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The frequency of tropical cyclones is a major factor affecting the vegetation of the Mariana Islands, where these storms are called typhoons. An average of about one typhoon per year has passed within ≈100 km of Guam during the past 50 years. The physiognomy of Guam's natural and urban forests is largely determined by these typhoons. The impact of each typhoon is determined by a long list of interacting factors such as species characteristics; environmental and horticultural conditions preceding the typhoon; the intensity, direction, and duration of winds; the amount of rainfall associated with the typhoon; and the environmental and horticultural conditions following the disturbance. Many species survive typhoons by reducing aerodynamic drag of the canopy by abscising inexpensive leaves or breakage of small stems which results in an intact major structural framework. Speed of recovery for nonlethal damage following disturbance depends on nonlimiting conditions during recovery. Thus, the most destructive typhoons are those that occur in sequence with other environmental stresses. The most common of these may be heat and high-light stress, associated with subsequent high pressure systems, and severe drought conditions. For example, the 230–298 km·h–1 winds of Typhoon Paka in Dec. 1997 were followed by the driest year on record for Guam. Typhoon debris and drought generated 1400 forest and grassland fires from Jan. through May 1998. Sequential typhoons are also severely damaging. For example, Guam experienced three direct eye passages and two more typhoons within 113 km during the months Aug. to Nov. 1992. Damage susceptibility and recovery dynamics will be discussed in relation to these and other physical, chemical, biological, and human-induced factors.

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In 1992, Hurricane Andrew destroyed over 1000 mature trees in the City of North Miami, located 50 mi north of the storm center. The cleanup cost over $1,000.000. Most of the tree failures were caused by structural faults: co-dominant leaders, narrow limb attachment, included bark, over-lifting, hatracking, poor vertical limb placement, crown imbalance, overly-dense crowns, crossing and in-growing branches. All could have been corrected with proper pruning. Action was taken to reduce future damage. The city arborist made a complete, computerized inventory of all trees on public property, creating a data-base with all structural problems identified. These were prioritized so the worst could be addressed first. After any pruning work was done on a city tree, a follow-up evaluation was made, and any additional pruning needed was scheduled. Pruning followed the recommendations of state specialists and three county extension agents with the University of Florida Cooperative Extension Service. City workers were taught using lectures, demonstrations, site visits, CES publications, and individualized instruction. In addition, all new trees purchased were grades FL Fancy or FL no. 1, based on Grades and Standards for Nursery Plants; such trees require little or no corrective pruning at planting and mature as structurally-sound trees which resist wind damage. Two later storms (1993, 1999) produced winds in North Miami similar to those of Hurricane Andrew. Together they destroyed only 35 trees which cost $35,000 to remove. These data demonstrate that following CES pruning recommendations reduces storm damage to trees, saving money and preserving the urban forest canopy.

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; McCullough et al., 2001 ). It is a significant tree species in urban forests, identified as the species of greatest importance in Washington, DC ( Nowak et al., 2006 ) and listed as one of the most important park trees in Boston ( Welch, 1994 ). Increased

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island. The amplified impact from multiple new alien arthropod species and an expansive military buildup will bring even greater need for understanding how to manage the urban forest ( Marler, 2013a , 2013b ; Marler and Moore, 2011 ). Elaeocarpus joga

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resources required to plant street trees are important factors in successful tree planting and urban forest management. Green et al. (p. 651) compared the planting cost of four different planting systems (balled-and-burlapped, bare-root, pot

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al., 2007 ). The UN-World Health Organization recommends at least 9 m 2 of urban green space per capita to mitigate several undesirable environmental effects and provide aesthetic benefits ( Deloya, 1993 ). Urban forests are particularly critical to

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London, UK Sun SX. 2013 Forest seedling technology Jindun Publishing Company Beijing, China Wang DM. 2014 Construction concept and layout of Taizhou urban forest Linye Gongcheng Xuebao. 28 04 136 140 https://doi.org/10.13360/j.issn.1000

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Sequestration Potential of Ornamental Plants in the Landscape Another potential C sink in ornamental plant production is the ability of plants to store C in biomass. Previous research has shown that urban forests have a significant potential for removing CO 2

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regions has been used in past studies to show the value of the urban forest on crime ( Snelgrove et al., 2004 ) and childhood asthma ( Pilat et al., 2012 ), future studies should perhaps focus on one individual MSA observing people’s relationship to tree

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dioxide reduction by Chicago’s urban forest, p. 83–94. In: McPherson, E.G., D.J. Nowak, and R.A. Rowntree (eds.). Chicago’s urban forest ecosystem: Results of the Chicago Urban Forest Climate Project. U.S. Dept. Agr., For. Serv., Northeastern For. Expt

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