Oral Abstract Details

Author(s):
Thomas Nyatta Legiandenyi, Kamran Abdollahi,Zhu Ning and Asebe Negatu

Affiliation:
Southern University A&M College

Presentation Type:
Oral

Topic Area:
Urban forestry and urban agriculture

Abstract Text:
With increasing concerns over raising concentration of carbon dioxide (CO2) in the atmosphere, forest researchers and managers are currently studying the effects of various arboricultural and urban forest management practices on the carbon dynamics of intensely managed urban forest ecosystems. Soil CO2 flux resulting from soil microbial activity and root respiration is one of the major components of the total carbon flux in forested ecosystems. However, the impact of arboricultural practices such as mulching on the soil respiration remains poorly understood. This limits our ability to understand the carbon budget at the urban forest ecosystem level, thus making it uncertain to predict the impact of arboricultural practices on soil respiration and its feedback. We determined the effects of five different mulch types on the establishment of urban trees for CO2 flux, plant nutrient uptake, shoot growth and selected soil chemical properties. We observed the relationship between microbial organisms and soil respiration and its feedback. To accomplish this study we applied a complete randomized block design and maintained it for two years. We were applied five different biobased mulch types namely: Pine Bark (PB=A). Mixed Hardwoods (MH=B), Pine Needles (PN=C), No-Mulch (D), Mixed Oaks (MO=E), and Pine Bark + Pine Wood (PB+PW=F) on the soil surface in the study plots. We assessed the impact of the five urban tree-based mulch types on net canopy CO2 uptake of Quercus nuttallii saplings and their associated soil CO2 fluxes. In the second year we analyzed the soil and nattall oak leafs for nutrients (N, P, K, Ca, Mg, Mn, Fe, Cu, Zn, S, B, Al). Soil CO2 flux (μmol CO2/m2/s) and tree canopy net CO2 uptake by tree saplings were not significantly impacted by pine bark and pine needle mulch types. Soil CO2 flux fluctuated significantly during the growing season under different mulch types. The largest increase in soil CO2 flux occurred during the month of May under the mixed hardwood mulch. Soil CO2 was highly correlated with time under all the mulch types. The objective of this study was to determine the effects of five different types of mulches on establishment of urban tree, plant nutrient uptake, shoot growth and selected soil chemical properties.