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Climate change is being intensified by anthropogenic emission of greenhouse gasses, highlighting the value of forests for carbon dioxide storing carbon in their biomass. Seasonally dry tropical forests are a neglected, threatened, but potentially critical biome for helping mitigate climate change. In South America, knowing the amount and distribution of carbon in Caatinga seasonally dry vegetation is essential to understand its contribution to the global carbon cycle and subsequently design a strategic plan for its conservation. The present study aimed to model and map the spatial distribution of the potential forest biomass stock across 32 forest fragments of Caatinga, in the state of Bahia, Brazil, using regression kriging and Inverse Square of Distance techniques, building from point measurements of vegetation biomass made on-the-ground in ecological plots. First, a model for estimating biomass was fitted as a function of environmental variables to apply regression kriging, and then applied to the maps of the selected components. Elevation, temperature, and precipitation explained 46% of the biomass variations in the Caatinga. The model residuals showed strong spatial dependence and were mapped based on geostatistical criteria, selecting the spherical semivariogram model for interpolation by ordinary kriging. Biomass was also mapped by the Inverse Square of Distance approach. The quality of the regression model suggests that there is good potential for estimating biomass here from environmental variables. The regression kriging showed greater detail in the spatial distribution and revealed a spatial trend of increasing biomass from the north to south of the domain. Additional studies with greater sampling intensity and the use of other explanatory variables are suggested to improve the model, as well as to maximize the technique’s ability to capture the actual biomass behavior in this newly studied seasonally dry ecosystem.

Premise: Data on plant distribution and diversity from natural history collections and taxonomic databases are increasingly becoming available online as exemplified by the Royal Botanic Gardens, Kew's Plants of the World Online (POWO) database. This growing accumulation of biodiversity information requires an advance in bioinformatic tools for accessing and processing the massive data for use in downstream science. We present herein expowo, an open-source package that facilitates extracting and using botanical data from POWO., Methods and Results: The expowo package is implemented in R and designed to handle the entire vascular plant tree of life. It includes functions to readily distill taxonomic and distributional information about all families, genera, or species of vascular plants. It outputs a complete list of species in each genus of any plant family, with the associated original publication, synonyms, and distribution, and plots global maps of species richness at the country and botanical country levels, as well as graphs displaying species-discovery accumulation curves and nomenclatural changes over time. To demonstrate expowo's strengths in producing easy-to-handle outputs, we also show empirical examples from a set of biodiverse countries and representative species-rich and ecologically important angiosperm families., Conclusions: By harnessing bioinformatic tools that accommodate varying levels of R programming proficiency, expowo functions assist users who have limited R programming expertise in efficiently distilling specific botanical information from online sources and producing maps and graphics for the further interpretation of biogeographic and taxonomic patterns., (© 2024 The Author(s). Applications in Plant Sciences published by Wiley Periodicals LLC on behalf of Botanical Society of America.)

Background and Aims: Geoxyles, a distinctive feature of Afrotropical savannas and grasslands, survive recurrent disturbances by resprouting subshrub branches from large below-ground woody structures. Underground trees are a type of geoxyle that independently evolved within woody genera of at least 40 plant families in Africa. The environmental limits and determinants of underground tree biogeography are poorly understood, with the relative influence of frost and fire debated in particular. We aim to quantify variability in the niche of underground tree species relative to their taller, woody tree/shrub congeners., Methods: Using occurrence records of four Afrotropical genera, Parinari (Chrysobalanaceae), Ozoroa (Anacardiaceae), Syzygium (Myrtaceae) and Lannea (Anacardiaceae), and environmental data of nine climate and disturbance variables, the biogeography and niche of underground trees are compared with their open and closed ecosystem congeners., Key Results: Along multiple environmental gradients and in a multidimensional environmental space, underground trees inhabit significantly distinct and extreme environments relative to open and closed ecosystem congeners. Niche overlap is low among underground trees and their congeners, and also among underground trees of the four genera. Of the study taxa, Parinari underground trees inhabit hotter, drier and more seasonal environments where herbivory pressure is greatest. Ozoroa underground trees occupy relatively more fire-prone environments, while Syzygium underground trees sustain the highest frost frequency and occur in relatively wetter conditions with seasonal waterlogging. Lannea underground trees are associated with the lowest temperatures, highest precipitation, and varying exposure to disturbance., Conclusions: While underground trees exhibit repeated convergent evolution, varied environments shape the ecology and biogeography of this iconic plant functional group. The multiplicity of extreme environments related to fire, frost, herbivory and waterlogging that different underground tree taxa occupy, and the distinctiveness of these environments, should be recognized in the management of African grassy ecosystems., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Annals of Botany Company.)

In 2004, David Frodin published a landmark review of the history and concepts of big plant genera. Two decades of taxonomic activity have taken place since, coinciding with a revolution in phylogenetics and taxonomic bioinformatics. Here we use data from the World Flora Online (WFO) to provide an updated list of big (more than 500 species) and megadiverse (more than 1000 species) flowering plant genera and highlight changes since 2004. The number of big genera has increased from 57 to 86; today one of every four plant species is classified as a member of a big genus, with 14% in just 28 megadiverse genera. Most (71%) of the growth in big genera since 2000 is the result of new species description, not generic re-circumscription. More than 15% of all currently accepted flowering plant species described in the last two decades are in big genera, suggesting that groups previously considered intractable are now being actively studied taxonomically. Despite this rapid growth in big genera, they remain a significant yet understudied proportion of plant diversity. They represent a significant proportion of global plant diversity and should remain a priority not only for taxonomy but for understanding global diversity patterns and plant evolution in general.

Keraunea is an enigmatic genus of lianescent shrubs endemic to Brazil and found within the Caatinga and Mata Atlântica phytogeographic regions. When first published, Keraunea was included in the Convolvulaceae and there has been considerable recent disagreement about its true family placement on the Angiosperm tree of life. Based on further assessment of morphology and a new comprehensively-sampled combined phylogenetic analysis of nuclear and plastid genes from recently published DNA sequence data, we settle the position of the genus within the Ehretiaceae as sister to the Australian genus Halgania Gaudich. and provide an expanded family description. We recognize five species within Keraunea , three of them newly described here: K.brasiliensis Cheek & Simão-Bianchini, K.bullata Moonlight & D.B.O.S.Cardoso, sp. nov. , K.capixaba Lombardi, K.confusa Moonlight & D.B.O.S.Cardoso, sp. nov. and K.velutina Moonlight & D.B.O.S.Cardoso, sp. nov. We also provide a full taxonomic revision of the genus, including a key, descriptions, map of geographical distribution and provisional IUCN threat assessments for all species., (Peter W. Moonlight, Domingos Benício Oliveira Silva Cardoso.)

There is high potential for ecosystem restoration across tropical savannah-dominated regions, but the benefits that could be gained from this restoration are rarely assessed. This study focuses on the Brazilian Cerrado, a highly species-rich savannah-dominated region, as an exemplar to review potential restoration benefits using three metrics: net biomass gains, plant species richness and ability to connect restored and native vegetation. Localized estimates of the most appropriate restoration vegetation type (grassland, savannah, woodland/forest) for pasturelands are produced. Carbon sequestration potential is significant for savannah and woodland/forest restoration in the seasonally dry tropics (net biomass gains of 58.2 ± 37.7 and 130.0 ± 69.4 Mg ha -1 ). Modelled restoration species richness gains were highest in the central and south-east of the Cerrado for savannahs and grasslands, and in the west and north-west for woodlands/forests. The potential to initiate restoration projects across the whole of the Cerrado is high and four hotspot areas are identified. We demonstrate that landscape restoration across all vegetation types within heterogeneous tropical savannah-dominated regions can maximize biodiversity and carbon gains. However, conservation of existing vegetation is essential to minimizing the cost and improving the chances of restoration success. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.

Traditional models for tropical species richness contrast rainforests as "museums" of old species or "cradles" of recent speciation. High plant species diversity in rainforests may be more likely to reflect high episodic evolutionary turnover of species--a scenario implicating high rates of both speciation and extinction through geological time.