Prairie Word of the Day – Phenology

Hello, and welcome to the fifth edition of the popular series, “Prairie Word of the Day.” This is the series that has previously brought you such inspiring words/phrases as Tiller, Habitat Heterogeneity, Disturbance and Shifting Mosaic of Habitat. Thank you for the many cards and letters expressing your gratitude for the explanations of these words, and suggesting future topics.

Today’s featured word is Phenology. In short, phenology is the study of the timing of various events in the lives of plants and animals and the factors that influence that timing. Phenology should not be confused with Phrenology, which is the long discredited study of how the shape and size of the human skull supposedly correlates with character traits and mental capacity. Phrenology has been used to bilk people of their money, support racist and sexist stereotypes, and bolster Nazi eugenics. Let’s not talk about that today.

Phenology, without the “r”, is a complex and important topic in ecology. You might hear someone talk about the phenology of plants related to when they begin emerging from the ground, when they flower, and when they begin to wilt and senesce at the end of the growing season. Additionally, however, phenology includes the timing of the emergence of insects from dormancy or their final molt into adulthood. It also includes the timing of animal migrations and hibernation, as well as many other events in the lives of myriad organisms.

This bee (either Melissodes agilis or M. trinodis) is a specialist feeder on sunflower pollen and is only active during the period of summer when sunflowers are blooming. If the bee emerged before sunflowers started blooming, it might not find anything to eat.

The factors that influence a species’ phenology often include temperature, light, and moisture – in combination with genetic signals. We still have a lot to learn about the phenology of most prairie species, especially in terms of how they might adapt to changing climate. In fact, rapid climate change has brought much recent attention to phenology because changes in the flowering time of plants, for example, have already helped illustrate the occurrence and impacts of climate change. In addition, there is great concern that species may not be able to adapt the timing of their lives quickly enough to match the changing climate, and/or that timing of interdependent species might not remain synchronized. For example, flowers might start blooming before or after their particular pollinators are active, or birds or insects might migrate to breeding areas before food is available at those sites. A couple years ago, monarch butterflies arrived in Nebraska way ahead of schedule, but fortunately they were still able to something to eat and lay eggs on.

When monarchs arrived in Nebraska much earlier than normal, dandelions were one of the few abundant wildflowers for them to feed on and they laid eggs on whorled milkweed because common milkweed hadn’t emerged yet.

Here in Nebraska, we got some interesting insight into the phenology of plants during 2012. The year ended up giving us the most severe single year drought in recorded history and it started out as a year of extraordinarily warm temperatures. In fact, spring and summer temperatures arrived so early that we recorded many plant species blooming weeks or months ahead of their typical schedule. I wrote a short blog post about this back in May of 2012 and a number of people from around North America responded with their own sightings. The observation that stood out most to me was the blooming of asters in May. I had never seen heath aster (Aster ericoides) or New England aster (Aster novae-engliae) bloom before late August or September.

Phenology is also important to land managers trying to sustain biological diversity in prairies. For example, around here, we are constantly fighting cool-season invasive grasses. The growth period for those species starts earlier and ends later than that of most native prairie plants. That gives us some opportunities to use herbicides to kill or suppress smooth brome, Kentucky bluegrass, or other invasive grasses when the chance of harming other plants is very low. In addition, we can use prescribed fire, grazing or mowing to target those grasses when they are most vulnerable. For example, we might try to burn a prairie right as those species are starting to bloom because it wipes out those plants’ entire season of energy investment in growth and flowering. The fire doesn’t kill those grasses, but it can knock them back enough to allow other plants – especially those just starting their growth periods – to flourish while the vigor of the invasive grasses is low.

We timed this burn to suppress cool-season invasive grasses, which were just starting to bloom. After the fire, many warm-season grasses (and other plants) responded quickly because they were just beginning their period of most active growth.

Timing of burns can also be aimed at suppressing many other kinds of plants. For example, we sometimes try to burn prairies when encroaching trees are just leafing out and highly vulnerable. Alternatively, burns can be timed to limit impacts on animal or plant species. That might include strategically scheduling a fire based on the emergence of rare insect species or before sensitive reptiles become active in the spring. Prescribed grazing can be employed in much the same way – strategically moving livestock in and out of an area to suppress the growth of particular plants or to create desired habitat structure prior to the arrival or emergence of particular animal species. In all these cases, land managers are acutely aware of the phenology of the species they are trying to suppress or assist.

If you’re someone who enjoys keeping track of when things happen each year, you might enjoy joining a citizen science effort to document changes in the phenology of many different phenomenon. You could start at the National Phenology Network and peruse some of the options they provide. Or, if you already have years of field notes that document when you see your first bumblebee, prairie clover flower, or grasshopper sparrow each year, I’d encourage you to contact a local expert on that/those particular species and let them know about your data. You might have information of great value to conservation.

Best of 2018 – Part 1

Every December, I post some my favorite photos and writings from the year.  This year, I was either particularly prolific or particularly bad at narrowing things down.  Regardless, I decided to split my “Best of 2018” blog post into two parts so I could include more without making a single overwhelmingly-large post.

Back in June, I photographed this goatsbeard seed stuck on a hoary verbena flower stem.

Of course, these “Best of” posts are common across many media platforms this year.  It’s fun to look back at previous work.  It’s also, of course, nice to take a break from creating NEW content and just recycle old content!  So yes, I’m being extra lazy by getting out of creating content twice instead of once.  If it makes me (I mean you) feel better, I’ve also been working on a lot of data that should provide fodder for some pithy posts within the next month or two.  Maybe that will help make up for my laziness this month.

In Part 1 of this two part series, then, I’m including half of my favorite photos from 2018, along with about half of the posts I thought were most interesting, or at least fun to write this year.  That, of course, includes the project that consumed much of my time this year – my square meter photography project.  After an initial post in January that described the project, I posted 6 updates throughout the year that summarized activity from the months of May, June, July, August, September, and October.  You can also read an encapsulation of the whole project here

This composite image shows all 110 species I found and photographed this year in my square meter plot.

This year, I had a couple posts this year that described the results from a couple simple but informative research projects.  The first was really easy, but addressed a question that I’d wondered about for a while – are the insects I find frozen in the top layers of ice on ponds and wetlands alive or dead?  I also conducted a second year of data collection on a basic research effort to figure out if the number of flowering stems produced by dotted gayfeather is related to grazing pressure.

I also wrote several natural history profiles, including this one on the secret lives of grasshoppers and this one on the oil beetle, which has larvae that trick bees into taking them home to eat baby bees.  Plants weren’t ignored either, as I wrote a post talking about the value of both ironweed and marestail, which are often misunderstood to be pests.

But hey, I’m sure you already read those posts and remember every detail.  If that’s the case, here is the first half of my favorite photos from 2018 for your perusal and (hopefully) enjoyment.  

Wind blows snow across the frozen surface of the wetland/pond (and a frozen damselfly larvae) at our family prairie.
Sandhill cranes leave their overnight roost as the sun rises over the Platte River in March.
A massive smoke plume signals the end of a prescribed fire.  Our crew patrols as the final head fire runs toward the areas we’d earlier burned out in order to catch and extinguish this  flaming front.
A rosette of fourpoint evening primrose leaves created some of the only green during the early spring in our Platte River Prairies.
Pasque flower blooms at The Niobrara Valley Preserve on the last day of April.
An ant explores a small Maximilian sunflower plant in May.
Colorful Sandhills prairie at The Niobrara Valley Preserve.
A pearl crescent suns itself in my square meter plot in Aurora.
Sideoats grama in full bloom.
Stiff sunflower at Lincoln Creek Prairie.
Curious cattle in the Platte River Prairies in July.
A beetle feeds on a Maximilian sunflower leaf in my square meter plot during early August.
A beautiful tiger swallowtail butterfly visits ironweed at our family prairie.
This beautiful digger bee is a specialist feeder on this species of blue sage (aka pitcher sage).
This spider was guarding its net on a cool foggy summer morning.
Dew drops on a spider web create a veil across a sensitive briar plant.
A bull bison stares stoically at me at The Niobrara Valley Preserve.
A hover fly feeds on Indiangrass pollen within my square meter plot.
A monarch butterfly feeds on pitcher sage at the Platte River Prairies.
A hover fly on a wilted sunflower leaf within my square meter plot.
A Chinese mantid appears to pose seductively within my square meter plot.
I was really grateful to find this tree frog in my square meter plot.  
Bison fight flies and graze while walking into the sunset at The Niobrara Valley Preserve.
Lead plant leaflets in the early autumn.
Dotted gayfeather seeds wait for a stiff wind to carry them off.
Prairie grass and snow in Aurora, Nebraska.
An ice skirt decorates this rush, protruding from a frozen wetland along the Platte River.