Science Enabled by Specimen Data
Williams, C. J. R., Lunt, D. J., Salzmann, U., Reichgelt, T., Inglis, G. N., Greenwood, D. R., Chan, W., Abe‐Ouchi, A., Donnadieu, Y., Hutchinson, D. K., Boer, A. M., Ladant, J., Morozova, P. A., Niezgodzki, I., Knorr, G., Steinig, S., Zhang, Z., Zhu, J., Huber, M., & Otto‐Bliesner, B. L. (2022). African hydroclimate during the early Eocene from the DeepMIP simulations. Paleoceanography and Paleoclimatology. Portico. https://doi.org/10.1029/2022pa004419 https://doi.org/10.1029/2022pa004419
The early Eocene (∼56‐48 million years ago) is characterised by high CO2 estimates (1200‐2500 ppmv) and elevated global temperatures (∼10 to 16°C higher than modern). However, the response of the hydrological cycle during the early Eocene is poorly constrained, especially in regions with sparse data coverage (e.g. Africa). Here we present a study of African hydroclimate during the early Eocene, as simulated by an ensemble of state‐of‐the‐art climate models in the Deep‐time Model Intercomparison Project (DeepMIP). A comparison between the DeepMIP pre‐industrial simulations and modern observations suggests that model biases are model‐ and geographically dependent, however these biases are reduced in the model ensemble mean. A comparison between the Eocene simulations and the pre‐industrial suggests that there is no obvious wetting or drying trend as the CO2 increases. The results suggest that changes to the land sea mask (relative to modern) in the models may be responsible for the simulated increases in precipitation to the north of Eocene Africa. There is an increase in precipitation over equatorial and West Africa and associated drying over northern Africa as CO2 rises. There are also important dynamical changes, with evidence that anticyclonic low‐level circulation is replaced by increased south‐westerly flow at high CO2 levels. Lastly, a model‐data comparison using newly‐compiled quantitative climate estimates from palaeobotanical proxy data suggests a marginally better fit with the reconstructions at lower levels of CO2.
Reichgelt, T., Greenwood, D. R., Steinig, S., Conran, J. G., Hutchinson, D. K., Lunt, D. J., Scriven, L. J., & Zhu, J. (2022). Plant Proxy Evidence for High Rainfall and Productivity in the Eocene of Australia. Paleoceanography and Paleoclimatology. Portico. https://doi.org/10.1029/2022pa004418 https://doi.org/10.1029/2022pa004418
During the early to middle Eocene, a mid‐to‐high latitudinal position and enhanced hydrological cycle in Australia would have contributed to a wetter and “greener” Australian continent where today arid to semi‐arid climates dominate. Here, we revisit 12 southern Australian plant megafossil sites from the early to middle Eocene to generate temperature, precipitation and seasonality paleoclimate estimates, net primary productivity (NPP) and vegetation type, based on paleobotanical proxies and compare to early Eocene global climate models. Temperature reconstructions are uniformly subtropical (mean annual, summer, and winter mean temperatures 19–21 °C, 25–27 °C and 14–16 °C, respectively), indicating that southern Australia was ∼5 °C warmer than today, despite a >20° poleward shift from its modern geographic location. Precipitation was less homogeneous than temperature, with mean annual precipitation of ∼60 cm over inland sites and >100 cm over coastal sites. Precipitation may have been seasonal with the driest month receiving 2–7× less than mean monthly precipitation. Proxy‐model comparison is favorable with an 1680 ppm CO2 concentration. However, individual proxy reconstructions can disagree with models as well as with each other. In particular, seasonality reconstructions have systemic offsets. NPP estimates were higher than modern, implying a more homogenously “green” southern Australia in the early to middle Eocene, when this part of Australia was at 48–64 °S, and larger carbon fluxes to and from the Australian biosphere. The most similar modern vegetation type is modern‐day eastern Australian subtropical forest, although distance from coast and latitude may have led to vegetation heterogeneity.
Chevalier, M. (2022). &lt;i&gt;crestr&lt;/i&gt;: an R package to perform probabilistic climate reconstructions from palaeoecological datasets. Climate of the Past, 18(4), 821–844. https://doi.org/10.5194/cp-18-821-2022 https://doi.org/10.5194/cp-18-821-2022
Abstract. Statistical climate reconstruction techniques are fundamental tools to study past climate variability from fossil proxy data. In particular, the methods based on probability density functions (or PDFs) can be used in various environments and with different climate proxies because they rely on elementary calibration data (i.e. modern geolocalised presence data). However, the difficulty of accessing and curating these calibration data and the complexity of interpreting probabilistic results have often limited their use in palaeoclimatological studies. Here, I introduce a new R package (crestr) to apply the PDF-based method CREST (Climate REconstruction SofTware) on diverse palaeoecological datasets and address these problems. crestr includes a globally curated calibration dataset for six common climate proxies (i.e. plants, beetles, chironomids, rodents, foraminifera, and dinoflagellate cysts) associated with an extensive range of climate variables (20 terrestrial and 19 marine variables) that enables its use in most terrestrial and marine environments. Private data collections can also be used instead of, or in combination with, the provided calibration dataset. The package includes a suite of graphical diagnostic tools to represent the data at each step of the reconstruction process and provide insights into the effect of the different modelling assumptions and external factors that underlie a reconstruction. With this R package, the CREST method can now be used in a scriptable environment and thus be more easily integrated with existing workflows. It is hoped that crestr will be used to produce the much-needed quantified climate reconstructions from the many regions where they are currently lacking, despite the availability of suitable fossil records. To support this development, the use of the package is illustrated with a step-by-step replication of a 790 000-year-long mean annual temperature reconstruction based on a pollen record from southeastern Africa.
Campbell, C., Granath, G., & Rydin, H. (2021). Climatic drivers of Sphagnum species distributions. Frontiers of Biogeography, 13(4). doi:10.21425/f5fbg51146 https://doi.org/10.21425/f5fbg51146
Peatmosses(genus Sphagnum) dominate most Northern mires and show distinct distributional limits in Europe despite having efficient dispersal and few dispersal barriers. This pattern indicates that Sphagnum species distributions are strongly linked to climate. Sphagnumdominated mires have been the la…
Freitas, C., Brum, F. T., Cássia-Silva, C., Maracahipes, L., Carlucci, M. B., Collevatti, R. G., & Bacon, C. D. (2021). Incongruent Spatial Distribution of Taxonomic, Phylogenetic, and Functional Diversity in Neotropical Cocosoid Palms. Frontiers in Forests and Global Change, 4. doi:10.3389/ffgc.2021.739468 https://doi.org/10.3389/ffgc.2021.739468
Biodiversity can be quantified by taxonomic, phylogenetic, and functional diversity. Current evidence points to a lack of congruence between the spatial distribution of these facets due to evolutionary and ecological constraints. A lack of congruence is especially evident between phylogenetic and ta…
Vasconcelos, T., Boyko, J. D., & Beaulieu, J. M. (2021). Linking mode of seed dispersal and climatic niche evolution in flowering plants. Journal of Biogeography. doi:10.1111/jbi.14292 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…
Xue, T., Gadagkar, S. R., Albright, T. P., Yang, X., Li, J., Xia, C., … Yu, S. (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. doi:10.1016/j.gecco.2021.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…
Grebennikov, K. (2021). Ecological niche modeling to assessment of potential distribution of Neodiprion abietis (Harris, 1841) (Insecta, Hymenoptera, Diprionidae) in Eurasia. International Journal of Agricultural Sciences and Technology, 1(1), 1–7. doi:10.51483/ijagst.1.1.2021.1-7 https://doi.org/10.51483/ijagst.1.1.2021.1-7
In the article first assesses the potential distribution in Eurasia of Neodiprion abietis (Harris, 1841) first time assessed. The species id a widely distributed in North America fir and spruce defoliator, intercepted in 2016 in the Netherlands. Analysis of the literature data on the known distribut…
López‐Delgado, J., & Meirmans, P. G. (2021). History or demography? Determining the drivers of genetic variation in North American plants. Molecular Ecology. doi:10.1111/mec.16230 https://doi.org/10.1111/mec.16230
Understanding the impact of historical and demographic processes on genetic variation is essential for devising conservation strategies and predicting responses to climate change. Recolonization after Pleistocene glaciations is expected to leave distinct genetic signatures, characterised by lower ge…
Fulkerson, J. R., & Lease, K. (2021). SHORTER NOTE. American Fern Journal, 111(3). doi:10.1640/0002-8444-111.3.214 https://doi.org/10.1640/0002-8444-111.3.214
(no abstract available)