跳至主要内容

Water Use of Juvenile Live Oak (Quercus virginiana) Trees over Five Years in a Humid Climate

Trees planted in urban landscapes often require irrigation during all stages of life. Landscape tree water management requires reasonable estimates of water demand in order to schedule irrigation amounts and timing to conserve water while maintaining tree health. Estimating tree water demand is not straightforward for water demand of isolated trees as typically found in urban landscapes is affected by numerous factors.

To meet minimum spring flows, water management districts in Florida sought to make both agriculture and urban landscapes water efficient, which includes tree farms. Quercus virginiana, commonly known as live oak trees, is endemic to Central Florida and among the most popular landscape trees for their gracefulness and spreading shade.

In this study, to provide a basis for irrigation allocations both during production and in landscapes, daily actual evapotranspiration (ETA) in liters for three live oak trees was measured with weighing lysimeters over five years, beginning with seedlings and continuing until trees averaged 7.2 meters in height. Empirical models were derived to calculate ETA based on crown horizontal projected area (PCA) or trunk caliper (TCSA), adjusted daily by changes in evapotranspiration (ETO). Average ETA to produce these live oaks was 62,218 L cumulative over 5.5 years. Effectively transpiring leaf, tree water use volume divided by ETO, was closely related to PCA over five years with the slope of this relationship being equivalent to a Plant Factor of 0.93. The product of ETO and this Plant Factor can be used to estimate depth of live oak water demand in urban landscapes. Also, this Plant Factor can estimate water demand volume in nurseries and landscapes when combined with PCA, and similarly the slopes for TCSA can be used to estimate ETA water volume from measured trunk diameter.

In conclusion, daily ETA of Quercus virginiana can be estimated with high precision based on the methods of calculating ETO and using the appropriate coefficients (for PCA or TCSA) for a given measure of tree capacity to move and transpire water. 

Article by Richard C. Beeson, et al, from University of Florida, Apopka, FL, USA.

Full access: http://mrw.so/3qjsKJ

Image by Ruy Urraca, from Flickr-cc.

评论

发表评论

此博客中的热门博文

A Comparison of Methods Used to Determine the Oleic/Linoleic Acid Ratio in Cultivated Peanut (Arachis hypogaea L.)

Cultivated peanut ( Arachis hypogaea L.) is an important oil and food crop. It is also a cheap source of protein, a good source of essential vitamins and minerals, and a component of many food products. The fatty acid composition of peanuts has become increasingly important with the realization that oleic acid content significantly affects the development of rancidity. And oil content of peanuts significantly affects flavor and shelf-life. Early generation screening of breeding lines for high oleic acid content greatly increases the efficiency of developing new peanut varieties. The objective of this study was to compare the accuracy of methods used to classify individual peanut seed as high oleic or not high oleic. Three hundred and seventy-four (374) seeds, spanning twenty-three (23) genotypes varying in oil composition (i.e. high oleic (H) or normal/not high oleic (NH) inclusive of all four peanut market-types (runner, Spanish, Valencia and Virginia), were individually tested ...
发表评论
阅读全文

Location Optimization of a Coal Power Plant to Balance Costs against Plant’s Emission Exposure

Fuel and its delivery cost comprise the biggest expense in coal power plant operations. Delivery of electricity from generation to consumers requires investment in power lines and transmission grids. Placing a coal power plant or multiple power plants near dense population centers can lower transmission costs. If a coalmine is nearby, transportation costs can also be reduced. However, emissions from coal plants play a key role in worsening health crises in many countries. And coal upon combustion produces CO 2 , SO 2 , NO x , CO, Metallic and Particle Matter (PM10 & PM2.5). The presence of these chemical compounds in the atmosphere in close vicinity to humans, livestock, and agriculture carries detrimental health consequences. The goal of the research was to develop a methodology to minimize the public’s exposure to harmful emissions from coal power plants while maintaining minimal operational costs related to electric distribution losses and coal logistics. The objective was...
发表评论
阅读全文

Evaluation of the Safety and Efficacy of Continuous Use of a Home-Use High-Frequency Facial Treatment Appliance

At present, many home-use beauty devices are available in the market. In particular, many products developed for facial treatment use light, e.g., a flash lamp or a light-emitting diode (LED). In this study, the safety of 4 weeks’ continuous use of NEWA TM , a high-frequency facial treatment appliance, every alternate day at home was verified, and its efficacy was evaluated in Japanese individuals with healthy skin aged 30 years or older who complained of sagging of the facial skin.  Transepidermal water loss (TEWL), melanin levels, erythema levels, sebum secretion levels, skin color changes and wrinkle improvement in the facial skin were measured before the appliance began to be used (study baseline), at 2 and 4 weeks after it had begun to be used, and at 2 weeks after completion of the 4-week treatment period (6 weeks from the study baseline). In addition, data obtained by subjective evaluation by the subjects themselves on a visual analog scale (VAS) were also analyzed. Fur...
发表评论
阅读全文