Treesearch

Abstract Thirty three unique quantitative trait loci (QTLs) affecting the timing of spring bud flush have been identified in an intraspecific mapping population of coastal Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco var. menziesii]. Both terminal and lateral bud flush were measured over a 4-year period on clonal replicates at two test sites, allowing for the repeated estimation of QTLs. QTLs were detected on 12 linkage groups and, in general, each explained a small proportion of the total phenotypic variance and were additive in effect. Several QTLs influence the timing of bud flush...

It is necessary to develop new satellite methods to monitor boreal forests responses to climate warming. Remotely sensed maps derived from hyperspectral Advanced Visible/Infrared Imaging Spectrometer (AVIRIS) data were developed and compared for the four conifer forest ecosystems at the Bonanza Creek Experimental Forest, a long-term ecological research site on the Tanana River flood plain near Fairbanks, Alaska. The site was first stratified into montane, lowland alluvial plain, and flood plain zones based on topography. A classification of six forest and three non-forest types was created...

Concern about climate change has evoked interest in the potential for urban vegetation to help reduce the levels of atmospheric carbon. This study applied computer simulations to try to quantify the modifying effects of existing vegetation on the indirect reduction of atmospheric carbon for two residential neighborhoods in north-west Chicago. The effects of shading, evapotranspiration, and windspeed reduction were considered and were found to have decreased carbon emissions by 3·2 to 3·9% per year for building types in study block 1 where tree cover was 33%, and −0·2 to 3·8% in block 2...

Tree height, crown height, crown width, diameter at breast height (dbh), and leaf area were measured for 16 species of commonly planted street trees in the coastal southern California city of Santa Monica, USA. The randomly sampled trees were planted from 1 to 44 years ago. Using number of years after planting or dbh as explanatory variables, mean values of dbh, tree height, crown width, and leaf area responses were modeled using two equations. There is strong correlation (adjusted R2 > 0.70) between dbh as a function of number of years after planting, and total height, crown diameter, and...

Although the modeling of energy-use reduction, air pollution uptake, rainfall interception, and microclimate modification associated with urban trees depends on data relating diameter at breast height (dbh) , crown height, crown diameter, and leaf area to tree age or dbh, scant information is available for common municipal tree species . I n this study , tree height , crow n width , crow n height , dbh , and leaf area were measured for 1 2 common street tree species in the Sa n Joaquin Valley city of Modesto, California , U.S . The randomly sample d tree s were planted from 2 to 8 9 years...

Interference between trees and sewer systems is likely to occur in old systems and in cracked pipes. Factors that contribute to damage include old pipes with joints, shallow pipes, small-dimension pipes, and fast-growing tree species. Because roots are reported to cause >50% of all sewer blockages, costs associated with root removal from sewers is substantial. In smaller-dimension pipes, root removal every year or every other year is common. Major resources are put into replacement and renewal of existing pipes, which is sometimes accelerated because of root intrusion. Collapse repair...

A survey of 15 Sacramento parking lots and computer modeling were used to evaluate parking capacity and compliance with the 1983 ordinance requiring 50% shade of paved areas (PA) 15 years after development. There were 6% more parking spaces than required by ordinance, and 36% were vacant during peak use periods. Current shade was 14% with 44% of this amount provided by covered parking. Shade was projected to increase to 27% (95% CI 24–37%) when all lots in the sample were 15-year-old. Annual benefits associated with the corresponding level of tree shade were estimated to be US$ 1.8 million...

Communities in the Inland Empire region of California contain over 8 million people, or about 25% of the state’s population. The region’s inhabitants derive great benefit from trees because compared to coastal areas, the summers are hotter and air pollution levels are higher. The region’s climate is still mild enough to grow a diverse mix of trees. The Inland Empire’s climate is influenced by the ocean less than 15% of the time and extends from Ojai east to Simi Valley, Glendale, Alhambra and Riverside, as well as south to Escondido.

The primary purpose of this report is to answer the question: Do the accrued benefits from Santa Monica's urban forest justify an annual municipal budget that exceeds $1.5 million? Our results indicate that the benefits residents obtain from Santa Monica’s urban forest do exceed management costs by over 50%. Over the years Santa Monica has invested millions in its municipal forest. Citizens are now receiving a relatively large return on that investment. Continued investment in management is critical to insuring that residents continue to receive a healthy return on investment.