A closer look at the significance of heritage trees on campus

UC Davis is home to a number of iconic symbols: the classic mustang insignia painted in bike roundabouts, the picture-perfect water towers, and, most prolific of all, the impressive heritage trees that reside all over campus.

According to campus arborist Melanie Gentles, there are over 10,000 trees on the main campus plus another 3,000 or more in the Arboretum — as well as over 1,000 in the peripheral areas of land owned by UC Davis. Roughly 700 of those in the Arboretum are different species of oaks. Many of these oaks, in the Arboretum and on central campus, are considered “heritage.”

“‘Heritage’ is a human value — if something is valuable culturally, aesthetically or has great age, then you refer to it as ‘heritage,’” said Warren G. Roberts, a superintendent emeritus and Arboretum volunteer. “If you think about it, these trees [in the Arboretum] were here when there were grizzly bears, and [these trees] watched covered wagons come through. In fact, one pair of my grandparents came through the arboretum in the 1850’s because that was the main road coming west, and they would have seen some of these trees.”

The Arboretum is home to a number of trees that are more than 300 years old. In fact, the Central Valley used to be dominated by one of California’s most unique and native trees: the Valley Oak. This species of oak tree, however, was decimated when settlers began agricultural practices in the area. Today, the Valley Oak is the most abundant oak tree in the Arboretum and on the UC Davis campus.

Many of the trees that line the Quad and other parts of central campus are Cork Oaks, most likely planted in the 60’s and 70’s. These oaks are easily distinguishable from their characteristic cork-like bark, which, historically, is harvested in their native lands and fashioned into various cork products. The largest Cork Oaks on campus are unequivocally deemed heritage trees, their massive trunks towering above passersby on the north side of the Memorial Union and just south of Hickey Gymnasium.

“Most of the oaks here thrive in a Mediterranean climate, which means dry summers, wet winters,” said Kamyar Aram, a plant pathology Ph.D. student in the Rizzo Lab at UC Davis. “Oaks have been intimately connected with human civilization, there’re a lot of old references in Roman literature to acorn eating, and of course the Native Americans.”

Aram and his colleagues focus on forest pathology as well as forest ecology related to the influences of disease in forests. He studies a group of pathogens called phytophthora and how the pathogens can induce Sudden Oak Death, which, he pointed out, only infects and kills trees in a collection of oak species called red oaks. The Cork Oaks that can be seen around the Quad are not susceptible to this disease, but other species on campus, like the Coastal Oaks that line Howard Way into the MU bus stop, do have the potential to be infected by this pathogen.

“[Sudden Oak Death] was introduced in the coast, most likely through the nursery trade,” Aram said. “It has a complex lifestyle, it mainly grows on bay trees, [where it] produces spores […] and [the spores] find their way underneath the bark of an oak tree and that’s when they kill the oak tree.”

Fortunately for UC Davis and the Central Valley, Sudden Oak Death is not a big issue as it mostly affects trees in more coastal habitats and live in environments where contact with bay trees is probable. There are, however, other challenges that are more relevant to the trees on campus.

“As a tree grows older, it can become more susceptible to pests and diseases,” said Emily Griswold, the director of GATEways Horticulture and Teaching Gardens. “In the urban landscape, often what kills oaks is things like construction impacts and compaction of the soil, so the roots don’t have as much access to oxygen. Also irrigation, a lot of our native oaks evolved in this climate that is summer-dry, so there can be certain diseases that […] can affect roots of oaks if they get water in the summertime.”

Griswold, Gentles, Roberts, Aram and other interested experts at UC Davis are all members of the Tree Committee. Whenever there is a development on campus, the committee convenes on the tree site to determine if any trees in the area are worthy of being saved — especially heritage trees.

“The first [category] is the heritage tree category,” Roberts said. “The second is trees that are beautiful and valuable but not quite heritage tree status, third is it’s a good tree but it’s going to need some help — in other words you can’t leave it as it is or problems will occur in the future. The fourth category is that the tree is dying or out of shape.”

Management practices of trees at UC Davis have become less reactive and increasingly proactive since Gentles began working here full-time about 10 years ago. The urban setting means that safety is the number one concern for Gentles and her fellow groundskeepers, but managing the trees for health and beauty is extremely important, especially considering the heritage oaks are what attract many people to Davis in the first place.

This past January, a storm swept through the Central Valley and eight large trees on campus toppled over, including a large oak tree that fell onto Haring Hall.

“This storm was the perfect combination,” Gentles said. “It was soil saturation, [so] the roots couldn’t hold on, especially on the taller top-heavy trees. All the ones we lost were evergreens, which means they have a heavier load in their canopy. It acts like a sail, and the high gusts of wind meant that the roots couldn’t hold on.”

Thanks to the proactive management of the grounds crew on campus, evidence of these trees’ deaths has already been erased. Gentles and her team keep close track of which trees struggle and which thrive in the area, and replacement planting is the main route for dealing with the loss of trees on campus.

With a quick glance around, it’s not hard to notice the great diversity of tree species at UC Davis. The oak trees lend a characteristic appeal to the school and instill a sense of pride in students. Neither a scientific or historical knowledge of oaks nor a complete understanding of what designates a tree as “heritage” is necessary to appreciate the inherent value in nature so present and beautiful.

“I love when people I know [understand] the natural world around me, and oak trees are something I see everyday in my life,” Aram said. “When we get to know the world around us, we put on new lenses, and seeing more of the world is knowing more of the world.”
Written by: Marlys Jeane — features@theaggie.org

Hybrid, online courses impact students, campus life

In an era of smart cars, smart phones and smart homes, the world has become increasingly accessible with the click of a button. As the world becomes more efficient, the education system is unsurprisingly seeking to accommodate more students and different learning styles in innovative ways.

Universities such as UC Davis are finding new ways of using technological advancements to enhance students’ education, including incorporating online and hybrid courses into numerous undergraduate departments. Carolyn Thomas, the vice provost and dean for Undergraduate Education, has played a significant role in incorporating such courses at UC Davis.

“I think online and hybrid courses, if done well, will enable students to be more flexible in the ways they’ve learned to learn,” Thomas said in an email interview. “I also think more online courses, especially in the summer, will help students complete their degrees within four years.”

Online courses at UC Davis are taught through video lectures and often supplemented with discussion boards, homework and quizzes. Apart from exams that require a proctor to supervise the students, the rest of the work is completed online. Hybrid courses offer a portion of a class online but also have a designated time during the week for students to meet with their respective professors or teaching assistants. Hybrid courses often allow for smaller class size so that students can ask questions and further discuss course material.

The flexible structure of these hybrid and online courses allows students to manage their time in a way that will be most productive for them. These types of courses can free up time during the week for students to participate in other activities they may not have been able to do otherwise. Noy Shaked, a fourth-year managerial economics major, found that taking a hybrid course allowed her to more effectively manage her time.

“For example, on Fridays I have an online lecture [and] I don’t have to watch [it] exactly at the time it’s assigned,” Shaked said. “I’m actually able to go to my internship meeting at that time [instead]. So I think that it just allows for more opportunities and flexibility.”

Students can pause, rewind and rewatch video lectures as many times as needed — a benefit unique to the medium. Meanwhile, in-person office hours and hybrid class periods still give students a chance to ask instructors questions about the lecture so that not all face-to-face communication is lost.

        With these options, UC Davis has created a flexible environment for students without disrupting the campus atmosphere. Hybrid and online courses foster opportunities for students to learn online at home and bring their questions to their professors either in class or during office hours.

“I think more online and hybrid courses might also enable us to have more students working closely with faculty in learning environments that are truly high impact,” Thomas said. “We would be able to use our human resources more wisely […in] discussion classes, seminars and in mentored internship or research experiences.”

Chi-Yuan Tsai, a teaching assistant for ECN 115BY — Hybrid Economic Development — found that students were able to ask more in-depth questions during his class after watching the lectures at home, making better use of class time.

“I think it’s more effective,” Tsai said. “If they already watch[ed] the video online then they can understand [or] find out their problem and then come to class and ask questions.”

Often, students move away from home and attend college not only for educational purposes but also for the social aspects of the “college experience.” According to John Theobald, a continuing lecturer in the Department of Communication, online and hybrid courses may not require as much on campus and in-person interaction, which can detract from the sense of community on campus.

“I think it depends on how much instruction comes from the online courses,” Theobald said. “I benefited greatly from being on campus. The interactions I had with other people […] were the most memorable influential parts of the whole experience. As long as that persists, I think the students will be benefited positively from online and hybrid instruction.”

Hybrid courses allow for smaller classroom sizes, allowing for increased flexibility. This creates space for more students to ask questions and for professors to cater lectures to the students’ needs.

“I would like our students to have a number of options when it comes to how and where they would like to learn,” Thomas said. “Classroom teaching, when students are engaged and in dialogue with their instructor, is wonderful and this is what we will always want the majority of our classes to be because there is no substitute for this kind of transformational learning. At the same time, online courses can be a very effective way to learn material, especially material that students need time to absorb or interact with in complex ways.”

The idea behind hybrid and online courses is not to transition entirely to online learning, but rather to enhance students’ educational experiences at UC Davis by broadening the way in which classes are taught. Online and hybrid courses offered at UC Davis are curated to supplement students’ education and maintain the unique experience UC Davis has to offer.

“[This structure] will give students an opportunity […] to do a lot more with their time,” Shaked said.
Written by: Elizabeth Marin – features@theaggie.org