Tree Talk

Dawn Roth-Ehlinger does — a lot. With roughly 4,500 trees covering Rice’s 300 acres, certified arborist Roth-Ehlinger, along with an additional 30 groundskeepers and tree specialists, helps to maintain the tree specimens across campus. As a designated arboretum and a Tree Campus Higher Education honoree, Rice and its leaders are committed to promoting the tree population and engaging students and staff in the process. Does she have a favorite? “Live oaks — big, gorgeous, tolerant, sturdy, long-lived. They’re the whole package.”

What is the tree population like on campus?

We don’t really have a diverse tree population, and that’s a concern — 50% are live oak (Quercus virginiana). Some places on campus have to have live oaks for aesthetics; in others, the tree canopy is very full and doesn’t allow enough light for other species to flourish. Our focus now is to add diversity whenever the opportunity presents itself, like after new construction at the new Sid Rich College, where bald cypresses (Taxodium distichum) were planted.

Do trees have knees?

When people think of a tree with knees, they are usually thinking of a kind of root structure on bald cypresses. It looks like a rounded knob on the tree root that is above the soil surface. In a typical urban landscape they are regularly hit with lawn mowers, so they never come to a point. I encourage people not to cut the knees or try to dig them out. The roots they form are the ones supporting the tree.

How does construction impact trees on campus?

Construction is probably the top cause of tree injury. Trees need to be removed to make way for new buildings, and sometimes heavy equipment runs over sensitive root zones or breaks limbs. Soil compaction is also a big killer. When vehicles drive over that soil under a tree canopy, it smashes those spaces, and that can lead to decline and death. I’d save and protect every one of them, but we are an academic institution and need the facilities to educate and house our students. My goal is to make our tree protection protocols as robust as possible and make project managers and contractors aware.

Besides construction, what other problems can trees incur?

There are a few diseases that are dangerous, so that’s what we keep an eye out for. There were two big water oaks (Quercus nigra) between Herzstein and Anderson halls that were removed in the last couple of years. They still had leaves, but their supporting structural roots and interior of the lower trunks had been significantly decayed by Ganoderma lucidum and other fungi. The risk of them falling had become too great. Those trees were at the end of their typical life expectancy, so what happened isn’t a surprise. Even trees don’t live forever.

How often do you conduct tree tours on campus?

We always do one for Texas Arbor Day (first Friday in November) and do several activities that we call Arbor Week. If you have a question about trees at Rice or would like to take a tour, email me at trees@rice.edu. — Tracey Rhoades