Photogrammetry as a tool to improve ecosystem restoration

Abstract

Ecosystem restoration has been practiced for over a century and is increasingly supported by the emergent applied science of restoration ecology. A prerequisite for successful ecosystem restoration is determining meaningful and measurable goals. This requires tools to monitor success in a standardized way. Photogrammetry uses images to reconstruct landscapes and organisms in three dimensions, enabling non-invasive measurement of key success indicators with unprecedented accuracy. We propose photogrammetry can improve restoration success by: (i) facilitating measurable goals; (ii) innovating and standardizing indicators of success; and (iii) standardizing monitoring. While the case we present is specific to coral reefs, photogrammetry has enormous potential to improve restoration practice in a wide range of ecosystems. The need for ecosystem restoration in the AnthropoceneEarth's ecosystems are highly degraded, and as we enter the Anthropocene their health will likely diminish further without concerted and innovative conservation efforts. There is growing recognition that ecosystems which are subject to novel and large-scale disturbances require active management interventions, such as ecosystem restoration. Thus, the United Nations (2019) has declared 2021-2030 as the 'Decade of Ecosystem Restoration' [United Nations Environment Agency (2019) Resolution 73/284: United Nations Decade on Ecosystem Restoration (2021-2030) (https://undocs.org/A/RES/73/284)]. For restoration to be successful, research is needed to answer how, when, and where to implement restoration interventions. The practice of ecosystem restoration is underpinned by the science of restoration ecology [1], and both will play an increasingly important role in ecosystem and biodiversity management in the Anthropocene.

Measuring habitat complexity and spatial heterogeneity in ecology

“…With the rise in remote sensing technologies (Section ‘ On the rise of remote‐sensing technologies in ecology ’), the idea of translating some metric of habitat complexity (e.g. obtained from scanning diverse or pristine natural environments) into real‐world solutions is tantalising (Calders et al, 2020 ; Ferrari et al, 2021 ). These solutions range from replanting or introducing trees and habitat‐forming species to adding physical elements to manipulate habitat structure in both natural and urban environments (Morris et al, 2019 ; Palmer et al, 2010 ).…”

“…Complexity metrics are also being used as success indicators for restoration programs. It has been suggested that techniques such as photogrammetry will improve restoration success by enabling the measurement of complexity with ‘unprecedented accuracy’ (Ferrari et al, 2021 ). Again, this premise is built on the assumption that we already have reliable, accurate metrics of complexity; but, unfortunately, we do not.…”

Mushroom to manoeuvre? Using photogrammetry to track the movement and survival of free-living corals

“…0.25 m 2 quadrats (Ohara et al 2021), with a restricted range of metrics collected. However, the development of underwater imaging tools such as 'structure from motion' (SfM) photogrammetry now enables researchers to track millimetre-scale changes in reef environments over large areas (> ~ 500 m 2 ) within a single dive (Bayley and Mogg 2020;Ferrari et al 2021). Survey locations can then be repeatedly returned to once marked, using photogrammetry to track various changes at the frequency of choice-be it days or years (Magel et al 2019;Bongaerts et al 2020;Cresswell et al 2020).…”

A fast, precise, in‐vivo method for micron‐level 3D models of corals using dental scanners

“…Traditionally, 3D growth forms in corals have been measured, including destructive computed tomography (CT; Foster et al, 2016) or non‐destructive ‘structure from motion’ (SfM; Friedman et al, 2012; Young et al, 2017). This latter work has included 3D reconstruction of individual colonies that are precise to the mm range (Ferrari et al, 2021; Lange & Perry, 2020; Million et al, 2021) or 3D scanning of the benthos over large areas (e.g. the ReefCloud program), including field photogrammetry of reefscapes.…”