1
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Borrero H, Oviedo‐Prieto R, Alvarez JC, Ticktin T, Cisneros M, Liu H. Populations of a tropical epiphytic orchid are destabilized in its peripheral range by hurricane and an exotic herbivore. Ecosphere 2023. [DOI: 10.1002/ecs2.4355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Haydee Borrero
- Department of Earth and Environment and International Center for Tropical Botany Florida International University Miami Florida USA
- Fairchild Tropical Botanic Garden Coral Gables Florida USA
| | - Ramona Oviedo‐Prieto
- The Institute of Ecology and Systematics National Herbarium “Onaney Muñiz” and Botanica Habana Cuba
| | - Julio C. Alvarez
- The Institute of Ecology and Systematics National Herbarium “Onaney Muñiz” and Botanica Habana Cuba
| | - Tamara Ticktin
- School of Life Sciences University of Hawai'i at Mānoa Honolulu Hawaii USA
| | - Mario Cisneros
- Department of Earth and Environment and International Center for Tropical Botany Florida International University Miami Florida USA
| | - Hong Liu
- Department of Earth and Environment and International Center for Tropical Botany Florida International University Miami Florida USA
- Fairchild Tropical Botanic Garden Coral Gables Florida USA
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2
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Ogilvie JE, CaraDonna PJ. The shifting importance of abiotic and biotic factors across the life cycles of wild pollinators. J Anim Ecol 2022; 91:2412-2423. [PMID: 36268682 DOI: 10.1111/1365-2656.13825] [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: 04/21/2022] [Accepted: 09/19/2022] [Indexed: 12/14/2022]
Abstract
Organisms living in seasonal environments are exposed to different environmental conditions as they transition from one life stage to the next across their life cycle. How different life stages respond to these varying conditions, and the extent to which different life stages are linked, are fundamental components of the ecology of an organism. Nevertheless, the influence of abiotic and biotic factors on different parts of an organism's life cycle is often not accounted for, which limits our understanding of the ecological consequences of environmental change. We investigated the relative importance of climate conditions, food availability, and previous life-stage abundance in an assemblage of seven wild bumble bee species, asking: how do these three factors directly influence bee abundance at each life stage? To do so, we used a 7-year dataset where we monitored climate conditions, floral resources, and abundances of bees in each life stage across the active colony life cycle in a highly seasonal subalpine ecosystem in the Colorado Rocky Mountains, USA. Bee abundance at different life stages responded to abiotic and biotic conditions in a broadly consistent manner across the seven species: the survival and recruitment stage of the life cycle (overwintered queens) responded negatively to longer winters; the growth stage (workers) responded positively to floral resource availability; and the reproductive stage (males) was positively related to the abundance of the previous life stage (workers). Most species also exhibited some idiosyncratic responses. Our long-term examination of annual bumble bees reveals a general set of responses in the abundance of each life stage to climate conditions, floral resource availability, and previous life stage. Across species, these three factors each directly influenced a distinct life stage, illustrating how their relative importance can shift throughout the life cycle. The life-cycle approach that we have taken highlights that important details about demography can be overlooked without considering life-stage-specific responses. Ultimately, it is these life-stage-specific responses that shape population outcomes, not only for animal pollinators but also for many organisms living in seasonal environments.
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Affiliation(s)
- Jane E Ogilvie
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, USA.,Chicago Botanic Garden, Glencoe, Illinois, USA
| | - Paul J CaraDonna
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, USA.,Chicago Botanic Garden, Glencoe, Illinois, USA.,Plant Biology and Conservation, Northwestern University, Evanston, Illinois, USA
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3
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Carley LN, Morris WF, Walsh R, Riebe D, Mitchell‐Olds T. Are genetic variation and demographic performance linked? Evol Appl 2022; 15:1888-1906. [DOI: 10.1111/eva.13487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 09/12/2022] [Indexed: 12/13/2022] Open
Affiliation(s)
- Lauren N. Carley
- University Program in Ecology Duke University Durham North Carolina USA
- Biology Department Duke University Durham North Carolina USA
- Department of Plant and Microbial Biology University of Minnesota Twin Cities St. Paul Minnesota USA
| | | | - Roberta Walsh
- Division of Biological Sciences University of Montana Missoula Montana USA
| | - Donna Riebe
- Division of Biological Sciences University of Montana Missoula Montana USA
| | - Tom Mitchell‐Olds
- Biology Department Duke University Durham North Carolina USA
- Division of Biological Sciences University of Montana Missoula Montana USA
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4
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Estimation of the present status of the species based on the theoretical bounds of environmental noise intensity: An illustration through a big abundance data and simulation. THEOR ECOL-NETH 2022. [DOI: 10.1007/s12080-022-00541-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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5
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Zettlemoyer MA. Monitoring demography of resurrected populations of locally extinct and extant species to investigate drivers of species loss. Am Nat 2022; 200:E36-E51. [DOI: 10.1086/720206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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6
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Berio Fortini L, Krushelnycky PD, Drake DR, Starr F, Starr K, Chimera CG. Complex demographic responses to contrasting climate drivers lead to divergent population trends across the range of a threatened alpine plant. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2021.e01954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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7
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Timsina B, Kindlmann P, Münzbergová Z, Rokaya MB. Six-Year Demographic Study of the Terrestrial Orchid, Crepidium acuminatum: Implications for Conservation. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.676993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Studies on population dynamics are helpful for understanding the factors determining population development and predicting the effects of disturbances, such as harvesting of plant species. In an investigation of the demography of a terrestrial medicinal orchid known as Crepidium acuminatum, the effects of harvesting on its population dynamics were recorded. Data on recruitment, growth and survival were collected in three populations of C. acuminatum over a 6-year period (2012–2017) in central Nepal. A matrix modeling method was used to determine the effect of different harvesting regimes on the population growth and survival of this species. Population growth rates (λ) of unharvested populations were relatively similar and stable in different years of the study. Harvesting significantly reduced λ. The results of this study indicate that the sustainable survival of a population that is subject to harvesting can only occur when it is either selective (only flowering individuals or only small amounts of vegetative individuals) or rotational (once every 3–5 or more years). This study demonstrates the necessity of using a sustainable method when harvesting natural populations. Our results are useful for developing efficient management strategies for this species. As each species has a different biology, similar studies are needed for other rare and/or economically important species in the Himalayan region and in other understudied parts of the world.
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8
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Rosenblatt CJ, Gates RJ, Matthews SN, Peterman WE, Stricker NJ. An integrated population model to project viability of a northern bobwhite population in Ohio. Ecosphere 2021. [DOI: 10.1002/ecs2.3731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Connor J. Rosenblatt
- School of Environment and Natural Resources The Ohio State University 2021 Coffey Road, 210 Kottman Hall Columbus Ohio 43210 USA
| | - Robert J. Gates
- School of Environment and Natural Resources The Ohio State University 2021 Coffey Road, 210 Kottman Hall Columbus Ohio 43210 USA
| | - Stephen N. Matthews
- School of Environment and Natural Resources The Ohio State University 2021 Coffey Road, 210 Kottman Hall Columbus Ohio 43210 USA
| | - William E. Peterman
- School of Environment and Natural Resources The Ohio State University 2021 Coffey Road, 210 Kottman Hall Columbus Ohio 43210 USA
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9
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Srivastava DS, Coristine L, Angert AL, Bontrager M, Amundrud SL, Williams JL, Yeung ACY, Zwaan DR, Thompson PL, Aitken SN, Sunday JM, O'Connor MI, Whitton J, Brown NEM, MacLeod CD, Parfrey LW, Bernhardt JR, Carrillo J, Harley CDG, Martone PT, Freeman BG, Tseng M, Donner SD. Wildcards in climate change biology. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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10
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Raventós J, Mújica E, González E, Bonet A, Ortega‐Larrocea MP. The effects of hurricanes on the stochastic population growth of the endemic epiphytic orchid
Broughtonia cubensis
living in Cuba. POPUL ECOL 2021. [DOI: 10.1002/1438-390x.12098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- José Raventós
- Department of Ecology University of Alicante Alicante Spain
| | | | | | - Andreu Bonet
- Department of Ecology University of Alicante Alicante Spain
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11
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Alahuhta KM, Crone EE, Lesica P. Comparing demography inferred from age vs. stage in a perennial plant. Ecology 2021; 102:e03322. [PMID: 33690901 DOI: 10.1002/ecy.3322] [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: 09/10/2019] [Revised: 11/14/2020] [Accepted: 01/11/2021] [Indexed: 11/08/2022]
Abstract
Life history theories analyze and predict variation in vital rates, such as survival and reproduction, based on age. The age-from-stage method to derive age-specific vital rates from stage data was developed because age-specific data are rarely obtained for plants. Age-specific vital rates derived by this method might underestimate effects of age on vital rates, because the models assume that vital rates do not vary within stage classes. Consequently, population models and life history summaries relying on these vital rates could be biased against detecting senescence. Here, we perform a comparative study of methods to estimate age-specific vital rates using monitoring data with known age and stage. We derived age-, stage-, and age-and-stage-specific vital rates with demographic data from a long-lived perennial, Silene spaldingii. Then, we derived three age-specific population matrix models (age, age-from-stage, and age-and-stage). For each model, we derived life history summaries commonly used in ecology: population growth rate, net reproductive value, relative reproductive values, stable age distribution, generation time, and sensitivity and elasticity of population growth rate. Many vital rates depended on both age and stage in S. spaldingii. However, this species does not senesce; in fact, the number of flowers increased with age. As expected, the age-from-stage method was not able to accurately recreate the age dependence in some life history summaries, such as relative reproductive value. The age-from-stage model suggested faster reproductive dynamics in S. spaldingii than the models based on known age, i.e., plants started to reproduce earlier, and fertility remained constant thereafter, which may lead to biased predictions about evolutionary consequences of age-dependent life history traits. However, population growth rate, generation time, and net reproductive rate did not differ significantly among the models. Our study demonstrated that some metrics are robust to imprecision in model structure, while others are more sensitive. In spite of these biases, this case study provides another example of the diversity of aging patterns in plants. Age can be essential information when studying senescence in plants, but demographic metrics that were not about age per se were similar across model structures.
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Affiliation(s)
- Kirsi M Alahuhta
- Department of Ecology and Genetics, University of Oulu, Pentti Kaiteran katu 1, Oulu, 90014, Finland
| | - Elizabeth E Crone
- Department of Biology, Tufts University, 200 College Avenue, Medford, Massachusetts, 02155, USA
| | - Peter Lesica
- Division of Biological Sciences, University of Montana, 32 Campus Drive HS 104, Missoula, Montana, 59812, USA
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12
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Tremblay RL, Tyre AJ, Pérez ME, Ackerman JD. Population projections from holey matrices: Using prior information to estimate rare transition events. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Goodsell RM, Childs DZ, Spencer M, Coutts S, Vergnon R, Swinfield T, Queenborough SA, Freckleton RP. Developing hierarchical density‐structured models to study the national‐scale dynamics of an arable weed. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Robert M. Goodsell
- Department of Animal and Plant Sciences University of Sheffield Sheffield S10 2TN United Kingdom
| | - Dylan Z. Childs
- Department of Animal and Plant Sciences University of Sheffield Sheffield S10 2TN United Kingdom
| | - Matthew Spencer
- School of Environmental Sciences University of Liverpool Liverpool L69 3GP United Kingdom
| | - Shaun Coutts
- Lincoln Institute for Agri‐food Technology University of Lincoln Lincoln LN2 2LG United Kingdom
| | - Remi Vergnon
- Department of Animal and Plant Sciences University of Sheffield Sheffield S10 2TN United Kingdom
| | - Tom Swinfield
- RSPB Potton road Sandy Bedfordshire SH19 2DL United Kingdom
| | - Simon A. Queenborough
- Yale School of Forestry & Environmental Studies Yale University New Haven Connecticut 06511 USA
| | - Robert P. Freckleton
- Department of Animal and Plant Sciences University of Sheffield Sheffield S10 2TN United Kingdom
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14
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Lasky JR, Hooten MB, Adler PB. What processes must we understand to forecast regional-scale population dynamics? Proc Biol Sci 2020; 287:20202219. [PMID: 33290672 PMCID: PMC7739927 DOI: 10.1098/rspb.2020.2219] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 11/12/2020] [Indexed: 12/14/2022] Open
Abstract
An urgent challenge facing biologists is predicting the regional-scale population dynamics of species facing environmental change. Biologists suggest that we must move beyond predictions based on phenomenological models and instead base predictions on underlying processes. For example, population biologists, evolutionary biologists, community ecologists and ecophysiologists all argue that the respective processes they study are essential. Must our models include processes from all of these fields? We argue that answering this critical question is ultimately an empirical exercise requiring a substantial amount of data that have not been integrated for any system to date. To motivate and facilitate the necessary data collection and integration, we first review the potential importance of each mechanism for skilful prediction. We then develop a conceptual framework based on reaction norms, and propose a hierarchical Bayesian statistical framework to integrate processes affecting reaction norms at different scales. The ambitious research programme we advocate is rapidly becoming feasible due to novel collaborations, datasets and analytical tools.
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Affiliation(s)
- Jesse R. Lasky
- Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Mevin B. Hooten
- U.S. Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit, Colorado State University, Fort Collins, CO, USA
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, USA
- Department of Statistics, Colorado State University, Fort Collins, CO, USA
| | - Peter B. Adler
- Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT, USA
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15
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Shefferson RP, Kurokawa S, Ehrlén J. lefko3
: Analysing individual history through size‐classified matrix population models. Methods Ecol Evol 2020. [DOI: 10.1111/2041-210x.13526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
| | - Shun Kurokawa
- Graduate School of Arts and Sciences University of Tokyo Tokyo Japan
| | - Johan Ehrlén
- Department of Ecology, Environment, and Plant Sciences Stockholm University Stockholm Sweden
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16
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Meier AJ, Meier AR, Stone J, Stone M, McPhail B. The Near Extirpation and Subsequent Restoration of Asarum canadense L. (Wild Ginger) (Aristolochiaceae) in Louisiana. SOUTHEAST NAT 2020. [DOI: 10.1656/058.019.0220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Albert J. Meier
- Western Kentucky University, Department of Biology, 1906 College Heights Boulevard #11080, Bowling Green, KY 42101
| | | | - Joleen Stone
- Lovee and Rose Farm, 650 W E Cole Road, Bowling Green, KY 42101
| | - Martin Stone
- Western Kentucky University Department of Agriculture and Food Sciences, 1906 College Heights Boulevard, Bowling Green, KY 42101
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17
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Romanov MS, Masterov VB. Low breeding performance of the Steller’s sea eagle (Haliaeetus pelagicus) causes the populations to decline. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2019.108877] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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Ticktin T, Mondragón D, Lopez‐Toledo L, Dutra‐Elliott D, Aguirre‐León E, Hernández‐Apolinar M. Synthesis of wild orchid trade and demography provides new insight on conservation strategies. Conserv Lett 2020. [DOI: 10.1111/conl.12697] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Tamara Ticktin
- Botany DepartmentUniversity of Hawaiʻi at Mānoa Honolulu Hawaii
| | | | - Leonel Lopez‐Toledo
- Instituto de Investigaciones sobre los Recursos NaturalesUniversidad Michoacana de San Nicolás de Hidalgo Morelia Mexico
| | | | | | - Mariana Hernández‐Apolinar
- Departamento de Ecologia y Recursos Naturales, Facultad de CienciasUniversidad Nacional Autónoma de México Mexico City Mexico
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19
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Peterson ML, Angert AL, Kay KM. Experimental migration upward in elevation is associated with strong selection on life history traits. Ecol Evol 2020; 10:612-625. [PMID: 32015830 PMCID: PMC6988539 DOI: 10.1002/ece3.5710] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 08/10/2019] [Accepted: 09/05/2019] [Indexed: 12/26/2022] Open
Abstract
One of the strongest biological impacts of climate change has been the movement of species poleward and upward in elevation. Yet, what is not clear is the extent to which the spatial distribution of locally adapted lineages and ecologically important traits may also shift with continued climate change. Here, we take advantage of a transplant experiment mimicking up-slope seed dispersal for a suite of ecologically diverse populations of yellow monkeyflower (Mimulus guttatus sensu lato) into a high-elevation common garden during an extreme drought period in the Sierra Nevada mountains, California, USA. We use a demographic approach to quantify fitness and test for selection on life history traits in local versus lower-elevation populations and in normal versus drought years to test the potential for up-slope migration and phenotypic selection to alter the distribution of key life history traits in montane environments. We find that lower-elevation populations tend to outperform local populations, confirming the potential for up-slope migration. Although selection generally favored some local montane traits, including larger flowers and larger stem size at flowering, drought conditions tended to select for earlier flowering typical of lower-elevation genotypes. Taken together, this suggests that monkeyflower lineages moving upward in elevation could experience selection for novel trait combinations, particularly under warmer and drier conditions that are predicted to occur with continued climate change.
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Affiliation(s)
- Megan L. Peterson
- Ecology and Evolutionary BiologyUniversity of California Santa CruzSanta CruzCalifornia
| | - Amy L. Angert
- Department of Botany and ZoologyUniversity of British ColumbiaVancouverBCCanada
| | - Kathleen M. Kay
- Ecology and Evolutionary BiologyUniversity of California Santa CruzSanta CruzCalifornia
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20
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Kerr NZ, Crone EE, Chew FS. Life history trade‐offs are more pronounced for a noninvasive, native butterfly compared to its invasive, exotic congener. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.12035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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21
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Ramula S, Kerr NZ, Crone EE. Using statistics to design and estimate vital rates in matrix population models for a perennial herb. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.12024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Satu Ramula
- Department of Biology University of Turku Turku Finland
| | - Natalie Z. Kerr
- Department of Biology Tufts University Medford Massachusetts
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22
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Trask AE, Fenn SR, Bignal EM, McCracken DI, Monaghan P, Reid JM. Evaluating the efficacy of independent versus simultaneous management strategies to address ecological and genetic threats to population viability. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13464] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amanda E. Trask
- School of Biological Sciences, Zoology Building University of Aberdeen Aberdeen UK
| | - Sarah R. Fenn
- School of Biological Sciences, Zoology Building University of Aberdeen Aberdeen UK
| | | | - Davy I. McCracken
- Department of Integrated Land Management Scotland's Rural College Auchincruive Ayr UK
| | - Pat Monaghan
- Institute of Biodiversity, Animal Health & Comparative Medicine University of Glasgow Glasgow UK
| | - Jane M. Reid
- School of Biological Sciences, Zoology Building University of Aberdeen Aberdeen UK
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23
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Shriver RK, Andrews CM, Arkle RS, Barnard DM, Duniway MC, Germino MJ, Pilliod DS, Pyke DA, Welty JL, Bradford JB. Transient population dynamics impede restoration and may promote ecosystem transformation after disturbance. Ecol Lett 2019; 22:1357-1366. [DOI: 10.1111/ele.13291] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/22/2018] [Accepted: 05/09/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Robert K. Shriver
- U.S. Geological SurveySouthwest Biological Science Center2255 N Gemini Rd Flagstaff AZ USA
| | - Caitlin M. Andrews
- U.S. Geological SurveySouthwest Biological Science Center2255 N Gemini Rd Flagstaff AZ USA
| | - Robert S. Arkle
- U.S. Geological SurveyForest and Rangeland Ecosystem Science Center970 S Lusk St Boise ID USA
| | - David M. Barnard
- U.S. Geological SurveyForest and Rangeland Ecosystem Science Center970 S Lusk St Boise ID USA
| | - Michael C. Duniway
- U.S. Geological SurveySouthwest Biological Science Center2290 Resource Blvd Moab UT USA
| | - Matthew J. Germino
- U.S. Geological SurveyForest and Rangeland Ecosystem Science Center970 S Lusk St Boise ID USA
| | - David S. Pilliod
- U.S. Geological SurveyForest and Rangeland Ecosystem Science Center970 S Lusk St Boise ID USA
| | - David A. Pyke
- U.S. Geological Survey Forest and Rangeland Ecosystem Science Center 3200 SW Jefferson Way Corvallis OR USA
| | - Justin L. Welty
- U.S. Geological SurveyForest and Rangeland Ecosystem Science Center970 S Lusk St Boise ID USA
| | - John B. Bradford
- U.S. Geological SurveySouthwest Biological Science Center2255 N Gemini Rd Flagstaff AZ USA
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24
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Riverón-Giró FB, Raventós J, Damon A, García-González A, Mújica E. Spatio-temporal dynamics of the invasive orchid Oeceoclades maculata (Orchidaceae), in four different habitats in southeast Chiapas, Mexico. Biol Invasions 2019. [DOI: 10.1007/s10530-019-01945-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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25
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Hanley BJ, Bunting EM, Schuler KL. How can we augment the few that remain? Using stable population dynamics to aid reintroduction planning of an iteroparous species. PeerJ 2019; 7:e6873. [PMID: 31106072 PMCID: PMC6500717 DOI: 10.7717/peerj.6873] [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: 10/24/2018] [Accepted: 03/30/2019] [Indexed: 11/20/2022] Open
Abstract
Restoration of depleted populations is an important method in biological conservation. Reintroduction strategies frequently aim to restore stable, increasing, self-sustaining populations. Knowledge of asymptotic system dynamics may provide advantage in selecting reintroduction strategies. We introduce interactive software that is designed to identify strategies for release of females that are immediately aligned with stable population dynamics from species represented by 2-, 3-, 4-, and 5-stage life history strategies. The software allows managers to input a matrix of interest, the desired number of breeding females, and the desired management timeline, and calls upon stable population theory to give release strategies that are in concert with both stable population status and the management goals. We demonstrate how the software can aid in assessing various strategies ahead of a hypothetical restoration. For the purpose of demonstration of the tool only, we use published vital rates of an ungulate species, but remark that the selection of species for demonstration is not central to the use of this tool. Adaption of this tool to real-life restorations of any 2-, 3-, 4-, or 5-stage iteroparous species may aid in understanding how to minimize undesirable recovery complications that may naturally arise from transient population dynamics. The software is freely available at: https//cwhl.vet.cornell.edu/tools/stapopd.
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Affiliation(s)
- Brenda J. Hanley
- Cornell Wildlife Health Lab, Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, United States of America
| | - Elizabeth M. Bunting
- Cornell Wildlife Health Lab, Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, United States of America
| | - Krysten L. Schuler
- Cornell Wildlife Health Lab, Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, United States of America
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26
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Plard F, Turek D, Grüebler MU, Schaub M. IPM
2
: toward better understanding and forecasting of population dynamics. ECOL MONOGR 2019. [DOI: 10.1002/ecm.1364] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Floriane Plard
- Swiss Ornithological Institute CH‐6204 Sempach Switzerland
| | - Daniel Turek
- Department of Mathematics and Statistics Williams College 18 Hoxsey Street Williamstown Massachusetts 01267 USA
| | | | - Michael Schaub
- Swiss Ornithological Institute CH‐6204 Sempach Switzerland
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27
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Caughlin TT, Damschen EI, Haddad NM, Levey DJ, Warneke C, Brudvig LA. Landscape heterogeneity is key to forecasting outcomes of plant reintroduction. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2019; 29:e01850. [PMID: 30821885 DOI: 10.1002/eap.1850] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/26/2018] [Accepted: 12/04/2018] [Indexed: 06/09/2023]
Abstract
Conservation and restoration projects often involve starting new populations by introducing individuals into portions of their native or projected range. Such efforts can help meet many related goals, including habitat creation, ecosystem service provisioning, assisted migration, and the reintroduction of imperiled species following local extirpation. The outcomes of reintroduction efforts, however, are highly variable, with results ranging from local extinction to dramatic population growth; reasons for this variation remain unclear. Here, we ask whether population growth following plant reintroductions is governed by variation at two scales: the scale of individual habitat patches to which individuals are reintroduced, and larger among-landscape scales in which similar patches may be situated in landscapes that differ in matrix type, soil conditions, and other factors. Quantifying demographic variation at these two scales will help prioritize locations for introduction and, once introductions take place, forecast population growth. This work took place within a large-scale habitat fragmentation experiment, where individuals of two perennial forb species were reintroduced into eight replicate ~50-ha landscapes, each containing a set of five ~1-ha patches that varied in their degree of isolation (connected by habitat corridors or unconnected) and edge-to-area ratio. Using data on individual growth, survival, reproductive output, and recruitment collected one to two years after reintroduction, we developed models to forecast population growth, then compared forecasts to observed population sizes, three and six years later. Both the type of patch (connected and unconnected) and identity of the landscape to which individuals were reintroduced had effects on forecasted population growth rates, but only variation associated with landscape identity was an accurate predictor of subsequently observed population growth rates. Models that did not include landscape identity had minimal forecasting ability, revealing the key importance of variation at this scale for accurate prediction. Of the five demographic rates used to model population dynamics, seed production was the most important source of forecast error in population growth rates. Our results point to the importance of accounting for landscape-scale variation in demographic models and demonstrate how such models might assist with prioritizing particular landscapes for species reintroduction projects.
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Affiliation(s)
- T Trevor Caughlin
- Department of Biological Sciences and Program in Ecology, Evolution, and Behavior, Boise State University, Boise, Idaho 83725 USA
| | - Ellen I Damschen
- Department of Integrative Biology, University of Wisconsin-Madison, 451 Birge Hall, 430 Lincoln Drive, Madison, Wisconsin, 53706, USA
| | - Nick M Haddad
- Kellogg Biological Station and Department of Integrative Biology, Michigan State University, Hickory Corners, Michigan, 49060, USA
| | - Douglas J Levey
- Division of Environmental Biology, National Science Foundation, Alexandria, Virginia, 22314, USA
| | - Christopher Warneke
- Department of Plant Biology and Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan 48824 USA
| | - Lars A Brudvig
- Department of Plant Biology and Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan 48824 USA
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28
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Wheeler ME, Barzen JA, Crimmins SM, Van Deelen TR. Effects of territorial status and life history on Sandhill Crane ( Antigone canadensis) population dynamics in south-central Wisconsin, USA. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Population growth rate in long-lived bird species is often most sensitive to changes in adult survival. Sandhill Cranes (Antigone canadensis (Linnaeus, 1758)) have long life spans, small broods, and delayed first reproduction. Only territorial adult Sandhill Cranes participate in breeding, and territory acquisition reflects the interplay between the availability of suitable territories and the variation in mortality of adult birds occupying those territories. We estimated vital rates of a population at equilibrium using long-term resightings data (2000–2014; n = 451 marked individuals) in a multistate mark–resight model and used a stage-structured projection matrix to assess how strongly territorial adult survival affects population growth rate. Elasticity analysis indicated territorial birds surviving and retaining territories had a 2.58 times greater impact on population growth compared with the next most important transition rate (survival of nonterritorial adults remaining nonterritorial). Knowing how changes in vital rates of various stage classes will differentially impact population growth rate allows for targeted management actions including encouraging growth in recovering populations, assessing opportunity for recreational harvest, or maintaining populations at a desired level. This study also highlights the value of collecting demographic data for all population segments, from which one can derive reproductive output or growth rate.
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Affiliation(s)
- Michael E. Wheeler
- Nelson Institute for Environmental Studies, University of Wisconsin–Madison, 1630 Linden Drive, Madison, WI 53706, USA
| | - Jeb A. Barzen
- International Crane Foundation, E-11376 Shady Lane Road, Baraboo, WI 53913, USA
| | - Shawn M. Crimmins
- College of Natural Resources, University of Wisconsin–Stevens Point, 800 Reserve Street, Stevens Point, WI 54481, USA
| | - Timothy R. Van Deelen
- Department of Forest and Wildlife Ecology, University of Wisconsin–Madison, 1630 Linden Drive, Madison, WI 53706, USA
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29
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Crain BJ, Tremblay RL, Ferguson JM. Sheltered from the storm? Population viability analysis of a rare endemic under periodic catastrophe regimes. POPUL ECOL 2018. [DOI: 10.1002/1438-390x.1002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Benjamin J. Crain
- Department of Biology; University of Puerto Rico-Río Piedras; San Juan Puerto Rico
| | - Raymond L. Tremblay
- Department of Biology; University of Puerto Rico-Río Piedras; San Juan Puerto Rico
- Center for Applied Tropical Ecology and Conservation, Department of Biology; University of Puerto Rico-Río Piedras; San Juan Puerto Rico
| | - Jake M. Ferguson
- NIMBioS; University of Tennessee-Knoxville; Knoxville Tennessee
- Fisheries, Wildlife & Conservation Biology; University of Minnesota; St. Paul Minnesota
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30
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Alexander HM, Collins CD, Reed AW, Kettle WD, Collis DA, Christiana LD, Salisbury VB. Effects of removing woody cover on long-term population dynamics of a rare annual plant ( Agalinis auriculata): A study comparing remnant prairie and oldfield habitats. Ecol Evol 2018; 8:11975-11986. [PMID: 30598792 PMCID: PMC6303752 DOI: 10.1002/ece3.4654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/17/2018] [Accepted: 09/19/2018] [Indexed: 11/13/2022] Open
Abstract
Worldwide, grasslands are becoming shrublands/forests. In North America, eastern red cedar (Juniperus virginiana) often colonizes prairies. Habitat management can focus on woody removal, but we often lack long-term data on whether removal leads to population recovery of herbaceous plants without seeding. We undertook a long-term study (17 years) of numbers of the rare annual plant Agalinis auriculata in a gridwork of 100 m2 plots in adjacent prairie and oldfield sites in Kansas, USA. We collected data before and after removal of Juniperus virginiana at the prairie. Plant population sizes were highly variable at both sites and over time. High numbers of plants in a plot 1 year were often followed by low numbers the following year, suggesting negative density-dependence. Plant numbers were lowest with extensive woody cover and with low precipitation. After woody plant removal, A. auriculata increased dramatically in abundance and occupancy in most years; increases were also seen at the oldfield, suggesting later survey years were overall more favorable. Synthesis and applications: Removal of woody plants led to increased numbers of a rare annual prairie plant, without seeding. Multiple years of data were essential for interpretation given extreme temporal variability in numbers. The largest prairie population was 7 years following tree removal, showing that positive effects of management can last this long. This species also fared well in oldfield habitat, suggesting restoration opportunities. Given that land managers are busy, time-efficient field methods and data analysis approaches such as ours offer advantages. In addition to general linear models, we suggest Rank Occupancy-Abundance Profiles (ROAPs), a simple-to-use data visualization and analysis method. Creation of ROAPs for sites before and after habitat management helps reveal the degree to which plant populations are responding to management with changes in local density, changes in occupancy, or both.
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Affiliation(s)
- Helen M. Alexander
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansas
| | | | - Aaron W. Reed
- School of Biological SciencesUniversity of Missouri‐Kansas CityKansas CityMissouri
| | - W. Dean Kettle
- Kansas Biological SurveyUniversity of KansasLawrenceKansas
| | - Daniel A. Collis
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansas
- Present address:
1623 E. 120th StreetOlatheKansas
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31
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Hindle BJ, Rees M, Sheppard AW, Quintana‐Ascencio PF, Menges ES, Childs DZ. Exploring population responses to environmental change when there is never enough data: a factor analytic approach. Methods Ecol Evol 2018. [DOI: 10.1111/2041-210x.13085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bethan J. Hindle
- Department of Animal and Plant SciencesUniversity of Sheffield Sheffield UK
| | - Mark Rees
- Department of Animal and Plant SciencesUniversity of Sheffield Sheffield UK
| | - Andy W. Sheppard
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Canberra ACT Australia
| | | | | | - Dylan Z. Childs
- Department of Animal and Plant SciencesUniversity of Sheffield Sheffield UK
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32
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Tredennick AT, Teller B, Adler PB, Hooker G, Ellner SP. Size‐by‐environment interactions: a neglected dimension of species' responses to environmental variation. Ecol Lett 2018; 21:1757-1770. [DOI: 10.1111/ele.13154] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/11/2018] [Accepted: 08/16/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Andrew T. Tredennick
- Department of Wildland Resources and the Ecology Center Utah State University Logan UT USA
| | - Brittany J. Teller
- Department of Biology Pennsylvania State University University Park PA USA
| | - Peter B. Adler
- Department of Wildland Resources and the Ecology Center Utah State University Logan UT USA
| | - Giles Hooker
- Department of Biological Statistics and Computational Biology Cornell University Ithaca NY USA
| | - Stephen P. Ellner
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
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33
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Meier AJ, Meier AH, Meier AD, Urbatsch LE, McPhail B. The Case of the 30-Year Persistence of the Single Known Population of Panax quinquefolius L. (Araliaceae) in Louisiana. SOUTHEAST NAT 2018. [DOI: 10.1656/058.017.0319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Albert J. Meier
- Western Kentucky University, Department of Biology, 1906 College Heights Boulevard #11080, Bowling Green, KY 42101
| | | | | | - Lowell E. Urbatsch
- Department of Biology, Louisiana State University, Baton Rouge, LA 70803
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34
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Inferring transient dynamics of human populations from matrix non-normality. POPUL ECOL 2018; 60:185-196. [PMID: 30008581 PMCID: PMC6018585 DOI: 10.1007/s10144-018-0620-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 05/09/2018] [Indexed: 11/01/2022]
Abstract
In our increasingly unstable and unpredictable world, population dynamics rarely settle uniformly to long-term behaviour. However, projecting period-by-period through the preceding fluctuations is more data-intensive and analytically involved than evaluating at equilibrium. To efficiently model populations and best inform policy, we require pragmatic suggestions as to when it is necessary to incorporate short-term transient dynamics and their effect on eventual projected population size. To estimate this need for matrix population modelling, we adopt a linear algebraic quantity known as non-normality. Matrix non-normality is distinct from normality in the Gaussian sense, and indicates the amplificatory potential of the population projection matrix given a particular population vector. In this paper, we compare and contrast three well-regarded metrics of non-normality, which were calculated for over 1000 age-structured human population projection matrices from 42 European countries in the period 1960 to 2014. Non-normality increased over time, mirroring the indices of transient dynamics that peaked around the millennium. By standardising the matrices to focus on transient dynamics and not changes in the asymptotic growth rate, we show that the damping ratio is an uninformative predictor of whether a population is prone to transient booms or busts in its size. These analyses suggest that population ecology approaches to inferring transient dynamics have too often relied on suboptimal analytical tools focussed on an initial population vector rather than the capacity of the life cycle to amplify or dampen transient fluctuations. Finally, we introduce the engineering technique of pseudospectra analysis to population ecology, which, like matrix non-normality, provides a more complete description of the transient fluctuations than the damping ratio. Pseudospectra analysis could further support non-normality assessment to enable a greater understanding of when we might expect transient phases to impact eventual population dynamics.
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35
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Louthan A, Doak D. Measurement error of state variables creates substantial bias in results of demographic population models. Ecology 2018; 99:2308-2317. [PMID: 30007078 DOI: 10.1002/ecy.2455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 06/05/2018] [Accepted: 06/24/2018] [Indexed: 11/06/2022]
Abstract
Integral projection and matrix population models are commonly used in ecological and conservation studies to assess the health and extinction risk of populations. These models use one (or more) measurable state variable(s), such as size or age, to predict individual performance, which, ideally, is the sole determinant of an individual's expected fate. However, even if ecologists successfully identify and measure the observable state variable(s) that best predicts individual fate, we are rarely, if ever, able to perfectly measure state for many species, especially those with size structure, where total plant biomass or starch stores, for example, may be the best predictors of fate. Here, we used a series of simulations to test how this imperfect quantification of actual state ("measurement error") leads to inaccurate prediction of state-dependent fates and influences the predictions of structured population models. We simulated 10 yr of best practice field data collection using known vital rate functions and incorporated measurement error of different magnitudes and types (completely random, temporal, and individual based) for two size-structured life histories. We found that even for conservative error rates, most types of measurement error increased the median predicted population growth rate by 1-2% growth per year. However, the magnitude of this error differed substantially with life history strategy and error type, with some scenarios resulting in >8% median overestimation of population growth rate. This effect arises largely from the well-known econometrics problem of "regression dilution" (overestimation of the intercept and underestimation of the slope of a regression when the predictor variable is measured with error), which in our simulations typically results in overly optimistic predictions of small or young individuals' vital rates. Our results suggest that the problem of measurement error for state variables, present in many demographic studies but virtually unacknowledged in the ecological literature, may lead to substantial misestimation of population behavior, resulting in erroneous inferences about not only growth, but also extinction risk and other aspects of population dynamics.
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Affiliation(s)
- Allison Louthan
- Department of Biology, Duke University, Durham, North Carolina, 27708, USA.,Environmental Studies Program, University of Colorado-Boulder, Boulder, Colorado, 80301, USA
| | - Daniel Doak
- Environmental Studies Program, University of Colorado-Boulder, Boulder, Colorado, 80301, USA
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36
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Lommen STE, Jongejans E, Leitsch-Vitalos M, Tokarska-Guzik B, Zalai M, Müller-Schärer H, Karrer G. Time to cut: population models reveal how to mow invasive common ragweed cost-effectively. NEOBIOTA 2018. [DOI: 10.3897/neobiota.39.23398] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Roadsides are an important habitat for invasive common ragweed, Ambrosiaartemisiifolia L., by facilitating seed dispersal. Reducing the size of roadside populations is therefore essential for confining this highly allergenic species. Here, we aim to determine the cost-effectiveness of mowing regimes varying in frequency and timing, by analysing population-level effects and underlying demographic processes. We constructed population models of A.artemisiifolia parameterised by demographic data for four unmanaged reference populations across Europe in two years. We integrated the effects of four experimental mowing regimes along Austrian road sides on plant performance traits of five years and experimental data on seed viability after cutting. All four experimental regimes reduced the projected intrinsic population growth rates (r) compared to the unmanaged controls by reducing plant height and seed viability, thereby counteracting increased size-dependent fecundity. The prevailing 2-cut regime in Austria (cutting during vegetative growth, here in June and just before seed ripening, here in September) performed least well and the reduction in r was mainly due to reduced seed viability after the second cut. The efficacy of the two best experimental regimes (alternative schemes for 2 or 3 cuts) was mainly due to cutting just before female flowering (here in August) by decreasing final adult plant height dramatically and thereby reducing seed numbers. Patterns were consistent across reference populations and years. Whether regimes reduced r below replacement level, however, varied per population, year and the survival rate of the seeds in the soil bank. Our model allowed projecting effects of five theoretical mowing regimes with untested combinations of cuts on r. By plotting r-cost relationships for all regimes, we identified the most cost-effective schemes for each cutting frequency (1–3 cuts). They all included the cut just before female flowering, highlighting the importance of cutting at this moment (here in August). Our work features i) the suitability of a modelling approach for the demography of an annual species with a seed bank, ii) the importance of seed viability in assessing mowing effects, iii) the use of population models in designing cost-effective mowing regimes.
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37
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Adler PB, Kleinhesselink A, Hooker G, Taylor JB, Teller B, Ellner SP. Weak interspecific interactions in a sagebrush steppe? Conflicting evidence from observations and experiments. Ecology 2018; 99:1621-1632. [PMID: 29705994 DOI: 10.1002/ecy.2363] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 03/02/2018] [Accepted: 03/20/2018] [Indexed: 11/09/2022]
Abstract
Stable coexistence requires intraspecific limitations to be stronger than interspecific limitations. The greater the difference between intra- and interspecific limitations, the more stable the coexistence, and the weaker the competitive release any species should experience following removal of competitors. We conducted a removal experiment to test whether a previously estimated model, showing surprisingly weak interspecific competition for four dominant species in a sagebrush steppe, accurately predicts competitive release. Our treatments were (1) removal of all perennial grasses and (2) removal of the dominant shrub, Artemisia tripartita. We regressed survival, growth, and recruitment on the locations, sizes, and species identities of neighboring plants, along with an indicator variable for removal treatment. If our "baseline" regression model, which accounts for local plant-plant interactions, accurately explains the observed responses to removals, then the removal coefficient should be non-significant. For survival, the removal coefficients were never significantly different from zero, and only A. tripartita showed a (negative) response to removals at the recruitment stage. For growth, the removal treatment effect was significant and positive for two species, Poa secunda and Pseudoroegneria spicata, indicating that the baseline model underestimated interspecific competition. For all three grass species, population models based on the vital rate regressions that included removal effects projected 1.4- to 3-fold increases in equilibrium population size relative to the baseline model (no removal effects). However, we found no evidence of higher response to removal in quadrats with higher pretreatment cover of A. tripartita, or by plants experiencing higher pre-treatment crowding by A. tripartita, raising questions about the mechanisms driving the positive response to removal. While our results show the value of combining observations with a simple removal experiment, more tightly controlled experiments focused on underlying mechanisms may be required to conclusively validate or reject predictions from phenomenological models.
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Affiliation(s)
- Peter B Adler
- Department of Wildland Resources and the Ecology Center, Utah State University, 5230 Old Main, Logan, Utah, USA
| | - Andrew Kleinhesselink
- Department of Wildland Resources and the Ecology Center, Utah State University, 5230 Old Main, Logan, Utah, USA
| | - Giles Hooker
- Department of Biological Statistics and Computational Biology, Cornell University, 1198 Comstock Hall, Ithaca, New York, USA
| | - Joshua B Taylor
- USDA, Agricultural Research Service, U.S. Sheep Experiment Station, 19 Office Loop, Dubois, Idaho, USA
| | - Brittany Teller
- Department of Wildland Resources and the Ecology Center, Utah State University, 5230 Old Main, Logan, Utah, USA
| | - Stephen P Ellner
- Department of Ecology and Evolutionary Biology, Cornell University, E145 Corson Hall, Ithaca, New York, USA
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38
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Tenhumberg B, Crone EE, Ramula S, Tyre AJ. Time-lagged effects of weather on plant demography: drought and Astragalus scaphoides. Ecology 2018; 99:915-925. [PMID: 29380874 DOI: 10.1002/ecy.2163] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/20/2017] [Accepted: 01/02/2018] [Indexed: 01/05/2023]
Abstract
Temperature and precipitation determine the conditions where plant species can occur. Despite their significance, to date, surprisingly few demographic field studies have considered the effects of abiotic drivers. This is problematic because anticipating the effect of global climate change on plant population viability requires understanding how weather variables affect population dynamics. One possible reason for omitting the effect of weather variables in demographic studies is the difficulty in detecting tight associations between vital rates and environmental drivers. In this paper, we applied Functional Linear Models (FLMs) to long-term demographic data of the perennial wildflower, Astragalus scaphoides, and explored sensitivity of the results to reduced amounts of data. We compared models of the effect of average temperature, total precipitation, or an integrated measure of drought intensity (standardized precipitation evapotranspiration index, SPEI), on plant vital rates. We found that transitions to flowering and recruitment in year t were highest if winter/spring of year t was wet (positive effect of SPEI). Counterintuitively, if the preceding spring of year t - 1 was wet, flowering probabilities were decreased (negative effect of SPEI). Survival of vegetative plants from t - 1 to t was also negatively affected by wet weather in the spring of year t - 1 and, for large plants, even wet weather in the spring of t - 2 had a negative effect. We assessed the integrated effect of all vital rates on life history performance by fitting FLMs to the asymptotic growth rate, log(λt). Log(λt) was highest if dry conditions in year t - 1 were followed by wet conditions in the year t. Overall, the positive effects of wet years exceeded their negative effects, suggesting that increasing frequency of drought conditions would reduce population viability of A. scaphoides. The drought signal weakened when reducing the number of monitoring years. Substituting space for time did not recover the weather signal, probably because the weather variables varied little between sites. We detected the SPEI signal when the analysis included data from two sites monitored over 20 yr (2 × 20 observations), but not when analyzing data from four sites monitored over 10 yr (4 × 10 observations).
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Affiliation(s)
- Brigitte Tenhumberg
- School of Biological Sciences and Department of Mathematics, University of Nebraska, Lincoln, Nebraska, 68588, USA
| | - Elizabeth E Crone
- Department of Biology, Tufts University, Medford, Massachusetts, 02155, USA
| | - Satu Ramula
- Section of Ecology, Department of Biology, University of Turku, FI-20014, Turku, Finland
| | - Andrew J Tyre
- School of Natural Resources, University of Nebraska, Lincoln, Nebraska, 68583, USA
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39
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Saunders SP, Cuthbert FJ, Zipkin EF. Evaluating population viability and efficacy of conservation management using integrated population models. J Appl Ecol 2018. [DOI: 10.1111/1365-2664.13080] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sarah P. Saunders
- Department of Integrative Biology College of Natural Science Michigan State University East Lansing MI USA
| | - Francesca J. Cuthbert
- Department of Fisheries, Wildlife, and Conservation Biology University of Minnesota St. Paul MN USA
| | - Elise F. Zipkin
- Department of Integrative Biology College of Natural Science Michigan State University East Lansing MI USA
- Ecology, Evolutionary Biology, and Behavior Program Michigan State University East Lansing MI USA
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40
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Csergő AM, Salguero-Gómez R, Broennimann O, Coutts SR, Guisan A, Angert AL, Welk E, Stott I, Enquist BJ, McGill B, Svenning JC, Violle C, Buckley YM. Less favourable climates constrain demographic strategies in plants. Ecol Lett 2017; 20:969-980. [PMID: 28609810 PMCID: PMC5575490 DOI: 10.1111/ele.12794] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/14/2017] [Accepted: 05/07/2017] [Indexed: 11/28/2022]
Abstract
Correlative species distribution models are based on the observed relationship between species’ occurrence and macroclimate or other environmental variables. In climates predicted less favourable populations are expected to decline, and in favourable climates they are expected to persist. However, little comparative empirical support exists for a relationship between predicted climate suitability and population performance. We found that the performance of 93 populations of 34 plant species worldwide – as measured by in situ population growth rate, its temporal variation and extinction risk – was not correlated with climate suitability. However, correlations of demographic processes underpinning population performance with climate suitability indicated both resistance and vulnerability pathways of population responses to climate: in less suitable climates, plants experienced greater retrogression (resistance pathway) and greater variability in some demographic rates (vulnerability pathway). While a range of demographic strategies occur within species’ climatic niches, demographic strategies are more constrained in climates predicted to be less suitable.
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Affiliation(s)
- Anna M Csergő
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland.,ARC Centre of Excellence for Environmental Decisions, University of Queensland, St Lucia, QLD, 4072, Australia
| | - Roberto Salguero-Gómez
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland.,ARC Centre of Excellence for Environmental Decisions, University of Queensland, St Lucia, QLD, 4072, Australia.,Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.,Max Planck Institute for Demographic Research, Konrad-Zuse-Straße 1, 18057, Rostock, Germany
| | - Olivier Broennimann
- Department of Ecology and Evolution, University of Lausanne, 1015, Lausanne, Switzerland.,Institute of Earth Surface Dynamics, University of Lausanne, 1015, Lausanne, Switzerland
| | - Shaun R Coutts
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland.,Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Antoine Guisan
- Department of Ecology and Evolution, University of Lausanne, 1015, Lausanne, Switzerland.,Institute of Earth Surface Dynamics, University of Lausanne, 1015, Lausanne, Switzerland
| | - Amy L Angert
- Departments of Botany and Zoology, Biodiversity Research Centre, University of British Columbia, 115-2212 Main Mall, Vancouver, BC, Canada
| | - Erik Welk
- Institute of Biology, Martin-Luther-University Halle-Wittenberg, 06099, Halle (Saale), Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Leipzig, Germany
| | - Iain Stott
- Max Planck Institute for Demographic Research, Konrad-Zuse-Straße 1, 18057, Rostock, Germany.,Department of Biology, Max Planck Odense Center, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Brian J Enquist
- Department of Ecology and Evolutionary Biology, The University of Arizona, 1040 E. Lowell St., Tucson, AZ, 85721, USA
| | - Brian McGill
- School of Biology and Ecology, The University of Maine, Deering Hall Room 202, Orono, ME, 04469, USA
| | - Jens-Christian Svenning
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, DK-8000, Aarhus C, Denmark
| | - Cyrille Violle
- CNRS, CEFE UMR 5175, Université de Montpellier - Université Paul Valéry - EPHE, 1919 Route de Mende, 34293, Montpellier Cedex 5, France
| | - Yvonne M Buckley
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland.,ARC Centre of Excellence for Environmental Decisions, University of Queensland, St Lucia, QLD, 4072, Australia
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Davy CM, Mastromonaco GF, Riley JL, Baxter-Gilbert JH, Mayberry H, Willis CKR. Conservation implications of physiological carry-over effects in bats recovering from white-nose syndrome. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2017; 31:615-624. [PMID: 27641049 DOI: 10.1111/cobi.12841] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/19/2016] [Accepted: 08/29/2016] [Indexed: 06/06/2023]
Abstract
Although it is well documented that infectious diseases can pose threats to biodiversity, the potential long-term consequences of pathogen exposure on individual fitness and its effects on population viability have rarely been studied. We tested the hypothesis that pathogen exposure causes physiological carry-over effects with a pathogen that is uniquely suited to this question because the infection period is specific and time limited. The fungus Pseudogymnoascus destructans causes white-nose syndrome (WNS) in hibernating bats, which either die due to the infection while hibernating or recover following emergence from hibernation. The fungus infects all exposed individuals in an overwintering site simultaneously, and bats that survive infection during hibernation clear the pathogen within a few weeks following emergence. We quantified chronic stress during the active season, when bats are not infected, by measuring cortisol in bat claws. Free-ranging Myotis lucifugus who survived previous exposure to P. destructans had significantly higher levels of claw cortisol than naïve individuals. Thus, cryptic physiological carry-over effects of pathogen exposure may persist in asymptomatic, recovered individuals. If these effects result in reduced survival or reproductive success, they could also affect population viability and even act as a third stream in the extinction vortex. For example, significant increases in chronic stress, such as those indicated here, are correlated with reduced reproductive success in a number of species. Future research should directly explore the link between pathogen exposure and the viability of apparently recovered populations to improve understanding of the true impacts of infectious diseases on threatened populations.
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Affiliation(s)
- Christina M Davy
- Natural Resources DNA Profiling and Forensics Centre, Trent University, Peterborough, ON, K9J 7B8, Canada
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
| | | | - Julia L Riley
- Division of Brain, Behaviour and Evolution, Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2122, Australia
| | - James H Baxter-Gilbert
- Division of Brain, Behaviour and Evolution, Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2122, Australia
| | - Heather Mayberry
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Craig K R Willis
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
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42
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Elasticity of population growth with respect to the intensity of biotic or abiotic driving factors. Ecology 2017; 98:1016-1025. [DOI: 10.1002/ecy.1687] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/26/2016] [Accepted: 11/15/2016] [Indexed: 11/07/2022]
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Regan HM, Bohórquez CI, Keith DA, Regan TJ, Anderson KE. Implications of different population model structures for management of threatened plants. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2017; 31:459-468. [PMID: 27596063 DOI: 10.1111/cobi.12831] [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: 02/16/2016] [Revised: 05/23/2016] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
Population viability analysis (PVA) is a reliable tool for ranking management options for a range of species despite parameter uncertainty. No one has yet investigated whether this holds true for model uncertainty for species with complex life histories and for responses to multiple threats. We tested whether a range of model structures yielded similar rankings of management and threat scenarios for 2 plant species with complex postfire responses. We examined 2 contrasting species from different plant functional types: an obligate seeding shrub and a facultative resprouting shrub. We exposed each to altered fire regimes and an additional, species-specific threat. Long-term demographic data sets were used to construct an individual-based model (IBM), a complex stage-based model, and a simple matrix model that subsumes all life stages into 2 or 3 stages. Agreement across models was good under some scenarios and poor under others. Results from the simple and complex matrix models were more similar to each other than to the IBM. Results were robust across models when dominant threats are considered but were less so for smaller effects. Robustness also broke down as the scenarios deviated from baseline conditions, likely the result of a number of factors related to the complexity of the species' life history and how it was represented in a model. Although PVA can be an invaluable tool for integrating data and understanding species' responses to threats and management strategies, this is best achieved in the context of decision support for adaptive management alongside multiple lines of evidence and expert critique of model construction and output.
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Affiliation(s)
- Helen M Regan
- Biology Department, University of California Riverside, 900 University Avenue, Riverside, CA, 92521, U.S.A
| | - Clara I Bohórquez
- Biology Department, University of California Riverside, 900 University Avenue, Riverside, CA, 92521, U.S.A
- Biology Department, Universidad Nacional de Colombia, Carrera 45 #26-85, Edif. Uriel Gutiérrez, Bogotá D.C., Colombia
| | - David A Keith
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
- New South Wales Office of Environment & Heritage, P.O. Box A290, Sydney South, NSW, 1232, Australia
| | - Tracey J Regan
- Arthur Rylah Institute for Environmental Research, The Department of Environment, Land, Water and Planning, 123 Brown Street, Heidelberg, VIC, 3084, Australia
- School of Biosciences, University of Melbourne, Parkville Campus, VIC, 3010, Australia
| | - Kurt E Anderson
- Biology Department, University of California Riverside, 900 University Avenue, Riverside, CA, 92521, U.S.A
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Climate change both facilitates and inhibits invasive plant ranges in New England. Proc Natl Acad Sci U S A 2017; 114:E3276-E3284. [PMID: 28348212 DOI: 10.1073/pnas.1609633114] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Forecasting ecological responses to climate change, invasion, and their interaction must rely on understanding underlying mechanisms. However, such forecasts require extrapolation into new locations and environments. We linked demography and environment using experimental biogeography to forecast invasive and native species' potential ranges under present and future climate in New England, United States to overcome issues of extrapolation in novel environments. We studied two potentially nonequilibrium invasive plants' distributions, Alliaria petiolata (garlic mustard) and Berberis thunbergii (Japanese barberry), each paired with their native ecological analogs to better understand demographic drivers of invasions. Our models predict that climate change will considerably reduce establishment of a currently prolific invader (A. petiolata) throughout New England driven by poor demographic performance in warmer climates. In contrast, invasion of B. thunbergii will be facilitated because of higher growth and germination in warmer climates, with higher likelihood to establish farther north and in closed canopy habitats in the south. Invasion success is in high fecundity for both invasive species and demographic compensation for Apetiolata relative to native analogs. For A. petiolata, simulations suggest that eradication efforts would require unrealistic efficiency; hence, management should focus on inhibiting spread into colder, currently unoccupied areas, understanding source-sink dynamics, and understanding community dynamics should A. petiolata (which is allelopathic) decline. Our results-based on considerable differences with correlative occurrence models typically used for such biogeographic forecasts-suggest the urgency of incorporating mechanism into range forecasting and invasion management to understand how climate change may alter current invasion patterns.
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Hernández-Pedrero R, Valverde T. The use of periodic matrices to model the population dynamics of the long-lived semelparous Furcraea parmentieri (Asparagaceae) in a temperate forest in central Mexico. POPUL ECOL 2017. [DOI: 10.1007/s10144-017-0572-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Affiliation(s)
- Doug P. Armstrong
- Wildlife Ecology Group; Massey University; PB 11-2222 Palmerston North New Zealand
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Stott I. Perturbation analysis of transient population dynamics using matrix projection models. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12543] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Iain Stott
- Max Planck Institute for Demographic Research; Konrad-Zuse Straße 1 Rostock 18057 Germany
- Max Planck Odense Center on the Biodemography of Aging; University of Southern Denmark; Campusvej 55 DK-5230 Odense M Denmark
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Forest succession and population viability of grassland plants: long repayment of extinction debt in Primula veris. Oecologia 2016; 181:125-35. [DOI: 10.1007/s00442-016-3569-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 01/21/2016] [Indexed: 10/22/2022]
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Brown LM, Crone EE. Minimum area requirements for an at-risk butterfly based on movement and demography. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2016; 30:103-112. [PMID: 26174312 DOI: 10.1111/cobi.12588] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 05/26/2015] [Accepted: 07/07/2015] [Indexed: 06/04/2023]
Abstract
Determining the minimum area required to sustain populations has a long history in theoretical and conservation biology. Correlative approaches are often used to estimate minimum area requirements (MARs) based on relationships between area and the population size required for persistence or between species' traits and distribution patterns across landscapes. Mechanistic approaches to estimating MAR facilitate prediction across space and time but are few. We used a mechanistic MAR model to determine the critical minimum patch size (CMP) for the Baltimore checkerspot butterfly (Euphydryas phaeton), a locally abundant species in decline along its southern range, and sister to several federally listed species. Our CMP is based on principles of diffusion, where individuals in smaller patches encounter edges and leave with higher probability than those in larger patches, potentially before reproducing. We estimated a CMP for the Baltimore checkerspot of 0.7-1.5 ha, in accordance with trait-based MAR estimates. The diffusion rate on which we based this CMP was broadly similar when estimated at the landscape scale (comparing flight path vs. capture-mark-recapture data), and the estimated population growth rate was consistent with observed site trends. Our mechanistic approach to estimating MAR is appropriate for species whose movement follows a correlated random walk and may be useful where landscape-scale distributions are difficult to assess, but demographic and movement data are obtainable from a single site or the literature. Just as simple estimates of lambda are often used to assess population viability, the principles of diffusion and CMP could provide a starting place for estimating MAR for conservation.
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Affiliation(s)
- Leone M Brown
- Department of Biology, Tufts University, 163 Packard Avenue, Medford, MA, 02155-5818, U.S.A..
- Odum School of Ecology, University of Georgia, 140 E. Green St., Athens, GA, 30602-2202, U.S.A..
| | - Elizabeth E Crone
- Department of Biology, Tufts University, 163 Packard Avenue, Medford, MA, 02155-5818, U.S.A
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Tremblay RL, Raventos J, Ackerman JD. When stable-stage equilibrium is unlikely: integrating transient population dynamics improves asymptotic methods. ANNALS OF BOTANY 2015; 116:381-90. [PMID: 25814059 PMCID: PMC4549953 DOI: 10.1093/aob/mcv031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 02/04/2015] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Evaluation of population projection matrices (PPMs) that are focused on asymptotically based properties of populations is a commonly used approach to evaluate projected dynamics of managed populations. Recently, a set of tools for evaluating the properties of transient dynamics has been expanded to evaluate PPMs and to consider the dynamics of populations prior to attaining the stable-stage distribution, a state that may never be achieved in disturbed or otherwise ephemeral habitats or persistently small populations. This study re-evaluates data for a tropical orchid and examines the value of including such analyses in an integrative approach. METHODS Six small populations of Lepanthes rubripetala were used as a model system and the R software package popdemo was used to produce estimates of the indices for the asymptotic growth rate (lambda), sensitivities, reactivity, first-time step attenuation, maximum amplification, maximum attenuation, maximal inertia and maximal attenuation. The response in lambda to perturbations of demographic parameters using transfer functions and multiple perturbations on growth, stasis and fecundity were also determined. The results were compared with previously published asymptotic indices. KEY RESULTS It was found that combining asymptotic and transient dynamics expands the understanding of possible population changes. Comparison of the predicted density from reactivity and first-time step attenuation with the observed change in population size in two orchid populations showed that the observed density was within the predicted range. However, transfer function analysis suggests that the traditional approach of measuring perturbation of growth rates and persistence (inertia) may be misleading and is likely to result in erroneous management decisions. CONCLUSIONS Based on the results, an integrative approach is recommended using traditional PPMs (asymptotic processes) with an evaluation of the diversity of dynamics that may arise when populations are not at a stable-stage distribution (transient processes). This method is preferable for designing rapid and efficient interventions after disturbances, and for developing strategies to establish new populations.
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Affiliation(s)
- Raymond L Tremblay
- Department of Biology, PO Box 860, University of Puerto Rico, Humacao, 00791, Puerto Rico,
| | - Josep Raventos
- Departamento de Ecología, Universidad de Alicante, Carretera S. Vicente del Raspeig s/n, 03080, San Vicente del Raspeig, Alicante, Spain
| | - James D Ackerman
- Department of Biology, PO Box 23360, University of Puerto Rico, Rio Piedras campus, San Juan, 00931-3360, Puerto Rico, Center for Applied Tropical Ecology and Conservation, PO Box 23360, University of Puerto Rico, Rio Piedras campus, San Juan, 00931-3360, Puerto Rico and
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