Biology subjects

Kirschke, G. E.

Publications and source records attributed to Kirschke, G. E..

2 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↗