Biology subjects

Ogilvie, J. E.

Publications and source records attributed to Ogilvie, J. E..

4 recordsLinked to original sources

bioRxiv2025

A Practical Roadmap For Sampling Floral Nectar From Communities of Many Plant Species

O_LIFloral nectar plays a critical role in shaping the ecology and evolution of plant-pollinator interactions. Effective and efficient methods that allow for broad-scale sampling of nectar volume and sugar concentration across a diversity of taxa are needed to improve our understanding of many dimensions of mutualistic plant-pollinator interactions--including their basic ecology and evolution, their responses to environmental change, and their conservation and restoration. C_LIO_LIDespite the key importance of nectar for mediating plant-pollinator interactions, quantifying floral nectar in the field from many different plant species is challenging because there is often no one-size-fits-all sampling method that is effective across a diversity of floral structures and nectar traits. Different methods require different preparation, and sampling from many species involves a variety of logistical challenges. C_LIO_LIHere we provide a methodological roadmap for sampling floral nectar in the field from many different plant species. We describe our nectar collection methods in detail, including necessary equipment, calculations, and approaches appropriate for different floral morphologies. We also provide a troubleshooting guide for common problems encountered while collecting nectar in the field. To demonstrate the utility and effectiveness of our methods for collecting nectar from many different species, we present results on nectar trait variation from 53 species in an ecosystem. C_LIO_LIOur method illustrates that nectar traits vary considerably within and among plant species, indicating that large-scale nectar sampling projects are an important consideration for many basic and applied questions in pollination ecology and evolution. We hope that across many plant communities and ecosystems, our paper provides a practical roadmap for how to navigate the complexities of quantifying floral nectar traits. C_LI

ecology↗

bioRxiv2025

Meta-analyses reveal no clear demographic consequences of phenological change across taxa

The timing of life-cycle events (phenology) is key to organism ecology and success. Climate change is shifting phenology to earlier dates globally, but generalizable trends of how phenological change impacts demography are still unknown. Therefore, we conducted a meta-analysis to quantify the effects of interannual phenological variation and phenological shifts on demographic vital rates (survival, growth, and reproduction). Our dataset includes 138 taxa from 83 studies, representing different study approaches (observational and experimental) for plants and animals. Using these data, we asked three primary questions: 1). How does phenological variation affect demographic vital rates? 2). Are directional shifts in phenology predictive of changes in demographic vital rates? 3.) Do relationships between phenology and demography depend on taxa, vital rate, and study type? For studies of phenological variation, earlier events conferred demographic benefits whereas later events were associated with demographic costs, with most of the evidence coming from bird and reproduction-focused studies. In contrast, directional phenological shifts were not predictive of demographic responses over time or in experiments. While there was evidence that phenological events shifted earlier through time, there was not significant change in demographic vital rates over those same time periods. These results are consistent with the hypothesis that organisms may be able to track environmental conditions to maintain demographic performance by shifting their phenology to earlier dates under climate change. Critically, our meta-analysis clarifies that while earlier phenological events tend to confer demographic benefits in the context of phenological variation, directional phenological shifts to earlier timing did not show demographic benefits.

ecology↗

bioRxiv2022

The shifting importance of abiotic and biotic factors across the life cycles of wild pollinators

O_LIOrganisms living in seasonal environments are exposed to different environmental conditions as they transition from one life stage to the next across their life cycle. How different life stages respond to these varying conditions is a fundamental aspect of biology and is critical for understanding how organisms will respond to environmental change. C_LIO_LIDespite the importance of animal pollinators, we lack a basic understanding of the influence of different environmental factors across their life cycles. We investigated the relative importance of climate conditions, food availability, and previous life stage abundance in a community of wild bumble bee species, asking: how do these three factors influence bee abundance at each life stage? C_LIO_LIWe used a 7-year dataset to examine the importance of environmental conditions on the abundance of life stages in seven wild bumble bee species. We monitored climate conditions, the abundance of floral resources, and abundances of bees in each life stage across the active colony life cycle in a highly seasonal subalpine ecosystem in the Colorado Rocky Mountains, USA. C_LIO_LIBee abundance at different life stages responded to environmental conditions in a consistent manner across the seven species. The survival and recruitment stage of the life cycle (assessed as abundance of overwintered queens) responded negatively to longer winters; the growth stage (assessed as abundance of workers) responded positively to floral resource availability; and the reproductive stage (assessed as abundance of males) was positively related to the abundance of the previous life stage (workers). C_LIO_LIOur long-term examination of annual bumble bees reveals a consistent set of responses in the abundance of each life stage to climate conditions, floral resource availability, and previous life stage abundance. Across species, these three factors each influenced a distinct life stage, illustrating how their relative importance can shift throughout the life cycle. The life-cycle approach we have taken with wild bumble bees highlights that important details about pollinator demography are overlooked without considering life stage-specific responses. Ultimately, it is these life-stage specific responses that shape population outcomes, not only for animal pollinators, but for many organisms living in seasonal environments. C_LI

ecology↗

bioRxiv2017

Phenological responses to multiple environmental drivers under climate change: insights from a long-term observational study and a manipulative field experiment

Climate change has induced pronounced shifts in the reproductive phenology of plants, with the timing of first flowering advancing in most species. Indeed, population persistence may be threatened by the inability to track climate change phenologically. Nevertheless, substantial variation exists in biological responses to climate change across taxa. Here, we explore the consequences of climate change for flowering phenology by integrating data from a long-term observational study and a manipulative experiment under contemporary conditions. Dissecting the environmental factors that influence phenological change will illuminate why interspecific variation exists in responses to climate change. We examine a 43-year record of first flowering for six species in subalpine meadows of Colorado in conjunction with a 3-year snow manipulation experiment on the perennial mustard Boechera stricta from the same site. We analyze shifts in the onset of flowering in relation to environmental drivers known to influence phenology: the timing of snowmelt, the accumulation of growing degree days, and photoperiod. At our study site, climate change is reducing snowpack and advancing the timing of spring snowmelt. We found that variation in phenological responses to climate change depended on the sequence in which species flowered, with early-flowering species flowering faster, at a lower heat sum, and under increasingly disparate photoperiods in comparison to species that flower later in the season. Furthermore, climate change is outpacing phenological change for all species. Early snow removal treatments confirm that the timing of snowmelt governs observed trends in flowering phenology of B. stricta and that climate change can reduce the probability of flowering, thereby depressing fitness. Shorter-term studies would not have captured the trends that we document in our observational and experimental datasets. Accurate predictions of the biological responses to climate change require a thorough understanding of the specific environmental factors driving shifts in phenology.

ecology↗