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Yancy AJ, Lee BR, Kuebbing SE, Neufeld HS, Spicer ME, Heberling JM. Evaluating the definition and distribution of spring ephemeral wildflowers in eastern North America. Am J Bot 2024:e16323. [PMID: 38659163 DOI: 10.1002/ajb2.16323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/24/2024] [Accepted: 02/26/2024] [Indexed: 04/26/2024]
Abstract
PREMISE The herbaceous layer accounts for the majority of plant biodiversity in eastern North American forests, encompassing substantial variation in life history strategy and function. One group of early-season herbaceous understory species, colloquially referred to as spring ephemeral wildflowers, are ecologically and culturally important, but little is known about the prevalence and biogeographic patterns of the spring ephemeral strategy. METHODS We used observations collected by the Global Biodiversity Information Facility (GBIF) to quantify the ephemerality of 559 understory forb species across eastern North America and classify them according to a continuous ephemerality index (ranging from 0 = never ephemeral to 1 = always ephemeral). We then used this information to model where ephemeral forbs were most common across the landscape with the goal of identifying geographic and environmental drivers important to their distributions and ranges. RESULTS Only 3.4% of all understory wildflower species were spring ephemerals in all parts of their range, and 18.4% (103 species) were ephemeral in at least part of their range. Spring ephemerals peaked in absolute species richness and relative proportion at mid latitudes. CONCLUSIONS Spring ephemeral phenology is an important shade-avoidance strategy for a large segment of the total understory species in temperate deciduous forests. In North America, the strategy is relatively most important for forest understories at mid latitudes. The definitions of spring ephemerality we provide here serve as an important ecological context for conservation priorities and to evaluate responses of this biodiverse group to future environmental change.
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Affiliation(s)
- Abby J Yancy
- Carnegie Museum of Natural History, Section of Botany, 4400 Forbes Ave., Pittsburgh, 15213 USA, PA
- Department of Geology and Environmental Sciences, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, 15260, PA, USA
| | - Benjamin R Lee
- Carnegie Museum of Natural History, Section of Botany, 4400 Forbes Ave., Pittsburgh, 15213 USA, PA
- Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Ave, Pittsburgh, 15260, PA, USA
- Holden Arboretum, 9550 Sperry Road, Kirtland, 44094, OH, USA
| | - Sara E Kuebbing
- Carnegie Museum of Natural History, Section of Botany, 4400 Forbes Ave., Pittsburgh, 15213 USA, PA
- The Forest School, Yale School of the Environment, Yale University, New Haven, 06511, CT, USA
| | - Howard S Neufeld
- Appalachian State University Dept. of Biology, 572 Rivers Street, Boone, 28608, NC, USA
| | - Michelle Elise Spicer
- Lehigh University Dept. of Earth and Environmental Science, 1 West Packer Avenue, Bethlehem, 18015, PA, USA
| | - J Mason Heberling
- Carnegie Museum of Natural History, Section of Botany, 4400 Forbes Ave., Pittsburgh, 15213 USA, PA
- Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Ave, Pittsburgh, 15260, PA, USA
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Zhang Q, Li M, Yin Y, Ge S, Li D, Ahmad IM, Nabi G, Sun Y, Luo X, Li D. Physiological but not morphological adjustments along latitudinal gradients in a human commensal species, the Eurasian tree sparrow. Integr Zool 2023; 18:891-905. [PMID: 36880561 DOI: 10.1111/1749-4877.12709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Human commensal species take advantage of anthropogenic conditions that are less likely to be challenged by the selective pressures of natural environments. Their morphological and physiological phenotypes can therefore dissociate from habitat characteristics. Understanding how these species adjust their morphological and physiological traits across latitudinal gradients is fundamental to uncovering the eco-physiological strategies underlying coping mechanisms. Here, we studied morphological traits in breeding Eurasian tree sparrows (ETSs; Passer montanus) among low-latitude (Yunnan and Hunan) and middle-latitude (Hebei) localities in China. We then compared body mass; lengths of bill, tarsometatarsus, wing, total body, and tail feather; and baseline and capture stress-induced levels of plasma corticosterone (CORT) and the metabolites including glucose (Glu), total triglyceride (TG), free fatty acid (FFA), total protein, and uric acid (UA). None of the measured morphological parameters varied with latitude except in the Hunan population, which demonstrated longer bills than those in other populations. Stress-induced CORT levels significantly exceeded baseline levels and decreased with increasing latitude, but total integrated CORT levels did not vary with latitude. Capture stress-induced significantly increased Glu levels and decreased TG levels, independent of site. However, the Hunan population had significantly higher baseline CORT, baseline and stress-induced FFA levels, but lower UA levels, which differed from other populations. Our results suggest that rather than morphological adjustments, physiological adjustments are mainly involved in coping mechanisms for middle-latitude adaptation in ETSs. It is worth investigating whether other avian species also exhibit such dissociation from external morphological designs while depending on physiological adjustments.
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Affiliation(s)
- Qian Zhang
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaborative Innovation Center for Eco-Environment, Hebei Normal University, Shijiazhuang, China
| | - Mo Li
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaborative Innovation Center for Eco-Environment, Hebei Normal University, Shijiazhuang, China
| | - Yuan Yin
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaborative Innovation Center for Eco-Environment, Hebei Normal University, Shijiazhuang, China
| | - Shiyong Ge
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaborative Innovation Center for Eco-Environment, Hebei Normal University, Shijiazhuang, China
| | - Danjie Li
- Key Laboratory for Conserving Wildlife with Small Populations in Yunnan, Faculty of Biodiversity and Conservation, Southwest Forestry University, Kunming, China
| | - Ibrahim M Ahmad
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaborative Innovation Center for Eco-Environment, Hebei Normal University, Shijiazhuang, China
| | - Ghulam Nabi
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaborative Innovation Center for Eco-Environment, Hebei Normal University, Shijiazhuang, China
| | - Yanfeng Sun
- Ocean College, Hebei Agricultural University, Qinhuangdao, China
| | - Xu Luo
- Key Laboratory for Conserving Wildlife with Small Populations in Yunnan, Faculty of Biodiversity and Conservation, Southwest Forestry University, Kunming, China
| | - Dongming Li
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaborative Innovation Center for Eco-Environment, Hebei Normal University, Shijiazhuang, China
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Paquette A, Hargreaves AL. Biotic interactions are more often important at species' warm versus cool range edges. Ecol Lett 2021; 24:2427-2438. [PMID: 34453406 DOI: 10.1111/ele.13864] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 12/11/2022]
Abstract
Predicting which ecological factors constrain species distributions is a fundamental ecological question and critical to forecasting geographic responses to global change. Darwin hypothesised that abiotic factors generally impose species' high-latitude and high-elevation (typically cool) range limits, whereas biotic interactions more often impose species' low-latitude/low-elevation (typically warm) limits, but empirical support has been mixed. Here, we clarify three predictions arising from Darwin's hypothesis and show that previously mixed support is partially due to researchers testing different predictions. Using a comprehensive literature review (885 range limits), we find that biotic interactions, including competition, predation and parasitism, contributed to >60% of range limits and influenced species' warm limits more often than cool limits. Abiotic factors contributed more often than biotic interactions to cool range limits, but temperature contributed frequently to both cool and warm limits. Our results suggest that most range limits will be sensitive to climate warming, but warm-limit responses in particular will depend strongly on biotic interactions.
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Villeneuve AR, Komoroske LM, Cheng BS. Environment and phenology shape local adaptation in thermal performance. Proc Biol Sci 2021; 288:20210741. [PMID: 34315262 PMCID: PMC8316808 DOI: 10.1098/rspb.2021.0741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/07/2021] [Indexed: 01/09/2023] Open
Abstract
Populations within species often exhibit variation in traits that reflect local adaptation and further shape existing adaptive potential for species to respond to climate change. However, our mechanistic understanding of how the environment shapes trait variation remains poor. Here, we used common garden experiments to quantify thermal performance in eight populations of the marine snail Urosalpinx cinerea across thermal gradients on the Atlantic and the Pacific coasts of North America. We then evaluated the relationship between thermal performance and environmental metrics derived from time-series data. Our results reveal a novel pattern of 'mixed' trait performance adaptation, where thermal optima were positively correlated with spawning temperature (cogradient variation), while maximum trait performance was negatively correlated with season length (countergradient variation). This counterintuitive pattern probably arises because of phenological shifts in the spawning season, whereby 'cold' populations delay spawning until later in the year when temperatures are warmer compared to 'warm' populations that spawn earlier in the year when temperatures are cooler. Our results show that variation in thermal performance can be shaped by multiple facets of the environment and are linked to organismal phenology and natural history. Understanding the impacts of climate change on organisms, therefore, requires the knowledge of how climate change will alter different aspects of the thermal environment.
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Affiliation(s)
- Andrew R. Villeneuve
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA 01003, USA
- Gloucester Marine Station, University of Massachusetts Amherst, Gloucester, MA 01930, USA
| | - Lisa M. Komoroske
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA 01003, USA
- Gloucester Marine Station, University of Massachusetts Amherst, Gloucester, MA 01930, USA
| | - Brian S. Cheng
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA 01003, USA
- Gloucester Marine Station, University of Massachusetts Amherst, Gloucester, MA 01930, USA
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Moreira X, Abdala-Roberts L, De Frenne P, Galmán A, Gaytán Á, Jaatinen R, Lago-Núñez B, Meeussen C, Pulkkinen P, Rasmussen PU, Ten Hoopen JPJG, Timmermans BGH, Vázquez-González C, Bos N, Castagneyrol B, Tack AJM. Effects of latitude and conspecific plant density on insect leaf herbivory in oak saplings and seedlings. Am J Bot 2021; 108:172-176. [PMID: 33448059 DOI: 10.1002/ajb2.1596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 09/24/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Abiotic factors and plant species traits have been shown to drive latitudinal gradients in herbivory, and yet, population-level factors have been largely overlooked within this context. One such factor is plant density, which may influence the strength of herbivory and may vary with latitude. METHODS We measured insect herbivory and conspecific plant density (CPD) of oak (Quercus robur) seedlings and saplings along a 17° latitudinal gradient (2700 km) to test whether herbivory exhibited a latitudinal gradient, whether herbivory was associated with CPD, and whether such an association changed with latitude. RESULTS We found a positive but saturating association between latitude and leaf herbivory. Furthermore, we found no significant relationship between CPD and herbivory, and such lack of density effects remained consistent throughout the sampled latitudinal gradient. CONCLUSIONS Despite the apparently negligible influence of plant density on herbivory for Q. robur, further research with other plant taxa and in different types of plant communities are needed to investigate density-dependent processes shaping geographical variation in plant-herbivore interactions.
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Affiliation(s)
- Xoaquín Moreira
- Misión Biológica de Galicia (MBG-CSIC), Apdo. 28, Pontevedra, Galicia, Spain
| | - Luis Abdala-Roberts
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimná. 97000. Mérida, Yucatán, Mexico
| | - Pieter De Frenne
- Forest and Nature Lab, Ghent University, Geraardsbergsesteenweg 267, BE-9090, Gontrode-Melle, Belgium
| | - Andrea Galmán
- Misión Biológica de Galicia (MBG-CSIC), Apdo. 28, Pontevedra, Galicia, Spain
| | - Álvaro Gaytán
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Svante Arrhenius väg 20A, Stockholm, Sweden
| | - Raimo Jaatinen
- Natural Resources Institute Finland. Haapastensyrjä Breeding Station, FI-16200, Läyliäinen, Finland
| | - Beatriz Lago-Núñez
- Misión Biológica de Galicia (MBG-CSIC), Apdo. 28, Pontevedra, Galicia, Spain
| | - Camille Meeussen
- Forest and Nature Lab, Ghent University, Geraardsbergsesteenweg 267, BE-9090, Gontrode-Melle, Belgium
| | - Pertti Pulkkinen
- Natural Resources Institute Finland. Haapastensyrjä Breeding Station, FI-16200, Läyliäinen, Finland
| | - Pil U Rasmussen
- The National Research Centre for the Working Environment, 2100, Copenhagen, Denmark
| | | | - Bart G H Timmermans
- Department of Agriculture, Louis Bolk Institute, Kosterijland 3-5, 3981 AJ, Bunnik, The Netherlands
| | | | - Nick Bos
- Section for Ecology and Evolution, University of Copenhagen, 2200, Copenhagen, Denmark
| | | | - Ayco J M Tack
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Svante Arrhenius väg 20A, Stockholm, Sweden
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Whalen MA, Whippo RDB, Stachowicz JJ, York PH, Aiello E, Alcoverro T, Altieri AH, Benedetti-Cecchi L, Bertolini C, Bresch M, Bulleri F, Carnell PE, Cimon S, Connolly RM, Cusson M, Diskin MS, D'Souza E, Flores AAV, Fodrie FJ, Galloway AWE, Gaskins LC, Graham OJ, Hanley TC, Henderson CJ, Hereu CM, Hessing-Lewis M, Hovel KA, Hughes BB, Hughes AR, Hultgren KM, Jänes H, Janiak DS, Johnston LN, Jorgensen P, Kelaher BP, Kruschel C, Lanham BS, Lee KS, Lefcheck JS, Lozano-Álvarez E, Macreadie PI, Monteith ZL, O'Connor NE, Olds AD, O'Leary JK, Patrick CJ, Pino O, Poore AGB, Rasheed MA, Raymond WW, Reiss K, Rhoades OK, Robinson MT, Ross PG, Rossi F, Schlacher TA, Seemann J, Silliman BR, Smee DL, Thiel M, Unsworth RKF, van Tussenbroek BI, Vergés A, Yeager ME, Yednock BK, Ziegler SL, Duffy JE. Climate drives the geography of marine consumption by changing predator communities. Proc Natl Acad Sci U S A 2020; 117:28160-6. [PMID: 33106409 DOI: 10.1073/pnas.2005255117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The global distribution of primary production and consumption by humans (fisheries) is well-documented, but we have no map linking the central ecological process of consumption within food webs to temperature and other ecological drivers. Using standardized assays that span 105° of latitude on four continents, we show that rates of bait consumption by generalist predators in shallow marine ecosystems are tightly linked to both temperature and the composition of consumer assemblages. Unexpectedly, rates of consumption peaked at midlatitudes (25 to 35°) in both Northern and Southern Hemispheres across both seagrass and unvegetated sediment habitats. This pattern contrasts with terrestrial systems, where biotic interactions reportedly weaken away from the equator, but it parallels an emerging pattern of a subtropical peak in marine biodiversity. The higher consumption at midlatitudes was closely related to the type of consumers present, which explained rates of consumption better than consumer density, biomass, species diversity, or habitat. Indeed, the apparent effect of temperature on consumption was mostly driven by temperature-associated turnover in consumer community composition. Our findings reinforce the key influence of climate warming on altered species composition and highlight its implications for the functioning of Earth's ecosystems.
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Lusk CH, Clearwater MJ, Laughlin DC, Harrison SP, Prentice IC, Nordenstahl M, Smith B. Frost and leaf-size gradients in forests: global patterns and experimental evidence. New Phytol 2018; 219:565-573. [PMID: 29766502 DOI: 10.1111/nph.15202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Explanations of leaf size variation commonly focus on water availability, yet leaf size also varies with latitude and elevation in environments where water is not strongly limiting. We provide the first conclusive test of a prediction of leaf energy balance theory that may explain this pattern: large leaves are more vulnerable to night-time chilling, because their thick boundary layers impede convective exchange with the surrounding air. Seedlings of 15 New Zealand evergreens spanning 12-fold variation in leaf width were exposed to clear night skies, and leaf temperatures were measured with thermocouples. We then used a global dataset to assess several climate variables as predictors of leaf size in forest assemblages. Leaf minus air temperature was strongly correlated with leaf width, ranging from -0.9 to -3.2°C in the smallest- and largest-leaved species, respectively. Mean annual temperature and frost-free period were good predictors of evergreen angiosperm leaf size in forest assemblages, but no climate variable predicted deciduous leaf size. Although winter deciduousness makes large leaves possible in strongly seasonal climates, large-leaved evergreens are largely confined to frost-free climates because of their susceptibility to radiative cooling. Evergreen leaf size data can therefore be used to enhance vegetation models, and to infer palaeotemperatures from fossil leaf assemblages.
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Affiliation(s)
- Christopher H Lusk
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, New Zealand
| | - Michael J Clearwater
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, New Zealand
| | - Daniel C Laughlin
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - Sandy P Harrison
- Geography and Environmental Science, University of Reading, Whiteknights, Reading, RG6 6AH, UK
| | - Iain Colin Prentice
- AXA Chair of Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Marisa Nordenstahl
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Benjamin Smith
- Department of Physical Geography and Ecosystem Science, Lund University, 22362, Lund, Sweden
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Morbey YE. Female-biased dimorphism in size and age at maturity is reduced at higher latitudes in lake whitefish Coregonus clupeaformis. J Fish Biol 2018; 93:40-46. [PMID: 29882273 DOI: 10.1111/jfb.13675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
Female-biased sexual dimorphism in size at maturity is a common pattern observed in freshwater fishes with indeterminate growth, yet can vary in magnitude among populations for reasons that are not well understood. According to sex-specific optimization models, female-biased sexual size dimorphism can evolve due to sexual selection favouring earlier maturation by males, even when sexes are otherwise similar in their growth and mortality regimes. The magnitude of sexual size dimorphism is expected to depend on mortality rate. When mortality rates are low, both males and females are expected to mature at older ages and larger sizes, with size determined by the von Bertalanffy growth equation. The difference between size at maturity in males and females becomes reduced when maturing at older ages, closer to asymptotic size. This phenomenon is called von Bertalanffy buffering. The predicted relationship between the magnitude of female-biased sexual dimorphism in age and size at maturity and mortality rate was tested in a comparative analysis of lake whitefish Coregonus clupeaformis from 26 populations across a broad latitudinal range in North America. Most C. clupeaformis populations displayed female-biased sexual dimorphism in size and age at 50% maturity. As predicted, female-biased sexual size dimorphism was less extreme among lower mortality, high-latitude populations.
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Affiliation(s)
- Yolanda E Morbey
- Department of Biology, University of Western Ontario, London, Canada
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Henkel SK, Nelson WG. Assessment of spatial patterns in benthic macrofauna of the U.S. west coast continental shelf. J Biogeogr 2018; 45:2701-2717. [PMID: 30996510 PMCID: PMC6463525 DOI: 10.1111/jbi.13451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
AIM We assessed whether currently described marine biogeographic boundaries apply to shelf macrofauna and which environmental drivers were most associated with species differences among regions. LOCATION Pacific coast of North America from the Strait of Juan de Fuca in Washington to the California-Mexico border. METHODS Van Veen grab samples were collected from soft sediment 28-138 m deep and sieved using 1 mm mesh. Spatial patterns of species richness, diversity, and abundance were examined in relation to latitude and environmental parameters (temperature, salinity, dissolved oxygen, sediment % fines, and total organic carbon). Analyses of latitudinal distribution patterns of individual species were combined with multivariate analyses of community composition to determine biogeographic and habitat boundaries for mid-depth continental shelf macrofauna. RESULTS Species richness, diversity, and abundance significantly decreased with increasing latitude, primarily between 32 and 40° N. There were positive associations of richness, diversity (H'), and abundance with upwelling index, sediment % fines, and TOC (<2%). Temperature and DO also were significant for richness and H' but not abundance. Assessment of individual species ranges found major faunal transitions at latitudes 33-34°, 37°, 44°, and 46-47°. Major assemblage differences were found at 34.5°, and 42°. Within each latitudinal region, significantly different macrofauna communities were found in sediment with <5% fines. MAIN CONCLUSIONS The biogeographic boundaries proposed under the Marine Ecoregions of the World schema are more closely aligned with shelf fauna distributions than those developed using west coast rocky intertidal communities. However, the proposed province boundary at Cape Mendocino is not apparent in the shelf macrofauna, and a transition appears to occur closer to the Oregon-California border. Further, the shelf macrofauna indicate the Channel Islands should be a separate subregion from mainland southern California Bight. Multivariate community analyses minimizing the impact of rare species appeared more useful in determining macrofaunal community biogeographic boundaries than analysis of individual species range endpoints, which are strongly influenced by uncommon species.
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Affiliation(s)
- Sarah K Henkel
- Hatfield Marine Science Center, Oregon State University, Newport, OR 97365,
| | - Walter G Nelson
- Western Ecology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Newport OR 97365, USA
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Ruskin KJ, Etterson MA, Hodgman TP, Borowske AC, Cohen JB, Elphick CS, Field CR, Longenecker RA, King E, Kocek AR, Kovach AI, O’Brien KM, Pau N, Shriver WG, Walsh J, Olsen BJ. Demographic analysis demonstrates systematic but independent spatial variation in abiotic and biotic stressors across 59 percent of a global species range. Auk 2017; 134:903-916. [PMID: 37534301 PMCID: PMC10395324 DOI: 10.1642/auk-16-230.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
The balance of abiotic and biotic stressors experienced by a species likely varies across its range, resulting in spatially heterogeneous limitations on the species' demographic rates. Support for spatial variation in stressors (often latitudinal gradients) has been found in many species, usually with physiological or correlative occupancy data, but it has rarely been estimated directly with demographic data. We collected demographic data from 23 sites spanning the majority of the Saltmarsh Sparrow (Ammodramus caudacutus) breeding range. Using data from 837 nests, we quantified the abiotic and biotic variables most important to nest survival, which is the dominant driver of both fecundity and population growth rate in this species. We separately estimated daily nest failure probability due to nest depredation (biotic stressor) and nest flooding (abiotic stressor), which collectively account for almost all nest failure in the species. Nest depredation decreased with latitude, whereas nest flooding was not related to latitude. Instead, nest flooding was best predicted by a combination of maximum high tide, extremity of rare flooding events, and date. For a single vital rate, we observed predictable variation in competing biotic and abiotic stressors across this species range. We observed that biotic and abiotic stressors were geographically independent, both on a large spatial scale and locally. Our results suggest that stressors on the fecundity of Saltmarsh Sparrow vary systematically across its range, but independently. The observed patterns of biotic and abiotic stress provide information for efforts to conserve the Saltmarsh Sparrow, which is considered threatened. Further, understanding the effects that different stressors, and their interactions, have on demographic rates is necessary to unravel the processes that govern species distributions and to effectively conserve biodiversity in the face of global change.
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Affiliation(s)
- Katharine J. Ruskin
- Ecology and Environmental Sciences Program and Climate Change Institute, University of Maine, Orono, Maine, USA
| | - Matthew A. Etterson
- U.S. Environmental Protection Agency, Mid-Continent Ecology Division, Duluth, Minnesota, USA
| | - Thomas P. Hodgman
- Bird Group, Maine Department of Inland Fisheries and Wildlife, Bangor, Maine, USA
| | - Alyssa C. Borowske
- Department of Ecology and Evolutionary Biology and Center for Conservation and Biodiversity, University of Connecticut, Storrs, Connecticut, USA
| | - Jonathan B. Cohen
- Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York, USA
| | - Chris S. Elphick
- Department of Ecology and Evolutionary Biology and Center for Conservation and Biodiversity, University of Connecticut, Storrs, Connecticut, USA
| | - Christopher R. Field
- Department of Ecology and Evolutionary Biology and Center for Conservation and Biodiversity, University of Connecticut, Storrs, Connecticut, USA
| | - Rebecca A. Longenecker
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, Delaware, USA
| | - Erin King
- U.S. Fish and Wildlife Service, Region 5 Division of Natural Resources, Stewart B. McKinney National Wildlife Refuge, Westbrook, Connecticut, USA
| | - Alison R. Kocek
- Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York, USA
| | - Adrienne I. Kovach
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA
| | - Kathleen M. O’Brien
- U.S. Fish and Wildlife Service, Rachel Carson National Wildlife Refuge, Wells, Maine, USA
| | - Nancy Pau
- U.S. Fish and Wildlife Service, Parker River National Wildlife Refuge, Newburyport, Massachusetts, USA
| | - W. Gregory Shriver
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, Delaware, USA
| | - Jennifer Walsh
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA
| | - Brian J. Olsen
- Ecology and Environmental Sciences Program and Climate Change Institute, University of Maine, Orono, Maine, USA
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Morán XAG, Gasol JM, Pernice MC, Mangot JF, Massana R, Lara E, Vaqué D, Duarte CM. Temperature regulation of marine heterotrophic prokaryotes increases latitudinally as a breach between bottom-up and top-down controls. Glob Chang Biol 2017; 23:3956-3964. [PMID: 28423463 DOI: 10.1111/gcb.13730] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
Planktonic heterotrophic prokaryotes make up the largest living biomass and process most organic matter in the ocean. Determining when and where the biomass and activity of heterotrophic prokaryotes are controlled by resource availability (bottom-up), predation and viral lysis (top-down) or temperature will help in future carbon cycling predictions. We conducted an extensive survey across subtropical and tropical waters of the Atlantic, Indian and Pacific Oceans during the Malaspina 2010 Global Circumnavigation Expedition and assessed indices for these three types of controls at 109 stations (mostly from the surface to 4,000 m depth). Temperature control was approached by the apparent activation energy in eV (ranging from 0.46 to 3.41), bottom-up control by the slope of the log-log relationship between biomass and production rate (ranging from -0.12 to 1.09) and top-down control by an index that considers the relative abundances of heterotrophic nanoflagellates and viruses (ranging from 0.82 to 4.83). We conclude that temperature becomes dominant (i.e. activation energy >1.5 eV) within a narrow window of intermediate values of bottom-up (0.3-0.6) and top-down 0.8-1.2) controls. A pervasive latitudinal pattern of decreasing temperature regulation towards the Equator, regardless of the oceanic basin, suggests that the impact of global warming on marine microbes and their biogeochemical function will be more intense at higher latitudes. Our analysis predicts that 1°C ocean warming will result in increased biomass of heterotrophic prokaryoplankton only in waters with <26°C of mean annual surface temperature.
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Affiliation(s)
- Xosé Anxelu G Morán
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Josep M Gasol
- Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Massimo C Pernice
- Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
- University of Stockholm, Stockholm, Sweden
| | | | - Ramon Massana
- Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Elena Lara
- Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Dolors Vaqué
- Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Carlos M Duarte
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
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12
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Silbiger NJ, Donahue MJ, Brainard RE. Environmental drivers of coral reef carbonate production and bioerosion: a multi-scale analysis. Ecology 2017; 98:2547-2560. [PMID: 28707327 DOI: 10.1002/ecy.1946] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/31/2017] [Accepted: 06/13/2017] [Indexed: 01/22/2023]
Abstract
The resilience of coral reefs depends on the balance between reef growth and reef breakdown, and their responses to changing environmental conditions. Across the 2500-km Hawaiian Archipelago, we quantified rates of carbonate production, bioerosion, and net accretion at regional, island, site, and within-site spatial scales and tested how these rates respond to environmental conditions across different spatial scales. Overall, there were four major outcomes from this study: (1) bioerosion rates were generally higher in the populated Main Hawaiian Islands (MHI) than the remote, protected Northwestern Hawaiian Islands (NWHI), while carbonate production rates did not vary significantly between the two regions; (2) variability in carbonate production, bioerosion, and net accretion rates was greatest at the smallest within-reef spatial scale; (3) carbonate production and bioerosion rates were associated with distinct sets of environmental parameters; and (4) the strongest correlates of carbonate production, bioerosion, and net accretion rates were different between the MHI region and the NWHI region: in the MHI, the dominant correlates were percent cover of macroalgae and herbivorous fish biomass for carbonate production and bioerosion, respectively, whereas in the NWHI, the top correlates were total alkalinity and benthic cover. This study highlights the need to understand accretion and erosion processes as well as local environmental conditions to predict net coral reef responses to future environmental changes.
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Affiliation(s)
- Nyssa J Silbiger
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, P.O. Box 1346, Kāne'ohe, Hawai'i, 96744, USA
| | - Megan J Donahue
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, P.O. Box 1346, Kāne'ohe, Hawai'i, 96744, USA
| | - Russell E Brainard
- Coral Reef Ecosystem Program, Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, 1845 Wasp Boulevard, Building 176, Honolulu, Hawaii, 96818, USA
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13
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Marquis RJ, Salazar D, Baer C, Reinhardt J, Priest G, Barnett K. Ode to Ehrlich and Raven or how herbivorous insects might drive plant speciation. Ecology 2017; 97:2939-2951. [PMID: 27870033 DOI: 10.1002/ecy.1534] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 06/27/2016] [Accepted: 07/07/2016] [Indexed: 11/06/2022]
Abstract
Fifty years ago, Ehrlich and Raven proposed that insect herbivores have driven much of plant speciation, particularly at tropical latitudes. There have been no explicit tests of their hypotheses. Indeed there were no proposed mechanisms either at the time or since by which herbivores might generate new plant species. Here we outline two main classes of mechanisms, prezygotic and postzygotic, with a number of scenarios in each by which herbivore-driven changes in host plant secondary chemistry might lead to new plant lineage production. The former apply mainly to a sympatric model of speciation while the latter apply to a parapatric or allopatric model. Our review suggests that the steps of each mechanism are known to occur individually in many different systems, but no scenario has been thoroughly investigated in any one system. Nevertheless, studies of Dalechampia and its herbivores and pollinators, and patterns of defense tradeoffs in trees on different soil types in the Peruvian Amazon provide evidence consistent with the original hypotheses of Ehrlich and Raven. For herbivores to drive sympatric speciation, our findings suggest that interactions with both their herbivores and their pollinators should be considered. In contrast, herbivores may drive speciation allopatrically without any influence by pollinators. Finally, there is evidence that these mechanisms are more likely to occur at low latitudes and thus more likely to produce new species in the tropics. The mechanisms we outline provide a predictive framework for further study of the general role that herbivores play in diversification of their host plants.
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Affiliation(s)
- Robert J Marquis
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA
| | - Diego Salazar
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA.,Department of Integrative Biology, University of California-Berkeley, 3040 Valley Life Sciences Bldg #3140, Berkeley, California, 94720, USA
| | - Christina Baer
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA
| | - Jason Reinhardt
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA.,Department of Forest Resources, University of Minnesota, 1530 Cleveland Ave. N., St. Paul, Minnesota, 55108, USA
| | - Galen Priest
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA
| | - Kirk Barnett
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Penrith, New South Wales, 2751, Australia
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14
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Ferrera I, Sarmento H, Priscu JC, Chiuchiolo A, González JM, Grossart HP. Diversity and Distribution of Freshwater Aerobic Anoxygenic Phototrophic Bacteria across a Wide Latitudinal Gradient. Front Microbiol 2017; 8:175. [PMID: 28275369 PMCID: PMC5320280 DOI: 10.3389/fmicb.2017.00175] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/24/2017] [Indexed: 11/13/2022] Open
Abstract
Aerobic anoxygenic phototrophs (AAPs) have been shown to exist in numerous marine and brackish environments where they are hypothesized to play important ecological roles. Despite their potential significance, the study of freshwater AAPs is in its infancy and limited to local investigations. Here, we explore the occurrence, diversity and distribution of AAPs in lakes covering a wide latitudinal gradient: Mongolian and German lakes located in temperate regions of Eurasia, tropical Great East African lakes, and polar permanently ice-covered Antarctic lakes. Our results show a widespread distribution of AAPs in lakes with contrasting environmental conditions and confirm that this group is composed of different members of the Alpha- and Betaproteobacteria. While latitude does not seem to strongly influence AAP abundance, clear patterns of community structure and composition along geographic regions were observed as indicated by a strong macro-geographical signal in the taxonomical composition of AAPs. Overall, our results suggest that the distribution patterns of freshwater AAPs are likely driven by a combination of small-scale environmental conditions (specific of each lake and region) and large-scale geographic factors (climatic regions across a latitudinal gradient).
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Affiliation(s)
- Isabel Ferrera
- Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar, Consejo Superior de Investigaciones CientíficasBarcelona, Spain; Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland FisheriesStechlin, Germany
| | - Hugo Sarmento
- Department of Hydrobiology, Universidade Federal de São Carlos São Carlos, Brazil
| | - John C Priscu
- Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Amy Chiuchiolo
- Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - José M González
- Department of Microbiology, University of La Laguna La Laguna, Spain
| | - Hans-Peter Grossart
- Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland FisheriesStechlin, Germany; Department of Biochemistry and Biology, Potsdam UniversityPotsdam, Germany
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15
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Amado AM, Roland F. Editorial: Microbial Role in the Carbon Cycle in Tropical Inland Aquatic Ecosystems. Front Microbiol 2017; 8:20. [PMID: 28154556 PMCID: PMC5243796 DOI: 10.3389/fmicb.2017.00020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 01/04/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- André M Amado
- Limnology Laboratory, Department of Oceanography and Limnology, Universidade Federal do Rio Grande do NorteRio Grande do Norte, Brazil; Aquatic Ecology Laboratory, Department of Biology, Universidade Federal de Juiz de ForaMinas Gerais, Brazil
| | - Fábio Roland
- Aquatic Ecology Laboratory, Department of Biology, Universidade Federal de Juiz de Fora Minas Gerais, Brazil
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16
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Bhattarai GP, Meyerson LA, Cronin JT. Geographic variation in apparent competition between native and invasive Phragmites australis. Ecology 2017; 98:349-358. [PMID: 27861789 DOI: 10.1002/ecy.1646] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/08/2016] [Accepted: 10/31/2016] [Indexed: 11/06/2022]
Abstract
Apparent competition, the negative interaction between species mediated by shared natural enemies, is thought to play an important role in shaping the structure and dynamics of natural communities. However, its importance in driving species invasions, and whether the strength of this indirect interaction varies across the latitudinal range of the invasion, has not been fully explored. We performed replicated field experiments at four sites spanning 900 km along the Atlantic Coast of the United States to assess the presence and strength of apparent competition between sympatric native and invasive lineages of Phragmites australis. Four herbivore guilds were considered: stem-feeders, leaf-miners, leaf-chewers and aphids. We also tested the hypothesis that the strength of this interaction declines with increasing latitude. Within each site, native and invasive plants of P. australis were cross-transplanted between co-occurring native and invasive patches in the same marsh habitat and herbivore damage was evaluated at the end of the growing season. Apparent competition was evident for both lineages and involved all but the leaf-chewer guild. For native plants, total aphids per plant was 296% higher and the incidence of stem-feeding and leaf-mining herbivores was 34% and 221% higher, respectively, when transplanted into invasive than native patches. These data suggest that invasive P. australis has a negative effect on native P. australis via apparent competition. Averaged among herbivore types, the indirect effects of the invasive lineage on the native lineage was 57% higher than the reverse situation, suggesting that apparent competition was asymmetric. We also found that the strength of apparent competition acting against the native lineage was comparable to the benefits to the invasive lineage from enemy release (i.e., proportionately lower mean herbivory of the invasive relative to the native taxa). Finally, we found the first evidence that the strength of apparent competition acting against the native lineage (from stem-feeders only) decreased with increasing latitude. These results suggest that not only could apparent competition be of tantamount importance to enemy release in enhancing the establishment and spread of invasive taxa, but also that these indirect and direct herbivore effects could vary over the invasion range.
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Affiliation(s)
- Ganesh P Bhattarai
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Laura A Meyerson
- Department of Natural Resources Sciences, University of Rhode Island, 1 Greenhouse Road, Kingston, Rhode Island, 02881, USA
| | - James T Cronin
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
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17
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Abstract
The specificity of the interactions between plants and their consumers varies considerably. The evolutionary and ecological factors underlying this variation are unclear. Several potential explanatory factors vary with latitude, for example plant species richness and the intensity of herbivory. Here, we use comparative phylogenetic methods to test the effect of latitude on host range in scale insects. We find that, on average, scale insects that occur in lower latitudes are more polyphagous. This result is at odds with the general pattern of greater host-plant specificity of insects in the tropics. We propose that this disparity reflects a high cost for host specificity in scale insects, stemming from unusual aspects of scale insect life history, for example, passive wind-driven dispersal. More broadly, the strong evidence for pervasive effects of geography on host range across insect groups stands in stark contrast to the weak evidence for constraints on host range due to genetic trade-offs.
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Affiliation(s)
- Nate B Hardy
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Daniel A Peterson
- Department of Biology and Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Benjamin B Normark
- Department of Biology and Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA
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18
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Lawson AM, Weir JT. Latitudinal gradients in climatic-niche evolution accelerate trait evolution at high latitudes. Ecol Lett 2014; 17:1427-36. [PMID: 25168260 DOI: 10.1111/ele.12346] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/12/2014] [Accepted: 07/28/2014] [Indexed: 11/26/2022]
Abstract
Despite the importance of divergent selection to the speed of evolution, it remains poorly understood if divergent selection is more prevalent in the tropics (where species richness is highest), or at high latitudes (where paleoclimate change has been most intense). We tested whether the rate of climatic-niche evolution - one proxy for divergent selection - varies with latitude for 111 pairs of bird species. Using Brownian motion and Ornsetin-Ulhenbeck models, we show that evolutionary rates along two important axes of the climatic-niche - temperature and seasonality - have been faster at higher latitudes. We then tested whether divergence of the climatic-niche was associated with evolution in traits important in ecological differentiation (body mass) and reproductive isolation (song), and found that climatic divergence is associated with faster rates in both measures. These results highlight the importance of climate-mediated divergent selection pressures in driving evolutionary divergence and reproductive isolation at high latitudes.
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Affiliation(s)
- Adam M Lawson
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M1C 1A4, Canada
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19
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Stoks R, Geerts AN, De Meester L. Evolutionary and plastic responses of freshwater invertebrates to climate change: realized patterns and future potential. Evol Appl 2013; 7:42-55. [PMID: 24454547 PMCID: PMC3894897 DOI: 10.1111/eva.12108] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 08/30/2013] [Indexed: 12/14/2022] Open
Abstract
We integrated the evidence for evolutionary and plastic trait changes in situ in response to climate change in freshwater invertebrates (aquatic insects and zooplankton). The synthesis on the trait changes in response to the expected reductions in hydroperiod and increases in salinity indicated little evidence for adaptive, plastic, and genetic trait changes and for local adaptation. With respect to responses to temperature, there are many studies on temporal trait changes in phenology and body size in the wild that are believed to be driven by temperature increases, but there is a general lack of rigorous demonstration whether these trait changes are genetically based, adaptive, and causally driven by climate change. Current proof for genetic trait changes under climate change in freshwater invertebrates stems from a limited set of common garden experiments replicated in time. Experimental thermal evolution experiments and common garden warming experiments associated with space-for-time substitutions along latitudinal gradients indicate that besides genetic changes, also phenotypic plasticity and evolution of plasticity are likely to contribute to the observed phenotypic changes under climate change in aquatic invertebrates. Apart from plastic and genetic thermal adjustments, also genetic photoperiod adjustments are widespread and may even dominate the observed phenological shifts.
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Affiliation(s)
- Robby Stoks
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven Leuven, Belgium
| | - Aurora N Geerts
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven Leuven, Belgium
| | - Luc De Meester
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven Leuven, Belgium
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20
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Abstract
Many groups show higher species richness in tropical regions but the underlying causes remain unclear. Despite many competing hypotheses to explain latitudinal diversity gradients, only three processes can directly change species richness across regions: speciation, extinction and dispersal. These processes can be addressed most powerfully using large-scale phylogenetic approaches, but most previous studies have focused on small groups and recent time scales, or did not separate speciation and extinction rates. We investigate the origins of high tropical diversity in amphibians, applying new phylogenetic comparative methods to a tree of 2871 species. Our results show that high tropical diversity is explained by higher speciation in the tropics, higher extinction in temperate regions and limited dispersal out of the tropics compared with colonization of the tropics from temperate regions. These patterns are strongly associated with climate-related variables such as temperature, precipitation and ecosystem energy. Results from models of diversity dependence in speciation rate suggest that temperate clades may have lower carrying capacities and may be more saturated (closer to carrying capacity) than tropical clades. Furthermore, we estimate strikingly low tropical extinction rates over geological time scales, in stark contrast to the dramatic losses of diversity occurring in tropical regions presently.
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Affiliation(s)
- R Alexander Pyron
- Department of Biological Sciences, The George Washington University, , 2023 G Street NW, Washington, DC 20052, USA, Department of Ecology and Evolutionary Biology, University of Arizona, , Tucson, AZ 85721-0088, USA
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21
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Pratt JD, Mooney KA. Clinal adaptation and adaptive plasticity in Artemisia californica: implications for the response of a foundation species to predicted climate change. Glob Chang Biol 2013; 19:2454-66. [PMID: 23505064 DOI: 10.1111/gcb.12199] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Accepted: 02/18/2013] [Indexed: 05/05/2023]
Abstract
Local adaptation and plasticity pose significant obstacles to predicting plant responses to future climates. Although local adaptation and plasticity in plant functional traits have been documented for many species, less is known about population-level variation in plasticity and whether such variation is driven by adaptation to environmental variation. We examined clinal variation in traits and performance - and plastic responses to environmental change - for the shrub Artemisia californica along a 700 km gradient characterized (from south to north) by a fourfold increase in precipitation and a 61% decrease in interannual precipitation variation. Plants cloned from five populations along this gradient were grown for 3 years in treatments approximating the precipitation regimes of the north and south range margins. Most traits varying among populations did so clinally; northern populations (vs. southern) had higher water-use efficiencies and lower growth rates, C : N ratios and terpene concentrations. Notably, there was variation in plasticity for plant performance that was strongly correlated with source site interannual precipitation variability. The high-precipitation treatment (vs. low) increased growth and flower production more for plants from southern populations (181% and 279%, respectively) than northern populations (47% and 20%, respectively). Overall, precipitation variability at population source sites predicted 86% and 99% of variation in plasticity in growth and flowering, respectively. These striking, clinal patterns in plant traits and plasticity are indicative of adaptation to both the mean and variability of environmental conditions. Furthermore, our analysis of long-term coastal climate data in turn indicates an increase in interannual precipitation variation consistent with most global change models and, unexpectedly, this increased variation is especially pronounced at historically stable, northern sites. Our findings demonstrate the critical need to integrate fundamental evolutionary processes into global change models, as contemporary patterns of adaptation to environmental clines will mediate future plant responses to projected climate change.
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Affiliation(s)
- Jessica D Pratt
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA.
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22
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Colautti RI, Maron JL, Barrett SCH. Common garden comparisons of native and introduced plant populations: latitudinal clines can obscure evolutionary inferences. Evol Appl 2008; 2:187-99. [PMID: 25567860 PMCID: PMC3352372 DOI: 10.1111/j.1752-4571.2008.00053.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Accepted: 11/24/2008] [Indexed: 11/26/2022] Open
Abstract
Common garden studies are increasingly used to identify differences in phenotypic traits between native and introduced genotypes, often ignoring sources of among-population variation within each range. We re-analyzed data from 32 common garden studies of 28 plant species that tested for rapid evolution associated with biological invasion. Our goals were: (i) to identify patterns of phenotypic trait variation among populations within native and introduced ranges, and (ii) to explore the consequences of this variation for how differences between the ranges are interpreted. We combined life history and physiologic traits into a single principal component (PCALL) and also compared subsets of traits related to size, reproduction, and defense (PCSIZE, PCREP, and PCDEF, respectively). On average, introduced populations exhibited increased growth and reproduction compared to native conspecifics when latitude was not included in statistical models. However, significant correlations between PC-scores and latitude were detected in both the native and introduced ranges, indicating population differentiation along latitudinal gradients. When latitude was explicitly incorporated into statistical models as a covariate, it reduced the magnitude and reversed the direction of the effect for PCALL and PCSIZE. These results indicate that unrecognized geographic clines in phenotypic traits can confound inferences about the causes of evolutionary change in invasive plants.
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Affiliation(s)
- Robert I Colautti
- Department of Ecology & Evolutionary Biology, University of Toronto Toronto, ON, Canada
| | - John L Maron
- Division of Biological Sciences, University of Montana Missoula, MT, USA
| | - Spencer C H Barrett
- Department of Ecology & Evolutionary Biology, University of Toronto Toronto, ON, Canada
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23
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Pautasso M, Chiarucci A. A test of the scale-dependence of the species abundance-people correlation for veteran trees in Italy. Ann Bot 2008; 101:709-715. [PMID: 18250107 PMCID: PMC2710175 DOI: 10.1093/aob/mcn010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 12/11/2007] [Accepted: 12/20/2007] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS The spatial correlation of the presence of people and species has been suggested to be scale-dependent. At local scales, large numbers of people often result in species impoverishment. At coarse scales, species-rich regions tend to be densely inhabited. Recently, broad-scale human presence has been shown to be correlated not only with numbers of species but also with their abundance, as predicted by the more-individuals hypothesis. However, it is not known whether the species abundance-human presence correlation could also be scale-dependent. METHODS This hypothesis was tested by use of a database of veteran trees in Italy. Veteran tree species richness and number of individuals were modelled as a function of human population size at two grains of analysis (provinces and regions), controlling for variations in area, latitude and spatial autocorrelation. KEY RESULTS A positive correlation was found between human presence and veteran tree species. As predicted, this correlation was stronger at a coarser resolution. However, only at the provincial but not regional level was there a positive correlation between human presence and veteran tree abundance when controlling for area and latitude. These results were confirmed for native and exotic trees. CONCLUSIONS The present findings rule out the more-individuals hypothesis as an explanation of the scale-dependence of the species-people correlation for veteran trees in Italy. Potential mechanisms behind the observed spatial coincidence of high numbers of people and veteran tree species are discussed and implications for conservation are highlighted.
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Affiliation(s)
- Marco Pautasso
- Division of Biology, Imperial College London, Wye Campus, High Street, Wye, Kent TN25 5AH, UK.
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24
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Abstract
As pollinators decline globally, competition for their services is expected to intensify, and this antagonism may be most severe where the number of plant species is the greatest. Using meta-analysis and comparative phylogenetic analysis, we provide a global-scale test of whether reproduction becomes more limited by pollen receipt (pollen limitation) as the number of coexisting plant species increases. As predicted, we find a significant positive relationship between pollen limitation and species richness. In addition, this pattern is particularly strong for species that are obligately outcrossing and for trees relative to herbs or shrubs. We suggest that plants occurring in species-rich communities may be more prone to pollen limitation because of interspecific competition for pollinators. As a consequence, plants in biodiversity hotspots may have a higher risk of extinction and/or experience increased selection pressure to specialize on certain pollinators or diversify into different phenological niches. The combination of higher pollen limitation and habitat destruction represents a dual risk to tropical plant species that has not been previously identified.
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Affiliation(s)
- Jana C Vamosi
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4.
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