Phenology: ecology on the clock

Eugenius Warming c. 1900

One of the key moments in the birth of ecology as a science began when Eugenius Warming’s research project* had its study area pinched down (for a variety of reasons).  Left to find insights on a scale smaller than 10 acres and larger than a single plant, Warming suddenly saw a new set of patterns emerging: the same plants kept showing up together.  Finding one became a cue to look around, for their pals were likely to be nearby.

More than 100 years later, “ecology”- the study of this relationship of biome members with each other – has become a household term.  Now, there’s a new subsection of this work creeping into the local parlance: phenology.

Phenomenon: the thing that is observed to be happening.

Phenology: studying the patterns of happenings.

This is the noun of nature (oak tree) becoming a verb (oak tree leafing out.)  More specifically, though, it’s taking that verb and pinning it on a calendar.  If ecology is the study of natural nouns in relationship to each other, phenology is the study of natural verbs in relation to each other.  

Given that quite a few things happen only annually, phenology starts stacking up the calendars: when does this happen, year over year over year?

washington dc cherry blossoms viewed at night

Taken at night by DC's Tidal Basin

The longest phenological record on the planet stretches back hundreds of years: Japan’s Hanami Festivals, which celebrate the flowering of the Sakura (cherry trees) and / or the Ume (plum trees), have taken place every spring since the 700’s.  By the 12th century, the cherry blossoms had trumped the ume for primary focus, and a continuous record of the hanami festival dates had begun in Kyoto.

(Aside: the DC Cherry Blossoms are predicted to peak in 2012 between March 24th and 31st.  I _highly_ recommend going in the evening or the early morning.**)

Phenology takes these observations and compares them not just with each other, but with other observation patterns.  Take the wildflower meadows high in the Rocky Mountains of Colorado:  over years of measuring snow pack, melt dates, bloom times, and bloom abundance, a few important things have been learned.

Colorado wildflowers and climate change

Colorado wildflowers (from LifeBiteNews)

When the snow is deep, it lasts a long time into the warming season.  This forces dormancy on the plants underneath.  By the time the flowers can stretch up to the sun and bloom, the frosts have passed.

What happens in low snow years? The sun warms the soil, the flowers wake up and begin to grow, and then a late frost whips down one night and kills off the new buds.  Bloom abundance is sharply reduced.  These plants have few frost defenses of their own- they’ve been counting on that snow pack to do the heavy lifting (“hit snooze!  hit snooze!”).

So how will global climate change impact the flowers, their butterflies, and the whole ecology that is built off that pairing? Depends on the snow.  If higher temps mean drier air and less snow, then this whole system is in trouble.  If higher temps mean more winter moisture and more snow- enough to last past the last frost of the season, they’ll be alright.

What’s been observed so far?  The flowers are creeping up the mountainsides, appearing higher and disappearing lower. Why? So far the snow pack has been melting earlier but the last frost date hasn’t been changing nearly as much.

Flowers blooming aren’t the only thing being studied: bird migrations, fall leaf color peaks, fall leaf fall, spring bud burst, animal hibernation times, mating seasons… if you can write the start, end, or peak on a calendar, there’s likely to be somebody interested in studying that.

The Colorado butterflies can go fly a little further up the mountains too, but what happens when birds hatch too early and there is no food waiting for them?  While animals can move themselves to a more comfortable-to-them climate zone, plants don’t move so fast.

Farmers and  gardeners especially are going to be crucial for helping generate seed sources for wild dispersal in new areas as the climate zones shift.  What’s the crucial detail?  This will only be helpful if the plants are the native plants that the displaced animals are looking for in their new homes.

If you are choosing between planting some new flowering shrub deeply hybridized from something that grows halfway around the world and planting something that provides bird food that used to not be plant-able north of 100 miles south of you, by all means, choose the second option.  Somebody’s babies may be counting on you.


*Eugenis Warming’s subsequent book, Oecology of Plants: An Introduction to the Study of Plant Communities (1895), is what took his observations out into the world.  No book, no credit for the ideas.

**(DC Cherry Blossoms: The closest metro is either Arlington Cemetery on the Blue line- then walk over the bridge to the Lincoln Memorial and turn right toward the Tidal Basin- or Smithsonian on the Orange line- hop out on the mall side and walk past the Washington Monument, then hang a left toward the Tidal Basin before you get to Lincoln.)


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One response to “Phenology: ecology on the clock

  1. Thanks for a new word “phenology” and new understanding stated in a very easy to understand way. Keep it up!
    Could the dates for the cherry blossoms for 2013 be appended?

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