Each year, The Holden Arboretum's Scientist Lecture Series invites you to delve deeper into the issues and conditions that impact the world around us. These free, academic lectures allow you to step back into the classroom and learn from the experts. This year, Holden has invited members of the faculty from three of the region's universities, as well as a research from the Morton Arboretum in Illinois to present their research.
Each lecture is free and open to the public, but registration is required.
Teachers attending all or part of the series can also qualify for graduate credit through Ashland University when combined with independent study. Contact Sharon Graper for information on graduate credit requirements and fees at 440.602.3843 or by email. International Society of Arboriculture (ISA) members also can earn CEUs for participation in the lectures indicated.
In forest and rangeland ecosystems across the globe, the domination of native plant communities by exotic species and declines in biodiversity are becoming widespread crises. Strong competitive interactions between resident native plant species and invading exotics are thought to reduce the spread and establishment of exotics, with increasing recognition of the context-dependence of this outcome. One key context is the abundance of herbivores. Research in Kalisz' lab investigates prominent hypotheses of invasion success through the experimental manipulation of deer access within the forest community. The results show that deer facilitate garlic mustard invasion by suppressing the competitive ability of native forest species and provide a clear mechanism for native species declines in the presence of this allelopathic invader. Disruption of the arbuscular mycorrhizal fungi-native plant mutualism by garlic mustard’s allelochemicals causes dramatic declines in plant physiology, carbon storage and shoot and root growth of the native species.
Urban trees have significant environmental, economic and social values; thus, are key components of urban green infrastructure. Urban tree establishment, growth, health and longevity are strongly dependent on soil and site conditions. Due to anthropogenic disturbances and inherent heterogeneity in urban landscapes, these soils pose unique challenges as substrates for urban trees. This presentation will cover research being performed in the Morton Arboretum Soil Science laboratory on assessing and managing soils for maximizing urban tree growth and health.
This presentation will discuss two case studies involving diseases of oaks in which the invasive soil fungus Phytophthora are either suspected or confirmed causal agents. The first case illustrates research pointing to the possible involvement of P. cinnamomi in a decline syndrome of white oaks in Southern Ohio. The second case includes our work on the development of chemical markers of coast live oak resistance to P. ramorum (the causal agent of sudden oak death) in California, and provides hope for a more rational approach to forest management in the face of this devastating disease.