Beautiful but invasive pest - African Tulip Tree

 If any of you are foolish enough to think that TPP is leaving the tropics and returning to the polar vortex now visiting the upper Midwest with truly arctic temperatures then you're crazy.  TPP is certain that temperatures like that will freeze some of his plant collection.  But more on this later this spring. Here in Maui, it is "spring" of a sorts and one of the ornamental trees that is in flower is the African Tulip Tree (Spathodea campanulata) a member of the Bignon family.  It has a big flowers that are bright orange.  It is a totally gaudy tree.  Supposedly perching birds visit these flower to get an interesting reward, a drink of water.  The flower buds are filled with water, and it you nip off the end of the calyx of an intact bud, and squeeze the base it will squirt out a stream.  Kids always know this trick.  The image shows that the flower is basically a cup.  A tree in flower has lots of flowers and flowers over a longish time.  Unfortunately in wetter areas, this tree is invasive along streams. And it has become a member of what TPP calls UTF (ubiquitous tropical flora).  It's certainly pretty, but what a pain.   

Bad Iris, bad Iris!

The Phactors have long had yellow flag iris (I. pseudacorus) as part of our gardens, and as Mrs. Phactor is the iris fancier, the fact that the yellow flag iris is an introduced species has never occurred to TPP, just never noticed.  According to an article in the recent issue of the American Journal of Botany this non-native species can be do all the bad things that invasive species can do: in Louisiana wetlands it displaces native vegetation, it reduces biodiversity, and it degrades wetlands. The blue/purple iris is the native I. hexagona. Up here in Lincolnland, 800 or so miles upstream, the yellow flag is not known to be a problem. And the yellow flag probably got to N. America because someone thought it was purty. Oh, one of these days TPP will have to tell you about water hyacinth. 

Messing with nature - you never can do just one thing

One of the most basic of ecological lessons, and a lesson most commonly ignored, is that you never can do just one thing.  Interactions among organisms and between organisms and their environment are complex and complicated, and when you willingly change one thing it can set off an entire chain or worse, an entire cascade of events.  Knock over one domino and it knocks down the next and so on, this is the simple case; what if when you knock over one domino, it knocks down three, and so on?  This lesson is at the absolute base of the problem of invasive species.  Here's an example.  Kudzu is a legume, a bean, and a vine.  It's a handsome enough plant under some circumstances and it was imported to North America as an ornamental species decades ago.  Because it can fix nitrogen like other legumes, kudzu will grow well on poor soil, so it was promoted across the south to help prevent soil erosion and help reclaim strip mine moonscapes.  But kudzu didn't stop there, and now the vine towers of kudzu are a familiar sight across the south as the vine clamors over trees, and fences, and barns, and anything else that isn't too fast moving.  The next event started in 2009 when a kudzu eating stink bug, also from Asia, was found in Georgia.  Somebody imported it because stink bugs just don't disperse that far on their own, and supposedly kudzu was its favorite food, but favorite doesn't mean only food.  What can possibly go wrong?  Well, what if this stink bug developed a taste for other legumes?  What if the legume was the soybean?  Somebody tries to be a do-gooder and import a bug that eats an invasive vine and the bug becomes a potential agricultural pest on a crop that is one of the USA's most important agricultural commodities.  See those dominos dropping?  Kudzu is also adapting to cooler climates and has been reported in Lincolnland as far north as Peoria, right in the middle of the maize and soybean desert.  And it appears this new invasive bug may be able to survive anywhere soybeans can grow.  So, there's the lesson.  Remember, you can't do just one thing.  Organisms just don't do what you expect them to do or want them to do, and you just start another cascade of unintended and unexpected events.  Let that be your lesson.

Field Work - Invasive Species

One of my study sites is a restored prairie, a particularly high quality one, but a bit small. Now this little prairie is being treatened by an invasive species, silky bush clover, an Asian relative of native bush clover. It's one of those things where the focus of your research was elsewhere, and when you finally become of aware of what is happening, it's too late. This week's field work, and probably next week too, will be to harvest the silky bush clover from our long term research quadrats to document its continued invasion and increasing density. How dismal. Because this invasive species is so well adapted to the prairie environment, no obvious mechanism exists for its removal, and this isn't just one or two plants here or there. So like good scientists the demise of this prairie will be recorded; it served us well for quite a number of years, but in another decade it will be quite a different plant community, one with dense stands of the clover, much lower species diversity, with some of the taller forbs, and the grasses persisting. Here's a view across a patch of silky bush clover and notice that you don't see much else except way back some grases mark the back edge.