Jiayi Song, Deby Arifiani, Jens G. Rohwer, David Kay Ferguson, Yong Yang
Premise
Floristic exchanges between Oceania and tropical Asia have significant asymmetrical characteristics. Many groups of plants have dispersed southward from Asia to Oceania, whereas a northward dispersal from Oceania to tropical Asia (i.e., the “Dacrycarpus pattern”) is rarely reported. The genus Endiandra (Lauraceae) is distributed from tropical Asia to Oceania, with higher species richness in Oceania, so it can contribute to our understanding of paleotropical biogeography.
Methods
We sequenced plastid genomes (plastomes) of 69 species using an herbariomic (genome skimming) approach, with 48 plastomes reported for the first time. We also reconstructed a phylogenomic tree, estimated divergence times, analyzed ancestral areas, and studied the biogeographic history of the genus.
Results
Our well-resolved phylogenomic tree depicts Endiandra as a paraphyletic group in which two Australian species of Beilschmiedia are nested. Dating analysis indicated that the stem and crown ages of the genus are 51.21 and 45.69 million years old, respectively. Ancestral area reconstruction indicates that the genus originated in Oceania and that several independent dispersal events across Wallace's Line shaped its modern distribution.
Conclusions
The geological history and environmental changes in the Neogene likely facilitated the dispersal of Endiandra. However, the inferred dispersal patterns proved more complicated than the classic “Dacrycarpus pattern”, helping improve our understanding of the paleotropical biogeographic history of plants.
{"title":"Dispersal across Wallace's Line: A case study in Endiandra","authors":"Jiayi Song, Deby Arifiani, Jens G. Rohwer, David Kay Ferguson, Yong Yang","doi":"10.1002/ajb2.70097","DOIUrl":"10.1002/ajb2.70097","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Floristic exchanges between Oceania and tropical Asia have significant asymmetrical characteristics. Many groups of plants have dispersed southward from Asia to Oceania, whereas a northward dispersal from Oceania to tropical Asia (i.e., the “<i>Dacrycarpus</i> pattern”) is rarely reported. The genus <i>Endiandra</i> (Lauraceae) is distributed from tropical Asia to Oceania, with higher species richness in Oceania, so it can contribute to our understanding of paleotropical biogeography.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We sequenced plastid genomes (plastomes) of 69 species using an herbariomic (genome skimming) approach, with 48 plastomes reported for the first time. We also reconstructed a phylogenomic tree, estimated divergence times, analyzed ancestral areas, and studied the biogeographic history of the genus.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our well-resolved phylogenomic tree depicts <i>Endiandra</i> as a paraphyletic group in which two Australian species of <i>Beilschmiedia</i> are nested. Dating analysis indicated that the stem and crown ages of the genus are 51.21 and 45.69 million years old, respectively. Ancestral area reconstruction indicates that the genus originated in Oceania and that several independent dispersal events across Wallace's Line shaped its modern distribution.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The geological history and environmental changes in the Neogene likely facilitated the dispersal of <i>Endiandra</i>. However, the inferred dispersal patterns proved more complicated than the classic “<i>Dacrycarpus</i> pattern”, helping improve our understanding of the paleotropical biogeographic history of plants.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 9","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145013687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maoqin Xia, Joongku Lee, Limin Yu, Xianyun Mu, Wei-Mei Jiang, Douglas E. Soltis, Luxian Liu, Pan Li
Premise
The demographic histories of temperate plants in Northeast Asia in response to Quaternary climate oscillations have long been the focus of evolutionary biologists, but have rarely been studied in herbaceous plants. Here, we investigated the phylogeographic patterns of Mukdenia and Oresitrophe.
Methods
We sequenced two plastid regions for O. rupifraga (22 populations, 222 individuals), M. acanthifolia (five populations, 50 individuals), and M. rossii (14 populations, 139 individuals). To better understand the phylogeographic patterns of these species, we analyzed genetic diversity/structure, divergence times, demographic history, and distributional changes (with ecological niche modeling). We compared the inferred niche space of these species and addressed isolation by distance (IBD) and isolation by environment (IBE).
Results
We confirmed the monophyly of each species and detected a phylogeographic division corresponding to an arid belt in North China. Oresitrophe rupifraga is inferred to have contracted into four refugia during Pleistocene interglacial periods. Mukdenia acanthifolia and M. rossii appear to have retreated to the Changbai Mountains and Korean Peninsula during that time. In contrast, a larger potential geographic distribution was inferred for each species during glacial periods. Significant ecological niche differentiation was detected among the three species, which may have been associated with their genetic divergence.
Conclusions
Refugial isolation, climatic barriers, and niche differentiation likely influenced the genetic divergence of Oresitrophe and Mukdenia. Our study has implications for the structure of plant diversity in temperate deciduous forests of Northeast Asia and provides insights into conservation units worthy of protection and management for species of both genera.
{"title":"Refugial isolation and ecological niche differentiation promote genetic divergence of Oresitrophe and Mukdenia in Northeast Asia","authors":"Maoqin Xia, Joongku Lee, Limin Yu, Xianyun Mu, Wei-Mei Jiang, Douglas E. Soltis, Luxian Liu, Pan Li","doi":"10.1002/ajb2.70088","DOIUrl":"10.1002/ajb2.70088","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The demographic histories of temperate plants in Northeast Asia in response to Quaternary climate oscillations have long been the focus of evolutionary biologists, but have rarely been studied in herbaceous plants. Here, we investigated the phylogeographic patterns of <i>Mukdenia</i> and <i>Oresitrophe</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We sequenced two plastid regions for <i>O. rupifraga</i> (22 populations, 222 individuals), <i>M. acanthifolia</i> (five populations, 50 individuals), and <i>M. rossii</i> (14 populations, 139 individuals). To better understand the phylogeographic patterns of these species, we analyzed genetic diversity/structure, divergence times, demographic history, and distributional changes (with ecological niche modeling). We compared the inferred niche space of these species and addressed isolation by distance (IBD) and isolation by environment (IBE).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We confirmed the monophyly of each species and detected a phylogeographic division corresponding to an arid belt in North China. <i>Oresitrophe rupifraga</i> is inferred to have contracted into four refugia during Pleistocene interglacial periods. <i>Mukdenia acanthifolia</i> and <i>M. rossii</i> appear to have retreated to the Changbai Mountains and Korean Peninsula during that time. In contrast, a larger potential geographic distribution was inferred for each species during glacial periods. Significant ecological niche differentiation was detected among the three species, which may have been associated with their genetic divergence.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Refugial isolation, climatic barriers, and niche differentiation likely influenced the genetic divergence of <i>Oresitrophe</i> and <i>Mukdenia</i>. Our study has implications for the structure of plant diversity in temperate deciduous forests of Northeast Asia and provides insights into conservation units worthy of protection and management for species of both genera.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 9","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144991125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Premise: Flower color polymorphism (FCP) is thought to be driven by multiple selection agents. Although widely associated with visual attraction of multiple pollinators, FCP is also often correlated with abiotic factors. We explored the links between abiotic conditions, flowering phenology, and FCP in the winter-flowering geophyte Anemone coronaria L., which forms color-polymorphic or red-only populations.
Methods: We mapped the geographical distribution of color diversity in A. coronaria in Israel using citizen-science data. We recorded the phenology and density of red and non-red flowers during two flowering seasons in 18 plots along a rainfall gradient. We related the spatiotemporal data to soil and climate measures.
Results: Color-polymorphic populations are restricted to Mediterranean sites (>450 mm annual rainfall, >60% soil saturation), whereas red populations are found in Mediterranean and in semiarid sites, and in soils with high (>15%) soil calcium carbonate (CaCO3) content. Greater soil electrical conductance (salts and water) was predictive of earlier first flowers. Flowering started earlier in Mediterranean than in semiarid plots, and earlier in non-red than in red flowers. Temperature and soil potassium concentrations (for non-red flowers) or sand content (for red flowers) were predictive of the timing of peak flowering.
Conclusions: The spatiotemporal patterns of FCP in A. coronaria may reflect adaptation of red flowers to stressful semiarid abiotic conditions and to pollinator preferences. Abiotic conditions that delay flowering may benefit red anemones by enhancing their probability of encountering glaphyrid beetles, their specialized pollinators.
{"title":"Color polymorphism in Anemone coronaria: Correlations with soil, climate, and flowering phenology.","authors":"Tzlil Labin, Banisha Phukela, Tamar Keasar, Nirit Lavie-Alon, Yuval Sapir","doi":"10.1002/ajb2.70093","DOIUrl":"https://doi.org/10.1002/ajb2.70093","url":null,"abstract":"<p><strong>Premise: </strong>Flower color polymorphism (FCP) is thought to be driven by multiple selection agents. Although widely associated with visual attraction of multiple pollinators, FCP is also often correlated with abiotic factors. We explored the links between abiotic conditions, flowering phenology, and FCP in the winter-flowering geophyte Anemone coronaria L., which forms color-polymorphic or red-only populations.</p><p><strong>Methods: </strong>We mapped the geographical distribution of color diversity in A. coronaria in Israel using citizen-science data. We recorded the phenology and density of red and non-red flowers during two flowering seasons in 18 plots along a rainfall gradient. We related the spatiotemporal data to soil and climate measures.</p><p><strong>Results: </strong>Color-polymorphic populations are restricted to Mediterranean sites (>450 mm annual rainfall, >60% soil saturation), whereas red populations are found in Mediterranean and in semiarid sites, and in soils with high (>15%) soil calcium carbonate (CaCO<sub>3</sub>) content. Greater soil electrical conductance (salts and water) was predictive of earlier first flowers. Flowering started earlier in Mediterranean than in semiarid plots, and earlier in non-red than in red flowers. Temperature and soil potassium concentrations (for non-red flowers) or sand content (for red flowers) were predictive of the timing of peak flowering.</p><p><strong>Conclusions: </strong>The spatiotemporal patterns of FCP in A. coronaria may reflect adaptation of red flowers to stressful semiarid abiotic conditions and to pollinator preferences. Abiotic conditions that delay flowering may benefit red anemones by enhancing their probability of encountering glaphyrid beetles, their specialized pollinators.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70093"},"PeriodicalIF":2.7,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144991120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hanna Makowski, Keric Lamb, Austin M. Kim, Emily Scott, Laura F. Galloway
Premise
Transitions from outcrossing to selfing often drive the evolution of floral traits in a predictable way. However, these expectations are not as straightforward for mixed-mating systems. In this study, we examine variation in pollen-collecting hairs, a floral structure involved in secondary pollen presentation within Campanulaceae. While secondary pollen presentation is hypothesized to have evolved to promote outcrossing, we evaluate the association of pollen-collecting hairs with selfing ability.
Methods
We characterized pollen-collecting hair morphology and retraction phenology in 15 populations of Campanula americana with known variation in self-fertilization ability using time-series collections and automated image analysis of pollen-collecting hair length.
Results
There was two-fold variation in the length of pollen-collecting hairs across populations that was associated with a population's within-flower selfing ability. Retraction rate of pollen-collecting hairs also varied among populations and was associated with selfing ability. Populations with greater selfing ability had longer hairs that retracted quickly early in floral anthesis.
Conclusions
We show pollen-collecting hairs, a trait thought to have evolved to promote outcrossing, is associated with within-flower selfing ability. Through developmental changes in length, pollen-collecting hairs appear to be a plastic phenotype that is both associated with autonomous selfing and with outcrossing in C. americana. This provides support for trait specialization rather than trade-offs, and for the ‘best of both worlds’ hypothesis of mixed mating-system evolution.
{"title":"Trait specialization facilitates autonomous selfing ability in a mixed-mating plant","authors":"Hanna Makowski, Keric Lamb, Austin M. Kim, Emily Scott, Laura F. Galloway","doi":"10.1002/ajb2.70095","DOIUrl":"10.1002/ajb2.70095","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Transitions from outcrossing to selfing often drive the evolution of floral traits in a predictable way. However, these expectations are not as straightforward for mixed-mating systems. In this study, we examine variation in pollen-collecting hairs, a floral structure involved in secondary pollen presentation within Campanulaceae. While secondary pollen presentation is hypothesized to have evolved to promote outcrossing, we evaluate the association of pollen-collecting hairs with selfing ability.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We characterized pollen-collecting hair morphology and retraction phenology in 15 populations of <i>Campanula americana</i> with known variation in self-fertilization ability using time-series collections and automated image analysis of pollen-collecting hair length.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>There was two-fold variation in the length of pollen-collecting hairs across populations that was associated with a population's within-flower selfing ability. Retraction rate of pollen-collecting hairs also varied among populations and was associated with selfing ability. Populations with greater selfing ability had longer hairs that retracted quickly early in floral anthesis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We show pollen-collecting hairs, a trait thought to have evolved to promote outcrossing, is associated with within-flower selfing ability. Through developmental changes in length, pollen-collecting hairs appear to be a plastic phenotype that is both associated with autonomous selfing and with outcrossing in <i>C. americana</i>. This provides support for trait specialization rather than trade-offs, and for the ‘best of both worlds’ hypothesis of mixed mating-system evolution.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 9","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70095","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144999480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kimberley J. Simpson, Claire M. Belcher, Sarah J. Baker
Premise
Humans have used fire to manage landscapes for millennia, but this use of fire is declining in many ecosystems. Understanding how plants respond to these changes is key to predicting ecosystem resilience and impacts on services such as biodiversity and carbon sequestration. However, many ecosystems lack data on plant fire responses. A solution is to infer these responses through studying functional traits that offer fitness benefits under fire by enabling species to resist fire, or persist through fire, by resprouting or recruitment from stored seed banks or dispersed seed. Studying these traits helps predict species performance under fire.
Methods
We used a trait-based approach to create a database of fire-relevant traits and fire responses for vascular and nonvascular plant species in UK heath and mire ecosystems managed by fire. By reviewing the available literature, we collected data on traits adaptive under frequent burns for 153 plant taxa that could then be used to make predictions about fire effects.
Results
Of the 153 taxa assessed, 97% had fire-adaptive traits; 149 taxa had resistance and/or persistence traits, enabling survival or regeneration after fire. Additionally, 20 taxa showed fire-enhanced recruitment, while only four lacked traits aiding survival during or after fire.
Conclusions
The database created here is designed to be a resource for those who study and manage heath and mire ecosystems. The use of fire in areas where heath is underlain by peat is much debated, and this database can inform how changing or removing the use of fire will impact plant communities.
{"title":"Adaptive plant traits under anthropogenic burning regimes: A database for UK heath and mire plant species","authors":"Kimberley J. Simpson, Claire M. Belcher, Sarah J. Baker","doi":"10.1002/ajb2.70090","DOIUrl":"10.1002/ajb2.70090","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Humans have used fire to manage landscapes for millennia, but this use of fire is declining in many ecosystems. Understanding how plants respond to these changes is key to predicting ecosystem resilience and impacts on services such as biodiversity and carbon sequestration. However, many ecosystems lack data on plant fire responses. A solution is to infer these responses through studying functional traits that offer fitness benefits under fire by enabling species to resist fire, or persist through fire, by resprouting or recruitment from stored seed banks or dispersed seed. Studying these traits helps predict species performance under fire.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used a trait-based approach to create a database of fire-relevant traits and fire responses for vascular and nonvascular plant species in UK heath and mire ecosystems managed by fire. By reviewing the available literature, we collected data on traits adaptive under frequent burns for 153 plant taxa that could then be used to make predictions about fire effects.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Of the 153 taxa assessed, 97% had fire-adaptive traits; 149 taxa had resistance and/or persistence traits, enabling survival or regeneration after fire. Additionally, 20 taxa showed fire-enhanced recruitment, while only four lacked traits aiding survival during or after fire.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The database created here is designed to be a resource for those who study and manage heath and mire ecosystems. The use of fire in areas where heath is underlain by peat is much debated, and this database can inform how changing or removing the use of fire will impact plant communities.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 10","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70090","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144939388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Niger Sultana, Cate Macinnis-Ng, Sarah J. Richardson, Md Azharul Alam, Xinglei Cui, Sarah V. Wyse, Daniel C. Laughlin, Katherine Seward, George L. W. Perry, Timothy J. Curran
Premise
Relationships between flammability and drought tolerance influence vegetation dynamics during fires. A goal of the emerging subdiscipline of pyro-ecophysiology is to identify ecophysiological traits that determine live fuel flammability, but empirical studies of these relationships are rare. Furthermore, drought tolerance has been suggested as a surrogate for low flammability when choosing species to plant near houses in fire-prone areas, but this hypothesis has not been tested.
Methods
We examined links between flammability and drought tolerance for 39 woody species, compiling existing data on shoot flammability and six drought-related variables: minimum leaf water potential (Ψmin; N = 15 species), leaf turgor loss point (πtlp; N = 20), root zone water deficits (N = 19), days to plant death (N = 14), xylem embolism resistance (P50; N = 20), and wood density (WD; N = 20).
Results
Drought-tolerant species did not have low shoot flammability, except for a negative relationship between ignition percentage and WD, and then only for conifers. In contrast, there were significant negative relationships between four of five shoot flammability variables and either or both Ψmin and πtlp, showing that the most drought-tolerant species were also the most flammable. Ψmin and πtlp were positively associated with leaf water status, producing higher correlations with shoot flammability than other drought-response indicators.
Conclusions
Pyro-ecophysiological traits, e.g. Ψmin and πtlp, are useful predictors of interspecific variation in live fuel flammability, showing how pyro-ecophysiology can provide insights into how plants might respond to a more drought- and fire-prone future.
前提：可燃性和耐旱性之间的关系影响火灾期间植被的动态。热生态生理学这一新兴分支学科的一个目标是确定决定燃料可燃性的生态生理特征，但对这些关系的实证研究很少。此外，在选择在火灾易发地区的房屋附近种植的树种时，耐旱性被认为是低可燃性的替代品，但这一假设尚未得到验证。方法：对39种木本植物的可燃性与耐旱性之间的关系进行了研究，收集了现有的6个与干旱相关的变量：最小叶片水势（Ψmin; N = 15种）、叶片膨松损失点（πtlp; N = 20）、根区水分缺水量（N = 19）、植株死亡时间（N = 14）、木质部栓塞抗性（P50; N = 20）和木材密度（WD; N = 20）。结果：耐旱树种的枝梢可燃性不低，但与WD呈负相关，其次为针叶树；相反，5个可燃性变量中有4个与Ψmin和π - tlp或两者均呈显著负相关，说明最耐旱的树种也是最易燃的树种。Ψmin和π - tlp与叶片水分状态呈正相关，与茎部可燃性的相关性高于其他干旱响应指标。结论：高温生态生理特征，如Ψmin和π - tlp，是生物燃料可燃性种间变化的有效预测因子，表明高温生态生理可以为植物如何应对更干旱和火灾的未来提供见解。
{"title":"Testing key tenets of pyro-ecophysiology: Indicators of drought response in relation to shoot flammability","authors":"Niger Sultana, Cate Macinnis-Ng, Sarah J. Richardson, Md Azharul Alam, Xinglei Cui, Sarah V. Wyse, Daniel C. Laughlin, Katherine Seward, George L. W. Perry, Timothy J. Curran","doi":"10.1002/ajb2.70091","DOIUrl":"10.1002/ajb2.70091","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Relationships between flammability and drought tolerance influence vegetation dynamics during fires. A goal of the emerging subdiscipline of pyro-ecophysiology is to identify ecophysiological traits that determine live fuel flammability, but empirical studies of these relationships are rare. Furthermore, drought tolerance has been suggested as a surrogate for low flammability when choosing species to plant near houses in fire-prone areas, but this hypothesis has not been tested.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We examined links between flammability and drought tolerance for 39 woody species, compiling existing data on shoot flammability and six drought-related variables: minimum leaf water potential (<i>Ψ</i><sub>min</sub>; <i>N</i> = 15 species), leaf turgor loss point (<i>π</i><sub>tlp</sub>; <i>N</i> = 20), root zone water deficits (<i>N</i> = 19), days to plant death (<i>N</i> = 14), xylem embolism resistance (P<sub>50</sub>; <i>N</i> = 20), and wood density (WD; <i>N</i> = 20).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Drought-tolerant species did not have low shoot flammability, except for a negative relationship between ignition percentage and WD, and then only for conifers. In contrast, there were significant negative relationships between four of five shoot flammability variables and either or both <i>Ψ</i><sub>min</sub> and <i>π</i><sub>tlp</sub>, showing that the most drought-tolerant species were also the most flammable. <i>Ψ</i><sub>min</sub> and <i>π</i><sub>tlp</sub> were positively associated with leaf water status, producing higher correlations with shoot flammability than other drought-response indicators.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Pyro-ecophysiological traits, e.g. <i>Ψ</i><sub>min</sub> and <i>π</i><sub>tlp</sub>, are useful predictors of interspecific variation in live fuel flammability, showing how pyro-ecophysiology can provide insights into how plants might respond to a more drought- and fire-prone future.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 10","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70091","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144939382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniele Buono, Gudrun Kadereit, Aaron Liston, Shahin Zarre, Diego F. Morales-Briones
Premise
With over 3100 species, Astragalus L. (Fabaceae) has long fascinated botanists as the largest genus of flowering plants. With an origin in the Middle Miocene, Astragalus has one of the highest diversification rates known in flowering plants. Comprehensive taxonomic treatments exist, and the genus is currently subdivided into 136 sections in the eastern hemisphere and 93 sections in the western hemisphere based on morphological characters. Despite considerable efforts, a comprehensive and well-resolved phylogeny of the genus is still lacking.
Methods
Here, we reconstruct the backbone phylogeny of Astragalus using a custom bait set capturing 819 loci specifically designed for a target enrichment approach in the Astragalean clade. We carefully selected a set of 107 taxa representing all major clades currently recognized in Astragalus. Of those, 80 newly sequenced taxa were obtained from herbarium specimens as old as 110 years.
Results
We retrieved all the targeted loci and additional off-target plastome sequences for all samples, including the 80 herbarium specimens. Our phylogenetic analysis reinforced the currently accepted backbone phylogeny of Astragalus with high support and novel details, additionally providing insights into cytonuclear phylogenetic conflicts in the genus. Evidence for potential reticulate evolution was found, providing a possible explanation for the conflicts observed.
Conclusions
This work represents an important milestone in obtaining a comprehensive, herbarium-based phylogeny of Astragalus, which will constitute the base to study a wealth of relevant biological questions, for example, the still unanswered question of what drove the rapid diversification of Astragalus, with important repercussions on our understanding of diversification in natural contexts.
{"title":"Building a robust backbone for Astragalus using a clade-specific target enrichment bait set","authors":"Daniele Buono, Gudrun Kadereit, Aaron Liston, Shahin Zarre, Diego F. Morales-Briones","doi":"10.1002/ajb2.70084","DOIUrl":"10.1002/ajb2.70084","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>With over 3100 species, <i>Astragalus</i> L. (Fabaceae) has long fascinated botanists as the largest genus of flowering plants. With an origin in the Middle Miocene, <i>Astragalus</i> has one of the highest diversification rates known in flowering plants. Comprehensive taxonomic treatments exist, and the genus is currently subdivided into 136 sections in the eastern hemisphere and 93 sections in the western hemisphere based on morphological characters. Despite considerable efforts, a comprehensive and well-resolved phylogeny of the genus is still lacking.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Here, we reconstruct the backbone phylogeny of <i>Astragalus</i> using a custom bait set capturing 819 loci specifically designed for a target enrichment approach in the Astragalean clade. We carefully selected a set of 107 taxa representing all major clades currently recognized in <i>Astragalus</i>. Of those, 80 newly sequenced taxa were obtained from herbarium specimens as old as 110 years.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We retrieved all the targeted loci and additional off-target plastome sequences for all samples, including the 80 herbarium specimens. Our phylogenetic analysis reinforced the currently accepted backbone phylogeny of <i>Astragalus</i> with high support and novel details, additionally providing insights into cytonuclear phylogenetic conflicts in the genus. Evidence for potential reticulate evolution was found, providing a possible explanation for the conflicts observed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This work represents an important milestone in obtaining a comprehensive, herbarium-based phylogeny of <i>Astragalus</i>, which will constitute the base to study a wealth of relevant biological questions, for example, the still unanswered question of what drove the rapid diversification of <i>Astragalus</i>, with important repercussions on our understanding of diversification in natural contexts.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144870835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas J. Kooyers, Mark A. Genung, Simon G. Innes, Andrea Turcu, Donna M. Hinrichs, Benjamin J. LeBlanc, Courtney M. Patterson
Premise
The increasing frequency and severity of heat waves across the globe is well known. However, few longitudinal studies have tracked demographic change and fitness within natural populations, and fewer still have spanned multiple extreme events. Determining how organisms tolerate, respond, and potentially adapt to extreme events is key for assessing long-term population viability.
Methods
We examined how mortality, fecundity, seed provisioning, and offspring germination differed across 12 populations of annual common monkeyflower (Mimulus guttatus) over 5 years.
Results
Two heat waves occurred within the study: a heat wave within the first 10 days of the growing season in 2019 and a heat dome event nearly a month into the growing season in 2021. Mortality was high, and fecundity decreased in a population-specific manner following each heat wave. However, the 2021 heat dome caused declines of 34.5% in seed size and 22.1% in the ability to germinate, while the 2019 heat wave did not significantly affect either. Structural equation models indicated that similar climatic factors—including early-season maximum temperatures and late-season precipitation—are associated with declines in fecundity and slower germination.
Conclusions
These results suggest that the consequences of heat waves will depend on the relative severity and timing of the heat wave in the growing season, and further suggest that this timing may have amplified longer-term impacts because offspring have less provisioning. Specifically, with growing seasons shifting earlier into the spring, later or slower germination could exacerbate population extirpation risk.
{"title":"Heat waves decrease fitness and alter maternal provisioning in natural populations of Mimulus guttatus","authors":"Nicholas J. Kooyers, Mark A. Genung, Simon G. Innes, Andrea Turcu, Donna M. Hinrichs, Benjamin J. LeBlanc, Courtney M. Patterson","doi":"10.1002/ajb2.70087","DOIUrl":"10.1002/ajb2.70087","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The increasing frequency and severity of heat waves across the globe is well known. However, few longitudinal studies have tracked demographic change and fitness within natural populations, and fewer still have spanned multiple extreme events. Determining how organisms tolerate, respond, and potentially adapt to extreme events is key for assessing long-term population viability.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We examined how mortality, fecundity, seed provisioning, and offspring germination differed across 12 populations of annual common monkeyflower (<i>Mimulus guttatus</i>) over 5 years.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Two heat waves occurred within the study: a heat wave within the first 10 days of the growing season in 2019 and a heat dome event nearly a month into the growing season in 2021. Mortality was high, and fecundity decreased in a population-specific manner following each heat wave. However, the 2021 heat dome caused declines of 34.5% in seed size and 22.1% in the ability to germinate, while the 2019 heat wave did not significantly affect either. Structural equation models indicated that similar climatic factors—including early-season maximum temperatures and late-season precipitation—are associated with declines in fecundity and slower germination.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These results suggest that the consequences of heat waves will depend on the relative severity and timing of the heat wave in the growing season, and further suggest that this timing may have amplified longer-term impacts because offspring have less provisioning. Specifically, with growing seasons shifting earlier into the spring, later or slower germination could exacerbate population extirpation risk.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144870836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ian S. Pearse, Zoe Becker, Paul J. Ode, John F. Gaskin, Natalie M. West
Premise
Clonality, a form of asexual reproduction and spread, is common among invasive plants, though sexual reproduction via seeds is often still important for their long-range dispersal. In small populations, clonality has been hypothesized to interfere with sexual reproduction by limiting outcrossing opportunities of a plant.
Methods
We developed a structural equation model based on estimates of genetic diversity and seed production of Lepidium draba, a problematic invasive clonal plant, at 26 sites in Colorado to test whether site characteristics relating to small founder populations resulted in low genetic diversity and sexual reproduction. The next year, in pollen supplementation experiments at six sites (three with high genetic diversity, three with low), we tested whether populations with low genetic diversity were limited by non-self pollen.
Results
Large populations and populations associated with rivers tended to have higher genetic diversity. Percentage seed fill and total seed production were considerably higher at sites with higher genetic diversity. At populations with low genetic diversity, supplementation with pollen from outside of the site, but not from within the site, increased seed production. At populations with high genetic diversity, pollen supplementation from off-site did not increase seed production.
Conclusions
Our study shows that, in low-diversity populations that are dominated by a few large clones, L. draba produces few seeds compared to high-diversity populations and that this appears to be due to limited availability of non-self pollen. The data indicate that low genetic diversity decreases sexual reproduction, which may greatly reduce long-distance dispersal from these populations.
{"title":"Low genetic diversity in populations of a clonal invasive plant limits sexual reproduction","authors":"Ian S. Pearse, Zoe Becker, Paul J. Ode, John F. Gaskin, Natalie M. West","doi":"10.1002/ajb2.70083","DOIUrl":"10.1002/ajb2.70083","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Clonality, a form of asexual reproduction and spread, is common among invasive plants, though sexual reproduction via seeds is often still important for their long-range dispersal. In small populations, clonality has been hypothesized to interfere with sexual reproduction by limiting outcrossing opportunities of a plant.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We developed a structural equation model based on estimates of genetic diversity and seed production of <i>Lepidium draba</i>, a problematic invasive clonal plant, at 26 sites in Colorado to test whether site characteristics relating to small founder populations resulted in low genetic diversity and sexual reproduction. The next year, in pollen supplementation experiments at six sites (three with high genetic diversity, three with low), we tested whether populations with low genetic diversity were limited by non-self pollen.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Large populations and populations associated with rivers tended to have higher genetic diversity. Percentage seed fill and total seed production were considerably higher at sites with higher genetic diversity. At populations with low genetic diversity, supplementation with pollen from outside of the site, but not from within the site, increased seed production. At populations with high genetic diversity, pollen supplementation from off-site did not increase seed production.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our study shows that, in low-diversity populations that are dominated by a few large clones, <i>L. draba</i> produces few seeds compared to high-diversity populations and that this appears to be due to limited availability of non-self pollen. The data indicate that low genetic diversity decreases sexual reproduction, which may greatly reduce long-distance dispersal from these populations.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large-scale disturbances significantly impact forest dynamics, structure, and biodiversity. Lianas proliferate rapidly after such events, likely through clonal reproduction. Understanding this process is challenging because it requires precise disturbance history and accurate estimation of whether individuals originated from clonal reproduction, seed reproduction, or preexisting vegetation.
Methods
We examined whether clonal reproduction drives liana proliferation in both early successional and mature forest conditions by analyzing the dominant liana species (Trachelospermum asiaticum var. asiaticum; Apocynaceae) in temperate forests on a volcanic island. The study included young forests recovering from a volcanic eruption 22 yr ago and old-growth forests unaffected by eruptions for >800 yr. We established six 100 m2 quadrats (three in each forest type), sampled 586 individuals, and used 11 microsatellite markers to assess genetic structure.
Results
Significant clonal expansion was observed in both forest types, but stem density and genetic diversity varied markedly. Old-growth forests had 14 times greater stem density and five times more genets (clones) than young forests, and exhibited unexpectedly greater clonal diversity despite their advanced successional stage. This indicates that clonal reproduction results in high abundance in both forest conditions, while both seed and clonal reproduction enhance clonal diversity in old-growth forests.
Conclusions
Our analysis revealed that a few genets, recruited via seed dispersal in early successional stages, rapidly expanded through extensive clonal reproduction, leading to long-term liana proliferation. These findings highlight how clonality and seed recruitment, together with environmental changes during succession, shape the population dynamics and clonal diversity of lianas following disturbances.
前提：大尺度扰动显著影响森林动态、结构和生物多样性。藤本植物在这些事件之后迅速繁殖，可能是通过无性繁殖。理解这一过程是具有挑战性的，因为它需要精确的干扰历史和准确的估计个体是来自无性繁殖、种子繁殖还是先前存在的植被。方法：通过分析优势藤本植物(Trachelospermum asiaticum var. asiaticum；夹竹桃科)生长于火山岛上的温带森林中。这项研究包括从22年前的火山爆发中恢复过来的年轻森林和800年前未受火山爆发影响的原始森林。我们建立了6个100 m2样方（每个森林类型3个），取样586个个体，使用11个微卫星标记对遗传结构进行评估。结果：两种林型克隆扩增均显著，但茎密度和遗传多样性差异显著。原生林的茎密度是幼林的14倍，基因（无性系）是幼林的5倍，尽管其演替阶段较晚，但却表现出出乎意料的更高的无性系多样性。这表明，在两种森林条件下，无性系繁殖都导致高丰度，而种子繁殖和无性系繁殖都增加了原生林的无性系多样性。结论：我们的分析表明，在演替早期通过种子传播获得的一些基因，通过广泛的无性系繁殖迅速扩展，导致藤本植物的长期增殖。这些发现强调了在演替过程中，无性系和种子招募以及环境变化如何影响干扰后藤本植物的种群动态和无性系多样性。
{"title":"Clonal reproduction as a driver of liana proliferation following large-scale disturbances in temperate forests","authors":"Hideki Mori, Takashi Kamijo","doi":"10.1002/ajb2.70085","DOIUrl":"10.1002/ajb2.70085","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Large-scale disturbances significantly impact forest dynamics, structure, and biodiversity. Lianas proliferate rapidly after such events, likely through clonal reproduction. Understanding this process is challenging because it requires precise disturbance history and accurate estimation of whether individuals originated from clonal reproduction, seed reproduction, or preexisting vegetation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We examined whether clonal reproduction drives liana proliferation in both early successional and mature forest conditions by analyzing the dominant liana species (<i>Trachelospermum asiaticum</i> var. <i>asiaticum</i>; Apocynaceae) in temperate forests on a volcanic island. The study included young forests recovering from a volcanic eruption 22 yr ago and old-growth forests unaffected by eruptions for >800 yr. We established six 100 m<sup>2</sup> quadrats (three in each forest type), sampled 586 individuals, and used 11 microsatellite markers to assess genetic structure.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Significant clonal expansion was observed in both forest types, but stem density and genetic diversity varied markedly. Old-growth forests had 14 times greater stem density and five times more genets (clones) than young forests, and exhibited unexpectedly greater clonal diversity despite their advanced successional stage. This indicates that clonal reproduction results in high abundance in both forest conditions, while both seed and clonal reproduction enhance clonal diversity in old-growth forests.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our analysis revealed that a few genets, recruited via seed dispersal in early successional stages, rapidly expanded through extensive clonal reproduction, leading to long-term liana proliferation. These findings highlight how clonality and seed recruitment, together with environmental changes during succession, shape the population dynamics and clonal diversity of lianas following disturbances.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70085","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144833748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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