GIS keeps watch on city trees
GIS keeps watch on city trees
Systems link crews with maps and digital photosBY TRUDY WALSH
| GCN STAFF
People need trees'for oxygen, shade and enjoyment'more than trees need people. And at least 30 city governments throughout the United States are using geographic information systems to keep track of their trees.
Mike Herron and his team have loaded data about 40,000 trees in Kansas City, Mo., into a GIS database.
Although trees aren't going to pick up their roots and walk away, urban forests require special care, city forestry managers said, because the stress of city life takes an extra toll on trees. For example, urban tree roots get more cramped from the pressure of streets and sidewalks than those of rural trees.
Kansas City, Mo., has inventoried about 40,000 trees out of the city's half million or so, and loaded the information into an ArcView GIS from Environmental Systems Research Institute of Redlands, Calif., said Mike Herron, superintendent of the city's Parks and Recreation Department's horticultural and boulevard services.
'We're definitely trying to get into the 20th century,' city forester Charles Knight said. 'When I came here we kept track of the trees on 3-by-5 cards.'
Now the city is using Tree Manager for Windows Version 5.0 from ACRT Environmental Services of Cuyahoga Falls, Ohio. Tree Manager is written in Delphi, and works on all Windows platforms, said Cathy Genest Godfrey, coordinator for GIS and computer-aided design products for ACRT. Tree Manager loads tree data into a database file with the common .dbf extension.
The software works with both ArcView and competing MapInfo GIS platforms from MapInfo Corp. of Troy, N.Y.
The latest version, Tree Manager for Windows Version 5.2, has a built-in mapping component, Godfrey said. 'It's not as elegant as an ArcView map, but it works just fine,' she said. Tree Manager's mapping component is written in MapObjects, ESRI's mapping language.Digital map
Using GeoExplorer 3 Global Positioning System handheld units from Trimble Navigation Ltd. of Sunnyvale, Calif., Kansas City Parks and Recreation crews go through the city's 350 square miles of urban forests and locate each tree in terms of x and y coordinates on a digital map, Herron said. City workers also take tree measurements, note species and assess each tree's condition. That information is also loaded into the database.
When city workers prune a tree or check it for disease, or a storm damages a tree, the city's tree maintenance crew will add still more information to the inventory.
Every tree in the city's 74-acre Jacob Loose Memorial Park has been loaded into the city's GIS, Herron said. 'It's just amazing to click on any dot on the map, and it will pull up the tree's size and history.' The park includes many valuable trees and shrubs in an arboretum and the Laura Conyers Smith Municipal Rose Garden, Herron said.Track everything
Before the city installed Tree Manager, Herron and his team reviewed their operations. The process led to a larger review of the city's plans, Herron said. 'It was through the framework of the tree inventory system that we've been able to streamline and synergize some of our services,' he said. 'We're right on the cusp of doing some things we couldn't do without having done the tree inventory first.'
'It's just amazing to click on any dot on the map, and it will pull up the tree's size and history,' Mike Herron said.
The tree inventory is stored in an Oracle database with the other city data and addresses, Knight said.
'We're very impressed with the accuracy of the GIS. It's accurate within inches,' he said.
Tree Manager lets municipal officials track the whole history of a tree, Knight said. 'It tracks everything: planting, pruning, removal. With a budget of less than a million dollars, and two crews of about six people each, you can imagine our work backlog,' he said. 'It's hard to ask for more money unless you can show that you're doing everything possible with what you have.'
Knight wants the city to develop a tree protection ordinance. 'This is the last piece of the puzzle. We'd like an ordinance that would dictate how trees are planted in subdivisions, what species can be planted, and what citizens can and can't do to trees.''Tree City'
Ithaca, N.Y., is sometimes called 'Tree City.' It is home to Cornell University's College of Agriculture and Life Sciences, long the nation's top-ranked program in plant sciences. For decades, plant pathology students planted experimental trees and shrubs throughout the city, leaving Ithaca with the legacy of a lush urban forest.
'We do have one of the most diverse urban forests in the Northeast,' said Andy Hillman, city forester for Ithaca. 'Our master plan is to not have more than 5 percent of our trees or woody shrubs be any one species.'
Ithaca uses Tree Manager Version 5.2 but has taken it a step farther than most by putting its city GIS'including the tree layer'on the Web at www.ithacamaps.org
Visitors to the Web site can click on any point on a city map and find details about the buildings, streets, voting districts, census information, fire hydrants and, of course, trees. Hillman and his crew have started taking digital photos of each point in the city and linking them to the GIS.
Hillman recalled the day a man rode his bike over to his office and said, 'Something is wrong with my tree.' He gave Hillman his address on Buffalo Street, which Hillman typed into the Web site, and in a few seconds, a digital photo of the man's house and adjacent trees popped up.
'Is that your tree?' Hillman asked.
'Yes, and that's my car and my house, too,' the man said.
Visitors can click on a single tree on the map, and find out species, genus, condition, size and when it was last inventoried.
The Ithaca GIS was originally built in Microstation from Bentley Systems Inc. of Exton, Pa., based on aerial photographs. City officials later broke the GIS into layers using MapInfo and ArcView. The city worked with local organizations'Cornell University, New York State Electric and Gas Corp., Tompkins County'to create a digital map from aerial photos. The city plans to buy a Trimble Navigation backpack-sized unit that sends GPS data directly to the GIS.
GIS used to be a standalone tool, at about $1,000 per seat, said Ruth Aslanis, Ithaca's planning systems manager. 'But now that GIS is on the Web, clients can view it over a browser. All of a sudden we don't worry about training costs or compatible operating systems,' she said.
GIS specialists in Ithaca and Kansas City agreed that the systems helped them care for the trees more efficiently, and said people and their computers are paying back some of the aesthetic and environmental benefits they have received.