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The effects of protected areas on the ecological niches of birds and mammals. Sci Rep 2022; 12:11601. [PMID: 35804004 PMCID: PMC9270413 DOI: 10.1038/s41598-022-15949-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 07/01/2022] [Indexed: 12/03/2022] Open
Abstract
Protected areas are a cornerstone for biodiversity conservation, and typically support more natural and undisturbed habitats compared to unprotected lands. The effect of protected areas on intra-specific ecological niche has been rarely investigated. Here, we explore potential differences in ecological niche properties of birds and mammals across protected and unprotected areas, and relate such differences to species traits. We combine two decades of survey data of birds and mammals from protected and unprotected areas, and apply robust matching to obtain a set of environmentally comparable protected and unprotected sites. Next, we calculate intra-specific niche volume change and habitat shift between protected and unprotected areas, and use generalized linear mixed models to explain these responses with species traits (habitat specialization, body mass, diet, and red list status). The majority of bird and mammal species (83% and 90%, respectively) show different habitat use when occurring within and outside protected areas, with the magnitude of this shift highly varying across species. A minority of species (16% of birds and 10% of mammals) do not change their niche volume nor shift their habitat between protected and unprotected areas. Variation in niche properties is largely unrelated to species traits. Overall, the varying ecological niche responses of birds and mammals to protected areas underscore that there is no universal niche-based response, and that niche responses to land protection are species-specific.
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2
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Gribben PE, Bishop MJ, O’Connor WA, Bradley DJ, Hughes AR. Intraspecific diversity in prey body size influences survivorship by conferring resistance to predation. Ecosphere 2020. [DOI: 10.1002/ecs2.3106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Paul E. Gribben
- Centre for Marine Science and Innovation School of Earth, Environmental and Biological Sciences University of New South Wales Sydney New South Wales 2052 Australia
- Sydney Institute of Marine Science 19 Chowder Bay Road Mosman New South Wales 2088 Australia
| | - Melanie J. Bishop
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
| | - Wayne A. O’Connor
- NSW Department of Primary Industries Nelson Bay New South Wales 2315 Australia
| | - Daniel J. Bradley
- School of Life Sciences University of Technology Sydney New South Wales 2007 Australia
| | - A. Randall Hughes
- Northeastern University Marine Science Centre 430 Nahant Raod Nahant Massachusetts 01908 USA
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3
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Ramamonjisoa N, Mori A. Growth, developmental, and size structure responses in tadpole prey under increasing threat from gape-limited newts. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2019-0067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Size variability within a cohort can have profound effects on community ecology and evolution. Although competition for resources generally increases size variability, the effect of (non-consumptive) predation on this demographic trait remains relatively poorly understood. Existing models suggest a positive correlation between growth rate (mediated by resource level) and expression of size variability (as measured by the coefficient of variation) in prey cohorts. We tested this prediction by exposing the tadpoles of the Japanese Forest Green Treefrog (Rhacophorus arboreus (Okada and Kawano, 1924) = Zhangixalus arboreus (Okada and Kawano, 1924)) to the non-lethal presence of gape-limited Japanese Fire-bellied Newts (Cynops pyrrhogaster (Boie, 1826)) at low and high predator densities in an outdoor mesocosm experiment. Tadpole growth rates and periphyton biomass increased with newt density. But in contrast to prediction, elevated growth rates did not increase but, reversely, decreased cohort size variability in the tadpoles. We discuss two potential mechanisms behind this outcome. First, increased resource availability mediated by predator feeding may have reduced the strength of competition, ultimately leading to more evenly distributed resource gains among individuals; second, if smaller individuals grew relatively faster than larger individuals, as to quicken entry to a size refuge against the gape-limited predator, then inter-individual size differences could diminish over time.
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Affiliation(s)
- Noelikanto Ramamonjisoa
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Akira Mori
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
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4
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Ohlberger J, Langangen Ø, Winfield IJ, Vindenes Y. The importance of variation in offspring body size for stability in cannibalistic populations. OIKOS 2019. [DOI: 10.1111/oik.05507] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jan Ohlberger
- Centre for Ecological and Evolutionary Synthesis, Dept of Biosciences, Univ. of Oslo PO Box 1066 Blindern NO‐0316 Oslo Norway
- School of Aquatic and Fishery Sciences, Univ. of Washington Seattle WA USA
| | - Øystein Langangen
- Centre for Ecological and Evolutionary Synthesis, Dept of Biosciences, Univ. of Oslo PO Box 1066 Blindern NO‐0316 Oslo Norway
| | - Ian J. Winfield
- Lake Ecosystems Group, Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg Lancaster Lancashire UK
| | - Yngvild Vindenes
- Centre for Ecological and Evolutionary Synthesis, Dept of Biosciences, Univ. of Oslo PO Box 1066 Blindern NO‐0316 Oslo Norway
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5
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Predation decreases cohort foraging activity and growth, yet increases individual size variation in prey. Evol Ecol 2019. [DOI: 10.1007/s10682-019-09977-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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6
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Carlson BE, Langkilde T. Body size variation in aquatic consumers causes pervasive community effects, independent of mean body size. Ecol Evol 2017; 7:9978-9990. [PMID: 29238530 PMCID: PMC5723604 DOI: 10.1002/ece3.3511] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/09/2017] [Accepted: 09/21/2017] [Indexed: 11/08/2022] Open
Abstract
Intraspecific phenotypic variation is a significant component of biodiversity. Body size, for example, is variable and critical for structuring communities. We need to understand how homogenous and variably sized populations differ in their ecological responses or effects if we are to have a robust understanding of communities. We manipulated body size variation in consumer (tadpole) populations in mesocosms (both with and without predators), keeping mean size and density of these consumers constant. Size-variable consumer populations exhibited stronger antipredator responses (reduced activity), which had a cascading effect of increasing the biomass of the consumer's resources. Predators foraged less when consumers were variable in size, and this may have mediated the differential effects of predators on the community composition of alternative prey (zooplankton). All trophic levels responded to differences in consumer size variation, demonstrating that intrapopulation phenotypic variability can significantly alter interspecific ecological interactions. Furthermore, we identify a key mechanism (size thresholds for predation risk) that may mediate impacts of size variation in natural communities. Together, our results suggest that phenotypic variability plays a significant role in structuring ecological communities.
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Affiliation(s)
- Bradley E. Carlson
- Department of Biology, Intercollege Graduate Degree Program in Ecology, and Center for Brain, Behavior, and CognitionThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Tracy Langkilde
- Department of Biology, Intercollege Graduate Degree Program in Ecology, and Center for Brain, Behavior, and CognitionThe Pennsylvania State UniversityUniversity ParkPAUSA
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7
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Van Buskirk J, Cereghetti E, Hess JS. Is bigger really better? Relative and absolute body size influence individual growth rate under competition. Ecol Evol 2017; 7:3745-3750. [PMID: 28616171 PMCID: PMC5468154 DOI: 10.1002/ece3.2978] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/06/2017] [Accepted: 03/08/2017] [Indexed: 11/29/2022] Open
Abstract
Models suggest that the mechanism of competition can influence the growth advantage associated with being large (in absolute body size or relative to other individuals in the population). Large size is advantageous under interference, but disadvantageous under exploitative competition. We addressed this prediction in a laboratory experiment on Rana temporaria tadpoles competing for limited food. There were 166 target individuals spanning a 10‐fold range in body mass reared for 3 days with three other individuals that were either the same size, half as large, or twice as large as the target. Relative growth rate (proportion per day) declined with size, and absolute growth rate (mass per day) reached a peak at intermediate size and declined thereafter. Tadpoles grew slowly if they were large relative to their competitors, although relative body size was less important than absolute size. As a result, size variation declined in groups that were initially composed of individuals of variable size. Thus, bigger was not better under exploitative competition. Our results help connect individual‐level behavior with individual growth and the size distribution of the population.
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Affiliation(s)
- Josh Van Buskirk
- Evolutionary Biology & Environmental Studies University of Zürich Zürich Switzerland
| | - Eva Cereghetti
- Evolutionary Biology & Environmental Studies University of Zürich Zürich Switzerland
| | - Julia S Hess
- Evolutionary Biology & Environmental Studies University of Zürich Zürich Switzerland
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9
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Warne RW, Crespi EJ. Larval growth rate and sex determine resource allocation and stress responsiveness across life stages in juvenile frogs. ACTA ACUST UNITED AC 2015; 323:191-201. [DOI: 10.1002/jez.1911] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 12/04/2014] [Accepted: 12/04/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Robin W. Warne
- Department of Biology; Vassar College; Poughkeepsie New York
| | - Erica J. Crespi
- Department of Biology; Vassar College; Poughkeepsie New York
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10
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A method for detecting positive growth autocorrelation without marking individuals. PLoS One 2013; 8:e76389. [PMID: 24204620 PMCID: PMC3810375 DOI: 10.1371/journal.pone.0076389] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 08/30/2013] [Indexed: 11/19/2022] Open
Abstract
In most ecological studies, within-group variation is a nuisance that obscures patterns of interest and reduces statistical power. However, patterns of within-group variability often contain information about ecological processes. In particular, such patterns can be used to detect positive growth autocorrelation (consistent variation in growth rates among individuals in a cohort across time), even in samples of unmarked individuals. Previous methods for detecting autocorrelated growth required data from marked individuals. We propose a method that requires only estimates of within-cohort variance through time, using maximum likelihood methods to obtain point estimates and confidence intervals of the correlation parameter. We test our method on simulated data sets and determine the loss in statistical power due to the inability to identify individuals. We show how to accommodate nonlinear growth trajectories and test the effects of size-dependent mortality on our method's accuracy. The method can detect significant growth autocorrelation at moderate levels of autocorrelation with moderate-sized cohorts (for example, statistical power of 80% to detect growth autocorrelation ρ2 = 0.5 in a cohort of 100 individuals measured on 16 occasions). We present a case study of growth in the red-eyed tree frog. Better quantification of the processes driving size variation will help ecologists improve predictions of population dynamics. This work will help researchers to detect growth autocorrelation in cases where marking is logistically infeasible or causes unacceptable decreases in the fitness of marked individuals.
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11
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Sigourney DB, Munch SB, Letcher BH. Combining a Bayesian nonparametric method with a hierarchical framework to estimate individual and temporal variation in growth. Ecol Modell 2012. [DOI: 10.1016/j.ecolmodel.2012.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Effects of size and size structure on predation and inter-cohort competition in red-eyed treefrog tadpoles. Oecologia 2012; 170:629-39. [PMID: 22565492 DOI: 10.1007/s00442-012-2332-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 04/05/2012] [Indexed: 10/28/2022]
Abstract
Individual and relative body size are key determinants of ecological performance, shaping the strength and types of interactions within and among species. Size-dependent performance is particularly important for iteroparous species with overlapping cohorts, determining the ability of new cohorts to invade habitats with older, larger conspecifics. We conducted two mesocosm experiments to examine the role of size and size structure in shaping growth and survival in tadpoles of the red-eyed treefrog (Agalychnis callidryas), a tropical species with a prolonged breeding season. First, we used a response surface design to quantify the competitive effect and response of two tadpole size classes across three competitive environments. Large tadpoles were superior per capita effect competitors, increasing the size difference between cohorts through time at high resource availability. Hatchlings were better per biomass response competitors, and maintained the size difference between cohorts when resource availability was low. However, in contrast to previous studies, small tadpoles never closed the size gap with large tadpoles. Second, we examine the relationship between body size, size structure, and predation by dragonfly nymphs (Anax amazili) on tadpole survival and growth. Hatchlings were more vulnerable to predation; predator and large competitor presence interacted to reduce hatchling growth. Again, the size gap between cohorts increased over time, but increased marginally more with predators present. These findings have implications for understanding how variation in resources and predation over the breeding season will shape population size structure through time and the ability of new cohorts to invade habitats with older conspecifics.
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13
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Bolnick DI, Amarasekare P, Araújo MS, Bürger R, Levine JM, Novak M, Rudolf VHW, Schreiber SJ, Urban MC, Vasseur DA. Why intraspecific trait variation matters in community ecology. Trends Ecol Evol 2011; 26:183-92. [PMID: 21367482 PMCID: PMC3088364 DOI: 10.1016/j.tree.2011.01.009] [Citation(s) in RCA: 1222] [Impact Index Per Article: 94.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 01/25/2011] [Accepted: 01/25/2011] [Indexed: 11/17/2022]
Abstract
Natural populations consist of phenotypically diverse individuals that exhibit variation in their demographic parameters and intra- and inter-specific interactions. Recent experimental work indicates that such variation can have significant ecological effects. However, ecological models typically disregard this variation and focus instead on trait means and total population density. Under what situations is this simplification appropriate? Why might intraspecific variation alter ecological dynamics? In this review we synthesize recent theory and identify six general mechanisms by which trait variation changes the outcome of ecological interactions. These mechanisms include several direct effects of trait variation per se and indirect effects arising from the role of genetic variation in trait evolution.
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Affiliation(s)
- Daniel I Bolnick
- Howard Hughes Medical Institute, Section of Integrative Biology, University of Texas at Austin, TX 78712, USA.
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14
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SMITH ANNAC, SHIMA JEFFREYS. Variation in the effects of larval history on juvenile performance of a temperate reef fish. AUSTRAL ECOL 2011. [DOI: 10.1111/j.1442-9993.2010.02223.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Benard MF, Middlemis Maher J. Consequences of intraspecific niche variation: phenotypic similarity increases competition among recently metamorphosed frogs. Oecologia 2011; 166:585-92. [DOI: 10.1007/s00442-010-1896-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 12/14/2010] [Indexed: 10/18/2022]
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16
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Huss M, Van Kooten T, Persson L. Intra-cohort cannibalism and size bimodality: a balance between hatching synchrony and resource feedbacks. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2010.18454.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Borcherding J, Beeck P, DeAngelis DL, Scharf WR. Match or mismatch: the influence of phenology on size-dependent life history and divergence in population structure. J Anim Ecol 2010; 79:1101-12. [DOI: 10.1111/j.1365-2656.2010.01704.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Wissinger SA, Whiteman HH, Denoël M, Mumford ML, Aubee CB. Consumptive and nonconsumptive effects of cannibalism in fluctuating age-structured populations. Ecology 2010; 91:549-59. [PMID: 20392019 DOI: 10.1890/08-1366.1] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Theory and empirical studies suggest that cannibalism in age-structured populations can regulate recruitment depending on the intensity of intraspecific competition between cannibals and victims and the nature of the cannibalism window, i.e., which size classes interact as cannibals and victims. Here we report on a series of experiments that quantify that window for age-structured populations of salamander larvae and paedomorphic adults. We determined body size limits on cannibalism in microcosms and then the consumptive and nonconsumptive (injuries, foraging and activity, diet, growth) effects on victims in mesocosms with seminatural levels of habitat complexity and alternative prey. We found that cannibalism by the largest size classes (paedomorphs and > or = age 3+ yr larvae) occurs mainly on young-of-the-year (YOY) victims. Surviving YOY and other small larvae had increased injuries, reduced activity levels, and reduced growth rates in the presence of cannibals. Data on YOY survival in an experiment in which we manipulated the density of paedomorphs combined with historical data on the number of cannibals in natural populations indicate that dominant cohorts of paedomorphs can cause observed recruitment failures. Dietary data indicate that ontogenetic shifts in diet should preclude strong intraspecific competition between YOY and cannibals in this species. Thus our results are consistent with previous empirical and theoretical work that suggests that recruitment regulation by cannibalism is most likely when YOY are vulnerable to cannibalism but have low dietary overlap with cannibals. Understanding the role of cannibalism in regulating recruitment in salamander populations is timely, given the widespread occurrences of amphibian decline. Previous studies have focused on extrinsic (including anthropogenic) factors that affect amphibian population dynamics, whereas the data presented here combined with long-term field observations suggest the potential for intrinsically driven population cycles.
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Affiliation(s)
- Scott A Wissinger
- Biology Department, Allegheny College, Meadville, Pennsylvania 16335, USA.
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19
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Huss M, Byström P, Persson L. Effetcs of ontogenetic scaling on resource exploitation and cohort size distributions. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2009.17897.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Zuidema PA, Brienen RJW, During HJ, Güneralp B. Do persistently fast-growing juveniles contribute disproportionately to population growth? A new analysis tool for matrix models and its application to rainforest trees. Am Nat 2009; 174:709-19. [PMID: 19778168 DOI: 10.1086/605981] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Plants and animals often exhibit strong and persistent growth variation among individuals within a species. Persistently fast-growing individuals have a higher chance of reaching reproductive size, do so at a younger age, and therefore contribute disproportionately to population growth (lambda). Here we introduce a new approach to quantify this "fast-growth effect." We propose using age-size-structured matrix models in which persistently fast and slow growers are distinguished as they occur in relatively young and old age classes for a given size category. Life-cycle pathways involving fast growth can then be identified, and their contribution to lambda is quantified through loop analysis. We applied this approach to an example species, the tropical rainforest tree Cedrela odorata, that shows persistent growth variation among individuals. Loop analysis showed that juvenile trees reaching the 10-cm diameter class at below-median age contributed twice as much to lambda as slow juvenile growers. Fast growth to larger-diameter categories also contributed disproportionately to lambda. The results were robust to changes in parameter values and life-history trade-offs. These results show that the fast-growth effect can be strong in long-lived species. Persistent growth differences among individuals should therefore be accommodated for in demographic models and life-history studies.
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Affiliation(s)
- Pieter A Zuidema
- Ecology and Biodiversity, Institute of Environmental Biology, Utrecht University, P.O. Box 80084, 3508 TB Utrecht, The Netherlands.
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Huss M, Byström P, Persson L. Resource heterogeneity, diet shifts and intra-cohort competition: effects on size divergence in YOY fish. Oecologia 2008; 158:249-57. [PMID: 18781331 DOI: 10.1007/s00442-008-1140-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 08/08/2008] [Indexed: 11/27/2022]
Abstract
Most organisms exhibit a substantial size variation among individuals due to individual differences in experienced biotic and abiotic environmental conditions and because individuals undergo growth and development during most of their life time. One important issue in this context is how size variation within cohorts may develop over time. Here, we tested the hypothesis, in gape-limited animals such as fish, that size divergence among individuals within a cohort depends on the opportunity to undergo size-dependent diet shifts, by allowing initially larger individuals to make an early diet shift when the first resource becomes limiting. We used young-of-the-year perch (Perca fluviatilis) as our study organism. Competitive intensity and the opportunity to undergo a diet shift from zooplankton to macroinvertebrates affected both mean growth rates and the extent to which inter-individual variation in growth was manifested. As predicted, increased competition combined with the presence of both zooplankton and benthic macroinvertebrates increased the degree of size variation. However, size divergence was also observed among individuals when only the initial resource, zooplankton, was available. We argue that only non-exploitative interactions, such as dominance structures and social interactions, could have caused this latter pattern, as exploitative competition is expected to lead to size convergence due to the superior competitive ability of smaller individuals. Our results suggest that diet shifts are not a prerequisite for size divergence in animal cohorts, and that dominance and social interactions may have similar effects on size variation within cohorts. Finally, development of size variation is suggested to have strong implications for overall cohort performance.
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Affiliation(s)
- Magnus Huss
- Department of Ecology and Environmental Science, Umeå University, 901 87, Umeå, Sweden.
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