Remote Sensing in Conservation Easement
By Steven Apfelbaum and Jason Carlson
Ecosystems serve many critical ecological functions for our land including flood reduction, air quality improvement, and soil stabilization to name a few. Efforts associated with conservation and land protection can help enhance, restore and prolong how well these ecosystem functions are being performed by natural systems. Land managers such as land trusts are currently providing easement monitoring and land protection services, which focus on legal obligations tied to holding these lands from ill treatment of lands. Unfortunately, these monitoring efforts fall short of evaluating, documenting and planning for ecological improvement. Applied Ecological Services (AES) has recently developed an aerial imagery and remotes sensing method that offers a cost-effective approach to serving both the legal and ecological monitoring obligations of conservation easements.
Conservation easement monitoring is necessary to confirm that responsible parties, typically landowners, are upholding legal terms of a conservation easement agreement. Easement agreements and Land Trust Alliance accreditation requirements necessitate an annual inspection and confirmation to protect against illegal land-use activities—fencing violations around easement boundaries, hunting, off-road vehicles use, logging, disposal or dumping of garbage or yard wastes and construction activities, such as placement of buildings and roads—on easement property. These are some of the called-out focused issues documented annually during easement monitoring inspections.
The land trustees report the findings of its annual survey to the landowner or party who impressed the easement. The relationship between the land trust stewards, who have taken on the role and responsibility for easement monitoring, and the landowner must be lasting and educational, especially to avoid transitional conflicts when the land passes over to the second generation or new owners, who may not understand or agree with the original intentions of the conservation easement. A durable and open relationship between all parties involved is therefore essential to the continued protection of the land held in easements.
A common point of frustration in relationships between land stewards and landowners stems from a lack of clear communication between the parties about the intent of the easement protection program and what it actually does for the land itself. This relationship may benefit from using new technology to provide all users with a clear picture of current ecological health of the land.
Many landowners want visible reassurance that their land is ecologically healthy instead of being referred to look at the legal terms of an easement agreement. This visible proof is available in the form of high resolution multi-spectral imaging aerial photography offered by Applied Ecological Services (AES), which contains data about the ecology of the land, benefitting landowners, trustees and, most importantly, the land itself.
AES’ aerial imagery provides an ecological snapshot of the land: it can be used to identify and map invasive species, erosion, tree and other vegetation diseases and dozens of other type of clear and precise measurements. The imagery can also show clearly if and where perfunctory legal terms of the agreement are being violated. Nearly everything required of most conservation easements can be monitored with this imagery.
Educating landowners can be a new way to build durable and next generation, or landowner, relationships. With aerial imaging, land trustees and landowners can discuss specifics and build relationships through common interests or problem solving. Being able to actually show landowners their declining ash trees from Emerald ash borer or pointing out where erosion of an agricultural ditch upstream is contributing to in-stream turbidity and sedimentation of a wetland actively engages the landowner and land trustees in the continued health of the land.
Why would a land trust consider purchasing imagery or photography besides the above stated benefits of increased ecological understandings and enhanced landowner relationship? Using aerial imagery is a cost-efficient strategy that allows for uniform, comprehensive annual monitoring. It is often difficult for land trustees to do a full examination of the property every year, especially if they have to walk over many acres of land. Imagery can cover an entire area quickly and can even provide monitoring at multiple times of the year. Imagery provides an extremely accurate record of the ground conditions and can also specifically focus on designated areas of risk, problem and uncertainty, providing annual records that are standardized and reproducible. Instead of having to superficially cover all 500 acres of an easement, the steward can focus where problems are detected: ecological and legal violations or concerns, which saves time and money.
High-resolution multi-spectral imagery allows for very precise characterizations of on-the-ground conditions. The combination of resolution, or clarity of the photo for the user to interpret detail, and the combined infrared reflectance data offer a unique tool for ecological mapping and interpretation. Color and black-and-white photography is also useful, but it is not able to provide the same level of depth and use for measuring, documenting and deciphering what is actually present on the site. We can use various wavelengths tied to the reflectance of multi-spectral data to characterize the health of the land: for example, imagery can detect if a tree is stressed due to Gypsy moths or Emerald ash borer.
Stewards can use the remote sensing imagery to detect and subsequently monitor many problem areas without extensive, time consuming field investigation that require managers to physically walk the entire easement property. Rather imagery can focus and minimize field investigation while provide a more comprehensive, consistent and continuous records of condition. If land trusts have changes in staff, or become financially constrained and are not able to walk an entire property, the use of this imagery allows for year-to-year consistency and every year a standardized perspective and analysis of the entire property.
Using multispectral imagery to monitor conservation easements is cost-efficient, allows for consistent, comprehensive ecological monitoring and is a way for land stewards to actively engage landowners. Fulfilling the ultimate, long-term conservation vision or purpose of the easement will only be possible if land trustees and landowners are able to efficiently communicate about the health and maintenance of the land. Imagery is an excellent tool for easement monitoring and provides all stakeholders with an accurate, comprehensive record, which can be used as a base for all future conservation efforts.
Steven Apfelbaum is the award-winning founder and principal ecologist of Applied Ecological Services, Inc., a leading environmental restoration firm with ten offices in the United States and two abroad. He is the author of Nature’s Second Chance, a personal memoir recognized as one the top 10 environmental books of 2009, and co-author of The Restoring Ecological Health to Your Land series, which shows readers of all skill levels how to design and implement small scale ecological restorations. Both books are available at www.amazon.com.
Jason Carlson is head of AES’ Geospatial Services Division. He has led conservation projects using aerial imagery, GIS and remote sensing analytical procedures. Recent projects include development of the green infrastructure in the Chicago region, participation in a Kansas City Natural Resource Inventory, and contributing to the statewide Illinois Natural Area Inventory.
For more information, visit www.appliedeco.com.