News & Publications

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Nature’s Notebook observations reveal clear changes in New Jersey

Mon, Mar 09, 2026
Publication Summary

Global temperatures are increasing and the impacts are numerous and wide ranging. Temperatures have been rising at a particularly fast rate in the northeastern U.S., including many densely populated areas like New Jersey. To document environmental changes and better understand the impacts of climate change in this region since the mid-1960s, researchers gathered data on sea and air temperatures, lake ice, and snowfall. They complimented the weather data with observations of spring leaf-out and flowering in local lilac plants. The researchers found clear evidence of climate change, with notable increases in both daytime and nighttime temperatures and earlier spring plant activity. These changes will have numerous economic, social, and ecological impacts. Among other effects, earlier spring onset has the potential to alter plant-pollinator interactions and the length of the pollen and growing seasons.

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Phenology Week! March 16-20, 2026

Tue, Feb 03, 2026
News

March 16-20, 2026 is Phenology Week - a virtual celebration of the seasonal cycles of plants and animals. The purpose of Phenology Week is to celebrate YOU, our Nature's Notebook observers, Local Phenology Programs, and partners! We'll have webinars, awards, daily challenges, observer stories, and more.

We want to hear from you! What did you enjoy about Phenology Week this year, what could be improved, what do you want to see next year? 

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2026 Heat Accumulation vs Rodent Prognostication

Mon, Feb 02, 2026
Seasonal Story

On February 2, 2026, Punxsutawney Phil made his annual prediction of what the next six weeks of weather will bring. According to Phil, more winter is on the way! But what does the science say?

Our maps of heat accumulation provide a more scientific look at how much heat has accumulated so far this year, and what's next. Our maps show that heat accumulation is ahead of schedule in much of the west, on time in the Midwest and upper Northeast, and behind schedule in the East.

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Spruce budworm affects more than just spruce trees

Fri, Jan 09, 2026
Publication Summary

Insect pests, like emerald ash borers and spongy moths, pose a significant threat to forests in North America. Management of these pests depends on information about which trees are at greatest risk and which treatments are likely to be most effective. Outbreaks of spruce budworm can devastate fir and spruce forests in the northeastern U.S. and Canada, but the risk to other tree species has not been well documented. Researchers in Maine used Nature’s Notebook observations and tree ring data to show that spruce budworms also feed on eastern hemlock trees, which leaf out at the same time as fir and spruce trees. Understanding the risk to eastern hemlock trees is important because the trees play a unique role in eastern forests and are also harvested commercially.

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Nature’s Notebook data reveal earlier spring activity under warmer conditions

Wed, Nov 05, 2025
Publication Summary

Results from many small-scale studies have shown that warming temperatures are causing plants to leaf-out and flower earlier than they have in the past. However, it has been difficult to know whether these patterns hold true for a wide variety of plant species at a continental scale. To answer this question, researchers used thousands of observations of plants in the eastern U.S. that were submitted to Nature’s Notebook, mainly by volunteers. They found that leaf-out and flowering occurred earlier with warmer temperatures, but the effects varied among species and locations. Invasive species, shrub species, and species at southern latitudes were more sensitive to warming temperatures than other species. These patterns were similar to results from analyses of data collected by professionals and consistent with results from previous scientific studies, demonstrating the value of Nature’s Notebook observations.

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Community scientists document a large diversity of plants in urban areas

Mon, Sep 15, 2025
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As the world becomes increasingly urban, it will become more important to maintain diverse plant communities in and around cities. A diverse plant community provides many benefits to people and wildlife inhabiting urban areas. In many cities, we have incomplete information about plant species and distributions. So, researchers gathered data from published scientific papers, unpublished reports, and observations submitted to community science programs like USA-NPN’s Nature’s Notebook to see whether combining information from all these sources provided a more complete picture of urban plant biodiversity. They compiled more than 171,000 observations of plants in the Chicago, Illinois area and documented more than 2,200 plant species. Community science programs contributed more observations of more plant species in more diverse locations than scientific studies or reports. However, professional scientists documented a significant number of native species with limited distributions that were not observed by community scientists. In all, the study highlighted the value in combining different types of data to better characterize and manage plant communities in urban areas.

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Extreme weather events affect when plants flower and when insects are active

Wed, Jul 09, 2025
Publication Summary

As the climate changes, there has been a significant increase in the frequency of extreme weather events like heat waves, droughts, and hurricanes. We know that increases in average temperatures affect the timing of plant and animal activities, but the effects of extreme weather events are largely unknown. To address this knowledge gap, researchers used millions of photos of plants, butterflies, and moths that were submitted to iNaturalist between 2016 and 2022 to evaluate the effects of extreme heat, cold, dry, or wet conditions on the timing of plant flowering and adult insect activity. The results showed that the onset and duration of plant and animal activities were impacted by extreme events and not just changes in average climate conditions. However, the effects of extreme weather were complex, often differing between plants and animals and varying regionally. Results from this study can help us predict how plant and insect populations will respond to extreme weather events, which are likely to occur more often with climate change.

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Trees damaged by late season frosts can see negative impacts for years

Fri, May 09, 2025
Publication Summary

Many trees in the Northern Hemisphere are leafing out earlier as the climate warms. But with leaves emerging earlier in the season, there is an increased risk of damage from a late spring frost. Researchers used experimental and observational data – including thousands of records from Nature’s Notebook – to evaluate the effects of late spring frosts on hundreds of tree species. The results indicated that late spring frosts have both short-term and long-term effects on tree growth and phenology. In the short-term, late spring frosts damage young leaves and limit tree growth that year. But more notably, late spring frost events also limit the amount of resources a tree can store that year, which results in delayed leaf emergence and reduced productivity the next calendar year. These results illustrate that the effects of extreme climate events on plant phenology and productivity may extend months, or years, into the future. The results may also help scientists generate more accurate predictions of how forests will respond to future climate change.

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A more complete picture of the timing of spring

Thu, Mar 13, 2025
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How early is spring this year and how does it compare to years past? We can answer this question using observations of plants and identifying the weather conditions that are needed for plants to leaf out and flower. For many years, the USA-NPN has shared maps, called the Spring Leaf Index and Spring Bloom Index, that show when weather conditions associated with events that signal the start of spring reached. However, an early start to spring does not necessarily mean that subsequent springtime events will also occur early. So, a team of researchers used thousands of observations submitted to Nature’s Notebook to identify conditions associated with events that occur later in the spring. And soon, maps for a Late Bloom Index, that depict the timing of activity in the latest-blooming plants will be added to the USA-NPN Status of Spring website. This new index, combined with the usual Spring Leaf and Spring Bloom Indices, will give us better understanding of how spring is progressing each year.

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Phenology Week! March 17-21, 2025

Wed, Feb 12, 2025
News

March 17-21, 2025 is Phenology Week - a virtual celebration of the seasonal cycles of plants and animals. The purpose of Phenology Week is to celebrate YOU, our Nature's Notebook observers, Local Phenology Programs, and partners! We'll have webinars, awards, daily challenges, observer stories, and more.

Phenology Week Media Kit

Share Phenology Week Content on your social media! Our media kit contains daily activities to share with your community!

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