Detecting Change in Conservation: The Value of Remote Sensing

In 2019, The Society for the Protection of New Hampshire Forests (SPNHF) began using satellite imagery to monitor the 204,000 acres they conserve. Previously, they’d relied on photographs captured by low-flying planes. Director of Easement Stewardship Naomi Bratlof described the organization’s approach in the early days of remote monitoring. “We used a volunteer pilot with staff hanging from the plane taking photos of properties,” she said. Today, SPNHF no longer relies on pilots to detect illegal logging, construction, or other violations on their protected properties. Instead, they order imagery through remote sensing technology company Upstream Tech.
With data ranging from satellite photography and 3D elevation models to change detection and vegetation indices, companies like Upstream Tech help clients access perspectives that are impossible to obtain from the ground. This data is useful not only to a land trust monitoring a conserved wetland, but also to a corporation looking to verify carbon sequestration in a forest. This article explores an ongoing initiative of the Land Trust Alliance (LTA) that encourages land trusts across the country to explore the utility of remote sensing. As conserving land to protect ecosystem services and mitigate climate change becomes increasingly important to a wide range of organizations, intermediaries like Upstream Tech and others are working to improve the accessibility of remotely sensed data.
Remote Monitoring for Conservation
The Remote Monitoring Grant Program—a partnership between LTA and The Nature Conservancy in California (TNC CA)—began in 2021. At the time, the Covid-19 pandemic had put a pause on in-person visits between land trust staff and property owners. The first year of the grant program saw awards to individual land trusts ranging from $1,400 to $20,000. With a new round of funding in 2022, 42 land trusts have now received a total of $435,000. “The whole hope with these grants was that we’d be pushing money to land trusts across the country to solicit products to force innovation in the field,” said Kate Losey, Remote Monitoring Project Manager for LTA. “And we’re seeing that.”
The field that Ms. Losey and her colleagues at LTA and TNC CA hope to influence—remote monitoring—involves the application of remotely sensed imagery from planes, drones, and satellites to detect change on the landscape over time. For land trusts, a central appeal of remote monitoring is the ability to detect violations of conservation easements–such as unauthorized construction or logging–from behind a computer screen. Remotely sensed data can also provide environmental insights that extend well beyond monitoring and compliance. Multispectral vegetation indices enable conservationists to measure tree and shrub regrowth after fire. One land trust involved in the grant program monitored the success of a prairie restoration, while another was able to use a water index tool to attribute unexpected foliage change to drought. 
To access the data, most land trusts involved in the Remote Monitoring Grant Program have chosen to invest in annual subscriptions with remote sensing technology companies Upstream Tech and Skytec. These companies serve as intermediaries, purchasing and reselling imagery captured by commercial imagery providers and making it accessible on user-friendly platforms that cater to the monitoring needs of land trusts and a range of other clients. “With this influx in grant money, having different land trusts invest in these companies, we’ve seen the companies making their products better and better tailored to the community,” said Ms. Losey.
As Project Director for Stewardship and Restoration at TNC California, Ethan Inlander worked with Upstream Tech to develop its remote monitoring software product Lens from 2018 to 2019. He recalled that in the 1990s, conservationists who wanted imagery had to obtain the data directly from Landsat servers. Using Lens, land trusts can now easily access powerful datasets such as infrared imagery, vegetation indices, and surface moisture data. “I think what these companies like Upstream Tech and Skytec are accomplishing is taking complex tech and tools and making them accessible.”
Prior to 2021, Maryland’s Lower Shore Land Trust (LSLT) had been using National Agriculture Imagery Project (NAIP) aerial imagery to view its properties from above. The resolution of this imagery is very high (6 inches), making it useful as a tool to inform stewardship efforts, but it is only collected every three years, which is not often enough to meet the land trust’s yearly monitoring needs. With $15,000 from the Remote Monitoring Grant Program, LSLT partnered with Maryland Environmental Trust to purchase a yearlong subscription to Lens for $2,500. In addition to the subscription fee, LSLT spent around $1,000 on satellite imagery for the year to cover the trust’s 136 easement properties totaling 23,647 acres. At 1.5 and 0.5 meters, the resolution of the satellite imagery available from Lens’ vendors was not as high as the Maryland NAIP imagery. It was, however, available much more frequently, allowing LSLT to fulfill annual monitoring requirements.
In addition to the promise of remote sensing as a tool for conservation, it can also lead to significant time and cost savings. To understand the potential value of their new remote monitoring program, LSLT conducted both in-person and remote monitoring on the same 58 properties to compare costs, staff time, and the percent of each property that could be monitored.
Time and Cost Savings
On-the-ground monitoring for the 58 properties cost an average of $202 per property and took staff and volunteers an average of nearly 5 hours per property. Remote monitoring of those same properties using Lens cost only $54 per property and took an average of 0.8 hours of staff time. LSLT projected these savings across their 134 properties and estimated a yearly savings from remote monitoring of $20,093 and 567 hours—significant money and time for an organization with only six full-time and two part-time employees.
Another benefit was that for all remotely monitored properties, the “percent monitored” was 100%, but dipped as low as 5% for in-person monitoring on some properties. About a quarter of LSLT’s conserved land consists of remote and difficult-to-access wildlife habitat and marshland along the coast of the Delmarva Peninsula. “For most easements around here you’re lucky to hit 20-40% of it in a ground visit, so it’s always nice to have that full property view,” said Jared Parks, LSLT’s Land Programs Manager.
With six full-time and two part-time employees monitoring 13,000 acres of land, the Northwest Connecticut Land Conservancy (NCLC)–like many land trusts across the country–faces challenges conducting yearly in-person visits to every property. Relying at least in part on remote monitoring is a necessity. “Time is money, and with limited staff, time is capacity. For a program like ours, remote monitoring is a real time saver,” said Paul Elconin, NCLC's former Director of Land Conservation. During the first year of the grant program, NCLC staff were able to monitor around half of their properties on the ground and half with satellite imagery. In the future, Mr. Elconin hopes to monitor 100% of NCLC’s land each year while also monitoring 20% on the ground.
Land Trusts and Beyond
In the grand scheme of things, the slice of the satellite imagery market that land trusts occupy is minuscule in comparison to that of large timber companies and the Department of Defense, for example, who purchase large batches of imagery at premiums. The emergence of ‘spatial finance’ has seen investment banks, insurance companies, and corporations integrate real-time, quantitative geospatial data into their risk mitigation, regulatory compliance, and Environmental, Social, and Governance (ESG) practices. To honor sustainability commitments to consumers, corporations bear the responsibility to verify environmental claims. For a corporation that holds investments in numerous companies with long, complex supply chains, for example, monitoring environmental impacts each step of the way can be extremely difficult. 
The Tennessee-based company Skytec currently provides data and services not only to land trusts and conservation organizations, but to a wide variety of corporate and nonprofit clients through its Ranger remote monitoring application. Ranger was designed around a partnership with Planet Labs, the only satellite imagery provider in the world that offers sub-4-meter resolution multispectral imagery of the entire earth, daily. In early 2022, Upstream Tech also announced a partnership between Lens and Planet. The availability of data at such frequency allows Skytec to offer automated change detection through Ranger, which helps users detect deforestation, property boundary encroachment, illegal construction, and even environmental changes that may be difficult to spot from the ground such as the early signs of drought or saltwater intrusion. Ranger’s complex suite of tools is built on a familiar ArcGIS platform, which helps ensure that land trusts already working with spatial data can integrate remote monitoring into their existing workflows. 
While remote sensing alone is an imperfect tool to assess the complexities of real environmental change, increasingly detailed and timely geospatial data is making previously undetectable landscape change visible. Planet Labs, for example, now offers on-demand access to 50-centimeter resolution imagery anywhere in the world with a 24-hour turnaround time. At the same time, machine learning promises to accelerate and streamline the detection of signals and patterns in these increasingly detailed datasets. “It’s really kind of the golden age in monitoring technology,” said Skytec Co-Founder and CTO Andy Carroll. “These massive data libraries are here and it’s a matter of connecting these and understanding your user.”
Yet while much of the technology has arrived, the biggest challenge Mr. Carroll sees for relatively resource-limited organizations such as land trusts is the cost of imagery. The higher the resolution, the more expensive imagery is to task. Requirements on the minimum tasking size for an area sometimes also mean that small land trusts must purchase imagery for larger regions than they need. Skytec is currently working with the Land Trust Alliance on the possibility of bringing smaller land trusts that share the same geographic regions into groups for more efficient, bulk purchases. Mr. Carroll also believes that imagery providers such as Planet, Airbus, and Maxar, could relax some of their policies to allow for multi-tenant usage of imagery within the land trust community.
Like Mr. Carroll, Mr. Inlander at TNC CA is hopeful that as time goes on, imagery providers will adopt a more philanthropic approach to conservation organizations. Yet he also believes that companies like Upstream Tech and Skytec may be able to prod imagery providers to pay attention to the needs of the land trust community. As prices come down and the frequency of available imagery continues to improve, more land trusts may find value in products such as Lens and Ranger. “That was our theory of change,” said Mr. Inlander, speaking about TNC California’s collaboration with Upstream Tech to develop Lens.  “If we could help Upstream Tech build a product that’s usable, there’s an economy of scale as far as users joining on.”