John Kabrick

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Oak decline is a chronic problem in Missouri Ozark forests. Red oak group species are most susceptible and decline is reportedly more severe on droughty, nutrient-poor sites. However, it was not clear whether greater decline severity was caused by poor site conditions or is simply due to the greater abundance of red oak group species found on poorer sites.(More)
Establishing trees in agricultural bottomlands is challenging because of intense competition, flooding and herbivory. A summary is presented of new practices and management systems for regenerating trees in former agricultural fields in the eastern USA. Innovations have come from improvements in planting stock and new silvicultural systems that restore(More)
To support investigations of flood tolerance occurring at a field-based research facility, changes in soil volumetric water content, temperature, redox potential, dissolved oxygen content, and pH over the course of flood events were monitored. Electronic sensors connected to dataloggers for continuous monitoring of these parameters were installed, and soil(More)
Regenerating oaks (Quercus spp.) has remained a widespread and persistent problem throughout their natural range. Research shows that abundant oak advance reproduction is crucial for success. Although it is recognized that oak advance reproduction accumulation is inversely related to site quality, there has been little effort to model oak advance(More)
World-wide, some biomes are densifying, or increasing in dense woody vegetation, and shifting to alternative stable states. We quantified densification and state transition between forests ecosystems in historical (ca. 1815–1850) and current (2004–2008) surveys of the Missouri Ozark Highlands, a 5-million ha landscape in southern Missouri, USA. To estimate(More)
Oaks (Quercus spp.) are one of the most important tree taxa in the northern hemisphere. Although they are dominant in mixed species forests and widely distributed, there are frequent reports of regeneration failures. An adequate population of large oak advance reproduction is a critical prerequisite to successful oak regeneration, and hence sustainability(More)
Research on oak (Quercus L.) regeneration has generally consisted of small-scale studies of treatments designed to favor oak, including consideration of site quality and topographic effects on oak regeneration. However, these experiments have not consistently factored in broader-scale ecological differences found in the eastern United States. Oak(More)
Regenerating oaks (Quercus L.) on mesic and hydric sites has remained a problem largely because of inadequate density and poor distribution of large oak advance reproduction prior to harvesting. We examined the effect of midstory and understory removal on the establishment and 3-year development of natural and artificial sources of pin oak (Q. palustris(More)
Oak decline and related mortality have periodically plagued upland oak–hickory forests, particularly oak species in the red oak group, across the Ozark Highlands of Missouri, Arkansas and Oklahoma since the late 1970s. Advanced tree age and periodic drought, as well as Armillaria root fungi and oak borer attack are believed to contribute to oak decline and(More)
In the Midwestern United States, the General Land Office (GLO) survey records provide the only reasonably accurate data source of forest composition and tree species distribution at the time of pre-European settlement (circa late 1800 to early 1850). However, GLO data have two fundamental limitations: coarse spatial resolutions (the square mile section and(More)