Evaluating Restoration Outcomes from Above

By Abby Smith on April 21, 2020

According to a report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), more than 75 percent of Earth’s land areas are substantially degraded. Riparian ecosystems in particular are an extremely important component of healthy watersheds and ecological function, providing wildlife habitat and facilitating water regulation. Recognizing the critical role that healthy riparian ecosystems play and the accelerating pace of degradation, many organizations are working to implement restoration projects to protect these valuable landscapes that underpin earth’s life support system.

Tidmarsh Farms Wildlife Sanctuary
Tidmarsh Farms Wildlife Sanctuary
Photo by Cyndi Jackson at Tidmarsh Farms Wildlife Sanctuary

Like the blue dot on Google Maps that shows your current location and tracks your progress in a trip, ecological metrics enable stakeholders to get their bearings on how an ecosystem is faring, and evaluate the effect of restoration actions over time. Insight into best practices and metrics for quantifying restoration success is necessary to inform future actions and mobilize financing opportunities to facilitate this important work.

Methods to evaluate the success of restoration work may take different forms, but in-person field visits are often the primary mode of data collection. Experts may track changes in species populations, for example, hoping to see a resurgence in certain native plants or keystone animal species. But for restoration projects that span large areas or long-term monitoring, this can be very expensive and time-consuming. Innovations in satellite technology offer a promising solution to capture consistent data at large scales and over the course of many seasons or years, without requiring field staff to manually traverse large areas to understand on-the-ground conditions.

Satellites enable us to pull back the curtains by comparing sites pre- and post-restoration and visualize landscape conditions in a few different ways. For example, remote sensing data on vegetation and water provide insight into landscape conditions and how they have changed over time. With this information, stakeholders can glean insights into the success of restoration work across large areas and with high frequency, thereby complementing field visits. Below we highlight two examples of organizations Upstream Tech is working with to leverage satellite data analysis for restoration monitoring and evaluation.

Improving Meadow Groundwater Retention Capacity

Over the last five years, the National Forest Foundation conducted extensive meadow and forest restoration across New Mexico and Arizona. Restoration efforts were targeted to increase the alpine meadows’ ability to retain groundwater through changes to the land and stream channels that slowed water and spread it over the meadow. Meadows which do not retain water cause vegetation to become drier and less green, while those which are able to retain water can support healthy plant life. So we used satellites to analyze whether there was an increase in vegetation intensity following restoration, and the length of time vegetation health was maintained following precipitation.

Vegetation vigor satellite image
Vegetation vigor satellite image
Three NFF meadow restoration sites are shown above. Darker green colors indicate higher photosynthetic activity and yellow or orange represents lower vegetation vigor.

Information on vegetation health, or photosynthetic activity, was captured through Normalized Difference Vegetation Index (NDVI) satellite data, is one key indicator of how the meadow health has changed over time. By lining up this data with historic drought information, our analysis found that vegetation in the restored meadow proved more resilient, even in the midst of droughts, than pre-restoration. Using vegetation health as a proxy for the meadow’s groundwater retention capacity, we were able to objectively quantify the ecological returns yielded by restoration work and communicate groundwater replenishment outcomes to stakeholders or funders.

Vegetation vigor graph illustrating restoration
Vegetation vigor graph illustrating restoration
The graph above shows vegetation on the y-axis, and time on the x-axis. Two restored meadows (shown as red and blue lines here) were restored in the early 2000s, and both sites show an increase in vegetation vigor in the years following restoration, which has been sustained for the last decade.

Restoring Cranberry Bogs to Wetlands

Living Observatory is an organization working to advance scientific knowledge and understanding of wetland ecology, using a former cranberry bog to evaluate best practices for stream and wetland restoration. As the cranberry farming industry transitions, there are numerous cranberry bogs across Massachusetts which are ripe for restoration to functioning wetlands. However, more research is needed to understand restoration outcomes and time horizons to inform future projects. To this end, Upstream Tech has been working closely with Living Observatory to synthesize a wealth of field data collected and remotely sensed information and analyze restoration outcomes.

To understand how restoration actions are impacting wetland health, Living Observatory is using Lens™ to monitor three wetland areas, in collaboration with researchers collecting field data. Each restoration project - Coonamessett, Tidmarsh, and Eel River - was conducted at different time periods, enabling researchers to understand how each site performs post-restoration over different time horizons. Historic imagery from before restoration work was performed is used to set a baseline for evaluation, and recent satellite data provides an up-to-date picture of wetland conditions.

In particular, high-resolution imagery provides visual indicators of ground conditions, and the water layer (derived from the Normalized Difference Water Index) gives insight into changes in hydrologic regimes. For example, higher levels of standing water on the restoration sites is a key indicator of success, and stakeholders can easily compare water presence between different time steps. Additionally, the ability to visualize data for the three sites in a web-based dashboard has enabled researchers to easily collaborate, as well as other technical and non-technical stakeholders to visualize changes over time to understand restoration outcomes.

Comparing imagery before and after cranberry bog restoration High-resolution imagery of a cranberry bog restoration site comparing before and after wetland restoration

The examples above illustrate the value of satellites and how they can aid organizations in capturing frequent and comprehensive data about restoration project outcomes. As these projects highlight, we have analyzed restoration outcomes in a range of ecosystems, including meadows, mine lands, wetlands, forests, and coasts, as described in our Monitoring financial returns for resilient coasts blog.

Restoring ecosystems spans many years, and the benefits of such work are often only visible on these longer time-horizons. Often limited by resources, capacity, and staff time, organizations may find it difficult to capture reliable and up-to-date information in a scalable way. With efficient, accessible, and cost-effective monitoring tools such as Lens, changes in riparian ecosystems can be tracked more easily than ever before. These insights can complement field visits and enable outcomes monitoring to inform future restoration efforts and help mobilize investments needed to rehabilitate degraded ecosystems.