Sunday, June 20, 2010
Among my summer reading list books is Alan Weisman's The World Without Us. I suspect the author has appeared on talk shows, on NPR interviews, in the NYRB discussing his book. I'm 3/4 through the book, and won't recommend it. Unfortunately, I think most of the premise is pretty trite, more along the lines of a science fiction story a la Robert Heinlein than a methodical account of natural history without humans. His examples and individual episodes are well researched and thoughtful, but when he throws in sentences that begin "Without humans..." I lose interest. With one foot in fact and another in supposition, his argument is hard to digest, his concepts of vibrant ecosystems reclaiming land in a historic landscape destroyed by agriculture, soils and microorganisms suffocated and permanently altered by concrete and chemicals, are based merely in wishful thinking.
Amidst his oddly positive book portending the world without human intervention, he references incidents of insouciance by BP long before the Deepwater Horizon spill occurred. Even if the general public had known in 2006 that BP was awarded the honor of "America's biggest polluter" by the EPA, I doubt anyone would have cared. But here, in an excerpt from The World Without Us, evidence that the company couldn't care less about their holdings across the pond before April 2010:
In March, 2005, a geyser of liquid hydrocarbons erupted from one of BP's isomerization stacks. When it hit the air, it ignited and killed 15 people. That July, at the same plant, a hydrogen pipe exploded. In August, a gas leak reeking of rotten eggs, which signals toxic hydrogen sulfide, shut much of BP down for a while. Days later, at a BP plastics manufacturing sibsidiary 15 miles south of Chocolate Bayou, flames exploded 50 ft. in the air. The blaze had to be left to burn itself out. It took 3 days.
So we've known for at least 5 years that BP is negligent. Why are we still discussing it and not doing more about it?
Posted by Allison Vaughn at 5:08 PM
Among my favorite activities, crouching over .25 m2 quadrats along a 50 m. transect on a high quality glade while being stung by tiny green bees (legs all laden with pollen) ranks in the Top 3 with floating down an Ozark stream (without cows in it) and setting fire to grassy woodlands. Vegetation monitoring season began last week, and the fulfilled anticipation of discovering species richness in every randomly selected quadrat was energizing, despite the searing sun and hot drinking water stowed in my pack.
Maybe it's luck, or that I design my own projects, that I find myself in such rich sites running transects with average species count per quadrat of 12 or more. Marching down the transect line to the next quadrat, it's hard not to be giddy, hoping that the next quadrat will include that cluster of Talinum calycinum you see ahead or at least one of those tall Kuhnia eupatorioides plants with its burgundy leaves. But, since I choose my own sites wisely, my quadrats always have great plants, no exotics, and total cover values of 50% or more (except when the three sided quadrat tool lands squarely on a huge dolomite boulder that takes up 25% of total cover).
Last week, I returned to the glade we burned in September 2009 to quantify the vegetation responses to a growing season fire versus a March 2009 fire. We set up transects on both sides of the fireline to determine -on a small, localized scale- whether the growing season fire favored forbs or grasses, or if fire seasonality impacted total cover value. Stepping out of the surrounding woodlands onto the glade, the difference between the two sites was obvious; the side burned during the growing season showed robust flowering stems, and the other side had few flowering stems (lots of Houstonia nigricans, but little else). How do you capture that with monitoring data? The Floristic Quality Index (FQI) alone won't filter out blooming plants, and, to boot, the plant composition and total plant density was similar on both sides. The plants blooming on one side were in the matrix on the other side, though in reduced numbers and not in flower. As expected, the spring fire favored grasses. This week, a computer program which will generate percentages of blooms/seeds in each quadrat and average by transect will be completed so the differences between each side of the fireline can be quantified...much better than anecdotal evidence.
We spent two days running transects here, calling out acronyms and cover values and, before setting out for the next quadrat, noting which plants were in bloom or in seed. By Friday, I was sitting in the air-conditioning typing in our quadrat data over the course of an 8 hour day. The reports generated showed a slight difference in species richness and FQI: 53 species/average FQI 5.094 recorded on the side burned during the growing season, and 38 species/average FQI 5.079 on the side of a spring fire. Pulling up data from the area's largest glade complex, long touted as one of the richest sites in the Niangua Basin, native species richness weighed in at 54 species/average FQI 4.981 across all transects. (It should be noted that cattle grazed this glade until the 1980s, and data were last recorded in 2003.)
Furthermore, the glade we sampled last week was used as a dump site for many years. Glass bottles, rusted tin cans, pop tops, and broken glass showed up in most of our quadrats in the growing season fire transects, though no acronym exists for these members of the total cover. Cattle grazing occurred here historically, but when the site became a local dump, the cows were moved to another nearby glade. The response to active management with fire on this old dump site has been remarkable.
For the next two years, a graduate student will be conducting a research project in the area to monitor effects on vegetation of various seasonality of fire on a high quality dolomite glade. As I've written many times before, successful fire regimes must include implementation during different times of the year of varying intensities and unevenly spaced fire return intervals to better mimic naturally occurring events. The growing season fire did not set back this year's flowering plants or destroy the glade as some have suggested, and by the end of the day we all had welts from the various pollinators who gorged on the rich bounty of forbs.
Post scriptum: while combing through files looking for a good Agalinis photo, I found this, the same site in mid-September, 2009:
Posted by Allison Vaughn at 8:37 AM
Saturday, June 19, 2010
We went to the woods to look for a clump of grass, a clump of Agrostis perennans, to be specific. Common in upland flatwoods, this elegant grass should be sending up a tall seedhead now. We were scouring the flatwoods, me and my trusty vegetation monitoring fieldmates, looking among the thick vegetation for the agrostis. Well, I was looking for the grass, and they, stooping down after every step, were quietly eating dewberries.
Rubus flagellaris, dewberry, is common throughout the state, and can be found in dry, rocky woodlands and on roadsides in the Ozarks. The white flowers of dewberries appear in early May, and their small, juicy fruits are ripening now, making every trip to the woods a little sweet, a little tart. Missouri is home to 14 species of drupe-producing berry vines. But unlike wild blackberries, which ripen in July in large clusters, dewberries do not produce prolifically. Berries are located singly along the long, trailing vines. Look for open woodlands with plenty of dappled light reaching the floor for these excellent wild berries.
Posted by Allison Vaughn at 1:19 PM
Thursday, June 17, 2010
Earlier this week, I overheard a colleague a few feet away and above a gray cubicle wall ask another colleague why the leaves on her white oaks were turning brown, despite the rainy weather. Throughout the Ozarks, especially around Springfield, Branson, and Lake of the Ozarks, the leaves on some otherwise healthy trees have turned brown, curled and twisted as a result of a common oak gall outbreak. This shall pass, even though the canopy may be a little unsightly for the rest of the summer. From the MDC Forestry website:
ROLLA, Mo.–Oak trees across a broad swath of Missouri are experiencing an unusual outbreak of a common parasite. Tree experts say the parasite is not fatal to healthy trees, even though the condition can look awful.
The Missouri Department of Conservation is receiving numerous reports from St. Louis to Branson of oak trees turning brown. The problem is especially severe in the area around Rolla, Lake of the Ozarks, Springfield and Table Rock Lake.
The main cause of the problem is a wasp of the family Cynipidae. These tiny wasps deposit their eggs on emerging leaves in the spring. As the eggs hatch and young wasp larvae begin feeding, leaves develop brown spots that grow into “galls.” Each of these button-like growths, which are about the size of a pinhead, provides food and shelter for one wasp larva. In severe cases, entire leaves turn brown over much of a tree.
“It looks worse than it really is,” said Conservation Department Resource Scientist Rob Lawrence. “Some people mistakenly think a tree has died when it turns brown. However, it is extremely rare for oaks to die from this insect. Only a few trees that are in serious decline before infestation are likely to succumb.”
Lawrence said trees that have been stressed in recent years by ice or wind damage are more vulnerable to declining health if they lose most of their leaves to gall damage. If most of a tree’s leaves turn brown or drop by early summer, it may produce a second flush of leaves. This added stress can lead to a long-term health decline.
Lawrence, a forest entomologist, urges tree owners not to cut down infested oaks. He said all that most trees need to recover is a little tender loving care, including supplemental watering during dry weather and possibly fertilizing next spring. Tree owners also can help minimize the severity of future outbreaks by burning or composting fallen leaves.
Avoiding any further injuries, such as wounds from lawn mowers or trimmers, is important for all trees, but especially those that already are stressed by previous storm damage. The use of pesticides is ineffective on the current gall damage.
Most jumping oak galls eventually drop to the ground. They get their name from the larval wasps’ habit of moving violently, causing the entire gall to jump. This causes them to settle into vegetation and soil crevices, where they are more protected.
Winter weather is one factor that helps determine how prevalent jumping oak galls are from year to year. Fewer jumping oak gall larvae survive in winters with repeated wide temperature swings, which encourage them to emerge early. Larvae survival is better in years when winter temperatures are more constant. Extended snow cover also helps the larvae survive by insulating them from cold.
More information about jumping oak galls is available at mdc.mo.gov/22967.
Although jumping oak galls are the main cause of oak trees turning brown, they are not the only cause of leaf discoloration in oak trees. Fungus infections also are causing some problems this year. Like the galls, this problem seldom is fatal to oaks. No actions are needed to help trees recover, other than those noted above.
Posted by Allison Vaughn at 8:58 PM
Tuesday, June 15, 2010
Kidneys were in his mind as he moved about the kitchen softly, righting her breakfast things on the humpy tray. Gelid light and air were in the kitchen but out of doors gentle summer morning everywhere. Made him feel a bit peckish. The coals were reddening.
Another slice of bread and butter: three, four, right. She didn’t like her plate full. Right.
-Hurry up with that tea, she said. I’m parched.
-The kettle is boiling, he said.
But he delayed to clear the chair: her striped petticoat, tossed soiled linen: and lifted all in an armful on to the foot of the bed.
As he went down the kitchen stairs she called:
-Scald the teapot.
On the boil sure enough: a plume of steam from the spout. He scalded and rinsed out the teapot and put in four full spoons of tea, tilting the kettle then to let the water flow in. Having set it to draw he took off the kettle, crushed the pan flat on the live coals and watched the lump of butter slide and melt. While he unwrapped the kidney the cat mewed hungrily against him. Give her too much and she’ll meat she won’t mouse. Say they won’t eat pork. Kosher. Here. He let the bloodsmeared paper fall to her and dropped the kidney amid the sizzling butter sauce. Pepper. He sprinkled it through his fingers ringwise from the chipped eggcup.
He prodded a fork into the kidney and slapped it over: then fitted the teapot on the tray. Its hump bumped as he took it up. Everything on it? Bread and butter, four, sugar, spoon, her cream. Yes. He carried it upstairs, his thumb hooked in the teapot handle.
She set the brasses jingling as she raised herself briskly, an elbow on the pillow.
She swallowed a draught of tea from her cup held by a nothandle and, having wiped her fingertips smartly on the blanket, began to search the text with the hairpin until she found the word.
-Met him what? He asked.
He leaned downward and read near her polished fingernail.
-Yes. Who’s he when he’s at home?
-Metempsychosis, he said, frowning. It’s Greek: from the Greek. That means the transmigration of souls.
-O, rocks! She said. Tell us in plain words.
Posted by Allison Vaughn at 3:32 PM
Tuesday, June 08, 2010
Because I will likely never call Aster azureus by its new name, Symphiotrichium oolentangiense. I think the natural world has much bigger problems to contend with than dealing with new nomenclature. We know A. azureus is dependent on a high quality ecosystem for sustainability. Let's focus our efforts on making sure that ecosystems are healthy enough to support such plants rather than wasting our time renaming them with fake Latin and Greek names.
Here's an article pertaining to taxonomic changes in warblers and how we really can't depend on DNA to tell us much:
Here's an article pertaining to taxonomic changes in warblers and how we really can't depend on DNA to tell us much:
Molecular methods are not sufficient in systematics and evolution
A lesson from flashy Central American warblers
Modern evolutionary systematists often use molecular methods, such like mitochondrial DNA analysis, to differentiate between species and subspecies. However, current research indicates that the picture painted by these methods may be incomplete, and only a creative combination of classical field-based ecology, museum-based systematics and DNA-based phylogenetics, can lead to right conclusions. In the last issue of the internationally acclaimed “Ornithological Monographs” (pages: 90-102), a team of biologists from the Universidad Central de Venezuela, Allegheny College in USA, Seoul National University in South Korea and Centre for Ecological Studies in Poland demonstrate how modern evolutionary biology needs the “old-style” biology in order to explain evolution and systematics of birds.
The team composed of Jorge Perez-Eman, Ronald Mumme, and Piotr Jablonski studied mitochondrial DNA, plumage coloration and behavior of 10 subspecies of a Central and South American warbler the Slate-throated redstart, an inhabitant of montane forests. Mitochondrial DNA analyses indicated that evolution of these birds started in northern and central areas of modern Mexico. From there, the birds rapidly expanded southwards to South America diversifying into several genetically and morphologically different subspecies. About 40-70 million years ago, when today’s montane forest types existed at lower elevations, a rapid expansion started producing several morphologically distinct subspecies that differ in the coloration of their bellies from yellow, orange, through red, and in the tail pattern from small to large white patches, but do not differ in the mitochondrial DNA. The researchers believe that during this rapid expansion of the populations, the genes responsible for these morphological traits have evolved rapidly due to adaptation to local habitats, while the mitochondrial genes often used in the phylogenetic research, remained unaffected by the evolutionary change.
Why would local conditions lead to rapid changes in the plumage pattern? The answer to this question can be found in the role of tail pattern in foraging of these warblers. The Slate-throated redstarts, as well as their relatives, the Painted Redstarts, use “flush-pursue foraging”. The foraging birds look like butterflies when they spread their tails and wings in order to be conspicuously visible by the insects. Insects, such like treehoppers or flies, are scared by the sudden visual displays and are flushed away from their resting sites on leaves and branches. The birds only wait for this to happen, and in elegant pursuits they catch the escaping insects in the air. Field experiments conducted by the research team with birds of the Costa Rican subspecies Myioborus miniatus comptus (see photo) and their key prey indicated that a contrasting black-and-white tail is critical to flush-pursuit foraging success, and that subspecific variation in the extent of white in the tail reflects evolutionary adaptation to regional prey or habitat characteristics that maximizes flush-pursuit foraging performance. Thus, even though the subspecies of the Central American clade are genetically homogeneous with respect to the mitochondrial genes, analysis of tail pattern and its effect on foraging performance suggests a recent adaptive evolutionary divergence, warranting the status of separate subspecies.
The researchers conclude: “Our findings serve as a reminder that mitochondrial DNA (mtDNA) gene trees will not always succeed in capturing all evolutionarily significant genetic change, and that manipulative field experiments can provide crucial information on the selective factors that lead to evolution of subspecies-specific morphological traits even in the absence of mtDNA diversification”
Posted by Allison Vaughn at 9:20 PM