Hemlock Tree study using the AISA Eagle 1K Hyperspectral Camera System

Hemlock trees in the Northeastern United States are an integral part of the environment. These trees stabilize stream banks, and provide specific food, habitat and nutrients to their ecosystem. Hemlocks are unique, making them irreplaceable by another species; therefore, forest management of hemlocks is imperative. There are four steps to managing forest health; Analysis, Treatment, Restoration and Monitoring. Helicopter Applicators Incorporated (HAI) has the ability to perform two of these steps in Analysis and Restoration.

Hemlock Woolly Adelgid (HWA) is proving to be a dire threat to hemlock health. The key to managing this threat is early detection. Through the use of hyperspectral imaging, HAI can provide concise identification of infestation and delineation of hemlock health in advance of detection by the human eye. Hyperspectral imaging is capable of detecting bands of the Electromagnetic Spectrum starting with the ultraviolet bands, all of the visible spectrum, and into infrared. Utilizing the AISA Eagle 1K Hyperspectral Sensor, HAI is capable of detecting the unique spectral signatures of hemlocks in varying stages of decline.

HAI has conducted a pilot study of a 200-acre plot of forest in Perry County, Pennsylvania. Flights were conducted in order to classify hemlock health and differentiate them from other plant species. Preliminary flights have resulted in classified, analyzed data that proves that hyperspectral imagery is successful at identifying species and delineating health levels. In the following example, the flight lines were gathered from a 1000 ft. altitude resulting in a sub-meter resolution, showing individual tree canopies.

Healthy Hemlock	50% Decline	Dead Hemlock

The above are raw image cubes of hemlocks collected by the AISA Eagle 1K.

The results of this pilot study were conclusive. HAI has established that hyperspectral analysis of hemlock trees can aid in the early detection of HWA spread as well as assist in determining the proper course of treatment. The AISA Eagle 1K can also classify hemlock health incrementally and specifically identify hemlocks. Results such as these can be obtained with minimal ground truthing and relatively little effort by the landowner. The final product will be geo-referenced and will allow landowners to locate specific trees of interest and apply the proper treatment. After treatment, the infestations should diminish allowing for restoration. This restoration will result in a longer life for these hemlocks.

After HAI performs the analysis, restoration of unhealthy trees can begin. HAI will work with certified biologists in order to plan the best course of restoration for ailing hemlocks. Studies have shown that treating trees with micronutrients goes a long way in improving their overall health. These micronutrients are applied aerially by HAI. Because a hemlock tree can have many thousands of needles, it is imperative to cover as many of them as possible to insure maximum efficiency.

HAI uses a rotary atomizer nozzle that breaks the water-based, specialized micronutrient into a fine mist. Each droplet of the mist is uniform in size and nutrient content. Once absorbed, the micronutrient is incorporated into the process of photosynthesis. This results in nutrients that were lost being absorbed back into the tree. These nutrients are similar to a vitamin in that they facilitate the healing of the tree. In order to be effective, these micronutrients must be specific based upon each tree individually. HAI and Pais Ecological Services, Inc., work hand-in-hand to prescribe "specialized" micronutrients based upon the needs of the tree.

Helicopter application	Spray boom with rotary atomizer nozzle

These specialized micronutrients meet the standards of the Department of Environmental Protection. They do not adversely affect streams, lakes or rivers, and have been proven to be non-harmful to marine life. The efficacy of specialized micronutrients has been studied at Bushkill Falls, in Bushkill, Pennsylvania. The results show that the restoration of trees using micronutrients markedly improved the health of infected hemlocks.

The analysis and restoration performed by HAI benefits landowners in several ways: it requires only a minimal amount of ground truthing; and reduces time, effort and expertise necessary to locate infected trees. Through aerial hyperspectral surveys, HAI can pinpoint these trees, leading to proper treatment. Proper treatment ensures the health of trees, and saves money by cutting down on experimental procedures. The bottom line is that it is cheaper to save the trees than it is to cut them down.

 

 

 

Helicopter Applicators, Inc. 1670 York Rd  Gettysburg, PA 17325