Abstract
Ecology is usually very good in making descriptive explanations of what is observed, but is often unable to make predictions of the response of ecosystems to change. This has implications in a human-dominated world where a suite of anthropogenic stresses are threatening the resilience and functioning of ecosystems that sustain mankind through a range of critical regulating and supporting services. In ecosystems, cause-and-effect relationships are difficult to elucidate because of complex networks of negative and positive feedbacks. Therefore, being able to effectively predict when and where ecosystems could pass into different (and potentially unstable) new states is vitally important under rapid global change. Here, we argue that such better predictions may be reached if we focus on organisms instead of species, because organisms are the principal biotic agents in ecosystems that react directly on changes in their environment. Several studies show that changes in ecosystems may be accurately described as the result of changes in organisms and their interactions. Organism-based theories are available that are simple and derived from first principles, but allow many predictions. Of these we discuss Trait-based Ecology, Agent Based Models, and Maximum Entropy Theory of Ecology and show that together they form a logical sequence of approaches that allow organism-based studies of ecological communities. Combining and extending them makes it possible to predict the spatiotemporal distribution of groups of organisms in terms of how metabolic energy is distributed over areas, time, and resources. We expect that this “Organism-based Ecology” (OE) ultimately will improve our ability to predict ecosystem dynamics.
1. Introduction
Natural ecosystems across the biosphere are increasingly being damaged or destroyed by a suite of anthropogenic processes, including deforestation, over-harvesting of plants and animals, agricultural intensification, pollution, invasive plants and animals, and climate change [–]. As a result, significant declines of biodiversity are being reported [, ]. The implications of global environmental changes and the loss of biodiversity for the structure of communities and the functioning of ecosystems are being widely discussed and debated [, ]. However, given that ecological responses are highly contingent, i.e., depending on location and time, ecology is often unable to accurately predict the response of ecosystems to change [–]. This is essential if we are to take remedial measures before critical tipping points are passed []. So, we not only need to know what will change, but also the mechanisms through which communities and ecosystems will change.
In the past, the amount of data that could be collected and analyzed has limited our ability to study ecosystems. After all, during one season, the properties of only a restricted number of organisms could be assessed in the field by one person, as could the population size of only a small number of species, or the state values of only a few abiotic factors. This is changing thanks to automatic data collection techniques and enlarged computer capacity ([, , ]; Appendix 1 in Supplementary material). We are now in the position that we can re-evaluate our need for data and develop new avenues of research. The ability of collecting more data and interpreting them with new technology will be helpful in many ways, but the question remains how to produce better predictions in ecology. We regard as “better predictions,” predictions of the empirical changes in ecosystems that are more accurate over larger spatial and longer time scales. We agree with Marquet et al. [] that, although more and better data are important, they can only result in better predictions of ecosystems changes when they are analyzed based on well-established concepts and theories. In this paper, we focus on predictions of the biotic part of ecosystems, that is the community (see Table 1 for our definitions of concepts), and suggest that better predictions of community behavior may be reached when we take organisms as fundamental units rather than species. For organisms “efficient theories,” i.e., theories that are simple, parsimonious, derived from first principles, quantitative, and mathematical, with few inputs and many predictions, are available, which is not true for species []. We will (1) argue that a shift in main emphasis from species to organisms is theoretically justified, and (2) show that such a shift has great theoretical and practical prospects for producing better predictions of the changes in communities.
Table 1
| Organism | A living entity that, limited by its genotype and experience, strives to survive and reproduce. Organisms are goal-oriented in the teleonomic sense of the word [–]. |
| Population | The set of organisms in a community that belong to the same taxon, usually a species. |
| Community | The complete set of organisms that live within a specific area during a specific time period []. A community is always part of an ecosystem. For practical reason, the “complete set of organisms” is usually limited to a high-level taxonomic unit, such as all higher plants or all birds. |
| Ecosystem | A predefined spatiotemporal unit, that is a specific area during a specific time period, that contains organisms and the energy, materials, fluxes, and processes that enable organisms to survive and reproduce in it []. |
| Operational Ecological Unit (OEU) | A set of organisms that are ecologically alike, that is a set of organisms that all have properties that lie in the same predefined trait value range for a predefined, limited set of traits. |
| Organism-Species-Community-based Ecology (OSCE) | The ecology that defines a population as a set of organisms, a community as a set of species, and a meta-community as a set of communities. |
| Organism-based Ecology (OE) | The ecology that defines not only populations, but also communities and sets of communities as sets of organisms []. |
| Trait-based Ecology (TE) | Ecology that focuses on the effect of differences in trait values among organisms []. In plant ecology it is also known as focusing on functional diversity []. |
| Agent-based Model (ABM) | A model designed to simulate the development of a population or community, based on the properties of individual organisms, locations and time [], previously also called individual-based model [–]. |
| Maximum Entropy Theory of Ecology (METE) | An ecological theory for generating unbiased null-models for communities with a limited number of constrains based on the first principle that in a system that is in equilibrium, particles will be distributed such that maximum information entropy will be reached. In ecology, the individual organisms are regarded as the particles and the theory describes for a community, among others, the distribution of organisms over species, metabolic requirement, and space []. |
Glossary of the key concepts.
2. The organism is the agent of ecology
In ecological literature, a population is usually defined as the set of organisms that belong to the same species, a community as the set of species, and a meta-community as the set of communities []. So, the organism is the entity that defines a population, the species that of a community, and the community that of a meta-community. This step-wise approach, which we could call “Organism-Species-Community-based Ecology” (OSCE; Table 1), has long proven to be successful as a conceptual approach. OSCE has led to our present body of knowledge on populations, communities, and meta-communities and our ability to explain many ecological phenomena and patterns. But OSCE has not succeeded in reaching the better predictions of community and ecosystem dynamics we need.
A stronger emphasis on organisms may help alleviating this lack of predictability. Organisms are fundamentally different from populations and communities, because an organism is a living entity that has an organized structure, maintains homeostasis, and can act opportunistically. To do that, it collects information of its surroundings and its past successes and failures. Organisms react directly to each other and to their environment in order to increase the chance that they will survive or participate in the reproduction. In this teleonomic sense they are goal-oriented, which cannot be said for populations and communities []. Organisms are therefore the principal agents in both populations and communities [–, –]. Or, as DeAngelis and Grimm [] paraphrased Dobzhansky “Nothing makes sense in ecology except in the light of the individual.” This can also be recognized in the definitions of ecology that one can find in handbooks: they essentially all start by stating that ecology is the study of the interactions among organisms and their environment. Importantly, the definitions are never about species or communities, such as [–]. In light of these definitions, it is remarkable that so much of ecology is about species, and not organisms []. Even more so when one realizes that a species is a taxonomic unit, not an ecological one.
Organisms can react on changes in their direct biotic and abiotic environment by changes in their metabolism, physiology, appearance, and behavior. These changes can be measured by assessing the distribution of organisms in space and time, and/or by assessing their properties, i.e., their internal or external trait values. Importantly, these changes are individual and fast as compared to changes in populations or communities. For example, measurements of stable isotope ratios of water in tree xylem allowed detecting the impacts of salinization on diminishing the resilience of salinity-intolerant trees up to 25 years before the glycophytic trees were actually threatened with a regime shift to halophytic ones [, ]. This kind of early detection provides critical lead time and valuable information for planning mitigation against the adverse impacts of, in this case, sea level rise and climate change. Furthermore, the example shows that the time scale of an organism-based study may be quite different from that of a species-based study of the same system.
Therefore, we postulate that studying the reactions of organisms to environmental changes may be a fruitful strategy when aiming to predict the functioning of communities and meta-communities. We follow Gouveia et al. [] in calling this “Organism-based Ecology” (OE). The above quote of DeAngelis and Grimm [] points out that in much ecological literature “individual” seems to be equivalent to “organism.” The individual is usually regarded as the smallest indivisible entity, irrespective of it being a goal-oriented entity or not. We prefer to use “organism” because we like to stress that the organism is the largest biotic entity that shows goal-orientation [, ].
3. Exploring the prospects of Organism-based Ecology (OE)
Because population biology is traditionally built on individual organisms as the basic research unit, most of traditional population ecology is OE, or rather it should be [, ]. But are community and meta-community studies also possible with organisms as basic units? In other words, can spatiotemporal patterns, which are now being explained with species and communities, also be explained at the organismal level? And, more importantly, can changes in communities and meta-communities also be predicted based on organisms? We think that the references we cited in the previous section have convincingly shown that better predictions can be expected, but that does not mean that we think that OE will always succeed. Much would already be gained if we could learn which community changes can be predicted and which not, and what would be the best way to do so. For that it is important that a consistent organism-based approach is chosen in all steps of a study, from the data collection and exploration, to the identification of potential mechanisms, and the statistical analysis of the data that results in predictions. A tentative procedure for that can be found in Figure 1, which combines three existing approaches that are all essential organism-based: Trait-based Ecology (TE), Agent-based Models (ABMs), and Maximum Entropy Theory of Ecology (METE).
Figure 1
When a community or meta-community is described as a set of organisms, our prediction task becomes essentially the estimation of the distribution in space and time of the future set of organism Ct+1 from the present set of organisms Ct and the expected changes in the state of the ecosystem. While Ct changes axiomatically into Ct+1 as result of birth, death, immigration, and emigration, the distribution of trait values over the organisms of Ct changes into that of Ct+1 because of selection (sensu Vellend []) and migration, including the stochastic effects of these processes. In essence, selection means that the organisms within a spatiotemporal set differ among themselves in their ability to survive and reproduce, and that the distribution of this ability changes from set Ct to future set Ct+1 as a consequence of changing biotic and abiotic factors [].
For clarity, we constrain the discussion on the causes of changes in selection and migration, to two types: (1) as being the result of changing abiotic factors, and (2) as being the result of changing interactions between organisms. We describe how the exploration of data, the study of mechanisms, the development of statistical models, and the applications of these models may be different between OSCE and OE.
3.1. Exploring data
It is common knowledge that the composition of a community in terms of properties of organism may change due to the change of abiotic factors. A well-known example of an organismic change in a community as a result of human activity is the decrease of body size of fish due to fishery []. Another example is the change in the relative size of body appendages of endotherms, such as bills, ears, and tails, due to climate change. The change is thought to be related to body cooling and has been observed both among and within species []. Both these examples could be regarded as examples of Trait-based Ecology (TE), ecology that focuses on the effect of differences in trait values among organisms []. TE has already a rich history, both in plant and animal ecology (Appendix 1). The exploration of trait distribution in communities, independent of species, could improve our ability to predict the community's biomass yield and resource use, as Fontana et al. [] did in their organism-based phytoplankton study.
To illustrate how an organism-based approach may improve predictions, we explore the changes in migratory birds in North America (Appendix 2 in Supplementary material). We chose this example because Weeks et al. [] provided an easily accessible, consistently measured, and extensive dataset of trait values of individual organisms belonging to many different species and measured over many years. Such datasets are extremely rare. Using an organism-based approach, i.e., when taxonomic association of the birds was ignored, resulted in models that were reliable, while models with species information included were overfitted. We found that since 2000 the changes in body size differed from those before 2000, especially in hatchlings, and that wing length changed before 2000 only in the birds that are older than hatchlings (Figure 2), a pattern that could not be discovered with species information included in the analysis. Moreover, this illustrates that when organisms are grouped as done by Weeks et al., that is according to age, viz hatchlings vs. older birds, meaningful ecological information is gained. We propose to call these kinds of trait groups, such as hatchlings and older birds, “Operational Ecological Units” (OEU) and thus revitalize the term of Hendrickson and Ehrlich [] under a slightly new definition: an OEU is here regarded as a set of organisms that are ecologically alike, i.e., they all have properties that lie in the same predefined trait value range for a predefined, limited set of traits (Table 1). An OEU differs from a population in that its members do not need to belong to the same taxon, nor is it necessary to include all individuals of a taxon. OEUs enable the study of the differences and interactions between functional, but taxon independent, groups of organisms.
Figure 2
Organism- and species-based approaches differ in how they treat biotic interactions. Interactions among organisms are local, that is organisms interact only with other organisms in their direct surroundings [
3.2. Exploring mechanisms
This is not the place to go into the discussion on mechanisms vs. statistical models (see [
ABMs are tailored at simulating organism-based processes [
In plant ecology, ABMs for population and community-level modeling have been developed largely independently from functional–structural plant models (FSPMs: models that describe the individual plant as build up out of modules, or metamers; Appendix 1). FSPMs and ABMs occupy a continuum of spatial and mechanistic detail. For example, plant growth rates are described by allometric equations that are individual-based in the LANDIS model [
In animal ecology, it has become possible to include pursuit and aversion behavior of organisms in ABMs by combining existing theories of foraging and avoidance of competition and danger, such as predation or traps [
Giacomini et al. [
ABMs may contain large numbers of parameters, and the question has been raised concerning whether the uncertainty in these parameters may propagate, resulting in model outcomes with great uncertainty [
When successful, simulations with ABMs meet the standards of pattern-oriented modeling. That is, they will agree reasonably well with at least a few empirical patterns in the system being modeled, so that it can be assumed that the underlying mechanisms are correctly represented in the model [
3.3. Exploring statistical models
A welcome advantage of OE is that it transforms communities and meta-communities from relatively “middle-number systems,” with a limited number of units (species or communities), into relatively “large-number systems,” with a large number of units (organisms), without the need to change the level of spatiotemporal scale [
The Maximum Entropy Theory of Ecology (METE) is a statistical tool to describe large-number communities as probability distribution models [
Figure 3

Results of the METE-analysis of the metabolic rate of North American migration birds. Lines are the predicted changes in (A) residuals of the METE predicted metabolic rate ignoring body size and (B) including the difference between small and large birds. Green lines are hatchlings, blue lines older birds, solid lines are large (≥5 g), and dashed lines small birds. Predictions were made with linear models, lm() in R version 4.0.3 [
In the current METE, probability distributions of commonality are available [
It may seem that the strictly statistical approach of METE is at odds with our previous statement that the organism is the agent of ecology. For METE, organisms behave like neutral particles, i.e., like particles that are all equivalent and have no differences in trait values, which is certainly not the case, as explained above. But application of METE can be defended because neutral behavior can be regarded as being an adequate proxy of the emergent behavior of a large set of organisms with different properties, that each react differently on many different local factors and on each other to achieve the common goal of sufficient fitness [
3.4. Exploring applications
Above we have described what we think it could mean to apply OE. We think that OE could start with combining existing ecological fields, such as TE, ABM, and METE (Figure 1). Because these existing fields are well-established in ecology, the development of each of them has resulted in a tradition in focus communities, sets of concepts, mathematical description, and research schools, for example [
An important question still to be answered is whether OE can provide predictions that are needed for nature conservation in a changing world. After all, good examples of organism-based field studies of eukaryote communities are still rare (Table 2). Some of the theories for organisms discussed above provide such predictions. For example, the MTE allows for the correction of body sizes and metabolic rates for temperature changes. And the adaptive foraging theory of Beckerman et al. [
Table 2
| Community | Results | References | |
|---|---|---|---|
| Microbes | Soil microbes | Microbe activity diversity depends on spatial and temporal environment heterogeneity | [ |
| Plants | Phytoplankton | Trait evenness is the most important predictor of community productivity | [ |
| Trees | Tree species diversity is explained by competition between organisms, not between species | [ | |
| Trait values relate to organismal growth rates, and these relationships depend on the environment of the organism | [ | ||
| Individual adaptation to sea level change affects interaction between vegetation types, which feedbacks to ground water salinity changes | [ | ||
| Animals | Arthropods | Abundance of arthropods may or may not depend on interactions between ecological type, body size, and local factors, but depends always on landscape complexity around sampling sites | [ |
| Fish | Body size decreases with increased fishery | [ | |
| Migratory birds | Temporal changes in metabolic rate depend on the age, sex, and body size of the organisms | Appendix 2 | |
| Endotherms | Sizes of body appendages change in response to climate change | [ |
Examples of empirical organism-based studies of communities.
4. Species diversity
The human fascination with and commitment to understanding species richness is so deep, that it often seems the reason why we are studying ecology in the first place [
5. Conclusions
With the growing evidence that human activities are reducing biodiversity at an accelerating rate, it becomes vital to predict their impacts on the functioning of communities and ecosystems. Accurate ecological predictions are a vital tool for alerting policy-makers and land managers about future scenarios with profoundly important societal consequences [
Statements
Data availability statement
Publicly available datasets were analyzed in this study. This data can be found at: Dryad Digital Repository: https://doi.org/10.5061/dryad.8pk0p2nhw.
Author contributions
CM and GS conceived the ideas. CM performed the statistical analyses and wrote the drafts. DD, JH, WM, and PB added to the ideas, improved and sharpened them, contributed critically to the drafts, and gave final approval for publication. All authors contributed to the article and approved the submitted version.
Funding
DD was supported by Greater Everglades Priority Ecosystem Science program.
Acknowledgments
We would like to thank James McAllister and Ellen Cieraad for the stimulating discussions and the reviewers for their helpful comments. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
Supplementary material
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fams.2023.1046185/full#supplementary-material
References
1.
CrutzenPJ. The “anthropocene”. In: Earth System Science in the Anthropocene. Berlin: Springer Verlag (2006). p. 13–8. 10.1007/3-540-26590-2_3
2.
SalafskyNSalzerDStatterfieldAJHilton-TaylorCNeugartenRButchart SHM etal. A standard lexicon for biodiversity conservation: Unified classifications of threats and actions. Conserv Biol. (2008) 22:897–911. 10.1111/j.1523-1739.2008.00937.x
3.
StoateCBáldiABejaPBoatmanNDHerzonIde Snoo GR etal. Ecological impacts of early 21st century agricultural change in Europe. A review. J Environ Manag. (2009) 91:22–46. 10.1016/j.jenvman.2009.07.005
4.
MorrisRJ. Anthropogenic impacts on tropical forest biodiversity: A network structure and ecosystem functioning perspective. Proc R Soc B. (2010) 365:3709–18. 10.1098/rstb.2010.0273
5.
EllisEC. Anthropogenic transformation of the terrestrial biosphere. Proc R Soc B. (2011) 369:1010–35. 10.1098/rsta.2010.0331
6.
LewisSLMaslinMA. Defining the anthropocene. Nature. (2015) 519:171–80. 10.1038/nature14258
7.
DirzoRYoungHSGalettiMCeballosGIsaacNJBCollenB. Defaunation in the anthropocene. Science. (2014) 345:401–6. 10.1126/science.1251817
8.
CeballosGEhrlichPRBarnoskyADGarcíaAPringleRMPalmerTM. Accelerated modern human–induced species losses: Entering the sixth mass extinction. Sci Adv. (2015) 1:e1400253. 10.1126/sciadv.1400253
9.
SrivastavaDSVellendM. Biodiversity-ecosystem function research: Is it relevant to conservation?Annu Rev Ecol Evol Syst. (2005) 36:267–94. 10.1146/annurev.ecolsys.36.102003.152636
10.
EisenhauerNBarnesADCesarzSCravenDFerlianOGottschall F etal. Biodiversity–ecosystem function experiments reveal the mechanisms underlying the consequences of biodiversity change in real world ecosystems. J Veget Sci. (2016) 27:1061–70. 10.1111/jvs.12435
11.
LawtonJH. Are there general laws in ecology?Oikos. (1999) 84:177–92. 10.2307/3546712
12.
PetersRH. A Critique for Ecology. Cambridge: Cambridge University Press (1991).
13.
CoreauAPinayGThompsonJDCheptouPOMermetL. The rise of research on futures in ecology: Rebalancing scenarios and predictions. Ecol Lett. (2009) 12:1277–86. 10.1111/j.1461-0248.2009.01392.x
14.
BellardCBertelsmeierCLeadleyPThuillerWCourchampF. Impacts of climate change on the future of biodiversity. Ecol Lett. (2012) 15:365–77. 10.1111/j.1461-0248.2011.01736.x
15.
EvansMRBithellMCornellSJDallSRXDíazSEmmott S etal. Predictive systems ecology. Proc R Soc B. (2013) 280:20131452. 10.1098/rspb.2013.1452
16.
ThuillerWLavergneSRoquetCBoulangeatILafourcadeBAraujoMBet al. Road map for integrating eco-evolutionary processes into biodiversity models. Ecol Lett. (2013) 16:94–105. 10.1111/ele.12104
17.
HarfootMTittensorDPNewboldTMcInernyGSmithMJScharlemannJPW. Integrated assessment models for ecologists: The present and the future. Glob Ecol Biogeogr. (2014) 23:124–43. 10.1111/geb.12100
18.
MouquetNLagadeucYDevictorVDoyenLDuputiéAEveillardDet al. Predictive ecology in a changing world. J Appl Ecol. (2015) 52:1293–310. 10.1111/1365-2664.12482
19.
GreenSJBrooksonCBHardyNACrowderLB. Trait-based approaches to global change ecology: Moving from description to prediction. Proc R Soc B. (2022) 289:20220071. 10.1098/rspb.2022.0071
20.
MaurerBA. Untangling Ecological Complexity. The Macroscopic Perspective. Chicago, IL: The University of Chicago Press (1999).
21.
EvansMRGrimmVJohstKKnuuttilaTde LangheRLessellsCMet al. Do simple models lead to generality in ecology?Tree. (2013) 28:578–83. 10.1016/j.tree.2013.05.022
22.
DakosVMatthewsBHendryALevineJLoeuilleNNorberg J etal. Ecosystem tipping points in an evolving world. Nat Ecol Evol. (2019) 3:355–62. 10.1038/s41559-019-0797-2
23.
SimberloffD. Community ecology: Is it time to move on?Am Nat. (2004) 163:787–99. 10.1086/420777
24.
ReichsteinMCamps-VallsGStevensBJungMDenzlerJCarvalhaisNet al. Deep learning and process understanding for data-driven Earth system science. Nature. (2019) 566:195–204. 10.1038/s41586-019-0912-1
25.
MarquetPAAllenAPBrownJHDunneJAEnquistBJGilloolyJFet al. On theory in ecology. Bioscience. (2014) 64:701–10. 10.1093/biosci/biu098
26.
AllenTFHHoekstraTW. Toward a Unified Ecology. 2nd Ed. New York, NY: Columbia University Press (2015). 10.7312/alle06918
27.
ThompsonNS. The misappropriation of teleonomy. Perspect Ethol. (1987) 7:259–74. 10.1007/978-1-4613-1815-6_10
28.
Godfrey-SmithP. Philosophy of Biology. Princeton, NJ: Princeton University Press (2014).
29.
BlewRD. On the definition of ecosystem. Bullet Ecol Soc Am. (1996) 1996:171–3. 10.2307/20168067
30.
GouveiaSFRubalcabaJGSoukhovolskyVTarasovaOBarbosaAMRealR. Ecophysics reload exploring applications of theoretical physics in macroecology. Ecol Modell. (2020) 424:109032. 10.1016/j.ecolmodel.2020.109032
31.
BolnickDIAmarasekarePAraújoMSBürgerRLevineJMNovakMet al. Why intraspecific trait variation matters in community ecology. Tree. (2011) 26:183–92. 10.1016/j.tree.2011.01.009
32.
GarnierENavasM-LGrigulisK. Plant Functional Diversity. Organism Traits, Community Structure, and Ecosystem Properties. Oxford: Oxford University Press (2016).
33.
DeAngelisDLDiazSG. Decision-making in Agent-Based Modeling: A current review and future prospectus. Front Ecol Evol. (2019) 6:237. 10.3389/fevo.2018.00237
34.
GrimmVRailsbackSF. Individual-Based Modelling and Ecology. Princeton, NJ: Princeton University Press (2005). 10.1515/9781400850624
35.
DeAngelisDLMooijWM. Individual-based models in ecology and evolutionary processes. Annu Rev Ecol Evol Syst. (2005) 36:147–68. 10.1146/annurev.ecolsys.36.102003.152644
36.
DeAngelisDLGrimmV. Individual-based models in ecology after four decades. F1000Prime Rep. (2014) 6:39. 10.12703/P6-39
37.
HarteJ. Maximum Entropy and Ecology. Oxford: Oxford University Press (2011).
38.
ŁomnickiA. Population Ecology of Individuals.Princeton, NJ: Princeton University Press (1988).
39.
MahnerMBungeM. Foundations of Biophilosophy. Heidelberg: Springer (1997). 10.1007/978-3-662-03368-5
40.
JagersOPAkkerhuisGAJM. Towards a hierarchical definition of life, the organism and death. Found Sci. (2010) 15:245–62. 10.1007/s10699-010-9177-8
41.
GrimmVAyllónDRailsbackSF. Next-generation Individual-Based Models integrate biodiversity and ecosystems: Yes we can, and yes we must. Ecosystems. (2017) 20:229–36. 10.1007/s10021-016-0071-2
42.
KnightCB. Basic Concepts of Ecology. New York, NY: The MacMillan Company (1965).
43.
KrebsCJ. Ecology: The Experimental Analysis of Distribution and Abundance. 2nd Ed. New York, NY: Harper and Row Publishers (1978).
44.
OdumEPBarrettGW. Fundamentals of Ecology. 5th Ed. Independence: Thomson Brooks/Cole (2005).
45.
BegonMTownsendCRHarperJL. Ecology. From Individuals to Ecosystems. 4th Ed. Hoboken, NJ: Blackwell Publishing (2005).
46.
JohnstonASABoydRJWatsonJWPaulAEvansLCGardnerELet al. Predicting population responses to environmental change from organismal level mechanisms: Towards a standardized mechanistic approach. Proc R Soc B. (2019) 286:20191916. 10.1098/rspb.2019.1916
47.
ZhaiLJiangJDeAngelisDLda Silveira Lobo SternbergL. Prediction of plant vulnerability to salinity increase in a coastal ecosystem by stable isotope composition (δ18O) of plant stem water: A model study. Ecosystems. (2016) 19:32–49. 10.1007/s10021-015-9916-3
48.
SubediSCSternbergLDeAngelisDLRossMSOgurcakDE. Using carbon isotope ratios to verify predictions of a model simulating the interaction between coastal plant communities and their effect on ground water salinity. Ecosystems. (2020) 23:570–85. 10.1007/s10021-019-00423-4
49.
VahlWK. Interference Competition Among Foraging Waders. (Dissertation), University of Groningen, Groningen, Netherlands (2006).
50.
VellendM. The Theory of Ecological Communities. Monographs in Population Biology. Princeton, NJ: Princeton University Press (2016). p. 57.
51.
OkashaS. Evolution and the Levels of Selection. Oxford: Oxford University Press (2006). 10.1093/acprof:oso/9780199267972.001.0001
52.
HeinoMDíaz PauliBDieckmannU. Fisheries-induced evolution. Annu Rev Ecol Evol Syst. (2015) 46:461–8. 10.1146/annurev-ecolsys-112414-054339
53.
RydingSKlaassenMTattersallGJGardnerJLSymondsMRE. Shape-shifting: Changing animal morphologies as a response to climatic warming. Tree. (2021) 7:6. 10.1016/j.tree.2021.07.006
54.
FontanaSThomasMKMoldoveanuMSpaakPPomatiF. Individual-level trait diversity predicts phytoplankton community properties better than species richness or evenness. ISME J. (2018) 12:356–66. 10.1038/ismej.2017.160
55.
WeeksBCWillardDEZimovaMEllisAAWitynskiMLHennenMet al. Shared morphological consequences of global warming in North American migratory birds. Ecol Lett. (2020) 23:316–25. 10.1111/ele.13434
56.
R Core Team. R: A Language and Environment for Statistical Computing. Vienna: R Foundation for Statistical Computing (2020).
57.
HendricksonJAEhrlichPR. An expanded concept of “Species diversity”. Notulae Naturae. (1971) 439:1–6.
58.
HustonMDeAngelisDLPostW. New computer models unify ecological theory. Bioscience. (1988) 38:682–91. 10.2307/1310870
59.
BergerUPiouPSchiffersKGrimmV. Competition among plants: Concepts, individual-based modelling approaches, and a proposal for a future research strategy. Perspect Plant Ecol Evol Syst. (2008) 9:121–35. 10.1016/j.ppees.2007.11.002
60.
JeltschFGrimmVReegJSchlägelUE. Give chance a chance: From coexistence to coviability in biodiversity theory. Ecosphere. (2021) 10:e02700. 10.1002/ecs2.2700
61.
UpadhyayaSKLamichhaneBRMustersCJMSubediNde SnooGRThapaPet al. Activity patterns of co-existing tigers and leopards. In: SK Upadhyaya , editors, Human-wildlife Interactions in the Western Terai of Nepal. An analysis of factors influencing conflicts between sympatric tigers (Panthera tigris tigris) and leopards (Panthera pardus fusca) and local communities around Bardia National Park, Nepal. (Dissertation), Leiden University, Leiden, Netherlands (2019). p. 27–42.
62.
ClarkJS. Individuals and the variation needed for high species diversity in forest trees. Science. (2010) 327:1129–32. 10.1126/science.1183506
63.
ClarkJSBellDMHershMHKwitMCMoranESalkCet al. Individual-scale variation, species-scale differences: Inference needed to understand diversity. Ecol Lett. (2011) 14:1273–87. 10.1111/j.1461-0248.2011.01685.x
64.
PaineCETBaralotoCChaveJHéraultB. Functional traits of individual trees reveal ecological constraints on community assembly in tropical rain forests. Oikos. (2011) 120:720–7. 10.1111/j.1600-0706.2010.19110.x
65.
LiuXSwensonNGLinDMiXUmañaMNSchmidBet al. Linking individual-level functional traits to tree growth in a subtropical forest. Ecology. (2016) 97:2396–405. 10.1002/ecy.1445
66.
YangJCaoMSwensonNG. Why functional traits do not predict tree demographic rates. Tree. (2018) 33:326–36. 10.1016/j.tree.2018.03.003
67.
ClarkJS. Beyond neutral science. Tree. (2009) 24:8–15. 10.1016/j.tree.2008.09.004
68.
McGillBJNekolaJC. Mechanisms in macroecology: AWOL or purloined letter? Towards a pragmatic view of mechanism. Oikos. (2010) 119:591–603. 10.1111/j.1600-0706.2009.17771.x
69.
GastonKJBlackburnTM. A critique for macroecology. Oikos. (1999) 84:353–68. 10.2307/3546417
70.
PetersRLovelockCLópez-PortilloJBathmannJWimmlerMCJiangJet al. Partial canopy loss of mangrove trees: Mitigating water scarcity by physical adaptation and feedback on porewater salinity. Estuar Coast Shelf Sci. (2021) 248:106797. 10.1016/j.ecss.2020.106797
71.
MladenoffDJ. LANDIS and forest landscape models. Ecol Modell. (2004) 180:7–19. 10.1016/j.ecolmodel.2004.03.016
72.
MaréchauxIChaveJ. An individual-based forest model to jointly simulate carbon and tree diversity in Amazonia: Description and applications. Ecol Monogr. (2017) 87:632–64. 10.1002/ecm.1271
73.
BathmannJPetersRNaumovDFischerFBergerUWaltherM. The MANgrove-GroundwAter feedback model (MANGA) – Describing belowground competition based on first principles. Ecol Modell. (2020) 420:108973. 10.1016/j.ecolmodel.2020.108973
74.
PretzschHGroteRReinekingBRötzerTSeifertS. Models for forest ecosystem management: A European perspective. Ann Bot. (2008) 101:1065–87. 10.1093/aob/mcm246
75.
GallagherAJCreelSWilsonRPCookeSJ. Energy landscapes and the landscape of fear. Tree. (2017) 32:88–96. 10.1016/j.tree.2016.10.010
76.
TeckentrupLGrimmVKramer-SchadtSJeltschF. Community consequences of foraging under fear. Ecol Modell. (2018) 383:80–90. 10.1016/j.ecolmodel.2018.05.015
77.
HeinAMAltshulerDLCadeDELiaoJCMartinBTTaylorGK. An algorithmic approach to natural behavior. Curr Biol. (2020) 30:R663–75. 10.1016/j.cub.2020.04.018
78.
VattiatoGPlankMJJamesABinnyRN. Individual heterogeneity affects the outcome of small mammal pest eradication. Theoret Ecol. (2021) 14:219–31. 10.1007/s12080-020-00491-6
79.
BrownJHGilloollyJFAllenAPSavageVMWestGB. Toward a metabolic theory of ecology. Ecology. (2004) 85:1771–89. 10.1890/03-9000
80.
BuchmannCMSchurrFMNathanRJeltschF. An allometric model of home range formation explains the structuring of animal communities exploiting heterogeneous resources. Oikos. (2011) 120:106–18. 10.1111/j.1600-0706.2010.18556.x
81.
GravesTChandlerRBRoyleJABeierPKendallKC. Estimating landscape resistance to dispersal. Landsc Ecol. (2014) 29:1201–12. 10.1007/s10980-014-0056-5
82.
ZhouJYuKLinGWangZ. Variance in tree growth rates provides a key link for completing the theory of forest size structure formation. J Theor Biol. (2021) 529:110857. 10.1016/j.jtbi.2021.110857
83.
GiacominiHCDeAngelisDLTrexlerJC. Petrere Jr M. Trait contributions to fish community assembly emerge from trophic interactions in an individual-based model. Ecol Model. (2013) 251:32–43. 10.1016/j.ecolmodel.2012.12.003
84.
MooijWMDeAngelisDL. Error propagation in spatially explicit population models: A reassessment. Biol Conserv. (1999) 13:30–3. 10.1046/j.1523-1739.1999.98153.x
85.
DeutschmanDHLevinSAPacalaSW. Error propagation in a forest succession model: The role of fine-scale heterogeneity in light. Ecology. (1999) 80:1927–43. 10.2307/176669
86.
DubéPFortinMJCanhamCDMarceauDJ. Quantifying gap dynamics at the patch mosaic level using a spatially-explicit model of a northern hardwood forest ecosystem. Ecol Modell. (2001) 142:39–60. 10.1016/S0304-3800(01)00238-1
87.
RailsbackSFHarveyBC. Individual-Based Model Formulation for Cutthroat Trout, Little Jones Creek, California. General Technical Report No PSW-GTR-182. Albany, NY: Forest Service, United States Department of Agriculture (2001).
88.
GrimmVRevillaEBergerUJeltschFMooijWMRailsbackSFet al. Pattern-oriented modeling of agent-based complex systems: Lessons from ecology. Science. (2005) 310:987–91. 10.1126/science.1116681
89.
GrimmVBergerUDeAngelisDLPolhillJGGiskeJRailsbackSF. The ODD protocol: A review and first update. Ecol Modell. (2010) 221:2760–8. 10.1016/j.ecolmodel.2010.08.019
90.
Van der VaartEJohnstonASSiblyRM. Predicting how many animals will be where: How to build, calibrate and evaluate individual-based models. Ecol Modell. (2016) 326:113–23. 10.1016/j.ecolmodel.2015.08.012
91.
GrimmVBergerUBastiansenFEliassenSGinotVGiske J etal. A standard protocol for describing individual-based and agent-based models. Ecol Modell. (2006) 198:115–26. 10.1016/j.ecolmodel.2006.04.023
92.
UchmańskiJKowalczykKOgrodowczykP. Evolution of theoretical ecology in last decades: Why did individual-based modelling emerge. Ecol Quest. (2008) 10:13–8. 10.12775/v10090-009-0002-3
93.
StillmanRARailsbackSFGiskeJBergerUGrimmV. Making predictions in a changing world: The benefits of Individual-Based Ecology. Bioscience. (2015) 65:140–50. 10.1093/biosci/biu192
94.
MartinBTJagerTNisbetRMPreussTGGrimmV. Predicting population dynamics from the properties of individuals: A cross-level test of Dynamic Energy Budget theory. Am Nat. (2013) 181:506–19. 10.1086/669904
95.
SutherlandWJFreckletonRPGodfrayHCJBeissingerSRBentonTCameronDDet al. Identification of 100 fundamental ecological questions. J Ecol. (2013) 101:58–67. 10.1111/1365-2745.12025
96.
FravettiM. Maximum entropy theory of ecology: A reply to harte. Entropy. (2018) 20:308. 10.3390/e20050308
97.
BrummerABNewmanEA. Derivations of the core functions of the maximum entropy theory of ecology. Entropy. (2019) 21:712. 10.3390/e21070712
98.
HarteJKitzesJNewmanEARomingerAJ. Taxon categories and the universal species-area relationship (a comment on Šizling et al. “Between Geometry and Biology: The Problem of Universality of the Species-Area Relationship”). Am Natural. (2013) 181:282–7. 10.1086/668821
99.
HarteJNewmanEA. Maximum information entropy: A foundation for ecological theory. Tree. (2014) 29:384–9. 10.1016/j.tree.2014.04.009
100.
HarteJUmemuraKBrushM. DynaMETE: A hybrid MaxEnt-plus-mechanism theory of dynamic macroecology. Ecol Lett. (2021) 24:935–49. 10.1111/ele.13714
101.
DewarRCPortéA. Statistical mechanics unifies different ecological patterns. J Theoret Biol. (2008) 251:389–403. 10.1016/j.jtbi.2007.12.007
102.
HarteJBrushMNewmanEAUmemuraK. An equation of state unifies diversity, productivity, abundance and biomass. Commun Biol. (2022) 5:874. 10.1038/s42003-022-03817-8
103.
WilliamsRJ. Simple MaxEnt models explain food web degree distributions. Theoret Ecol. (2010) 3:45–52. 10.1007/s12080-009-0052-6
104.
CiminiGSquartiniTSaraccoFGarlaschelliDGabrielliACaldarelliG. The statistical physics of real-world networks. Nat. Rev. Phys. (2019) 1:58–71. 10.1038/s42254-018-0002-6
105.
BanvilleFGravelDPoisotT. What constrains food webs? A maximum entropy ramework for predicting their structure with minimal biases. arXiv:2210.03190v1. (2022). 10.48550/arXiv.2210.03190
106.
WilcoxKRKomatsuKJAvolioML. Improving collaborations between empiricists and modelers to advance grassland community dynamics in ecosystem models. N Phytolog. (2020) 228:1467–71. 10.1111/nph.16900
107.
BodelierPLEMeima-FrankeMHordijkCASteenberghAKHeftingMMBodrossyLet al. Microbial minorities modulate methane consumption through niche partitioning. ISME J. (2013) 7:2214–28. 10.1038/ismej.2013.99
108.
MustersCJMEvansTRWiggersJMRvan ‘t-ZelfdeMde SnooGR. Distribution of flying insects across landscapes with intensive agriculture in temperate areas. Ecol. Indic. (2021) 129:107889. 10.1016/j.ecolind.2021.107889
109.
MustersCJMWiggersJMRde SnooGR. Distribution of ground-dwelling arthropods across landscapes with intensive agriculture in temperate areas. Ecol Indic. (2022) 140:109042. 10.1016/j.ecolind.2022.109042
110.
BeckermanAPPetcheyOLWarrenPH. Foraging biology predicts food web complexity. Proc Natl Acad Sci USA. (2006) 37:13745–9. 10.1073/pnas.0603039103
111.
NewmanEAWilberMQKopperKEMoritzMAFalkDAMcKenzieDet al. Disturbance macroecology: A comparative study of community structure metrics in a high-severity disturbance regime. Ecosphere. (2020) 11:e03022. 10.1002/ecs2.3022
112.
BuchmannCMSchurrFMNathanRJeltschF. Habitat loss and fragmentation affecting mammal and bird communities - The role of interspecific competition and individual space use. Ecol Inform. (2013) 14:90–8. 10.1016/j.ecoinf.2012.11.015
113.
McLeanMStuart-SmithRDVillégerSAuberAEdgarGJMacNeilMAet al. Trait similarity in reef fish faunas across the world's oceans. Proc Natl Acad Sci USA. (2021) 12:e2012318118. 10.1073/pnas.2012318118
114.
SutherlandWJFreckletonRP. Making predictive ecology more relevant to policy makers and practitioners. Proc R Soc B. (2012) 367:322–30. 10.1098/rstb.2011.0181
Summary
Keywords
community ecology, organism-based, Operational Ecological Unit, Trait-based Ecology, Agent-based Models, Maximum Entropy Theory of Ecology
Citation
Musters CJM, DeAngelis DL, Harvey JA, Mooij WM, van Bodegom PM and de Snoo GR (2023) Enhancing the predictability of ecology in a changing world: A call for an organism-based approach. Front. Appl. Math. Stat. 9:1046185. doi: 10.3389/fams.2023.1046185
Received
16 September 2022
Accepted
06 January 2023
Published
24 January 2023
Volume
9 - 2023
Edited by
Ivo Siekmann, Liverpool John Moores University, United Kingdom
Reviewed by
Volker Grimm, Helmholtz Association of German Research Centres (HZ), Germany; Erica A. Newman, University of Arizona, United States; Raluca Eftimie, University of Franche-Comté, France; Frank Hilker, Osnabrück University, Germany
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© 2023 Musters, DeAngelis, Harvey, Mooij, van Bodegom and de Snoo.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: C. J. M. Musters ✉ musters@cml.leidenuniv.nl
This article was submitted to Mathematical Biology, a section of the journal Frontiers in Applied Mathematics and Statistics
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