Clover in the Eye of the Beholder

Arron Cannon - UNT Geography Major

Image from psdgraphics.com.

In today’s observation I looked at clovers and the relationship between the four leafed and the three leafed clovers. I questioned if there was any significance to the uniqueness of the four leafed clover and if the extra leaf aided in photosynthesis. Upon further research I concluded that as of today, there is no scientific evidence other than the four leafed clover possesses a very rare recessive gene, one in ten thousand clovers retain this sporadic gene that causes the tiny plant to bloom an extra leaf. The same process causes the uniqueness of eye color and, even less common, how some humans possess an infrequent genetic trait that allows for one eye that is one color and the other eye another. As with the four-leafed clover, one in ten thousand humans are also gifted with a rare recessive gene that allows for different color eyes.

I also found that the color of clovers was not consistent, one particular clover I observed had a purplish ink-splotch pigmentation right in the middle of the clover leaf. Did this color change right in the middle of the leaf to help this tiny clover species flourish more so than other clover types? One particular article I found suggested that the color difference is an insect deterrent. This tiny splotch makes the leaf appear different to insects that feed on clovers; insects have a different spectrum of color than humans do. To an insect looking for the healthiest clover, the tiny purple splotch looks as though the clover is dying and that the nutritional value is not as high as other all green clovers.

This observation helped me understand that the smallest differences can make a huge impact on the diversity life among species. The difference between life and death of a plant can hinge on one pigmentation difference.

On a Clear Day...

Skip Warren - UNT History Major

This is the first day I am able to observe the minnow mandala without overcast skies. The sky is cloudless, with a brisk north wind that whips through the trees and around the building’s corners. The breeze makes ripples across the bulk of the pond that makes observation of the bottom nearly impossible. It’s calm however at my usual observation point and the sun is streaming into the area making the minnows much more active. They are much more numerous as well. I count 30+. They still prefer the calm behind and around the rock island but many more are venturing into the slow deep whirlpool that is generated by the waterfall on the other side of the rock.

Looking closer I see my first dead minnow, a larger one, slowly being pushed around the edges of the whirlpool. Then another smaller one appears, and then another. A few minutes later another struggling minnow gets caught in the flow. It does slow rolls as it tries to keep motion through its gills. It will be dead soon as well. Four dead minnows; other minnows swim up occasionally to watch them. At first I think they’re eating they’re own dead but it turns out they’re just curious.

Life expectancy for these fathead minnows is two to three years, the longevity of which surprises me. I guess these examples had reached their limiting factor. Some were not full grown. Maybe they had spent valuable energy trying to brave the rapids. Old age or lack of food caused by too large of population could be a cause. The onset of some disease perhaps that may affect the rest of the minnow community could be a cause.

Both limiting and enabling factors influence the fish. The pond is limited by its human-made area, which in turn limits minnow size and population. There are no bugs to fill the diet due to winter, also a limit. The lack of bugs as a food source is made up for by plenty of algae. The pond’s configuration limits natural predators which in turn is an enabling factor for minnows. During a heavy rain the water will change chemical composition as there is no runoff in this contained area. This may affect the fish in some way. The fish also depend on human intervention if the water becomes depleted. So the pond has its share of limiting and enabling factors that will influence the minnow’s lives.

The death of the four minnows is an enabler of recycled life in the pond. They will eventually provide the pond with nutrients from their decay, which in turn will enable bug larvae and plants to feed once the season transitions out of winter. These will provide more food for the minnows. Their deaths have also enabled more room in the environment and less competition. If the larger minnow’s size had proved a threat to the smaller fish, then that threat too has been removed. But so has the protection larger size may have provided. Another large minnow will fill the void. The death of the four may have unseen consequences. One of them may have been carrying the last gene mutation that would have prevented a future disease. Conversely, one may have taken to its death the last of a detrimental gene. For now however their bodies are all just riding an endless circle around the whirlpool along with bits of algae and dead leaves.

I got to look a little closer at surrounding ground cover today as well. At first glance I thought I spied dollar weed. But closer inspection showed a carpet of some type of small-leafed green fern with a few strands of dollar weed trying to compete for space. Dollar weed won’t win that battle this season. Nothing flying today either. I fear the yellow-jacket from week #1 was lulled into a premature Sacre du Printemps.

Mistletoe in the Mandala

Jacob Korte - UNT History Major

Today I turned my focus to the mistletoe growing out of the cottonwood that is located in the Mandala. Being an evergreen species the mistletoe has remained green and alive throughout the winter even while the trees it grows on have receded into themselves and into their cells in order to escape the cold weather. From what I learned the other week, mistletoe is a parasitic plant that grows into the tree that hosts it. That gives an appearance that the reason the mistletoe is able to stay alive and live as an evergreen throughout the year is because it just feeds off the tree it is on.

Mistletoe growing from a tree trunk; photo credits here.

My question is, what part of the tree exactly does the mistletoe gets its nutrients from? And, how does it get those nutrients? It appears after doing research that some species of mistletoe will partake in photosynthesis to varying degrees, which can reduce the strain of its feeding off of the host tree. The level of photosynthesis by the mistletoe will cause variability in the color of the leaves, ranging from green or yellow. Green indicates a heavier reliance on photosynthesis, yellow means that the mistletoe doesn’t photosynthesize at all. Mistletoe depends on the host tree for water and mineral nutrients as well as carbohydrates, all of which they take directly from the living tree. Another question I had is, how does mistletoe pick what trees to grow on? I noticed large amounts of mistletoe in two large trees, a post oak and the cottonwood. Also in one of two smaller post oaks, but not the other, it turns out that this depends on elevation, what type of tree it will infect. Another indicator is the maturity of the tree.