Growth Of Street Trees Research Articles

Appraisal of Key Abiotic Parameters Affecting Street Tree Growth

Street trees must cope with severe environmental conditions. Identification of factors that modulate their survival and growth is a key process for successful management. To estimate these factors, contingency analyses were carried out using abiotic data collected locally for Norway maple (Acer platanoides L.), silver maple (Acer saccharinum L.), hackberry (Celtis occidentalis L.), green ash (Fraxinus pennsylvanica Marsh.), honeylocust (Gleditsia triacanthos L.), littleleaf linden (Tilia cordata Mill.), and Siberian elm (Ulmus pumila L.) trees. Also, comparable analyses were performed on a merged all-species data set. Whereas sharp differential growth was found between commercial zones and residential areas, studied species demonstrated ecological tolerance as individuals were found normally or vigorously growing in severe conditions. In this situation, ample irradiation intensity might be an important factor contributing to urban tree growth. Statistical analyses led to the identification of a threshold level (80% of total potential irradiation) above which optimal growth was found in commercial zones. Research results also brought out the importance of the underlying surficial deposits: slow growth rates were linked to the presence of sand/gravel deposits. Finally, higher soil de-icing salt concentrations were found in tree pits where trees were transplanted closer to the curb and on wider streets.

Predicting the growth in tree height and crown size of three street tree species in the City of Tshwane, South Africa

The aim of the study was to determine the relationships between tree age and various parameters of tree size in order to develop models to predict the growth of street trees. Three indigenous species, Combretum erythrophyllum, Searsia lancea and Searsia pendulina commonly used as street trees in South Africa were the focus of this study. The relationship between tree height and age, crown height and age, as well as crown diameter and age for all three species were investigated. The logarithmic function provided a good fit to the data on age against tree height ( r 2=0.73, 0.66 and 0.67 for the three species) and age against crown diameter ( r 2=0.74, 0.75 and 0.69 for the three species) whereas the fit for age against crown height was slightly poorer ( r 2=0.74, 0.54 and 0.59 for the three species). The logarithmic equations derived for the three species were applied to predict tree height at different ages and growth rates for different time intervals. A comparison between the species revealed that C. erythrophyllum starts with a mean annual tree height growth rate of 912 mm yr −1 for the first 5 years of growth while that of S. lancea is 786 mm yr −1 and S. pendulina 894 mm yr −1. However, S. pendulina and C. erythrophyllum have the same mean annual growth rate for the 5–10 years (467 mm yr −1) and 10–15 years periods (315–317 mm yr −1). Both mean annual crown height and crown diameter growth rate consistently ranked the species in the order of C. erythrophyllum > S. lancea > S. pendulina.

Growth of Street Trees in Copenhagen With Emphasis on the Effect of Different Establishment Concepts

Limited rooting space is considered a major problem for growth of street trees. Different approaches to extend the soil volume accessible to roots have been implemented in Copenhagen, Denmark, during the last 15 years. The presented survey investigates growth and vitality of trees planted in 1) structural, load-bearing soil; 2) sand-based load-bearing soil; and 3) so-called super planting pits and trees planted in conventional planting pits. The trees were either street trees or situated on paved squares. The results provide evidence that vitality of recently established street trees in Copenhagen generally is on an acceptable level. Furthermore, tree growth in both of the load-bearing materials allowing for root growth was found to be comparable to tree growth in conventional planting pits, and those methods are therefore considered applicable at sites where conventional pits cannot be established. However, tree growth in super planting pits was superior to any of the other methods both in regard to growth rates and vitality. This method is therefore recommended wherever space for large planting pits with open surfaces can be made available. Growth of trees planted in conventional pits varied considerably, reflecting the broad range of different conditions the term “conventional planting” pit covers.

神戸市における市民の植枡利用が街路樹の生育環境に与える影響とその認識に関する研究

Street tree planting plots are used in various ways by citizens, because these spaces are precious for residents in urban area to enjoy gardening. However, these uses may influence the growth of street trees. Therefore, we investigated the growth conditions of street trees where gardening occurred in the planting plots, the neighborhoods awareness toward this use, and the users interest in planting area. Consequently, the findings showed no serious influence upon growth, and gardening soil in the planting plots is better for plants than not. Moreover, some pedestrians are concerned about the street landscape rather than safety because insufficient maintenance and disrupts the streetscape design, and the plantings cause narrowing of the sidewalk. To resolve this, we recommend establishing rules on the use of street tree planting plots for gardening by citizens. For example sufficient watering, proper pruning, and keeping flowerpots inside of tree planting plots, will resolve these issues.

Plant Moisture Stress of Green Ash Trees in Contrasting Urban Sites

On three dates in the late summer and early fall of 1994 we measured leaf water potential and gas exchange on green ash trees in 1) a park-like stand on the University of Nebraska-Lincoln campus, 2) in large planters (5.1 m2) in an asphalt parking lot and 3) in small planters (1.8 m2) in the same parking lot. The trees on the campus had consistently higher pre-dawn leaf water potential (\|/) and photosynthetic rates (Ps) than trees growing in the nearby parking lot. Within the parking lot, trees grown in the small planters had lower \|/ and Ps than trees grown in large planters. The results support the supposition that urban environments increase plant moisture stress. Differences in growth and physiological performance between trees in the two planter types in the parking lot suggest that the adverse effects of the 'heat island' may be at least partially offset by adjusting the size of planter opening. Furthermore, models based on projected crown area, such as those developed by Bakker and Lindsey and Bassuk, provide useful guides for planning the amount of soil volume needed to ensure the survival and healthy growth of street trees.

Street Tree Performance Tests of Crabapple Cultivars: Initial Results

Ten crabapple cultivars are being evaluated as street trees in twelve communities. Using standardized methods, cooperators in the Municipal Tree Restoration Program design plantings, plant trees, and take annual measurements in the first three growing seasons after which they are repeated triennially. Growth in height and trunk diameter varied considerably among locations, as did exposure to diseases and insects. The principal pests were gypsy moth, Japanese beetle, scab, and aphid. The large fruit of Brandywine caused problems in one community, but not in two others. All ten cultivars grew well and remained healthy at most locations, which could be expected because they had been selected for superior street tree growth habit and disease resistance. Minor differences in performance of cultivars during the first three years were not large or uniform enough to recommend one over another, though this may change as evaluations continue. Until then, selections can be based on other traits such as color of flowers or fruit, tree size, and branching habit.

Newly Planted Street Tree Growth and Mortality

Two-year growth and mortality rates were analyzed for 254 black locust, 199 southern magnolia and 27 London plane trees planted along a major boulevard extending from southern Berkeley through western inner-city Oakland, California. After the first two years, 34% of these newly planted trees were either dead or removed. The average annual mortality rate was 19% with no significant difference in mortality among the species or between years. Areas of lower socio-economic status exhibited the most tree mortality with pecent mortality most strongly correlated with percent unemployment (r=0.78). Trees with adjacent land uses of apartments and public greenspaces had significantly high mortality while trees next to single family houses and rapid transit stations exhibited low mortality.

VILLAGE AND CITY STREET TREE RESOURCES: A COMPARISON OF STRUCTURE

Summary The degree to which the street tree and streetside space resources of small communities are miniaturizations of the resources of larger cities may affect tree management. In this case study, the streetside space and street tree resources of two small villages, Jordan and Baldwinsville, are compared to those of a nearby city, Syracuse, New York. The two villages differ in the extent to which they are miniaturizations of Syracuse. The proportion of severely restricted streetside spaces is lower in the villages due in part to their disproportionately smaller areas of commercial land use. Surfacing of most streetside strips abutting commercial land use presents the most adverse conditions for street tree growth. Each of the communities in this study, though physiographically similar, has a unique street tree population due in part to the history of the street trees in that community, as well as the current phase of the population life cycle—establishment, maturity and replacement.

樹路樹の生態に関する基礎的研究

This study intends to research the effect of the state of soil on the growth of street trees in the city. The most of street trees, generally, lost vigour. Growth effections is rather less by air pollution, but more by physical and chemical condition of soil and subsoil, showing vital forces of such trees. Principal reasons to show poor growth are considered following data:1. Gravel and gravel horizon are frequent in soil.2. There is hardpan in the subsoil.3. Soil is hard and compact.4. Soil water permeability is not favourable.5. There is decline in soil water-holding ability.6. Soil acidity is excessive alkalization.7. There is lacking in major elements of fertilizer, especially nitrogen and phosphoric acid in soil.8. There are contained too much injurious materials against growing in soil.