Treesearch

Toxic effects of photochemical smog on ponderosa and Jeffrey pines in the San Bernardino Mountains were discovered in the 1950s. It was revealed that ozone is the main cause of foliar injury manifested as chlorotic mottle and premature needle senescence. Various morphological, physiological and biochemical alterations in the affected plants have been reported over a period of about 40 years of multidisciplinary research. Recently, the focus of research has shifted from studying the effects of ozone to multiple pollutant effects. Recent studies have indicated that the combination of ozone...

The quality of aquatic and riparian ecosystems is a function of their condition and the integrity of adjacent uplands in their watersheds. While small streams make up a large proportion of the overall stream network, our knowledge of how they function is still limited. The Kings River Experimental Watershed (KREW) was initiated in 2000 to quantify the variability in characteristics of small stream ecosystems and their associated watersheds in the Sierra Nevada of California. The primary management questions to be answered are the effects of prescribed fire and mechanical thinning on the...

This tree guide quantifies benefits and costs for typical large-, medium-, small-stature, deciduous trees, as well as a conifer. The analysis assumed that trees were planted in a residential yard site or a public (street/park) site, under a 40-year time frame, and having a 60% survival rate. Tree care costs were based on findings from a survey of municipal and commercial arborists. Benefits were calculated using tree growth curves and numerical models that considered regional climate, building characteristics, air pollutant concentrations, and prices.

The primary purpose of this report is to answer the question: Do the accrued benefits from Fort Collins’ urban forest justify an annual municipal budget that is nearly $1 million? Our results indicate that the 31,000 streets and park trees in Fort Collins produce substantial benefits. Net annual benefits total $1.17 million ($38/tree, $9/capita). For every $1 invested in tree management, residents receive $2.18 in benefits for increased property values, reduced stormwater runoff, cleaner air, energy conservation, and reduced atmospheric carbon dioxide. Over the years Fort Collins has...

The accurate modeling of the physiological and functional processes of urban forests requires information on the leaf area of urban tree species. Several non-destructive, indirect leaf area sampling methods have shown good performance for homogenous canopies. These methods have not been evaluated for use in urban settings where trees are typically isolated and measurement may be complicated by proximity to residential areas, buildings, signs, and other infrastructure elements. We evaluated the accuracy, precision, efficiency and other practical considerations associated with four methods...

Literature relevant to tree root and urban infrastructure conflicts is reviewed. Although tree roots can conflict with many infrastructure elements, sidewalk and curb conflicts are the focus of this review. Construction protocols, urban soils, root growth, and causal factors (soil conditions, limited planting space, tree size, variation in root architecture, management practices, and construction materials) are discussed. Because costs related to sidewalk and curb damage are substantial, a review of research addressing repair, mitigation, prevention, and litigation costs is included....

This study demonstrates an approach to quantify the structure, benefits, and costs of street tree populations in resource-limited communities without tree inventories. Using the city of Davis, California, U.S., as a model, existing data on the benefits and costs of municipal trees were applied to the results of a sample inventory of the city’s public and private street trees. Results indicate that Davis maintained nearly 24,000 public street trees that provided $1.2 million in net annual environmental and property value benefits, with a benefit–cost ratio of 3.8:1. The city can improve...

Forestry and urban forestry have more in common than practitioners in either field may think. The two disciplines could each take better advantage of the other’s expertise, such as foresters' impressive range of scientific theory and technological sophistication, and urban foresters' experience in working with diverse stakeholders in the public arena. The wildland-urban interface is geographic center of convergence, and the nexus of forest ecology and human ecology will become forestry's next frontier—where forestry and urban forestry join together to construct healthier habitats for humans.

Tree work records for ten species were analyzed to estimate average annual management costs by dbh class for six activity areas. Average annual benefits were calculated by dbh class for each species with computer modeling. Average annual net benefits per tree were greatest for London plane (Platanus acerifolia) ($178.57), hackberry (Celtis sinensis) ($148.42), and Modesto ash (Fraxinus velutina‘Modesto’) ($126.16) and least for pear (Pyrus calleryana cvs.)($33.65), pistache (Pistacia chinensis) ($64.98), and camphor (Cinnamomum camphora) ($71.36). Benefit–cost ratios (BCRs) were greatest...

Tree canopy cover data from aerial photographs and building energy simulations were applied to estimate energy savings from existing trees and new plantings in California. There are approximately 177.3 million energy-conserving trees in California communities and 241.6 million empty planting sites. Existing trees are projected to reduce annual air conditioning energy use by 2.5% with a wholesale value of $ 485.8 million. Peak load reduction by existing trees saves utilities 10% valued at approximately $778.5 million annually, or $ 4.39/tree. Planting 50 million trees to shade east and west...