Hurricanes strike the Gulf Coast of the United States every few years. We briefly describe generalized hurricane tracks for the Gulf Coast and vegetation damage using NDVI satellite imagery as well as slides of damaged urban trees in Florida. The impact of recent hurricanes on both pecan defoliation and production and on initial damage and subsequent recovery of various ornamental trees is described. Pecan harvests were greatly reduced by hurricanes that struck late in the season in both Alabama and Texas. Varieties of pecans varied in their susceptibility to various stresses. Pine forests were sometimes devastated by certain hurricanes while live oaks, various shrubs, and important insects often survived the same storms with little damage. Many exotic ornamental plants including Chinese tallow are either adventive or invasive along the Gulf Coast. Species escape from cultivation over a long period of time and exhibit different invasion lag phases. In Texas and Louisiana, hurricane damage to native trees allowed Chinese tallow seedlings and saplings to subsequently dominate some areas as a result of the disturbance. One delayed ecological response to hurricanes and typhoons is an acceleration of ongoing exotic plant invasions.
A program called “Writing Across the Curriculum” has been initiated in many universities across the nation. In response to this initiative, the Horticulture Department at Clemson University is promoting writing in all areas of study. As part of this effort, an independent study was conducted to produce an educational booklet providing an account of a major landscape project. The project involved a tree inventory, landscape designs, and tree plantings along Highway 123. This interdisciplinary effort was completed by the City of Clemson and Clemson University's Horticulture 308 Landscape Design class with funding from America the Beautiful.
Included in the booklet are student articles, concepts, and designs, as well as an account of the process they followed. Layout was completed on the Macintosh IIsi with Pagemaker software.
The South Carolina Forestry Commission is publishing the booklet, which will be used by local officials as they implement future phases of the project. It will also be distributed to communities throughout the South to be used as an educational tool, showing the process our city followed in enhancing our urban tree cover.
This research was made possible by a grant from the National Urban and Community Forestry Advisory Committee of the U.S. Forest Service, along with funding from the American Nursery and Landscape Association (ANLA) and the Associated Landscape
New Jersey has two active quarantines currently under the jurisdiction of the USDA's Cooperative Asian Longhorned Beetle (ALB) Eradication Project. Encompassing just over twenty (20.2) square miles, these quarantines are located in the northeastern and central coastal regions of the state, in close proximity to the ports of New York, Newark, and Elizabeth. Public education and media outreach have been instrumental in confirming the presence of ALB in New Jersey, as both quarantines are the result of citizens' reports. Twenty five personnel have been directly assigned to this eradication effort, with outside contractors taking up the remaining effort. Nearly 33,000 trees have been inspected, resulting in 11,000 (33%) removals of infested or high-risk host species trees. Major losses have occurred in populations of Norway and red maple, London planetree, and American elm, species which have received widespread praise (and unfortunate over-planting) for their tolerance of urban planting sites. Regulatory Contracts (597) and Compliance Agreements (137) were necessary to formalize the quarantine and to create strong working partnerships between the USDA, municipalities, and industry to gain access to all trees and to control the movement of all “green material” in the quarantine areas. Municipalities currently cooperating in the New Jersey Community Forestry Program have begun offsetting this major deforestation and canopy cover loss with the planting of 2,545 nonhost trees, with full reforestation expected over the next several years. In addition, >22,000 trees have been treated with Imidacloprid as a possible deterrent to any activity or spread of ALB in the Garden State.
mention the cultural ecosystem services provided by urban trees. They allude to a number of studies but do not cite references. The attractive photographs in this section complement the text, but the staccato captions (e.g., “ Ulmus americana , Princeton
size in an urban setting ( Maco and McPherson, 2003 ). With this in mind, hindering tree growth slows the financial return associated with the initial investment of tree planting. This diminished return is quantified as a reduction in carbon
The Mediterranean region is a center of great plant diversity, harboring around 25,000 plant species, more than 20% of them endemic. Since the last Lebanese flora record in 1966, the country has experienced habitat fragmentation and destruction, due to overgrazing, overexploitation of natural resources, and urban expansion. A large number of Lebanese tree species have unexplored economic potential as either ornamental or medicinal plants. This study aimed at exploring the effects of two nitrogen fertility treatments on the growth and water use of 2-year-old Cercis siliquastrum seedlings. C. siliquastrum seeds were collected from different locations and mother trees in Lebanon in mid-Aug. 2001. Two-year old plants were then transplanted into 3-gal. containers and were randomly assigned to one of two N fertility programs, 25 ppm or 100 ppm. Plants from all redbud sources were significantly taller in the low N treatment and had significantly higher RGR than plants growing at 100 ppm N. On the other hand, plants growing at 100 ppm N level had significantly higher LAR and lower NAR than plants growing at 25 ppm N. There were significant differences in LAR and plant heights among the different sources. Water use was conducted monthly. It ranged from 3.6 × 10-4 to 1.3 × 10-3 g·cm Ht-1 per hour at 25 ppm and from 2.6 × 10-4 to 1.3 × 10-3 g·cm Ht-1 per hour at 100 ppm N through the experiment.
Flowering dogwood (Cornus florida L.) is an important tree of forests and urban landscapes in the eastern United States. Currently, there are over 100 cultivars of flowering dogwood commercially available. An identification process based on genotype would be of use to researchers, breeders, and nurserymen, as many cultivars are similar phenotypically. Molecular markers offer a promising way of definitively identifying flowering dogwood cultivars. Amplified fragment length polymorphism (AFLP) is a technique that can be used to generate DNA fingerprints. DNA was isolated from leaves of 17 common cultivars of dogwood and AFLP fingerprints were generated by a Beckman Coulter CEQ™ 8000. Fingerprints were converted to binary data and verified manually. Two drafts of a cultivar identification key were generated based on the corrected, verified binary data and cultivar-specific peaks. Six primer combinations were used to construct all keys and were tested with seven unknown dogwood cultivar samples. Six unknown samples were correctly identified using the keys. Only one unknown, `Cherokee Brave', was unidentifiable with any key. In all cases, some intracultivar variation was observed. A similarity index was calculated and visualized with a tree of genetic relatedness using NTSYSpc. Intracultivar variation was observed in the similarity index as well. This database for cultivar-specific molecular markers will serve as a starting point to which other cultivars can be added and also can be used in breeding applications, patent application and other projects, such as mapping the C. florida genome.
Responses of five bottomland tree taxa to drought and flooding were studied to identify those adapted to urban environments. During one experiment, containerized `Franksred' red maple [Acer rubrum L. `Franksred' (trademark = Red Sunset)], sweetbay magnolia (Magnolia virginiana L.), black tupelo (Nyssa sylvatica Marsh.), bald cypress [Taxodium distichum (L.) Rich.], and pawpaw [Asimina triloba (L.) Dunal.] were treated with various irrigation regimes for up to 118 days. Net assimilation rate (NAR) and relative growth rate (RGR) were reduced more by flooding than by drought for plants of all taxa, except pawpaw, which showed similar NAR and RGR during flooding and drought. Only sweetbay magnolia and bald cypress maintained positive NAR and RGR during flooding, and sweetbay magnolia was the only taxon that did not produce significantly less leaf surface area, shoot dry mass, and root dry mass during flooding and drought. Apparent morphological mechanisms of stress resistance included an increase in specific mass of leaves (mg·cm-2) during drought for red maple and bald cypress and a 385% increase in the root: shoot mass ratio for droughted plants of pawpaw. Leaf water relations of drought- and flood-stressed `Franksred' red maple and sweetbay magnolia were determined in a second experiment. Predawn and mid-day leaf water potential (ψ) decreased with decreasing root-zone matric potential for both taxa, and transpiration rate was reduced by drought and flooding. Pressure-volume analysis showed that leaves of `Franksred' red maple responded to drought by shifting symplastic water to the apoplast. Leaves of drought-stressed sweetbay magnolia adjusted osmotically by reducing osmotic potential (ψπ) at full turgor by 0.26 MPa. Our results suggest that sweetbay magnolia and bald cypress will perform well at urban planting sites where episodes of drought and flooding regularly occur.
; Struve et al., 2000 ). A similar phenomenon may be observed when trenching severed roots on established trees in urban environments. Various techniques have been suggested to improve survivability and promote recovery of root-pruned trees in nurseries and