Jessica M. Budke

Mosses experience a complex relationship between generations because the offspring sporophyte is physically attached to and dependent on the parental gametophyte, obtaining water and nutrients from the gametophyte's conducting cells (when present). We aim to address the question: How do the water conducting cells (hydroids) of the parental gametophyte developmentally respond to archegonia production and fertilization? We used histology methods to quantify the gametophyte stem anatomy of Dicranum scoparium across three developmental Stages. We observed a significant increase in hydroid number, size, and area in the gametophyte after sporophyte production. This indicates that the anatomical ability of the parental gametophyte to supply resources to the offspring sporophyte increases post-fertilization. Whether this change is induced by the gametophyte itself or by hormonal signals from the sporophyte is unknown. Examining the relationship between anatomical development and hormones could give additional insight into the nature of the parent-offspring relationship in mosses.

An herbarium must have its specimens processed, identified and accessioned so that members of the botanical community can readily consult these materials. However, many herbaria struggle to keep up with the influx of specimens and accumulate a backlog of unaccessioned specimens. In this study, we surveyed herbarium staff about their institution’s specimen backlog, focusing on the number and taxonomic lineage of backlogged specimens as well as the challenges associated with specimen curation. Based on responses from staff members at 65 herbaria, we calculated an average of 30,372 unaccessioned specimens per herbarium across all plant and fungal taxa. According to Index Herbariorum, there were 3,426 active herbaria in 2020 and, thus, we estimate at least 104 million specimens are present in herbarium backlogs worldwide. We also asked specific questions about unaccessioned bryophyte specimens in order to explore these collections in depth. While bryophytes represent only 9.0% of the accessioned specimens reported in our survey, they are overrepresented in the specimen backlog (16.0%). More than half of the bryophyte backlog is stored in field packets without labels and approximately three-quarters of these unaccessioned bryophytes lack species level identifications. Obstacles to backlog accessioning include labour shortages, insufficient bryological expertise and challenges integrating partially curated materials. Drawing on our survey responses, we offer strategies for reducing backlogs, such as accessioning straightforward specimens first and organising backlogs according to tasks leading to accessioning.

Aim : Monitoring plant communities in response to drivers of global change is essential for understanding ecosystem health and conservation over time. Natural history collections are underutilized, open-source data that can be leveraged to study how communities change over time. This informs how under surveyed organisms, like bryophytes, may be impacted by drivers of global change. Location : We used herbarium specimen data to examine bryophyte community change in the southern Appalachians before and after the arrival of the balsam wooly adelgid (BWA). Methods : We used herbarium collections to examine raw and rarefied alpha diversity, as well as rarefied dissimilarity, over time. We compared two timespans, pre-BWA invasion and initial canopy recovery from invasion, to determine if species were either lost from, persisted in, or were new to high elevation areas and if these species had any shared features. Results : We found that mountains with greater disturbance resulted in lower levels of rarefied richness and that more extreme management practices may drive greater changes to the bryophyte community. However, this result cannot be decoupled from the disturbance with our data. Finally, we found that generalists significantly persisted through time compared to expected and compared to specialist species. Main conclusions : This is a promising use of herbarium specimens as the results match those of field-based experiments. As such, herbarium collections may be used as a substitute for permanent plots for lands with limited resources or a lack of expertise to determine the impacts management practices or invasion events have on ecological communities.

We surveyed bryophyte communities at 36 sites containing either waterfalls, rivers, wetlands, or rock outcrops in Shenandoah National Park in Virginia to determine the location and distribution of rare bryophytes and to explore whether human disturbance negatively impacted bryophyte communities. An intentional meander through the 36 sites was conducted to collect and document all unique species. In addition, we examined overlapping transect lines to calculate species level bryophyte cover at 16 of the sites, eight containing water features and eight with rock outcrops with varying levels of human disturbance. We found 247 species, three of which were rare at the global or state level, one that was a new state record for Virginia, and 76 of which were new to the park compared to historical specimens and records from the park. We found that visitation intensity (level of disturbance) did not significantly impact bryophyte diversity or percent cover at either site type. However, we observed high levels of bryophyte community dissimilarity between disturbed and undisturbed sites, and these sites clustered independently from one another in both rock outcrops and water feature sites. This suggests that human disturbance impacts the bryophyte community composition; however, the number of unique species and their abundance is not different between disturbed and undisturbed sites. This may be because some species can tolerate disturbances, and human foot traffic may create opportunities for more disturbance-resilient species to occupy the space, as these species face less competition from disturbance-sensitive species that typically share the same niche. Investment in the preservation of bryophyte biodiversity within the park should be targeted towards sites with low levels of disturbance and those housing rare species, to ensure disturbance-sensitive and rare species’ habitat is protected from human trampling damage.

Summary: Parent–offspring relationships present a paradox wherein parents must balance limited resources between provisioning their offspring to increase their chances of survival and maturation, and reserving resources for their own survival and future reproduction. Bryophytes provide a unique system to explore this relationship due to the dependency of sporophytes on parental gametophytes throughout their lifespan. We investigate the morphological evolution of gametophyte and sporophyte characters to test for evidence of coadaptation in the Dicranaceae Schimp. and Grimmiaceae Arn. We also examine these morphological features in Grimmiaceae species with different sexual systems to test for higher levels of parent–offspring conflict in species that are exclusively outcrossing. Our study is the first to test this prediction with empirical data. Our study reveals significant correlations between parental gametophyte and offspring sporophyte morphology, which provides evidence of coadaptation. We found that species with unisexual gametophytes have larger calyptrae, which may decrease offspring resource acquisition, as well as larger capsules and larger setae, which may increase resource acquisition, than species with bisexual gametophytes. These findings suggest that the sexual system influences the relationship between gametophyte and sporophyte morphology, indicating higher levels of parent–offspring conflict in outcrossing species.

A comprehensive overview of volunteer-driven public programs focused on activities to enhance natural history collections (NHCs) is provided. The initiative revolves around the WeDigBio events and the Collections Club at the Field Museum, aiming to deepen the public’s connection with scientific collections, enhance participatory science, and improve data associated with natural history specimens. The implementation and journey of these programs are outlined, including surveys conducted from 2015 through 2021 to gauge participant motivation, satisfaction, and the impact of these events on public engagement with NHCs. Results show trends in on-site and virtual volunteer participation over the years, especially during the peak period of the COVID-19 pandemic. The majority of participants expressed high satisfaction, indicating a willingness to continue participating in similar activities. The surveys revealed a shift towards more altruistic motivations for participation over time, with increased emphasis on supporting the Field Museum and contributing to the scientific community. The success of participatory science events demonstrates the potential of volunteer-driven programs to contribute meaningfully to the preservation, digitisation, and understanding of biodiversity collections, ultimately transforming spectators into stewards of natural history. From 2015 to present participants celebrate a significant milestone, with over a thousand community scientists contributing to the inventorying, collection care, curation, databasing, or transcription of 286,071 specimens, objects or records. We also discuss accuracy and quality control as well as a checklist and recommendations for similar activities.

The sporophytes of moss plants are dependent on the gametophytes for both photosynthesis and water, which makes conducting cells (hydroids and leptoids) an important part of the sporophyte anatomy. A previous study found that Physcomitrium pyriforme, which has shorter sporophytes, had higher rates of water transport than Funaria hygrometrica, which has taller sporophytes. The aim of this study is to test for differences in the conducting cell anatomy between these two moss species, which could be responsible for differences in water transport rates. We used histology methods to fix, embed, and section sporophyte seta and then quantified the numbers and sizes of the conducting cells. The results revealed that leptoids comprise a higher proportion of the conducting cell area in P. pyriforme, while hydroids comprise more of the conducting cell area in F. hygrometrica. These results point toward the leptoids playing a role in water transport in the moss sporophyte.

A comprehensive overview of volunteer-driven public programs focused on activities to enhance natural history collections (NHCs) is provided. The initiative revolves around the WeDigBio events and the Collections Club at the Field Museum, aiming to deepen the public's connection with scientific collections, enhance participatory science, and improve data associated with natural history specimens. The implementation and journey of these programs are outlined, including surveys conducted from 2015 through 2021 to gauge participant motivation, satisfaction, and the impact of these events on public engagement with NHCs. Results show trends in on-site and virtual volunteer participation over the years, especially during the peak period of the COVID-19 pandemic. The majority of participants expressed high satisfaction, indicating a willingness to continue participating in similar activities. The surveys revealed a shift towards more altruistic motivations for participation over time, with increased emphasis on supporting the Field Museum and contributing to the scientific community. The success of participatory science events demonstrates the potential of volunteer-driven programs to contribute meaningfully to the preservation, digitisation, and understanding of biodiversity collections, ultimately transforming spectators into stewards of natural history. From 2015 to present participants celebrate a significant milestone, with over a thousand community scientists contributing to the inventorying, collection care, curation, databasing, or transcription of 286,071 specimens, objects or records. We also discuss accuracy and quality control as well as a checklist and recommendations for similar activities.

Premise: Plant phenological shifts are among the clearest indicators of the effects of climate change. In North America, numerous studies in the northeastern United States have demonstrated earlier spring flowering compared to historical records. However, few studies have examined phenological shifts in the southeastern United States, a highly biodiverse region of North America characterized by dramatic variations in abiotic conditions over small geographic areas.Methods: We examined 1000+ digitized herbarium records along with location‐specific temperature data to analyze phenological shifts of 14 spring‐flowering species in two adjacent ecoregions in eastern Tennessee.Results: Spring‐flowering plant communities in the Blue Ridge and the Ridge and Valley ecoregions differed in their sensitivity to temperature; plants in the Ridge and Valley flower 0.73 days earlier/°C on average compared to 1.09 days/°C for plants in the Blue Ridge. Additionally, for the majority of species in both ecoregions, flowering is sensitive to spring temperature; i.e., in warmer years, most species flowered earlier. Despite this sensitivity, we did not find support for community‐level shifts in flowering within eastern Tennessee in recent decades, likely because increases in annual temperature in the southeast are driven primarily by warming summer (rather than spring) temperatures.Conclusions: These results highlight the importance of including ecoregion as a predictor in phenological models for capturing variation in sensitivity among populations and suggest that even small shifts in temperature can have dramatic effects on phenology in response to climate in the southeastern United States.