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Thomas MK, Ranjan R. Designing More Informative Multiple-Driver Experiments. Ann Rev Mar Sci 2024; 16:513-536. [PMID: 37625127 DOI: 10.1146/annurev-marine-041823-095913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
For decades, multiple-driver/stressor research has examined interactions among drivers that will undergo large changes in the future: temperature, pH, nutrients, oxygen, pathogens, and more. However, the most commonly used experimental designs-present-versus-future and ANOVA-fail to contribute to general understanding or predictive power. Linking experimental design to process-based mathematical models would help us predict how ecosystems will behave in novel environmental conditions. We review a range of experimental designs and assess the best experimental path toward a predictive ecology. Full factorial response surface, fractional factorial, quadratic response surface, custom, space-filling, and especially optimal and sequential/adaptive designs can help us achieve more valuable scientific goals. Experiments using these designs are challenging to perform with long-lived organisms or at the community and ecosystem levels. But they remain our most promising path toward linking experiments and theory in multiple-driver research and making accurate, useful predictions.
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Affiliation(s)
- Mridul K Thomas
- Department F.-A. Forel for Environmental and Aquatic Sciences and Institute for Environmental Sciences, University of Geneva, Geneva, Switzerland;
| | - Ravi Ranjan
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg, Oldenburg, Germany;
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Hanse-Wissenschaftskolleg Institute for Advanced Study, Delmenhorst, Germany
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2
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McIntire EJB, Chubaty AM, Cumming SG, Andison D, Barros C, Boisvenue C, Haché S, Luo Y, Micheletti T, Stewart FEC. PERFICT: A Re-imagined foundation for predictive ecology. Ecol Lett 2022; 25:1345-1351. [PMID: 35315961 PMCID: PMC9310704 DOI: 10.1111/ele.13994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 02/10/2022] [Indexed: 12/02/2022]
Abstract
Making predictions from ecological models—and comparing them to data—offers a coherent approach to evaluate model quality, regardless of model complexity or modelling paradigm. To date, our ability to use predictions for developing, validating, updating, integrating and applying models across scientific disciplines while influencing management decisions, policies, and the public has been hampered by disparate perspectives on prediction and inadequately integrated approaches. We present an updated foundation for Predictive Ecology based on seven principles applied to ecological modelling: make frequent Predictions, Evaluate models, make models Reusable, Freely accessible and Interoperable, built within Continuous workflows that are routinely Tested (PERFICT). We outline some benefits of working with these principles: accelerating science; linking with data science; and improving science‐policy integration.
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Affiliation(s)
- Eliot J B McIntire
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia, Canada.,Faculty of Forestry, Forest Resources Management, The University of British Columbia, Vancouver, British Columbia, Canada.,Département des sciences du bois et de la forêt, Pavillon Abitibi-Price, 2405, rue de la Terrasse, Université Laval, Québec City, Québec, Canada
| | - Alex M Chubaty
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia, Canada.,Département des sciences du bois et de la forêt, Pavillon Abitibi-Price, 2405, rue de la Terrasse, Université Laval, Québec City, Québec, Canada.,FOR-CAST Research & Analytics, Calgary, Alberta, Canada
| | - Steven G Cumming
- Département des sciences du bois et de la forêt, Pavillon Abitibi-Price, 2405, rue de la Terrasse, Université Laval, Québec City, Québec, Canada
| | - Dave Andison
- Faculty of Forestry, Forest Resources Management, The University of British Columbia, Vancouver, British Columbia, Canada.,Bandaloop Landscape-Ecosystem Services Ltd., Nelson, British Columbia, Canada
| | - Ceres Barros
- Faculty of Forestry, Forest Resources Management, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Céline Boisvenue
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia, Canada.,Faculty of Forestry, Forest Resources Management, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Samuel Haché
- Canadian Wildlife Service, Environment and Climate Change Canada, Yellowknife, Northwest Territories, Canada
| | - Yong Luo
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia, Canada.,Forest Analysis and Inventory Branch, BC Ministry of Forests, Victoria, British Columbia, Canada
| | - Tatiane Micheletti
- Faculty of Forestry, Forest Resources Management, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Frances E C Stewart
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia, Canada.,University of Victoria, School of Environmental Studies, Victoria, British Columbia, Canada.,Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada
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3
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Wang G, Gao Q, Yang Y, Hobbie SE, Reich PB, Zhou J. Soil enzymes as indicators of soil function: A step toward greater realism in microbial ecological modeling. Glob Chang Biol 2022; 28:1935-1950. [PMID: 34905647 DOI: 10.1111/gcb.16036] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/23/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
Soil carbon (C) and nitrogen (N) cycles and their complex responses to environmental changes have received increasing attention. However, large uncertainties in model predictions remain, partially due to the lack of explicit representation and parameterization of microbial processes. One great challenge is to effectively integrate rich microbial functional traits into ecosystem modeling for better predictions. Here, using soil enzymes as indicators of soil function, we developed a competitive dynamic enzyme allocation scheme and detailed enzyme-mediated soil inorganic N processes in the Microbial-ENzyme Decomposition (MEND) model. We conducted a rigorous calibration and validation of MEND with diverse soil C-N fluxes, microbial C:N ratios, and functional gene abundances from a 12-year CO2 × N grassland experiment (BioCON) in Minnesota, USA. In addition to accurately simulating soil CO2 fluxes and multiple N variables, the model correctly predicted microbial C:N ratios and their negative response to enriched N supply. Model validation further showed that, compared to the changes in simulated enzyme concentrations and decomposition rates, the changes in simulated activities of eight C-N-associated enzymes were better explained by the measured gene abundances in responses to elevated atmospheric CO2 concentration. Our results demonstrated that using enzymes as indicators of soil function and validating model predictions with functional gene abundances in ecosystem modeling can provide a basis for testing hypotheses about microbially mediated biogeochemical processes in response to environmental changes. Further development and applications of the modeling framework presented here will enable microbial ecologists to address ecosystem-level questions beyond empirical observations, toward more predictive understanding, an ultimate goal of microbial ecology.
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Affiliation(s)
- Gangsheng Wang
- Institute for Water-Carbon Cycles and Carbon Neutrality, State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA
| | - Qun Gao
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Sarah E Hobbie
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, Minnesota, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St Paul, Minnesota, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Jizhong Zhou
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA
- School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Oklahoma, USA
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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4
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Hicks LC, Frey B, Kjøller R, Lukac M, Moora M, Weedon JT, Rousk J. Toward a function-first framework to make soil microbial ecology predictive. Ecology 2021; 103:e03594. [PMID: 34807459 DOI: 10.1002/ecy.3594] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/27/2021] [Accepted: 09/10/2021] [Indexed: 01/21/2023]
Abstract
Soil microbial communities perform vital ecosystem functions, such as the decomposition of organic matter to provide plant nutrition. However, despite the functional importance of soil microorganisms, attribution of ecosystem function to particular constituents of the microbial community has been impeded by a lack of information linking microbial function to community composition and structure. Here, we propose a function-first framework to predict how microbial communities influence ecosystem functions. We first view the microbial community associated with a specific function as a whole and describe the dependence of microbial functions on environmental factors (e.g., the intrinsic temperature dependence of bacterial growth rates). This step defines the aggregate functional response curve of the community. Second, the contribution of the whole community to ecosystem function can be predicted, by combining the functional response curve with current environmental conditions. Functional response curves can then be linked with taxonomic data in order to identify sets of "biomarker" taxa that signal how microbial communities regulate ecosystem functions. Ultimately, such indicator taxa may be used as a diagnostic tool, enabling predictions of ecosystem function from community composition. In this paper, we provide three examples to illustrate the proposed framework, whereby the dependence of bacterial growth on environmental factors, including temperature, pH, and salinity, is defined as the functional response curve used to interlink soil bacterial community structure and function. Applying this framework will make it possible to predict ecosystem functions directly from microbial community composition.
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Affiliation(s)
- Lettice C Hicks
- Section of Microbial Ecology, Department of Biology, Lund University, Ecology Building, Lund, 22362, Sweden
| | - Beat Frey
- Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland
| | - Rasmus Kjøller
- Department of Biology, Terrestrial Ecology Section, University of Copenhagen, Universitetsparken 15, Copenhagen, 2100, Denmark
| | - Martin Lukac
- School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, United Kingdom.,Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, 16500, Czech Republic
| | - Mari Moora
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu, 51005, Estonia
| | - James T Weedon
- Systems Ecology, Department of Ecological Science, Vrije Universiteit Amsterdam, Amsterdam, 1081 HV, The Netherlands
| | - Johannes Rousk
- Section of Microbial Ecology, Department of Biology, Lund University, Ecology Building, Lund, 22362, Sweden
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5
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Gallagher CA, Chimienti M, Grimm V, Nabe-Nielsen J. Energy-mediated responses to changing prey size and distribution in marine top predator movements and population dynamics. J Anim Ecol 2021; 91:241-254. [PMID: 34739086 DOI: 10.1111/1365-2656.13627] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/27/2021] [Indexed: 11/26/2022]
Abstract
Climate change is modifying the structure of marine ecosystems, including that of fish communities. Alterations in abiotic and biotic conditions can decrease fish size and change community spatial arrangement, ultimately impacting predator species which rely on these communities. To conserve predators and understand the drivers of observed changes in their population dynamics, we must advance our understanding of how shifting environmental conditions can impact populations by limiting food available to individuals. To investigate the impacts of changing fish size and spatial aggregation on a top predator population, we applied an existing agent-based model parameterized for harbour porpoises Phocoena phocoena which represents animal energetics and movements in high detail. We used this framework to quantify the impacts of shifting prey size and spatial aggregation on porpoise movement, space use, energetics and population dynamics. Simulated individuals were more likely to switch from area-restricted search to transit behaviour with increasing prey size, particularly when starving, due to elevated resource competition. In simulations with highly aggregated prey, higher prey encounter rates counteracted resource competition, resulting in no impacts of prey spatial aggregation on movement behaviour. Reduced energy intake with decreasing prey size and aggregation level caused population decline, with a 15% decrease in fish length resulting in total population collapse Increasing prey consumption rates by 42.8 ± 4.5% could offset population declines; however, this increase was 21.3 ± 12.7% higher than needed to account for changes in total energy availability alone. This suggests that animals in realistic seascapes require additional energy to locate smaller prey which should be considered when assessing the impacts of decreased energy availability. Changes in prey size and aggregation influenced movements and population dynamics of simulated harbour porpoises, revealing that climate-induced changes in prey structure, not only prey abundance, may threaten predator populations. We demonstrate how a population model with realistic animal movements and process-based energetics can be used to investigate population consequences of shifting food availability, such as those mediated by climate change, and provide a mechanistic explanation for how changes in prey structure can impact energetics, behaviour and ultimately viability of predator populations.
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Affiliation(s)
- Cara A Gallagher
- Department of Ecoscience, Aarhus University, Roskilde, Denmark.,Plant Ecology and Nature Conservation, University of Potsdam, Potsdam, Germany
| | - Marianna Chimienti
- Department of Ecoscience, Aarhus University, Roskilde, Denmark.,Centre d'Etudes Biologiques de Chizé, Villiers-en-Bois, France
| | - Volker Grimm
- Plant Ecology and Nature Conservation, University of Potsdam, Potsdam, Germany.,Department of Ecological Modelling, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
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6
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Ramazi P, Kunegel‐Lion M, Greiner R, Lewis MA. Predicting insect outbreaks using machine learning: A mountain pine beetle case study. Ecol Evol 2021; 11:13014-13028. [PMID: 34646449 PMCID: PMC8495826 DOI: 10.1002/ece3.7921] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 06/29/2020] [Accepted: 07/20/2020] [Indexed: 11/09/2022] Open
Abstract
Planning forest management relies on predicting insect outbreaks such as mountain pine beetle, particularly in the intermediate-term future, e.g., 5-year. Machine-learning algorithms are potential solutions to this challenging problem due to their many successes across a variety of prediction tasks. However, there are many subtle challenges in applying them: identifying the best learning models and the best subset of available covariates (including time lags) and properly evaluating the models to avoid misleading performance-measures. We systematically address these issues in predicting the chance of a mountain pine beetle outbreak in the Cypress Hills area and seek models with the best performance at predicting future 1-, 3-, 5- and 7-year infestations. We train nine machine-learning models, including two generalized boosted regression trees (GBM) that predict future 1- and 3-year infestations with 92% and 88% AUC, and two novel mixed models that predict future 5- and 7-year infestations with 86% and 84% AUC, respectively. We also consider forming the train and test datasets by splitting the original dataset randomly rather than using the appropriate year-based approach and show that this may obtain models that score high on the test dataset but low in practice, resulting in inaccurate performance evaluations. For example, a k-nearest neighbor model with the actual performance of 68% AUC, scores the misleadingly high 78% on a test dataset obtained from a random split, but the more accurate 66% on a year-based split. We then investigate how the prediction accuracy varies with respect to the provided history length of the covariates and find that neural network and naive Bayes, predict more accurately as history-length increases, particularly for future 1- and 3-year predictions, and roughly the same holds with GBM. Our approach is applicable to other invasive species. The resulting predictors can be used in planning forest and pest management and planning sampling locations in field studies.
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Affiliation(s)
- Pouria Ramazi
- Department of Mathematical and Statistical SciencesUniversity of AlbertaEdmontonABCanada
- Department of Computing ScienceUniversity of AlbertaEdmontonABCanada
| | | | - Russell Greiner
- Department of Computing ScienceUniversity of AlbertaEdmontonABCanada
- Alberta Machine Intelligence InstituteEdmontonABCanada
| | - Mark A. Lewis
- Department of Mathematical and Statistical SciencesUniversity of AlbertaEdmontonABCanada
- Department of Biological SciencesUniversity of AlbertaEdmontonABCanada
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7
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Gallagher CA, Chudzinska M, Larsen-Gray A, Pollock CJ, Sells SN, White PJC, Berger U. From theory to practice in pattern-oriented modelling: identifying and using empirical patterns in predictive models. Biol Rev Camb Philos Soc 2021; 96:1868-1888. [PMID: 33978325 DOI: 10.1111/brv.12729] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 01/21/2023]
Abstract
To robustly predict the effects of disturbance and ecosystem changes on species, it is necessary to produce structurally realistic models with high predictive power and flexibility. To ensure that these models reflect the natural conditions necessary for reliable prediction, models must be informed and tested using relevant empirical observations. Pattern-oriented modelling (POM) offers a systematic framework for employing empirical patterns throughout the modelling process and has been coupled with complex systems modelling, such as in agent-based models (ABMs). However, while the production of ABMs has been rising rapidly, the explicit use of POM has not increased. Challenges with identifying patterns and an absence of specific guidelines on how to implement empirical observations may limit the accessibility of POM and lead to the production of models which lack a systematic consideration of reality. This review serves to provide guidance on how to identify and apply patterns following a POM approach in ABMs (POM-ABMs), specifically addressing: where in the ecological hierarchy can we find patterns; what kinds of patterns are useful; how should simulations and observations be compared; and when in the modelling cycle are patterns used? The guidance and examples provided herein are intended to encourage the application of POM and inspire efficient identification and implementation of patterns for both new and experienced modellers alike. Additionally, by generalising patterns found especially useful for POM-ABM development, these guidelines provide practical help for the identification of data gaps and guide the collection of observations useful for the development and verification of predictive models. Improving the accessibility and explicitness of POM could facilitate the production of robust and structurally realistic models in the ecological community, contributing to the advancement of predictive ecology at large.
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Affiliation(s)
- Cara A Gallagher
- Department of Plant Ecology and Conservation Biology, University of Potsdam, Am Mühlenberg 3, Potsdam, 14469, Germany.,Department of Bioscience, Aarhus University, Frederiksborgvej 399, Roskilde, 4000
| | - Magda Chudzinska
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 9ST, U.K
| | - Angela Larsen-Gray
- Department of Integrative Biology, University of Wisconsin-Madison, 250 N. Mills St., Madison, WI, 53706, U.S.A
| | | | - Sarah N Sells
- Montana Cooperative Wildlife Research Unit, The University of Montana, 205 Natural Sciences, Missoula, MT, 59812, U.S.A
| | - Patrick J C White
- School of Applied Sciences, Edinburgh Napier University, 9 Sighthill Ct., Edinburgh, EH11 4BN, U.K
| | - Uta Berger
- Institute of Forest Growth and Computer Science, Technische Universität Dresden, Dresden, 01062, Germany
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8
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Boult VL, Evans LC. Mechanisms matter: Predicting the ecological impacts of global change. Glob Chang Biol 2021; 27:1689-1691. [PMID: 33501769 DOI: 10.1111/gcb.15527] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/20/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Victoria L Boult
- National Centre for Atmospheric Sciences and Department of Meteorology, University of Reading, Reading, UK
| | - Luke C Evans
- School of Biological Sciences, University of Reading, Reading, UK
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9
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DeLaMater DS, Couture JJ, Puzey JR, Dalgleish HJ. Range-wide variations in common milkweed traits and their effect on monarch larvae. Am J Bot 2021; 108:388-401. [PMID: 33792047 DOI: 10.1002/ajb2.1630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/08/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Leaf economic spectrum (LES) theory has historically been employed to inform vegetation models of ecosystem processes, but largely neglects intraspecific variation and biotic interactions. We attempt to integrate across environment-plant trait-herbivore interactions within a species at a range-wide scale. METHODS We measured traits in 53 populations spanning the range of common milkweed (Asclepias syriaca) and used a common garden to determine the role of environment in driving patterns of intraspecific variation. We used a feeding trial to determine the role of plant traits in monarch (Danaus plexippus) larval development. RESULTS Trait-trait relationships largely followed interspecific patterns in LES theory and persisted in a common garden when individual traits change. Common milkweed showed intraspecific variation and biogeographic clines in traits. Clines did not persist in a common garden. Larvae ate more and grew larger when fed plants with more nitrogen. A longitudinal environmental gradient in precipitation corresponded to a resource gradient in plant nitrogen, which produces a gradient in larval performance. CONCLUSIONS Biogeographic patterns in common milkweed traits can sometimes be predicted from LES, are largely driven by environmental conditions, and have consequences for monarch larval performance. Changes to nutrient dynamics of landscapes with common milkweed could potentially influence monarch population dynamics. We show how biogeographic trends in intraspecific variation can influence key ecological interactions, especially in common species with large distributions.
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Affiliation(s)
- David S DeLaMater
- Department of Biology, William & Mary, 540 Landrum Drive, Williamsburg, VA, 23185, USA
| | - John J Couture
- Departments of Entomology and Forestry and Natural Resources, Purdue University, 170 S. University Street, West Lafayette, IN, 47907, USA
| | - Joshua R Puzey
- Department of Biology, William & Mary, 540 Landrum Drive, Williamsburg, VA, 23185, USA
| | - Harmony J Dalgleish
- Department of Biology, William & Mary, 540 Landrum Drive, Williamsburg, VA, 23185, USA
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Andersen TK, Nielsen A, Jeppesen E, Hu F, Bolding K, Liu Z, Søndergaard M, Johansson LS, Trolle D. Predicting ecosystem state changes in shallow lakes using an aquatic ecosystem model: Lake Hinge, Denmark, an example. Ecol Appl 2020; 30:e02160. [PMID: 32363772 PMCID: PMC7583379 DOI: 10.1002/eap.2160] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 12/26/2019] [Accepted: 03/30/2020] [Indexed: 05/06/2023]
Abstract
In recent years, considerable efforts have been made to restore turbid, phytoplankton-dominated shallow lakes to a clear-water state with high coverage of submerged macrophytes. Various dynamic lake models with simplified physical representations of vertical gradients, such as PCLake, have been used to predict external nutrient load thresholds for such nonlinear regime shifts. However, recent observational studies have questioned the concept of regime shifts by emphasizing that gradual changes are more common than sudden shifts. We investigated if regime shifts would be more gradual if the models account for depth-dependent heterogeneity of the system by including the possibility of vertical gradients in the water column and sediment layers for the entire depth. Hence, bifurcation analysis was undertaken using the 1D hydrodynamic model GOTM, accounting for vertical gradients, coupled to the aquatic ecosystem model PCLake, which is implemented in the framework for aquatic biogeochemical modeling (FABM). First, the model was calibrated and validated against a comprehensive data set covering two consecutive 7-yr periods from Lake Hinge, a shallow, eutrophic Danish lake. The autocalibration program Auto-Calibration Python (ACPy) was applied to achieve a more comprehensive adjustment of model parameters. The model simulations showed excellent agreement with observed data for water temperature, total nitrogen, and nitrate and good agreement for ammonium, total phosphorus, phosphate, and chlorophyll a concentrations. Zooplankton and macrophyte coverage were adequately simulated for the purpose of this study, and in general the GOTM-FABM-PCLake model simulations performed well compared with other model studies. In contrast to previous model studies ignoring depth heterogeneity, our bifurcation analysis revealed that the spatial extent and depth limitation of macrophytes as well as phytoplankton chlorophyll-a responded more gradually over time to a reduction in the external phosphorus load, albeit some hysteresis effects still appeared. In a management perspective, our study emphasizes the need to include depth heterogeneity in the model structure to more correctly determine at which external nutrient load a given lake changes ecosystem state to a clear-water condition.
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Affiliation(s)
- Tobias Kuhlmann Andersen
- Department of BioscienceAarhus University8600SilkeborgDenmark
- Sino‐Danish Center for Education and ResearchUniversity of Chinese Academy of SciencesBeijing100049China
| | - Anders Nielsen
- Department of BioscienceAarhus University8600SilkeborgDenmark
| | - Erik Jeppesen
- Department of BioscienceAarhus University8600SilkeborgDenmark
- Sino‐Danish Center for Education and ResearchUniversity of Chinese Academy of SciencesBeijing100049China
| | - Fenjuan Hu
- Department of BioscienceAarhus University8600SilkeborgDenmark
| | - Karsten Bolding
- Department of BioscienceAarhus University8600SilkeborgDenmark
- Sino‐Danish Center for Education and ResearchUniversity of Chinese Academy of SciencesBeijing100049China
| | - Zhengwen Liu
- Sino‐Danish Center for Education and ResearchUniversity of Chinese Academy of SciencesBeijing100049China
- State Key Laboratory of Lake Science and EnvironmentNanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing210008China
- Department of EcologyJinan UniversityGuangzhou510632China
| | - Martin Søndergaard
- Department of BioscienceAarhus University8600SilkeborgDenmark
- Sino‐Danish Center for Education and ResearchUniversity of Chinese Academy of SciencesBeijing100049China
| | | | - Dennis Trolle
- Department of BioscienceAarhus University8600SilkeborgDenmark
- Sino‐Danish Center for Education and ResearchUniversity of Chinese Academy of SciencesBeijing100049China
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11
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Louarn G, Song Y. Two decades of functional-structural plant modelling: now addressing fundamental questions in systems biology and predictive ecology. Ann Bot 2020; 126:501-509. [PMID: 32725187 PMCID: PMC7489058 DOI: 10.1093/aob/mcaa143] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 07/25/2020] [Indexed: 05/16/2023]
Abstract
BACKGROUND Functional-structural plant models (FSPMs) explore and integrate relationships between a plant's structure and processes that underlie its growth and development. In the last 20 years, scientists interested in functional-structural plant modelling have expanded greatly the range of topics covered and now handle dynamical models of growth and development occurring from the microscopic scale, and involving cell division in plant meristems, to the macroscopic scales of whole plants and plant communities. SCOPE The FSPM approach occupies a central position in plant science; it is at the crossroads of fundamental questions in systems biology and predictive ecology. This special issue of Annals of Botany features selected papers on critical areas covered by FSPMs and examples of comprehensive models that are used to solve theoretical and applied questions, ranging from developmental biology to plant phenotyping and management of plants for agronomic purposes. Altogether, they offer an opportunity to assess the progress, gaps and bottlenecks along the research path originally foreseen for FSPMs two decades ago. This review also allows discussion of current challenges of FSPMs regarding (1) integration of multidisciplinary knowledge, (2) methods for handling complex models, (3) standards to achieve interoperability and greater genericity and (4) understanding of plant functioning across scales. CONCLUSIONS This approach has demonstrated considerable progress, but has yet to reach its full potential in terms of integration and heuristic knowledge production. The research agenda of functional-structural plant modellers in the coming years should place a greater emphasis on explaining robust emergent patterns, and on the causes of possible deviation from it. Modelling such patterns could indeed fuel both generic integration across scales and transdisciplinary transfer. In particular, it could be beneficial to emergent fields of research such as model-assisted phenotyping and predictive ecology in managed ecosystems.
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Affiliation(s)
| | - Youhong Song
- Anhui Agricultural University, School of Agronomy, Hefei, Anhui Province, PR China
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Lever JJ, van de Leemput IA, Weinans E, Quax R, Dakos V, van Nes EH, Bascompte J, Scheffer M. Foreseeing the future of mutualistic communities beyond collapse. Ecol Lett 2020; 23:2-15. [PMID: 31707763 PMCID: PMC6916369 DOI: 10.1111/ele.13401] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/20/2019] [Accepted: 09/14/2019] [Indexed: 02/02/2023]
Abstract
Changing conditions may lead to sudden shifts in the state of ecosystems when critical thresholds are passed. Some well-studied drivers of such transitions lead to predictable outcomes such as a turbid lake or a degraded landscape. Many ecosystems are, however, complex systems of many interacting species. While detecting upcoming transitions in such systems is challenging, predicting what comes after a critical transition is terra incognita altogether. The problem is that complex ecosystems may shift to many different, alternative states. Whether an impending transition has minor, positive or catastrophic effects is thus unclear. Some systems may, however, behave more predictably than others. The dynamics of mutualistic communities can be expected to be relatively simple, because delayed negative feedbacks leading to oscillatory or other complex dynamics are weak. Here, we address the question of whether this relative simplicity allows us to foresee a community's future state. As a case study, we use a model of a bipartite mutualistic network and show that a network's post-transition state is indicated by the way in which a system recovers from minor disturbances. Similar results obtained with a unipartite model of facilitation suggest that our results are of relevance to a wide range of mutualistic systems.
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Affiliation(s)
- J. Jelle Lever
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichWinterthurerstrasse 190CH‐8057ZurichSwitzerland
- Department of Aquatic Ecology and Water Quality ManagementWageningen UniversityP.O. Box 47NL‐6700 AAWageningenThe Netherlands
| | - Ingrid A. van de Leemput
- Department of Aquatic Ecology and Water Quality ManagementWageningen UniversityP.O. Box 47NL‐6700 AAWageningenThe Netherlands
| | - Els Weinans
- Department of Aquatic Ecology and Water Quality ManagementWageningen UniversityP.O. Box 47NL‐6700 AAWageningenThe Netherlands
| | - Rick Quax
- Computational Science LabUniversity of AmsterdamNL‐1098 XHAmsterdamThe Netherlands
- Institute of Advanced StudiesUniversity of Amsterdam1012 GCAmsterdamThe Netherlands
| | - Vasilis Dakos
- Institut des Sciences de l'Evolution de Montpellier (ISEM)BioDICée TeamCNRSUniversité de MontpellierMontpellierFrance
| | - Egbert H. van Nes
- Department of Aquatic Ecology and Water Quality ManagementWageningen UniversityP.O. Box 47NL‐6700 AAWageningenThe Netherlands
| | - Jordi Bascompte
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichWinterthurerstrasse 190CH‐8057ZurichSwitzerland
| | - Marten Scheffer
- Department of Aquatic Ecology and Water Quality ManagementWageningen UniversityP.O. Box 47NL‐6700 AAWageningenThe Netherlands
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Rath KM, Maheshwari A, Rousk J. Linking Microbial Community Structure to Trait Distributions and Functions Using Salinity as an Environmental Filter. mBio 2019; 10:e01607-19. [PMID: 31337729 DOI: 10.1128/mBio.01607-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The structure and function of microbial communities vary along environmental gradients; however, interlinking the two has been challenging. In this study, salinity was used as an environmental filter to study how it could shape trait distributions, community structures, and the resulting functions of soil microbes. The environmental filter was applied by salinizing nonsaline soil (0 to 22 mg NaCl g-1). Our targeted community trait distribution (salt tolerance) was determined with dose-response relationships between bacterial growth and salinity. The bacterial community structure responses were resolved with Illumina 16S rRNA gene amplicon sequencing, and the microbial functions determined were respiration and bacterial and fungal growth. Salt exposure quickly resulted in filtered trait distributions, and stronger filters resulted in larger shifts. The filtered trait distributions correlated well with community composition differences, suggesting that trait distribution shifts were driven at least partly by species turnover. While salt exposure decreased respiration, microbial growth responses appeared to be characterized by competitive interactions. Fungal growth was highest when bacterial growth was inhibited by the highest salinity, and it was lowest when the bacterial growth rate peaked at intermediate salt levels. These findings corroborated a higher potential for fungal salt tolerance than bacterial salt tolerance for communities derived from a nonsaline soil. In conclusion, by using salt as an environmental filter, we could interlink the targeted trait distribution with both the community structure and resulting functions of soil microbes.IMPORTANCE Understanding the role of ecological communities in maintaining multiple ecosystem processes is a central challenge in ecology. Soil microbial communities perform vital ecosystem functions, such as the decomposition of organic matter to provide plant nutrition. However, despite the functional importance of soil microorganisms, attribution of ecosystem function to particular constituents of the microbial community has been impeded by a lack of information linking microbial processes to community composition and structure. Here, we apply a conceptual framework to determine how microbial communities influence ecosystem processes, by applying a "top-down" trait-based approach. By determining the dependence of microbial processes on environmental factors (e.g., the tolerance to salinity), we can define the aggregate response trait distribution of the community, which then can be linked to the community structure and the resulting function performed by the microbial community.
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Soininen EM, Henden J, Ravolainen VT, Yoccoz NG, Bråthen KA, Killengreen ST, Ims RA. Transferability of biotic interactions: Temporal consistency of arctic plant-rodent relationships is poor. Ecol Evol 2018; 8:9697-9711. [PMID: 30386568 PMCID: PMC6202721 DOI: 10.1002/ece3.4399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/29/2018] [Accepted: 07/02/2018] [Indexed: 01/13/2023] Open
Abstract
Variability in biotic interaction strength is an integral part of food web functioning. However, the consequences of the spatial and temporal variability of biotic interactions are poorly known, in particular for predicting species abundance and distribution. The amplitude of rodent population cycles (i.e., peak-phase abundances) has been hypothesized to be determined by vegetation properties in tundra ecosystems. We assessed the spatial and temporal predictability of food and shelter plants effects on peak-phase small rodent abundance during two consecutive rodent population peaks. Rodent abundance was related to both food and shelter biomass during the first peak, and spatial transferability was mostly good. Yet, the temporal transferability of our models to the next population peak was poorer. Plant-rodent interactions are thus temporally variable and likely more complex than simple one-directional (bottom-up) relationships or variably overruled by other biotic interactions and abiotic factors. We propose that parametrizing a more complete set of functional links within food webs across abiotic and biotic contexts would improve transferability of biotic interaction models. Such attempts are currently constrained by the lack of data with replicated estimates of key players in food webs. Enhanced collaboration between researchers whose main research interests lay in different parts of the food web could ameliorate this.
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Affiliation(s)
| | | | | | | | | | | | - Rolf A. Ims
- UiTThe Arctic University of NorwayTromsøNorway
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Abstract
In the face of global biodiversity declines, predicting the fate of biological systems is a key goal in ecology. One popular approach is the search for early warning signals (EWSs) based on alternative stable states theory. In this review, we cover the theory behind nonlinearity in dynamic systems and techniques to detect the loss of resilience that can indicate state transitions. We describe the research done on generic abundance-based signals of instability that are derived from the phenomenon of critical slowing down, which represent the genesis of EWSs research. We highlight some of the issues facing the detection of such signals in biological systems - which are inherently complex and show low signal-to-noise ratios. We then document research on alternative signals of instability, including measuring shifts in spatial autocorrelation and trait dynamics, and discuss potential future directions for EWSs research based on detailed demographic and phenotypic data. We set EWSs research in the greater field of predictive ecology and weigh up the costs and benefits of simplicity vs. complexity in predictive models, and how the available data should steer the development of future methods. Finally, we identify some key unanswered questions that, if solved, could improve the applicability of these methods.
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Affiliation(s)
- Christopher F Clements
- School of Biosciences, The University of Melbourne, Parkville, Vic., 3010, Australia.,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, 8057, Switzerland
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, 8057, Switzerland
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Kadowaki K, Barbera CG, Godsoe W, Delsuc F, Mouquet N. Predicting biotic interactions and their variability in a changing environment. Biol Lett 2016; 12:rsbl.2015.1073. [PMID: 27220858 DOI: 10.1098/rsbl.2015.1073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/27/2016] [Indexed: 11/12/2022] Open
Abstract
Global environmental change is altering the patterns of biodiversity worldwide. Observation and theory suggest that species' distributions and abundances depend on a suite of processes, notably abiotic filtering and biotic interactions, both of which are constrained by species' phylogenetic history. Models predicting species distribution have historically mostly considered abiotic filtering and are only starting to integrate biotic interaction. However, using information on present interactions to forecast the future of biodiversity supposes that biotic interactions will not change when species are confronted with new environments. Using bacterial microcosms, we illustrate how biotic interactions can vary along an environmental gradient and how this variability can depend on the phylogenetic distance between interacting species.
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Affiliation(s)
- Kohmei Kadowaki
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan Institut des Sciences de l'Evolution, UMR 5554, Université de Montpellier, CNRS, IRD, EPHE, CC 065, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Claire G Barbera
- Institut des Sciences de l'Evolution, UMR 5554, Université de Montpellier, CNRS, IRD, EPHE, CC 065, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - William Godsoe
- BioProtection Research Centre, Lincoln University, Lincoln, Canterbury, New Zealand
| | - Frédéric Delsuc
- Institut des Sciences de l'Evolution, UMR 5554, Université de Montpellier, CNRS, IRD, EPHE, CC 065, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Nicolas Mouquet
- Institut des Sciences de l'Evolution, UMR 5554, Université de Montpellier, CNRS, IRD, EPHE, CC 065, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France MARBEC (MARine Biodiversity Exploitation and Conservation), UMR IRD-CNRS-UM-IFREMER 9190, Université Montpellier, CC 093, 34095 Montpellier Cedex 5, France
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Abstract
Understanding, modeling, and predicting the impact of global change on ecosystem functioning across biogeographical gradients can benefit from enhanced capacity to represent biota as a continuous distribution of traits. However, this is a challenge for the field of biogeography historically grounded on the species concept. Here we focus on the newly emergent field of functional biogeography: the study of the geographic distribution of trait diversity across organizational levels. We show how functional biogeography bridges species-based biogeography and earth science to provide ideas and tools to help explain gradients in multifaceted diversity (including species, functional, and phylogenetic diversities), predict ecosystem functioning and services worldwide, and infuse regional and global conservation programs with a functional basis. Although much recent progress has been made possible because of the rising of multiple data streams, new developments in ecoinformatics, and new methodological advances, future directions should provide a theoretical and comprehensive framework for the scaling of biotic interactions across trophic levels and its ecological implications.
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