Open-Earth-Monitor Science Webinar – May 8th 2025

The case of forest monitoring using vegetation vigour evolution over phenological cycles

By Codrina Maria Ilie
Terrasigna

The opportunity provided by the Earth Observation programs to monitor forests across the globe has been taken very seriously by researchers, not-for-profit organisations, governments, as well as private companies in the last 7 decades and, as a result, the panoply of related EO based products and services has improved constantly and significantly. Given their prevalence, within the OpenEarthMonitor the team, in collaboration with the stakeholders, researched potential improvements that could be brought to the existing portfolio. In this context, we have defined a new, interesting and useful addition to the already known EO-based products for forest monitoring: the forest vegetation vigour.

The vegetation vigour (VV) product is a custom type of pixel-based index that characterises the vegetation during long periods of time, preferably during a complete phenological cycle, based on NDVI values. The product does not represent a snapshot of the vegetation, but it characterises its cumulative state over time. For each pixel, the VV is proportionally higher as the NDVI values are higher, over the entire analysed period. Thus, the VV can be used to qualitatively compare regions of classes of vegetation, over multiple phenological cycles. 

Six sample regions have been chosen to address different forestry ecoregions, including shrubs to test the hypothesis that the new algorithm can be successfully used in regions with highly diverse types of vegetation.  Also, there is high emphasis on the qualitative nature of the generated product and thus the requirement for a technical specialist to determine the thresholds with respect to the events identified within the product. 

The data is available on zenodo.org, DOI: 10.5281/zenodo.14712961.

In this talk, the authors will showcase the utility of the vegetation vigour EO-based product, as well as its limitations.

Beyond the Canopy: Seeing the Forest from the Trees with UAV and Terrestrial Mobile LiDAR

By Mihai Daniel Nita 1,2

1 Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Faculty of Silviculture and Forest Engineering, at Transilvania University of Brașov, Romania

2SC Forest Design SRL

Complex forest ecosystems, particularly those with multilayered canopies and dense understories, present persistent challenges for accurate and complete geo-spatial data collection. This presentation investigates how UAV-mounted LiDAR systems and terrestrial mobile LiDAR scanners can be combined to effectively penetrate forest canopies and map what lies beneath—enabling a comprehensive understanding of forest structure from canopy top to forest floor. Focusing on a case study from Carpathian Mountains, Romania, we present an integrated workflow that couples aerial LiDAR for upper-canopy characterization with mobile ground-based scanning for detailed reconstruction of tree stems, understory vegetation, and microtopography.

To bridge scales and extend insights beyond plot-level data, we integrate these terrestrial and UAV-derived point clouds with satellite-derived products, including canopy height models and forest cover maps from missions such as GEDI and Sentinel. This multi-source data fusion not only enhances vertical profiling of forests but also serves as a foundational layer for building and updating forest digital twins. We explore whether digital twinning in forestry is merely conceptual or already a practical reality—highlighting automated data processing workflows, calibration between sensor types, and implications for biomass estimation and ecosystem monitoring. The talk concludes with perspectives on scaling these approaches for regional forest assessments and supporting sustainable management under climate change scenarios.

Do not miss the upcoming OEMC science webinar, on Thursday, June 5th, from 2 to 3 PM (CET)! Register here. 

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