Phenology in Indiana: Observing Nature Across Time

Speaker: Amanda Wanlass

Phenology—the study of seasonal events in plants and animals—is one of the oldest and most accessible forms of scientific observation. From early records by Chinese emperors to naturalists like Thoreau and Indiana’s Charles C. Deam, to modern citizen science programs, phenology helps us understand how species interact and respond to environmental change. The presentation reviews the history of phenology observation, both broadly and in Indiana, and shows how past records connect to present-day research. It also highlights current efforts to document seasonal events in Indiana and the tools used to track and understand local ecosystems and climate impacts across the state.

Amanda Wanlass is the Executive Director of Indiana Phenology, where she uses citizen science observations, historical records, and ecological data to examine temporal and spatial trends and patterns in plant phenology across Indiana. She holds master’s degrees in Environmental Science and Public Affairs from Indiana University and works with Butler University’s Friesner Herbarium, supporting specimen preparation, curation, and data management.

Program: Phenology in Indiana: Observing Nature Across Time

Speaker: Amanda Wanlass, MPA - MSES, Founder and Executive Director, Indiana Phenology and more

Introduced By: Betty Yan

Attendance: NESC: 100, Zoom: 20

Guest(s): Anne Fester, Billy Blythe, Sherie Kendall

Scribe: AI generated

Editor: Bill Elliott

Talk’s Zoom recording found at: https://www.scientechclubvideos.org/zoom/04202026.mp4

Phenology: The Science of Seasonal Life Cycle Events

Definition and Scope

· Phenology studies the timing of recurring life cycle events (phenophases) in plants and animals:

· Plants: leafing, flowering, fruiting.

· Animals: activity, reproduction, migration, emergence (e.g., insects, birds).

· It connects biological events to environmental cues like weather and climate.

· Essentially, it is the science of the seasons, observable everywhere life exists.

Historical Context

· Humans have observed phenology for centuries:

· Qing dynasty emperors documented phenological events in poetry.

· Thomas Jefferson and Henry David Thoreau kept detailed phenology records.

· Aldo Leopold and Nina Leopold Bradley tracked migratory birds.

· Indiana botanist Charles Dean documented local phenology (1920s–1950s).

· Long-term data sets, such as over 1,000 years of cherry blossom records in Japan, reveal trends like earlier flowering linked to climate change.

Ecological and Human Importance

· Phenology affects:

· Species abundance, diversity, and interactions within ecosystems.

· Food webs and ecological functions (e.g., caterpillars depend on oak leaves, birds on caterpillars).

· Global cycles of water, carbon, and nutrients.

· Human relevance includes:

· Timing of allergies (earlier flowering causes earlier allergy seasons).

· Mosquito activity and disease risk.

· Agricultural planning (fertilizer and pesticide timing).

· Recreation and conservation activities.

· Phenology is a critical indicator of climate change impacts:

· Shifts in timing of life cycle events are some of the most sensitive biological responses.

· Spring events occur on average 2 days earlier per decade in ~62% of species studied.

· Regional and species-specific variations complicate ecological balance.

Phenological Mismatch and Climate Change

· Phenological mismatch occurs when species that depend on each other become uncoordinated:

· Example: Migratory birds lay eggs based on wintering ground cues, but if caterpillars (their food) emerge earlier due to warming, hatchlings may starve.

· Resulting mismatches have caused up to 90% declines in some bird populations.

· Climate change disrupts food webs and survival strategies globally.

Citizen Science and Phenology Data Collection

· Citizen science engages volunteers to collect phenology data, expanding research breadth and depth beyond what professional scientists can cover.

· Indiana Phenology Society coordinates volunteer efforts across Indiana’s 92 counties, focusing on plants and animals.

· Programs include:

· Backyard Observers (individual/family participation).

· Phenology Trail (partnerships with nature centers and parks).

· School programs (student engagement).

· Data collected include timing of leaf bud break, flowering, fruiting, and leaf senescence.

Data Sources and Tools

· Historical data: Nature Study Club wildflower census (1927), personal journals (1971-1986), herbarium specimens.

· Contemporary data collection platforms:

· iNaturalist: Photo-based biodiversity tool; users upload photos with date/location; community helps identify species; used for incidental phenology data.

· Nature’s Notebook: USA National Phenology Network platform; standardized protocols for repeated, detailed observations; data feed into national research.

· Key statistics from recent years:

· Over 400,000 phenology status records collected.

· Active observers in 20-30 Indiana counties typically.

· Visualizations:

· Phenology Calendars: Timelines showing presence of leaves, flowers, and fruits for species over months and years.

· Activity Curves: Graphs showing intensity and timing of phenophases, illustrating year-to-year and species variation.

Challenges and Considerations

· Regional variation in phenological shifts complicates predictions.

· Invasive species impact native phenology by extending leaf periods, shading natives, and altering habitats.

· Phenology also reflects biodiversity trends; declines in bird and insect populations are evident (e.g., fewer dead insects on windshields).

· Observing nocturnal or elusive species is challenging but possible with effort.

Opportunities for Participation

· Citizen scientists can contribute by:

· Using iNaturalist or Nature’s Notebook apps to document observations.

· Participating in events like the City Nature Challenge, a global urban wildlife documentation over a weekend.

· This participation enriches phenological datasets, aiding climate change research, and ecological understanding.

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Summary & Key Takeaways

· Phenology links life cycle timing in plants and animals to environmental factors, serving as a vital measure of ecosystem health and climate impact.

· Long-term and contemporary data show many species are shifting life cycle events earlier, but uneven shifts cause ecological mismatches threatening wildlife survival.

· Citizen science is essential for phenology research, especially in under-studied regions like Indiana, enabling widespread, detailed monitoring.

· Tools like iNaturalist and Nature’s Notebook facilitate data collection by amateurs and professionals alike.

· Phenology impacts humans directly via allergies, agriculture, disease risk, and conservation planning.

· Invasive species and biodiversity loss are significant phenology-related concerns.

· Participation in phenology observation offers a personal connection to nature and contributes to vital scientific knowledge.

Amanda Wanlass