Flowering Time and Temperature Variation

Posted on February 2, 2013 by prairiebotanist

I have been at this for some time with Ben VanderWeide, and hopefully we are nearing publication. The focus of most work to date that studies how variation in temperature affects when things flower has focused on species that flower early. I think people focus on these species, in part, because their early flowering is conspicuous. We are all looking for blossoms in spring. These species also clearly respond to temperature around and immediately before they flower. The prevailing view is that later flowering species are less sensitive to warming. This, however, is not borne out by data from 261 species in the northern Flint Hills of Kansas dating back to 1893.

Instead, regardless of when they flower on average, species respond to spring warmth by advancing flowering. Late species, however (and other studies have shown this too) delay flowering in response to warmth during other times of the year, particularly later in summer. The result of this is that later species are actually more sensitive to warming, if one sums sensitivity to warming (slope estimates of regressions of mean first flowering date (FFD) against monthly mean temperatures) across months during the year leading up to flowering. The figure below shows this nicely. Cumulative sensitivity (the sum of absolute values of positive and negative sensitivities) is greater, in general, for species flower later in the year (panel A), and this seems to be because they have greater delays (panel C), while there is not much relationship between mean FFD and phenological advancement (panel B). We used quantile regression, because of heteroscedasticity (more variation for later flowering species), but in panels A and C all positive slopes are significant.

quantilereg3

Posted in native plants, Phenology, Weather and Climate | Tagged , , , , , , , | Leave a comment

What the January?

Posted on January 28, 2013 by prairiebotanist

Surface temperature analysis for the afternoon of 1/28.

Surface temperature analysis for the afternoon of 1/28.


I feel like I blog as much about weather as I do about ecology, but the craziness on the plains is impossible to ignore.

Today Topeka, KS surpassed its record high for the MONTH of January. It was 75 degrees. The old record was 74, and the record for the date was 67. It was 76 in Manhattan, KS, but the NWS doesn’t keep extremes records for MHK. Temperatures have surpassed 60 degrees six times this month in Manhattan (30-40 degrees is average).

So what? It is supposed to cool down to slightly below average later this week (before rising back up to the 50-60 degree range).

Well, context is key. Look at the most recent drought monitor.

1/22/13 Drought Monitor for KS.

1/22/13 Drought Monitor for KS.

And look at the 6-10 and 8-14 temperature outlooks (precip is equal chances above or below average).

There is a high probability that the plains will be warmer than average next week.

There is a high probability that the plains will be warmer than average next week.

and the week after next as well!

and the week after next as well!

We just keep piling one unprecented event on top of the next. It isn’t for certain that 2013 will see terrible drought on the plains, but it looks more and more likely, and drought in its second, third, or fourth year (depending on where you are from the Dakotas to TX) is going to have consequences for the ecosystems we study, the food we eat, barge traffic, and for some of us, how much we are able to enjoy where we live.

But I’m in Oregon now. Looking at climate change projections, the Great Plains is not the place to be in coming decades.

Update: Manhattan and Topeka also broke records on 1/29 between midnight 2am, 68 and 70 degrees, respectively…70 after midnight in January in Topeka. That is jaw-dropping.

Posted in Weather and Climate | Tagged , , , , , | Leave a comment

Hotter than ever, but average in 80 years

Posted on January 8, 2013 by prairiebotanist

It’s official. 2012 was the hottest year in 118 years of record keeping for the U.S. It was the hottest year on record from South Dakota to Texas and from Kansas to Illinois. In almost all other states with appreciable grasslands, this was one of the warmest three years on record. Over 99 million people experienced 10 or more days above 100 degrees where they live this year. There were 356 all-time record highs set in the U.S. There were 4 all-time record lows.

(Courtesy NOAA) The mid-continent truly burned in 2012.

In grassland continental climates, heat is associated with drought, and 2012 was true to form. Last year was among the driest ever for much of the middle of the country. In 2011, flooding plagued the Midwest. By the end of 2012, the mighty Mississippi was reduced to mud, sand bars, and a trickle. At least the reduction of exports on barge traffic is associated with a decrease in the export of sediment and nutrients.

(Courtesy NOAA) This year was exceptionally dry for the Central U.S. It should also be noted that the southern species have seen relatively dry conditions now for three consecutive years. In contrast, much of Nebraska, was wetter than average last year.

In 2012, 9.2 million acres burned in wildfires. Some of these fires consumed areas beyond my comprehension.

The Long Draw fire in the sage-steppe grassland southeastern Oregon burned over 550k acres. The scale of the burn scar rivals or surpasses those of the mighty fault block Steens Mountain and Alvord Deserts just to the northwest (green and white respectively).

The shit truly hit the fan in 2012, and although much of it was unprecedented in our records, it was not beyond the capabilities of our natural systems for recovery. The problem that I see as a conservationist and restorationist is that there will be a day in our children’s lifetimes and in some of our lifetimes that this will be the norm. It will be the norm if we take action on climate now. If we don’t take action now, years like this year will be a cakewalk.

We can view a prairie after a drought or forest or sage-steppe grassland after a severe fire and comfort ourselves in the resilience of these systems, but resilience assumes that there is a window of conditions for recovery. In eighty years the recovery window, which is yesterday’s normal, will be an anomaly…as anomalous as 2012 with respect to the current climate record. If we don’t drag our feet, we have a lot of hope for saving species. If we’re really smart and lucky, we’ll be able to save the physical structures and functions of natural systems. I don’t think we can possibly learn what we ought to do fast enough. All we can do is improve our odds.

Will anyone born in 2012 share this flower with their children?

Will anyone born in 2012 share this flower with their children?

Posted in Uncategorized | Leave a comment