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 So, researchers gathered data from published scientific papers, unpublished reports, and observations submitted to community science programs like USA-NPN’s Nature’s Notebook to see whether combining information from all these sources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.

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.