DOI: 10.5091/plecevo.164557

Authors: Cynthia Hong-Wa, Guillaume Besnard

Abstract: Background and aims – Madagascar’s rich flora originated mostly from in situ diversification, and the large-scale plant species richness pattern is mainly explained by spatial heterogeneity. However, mechanisms underlying plant community assembly remain largely unexplored. We aimed to understand the coexistence of a species swarm in the Malagasy olive (Noronhia, Oleaceae) on the northern massif of Montagne d’Ambre and to gain insights into the factors influencing community assembly. Material and methods – We used 13 environmental and 17 trait variables sampled across 24 plots and 13 species on the mountain, respectively. We determined likely trait-environment relationships across space using the multivariate RLQ analysis, the bivariate fourth-corner method, and their combination. We also checked for phylogenetic signal (Blomberg’s K and Moran’s I) among traits and assessed the phylogenetic community structure (SES.MPD and SES.MNTD) using nested spatial and phylogenetic scales. Key results – Significant trait-environment relationships were recovered with the multivariate and the combined multi–bivariate analyses at a large spatial scale, whereas patterns at small spatial scales were unclear. Distinct assemblages at lower and higher elevations were identified and appeared to be influenced by bioclimate and soil gradients. Strong phylogenetic signals were detected in seven traits across spatial scales, regardless of phylogenetic scales. The communities exhibited an overall pattern of phylogenetic clustering with a large phylogenetic scale, while a hint of overdispersion emerged in the low-elevation assemblage with a small phylogenetic scale. Conclusion – Multiple mechanisms may influence the coexistence of the Noronhia swarm on Montagne d’Ambre, with environmental filtering and niche partitioning seemingly acting on vegetative and reproductive functions, respectively. More focus on reproductive biology will provide further insights into the assembly of Malagasy plant communities. This study also highlights the conservation values of Montagne d’Ambre as a unique ecosystem supporting the flora, fauna, and human populations of the northernmost region of Madagascar.

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DOI: 10.5091/plecevo.172513

Authors: Luiz Henrique M. Fonseca, Ricardo da Silva Ribeiro

Abstract: Background and aims – During ongoing morphological studies of Adenocalymma, we realized that nomenclatural updates are necessary in the genus. Here, we propose a new circumscription of A. acutissimum and the description of the new species A. darwinii. Material and methods – Morphological and phylogenetic evidence support the new circumscription of A. acutissimum, while the new species is recognized based on morphological grounds and compared to A hirtum and A. salmoneum. Key results – We removed the taxa A. comosum, A. comosum var. lanceolatum, and A. nitidum as synonyms of A. acutissimum. We also presented a detailed description for A. darwinii sp. nov., an illustration, and information on its distribution, habitat, phenology, and extinction risk. A map showing the occurrence of both A. comosum and A. darwinii sp. nov. is shown. Conclusion – These results emphasize once again the importance of taxonomic studies in the Brazilian Atlantic Forest and highlight conservation concerns for its flora.

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DOI: 10.5091/plecevo.157560

Authors: Santiago A. García, María J. Nores, Fernando de Diego, Hernán G. Bach, Patricia A. Peralta, Federico O. Robbiati

Abstract: Background and aims – Climate change is driving biodiversity loss globally, including species with medicinal and aromatic properties. In this study, we assessed the potential distributions of three plants, Lippia alba, L. turbinata, and Salimenaea integrifolia, widely consumed in South America. In this study, we aimed i) to predict their current geographic distribution through SDM, ii) to estimate the importance of abiotic factors in their distribution, iii) to evaluate the potential change in future distribution under different scenarios of climate change. Material and methods – Using MaxEnt, we modelled the current and future potential distributions of these three species under three Representative Concentration Pathways (RCPs 2.6, 4.5, and 8.5) for the period 2070 (2061–2080). Key results – The distribution of L. alba is primarily influenced by precipitation seasonality and mean annual temperature, whereas L. turbinata and S. integrifolia are shaped by mean annual temperature and annual precipitation. The most favourable areas for L. alba are found in the Chacoan, Espinal, Pampean, Paranaense, Caatinga, Atlantic, and Amazonian biogeographic provinces (2,250,640 km2). Lippia turbinata thrives in the Chacoan, Espinal, Monte, Pampean, and Yungas provinces (671,851 km2), while S. integrifolia is best suited to the Monte, Chacoan, and Puna/Prepuna provinces (197,022 km2). Our results indicate heterogeneous responses to climate change in the future: L. turbinata and S. integrifolia may experience range expansion (15.12 to 19.86% and 1.48 to 3.46%, respectively), while L. alba is projected to face range contraction (-4.60 to -23.23%), particularly in the northern edge of its distribution. Conclusion – These findings emphasize the species-specific responses of medicinal and aromatic plants to climate change. Moreover, they highlight the need to develop tailored conservation strategies to safeguard vulnerable populations and preserve valuable medicinal resources.

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DOI: 10.5091/plecevo.161641

Authors: Ivan Pančo, Paul Temple, Geovanys Rodríguez Cobas, Noel Coutin Lobaina, Ivana Matisova, Yoannis Domínguez

Abstract: Background and aims – Pinguicula is a cosmopolitan genus of carnivorous plants with more than 100 species, most of them distributed in two centres of diversity: Europe and the Central American-Caribbean region. Fourteen species are reported for Cuba. During fieldwork to study Pinguicula populations in eastern Cuba, a white-flowered taxon, previously misidentified as Pinguicula albida or Pinguicula jaraguana, was collected in the mountainous regions of the Alejandro de Humboldt National Park. This taxon represents a new species for which we present a full description, a distribution map, illustrations, photographs, and a conservation status. Material and methods – Living and preserved material of several populations of white-flowered Pinguicula from Cuba were analysed, measured, and described based on vegetative and reproductive characters. Statistical analyses were carried out to explore the differences among the collections. The preliminary conservation status of the new species was assessed based on the IUCN guidelines and criteria. Key results – Pinguicula panfetiae is described as a new species endemic to eastern Cuba. It thrives on permanently wet, ferritic soils derived from serpentine bedrocks, on slopes above the banks of the River Toa in association with surrounding semi-arid montane serpentine shrubwood (charrascal). It differs from the closely related species, Pinguicula albida and Pinguicula jaraguana, primarily by its smaller rosettes with obovate, suberect to erect leaves, non-involute leaf margins, smaller flowers up to 1–1.3 cm including the spur, longer (0.6–0.7 mm) and wider (0.18–0.22 mm) seeds, and that it grows in full sun. Conclusion – The newly described species increases the number of Pinguicula in the Cuban archipelago to 15. Pinguicula panfetiae is preliminarily assessed as Critically Endangered (CR) according to the IUCN Red List Categories and Criteria.

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DOI: 10.5091/plecevo.90511

Authors: Taynara Rabelo-Costa, Paulo Weslem Portal Gomes, Brenda Oliveira Rocha, Iury Leite Cruz, Ravena Santiago Alves, Tiê Rocha de Sousa Oliveira, José Luís Passos Cordeiro, Moabe Ferreira Fernandes, Eimear Nic Lughadha, Marcelo Freire Moro

Abstract: Background and aims – Climatic fluctuations during the Pleistocene altered the distribution of many species and even entire biomes, allowing some species to increase their range while others underwent reductions. Recent and ongoing anthropogenic climate change is altering climatic patterns very rapidly and is likely to impact species’ distributions over shorter timescales than previous natural fluctuations. Therefore, we aimed to understand how Pleistocene and Holocene climatic fluctuations might have shaped the current distribution of Holoregmia and explore its expected distribution under future climate scenarios. Material and methods – We modelled the potential distribution of Holoregmia viscida (Martyniaceae), a monospecific plant genus endemic to the semi-arid Caatinga Domain in Brazil. We used an ensemble approach to model suitable areas for Holoregmia under present conditions, Paleoclimatic scenarios, and global warming scenarios in 2050 and 2090. Key results – Holocene climates in most Caatinga were too humid for Holoregmia, which restricted its suitable areas to the southern Caatinga, similar to its current distribution. However, under global warming scenarios, the Caatinga is expected to become too dry for this lineage, resulting in a steady decline in the area suitable for Holoregmia and even its possible extinction under the most pessimistic scenario modelled. Conclusion – The predicted extinction of the ancient and highly specialized Holoregmia viscida highlights the possible consequences of climate change for some species of endemic Caatinga flora. Invaluable phylogenetic diversity may be lost in the coming decades, representing millions of years of unique evolutionary history and consequent loss of evolutionary potential to adapt to future environmental changes in semi-arid environments.

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DOI: 10.5091/plecevo.89394

Authors: Salvatora Nsenga Nkulu, Pierre Meerts, Edouard Ilunga wa Ilunga, Mylor Ngoy Shutcha, David Bauman

Abstract: Background and aims – Sustainable management of the medicinal plant resources provided by tropical forests is of utmost importance to human populations in developing countries. Trees and shrubs of the genus Vitex (Lamiaceae) are of great medicinal importance in Haut-Katanga (SE D.R. Congo), frequently used to treat tropical diseases. However, the security of supply is threatened, particularly by urban sprawl and mining. A conservation strategy for medicinal plants is urgently needed. In this context, we try to better understand the ecological factors (mostly soil) explaining the distribution of three medicinal species of Vitex (Lamiaceae) (V. fischeri, V. madiensis, and V. mombassae) that co-occur in the tropical dry woodlands in the region of Lubumbashi. Material and methods – In 114 plots (10 m radius), comprising at least one species of Vitex, all woody species with a DBH ≥ 10 cm were inventoried and soil samples were collected. Multivariate Regression Trees (MRT) combined with indicator species index IndVal and Redundancy analysis (RDA) were used to characterise habitats and woody plant communities associated to each Vitex species and to explain the variability of plant community composition. Key results – Four habitats were identified, and the three Vitex species differ significantly in ecological range. Vitex fischeri is a specialist of a most distinctive community on high Mg and low Al soil (termite mounds). Vitex mombassae is indicative of one habitat, corresponding to low altitude (< 1230 m) plots. Vitex madiensis has a broader range, being a generalist of all habitats except termite mounds. Conclusion – These results emphasise the importance of a detailed knowledge of species ecology to design species-specific conservation strategies, even for congeneric species occurring in sympatry in the same landscape.

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