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Karl J. Niklas - One of the best experts on this subject based on the ideXlab platform.
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a phyletic perspective on the allometry of plant biomass partitioning patterns and functionally equivalent organ categories
New Phytologist, 2006Co-Authors: Karl J. NiklasAbstract:Contents Summary 27 I. Introduction 28 II. Statistical considerations 30 III. Phyletic considerations and the null hypothesis 31 IV. Observable biomass-partitioning patterns 32 V. Two intraspecific digressions 34 VI. The functional equivalence hypothesis 35 VII. Plato's cave 38 VIII. Conclusions 38 Acknowledgements 39 References 39 Summary Biomass-partitioning patterns influence the functioning of aquatic and terrestrial vegetation at all levels, ranging from individual growth and reproduction to the flow of mass and energy through entire communities. For this reason, leaf, stem and root dry biomass-partitioning patterns across taxonomically and ecologically diverse seed plants (Spermatophytes) have been intensively investigated, both empirically and theoretically. By contrast, phyletically disparate plants (e.g. green and brown algal macrophytes, mosses and pteridophytes) have not been examined to determine whether the partitioning of their body parts into ‘leaf’, ‘stem’ and ‘root’ analogs accords with that of Spermatophytes. In this review, the biomass-partitioning patterns of siphonous and brown algal macrophytes, mosses and pteridophytes were compared allometrically with those of Spermatophytes and were shown to be largely in statistical accordance (thus lending support to the hypothesis that a single scaling relationship exists across eukaryotic photoautotrophs). This concordance is argued to support the hypothesis of functional equivalence across analogous, but developmentally different, body parts, a feature that permits the use of simpler biological model systems with which to derive analytical explanations for the biomass-partitioning patterns reported for more complex seed plants.
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A phyletic perspective on the allometry of plant biomass‐partitioning patterns and functionally equivalent organ‐categories
The New phytologist, 2006Co-Authors: Karl J. NiklasAbstract:Biomass-partitioning patterns influence the functioning of aquatic and terrestrial vegetation at all levels, ranging from individual growth and reproduction to the flow of mass and energy through entire communities. For this reason, leaf, stem and root dry biomass-partitioning patterns across taxonomically and ecologically diverse seed plants (Spermatophytes) have been intensively investigated, both empirically and theoretically. By contrast, phyletically disparate plants (e.g. green and brown algal macrophytes, mosses and pteridophytes) have not been examined to determine whether the partitioning of their body parts into 'leaf', 'stem' and 'root' analogs accords with that of Spermatophytes. In this review, the biomass-partitioning patterns of siphonous and brown algal macrophytes, mosses and pteridophytes were compared allometrically with those of Spermatophytes and were shown to be largely in statistical accordance (thus lending support to the hypothesis that a single scaling relationship exists across eukaryotic photoautotrophs). This concordance is argued to support the hypothesis of functional equivalence across analogous, but developmentally different, body parts, a feature that permits the use of simpler biological model systems with which to derive analytical explanations for the biomass-partitioning patterns reported for more complex seed plants.
José María Fernández-palacios - One of the best experts on this subject based on the ideXlab platform.
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The anagenetic world of spore‐producing land plants
The New phytologist, 2013Co-Authors: Jairo Patiño, José María Fernández-palacios, Mark A. Carine, Rüdiger Otto, Hanno Schaefer, Alain VanderpoortenAbstract:A fundamental challenge to our understanding of biodiversity is to explain why some groups of species diversify, whereas others do not. On islands, the gradual evolution of a new species from a founder event has been called 'anagenetic speciation'. This process does not lead to rapid and extensive speciation within lineages and has received little attention. Based on a survey of the endemic bryophyte, pteridophyte and Spermatophyte floras of nine oceanic archipelagos, we show that anagenesis, as measured by the proportion of genera with single endemic species within a genus, is much higher in bryophytes (73%) and pteridophytes (65%) than in Spermatophytes (55%). Anagenesis contributed 49% of bryophyte and 40% of endemic pteridophyte species, but only 17% of Spermatophytes. The vast majority of endemic bryophytes and pteridophytes are restricted to subtropical evergreen laurel forests and failed to diversify in more open environments, in contrast with the pattern exhibited by Spermatophytes. We propose that the dominance of anagenesis in island bryophytes and pteridophytes is a result of a mixture of intrinsic factors, notably their strong preference for (sub)tropical forest environments, and extrinsic factors, including the long-term macro-ecological stability of these habitats and the associated strong phylogenetic niche conservatism of their floras.
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Additive partitioning as a tool for investigating the flora diversity in oceanic archipelagos
Perspectives in Plant Ecology Evolution and Systematics, 2010Co-Authors: Alessandro Chiarucci, Giovanni Bacaro, José Ramón Arévalo, Juan D. Delgado, José María Fernández-palaciosAbstract:This paper introduces the integration of additive partitioning with species—area relationships to island biogeography in order to address the question ''How are the pteridophyte and Spermatophyte native and endemic flora of different oceanic archipelagos partitioned across islands?''. Species richness data of all endemic species and all native species of pteridophytes and Spermatophytes were obtained for the Azores, Canaries and Cape Verde in the Atlantic Ocean and Galapagos, Hawaii and Marquesas in the Pacific Ocean. Additive partitioning of species diversity was used to quantify how much of the total diversity of an oceanic archipelago flora (g-diversity) is due to (i) the mean species richness of the flora of each island (a-diversity), (ii) the variability in species richness of the floras across islands (bNestedness) and (iii) the complementarity in species composition of the floras of different islands (bReplacement). The analysis was separately performed for the native and endemic pteridophyte and Spermatophyte floras. The diversity partitioning of the six archipelagos showed large differences in how the flora of each archipelago is partitioned among the a, bNestedness and bReplacement components, for pteridophytes and Spermatophytes and for all endemic species and all native species. The a-diversity was more important for all native species than for endemic species and more important for pteridophytes than for Spermatophytes, with the Azores showing outstanding high values of a-diversity. The bNestedness was higher for pteridophytes than for Spermatophytes and higher for endemic species than for all native species in both pteridophytes and Spermatophytes. The values of bReplacement suggested that: (i) the Spermatophyte native flora is more differentiated across islands than the pteridophyte native flora and (ii) the pteridophyte endemic flora and, especially, the Spermatophyte endemic flora are more differentiated across islands than the corresponding native flora. An outstanding value of bReplacement for endemic and all native Spermatophytes was found in Hawaii, confirming the biogeographical island differentiation in this archipelago. & 2010 R ¨ ubel Foundation, ETH Z ¨
Cyrille Prestianni - One of the best experts on this subject based on the ideXlab platform.
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Early seed plants from Western Gondwana: Paleobiogeographical and ecological implications based on Tournaisian (Lower Carboniferous) records from Argentina
Palaeogeography Palaeoclimatology Palaeoecology, 2015Co-Authors: Cyrille Prestianni, Juan José Rustán, Diego Balseiro, E. Vaccari, Andrea F. Sterren, Philippe Steemans, Claudia V. Rubinstein, Ricardo A. AstiniAbstract:The oldest seed occurrences in Western Gondwana have been recognized in a new stratigraphic section located in Western Argentina (Precordillera Basin). Palynological evidence indicates an Early Mississippian (probably Tournaisian) age for this new succession. The two identified early seeds generas, Pseudosporogonites cf. hallei and Warsteinia sancheziae n. sp. were up to now considered as restricted to the Devonian of Laurussia. This finding suggests a dispersal of earliest Spermatophytes between Laurussia and Gondwana during Devonian/Tournaisian times, thus accounting for the Rheic Ocean as a surmountable biogeographic barrier for continental biotas. Alternatively, contrasting biogeographic hypotheses dealing with early Spermatophytes rising in paleotropics and then displacing herbaceous communities of non-Spermatophytes typical from cool high latitudinal regions, are explored for explaining the recognized paleobiogeographical pattern. The new information supports a weak impact of the Devonian/Carboniferous biotic crisis on earliest seed plant diversity. Based on preliminary evidences of niches differentiation and ecological dynamics probably affected by wildfires, Tournaisian Gondwanan plant communities from high latitudes are interpreted as being more complex than previously thought, and more similar to those reported from Laurussia. In addition, their discovery in a sedimentary environment associated to glacigenic deposits, show that this new record might be linked to the coeval glacial age widely recorded elsewhere in Gondwana.
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Thorezia vezerensisgen. et sp. nov., a new seed plant with multiovulate cupules from the Late Devonian of Belgium
Historical Biology, 2014Co-Authors: Cyrille Prestianni, Philippe GerrienneAbstract:The multiovulate cupule of a new Spermatophyte, Thorezia vezerensisgen. et sp. nov., is described from the Late Devonian aged sediments from Trooz Quarry in Belgium. In gross morphology, it conforms to the Moresnetia morphotype and has a cupule that is composed of four independent quarters that each dichotomises three times. Each cupule quarter contains one single ovoid preovule with a long pedicel and an integument that has small apical teeth surrounding a rudimentary micropyle. Morphological variability in the materials examined is interpreted as being related to preovule maturity, and from this a good understanding of the ontogenetic development from preceding dispersal has been developed. Up to now, 17 Spermatophyte species have been described, 11 of which come from eastern Laurussia. This diversity in eastern Laurussia contrasts strongly with the low diversity characterizing contemporaneous floras from other phytogeographical areas. We suggest here that the arid climatic conditions prevailing in east...
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Late Devonian Spermatophyte diversity and paleoecology at Red Hill, north-central Pennsylvania, USA
International Journal of Coal Geology, 2009Co-Authors: Walter L. Cressler, Cyrille Prestianni, Ben A. LepageAbstract:Early Spermatophytes have been discovered at Red Hill, a Late Devonian (Famennian) fossil locality in north-central Pennsylvania, USA. The Red Hill locality contains an Archaeopteris-dominated flora within an outcrop of the Duncannon Member of the Catskill Formation. Palynological analyses of the plant fossil-bearing horizons within the Red Hill outcrop indicate deposition within the VCo palynozone. This is the earliest time horizon known to contain evidence for Spermatophytes, and is contemporaneous with well-known Spermatophyte-bearing deposits in West Virginia and Belgium. Some of the Spermatophyte material from Red Hill compares well with Aglosperma sp., previously known as isolated ovules from the latest Devonian of South Wales and England, thus extending its geographic and stratigraphic range. Red Hill specimens of Aglosperma sp. occur both as isolated ovules and attached to dichotomously forking axes. Additional Spermatophyte cupules discovered at Red Hill are morphologically similar to those of the previously described Late Devonian Spermatophytes Elkinsia Rothwell, Scheckler, et Gillespie, Moresnetia Stockmans, and Xenotheca Arber et Goode. Some of the Red Hill cupule complexes are distinct from the aforementioned taxa in consisting of slender dichotomously forking axes terminating in paired cupules with highly fused and symmetric cupule quadrant lobes. The distinctive nature of these Red Hill specimens warrants the creation of Duodimidia pfefferkornii Cressler, Prestianni, et LePage gen. et sp. nov. Plant fossil remains with sphenopteroid foliage are also present at Red Hill, possibly attributable to the Spermatophytes. Previous systematic sampling of the rich plant-fossil bearing layer at Red Hill and analysis of its floristic diversity and abundance as well as the presence and absence of charcoal suggests a pattern of floral turnover from a local-scale Rhacophyton-dominated community to Spermatophyte colonization following disturbance by wildfires.
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Catskill Formation Charcoal
2009Co-Authors: Walter L. Cressler, Cyrille Prestianni, Walter Cressler Iii L. A, Cyrille Prestianni BAbstract:Late Devonian Spermatophyte diversity and paleoecology at Red Hill, north-centra
Jesús Muñoz - One of the best experts on this subject based on the ideXlab platform.
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The mossy north: an inverse latitudinal diversity gradient in European bryophytes
Scientific Reports, 2016Co-Authors: Rubén G. Mateo, Olivier Broennimann, Signe Normand, Blaise Petitpierre, Miguel B. Araújo, Jens-c. Svenning, Andrés Baselga, Federico Fernández-gonzález, Virgilio Gómez-rubio, Jesús MuñozAbstract:It remains hotly debated whether latitudinal diversity gradients are common across taxonomic groups and whether a single mechanism can explain such gradients. Investigating species richness (SR) patterns of European land plants, we determine whether SR increases with decreasing latitude, as predicted by theory and whether the assembly mechanisms differ among taxonomic groups. SR increases towards the south in Spermatophytes, but towards the north in ferns and bryophytes. SR patterns in Spermatophytes are consistent with their patterns of beta diversity, with high levels of nestedness and turnover in the north and in the south, respectively, indicating species exclusion towards the north and increased opportunities for speciation in the south. Liverworts exhibit the highest levels of nestedness, suggesting that they represent the most sensitive group to the impact of past climate change. Nevertheless, although the extent of liverwort species turnover in the south is substantially and significantly lower than in Spermatophytes, liverworts share with the latter a higher nestedness in the north and a higher turn-over in the south, in contrast to mosses and ferns. The extent to which the similarity in the patterns displayed by Spermatophytes and liverworts reflects a similar assembly mechanism remains, however, to be demonstrated.
Alessandro Chiarucci - One of the best experts on this subject based on the ideXlab platform.
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Additive partitioning as a tool for investigating the flora diversity in oceanic archipelagos
Perspectives in Plant Ecology Evolution and Systematics, 2010Co-Authors: Alessandro Chiarucci, Giovanni Bacaro, José Ramón Arévalo, Juan D. Delgado, José María Fernández-palaciosAbstract:This paper introduces the integration of additive partitioning with species—area relationships to island biogeography in order to address the question ''How are the pteridophyte and Spermatophyte native and endemic flora of different oceanic archipelagos partitioned across islands?''. Species richness data of all endemic species and all native species of pteridophytes and Spermatophytes were obtained for the Azores, Canaries and Cape Verde in the Atlantic Ocean and Galapagos, Hawaii and Marquesas in the Pacific Ocean. Additive partitioning of species diversity was used to quantify how much of the total diversity of an oceanic archipelago flora (g-diversity) is due to (i) the mean species richness of the flora of each island (a-diversity), (ii) the variability in species richness of the floras across islands (bNestedness) and (iii) the complementarity in species composition of the floras of different islands (bReplacement). The analysis was separately performed for the native and endemic pteridophyte and Spermatophyte floras. The diversity partitioning of the six archipelagos showed large differences in how the flora of each archipelago is partitioned among the a, bNestedness and bReplacement components, for pteridophytes and Spermatophytes and for all endemic species and all native species. The a-diversity was more important for all native species than for endemic species and more important for pteridophytes than for Spermatophytes, with the Azores showing outstanding high values of a-diversity. The bNestedness was higher for pteridophytes than for Spermatophytes and higher for endemic species than for all native species in both pteridophytes and Spermatophytes. The values of bReplacement suggested that: (i) the Spermatophyte native flora is more differentiated across islands than the pteridophyte native flora and (ii) the pteridophyte endemic flora and, especially, the Spermatophyte endemic flora are more differentiated across islands than the corresponding native flora. An outstanding value of bReplacement for endemic and all native Spermatophytes was found in Hawaii, confirming the biogeographical island differentiation in this archipelago. & 2010 R ¨ ubel Foundation, ETH Z ¨
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Additive partitioning as a tool for investigating the flora diversity in oceanic archipelagos
'Elsevier BV', 2010Co-Authors: Alessandro Chiarucci, Bacaro G, Delgado J.dAbstract:This paper introduces the integration of additive partitioning with species--area relationships to island biogeography in order to address the question "How are the pteridophyte and Spermatophyte native and endemic flora of different oceanic archipelagos partitioned across islands?". Species richness data of all endemic species and all native species of pteridophytes and Spermatophytes were obtained for the Azores, Canaries and Cape Verde in the Atlantic Ocean and Galbpagos, Hawaii and Marquesas in the Pacific Ocean. Additive partitioning of species diversity was used to quantify how much of the total diversity of an oceanic archipelago flora ([gamma]-diversity) is due to (i) the mean species richness of the flora of each island ([alpha]-diversity), (ii) the variability in species richness of the floras across islands ([beta]Nestedness) and (iii) the complementarity in species composition of the floras of different islands ([beta]Replacement). The analysis was separately performed for the native and endemic pteridophyte and Spermatophyte floras. The diversity partitioning of the six archipelagos showed large differences in how the flora of each archipelago is partitioned among the [alpha], [beta]Nestedness and [beta]Replacement components, for pteridophytes and Spermatophytes and for all endemic species and all native species. The [alpha]-diversity was more important for all native species than for endemic species and more important for pteridophytes than for Spermatophytes, with the Azores showing outstanding high values of [alpha]-diversity. The [beta]Nestedness was higher for pteridophytes than for Spermatophytes and higher for endemic species than for all native species in both pteridophytes and Spermatophytes. The values of [beta]Replacement suggested that: (i) the Spermatophyte native flora is more differentiated across islands than the pteridophyte native flora and (ii) the pteridophyte endemic flora and, especially, the Spermatophyte endemic flora are more differentiated across islands than the corresponding native flora. An outstanding value of [beta]Replacement for endemic and all native Spermatophytes was found in Hawaii, confirming the biogeographical island differentiation in this archipelag