Science Enabled by Specimen Data

Zhang, Q., J. Ye, C. Le, D. M. Njenga, N. R. Rabarijaona, W. O. Omollo, L. Lu, et al. 2022. New insights into the formation of biodiversity hotspots of the Kenyan flora. Diversity and Distributions. https://doi.org/10.1111/ddi.13624

Aim This study aimed to investigate the distribution patterns of plant diversity in Kenya, how climatic fluctuations and orogeny shaped them, and the formation of its β-diversity. Location Kenya, East Africa. Taxon Angiosperms. Methods We quantified patterns of turnover and nestedness components of phylogenetic β-diversity for angiosperm species among neighbouring sites using a well-resolved phylogenetic tree and extensive distribution records from public databases and other published sources. We applied clustering methods to delineate biota based on pairwise similarities among multiple sites and used a random assembly null model to assess the effects of species abundance distribution on phylogenetic β-diversity. Results The phylogenetic turnover of the Kenyan flora, intersecting with the biodiversity hotspots Eastern Afromontane, Coastal Forests of Eastern Africa, and Horn of Africa, shows a non-monotonic pattern along a latitudinal gradient that is strongly structured into volcanic and coastal areas. The other areas are mainly dominated by phylogenetic nestedness, even in the eastern part of the equatorial region parallel to the volcanic area. Phylogenetic diversity and phylogenetic structure analyses explain the mechanism of the observed phylogenetic turnover and nestedness patterns. We identified five phytogeographical regions in Kenya: the Mandera, Turkana, Volcanic, Pan Coastal and West Highland Regions. Conclusions Variations in turnover gradient and coexistence are highly dependent on the regional biogeographical history resulting from climatic fluctuations and long-lasting orogeny, which jointly shaped the biodiversity patterns of the Kenyan flora. The nestedness component dominated climatically unstable regions and is presumed to have been caused by heavy local species extinction and recolonization from the Volcanic Region. The high turnover component in climatically stable regions may have preserved old lineages and the prevalence of endemic species within narrow ranges.

Sluiter, I. R. K., G. R. Holdgate, T. Reichgelt, D. R. Greenwood, A. P. Kershaw, and N. L. Schultz. 2022. A new perspective on Late Eocene and Oligocene vegetation and paleoclimates of South-eastern Australia. Palaeogeography, Palaeoclimatology, Palaeoecology 596: 110985. https://doi.org/10.1016/j.palaeo.2022.110985

We present a composite terrestrial pollen record of latest Eocene through Oligocene (35.5–23 Ma) vegetation and climate change from the Gippsland Basin of south-eastern Australia. Climates were overwhelmingly mesothermic through this time period, with mean annual temperature (MAT) varying between 13 and 18 °C, with an average of 16 °C. We provide evidence to support a cooling trend through the Eocene–Oligocene Transition (EOT), but also identify three subsequent warming cycles through the Oligocene, leading to more seasonal climates at the termination of the Epoch. One of the warming episodes in the Early Oligocene appears to have also occurred at two other southern hemisphere sites at the Drake Passage as well as off eastern Tasmania, based on recent research. Similarities with sea surface temperature records from modern high southern latitudes which also record similar cycles of warming and cooling, are presented and discussed. Annual precipitation varied between 1200 and 1700 mm/yr, with an average of 1470 mm/yr through the sequence. Notwithstanding the extinction of Nothofagus sg. Brassospora from Australia and some now microthermic humid restricted Podocarpaceae conifer taxa, the rainforest vegetation of lowland south-eastern Australia is reconstructed to have been similar to present day Australian Evergreen Notophyll Vine Forests existing under the sub-tropical Köppen-Geiger climate class Cfa (humid subtropical) for most of the sequence. Short periods of cooler climates, such as occurred through the EOT when MAT was ~ 13 °C, may have supported vegetation similar to modern day Evergreen Microphyll Fern Forest. Of potentially greater significance, however, was a warm period in the Early to early Late Oligocene (32–26 Ma) when MAT was 17–18 °C, accompanied by small but important increases in Araucariaceae pollen. At this time, Araucarian Notophyll/Microphyll Vine Forest likely occurred regionally.

Vasconcelos, T., J. D. Boyko, and J. M. Beaulieu. 2021. Linking mode of seed dispersal and climatic niche evolution in flowering plants. Journal of Biogeography. https://doi.org/10.1111/jbi.14292

Aim: Due to the sessile nature of flowering plants, movements to new geographical areas occur mainly during seed dispersal. Frugivores tend to be efficient dispersers because animals move within the boundaries of their preferable niches, so seeds are more likely to be transported to environments tha…

Alban, D. M., E. M. Biersma, J. W. Kadereit, and M. S. Dillenberger. 2021. Colonization of the Southern Hemisphere by Sagina and Colobanthus (Caryophyllaceae). Plant Systematics and Evolution 308. https://doi.org/10.1007/s00606-021-01793-w

Colobanthus (23 species) and Sagina (30–33 species) together are sister to Facchinia. Whereas Facchinia is distributed in western Eurasia, Colobanthus is almost exclusively distributed in the Southern Hemisphere, and Sagina is distributed in both hemispheres with the highest species diversity in wes…

Xue, T., S. R. Gadagkar, T. P. Albright, X. Yang, J. Li, C. Xia, J. Wu, and S. Yu. 2021. Prioritizing conservation of biodiversity in an alpine region: Distribution pattern and conservation status of seed plants in the Qinghai-Tibetan Plateau. Global Ecology and Conservation 32: e01885. https://doi.org/10.1016/j.gecco.2021.e01885

The Qinghai-Tibetan Plateau (QTP) harbors abundant and diverse plant life owing to its high habitat heterogeneity. However, the distribution pattern of biodiversity hotspots and their conservation status remain unclear. Based on 148,283 high-resolution occurrence coordinates of 13,450 seed plants, w…

Allstädt, F. J., A. Koutsodendris, E. Appel, W. Rösler, T. Reichgelt, S. Kaboth-Bahr, A. A. Prokopenko, and J. Pross. 2021. Late Pliocene to early Pleistocene climate dynamics in western North America based on a new pollen record from paleo-Lake Idaho. Palaeobiodiversity and Palaeoenvironments 101: 177–195. https://doi.org/10.1007/s12549-020-00460-1

Marked by the expansion of ice sheets in the high latitudes, the intensification of Northern Hemisphere glaciation across the Plio/Pleistocene transition at ~ 2.7 Ma represents a critical interval of late Neogene climate evolution. To date, the characteristics of climate change in North America duri…

van Treuren, R., R. Hoekstra, R. Wehrens, and T. van Hintum. 2020. Effects of climate change on the distribution of crop wild relatives in the Netherlands in relation to conservation status and ecotope variation. Global Ecology and Conservation 23: e01054. https://doi.org/10.1016/j.gecco.2020.e01054

Crop wild relatives (CWR) are wild plant taxa that are genetically related to a cultivated species and are considered rich sources of useful traits for crop improvement. CWR are generally underrepresented in genebanks, while their survival in nature is not guaranteed. Inventories and risk analyses a…

Léveillé-Bourret, É., B.-H. Chen, M.-È. Garon-Labrecque, B. A. Ford, and J. R. Starr. 2020. RAD sequencing resolves the phylogeny, taxonomy and biogeography of Trichophoreae despite a recent rapid radiation (Cyperaceae). Molecular Phylogenetics and Evolution 145: 106727. https://doi.org/10.1016/j.ympev.2019.106727

Trichophoreae is a nearly cosmopolitan Cyperaceae tribe that contains ∼17 species displaying striking variation in size, inflorescence complexity, and perianth morphology. Although morphologically distinct, the status of its three genera (Cypringlea, Oreobolopsis and Trichophorum) are controversial …

Fletcher, T. L., L. Warden, J. S. Sinninghe Damsté, K. J. Brown, N. Rybczynski, J. C. Gosse, and A. P. Ballantyne. 2019. Evidence for fire in the Pliocene Arctic in response to amplified temperature. Climate of the Past 15: 1063–1081. https://doi.org/10.5194/cp-15-1063-2019

The mid-Pliocene is a valuable time interval for investigating equilibrium climate at current atmospheric CO2 concentrations because atmospheric CO2 concentrations are thought to have been comparable to the current day and yet the climate and distribution of ecosystems were quite different. One intr…

Folk, R. A., R. L. Stubbs, M. E. Mort, N. Cellinese, J. M. Allen, P. S. Soltis, D. E. Soltis, and R. P. Guralnick. 2019. Rates of niche and phenotype evolution lag behind diversification in a temperate radiation. Proceedings of the National Academy of Sciences 116: 10874–10882. https://doi.org/10.1073/pnas.1817999116

Environmental change can create opportunities for increased rates of lineage diversification, but continued species accumulation has been hypothesized to lead to slowdowns via competitive exclusion and niche partitioning. Such density-dependent models imply tight linkages between diversification and…