Scent-mediated bee pollination and myrmecochory in an enigmatic geophyte with pyrogenic flowering and subterranean development of fleshy fruits.

PREMISE: Volatile emissions from flowers and fruits play a key role in signalling to animals responsible for pollination and seed dispersal. Here, we investigated the pollination biology and chemical ecology of reproduction in Apodolirion buchananii, an African amaryllid that flowers in a leafless state soon after grassland vegetation is burnt in the dry late-winter season. METHODS: Pollinators were identified through field collection and pollen loads were quantified. Floral traits including spectral reflectance and scent chemistry were documented. Bioassays using cup traps were used to test the function of floral volatiles. Fruiting biology was investigated using controlled hand-pollination experiments and chemical analysis of fruit scent. Seed germination was scored in greenhouse trials. Seed dispersal was monitored using observations and camera trapping. RESULTS: The sweetly scented white flowers of A. buchananii are pollen-rewarding and pollinated mainly by a diverse assemblage of bees. Cup-trap experiments demonstrated that pollinators are attracted to phenylacetaldehyde, the dominant volatile in the floral scent. Plants are shown to be self-incompatible, and the fleshy fruits were found to emerge from the soil six months after pollination during the peak of the summer rains. Fruits emit a diverse blend of aliphatic and aromatic esters and contain large fleshy recalcitrant seeds which germinate within days of fruits splitting open. Seed dispersal by ants was recorded. CONCLUSIONS: This first account of the reproductive biology of a species in the genus Apodolirion highlights an outcrossing mating system involving bees attracted to color and scent as well as the unusual fruiting biology and ant-mediated system of seed dispersal.

Three-dimensional vegetation structure drives patterns of seed dispersal by African hornbills.

Three-dimensional (3D) vegetation structure influences animal movements and, consequently, ecosystem functions. Animals disperse the seeds of 60%-90% of trees in tropical rainforests, which are among the most structurally complex ecosystems on Earth. Here, we investigated how 3D rainforest structure influences the movements of large, frugivorous birds and resulting spatial patterns of seed dispersal. We GPS-tracked white-thighed (Bycanistes albotibialis) and black-casqued hornbills (Ceratogymna atrata) in a study area surveyed by light detection and ranging (LiDAR) in southern Cameroon. We found that both species preferred areas of greater canopy height and white-thighed hornbill preferred areas of greater vertical complexity. In addition, 33% of the hornbills preferred areas close to canopy gaps, while 16.7% and 27.8% avoided large and small gaps, respectively. White-thighed hornbills avoided swamp habitats, while black-casqued increased their preference for swamps during the hottest temperatures. We mapped spatial probabilities of seed dispersal by hornbills, showing that 3D structural attributes shape this ecological process by influencing hornbill behaviour. These results provide evidence of a possible feedback loop between rainforest vegetation structure and seed dispersal by animals. Interactions between seed dispersers and vegetation structure described here are essential for understanding ecosystem functions in tropical rainforests and critical for predicting how rainforests respond to anthropogenic impacts.

Seed functional ecology in Brazilian rock outcrop vegetation: an integrative synthesis.

BACKGROUND AND AIMS: Rock outcrop vegetation is distributed worldwide and hosts a diverse and unique flora that evolved under harsh environmental conditions. Unfortunately, seed ecology in such ecosystems has received little attention, especially regarding seed traits, germination responses to abiotic factors and the potential role of phylogenetic relatedness on such features Here, we provide the first quantitative and phylogenetically-informed synthesis of the seed functional ecology of Brazilian rock outcrop vegetation, with a particular focus on quartzitic and ironstone campo rupestre. METHODS: Using a database of functional trait data, we calculated the phylogenetic signal of seven seed traits for 371 taxa and tested whether they varied among growth forms, geographic distribution, and microhabitats. We also conducted meta-analyses that included 4,252 germination records for 102 taxa to assess the effects of light, temperature, and fire-related cues on the germination of campo rupestre species and explored how the aforementioned ecological groups and seed traits modulate germination responses. KEY RESULTS: All traits and germination responses showed a moderate-to-strong phylogenetic signal. Campo rupestre species responded positively to light and had maximum germination between 20-25 ºC. The effect of temperatures beyond this range was moderated by growth form, species geographic distribution, and microhabitat. Seeds exposed to heat shocks above 80 °C lost viability, but smoke accelerated germination. We found a moderating effect of seed mass for in responses to light and heat shocks, with larger, dormant seeds tolerating heat better but less sensitive to light. Species from xeric habitats evolved phenological strategies to synchronise germination during periods of increased soil water availability. CONCLUSIONS: Phylogenetic relatedness plays a major role in shaping seed ecology of Brazilian rock outcrop vegetation. Nevertheless, seed traits and germination responses varied significantly between growth forms, species geographic distribution and microhabitats, providing support to the regeneration niche hypothesis and the role of functional traits in shaping germination in these ecosystems.

A review of plant phenolics and endozoochory.

Phenolic compounds (phenolics) are secondary metabolites ubiquitous across plants. The earliest phenolics are linked to plants' successful transition from an aquatic to a terrestrial environment, serving as protection against damaging ultraviolet (UV) radiation, and as antioxidants to reduce oxidative stress in an atmosphere with an increasingly high O2:CO2 ratio. In modern plants, phenolics are best known for the defense against fungal and bacterial pathogens and as antifeedants that deter herbivory. Phenolics also play a role in seed dormancy, delaying germination, and lengthening viability in the seed bank. Many plants' seeds are endozoochorous - dispersed by animals, like birds, who eat and later excrete the seeds. Plants send visual signals to attract birds with UV-sensitive (UVS) vision for pollination and seed dispersal. As fruits ripen, antioxidant activity and phenolic content decrease. The waxy cuticle of fruits increases in UV reflection as phenolic rings, which absorb UV light, degrade. The UV contrast that birds detect may act as an honest signal, indicating nutritional changes in the fruit. However, there is little evidence to support the evolution of UV coloration during ripening being driven by frugivore selection. Antioxidant properties of fruit phenolics may be dually adaptive in plants and avian frugivores.

Bold rats (Niviventer confucianus) are more effective in seed dispersal: evidence both under enclosure conditions and in the field.

Rodents are important seed dispersers of plants because they move seeds far away from the parent trees and hoard seeds in the soil, benefiting seed dispersal and regeneration. Traits of plant seeds and animals are associated with rodent-mediated seed dispersal, but animal personality, the consistent individual behavioral differences in time and environments, has not been fully considered. Here, we first measured the personality of 26 Niviventer confucianus in the laboratory, and 10 individuals in the field of one population, and then tested their behavior of seed consumption and hoarding both in semi-natural enclosures and the field. We tested the hypothesis that individuals with different personalities have different preferences for seed consumption and hoarding, which has different implications for seed dispersal and regeneration. Under the enclosure conditions, all parameters of personality are repeatable; bold individuals harvested fewer seeds but scatter-hoarded more seeds and dispersed farther than timid ones, whereas active individuals consumed more seeds, but left fewer seeds on the ground surface than inactive ones. In the field, boldness, activity, and exploration of the animals are repeatable; bold individuals scatter-hoarded more seeds to farther distances than timid ones, whereas active individuals harvested and consumed more seeds than inactive ones. These results suggest that bold rats tended to scatter hoard seeds and disperse them to a longer distance, implying they are more effective in seed dispersal. In the future, animal personality (e.g. boldness and activity) should be considered in seed dispersal studies and ecological-based manipulation in seed dispersal and regeneration of forests.

Correlated evolution of dispersal traits and habitat preference in the melicgrasses.

PREMISE: Seed dispersal is a critical process impacting individual plants and their communities. Plants have evolved numerous strategies and structures to disperse their seeds, but the evolutionary drivers of this diversity remain poorly understood in most lineages. We tested the hypothesis that the evolution of wind dispersal traits within the melicgrasses (Poaceae: Meliceae Link ex Endl.) was correlated with occupation of open and disturbed habitats. METHODS: To evaluate wind dispersal potential, we collected seed dispersal structures (diaspores) from 24 melicgrass species and measured falling velocity and estimated dispersal distances. Species' affinity for open and disturbed habitats were recorded using georeferenced occurrence records and land cover maps. To test whether habitat preference and dispersal traits were correlated, we used phylogenetically informed multilevel models. RESULTS: Melicgrasses display several distinct morphologies associated with wind dispersal, suggesting likely convergence. Open habitat taxa had slower-falling diaspores, consistent with increased wind dispersal potential. However, their shorter stature meant that dispersal distances, at a given wind speed, were not higher than those of their forest-occupying relatives. Species with affinities for disturbed sites had slower-falling diaspores and greater wind dispersal distances, largely explained by lighter diaspores. CONCLUSIONS: Our results are consistent with the hypothesized evolutionary relationship between habitat preference and dispersal strategy. However, phylogenetic inertia and other plant functions (e.g., water conservation) likely shaped dispersal trait evolution in melicgrasses. It remains unclear if dispersal trait changes were precipitated by or predated changing habitat preferences. Nevertheless, our study provides promising results and a framework for disentangling dispersal strategy evolution.

Dispersal distances from splash-cup plants depend on the cup's angle and contents.

Splash-cup plants disperse propagules via raindrops striking cup-shaped fruiting bodies. The seeds are ejected at velocities up to five times the impact speed of the raindrop and are dispersed up to 1 m from the parent plant. Here, we examine the effects of cup angles and the presence of seed mimics to understand the dynamics of this unique method of dispersal. Our findings demonstrate that: (i) cup angles that launched seeds the furthest ranged from approximately 30° to 50°, matching the range of angles seen in splash-cup plants. (ii) Seeds travel shorter distances than water droplets alone, and this distance depends on the number of seeds in the cup. (iii) Not all seeds are ejected from initially dry cups, leaving cups with some seeds and some water. (iv) Nearly all seeds are ejected from cups that contain both water and seeds, and those that are ejected travel significantly further than those from dry cups. These results confirm the possibility that the conical shape of splash cup plants may be adapted to maximize dispersal distance and benefit from multiple splash events. Our results also illustrate that future work on these plants should include seeds rather than water droplets alone.

FRUGIVORY CAMTRAP: A dataset of plant-animal interactions recorded with camera traps.

Ecological interactions are a key component of biodiversity, essential for understanding ecosystem services and functioning. Recording and quantifying ecological interactions is challenging, frequently requiring complex logistics and substantial effort in the field. Camera traps are routinely used in ecology for various applications, and have proven to be an excellent method for passive and non-invasive sampling of plant-animal interactions. We implemented a standardized camera trap protocol to document vertebrate frugivores-fleshy fruited plants interactions in Doñana National Park, SW Spain, with the central objective of inventorying the diversity of plant-animal ecological interactions providing seed dispersal services. From 2018 to 2023 we recorded pairwise interactions from which we obtained qualitative (presence-absence) and quantitative (frequency of visits) information. Each record in the dataset contains information of a visit by an individual animal to an individual plant, resulting in any form of fleshy-fruit use and provides information on visitation phenology, visit length, and feeding behavior. The dataset presented here includes 10,659 frugivory interaction events for 59 vertebrate species (46 birds, 13 mammals) recorded on 339 plant individuals from 13 different plant species which dominate the fleshy-fruited plant assemblage in the Doñana National Park. The most recorded animal species consuming fruits and playing a legitimate seed dispersal role was Curruca melanocephala (1678 records) among birds and Vulpes vulpes among mammals (751 records). Cervus elaphus, a fruit consumer with a marginal role as legitimate seed disperser, was the most recorded mammal species (1508 records). Avian frugivores, particularly those from the Sylviidae and Turdidae families, are widespread in the region and play a crucial role in maintaining the dispersal service for the fleshy-fruited plant populations in the area. The dataset offers highly versatile quantitative information that can be used to investigate frugivory from the highest resolution scale, the interaction event between pairs of individuals. In addition, other information that can be extracted includes the timing of interactions of animals and plants (their phenological couplings), activity periods of the animals, behavior during the events and preferences for individual plants within populations. There are no copyright restrictions on the data. When using the data from this data paper in publications, we kindly request that you cite the paper accordingly. Additionally, we encourage researchers and educators to inform us about how they are using this data, as we value feedback and would like to be aware of its various applications.

A Biodegradable, Porous Flier Inspired by a Parachute-Like Tragopogon Fruit for Environmental Preservation.

New devices inspired by flying seeds, or more technically by fruits with dispersal units, could have a significant impact for environmental monitoring and aerial seeding. Among the various types of dispersal units (e.g., winged, gliding), parachuted or plumed units offer the lowest vertical descent speed (i.e., 0.3-0.7 m s-1), making them an appealing solution for wind-driven distribution over large areas. Here, a biodegradable and porous parachute flier based on cellulose acetate, inspired by a Tragopogon pratensis fruit is presented. A micrometric-thick pappus is 3D printed and integrated with a porous colorimetric indicator or a porous beak, with micrometric pores, fabricated through injection molding and leaching techniques. Thanks to the bioinspired design and the lightweight porous structure, the artificial Tragopogon mimics the aerodynamics and descent speed of the natural species. Its feasibility is demonstrated in aerial seeding by integrating the beak with a mustard seed (as a model), and in environmental monitoring by coupling it with colorimetric indicators for rain pH and nitrate levels in soils. The proposed flier represents a significant advancement as it is the first parachute-like biodegradable solution, seamlessly integrated into natural ecosystems, thus contributing to moving a step forward in artificial solutions with zero impact.

Divergent seed dispersal outcomes: Interactions between seed, disperser, and forest traits.

Animals disperse seeds in various ways that affect seed deposition sites and seed survival, ultimately shaping plant species distribution, community composition, and ecosystem structure. Some animal species can disperse seeds through multiple pathways (e.g., defecation, regurgitation, epizoochory), each likely producing distinct seed dispersal outcomes. We studied how seed traits (size and toughness) interact with disperser species to influence seed dispersal pathway and how this ultimately shapes the proportion of seeds deposited in various habitat types. We focused on three frugivorous species of duikers (African forest antelopes) in the Dja Faunal Reserve, a tropical rainforest in southern Cameroon. Duikers can both defecate and regurgitate seeds, the latter predominantly occurring during rumination at their bedding sites (or "nests"). We located duiker nests and dungs along 18 linear 1-km-transects to assess: (1) how seed traits affect the likelihood of dispersal via defecation versus regurgitation, (2) if defecated versus regurgitated seeds are deposited at different rates in different forest types (assessed by indigenous Baka), microhabitats, and forest structural attributes (measured by drone lidar), and (3) if these differ between three duiker species that vary in size and diel activity patterns. We found that duikers predominantly defecated small seeds (<3 mm length) and regurgitated larger and tougher seeds (>10 mm length), the latter including 25 different plant species. The three duiker species varied in their nesting habits, with nocturnal bay duikers (Cephalophus dorsalis) nesting in dense understory vegetation at proportions 3-4 times higher than Peter's and yellow-backed duikers (Cephalophus callipygus and Cephalophus silvicultor). As a result, bay duikers deposited larger regurgitated seeds at a higher rate in habitats with denser understory where lianas and palms predominate and near fallen trees. This directed regurgitation seed deposition likely plays an important and unique role in forest succession and structure. This study highlights the importance of ungulate seed dispersal by regurgitation, a vastly understudied process that could impact many ecosystems given the prevalence of ruminating ungulates worldwide.

Effects of temperature gradient on functional fruit traits: an elevation-for-temperature approach.

Fruit traits mediate animal-plant interactions and have to a large degree evolved to match the sensory capacities and morphology of their respective dispersers. At the same time, fruit traits are affected by local environmental factors, which may affect frugivore-plant trait match. Temperature has been identified as a major factor with a strong effect on the development of fruits, which is of serious concern because of the rising threat of global warming. Nonetheless, this primarily originates from studies on domesticated cultivars in often controlled environments. Little is known on the effect of rising temperatures on fruit traits of wild species and the implications this could have to seed dispersal networks, including downstream consequences to biodiversity and ecosystem functioning. In a case study of five plant species from eastern Madagascar, we addressed this using the elevation-for-temperature approach and examined whether a temperature gradient is systematically associated with variation in fruit traits relevant for animal foraging and fruit selection. We sampled across a gradient representing a temperature gradient of 1.5-2.6 °C, corresponding to IPCC projections. The results showed that in most cases there was no significant effect of temperature on the traits evaluated, although some species showed different effects, particularly fruit chemical profiles. This suggests that in these species warming within this range alone is not likely to drive substantial changes in dispersal networks. While no systemic effects were found, the results also indicate that the effect of temperature on fruit traits differs across species and may lead to mismatches in specific animal-plant interactions.

Substrate scent-induced disproportionate seed dispersal by rodents.

Conspecific adults impose strong negative density-dependent effects on seed survival nearby parent trees, however, the underlying mechanisms are diversified and remain unclear. In this study, we presented consistent evidence that parent-scented forest floor masked seed odor, reduced cache recovery rate by scatter-hoarding animals, and then increased seed dispersal far away from mother trees. Our results showed that seed odors of Korean pine Pinus koraiensis match well with the volatile profile of their forest floor. Moreover, scatter-hoarding animals selectively transported P. koraiensis seeds toward the areas where seed odor was more contrasting against the background substrate, possibly due to the fact that accumulation of conspecific volatile compounds in caches hindered seed detection by scatter-hoarding animals. Our study provides insight into the role of leaf litter in directing seed dispersal process, representing a novel mechanism by which P. koraiensis increases selection for seed dispersal far away from the parent tree.

Examining the structure of plant-lemur interactions in the face of imperfect knowledge.

Biotic interactions, such as plant-animal seed dispersal mutualisms, are essential for ecosystem function. Such interactions are threatened by the possible extinction of the animal partners. Using a data set that includes plant-lemur interactions across Madagascar, we studied the current state of knowledge of these interactions and their structure to determine which plant species are most at risk of losing dispersal services due to the loss of lemurs. We found substantial gaps in understanding of plant-lemur interactions; data were substantially skewed toward a few lemur species and locations. There was also a large gap in knowledge on the interactions of plants and small-bodied or nocturnal lemurs and lemurs outside a few highly studied locations. Of the recorded interactions, a significant portion occurred between lemurs and endemic plants, rather than native or introduced plants. We also found that lemur species tended to primarily consume closely related plant species. Such interaction patterns may indicate the threats to Malagasy endemic plants and highlight how lemur population loss or reductions could affect plant phylogenetic diversity. When examining the impacts of lemur extinction, losing critically endangered species left 164 plant species with no known lemur frugivore partners. Despite phylogenetic patterns in lemur diet, plants for which the only known lemur frugivore is critically endangered were not closely related. These results emphasize the need for further studies to complete our knowledge on these essential interactions and to inform conservation priorities.

Análisis de la estructura de las interacciones entre lémures y plantas de cara al conocimiento incompleto Resumen Las interacciones bióticas, como el mutualismo entre plantas y animales para la dispersión de semillas, son esenciales para que el ecosistema funcione. Dichas interacciones se encuentran amenazadas por la posible extinción del animal que participa en ellas. Usamos un conjunto de datos que incluye las interacciones entre lémures y plantas en Madagascar para estudiar el estado actual del conocimiento de estas interacciones y su estructura. Con lo anterior determinamos cuáles especies botánicas tienen mayor riesgo de perder la dispersión de semillas debido a la extinción de los lémures. Encontramos vacíos sustanciales en el entendimiento de las interacciones entre lémures y plantas; los datos estaban sesgados para unas cuantas especies de lémures y localidades. Hubo un gran vacío de conocimiento para las interacciones entre las plantas y los lémures pequeños o nocturnos y aquellos fuera de unas cuantas localidades estudiadas. De las interacciones registradas, una porción importante ocurrió entre los lémures y plantas endémicas, en lugar de plantas nativas o introducidas. También encontramos que las especies de lémures tienden a consumir especies botánicas con filogenia cercana. Dichos patrones de interacción podrían indicar las amenazas para las plantas endémicas de Madagascar y enfatizar cómo la pérdida o reducción de las poblaciones de lémures podrían afectar la diversidad filogenética de las plantas. Cuando examinamos el impacto de la extinción de los lémures, la pérdida de especies en peligro crítico dejó a 164 especies de plantas sin un lémur frugívoro mutualista. A pesar de los patrones filogenéticos en la dieta de los lémures, las plantas cuyo único lémur frugívoro se encuentra en peligro crítico no tienen una filogenia cercana. Estos resultados resaltan la necesidad de más estudios para completar nuestro conocimiento sobre estas interacciones esenciales y para guiar las prioridades de conservación.

Amphicarpic development in Cardamine chenopodiifolia.

Amphicarpy is an unusual trait where two fruit types develop on the same plant: one above and the other belowground. This trait is not found in conventional model species. Therefore, its development and molecular genetics remain under-studied. Here, we establish the allooctoploid Cardamine chenopodiifolia as an emerging experimental system to study amphicarpy. We characterized C. chenopodiifolia development, focusing on differences in morphology and cell wall histochemistry between above- and belowground fruit. We generated a reference transcriptome with PacBio full-length transcript sequencing and analysed differential gene expression between above- and belowground fruit valves. Cardamine chenopodiifolia has two contrasting modes of seed dispersal. The main shoot fails to bolt and initiates floral primordia that grow underground where they self-pollinate and set seed. By contrast, axillary shoots bolt and develop exploding seed pods aboveground. Morphological differences between aerial explosive fruit and subterranean nonexplosive fruit were reflected in a large number of differentially regulated genes involved in photosynthesis, secondary cell wall formation and defence responses. Tools established in C. chenopodiifolia, such as a reference transcriptome, draft genome assembly and stable plant transformation, pave the way to study amphicarpy and trait evolution via allopolyploidy.

Diet and seed dispersal of bearded capuchin monkeys (Sapajus libidinosus) in Brasilia National Park.

The dietary ecology of a species can provide information on habitat requirements, food resources, and trophic interactions, important to guide conservation efforts of wildlife populations in endangered habitats. In this study, we investigated the dietary ecology of bearded capuchin monkeys (Sapajus libidinosus) in Brasilia National Park, in the endangered Cerrado biome of central Brazil. To obtain diet composition and evaluate the role of these primates as seed dispersers of local tree species, fecal sample collections and feeding observations were performed for a 7-month period. To determine whether seeds germinated better after passing through a primate gut, we conducted germination trials with (i) pulped seeds from trees, (ii) depulped seeds from trees, (iii) seeds from feces planted with feces, and (iv) seeds from feces planted without feces. During experimental procedures, 7308 seeds from 8 families and 10 species were planted. We found that S. libidinosus spent more time feeding on fruits than on any other food item and the diet consisted of 33 plant species from 21 families. However, 20% of their diet consisted of anthropic food. Most seeds planted with feces germinated faster compared to seeds in other experimental treatments, suggesting that passing through the gut and being deposited with fecal material is advantageous. The bearded capuchins also defecated many medium- (5 species) and large-sized (2 species) seeds that may be inaccessible to smaller arboreal frugivores. The results obtained emphasize the important role of bearded capuchins as seed dispersers for the maintenance and conservation of the endangered Cerrado biome.

Negative density dependence characterizes mutualistic interactions between birds and fruiting plants across latitudes.

Negative density dependence (NDD) in biotic interactions of interference such as plant-plant competition, granivory and herbivory are well-documented mechanisms that promote species' coexistence in diverse plant communities worldwide. Here, we investigated the generality of a novel type of NDD mechanism that operates through the mutualistic interactions of frugivory and seed dispersal among fruit-eating birds and plants. By sampling community-wide frugivory interactions at high spatial and temporal resolution in Pennsylvania, Puerto Rico, Peru, Brazil and Argentina, we evaluated whether interaction frequencies between birds and fruit resources occurred more often (selection), as expected, or below expectations (under-utilization) set by the relative fruit abundance of the fruit resources of each plant species. Our models considered the influence of temporal scales of fruit availability and bird phylogeny and diets, revealing that NDD characterizes frugivory across communities. Irrespective of taxa or dietary guild, birds tended to select fruits of plant species that were proportionally rare in their communities, or that became rare following phenological fluctuations, while they mostly under-utilized abundant fruit resources. Our results demonstrate that negative density-dependence in frugivore-plant interactions provides a strong equalizing mechanism for the dispersal processes of fleshy-fruited plant species in temperate and tropical communities, likely contributing to building and sustaining plant diversity. This article is part of the theme issue 'Diversitydependence of dispersal: interspecific interactions determine spatial dynamics'.

The role of seed rain, seed bank, and clonal growth in plant colonization of ancient and restored grasslands.

Understanding the establishment of plant species is important to inform management of restored grasslands and to preserve biodiversity in ancient grasslands. In grassland communities, plant species can establish from seeds arriving via spatial dispersal, from seeds in the soil seed bank or through vegetative spread from nearby source individuals. However, this colonization potential and the likelihood of species establishment can vary in grasslands with different land-use history. We investigated the relative importance of local species recruitment sources, such as dispersal in space and time and species presence in adjacent grasslands, in determining establishment of plant species in eight grasslands with different land-use history (paired ancient grasslands continuously managed as pasture vs. restored grasslands on former forest). At each grassland, we established plots (0.25 m2) to monitor seedling emergence from seed dispersal, seed bank, and recorded clonal growth over two growing periods. We found that the likelihood of species establishment was highest from local seed rain, and that species present in the local species pool were more able to germinate and establish in both type of grasslands. Species from the seed bank and clonal growth contributed to a lesser extent to species establishment, but represented a greater proportion of the recolonization and regeneration of species in ancient grasslands. These results demonstrate that surrounding grasslands serve as a source for colonizing species and that dispersal from the adjacent grasslands is the key process in regeneration and colonization of plants. These results imply that the recovery of grasslands depends heavily upon to links to species source in grasslands, especially in restored grasslands. Therefore, management plans should incorporate rotational livestock grazing and larger networks of grassland in restoration efforts, which will enable to desirable species to establish and persist in grasslands.

Intraspecific divergence in a coastal plant, Euphorbia jolkinii, at a major biogeographic boundary in East Asia.

PREMISE: Quaternary climatic fluctuations and long-distance seed dispersal across the sea are critical factors affecting the distribution of coastal plants, but the spatiotemporal nature of population expansion and distribution change of East Asian coastal plants during this period are rarely examined. To explore this process, we investigated the genome-wide phylogenetic patterns of Euphorbia jolkinii Boiss. (Euphorbiaceae), which grows widely on littoral areas of Japan, Korea, and Taiwan. METHODS: We used plastome sequences and genome-wide single nucleotide polymorphisms in samples across the species range to reveal phylogeographic patterns and spatiotemporal distributional changes. We conducted ecological niche modeling for the present and the last glacial maximum (LGM). RESULTS: Genetic differentiation was observed between the northern and southern populations of E. jolkinii, separated by the major biogeographic boundary, the Tokara Gap. These two groups of populations differentiated during the glacial period and subsequently intermingled in the intermorainic areas of the central Ryukyu Islands after the LGM. Ecological niche models suggested that the potential range of E. jolkinii was restricted to southern Kyushu; however, it was widespread in the southern Ryukyu Islands and Taiwan during the LGM. CONCLUSIONS: This study provides evidence of genetic differentiation among coastal plant populations separated by the prominent biogeographical boundary. Although coastal plants are typically expected to maintain population connectivity through sea-drifted seed dispersal, our findings suggest that genetic differences may arise because of a combination of limited gene flow and changes in climate during the glacial period.

A leading-edge scenario in the phylogeography and evolutionary history of East Asian insular Taxus in Taiwan and the Philippines.

The cool temperate origin of gymnosperm Taxus species in East Asia is specifically diverse and widespread. Certain lineages have managed to extend their distribution further south to subtropical and tropical islands such as Taiwan and the Philippines. To address questions including whether these insular lineages, recently identified as T. phytonii, have become genetically distinct from each other and from their continental relatives, and when and how they colonized their residing islands, we sampled over 11 populations, covering 179 Taxus individuals from Taiwan and the Philippines. Using four cpDNA and one nuclear marker, we showed in population genetic and genealogical analyses that the two insular lineages were genetically distinct from each other and also from other continental Taxus and that they represented each other's closest relative. Estimated with the coalescent-based multi-type tree (MTT) analyses, we inferred an origin of Taiwanese T. phytonii more ancient than 2.49 Mya and that of Philippine T. phytonii more ancient than 1.08 Mya. In addition, the divergence demographic history revealed by both MTT and isolation with migration (IM) analyses indicated the presence of recent post-split migrations from a continental taxon, T. mairei, to Taiwanese T. phytonii, as well as from Taiwanese T. phytonii to Philippine T. phytonii. Overall, this study suggests Taiwan as a stepping stone through which the temperate-origin yew trees can extend their distributions to tropical regions such as the Philippines.