Riley D. Thoen, Lauren B. Hendricks, Graham T. Bailes, Bart R. Johnson, Laurel Pfeifer-Meister, Paul B. Reed, Bitty A. Roy, Megan L. DeMarche
Premise
Understanding how population dynamics vary in space and time is critical for understanding the basic life history and conservation needs of a species, especially for narrow endemic species whose populations are often in similar environments and therefore at increased risk of extinction under climate change. Here, we investigated the spatial and temporal variation in population dynamics of Ranunculus austro-oreganus, a perennial buttercup endemic to fragmented prairie habitat in one county in southern Oregon.
Methods
We performed demographic surveys of three populations of R. austro-oreganus over 4 years (2015–2018). We used size-structured population models and life table response experiments to investigate vital rates driving spatiotemporal variation in population growth.
Results
Overall, R. austro-oreganus had positive or stable stochastic population growth rates, though individual vital rates and overall population growth varied substantially among sites and years. All populations had their greatest growth in the same year, suggesting potential synchrony associated with climate conditions. Differences in survival contributed most to spatial variation in population growth, while differences in reproduction contributed most to temporal variation in population growth.
Conclusions
Populations of this extremely narrow endemic appear stable, with positive growth during our study window. These results suggest that populations of R. austro-oreganus are able to persist if their habitat is not eliminated by land-use change. Nonetheless, its narrow distribution and synchronous population dynamics suggest the need for continued monitoring, particularly with ongoing habitat loss and climate change.
{"title":"Spatiotemporal variation in population dynamics of a narrow endemic, Ranunculus austro-oreganus","authors":"Riley D. Thoen, Lauren B. Hendricks, Graham T. Bailes, Bart R. Johnson, Laurel Pfeifer-Meister, Paul B. Reed, Bitty A. Roy, Megan L. DeMarche","doi":"10.1002/ajb2.16446","DOIUrl":"10.1002/ajb2.16446","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Understanding how population dynamics vary in space and time is critical for understanding the basic life history and conservation needs of a species, especially for narrow endemic species whose populations are often in similar environments and therefore at increased risk of extinction under climate change. Here, we investigated the spatial and temporal variation in population dynamics of <i>Ranunculus austro-oreganus</i>, a perennial buttercup endemic to fragmented prairie habitat in one county in southern Oregon.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We performed demographic surveys of three populations of <i>R. austro-oreganus</i> over 4 years (2015–2018). We used size-structured population models and life table response experiments to investigate vital rates driving spatiotemporal variation in population growth.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Overall, <i>R. austro-oreganus</i> had positive or stable stochastic population growth rates, though individual vital rates and overall population growth varied substantially among sites and years. All populations had their greatest growth in the same year, suggesting potential synchrony associated with climate conditions. Differences in survival contributed most to spatial variation in population growth, while differences in reproduction contributed most to temporal variation in population growth.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Populations of this extremely narrow endemic appear stable, with positive growth during our study window. These results suggest that populations of <i>R. austro-oreganus</i> are able to persist if their habitat is not eliminated by land-use change. Nonetheless, its narrow distribution and synchronous population dynamics suggest the need for continued monitoring, particularly with ongoing habitat loss and climate change.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11744433/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845590","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}
Hydraulic segmentation, caused by the difference in embolism resistance across plant organs, provides a sacrificial layer of cheaper plant organs, like leaves, to protect more costly organs, such as stems, during drought. Within-leaf hydraulic segmentation has been observed in two compound-leaved tree species, with leaflets being more vulnerable than the rachis or petiole. Many herbaceous species have compound leaves, and some species have leaflets that are associated with pulvini at the base of the lamina, which could provide an anatomical means of preventing embolism from spreading within a leaf because of the higher number of vessel endings in the pulvinus.
Methods
We used the optical vulnerability method to investigate whether differences in embolism resistance were observed across the leaf tissues of six herbaceous species and one deciduous tree species with compound leaves. Our species selection included both palmately and pinnately-compound leaved species, one of each with a pulvinus at the base of the leaflets.
Results
We found considerable variation in embolism resistance across the species measured, but no evidence of variation in embolism resistance within the leaf. In two species with pulvini, we observed major embolism events crossing the pulvinus, spreading from the rachis or petiole into the lamina, and embolizing both tissues at the same water potential.
Conclusions
We conclude that within-leaf hydraulic segmentation, caused by variation in embolism resistance, is not a universal phenomenon to compound-leaved species and that the presence of a pulvinus does not provide a barrier to embolism spread in compound leaves.
{"title":"Within-leaf variation in embolism resistance is not a rule for compound-leaved angiosperms","authors":"Ian M. Rimer, Scott A. M. McAdam","doi":"10.1002/ajb2.16447","DOIUrl":"10.1002/ajb2.16447","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Hydraulic segmentation, caused by the difference in embolism resistance across plant organs, provides a sacrificial layer of cheaper plant organs, like leaves, to protect more costly organs, such as stems, during drought. Within-leaf hydraulic segmentation has been observed in two compound-leaved tree species, with leaflets being more vulnerable than the rachis or petiole. Many herbaceous species have compound leaves, and some species have leaflets that are associated with pulvini at the base of the lamina, which could provide an anatomical means of preventing embolism from spreading within a leaf because of the higher number of vessel endings in the pulvinus.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used the optical vulnerability method to investigate whether differences in embolism resistance were observed across the leaf tissues of six herbaceous species and one deciduous tree species with compound leaves. Our species selection included both palmately and pinnately-compound leaved species, one of each with a pulvinus at the base of the leaflets.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found considerable variation in embolism resistance across the species measured, but no evidence of variation in embolism resistance within the leaf. In two species with pulvini, we observed major embolism events crossing the pulvinus, spreading from the rachis or petiole into the lamina, and embolizing both tissues at the same water potential.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We conclude that within-leaf hydraulic segmentation, caused by variation in embolism resistance, is not a universal phenomenon to compound-leaved species and that the presence of a pulvinus does not provide a barrier to embolism spread in compound leaves.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16447","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142833550","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}
Caio César Pires de Paula, Jiří Bárta, Jakub Borovec, Jan Frouz, Pavel Rychtecký, Dagmara Sirová
Premise
Despite the high functional importance of endophytes, we still have limited understanding of the biotic and abiotic factors that influence colonization of plant hosts along major ecological gradients and lack quantitative estimates of their colonization extent. In this study, we hypothesized that the developmental stage of the ecosystem will affect the levels of bacterial and fungal endophytic assemblages in the foliar endosphere.
Methods
We quantified levels of bacterial and fungal endophytes in leaves of four plant hosts at four stages of vegetation succession using an optimized qPCR protocol with bacteria-specific 16S and fungi-targeting primers.
Results
(1) The ecosystem developmental stage did not have a significant effect on the colonization levels of bacterial or fungal endophytes. (2) Colonization levels by bacterial and fungal endophytes were governed by different mechanisms. (3) Endophytic colonization levels and their relationship to foliar tissue stoichiometry were highly host specific.
Conclusions
Quantifying colonization levels is important in the study of endophytic ecology, and the fast, relatively low-cost qPCR-based method can supply useful ecological information, which can significantly enhance the interpretation potential of descriptive data generated, for example, by next-generation sequencing.
{"title":"qPCR-based quantification reveals high plant host-specificity of endophytic colonization levels in leaves","authors":"Caio César Pires de Paula, Jiří Bárta, Jakub Borovec, Jan Frouz, Pavel Rychtecký, Dagmara Sirová","doi":"10.1002/ajb2.16448","DOIUrl":"10.1002/ajb2.16448","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Despite the high functional importance of endophytes, we still have limited understanding of the biotic and abiotic factors that influence colonization of plant hosts along major ecological gradients and lack quantitative estimates of their colonization extent. In this study, we hypothesized that the developmental stage of the ecosystem will affect the levels of bacterial and fungal endophytic assemblages in the foliar endosphere.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We quantified levels of bacterial and fungal endophytes in leaves of four plant hosts at four stages of vegetation succession using an optimized qPCR protocol with bacteria-specific 16S and fungi-targeting primers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>(1) The ecosystem developmental stage did not have a significant effect on the colonization levels of bacterial or fungal endophytes. (2) Colonization levels by bacterial and fungal endophytes were governed by different mechanisms. (3) Endophytic colonization levels and their relationship to foliar tissue stoichiometry were highly host specific.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Quantifying colonization levels is important in the study of endophytic ecology, and the fast, relatively low-cost qPCR-based method can supply useful ecological information, which can significantly enhance the interpretation potential of descriptive data generated, for example, by next-generation sequencing.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11744438/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142833538","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}
Luis Y. Santiago-Rosario, Jordan Book, Sarah Mathews
Premise
Showy mistletoes are obligate hemiparasites of woody plants. Host specificity is therefore a fundamental determinant of mistletoe diversity, persistence, geographic distribution, and abundance. Investigations of host specificity in Australian Loranthaceae have focused mostly on host range (taxon counts), but additional insights into specificity are gained by quantifying mistletoe prevalence on taxa in their host range and by exploring specificity in a phylogenetic context.
Methods
We estimated measures of host specificity to characterize mistletoe–host interactions at a continental scale by using occurrence records in the Atlas of Living Australia. We calculated host taxon richness, mistletoe prevalence, and phylogenetic diversity, and used rarefaction curves to evaluate sampling coverage.
Results
Many mistletoe taxa were represented by few records that listed the host, which often was identified to genus only. Mistletoe genera were recorded on 29 orders and 80 families, and no association was observed between host richness and number of records per genus. Rarefaction curves suggested that additional host orders and families remain to be discovered for Amylotheca, Decaisnina, Dendrophthoe, and Muellerina. Four mistletoe genera were most prevalent on Myrtales, one on Fabales, and one on Laurales. Rosids were most often the recorded hosts (84.3% of all records). We found evidence of significant phylogenetic clustering in host use by Amyema, Amylotheca, and Decasinina.
Conclusions
Our results, particularly the high prevalence on rosids, suggest that relationships of mistletoes with rainforest lineages may have been established early in the history of Australian Loranthaceae and that some lineages co-diversified with their hosts in arid regions.
{"title":"Continental-scale interactions of Australian showy mistletoes and their hosts","authors":"Luis Y. Santiago-Rosario, Jordan Book, Sarah Mathews","doi":"10.1002/ajb2.16443","DOIUrl":"10.1002/ajb2.16443","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Showy mistletoes are obligate hemiparasites of woody plants. Host specificity is therefore a fundamental determinant of mistletoe diversity, persistence, geographic distribution, and abundance. Investigations of host specificity in Australian Loranthaceae have focused mostly on host range (taxon counts), but additional insights into specificity are gained by quantifying mistletoe prevalence on taxa in their host range and by exploring specificity in a phylogenetic context.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We estimated measures of host specificity to characterize mistletoe–host interactions at a continental scale by using occurrence records in the Atlas of Living Australia. We calculated host taxon richness, mistletoe prevalence, and phylogenetic diversity, and used rarefaction curves to evaluate sampling coverage.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Many mistletoe taxa were represented by few records that listed the host, which often was identified to genus only. Mistletoe genera were recorded on 29 orders and 80 families, and no association was observed between host richness and number of records per genus. Rarefaction curves suggested that additional host orders and families remain to be discovered for <i>Amylotheca</i>, <i>Decaisnina</i>, <i>Dendrophthoe</i>, and <i>Muellerina</i>. Four mistletoe genera were most prevalent on Myrtales, one on Fabales, and one on Laurales. Rosids were most often the recorded hosts (84.3% of all records). We found evidence of significant phylogenetic clustering in host use by <i>Amyema</i>, <i>Amylotheca</i>, and <i>Decasinina</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results, particularly the high prevalence on rosids, suggest that relationships of mistletoes with rainforest lineages may have been established early in the history of Australian Loranthaceae and that some lineages co-diversified with their hosts in arid regions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16443","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816973","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}
Microbes regulate many dimensions of plant performance with multiscale implications for plant fitness, competition, coexistence, and ecosystem functioning. Yet, this fascinating and diverse arena of study has been limited to a few thematic areas, ecosystems, and regions. In particular, despite growing evidence that microbes may be critical players in the dynamics of plant communities in tropical and subtropical ecosystems, these regions remain poorly represented in studies of plant–microbe interactions. Such geographical gaps limit our ability to draw general inferences to comprehend how microbial effects on plant community dynamics may vary with context and, by extension, respond to global environmental change. In this special section of the American Journal of Botany, we bring together a diverse set of research on plant–microbe interactions from tropical and subtropical ecosystems. These papers explore intraspecific variation of soil microbial communities, the context dependency of host-specific assembly of microbial communities on plants, and the new and exciting frontier of the microbiome of epiphytic plants. We hope that this compilation will fuel deeper forays into the many dimensions of plant–microbe interactions in megadiverse tropical and subtropical forests.
{"title":"Plant–microbe interactions in tropical and subtropical ecosystems","authors":"Meghna Krishnadas, Gaurav Kandlikar, Adriana Corrales","doi":"10.1002/ajb2.16444","DOIUrl":"10.1002/ajb2.16444","url":null,"abstract":"<p>Microbes regulate many dimensions of plant performance with multiscale implications for plant fitness, competition, coexistence, and ecosystem functioning. Yet, this fascinating and diverse arena of study has been limited to a few thematic areas, ecosystems, and regions. In particular, despite growing evidence that microbes may be critical players in the dynamics of plant communities in tropical and subtropical ecosystems, these regions remain poorly represented in studies of plant–microbe interactions. Such geographical gaps limit our ability to draw general inferences to comprehend how microbial effects on plant community dynamics may vary with context and, by extension, respond to global environmental change. In this special section of the <i>American Journal of Botany</i>, we bring together a diverse set of research on plant–microbe interactions from tropical and subtropical ecosystems. These papers explore intraspecific variation of soil microbial communities, the context dependency of host-specific assembly of microbial communities on plants, and the new and exciting frontier of the microbiome of epiphytic plants. We hope that this compilation will fuel deeper forays into the many dimensions of plant–microbe interactions in megadiverse tropical and subtropical forests.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16444","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805900","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}
Peijian Shi, Linli Deng, Qinyue Miao, Long Chen, Han Yu, Fuyuan Zhu, Karl J. Niklas
Premise
Although previous studies have reported a positive correlation between leaf dry mass per unit area (LMA) and mean leaf thickness (LT), the LMA versus LT scaling relationship has not been determined due to limited sample sizes, despite its importance in estimating leaf bulk tissue density (mass per unit volume).
Methods
This issue was addressed using between 174 and 185 leaves from each of nine phylogenetically diverse species to investigate the LMA vs. LT scaling relationship. For each leaf, lamina thickness was measured at 12 positions (avoiding midribs and major veins) to calculate LT, and LMA was measured based on leaf area and dry mass measurements. Reduced major axis regression protocols were used to determine the LMA vs. LT scaling exponent (i.e., the slope). Bootstrap percentile methods were used to calculate the 95% confidence intervals of slopes.
Results
A statistically significant LMA vs. LT relationship was found for each species; seven of the nine scaling exponents were significantly greater than unity indicating that LMA (and thus leaf bulk tissue density) disproportionately increased with increasing LT. In addition, the conspecific variation in LMA exceeded the interspecific variation in LMA as a consequence of differences in LT.
Conclusions
These results indicate that empirical measurements of LMA and LT can be used to accurately estimate leaf bulk tissue density, which provides insights into adaptive life-history strategies, conspecific variation, and (with sufficiently large data sets) phylogenetic trends.
{"title":"Scaling relationships of lamina mass per unit area, mean thickness, and leaf bulk tissue density across nine diverse species","authors":"Peijian Shi, Linli Deng, Qinyue Miao, Long Chen, Han Yu, Fuyuan Zhu, Karl J. Niklas","doi":"10.1002/ajb2.16442","DOIUrl":"10.1002/ajb2.16442","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Although previous studies have reported a positive correlation between leaf dry mass per unit area (LMA) and mean leaf thickness (LT), the LMA versus LT scaling relationship has not been determined due to limited sample sizes, despite its importance in estimating leaf bulk tissue density (mass per unit volume).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This issue was addressed using between 174 and 185 leaves from each of nine phylogenetically diverse species to investigate the LMA vs. LT scaling relationship. For each leaf, lamina thickness was measured at 12 positions (avoiding midribs and major veins) to calculate LT, and LMA was measured based on leaf area and dry mass measurements. Reduced major axis regression protocols were used to determine the LMA vs. LT scaling exponent (i.e., the slope). Bootstrap percentile methods were used to calculate the 95% confidence intervals of slopes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A statistically significant LMA vs. LT relationship was found for each species; seven of the nine scaling exponents were significantly greater than unity indicating that LMA (and thus leaf bulk tissue density) disproportionately increased with increasing LT. In addition, the conspecific variation in LMA exceeded the interspecific variation in LMA as a consequence of differences in LT.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These results indicate that empirical measurements of LMA and LT can be used to accurately estimate leaf bulk tissue density, which provides insights into adaptive life-history strategies, conspecific variation, and (with sufficiently large data sets) phylogenetic trends.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790979","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}
Maiara Matilde da Silva, Maria Regina Torres Boeger, João Carlos Ferreira de Melo-Júnior
Premise
Plants can limit the leaf tissue consumed by insect herbivores through chemical, structural, and nutritional leaf defenses or by escaping in space and time. Escaping is related to the phenological patterns of plants, which in turn respond to climatic factors. This study evaluated leaf production in a coastal plant community in southern Brazil to test the following hypotheses: (1) Leaves are continuously produced in this ecosystem, and (2) synchrony acts as an escape strategy from herbivory.
Methods
We evaluated leaf production patterns of 20 herbaceous, shrub, and tree species for 2 years using the Fournier index then measured leaf consumption in the second year. The Rayleigh test was used to verify the synchrony of phenological events. Correlations between leaf production and climatic factors and between leaf production synchrony and herbivory were analyzed.
Results
New leaves were continuously produced at the plant community scale, but herbaceous and shrub species showed a phenological pattern distinct from that of tree species. Trees had peaks of synchrony in leaf production that were positively correlated with amount of leaf tissue consumed, refuting the hypothesis that synchrony acts as an escape strategy.
Conclusions
The phenological and herbivory patterns in this plant community may be due to the supply of resources in the soil and the composition of the insect community.
{"title":"Phenological indicators of resources offered to leaf herbivores in restinga communities","authors":"Maiara Matilde da Silva, Maria Regina Torres Boeger, João Carlos Ferreira de Melo-Júnior","doi":"10.1002/ajb2.16445","DOIUrl":"10.1002/ajb2.16445","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Plants can limit the leaf tissue consumed by insect herbivores through chemical, structural, and nutritional leaf defenses or by escaping in space and time. Escaping is related to the phenological patterns of plants, which in turn respond to climatic factors. This study evaluated leaf production in a coastal plant community in southern Brazil to test the following hypotheses: (1) Leaves are continuously produced in this ecosystem, and (2) synchrony acts as an escape strategy from herbivory.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We evaluated leaf production patterns of 20 herbaceous, shrub, and tree species for 2 years using the Fournier index then measured leaf consumption in the second year. The Rayleigh test was used to verify the synchrony of phenological events. Correlations between leaf production and climatic factors and between leaf production synchrony and herbivory were analyzed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>New leaves were continuously produced at the plant community scale, but herbaceous and shrub species showed a phenological pattern distinct from that of tree species. Trees had peaks of synchrony in leaf production that were positively correlated with amount of leaf tissue consumed, refuting the hypothesis that synchrony acts as an escape strategy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The phenological and herbivory patterns in this plant community may be due to the supply of resources in the soil and the composition of the insect community.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790964","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}
Ian D. Medeiros, Alicia Ibáñez, A. Elizabeth Arnold, Terry A. Hedderson, Jolanta Miadlikowska, Adam Flakus, Ignazio Carbone, Scott LaGreca, Nicolas Magain, Edyta Mazur, Reinaldo Vargas Castillo, József Geml, Maya Kaup, Gillian Maggs-Kölling, Shuzo Oita, Jaya Seelan Sathiya Seelan, Elizaveta Terlova, Erik F. Y. Hom, Louise A. Lewis, François Lutzoni
Premise
Southern Africa is a biodiversity hotspot rich in endemic plants and lichen-forming fungi. However, species-level data about lichen photobionts in this region are minimal. We focused on Trebouxia (Chlorophyta), the most common lichen photobiont, to understand how southern African species fit into the global biodiversity of this genus and are distributed across biomes and mycobiont partners.
Methods
We sequenced Trebouxia nuclear ribosomal ITS and rbcL of 139 lichen thalli from diverse biomes in South Africa and Namibia. Global Trebouxia phylogenies incorporating these new data were inferred with a maximum likelihood approach. Trebouxia biodiversity, biogeography, and mycobiont–photobiont associations were assessed in phylogenetic and ecological network frameworks.
Results
An estimated 43 putative Trebouxia species were found across the region, including seven potentially endemic species. Only five clades represent formally described species: T. arboricola s.l. (A13), T. cf. cretacea (A01), T. incrustata (A06), T. lynniae (A39), and T. maresiae (A46). Potential endemic species were not significantly associated with the Greater Cape Floristic Region or desert. Trebouxia species occurred frequently across multiple biomes. Annual precipitation, but not precipitation seasonality, was significant in explaining variation in Trebouxia communities. Consistent with other studies of lichen photobionts, the Trebouxia–mycobiont network had an anti-nested structure.
Conclusions
Depending on the metric used, ca. 20–30% of global Trebouxia biodiversity occurs in southern Africa, including many species yet to be described. With a classification scheme for Trebouxia now well established, tree-based approaches are preferable over “barcode gap” methods for delimiting new species.
{"title":"Eco-phylogenetic study of Trebouxia in southern Africa reveals interbiome connectivity and potential endemism in a green algal lichen photobiont","authors":"Ian D. Medeiros, Alicia Ibáñez, A. Elizabeth Arnold, Terry A. Hedderson, Jolanta Miadlikowska, Adam Flakus, Ignazio Carbone, Scott LaGreca, Nicolas Magain, Edyta Mazur, Reinaldo Vargas Castillo, József Geml, Maya Kaup, Gillian Maggs-Kölling, Shuzo Oita, Jaya Seelan Sathiya Seelan, Elizaveta Terlova, Erik F. Y. Hom, Louise A. Lewis, François Lutzoni","doi":"10.1002/ajb2.16441","DOIUrl":"10.1002/ajb2.16441","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Southern Africa is a biodiversity hotspot rich in endemic plants and lichen-forming fungi. However, species-level data about lichen photobionts in this region are minimal. We focused on <i>Trebouxia</i> (Chlorophyta), the most common lichen photobiont, to understand how southern African species fit into the global biodiversity of this genus and are distributed across biomes and mycobiont partners.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We sequenced <i>Trebouxia</i> nuclear ribosomal ITS and <i>rbcL</i> of 139 lichen thalli from diverse biomes in South Africa and Namibia. Global <i>Trebouxia</i> phylogenies incorporating these new data were inferred with a maximum likelihood approach. <i>Trebouxia</i> biodiversity, biogeography, and mycobiont–photobiont associations were assessed in phylogenetic and ecological network frameworks.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>An estimated 43 putative <i>Trebouxia</i> species were found across the region, including seven potentially endemic species. Only five clades represent formally described species: <i>T. arboricola</i> s.l. (A13), <i>T</i>. cf. <i>cretacea</i> (A01), <i>T. incrustata</i> (A06), <i>T. lynniae</i> (A39), and <i>T. maresiae</i> (A46). Potential endemic species were not significantly associated with the Greater Cape Floristic Region or desert. <i>Trebouxia</i> species occurred frequently across multiple biomes. Annual precipitation, but not precipitation seasonality, was significant in explaining variation in <i>Trebouxia</i> communities. Consistent with other studies of lichen photobionts, the <i>Trebouxia</i>–mycobiont network had an anti-nested structure.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Depending on the metric used, ca. 20–30% of global <i>Trebouxia</i> biodiversity occurs in southern Africa, including many species yet to be described. With a classification scheme for <i>Trebouxia</i> now well established, tree-based approaches are preferable over “barcode gap” methods for delimiting new species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783927","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}
Audrey Labonté, Valérie Le Corre, Annick Matejicek, Emeline Felten, Mélinda Turpin, Emilien Laurent, Séverine Michel, Chantal Ducourtieux, Eric Vieren, Willem Proesmans, Violaine Deytieux, Stéphane Cordeau, Adam J. Vanbergen
Premise
Restoration of seminatural field margins can elevate pollinator activity. However, how they support wild plant gene flow through interactions between pollinators and spatiotemporal gradients in floral resources remains largely unknown.
Methods
Using a farm-scale experiment, we tested how mating outcomes (expected heterozygosity and paternity correlation) of the wild, self-incompatible plant Cyanus segetum transplanted into field margins (sown wildflower or grass-legume strips) were affected by the abundance of different pollinator functional groups (defined by species traits). We also investigated how the maternal plant attractiveness, conspecific pollen donor density, and heterospecific floral richness and density interacted with pollinator functional group abundance to modulate C. segetum mating outcomes.
Results
Multiple paternity increased (=lower paternity correlation) with greater local abundance of hoverflies (syrphids) and female medium-sized wild bees (albeit the latter's effect diminished with decreasing maternal plant attractiveness), and the presence of male bumblebees (Bombus) under low local floral richness. Cyanus segetum progeny genetic diversity increased with male Bombus presence but decreased with greater abundance of syrphids and honey bees (Apis mellifera).
Conclusions
Overall, field margins supported plant-pollinator interactions ensuring multiple paternity and conservation of allelic diversity in C. segetum progeny. The contribution to plant mating outcomes of different pollinator functional groups was dictated by their local abundance or traits affecting pollen transfer efficiency. The local floral richness or maternal plant attractiveness sometimes modulated these relationships. This complex response of wild plant mating patterns to community interactions has implications for the use of field margins to restore functional pollination systems in farmed landscapes.
前提：恢复半自然的田野边缘可以提高授粉者的活动。然而，它们如何通过传粉昆虫之间的相互作用以及花卉资源的时空梯度来支持野生植物基因流，在很大程度上仍是未知数：方法：我们利用农场规模的实验，测试了野生自交不亲和植物赛格兰（Cyanus segetum）移植到田间边缘（播种野花或草-豆科植物带）的交配结果（预期杂合度和亲子相关性）如何受到不同传粉昆虫功能群（根据物种特征定义）丰度的影响。我们还研究了母本植物的吸引力、同种花粉供体密度、异种花的丰富度和密度如何与传粉昆虫功能群的丰富度相互影响，从而调节蓝花楹的交配结果：结果：在当地花卉丰富度较低的情况下，随着食蚜蝇（蚜虫）和雌性中型野生蜜蜂（尽管后者的作用会随着母本植物吸引力的降低而减弱）在当地越多，以及雄性熊蜂（Bombus）的存在，多重父子关系越强（=父子关系相关性越低）。随着雄性熊蜂的出现，半灌木矢车菊后代的遗传多样性增加，但随着蚜虫和蜜蜂（Apis mellifera）数量的增加，遗传多样性减少：总体而言，田间边缘支持植物与授粉者之间的相互作用，确保了多父子关系，并保护了 C. segetum 后代的等位基因多样性。不同传粉昆虫功能群对植物交配结果的贡献取决于它们在当地的丰度或影响花粉传递效率的性状。当地花卉的丰富程度或母本植物的吸引力有时会调节这些关系。野生植物交配模式对群落相互作用的这种复杂反应，对利用田边恢复农耕景观中的功能性授粉系统具有重要意义。
{"title":"Pollinator functional group abundance and floral heterogeneity in an agroecological context affect mating patterns in a self-incompatible wild plant","authors":"Audrey Labonté, Valérie Le Corre, Annick Matejicek, Emeline Felten, Mélinda Turpin, Emilien Laurent, Séverine Michel, Chantal Ducourtieux, Eric Vieren, Willem Proesmans, Violaine Deytieux, Stéphane Cordeau, Adam J. Vanbergen","doi":"10.1002/ajb2.16440","DOIUrl":"10.1002/ajb2.16440","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Restoration of seminatural field margins can elevate pollinator activity. However, how they support wild plant gene flow through interactions between pollinators and spatiotemporal gradients in floral resources remains largely unknown.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using a farm-scale experiment, we tested how mating outcomes (expected heterozygosity and paternity correlation) of the wild, self-incompatible plant <i>Cyanus segetum</i> transplanted into field margins (sown wildflower or grass-legume strips) were affected by the abundance of different pollinator functional groups (defined by species traits). We also investigated how the maternal plant attractiveness, conspecific pollen donor density, and heterospecific floral richness and density interacted with pollinator functional group abundance to modulate <i>C. segetum</i> mating outcomes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Multiple paternity increased (=lower paternity correlation) with greater local abundance of hoverflies (syrphids) and female medium-sized wild bees (albeit the latter's effect diminished with decreasing maternal plant attractiveness), and the presence of male bumblebees (<i>Bombus</i>) under low local floral richness. <i>Cyanus segetum</i> progeny genetic diversity increased with male <i>Bombus</i> presence but decreased with greater abundance of syrphids and honey bees (<i>Apis mellifera</i>).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Overall, field margins supported plant-pollinator interactions ensuring multiple paternity and conservation of allelic diversity in <i>C. segetum</i> progeny. The contribution to plant mating outcomes of different pollinator functional groups was dictated by their local abundance or traits affecting pollen transfer efficiency. The local floral richness or maternal plant attractiveness sometimes modulated these relationships. This complex response of wild plant mating patterns to community interactions has implications for the use of field margins to restore functional pollination systems in farmed landscapes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16440","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142724374","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}
Vicky Beckers, Mary Endress, Pieter Baas, Erik Smets, Frederic Lens
Premise
This paper provides an overview of the wood anatomy of the dogbane family (Apocynaceae), reconstructs wood anatomical trait evolution, and links this evolution with woody growth-form transitions and floral and seed trait innovations across the family.
Methods
Over 200 published wood anatomical descriptions were revised, and original light microscopic sections were made and described for another 50 species. Changes in wood anatomical characters through time were visualized with ancestral state reconstructions. Tests for correlated evolution were performed using a combined data set of anatomical and key floral and seed traits to identify potential synnovations and traits associated with growth-form adaptations.
Results
There was a shift toward a suite of wood anatomical traits that separate the rauvolfioids and early-branching apocynoids from the core apocynoids, including an increased presence of vessel multiples, vessel dimorphism, laticifers, vascular (cambial) variants, and paratracheal axial parenchyma. The presence of this trait suite, which continues in Periplocoideae, Secamonoideae, and Asclepiadoideae, coincides with a progression of floral morphological innovations that evolved on consecutive nodes in the family, and also relates to more frequent transitions toward the climbing and herbaceous habits. In addition, a considerable shortening of vessel elements and fibers along the phylogenetic backbone of the family is correlated with a general reduction in plant size.
Conclusions
There are clear evolutionary transitions in the wood anatomy of Apocynaceae representing structural adaptations across the family that are associated with a quick succession of evolutionary changes of the floral bauplan.
{"title":"Apocynaceae wood evolution matches key morphological innovations","authors":"Vicky Beckers, Mary Endress, Pieter Baas, Erik Smets, Frederic Lens","doi":"10.1002/ajb2.16436","DOIUrl":"10.1002/ajb2.16436","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>This paper provides an overview of the wood anatomy of the dogbane family (Apocynaceae), reconstructs wood anatomical trait evolution, and links this evolution with woody growth-form transitions and floral and seed trait innovations across the family.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Over 200 published wood anatomical descriptions were revised, and original light microscopic sections were made and described for another 50 species. Changes in wood anatomical characters through time were visualized with ancestral state reconstructions. Tests for correlated evolution were performed using a combined data set of anatomical and key floral and seed traits to identify potential synnovations and traits associated with growth-form adaptations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>There was a shift toward a suite of wood anatomical traits that separate the rauvolfioids and early-branching apocynoids from the core apocynoids, including an increased presence of vessel multiples, vessel dimorphism, laticifers, vascular (cambial) variants, and paratracheal axial parenchyma. The presence of this trait suite, which continues in Periplocoideae, Secamonoideae, and Asclepiadoideae, coincides with a progression of floral morphological innovations that evolved on consecutive nodes in the family, and also relates to more frequent transitions toward the climbing and herbaceous habits. In addition, a considerable shortening of vessel elements and fibers along the phylogenetic backbone of the family is correlated with a general reduction in plant size.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>There are clear evolutionary transitions in the wood anatomy of Apocynaceae representing structural adaptations across the family that are associated with a quick succession of evolutionary changes of the floral bauplan.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11584039/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685708","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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