Honeysuckle in the Taconics Inventory and Monitoring Forest Invasive Species with Airborne Remote Sensing: Honeysuckle in the Taconics Should I add multispectral analysis here too, or just say “Assessing Invasive Plants with Remote Sensing Tools?” Katie Joseph and Robert Turner, RJ Turner Company Vermont Monitoring Cooperative 10.30.06

The Question Can invasive plants be detected over a large scale in forested systems using remote sensing technology? High resolution multispectral analysis with stereo capability (3D)

The Opportunity Vermont TNC was investigating 3,700 acres in core of Equinox Highlands matrix block Matrix block: large scale, relatively unfragmented landscape, bounded by fragmenting features such as roads Enriched hardwood community. Taconics dominated by enriched northern hardwoods. Unfragmented blocks of this size are unusual.

The Opportunity Timber cruise plus information on presence of invasives Opportunity to apply new technology to the problem AIMS-1 technology: high resolution multispectral airborne imagery with stereo capability We had a timber cruise into which we added requirements for northern hardwood forest KEAs (key ecological attributes) including the presence and abundance (qualitative) of invasive terrestrial plants. Plus a consulting forester approached us with an idea to analyze the feasibility of using some remote sensing techniques to see if the presence of invasives could be detected over a large scale. The timber cruise data would provide groundtruthing for the remote sensing analysis, plus a few additional days in the field. Partners Mt. Holyoke GeoProcessing Laboratory and RJ Turner Company are interested in applying remote sensing technology to the invasive problem. There are examples of applications using remote sensing for other terrestrial inavsives, aquatic invasives, but nothing for shade tolerant invasives in northern hardwoods-Collaboration in the past with LULC for Vermont in 1996-98 RS enhanced by the ability to view the entire area of interest in stereo AIMS (Airborne Imaging Multispectral Sensor)

The Site Equinox Highlands 63,000 A landscape Northern Taconics Mountainous (3,800 ft) 90% forested Marbles; carbonates Mt. Equinox Equinox Highlands is an unfragmented 63,000 acre landscape bounded by roads (yellow line is imaginary boundary.) It is at the north end of the Taconic Mountain Range, in the Lower New England / Northern Piedmont Ecoregion (see insert.) It is steep, low-elevation mountainous terrain; named for Mt. Equinox, the highest peak in the Taconics at 3,800 ft. The landscape is 90% forested, and the bedrock on the eastern side is highly calcareous (limestones & marbles.) The lime-rich bedrock makes this places susceptible to invasion by many invasive species.

The Threat Bush honeysuckles Japanese barberry Buckthorn Burning bush not a target, but buckthorn was Remove burning bush photo and replace with Buckthorn Share similar structure and ecological characteristics

The Threat Insert Map of cruise points with colors indicating the presence of honeysuckle and barberry Timber cruise data gives us an indication of where invasion is occurring and what species pose the greatest threat Invasive species occurrence was noted during the timber cruise when observed from the cruise point. Therefore the cruise point itself does not represent the actual location of the invasive shrub. Additionally, the abundance of the invasive at these locations is not noted. Is it just a tiny plant or full grown shrub 2 meters in diameter? For ground truthing or training/accuracy assessment, it would be ideal to know the amount of the invasive (how much ground – or number of pixels- does the shrub cover) and the exact location. So, these cruise points cannot necessarily be used for ground truthing in all instances. The timber cruise does indicate that honeysuckle is the abundant invasive shrub on the property and gives us an idea of the distribution Timber cruise- scan the visual acre from plot center.. Any evidence of invasive was recorded with species

Our Goal: Differentiate invasives from surrounding, native vegetation The 3 invasives leaf out early, stay late Heights are definable, shrub strata High probability of invasion near disturbed and open areas Spectral, height strata, possibly land use information

The Tools Low elevation photography 75 cm pixel size: full coverage 15 cm pixel size: sample coverage Multispectral (red, blue, green, and near infrared) Stereo capability for both 15 cm and 75 cm (3D viewing) Near infrared enhances the ability to detect and distinguish vegetation types and has been traditionally used in remote sensing, including satellite sensors such as Landsat TM (which has a pixel resolution of 30 meters and no stereo capability) Literature discussion- what tools exist.. Relation to invasives, why forested ecosystems have not been fully explored

The Process: Data April 26, 2006: Flight with the AIMS-1 sensor (Mt Holyoke Geoprocessing Lab) Initial Ground Control Collection with GPS Fall 2006: Additional Ground Control Collection with GPS Insert Map of photo centers: 15 cm and 75 cm (Flight Paths) From the spring GPS points we have an idea of what will be ‘confused’ with target invasives. In the fall we will go to collect additional GPS points concentration on those vegetation types that will be difficult to differentiate from the imagery. Flight and initial Ground Control occurred on the same date Spring flight had to be timed with the leaf expression of invasives and leaf-off of canopy; weather dependent Ground Control Collection: GPS of differing vegetation types (potentially confused vegetation types)

The Process: Image Preparation Image pre-processing Create stereo blocks for stereo interpretation: 3D viewing Create orthophotos (correct for variation in terrain) and orthomosaic (stitch all of the orthophotos together to make a single image) These are the steps to convert the ‘raw’ image data (digital pictures) into something usable.

15 cm resolution 75 cm resolution Robert and Katie might embellish this by saying what kinds of things you can pick out with 15 cm resolution, such as downed coarse woody debris. Rose spent time on this slide helping folks to understand the relationship between the two resolutions and the size of a honeysuckle crown, and which resolution you need is related to whether you have big patches of your target (in this case honeysuckle) or whether you’ll need to find individual bushes. 15 cm resolution 75 cm resolution

The Process: Analysis Stereo interpretation (3D viewing) used to differentiate vegetation types and strata Serves as training in classification use GPS and timber cruise ground truth points as references for interpretation

The Process: Analysis Supervised Classification Accuracy Assessment: How did we do? Supervised classification is the process of using groups of pixels of known identity or class (Training areas with classes such as Honeysuckle, Hardwood, Softwood, etc.) with unique spectral signatures to assign a class to pixels of unknown identity. There are several different supervised classification algorithms such as Maximum Likelihood, Minimum Distance to Means, and Classification Trees that are common in Remote Sensing Applications. When our full set of field points have been collected we will test a few common classifiers that have had proven success in a variety of types of classifications and will determine the best type for this application. An essential step in image classification is accuracy assessment. The most common way to perform an accuracy assessment is to use points (pixels) of known identity (from GPS points) that were NOT used in the classification process, to check the classified map.

Results so far More ground-truthing needed this fall Preliminary results—honeysuckle detectable Spatial accuracy better than timber cruise, we can get precise location for single shrubs Remaining question whether honeysuckle signature “clean enough” Yes, more ground truthing will be needed in the fall. With the limited amount of information that we have thus far, we have been able to pick out honeysuckle (the only invasive that is abundant on the property). There is confusion with some other cover types such as Rubus sp (which was showing some leaf expression during the acquisition). The spatial accuracy will be better than the timber cruise since we can get an exact location of a honeysuckle bush (at least a larger one). The biggest question is whether or not we will be able to get a spectral signature that is ‘clean’ enough. If so, we will definitely have a more accurate map of the location and coverage of honeysuckle.

Feasibility Cost Remote sensing expertise & software needed Imagery can be custom flown, easily arranged *The timber cruise gave us an idea of where to find invasives and what invasives were out there, but not spatially accurate enough for training or ground truthing- not completely necessary but helpful *Remote sensing expertise and software are necessary, mainly in the data preparation stage *Imagery can be custom flown and can be easily arranged; extreme topography can be limiting; AIMS-1 sensor has been used in Southwest, South America, Northeast

Additional Remote Sensing Opportunities with AIMS-1 products Forest stand typing Forest inventory Coarse woody debris inventory Future flights: Invasive plant monitoring over time *Emphasis on stereo capability

Additional Remote Sensing Opportunities with AIMS-1 products Current projects associated with the AIMS-1 Sensor include Hemlock Wooly Adelgid monitoring Detailed Crown Cover Mapping Spatial Database Creation of Drainage Features Habitat Feature Extraction Along the Lamprey River, Energy Modeling of Hydrologic Features

Project Credits Rose Paul Thomas Millette Jeremy Turner 603-526-8686 The Nature Conservancy rpaul@TNC.ORG> Thomas Millette Mt. Holyoke College Geoprocessing Lab tmillett@mtholyoke.edu Jeremy Turner 603-526-8686 Meadowsend Timberlands Ltd.

Rich Northern Hardwood Forest