2020 Sept 5 ISSUE – CORRALES TREE CANOPY NEEDS CARE

The chairman of the Tree Preservation Advisory Committee, John Thompson, is concerned about the decline in the Corrales tree canopy. In a presentation to the Village Council August 18 Thompson laid out an approach to tree care for the council, asking “Is there a problem with Corrales trees?”

He and his committee think so: he touched on the effects of drought on tree health, trees’ increasing susceptibility to disease and pests, the loss of trees along the acequias, even the increased number of cottonwoods with mistletoe in their branches. Infestations of mistletoe often indicate a stressed or unhealthy tree.

The Village of Corrales is certified by the Arbor Day Foundation as a Tree City USA with the goal of securing a healthier tree canopy. The Tree Preservation Advisory Board (TPAC) has been serving as a de facto Tree Board for five years to assist the Village in maintaining that certification, but without a mission defined by ordinance or a budget to achieve the desired goals and benefits of proactive tree care.

The committee’s additional concerns include the lack of tree species diversity, the dying and dead cottonwoods in the sandhills, and an increase in invasive species such as the ubiquitous Siberian elms, tamarisks, Russian olives, and Ailanthus altissima, or trees of heaven. Tamarisks, for example, though plentiful with pink blossoms, achieve that beauty by grabbing up light, water and nutrients from native plants. Native to Eurasia, tamarisk were brought to North America in the 1800s to shore up riverbanks. Their love of alkaline soil, common to the Southwest, has ginned up even more salty soils, which this plant is able to produce.

The committee, which includes Fred Hashimoto, Don Welsh, Carol Conoboy and Ian Daitz, asserts that Corrales hosts fewer healthy orchards as well. It thinks that the establishment of a Tree Board, in place of TPAC, will insure the Village acknowledges that “trees make major contributions to public health and safety, economic and spiritual value, local food security, wildlife and climate change resiliency.” And it will demonstrate the Village’s “dedication to the enhancement and protection of the community forest, landmark trees, and public green spaces.”

The board itself is prepared to take on a bundle: “Increase public awareness of health, environment, economic benefits of tree canopy; educate in tree selection, planting, and care; train Public Works, Parks & Rec, Fire Departments; update the tree ordinance; obtain alternate sources of funding for tree planting, care; promote climate-adapted species and age diversity; and provide a ‘tree care plan’ to provide better maintenance for existing public trees, reduce the number of hazardous trees, and create new tree planting goals.”

According to Thompson, “The plan aims to be the key document for managing, maintaining, protecting, preserving and planting trees within the Village of Corrales. This plan details specific goals and objectives for tree inventories, tree risk management, tree protection and tree pruning standards. “This is intended to be a living document that is updated yearly to provide schedules for community education, tree planting programs, and updates to relevant information on tree selection and planting, best management practices, and progress in stakeholder involvement in tree care.”

Creating a “tree care plan” will take much effort as the board wrestles with the fact of climate change on trees, hotter summers, and possible lower temperatures in winter. Local Cottonwoods are high water users, which do not easily reproduce outside of flood plains, the latter almost gone from Corrales. Planners must deal with drought stress, soil compaction, lack of diversity, even concrete acequias which cut off moisture to trees along its banks.

As well as disease and pests. Did we know the emerald ash borer was coming? Smaller than a dime, it’s a green beetle from Asia gifted at leveling tall stands of trees. Ash trees, thus far primarily in the Midwest and east, but, increasingly planted in New Mexico. Among them the velvet ash and associated cultivars, including the Modesto ash, green and white ash, Raywood ash, fragrant ash and others.

So what is the true value of a community forest? And what exactly is tree canopy? Ian Leahy, director of Urban Forest Programs at American Forests, writes that “tree canopy is any area covered by the branches of trees.” And, “tree canopy is the only type of infrastructure that increases in value after you install it.”  American Forests, established in 1875, is the oldest national conservation organization in the country.

The Corrales Bosque Preserve comprises one square mile of riparian forest, co-managed by Middle Rio Grande Conservancy District and the Village. 10,000 trees, providing 50 percent canopy. The greenbelt area is five square miles of irrigated agricultural fields, orchards, mature cottonwoods and elms. That’s 10,000 trees, with 14 percent canopy. The sandhills are five square miles, with 2,000 developed lots. It includes sparse plantings of fruit, shade, ornamental trees and native shrubs. So 4,000 trees, with two percent canopy.

The size of the tree canopy is a means of measuring the health and potential benefits of the community forest. An initial estimate of the Corrales tree canopy using i-Tree, a software tool from the U.S. Department of Agriculture, shows that Corrales has an average tree canopy of about 12 percent. In comparison, the tree canopy in Albuquerque is about ten percent and is known to have been in decline over the last few decades. What are these 24,000 Corrales trees worth? According to the USDA, U.S. Forest Service, Pacific Southwest Research Corporation, the answer is $75,000,000.

They remove CO2 and air pollutants. They catch rainwater and reduce stormwater runoff. Tree-filled communities may be safer, less stress-filled. Trees cut down on wind, and reduce temperatures. Shaded buildings benefit from energy savings. Businesses do better on tree-lined streets, and property values increase by ten percent due to the aesthetic value of trees.

The tree plan has many goals, including tree surveys and educational outreach. Estimated cost of the plan in the first year is $39,000, which includes Village personnel hours, tree purchases, contracted International Society of Arboriculture or ISA-certified arborists, and trained volunteers.That amount is offset by an estimated $20,000 in donations and volunteer hours. (This budget exceeds the Tree City USA guideline of $2 per capita.)

Perhaps no goal in the plan, however, is more compelling than this: to plant a tree for every child in Corrales, so about 1,500 over the next ten years.