Trees Hanging onto Leaves: Driving in the country or in towns I tend to observe what’s going on in the fields, but also observe what’s occurring with the trees. Right now I’m noticing many maples trees looking like mine: hanging onto a portion of greenish/gray/brown leaves. Typically my silver maples are the first to lose their leaves each fall along with a neighboring ash. But the season didn’t start off typical for them either! Some of you, like me, have dealt all year with the huge seed load produced by these and other trees this spring. So why are some trees hanging onto leaves this fall? Most likely a cold snap in early fall interrupted the normal process deciduous trees follow to prepare for winter survival. As days shorten, a layer of cells (abscission zone) form between the tree branch and the individual petioles (stems of leaves), allowing the leaves to fall from the tree. This helps protect the tree from water loss in the winter. Some tree species, such as oaks, have an adaptation to maintain their leaves during the winter called leaf marcescence. It’s unknown exactly why. The hypotheses for why oaks maintain their leaves include: better protection of winter buds, allow for trapping of snow around the tree base, and allow for a flush of nutrients when leaves drop and are decomposed in the spring. So while it’s not normal for maples, lindens, ash, and other species to maintain leaves over the winter, there’s nothing we can do about the delay in leaf drop. If the leaves don’t drop this fall/winter, they will be pushed off by new growth from buds next spring. Leaves may continue to drop this fall/winter with wind and snow events. One thing to be aware of is the potential for increased limb breakage from wind/snow events in trees maintaining heavy leaf loads.
Are you interested in helping understand the noise of farming? Researchers at the University of Iowa developed (and are currently testing) a ‘HearSafe’ system to measure noise exposure of farmers. The goal is to provide information about exposure to loud sounds on the farm and how to protect one’s hearing. This system will consist of a small noise monitor, smart phone, and a laptop. They are looking for farm workers to try these new devices. The research activities are short term (between 1 day and 2 weeks), equipment and training are provided, and there’s compensation for participation. Those ages 18-65, active in farm production (20+ hours per week on average), who have access to a device with high-speed internet are eligible to participate. For more information please contact Jackie Curnick at firstname.lastname@example.org or (319) 335-4425.
Nov. 25 Heuermann Lecture Focuses on Protecting Ecosystems while Advancing Agriculture: Strategies for achieving agricultural advances while preserving Nebraska’s healthy agricultural ecosystems will be discussed at the Heuermann Lecture Nov. 25. It will be held at 3:30 p.m. at the Nebraska Innovation Campus Conference Center in Lincoln and via livestream at: https://heuermannlectures.unl.edu. Following the discussion will be a showing of the documentary film “Follow the Water.” Dinner is included to those staying for the showing. The event is free and open to the public.
Panelists will include Craig Allen, professor in the School of Natural Resources and director of the Center for Resilience in Working Agricultural Landscapes; Andrea Basche, assistant professor in the Department of Agronomy and Horticulture; and Michael Forsberg, co-founder of the Platte Basin Time-lapse Project and assistant professor of practice in the Department of Agricultural Leadership, Education and Communication. The film tells the story of connections between the environment and people, and a river that shaped the land. Forsberg, a conservation photographer, and Pete Stegen, a filmmaker, journeyed for 55 days through the watershed by bike, foot and canoe, gathering footage with their smartphones. A panel discussion will follow the viewing so the audience can explore the themes of the film with Forsberg and his team.
Heuermann Lectures are funded by a gift from B. Keith and Norma Heuermann of Phillips. The Heuermanns are longtime university supporters with a strong commitment to Nebraska’s production agriculture, natural resources, rural areas and people.