Science Enabled by Specimen Data

Dantas, V. L., L. C. S. Oliveira, C. R. Marcati, and J. Sonsin‐Oliveira. 2024. Coordination of bark and wood traits underlies forest‐to‐savanna evolutionary transitions. Journal of Biogeography. https://doi.org/10.1111/jbi.14850

Aim To test the hypothesis that adaptive shifts leading to the assembly of tropical savannas involved coordination between bark and wood traits and to understand the underlying mechanisms.LocationTropical South America.TaxonAngiosperms (woody).MethodsWe compiled data on three bark traits (total, inner and outer relative bark thickness), wood density, maximum height, five secondary xylem traits and on species' habitat information (light environment, climate, soil and fire history) for Neotropical savanna, forest and generalist species (biome groups). We tested for pairwise and multivariate associations among traits across species and if biome group and habitat conditions explained species positions along the resulting strategy axes.ResultsTraits covaried along four different axes. The first axis was consistent with a trade‐off between fire (thick barks) and shade tolerance (low bark to diameter ratio, high vessel density) and contributed to differentiate the three biome groups according to the preference for shaded environments. Forest species also differed from savanna and generalist species in a separate axis by being more resource acquisitive. Maximum height and wood density did not strongly trade‐off with bark thickness, although maximum height was negatively covaried with relative outer bark thickness. Preference for shaded conditions was the main driver of variation in the two principal strategy axes, but temperature, fire and soil sand content also explained differences in plant stature between savanna and generalist species.Main ConclusionsAllocation to bark is constrained by trade‐offs with wood, opposing shade‐tolerant and acquisitive forest species to fire‐resistant and conservative savanna species. Rather than a single strategy axis, three axes are necessary to understand the functional differences among savanna, forest and generalist species. Because two of these axes are controlled by light availability, the associated traits tend to covary in space and time, but not across species.

Serra‐Diaz, J. M., J. Borderieux, B. Maitner, C. C. F. Boonman, D. Park, W. Guo, A. Callebaut, et al. 2024. occTest: An integrated approach for quality control of species occurrence data. Global Ecology and Biogeography. https://doi.org/10.1111/geb.13847

Aim Species occurrence data are valuable information that enables one to estimate geographical distributions, characterize niches and their evolution, and guide spatial conservation planning. Rapid increases in species occurrence data stem from increasing digitization and aggregation efforts, and citizen science initiatives. However, persistent quality issues in occurrence data can impact the accuracy of scientific findings, underscoring the importance of filtering erroneous occurrence records in biodiversity analyses.InnovationWe introduce an R package, occTest, that synthesizes a growing open‐source ecosystem of biodiversity cleaning workflows to prepare occurrence data for different modelling applications. It offers a structured set of algorithms to identify potential problems with species occurrence records by employing a hierarchical organization of multiple tests. The workflow has a hierarchical structure organized in testPhases (i.e. cleaning vs. testing) that encompass different testBlocks grouping different testTypes (e.g. environmental outlier detection), which may use different testMethods (e.g. Rosner test, jacknife,etc.). Four different testBlocks characterize potential problems in geographic, environmental, human influence and temporal dimensions. Filtering and plotting functions are incorporated to facilitate the interpretation of tests. We provide examples with different data sources, with default and user‐defined parameters. Compared to other available tools and workflows, occTest offers a comprehensive suite of integrated tests, and allows multiple methods associated with each test to explore consensus among data cleaning methods. It uniquely incorporates both coordinate accuracy analysis and environmental analysis of occurrence records. Furthermore, it provides a hierarchical structure to incorporate future tests yet to be developed.Main conclusionsoccTest will help users understand the quality and quantity of data available before the start of data analysis, while also enabling users to filter data using either predefined rules or custom‐built rules. As a result, occTest can better assess each record's appropriateness for its intended application.

Ferreira, G. E., J. L. Clark, L. Clavijo, A. Zuluaga, A. Chautems, M. J. G. Hopkins, A. O. Araujo, and M. Perret. 2024. Phylogenetics, character evolution, and historical biogeography of the Neotropical genus Besleria (Gesneriaceae). Botanical Journal of the Linnean Society. https://doi.org/10.1093/botlinnean/boae007

Besleria, a genus of perennial herbs, shrubs, or small trees growing in the understorey of rainforests, is one of the largest genera of neotropical Gesneriaceae, with over 165 species. Despite the ecological importance and ubiquity of Besleria in rainforest ecosystems, taxonomic and evolutionary studies of Besleria are limited. Here, we generated a phylogenetic analysis of Besleria using four nuclear and chloroplast DNA regions (ITS, matK, rps16, and trnL-trnF) covering more than 50% of the recognized species, along with two secondary calibration points to infer divergence times. Our results support the monophyly of Besleria and allowed us to revise the infrageneric classification and biogeographical history of the genus. We identified five major clades that do not correspond to sections or subsections in previous classifications. These clades are well circumscribed geographically but remain difficult to characterize using previously hypothesized morphological characters. Biogeographical reconstructions indicate an origin in the northern Andes during the Middle Miocene (ca. 15 Mya). The current distribution patterns of this plant group have been significantly shaped by geological and climatic events, particularly Andean uplift and the formation of the Panama Isthmus.

Ramírez-Barahona, S. 2024. Incorporating fossils into the joint inference of phylogeny and biogeography of the tree fern order Cyatheales R. Warnock, and M. Zelditch [eds.],. Evolution. https://doi.org/10.1093/evolut/qpae034

Present-day geographic and phylogenetic patterns often reflect the geological and climatic history of the planet. Neontological distribution data are often sufficient to unravel a lineage’s biogeographic history, yet ancestral range inferences can be at odds with fossil evidence. Here, I use the fossilized birth–death process and the dispersal–extinction cladogenesis model to jointly infer the dated phylogeny and range evolution of the tree fern order Cyatheales. I use data for 101 fossil and 442 extant tree ferns to reconstruct the biogeographic history of the group over the last 220 million years. Fossil-aware reconstructions evince a prolonged occupancy of Laurasia over the Triassic–Cretaceous by Cyathealean tree ferns, which is evident in the fossil record but hidden from analyses relying on neontological data alone. Nonetheless, fossil-aware reconstructions are affected by uncertainty in fossils’ phylogenetic placement, taphonomic biases, and specimen sampling and are sensitive to interpretation of paleodistributions and how these are scored. The present results highlight the need and challenges of incorporating fossils into joint inferences of phylogeny and biogeography to improve the reliability of ancestral geographic range estimation.

Ramos, R. S., G. M. Via do Pico, M. Brea, and D. M. Kröhling. 2024. New fossil woods (upper Pleistocene) from the lower-middle Uruguay river basin (South America) reveal the past distribution of Aspidosperma (Apocynaceae). Quaternary International. https://doi.org/10.1016/j.quaint.2024.03.004

The present work describes the taxonomic and paleobiogeographic study of two fossil woods related to extant Aspidosperma. The silicified specimens come from the fossil localities of Santa Ana (30°54′S, 57°55′W) and Concordia (31°19′S, 57°59′W), Entre Ríos Province, Argentina, belonging to the El Palmar Formation (Late Pleistocene). This unit represents the sedimentary body of the upper fluvial terrace generated by the Uruguay River in its middle basin in eastern Argentina. The anatomical features that distinguish the woods are growth rings delimited by axial parenchyma and fibers, semi-ring to-diffuse-porous woods; mainly solitary vessels; simple perforation plates; alternate, bordered, and vestured intervessel pits; scarce paratracheal and diffuse apotracheal axial parenchyma; homocellular, and uniseriate to-triseriate rays; non-septate fibers. Climate reconstruction modelled at the regional scale (Ecological Niche Modeling) revealed variations in macroecological diversity patterns of the nearest living relatives (Aspidosperma australe and A. polyneuron) over the last ca. 130,000 years. Optically stimulated luminescence dating of sediments from the upper part of the El Palmar Formation in the type area reveals that the unit spans from the Last Interglacial period (warm substage, MIS marine isotope stage 5a), to the penultimate interglacial (MIS 7). This period was characterized by warmer and wetter conditions than those observed today. The eco-anatomical characteristics of the fossil record reflect this type of environment. The modern analogues of the fossils studied here are now part of the forests that integrate the Atlantic forest and Araucaria forest biogeographic provinces in South America.

Anest, A., Y. Bouchenak-Khelladi, T. Charles-Dominique, F. Forest, Y. Caraglio, G. P. Hempson, O. Maurin, and K. W. Tomlinson. 2024. Blocking then stinging as a case of two-step evolution of defensive cage architectures in herbivore-driven ecosystems. Nature Plants. https://doi.org/10.1038/s41477-024-01649-4

Dense branching and spines are common features of plant species in ecosystems with high mammalian herbivory pressure. While dense branching and spines can inhibit herbivory independently, when combined, they form a powerful defensive cage architecture. However, how cage architecture evolved under mammalian pressure has remained unexplored. Here we show how dense branching and spines emerged during the age of mammalian radiation in the Combretaceae family and diversified in herbivore-driven ecosystems in the tropics. Phylogenetic comparative methods revealed that modern plant architectural strategies defending against large mammals evolved via a stepwise process. First, dense branching emerged under intermediate herbivory pressure, followed by the acquisition of spines that supported higher speciation rates under high herbivory pressure. Our study highlights the adaptive value of dense branching as part of a herbivore defence strategy and identifies large mammal herbivory as a major selective force shaping the whole plant architecture of woody plants. This study explores the evolution of two traits, branching density and spine presence, in the globally distributed plant family Combretaceae. These traits were found to have appeared in a two-step process in response to mammalian herbivory pressure, revealing the importance of large mammals in the evolution of plant architecture diversity.

Prochazka, L. S., S. Alcantara, J. G. Rando, T. Vasconcelos, R. C. Pizzardo, and A. Nogueira. 2024. Resource availability and disturbance frequency shape evolution of plant life forms in Neotropical habitats. New Phytologist. https://doi.org/10.1111/nph.19601

Organisms use diverse strategies to thrive in varying habitats. While life history theory partly explains these relationships, the combined impact of resource availability and disturbance frequency on life form strategy evolution has received limited attention.We use Chamaecrista species, a legume plant lineage with a high diversity of plant life forms in the Neotropics, and employ ecological niche modeling and comparative phylogenetic methods to examine the correlated evolution of plant life forms and environmental niches.Chamaephytes and phanerophytes have optima in environments characterized by moderate water and nutrient availability coupled with infrequent fire disturbances. By contrast, annual plants thrive in environments with scarce water and nutrients, alongside frequent fire disturbances. Similarly, geophyte species also show increased resistance to frequent fire disturbances, although they thrive in resource‐rich environments.Our findings shed light on the evolution of plant strategies along environmental gradients, highlighting that annuals and geophytes respond differently to high incidences of fire disturbances, with one enduring it as seeds in a resource‐limited habitat and the other relying on reserves and root resprouting systems in resource‐abundant habitats. Furthermore, it deepens our understanding of how organisms evolve associated with their habitats, emphasizing a constraint posed by low‐resource and high‐disturbance environments.

Minghetti, E., P. M. Dellapé, M. Maestro, and S. I. Montemayor. 2024. Evaluating the climatic suitability of Engytatus passionarius Minghetti et al. (Heteroptera, Miridae) as a biological control agent of the invasive stinking passion flower Passiflora foetida L. in Australia through ecological niche models. Biological Control 191: 105461. https://doi.org/10.1016/j.biocontrol.2024.105461

Passiflora foetida is a climbing vine, native to the Neotropical Region that is causing major economic and ecological damage in Australia, where it is rapidly spreading. Traditional control options, such as cutting, manual uprooting, and herbicide applications are only effective for local management. Currently, the plant bug Engytatus passionarius is the most promising biological control agent. Specificity tests performed in its native range in Argentina suggest it is highly specific to the plant, and it has not been observed in the field associated with other plants. As climate determines the establishment of insects, knowing if the environmental conditions suit their requirements is key to introducing a species in a region. Also, an overlap between the climatic niches of species is an indicator of similar requirements. To explore the possibilities of a successful establishment of E. passionarius in Australia, ecological niche models (ENM) were built for the plant bug and for the vine and their overlap was measured. The ENM projected to Australia recognized suitable environmental conditions for the establishment of E. passionarius in several regions where P. foetida is present, both for current and future scenarios. Moreover, the niche of the plant bug is almost completely overlapped with that of the vine. All the aforementioned evidence seems to indicate that E. passionarius has a good chance to become an effective biological control agent of P. foetida.

Roberts, J., K. Dhileepan, and S. Florentine. 2024. A review of the biology, distribution, and management challenges posed by the invasive weed Ziziphus mauritianaL., with special reference to its invasion in Australia. Weed Research. https://doi.org/10.1111/wre.12610

Ziziphus mauritiana is an economically detrimental and environmentally destructive plant in non‐native areas where it has escaped cultivation. It forms dense, impenetrable thickets that restrict the movement of livestock across the landscape and has the capacity to alter various ecological functions at the site of invasion, all of which contribute towards land degradation and the reduction of economic profitability. Although there are several management strategies implemented to control Z. mauritiana, it is clear that no single‐method approach will effectively control the species in the long‐term. Whilst chemical and mechanical methods appear to show promising results, they tend to be restricted to areas that are easily accessible and, even so, can be challenging and laborious to treat evenly across dense thicket areas. Several prospective biological control agents have been identified for Z. mauritiana, although further investigations are required to ascertain the host specificity, and to explore and identify their climatic and environmental suitability of host specific agents for release in non‐native regions. Ecological burning alone is not effective in controlling Z. mauritiana and will likely increase its emergence. As such, it could be adopted as part of an integrated management approach to assist other methods for long‐term control, but again the development of such an approach requires further investigation. To contribute towards the control of Z. mauritiana, this review explores its biology, distribution and management challenges whilst identifying areas of research that will assist in the long‐term and confident control of the species, with an emphasis on its invasion in Australia.

Kolanowska, M. 2023. Future distribution of the epiphytic leafless orchid (Dendrophylax lindenii), its pollinators and phorophytes evaluated using niche modelling and three different climate change projections. Scientific Reports 13. https://doi.org/10.1038/s41598-023-42573-5

The identification of future refugia for endangered species from the effects of global warming is crucial for improving their conservation. Because climate-driven shifts in ranges and local extinctions can result in a spatial mismatch with their symbiotic organisms, however, it is important to incorporate in niche modelling the ecological partners of the species studied. The aim of this study was to evaluate the effect of climate change on the distribution of suitable niches for the ghost orchid ( Dendrophylax lindenii ) and its phorophytes and pollinators. Thus, its five species of host trees and three pollen vectors were included in the analysis. Climatic preferences of all the species studied were evaluated. The modelling was based on three different climate change projections and four Shared Socio-economic Pathway trajectories. All the species analysed are characterized by narrow temperature tolerances, which with global warming are likely to result in local extinctions and range shifts. D. lindenii is likely to be subjected to a significant loss of suitable niches, but within a reduced geographical range, both host trees and pollen vectors will be available in the future. Future conservation of this orchid should focus on areas that are likely be suitable for it and its ecological partners.