I recall April of 2007 very well. I remember that late frost that literally nipped Missouri's grape harvest in the bud -a well-advanced bud at the time- and the same frost that turned all of the fresh spring green in the canopy into rustling immature black leaves. Walking through the woods in late April was reminiscent of mid-October with leaves falling all around and crinkling in the wind. For a while in spring of 2007, there was a huge flush of understory production under the canopy impacted by the very late hard, killing frost. I remember the Carex socialis that served as a lush, an unnaturally occurring carpet in the Bootheel's bottomland woodlands I was stationed in that spring, all thanks to that late frost and the newly available sunlight. I recall asking professionals if the frost would damage the hickories which had already leafed out, or if the frost would impact acorn production that year or in 2008. There may have been some lasting damage to trees, shrubs and woody vines that year, and I know for certain that it is very difficult to find a Missouri-grown 2007 vintage of Norton, with the grapes having been set back significantly because of that frost. But I was never really given a sufficient answer about the short-lived or lasting impacts of that killing frost to our natural systems.
Fast forward to the drought of 2012 which ravaged the Midwest and the entire Ozark Highlands of Missouri. We had summer wildfires that August, huge wildfires that threatened to move into storm damaged areas, a 100 mile swath in the Ozarks that witnessed massive straight line winds that swept through the region on May 8, 2009. All of the drought-cured downed wood, the dense flush of woody sprouts and understory components including highly flammable warm season grasses and rank forbs were in the line of wildfires. The extreme weather event in 2009 undoubtedly caused lasting impacts: in 2011 I worked on a landscape-scale bird survey in areas impacted by that May derecho, (a new word for most of us, coined by the folks at NOAA, the Spanish word for a bow-echo effect resulting in straight line winds at hurricane force) where I surveyed bird response to areas impacted by the wind event compared to control units, areas that did not see the winds in excess of 100mph. I hired the best botanist in the Midwest to help with the vegetation component in an effort to compare areas impacted by the wind event to those that had seen only regularly occurring fires for 25 years. But I won't get into that study here, though it was very interesting and a fun project, barring the hours and hours of busting through the thankfully unsalvaged woods, a whole landscape of beetle food, an impenetrable network of downed trees and a ridiculous flush of understory plants and associated bird populations. Yellow-breasted chat and prairie warbler city.
What was notable in the years following both of these "natural" events is the lack of monitoring and research. Here we have a perfect laboratory of natural systems in the Ozarks, most of them highly damaged by years of grazing, logging, and fire suppression, but still wooded landscapes with some semblance of what folks in other fields call "ecosystem services." Birds, bats, mammals, insects (including the pollinators!), thousands of species of life exist in our damaged Ozark natural communities. So one would hope that teams of scientists are measuring how extreme weather events are impacting not only vast suites of wildlife, but also the fragile flora, the last remnants of our biodiversity that has managed to persist through 200 years of extraction. I work with some folks who work in research and I have personally not learned of much research being conducted on the impacts of weather events in recent years. I'm probably out of the proverbial loop and perhaps I'll catch a lot of flak for even questioning the integrity of our researchers in the Ozarks. I would love to be called out....with valid proposals with valid questions and true science in hand. I just don't see much of that, of Science, being practiced in Missouri, even in our fancy universities. A classic Caesarian recusatio:I won't write here about how shameful it is that organismal biology is being shown the door, that herbaria are dissolving, or that students wanting to conduct research continually fail to make contact with experts in the field in which they aspire to become an expert and therefore produce shoddy work. No, I won't talk about that here.
So, wildfires from the drought of 2012 left a scorched landscape and I have not yet seen or heard of any vegetation monitoring occurring on these areas. But let's fast forward to spring 2013 when I am driving down Hwy. 54 between Eldon and Camdenton and I see a roadside covered in pale blue flowers. I had never seen a blue spring wildflower on this route before, and I travel Hwy. 54 at least once a week and have done so since December 2005. I pulled over at Linn Creek next to the post office exit and take a look: a vicious plant, hundreds of them on the roadside, robust plants with millions of little threadlike thorns surrounding pretty blue flowers. Viper's Buggloss, once listed in Illinois as a noxious weed akin to today's sericea (Lespedeza cuneata) in Missouri. One report from Illinois in the 1960s suggested that Viper's buggloss would "take over" every natural system. I had never seen it before spring 2013. And I haven't seen it since.
Was it a response to the 2012 drought that latent seeds of this weed germinated in the otherwise bare ground? Is it still there? I don't see it. I've pulled over at the post office again to see if I could find it to no avail. Now that we're in a somewhat normal rain pattern, barring June's daily rain tally, typical roadside weeds have shown their normal colors of typical thick, rank, weedy roadside vegetation. No Viper's buggloss. However, on the same route, princess tree is skyrocketing--Paulownia, a major invader of southeastern states, has appeared almost overnight on Hwy. 54. I have never seen it outside of the Bootheel, and here it is in the Niangua Basin, which is scary.
Similarly, take Gaura biennis. During the drought, roadsides around Salem and the surrounding Current River country were flush with the pale pinkish blooms of Gaura, a real pretty thing, but highly weedy, low C value of 0 or 1. I haven't seen it in robust populations since the drought. In fact, it's hard to find Gaura on roadsides in 2015. It's even disappeared from my yard, even though I know exactly where it was in 2012.
Drive Western Ozark roads this month and witness an amazing explosion of sunflowers with a profusion of blooms. Who doesn't like roadsides with wildflowers, especially nice -and native- sunflowers with persistent blooms? But is it a result of our unnaturally wet and rainy June followed by a dry August? Are the weather extremes are directly impacting vegetation? My observations are anecdotal, but anecdotally I can attest that I have never seen so much Helianthus on Ozark roadsides as I have this year. Is anyone measuring the impacts of weather events and patterns on vegetation? Granted, I'm mostly mentioning roadsides, but also anecdotally I can attest to a flush of woody shrubs in high quality, burned, nice woods. Is this a natural event or is the woody flush, the crazy sunflowers on the roadsides, the thick populations of Asclepias stenophylla on glades a result of extreme weather events? The predictability of nature and natural events is gone, and in short order.
Notably, the species that are spreading, growing robustly and reproducing and thriving are generally low quality plants, barring a few exceptions (such as the A. stenophylla). The weedy generalists are doing just fine with climate change, if that's the cause of the boom and bust, but the conservative and loyal to high quality soils and systems are not. Instead, the high quality species are being predated by deer overpopulation, misapplied herbicide, lack of appropriately placed prescribed fire or prescribed fire out of prescription, or just plain neglect. Biotic homogenization is occurring more rapidly than any of us could have ever imagined.