilum is a common ectomycorrhizal fungus important to plant and forest soil biogeochemical cycles. The seasonal and inter-annual patterns of production and persistence of mycorrhiz...

Ecosystem functioning relies heavily on below‐ground processes, which are largely regulated by plant fine‐roots and their functional traits. However, our knowledge of fine‐root trait distribution relies to date on local‐ and regional‐scale studies with limited numbers of species, growth forms and environmental variation. We compiled a world‐wide fi...

Trait-based approaches provide a useful framework to investigate plant strategies for resource acquisition, growth, and competition, as well as plant impacts on ecosystem processes. Despite significant progress capturing trait variation within and among stems and leaves, identification of trait syndromes within fine-root systems and between fine ro...

Background and AimsAbsorptive roots active in soil resource uptake are often intimately associated with mycorrhizal fungi, yet it remains unclear how nitrogen (N) loading affects lifespan of absorptive roots associating with ectomycorrhizal (ECM) fungi. Methods Through a three-year minirhizotron experiment, we investigated the responses of ECM life...

Variation and tradeoffs within and among plant traits are increasingly being harnessed by empiricists and modelers to understand and predict ecosystem processes under changing environmental conditions. While fine roots play an important role in ecosystem functioning, fine-root traits are underrepresented in global trait databases. This has hindered...

Compared with ectomycorrhizal ( ECM ) forests, arbuscular mycorrhizal ( AM ) forests are hypothesized to have higher carbon (C) cycling rates and a more open nitrogen (N) cycle. To test this hypothesis, we synthesized 645 observations, including 22 variables related to below‐ground C and N dynamics from 100 sites, where AM and ECM forests co‐occurr...

Plant functional traits may be altered as plants adapt to various environmental constraints. Cold, low fertility growing conditions are often associated with root adjustments to increase acquisition of limiting nutrient resources, but they may also result in construction of roots with reduced uptake potential but higher tissue persistence. It is ul...

Here, in the letter published in this issue of New Phytologist (pp. 310-312), 'Fine roots - functional definition expanded to crop species?' Dr. Zobel emphasizes the importance of heterogeneity within crop-root systems.

The roots of the majority of tree species are associated with either arbuscular mycorrhizal (AM) or ectomycorrhizal (EM) fungi. The absorptive roots of tree species also vary widely in their diameter. The linkages between root thickness, mycorrhiza type and nutrient foraging are poorly understood. We conducted a large root ingrowth experiment in th...

Patterns of plant biomass allocation and functional adjustments along climatic gradients are poorly understood, particularly belowground. Generally, low temperatures suppress nutrient release and uptake, and forests under such conditions have a greater proportion of their biomass in roots. However, it is not clear whether ‘more roots’ means better...

Plant phenology is one of the strongest indicators of ecological responses to climate change, and altered phenology can have pronounced effects on net primary production, species composition in local communities, greenhouse gas fluxes, and ecosystem processes. Although many studies have shown that aboveground plant phenology advances with warmer te...

Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1–2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root...

Soil organic matter (SOM) plays an important role in the maintenance of ecosystem productivity. In particular, the fractions, spatial distribution, and spatial dependency of SOM are important factors influencing multiple ecosystem processes including nutrient cycling, retention, and availability for plant growth. In the present study, geostatistica...

土壤有机质(SOM)对于维持生态系统生产力具有非常重要的意义,有机质的组成、空间分布和空间关联性是影响和控制诸多生态系统过程的重要因素。应用地统计学方法,本研究对长白山原始阔叶红松林局部尺度内0—20 cm土壤有机质与活性有机质的空间异质性进行了研究,并通过交叉半方差分析探讨了二者之间的相关性。研究结果表明:(1)总体上来说,土壤有机碳(SOC)、全氮(TN)、颗粒态有机碳(POC)和颗粒态有机氮(PON)空间异质性较小;而土壤微生物量碳(MBC)、微生物量氮(MBN)和表层(0—10 cm)溶解性有机碳(DOC)的空间异质性较大;(2)SOC、TN、MBC、DOC、POC和PON随着深度的增加空间自相关性增加;而溶解性有机氮(DON)的空间自相关性随深度的增加变化不大;(3)SOC与TN在...