{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:46:53Z","timestamp":1760233613713,"version":"build-2065373602"},"reference-count":59,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,2,1]],"date-time":"2021-02-01T00:00:00Z","timestamp":1612137600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004406","name":"Universitatea Transilvania din Brasov","doi-asserted-by":"publisher","award":["8034\/14.07.2017 (DRONSAT)"],"award-info":[{"award-number":["8034\/14.07.2017 (DRONSAT)"]}],"id":[{"id":"10.13039\/501100004406","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006730","name":"Ministry of Education and Research, Romania","doi-asserted-by":"publisher","award":["PN 19070204"],"award-info":[{"award-number":["PN 19070204"]}],"id":[{"id":"10.13039\/501100006730","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Dynamics of habitat conditions drive important changes in distribution and abundance of animal species making monitoring an important but also a challenging task when data from the past are scarce. We compared the distribution of ant mounds in the 1960s with recent inventories (2018), looking at changes in canopy cover over time, in a managed forest. Both historical and recent sources of information were used. Habitat suitability at present was determined using a Normalized Difference Vegetation Index (NDVI) image as a proxy for stand canopy cover. The NDVI product was obtained using Google Earth Engine and Sentinel 2 repository. For past conditions (no spectral information available), presence of edges and more open canopies was assessed on a Corona spy-satellite image and based on information from old forest management plans. A threshold distance of 30 m was used to assess location of ant nests compared to favorable habitats. Both old and new information sources showed that ants prefer intermediate canopy cover conditions in their vicinity. Nests remained clustered because of the heterogeneous habitat conditions, but spatial distribution has changed due to canopy alteration along time. The analysis on the NDVI was effective for 82% of cases (i.e., nests occurred within 30 m from favorable habitats). For all the remaining nests (18%), the Google Earth high resolution satellite image revealed in their vicinity the presence of small canopy gaps (undetected by the NDVI). These results show that historical satellite images are very useful for explaining the long-term dynamics of ant colonies. In addition, the use of modern remote sensing techniques provides a reliable and expedite method in determining the presence of favorable small-scale habitat, offering a very useful tool for ecological monitoring across large landscapes and in very different areas, especially in the context of ecosystem dynamics driven and exacerbated by climate change.<\/jats:p>","DOI":"10.3390\/rs13030520","type":"journal-article","created":{"date-parts":[[2021,2,1]],"date-time":"2021-02-01T22:18:36Z","timestamp":1612217916000},"page":"520","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Ecological Monitoring with Spy Satellite Images\u2014The Case of Red Wood Ants in Romania"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9071-7141","authenticated-orcid":false,"given":"Dietrich","family":"Klimetzek","sequence":"first","affiliation":[{"name":"Department of Biometry and Environmental System Analysis, Faculty of Environment and Natural Resources, University of Freiburg, Tennenbacherstrasse 4, D-79085 Freiburg, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3293-7087","authenticated-orcid":false,"given":"Petru Tudor","family":"St\u0103ncioiu","sequence":"additional","affiliation":[{"name":"Faculty of Silviculture and Forest Engineering, Transilvania University of Bra\u015fov, \u0218irul Beethoven 1, Ro-500123 Bra\u015fov, Romania"}]},{"given":"Marius","family":"Paraschiv","sequence":"additional","affiliation":[{"name":"National Institute for Research and Development in Forestry, \u201cMarin Dr\u0103cea\u201d, Clo\u0219ca Street 13, Ro-500040 Bra\u015fov, Romania"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6072-7784","authenticated-orcid":false,"given":"Mihai Daniel","family":"Ni\u021b\u0103","sequence":"additional","affiliation":[{"name":"Faculty of Silviculture and Forest Engineering, Transilvania University of Bra\u015fov, \u0218irul Beethoven 1, Ro-500123 Bra\u015fov, Romania"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1016\/j.ecolmodel.2016.05.009","article-title":"Habitat degradation and loss as key drivers of regional population extinction","volume":"335","author":"Heinrichs","year":"2016","journal-title":"Ecol. 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