Simple techniques can describe how maple trees are responding to climate change

Posted by Libby Ellwood and Richard B. Primack

“Our life is frittered away by detail. Simplify, simplify.”

-Henry David Thoreau

In a study recently published in a Special Issue of Applications in Plants Sciences, we found that simple annotations of plant specimens are as effective as more detailed ones for phenological research. With climate change increasingly effecting plants and animals around the world, phenology is an important metric for us to readily monitor the extent to which organisms are responding. Plant specimens are a critical resource for this as they record the phenological state of a plant at a specific place and time. Each specimen therefore provides evidence of such events as flowering, leaf out, and even dormancy.

Red maple specimens are evaluated for their
flowering stage, along with information
on where and when collected.

However, is it necessary to record the fine-scale phenology of a specimen, such as flower buds, early flowers, or peak flowers? Or, is simply noting “flowering” enough to see patterns of change? In researching this question, we found that the simpler approach of noting “flowering” was sufficient to see that the phenology of our study species, the red maple, has been advancing by about 2 days for each one degree F of warming temperature. These are the same results we found with a more detailed approached.

We evaluated specimens from across eastern North America.

Detailed phenological information may be necessary for certain research, though our study demonstrates that in many cases a simpler approach is just as effective. This finding is especially important as scientists work with members of the public, citizen scientists, to monitor phenology and annotate specimens. It is much easier to teach an armchair botanist to recognize flowering or non-flowering as opposed to finer phenological details, and now we know that the results will not be comprised with this approach.

Read the full paper here: Ellwood, E. R., R. B. Primack, C. G. Willis, Janneke HilleRisLambers. 2019. Phenology models using herbarium specimens are only slightly improved by using finer-scale stages of reproduction. Applications in Plant Sciences 7(3): e1225

Trails-as-transects is published!

posted by Caitlin McDonough MacKenzie

Trails-as-transects: phenology monitoring across heterogenous microclimates in Acadia National Park, Maine was published last week in the journal Ecosphere.

Lowbush blueberry flowers on an Acadia transect

Caitlin hiked Cadillac, Pemetic, and Sargent Mountains repeatedly each spring to collect local leaf out and flowering phenology data across the environmental gradients in Acadia National Park. While it might seem like her dissertation field work was a walk in the park, she and her field assistants gathered over 20,000 phenology observations and successfully estimated shifts in leaf out and flowering (in days/°C) for nine common  plant species.

Emerging Canada mayflower leaves on an Acadia transect

This work supports Acadia National Park’s efforts to identify species vulnerable to climate change and sets the stage for future citizen science phenology programming on the hiking trails.

Four years of fieldwork selfies — Caitlin's favorite photo from each year on her Acadia transects

Read the paper here. Caitlin also published a long post about the hiking fieldwork, including calculations of how long it really took to hike each mountain transect, at the PLoS Ecology Community blog.

Dioramas as reality

By Richard B. Primack

“When was it that men agreed to respect the appearance and not the reality?”

 Henry David Thoreau 

Museum dioramas can depict dramatic natural scenes that would be difficult or impossible to see in the wild. Dioramas at the Carnegie Museum of Natural History in Pittsburgh, for example, allow visitors to see a range of species and biological communities—all in one place in the middle of winter.

A mother bear and her cubs feeding along a stream. (In the wild, most people would avoid coming this close to bears.)

Zebras, wildebeest, warthogs, and other wildlife on the African plain. (This diversity of large mammals would be hard to find in a single place—and it would be a long way from Pittsburgh.) 

Wildflowers in a mountain meadow. (Visitors get the beauty without having to climb a mountain.)

The four seasons in Pennsylvania. (Spring, summer, fall, and winter in one day—and one scene.)

Dioramas clearly provide an exciting way to experience nature. On the other hand, these striking icicles hanging off of exposed shale along the Trillium Trail Nature reserve outside of Pittsburgh provide an unexpected surprise for those who keep their eyes open for unfiltered reality. 

Museum dioramas provide dramatic scenes and learning opportunities that are tough to get otherwise, but don't forget there are dramatic scenes and learning opportunities just outside, too, even in the cold of winter.