scholarly journals Comparing Genetic Diversity in Three Threatened Oaks

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 561
Author(s):  
Emma Suzuki Spence ◽  
Jeremie B. Fant ◽  
Oliver Gailing ◽  
M. Patrick Griffith ◽  
Kayri Havens ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Rare Species ◽  
Genetic Erosion ◽  
Geographic Range ◽  
Range Size ◽  
Ex Situ ◽  
Botanic Gardens ◽  
Geographic Range Size

Genetic diversity is a critical resource for species’ survival during times of environmental change. Conserving and sustainably managing genetic diversity requires understanding the distribution and amount of genetic diversity (in situ and ex situ) across multiple species. This paper focuses on three emblematic and IUCN Red List threatened oaks (Quercus, Fagaceae), a highly speciose tree genus that contains numerous rare species and poses challenges for ex situ conservation. We compare the genetic diversity of three rare oak species—Quercus georgiana, Q. oglethorpensis, and Q. boyntonii—to common oaks; investigate the correlation of range size, population size, and the abiotic environment with genetic diversity within and among populations in situ; and test how well genetic diversity preserved in botanic gardens correlates with geographic range size. Our main findings are: (1) these three rare species generally have lower genetic diversity than more abundant oaks; (2) in some cases, small population size and geographic range correlate with genetic diversity and differentiation; and (3) genetic diversity currently protected in botanic gardens is inadequately predicted by geographic range size and number of samples preserved, suggesting non-random sampling of populations for conservation collections. Our results highlight that most populations of these three rare oaks have managed to avoid severe genetic erosion, but their small size will likely necessitate genetic management going forward.

scholarly journals Of mice and wrens: the relation between abundance and geographic range size in British mammals and birds

1997 ◽  
Vol 352 (1352) ◽  
pp. 419-427 ◽  
Author(s):  
T. M. Blackburn ◽  
K. J. Gaston ◽  
R. M. Quinn ◽  
H. Arnold ◽  
R. D. Gregory
Keyword(s):  
Population Size ◽  
Body Mass ◽  
Comparative Method ◽  
Geographic Range ◽  
Range Size ◽  
Mammal Species ◽  
Geographic Ranges ◽  
Geographic Range Size ◽  
The Difference ◽  
Size Relation

We examine the relation between population size and geographic range size for British breeding birds and mammals. As for most other assemblages studied, a strong positive interspecific correlation is found in both taxa. The relation is also recovered once the phylogenetic relatedness of species has been controlled for using an evolutionary comparative method. The slope of the relation is steeper for birds than for mammals, but this is due in large part to two species of mammals that have much higher population sizes than expected from their small geographic ranges. These outlying mammal species are the only ones in Britain to be found only on small offshore islands, and so may be exhibiting density compensation effects. With them excluded, the slope of the abundance–range size relation for mammals is not significantly different to that for birds. However, the elevation of the relation is higher for mammals than for birds, indicating that mammals are approximately 30 times more abundant than birds of equivalent geographic range size. An earlier study of these assemblages showed that, for a given body mass, bats had abundances more similar to birds than to non–volant mammals, suggesting that the difference in abundance between mammals and birds might be due to constraints of flight. Our analyses show that the abundance–range size relation for bats is not different for that from other mammals, and that the anomalously low abundance of bats for their body mass may result because they have smaller than expected geographic extents for their size. Other reasons why birds and mammals might have different elevations for the relation between population size and geographic range size are discussed, together with possible reasons for why the slopes of these relations might be similar.

scholarly journals Patterns of Genetic Diversity and Implications for In Situ Conservation of Wild Celery (Apium graveolens L. ssp. graveolens)

Agriculture ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 129 ◽  
Author(s):  
Lothar Frese ◽  
Maria Bönisch ◽  
Marion Nachtigall ◽  
Uta Schirmak
Keyword(s):  
Genetic Diversity ◽  
Conservation Status ◽  
Sampling Site ◽  
In Situ Conservation ◽  
Genetic Erosion ◽  
Ex Situ ◽  
Apium Graveolens ◽  
Distribution Area ◽  
Genetic Reserve

In Germany, the wild ancestor (Apium graveolens L. ssp. graveolens) of celery and celeriac is threatened by genetic erosion. Seventy-eight potentially suitable genetic reserve sites representing differing ecogeographic units were assessed with regard to the conservation status of the populations. At 27 of the 78 sites, 30 individual plants were sampled and genetically analyzed with 16 polymorphic microsatellite makers. The Discriminant Analysis of Principal Components (DAPC) was applied to identify clusters of genetically similar individuals. In most cases (25 out of 27 occurrences) individuals clustered into groups according to their sampling site. Next to three clearly separated occurrences (AgG, AgUW, AgFEH) two large groups of inland and Baltic Sea coast occurrences, respectively, were recognized. Occurrences from the coastal part of the distribution area were interspersed into the group of inland occurrences and vice versa. The genetic distribution pattern is therefore complex. The complementary compositional genetic differentiation Δj was calculated to identify the Most Appropriate Wild Populations (MAWP) for the establishment of genetic reserves. Altogether 15 sites are recommended to form a genetic reserve network. This organisational structure appears suitable for promoting the in situ conservation of intraspecific genetic diversity and the species’ adaptability. As seed samples of each MAWP will be stored in a genebank, the network would likewise contribute to the long-term ex situ conservation of genetic resources for plant breeding.

scholarly journals Conservation of Genetic Diversity of Tomatoes (Lycopersicon esculentum Mill.)

2021 ◽  
Vol 78 (1) ◽  
pp. 11
Author(s):  
Cristian ALBU ◽  
Aurel MAXIM ◽  
Raluca Maria PÂRLICI
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Western Europe ◽  
Genetic Erosion ◽  
Farming Systems ◽  
Ex Situ ◽  
International Convention ◽  
High Productivity ◽  
Convention On Biodiversity

Among the main problems encountered with crop plants, the most important one is represented by genetic erosion. At world level this issue has been debated within the Convention on Biodiversity adopted in UN Conference of Rio de Janeiro and The International Convention regarding Genetic Resources of Plants for Alimentation and Agriculture. In Europe, the regulations in this field are made by the European Directive 98/95 EEC. Across time tomatoes have suffered a heightened process of genetic diversity, phenomenon caused by industrialized farming which is based on the use of very uniform varieties with high productivity. The extension of green agriculture, has led to the use of landraces, because they respond best to the traditional farming systems. In Western Europe organizations of peasants had been founded and, they are involved in different activities aiming at conservation of traditional forms of agriculture and the use of old varieties. In Romania the institutions with continuous preoccupations in the field of vegetal genetic conservation, especially landraces, are the Gene Bank from Suceava and UASMV Cluj-Napoca. By using conservation methods (in situ and ex situ), the genetic erosion surely phenomenon of vegetal genetic resources, implicitly tomatoes, is reduced, the future generations will benefit from valuable genetic resources.

scholarly journals Pollinator habitat plantings benefit wild, native bees, but do not necessarily favor rare species

2021 ◽  
Author(s):  
Daniel P. Cariveau ◽  
Michael Roswell ◽  
Tina Harrison ◽  
Mark A. Genung ◽  
Jason Gibbs ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Rare Species ◽  
Null Model ◽  
Common Species ◽  
Geographic Range ◽  
Range Size ◽  
Habitat Types ◽  
Geographic Range Size ◽  
Habitat Enhancement ◽  
Number Of Individuals

Installing pollinator habitat is a ubiquitous conservation tool, but little is known about which pollinator taxa require support, or which benefit from habitat installations. We studied the response of rare and common bees to pollinator habitat enhancement. We used independent regional datasets to designate bee species as common or rare based on their rank according to one of three metrics: a) site occurrence frequency, b) local relative abundance, and c) geographic range size. We asked whether the abundance or richness of rare and common bees were greater in pollinator habitat, relative to old-field controls. Because we used an arbitrary, quantile-based cutoff to categorize species rarity, we conducted sensitivity analysis and controlled for rarity classification errors with a null model. With this null model, we determined whether rare and/or common species responded to pollinator habitat disproportionately, compared to the expectation for "typical" bee species. We found that the number of individuals and of species designated as rare based on local relative abundance was greater in pollinator habitat enhancements. The number of individuals from bee species designated as rare based on site occurrence was lower in pollinator habitat enhancements, but the number of species was not clearly different between habitat types. We did not find a clear positive nor negative effect of habitat enhancement for species designated rare based on geographic range size. For all three rarity metrics, common species increased in abundance and richness in pollinator habitat relative to controls. Null models indicated that in most cases, neither rare nor common species disproportionately benefited from pollinator habitat. Synthesis and Applications: Our results suggest that pollinator habitat can lead to an increase in the abundance and richness of bees, including species that are rare and that are common. However, rare species appeared to respond differently than typical species, and depending on how species were classified as rare, could display muted or even negative responses to habitat enhancement. Targeting rare species with specific floral resources or unique habitat types may lead to better outcomes for rare and threatened species.

scholarly journals The Development of Plant Conservation in Botanic Gardens and the Current and Future Role of Conservation Genetics for Enhancing Those Conservation Efforts

2019 ◽  
Vol 03 (01) ◽  
pp. 44-65 ◽  
Author(s):  
Christine E. Edwards ◽  
Peter Wyse Jackson
Keyword(s):  
Genetic Diversity ◽  
Conservation Genetics ◽  
Plant Conservation ◽  
Molecular Techniques ◽  
Ex Situ ◽  
Botanic Gardens ◽  
Future Role

Botanic gardens play major roles in plant conservation globally. Since the 1980s, the number of botanic gardens worldwide and their involvement in integrating ex situ and in situ plant conservation has increased significantly, with a growing focus on understanding, documenting, and capturing genetic diversity in their living collections. This article outlines why genetic diversity is important for conservation, and explores how botanic gardens can establish and expand the use of molecular techniques to support their plant conservation efforts.

scholarly journals Geographic contingency, not species sorting, dominates macroevolutionary dynamics in an extinct clade of neogastropods (Volutospina; Volutidae)

Paleobiology ◽  
2021 ◽  
pp. 1-15
Author(s):  
Dana S. Friend ◽  
Brendan M. Anderson ◽  
Warren D. Allmon
Keyword(s):  
Middle Eocene ◽  
Ecological Factors ◽  
Geographic Range ◽  
Late Eocene ◽  
Range Size ◽  
Species Sorting ◽  
Extinction Rates ◽  
Geographic Range Size ◽  
Speciation Rates ◽  
Planktotrophic Larvae

Abstract Rates of speciation and extinction are often linked to many ecological factors, traits (emergent and nonemergent) such as environmental tolerance, body size, feeding type, and geographic range. Marine gastropods in particular have been used to examine the role of larval dispersal in speciation. However, relatively few studies have been conducted placing larval modes in species-level phylogenetic context. Those that have, have not incorporated fossil data, while landmark macroevolutionary studies on fossil clades have not considered both phylogenetic context and net speciation (speciation–extinction) rates. This study utilizes Eocene volutid Volutospina species from the U.S. Gulf Coastal Plain and the Hampshire Basin, U.K., to explore the relationships among larval mode, geographic range, and duration. Based on the phylogeny of these Volutospina, we calculated speciation and extinction rates in order to compare the macroevolutionary effects of larval mode. Species with planktotrophic larvae had a median duration of 9.7 Myr, which compared significantly to 4.7 Myr for those with non-planktotrophic larvae. Larval mode did not significantly factor into geographic-range size, but U.S. and U.K. species do differ, indicating a locality-specific component to maximum geographic-range size. Non-planktotrophs (NPTs)were absent among the Volutospina species during the Paleocene–early Eocene. The relative proportions of NPTs increased in the early middle Eocene, and the late Eocene was characterized by disappearance of planktotrophs (PTs). The pattern of observed lineage diversity shows an increasing preponderance of NPTs; however, this is clearly driven by a dramatic extinction of PTs, rather than higher NPT speciation rates during the late Eocene. This study adds nuance to paleontology's understanding of the macroevolutionary consequences of larval mode.

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