1
|
Barabás G. Parameter Sensitivity of Transient Community Dynamics. Am Nat 2024; 203:473-489. [PMID: 38489777 DOI: 10.1086/728764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
AbstractTransient dynamics have always intrigued ecologists, but current rapid environmental change (inducing transients even in previously undisturbed systems) has highlighted their importance more than ever. Here, I introduce a method for analyzing the sensitivity of transient ecological dynamics to parameter perturbations. The question the method answers is: how would the community dynamics have unfolded for some time horizon had the parameters been slightly different? I apply the method to three empirically parameterized models: competition between native forbs and exotic grasses in California, a host-parasitoid system, and an experimental chemostat predator-prey model. These applications showcase the ecological insights one can gain from models using transient sensitivity analysis. First, one can find parameters and their combinations whose perturbations disproportionately affect a system. Second, one can identify particular windows of time during which the predicted deviation from the unperturbed trajectories is especially large and utilize this information for management purposes. Third, there is an inverse relationship between transient and long-term sensitivities whenever the interacting populations are ecologically similar; paradoxically, the smaller the immediate response of the system, the more extreme its long-term response will be.
Collapse
|
2
|
Levine JI, Pacala SW, Levine JM. Competition for time: Evidence for an overlooked, diversity-maintaining competitive mechanism. Ecol Lett 2024; 27:e14422. [PMID: 38549235 DOI: 10.1111/ele.14422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 02/28/2024] [Accepted: 03/13/2024] [Indexed: 04/02/2024]
Abstract
Understanding how diversity is maintained in plant communities requires that we first understand the mechanisms of competition for limiting resources. In ecology, there is an underappreciated but fundamental distinction between systems in which the depletion of limiting resources reduces the growth rates of competitors and systems in which resource depletion reduces the time available for competitors to grow, a mechanism we call 'competition for time'. Importantly, modern community ecology and our framing of the coexistence problem are built on the implicit assumption that competition reduces the growth rate. However, recent theoretical work suggests competition for time may be the predominant competitive mechanism in a broad array of natural communities, a significant advance given that when species compete for time, diversity-maintaining trade-offs emerge organically. In this study, we first introduce competition for time conceptually using a simple model of interacting species. Then, we perform an experiment in a Mediterranean annual grassland to determine whether competition for time is an important competitive mechanism in a field system. Indeed, we find that species respond to increased competition through reductions in their lifespan rather than their rate of growth. In total, our study suggests competition for time may be overlooked as a mechanism of biodiversity maintenance.
Collapse
Affiliation(s)
- Jacob I Levine
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Stephen W Pacala
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Jonathan M Levine
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| |
Collapse
|
3
|
Otake Y, Yamamichi M, Hirata Y, Odagiri H, Yoshida T. Different photoperiodic responses in diapause induction can promote the maintenance of genetic diversity via the storage effect in Daphnia pulex. Proc Biol Sci 2024; 291:20231860. [PMID: 38351804 PMCID: PMC10865009 DOI: 10.1098/rspb.2023.1860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 01/04/2024] [Indexed: 02/16/2024] Open
Abstract
Understanding mechanisms that promote the maintenance of biodiversity (genetic and species diversity) has been a central topic in evolution and ecology. Previous studies have revealed that diapause can contribute to coexistence of competing genotypes or species in fluctuating environments via the storage effect. However, they tended to focus on differences in reproductive success (e.g. seed yield) and diapause termination (e.g. germination) timing. Here we tested whether different photoperiodic responses in diapause induction can promote coexistence of two parthenogenetic (asexual) genotypes of Daphnia pulex in Lake Fukami-ike, Japan. Through laboratory experiments, we confirmed that short day length and low food availability induced the production of diapausing eggs. Furthermore, we found that one genotype tended to produce diapausing eggs in broader environmental conditions than the other. Terminating parthenogenetic reproduction earlier decreases total clonal production, but the early diapausing genotype becomes advantageous by assuring reproduction in 'short' years where winter arrival is earlier than usual. Empirically parameterized theoretical analyses suggested that different photoperiodic responses can promote coexistence via the storage effect with fluctuations of the growing season length. Therefore, timing of diapause induction may be as important as diapause termination timing for promoting the maintenance of genetic diversity in fluctuating environments.
Collapse
Affiliation(s)
- Yurie Otake
- Department of General Systems Studies, The University of Tokyo, Komaba, Meguro, Tokyo, 153-8902, Japan
| | - Masato Yamamichi
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, 852-8523, Japan
| | - Yuka Hirata
- Department of General Systems Studies, The University of Tokyo, Komaba, Meguro, Tokyo, 153-8902, Japan
| | - Haruka Odagiri
- Department of General Systems Studies, The University of Tokyo, Komaba, Meguro, Tokyo, 153-8902, Japan
| | - Takehito Yoshida
- Department of General Systems Studies, The University of Tokyo, Komaba, Meguro, Tokyo, 153-8902, Japan
- Research Institute for Humanity and Nature, Motoyama, Kamigamo, Kita-ku, Kyoto, 603-8047, Japan
| |
Collapse
|
4
|
Werner CM, Young TP, Stuble KL. Year effects drive beta diversity, but unevenly across plant community types. Ecology 2024; 105:e4188. [PMID: 37877213 DOI: 10.1002/ecy.4188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 05/08/2023] [Accepted: 05/31/2023] [Indexed: 10/26/2023]
Abstract
Year of establishment can be a critical driver of plant communities with the establishment stage of community development particularly susceptible to factors including ambient rain, temperature, and other temporally variable drivers (e.g., seed and seedling predators). However, while year effects have been shown to drive community structure at local (patch) scales, it is yet unexplored how these within-patch effects scale up to drive landscape-level patterns of biodiversity. These dynamics are likely to be critical but are overlooked in many systems including those with high-frequency disturbance regimes or active management. Here we leveraged a series of field-based grassland mesocosms established identically at three sites across 5 years, and each monitored for 4-8 years. We compared the strength of these temporal and spatial drivers (year effects and site effects) on consequent patterns of spatial and temporal variability (beta diversity and turnover) between plots seeded with native perennial species versus those seeded with nonnative annual species. The composition of plots seeded with perennial species showed strong effects of planting year and consequently exhibited higher beta diversity within sites (across mesocosms established in five different years within sites), while plots seeded with annual species had higher between-site variation but low beta diversity within sites. Plots with annual species were also more temporally variable than plots with perennial species. These findings have important implications for our understanding of key drivers of biodiversity across landscapes. Specifically, we showed that variable trajectories in community composition generated by site and year effects during establishment can promote beta diversity across landscapes dominated by perennial species, but are considerably less impactful in annual-dominated systems. These findings further our understanding of the importance of assembly dynamics on landscape-scale patterns of diversity, and have important management implications for restoration efforts.
Collapse
Affiliation(s)
- Chhaya M Werner
- Department of Botany, University of Wyoming, Laramie, Wyoming, USA
| | - Truman P Young
- Department of Plant Sciences, University of California Davis, Davis, California, USA
| | | |
Collapse
|
5
|
Sisk-Hackworth L, Brown J, Sau L, Levine AA, Tam LYI, Ramesh A, Shah RS, Kelley-Thackray ET, Wang S, Nguyen A, Kelley ST, Thackray VG. Genetic hypogonadal mouse model reveals niche-specific influence of reproductive axis and sex on intestinal microbial communities. Biol Sex Differ 2023; 14:79. [PMID: 37932822 PMCID: PMC10626657 DOI: 10.1186/s13293-023-00564-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/23/2023] [Indexed: 11/08/2023] Open
Abstract
BACKGROUND The gut microbiome has been linked to many diseases with sex bias including autoimmune, metabolic, neurological, and reproductive disorders. While numerous studies report sex differences in fecal microbial communities, the role of the reproductive axis in this differentiation is unclear and it is unknown how sex differentiation affects microbial diversity in specific regions of the small and large intestine. METHODS We used a genetic hypogonadal mouse model that does not produce sex steroids or go through puberty to investigate how sex and the reproductive axis impact bacterial diversity within the intestine. Using 16S rRNA gene sequencing, we analyzed alpha and beta diversity and taxonomic composition of fecal and intestinal communities from the lumen and mucosa of the duodenum, ileum, and cecum from adult female (n = 20) and male (n = 20) wild-type mice and female (n = 17) and male (n = 20) hypogonadal mice. RESULTS Both sex and reproductive axis inactivation altered bacterial composition in an intestinal section and niche-specific manner. Hypogonadism was significantly associated with bacteria from the Bacteroidaceae, Eggerthellaceae, Muribaculaceae, and Rikenellaceae families, which have genes for bile acid metabolism and mucin degradation. Microbial balances between males and females and between hypogonadal and wild-type mice were also intestinal section-specific. In addition, we identified 3 bacterial genera (Escherichia Shigella, Lachnoclostridium, and Eggerthellaceae genus) with higher abundance in wild-type female mice throughout the intestinal tract compared to both wild-type male and hypogonadal female mice, indicating that activation of the reproductive axis leads to female-specific differentiation of the gut microbiome. Our results also implicated factors independent of the reproductive axis (i.e., sex chromosomes) in shaping sex differences in intestinal communities. Additionally, our detailed profile of intestinal communities showed that fecal samples do not reflect bacterial diversity in the small intestine. CONCLUSIONS Our results indicate that sex differences in the gut microbiome are intestinal niche-specific and that sampling feces or the large intestine may miss significant sex effects in the small intestine. These results strongly support the need to consider both sex and reproductive status when studying the gut microbiome and while developing microbial-based therapies.
Collapse
Affiliation(s)
- Laura Sisk-Hackworth
- University of California San Diego, La Jolla, CA, USA
- San Diego State University, San Diego, CA, USA
| | - Jada Brown
- University of California San Diego, La Jolla, CA, USA
| | - Lillian Sau
- University of California San Diego, La Jolla, CA, USA
| | | | | | | | - Reeya S Shah
- University of California San Diego, La Jolla, CA, USA
| | | | - Sophia Wang
- University of California San Diego, La Jolla, CA, USA
| | - Anita Nguyen
- University of California San Diego, La Jolla, CA, USA
| | | | | |
Collapse
|
6
|
Heiland L, Kunstler G, Šebeň V, Hülsmann L. Which demographic processes control competitive equilibria? Bayesian calibration of a size-structured forest population model. Ecol Evol 2023; 13:e10232. [PMID: 37408631 PMCID: PMC10318622 DOI: 10.1002/ece3.10232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 06/12/2023] [Indexed: 07/07/2023] Open
Abstract
In forest communities, light competition is a key process for community assembly. Species' differences in seedling and sapling tolerance to shade cast by overstory trees is thought to determine species composition at late-successional stages. Most forests are distant from these late-successional equilibria, impeding a formal evaluation of their potential species composition. To extrapolate competitive equilibria from short-term data, we therefore introduce the JAB model, a parsimonious dynamic model with interacting size-structured populations, which focuses on sapling demography including the tolerance to overstory competition. We apply the JAB model to a two-"species" system from temperate European forests, that is, the shade-tolerant species Fagus sylvatica L. and the group of all other competing species. Using Bayesian calibration with prior information from external Slovakian national forest inventory (NFI) data, we fit the JAB model to short time series from the German NFI. We use the posterior estimates of demographic rates to extrapolate that F. sylvatica will be the predominant species in 94% of the competitive equilibria, despite only predominating in 24% of the initial states. We further simulate counterfactual equilibria with parameters switched between species to assess the role of different demographic processes for competitive equilibria. These simulations confirm the hypothesis that the higher shade tolerance of F. sylvatica saplings is key for its long-term predominance. Our results highlight the importance of demographic differences in early life stages for tree species assembly in forest communities.
Collapse
Affiliation(s)
- Lukas Heiland
- Bayreuth Center of Ecology and Environmental Research (BayCEER), Ecosystem Analysis and Simulation (EASI) LabUniversity of BayreuthBayreuthGermany
- Theoretical EcologyUniversity of RegensburgRegensburgGermany
| | | | | | - Lisa Hülsmann
- Bayreuth Center of Ecology and Environmental Research (BayCEER), Ecosystem Analysis and Simulation (EASI) LabUniversity of BayreuthBayreuthGermany
| |
Collapse
|
7
|
Gokhale CS, Sharma N. Optimizing crop rotations via Parrondo's paradox for sustainable agriculture. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221401. [PMID: 37206968 PMCID: PMC10189593 DOI: 10.1098/rsos.221401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 04/25/2023] [Indexed: 05/21/2023]
Abstract
Crop rotation, a sustainable agricultural technique, has been at humanity's disposal since time immemorial and is practised globally. Switching between cover crops and cash crops helps avoid the adverse effects of intensive farming. Determining the optimum cash-cover rotation schedule for maximizing yield has been tackled on multiple fronts by agricultural scientists, economists, biologists and computer scientists, to name a few. However, considering the uncertainty due to diseases, pests, droughts, floods and impending effects of climate change is essential when designing rotation strategies. Analysing this time-tested technique of crop rotations with a new lens of Parrondo's paradox allows us to optimally use the rotation technique in synchrony with uncertainty. While previous approaches are reactive to the diversity of crop types and environmental uncertainties, we make use of the said uncertainties to enhance crop rotation schedules. We calculate optimum switching probabilities in a randomized cropping sequence and suggest optimum deterministic sequences and judicious use of fertilizers. Our methods demonstrate strategies to enhance crop yield and the eventual profit margins for farmers. Conforming to translational biology, we extend Parrondo's paradox, where two losing situations can be combined eventually into a winning scenario, to agriculture.
Collapse
Affiliation(s)
- Chaitanya S. Gokhale
- Center for Computational and Theoretical Biology (CCTB), University of Würzburg, Würzburg, Germany
- Research Group for Theoretical Models of Eco-evolutionary Dynamics, Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, August-Thienemann-Straße 2, 24306 Plön, Germany
| | - Nikhil Sharma
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, August-Thienemann-Straße 2, 24306 Plön, Germany
| |
Collapse
|
8
|
Native annual forbs decline in California coastal prairies over 15 years despite grazing. PLoS One 2022; 17:e0278608. [PMID: 36472993 PMCID: PMC9725146 DOI: 10.1371/journal.pone.0278608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
Livestock grazing is often used as a land management tool to maximize vegetation diversity in grassland ecosystems worldwide. Prior research has shown that cattle grazing benefits native annual forb species in California's coastal prairies, but drought and increasing aridity may alter this relationship. In 2016 and 2017, we resurveyed the vegetation structure, native annual forb cover, and native annual forb richness in ten grazed and ungrazed prairies that were originally measured in 2000 and 2001 along a 200-km gradient from Monterey to Sonoma counties in California. We found that grazed prairies continued to have significantly lower vegetation height and thatch depth than ungrazed prairies, and that shrub encroachment over the 15-year period was significantly greater in ungrazed prairies. Furthermore, grazed prairies continued to have greater native annual forb richness (4.9 species per site) than ungrazed sites (3.0 species per site), but native annual forb richness declined by 2.8 species per site in grazed prairies and 0.1 species per site in ungrazed prairies between survey periods. We suggest that severe drought and increasing aridity may be driving declines in native annual forb richness in grazed prairies. The species we recorded only in earlier surveys were disproportionately wetland-associated and had higher average specific leaf area than species that remained through the second survey period. Finally, the cover of native annual species increased regardless of whether prairies were grazed, suggesting that the high precipitation in 2017 may have benefitted the native annual forb species that persisted at sites between surveys. Our study shows that weather conditions affect the outcomes of land management strategies.
Collapse
|
9
|
Picoche C, Barraquand F. Seed banks can help to maintain the diversity of interacting phytoplankton species. J Theor Biol 2022; 538:111020. [PMID: 35032473 DOI: 10.1016/j.jtbi.2022.111020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 01/01/2022] [Accepted: 01/06/2022] [Indexed: 10/19/2022]
Abstract
Seed formation is part of the reproductive cycle, leading to the accumulation of resistance stages that can withstand harsh environmental conditions for long periods of time. At the community level, multiple species with such long-lasting life stages can be more likely to coexist. While the implications of this process for biodiversity have been studied in terrestrial plants, seed banks are usually neglected in phytoplankton multispecies dynamic models, in spite of widespread empirical evidence for such seed banks. In this study, we build a metacommunity model of interacting phytoplankton species, including a resting stage supplying the seed bank. The model is parameterized with empirically-driven growth rate functions and field-based interaction estimates, which include both facilitative and competitive interactions. Exchanges between compartments (coastal pelagic cells, coastal resting cells on the seabed, and open ocean pelagic cells) are controlled by hydrodynamical parameters to which the sensitivity of the model is assessed. We consider two models, i.e., with and without a saturating effect of the interactions on the growth rates. Our results are consistent between models, and show that a seed bank allows to maintain all species in the community over 30 years. Indeed, a fraction of the species are vulnerable to extinction at specific times within the year, but this process is buffered by their survival in their resting stage. We thus highlight the potential role of the seed bank in the recurrent re-invasion of the coastal community, and of coastal environments in re-seeding oceanic regions. Moreover, the seed bank enables populations to tolerate stronger interactions within the community as well as more severe changes in the environment, such as those predicted within a climate change context. Our study therefore shows how a resting stage may help phytoplanktonic diversity maintenance.
Collapse
Affiliation(s)
- Coralie Picoche
- Institute of Mathematics of Bordeaux, University of Bordeaux and CNRS, Talence, France; Integrative and Theoretical Ecology, LabEx COTE, University of Bordeaux, Pessac, France.
| | - Frédéric Barraquand
- Institute of Mathematics of Bordeaux, University of Bordeaux and CNRS, Talence, France; Integrative and Theoretical Ecology, LabEx COTE, University of Bordeaux, Pessac, France
| |
Collapse
|
10
|
Grainger TN, Senthilnathan A, Ke PJ, Barbour MA, Jones NT, DeLong JP, Otto SP, O’Connor MI, Coblentz KE, Goel N, Sakarchi J, Szojka MC, Levine JM, Germain RM. An Empiricist’s Guide to Using Ecological Theory. Am Nat 2022; 199:1-20. [DOI: 10.1086/717206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
11
|
Wisnoski NI, Shoemaker LG. Seed banks alter metacommunity diversity: The interactive effects of competition, dispersal and dormancy. Ecol Lett 2021; 25:740-753. [PMID: 34965013 DOI: 10.1111/ele.13944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/10/2021] [Accepted: 11/24/2021] [Indexed: 01/12/2023]
Abstract
Dispersal and dormancy are two common strategies allowing for species persistence and the maintenance of biodiversity in variable environments. However, theory and empirical tests of spatial diversity patterns tend to examine either mechanism in isolation. Here, we developed a stochastic, spatially explicit metacommunity model incorporating seed banks with varying germination and survival rates. We found that dormancy and dispersal had interactive, nonlinear effects on the maintenance and distribution of metacommunity diversity. Seed banks promoted local diversity when seed survival was high and maintained regional diversity through interactions with dispersal. The benefits of seed banks for regional diversity were largest when dispersal was high or intermediate, depending on whether local competition was equal or stabilising. Our study shows that classic predictions for how dispersal affects metacommunity diversity can be strongly influenced by dormancy. Together, these results emphasise the need to consider both temporal and spatial processes when predicting multi-scale patterns of diversity.
Collapse
Affiliation(s)
- Nathan I Wisnoski
- Wyoming Geographic Information Science Center, University of Wyoming, Laramie, Wyoming, USA
| | | |
Collapse
|
12
|
Raymundo M, Pastore A, HilleRisLambers J, Mayfield MM. Annual rainfall variation and dispersal limitation combine to alter invaded plant community diversity, dominance hierarchies and seeding phenology. CLIMATE CHANGE ECOLOGY 2021. [DOI: 10.1016/j.ecochg.2021.100024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
13
|
Dallas TA, Kramer AM. Temporal variability in population and community dynamics. Ecology 2021; 103:e03577. [PMID: 34714929 DOI: 10.1002/ecy.3577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 07/15/2021] [Accepted: 08/23/2021] [Indexed: 11/12/2022]
Abstract
Populations and communities fluctuate in their overall numbers through time, and the magnitude of fluctuations in individual species may scale to communities. However, the composite variability at the community scale is expected to be tempered by opposing fluctuations in individual populations, a phenomenon often called the portfolio effect. Understanding population variability, how it scales to community variability, and the spatial scaling in this variability are pressing needs given shifting environmental conditions and community composition. We explore evidence for portfolio effects using null community simulations and a large collection of empirical community time series from the BioTIME database. Additionally, we explore the relative roles of habitat type and geographic location on population and community temporal variability. We find strong portfolio effects in our theoretical community model, but weak effects in empirical data, suggesting a role for shared environmental responses, interspecific competition, or a litany of other factors. Furthermore, we observe a clear latitudinal signal - and differences among habitat types - in population and community variability. Together, this highlights the need to develop realistic models of community dynamics, and hints at spatial, and underlying environmental, gradients in variability in both population and community dynamics.
Collapse
Affiliation(s)
- Tad A Dallas
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA.,Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Andrew M Kramer
- Department of Integrative Biology, University of South Florida, Tampa, Florida, 33620, USA
| |
Collapse
|
14
|
Eskelinen A, Elwood E, Harrison S, Beyen E, Gremer JR. Vulnerability of grassland seed banks to resource-enhancing global changes. Ecology 2021; 102:e03512. [PMID: 34358331 DOI: 10.1002/ecy.3512] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/20/2021] [Accepted: 05/27/2021] [Indexed: 12/18/2022]
Abstract
Soil seed banks represent reservoirs of diversity in the soil that may increase resilience of communities to global changes. Two global change factors that can dramatically alter the composition and diversity of aboveground communities are nutrient enrichment and increased rainfall. In a full-factorial nutrient and rainfall addition experiment in an annual Californian grassland, we asked whether shifts in aboveground composition and diversity were reflected in belowground seed banks. Nutrient and rainfall additions increased exotic and decreased native abundances, while rainfall addition increased exotic richness, both in aboveground communities and seed banks. Under nutrient addition, forbs and short-statured plants were replaced by grasses and tall-statured species, both above and below ground, and whole-community responses to the treatments were similar. Structural equation models indicated that especially nutrient addition effects on seed banks were largely indirect via aboveground communities. However, rainfall addition also had a direct negative effect on native species richness and abundance of species with high specific leaf area (SLA) in seed banks, showing that seed banks are sensitive to the direct effects of temporary increases in rainfall. Our findings highlight the vulnerability of seed banks in annual, resource-poor grasslands to shifts in compositional and trait changes in aboveground communities and show how invasion of exotics and depletion of natives are critical for these above-belowground compositional shifts. Our findings suggest that seed banks have limited potential to buffer resource-poor annual grasslands from the community changes caused by resource enrichment.
Collapse
Affiliation(s)
- Anu Eskelinen
- Department of Physiological Diversity, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig, 04318, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, Leipzig, 04103, Germany.,Department of Ecology and Genetics, University of Oulu, P.O. Box 8000, Oulu, FI-90014, Finland
| | - Elise Elwood
- Department of Evolution and Ecology, University of California, Davis, California, 95616, USA
| | - Susan Harrison
- Department of Environmental Science and Policy, University of California, Davis, California, 95616, USA
| | - Eva Beyen
- Department of Evolution and Ecology, University of California, Davis, California, 95616, USA
| | - Jennifer R Gremer
- Department of Evolution and Ecology, University of California, Davis, California, 95616, USA
| |
Collapse
|
15
|
Van Allen B, Jones N, Gilbert B, Carscadden K, Germain R. Maternal effects and the outcome of interspecific competition. Ecol Evol 2021; 11:7544-7556. [PMID: 34188833 PMCID: PMC8216948 DOI: 10.1002/ece3.7586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 03/11/2021] [Accepted: 03/23/2021] [Indexed: 12/15/2022] Open
Abstract
Maternal environmental effects create lagged population responses to past environments. Although they are ubiquitous and vary in expression across taxa, it remains unclear if and how their presence alters competitive interactions in ecological communities.Here, we use a discrete-time competition model to simulate how maternal effects alter competitive dynamics in fluctuating and constant environments. Further, we explore how omitting maternal effects alter estimates of known model parameters from observational time series data.Our simulations demonstrate that (i) maternal effects change competitive outcomes, regardless of whether competitors otherwise interact neutrally or exhibit non-neutral competitive differences, (ii) the consequences of maternal effects for competitive outcomes are mediated by the temporal structure of environmental variation, (iii) even in constant conditions, competitive outcomes are influenced by species' maternal effects strategies, and (iv) in observational time series data, omitting maternal effects reduces variation explained by models and biases parameter estimates, including competition coefficients.Our findings demonstrate that the ecological consequences of maternal effects hinge on the competitive environment. Evolutionary biologists have long recognized that maternal effects can be an important but often overlooked strategy buffering populations from environmental change. We suggest that maternal effects are similarly critical to ecology and call for research into maternal effects as drivers of dynamics in populations and communities.
Collapse
Affiliation(s)
- Benjamin Van Allen
- Ecology, Behavior, and EvolutionUniversity of California San DiegoSan DiegoCAUSA
| | - Natalie Jones
- School of Biological SciencesUniversity of QueenslandBrisbaneQldAustralia
| | - Benjamin Gilbert
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - Kelly Carscadden
- Ecology and Evolutionary BiologyUniversity of Colorado BoulderBoulderCOUSA
| | - Rachel Germain
- Zoology & Biodiversity Research CentreThe University of British ColumbiaVancouverBCCanada
| |
Collapse
|
16
|
Rodríguez‐Caro RC, Capdevila P, Graciá E, Barbosa JM, Giménez A, Salguero‐Gómez R. The limits of demographic buffering in coping with environmental variation. OIKOS 2021. [DOI: 10.1111/oik.08343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Roberto C. Rodríguez‐Caro
- Depto de Biología Aplicada, Univ. Miguel Hernández Elche Alicante Spain
- Dept of Zoology, Oxford Univ. Oxford UK
| | - Pol Capdevila
- Dept of Zoology, Oxford Univ. Oxford UK
- School of Biological Sciences, Univ. of Bristol Bristol UK
| | - Eva Graciá
- Depto de Biología Aplicada, Univ. Miguel Hernández Elche Alicante Spain
- Centro de Investigación e Innovación Agroalimentaria y Agroambiental (CIAGRO‐UMH), Univ. Miguel Hernández Spain
| | - Jomar M. Barbosa
- Depto de Biología Aplicada, Univ. Miguel Hernández Elche Alicante Spain
- Dept of Conservation Biology, Estación Biológica de Doñana, C.S.I.C. Seville Spain
| | - Andrés Giménez
- Depto de Biología Aplicada, Univ. Miguel Hernández Elche Alicante Spain
- Centro de Investigación e Innovación Agroalimentaria y Agroambiental (CIAGRO‐UMH), Univ. Miguel Hernández Spain
| | - Rob Salguero‐Gómez
- Dept of Zoology, Oxford Univ. Oxford UK
- Centre for Biodiversity and Conservation Science, Univ. of Queensland St Lucia QLD Australia
| |
Collapse
|
17
|
Beck JJ, Givnish TJ. Fine-scale environmental heterogeneity and spatial niche partitioning among spring-flowering forest herbs. AMERICAN JOURNAL OF BOTANY 2021; 108:63-73. [PMID: 33426671 DOI: 10.1002/ajb2.1593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 09/14/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Environmental heterogeneity influences plant distributions and diversity at several spatial scales. In temperate forests, fine-scale environmental variation may promote local coexistence among herbaceous species by allowing plants to spatially partition microsites within forest stands. Here we argue that shallow soils, low soil water-holding capacity and fertility, and reduced light near tree boles should favor short, shallow-rooted, evergreen species like Anemone acutiloba with low moisture, nutrient, and light requirements. Farther from trees, richer, deeper soils should favor taller, deeper-rooted herbs with greater moisture and nutrient demands, such as Sanguinaria canadensis and Trillium flexipes. METHODS We tested these hypotheses by mapping the fine-scale distributions of Anemone, Sanguinaria, and Trillium individuals within a 50 × 50 m plot, comparing local species' distributions with respect to soil depth and proximity to neighboring trees, and characterizing intraspecific and interspecific spatial associations. RESULTS Local plant distributions were consistent with our predictions based on leaf height, physiology, and phenology. Anemone was found in microsites on shallower soils and closer to trees than either Sanguinaria or Trillium. In all three species, individual plants were spatially aggregated within 2 m, but spatially segregated from individuals of the other species beyond 2 m. CONCLUSIONS Differential plant responses to fine-scale environmental heterogeneity and observed spatial associations suggest that local species-environment associations could facilitate coexistence. These findings illustrate how fine-scale environmental heterogeneity coupled with phenological and physiological differences likely contribute to spatial niche partitioning among spring-flowering forest herbs and maintain high local plant diversity within temperate forests.
Collapse
Affiliation(s)
- Jared J Beck
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706
| | - Thomas J Givnish
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706
| |
Collapse
|
18
|
Koh JM, Cheong KH. Generalized Solutions of Parrondo's Games. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2001126. [PMID: 33344113 PMCID: PMC7740106 DOI: 10.1002/advs.202001126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/18/2020] [Indexed: 05/04/2023]
Abstract
In game theory, Parrondo's paradox describes the possibility of achieving winning outcomes by alternating between losing strategies. The framework had been conceptualized from a physical phenomenon termed flashing Brownian ratchets, but has since been useful in understanding a broad range of phenomena in the physical and life sciences, including the behavior of ecological systems and evolutionary trends. A minimal representation of the paradox is that of a pair of games played in random order; unfortunately, closed-form solutions general in all parameters remain elusive. Here, we present explicit solutions for capital statistics and outcome conditions for a generalized game pair. The methodology is general and can be applied to the development of analytical methods across ratchet-type models, and of Parrondo's paradox in general, which have wide-ranging applications across physical and biological systems.
Collapse
Affiliation(s)
- Jin Ming Koh
- Science, Mathematics and Technology ClusterSingapore University of Technology and Design (SUTD)8 Somapah RdSingaporeS487372Singapore
- California Institute of TechnologyPasadenaCA91125USA
| | - Kang Hao Cheong
- Science, Mathematics and Technology ClusterSingapore University of Technology and Design (SUTD)8 Somapah RdSingaporeS487372Singapore
- SUTD‐Massachusetts Institute of Technology International Design Centre8 Somapah RdSingaporeS487372Singapore
| |
Collapse
|
19
|
Abreu CI, Andersen Woltz VL, Friedman J, Gore J. Microbial communities display alternative stable states in a fluctuating environment. PLoS Comput Biol 2020; 16:e1007934. [PMID: 32453781 PMCID: PMC7274482 DOI: 10.1371/journal.pcbi.1007934] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/05/2020] [Accepted: 05/07/2020] [Indexed: 12/24/2022] Open
Abstract
The effect of environmental fluctuations is a major question in ecology. While it is widely accepted that fluctuations and other types of disturbances can increase biodiversity, there are fewer examples of other types of outcomes in a fluctuating environment. Here we explore this question with laboratory microcosms, using cocultures of two bacterial species, P. putida and P. veronii. At low dilution rates we observe competitive exclusion of P. veronii, whereas at high dilution rates we observe competitive exclusion of P. putida. When the dilution rate alternates between high and low, we do not observe coexistence between the species, but rather alternative stable states, in which only one species survives and initial species’ fractions determine the identity of the surviving species. The Lotka-Volterra model with a fluctuating mortality rate predicts that this outcome is independent of the timing of the fluctuations, and that the time-averaged mortality would also lead to alternative stable states, a prediction that we confirm experimentally. Other pairs of species can coexist in a fluctuating environment, and again consistent with the model we observe coexistence in the time-averaged dilution rate. We find a similar time-averaging result holds in a three-species community, highlighting that simple linear models can in some cases provide powerful insight into how communities will respond to environmental fluctuations. The effect of environmental fluctuations on community structure and function is a fundamental question in ecology. A significant body of work suggests that fluctuations increase diversity due to a variety of proposed mechanisms. In this study, we compare the effects of constant and fluctuating dilution regimes on simple microbial communities with two or three species. We find that in all cases, the outcome in a fluctuating environment is the same as that in a constant environment in which the fluctuations are time-averaged. This surprising result highlights that in some communities, ecological stable states may be predicted by averaging environmental parameters, rather than by the variation itself.
Collapse
Affiliation(s)
- Clare I. Abreu
- Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail: (CIA); (JG)
| | - Vilhelm L. Andersen Woltz
- Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Jonathan Friedman
- Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Jeff Gore
- Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail: (CIA); (JG)
| |
Collapse
|
20
|
Zang YX, Min XJ, de Dios VR, Ma JY, Sun W. Extreme drought affects the productivity, but not the composition, of a desert plant community in Central Asia differentially across microtopographies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 717:137251. [PMID: 32092808 DOI: 10.1016/j.scitotenv.2020.137251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/04/2020] [Accepted: 02/09/2020] [Indexed: 06/10/2023]
Abstract
Extreme climatic conditions are major drivers of ecosystem function and dynamics and their frequency is increasing under climate change. Climatic conditions interact with local microtopography, which might either buffer or exacerbate the degree of climatic stress. Here we sought to understand how extremely dry growing seasons affected the composition and productivity of desert ephemeral communities growing in sand dunes from the Gurbantunggut desert in Central Asia, and to which extent did microtopography modulate the response. We set up a rainfall manipulation study on four sand dune microtopographies and, during two consecutive years, we measured soil moisture, nutrients and texture, ephemeral layer composition, plant phenology, biomass accumulation and biomass allocation patterns for the dominant species. We observed significant biomass reductions during the extreme drought but plant community richness and composition were not affected, indicating that the composition of the ephemeral layer in this desert ecosystem may resist under extreme conditions. Additionally, extreme drought increased biomass allocation to reproductive organs of the dominant species. There were also significant microtopographic effects as the sensitivity of biomass to drought in western aspects was larger than in eastern aspects. Our results indicate that previously overlooked microtopographical differences may mediate the impact of climate change on plant communities.
Collapse
Affiliation(s)
- Yong-Xin Zang
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Fukang Station of Desert Ecology, Chinese Academy of Sciences, Fukang, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xiao-Jun Min
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Fukang Station of Desert Ecology, Chinese Academy of Sciences, Fukang, China; University of Chinese Academy of Sciences, Beijing, China
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China; Department of Crop and Forest Sciences & Agrotecnio Center, Universitat de Lleida, Lleida, Spain
| | - Jian-Ying Ma
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Fukang Station of Desert Ecology, Chinese Academy of Sciences, Fukang, China.
| | - Wei Sun
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China.
| |
Collapse
|
21
|
Cheong KH, Koh JM, Jones MC. Paradoxical Survival: Examining the Parrondo Effect across Biology. Bioessays 2020; 41:e1900027. [PMID: 31132170 DOI: 10.1002/bies.201900027] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/26/2019] [Indexed: 01/17/2023]
Abstract
Parrondo's paradox, in which losing strategies can be combined to produce winning outcomes, has received much attention in mathematics and the physical sciences; a plethora of exciting applications has also been found in biology at an astounding pace. In this review paper, the authors examine a large range of recent developments of Parrondo's paradox in biology, across ecology and evolution, genetics, social and behavioral systems, cellular processes, and disease. Intriguing connections between numerous works are identified and analyzed, culminating in an emergent pattern of nested recurrent mechanics that appear to span the entire biological gamut, from the smallest of spatial and temporal scales to the largest-from the subcellular to the complete biosphere. In analyzing the macro perspective, the pivotal role that the paradox plays in the shaping of biological life becomes apparent, and its identity as a potential universal principle underlying biological diversity and persistence is uncovered. Directions for future research are also discussed in light of this new perspective.
Collapse
Affiliation(s)
- Kang Hao Cheong
- Science and Math Cluster, Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore, Singapore
| | - Jin Ming Koh
- Science and Math Cluster, Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore, Singapore
| | | |
Collapse
|
22
|
Postuma M, Schmid M, Guillaume F, Ozgul A, Paniw M. The effect of temporal environmental autocorrelation on eco‐evolutionary dynamics across life histories. Ecosphere 2020. [DOI: 10.1002/ecs2.3029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Maarten Postuma
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich 8057 Switzerland
- Department of Animal Ecology & Physiology Radboud University Nijmegen The Netherlands
- Plant Ecology and Nature Conservation Group Wageningen University Wageningen 6700 AA The Netherlands
| | - Max Schmid
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich 8057 Switzerland
| | - Frédéric Guillaume
- 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
| | - Maria Paniw
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich 8057 Switzerland
- Ecological and Forestry Applications Research Centre (CREAF) Campus de Bellaterra (UAB) Edifici C Cerdanyola del Valles ES‐08193 Spain
| |
Collapse
|
23
|
Shoemaker LG, Sullivan LL, Donohue I, Cabral JS, Williams RJ, Mayfield MM, Chase JM, Chu C, Harpole WS, Huth A, HilleRisLambers J, James ARM, Kraft NJB, May F, Muthukrishnan R, Satterlee S, Taubert F, Wang X, Wiegand T, Yang Q, Abbott KC. Integrating the underlying structure of stochasticity into community ecology. Ecology 2020; 101:e02922. [PMID: 31652337 PMCID: PMC7027466 DOI: 10.1002/ecy.2922] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 08/26/2019] [Accepted: 09/10/2019] [Indexed: 01/13/2023]
Abstract
Stochasticity is a core component of ecology, as it underlies key processes that structure and create variability in nature. Despite its fundamental importance in ecological systems, the concept is often treated as synonymous with unpredictability in community ecology, and studies tend to focus on single forms of stochasticity rather than taking a more holistic view. This has led to multiple narratives for how stochasticity mediates community dynamics. Here, we present a framework that describes how different forms of stochasticity (notably demographic and environmental stochasticity) combine to provide underlying and predictable structure in diverse communities. This framework builds on the deep ecological understanding of stochastic processes acting at individual and population levels and in modules of a few interacting species. We support our framework with a mathematical model that we use to synthesize key literature, demonstrating that stochasticity is more than simple uncertainty. Rather, stochasticity has profound and predictable effects on community dynamics that are critical for understanding how diversity is maintained. We propose next steps that ecologists might use to explore the role of stochasticity for structuring communities in theoretical and empirical systems, and thereby enhance our understanding of community dynamics.
Collapse
Affiliation(s)
- Lauren G. Shoemaker
- Department of BotanyUniversity of Wyoming1000 E. University Ave.LaramieWyoming82017USA
- Department of Ecology, Evolution, and BehaviorUniversity of Minnesota1987 Upper Buford CircleSaint PaulMinnesota55108USA
- Department of Ecology and Evolutionary BiologyUniversity of Colorado1900 Pleasant StreetBoulderColorado80309USA
| | - Lauren L. Sullivan
- Department of Ecology, Evolution, and BehaviorUniversity of Minnesota1987 Upper Buford CircleSaint PaulMinnesota55108USA
- Division of Biological SciencesUniversity of Missouri105 Tucker HallColumbiaMissouri65211USA
| | - Ian Donohue
- Department of Zoology, School of Natural SciencesTrinity CollegeCollege Green Dublin 2Ireland
| | - Juliano S. Cabral
- Synthesis Centre of the German Centre for Integrative Biodiversity Research (sDiv) Halle-Jena-LeipzigDeutscher Platz 5eLeipzig04103Germany
- Ecosystem Modeling, Center of Computation and Theoretical BiologyUniversity of WürzburgEmil-Fischer-Strasse 3297074WürzburgGermany
| | - Ryan J. Williams
- Division of Biological SciencesUniversity of Missouri105 Tucker HallColumbiaMissouri65211USA
| | - Margaret M. Mayfield
- The University of QueenslandSchool of Biological SciencesGoddard BuildingBrisbaneQueensland4072Australia
| | - Jonathan M. Chase
- German Centre for Integrative Biodiversity Research (iDiv)Deutscher Platz 5eLeipzig04103Germany
- Institute for Computer ScienceMartin Luther University Halle-WittenbergHalle06099Germany
| | - Chengjin Chu
- Department of Ecology, State Key Laboratory of Biocontrol and School of Life SciencesSun Yat-sen University510275GuangzhouGuangdongChina
| | - W. Stanley Harpole
- German Centre for Integrative Biodiversity Research (iDiv)Deutscher Platz 5eLeipzig04103Germany
- Helmholtz Center for Environmental Research–UFZPermoserstrasse 1504318LeipzigGermany
- Institute of BiologyMartin Luther University Halle-WittenbergAm Kirchtor 106108Halle (Saale)Germany
| | - Andreas Huth
- German Centre for Integrative Biodiversity Research (iDiv)Deutscher Platz 5eLeipzig04103Germany
- Helmholtz Center for Environmental Research–UFZPermoserstrasse 1504318LeipzigGermany
- Institute of Environmental Research SystemsUniversity of OsnabrückP.O. Box 44 69,49069OsnabrückGermany
| | | | - Aubrie R. M. James
- Department of Ecology and Evolutionary BiologyCornell UniversityE145 Corson HallIthacaNew York14853USA
| | - Nathan J. B. Kraft
- Department of Ecology and Evolutionary BiologyUniversity of California, Los Angeles621 Charles E. Young Drive East, P.O. Box 957246Los AngelesCA90095USA
| | - Felix May
- German Centre for Integrative Biodiversity Research (iDiv)Deutscher Platz 5eLeipzig04103Germany
- Institute for Computer ScienceMartin Luther University Halle-WittenbergHalle06099Germany
- Center for MethodologyLeuphana University LüneburgUniversitätsallee 1D‐21335LüneburgGermany
| | - Ranjan Muthukrishnan
- Environmental Resilience InstituteIndiana University717 E 8th StBloomingtonIndiana 47408USA
- Department of Fisheries, Wildlife, and Conservation BiologyUniversity of Minnesota2003 Upper Buford CircleSt. PaulMinnesota55108USA
| | - Sean Satterlee
- Department of Ecology, Evolution, and Organismal BiologyIowa State University251 Bessey HallAmesIowa50011USA
| | - Franziska Taubert
- Helmholtz Center for Environmental Research–UFZPermoserstrasse 1504318LeipzigGermany
| | - Xugao Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China
| | - Thorsten Wiegand
- German Centre for Integrative Biodiversity Research (iDiv)Deutscher Platz 5eLeipzig04103Germany
- Helmholtz Center for Environmental Research–UFZPermoserstrasse 1504318LeipzigGermany
| | - Qiang Yang
- Department of Zoology, School of Natural SciencesTrinity CollegeCollege Green Dublin 2Ireland
- Department of BiologyUniversity of KonstanzUniversitätsstraße 1078464KonstanzGermany
| | - Karen C. Abbott
- Department of BiologyCase Western Reserve University10900 Euclid AvenueClevelandOH44106USA
| |
Collapse
|
24
|
Tan Z, Koh JM, Koonin EV, Cheong KH. Predator Dormancy is a Stable Adaptive Strategy due to Parrondo's Paradox. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1901559. [PMID: 32042555 PMCID: PMC7001654 DOI: 10.1002/advs.201901559] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/09/2019] [Indexed: 05/20/2023]
Abstract
Many predators produce dormant offspring to escape harsh environmental conditions, but the evolutionary stability of this adaptation has not been fully explored. Like seed banks in plants, dormancy provides a stable competitive advantage when seasonal variations occur, because the persistence of dormant forms under harsh conditions compensates for the increased cost of producing dormant offspring. However, dormancy also exists in environments with minimal abiotic variation-an observation not accounted for by existing theory. Here it is demonstrated that dormancy can out-compete perennial activity under conditions of extensive prey density fluctuation caused by overpredation. It is shown that at a critical level of prey density fluctuations, dormancy becomes an evolutionarily stable strategy. This is interpreted as a manifestation of Parrondo's paradox: although neither the active nor dormant forms of a dormancy-capable predator can individually out-compete a perennially active predator, alternating between these two losing strategies can paradoxically result in a winning strategy. Parrondo's paradox may thus explain the widespread success of quiescent behavioral strategies such as dormancy, suggesting that dormancy emerges as a natural evolutionary response to the self-destructive tendencies of overpredation and related biological phenomena.
Collapse
Affiliation(s)
- Zhi‐Xuan Tan
- Science and Math ClusterSingapore University of Technology and Design (SUTD)SingaporeS487372Singapore
| | - Jin Ming Koh
- Science and Math ClusterSingapore University of Technology and Design (SUTD)SingaporeS487372Singapore
| | - Eugene V. Koonin
- National Center for Biotechnology InformationNational Library of MedicineNational Institutes of HealthBethesdaMD20894USA
| | - Kang Hao Cheong
- Science and Math ClusterSingapore University of Technology and Design (SUTD)SingaporeS487372Singapore
- SUTD‐Massachusetts Institute of Technology International Design CentreSingaporeS487372Singapore
| |
Collapse
|
25
|
|
26
|
Hallett LM, Shoemaker LG, White CT, Suding KN. Rainfall variability maintains grass-forb species coexistence. Ecol Lett 2019; 22:1658-1667. [PMID: 31298471 DOI: 10.1111/ele.13341] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/18/2019] [Accepted: 06/19/2019] [Indexed: 11/28/2022]
Abstract
Environmental variability can structure species coexistence by enhancing niche partitioning. Modern coexistence theory highlights two fluctuation-dependent temporal coexistence mechanisms -the storage effect and relative nonlinearity - but empirical tests are rare. Here, we experimentally test if environmental fluctuations enhance coexistence in a California annual grassland. We manipulate rainfall timing and relative densities of the grass Avena barbata and forb Erodium botrys, parameterise a demographic model, and partition coexistence mechanisms. Rainfall variability was integral to grass-forb coexistence. Variability enhanced growth rates of both species, and early-season drought was essential for Erodium persistence. While theoretical developments have focused on the storage effect, it was not critical for coexistence. In comparison, relative nonlinearity strongly stabilised coexistence, where Erodium experienced disproportionately high growth under early-season drought due to competitive release from Avena. Our results underscore the importance of environmental variability and suggest that relative nonlinearity is a critical if underappreciated coexistence mechanism.
Collapse
Affiliation(s)
- Lauren M Hallett
- Environmental Studies Program and Department of Biology, University of Oregon, Eugene, OR, 97403, USA
| | | | - Caitlin T White
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Katharine N Suding
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, 80309, USA
| |
Collapse
|
27
|
Zepeda V, Martorell C. Fluctuation‐independent niche differentiation and relative non‐linearity drive coexistence in a species‐rich grassland. Ecology 2019; 100:e02726. [DOI: 10.1002/ecy.2726] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/31/2019] [Accepted: 02/21/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Verónica Zepeda
- Facultad de Ciencias Departamento de Ecología y Recursos Naturales Universidad Nacional Autónoma de México Circuito Exterior S/N, Ciudad Universitaria Mexico City 04510 Mexico
- Posgrado en Ciencias Biológicas Unidad de Posgrado Edificio A, 1° Piso, Circuito de Posgrados, Ciudad Universitaria Mexico City C.P. 04510 Mexico
| | - Carlos Martorell
- Facultad de Ciencias Departamento de Ecología y Recursos Naturales Universidad Nacional Autónoma de México Circuito Exterior S/N, Ciudad Universitaria Mexico City 04510 Mexico
| |
Collapse
|
28
|
Genetic Variation of Growth Traits and Genotype-by-Environment Interactions in Clones of Catalpa bungei and Catalpa fargesii f. duclouxii. FORESTS 2019. [DOI: 10.3390/f10010057] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Clones of Catalpa bungei and Catalpa fargesii f. duclouxii were studied over several years in central China to explore genetic variation in growth traits and to identify clones of high wood yield and high stability. The genetic parameters for height, diameter at breast height (DBH), and stem volume of clones, were estimated. The effect of clone × year on the increment of stem volume in the two species was analyzed by genotype and genotype × environment (GGE) biplot methods. Significant differences in growth traits among clones and between species were found. The growth of C. bungei exceeded that of C. fargesii f. duclouxii after 4 years. Furthermore, from the 5th year, the repeatability and genetic variation coefficient (GCV) of the C. bungei clones were higher than those of the C. fargesii f. duclouxii clones in most cases. The phenotypic variation coefficient (PCV) of the C. fargesii f. duclouxii clones was significantly lower than that of the C. bungei clones. The repeatability of stem volume was intermediate or high in the two species. ANOVA revealed significant effects of the clone by year interaction in these two species. GGE biplot analysis revealed that wood yield and stability were largely independent in C. bungei; clones 22-03, 19-27, and 20-01 were the optimal clones in this species. In contrast, the optimal clones 63 and 128 of C. fargesii f. duclouxii combined the desired characteristics of high yield and high stability. In conclusion, our results indicated that the height and stem volume of C. bungei was under strong genetic control, whereas that of C. fargesii f. duclouxii was influenced by the environment more than by genetic effects. Genetic improvement by clone selection can be expected to be effective, as the repeatability of stem volume was high. Francis and Kannenberg’s method and GGE biplot analysis were used in combination to evaluate the clones. C. bungei clone 22-03 and C. fargesii f. duclouxii clones 63 and 128 were identified as the optimal clones, which exhibited both a high increment of stem volume and high stability.
Collapse
|
29
|
Lesage JC, Howard EA, Holl KD. Homogenizing biodiversity in restoration: the “perennialization” of California prairies. Restor Ecol 2018. [DOI: 10.1111/rec.12887] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Josephine C. Lesage
- Department of Environmental Studies; University of California; 1156 High Street, Santa Cruz CA 95064 U.S.A
| | - Elizabeth A. Howard
- UC Santa Cruz Natural Reserves; 130 McAllister Way, Santa Cruz CA 95064 U.S.A
| | - Karen D. Holl
- Department of Environmental Studies; University of California; 1156 High Street, Santa Cruz CA 95064 U.S.A
| |
Collapse
|
30
|
Germain RM, Grainger TN, Jones NT, Gilbert B. Maternal provisioning is structured by species’ competitive neighborhoods. OIKOS 2018. [DOI: 10.1111/oik.05530] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Rachel M. Germain
- Dept Botany and Dept of Zoology, Univ. of British Columbia; Vancouver BC Canada
| | - Tess N. Grainger
- Dept Ecology and Evolutionary Biology, Univ. of Toronto; Toronto ON Canada
| | - Natalie T. Jones
- Dept Biological Sciences, Univ. of California - San Diego; San Diego CA USA
| | - Benjamin Gilbert
- Dept Ecology and Evolutionary Biology, Univ. of Toronto; Toronto ON Canada
| |
Collapse
|
31
|
Harrison SP, LaForgia ML, Latimer AM. Climate-driven diversity change in annual grasslands: Drought plus deluge does not equal normal. GLOBAL CHANGE BIOLOGY 2018; 24:1782-1792. [PMID: 29244898 DOI: 10.1111/gcb.14018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/07/2017] [Accepted: 12/07/2017] [Indexed: 06/07/2023]
Abstract
Climate forecasts agree that increased variability and extremes will tend to reduce the availability of water in many terrestrial ecosystems. Increasingly severe droughts may be exacerbated both by warmer temperatures and by the relative unavailability of water that arrives in more sporadic and intense rainfall events. Using long-term data and an experimental water manipulation, we examined the resilience of a heterogeneous annual grassland community to a prolonged series of dry winters that led to a decline in plant species richness (2000-2014), followed by a near-record wet winter (2016-2017), a climatic sequence that broadly resembles the predicted future in its high variability. In our 80, 5-m2 observational plots, species richness did not recover in response to the wet winter, and the positive relationship of richness to annual winter rainfall thus showed a significant weakening trend over the 18-year time period. In experiments on 100, 1-m2 plots, wintertime water supplementation increased and drought shelters decreased the seedling survival and final individual biomass of native annual forbs, the main functional group contributing to the observed long-term decline in richness. Water supplementation also increased the total cover of native annual forbs, but only increased richness within nested subplots to which seeds were also added. We conclude that prolonged dry winters, by increasing seedling mortality and reducing growth of native forbs, may have diminished the seedbank and thus the recovery potential of diversity in this community. However, the wet winter and the watering treatment did cause recovery of the community mean values of a key functional trait (specific leaf area, an indicator of drought intolerance), suggesting that some aggregate community properties may be stabilized by functional redundancy among species.
Collapse
Affiliation(s)
- Susan P Harrison
- Department of Environmental Science and Policy, University of California, Davis, CA, USA
| | - Marina L LaForgia
- Department of Plant Sciences, University of California, Davis, CA, USA
| | - Andrew M Latimer
- Department of Plant Sciences, University of California, Davis, CA, USA
| |
Collapse
|
32
|
Bowd EJ, Lindenmayer DB, Banks SC, Blair DP. Logging and fire regimes alter plant communities. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:826-841. [PMID: 29411919 DOI: 10.1002/eap.1693] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/28/2017] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
Disturbances are key drivers of plant community composition, structure, and function. Plant functional traits, including life forms and reproductive strategies are critical to the resilience and resistance of plant communities in the event of disturbance. Climate change and increasing anthropogenic disturbance are altering natural disturbance regimes globally. When these regimes shift beyond the adaptive resilience of plant functional traits, local populations and ecosystem functions can become compromised. We tested the influence of multiple disturbances, of varying intensity and frequency, on the composition and abundance of vascular plant communities and their respective functional traits (life forms and reproductive strategies) in the wet sclerophyll, Mountain Ash Eucalyptus regnans forests of southeastern Australia. Specifically, we quantified the effect of the type and number of disturbances (including fires, clearcut logging, and salvage logging) on plant community composition. We found that clearcut and salvage logging and the number of fires significantly influenced plant community composition and functional traits. Specifically, multiple fires resulted in lower populations of species that depend on on-site seeding for persistence. This includes the common tree species Eucalyptus regnans, Pomaderris aspera, and Acacia dealbata. In contrast, clearcut and salvage logged sites supported abundant on-site seeder species. However, species that depend on resprouting by surviving individuals, such as common and keystone "tree ferns" Dicksonia antarctica and Cyathea australis, declined significantly. Our data have important implications for understanding the relationship between altered disturbance regimes and plant communities and the respective effects on ecosystem function. In a period of rapid global environmental change, with disturbances predicted to increase and intensify, it is critical to address the impact of altered disturbance regimes on biodiversity.
Collapse
Affiliation(s)
- Elle J Bowd
- Fenner School of Environment and Society, The Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - David B Lindenmayer
- Fenner School of Environment and Society, The Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Sam C Banks
- Fenner School of Environment and Society, The Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - David P Blair
- Fenner School of Environment and Society, The Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| |
Collapse
|
33
|
LaForgia ML, Spasojevic MJ, Case EJ, Latimer AM, Harrison SP. Seed banks of native forbs, but not exotic grasses, increase during extreme drought. Ecology 2018; 99:896-903. [PMID: 29494753 DOI: 10.1002/ecy.2160] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/23/2017] [Accepted: 01/08/2018] [Indexed: 11/06/2022]
Abstract
Extreme droughts such as the one that affected California in 2012-2015 have been linked to severe ecological consequences in perennial-dominated communities such as forests. In annual communities, drought impacts are difficult to assess because many species persist through facultative multiyear seed dormancy, which leads to the development of seed banks. Impacts of extreme drought on the abundance and composition of the seed banks of whole communities are little known. In 80 heterogeneous grassland plots where cover is dominated by ~15 species of exotic annual grasses and diversity is dominated by ~70 species of native annual forbs, we grew out seeds from soil cores collected early in the California drought (2012) and later in the multiyear drought (2014), and analyzed drought-associated changes in the seed bank. Over the course of the study we identified more than 22,000 seedlings to species. We found that seeds of exotic annual grasses declined sharply in abundance during the drought while seeds of native annual forbs increased, a pattern that resembled but was even stronger than the changes in aboveground cover of these groups. Consistent with the expectation that low specific leaf area (SLA) is an indicator of drought tolerance, we found that the community-weighted mean SLA of annual forbs declined both in the seed bank and in the aboveground community, as low-SLA forbs increased disproportionately. In this system, seed dormancy reinforces the indirect benefits of extreme drought to the native forb community.
Collapse
Affiliation(s)
- Marina L LaForgia
- Department of Plant Sciences, University of California, One Shields Ave, Davis, California, 95616, USA
| | - Marko J Spasojevic
- Department of Evolution, Ecology, and Organismal Biology, University of California, 900 University Ave, Riverside, California, 92521, USA
| | - Erica J Case
- Department of Land, Air and Water Resources, University of California, One Shields Ave, Davis, California, 95616, USA
| | - Andrew M Latimer
- Department of Plant Sciences, University of California, One Shields Ave, Davis, California, 95616, USA
| | - Susan P Harrison
- Department of Environmental Science and Policy, University of California, 900 University Ave, Davis, California, 92521, USA
| |
Collapse
|
34
|
Paniw M, Ozgul A, Salguero‐Gómez R. Interactive life‐history traits predict sensitivity of plants and animals to temporal autocorrelation. Ecol Lett 2017; 21:275-286. [DOI: 10.1111/ele.12892] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 10/04/2017] [Accepted: 11/09/2017] [Indexed: 02/03/2023]
Affiliation(s)
- Maria Paniw
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich8057 Switzerland
- Department Biology University of Cadiz Puerto Real 11510 Spain
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich8057 Switzerland
| | - Roberto Salguero‐Gómez
- Department of Zoology Oxford University New Radcliffe House Radcliffe Observatory Quarter Woodstock Rd OxfordOX2 6GGUK
- Department of Animal & Plant Sciences University of Sheffield Alfred Denny Building, Western Bank SheffieldS10 2TN UK
- Centre for Biodiversity and Conservation Science University of Queensland St Lucia4071 Qld. Australia
- Evolutionary Demography Laboratory Max Plank Institute for Demographic Research Rostock18057 Germany
| |
Collapse
|
35
|
D'Antonio CM, Ostertag R, Cordell S, Yelenik S. Interactions Among Invasive Plants: Lessons from Hawai‘i. ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2017. [DOI: 10.1146/annurev-ecolsys-110316-022620] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Most ecosystems have multiple-plant invaders rather than single-plant invaders, yet ecological studies and management actions focus largely on single invader species. There is a need for general principles regarding invader interactions across varying environmental conditions, so that secondary invasions can be anticipated and managers can allocate resources toward pretreatment or postremoval actions. By reviewing removal experiments conducted in three Hawaiian ecosystems (a dry tropical forest, a seasonally dry mesic forest, and a lowland wet forest), we evaluate the roles environmental harshness, priority effects, productivity potential, and species interactions have in influencing secondary invasions, defined here as invasions that are influenced either positively (facilitation) or negatively (inhibition/priority effects) by existing invaders. We generate a conceptual model with a surprise index to describe whether long-term plant invader composition and dominance is predictable or stochastic after a system perturbation such as a removal experiment. Under extremely low resource availability, the surprise index is low, whereas under intermediate-level resource environments, invader dominance is more stochastic and the surprise index is high. At high resource levels, the surprise index is intermediate: Invaders are likely abundant in the environment but their response to a perturbation is more predictable than at intermediate resource levels. We suggest further testing across environmental gradients to determine key variables that dictate the predictability of postremoval invader composition.
Collapse
Affiliation(s)
- Carla M. D'Antonio
- Environmental Studies Program and Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106
| | - Rebecca Ostertag
- Department of Biology, University of Hawai‘i, Hilo, Hawai‘i 96720
| | - Susan Cordell
- Institute of Pacific Islands Forestry, USDA Forest Service, Hilo, Hawai‘i 96720
| | - Stephanie Yelenik
- USGS Pacific Islands Ecosystem Research Center, Volcano, Hawai‘i 96718
| |
Collapse
|
36
|
Thomson DM, King RA, Schultz EL. Between invaders and a risky place: Exotic grasses alter demographic tradeoffs of native forb germination timing. Ecosphere 2017. [DOI: 10.1002/ecs2.1987] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Diane M. Thomson
- W. M. Keck Science Department The Claremont Colleges 925 N. Mills Avenue Claremont California 91711 USA
| | - Rachel A. King
- W. M. Keck Science Department The Claremont Colleges 925 N. Mills Avenue Claremont California 91711 USA
| | - Emily L. Schultz
- W. M. Keck Science Department The Claremont Colleges 925 N. Mills Avenue Claremont California 91711 USA
| |
Collapse
|
37
|
Climate variability affects the germination strategies exhibited by arid land plants. Oecologia 2017; 185:437-452. [DOI: 10.1007/s00442-017-3958-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 09/08/2017] [Indexed: 10/18/2022]
|
38
|
Lee AM, Saether BE, Markussen SS, Engen S. Modelling time to population extinction when individual reproduction is autocorrelated. Ecol Lett 2017; 20:1385-1394. [PMID: 28925038 DOI: 10.1111/ele.12834] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/02/2017] [Accepted: 08/08/2017] [Indexed: 11/30/2022]
Abstract
In nature, individual reproductive success is seldom independent from year to year, due to factors such as reproductive costs and individual heterogeneity. However, population projection models that incorporate temporal autocorrelations in individual reproduction can be difficult to parameterise, particularly when data are sparse. We therefore examine whether such models are necessary to avoid biased estimates of stochastic population growth and extinction risk, by comparing output from a matrix population model that incorporates reproductive autocorrelations to output from a standard age-structured matrix model that does not. We use a range of parameterisations, including a case study using moose data, treating probabilities of switching reproductive class as either fixed or fluctuating. Expected time to extinction from the two models is found to differ by only small amounts (under 10%) for most parameterisations, indicating that explicitly accounting for individual reproductive autocorrelations is in most cases not necessary to avoid bias in extinction estimates.
Collapse
Affiliation(s)
- Aline Magdalena Lee
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Bernt-Erik Saether
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Stine Svalheim Markussen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Steinar Engen
- Centre for Biodiversity Dynamics, Department of Mathematical Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| |
Collapse
|
39
|
Stuble KL, Fick SE, Young TP. Every restoration is unique: testing year effects and site effects as drivers of initial restoration trajectories. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.12861] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katharine L. Stuble
- Department of Plant Sciences University of California Davis CA 95616 USA
- The Holden Arboretum 9500 Sperry Road Kirtland OH 44094 USA
| | - Stephen E. Fick
- Department of Plant Sciences University of California Davis CA 95616 USA
- Stockholm Environmental Institute Box 24218 104 51 Stockholm Sweden
| | - Truman P. Young
- Department of Plant Sciences University of California Davis CA 95616 USA
| |
Collapse
|
40
|
Divergent demographic strategies of plants in variable environments. Nat Ecol Evol 2017; 1:29. [PMID: 28812611 DOI: 10.1038/s41559-016-0029] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 11/10/2016] [Indexed: 11/08/2022]
Abstract
One of the best-supported patterns in life history evolution is that organisms cope with environmental fluctuations by buffering their most important vital rates against them. This demographic buffering hypothesis is evidenced by a tendency for temporal variation in rates of survival and reproduction to correlate negatively with their contribution to fitness. Here, we show that widespread evidence for demographic buffering can be artefactual, resulting from natural relationships between the mean and variance of vital rates. Following statistical scaling, we find no significant tendency for plant life histories to be buffered demographically. Instead, some species are buffered, whereas others have labile life histories with higher temporal variation in their more important vital rates. We find phylogenetic signal in the strength and direction of variance-importance correlations, suggesting that clades of plants are prone to being either buffered or labile. Species with simple life histories are more likely to be demographically labile. Our results suggest important evolutionary nuances in how species deal with environmental fluctuations.
Collapse
|
41
|
Tan ZX, Cheong KH. Nomadic-colonial life strategies enable paradoxical survival and growth despite habitat destruction. eLife 2017; 6. [PMID: 28084993 PMCID: PMC5319843 DOI: 10.7554/elife.21673] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 01/11/2017] [Indexed: 11/13/2022] Open
Abstract
Organisms often exhibit behavioral or phenotypic diversity to improve population fitness in the face of environmental variability. When each behavior or phenotype is individually maladaptive, alternating between these losing strategies can counter-intuitively result in population persistence-an outcome similar to the Parrondo's paradox. Instead of the capital or history dependence that characterize traditional Parrondo games, most ecological models which exhibit such paradoxical behavior depend on the presence of exogenous environmental variation. Here we present a population model that exhibits Parrondo's paradox through capital and history-dependent dynamics. Two sub-populations comprise our model: nomads, who live independently without competition or cooperation, and colonists, who engage in competition, cooperation, and long-term habitat destruction. Nomads and colonists may alternate behaviors in response to changes in the colonial habitat. Even when nomadism and colonialism individually lead to extinction, switching between these strategies at the appropriate moments can paradoxically enable both population persistence and long-term growth.
Collapse
Affiliation(s)
| | - Kang Hao Cheong
- Engineering Cluster, Singapore Institute of Technology, , Singapore
| |
Collapse
|
42
|
Barabás G, J Michalska-Smith M, Allesina S. The Effect of Intra- and Interspecific Competition on Coexistence in Multispecies Communities. Am Nat 2016; 188:E1-E12. [PMID: 27322128 DOI: 10.1086/686901] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
For two competing species, intraspecific competition must exceed interspecific competition for coexistence. To generalize this well-known criterion to multiple competing species, one must take into account both the distribution of interaction strengths and community structure. Here we derive a multispecies generalization of the two-species rule in the context of symmetric Lotka-Volterra competition and obtain explicit stability conditions for random competitive communities. We then explore the influence of community structure on coexistence. Results show that both the most and least stabilized cases have striking global structures, with a nested pattern emerging in both cases. The distribution of intraspecific coefficients leading to the most and least stabilized communities also follows a predictable pattern that can be justified analytically. In addition, we show that the size of the parameter space allowing for feasible communities always increases with the strength of intraspecific effects in a characteristic way that is independent of the interspecific interaction structure. We conclude by discussing possible extensions of our results to nonsymmetric competition.
Collapse
|
43
|
Zeng Y, Liu T, Zhou XB, Sun QM, Han ZQ, Liu K. Effects of climate change on plant composition and diversity in the Gurbantünggüt Desert of northwestern China. Ecol Res 2016. [DOI: 10.1007/s11284-016-1352-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
44
|
Lacher I, Schwartz MW. Empirical test on the relative climatic sensitivity between individuals of narrowly and broadly distributed species. Ecosphere 2016. [DOI: 10.1002/ecs2.1227] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Iara Lacher
- Department of Environmental Science and PolicyUniversity of California, DavisDavisCalifornia95616USA
| | - Mark W. Schwartz
- Department of Environmental Science and PolicyUniversity of California, DavisDavisCalifornia95616USA
- John Muir Institute of the EnvironmentUniversity of California, DavisDavisCalifornia95616USA
| |
Collapse
|
45
|
Napier JD, Mordecai EA, Heckman RW. The role of drought- and disturbance-mediated competition in shaping community responses to varied environments. Oecologia 2016; 181:621-32. [DOI: 10.1007/s00442-016-3582-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Accepted: 02/04/2016] [Indexed: 02/02/2023]
|
46
|
Stephens EL, Quintana-Ascencio PF. Effects of habitat degradation, microsite, and seed density on the persistence of two native herbs in a subtropical shrubland. AMERICAN JOURNAL OF BOTANY 2015; 102:1978-1995. [PMID: 26620096 DOI: 10.3732/ajb.1500125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 10/13/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Species in degraded ecosystems may interact differently with their surroundings from those under historic conditions. Understanding factors affecting variation in early life history stages of plants is fundamental to assessing their persistence in intact and degraded habitats, and the value of degraded lands. We evaluated the effect of seed density on the seed dynamics of two herbaceous species (annual, biennial), and considered how seed availability may influence population dynamics in different habitats (degraded, intact Florida scrub) and microsites (bare sand, leaf litter, shrub). METHODS We used data on responses to experimental treatments (seed removal, seedling emergence, establishment) and models to evaluate how effects of these factors may change over time since the last disturbance. KEY RESULTS Probability of any seed removal, emergence, and establishment per unit increased with seed density, although proportion removal for Chamaecrista fasciculata, proportion emergence for Balduina angustifolia, and proportion establishment for both species decreased with density. When animals were given selective access to seeds, invertebrates were primarily responsible for seed removal of both study species. Models with dynamics changing with time-since-disturbance for both species predicted that population growth may decrease slightly if local available seed density increases. CONCLUSIONS Detailed demographic comparisons of populations in intact and degraded conditions can be used to understand the way that environmental conditions (habitat, microsite) combine with seed density effects to influence population dynamics of herb species. Degraded habitat may act as a transitional state in a trajectory toward intact conditions for some species, or as refugia for other native species.
Collapse
Affiliation(s)
- Elizabeth L Stephens
- Department of Biology, University of Central Florida, Orlando, Florida 32816-2368 USA
| | | |
Collapse
|
47
|
Harrison SP, Gornish ES, Copeland S. Climate-driven diversity loss in a grassland community. Proc Natl Acad Sci U S A 2015; 112:8672-7. [PMID: 26100891 PMCID: PMC4507231 DOI: 10.1073/pnas.1502074112] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Local ecological communities represent the scale at which species coexist and share resources, and at which diversity has been experimentally shown to underlie stability, productivity, invasion resistance, and other desirable community properties. Globally, community diversity shows a mixture of increases and decreases over recent decades, and these changes have relatively seldom been linked to climatic trends. In a heterogeneous California grassland, we documented declining plant diversity from 2000 to 2014 at both the local community (5 m(2)) and landscape (27 km(2)) scales, across multiple functional groups and soil environments. Communities became particularly poorer in native annual forbs, which are present as small seedlings in midwinter; within native annual forbs, community composition changed toward lower representation of species with a trait indicating drought intolerance (high specific leaf area). Time series models linked diversity decline to the significant decrease in midwinter precipitation. Livestock grazing history, fire, succession, N deposition, and increases in exotic species could be ruled out as contributing causes. This finding is among the first demonstrations to our knowledge of climate-driven directional loss of species diversity in ecological communities in a natural (nonexperimental) setting. Such diversity losses, which may also foreshadow larger-scale extinctions, may be especially likely in semiarid regions that are undergoing climatic trends toward higher aridity and lower productivity.
Collapse
Affiliation(s)
- Susan P Harrison
- Department of Environmental Science and Policy, University of California, Davis, CA 95616;
| | - Elise S Gornish
- Department of Plant Sciences, University of California, Davis, CA 95616
| | - Stella Copeland
- Department of Environmental Science and Policy, University of California, Davis, CA 95616
| |
Collapse
|
48
|
Beck JJ, Hernández DL, Pasari JR, Zavaleta ES. Grazing maintains native plant diversity and promotes community stability in an annual grassland. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2015; 25:1259-1270. [PMID: 26485954 DOI: 10.1890/14-1093.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Maintaining native biodiversity in grasslands requires management and mitigation of anthropogenic changes that have altered resource availability, grazing regimes, and community composition. In California (USA), high levels of atmospheric nitrogen (N) deposition have facilitated the invasion of exotic grasses, posing a threat to the diverse plant and insect communities endemic to serpentine grasslands. Cattle grazing has been employed to mitigate the consequences of exotic grass invasion, but the ecological effects of grazing in this system are not fully understood. To characterize the effects of realistic N deposition on serpentine plant communities and to evaluate the efficacy of grazing as a management tool, we performed a factorial experiment adding N and excluding large herbivores in California's largest serpentine grassland. Although we observed significant interannual variation in community composition related to climate in our six-year study, exotic cover was consistently and negatively correlated with native plant richness. Sustained low-level N addition did not influence plant community composition, but grazing reduced grass abundance while maintaining greater native forb cover, native plant diversity, and species richness in comparison to plots excluding large herbivores. Furthermore, grazing increased the temporal stability of plant communities by decreasing year-to-year variation in native forb cover, native plant diversity, and native species richness. Taken together, our findings demonstrate that moderate-intensity cattle grazing can be used to restrict the invasive potential of exotic grasses and maintain native plant communities in serpentine grasslands. We hypothesize that the reduced temporal variability in serpentine plant communities managed by grazing may directly benefit populations of the threatened Edith's Bay checkerspot butterfly (Euphydryas editha bayensis).
Collapse
|
49
|
Gidoin C, Roques L, Boivin T. Linking niche theory to ecological impacts of successful invaders: insights from resource fluctuation-specialist herbivore interactions. J Anim Ecol 2014; 84:396-406. [DOI: 10.1111/1365-2656.12303] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 09/25/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Cindy Gidoin
- UR 629 Écologie des Forêts Méditerranéennes; INRA; F-84914 Avignon France
| | - Lionel Roques
- UR 546 Biostatistique et Processus Spatiaux; INRA; F-84914 Avignon France
| | - Thomas Boivin
- UR 629 Écologie des Forêts Méditerranéennes; INRA; F-84914 Avignon France
| |
Collapse
|
50
|
Barabás G, Pásztor L, Meszéna G, Ostling A. Sensitivity analysis of coexistence in ecological communities: theory and application. Ecol Lett 2014; 17:1479-94. [DOI: 10.1111/ele.12350] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/18/2014] [Accepted: 08/01/2014] [Indexed: 11/29/2022]
Affiliation(s)
- György Barabás
- Department of Ecology and Evolution; University of Chicago; 1101 E 57th St Chicago IL 60637 USA
| | - Liz Pásztor
- Department of Genetics; Eötvös Loránd University; Pázmány Péter sétány 1C H-1117 Budapest Hungary
| | - Géza Meszéna
- Department of Biological Physics; Eötvös Loránd University; Pázmány Péter sétány 1A H-1117 Budapest Hungary
| | - Annette Ostling
- Department of Ecology and Evolutionary Biology; University of Michigan; 830 North University Ann Arbor MI 48109-1048 USA
| |
Collapse
|