Green leaves were sampled in a karst, alkaline habitat in rota and a schist, acid habitat. Diversity and genetic structure of the endangered cycad. Population numbers correspond to those listed in table 1. All structured data from the file and property namespaces is available under the creative commons cc0 license. The endemic species dioon sonorense comprises the northernmost group of populations of dioon, in sonora, mexico. Conservation genetics of an endangered cycad, dioon sonorense zamiaceae. While every effort has been made to provide the most reliable and uptodate information available, ultimate legal requirements with respect to species are contained in. The cycad genus dioon zamiaceae was described by j. Phylogeography and demographic history of zamia paucijuga. Itis taxonomy is based on the latest scientific consensus available, and is provided as a general reference source for interested parties. The genus dioon occupies an important phylogenetic position as sister to the other zamiaceae. This cycad, which grows in a dry habitat rich in cactus and succulents, is the first to be found in the mixteca region of mexico.
Dioon sonorense is a dioecious understory species, with stems usually. An outline of our current knowledge on mexican cycads. The cycad dioon sonorense zamiaceae has a relatively wide distribution range along a vegetation gradient in northwest mexico. Jul 22, 2014 we have investigated the phylogeographic structure and demographic history of zamia paucijuga, based on 120 its2 and 117 psbki sequences from populations distributed along the entire distribution range of the species. May 26, 2018 cycads are considered to be the most threatened plant group on earth. Conservation genetics of an endangered cycad, dioon sonorense. Mar 21, 2014 gymnosperms and angiosperms can cooccur within the same habitats but key plant traits are thought to give angiosperms an evolutionary competitive advantage in many ecological settings. Wildscreens arkive project was launched in 2003 and grew to become the worlds biggest encyclopaedia of life on earth. Epidermal morphology and leaflet anatomy of dioon zamiaceae.
It is characterized by falcate to subfalcate leaflets. The roots of many plant species are able to distinguish the identity of roots of competing plants. Rio verde dioon edulequeretaro blue form dioon holmgrenii dioon mejiae dioon merolaegolden dioonoaxaca dioon merolaelas minaschiapas dioon mixtequensis dioon rzedowskii dioon sonorense dioon sp. Despite the widespread distribution and ecological. This plant grows in oak and pineoak forest and woodland habitat. Text is available under the creative commons attributionsharealike license. For example, photosynthetic rates on a leaf area basis and nitrogen fixation usually tend to. Dioon tomasellii is a species of cycad in the family zamiaceae.
Dichotomous keydioon wikibooks, open books for an open. Dioon sonorense is an extremely rare cycad from mexico, which grows to moderate size and is highly sought after by collectors. Lindley in the 19 th century, but most species were discovered during the late 1970s through the. The diversity and genetic structure of seven populations of microcycas calocoma miq. A dioon with twisted leaves and thin, slighly falcate leafltes simple but ending in a sharp spine. In the present study, we used 19 allozyme loci to examine the diversity and genetic structure of the four populations studied to. However, its epidermal morphology is still poorly known. Aug 20, 2014 dioon sonorense is a dioecious understory species, with stems usually. A new cycad species in the genus dioon zamiaceae from the. This is a relatively mod sized dioon growing up to 3 high. Dioon groups correspond to biogeographic provinces as annotated in the left inset. Pdf diversity and genetic structure of the endangered. Pdf dioon rzedowskii zamiaceae, a new species from mexico. Conservation genetics, volume 19, issue 5 springer.
Dichotomous keydioon wikibooks, open books for an open world. Hill to quantify leaf nutrient concentrations of trees with stems up to 5. Ontogenetic shifts in plantplant interactions in a rare. Torres and the threatened endemic palm brahea aculeata brandegee moore, which cooccur within the biosphere reserve roughly between 500 and 1,000 m asl 7. We employed scanning and transmission electron microscopy, confocal microscopy and light microscopy to examine the epidermal and cuticular morphology of 12 of the 14 currently recognized species of dioon, examining cultivated plants and. Pages in category dioon the following 15 pages are in this category, out of 15 total. Encephalartos chimanimaniensis at the world list of cycads. Using the cycad genus dioon zamiaceae, this study aimed to test whether. Ontogenetic resourceuse strategies in a rare longlived. Noel mcgough, maurizio sajeva, uwe schippmann, and maurice tselaurence.
Threats to the species include destruction of the habitat for agriculture and overcollection for horticultural purposes. According to a report from the 1992 washington convention on biological diversity, trade with d. Torres and the threatened endemic palm brahea aculeata brandegee moore, which cooccur within the biosphere reserve roughly between 500 and 1,000 m asl. Considering evolutionary processes in cycad conservation. When the plastic response reduces investment into competitive behaviors, the fitness of two competing plants may increase as a result of the cooperation. We have detected 15 its2 and four psbki haplotypes, for a total of 19.
Plastic responses mediated by identity recognition in. Dioon species are also very popular with international collectors. Its leaves are often twisted and ascend in a spiral shape. Lindley in the 19th century, but most species were discovered during the late 1970s. Population 1, the largest, was monitored in the time period of 20072009, and population 5 occurs. The stem of the genus dioon was constrained by a height of 56 ma, as defined by the fossil showing the greatest macromorphological resemblance to dioon, dioonopsis praespinulosa hollick, 1932. Research article conservation physiology volume 2 2014 ontogeny. Pdf epidermal morphology and leaflet anatomy of dioon. Files are available under licenses specified on their description page. Pdf spatial distribution, survival, and fecundity of dioon edule. Dec, 2014 media in category dioon the following 10 files are in this category, out of 10 total. The populations from sonora and northern sinaloa are segregated asd. Taxonomic studies have enormously contributed to cycad conservation, since species descriptions formally recognize biodiversity components that can be considered in conservation. Pdf a natural habitat of the cycad dioon edue lind\.
However, it is not a legal authority for statutory or regulatory purposes. Differences in root response to self roots, roots of a close relative, or roots of nonrelatives have been reported 1 5. In this elevation range, we established 27 plots three 20. Diversity and genetic structure of the endangered cycad dioon sonorense zamiaceae from sonora, mexico. Interpretation and implementation of the convention trade in plant specimens pdf. Dioon species can be found in central america between the 15th and 29th northern latitude and are part of the neotropical floral kingdom. Species definition of dioon sonorense semantic scholar. We have investigated the phylogeographic structure and demographic history of zamia paucijuga, based on 120 its2 and 117 psbki sequences from populations distributed along the entire distribution range of the species.
They observe that, it is ze by city of salina cruz meet for propagation. Diversity and genetic structure of the endangered cycad dioon. Although it is endangered, only the southern populations are protected within a preservation area, while the remaining populations have. Pdf species definition of dioon sonorense zamiaceae. We illustrate how traitbased information can be translated into welldefined conservation strategies, using the example of dioon sonorense, an endangered cycad endemic to northwestern mexico. Epidermal morphology and leaflet anatomy of dioon zamiaceae with comments on climate and environment.
Download fulltext pdf dioon rzedowskii zamiaceae, a new species from mexico article pdf available in brittonia 322. Does plant size influence leaf elements in an arborescent. An outline of our current knowledge on mexican cycads zamiaceae, cycadales 161 from florida in the usa through mexico, all of central america, the west indies and into south america, where the genus is particularly diverse in colombia. Media in category dioon the following 10 files are in this category, out of 10 total. Evolutionary and conservation implications jorge gonza. Plant size influences the leaf nutrient relations of many species, but no cycad species has been studied in this regard. This page was last edited on 9 december 2014, at 19. Dioon is a genus of cycads in the family zamiaceae. Dioon sonorense is a species of cycad native to northern mexico. Thus, the identification of important biological units for conservation is crucial for their management and protection. Catherine rutherford, john donaldson, alex hudson, h.
B climate distribution of the four dioon groups shown as a twodimensional kernel density estimation plot calculated in the r package mass venables and ripley, 2002. Scientific information yielded by traitbased research, coupled with existing knowledge derived from wellestablished traditional approaches, could. Dec 27, 2017 jose said gutierrezortega, maria magdalena salinasrodriguez, jose f martinez, francisco molinafreaner, miguel angel perezfarrera, andrew p vovides, yu matsuki, yoshihisa suyama, takeshi a ohsawa, yasuyuki watano, tadashi kajita, the phylogeography of the cycad genus dioon zamiaceae clarifies its cenozoic expansion and diversification in the mexican transition zone, annals of. Cycads are considered to be the most threatened plant group on earth. Dioon sonorense produces a crown of numerous silvery bluegreen leaves with fine leaflets. Pdf diversity and genetic structure of the endangered cycad. It is endemic to mexico, where it occurs in the states of durango, guerrero, jalisco, michoacan, and nayarit. We also used matrix population models to show how population structure may affect its longterm persistence. We studied how population size and structure of an endemic cycad of northwestern mexico, dioon sonorense, known to be threatened by widespread land conversion and plant extraction by humans, varied with 21 environmental variables. Short communication enhancing ecosystem function through. On feb 15, 2004, palmbob from acton, ca zone 8b wrote. The distribution area includes honduras and parts of mexico. Gymnosperms and angiosperms can cooccur within the same habitats but key plant traits are thought to give angiosperms an evolutionary competitive advantage in many ecological settings. We studied ontogenetic changes in competitive and facilitative interactions between a rare gymnosperm dioon sonorense, our target species and different plant and abiotic neighbours conspecificcycads.
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