ORCID Profile
0000-0003-4724-8110
Current Organisations
State Herbarium of South Australia
,
University of Adelaide
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Publisher: Elsevier BV
Date: 10-2013
Publisher: Proceedings of the National Academy of Sciences
Date: 28-07-2009
Abstract: Coastal ecosystems and the services they provide are adversely affected by a wide variety of human activities. In particular, seagrass meadows are negatively affected by impacts accruing from the billion or more people who live within 50 km of them. Seagrass meadows provide important ecosystem services, including an estimated $1.9 trillion per year in the form of nutrient cycling an order of magnitude enhancement of coral reef fish productivity a habitat for thousands of fish, bird, and invertebrate species and a major food source for endangered dugong, manatee, and green turtle. Although in idual impacts from coastal development, degraded water quality, and climate change have been documented, there has been no quantitative global assessment of seagrass loss until now. Our comprehensive global assessment of 215 studies found that seagrasses have been disappearing at a rate of 110 km 2 yr −1 since 1980 and that 29% of the known areal extent has disappeared since seagrass areas were initially recorded in 1879. Furthermore, rates of decline have accelerated from a median of 0.9% yr −1 before 1940 to 7% yr −1 since 1990. Seagrass loss rates are comparable to those reported for mangroves, coral reefs, and tropical rainforests and place seagrass meadows among the most threatened ecosystems on earth.
Publisher: Oxford University Press (OUP)
Date: 06-2000
Publisher: Inter-Research Science Center
Date: 10-02-2011
DOI: 10.3354/MEPS08962
Publisher: Frontiers Media SA
Date: 08-10-2021
DOI: 10.3389/FMARS.2021.740958
Abstract: Halophila johnsonii is an endangered seagrass species that is restricted to the southeast coast of Florida, United States. Its taxonomic status has been called into question, in particular, given the close morphological and genetic similarity of H. johnsonii and the widely distributed and morphologically variable Halophila ovalis , which is largely restricted to the Indo-Pacific region. While a close relationship to H. ovalis is uncontroversial, it remains uncertain whether H. johnsonii represents a distinct lineage or is a recent introduction to the Florida region. Given the conservation status of H. johnsonii , distinguishing these alternatives has important implications for the management of the species and its habitat. Here, we develop molecular data sets for s les of H. johnsonii and H. ovalis including DNA sequences, genome-wide SNPs and microsatellites with the view to resolving the affinities of H. johnsonii with respect to the wider H. ovalis complex. Phylogenetic hypotheses based upon plastid (∼18000 bp) and low copy nuclear DNA (∼6500 bp) sequences derived from hybrid capture, along with 990 genome-wide ddRAD SNPs consistently resolved H. johnsonii within H. ovalis. Specifically, we found a close affinity between H. johnsonii and H. ovalis s led from the east coast of Africa. In addition, Halophila specimens collected in Antigua, which are within the range of morphological variation typical for H. ovalis , are virtually identical to H. johnsonii and the East African H. ovalis s les based upon DNA sequence analyses and these group together using Bayesian clustering analyses of microsatellites and ddRAD SNPs. We conducted population genetic analyses using large number of H. johnsonii s les collected over a 17-year period. Genotypic data generated through microsatellites and ddRAD SNPs revealed genetic uniformity for all 132 H. johnsonii s les across the Indian River Lagoon, Florida, while s les of H. ovalis from Antigua shared the same genotype as H. johnsonii . We conclude that the lack of genetic ersity and the absence of sexual reproduction strongly indicates that the total range of H. johnsonii is actually one clone that is closely related to populations in Africa and Antigua and may be derived from a recent introduction from one of those regions.
Publisher: Wiley
Date: 09-2004
Abstract: In phylogenetic analyses of nuclear ITS and chloroplast trnL DNA sequences, the mostly endemic Australian genera Halosarcia, Pachycornia, Sclerostegia, Tecticornia, and Tegicornia of the subfamily Salicornioideae (Chenopodiaceae) together form a monophyletic group, congruent with the hypothesis that they evolved from a common ancestor. However, limited genetic differentiation evident in both nrDNA and cpDNA sequences among these taxa suggests a possible rapid radiation. Based on fossil pollen records and climatic models of other authors, it is hypothesized that the expansion of the Australian endemic Salicornioideae most likely occurred during the Late Miocene to Pliocene, when increasing aridity caused the formation of extensive salt lakes along endorheic paleodrainage channels. Moreover, Australian Sarcocornia representatives were supported as monophyletic, nested within a paraphyletic Sarcocornia clade that also comprised European Salicornia in the ITS analysis. This suggests that Sarcocornia arrived in Australia subsequent to the ancestor of the Australian endemic genera most likely via long-distance dispersal.
Publisher: Frontiers Media SA
Date: 06-04-2018
Publisher: Wiley
Date: 04-2011
DOI: 10.3732/AJB.1000356
Abstract: The first microsatellite primers were developed for Solanum centrale, a native Australian species used in the bush foods industry. Existing markers developed for other Solanum species were also lified. Using an enrichment cloning protocol, seven novel markers were developed, and 48 existing markers from other Solanum species were tested, resulting in the characterization of a set of six highly polymorphic co-dominant loci for use in S. centrale. Microsatellite screening revealed polyploidy. Among the six highly polymorphic loci, allelic ersity ranged from 7 to 14. These markers will be useful for investigating genetic ersity and as a simple way of estimating ploidy of wild populations.
Publisher: Wiley
Date: 10-2010
DOI: 10.3732/AJB.1000213
Abstract: Microsatellite primers were developed for the first time in the native Australian sandalwood species Santalum lanceolatum. • Using an enrichment cloning protocol, five novel polymorphic codominant loci were developed and characterized in S. lanceolatum and S. leptocladum. In addition to these, three existing microsatellite loci from other sandalwood species were successfully lified and characterized for S. lanceolatum and S. leptocladum. Among the eight loci, allelic ersity ranged from 4 to 29. • Primers will be useful for studies of clonality, genetic ersity and spatial genetic structure in wild populations. When coupled with other molecular techniques will help investigate the relationship between S. lanceolatum and S. leptocladum, species of commercial and conservation interest.
Publisher: Oxford University Press (OUP)
Date: 06-2000
No related grants have been discovered for Ainsley Calladine.