Latest Articles from Plant Ecology and Evolution Latest 10 Articles from Plant Ecology and Evolution https://plecevo.eu/ Thu, 28 Mar 2024 15:05:15 +0200 Pensoft FeedCreator https://plecevo.eu/i/logo.jpg Latest Articles from Plant Ecology and Evolution https://plecevo.eu/ Dispersal and persistence of cup plant seeds (Silphium perfoliatum): do they contribute to potential invasiveness? https://plecevo.eu/article/104640/ Plant Ecology and Evolution 157(1): 75-87

DOI: 10.5091/plecevo.104640

Authors: L. Marie Ende, Lukas Hummel, Marianne Lauerer

Abstract: Background and aims – The cup plant (Silphium perfoliatum) is being grown in Germany as a promising new bioenergy crop with an increasing area under cultivation in the last years. Its alien status, its high productivity, and high reproductive potential could carry the risk of this species becoming invasive. The present study investigates the dispersal and persistence of cup plant seeds, to contribute to the assessment of its invasive potential. Material and methods – For this purpose, four experimental studies were conducted in Germany, Central Europe: wind dispersal distance was measured in a field experiment for wind speeds up to 7 m.s-1. The seeds were offered to rodents in different habitats near to a cup plant field. We observed seed persistence and germination over 4 weeks storing in water and over 4 years storing in different soil depths. Key results – Cup plant seeds are dispersed by wind only over a few meters. In the forest, rodents removed 100% of the offered seeds, in open habitats none. Independent of the duration of storage in water, germination rate of the cup plant seeds was constantly high. Most of the seeds already germinated in water in the first two weeks. Stored on the soil surface and at 10 cm soil depth, the seeds germinated already in the first two years. Stored at 30 cm depth, one third of the seeds retained their germination ability over four years. Conclusion – Wind serves as short-distance dispersal vector for cup plant seeds. Rodents remove the seeds, but it is unknown whether they disperse them or just eat them. Water could disperse the seeds, which retain their germination ability, over long distances. The cup plant could therefore spread and possibly become invasive in Central Europe, and therefore measures are suggested to prevent its dispersal and spontaneous settlement.

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Research Article Wed, 14 Feb 2024 09:30:00 +0200
Floristic and structural distinctness of monodominant Gilbertiodendron dewevrei forest in the western Congo Basin https://plecevo.eu/article/111539/ Plant Ecology and Evolution 157(1): 55-74

DOI: 10.5091/plecevo.111539

Authors: Ellen Heimpel, Antje Ahrends, Kyle G. Dexter, Jefferson S. Hall, Josérald Mamboueni, Vincent P. Medjibe, David Morgan, Crickette Sanz, David J. Harris

Abstract: Background and aims – The forests of the Congo Basin contain high levels of biodiversity, and are globally important for carbon storage. In order to design effective conservation strategies, and to accurately model carbon stocks, a fine-scale understanding of the different forest types that make up this forest block is needed. Monodominant Gilbertiodendron dewevrei forest covers large areas of the Congo Basin, but it is currently unclear whether it is sufficiently distinct from adjacent mixed terre firme forest to warrant separate treatment for conservation planning and carbon calculations. This study aimed to compare the structure and diversity of monodominant and mixed forest, and ask whether there is a unique vascular plant community associated with G. dewevrei forest. Material and methods – We utilised a combination of plot data and herbarium specimens collected in the Sangha Trinational (a network of protect areas in Cameroon, Central African Republic, and the Republic of Congo). Plot inventories were used to compare G. dewevrei forest and mixed forest for stem density, basal area, above ground biomass, stem size distribution, species diversity, and species composition. In addition, a database of 3,557 herbarium specimens was used to identify species of vascular plant that are associated with G. dewevrei forest. Key results – Gilbertiodendron dewevrei forest is distinct in both structure and species composition from mixed forest. Gilbertiodendron dewevrei forest has a lower stem number (of trees ≥ 10 cm), but a greater proportion of larger trees (> 70 cm), suggesting higher carbon stocks. The species composition is distinct from mixed forest, with 56 species of vascular plant significantly associated with G. dewevrei forest. Conclusion – Monodominant G. dewevrei forest in the Sangha Trinational is both compositionally and structurally distinct from mixed forest. We therefore recommend this forest type be considered separately from mixed forest for conservation planning and carbon stock calculations.

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Research Article Wed, 7 Feb 2024 09:55:00 +0200
Diversity and distribution of ferns and clubmosses in the eastern canyons of Isalo National Park, Madagascar https://plecevo.eu/article/101827/ Plant Ecology and Evolution 157(1): 3-19

DOI: 10.5091/plecevo.101827

Authors: Rivoharifara Randrianarimanana, France Rakotondrainibe, Elodie Boucheron-Dubuisson, Lovanomenjanahary Marline, Mijoro Rakotoarinivo, Catherine Reeb

Abstract: Background and aims – In contrast to the flowering plants, the pteridophyte flora of Madagascar is still understudied. While several studies have been published on the eastern and central parts of the island, there are currently few works dedicated to the pteridophytes of southwestern Madagascar. The aim of this work is to increase the knowledge of the pteridophyte flora of the Isalo massif in southwestern Madagascar. It presents a checklist of Isalo’s pteridophytes and an analysis of the diversity and distribution patterns of pteridophyte communities across ecological gradients in the eastern canyons of Isalo. Material and methods – Eighty plots were placed in six canyons. In each plot, pteridophyte species abundance was inventoried, as well as several ecological and geomorphological variables. A census in the field and observations on specimens in herbaria were carried to make a checklist of all the pteridophyte species known for Isalo. Statistical analysis was carried out to understand the pteridophyte diversity and distribution patterns in the Isalo’s canyons: (1) exploratory analysis (FAMD and HCPC) highlights the general patterns of ecological gradients, (2) a rarefaction curve was used to compare species diversity, and (3) co-inertia analysis investigated the relationship between ecological gradient and pteridophyte communities. Key results – In total, 60 species of ferns and lycophytes have been recorded in the massif, including ten endemic species to Madagascar and 11 species reported for the first time in the Isalo massif. Species diversity is especially high in the northern canyons (Anjofo, Andramanero, Antsifotra) in contrast to the middle (Maki and Rats) and southern (Namaza) canyons. Fern distribution patterns were correlated to a combination of environmental factors, highlighting species-specific ecological preferences.

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Research Article Wed, 10 Jan 2024 10:29:00 +0200
Leaf traits of understory woody species in the Congo Basin forests changed over a 60-year period https://plecevo.eu/article/104593/ Plant Ecology and Evolution 156(3): 339-351

DOI: 10.5091/plecevo.104593

Authors: Yves Hatangi, Hippolyte Nshimba, Piet Stoffelen, Benoît Dhed’a, Jonas Depecker, Ludivine Lassois, Filip Vandelook

Abstract: Background and aims – While tropical forests play an important role in carbon sequestration, they are assumed to be sensitive to rising temperatures and prolonged drought. Plant functional traits are useful for understanding and predicting the effects of such changes in plant communities. Here, we analyse the variation of leaf traits of understory woody species of the Congo Basin rainforests over a 60-year period using herbaria as tools and we verify if this variation is potentially related to recent climate change. Material and methods – Leaves of five shrub species were collected in 2019–2022 in Congolese old-growth forests (Yangambi Biosphere Reserve, DR Congo) from different positions on the shrub. These leaves were compared with herbarium specimens collected in the same area before 1960. For both periods, we assessed leaf size, specific leaf area, stomatal size, and stomatal density for all species. Key results – The variability of the functional traits of the understory woody species are independent of the position of the leaves in the crown. This allows for the use of historic herbarium collections for trait analyses on tropical understory shrubs. The traits of the recently collected leaves were notably different from the traits of herbarium leaves collected in pre-1960: recent leaves were significantly larger, had a higher Specific Leaf Area, a smaller stomata pore length, and, apart from Coffea canephora, showed a lower stomatal density. Conclusion – The difference in traits over time is probably related to the increase in temperature and to atmospheric CO2 concentration, as the average temperature at Yangambi over the past 60 years has shown an upward trend consistent with global increasing CO2 levels, while the average annual rainfall has remained unchanged. Our results provide a first insight into the response of forest species to climate change in the Congo Basin forests, and on how the understory species and the ecosystem will react in the long term, when the temperature further increases.

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Research Article Fri, 29 Sep 2023 10:40:00 +0300
Indications of an Achaea sp. caterpillar outbreak disrupting fruiting of an ectomycorrhizal tropical tree in Central African rainforest https://plecevo.eu/article/96572/ Plant Ecology and Evolution 156(1): 46-58

DOI: 10.5091/plecevo.96572

Authors: Julian M. Norghauer, David M. Newbery, Godlove A. Neba

Abstract: Background and aims – Where one or several tree species come to dominate patches of tropical forest, as many masting ectomycorrhizal legumes do in Central Africa, ecological theory predicts they may be prone to herbivory, which might alter their reproductive output. This was indirectly investigated in lowland rainforest in Cameroon for Tetraberlinia korupensis, whose crowns were attacked in 2008 by an outbreaking black caterpillar—identified as an Achaea sp., probably A. catocaloides—in Korup National Park. Material and methods – Field-collected data on tree-level seed and fruit (pod) production of T. korupensis in its 2008 masting event were compared with that of its two co-dominant neighbours (T. bifoliolata, Microberlinia bisulcata), whose populations masted in 2007 (and 2010). To do this, bivariate regression models (linear, polynomial, ZiG [zero-inflated gamma model]), contingency table analysis, and non-parametric measures of dispersion were used. Key results – Assuming T. korupensis is prone to Achaea caterpillar attacks, empirical data support the hypothesized lower proportion of adults participating in its masting (54% in 2008) than for either masting population of M. bisulcata (98% in 2007, 89% in 2010) or T. bifoliolata (96% in 2007, 78% in 2010). These fruiting T. korupensis trees were about one-third larger in stem diameter than conspecific non-fruiters and produced as many pods and seeds per capita as T. bifoliolata. However, regressions only modestly support the hypothesis that the positive tree size–fecundity relationship for T. korupensis was weaker (i.e. lower adj. R2) than for M. bisulcata (whose leaves are morphologically similar) or T. bifoliolata, with mostly similar dispersion about the median among these species. Conclusion – Altogether, the findings suggest a role for tolerance in nutrient-poor forests. It is postulated that instead of conferring resistance to herbivores, the ectomycorrhizas associated with these trees may enable them to more quickly recover from potential yet unpredictable insect outbreaks.

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Research Article Wed, 22 Feb 2023 11:42:00 +0200
Why fitness impacts of different herbivores may combine nonadditively, and why it matters to the ecology and evolution of plant-herbivore communities https://plecevo.eu/article/95982/ Plant Ecology and Evolution 156(1): 13-28

DOI: 10.5091/plecevo.95982

Authors: Michael J. Wise

Abstract: Background and aims – The manner by which the effects of multiple antagonists combine is a fundamental issue in ecology. This issue has been especially important in plant-herbivore evolutionary ecology—particularly predicting whether the combined fitness impacts of multiple herbivores on a shared host plant can be inferred by simply adding the individual impacts that each herbivore has when feeding alone. Despite accumulating empirical data, relatively little theoretical progress has been made in explaining why impacts of herbivore damage often combine nonadditively, as well as predicting the conditions that lead to a greater-than-additive (synergistic) or to a less-than-additive (subadditive) pattern. Material and methods – Based on considerations of limiting resources and source-sink relationships, I proposed and tested two hypotheses: 1) The fitness impacts of two species of herbivores that affect the same resource (i.e. feed on the same tissue in a similar fashion) will combine in a synergistic pattern (if that resource is not limiting reproduction when plants do not experience herbivory), and 2) The fitness impacts of two herbivores that affect different resources (i.e. feed on different tissues) will combine in a subadditive pattern. I performed a field experiment in which horsenettle (Solanum carolinense) was exposed to a factorial combination of four levels of leaf herbivory and five levels of simulated floral herbivory. Key results – The results were consistent with both hypotheses: 1) The combined fitness impact of flower damage that was simulated as being caused by two florivorous species feeding on the same plants was greater than the sum of the same total amount of damage when the two species were simulated as feeding individually; and 2) The combined fitness impact of the leaf and floral damage was less than the sum of the same total amount of damage when the two species fed individually. Conclusions – The main ecoevolutionary implication of these results is that subadditive impacts of leaf- and flower-feeding herbivores could weaken selection for resistance in horsenettle (or any plant species that hosts multiple herbivores), and thus subadditive impacts may contribute to the maintenance of diverse herbivore communities sharing a species of host plant.

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Research Article Wed, 8 Feb 2023 11:00:00 +0200
Medicinal Vitex species (Lamiaceae) occupy different niches in Haut-Katanga tropical dry woodlands https://plecevo.eu/article/89394/ Plant Ecology and Evolution 155(2): 236-247

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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Research Article Wed, 29 Jun 2022 12:01:18 +0300
Flora and fire in an old-growth Central African forest-savanna mosaic: a checklist of the Parc National des Plateaux Batéké (Gabon) https://plecevo.eu/article/85954/ Plant Ecology and Evolution 155(2): 189-206

DOI: 10.5091/plecevo.85954

Authors: Gretchen M. Walters, Diosdado Nguema, Raoul Niangadouma

Abstract: Background and aims – Old-growth savannas in Africa are impacted by fire, have endemic and geoxylic suffrutices, and are understudied. This paper explores the Parc National des Plateaux Batéké (PNPB) in Gabon and the impact of fire on its flora to understand if it is an old-growth savanna. It presents 1) a vascular plant checklist, including endemic species and geoxylic suffrutices and 2) an analysis of the impact of fire on the savanna herbaceous flora, followed by recommendations for fire management to promote plant diversity. Material and methods – 1,914 botanical collections from 2001–2019 collected by the authors and others were extracted from two herbaria databases in 2021 to create the checklist. The impact of fire was explored through a three season plot-based inventory of plant species (notably forbs and geoxylic suffrutices) in five annually, dry-season burned study areas located at 600 m in elevation. A two-factor ANOVA was conducted across two burn treatments and three season treatments. Key results – The area has a vascular flora of 615 taxa. Seven species are endemic to the Plateaux Batéké forest-savanna mosaic. Seventeen species are fire-dependent geoxylic suffrutices, attesting to the ancient origins of these savannas. Burning promotes fire-dependent species. Conclusion – The PNPB aims to create a culturally-adapted fire management plan. The combination of customary fire and fire-adapted species in the savanna creates a unique ancient forest-savanna mosaic in Central Africa that merits protection while recognising the role that the Batéké-Alima people have in shaping and governing this landscape.

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Research Article Thu, 5 May 2022 12:10:00 +0300
The hyperdominant tropical tree Eschweilera coriacea (Lecythidaceae) shows higher genetic heterogeneity than sympatric Eschweilera species in French Guiana https://plecevo.eu/article/24500/ Plant Ecology and Evolution 153(1): 67-81

DOI: 10.5091/plecevo.2020.1565

Authors: Myriam Heuertz, Henri Caron, Caroline Scotti-Saintagne, Pascal Pétronelli, Julien Engel, Niklas Tysklind, Sana Miloudi, Fernanda Gaiotto, Jérôme Chave, Jean-François Molino, Daniel Sabatier, João Loureiro, Katharina Budde

Abstract: Background and aims – The evolutionary history of Amazonia’s hyperabundant tropical tree species, also known as “hyperdominant” species, remains poorly investigated. We assessed whether the hyperdominant Eschweilera coriacea (DC.) S.A.Mori (Lecythidaceae) represents a single genetically cohesive species, and how its genetic constitution relates to other species from the same clade with which it occurs sympatrically in French Guiana.Methods – We sampled 152 individuals in nine forest sites in French Guiana, representing 11 species of the genus Eschweilera all belonging to the Parvifolia clade, with emphasis on E. coriacea. Samples were genotyped at four simple sequence repeat (SSR) markers. We delimited gene pools, i.e., genetically coherent putative taxa, using STRUCTURE software and principal component analysis. We compared the genetic assignment of individuals with their morphological species determination and estimated genetic diversity and differentiation for gene pools and species. We also estimated genome size using flow cytometry.Key results – SSR profiles commonly displayed up to four alleles per genotype, suggesting that the investigated Eschweilera species bear a paleopolyploid signature. Flow cytometry suggested that the studied species are diploid with haploid genome sizes of 871–1046 Mbp. We detected five gene pools and observed a good correspondence between morphological and genetic delimitation for Eschweilera sagotiana Miers and the undescribed morphospecies E. sp. 3 (which resembles E. grandiflora (Aubl.) Sandwith), and to a lesser extent for E. decolorans Sandwith and E. micrantha (O.Berg) Miers. Eschweilera coriacea was the most genetically diverse species and included individuals assigned to each gene pool. Conclusions – We found no conclusive evidence for cryptic species within E. coriacea in French Guiana. SSRs detected fewer gene pools than expected based on morphology in the Parvifolia clade but discriminated evolutionary relationships better than available plastid markers. A positive trend between demographic abundance of species and allelic richness illustrates that hyperdominants may have a high evolutionary potential. This hypothesis can be tested using more powerful genomic data in combination with tree phenotypic trait variation and characterization of niche breadth, to enhance our understanding of the causes of hyperdominance in Amazonian trees.

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Regular Paper Thu, 26 Mar 2020 00:00:00 +0200
Assessment of plant species diversity associated with the carob tree (Ceratonia siliqua, Fabaceae) at the Mediterranean scale https://plecevo.eu/article/24537/ Plant Ecology and Evolution 151(2): 185-193

DOI: 10.5091/plecevo.2018.1423

Authors: Alex Baumel, Pascal Mirleau, Juan Viruel, Magda Bou Dagher Kharrat, Stefano La Malfa, Lahcen Ouahmane, Katia Diadema, Marwa Moakhar, Hervé Sanguin, Frédéric Médail

Abstract: Background and aims – The thermophilous woodlands of the Mediterranean region constitute reservoirs of genetic resources for several fruit trees. Among them, the carob tree (Ceratonia siliqua) is a key component of traditional Mediterranean agroecosystems but its ecology was never assessed at the scale of its whole distribution area. Fortunately, phytosociological literature shelters invaluable resources for several issues in conservation, among them the possibility to analyse plant biodiversity at regional or continental scale. Here, we present the results of a comprehensive survey of the phytosociological literature associated to carob tree. Methods – We collected 1542 floristic relevés performed in 18 geographical areas distributed around the Mediterranean in which the presence of C. siliqua was recorded. Species composition of the plant communities was analysed by multivariate ordination and hierarchical classification, and species diversity was evaluated by rarefaction and prediction analyses of Hill numbers. Key results – Multivariate analyses revealed that plant communities associated with the carob tree are well differentiated between the Western and Eastern basins. A wider range of floristic differentiation is revealed in the Western basin where the vegetation reaches its maximal heterogeneity. By comparison, in the Eastern basin the plant assemblages associated with the carob tree are more homogeneous and with a lower species richness but a higher Simpson diversity. Conclusions – The large ecological range of the Mediterranean carob trees is potentially an important evolutionary legacy for the conservation of genetic resources and seed sourcing for new uses such as restoration ecology.

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Regular Paper Wed, 22 Aug 2018 00:00:00 +0300