Matteo Rizzuto | Yale University (original) (raw)

Papers by Matteo Rizzuto

Landscape Ecology, Sep 21, 2021

Context Spatially explicit correlates of foliar elemental, stoichiometric, and phytochemical (ESP... more Context Spatially explicit correlates of foliar elemental, stoichiometric, and phytochemical (ESP) traits represent links to landscape patterns of resource quality. Objectives We investigate spatial correlates for multiple foliar ESP traits at the species level and across species at the trait level for five boreal forest understory plants. Methods On the island of Newfoundland, Canada, we collected plot-level foliar material from four chronosequenced forest grids. We integrate plot-level response variables of foliar elemental (C, N, P, percent and quantity), stoichiometric (C:N, C:P, N:P), and phytochemical (terpenoids) traits, with spatial predictors available for the whole landscape to test multiple competing hypotheses. These hypotheses include the effects of land cover (e.g., coniferous, deciduous, mixedwood), productivity (e.g., enhanced vegetation index), biotic (e.g., stand age/height, canopy closure) and abiotic (e.g., elevation, aspect, slope) factors. Results Spatial correlates of foliar ESP traits were generally species specific. However, at the trait level, some species shared spatial predictors, notably for foliar percent carbon, C:P, N:P, sesquiterpene traits. Here we highlight that foliar C, C:P, and sesquiterpene traits between different species were explained by abiotic spatial correlates alone. Similarly, foliar terpenoid traits between different species were related to a combination of abiotic and biotic factors (mean R 2 = 0.26). Conclusions Spatial-trait relationships mainly occur at the species level, with some commonalities at the trait level. By linking plot-level foliar ESP traits to spatial predictors, we can map plant chemical composition patterns that influence landscape-scale ecosystem processes and thus inform sustainable landscape management.

bioRxiv (Cold Spring Harbor Laboratory), Jul 15, 2023

Most carbon cycle models do not consider animal-mediated effects, focusing instead on carbon exch... more Most carbon cycle models do not consider animal-mediated effects, focusing instead on carbon exchanges among plants, microbes, and the atmosphere. Yet, a growing body of empirical evidence from diverse ecosystems points to pervasive animal effects on ecosystem carbon cycling and shows that ignoring them could lead to misrepresentation of an ecosystem's carbon cycle. We develop a new theoretical framework to account for animal effects on ecosystem carbon cycling. We combine a classic ecosystem compartment modeling approach with a classic carbon model to account for carbon flux and storage among plant, animal, and soil microbial trophic compartments. We show, by way of numerical analyses of steady state conditions, that herbivore presence alters the dominant pathways of control over carbon storage and capture. This altered control arises via direct, consumptive effects and especially via indirect, non-consumptive pathways by instigating faster nutrient recycling. This leads to a quantitative change in the ecosystem's carbon balance, increasing the amount of carbon captured and stored in the ecosystem by 2-3 fold. The modeling shows that animals could play a larger role in ecosystem carbon cycle than previously thought. Our framework provides further guidance for empirical research aimed at quantifying animalmediated control of carbon cycling and to inform the development of nature-based climate change solutions that leverage animal influence on the carbon cycle to help mitigate climate change. 2 .

Oikos, Mar 2, 2022

Fluxes of matter, energy and information over space and time contribute to ecosystems' functi... more Fluxes of matter, energy and information over space and time contribute to ecosystems' functioning and stability. The meta‐ecosystem framework addresses the dynamics of ecosystems linked by these fluxes but, to date, has focused solely on energy and matter. Here, we synthesize existing knowledge of information's effects on local and connected ecosystems and demonstrate how new hypotheses emerge from the integration of ecological information into meta‐ecosystem theory. We begin by defining information and reviewing how it flows among ecosystems to affect connectivity, local ecosystem function and meta‐ecosystem dynamics. We focus on the role of semiotic information: that which can reduce an individual's – or a group's – uncertainty about the state of the world. Semiotic information elicits behavioral, developmental and life history responses from organisms, potentially leading to fitness consequences. Organisms' responses to information can ripple through trophic interactions to influence ecosystem processes, their local and regional dynamics, and the spatiotemporal flows of energy and matter, therefore information should affect meta‐ecosystem dynamics such as stability and productivity. While specific subdisciplines of ecology currently consider different types of information (e.g. social and cultural information, natural and artificial light or sound, body condition, genotype and phenotype), many ecological models currently account for neither the spatio–temporal distribution of information nor its perception by organisms. We identify the empirical, theoretical and philosophical challenges in developing a robust information meta‐ecology and offer ways to overcome them. Finally, we present new hypotheses for how accounting for realistic information perception and responses by organisms could impact processes such as home range formation and spatial insurance, and thus our understanding of ecological dynamics across spatial and temporal scales. Accounting for information will be essential to understanding how dynamics such as fitness, organismal movement and trophic interactions influence meta‐ecosystem functioning, and predicting how ecosystem processes are affected by anthropogenic pressures.

Ecology and Evolution, Dec 1, 2019

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Fluxes of matter, energy, and information over space and time contribute to ecosystems’ functioni... more Fluxes of matter, energy, and information over space and time contribute to ecosystems’ functioning. The meta-ecosystem framework addresses the dynamics of ecosystems linked by these fluxes, however, to date, meta-ecosystem research focused solely on fluxes of energy and matter, neglecting information. This is problematic due to organisms’ varied responses to information, which influence local ecosystem dynamics and can alter spatial flows of energy and matter. Furthermore, information itself can move between ecosystems. Therefore, information should contribute to meta-ecosystem dynamics, such as stability and productivity. Specific subdisciplines of ecology currently consider different types of information (e.g., social and cultural information, natural and artificial light or sound, body condition, genotype, and phenotype). Yet neither the spatiotemporal distribution of information nor its perception are currently accounted for in general ecological theories. Here, we provide a roadmap to synthesize information and meta-ecosystem ecology. We begin by defining information in a meta-ecological context. We then review and identify challenges to be addressed in developing information meta-ecology. Finally, we present new hypotheses for how information could impact dynamics across scales of spatio-temporal and biological organization.

Ecology and Evolution, Nov 18, 2020

Herbivores consider the variation of forage qualities (nutritional content and digestibility) as ... more Herbivores consider the variation of forage qualities (nutritional content and digestibility) as well as quantities (biomass) when foraging. Such selection patterns may change based on the scale of foraging, particularly in the case of ungulates that forage at many scales. To test selection for quality and quantity in free‐ranging herbivores across scales, however, we must first develop landscape‐wide quantitative estimates of both forage quantity and quality. Stoichiometric distribution models (StDMs) bring opportunity to address this because they predict the elemental measures and stoichiometry of resources at landscape extents. Here, we use StDMs to predict elemental measures of understory white birch quality (% nitrogen) and quantity (g carbon/m2) across two boreal landscapes. We analyzed global positioning system (GPS) collared moose (n = 14) selection for forage quantity and quality at the landscape, home range, and patch extents using both individual and pooled resource selection analyses. We predicted that as the scale of resource selection decreased from the landscape to the patch, selection for white birch quantity would decrease and selection for quality would increase. Counter to our prediction, pooled‐models showed selection for our estimates of quantity and quality to be neutral with low explanatory power and no scalar trends. At the individual‐level, however, we found evidence for quality and quantity trade‐offs, most notably at the home‐range scale where resource selection models explain the largest amount of variation in selection. Furthermore, individuals did not follow the same trade‐off tactic, with some preferring forage quantity over quality and vice versa. Such individual trade‐offs show that moose may be flexible in attaining a limiting nutrient. Our findings suggest that herbivores may respond to forage elemental compositions and quantities, giving tools like StDMs merit toward animal ecology applications. The integration of StDMs and animal movement data represents a promising avenue for progress in the field of zoogeochemistry.

Journal of Animal Ecology, Jun 3, 2021

Energy, nutrients and organisms move over landscapes, connecting ecosystems across space and time... more Energy, nutrients and organisms move over landscapes, connecting ecosystems across space and time. Meta‐ecosystem theory investigates the emerging properties of local ecosystems coupled spatially by these movements of organisms and matter, by explicitly tracking exchanges of multiple substances across ecosystem borders. To date, meta‐ecosystem research has focused mostly on abiotic flows—neglecting biotic nutrient flows. However, recent work has indicated animals act as spatial nutrient vectors when they transport nutrients across landscapes in the form of excreta, egesta and their own bodies. Partly due to its high level of abstraction, there are few empirical tests of meta‐ecosystem theory. Furthermore, while animals may be viewed as important mediators of ecosystem functions, better integration of tools is needed to develop predictive insights of their relative roles and impacts on diverse ecosystems. We present a methodological roadmap that explains how to do such integration by discussing how to combine insights from movement, foraging and ecosystem ecology to develop a coherent understanding of animal‐vectored nutrient transport on meta‐ecosystems processes. We discuss how the slate of newly developed technologies and methods—tracking devices, mechanistic movement models, diet reconstruction techniques and remote sensing—that when integrated have the potential to advance the quantification of animal‐vectored nutrient flows and increase the predictive power of meta‐ecosystem theory. We demonstrate that by integrating novel and established tools of animal ecology, ecosystem ecology and remote sensing, we can begin to identify and quantify animal‐mediated nutrient translocation by large animals. We also provide conceptual examples that show how our proposed integration of methodologies can help investigate ecosystem impacts of large animal movement. We conclude by describing practical advancements to understanding cross‐ecosystem contributions of animals on the move. Understanding the mechanisms by which animals shape ecosystem dynamics is important for ongoing conservation, rewilding and restoration initiatives around the world, and for developing more accurate models of ecosystem nutrient budgets. Our roadmap will enable ecologists to better qualify and quantify animal‐mediated nutrient translocation for animals on the move.

bioRxiv (Cold Spring Harbor Laboratory), Mar 6, 2023

Organisms moving across landscapes connect ecosystems in space and time, mediating nutrient, ener... more Organisms moving across landscapes connect ecosystems in space and time, mediating nutrient, energy, and biomass exchanges. Meta-ecosystem ecology offers a framework to study how these flows affect ecosystem functions in space and time. However, meta-ecosystem models often represent consumer movement as diffusion along gradients of resources. Crucially, this assumes that consumer movement connects the same trophic compartments among patches of the same ecosystem. Yet, empirical evidence shows that organisms move across different ecosystems and connect diverse trophic compartments in diffusive and non-diffusive ways. Here, we derive a two-patch meta-ecosystem model that accounts for both types of organismal movement, and we investigate their influences on local and meta-ecosystem functions. We integrate two novel approaches in this classic meta-ecosystem model: a dispersers' pool to capture the fraction of moving organisms and time scales separation to partition local and regional dynamics. We show that non-diffusive consumer movement increases landscape heterogeneity while diffusive consumer movement enhances source-sink dynamics. Local ecosystem differences driven by consumer movement type are less prevalent at meta-ecosystem extents. Thus, movement type is essential for predicting local ecosystem dynamics. Our results support recent calls to explicitly consider the role of consumers in shaping and maintaining ecosystem functions in space and time.

bioRxiv (Cold Spring Harbor Laboratory), Jul 16, 2023

Pollution is one of the major drivers of ecosystem change in the Anthropocene. Toxic chemicals ar... more Pollution is one of the major drivers of ecosystem change in the Anthropocene. Toxic chemicals are not constrained to their source of origin as they cross ecosystem boundaries via biotic (e.g., animal migration) and abiotic (e.g., water flow) vectors. Meta-ecology has led to important insights on how spatial flows or subsidies of matter across ecosystem boundaries can have broad impacts on local and regional ecosystem dynamics but has not yet addressed the dynamics of pollutants. Understanding how these meta-ecosystem processes on contaminant dynamics may reverberate up a food chain is important even if they might be difficult to predict. Here we derive a modelling framework to predict how spatial ecosystem fluxes can influence contaminant dynamics and how the severity of this impact is dependent on the type of ecosystem flux leading to the spatial coupling (e.g., herbivore movement vs abiotic chemical flows). We mix an analytical and numerical approach to analyze our integrative model which couples two distinct sub-components-an ecosystem model and a contaminant model. We observe an array of dynamics for how chemical concentrations change with increasing nutrient input and loss rate across trophic levels. When we tailor our range of chemical parameter values to specific organic chemicals our results demonstrate that increasing nutrient input rates can lead to trophic dilution in pollutants such as polychlorinated biphenyls across trophic levels. Yet, increasing nutrient loss rate causes an increase in concentrations of chemicals across all trophic levels. A sensitivity analysis demonstrates that nutrient recycling is an important ecosystem process impacting contaminant concentrations, generating predictions to be addressed by future empirical studies. Importantly, our model demonstrates the utility of our framework for identifying drivers of contaminant dynamics in connected ecosystems including the importance that a) ecosystem processes, and b) movement, especially movement of lower trophic levels, have on contaminant .

bioRxiv (Cold Spring Harbor Laboratory), Feb 17, 2021

Intraspecific feeding choices account for a large portion of herbivore foraging in many ecosystem... more Intraspecific feeding choices account for a large portion of herbivore foraging in many ecosystems. Plant resource quality is heterogeneously distributed, affected by nutrient availability and growing conditions. Herbivores navigate landscapes, making feeding decisions according to food qualities, but also energetic and nutritional demands. We test three nonexclusive foraging hypotheses using the snowshoe hare (Lepus americanus): 1) herbivores feeding choices and body conditions respond to intraspecific plant quality variation, 2) feeding responses are mitigated when energetic demands are high, and 3) feeding responses are inflated when nutritional demands are high. We measured black spruce (Picea mariana) nitrogen, phosphorus, and terpene compositions, as indicators of quality, within a snowshoe hare trapping grid and found plant growing conditions to explain spruce quality variation (R 2 < 0.36). We then offered two qualities of spruce (H1) from the trapping grid to hares in cafeteria-style experiments and measured their feeding and body condition responses (n = 75). We proxied energetic demands (H2) with ambient temperature and coat insulation (% white coat) and nutritional demands (H3) with the spruce quality (nitrogen and phosphorus content) in home ranges. Hares that preferred higher-quality spruce lost less weight during experiments (p = 0.018). The results supported our energetic predictions: hares in colder temperatures and with less-insulative coats (lower % white) consumed more spruce and were less selective towards high-quality spruce. Collectively, we found variation in plant growing conditions within herbivore home ranges substantial enough to affect herbivore body conditions, but any plant-herbivore interactions are also mediated by animal energetic states.

bioRxiv (Cold Spring Harbor Laboratory), Jan 27, 2021

Context: Spatially explicit drivers of foliar chemical traits link plants to ecosystem processes ... more Context: Spatially explicit drivers of foliar chemical traits link plants to ecosystem processes to reveal landscape functionality. Specifically, foliar elemental, stoichiometric, and phytochemical (ESP) compositions represent key indicator traits. Objectives: Here, we investigate the spatial drivers of foliar ESP at the species level and across species at the trait level for five commonly occurring boreal forest understory plants. Methods: On the island of Newfoundland, Canada, we collected foliar material from four chronosequenced forest grids. Using response variables of foliar elemental (C, N, P, percent and quantity), stoichiometric (C:N, C:P, N:P), and phytochemical (terpenoids) composition, we tested multiple competing hypotheses using spatial predictors of land cover (e.g., coniferous, deciduous, mixedwood), productivity (e.g., enhanced vegetation index), biotic (e.g., stand age/height, canopy closure) and abiotic (e.g., elevation, aspect, slope) factors. Results: We found evidence to support spatial relationships of foliar ESP for most species (mean R 2 = 0.22, max = 0.65). Spatial variation in elemental quantity traits of C, N, P were related to land cover along with biotic and abiotic factors for 2 of 5 focal species. Notably, foliar C, C:P, and sesquiterpene traits between different species were related to abiotic factors. Similarly, foliar terpenoid traits between different species were related to a combination of abiotic and biotic factors (mean R 2 = 0.26). Conclusions: Spatial-trait relationships mainly occur at the species level, with some commonalities occurring at the trait level. By linking foliar ESP traits to spatial predictors, we can map plant chemical composition patterns that influence landscape-scale ecosystem processes.

Ecology and Evolution, Sep 1, 2022

Journal of Plant Ecology, Dec 22, 2020

Aims Intraspecific variation in plant traits has important consequences for individual fitness an... more Aims Intraspecific variation in plant traits has important consequences for individual fitness and herbivore foraging. For plants, trait variability across spatial dimensions is well documented. However, temporal dimensions of trait variability are less well known, and may be influenced by seasonal differences in growing degree days (GDD), temperature and precipitation. Here, we aim to quantify intraspecific temporal variation in traits and the underlying drivers for four commonly occurring boreal plant species. Methods We sampled the elemental and stoichiometric traits (%C, %N, %P, C:N, C:P, N:P) of four common browse species' foliage across 2 years. Using a two-step approach, we first fitted generalized linear models (GzLM, n = 24) to the species' elemental and stoichiometric traits, and tested if they varied across years. When we observed evidence for temporal variability, we fitted a second set of GzLMs (n = 8) with temperature, productivity and moisture as explanatory variables. Important Findings We found no evidence of temporal variation for most of the elemental and stoichiometric traits of our four boreal plants, with two exceptions. Year was an important predictor for percent carbon across all four species (R 2 = 0.47-0.67) and for multiple elemental and stoichiometric traits in balsam fir (5/8, R 2 = 0.29-0.67). Thus, variation in percent carbon was related to interannual differences, more so than nitrogen and phosphorus, which are limiting nutrients in the boreal forest. These results also indicate that year may explain more variation in conifers' stoichiometry than for deciduous plants due to life history differences. GDD was the most frequently occurring variable in the second round of models (8/8 times, R 2 = 0.21-0.41), suggesting that temperature is an important driver of temporal variation in these traits.

Nature Ecology and Evolution, Dec 4, 2017

We would like to thank three anonymous reviewers for their detailed and helpful comments that gre... more We would like to thank three anonymous reviewers for their detailed and helpful comments that greatly improved this paper. We would also like to thank Vito Muggeo and Dimitrios-Georgios Kontopoulos for their advice on the phylogenetically independent contrast and phylogenetic piecewise regression analyses.

Oecologia, Jun 15, 2021

Consumers make space use decisions based on resource quality. Most studies that investigate the i... more Consumers make space use decisions based on resource quality. Most studies that investigate the influence of resource quality on the spatial ecology of consumers use diverse proxies for quality including measures based on habitat classification, forage species diversity and abundance, and nutritional indicators, e.g., protein. Ecological stoichiometry measures resource quality in terms of elemental ratios, e.g., carbon (C):nitrogen (N) ratio, but rarely have these currencies been used to study consumer space use decisions. Yet, elemental ratios provide a uniquely quantitative way to assess resource quality. Consequently, ecological stoichiometry allows for investigation of how consumers respond to spatial heterogeneity in resource quality by changing their space use, e.g. their home range size, and how this may influence ecosystem dynamics and trophic interactions. Here, we test whether the home range size of a keystone boreal herbivore, the snowshoe hare (Lepus americanus), varies with differences in 1. CC-BY-NC-ND 4.

Journal of Mammalogy, 2021

Herbivores making space use decisions must consider the trade-off between perceived predation ris... more Herbivores making space use decisions must consider the trade-off between perceived predation risk and forage quality. Herbivores, specifically snowshoe hares (Lepus americanus), must constantly navigate landscapes that vary in predation risk and food quality, providing researchers with the opportunity to explore the factors that govern their foraging decisions. Herein, we tested predictions that intersect the risk allocation hypothesis (RAH) and optimal foraging theory (OFT) in a spatially explicit ecological stoichiometry framework to assess the trade-off between predation risk and forage quality. We used individual and population estimates of snowshoe hare (n = 29) space use derived from biotelemetry across three summers. We evaluated resource forage quality for lowbush blueberry (Vaccinium angustifolium), a common and readily available forage species within our system, using carbon:nitrogen and carbon:phosphorus ratios. We used habitat complexity to proxy perceived predation ris...

Organisms moving across landscapes connect ecosystems in space and time, mediating nutrient, ener... more Organisms moving across landscapes connect ecosystems in space and time, mediating nutrient, energy, and biomass exchanges. Meta-ecosystem ecology offers a framework to study how these flows affect ecosystem functions in space and time. However, meta-ecosystem models often represent consumer movement as diffusion along gradients of resources. Crucially, this assumes that consumer movement connects the same trophic compartments among patches of the same ecosystem. Yet, empirical evidence shows that organisms move across different ecosystems and connect diverse trophic compartments in diffusive and non-diffusive ways. Here, we derive a two-patch meta-ecosystem model that accounts for both types of organismal movement, and we investigate their influences on local and meta-ecosystem functions. We integrate two novel approaches in this classic meta-ecosystem model: a dispersers’ pool to capture the fraction of moving organisms and time scales separation to partition local and regional dy...

Ecology and Evolution

Landscape Ecology, Sep 21, 2021

bioRxiv (Cold Spring Harbor Laboratory), Jul 15, 2023

Oikos, Mar 2, 2022

Ecology and Evolution, Dec 1, 2019

Ecology and Evolution, Nov 18, 2020

Journal of Animal Ecology, Jun 3, 2021

bioRxiv (Cold Spring Harbor Laboratory), Mar 6, 2023

bioRxiv (Cold Spring Harbor Laboratory), Jul 16, 2023

bioRxiv (Cold Spring Harbor Laboratory), Feb 17, 2021

bioRxiv (Cold Spring Harbor Laboratory), Jan 27, 2021

Ecology and Evolution, Sep 1, 2022

Journal of Plant Ecology, Dec 22, 2020

Nature Ecology and Evolution, Dec 4, 2017

Oecologia, Jun 15, 2021

Journal of Mammalogy, 2021

Organisms moving across landscapes connect ecosystems in space and time, mediating nutrient, ener... more Organisms moving across landscapes connect ecosystems in space and time, mediating nutrient, energy, and biomass exchanges. Meta-ecosystem ecology offers a framework to study how these flows affect ecosystem functions in space and time. However, meta-ecosystem models often represent consumer movement as diffusion along gradients of resources. Crucially, this assumes that consumer movement connects the same trophic compartments among patches of the same ecosystem. Yet, empirical evidence shows that organisms move across different ecosystems and connect diverse trophic compartments in diffusive and non-diffusive ways. Here, we derive a two-patch meta-ecosystem model that accounts for both types of organismal movement, and we investigate their influences on local and meta-ecosystem functions. We integrate two novel approaches in this classic meta-ecosystem model: a dispersers’ pool to capture the fraction of moving organisms and time scales separation to partition local and regional dy...

Ecology and Evolution