As the weather turns chilly, even here in the Sonoran Desert, I keep seeing a particular word pop up: marcescence. This phenomenon is defined as plants hanging onto their dried and dead leaves through the winter rather than shedding them in autumn. Beech, oaks, and witch hazel are some of the plants that display marcescence. Learn more about this phenomenon, and potential reasons why it is advantageous to plants, in an article from University of Maryland Extension. You might also check out this recent New York Times article that digs into what cues plants to shut down in winter.

As for Nature's Notebook, once a leaf is dried/dead, it no longer counts as a leaf, so you would report "no" for Leaves and Colored leaves for these dead leaves that still cling to the tree. And what should you report if these dead leaves fall off your plant later on in the winter? To answer this question, one only needs to look at the definition for Falling leaves, which states: Do not include fully dried or dead leaves that remain on the plant for many days before falling.

Photo: Dead white oak leaves cling to a branch, Credit:

I'll leave you with a poem that an observer in New Mexico recently passed along, as it pays tribute to marcescence and other autumn phenology. And, of course, with my gratitude for all that you do for our Network!


What's new at Nature's Notebook and USA-NPN

New and returning USA-NPN students

Viviana Beltran, originally from San Luis, AZ, has always had a passion for STEM educational outreach in underrepresented communities such as her hometown. She is currently a graduate student at the University of Arizona studying educational psychology to bridge the gap between environmental science knowledge and educational community outreach. She is very excited to work with USA-NPN as a Spanish translator and find ways to make Nature’s Notebook more accessible to different underrepresented communities!

Sofia Guadalupe Delgado is an undergraduate at the University of Arizona pursuing a Bachelor's degree in Ecology and Evolutionary Biology and is a current NASA Space Grant intern with the USA-NPN. Sofia's project involves summarizing information about phenological changes in US Fish and Wildlife priority species and ecosystems.

Carla Arreguín is an undergraduate student from Mexico City in an internship program with the USA-NPN. She is pursuing her Bachelor’s degree in Geography at the Universidad Nacional Autónoma de México, and is currently doing her thesis project in the impacts of climate and land use change in species of fireflies. Carla is assisting the USA-NPN to develop monitoring protocols for multiple firefly species.

Ava Lasater is a returning undergraduate student at the University of Arizona majoring in Bioinformatics and is in the Honors College. Ava is from Golden, Colorado, and is interested in climate change and how changes in the environment and ecology affect human health.

Learn more about the students »

A new integration of phenology data

We often get asked about whether USA-NPN data are combined with phenology data from other programs such as iNaturalist or Project Budburst. A new project will make that possible! A team of collaborators was recently funded to develop Phenobase, an open source, global scale knowledge base that will integrate millions of existing plant phenological observations from in situ monitoring programs like the USA-NPN and NEON, community science images contributed to iNaturalist and Budburst, and digitized herbarium specimens compiled by iDigBio and GBIF. The team is currently looking for a data scientist to contribute to the project (see below).

Learn more about Phenobase »

NEON and USA-NPN webinar

Earlier this month, USA-NPN's Alyssa Rosemartin and Theresa Crimmins presented in the monthly science seminar series of the National Ecological Observatory Network (NEON). The presentation covered the history of our organizations' collaboration and opportunities that exist for data collectors and users.

Watch the webinar recording »

Recent happenings in the field of phenology

Differential advancements in leaf-out among plant functional type

Changing climate conditions may affect the timing of leaf-out among trees and forbs in different ways. A research team based at the University of Ottawa evaluated anticipated changes in leaf-out among these two groups of plants using contributed to Nature’s Notebook from 965 sites across northeastern North America. This geographically extensive set of observations revealed that understory herbs are advancing leaf-out at a greater rate than trees, especially at higher latitudes. This more rapid advancement in leaf-out could result in a longer growing season and increased carbon uptake for these plants as temperatures increase.

Learn more »

See all Highlighted Publications »

Credit: Ellen G. Denny

Warmer winters confuse crops

Many plants require a certain amount of winter chill before they come out of dormancy.  Authors of a new study found annual crops, such as canola, also require this chilling period. Warmer winters may lead to reduced crop yields, which may force growers to try varieties that are better suited to warmer climates.

Learn more »

Especially for Local Phenology Leaders

Summarize your 2022 accomplishments

As the end of the year approaches, it's a great time to reflect on all you achieved this year with your Local Phenology Program! One way to do this is with an Annual Report that outlines your activities, accomplishments, and challenges from the year. Our Phenology Report Guide gives you an outline to follow, and you can pick and choose which sections you want to incorporate.

We'll be continuing to discuss Annual Reports in our Local Phenology Leader Monthly Call next month on December 16th. I hope you'll join us! You can sign up for reminders about the call time and topic.

View the Phenology Report Guide »

Join the LPL Monthly Call List »

Visualize your phenology data

Looking to explore your Local Phenology Program data and not sure where to start? You may find inspiration from this great one-pager from McDowell Sonoran Conservancy's Parsons Field Institute, which has been collecting data since 2017. In this summary, Local Phenology Leader Jerry Holden explores the synchrony between saguaro cactus flowering and fruiting and presence of White-winged Dove, which is an important migratory pollinator of saguaros.

You can explore your own LPP's data in the USA-NPN's Viz Tool by finding your LPP's custom link to the Viz Tool on our Active LPP page.

View the data summary »

Find your LPP's custom Viz Tool link »

Related resources

Give your feedback on NCA5

The Fifth National Climate Assessment provides an updated look at the impacts of global change in the U.S. A draft is now available for 12-week public review and comment. Informational webinars are available. Comments must be submitted by January 27th, 2023.

Learn more »

Phenobase post-doctoral opportunity

Applications are invited for a Data Scientist position in the Li Lab at Louisiana State University to support the NSF-funded Phenobase project. Major duties of this position include developing machine learning methods to extract phenological information from images, building software to integrate existing phenological records from different networks, disseminating and maintaining Phenobase through online web portal and R/Python packages, and developing and organizing workshops and tutorials to train users to use Phenobase and the developed machine learning methods.

Learn more and apply »

American Climate Leadership Awards

The American Climate Leadership Awards (ACLA) offers $175,000 in financial rewards and national recognition to exemplary climate leaders and organizations building public support and political resolve for climate solutions at local, regional, and national levels. Nominate someone or apply by December 15, 2022.

Learn more »

Erin Posthumus
Outreach Coordinator
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