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Dynesius M, Jansson R. Persistence of within-species lineages: a neglected control of speciation rates. Evolution 2013; 68:923-34. [PMID: 24329123 DOI: 10.1111/evo.12316] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 11/07/2013] [Indexed: 11/30/2022]
Abstract
We present a framework distinguishing three principal controls of speciation rate: rate of splitting, level of persistence, and length of speciation duration. We contend that discussions on diversification become clearer in the light of this framework, because speciation rate variation could be attributed to any of these controls. In particular, we claim that the role of persistence of within-species lineages in controlling speciation rates has been greatly underappreciated. More emphasis on the persistence control would change expectations of the role of several biological traits and environmental factors, because they may drive speciation rate in one direction through the persistence control and in the opposite direction through the other two controls. Traits and environments have been little studied regarding their influence on speciation rate through the persistence control, with climatic fluctuations being a relatively well-studied exception. Considering the recent advances in genomic and phylogenetic analysis, we think that the time is ripe for applying the framework in empirical research. Variation among clades and areas (and thus among traits and environments) in the importance of the three rate controls could be addressed for example by dating splitting events, detecting within-species lineages, and scanning genomes for evidence of divergent selection.
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Affiliation(s)
- Mats Dynesius
- Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden.
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Wernberg T, Thomsen MS, Connell SD, Russell BD, Waters JM, Zuccarello GC, Kraft GT, Sanderson C, West JA, Gurgel CFD. The footprint of continental-scale ocean currents on the biogeography of seaweeds. PLoS One 2013; 8:e80168. [PMID: 24260352 PMCID: PMC3832649 DOI: 10.1371/journal.pone.0080168] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 09/29/2013] [Indexed: 11/18/2022] Open
Abstract
Explaining spatial patterns of biological organisation remains a central challenge for biogeographic studies. In marine systems, large-scale ocean currents can modify broad-scale biological patterns by simultaneously connecting environmental (e.g. temperature, salinity and nutrients) and biological (e.g. amounts and types of dispersed propagules) properties of adjacent and distant regions. For example, steep environmental gradients and highly variable, disrupted flow should lead to heterogeneity in regional communities and high species turnover. In this study, we investigated the possible imprint of the Leeuwin (LC) and East Australia (EAC) Currents on seaweed communities across ~7,000 km of coastline in temperate Australia. These currents flow poleward along the west and east coasts of Australia, respectively, but have markedly different characteristics. We tested the hypothesis that, regional seaweed communities show serial change in the direction of current flow and that, because the LC is characterised by a weaker temperature gradient and more un-interrupted along-shore flow compared to the EAC, then coasts influenced by the LC have less variable seaweed communities and lower species turnover across regions than the EAC. This hypothesis was supported. We suggest that this pattern is likely caused by a combination of seaweed temperature tolerances and current-driven dispersal. In conclusion, our findings support the idea that the characteristics of continental-scale currents can influence regional community organisation, and that the coupling of ocean currents and marine biological structure is a general feature that transcends taxa and spatial scales.
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Affiliation(s)
- Thomas Wernberg
- UWA Oceans Institute & School of Plant Biology, University of Western Australia, Perth, Western Australia, Australia
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53
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Abstract
Inference of past and present global biodiversity requires enough global data to distinguish biological pattern from sampling artifact. Pertinently, many studies have exposed correlated relationships between richness and sampling in the fossil record, and methods to circumvent these biases have been proposed. Yet, these studies often ignore paleobiogeography, which is undeniably a critical component of ancient global diversity. Alarmingly, our global analysis of 481,613 marine fossils spread throughout the Phanerozoic reveals that where localities are and how intensively they have been sampled almost completely determines empirical spatial patterns of richness, suggesting no separation of biological pattern from sampling pattern. To overcome this, we analyze diversity using occurrence records drawn from two discrete paleolatitudinal bands which cover the bulk of the fossil data. After correcting the data for sampling bias, we find that these two bands have similar patterns of richness despite markedly different spatial coverage. Our findings suggest that i) long-term diversity trends result from large-scale tectonic evolution of the planet, ii) short-term diversity trends are region-specific, and iii) paleodiversity studies must constrain their analyses to well-sampled regions to uncover patterns not driven by sampling.
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Affiliation(s)
- Daril A. Vilhena
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| | - Andrew B. Smith
- Department of Earth Sciences, The Natural History Museum, London, England, United Kingdom
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Miloslavich P, Cruz-Motta JJ, Klein E, Iken K, Weinberger V, Konar B, Trott T, Pohle G, Bigatti G, Benedetti-Cecchi L, Shirayama Y, Mead A, Palomo G, Ortiz M, Gobin J, Sardi A, Díaz JM, Knowlton A, Wong M, Peralta AC. Large-scale spatial distribution patterns of gastropod assemblages in rocky shores. PLoS One 2013; 8:e71396. [PMID: 23967204 PMCID: PMC3742765 DOI: 10.1371/journal.pone.0071396] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 06/28/2013] [Indexed: 11/19/2022] Open
Abstract
Gastropod assemblages from nearshore rocky habitats were studied over large spatial scales to (1) describe broad-scale patterns in assemblage composition, including patterns by feeding modes, (2) identify latitudinal pattern of biodiversity, i.e., richness and abundance of gastropods and/or regional hotspots, and (3) identify potential environmental and anthropogenic drivers of these assemblages. Gastropods were sampled from 45 sites distributed within 12 Large Marine Ecosystem regions (LME) following the NaGISA (Natural Geography in Shore Areas) standard protocol (www.nagisa.coml.org). A total of 393 gastropod taxa from 87 families were collected. Eight of these families (9.2%) appeared in four or more different LMEs. Among these, the Littorinidae was the most widely distributed (8 LMEs) followed by the Trochidae and the Columbellidae (6 LMEs). In all regions, assemblages were dominated by few species, the most diverse and abundant of which were herbivores. No latitudinal gradients were evident in relation to species richness or densities among sampling sites. Highest diversity was found in the Mediterranean and in the Gulf of Alaska, while highest densities were found at different latitudes and represented by few species within one genus (e.g. Afrolittorina in the Agulhas Current, Littorina in the Scotian Shelf, and Lacuna in the Gulf of Alaska). No significant correlation was found between species composition and environmental variables (r≤0.355, p>0.05). Contributing variables to this low correlation included invasive species, inorganic pollution, SST anomalies, and chlorophyll-a anomalies. Despite data limitations in this study which restrict conclusions in a global context, this work represents the first effort to sample gastropod biodiversity on rocky shores using a standardized protocol across a wide scale. Our results will generate more work to build global databases allowing for large-scale diversity comparisons of rocky intertidal assemblages.
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Affiliation(s)
- Patricia Miloslavich
- Departamento de Estudios Ambientales and Centro de Biodiversidad Marina, Universidad Simón Bolívar, Caracas, Miranda, Venezuela.
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Baumann H, Doherty O. Decadal Changes in the World's Coastal Latitudinal Temperature Gradients. PLoS One 2013; 8:e67596. [PMID: 23825672 PMCID: PMC3689001 DOI: 10.1371/journal.pone.0067596] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 05/20/2013] [Indexed: 11/18/2022] Open
Abstract
Most of the world's living marine resources inhabit coastal environments, where average thermal conditions change predictably with latitude. These coastal latitudinal temperature gradients (CLTG) coincide with important ecological clines,e.g., in marine species diversity or adaptive genetic variations, but how tightly thermal and ecological gradients are linked remains unclear. A first step is to consistently characterize the world's CLTGs. We extracted coastal cells from a global 1°×1° dataset of weekly sea surface temperatures (SST, 1982–2012) to quantify spatial and temporal variability of the world's 11 major CLTGs. Gradient strength, i.e., the slope of the linear mean-SST/latitude relationship, varied 3-fold between the steepest (North-American Atlantic and Asian Pacific gradients: −0.91°C and −0.68°C lat−1, respectively) and weakest CLTGs (African Indian Ocean and the South- and North-American Pacific gradients: −0.28, −0.29, −0.32°C lat−1, respectively). Analyzing CLTG strength by year revealed that seven gradients have weakened by 3–10% over the past three decades due to increased warming at high compared to low latitudes. Almost the entire South-American Pacific gradient (6–47°S), however, has considerably cooled over the study period (−0.3 to −1.7°C, 31 years), and the substantial weakening of the North-American Atlantic gradient (−10%) was due to warming at high latitudes (42–60°N, +0.8 to +1.6°C,31 years) and significant mid-latitude cooling (Florida to Cape Hatteras 26–35°N, −0.5 to −2.2°C, 31 years). Average SST trends rarely resulted from uniform shifts throughout the year; instead individual seasonal warming or cooling patterns elicited the observed changes in annual means. This is consistent with our finding of increased seasonality (i.e., summer-winter SST amplitude) in three quarters of all coastal cells (331 of 433). Our study highlights the regionally variable footprint of global climate change, while emphasizing ecological implications of changing CLTGs, which are likely driving observed spatial and temporal clines in coastal marine life.
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Affiliation(s)
- Hannes Baumann
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
| | - Owen Doherty
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America
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56
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Kuklinski P. Biodiversity and abundance patterns of rock encrusting fauna in a temperate fjord. MARINE ENVIRONMENTAL RESEARCH 2013; 87-88:61-72. [PMID: 23615496 DOI: 10.1016/j.marenvres.2013.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 03/14/2013] [Accepted: 03/18/2013] [Indexed: 06/02/2023]
Abstract
Fjords are semi-enclosed systems often with usually strong physical and chemical gradients. These gradients provide the opportunity to test the influence of various physical and chemical factors on biodiversity. However study area of this investigation, Trondheimsfjord, is a large water body where especially salinity gradient along the fjord is not well pronounced. The goal of this study was to establish within a temperate fjord a baseline identifying encrusting fauna on rocks and determine the factors driving changes along the length of the fjord and changing depths. There was no trend in species composition change and increase or decrease in number of species, diversity and number of individuals along the fjord. This was likely due to the relative homogeneity of both substrate (rocks) and environmental parameters. Nevertheless, the influence of fresh water inflow in the vicinity of the river mouth was apparent by the presence of characteristic brackish-water species at these locations. Multidimensional scaling analysis revealed three separate assemblages: intertidal, shallow and deep subtidal (below 50 m). Intertidal assemblages were species poor (one to 11 species) but relatively abundant (six to 2374 indiv./m(2) of rocks). Number of individuals and biomass was highest in the shallow subtidal (2059-13,587 indiv./m(2) of rocks). Overall the highest species number (45) was recorded at 50 m depth which is probably result of low competition pressure yet still relatively high nutrient concentration in comparison to shallower locations. Environmental parameters (i.e., tidal currents, wave action, salinity) change more drastically with depth than along the fjord and these changes are the major driving forces in shaping encrusting assemblages in Trondheimsfjord.
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Affiliation(s)
- Piotr Kuklinski
- Institute of Oceanology, Polish Academy of Sciences, ul. Powstancow Warszawy 55, Sopot 81-712, Poland.
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57
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Beta diversity of demersal fish assemblages in the North-Eastern Pacific: interactions of latitude and depth. PLoS One 2013; 8:e57918. [PMID: 23526960 PMCID: PMC3602450 DOI: 10.1371/journal.pone.0057918] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 01/27/2013] [Indexed: 11/29/2022] Open
Abstract
Knowledge of broad-scale global patterns in beta diversity (i.e., variation or turnover in identities of species) for marine systems is in its infancy. We analysed the beta diversity of groundfish communities along the North American Pacific coast, from trawl data spanning 32.57°N to 48.52°N and 51 m to 1200 m depth. Analyses were based on both the Jaccard measure and the probabilistic Raup-Crick measure, which accounts for variation in alpha diversity. Overall, beta diversity decreased with depth, and this effect was strongest at lower latitudes. Superimposed on this trend were peaks in beta diversity at around 400–600 m and also around 1000–1200 m, which may indicate high turnover around the edges of the oxygen minimum zone. Beta diversity was also observed to decrease with latitude, but this effect was only observed in shallower waters (<200 m); latitudinal turnover began to disappear at depths >800 m. At shallower depths (<200 m), peaks in latitudinal turnover were observed at ∼43°N, 39°N, 35°N and 31°N, which corresponded well with several classically observed oceanographic boundaries. Turnover with depth was stronger than latitudinal turnover, and is likely to reflect strong environmental filtering over relatively short distances. Patterns in beta diversity, including latitude-by-depth interactions, should be integrated with other biodiversity measures in ecosystem-based management and conservation of groundfish communities.
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Sanciangco JC, Carpenter KE, Etnoyer PJ, Moretzsohn F. Habitat availability and heterogeneity and the indo-pacific warm pool as predictors of marine species richness in the tropical Indo-Pacific. PLoS One 2013; 8:e56245. [PMID: 23457533 PMCID: PMC3574161 DOI: 10.1371/journal.pone.0056245] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 01/07/2013] [Indexed: 11/20/2022] Open
Abstract
Range overlap patterns were observed in a dataset of 10,446 expert-derived marine species distribution maps, including 8,295 coastal fishes, 1,212 invertebrates (crustaceans and molluscs), 820 reef-building corals, 50 seagrasses, and 69 mangroves. Distributions of tropical Indo-Pacific shore fishes revealed a concentration of species richness in the northern apex and central region of the Coral Triangle epicenter of marine biodiversity. This pattern was supported by distributions of invertebrates and habitat-forming primary producers. Habitat availability, heterogeneity, and sea surface temperatures were highly correlated with species richness across spatial grains ranging from 23,000 to 5,100,000 km2 with and without correction for autocorrelation. The consistent retention of habitat variables in our predictive models supports the area of refuge hypothesis which posits reduced extinction rates in the Coral Triangle. This does not preclude support for a center of origin hypothesis that suggests increased speciation in the region may contribute to species richness. In addition, consistent retention of sea surface temperatures in models suggests that available kinetic energy may also be an important factor in shaping patterns of marine species richness. Kinetic energy may hasten rates of both extinction and speciation. The position of the Indo-Pacific Warm Pool to the east of the Coral Triangle in central Oceania and a pattern of increasing species richness from this region into the central and northern parts of the Coral Triangle suggests peripheral speciation with enhanced survival in the cooler parts of the Coral Triangle that also have highly concentrated available habitat. These results indicate that conservation of habitat availability and heterogeneity is important to reduce extinction of marine species and that changes in sea surface temperatures may influence the evolutionary potential of the region.
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Affiliation(s)
- Jonnell C Sanciangco
- Marine Biodiversity Unit/Global Marine Species Assessment, Global Species Programme, International Union for Conservation of Nature, Gland, Switzerland.
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59
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Global environmental predictors of benthic marine biogeographic structure. Proc Natl Acad Sci U S A 2012; 109:14046-51. [PMID: 22904189 DOI: 10.1073/pnas.1212381109] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Analyses of how environmental factors influence the biogeographic structure of biotas are essential for understanding the processes underlying global diversity patterns and for predicting large-scale biotic responses to global change. Here we show that the large-scale geographic structure of shallow-marine benthic faunas, defined by existing biogeographic schemes, can be predicted with 89-100% accuracy by a few readily available oceanographic variables; temperature alone can predict 53-99% of the present-day structure along coastlines. The same set of variables is also strongly correlated with spatial changes in species compositions of bivalves, a major component of the benthic marine biota, at the 1° grid-cell resolution. These analyses demonstrate the central role of coastal oceanography in structuring benthic marine biogeography and suggest that a few environmental variables may be sufficient to model the response of marine biogeographic structure to past and future changes in climate.
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60
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Yasuhara M, Hunt G, Dowsett HJ, Robinson MM, Stoll DK. Latitudinal species diversity gradient of marine zooplankton for the last three million years. Ecol Lett 2012; 15:1174-9. [DOI: 10.1111/j.1461-0248.2012.01828.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/30/2012] [Accepted: 06/06/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Moriaki Yasuhara
- School of Biological Sciences; University of Hong Kong; Pok Fu Lam Road Hong Kong SAR China
- Swire Institute of Marine Science; University of Hong Kong; Cape d'Aguilar Road, Shek O Hong Kong SAR China
- Department of Earth Sciences; University of Hong Kong; Pok Fu Lam Road Hong Kong SAR China
- Center for Advanced Marine Core Research; Kochi University; Nankoku Kochi 783-8502 Japan
- Department of Paleobiology; National Museum of Natural History; Smithsonian Institution; Washington DC 20013-7012 USA
| | - Gene Hunt
- Department of Paleobiology; National Museum of Natural History; Smithsonian Institution; Washington DC 20013-7012 USA
| | - Harry J. Dowsett
- Eastern Geology and Paleoclimate Science Center; U.S. Geological Survey; Reston VA 20192 USA
| | - Marci M. Robinson
- Eastern Geology and Paleoclimate Science Center; U.S. Geological Survey; Reston VA 20192 USA
| | - Danielle K. Stoll
- Eastern Geology and Paleoclimate Science Center; U.S. Geological Survey; Reston VA 20192 USA
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61
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Ávila SP, Goud J, de Frias Martins AM. Patterns of diversity of the Rissoidae (Mollusca: Gastropoda) in the Atlantic and the Mediterranean region. ScientificWorldJournal 2012; 2012:164890. [PMID: 22693430 PMCID: PMC3366234 DOI: 10.1100/2012/164890] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 12/22/2011] [Indexed: 11/17/2022] Open
Abstract
The geographical distribution of the Rissoidae in the Atlantic Ocean and Mediterranean Sea was compiled and is up-to-date until July 2011. All species were classified according to their mode of larval development (planktotrophic and nonplanktotrophic), and bathymetrical zonation (shallow species--those living between the intertidal and 50 m depth, and deep species--those usually living below 50 m depth). 542 species of Rissoidae are presently reported to the Atlantic Ocean and the Mediterranean Sea, belonging to 33 genera. The Mediterranean Sea is the most diverse site, followed by Canary Islands, Caribbean, Portugal, and Cape Verde. The Mediterranean and Cape Verde Islands are the sites with higher numbers of endemic species, with predominance of Alvania spp. in the first site, and of Alvania and Schwartziella at Cape Verde. In spite of the large number of rissoids at Madeira archipelago, a large number of species are shared with Canaries, Selvagens, and the Azores, thus only about 8% are endemic to the Madeira archipelago. Most of the 542-rissoid species that live in the Atlantic and in the Mediterranean are shallow species (323), 110 are considered as deep species, and 23 species are reported in both shallow and deep waters. There is a predominance of nonplanktotrophs in islands, seamounts, and at high and medium latitudes. This pattern is particularly evident in the genera Crisilla, Manzonia, Onoba, Porosalvania, Schwartziella, and Setia. Planktotrophic species are more abundant in the eastern Atlantic and in the Mediterranean Sea. The results of the analysis of the probable directions of faunal flows support the patterns found by both the Parsimony Analysis of Endemicity and the geographical distribution. Four main source areas for rissoids emerge: Mediterranean, Caribbean, Canaries/Madeira archipelagos, and the Cape Verde archipelago. We must stress the high percentage of endemics that occurs in the isolated islands of Saint Helena, Tristan da Cunha, Cape Verde archipelago and also the Azores, thus reinforcing the legislative protective actions that the local governments have implemented in these islands during the recent years.
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Affiliation(s)
- Sérgio P Ávila
- Departamento de Biologia, Universidade dos Açores, 9501-801 Ponta Delgada, Açores, Portugal.
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62
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Luo Z, Tang S, Li C, Fang H, Hu H, Yang J, Ding J, Jiang Z. Environmental effects on vertebrate species richness: testing the energy, environmental stability and habitat heterogeneity hypotheses. PLoS One 2012; 7:e35514. [PMID: 22530038 PMCID: PMC3329479 DOI: 10.1371/journal.pone.0035514] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 03/16/2012] [Indexed: 11/19/2022] Open
Abstract
Background Explaining species richness patterns is a central issue in biogeography and macroecology. Several hypotheses have been proposed to explain the mechanisms driving biodiversity patterns, but the causes of species richness gradients remain unclear. In this study, we aimed to explain the impacts of energy, environmental stability, and habitat heterogeneity factors on variation of vertebrate species richness (VSR), based on the VSR pattern in China, so as to test the energy hypothesis, the environmental stability hypothesis, and the habitat heterogeneity hypothesis. Methodology/Principal Findings A dataset was compiled containing the distributions of 2,665 vertebrate species and eleven ecogeographic predictive variables in China. We grouped these variables into categories of energy, environmental stability, and habitat heterogeneity and transformed the data into 100×100 km quadrat systems. To test the three hypotheses, AIC-based model selection was carried out between VSR and the variables in each group and correlation analyses were conducted. There was a decreasing VSR gradient from the southeast to the northwest of China. Our results showed that energy explained 67.6% of the VSR variation, with the annual mean temperature as the main factor, which was followed by annual precipitation and NDVI. Environmental stability factors explained 69.1% of the VSR variation and both temperature annual range and precipitation seasonality had important contributions. By contrast, habitat heterogeneity variables explained only 26.3% of the VSR variation. Significantly positive correlations were detected among VSR, annual mean temperature, annual precipitation, and NDVI, whereas the relationship of VSR and temperature annual range was strongly negative. In addition, other variables showed moderate or ambiguous relations to VSR. Conclusions/Significance The energy hypothesis and the environmental stability hypothesis were supported, whereas little support was found for the habitat heterogeneity hypothesis.
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Affiliation(s)
- Zhenhua Luo
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Songhua Tang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Chunwang Li
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Hongxia Fang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Huijian Hu
- South China Institute of Endangered Animals, Guangdong Academy of Sciences, Guangzhou, China
| | - Ji Yang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | | | - Zhigang Jiang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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63
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Curini-Galletti M, Artois T, Delogu V, De Smet WH, Fontaneto D, Jondelius U, Leasi F, Martínez A, Meyer-Wachsmuth I, Nilsson KS, Tongiorgi P, Worsaae K, Todaro MA. Patterns of diversity in soft-bodied meiofauna: dispersal ability and body size matter. PLoS One 2012; 7:e33801. [PMID: 22457790 PMCID: PMC3311549 DOI: 10.1371/journal.pone.0033801] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 02/17/2012] [Indexed: 11/30/2022] Open
Abstract
Background Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups. Methodology/Principal Findings As a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat. Conclusion/Significance Our macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37%) highlights that the census of marine meiofauna is still very far from being complete.
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Affiliation(s)
- Marco Curini-Galletti
- Dipartimento di Zoologia e Genetica Evoluzionistica, Università di Sassari, Sassari, Italy
| | - Tom Artois
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Valentina Delogu
- Dipartimento di Zoologia e Genetica Evoluzionistica, Università di Sassari, Sassari, Italy
| | | | - Diego Fontaneto
- Department of Invertebrate Zoology, Swedish Museum of Natural History, Stockholm, Sweden
- Division of Biology, Imperial College London, Ascot, United Kingdom
| | - Ulf Jondelius
- Department of Invertebrate Zoology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Francesca Leasi
- Division of Biology, Imperial College London, Ascot, United Kingdom
- Dipartimento di Biologia, Universtità di Modena e Reggio Emilia, Modena, Italy
| | | | - Inga Meyer-Wachsmuth
- Department of Invertebrate Zoology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Karin Sara Nilsson
- Department of Invertebrate Zoology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Paolo Tongiorgi
- Dipartimento di Biologia, Universtità di Modena e Reggio Emilia, Modena, Italy
| | - Katrine Worsaae
- Marine Biological Section, University of Copenhagen, Helsingør, Denmark
| | - M. Antonio Todaro
- Dipartimento di Biologia, Universtità di Modena e Reggio Emilia, Modena, Italy
- * E-mail:
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64
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Marquis RJ, Ricklefs RE, Abdala-Roberts L. Testing the low latitude/high defense hypothesis for broad-leaved tree species. Oecologia 2012; 169:811-20. [PMID: 22271200 DOI: 10.1007/s00442-012-2249-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Accepted: 01/04/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Robert J Marquis
- Department of Biology, University of Missouri-St. Louis, One University Boulevard, St. Louis, MO 63121-4499, USA.
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Miloslavich P, Klein E, Díaz JM, Hernández CE, Bigatti G, Campos L, Artigas F, Castillo J, Penchaszadeh PE, Neill PE, Carranza A, Retana MV, Díaz de Astarloa JM, Lewis M, Yorio P, Piriz ML, Rodríguez D, Yoneshigue-Valentin Y, Gamboa L, Martín A. Marine biodiversity in the Atlantic and Pacific coasts of South America: knowledge and gaps. PLoS One 2011; 6:e14631. [PMID: 21304960 PMCID: PMC3031619 DOI: 10.1371/journal.pone.0014631] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 01/04/2011] [Indexed: 11/18/2022] Open
Affiliation(s)
- Patricia Miloslavich
- Departamento de Estudios Ambientales and Centro de Biodiversidad Marina, Universidad Simón Bolívar, Caracas, Venezuela.
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66
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Differential extinction and the contrasting structure of polar marine faunas. PLoS One 2010; 5:e15362. [PMID: 21203524 PMCID: PMC3008738 DOI: 10.1371/journal.pone.0015362] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 11/11/2010] [Indexed: 11/19/2022] Open
Abstract
Background The low taxonomic diversity of polar marine faunas today reflects both the failure of clades to colonize or diversify in high latitudes and regional extinctions of once-present clades. However, simple models of polar evolution are made difficult by the strikingly different faunal compositions and community structures of the two poles. Methodology/Principal Findings A comparison of early Cenozoic Arctic and Antarctic bivalve faunas with modern ones, within the framework of a molecular phylogeny, shows that while Arctic losses were randomly distributed across the tree, Antarctic losses were significantly concentrated in more derived families, resulting in communities dominated by basal lineages. Potential mechanisms for the phylogenetic structure to Antarctic extinctions include continental isolation, changes in primary productivity leading to turnover of both predators and prey, and the effect of glaciation on shelf habitats. Conclusions/Significance These results show that phylogenetic consequences of past extinctions can vary substantially among regions and thus shape regional faunal structures, even when due to similar drivers, here global cooling, and provide the first phylogenetic support for the “retrograde” hypothesis of Antarctic faunal evolution.
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67
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Carranza A, Defeo O, Arim M. Taxonomic relatedness and spatial structure of a shelf benthic gastropod assemblage. DIVERS DISTRIB 2010. [DOI: 10.1111/j.1472-4642.2010.00720.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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68
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Bjorbækmo MFM, Carlsen T, Brysting A, Vrålstad T, Høiland K, Ugland KI, Geml J, Schumacher T, Kauserud H. High diversity of root associated fungi in both alpine and arctic Dryas octopetala. BMC PLANT BIOLOGY 2010; 10:244. [PMID: 21070665 PMCID: PMC3095326 DOI: 10.1186/1471-2229-10-244] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 11/11/2010] [Indexed: 05/05/2023]
Abstract
BACKGROUND Dryas octopetala is a widespread dwarf shrub in alpine and arctic regions that forms ectomycorrhizal (ECM) symbiotic relationships with fungi. In this study we investigated the fungal communities associated with roots of D. octopetala in alpine sites in Norway and in the High Arctic on Svalbard, where we aimed to reveal whether the fungal diversity and species composition varied across the Alpine and Arctic regions. The internal transcribed spacer (ITS) region of nuclear ribosomal DNA was used to identify the fungal communities from bulk root samples obtained from 24 plants. RESULTS A total of 137 operational taxonomic units (OTUs) were detected (using 97% similarity cut off during sequence clustering) and well-known ECM genera such as Cenococcum, Cortinarius, Hebeloma, Inocybe and Tomentella occurred frequently. There was no decrease in fungal diversity with increasing latitude. The overall spatial heterogeneity was high, but a weak geographical structuring of the composition of OTUs in the root systems was observed. Calculated species accumulation curves did not level off. CONCLUSIONS This study indicates that the diversity of fungi associated with D. octopetala does not decrease in high latitude arctic regions, which contrasts observations made in a wide spectrum of other organism groups. A high degree of patchiness was observed across root systems, but the fungal communities were nevertheless weakly spatially structured. Non-asymptotical species accumulation curves and the occurrence of a high number of singletons indicated that only a small fraction of the fungal diversity was detected.
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Affiliation(s)
| | - Tor Carlsen
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
| | - Anne Brysting
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
| | - Trude Vrålstad
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
| | - Klaus Høiland
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
| | - Karl Inne Ugland
- Marine Biology, Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
| | - Jozsef Geml
- Kits van Waveren Foundation, Nationaal Herbarium Nederland, Universiteit Leiden, P.O. Box 9514, 2300 RA Leiden, Nederland
| | - Trond Schumacher
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
| | - Håvard Kauserud
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
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69
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Current patterns of macroalgal diversity and biomass in northern hemisphere rocky shores. PLoS One 2010; 5:e13195. [PMID: 20949030 PMCID: PMC2951897 DOI: 10.1371/journal.pone.0013195] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 09/10/2010] [Indexed: 11/30/2022] Open
Abstract
Latitudinal gradients in species abundance and diversity have been postulated for nearshore taxa but few analyses have been done over sufficiently broad geographic scales incorporating various nearshore depth strata to empirically test these gradients. Typically, gradients are based on literature reviews and species lists and have focused on alpha diversity across the entire nearshore zone. No studies have used a standardized protocol in the field to examine species density among sites across a large spatial scale while also focusing on particular depth strata. The present research used field collected samples in the northern hemisphere to explore the relationships between macroalgal species density and biomass along intertidal heights and subtidal depths and latitude. Results indicated no overall correlations between either estimates of species density or biomass with latitude, although the highest numbers of both were found at mid-latitudes. However, when strata were examined separately, significant positive correlations were found for both species numbers and biomass at particular strata, namely the intertidal ones. While the data presented in this paper have some limitations, we show that latitudinal macroalgal trends in species density and biomass do exist for some strata in the northern hemisphere with more taxa and biomass at higher latitudes.
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70
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Harnik PG, Jablonski D, Krug AZ, Valentine JW. Genus age, provincial area and the taxonomic structure of marine faunas. Proc Biol Sci 2010; 277:3427-35. [PMID: 20534619 DOI: 10.1098/rspb.2010.0628] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Species are unevenly distributed among genera within clades and regions, with most genera species-poor and few species-rich. At regional scales, this structure to taxonomic diversity is generated via speciation, extinction and geographical range dynamics. Here, we use a global database of extant marine bivalves to characterize the taxonomic structure of climate zones and provinces. Our analyses reveal a general, Zipf-Mandelbrot form to the distribution of species among genera, with faunas from similar climate zones exhibiting similar taxonomic structure. Provinces that contain older taxa and/or encompass larger areas are expected to be more species-rich. Although both median genus age and provincial area correlate with measures of taxonomic structure, these relationships are interdependent, nonlinear and driven primarily by contrasts between tropical and extra-tropical faunas. Provincial area and taxonomic structure are largely decoupled within climate zones. Counter to the expectation that genus age and species richness should positively covary, diverse and highly structured provincial faunas are dominated by young genera. The marked differences between tropical and temperate faunas suggest strong spatial variation in evolutionary rates and invasion frequencies. Such variation contradicts biogeographic models that scale taxonomic diversity to geographical area.
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Affiliation(s)
- Paul G Harnik
- Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637, USA.
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71
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Cardinale BJ, Bennett DM, Nelson CE, Gross K. Does productivity drive diversity or vice versa? A test of the multivariate productivity-diversity hypothesis in streams. Ecology 2009; 90:1227-41. [PMID: 19537544 DOI: 10.1890/08-1038.1] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The idea that productivity regulates species diversity is deeply ingrained in the field of ecology. Yet, over the past few decades, an increasing number of experiments have shown that species diversity controls, rather than simply responds to, biomass production. These contrasting perspectives have led to a seeming paradox: Is diversity the cause or the consequence of biological production? Here we present empirical evidence for the multivariate productivity-diversity (MPD) hypothesis, which argues that differing perspectives on productivity-diversity relationships can be resolved by recognizing that historical research has focused on how resource supply regulates both the productivity and richness of local competitors, whereas more recent studies have focused on how the richness of a colonist pool regulates the efficiency by which resources are captured and converted into new tissue. The MPD hypothesis predicts that three pathways operate concurrently to generate productivity diversity relationships in nature: (1) resource supply directly limits the standing biomass and/or rate of new production by primary producers, (2) producer biomass is directly influenced by the richness of species that locally compete for resources, and (3) resource supply rate indirectly affects producer biomass by influencing the fraction of species from a colonist pool that locally coexist. To examine whether this set of pathways explains covariation between productivity and diversity in natural streams, we used nutrient-diffusing agar "patches" to manipulate resource supply rates in 20 streams throughout the Sierra Nevada mountain range, California, USA. We then measured the fraction of periphyton species from the stream colonist pool co-occurring on each nutrient patch, as well as the standing biomass and rates of primary production. Natural patterns of covariation agreed with predictions of the MPD hypothesis. Algal biomass was an increasing function of nutrient supply, and an increasing function of local richness. The fraction of species from the colonist pool found co-occurring on a patch was a concave-down function of nutrient supply, causing nutrients to indirectly affect biomass via control over local richness. These results suggest that the MPD hypothesis is a viable explanation of patterns of diversity and productivity in natural stream ecosystems, and that it has potential to merge the historical view that productivity drives diversity with a parallel view that diversity drives productivity.
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Affiliation(s)
- Bradley J Cardinale
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, California 93106, USA.
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72
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Fernández M, Astorga A, Navarrete SA, Valdovinos C, Marquet PA. Deconstructing latitudinal species richness patterns in the ocean: does larval development hold the clue? Ecol Lett 2009; 12:601-11. [DOI: 10.1111/j.1461-0248.2009.01315.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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73
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Rombouts I, Beaugrand G, Ibanez F, Gasparini S, Chiba S, Legendre L. Global latitudinal variations in marine copepod diversity and environmental factors. Proc Biol Sci 2009; 276:3053-62. [PMID: 19515670 DOI: 10.1098/rspb.2009.0742] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Latitudinal gradients in diversity are among the most striking features in ecology. For terrestrial species, climate (i.e. temperature and precipitation) is believed to exert a strong influence on the geographical distributions of diversity through its effects on energy availability. Here, we provide the first global description of geographical variation in the diversity of marine copepods, a key trophic link between phytoplankton and fish, in relation to environmental variables. We found a polar-tropical difference in copepod diversity in the Northern Hemisphere where diversity peaked at subtropical latitudes. In the Southern Hemisphere, diversity showed a tropical plateau into the temperate regions. This asymmetry around the Equator may be explained by climatic conditions, in particular the influence of the Inter-Tropical Convergence Zone, prevailing mainly in the northern tropical region. Ocean temperature was the most important explanatory factor among all environmental variables tested, accounting for 54 per cent of the variation in diversity. Given the strong positive correlation between diversity and temperature, local copepod diversity, especially in extra-tropical regions, is likely to increase with climate change as their large-scale distributions respond to climate warming.
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Affiliation(s)
- Isabelle Rombouts
- UPMC Université Paris 06, UMR 7093, Laboratoire d'Océanographie de Villefranche, 06230 Villefranche-sur-Mer, France.
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Bar-coded pyrosequencing reveals shared bacterial community properties along the temperature gradients of two alkaline hot springs in Yellowstone National Park. Appl Environ Microbiol 2009; 75:4565-72. [PMID: 19429553 DOI: 10.1128/aem.02792-08] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
An understanding of how communities are organized is a fundamental goal of ecology but one which has historically been elusive for microbial systems. We used a bar-coded pyrosequencing approach targeting the V3 region of the bacterial small-subunit rRNA gene to address the factors that structure communities along the thermal gradients of two alkaline hot springs in the Lower Geyser Basin of Yellowstone National Park. The filtered data set included a total of nearly 34,000 sequences from 39 environmental samples. Each was assigned to one of 391 operational taxonomic units (OTUs) identified by their unique V3 sequence signatures. Although the two hot springs differed in their OTU compositions, community resemblance and diversity changed with strikingly similar dynamics along the two outflow channels. Two lines of evidence suggest that these community properties are controlled primarily by environmental temperature. First, community resemblance decayed exponentially with increasing differences in temperature between samples but was only weakly correlated with physical distance. Second, diversity decreased with increasing temperature at the same rate along both gradients but was uncorrelated with other measured environmental variables. This study also provides novel insights into the nature of the ecological interactions among important taxa in these communities. A strong negative association was observed between cyanobacteria and the Chloroflexi, which together accounted for approximately 70% of the sequences sampled. This pattern contradicts the longstanding hypothesis that coadapted lineages of these bacteria maintain tightly cooccurring distributions along these gradients as a result of a producer-consumer relationship. We propose that they instead compete for some limiting resource(s).
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75
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Congruence of morphologically-defined genera with molecular phylogenies. Proc Natl Acad Sci U S A 2009; 106:8262-6. [PMID: 19416868 DOI: 10.1073/pnas.0902973106] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Morphologically-defined mammalian and molluscan genera (herein "morphogenera") are significantly more likely to be monophyletic relative to molecular phylogenies than random, under 3 different models of expected monophyly rates: approximately 63% of 425 surveyed morphogenera are monophyletic and 19% are polyphyletic, although certain groups appear to be problematic (e.g., nonmarine, unionoid bivalves). Compiled nonmonophyly rates are probably extreme values, because molecular analyses have focused on "problem" taxa, and molecular topologies (treated herein as error-free) contain contradictory groupings across analyses for 10% of molluscan morphogenera and 37% of mammalian morphogenera. Both body size and geographic range, 2 key macroevolutionary and macroecological variables, show significant rank correlations between values for morphogenera and molecularly-defined clades, even when strictly monophyletic morphogenera are excluded from analyses. Thus, although morphogenera can be imperfect reflections of phylogeny, large-scale statistical treatments of diversity dynamics or macroevolutionary variables in time and space are unlikely to be misleading.
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76
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Roy K, Hunt G, Jablonski D, Krug AZ, Valentine JW. A macroevolutionary perspective on species range limits. Proc Biol Sci 2009; 276:1485-93. [PMID: 19324820 DOI: 10.1098/rspb.2008.1232] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Understanding the factors that determine the geographic range limits of species is important for many questions in ecology, evolution and conservation biology. These limits arise from complex interactions among ecology and dispersal ability of species and the physical environment, but many of the underlying traits can be conserved among related species and clades. Thus, the range limits of species are likely to be influenced by their macroevolutionary history. Using palaeontological and biogeographic data for marine bivalves, we find that the range limits of genera are significantly related to their constituent species richness, but the effects of age are weak and inconsistent. In addition, we find a significant phylogenetic signal in the range limits at both genus and family levels, although the strength of this effect shows interoceanic variation. This phylogenetic conservatism of range limits gives rise to an evolutionary pattern where wide-ranging lineages have clusters of species within the biogeographic provinces, with a few extending across major boundaries.
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Affiliation(s)
- Kaustuv Roy
- Section of Ecology, Behavior and Evolution, University of California San Diego, La Jolla, CA 92093-0116, USA.
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77
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Williams M, Haywood AM, Harper EM, Johnson ALA, Knowles T, Leng MJ, Lunt DJ, Okamura B, Taylor PD, Zalasiewicz J. Pliocene climate and seasonality in North Atlantic shelf seas. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2009; 367:85-108. [PMID: 18852093 DOI: 10.1098/rsta.2008.0224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This paper reviews North Atlantic shelf seas palaeoclimate during the interval 4-3Ma, prior to and incorporating the 'Mid-Pliocene warm period' (ca 3.29-2.97Ma). Fossil assemblages and stable isotope data demonstrate northwards extension of subtropical faunas along the coast of the Carolinas-Virginia (Yorktown and Duplin Formations) relative to the present day, suggesting a more vigorous Florida Current, with reduced seasonality and warm water extending north of Cape Hatteras (reconstructed annual range for Virginia 12-30 degrees C). This interpretation supports conceptual models of increased meridional heat transport for the Pliocene. Sea temperatures for Florida (Lower Pinecrest Beds) were similar to or slightly cooler than (summers 25-27 degrees C) today, and were probably influenced by seasonal upwelling of cold deep water. Reduced seasonality is also apparent in the Coralline Crag Formation of the southern North Sea, with ostracods suggesting winter sea temperatures of 10 degrees C (modern 4 degrees C). However, estimates from Pliocene bivalves (3.6-16.6 degrees C) are similar to or cooler than the present day. This 'mixed' signal is problematic given warmer seas in the Carolinas-Virginia, and climate model and oceanographic data that show warmer seas in the 'Mid-Pliocene' eastern North Atlantic. This may be because the Coralline Crag Formation was deposited prior to peak Mid-Pliocene warmth.
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Affiliation(s)
- Mark Williams
- Department of Geology, University of Leicester, Leicester LE1 7RH, UK.
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78
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Oleinik A, Marincovich Jr. L, B. Barinov K, K. Swart P. Magnitude of Middle Miocene warming in North Pacific high latitudes: stable isotope evidence from Kaneharaia (Bivalvia, Dosiniinae). ACTA ACUST UNITED AC 2009. [DOI: 10.9795/bullgsj.59.339] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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79
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Witman JD, Cusson M, Archambault P, Pershing AJ, Mieszkowska N. THE RELATION BETWEEN PRODUCTIVITY AND SPECIES DIVERSITY IN TEMPERATE–ARCTIC MARINE ECOSYSTEMS. Ecology 2008; 89:S66-80. [DOI: 10.1890/07-1201.1] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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80
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Fabricius KE, De'ath G. PHOTOSYNTHETIC SYMBIONTS AND ENERGY SUPPLY DETERMINE OCTOCORAL BIODIVERSITY IN CORAL REEFS. Ecology 2008; 89:3163-3173. [DOI: 10.1890/08-0005.1] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 03/03/2008] [Accepted: 03/17/2008] [Indexed: 11/18/2022]
Affiliation(s)
- K. E. Fabricius
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Queensland 4810 Australia
| | - G. De'ath
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Queensland 4810 Australia
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81
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Fisher JAD, Frank KT, Petrie B, Leggett WC, Shackell NL. Temporal dynamics within a contemporary latitudinal diversity gradient. Ecol Lett 2008; 11:883-97. [PMID: 18616548 DOI: 10.1111/j.1461-0248.2008.01216.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Poleward declines in species diversity [latitudinal diversity gradients (LDG)] remain among the oldest and most widespread of macroecological patterns. However, their contemporary dynamics remain largely unexplored even though changing ecological conditions, including global change, may modify LDG and their respective ecosystems. Here, we examine temporal variation within a temperate Northwest Atlantic LDG using 31 years of annual fisheries-independent surveys and explore its dynamics in relation to a dominant climate signal [the wintertime North Atlantic Oscillation (NAO)] that varies interannually and alters the latitudinal gradient of Northwest Atlantic continental shelf bottom water temperatures. We found that the slopes of the annual LDG vary dramatically due to changes in geographic distributions of 100+ species, variations that are concealed within the cumulative, static LDG. These changes are strongly associated with changes in NAO sign and strength. This is the first illustration of temporal dynamics in a contemporary LDG and the first demonstration of the speed at which local environmental variations can alter an LDG. Our findings underscore the need to investigate factors that modify LDG separately from those that contribute to their origins.
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82
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Abstract
For two centuries, biologists have documented a gradient of animal and plant biodiversity from the tropics to the poles but have been unable to agree whether it is controlled primarily by productivity, temperature, or historical factors. Recent reports that find latitudinal diversity gradients to be reduced or absent in some unicellular organisms and attribute this to their high abundance and dispersal capabilities would suggest that bacteria, the smallest and most abundant organisms, should exhibit no latitudinal pattern of diversity. We used amplified ribosomal intergenic spacer analysis (ARISA) whole-assemblage genetic fingerprinting to quantify species richness in 103 near-surface samples of marine bacterial plankton, taken from tropical to polar in both hemispheres. We found a significant latitudinal gradient in richness. The data can help to evaluate hypotheses about the cause of the gradient. The correlations of richness with latitude and temperature were similarly strong, whereas correlations with parameters relating to productivity (chlorophyll, annual primary productivity, bacterial abundance) and other variables (salinity and distance to shore) were much weaker. Despite the high abundance and potentially high dispersal of bacteria, they exhibit geographic patterns of species diversity that are similar to those seen in other organisms. The latitudinal gradient in marine bacteria supports the hypothesis that the kinetics of metabolism, setting the pace for life, has strong influence on diversity.
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83
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Mora C, Tittensor DP, Myers RA. The completeness of taxonomic inventories for describing the global diversity and distribution of marine fishes. Proc Biol Sci 2008; 275:149-55. [PMID: 17999950 DOI: 10.1098/rspb.2007.1315] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Taxonomic inventories (or species censuses) are the most elementary data in biogeography, macroecology and conservation biology. They play fundamental roles in the construction of species richness patterns, delineation of species ranges, quantification of extinction risk and prioritization of conservation efforts in hot spot areas. Given their importance, any issue related to the completeness of taxonomic inventories can have far-reaching consequences. Here, we used the largest publicly available database of georeferenced marine fish records to determine its usefulness in depicting the diversity and distribution of this taxonomic group. All records were grouped at multiple spatial resolutions to generate accumulation curves, from which the expected number of species were extrapolated using a variety of nonlinear models. Comparison of the inventoried number of species with that expected from the models was used to calculate the completeness of the taxonomic inventory at each resolution. In terms of the global number of fish species, we found that approximately 21% of the species remain to be described. In terms of spatial distribution, we found that the completeness of taxonomic data was highly scale dependent, with completeness being lower at finer spatial resolutions. At a 3 degrees (approx. 350km2) spatial resolution, less than 1.8% of the world's oceans have above 80% of their fish fauna currently described. Censuses of species were particularly incomplete in tropical areas and across the entire range of countries' gross domestic product (GDP), although the few censuses nearing completion were all along the coasts of a few developed countries or territories. Our findings highlight that failure to quantify the completeness of taxonomic inventories can introduce substantial flaws in the description of diversity patterns, and raise concerns over the effectiveness of conservation strategies based upon data that remain largely precarious.
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Affiliation(s)
- Camilo Mora
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J1.
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84
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Pörtner HO, Peck L, Somero G. Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view. Philos Trans R Soc Lond B Biol Sci 2008; 362:2233-58. [PMID: 17553776 PMCID: PMC2443174 DOI: 10.1098/rstb.2006.1947] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
A cause and effect understanding of thermal limitation and adaptation at various levels of biological organization is crucial in the elaboration of how the Antarctic climate has shaped the functional properties of extant Antarctic fauna. At the same time, this understanding requires an integrative view of how the various levels of biological organization may be intertwined. At all levels analysed, the functional specialization to permanently low temperatures implies reduced tolerance of high temperatures, as a trade-off. Maintenance of membrane fluidity, enzyme kinetic properties (Km and k(cat)) and protein structural flexibility in the cold supports metabolic flux and regulation as well as cellular functioning overall. Gene expression patterns and, even more so, loss of genetic information, especially for myoglobin (Mb) and haemoglobin (Hb) in notothenioid fishes, reflect the specialization of Antarctic organisms to a narrow range of low temperatures. The loss of Mb and Hb in icefish, together with enhanced lipid membrane densities (e.g. higher concentrations of mitochondria), becomes explicable by the exploitation of high oxygen solubility at low metabolic rates in the cold, where an enhanced fraction of oxygen supply occurs through diffusive oxygen flux. Conversely, limited oxygen supply to tissues upon warming is an early cause of functional limitation. Low standard metabolic rates may be linked to extreme stenothermy. The evolutionary forces causing low metabolic rates as a uniform character of life in Antarctic ectothermal animals may be linked to the requirement for high energetic efficiency as required to support higher organismic functioning in the cold. This requirement may result from partial compensation for the thermal limitation of growth, while other functions like hatching, development, reproduction and ageing are largely delayed. As a perspective, the integrative approach suggests that the patterns of oxygen- and capacity-limited thermal tolerance are linked, on one hand, with the capacity and design of molecules and membranes, and, on the other hand, with life-history consequences and lifestyles typically seen in the permanent cold. Future research needs to address the detailed aspects of these interrelationships.
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Affiliation(s)
- Hans O Pörtner
- Alfred-Wegener-Institut für Polar- und Meeresforschung, Physiologie mariner Tiere, 27515, Bremerhaven, Germany.
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85
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Pavlíček T, Frenkel Z, Korol AB, Beiles A, Nevo E. Drosophila at the "Evolution Canyon" Microsite, MT. Carmel, Israel: Selection Overrules Migration. Isr J Ecol Evol 2008. [DOI: 10.1080/15659801.2008.10639620] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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86
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Stachowicz JJ, Bruno JF, Duffy JE. Understanding the Effects of Marine Biodiversity on Communities and Ecosystems. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2007. [DOI: 10.1146/annurev.ecolsys.38.091206.095659] [Citation(s) in RCA: 299] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- John J. Stachowicz
- Section of Evolution and Ecology, University of California, Davis, California 95616;
| | - John F. Bruno
- Department of Marine Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3300
| | - J. Emmett Duffy
- Virginia Institute of Marine Sciences, College of William and Mary, Gloucester Point, Virginia 23062
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87
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Longenecker K. Devil in the Details: High-resolution Dietary Analysis Contradicts a Basic Assumption of Reef-Fish Diversity Models. COPEIA 2007. [DOI: 10.1643/0045-8511(2007)2007[543:ditdhd]2.0.co;2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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88
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Roy K, Goldberg EE. Origination, Extinction, and Dispersal: Integrative Models for Understanding Present‐Day Diversity Gradients. Am Nat 2007; 170 Suppl 2:S71-85. [PMID: 17874386 DOI: 10.1086/519403] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Species diversity gradients seen today are, to a large degree, a product of history. Spatially nonrandom originations, extinctions, and changes in geographic distributions can create gradients in species and higher-taxon richness, but the relative roles of each of these processes remain poorly documented. Existing explanations of diversity gradients have tended to focus on either macroevolutionary or biogeographic processes; integrative models that include both are largely lacking. We used simple models that incorporate origination and extinction rates along with dispersal of taxa between regions to show that dispersal not only affects regional richness patterns but also has a strong influence on the average age of taxa present in a region. Failure to take into account the effects of dispersal can, in principle, lead to biased estimates of diversification rates and potentially wrong conclusions regarding processes driving latitudinal and other gradients in diversity. Thus, it is critical to include the effects of dispersal when formulating and testing hypotheses about the causes of large-scale gradients in diversity. Finally, the model results, in conjunction with the results of existing empirical studies, suggest that the nature of macroevolutionary and biogeographic processes may differ between terrestrial and marine diversity gradients.
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Affiliation(s)
- Kaustuv Roy
- Section of Ecology, Behavior and Evolution, University of California San Diego, La Jolla, California 92093, USA.
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89
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Goldberg EE, Lande R. Species’ Borders and Dispersal Barriers. Am Nat 2007; 170:297-304. [PMID: 17874380 DOI: 10.1086/518946] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Accepted: 03/27/2007] [Indexed: 11/03/2022]
Abstract
Range limits of species are determined by combined effects of physical, historical, ecological, and evolutionary forces. We consider a subset of these factors by using spatial models of competition, hybridization, and local adaptation to examine the effects of partial dispersal barriers on the locations of borders between similar species. Prompted by results from population genetic models and biogeographic observations, we investigate the conditions under which species' borders are attracted to regions of reduced dispersal. For borders maintained by competition or hybridization, we find that dispersal barriers can attract borders whose positions would otherwise be either neutrally stable or moving across space. Borders affected strongly by local adaptation and gene flow, however, are repelled from dispersal barriers. These models illustrate how particular biotic and abiotic factors may combine to limit species' ranges, and they help to elucidate mechanisms by which range limits of many species may coincide.
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Affiliation(s)
- Emma E Goldberg
- Division of Biological Sciences, University of California, San Diego, La Jolla, California 92903, USA.
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90
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Vamosi S, Naydani C, Vamosi J. Body size and species richness along geographical gradients in Albertan diving beetle (Coleoptera: Dytiscidae) communities. CAN J ZOOL 2007. [DOI: 10.1139/z07-021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Species richness and body size often vary predictably along latitudinal and elevational gradients. Although these patterns have been well documented for a variety of taxa, the vast majority of studies have focused on terrestrial plants and animals. We used species lists of predaceous diving beetles (Coleoptera: Dytiscidae) collected from >400 lentic water bodies in southern Alberta to investigate the influences of latitude and elevation on species richness and body size. Because our data were based on species lists, we used proportion of, and probability of encountering at least one, large (i.e., mean body length >10 mm) diving beetle species as surrogates for the mean body size of diving beetles in a given water body. Species richness did not change with latitude and displayed a hump-shaped relationship with elevation, peaking at mid-elevations. High elevation (>2000 m) water bodies had markedly low species richness. Proportion of large species increased with latitude, although there was no effect on probability of occupancy by large species. Conversely, both measures tended to decrease with elevation, suggesting that large species are less prevalent at high elevations. We discuss potential factors contributing to the observed responses to latitude and elevation, with an emphasis on the potential impacts of oxygen limitation, productivity, and isolation at high elevation.
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Affiliation(s)
- S.M. Vamosi
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - C.J. Naydani
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - J.C. Vamosi
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
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91
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Soft bottom species richness and diversity as a function of depth and iceberg scour in Arctic glacial Kongsfjorden (Svalbard). Polar Biol 2007. [DOI: 10.1007/s00300-007-0263-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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92
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Abstract
In recent years population genetics and phylogeographic studies have become increasingly valuable tools for inferring both historical and present-day genetic patterns within marine species. Here, we take a comparative approach to population-level study, analyzing original mitochondrial DNA data from 969 individuals representing 28 chiton (Mollusca: Polyplacophora) species to uncover large-scale genetic patterns along the Pacific coast of North America. The data reveal a distinct latitudinal connectivity gradient among chitons: species that exist at lower latitudes tend to have more isolated populations. This trend appears to be a product of between-species differences; within species, no significant gradient in connectivity is observed. Lower average annual sea surface temperatures are hypothesized to contribute to longer larval duration (and by extension, greater connectivity) among lecithotrophic species, providing a mechanism for the observed positive correlation between gene flow and latitude. Because increased isolation among populations may lead to speciation, a latitudinal trend in gene flow may contribute to the increased species diversity observed at lower latitudes.
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Affiliation(s)
- Ryan P Kelly
- Columbia University, Department of Ecology, Evolution, and Environmental Biology, 10th Floor, Schermerhorn Extension, 1200 Amsterdam Avenue, New York, NY 10027, USA.
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93
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Clarke A, Gaston KJ. Climate, energy and diversity. Proc Biol Sci 2006; 273:2257-66. [PMID: 16928626 PMCID: PMC1636092 DOI: 10.1098/rspb.2006.3545] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Accepted: 03/08/2006] [Indexed: 11/12/2022] Open
Abstract
In recent years, a number of species-energy hypotheses have been developed to explain global patterns in plant and animal diversity. These hypotheses frequently fail to distinguish between fundamentally different forms of energy which influence diversity in dissimilar ways. Photosynthetically active radiation (PAR) can be utilized only by plants, though their abundance and growth rate is also greatly influenced by water. The Gibbs free energy (chemical energy) retained in the reduced organic compounds of tissue can be utilized by all heterotrophic organisms. Neither PAR nor chemical energy influences diversity directly. Both, however, influence biomass and/or abundance; diversity may then increase as a result of secondary population dynamic or evolutionary processes. Temperature is not a form of energy, though it is often used loosely by ecologists as a proxy for energy; it does, however, influence the rate of utilization of chemical energy by organisms. It may also influence diversity by allowing a greater range of energetic lifestyles at warmer temperatures (the metabolic niche hypothesis). We conclude that there is no single species/energy mechanism; fundamentally different processes link energy to abundance in plants and animals, and diversity is affected secondarily. If we are to make progress in elucidating these mechanisms, it is important to distinguish climatic effects on species' distribution and abundance from processes linking energy supply to plant and animal diversity.
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Affiliation(s)
- Andrew Clarke
- Biological Sciences, British Antarctic Survey, NERC, Cambridge, UK.
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94
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Evans KL, Jackson SF, Greenwood JJD, Gaston KJ. Species traits and the form of individual species-energy relationships. Proc Biol Sci 2006; 273:1779-87. [PMID: 16790411 PMCID: PMC1634787 DOI: 10.1098/rspb.2006.3487] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Environmental energy availability explains much of the spatial variation in species richness at regional scales. While numerous mechanisms that may drive such total species-energy relationships have been identified, knowledge of their relative contributions is scant. Here, we adopt a novel approach to identify these drivers that exploits the composite nature of species richness, i.e. its summation from individual species distributions. We construct individual species-energy relationships (ISERs) for each species in the British breeding avifauna using both solar (temperature) and productive energy metrics (normalized difference vegetation index) as measures of environmental energy availability. We use the slopes of these relationships and the resultant change in deviance, relative to a null model, as measures of their strength and use them as response variables in multiple regressions that use ecological traits as predictors. The commonest species exhibit the strongest ISERs, which is counter to the prediction derived from the more individuals hypothesis. There is no evidence that predatory species have stronger ISERs, which is incompatible with the suggestion that high levels of energy availability increase the length of the food chain allowing larger numbers of predators to exist. We find some evidence that species with narrow niche breadths have stronger ISERs, thus providing one of the few pieces of supportive evidence that high-energy availability promotes species richness by increasing the occurrence of specialist species that use a narrow range of resources.
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Affiliation(s)
- Karl L Evans
- Biodiversity & Macroecology Group, Department of Animal & Plant Sciences, University of Sheffield, UK.
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95
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Abstract
Environmental energy availability can explain much of the spatial variation in species richness. Such species-energy relationships encompass a diverse range of forms, and there is intense debate concerning which of these predominate, and the factors promoting this diversity. Despite this there has been relatively little investigation of whether the form, and relative strength, of species-energy relationships varies with (i) the currency of energy availability that is used, and (ii) the ecological characteristics of the constituent species. Such investigations can, however, shed light on the causal mechanisms underlying species-energy relationships. We illustrate this using the British breeding avifauna. The strength of the species-energy relationship is dependent on the energy metric used, with species richness being more closely correlated with temperature than the Normalized Difference Vegetation Index, which is a strong correlate of net primary productivity. We find little evidence, however, for the thermoregulatory load hypothesis that high temperatures enable individuals to invest in growth and reproduction, rather than thermoregulation, increasing population sizes that buffer species from extinction. High levels of productive energy may also elevate population size, which is related to extinction risk by a negative decelerating function. Therefore, the rarest species should exhibit the strongest species-energy relationship. We find evidence to the contrary, together with little support for suggestions that high-energy availability elevates species richness by increasing the numbers of specialists or predators.
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Affiliation(s)
- Karl L Evans
- Biodiversity and Macroecology Group, Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
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96
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Peck LS, Convey P, Barnes DKA. Environmental constraints on life histories in Antarctic ecosystems: tempos, timings and predictability. Biol Rev Camb Philos Soc 2005; 81:75-109. [PMID: 16293196 DOI: 10.1017/s1464793105006871] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Revised: 07/12/2005] [Accepted: 07/18/2005] [Indexed: 11/06/2022]
Abstract
Knowledge of Antarctic biotas and environments has increased dramatically in recent years. There has also been a rapid increase in the use of novel technologies. Despite this, some fundamental aspects of environmental control that structure physiological, ecological and life-history traits in Antarctic organisms have received little attention. Possibly the most important of these is the timing and availability of resources, and the way in which this dictates the tempo or pace of life. The clearest view of this effect comes from comparisons of species living in different habitats. Here, we (i) show that the timing and extent of resource availability, from nutrients to colonisable space, differ across Antarctic marine, intertidal and terrestrial habitats, and (ii) illustrate that these differences affect the rate at which organisms function. Consequently, there are many dramatic biological differences between organisms that live as little as 10 m apart, but have gaping voids between them ecologically. Identifying the effects of environmental timing and predictability requires detailed analysis in a wide context, where Antarctic terrestrial and marine ecosystems are at one extreme of the continuum of available environments for many characteristics including temperature, ice cover and seasonality. Anthropocentrically, Antarctica is harsh and as might be expected terrestrial animal and plant diversity and biomass are restricted. By contrast, Antarctic marine biotas are rich and diverse, and several phyla are represented at levels greater than global averages. There has been much debate on the relative importance of various physical factors that structure the characteristics of Antarctic biotas. This is especially so for temperature and seasonality, and their effects on physiology, life history and biodiversity. More recently, habitat age and persistence through previous ice maxima have been identified as key factors dictating biodiversity and endemism. Modern molecular methods have also recently been incorporated into many traditional areas of polar biology. Environmental predictability dictates many of the biological characters seen in all of these areas of Antarctic research.
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Affiliation(s)
- Lloyd S Peck
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK.
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97
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The Latitudinal Diversity Gradient Through Deep Time: Testing the “Age of the Tropics” Hypothesis Using Carboniferous Productidine Brachiopods. Evol Ecol 2005. [DOI: 10.1007/s10682-005-1021-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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98
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Rex MA, Crame JA, Stuart CT, Clarke A. LARGE-SCALE BIOGEOGRAPHIC PATTERNS IN MARINE MOLLUSKS: A CONFLUENCE OF HISTORY AND PRODUCTIVITY? Ecology 2005. [DOI: 10.1890/04-1056] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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99
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100
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Brayard A, Escarguel G, Bucher H. Latitudinal gradient of taxonomic richness: combined outcome of temperature and geographic mid-domains effects? J ZOOL SYST EVOL RES 2005. [DOI: 10.1111/j.1439-0469.2005.00311.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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