Temperature variation in time and space, and its effects on insects

Nature is variable. Unfortunately, compressed representations of this variable world, like averages, are often lossy and insufficient for ecological purposes. This is particularly true for temperature variation, which organisms typically respond to in a nonlinear way. As biologists, we must therefore be careful to study temperature variation at the appropriate scales, and assess its consequences in the right biological contexts. In this dissertation, I tackle the interplay between temperature variation, seasonality, and life histories of insects, primarily focusing on Pieris butterflies. In Chapter I, I demonstrate that insect development times in naturally fluctuating settings can be accurately predicted using thermal performance curves established under constant settings. However, this accuracy is contingent upon the incorporation of environmental temperature data high-resolved in both time and space. My work in Chapter II investigates the divergent seasonal population dynamics exhibited by Pieris rapae and P. napi, two closely related and ecologically similar butterflies. The species’ differences in season-specific success correlate with distinct thermal adaptations, and delineate P. rapae and P. napi into the roles of summer and winter specialists, respectively. We hypothesize that warm-adapted summer specialists will be favored by climate warming, but that cold-tolerant winter specialists will find refuge in places with very short growth seasons. In Chapter III, a comprehensive examination spanning a 750 km latitudinal cline unveils discernible latitude-specific photoperiodic reaction norms in P. napi, yet an absence of parallel trends in their thermal responses. We argue that, in seasonal environments, the reliability of photoperiodic cues and the clear link between photoperiodism and fitness make photoperiodic responses evolve more readily than temperature responses. In Chapter IV, I integrate principles from signal processing into thermal ecology. I show that relatively sparse temperature time-series can be effectively interpolated using well-known signal processing techniques, improving the accuracy of ecological predictions. The Earth is warmer now than it was just a century ago, and will likely keep facing drastic temperature changes in the near future. This will have complex downstream effects on living organisms all over the world. As a concluding remark, I would therefore like to emphasize the importance of a nuanced perspective on the consequences of temperature variation in nature

Temperature variation in time and space, and its effects on insects

Nature is variable. Unfortunately, compressed representations of this variable world, like averages, are often lossy and insufficient for ecological purposes. This is particularly true for temperature variation, which organisms typically respond to in a nonlinear way. As biologists, we must therefore be careful to study temperature variation at the appropriate scales, and assess its consequences in the right biological contexts. In this dissertation, I tackle the interplay between temperature variation, seasonality, and life histories of insects, primarily focusing on Pieris butterflies. In Chapter I, I demonstrate that insect development times in naturally fluctuating settings can be accurately predicted using thermal performance curves established under constant settings. However, this accuracy is contingent upon the incorporation of environmental temperature data high-resolved in both time and space. My work in Chapter II investigates the divergent seasonal population dynamics exhibited by Pieris rapae and P. napi, two closely related and ecologically similar butterflies. The species’ differences in season-specific success correlate with distinct thermal adaptations, and delineate P. rapae and P. napi into the roles of summer and winter specialists, respectively. We hypothesize that warm-adapted summer specialists will be favored by climate warming, but that cold-tolerant winter specialists will find refuge in places with very short growth seasons. In Chapter III, a comprehensive examination spanning a 750 km latitudinal cline unveils discernible latitude-specific photoperiodic reaction norms in P. napi, yet an absence of parallel trends in their thermal responses. We argue that, in seasonal environments, the reliability of photoperiodic cues and the clear link between photoperiodism and fitness make photoperiodic responses evolve more readily than temperature responses. In Chapter IV, I integrate principles from signal processing into thermal ecology. I show that relatively sparse temperature time-series can be effectively interpolated using well-known signal processing techniques, improving the accuracy of ecological predictions. The Earth is warmer now than it was just a century ago, and will likely keep facing drastic temperature changes in the near future. This will have complex downstream effects on living organisms all over the world. As a concluding remark, I would therefore like to emphasize the importance of a nuanced perspective on the consequences of temperature variation in nature

Seasonal specialization drives divergent population dynamics in two closely related butterflies

Abstract Seasons impose different selection pressures on organisms through contrasting environmental conditions. How such seasonal evolutionary conflict is resolved in organisms whose lives span across seasons remains underexplored. Through field experiments, laboratory work, and citizen science data analyses, we investigate this question using two closely related butterflies (Pieris rapae and P. napi). Superficially, the two butterflies appear highly ecologically similar. Yet, the citizen science data reveal that their fitness is partitioned differently across seasons. Pieris rapae have higher population growth during the summer season but lower overwintering success than do P. napi. We show that these differences correspond to the physiology and behavior of the butterflies. Pieris rapae outperform P. napi at high temperatures in several growth season traits, reflected in microclimate choice by ovipositing wild females. Instead, P. rapae have higher winter mortality than do P. napi. We conclude that the difference in population dynamics between the two butterflies is driven by seasonal specialization, manifested as strategies that maximize gains during growth seasons and minimize harm during adverse seasons, respectively

Data and Code for Greiser et al. (2022, Functional Ecology) "Microclimatic variation affects developmental phenology, synchrony and voltinism in an insect population"

Code and data for the rate summation (phenology models) and the visualization of results. listed are the code files. See Readme.docx for list of data files. 1_rate_summation.r code for rate summation, i.e. the integration of species- and life stage specific thermal performance curves for developmental rate over hourly temperature measurements at ca 100 logger sites. Produces phenology_data.txt (which is also provided in the repository) 2_plot_rate_summation.rmd code for plotting the results for one of nine specific scenarios (need to chose manually in the beginning) 3_plot_rate_summation_summaries.r code for plotting summary results over all scenarios. All code for R 4.0.3 (2020-10-10) </p

Microclimate, an important part of ecology and biogeography

Brief introduction: What are microclimates and why are they important?: Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystems, and where this field is heading next. Microclimate investigations in ecology and biogeography: We highlight the latest research on interactions between microclimates and organisms, including how microclimates influence individuals, and through them populations, communities and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimates from the tropics to the poles. Microclimate applications in ecosystem management: Microclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity. Methods for microclimate science: We showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling and solutions for computational challenges that have pushed the state‐of‐the‐art of the field. What's next?: We identify major knowledge gaps that need to be filled for further advancing microclimate investigations, applications and methods. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management

Microclimate, an inseparable part of ecology and biogeography

Abstract Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography, and where this field is heading next. We showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping, and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling, and solutions for computational challenges that have pushed the state-of-the-art of the field. We highlight the latest research on interactions between microclimate and organisms, including how microclimate influences individuals, and through them populations, communities, and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimate from the tropics to the poles. Microclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry, and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity. We identify major knowledge gaps that need to be filled for further advancing microclimate methods, investigations, and applications. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management. &nbsp; Biosketch The authors are participants of the Microclimate Ecology and Biogeography conference held in Antwerp, Belgium in 2022. Together they collaboratively wrote this perspective paper that brings together 97 experts and their views on the recent advancements and knowledge gaps in terrestrial microclimate. The paper was coordinated by Julia Kemppinen, Jonas Lembrechts, Koenraad Van Meerbeek, and Pieter De Frenne, and writing different sections was led by Jofre Carnicer, Nathalie Chardon, Paul Kardol, Jonathan Lenoir, Daijun Liu, Ilya Maclean, Jan Pergl, Patrick Saccone, Rebecca Senior, Ting Shen, Sandra Słowińska, Vigdis Vandvik, and Jonathan von Oppen. For more details on authors statistics and how the work was organised, please see Supplementary information Figures S1-3.</p