E. Hersh, Erica J. Wheeler, Brenda Costanzo, Alisa P. Ramakrishnan, Allyson E. Miscampbell, C. Ritland, J. Whitton, J. Gorrell, W. Harrower
It is often assumed that the northern periphery of species’ ranges are genetically depauperate due in part to founder effects from post-glacial colonization. The majority of federally protected plant species are peripheral in Canada, yet we have little information about their patterns of genetic diversity and structure. In British Columbia, the majority of these protected plant species occur in two threatened habitats: the Garry oak and Okanagan shrub-steppe ecosystems. Using universal non-coding chloroplast DNA markers, we investigated genetic diversity and genetic structure in four rare and common plant species pairs inhabiting these two ecosystems. We found that rare species had lower genetic diversity than their common congeners, and detected contrasting patterns of regional diversity and structure based on ecosystem. Species from the Garry oak ecosystem showed lower genetic diversity in the northern deglaciated region and significant differentiation between regions, likely due to limited dispersal between Vancouver Island and the mainland. Species from the Okanagan shrub-steppe, however, tended to have uniform diversity across their range and lack regional structure. This study provides an important first look at the phylogeographic patterns of four rare plant species in British Columbia.
{"title":"Diversity among rare and common congeneric plant species from the Garry oak and Okanagan shrub-steppe ecosystems in British Columbia: implications for conservation","authors":"E. Hersh, Erica J. Wheeler, Brenda Costanzo, Alisa P. Ramakrishnan, Allyson E. Miscampbell, C. Ritland, J. Whitton, J. Gorrell, W. Harrower","doi":"10.1139/cjb-2022-0064","DOIUrl":"https://doi.org/10.1139/cjb-2022-0064","url":null,"abstract":"It is often assumed that the northern periphery of species’ ranges are genetically depauperate due in part to founder effects from post-glacial colonization. The majority of federally protected plant species are peripheral in Canada, yet we have little information about their patterns of genetic diversity and structure. In British Columbia, the majority of these protected plant species occur in two threatened habitats: the Garry oak and Okanagan shrub-steppe ecosystems. Using universal non-coding chloroplast DNA markers, we investigated genetic diversity and genetic structure in four rare and common plant species pairs inhabiting these two ecosystems. We found that rare species had lower genetic diversity than their common congeners, and detected contrasting patterns of regional diversity and structure based on ecosystem. Species from the Garry oak ecosystem showed lower genetic diversity in the northern deglaciated region and significant differentiation between regions, likely due to limited dispersal between Vancouver Island and the mainland. Species from the Okanagan shrub-steppe, however, tended to have uniform diversity across their range and lack regional structure. This study provides an important first look at the phylogeographic patterns of four rare plant species in British Columbia.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48150540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flávio Sousa Souto, A. Silva, E. Santos, M. F. Agra
Senna ser. Bacillares comprises approximately 50 species, 23 of which are found in Brazil. Micromorphological studies of the leaflet epidermis were performed on ten species of Senna ser. Bacillares collected in the Atlantic Forest north of the São Francisco River, in Northeastern Brazil, to identify qualitative and quantitative characters supporting their taxonomy. All species showed an uniseriate epidermis, hypostomatic leaflets, and more than one type of stomata (the paracytic type being predominant). Different types of epicuticular waxes were observed, including microplatelets as rosettes (characteristic of Fabaceae), fissured layers, and membranous platelets. A glabrous epidermis on both surfaces was characteristic of S. splendida, and disperse trichomes were observed on the abaxial surface of S. quinquangulata. Straight to curved anticlinal cell walls were observed in most species, the curved pattern was exclusive to S. quinquangulata and sinuous types on the abaxial surfaces of S. macranthera and S. splendida. A papillose epidermis on the abaxial surface was common to seven species. Four types of stomata were observed, including the anomotetracytic type, which has not been previously reported in Senna. Spherical crystals and crystal sand are reported here for Senna for the first time. Those sets of micromorphological characters provide additional subsidies for the taxonomy of Senna ser. Bacillares, as well as for the genus Senna.
{"title":"Micromorphology of leaflets of Senna series Bacillares (Leguminosae) and its taxonomic significance","authors":"Flávio Sousa Souto, A. Silva, E. Santos, M. F. Agra","doi":"10.1139/cjb-2022-0060","DOIUrl":"https://doi.org/10.1139/cjb-2022-0060","url":null,"abstract":"Senna ser. Bacillares comprises approximately 50 species, 23 of which are found in Brazil. Micromorphological studies of the leaflet epidermis were performed on ten species of Senna ser. Bacillares collected in the Atlantic Forest north of the São Francisco River, in Northeastern Brazil, to identify qualitative and quantitative characters supporting their taxonomy. All species showed an uniseriate epidermis, hypostomatic leaflets, and more than one type of stomata (the paracytic type being predominant). Different types of epicuticular waxes were observed, including microplatelets as rosettes (characteristic of Fabaceae), fissured layers, and membranous platelets. A glabrous epidermis on both surfaces was characteristic of S. splendida, and disperse trichomes were observed on the abaxial surface of S. quinquangulata. Straight to curved anticlinal cell walls were observed in most species, the curved pattern was exclusive to S. quinquangulata and sinuous types on the abaxial surfaces of S. macranthera and S. splendida. A papillose epidermis on the abaxial surface was common to seven species. Four types of stomata were observed, including the anomotetracytic type, which has not been previously reported in Senna. Spherical crystals and crystal sand are reported here for Senna for the first time. Those sets of micromorphological characters provide additional subsidies for the taxonomy of Senna ser. Bacillares, as well as for the genus Senna.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44011912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Celeste Ceballos, M. C. Ferrero, N. L. Aliscioni, M. L. Las Peñas, D. Gurvich
In iteroparous plants, an increase in allocation to reproduction is expected with increasing plant size. The aim of this study was to analyze how plant diameter is related to total produced seed mass, seed number, mean seed mass, percentage and mean germination time (MGT), and seedling size and shape in Wigginsia sessiliflora (Cactaceae), a slow-growing globose species from central Argentina. Plant diameter was measured in a population of n185 individuals, and fruits were collected. We counted all seeds to obtain seed number, and weighed them to get seed mass and total seed mass. Seeds were germinated and data of germination percentage and MGT were collected. We also measured the size (height and width) and shape of seedlings (height/width relationship). Fifty four percent of the plants did not produce fruits. Plant diameter was unimodally related to fruit number, total seed mass, and seed number, i.e. intermediate-sized plants presented the highest values. Height and shape of seedlings were positively related to plant diameter. Surprisingly, plant diameter was related in a unimodal way to reproductive outputs. As plants grow, surface-volume ratio decreases, meaning that respiratory losses would be higher than the increase in photosynthetic capacity; therefore, fewer resources may be available for reproduction.
{"title":"Do larger plants produce more and better seeds and seedlings? Testing the hypothesis in a globose cactus, Wigginsia sessiliflora.","authors":"Celeste Ceballos, M. C. Ferrero, N. L. Aliscioni, M. L. Las Peñas, D. Gurvich","doi":"10.1139/cjb-2022-0063","DOIUrl":"https://doi.org/10.1139/cjb-2022-0063","url":null,"abstract":"In iteroparous plants, an increase in allocation to reproduction is expected with increasing plant size. The aim of this study was to analyze how plant diameter is related to total produced seed mass, seed number, mean seed mass, percentage and mean germination time (MGT), and seedling size and shape in Wigginsia sessiliflora (Cactaceae), a slow-growing globose species from central Argentina. Plant diameter was measured in a population of n185 individuals, and fruits were collected. We counted all seeds to obtain seed number, and weighed them to get seed mass and total seed mass. Seeds were germinated and data of germination percentage and MGT were collected. We also measured the size (height and width) and shape of seedlings (height/width relationship). Fifty four percent of the plants did not produce fruits. Plant diameter was unimodally related to fruit number, total seed mass, and seed number, i.e. intermediate-sized plants presented the highest values. Height and shape of seedlings were positively related to plant diameter. Surprisingly, plant diameter was related in a unimodal way to reproductive outputs. As plants grow, surface-volume ratio decreases, meaning that respiratory losses would be higher than the increase in photosynthetic capacity; therefore, fewer resources may be available for reproduction.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44703156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cuphea calophylla Cham. & Schltdl. is a Lythraceae subshrub that occurs in different environmental conditions. The aerial portions of this plant have medicinal properties and are used for soap production. We assessed the structure, ultrastructure, and histochemistry of the secretory cells and tissues in C. calophylla leaves and stems to further understand its secretory system. Hydathodes with epithem, tracheary elements, and water pores occur at the leaf border and are here described for the first time for a Cuphea species. Glandular appendages occur in leaves and stems and are characterized by a wide basis and a narrower apical portion that exuded sticky material. Ontogenetical analysis showed that these appendages are glandular emergences; phenolic compounds, mucilage, and lipids were produced in their cells which exhibited Golgi bodies, vesicles, smooth endoplasmic reticulum, oil drops, and plastids. The epidermis of the leaf blade has bi-compartmentalized secretory cells divided by a cellulosic septum in their equatorial region. These cells contain phenolic compounds in the upper compartment and mucilage in the lower compartment. Our results shed light on the sites producing bioactive compounds in C. calophylla and expand the knowledge on the secretory system in Lythraceae, promoting a reclassification and an identification of new structures.
{"title":"Secretory system in Cuphea calophylla (Lythraceae): the bi-compartmentalization of epidermal cells, reclassification of glandular appendages, and the first report of hydathodes","authors":"D. P. Seixas, T. M. Rodrigues","doi":"10.1139/cjb-2022-0031","DOIUrl":"https://doi.org/10.1139/cjb-2022-0031","url":null,"abstract":"Cuphea calophylla Cham. & Schltdl. is a Lythraceae subshrub that occurs in different environmental conditions. The aerial portions of this plant have medicinal properties and are used for soap production. We assessed the structure, ultrastructure, and histochemistry of the secretory cells and tissues in C. calophylla leaves and stems to further understand its secretory system. Hydathodes with epithem, tracheary elements, and water pores occur at the leaf border and are here described for the first time for a Cuphea species. Glandular appendages occur in leaves and stems and are characterized by a wide basis and a narrower apical portion that exuded sticky material. Ontogenetical analysis showed that these appendages are glandular emergences; phenolic compounds, mucilage, and lipids were produced in their cells which exhibited Golgi bodies, vesicles, smooth endoplasmic reticulum, oil drops, and plastids. The epidermis of the leaf blade has bi-compartmentalized secretory cells divided by a cellulosic septum in their equatorial region. These cells contain phenolic compounds in the upper compartment and mucilage in the lower compartment. Our results shed light on the sites producing bioactive compounds in C. calophylla and expand the knowledge on the secretory system in Lythraceae, promoting a reclassification and an identification of new structures.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46350759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Y. de la Bastide, T. Finston, L. Hermanutz, W. Hintz
Long’s (Braya longii) and Fernald’s (B. fernaldii) Braya are endemic to the Great Northern Peninsula of Newfoundland, Canada. These herbaceous perennials are endangered due to habitat loss and degradation, as well as ongoing threats from fungal infections and insect herbivory. While recovery plans are being implemented, the identity of pathogenic fungi and their origins remain largely unknown. This study was initiated to describe the associated fungal community and infection symptoms. Plant tissues from three populations were sampled over five years yielding 326 fungal isolates identified primarily by nucleotide sequence analysis of the ITS-rDNA region. Isolates included 36 taxa, 16 of which were detected once and 5 detected three times or less. In contrast, 12 taxa were detected across multiple sites, sampling intervals and years. These included two species of Alternaria, Boeremia exigua, closely related species of the Didymellaceae, Botrytis cinerea, Fusarium sp., Colletotrichum sp., Stagonosporopsis sp., Pleospora sp. and Truncatella angustata. Some common taxa showed seasonal trends. The isolated fungi included known pathogens of Brassicaceae. The plants in this study frequently showed symptoms indicative of fungal infection and insect herbivory. These findings improve our knowledge of Braya endophyte communities and will inform recovery efforts for these endangered species.
{"title":"Fungal endophytes affecting the health and recovery of Long’s Braya (Braya longii) and Fernald’s Braya (Braya fernaldii), endangered endemic species of Newfoundland, Canada","authors":"P. Y. de la Bastide, T. Finston, L. Hermanutz, W. Hintz","doi":"10.1139/cjb-2022-0058","DOIUrl":"https://doi.org/10.1139/cjb-2022-0058","url":null,"abstract":"Long’s (Braya longii) and Fernald’s (B. fernaldii) Braya are endemic to the Great Northern Peninsula of Newfoundland, Canada. These herbaceous perennials are endangered due to habitat loss and degradation, as well as ongoing threats from fungal infections and insect herbivory. While recovery plans are being implemented, the identity of pathogenic fungi and their origins remain largely unknown. This study was initiated to describe the associated fungal community and infection symptoms. Plant tissues from three populations were sampled over five years yielding 326 fungal isolates identified primarily by nucleotide sequence analysis of the ITS-rDNA region. Isolates included 36 taxa, 16 of which were detected once and 5 detected three times or less. In contrast, 12 taxa were detected across multiple sites, sampling intervals and years. These included two species of Alternaria, Boeremia exigua, closely related species of the Didymellaceae, Botrytis cinerea, Fusarium sp., Colletotrichum sp., Stagonosporopsis sp., Pleospora sp. and Truncatella angustata. Some common taxa showed seasonal trends. The isolated fungi included known pathogens of Brassicaceae. The plants in this study frequently showed symptoms indicative of fungal infection and insect herbivory. These findings improve our knowledge of Braya endophyte communities and will inform recovery efforts for these endangered species.","PeriodicalId":9092,"journal":{"name":"Botany","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63989504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Félix-Gastélum, K. Y. Leyva-Madrigal, Luis Roberto Sánchez-Parra, G. A. Mora-Romero
Peronospora variabilis was observed to be consistently associated with downy mildew of pitseed goosefoot (Chenopodium berlandieri). Morphological characteristics of the conidiophores, conidia and oospores of the oomycete corresponded to those of P. variabilis. The morphological identification was complemented by a phylogenetic analysis of the ITS region. To our knowledge, this is the first report of P. variabilis on C. berlandieri in Mexico.
{"title":"Peronospora variabilis is associated with downy mildew of Chenopodium berlandieri in Mexico","authors":"R. Félix-Gastélum, K. Y. Leyva-Madrigal, Luis Roberto Sánchez-Parra, G. A. Mora-Romero","doi":"10.1139/cjb-2022-0074","DOIUrl":"https://doi.org/10.1139/cjb-2022-0074","url":null,"abstract":"Peronospora variabilis was observed to be consistently associated with downy mildew of pitseed goosefoot (Chenopodium berlandieri). Morphological characteristics of the conidiophores, conidia and oospores of the oomycete corresponded to those of P. variabilis. The morphological identification was complemented by a phylogenetic analysis of the ITS region. To our knowledge, this is the first report of P. variabilis on C. berlandieri in Mexico.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43000003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Johnson, E. Janssen, Nicholas Glass, P. Dickerson, C. Whelan, B. Molano‐Flores
Changes in resource allocation from parent to offspring can have effects on the dispersal, recruitment, and survival of progeny, with impacts sometimes extending across generations. In plants, environmental stressors not only impact the growth of mature individuals but can also alter the provisioning of resources to developing seeds, further extending to embryo development and reproduction. In this study, we compare seed biomass, morphology, seed set, and germination among two natural populations and three additional seed sources of Thuja occidentalis (Northern White Cedar), a fen-dependent species in the Chicago IL region. Chicago Junior School and Trout Park were once contiguous populations, now bisected by the I-90 toll road, and are heavily impacted by human disturbance and external pollutants. Variation was observed in seed morphology, cone biomass, and seed set among study sites with Trout Park trees producing fewer seeds and smaller cones than any other site in our study. Despite morphological differences, germination was low overall except for commercial seed. Differences among the two neighboring sites implicate that Trout Park is disproportionately affected by environmental factors (e.g., road salts and altered hydrology) compared to Chicago Junior School, potentially impacting the growth and recruitment of Thuja occidentalis in these urban populations.
{"title":"The role of environmental stressors on reproduction, seed morphology, and germination: A case-study of Northern White Cedar, Thuja occidentalis L.","authors":"S. Johnson, E. Janssen, Nicholas Glass, P. Dickerson, C. Whelan, B. Molano‐Flores","doi":"10.1139/cjb-2022-0007","DOIUrl":"https://doi.org/10.1139/cjb-2022-0007","url":null,"abstract":"Changes in resource allocation from parent to offspring can have effects on the dispersal, recruitment, and survival of progeny, with impacts sometimes extending across generations. In plants, environmental stressors not only impact the growth of mature individuals but can also alter the provisioning of resources to developing seeds, further extending to embryo development and reproduction. In this study, we compare seed biomass, morphology, seed set, and germination among two natural populations and three additional seed sources of Thuja occidentalis (Northern White Cedar), a fen-dependent species in the Chicago IL region. Chicago Junior School and Trout Park were once contiguous populations, now bisected by the I-90 toll road, and are heavily impacted by human disturbance and external pollutants. Variation was observed in seed morphology, cone biomass, and seed set among study sites with Trout Park trees producing fewer seeds and smaller cones than any other site in our study. Despite morphological differences, germination was low overall except for commercial seed. Differences among the two neighboring sites implicate that Trout Park is disproportionately affected by environmental factors (e.g., road salts and altered hydrology) compared to Chicago Junior School, potentially impacting the growth and recruitment of Thuja occidentalis in these urban populations.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43562154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-06eCollection Date: 2024-01-01DOI: 10.1093/workar/waac026
Jared F Benge, Alyssa Aguirre, Michael K Scullin, Andrew M Kiselica, Robin C Hilsabeck, David Paydarfar, Michael Douglas
In response to social distancing measures during the COVID-19 pandemic, there was a need to increase the frequency of internet enabled behaviors (IEBs). To date, little is known about how the pandemic impacted IEBs in older adults, a population that has historically been linked to lower digital literacy and utilization. We administered an online survey between April and July 2021 to 298 adults who were over age 50 (mean age = 73 years; 93.5% non-Hispanic white; 94% smart phone owners; 83.5% retired). Older adults self-reported IEBs for social, shopping, medical, and leisure activities during the pandemic, plans for continued use of these behaviors, and completed measures of psychosocial functioning. 66.8% of respondents reported an overall increase in IEBs during the pandemic, most notably for online meeting attendance. More frequent online meeting use was associated with less depression (r = -0.12, p = .04) and less loneliness (r = -0.14, p = .02). With regard to plans for continued use, 82.5% of the sample reported at least one IEB (M = 2.18, SD = 1.65) that they increased during the pandemic and planned to maintain over time (e.g., online shopping for household goods). Plans for continued use were more likely in participants who used IEBs more overall during the pandemic (r = 0.56, p < .001), and who frequently sought technical support on search engines (r = 0.22, p < .001), or online video sites (r = 0.16, p = .006). In summary, IEBs during the pandemic were associated with favorable psychosocial functioning and expectations for continued use in this sample of predominantly white older adults who had some baseline technological familiarity.
{"title":"Internet-Enabled Behaviors in Older Adults During the Pandemic: Patterns of Use, Psychosocial Impacts, and Plans for Continued Utilization.","authors":"Jared F Benge, Alyssa Aguirre, Michael K Scullin, Andrew M Kiselica, Robin C Hilsabeck, David Paydarfar, Michael Douglas","doi":"10.1093/workar/waac026","DOIUrl":"10.1093/workar/waac026","url":null,"abstract":"<p><p>In response to social distancing measures during the COVID-19 pandemic, there was a need to increase the frequency of internet enabled behaviors (IEBs). To date, little is known about how the pandemic impacted IEBs in older adults, a population that has historically been linked to lower digital literacy and utilization. We administered an online survey between April and July 2021 to 298 adults who were over age 50 (mean age = 73 years; 93.5% non-Hispanic white; 94% smart phone owners; 83.5% retired). Older adults self-reported IEBs for social, shopping, medical, and leisure activities during the pandemic, plans for continued use of these behaviors, and completed measures of psychosocial functioning. 66.8% of respondents reported an overall increase in IEBs during the pandemic, most notably for online meeting attendance. More frequent online meeting use was associated with less depression (<i>r</i> = -0.12, <i>p</i> = .04) and less loneliness (<i>r = -</i>0.14, <i>p</i> = .02). With regard to plans for continued use, 82.5% of the sample reported at least one IEB (<i>M</i> = 2.18, <i>SD</i> = 1.65) that they increased during the pandemic and planned to maintain over time (e.g., online shopping for household goods). Plans for continued use were more likely in participants who used IEBs more overall during the pandemic (<i>r</i> = 0.56, <i>p</i> < .001), and who frequently sought technical support on search engines (<i>r</i> = 0.22, <i>p</i> < .001), or online video sites (<i>r</i> = 0.16, <i>p</i> = .006). In summary, IEBs during the pandemic were associated with favorable psychosocial functioning and expectations for continued use in this sample of predominantly white older adults who had some baseline technological familiarity.</p>","PeriodicalId":9092,"journal":{"name":"Botany","volume":"36 1","pages":"6-13"},"PeriodicalIF":3.7,"publicationDate":"2022-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10772966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86637437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Lavoie, P. Grondin, C. Caron, A. Larouche, Véronique Poirier
Some ombrotrophic peatlands in temperate regions have been characterized by a process of rapid densification of their forest cover for several decades. This phenomenon is particularly marked in southern Québec (Canada), where a number of peatlands now contain mixed forest stands. The present study aimed to document the woody encroachment dynamics of a peatland colonized by Larix laricina (Du Roi) K. Koch and Acer rubrum L. The specific objectives were to characterize the contemporary dynamics of the forest cover through analysis of dendrometric, dendrochronological, and aerial photographs, and to reconstruct the evolution of tree species present in situ since the peatland’s origin through botanical identification of ligneous remains collected in excavations of the peat as well as macrofossil analysis of a sedimentary core. The vegetation cover underwent rapid transformation beginning in the 1970s, first by the densification of L. laricina, followed by the expansion of A. rubrum. This transformation followed several millennia during which the peatland continuously presented a shrub-dominated cover with a few scattered coniferous trees. The rapid expansion of a mixed forest cover is a unique event in the peatland’s history. Acer rubrum progressively replaced L. laricina and, in the more or less long-term, should become the dominant species.
几十年来，温带地区的一些营养型泥炭地的特点是森林覆盖迅速增加。这种现象在魁省(加拿大)南部特别明显，那里的一些泥炭地现在有混交林。本研究旨在记录落叶松(Larix laricina (Du Roi) K. Koch)和红槭(Acer rubrum L.)殖民的泥炭地的木材侵蚀动态，具体目标是通过树木测量、树木年代学和航空摄影分析来表征森林覆盖的当代动态。并通过对泥炭发掘中收集的木质遗骸进行植物学鉴定以及对沉积岩心进行宏观化石分析，重建泥炭地起源以来原地存在的树种进化。从20世纪70年代开始，植被覆盖经历了快速的变化，首先是落叶松(L. laricina)的密度增大，其次是红毛杨(a.b rubrum)的扩张。这种转变持续了几千年，在此期间，泥炭地不断呈现出以灌木为主的覆盖层，并有一些零星的针叶树。混交林覆盖面积的迅速扩大是泥炭地历史上独一无二的事件。红槭逐渐取代落叶松，并在较长时间内成为优势种。
{"title":"Rapid mixed forest encroachment and the expansion of red maple (Acer rubrum) in a peatland: a dendroecological and paleoecological approach","authors":"M. Lavoie, P. Grondin, C. Caron, A. Larouche, Véronique Poirier","doi":"10.1139/cjb-2021-0171","DOIUrl":"https://doi.org/10.1139/cjb-2021-0171","url":null,"abstract":"Some ombrotrophic peatlands in temperate regions have been characterized by a process of rapid densification of their forest cover for several decades. This phenomenon is particularly marked in southern Québec (Canada), where a number of peatlands now contain mixed forest stands. The present study aimed to document the woody encroachment dynamics of a peatland colonized by Larix laricina (Du Roi) K. Koch and Acer rubrum L. The specific objectives were to characterize the contemporary dynamics of the forest cover through analysis of dendrometric, dendrochronological, and aerial photographs, and to reconstruct the evolution of tree species present in situ since the peatland’s origin through botanical identification of ligneous remains collected in excavations of the peat as well as macrofossil analysis of a sedimentary core. The vegetation cover underwent rapid transformation beginning in the 1970s, first by the densification of L. laricina, followed by the expansion of A. rubrum. This transformation followed several millennia during which the peatland continuously presented a shrub-dominated cover with a few scattered coniferous trees. The rapid expansion of a mixed forest cover is a unique event in the peatland’s history. Acer rubrum progressively replaced L. laricina and, in the more or less long-term, should become the dominant species.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42563611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Martínez-Domínguez, Fernando Nicolalde‐Morejón, Francisco Vergara-Silva, D. Stevenson
The reproductive phenology in plants consists of successive life cycle phases leading to reproductive success. In seed plants, cycads and other dioecious groups have complex reproductive systems, where individuals require synchronizations among two sexes and populations of the same species. Here we analyzed phenology between populations of three geographically close species in the cycad genus Ceratozamia. We described the lifespan of pollen and ovulate strobili and their morphological changes throughout ontogeny and evaluated synchrony among reproductive events, focusing on the timing and abundance of the receptivity and open pollen phases. Our results showed that the reproductive timing in the three species was highly synchronous, and that the overlap between the receptivity and open pollen phases could point to gene flow among populations of different species. We identified a correlation between the reproductive patterns and the temperature and precipitation regimes. Pollen and ovulate strobili were produced during the rainy season, whereas the period of synchrony between receptivity and pollen occurred during the dry season. The seed release occurred during the rainy season, which could contribute to keep the seed moist and prevent the embryo from drying out. Finally, we highlight the utility of studies in wild populations for the ecological and evolutionary understanding of phenological patterns in cycads.
{"title":"Temporal shifts in reproductive phenology of cycads: a comparative study in Ceratozamia","authors":"L. Martínez-Domínguez, Fernando Nicolalde‐Morejón, Francisco Vergara-Silva, D. Stevenson","doi":"10.1139/cjb-2022-0053","DOIUrl":"https://doi.org/10.1139/cjb-2022-0053","url":null,"abstract":"The reproductive phenology in plants consists of successive life cycle phases leading to reproductive success. In seed plants, cycads and other dioecious groups have complex reproductive systems, where individuals require synchronizations among two sexes and populations of the same species. Here we analyzed phenology between populations of three geographically close species in the cycad genus Ceratozamia. We described the lifespan of pollen and ovulate strobili and their morphological changes throughout ontogeny and evaluated synchrony among reproductive events, focusing on the timing and abundance of the receptivity and open pollen phases. Our results showed that the reproductive timing in the three species was highly synchronous, and that the overlap between the receptivity and open pollen phases could point to gene flow among populations of different species. We identified a correlation between the reproductive patterns and the temperature and precipitation regimes. Pollen and ovulate strobili were produced during the rainy season, whereas the period of synchrony between receptivity and pollen occurred during the dry season. The seed release occurred during the rainy season, which could contribute to keep the seed moist and prevent the embryo from drying out. Finally, we highlight the utility of studies in wild populations for the ecological and evolutionary understanding of phenological patterns in cycads.","PeriodicalId":9092,"journal":{"name":"Botany","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45088588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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