BY ANGELA PRADA
Horticulture & 4-H Agent
Los Alamos Cooperative Extension Service

Editor’s note: The Los Alamos Reporter reached out to our local Horticulture & 4-H Agent Angela Prada for her take on the number of dead pine trees in the County.

The landscape in the county has changed dramatically in the past 5-10 years in both residential areas and the townsite. What used to be the ideal climate for native Ponderosa Pine trees and other conifer species is rapidly shifting. Data from the Los Alamos National Laboratory Meteorology Program shows an average annual increase in temperature of 1.9 degrees Fahrenheit and an average decrease in annual precipitation of 1.9 inches across the county over the past decade. In a region that typically receives an average of 10-12 inches of precipitation annually, these numbers represent a significant impact on the landscape. Most recently, in the winter of 2024 and spring of 2025, the county received no precipitation for a six-month period. When ambient temperatures rise, the transpiration rate of plants also increases and creates a greater demand for water by the plants. Sporadic weather events, typical in desert our region, require additional irrigation from ground water to maintain these trees.

The Cooperative Extension Agent receives on average 1-2 calls per week related to declining conifers, specifically pines trees in the county. The concern is often the presence of disease or pests. Over the past 3 years, only approximately 10% of samples sent to the NMSU Plant clinic were diagnosed with disease or pests, indicating the majority are suffering from ongoing drought. However, wood boring insects are commonly seen in stressed conifer trees throughout the county and will cause significant damage over time. They can be treated with systemic insecticide but with little success because they move frequently between hosts and are difficult to target. These pests are secondary to the primary issue of drought stress. Strategies for integrated pest management should target the primary issue first, then address the secondary once the tree is restored to a healthy state. Recommendations can be made for supplemental irrigation based on the goal of the homeowner, specifically when to water, how much, and where irrigation is needed. In some cases, the recommendation is to conserve resources and remove the tree.

It is predicted that we will lose many of our Ponderosa Pine trees in Los Alamos county at an alarming rate in the coming years. Unfortunately, many of these are quite mature and will require a professional service to remove, which presents a substantial financial obligation. However, the risk of property damage or human injury due to complete failure is a priority in many cases.