There is no simple method for determining how much a tree is worth. If you have watered, fertilized and pruned the tree since it was a mere sapling, you may figure the tree is quite valuable. If it's a naturally occurring tree, you may have less attachment.

Well-maintained, mature, healthy trees can increase the value of your property by as much as 25 percent, depending on their size, species and location. Check the real estate classifieds, and see how many ads mention a "well-landscaped yard," "shaded patio," "great view of trees" or some other tree-related description.

A tree can be valued from $300 (for firewood) to $10,000 for an appraised tree with maximum benefits. A homeowner might value a tree as priceless because of special memories attached to it.

Trees have a monetary value that can be calculated and often recovered when they are damaged or lost. A knowledgeable arborist is the best person to perform an appraisal of your trees. You should document their value with photos and a professional landscape appraisal if you want maximum proof for insurance and tax purposes.

The replacement method is one of two main methods to value trees. Trees are measured at breast height or 4-feet above ground. With this method, replacement cost is the average cost local nurseries charge for the same size and species tree. The cost may include labor for removing the old tree and planting a new one. Often, however, it's not possible to replace mature trees. Special "tree spades" can move trees as tall as 35 feet, and larger ones can be craned on to a flatbed truck, but now we're talking some big money.

The second technique for determining tree value is called the basic formula method. Value is determined by multiplying the number of square inches in a trunk cross section 4 feet above ground. Adjustments are made for the species, condition and location. Regardless of the method used, it takes technical competence and experience to determine a tree's worth.

Physical condition affects a tree's value. Parts deformed by crowding, storm drainage, fire, insect damage, disease or other causes deduct from its worth. Plant location, especially when it is near buildings, utility lines or other plants, can be a detriment. Trees in planned landscapes often have higher appraised values than those growing wild.

Trees can be worth more for the shade they provide. That's because they help reduce temperatures in and around buildings. According to a technical guide from the USDA Forest Service, three well-placed trees can cut air-conditioning costs by 10 to 15 percent. According to www.treefolks.org, properly placed shade trees can reduce energy consumption by as much as 30 percent. If storm water runoff is a problem in your area, you should be aware that a tree with a modest canopy could reduce runoff by 12 percent to the value of your property, according to Michigan State University. With little or no maintenance, trees usually increase in value from 5 to 10 percent each year.

When trees are appraised, the Guide for Plant Appraisal is cited often. Written by the Council of Tree and Landscape Appraisers, it's the reference professionals use to properly determine factors affecting the value of plants. The April 2000 edition is $125 from the