45 research outputs found

    Timing of deployment does not affect the biodiversity outcomes of ecological enhancement of coastal flood defences in northern Europe

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    Timing of installation is an important factor when planning the deployment of ecological enhancements to intertidal coastal and marine infrastructure. Such nature-based solutions (NbS) are increasingly used worldwide, so understanding whether the timing of deployment affects colonisation success is crucial to enhance their success and identify any ecological sensitivities that must be taken into consideration during construction. To date, none of the previous marine eco-engineering studies globally have looked specifically at timing. An unexpected COVID19 interruption in retrofitting Ecotiles designed to improve urban marine biodiversity provided a unique window of opportunity to address this research gap. We examined if time of deployment affects the early colonisation (within 18 months) success of eco-engineering enhancements. Thirty concrete tiles (Ecotiles) cast with a novel multi-scale, multi-species textured formliner were deployed on rock armour in three sites along the coast in Edinburgh, Scotland, at two different time periods (early March and late May 2020). After two settlement seasons, the colonisation success of 85% of the studied species did not vary between the times of deployment. Early colonisation success of intertidal species equalised within two settlement seasons of deployment, along with an overall increase in species richness. Crucially, these results also show that summer construction periods designed to reduce impacts on overwintering birds, do not adversely impact intertidal species during their peak (spring-summer) recruitment period in northern Europe. This novel result provides further support for widespread use of eco-engineering to enhance large coastal infrastructure projects and achieve ecological goals in northern Europe. More widely, this work contributes to the understanding of the impact of deployment timing on the success of similar NbS worldwide

    A reassessment of the Ceratozamia miqueliana species complex (Zamiaceae) of southeastern Mexico, with comments on species relationships

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    A reassessment of the Ceratozamia miqueliana species complex (Zamiaceae) of southeastern Mexico, with comments on species relationships Abstract The Ceratozamia miqueliana species complex has been revised from a morphological, anatomical and biogeographical perspective. The complex consists of five closely related species, one of which is new, C. santillanii sp. nov., and is described and illustrated from the northern highlands of Chiapas. The five species, although not sympatric, occur in the 'Arc' Pleistocene floristic refuge that covers southern Mexico, including northern Oaxaca and Chiapas, as well as southern Tabasco and Veracruz. The five species are characterised by oblong, oblanceolate to widely oblanceolate leaflets with decumbent or erect megastrobili when ripe. The species complex consists of C. becerrae Pérez-Farr., Vovides & Schutzman C. euryphyllidia Våzq.Torres, Sabato & D.W. Stev., C. miqueliana H. Wendl., C. zoquorum Pérez-Farr., Vovides & Iglesias and the new species which is related to C. zoquorum, but differs from these in leaf, male and female cone growth habit, as well as inter-leaflet distance. Discriminant analysis using the five species with 14 variables showed significant differences (Wilks λ test, P < 0.01) for four functions among the five species. Mahalanobis distances were also highly significant among the five species (P < 0.01). Ceratozamia euryphyllidia and C. becerrae were the most distant, whereas C. zoquorum and C. becerrae were closest

    Pantropical variability in tree crown allometry

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    Aim: Tree crowns determine light interception, carbon and water exchange. Thus, understanding the factors causing tree crown allometry to vary at the tree and stand level matters greatly for the development of future vegetation modelling and for the calibration of remote sensing products. Nevertheless, we know little about large‐scale variation and determinants in tropical tree crown allometry. In this study, we explored the continental variation in scaling exponents of site‐specific crown allometry and assessed their relationships with environmental and stand‐level variables in the tropics. / Location: Global tropics. / Time period: Early 21st century. / Major taxa studied: Woody plants. / Methods: Using a dataset of 87,737 trees distributed among 245 forest and savanna sites across the tropics, we fitted site‐specific allometric relationships between crown dimensions (crown depth, diameter and volume) and stem diameter using power‐law models. Stand‐level and environmental drivers of crown allometric relationships were assessed at pantropical and continental scales. / Results: The scaling exponents of allometric relationships between stem diameter and crown dimensions were higher in savannas than in forests. We identified that continental crown models were better than pantropical crown models and that continental differences in crown allometric relationships were driven by both stand‐level (wood density) and environmental (precipitation, cation exchange capacity and soil texture) variables for both tropical biomes. For a given diameter, forest trees from Asia and savanna trees from Australia had smaller crown dimensions than trees in Africa and America, with crown volumes for some Asian forest trees being smaller than those of trees in African forests. / Main conclusions: Our results provide new insight into geographical variability, with large continental differences in tropical tree crown allometry that were driven by stand‐level and environmental variables. They have implications for the assessment of ecosystem function and for the monitoring of woody biomass by remote sensing techniques in the global tropics

    Tallo: A global tree allometry and crown architecture database.

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    This is the final version. Available from Wiley via the DOI in this record. Data capturing multiple axes of tree size and shape, such as a tree's stem diameter, height and crown size, underpin a wide range of ecological research-from developing and testing theory on forest structure and dynamics, to estimating forest carbon stocks and their uncertainties, and integrating remote sensing imagery into forest monitoring programmes. However, these data can be surprisingly hard to come by, particularly for certain regions of the world and for specific taxonomic groups, posing a real barrier to progress in these fields. To overcome this challenge, we developed the Tallo database, a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. These data were collected at 61,856 globally distributed sites, spanning all major forested and non-forested biomes. The majority of trees in the database are identified to species (88%), and collectively Tallo includes data for 5163 species distributed across 1453 genera and 187 plant families. The database is publicly archived under a CC-BY 4.0 licence and can be access from: https://doi.org/10.5281/zenodo.6637599. To demonstrate its value, here we present three case studies that highlight how the Tallo database can be used to address a range of theoretical and applied questions in ecology-from testing the predictions of metabolic scaling theory, to exploring the limits of tree allometric plasticity along environmental gradients and modelling global variation in maximum attainable tree height. In doing so, we provide a key resource for field ecologists, remote sensing researchers and the modelling community working together to better understand the role that trees play in regulating the terrestrial carbon cycle.Natural Environment Research Council (NERC)Natural Environment Research Council (NERC); Ministry of Education, Youth and Sports of the Czech RepublicFAPEMIGUniversidad Nacional AutĂłnoma de MĂ©xicoUniversidad Nacional AutĂłnoma de MĂ©xicoConsejo Nacional de Ciencia y TecnologĂ­aSwedish Energy AgencyUKRIFederal Ministry of Education and ResearchNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Science FoundationNational Science FoundationInternational Foundation for ScienceP3FACDynAfForNanjing Forestry UniversityJiangsu Science and Technology Special ProjectHebei UniversityAgence Nationale de la RechercheAgence Nationale de la RechercheAgua Salud ProjectU.S. Department of EnergyCAPE

    A new Zamia (Zamiaceae, Cycadales) from eastern Chiapas, Mexico

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    Volume: 8Start Page: 441End Page: 44

    A new species of Ceratozamia (Zamiaceae) from Veracruz, Mexico

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    Volume: 8Start Page: 87End Page: 9

    A new species of Ceratozamia (Zamiaceae, Cycadales) from Chiapas, Mexico

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    Volume: 9Start Page: 410End Page: 41

    Another new species of Ceratozamia (Zamiaceae) from Chiapas, Mexico

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    Ceratozamia mirandai sp. nov. from the Sepultura Biosphere reserve of Chiapas, Mexico, is described and illustrated. Its closest affinities are with C. kuesteriana Regel from Tamaulipas of north-east Mexico, but differs in male and female cone and trunk morphology

    New cycad (Zamiaceae) reports from Chiapas, Oaxaca, and Tabasco, Mexico

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    Volume: 105Start Page: 379End Page: 38

    Evolutionary signal of leaflet anatomy in the Zamiaceae

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    Premise of research: The morphology of leaves is shaped by both historical and current selection acting on constrained developmental systems. For this reason, the phylogenetic signal of these characters is usually overlooked. Methodology: We investigate morphology of the leaflets of all genera of the Zamiaceae using multiple microscopical techniques to test whether leaf characters present a phylogenetic signal and whether they are useful to define clades at a suprageneric level. Pivotal results: Our investigation shows that most genera are quite uniform in their leaflet anatomy, with the largest genera (Zamia, Encephalartos) presenting the highest degree of variation. Using both Bayesian and parsimony methods on two different molecular scaffolds, we are able to show that leaflet anatomy has a strong phylogenetic signal in the Zamiaceae and that many clades retrieved by molecular analyses present potential synapomorphies in their leaflet anatomy. Particularly, the placement of Stangeria in a clade with Zamia and Microcycas is supported by the presence of both an adaxial and an abaxial girder sclerenchyma and the absence of sclerified hypodermis. The placement of Stangeria as sister to Bowenia, on the other hand, is not supported by our analysis. Instead, our results put into question the homology of the similar guard cell morphology in the two genera. Conclusions: We show that leaflet anatomy has a substantial amount of phylogenetic signal in the Zamiaceae, supporting relationships that are not supported by general morphology. Therefore, anatomical investigation represents a promising avenue for plant systematists
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