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Mosaic habitats at Woranso-Mille (Ethiopia) during the Pliocene and implications for Australopithecus paleoecology and taxonomic diversity. J Hum Evol 2022; 163:103076. [PMID: 34998271 DOI: 10.1016/j.jhevol.2021.103076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 08/27/2021] [Accepted: 08/27/2021] [Indexed: 11/21/2022]
Abstract
Many important Pliocene hominin specimens have been recovered from Woranso-Mille, a paleontological research area in the Afar region of Ethiopia, including the complete cranium of Australopithecus anamensis, a partial skeleton of Australopithecus afarensis, mandibular and maxillary elements representing a new species, Australopithecus deyiremeda, and a partial foot of an as-yet-unnamed species. Woranso-Mille is the only site, so far, to have reported the co-existence of more than one early hominin species between 3.8 and 3.3 Ma and the temporal overlap between A. anamensis and A. afarensis. Thus, the site has important implications for our understanding of the paleoecology and taxonomic diversity of early hominins and their ecological niche. This paper explores the paleohabitats of Woranso-Mille through its faunal community ecological structure and taxonomic composition using correspondence analysis and Forbes modified similarity index. The results suggest that Pliocene Woranso-Mille was a mosaic of different habitat types, with riparian woodland and floodplain grassland along rivers draining into a lake, along with less mesic habitats such as woodland, grassland, and shrubland. The apparent high level of vegetation heterogeneity may have promoted dietary specializations and niche differentiation among the different Australopithecus species at Woranso-Mille and allowed for their co-existence at the site.
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Jins VJ, Panigrahi M, Jayapal R, Bishop TR. Elevational gradients of reptile richness in the southern Western Ghats of India: Evaluating spatial and bioclimatic drivers. Biotropica 2020. [DOI: 10.1111/btp.12878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- V. J. Jins
- Department of Zoology Sikkim University Gangtok India
| | | | - Rajah Jayapal
- Sálim Ali Centre for Ornithology & Natural History Coimbatore India
| | - Tom R. Bishop
- Department of Earth, Ocean and Ecological Sciences University of Liverpool Liverpool UK
- Department of Zoology and Entomology Centre for Invasion Biology University of Pretoria Pretoria South Africa
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Jaskuła R, Płóciennik M, Schwerk A. From climate zone to microhabitat-environmental factors affecting the coastal distribution of tiger beetles (Coleoptera: Cicindelidae) in the south-eastern European biodiversity hotspot. PeerJ 2019; 7:e6676. [PMID: 30993037 PMCID: PMC6461030 DOI: 10.7717/peerj.6676] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 02/25/2019] [Indexed: 11/21/2022] Open
Abstract
Background Tiger beetles (Coleoptera: Cicindelidae) are predatory insects usually occurring in various sandy habitats. In south-eastern Europe, especially in lowland areas located close to the sea coast, the diversity of Cicindelidae is one of the highest in the Palaearctic realm. Although previous studies conducted in different areas of the world show that many species are habitat specialists, unfortunately little is known about environmental factors affecting the diversity and distribution of tiger beetles in this region. Material and Methods Habitat preferences for 12 tiger beetles taxa were analysed. Over 100 samples collected in eight countries located in coastal areas of the Black and Mediterranean Seas were studied, for which climate data, macrohabitat types, and soil parameters (soil humidity, salinity, pH, and structure) were investigated. Results Most studied Cicindelidae were characterised by narrow or very narrow habitat specialisation and did not co-occur with other ones, including 11 taxa found as habitat specialists occurring only in one or two types of macrohabitat. The most eurythopic species was Calomera littoralis nemoralis which occupied four macrohabitat types. The climatic zone, altitude, and humidity were found as the most important factors in the distribution of the studied tiger beetle species. Salt marshes and sandy sea beaches were noted as the most diverse macrohabitat types. Discussion Tiger beetle fauna of south-eastern Europe consists mainly of habitat specialists sensitive to environmental changes, which makes these beetles perfect bioindicators. Moreover, as a great number of studied Cicindelidae taxa occur in habitats which are under a significant human impact, we suggest that in the studied area the group can be successfully used as a flagship taxon for insect and nature conservation.
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Affiliation(s)
- Radomir Jaskuła
- Department of Invertebrate Zoology and Hydrobiology/Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Mateusz Płóciennik
- Department of Invertebrate Zoology and Hydrobiology/Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Axel Schwerk
- Laboratory of Evaluation and Assessment of Natural Resources, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
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Kerfahi D, Tripathi BM, Dong K, Kim M, Kim H, Ferry Slik JW, Go R, Adams JM. From the High Arctic to the Equator: Do Soil Metagenomes Differ According to Our Expectations? MICROBIAL ECOLOGY 2019; 77:168-185. [PMID: 29882154 DOI: 10.1007/s00248-018-1215-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 05/28/2018] [Indexed: 06/08/2023]
Abstract
Comparing the functional gene composition of soils at opposite extremes of environmental gradients may allow testing of hypotheses about community and ecosystem function. Here, we were interested in comparing how tropical microbial ecosystems differ from those of polar climates. We sampled several sites in the equatorial rainforest of Malaysia and Brunei, and the high Arctic of Svalbard, Canada, and Greenland, comparing the composition and the functional attributes of soil biota between the two extremes of latitude, using shotgun metagenomic Illumina HiSeq2000 sequencing. Based upon "classical" views of how tropical and higher latitude ecosystems differ, we made a series of predictions as to how various gene function categories would differ in relative abundance between tropical and polar environments. Results showed that in some respects our predictions were correct: the polar samples had higher relative abundance of dormancy related genes, and lower relative abundance of genes associated with respiration, and with metabolism of aromatic compounds. The network complexity of the Arctic was also lower than the tropics. However, in various other respects, the pattern was not as predicted; there were no differences in relative abundance of stress response genes or in genes associated with secondary metabolism. Conversely, CRISPR genes, phage-related genes, and virulence disease and defense genes, were unexpectedly more abundant in the Arctic, suggesting more intense biotic interaction. Also, eukaryote diversity and bacterial diversity were higher in the Arctic of Svalbard compared to tropical Brunei, which is consistent with what may expected from amplicon studies in terms of the higher pH of the Svalbard soil. Our results in some respects confirm expectations of how tropical versus polar nature may differ, and in other respects challenge them.
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Affiliation(s)
- Dorsaf Kerfahi
- Department of Biological Sciences, Seoul National University, Gwanak-Gu, Seoul, 151-747, Republic of Korea
| | - Binu M Tripathi
- Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon, 21990, Republic of Korea
| | - Ke Dong
- Department of Biological Sciences, Seoul National University, Gwanak-Gu, Seoul, 151-747, Republic of Korea
| | - Mincheol Kim
- Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon, 21990, Republic of Korea
| | - Hyoki Kim
- Celemics Inc., 19F, Bldg. A, BYC High City, 131, Gasandigital 1-ro, Geumcheon-gu, Seoul, 153-718, Republic of Korea
| | - J W Ferry Slik
- Faculty of Science, Universiti Brunei Darussalam, Gadong, Brunei Darussalam
| | - Rusea Go
- Department of Biology, Faculty of Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Jonathan M Adams
- Division of Agrifood and Environment, School of Water, Energy and Environment, Cranfield University, Bedfordshire, MK43 0AL, UK.
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de Mendoza G, Traunspurger W, Palomo A, Catalan J. Nematode distributions as spatial null models for macroinvertebrate species richness across environmental gradients: A case from mountain lakes. Ecol Evol 2017; 7:3016-3028. [PMID: 28480001 PMCID: PMC5415540 DOI: 10.1002/ece3.2842] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 01/13/2017] [Accepted: 01/28/2017] [Indexed: 11/09/2022] Open
Abstract
Nematode species are widely tolerant of environmental conditions and disperse passively. Therefore, the species richness distribution in this group might largely depend on the topological distribution of the habitats and main aerial and aquatic dispersal pathways connecting them. If so, the nematode species richness distributions may serve as null models for evaluating that of other groups more affected by environmental gradients. We investigated this hypothesis in lakes across an altitudinal gradient in the Pyrenees. We compared the altitudinal distribution, environmental tolerance, and species richness, of nematodes with that of three other invertebrate groups collected during the same sampling: oligochaetes, chironomids, and nonchironomid insects. We tested the altitudinal bias in distributions with t-tests and the significance of narrow-ranging altitudinal distributions with randomizations. We compared results between groups with Fisher's exact tests. We then explored the influence of environmental factors on species assemblages in all groups with redundancy analysis (RDA), using 28 environmental variables. And, finally, we analyzed species richness patterns across altitude with simple linear and quadratic regressions. Nematode species were rarely biased from random distributions (5% of species) in contrast with other groups (35%, 47%, and 50%, respectively). The altitudinal bias most often shifted toward low altitudes (85% of biased species). Nematodes showed a lower portion of narrow-ranging species than any other group, and differed significantly from nonchironomid insects (10% and 43%, respectively). Environmental variables barely explained nematode assemblages (RDA adjusted R2 = 0.02), in contrast with other groups (0.13, 0.19 and 0.24). Despite these substantial differences in the response to environmental factors, species richness across altitude was unimodal, peaking at mid elevations, in all groups. This similarity indicates that the spatial distribution of lakes across altitude is a primary driver of invertebrate richness. Provided that nematodes are ubiquitous, their distribution offers potential null models to investigate species richness across environmental gradients in other ecosystem types and biogeographic regions.
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Affiliation(s)
- Guillermo de Mendoza
- Centre for Advanced Studies of BlanesSpanish National Research Council (CEAB‐CSIC)BlanesSpain
- Laboratoire GEODE UMR 5602 CNRSUniversité Toulouse‐Jean JaurèsToulouseFrance
| | - Walter Traunspurger
- Department of Animal EcologyFaculty of BiologyUniversity of BielefeldBielefeldGermany
| | - Alejandro Palomo
- Department of Animal Biology, Plant Biology and EcologyFaculty of BiosciencesAutonomous University of BarcelonaCerdanyola del VallèsSpain
| | - Jordi Catalan
- CREAFCSICEdifici CCampus de Bellaterra (UAB)Cerdanyola del VallèsSpain
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Buschke FT, Brendonck L, Vanschoenwinkel B. Adding energy gradients and long-distance dispersal to a neutral model improves predictions of Madagascan bird diversity. Ecol Evol 2016; 6:6919-6929. [PMID: 28725369 PMCID: PMC5513242 DOI: 10.1002/ece3.2379] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 07/20/2016] [Indexed: 12/20/2022] Open
Abstract
Macroecological patterns are likely the result of both stochastically neutral mechanisms and deterministic differences between species. In Madagascar, the simplest stochastically neutral hypothesis - the mid-domain effects (MDE) hypothesis - has already been rejected. However, rejecting the MDE hypothesis does not necessarily refute the existence of all other neutral mechanisms. Here, we test whether adding complexity to a basic neutral model improves predictions of biodiversity patterns. The simplest MDE model assumes that: (1) species' ranges are continuous and unfragmented, (2) are randomly located throughout the landscape, and (3) can be stacked independently and indefinitely. We designed a simulation based on neutral theory that allowed us to weaken each of these assumptions incrementally by adjusting the habitat capacity as well as the likelihood of short- and long-distance dispersal. Simulated outputs were compared to four empirical patterns of bird diversity: the frequency distributions of species richness and range size, the within-island latitudinal diversity gradient, and the distance-decay of species compositional similarity. Neutral models emulated empirical diversity patterns for Madagascan birds accurately. The frequency distribution of range size, latitudinal diversity gradient, and the distance-decay of species compositional similarity could be attributed to stochastic long-distance migration events and zero-sum population dynamics. However, heterogenous environmental gradients improved predictions of the frequency distribution of species richness. Patterns of bird diversity in Madagascar can broadly be attributed to stochastic long-distance migration events and zero-sum population dynamics. This implies that rejecting simple hypotheses, such as MDE, does not serve as evidence against stochastic processes in general. However, environmental gradients were necessary to explain patterns of species richness and deterministic differences between species are probably important for explaining the distributions of narrow-range and endemic species.
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Affiliation(s)
- Falko T. Buschke
- Centre for Environmental Management (67)University of the Free StateP.O. Box 339Bloemfontein9300South Africa
- Laboratory of Aquatic Ecology, Evolution and ConservationKU LeuvenCh Deberiotstraat 323000LeuvenBelgium
| | - Luc Brendonck
- Laboratory of Aquatic Ecology, Evolution and ConservationKU LeuvenCh Deberiotstraat 323000LeuvenBelgium
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Mouchet M, Levers C, Zupan L, Kuemmerle T, Plutzar C, Erb K, Lavorel S, Thuiller W, Haberl H. Testing the Effectiveness of Environmental Variables to Explain European Terrestrial Vertebrate Species Richness across Biogeographical Scales. PLoS One 2015; 10:e0131924. [PMID: 26161981 PMCID: PMC4498906 DOI: 10.1371/journal.pone.0131924] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/08/2015] [Indexed: 11/25/2022] Open
Abstract
We compared the effectiveness of environmental variables, and in particular of land-use indicators, to explain species richness patterns across taxonomic groups and biogeographical scales (i.e. overall pan-Europe and ecoregions within pan-Europe). Using boosted regression trees that handle non-linear relationships, we compared the relative influence (as a measure of effectiveness) of environmental variables related to climate, landscape (or habitat heterogeneity), land-use intensity or energy availability to explain European vertebrate species richness (birds, amphibians, and mammals) at the continental and ecoregion scales. We found that dominant land cover and actual evapotranspiration that relate to energy availability were the main correlates of vertebrate species richness over Europe. At the ecoregion scale, we identified four distinct groups of ecoregions where species richness was essentially associated to (i) seasonality of temperature, (ii) actual evapotranspiration and/or mean annual temperature, (iii) seasonality of precipitation, actual evapotranspiration and land cover) and (iv) and an even combination of the environmental variables. This typology of ecoregions remained valid for total vertebrate richness and the three vertebrate groups taken separately. Despite the overwhelming influence of land cover and actual evapotranspiration to explain vertebrate species richness patterns at European scale, the ranking of the main correlates of species richness varied between regions. Interestingly, landscape and land-use indicators did not stand out at the continental scale but their influence greatly increased in southern ecoregions, revealing the long-lasting human footprint on land-use-land-cover changes. Our study provides one of the first multi-scale descriptions of the variability in the ranking of correlates across several taxa.
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Affiliation(s)
- Maud Mouchet
- Univ. Grenoble Alpes, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
- CNRS, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
| | - Christian Levers
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
| | - Laure Zupan
- Univ. Grenoble Alpes, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
- CNRS, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
| | - Tobias Kuemmerle
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
- Integrative Research Institute on Transformations of Human-Environment Systems (IRI THESys), Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
| | - Christoph Plutzar
- Institute of Social Ecology Vienna, Alpen-Adria Universität Klagenfurt, Wien, Graz, Schottenfeldgasse 29, 1070, Wien, Austria
| | - Karlheinz Erb
- Institute of Social Ecology Vienna, Alpen-Adria Universität Klagenfurt, Wien, Graz, Schottenfeldgasse 29, 1070, Wien, Austria
| | - Sandra Lavorel
- Univ. Grenoble Alpes, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
- CNRS, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
| | - Wilfried Thuiller
- Univ. Grenoble Alpes, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
- CNRS, Laboratoire d’Ecologie Alpine (LECA), F-38000, Grenoble, France
| | - Helmut Haberl
- Institute of Social Ecology Vienna, Alpen-Adria Universität Klagenfurt, Wien, Graz, Schottenfeldgasse 29, 1070, Wien, Austria
- Integrative Research Institute on Transformations of Human-Environment Systems (IRI THESys), Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
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Munyai TC, Foord SH. Temporal patterns of ant diversity across a mountain with climatically contrasting aspects in the tropics of Africa. PLoS One 2015; 10:e0122035. [PMID: 25774670 PMCID: PMC4361397 DOI: 10.1371/journal.pone.0122035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 02/06/2015] [Indexed: 11/18/2022] Open
Abstract
Factors that drive species richness over space and time are still poorly understood and are often context specific. Identifying these drivers for ant diversity has become particularly relevant within the context of contemporary global change events. We report on a long-term bi-annual (wet and dry seasons), standardized sampling of epigeal ants over a five year period on the mesic and arid aspects of an inselberg (Soutpansberg Mountain Range) in the tropics of Africa. We detail seasonal, annual and long-term trends of species density, test the relative contribution of geometric constraints, energy, available area, climate, local environmental variables, time, and space in explaining ant species density patterns through Generalized Linear Mixed Models (GLMM) where replicates were included as random factors to account for temporal pseudo-replication. Seasonal patterns were very variable and we found evidence of decreased seasonal variation in species density with increased elevation. The extent and significance of a decrease in species density with increased elevation varied with season. Annual patterns point to an increase in ant diversity over time. Ant density patterns were positively correlated with mean monthly temperature but geometric constraints dominated model performance while soil characteristics were minor correlates. These drivers and correlates accounted for all the spatio-temporal variability in the database. Ant diversity was therefore mainly determined by geometric constraints and temperature while soil characteristics (clay and carbon content) accounted for smaller but significant amounts of variation. This study documents the role of season, elevation and their interaction in affecting ant species densities while highlighting the importance of neutral processes and temperature in driving these patterns.
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Affiliation(s)
- Thinandavha Caswell Munyai
- Centre for Invasion Biology and Department of Ecology and Resource Management, University of Venda, Thohoyandou, Limpopo Province, South Africa
- * E-mail:
| | - Stefan Hendrik Foord
- Centre for Invasion Biology, South African Research Chair on Biodiversity Value & Change, and Department of Zoology, University of Venda, Thohoyandou, Limpopo Province, South Africa
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Horsák M, Chytrý M. Unimodal latitudinal pattern of land-snail species richness across northern Eurasian lowlands. PLoS One 2014; 9:e104035. [PMID: 25090628 PMCID: PMC4121278 DOI: 10.1371/journal.pone.0104035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 07/09/2014] [Indexed: 12/02/2022] Open
Abstract
Large-scale patterns of species richness and their causes are still poorly understood for most terrestrial invertebrates, although invertebrates can add important insights into the mechanisms that generate regional and global biodiversity patterns. Here we explore the general plausibility of the climate-based “water-energy dynamics” hypothesis using the latitudinal pattern of land-snail species richness across extensive topographically homogeneous lowlands of northern Eurasia. We established a 1480-km long latitudinal transect across the Western Siberian Plain (Russia) from the Russia-Kazakhstan border (54.5°N) to the Arctic Ocean (67.5°N), crossing eight latitudinal vegetation zones: steppe, forest-steppe, subtaiga, southern, middle and northern taiga, forest-tundra, and tundra. We sampled snails in forests and open habitats each half-degree of latitude and used generalized linear models to relate snail species richness to climatic variables and soil calcium content measured in situ. Contrary to the classical prediction of latitudinal biodiversity decrease, we found a striking unimodal pattern of snail species richness peaking in the subtaiga and southern-taiga zones between 57 and 59°N. The main south-to-north interchange of the two principal diversity constraints, i.e. drought stress vs. cold stress, explained most of the variance in the latitudinal diversity pattern. Water balance, calculated as annual precipitation minus potential evapotranspiration, was a single variable that could explain 81.7% of the variance in species richness. Our data suggest that the “water-energy dynamics” hypothesis can apply not only at the global scale but also at subcontinental scales of higher latitudes, as water availability was found to be the primary limiting factor also in this extratropical region with summer-warm and dry climate. A narrow zone with a sharp south-to-north switch in the two main diversity constraints seems to constitute the dominant and general pattern of terrestrial diversity across a large part of northern Eurasia, resulting in a subcontinental diversity hotspot of various taxa in this zone.
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Affiliation(s)
- Michal Horsák
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic
- * E-mail:
| | - Milan Chytrý
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic
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Carrascal L, Seoane J, Villén-Pérez S. Temperature and food constraints in wintering birds — an experimental approach in montane Mediterranean oakwoods. COMMUNITY ECOL 2012. [DOI: 10.1556/comec.13.2012.2.12] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ferrer-Paris JR, Rodríguez JP, Good TC, Sánchez-Mercado AY, Rodríguez-Clark KM, Rodríguez GA, Solís A. Systematic, large-scale national biodiversity surveys: NeoMaps as a model for tropical regions. DIVERS DISTRIB 2012. [DOI: 10.1111/ddi.12012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- José R. Ferrer-Paris
- Centro de Ecología; Instituto Venezolano de Investigaciones Científicas (IVIC); Apartado 20632; Caracas; 1020-A; Venezuela
| | - Jon P. Rodríguez
- Centro de Ecología; Instituto Venezolano de Investigaciones Científicas (IVIC); Apartado 20632; Caracas; 1020-A; Venezuela
| | - Tatjana C. Good
- Centro de Ecología; Instituto Venezolano de Investigaciones Científicas (IVIC); Apartado 20632; Caracas; 1020-A; Venezuela
| | - Ada Y. Sánchez-Mercado
- Centro de Ecología; Instituto Venezolano de Investigaciones Científicas (IVIC); Apartado 20632; Caracas; 1020-A; Venezuela
| | - Kathryn M. Rodríguez-Clark
- Centro de Ecología; Instituto Venezolano de Investigaciones Científicas (IVIC); Apartado 20632; Caracas; 1020-A; Venezuela
| | - Gustavo A. Rodríguez
- Centro de Ecología; Instituto Venezolano de Investigaciones Científicas (IVIC); Apartado 20632; Caracas; 1020-A; Venezuela
| | - Angel Solís
- Instituto Nacional de Biodiversidad (INBio); Apartado 22-3100; Santo Domingo de Heredia; Costa Rica
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Horsák M, Chytrý M, Axmanová I. Exceptionally poor land snail fauna of central Yakutia (NE Russia): climatic and habitat determinants of species richness. Polar Biol 2012. [DOI: 10.1007/s00300-012-1249-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bhatt JP, Manish K, Pandit MK. Elevational gradients in fish diversity in the Himalaya: water discharge is the key driver of distribution patterns. PLoS One 2012; 7:e46237. [PMID: 23029444 PMCID: PMC3459831 DOI: 10.1371/journal.pone.0046237] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 08/29/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Studying diversity and distribution patterns of species along elevational gradients and understanding drivers behind these patterns is central to macroecology and conservation biology. A number of studies on biogeographic gradients are available for terrestrial ecosystems, but freshwater ecosystems remain largely neglected. In particular, we know very little about the species richness gradients and their drivers in the Himalaya, a global biodiversity hotspot. METHODOLOGY/PRINCIPAL FINDINGS We collated taxonomic and distribution data of fish species from 16 freshwater Himalayan rivers and carried out empirical studies on environmental drivers and fish diversity and distribution in the Teesta river (Eastern Himalaya). We examined patterns of fish species richness along the Himalayan elevational gradients (50-3800 m) and sought to understand the drivers behind the emerging patterns. We used generalized linear models (GLM) and generalized additive models (GAM) to examine the richness patterns; GLM was used to investigate relationship between fish species richness and various environmental variables. Regression modelling involved stepwise procedures, including elimination of collinear variables, best model selection, based on the least Akaike's information criterion (AIC) and the highest percentage of deviance explained (D(2)). This maiden study on the Himalayan fishes revealed that total and non-endemic fish species richness monotonously decrease with increasing elevation, while endemics peaked around mid elevations (700-1500 m). The best explanatory model (synthetic model) indicated that water discharge is the best predictor of fish species richness patterns in the Himalayan rivers. CONCLUSIONS/SIGNIFICANCE This study, carried out along one of the longest bioclimatic elevation gradients of the world, lends support to Rapoport's elevational rule as opposed to mid domain effect hypothesis. We propose a species-discharge model and contradict species-area model in predicting fish species richness. We suggest that drivers of richness gradients in terrestrial and aquatic ecosystems are likely to be different. These studies are crucial in context of the impacts of unprecedented on-going river regulation on fish diversity and distribution in the Himalaya.
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Affiliation(s)
- Jay P. Bhatt
- Centre for Interdisciplinary Studies of Mountain and Hill Environment, University of Delhi, Delhi, India
| | - Kumar Manish
- Centre for Interdisciplinary Studies of Mountain and Hill Environment, University of Delhi, Delhi, India
- Department of Environmental Studies, University of Delhi, Delhi, India
| | - Maharaj K. Pandit
- Centre for Interdisciplinary Studies of Mountain and Hill Environment, University of Delhi, Delhi, India
- Department of Environmental Studies, University of Delhi, Delhi, India
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Manrubia SC, Axelsen JB, Zanette DH. Role of demographic dynamics and conflict in the population-area relationship for human languages. PLoS One 2012; 7:e40137. [PMID: 22815726 PMCID: PMC3399868 DOI: 10.1371/journal.pone.0040137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 06/01/2012] [Indexed: 11/18/2022] Open
Abstract
Many patterns displayed by the distribution of human linguistic groups are similar to the ecological organization described for biological species. It remains a challenge to identify simple and meaningful processes that describe these patterns. The population size distribution of human linguistic groups, for example, is well fitted by a log-normal distribution that may arise from stochastic demographic processes. As we show in this contribution, the distribution of the area size of home ranges of those groups also agrees with a log-normal function. Further, size and area are significantly correlated: the number of speakers p and the area a spanned by linguistic groups follow the allometric relation a proportional to p2, with an exponent z varying accross different world regions. The empirical evidence presented leads to the hypothesis that the distributions of p and a, and their mutual dependence, rely on demographic dynamics and on the result of conflicts over territory due to group growth. To substantiate this point, we introduce a two-variable stochastic multiplicative model whose analytical solution recovers the empirical observations. Applied to different world regions, the model reveals that the retreat in home range is sublinear with respect to the decrease in population size, and that the population-area exponent z grows with the typical strength of conflicts. While the shape of the population size and area distributions, and their allometric relation, seem unavoidable outcomes of demography and inter-group contact, the precise value of z could give insight on the cultural organization of those human groups in the last thousand years.
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Affiliation(s)
- Susanna C Manrubia
- Centro de Astrobiologa, Instituto Nacional de Técnica Aeroespacial and Consejo Superior de Investigaciones Científicas, Torrejón de Ardoz, Madrid, Spain.
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16
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Gotelli NJ, Anderson MJ, Arita HT, Chao A, Colwell RK, Connolly SR, Currie DJ, Dunn RR, Graves GR, Green JL, Grytnes JA, Jiang YH, Jetz W, Kathleen Lyons S, McCain CM, Magurran AE, Rahbek C, Rangel TFLVB, Soberón J, Webb CO, Willig MR. Patterns and causes of species richness: a general simulation model for macroecology. Ecol Lett 2009; 12:873-86. [PMID: 19702748 DOI: 10.1111/j.1461-0248.2009.01353.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nicholas J Gotelli
- Department of Biology, University of Vermont, Burlington, VT 05405, USA.
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17
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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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18
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Joppa LN, Loarie SR, Pimm SL. On the protection of "protected areas". Proc Natl Acad Sci U S A 2008; 105:6673-8. [PMID: 18451028 PMCID: PMC2365567 DOI: 10.1073/pnas.0802471105] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Indexed: 11/18/2022] Open
Abstract
Tropical moist forests contain the majority of terrestrial species. Human actions destroy between 1 and 2 million km(2) of such forests per decade, with concomitant carbon release into the atmosphere. Within these forests, protected areas are the principle defense against forest loss and species extinctions. Four regions-the Amazon, Congo, South American Atlantic Coast, and West Africa-once constituted about half the world's tropical moist forest. We measure forest cover at progressively larger distances inside and outside of protected areas within these four regions, using datasets on protected areas and land-cover. We find important geographical differences. In the Amazon and Congo, protected areas are generally large and retain high levels of forest cover, as do their surroundings. These areas are protected de facto by being inaccessible and will likely remain protected if they continue to be so. Deciding whether they are also protected de jure-that is, whether effective laws also protect them-is statistically difficult, for there are few controls. In contrast, protected areas in the Atlantic Coast forest and West Africa show sharp boundaries in forest cover at their edges. This effective protection of forest cover is partially offset by their very small size: little area is deep inside protected area boundaries. Lands outside protected areas in the Atlantic Coast forest are unusually fragmented. Finally, we ask whether global databases on protected areas are biased toward highly protected areas and ignore "paper parks." Analysis of a Brazilian database does not support this presumption.
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Affiliation(s)
- Lucas N. Joppa
- Nicholas School of the Environment and Earth Sciences, Box 90328, Duke University, Durham, NC 23708
| | - Scott R. Loarie
- Nicholas School of the Environment and Earth Sciences, Box 90328, Duke University, Durham, NC 23708
| | - Stuart L. Pimm
- Nicholas School of the Environment and Earth Sciences, Box 90328, Duke University, Durham, NC 23708
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19
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Evans KL, Newson SE, Storch D, Greenwood JJD, Gaston KJ. Spatial scale, abundance and the species–energy relationship in British birds. J Anim Ecol 2008; 77:395-405. [DOI: 10.1111/j.1365-2656.2007.01332.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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21
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Lees DC, Colwell RK. A strong Madagascan rainforest MDE and no equatorward increase in species richness: re-analysis of 'The missing Madagascan mid-domain effect', by Kerr J.T., Perring M. & Currie D.J. (Ecology Letters 9:149-159, 2006). Ecol Lett 2007; 10:E4-8; author reply E9-10. [PMID: 17663706 DOI: 10.1111/j.1461-0248.2007.01040.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By reanalysing inaccurately presented data of Kerr et al. (2006), we refute their claims that area-corrected species richness of endemic Madagascan birds and mammals increases toward the Equator and is best explained by environmental factors, and that the rainforest mid-domain effect (MDE) Lees et al. (1999) demonstrated is artefactual.
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Affiliation(s)
- David C Lees
- Department of Entomology, Natural History Museum, South Kensington, UK.
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22
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Martin PR, Bonier F, Tewksbury JJ. Revisiting Jablonski (1993): cladogenesis and range expansion explain latitudinal variation in taxonomic richness. J Evol Biol 2007; 20:930-6. [PMID: 17465904 DOI: 10.1111/j.1420-9101.2007.01317.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The increase in diversity towards the equator arises from latitudinal variation in rates of cladogenesis, extinction, immigration and/or emigration of taxa. We tested the relative contribution of all four processes to the latitudinal gradient in 26 marine invertebrate orders with extensive fossil records, examined previously by David Jablonski. Coupling Jablonski's estimates of latitudinal variation in cladogenesis with new data on patterns of extinction and current distributions, we show that the present-day gradient in diversity is caused by higher rates of cladogenesis and subsequent range expansion (immigration) at lower latitudes. In contrast, extinction and emigration were not important in the creation of the latitudinal gradient in ordinal richness. This work represents one of the first simultaneous tests of the role of all four processes in the creation of the latitudinal gradient in taxonomic richness, and suggests that low tropical extinction rates are not essential to the creation of latitudinal diversity gradients.
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Affiliation(s)
- P R Martin
- Department of Biology, University of Washington, Seattle, WA, USA.
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23
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Loyola RD, Kubota U, Lewinsohn TM. Endemic vertebrates are the most effective surrogates for identifying conservation priorities among Brazilian ecoregions. DIVERS DISTRIB 2007. [DOI: 10.1111/j.1472-4642.2007.00345.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Rafael D. Loyola
- Graduate Program in Ecology, IB, Unicamp,
- Laboratório de Interações Insetos‐Plantas, Instituto de Biologia — Unicamp, CEP 13083‐970 — C. Postal 6109, Campinas, SP, Brazil
| | - Umberto Kubota
- Graduate Program in Ecology, IB, Unicamp,
- Laboratório de Interações Insetos‐Plantas, Instituto de Biologia — Unicamp, CEP 13083‐970 — C. Postal 6109, Campinas, SP, Brazil
| | - Thomas M. Lewinsohn
- Laboratório de Interações Insetos‐Plantas, Instituto de Biologia — Unicamp, CEP 13083‐970 — C. Postal 6109, Campinas, SP, Brazil
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Evans KL, Greenwood JJD, Gaston KJ. Relative contribution of abundant and rare species to species-energy relationships. Biol Lett 2007; 1:87-90. [PMID: 17148135 PMCID: PMC1629054 DOI: 10.1098/rsbl.2004.0251] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A major goal of ecology is to understand spatial variation in species richness. The latter is markedly influenced by energy availability and appears to be influenced more by common species than rare ones; species-energy relationships should thus be stronger for common species. Species-energy relationships may arise because high-energy areas support more individuals, and these larger populations may buffer species from extinction. As extinction risk is a negative decelerating function of population size, this more-individuals hypothesis (MIH) predicts that rare species should respond more strongly to energy. We investigate these opposing predictions using British breeding bird data and find that, contrary to the MIH, common species contribute more to species-energy relationships than rare ones.
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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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25
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Davies TJ, Grenyer R, Gittleman JL. Phylogeny can make the mid-domain effect an inappropriate null model. Biol Lett 2007; 1:143-6. [PMID: 17148150 PMCID: PMC1626208 DOI: 10.1098/rsbl.2005.0297] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The mid-domain effect (MDE), a bias in species richness towards the midpoint of a given geographical dimension, has been used as a null model in macro-ecological studies. Departures from a MDE are often thought of as interesting. The MDE is a product of the interaction between geometric boundaries and range locations, with species being forced to occupy more central positions in proportion to their range size. We criticize this mechanism for assuming species' locations to be wholly independent from their evolutionary past. We present a simple simulation model that shows how range locations arising as part of a phylogenetic process depart from a MDE. The amount of departure is positively correlated with phylogenetic imbalance (tree shape), but a deviation from an equal-rates Markov speciation model is not necessary to negate a MDE. We suggest that the MDE is an appropriate ecological null model only when phylogenetic influence on range location is demonstrably low or non-existent.
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Affiliation(s)
- T Jonathan Davies
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA.
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26
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Rahbek C, Gotelli NJ, Colwell RK, Entsminger GL, Rangel TFL, Graves GR. Predicting continental-scale patterns of bird species richness with spatially explicit models. Proc Biol Sci 2007; 274:165-74. [PMID: 17148246 PMCID: PMC1685854 DOI: 10.1098/rspb.2006.3700] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Accepted: 08/05/2006] [Indexed: 11/12/2022] Open
Abstract
The causes of global variation in species richness have been debated for nearly two centuries with no clear resolution in sight. Competing hypotheses have typically been evaluated with correlative models that do not explicitly incorporate the mechanisms responsible for biotic diversity gradients. Here, we employ a fundamentally different approach that uses spatially explicit Monte Carlo models of the placement of cohesive geographical ranges in an environmentally heterogeneous landscape. These models predict species richness of endemic South American birds (2248 species) measured at a continental scale. We demonstrate that the principal single-factor and composite (species-energy, water-energy and temperature-kinetics) models proposed thus far fail to predict (r(2) < or =.05) the richness of species with small to moderately large geographical ranges (first three range-size quartiles). These species constitute the bulk of the avifauna and are primary targets for conservation. Climate-driven models performed reasonably well only for species with the largest geographical ranges (fourth quartile) when range cohesion was enforced. Our analyses suggest that present models inadequately explain the extraordinary diversity of avian species in the montane tropics, the most species-rich region on Earth. Our findings imply that correlative climatic models substantially underestimate the importance of historical factors and small-scale niche-driven assembly processes in shaping contemporary species-richness patterns.
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Affiliation(s)
- Carsten Rahbek
- Center of Macroecology, Institute of Biology, University of CopenhagenUniversitetsparken 15, 2100 Copenhagen O, Denmark
| | | | - Robert K Colwell
- Department of Ecology & Evolutionary Biology, University of ConnecticutStorrs, CT 06269-3043, USA
| | - Gary L Entsminger
- Acquired Intelligence, Inc., Rocky Mountain Biological Laboratory23625 V66 Trail, Montrose, CO 81401, USA
| | - Thiago Fernando L.V.B Rangel
- Graduate Program in Ecology and Evolution, Departamento de Biologia Geral, ICB, Universidade Federal de GoiásCaixa Postal 131, 74.001-970 Goiânia, GO, Brasil
| | - Gary R Graves
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian InstitutionWashington, DC 20560, USA
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27
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Abstract
Species richness varies enormously across geographical gradients, a well-known phenomenon for which there are many hypothesized explanations. One recent hypothesis uses null models to demonstrate that random re-distribution of species' ranges within a given domain leads to a 'mid-domain effect' (MDE): increasing species richness towards the centre of the area. Madagascar is especially well-suited for empirical evaluation of mid-domain models by virtue of its large endemic fauna and its clearly defined boundaries. Lees et al. [Biol. J. Linn. Soc.67 (1999) 529] observed patterns of species richness consistent with MDEs in the Madagascan rainforest (a slim, north-south belt). In this study, we test one-dimensional and two-dimensional mid-domain model predictions for the birds and mammals of the entire island of Madagascar. When only latitudinal extents of species' distribution are considered, patterns of richness in Madagascar show an MDE. However, this pattern disappears for both taxa after accounting for the tendency of latitudinal bands nearer the middle of the country to be larger. Two-dimensional mid-domain model predictions of species richness are qualitatively opposite to observed patterns. Instead, island-wide spatial gradients of species richness in Madagascar relate strongly to patterns of primary productivity and amount of remaining natural habitat. Earlier work that showed a mid-domain peak within the rainforest biome (effectively after controlling for climate and natural habitat) seems likely to have reflected methodological artefacts. The classic case in which MDEs should occur is, in fact, inconsistent with the mid-domain hypothesis.
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28
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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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29
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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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30
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Lamoreux JF, Morrison JC, Ricketts TH, Olson DM, Dinerstein E, McKnight MW, Shugart HH. Global tests of biodiversity concordance and the importance of endemism. Nature 2005; 440:212-4. [PMID: 16382239 DOI: 10.1038/nature04291] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Accepted: 09/29/2005] [Indexed: 11/09/2022]
Abstract
Understanding patterns of biodiversity distribution is essential to conservation strategies, but severe data constraints make surrogate measures necessary. For this reason, many studies have tested the performance of terrestrial vertebrates as surrogates for overall species diversity, but these tests have typically been limited to a single taxon or region. Here we show that global patterns of richness are highly correlated among amphibians, reptiles, birds and mammals, as are endemism patterns. Furthermore, we demonstrate that although the correlation between global richness and endemism is low, aggregate regions selected for high levels of endemism capture significantly more species than expected by chance. Although areas high in endemism have long been targeted for the protection of narrow-ranging species, our findings provide evidence that endemism is also a useful surrogate for the conservation of all terrestrial vertebrates.
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Affiliation(s)
- John F Lamoreux
- Department of Environmental Sciences, University of Virginia, 291 McCormick Road, Charlottesville, Virginia 22904, USA.
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Hawkins BA, Diniz-Filho JAF, Weis AE. The Mid‐Domain Effect and Diversity Gradients: Is There Anything to Learn? Am Nat 2005; 166:E140-3. [PMID: 16224716 DOI: 10.1086/491686] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Accepted: 11/22/2004] [Indexed: 11/03/2022]
Abstract
The mid-domain effect (MDE) has been proposed as a null model for diversity gradients and an explanation for observed patterns. Here we respond to a recent defense of the concept, explaining that it cannot represent a viable model in either real or null worlds. First, the MDE misrepresents the nature of species ranges. There is also an internal logical inconsistency underlying the MDE because the range size frequency distribution, necessary to generate a hump-shaped pattern under randomization, cannot exist in the absence of environmental gradients and is generated by the ecological and historical processes that the MDE claims to exclude.
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Affiliation(s)
- Bradford A Hawkins
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA.
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Oommen MA, Shanker K. ELEVATIONAL SPECIES RICHNESS PATTERNS EMERGE FROM MULTIPLE LOCAL MECHANISMS IN HIMALAYAN WOODY PLANTS. Ecology 2005. [DOI: 10.1890/04-1837] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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34
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Zapata FA, Gaston KJ, Chown SL. The mid-domain effect revisited. Am Nat 2005; 166:E144-8; discussion E149-54. [PMID: 16224717 DOI: 10.1086/491685] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2004] [Accepted: 02/28/2005] [Indexed: 11/03/2022]
Abstract
We revisit the proposition that boundary constraints on species' ranges cause species richness gradients (the mid-domain effect [MDE] hypothesis). In the absence of environmental gradients, species should not retain their observed range sizes as assumed by MDE models. Debate remains regarding the definition of domain limits, valid predictions for testing the models, and their statistical assessment. Empirical support for the MDE is varied but often weak, suggesting that geometric constraints on species' ranges do not provide a general explanation for richness gradients. Criticism of MDE model assumptions does not, however, imply opposition to the use of null models in ecology.
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Affiliation(s)
- Fernando A Zapata
- Department of Biology, Universidad de Valle, Apartado Aéreo 25360, Cali, Colombia.
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35
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Mora C, Robertson DR. CAUSES OF LATITUDINAL GRADIENTS IN SPECIES RICHNESS: A TEST WITH FISHES OF THE TROPICAL EASTERN PACIFIC. Ecology 2005. [DOI: 10.1890/04-0883] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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36
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Bellwood DR, Hughes TP, Connolly SR, Tanner J. Environmental and geometric constraints on Indo-Pacific coral reef biodiversity. Ecol Lett 2005. [DOI: 10.1111/j.1461-0248.2005.00763.x] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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37
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Arita HT. Range size in mid-domain models of species diversity. J Theor Biol 2005; 232:119-26. [PMID: 15498599 DOI: 10.1016/j.jtbi.2004.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2004] [Revised: 06/29/2004] [Accepted: 08/04/2004] [Indexed: 11/15/2022]
Abstract
Geographical patterns of species diversity have been examined using mid-domain null models, in which the ranges of individual species are simulated by randomly arranging them on a bounded one- or two-dimensional continent. These models have shown that structured patterns in the geographical distribution of biodiversity can arise even under a fully stochastic procedure. In particular, mid-domain models have demonstrated that the random generation of ranges of different sizes and locations can produce a gradient of species diversity similar to the one found in real assemblages, with a peak at the middle of a continent. A less explored feature of mid-domain models is the pattern of range-size frequency distribution. Numerical simulations have provided some insights about the geographic pattern of average range size, but no exploration of the shape of range-size frequency distributions has been carried out. Here I present analytical and numerical models that generate explicit predictions for patterns of range size under the assumptions of mid-domain models of species diversity. Some generalizations include: (1) Mid-domain models predict no geographic gradient of average range size; the mean range size of species occurring at any point on a continent is constant (0.5 of the extent of the continent in the one-dimensional model, 0.25 of the area of the continent in the two-dimensional case); (2) Variance in range size is lowest at the middle of a continent and highest near the corners of a square-shaped continent; (3) The range-size frequency distribution is highly right-skewed at any point of a continent, but the skewness is highest near the corners. Despite their alleged weaknesses, mid-domain models are adequate null models against which real-world patterns can be contrasted.
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Affiliation(s)
- Héctor T Arita
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, CP 04510 México DF, México.
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38
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Romdal TS, Colwell RK, Rahbek C. THE INFLUENCE OF BAND SUM AREA, DOMAIN EXTENT, AND RANGE SIZES ON THE LATITUDINAL MID-DOMAIN EFFECT. Ecology 2005. [DOI: 10.1890/04-0096] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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40
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Jetz W, Rahbek C, Colwell RK. The coincidence of rarity and richness and the potential signature of history in centres of endemism. Ecol Lett 2004. [DOI: 10.1111/j.1461-0248.2004.00678.x] [Citation(s) in RCA: 262] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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