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118 results on '"Eklundh, L"'

1. First assessment of the plant phenology index (PPI) for estimating gross primary productivity in African semi-arid ecosystems

Author

Abdi, A. M., Boke-Olen, N., Jin, H., Eklundh, L., Tagesson, T., Lehsten, V., and Ardo, J.

Subjects
Quantitative Biology - Populations and Evolution
Abstract

The importance of semi-arid ecosystems in the global carbon cycle as sinks for CO2 emissions has recently been highlighted. Africa is a carbon sink and nearly half its area comprises arid and semi-arid ecosystems. However, there are uncertainties regarding CO2 fluxes for semi-arid ecosystems in Africa, particularly savannas and dry tropical woodlands. In order to improve on existing remote-sensing based methods for estimating carbon uptake across semi-arid Africa we applied and tested the recently developed plant phenology index (PPI). We developed a PPI-based model estimating gross primary productivity (GPP) that accounts for canopy water stress, and compared it against three other Earth observation-based GPP models: the temperature and greenness model, the greenness and radiation model and a light use efficiency model. The models were evaluated against in situ data from four semi-arid sites in Africa with varying tree canopy cover (3 to 65 percent). Evaluation results from the four GPP models showed reasonable agreement with in situ GPP measured from eddy covariance flux towers (EC GPP) based on coefficient of variation, root-mean-square error, and Bayesian information criterion. The PPI-based GPP model was able to capture the magnitude of EC GPP better than the other tested models. The results of this study show that a PPI-based GPP model is a promising tool for the estimation of GPP in the semi-arid ecosystems of Africa., Comment: Accepted manuscript; 12 pages, 4 tables, 9 figures

Published
2019

3. Response and resilience to drought in northern forests revealed by Sentinel-2.

Author

Müller, M., Olsson, P.-O., Eklundh, L., Jamali, S., and Ardö, J.

Subjects
DROUGHT management, FOREST resilience, VEGETATION monitoring, FOREST management, FOREST reserves, TAIGAS, DROUGHTS
Abstract

Enhancing forest drought resilience is important for preserving ecosystem services in the face of climate change, but operational management methods for boreal forests aiming to preserve ecosystem services under drought are still largely missing. This study explores the use of satellite remote sensing to monitor vegetation stress phases related to drought progression and to quantify both short- and long-term impacts on forest growth. Data from the Sentinel-2 satellite mission were used to calculate the response of vegetation indices across six forest types, using the time period from 2015 to 2017 as a reference dataset. The percentual difference between the drought year of 2018 and the reference period was used to represent disturbance intensity and the system's capability to resist it. Additionally, the recovery time was taken into consideration. Breakpoint detection with daily temporal resolution was used to quantify the response time of each forest type in relation to the onset date of meteorological drought. Results indicate that Sentinel-2 data can be used to monitor vegetation stress associated with drought progression and estimate the characteristics of forest resilience. High temporal resolution observations should be prioritized over annual maximum vegetation index values to determine the intensity of disturbance. Consistent severe impacts were observed in areas with limited soil moisture availability. The recovery time of forests took up to 4 years. Drought exposure during consecutive years could be especially damaging for species requiring a longer recovery time than a single growing season. Sentinel-2-based monitoring approach could benefit decision-support systems for forest management aiming to enhance drought resilience. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Global maps of soil temperature

Author

Lembrechts, J. J. (Jonas J.), van den Hoogen, J. (Johan), Aalto, J. (Juha), Ashcroft, M. B. (Michael B.), De Frenne, P. (Pieter), Kemppinen, J. (Julia), Kopecky, M. (Martin), Luoto, M. (Miska), Maclean, I. M. (Ilya M. D.), Crowther, T. W. (Thomas W.), Bailey, J. J. (Joseph J.), Haesen, S. (Stef), Klinges, D. H. (David H.), Niittynen, P. (Pekka), Scheffers, B. R. (Brett R.), Van Meerbeek, K. (Koenraad), Aartsma, P. (Peter), Abdalaze, O. (Otar), Abedi, M. (Mehdi), Aerts, R. (Rien), Ahmadian, N. (Negar), Ahrends, A. (Antje), Alatalo, J. M. (Juha M.), Alexander, J. M. (Jake M.), Allonsius, C. N. (Camille Nina), Altman, J. (Jan), Ammann, C. (Christof), Andres, C. (Christian), Andrews, C. (Christopher), Ardo, J. (Jonas), Arriga, N. (Nicola), Arzac, A. (Alberto), Aschero, V. (Valeria), Assis, R. L. (Rafael L.), Assmann, J. J. (Jakob Johann), Bader, M. Y. (Maaike Y.), Bahalkeh, K. (Khadijeh), Barancok, P. (Peter), Barrio, I. C. (Isabel C.), Barros, A. (Agustina), Barthel, M. (Matti), Basham, E. W. (Edmund W.), Bauters, M. (Marijn), Bazzichetto, M. (Manuele), Marchesini, L. B. (Luca Belelli), Bell, M. C. (Michael C.), Benavides, J. C. (Juan C.), Benito Alonso, J. L. (Jose Luis), Berauer, B. J. (Bernd J.), Bjerke, J. W. (Jarle W.), Bjork, R. G. (Robert G.), Bjorkman, M. P. (Mats P.), Bjornsdottir, K. (Katrin), Blonder, B. (Benjamin), Boeckx, P. (Pascal), Boike, J. (Julia), Bokhorst, S. (Stef), Brum, B. N. (Barbara N. S.), Bruna, J. (Josef), Buchmann, N. (Nina), Buysse, P. (Pauline), Camargo, J. L. (Jose Luis), Campoe, O. C. (Otavio C.), Candan, O. (Onur), Canessa, R. (Rafaella), Cannone, N. (Nicoletta), Carbognani, M. (Michele), Carnicer, J. (Jofre), Casanova-Katny, A. (Angelica), Cesarz, S. (Simone), Chojnicki, B. (Bogdan), Choler, P. (Philippe), Chown, S. L. (Steven L.), Cifuentes, E. F. (Edgar F.), Ciliak, M. (Marek), Contador, T. (Tamara), Convey, P. (Peter), Cooper, E. J. (Elisabeth J.), Cremonese, E. (Edoardo), Curasi, S. R. (Salvatore R.), Curtis, R. (Robin), Cutini, M. (Maurizio), Dahlberg, C. J. (C. Johan), Daskalova, G. N. (Gergana N.), Angel de Pablo, M. (Miguel), Della Chiesa, S. (Stefano), Dengler, J. (Juergen), Deronde, B. (Bart), Descombes, P. (Patrice), Di Cecco, V. (Valter), Di Musciano, M. (Michele), Dick, J. (Jan), Dimarco, R. D. (Romina D.), Dolezal, J. (Jiri), Dorrepaal, E. (Ellen), Dusek, J. (Jiri), Eisenhauer, N. (Nico), Eklundh, L. (Lars), Erickson, T. E. (Todd E.), Erschbamer, B. (Brigitta), Eugster, W. (Werner), Ewers, R. M. (Robert M.), Exton, D. A. (Dan A.), Fanin, N. (Nicolas), Fazlioglu, F. (Fatih), Feigenwinter, I. (Iris), Fenu, G. (Giuseppe), Ferlian, O. (Olga), Fernandez Calzado, M. R. (M. Rosa), Fernandez-Pascual, E. (Eduardo), Finckh, M. (Manfred), Higgens, R. F. (Rebecca Finger), Forte, T. G. (T'ai G. W.), Freeman, E. C. (Erika C.), Frei, E. R. (Esther R.), Fuentes-Lillo, E. (Eduardo), Garcia, R. A. (Rafael A.), Garcia, M. B. (Maria B.), Geron, C. (Charly), Gharun, M. (Mana), Ghosn, D. (Dany), Gigauri, K. (Khatuna), Gobin, A. (Anne), Goded, I. (Ignacio), Goeckede, M. (Mathias), Gottschall, F. (Felix), Goulding, K. (Keith), Govaert, S. (Sanne), Graae, B. J. (Bente Jessen), Greenwood, S. (Sarah), Greiser, C. (Caroline), Grelle, A. (Achim), Guenard, B. (Benoit), Guglielmin, M. (Mauro), Guillemot, J. (Joannes), Haase, P. (Peter), Haider, S. (Sylvia), Halbritter, A. H. (Aud H.), Hamid, M. (Maroof), Hammerle, A. (Albin), Hampe, A. (Arndt), Haugum, S. V. (Siri, V), Hederova, L. (Lucia), Heinesch, B. (Bernard), Helfter, C. (Carole), Hepenstrick, D. (Daniel), Herberich, M. (Maximiliane), Herbst, M. (Mathias), Hermanutz, L. (Luise), Hik, D. S. (David S.), Hoffren, R. (Raul), Homeier, J. (Juergen), Hörtnagl, L. (Lukas), Hoye, T. T. (Toke T.), Hrbacek, F. (Filip), Hylander, K. (Kristoffer), Iwata, H. (Hiroki), Jackowicz-Korczynski, M. A. (Marcin Antoni), Jactel, H. (Herve), Jarveoja, J. (Jarvi), Jastrzebowski, S. (Szymon), Jentsch, A. (Anke), Jimenez, J. J. (Juan J.), Jonsdottir, I. S. (Ingibjorg S.), Jucker, T. (Tommaso), Jump, A. S. (Alistair S.), Juszczak, R. (Radoslaw), Kanka, R. (Robert), Kaspar, V. (Vit), Kazakis, G. (George), Kelly, J. (Julia), Khuroo, A. A. (Anzar A.), Klemedtsson, L. (Leif), Klisz, M. (Marcin), Kljun, N. (Natascha), Knohl, A. (Alexander), Kobler, J. (Johannes), Kollar, J. (Jozef), Kotowska, M. M. (Martyna M.), Kovacs, B. (Bence), Kreyling, J. (Juergen), Lamprecht, A. (Andrea), Lang, S. I. (Simone, I), Larson, C. (Christian), Larson, K. (Keith), Laska, K. (Kamil), Maire, G. I. (Guerric Ie), Leihy, R. I. (Rachel, I), Lens, L. (Luc), Liljebladh, B. (Bengt), Lohila, A. (Annalea), Lorite, J. (Juan), Loubet, B. (Benjamin), Lynn, J. (Joshua), Macek, M. (Martin), Mackenzie, R. (Roy), Magliulo, E. (Enzo), Maier, R. (Regine), Malfasi, F. (Francesco), Malis, F. (Frantisek), Man, M. (Matej), Manca, G. (Giovanni), Manco, A. (Antonio), Manise, T. (Tanguy), Manolaki, P. (Paraskevi), Marciniak, F. (Felipe), Matula, R. (Radim), Clara Mazzolari, A. (Ana), Medinets, S. (Sergiy), Medinets, V. (Volodymyr), Meeussen, C. (Camille), Merinero, S. (Sonia), Guimaraes Mesquita, R. d. (Rita de Cassia), Meusburger, K. (Katrin), Meysman, F. J. (Filip J. R.), Michaletz, S. T. (Sean T.), Milbau, A. (Ann), Moiseev, D. (Dmitry), Moiseev, P. (Pavel), Mondoni, A. (Andrea), Monfries, R. (Ruth), Montagnani, L. (Leonardo), Moriana-Armendariz, M. (Mikel), di Cella, U. M. (Umberto Morra), Moersdorf, M. (Martin), Mosedale, J. R. (Jonathan R.), Muffler, L. (Lena), Munoz-Rojas, M. (Miriam), Myers, J. A. (Jonathan A.), Myers-Smith, I. H. (Isla H.), Nagy, L. (Laszlo), Nardino, M. (Marianna), Naujokaitis-Lewis, I. (Ilona), Newling, E. (Emily), Nicklas, L. (Lena), Niedrist, G. (Georg), Niessner, A. (Armin), Nilsson, M. B. (Mats B.), Normand, S. (Signe), Nosetto, M. D. (Marcelo D.), Nouvellon, Y. (Yann), Nunez, M. A. (Martin A.), Ogaya, R. (Roma), Ogee, J. (Jerome), Okello, J. (Joseph), Olejnik, J. (Janusz), Olesen, J. E. (Jorgen Eivind), Opedal, O. H. (Oystein H.), Orsenigo, S. (Simone), Palaj, A. (Andrej), Pampuch, T. (Timo), Panov, A. V. (Alexey V.), Pärtel, M. (Meelis), Pastor, A. (Ada), Pauchard, A. (Aníbal), Pauli, H. (Harald), Pavelka, M. (Marian), Pearse, W. D. (William D.), Peichl, M. (Matthias), Pellissier, L. (Loïc), Penczykowski, R. M. (Rachel M.), Penuelas, J. (Josep), Petit Bon, M. (Matteo), Petraglia, A. (Alessandro), Phartyal, S. S. (Shyam S.), Phoenix, G. K. (Gareth K.), Pio, C. (Casimiro), Pitacco, A. (Andrea), Pitteloud, C. (Camille), Plichta, R. (Roman), Porro, F. (Francesco), Portillo-Estrada, M. (Miguel), Poulenard, J. (Jérôme), Poyatos, R. (Rafael), Prokushkin, A. S. (Anatoly S.), Puchalka, R. (Radoslaw), Pușcaș, M. (Mihai), Radujković, D. (Dajana), Randall, K. (Krystal), Ratier Backes, A. (Amanda), Remmele, S. (Sabine), Remmers, W. (Wolfram), Renault, D. (David), Risch, A. C. (Anita C.), Rixen, C. (Christian), Robinson, S. A. (Sharon A.), Robroek, B. J. (Bjorn J. M.), Rocha, A. V. (Adrian V.), Rossi, C. (Christian), Rossi, G. (Graziano), Roupsard, O. (Olivier), Rubtsov, A. V. (Alexey V.), Saccone, P. (Patrick), Sagot, C. (Clotilde), Sallo Bravo, J. (Jhonatan), Santos, C. C. (Cinthya C.), Sarneel, J. M. (Judith M.), Scharnweber, T. (Tobias), Schmeddes, J. (Jonas), Schmidt, M. (Marius), Scholten, T. (Thomas), Schuchardt, M. (Max), Schwartz, N. (Naomi), Scott, T. (Tony), Seeber, J. (Julia), Segalin De Andrade, A. C. (Ana Cristina), Seipel, T. (Tim), Semenchuk, P. (Philipp), Senior, R. A. (Rebecca A.), Serra-Diaz, J. M. (Josep M.), Sewerniak, P. (Piotr), Shekhar, A. (Ankit), Sidenko, N. V. (Nikita V.), Siebicke, L. (Lukas), Siegwart Collier, L. (Laura), Simpson, E. (Elizabeth), Siqueira, D. P. (David P.), Sitková, Z. (Zuzana), Six, J. (Johan), Smiljanic, M. (Marko), Smith, S. W. (Stuart W.), Smith-Tripp, S. (Sarah), Somers, B. (Ben), Sørensen, M. V. (Mia Vedel), Souza, J. J. (José João L. L.), Souza, B. I. (Bartolomeu Israel), Dias, A. S. (Arildo Souza), Spasojevic, M. J. (Marko J.), Speed, J. D. (James D. M.), Spicher, F. (Fabien), Stanisci, A. (Angela), Steinbauer, K. (Klaus), Steinbrecher, R. (Rainer), Steinwandter, M. (Michael), Stemkovski, M. (Michael), Stephan, J. G. (Jörg G.), Stiegler, C. (Christian), Stoll, S. (Stefan), Svátek, M. (Martin), Svoboda, M. (Miroslav), Tagesson, T. (Torbern), Tanentzap, A. J. (Andrew J.), Tanneberger, F. (Franziska), Theurillat, J.-P. (Jean-Paul), Thomas, H. J. (Haydn J. D.), Thomas, A. D. (Andrew D.), Tielbörger, K. (Katja), Tomaselli, M. (Marcello), Treier, U. A. (Urs Albert), Trouillier, M. (Mario), Turtureanu, P. D. (Pavel Dan), Tutton, R. (Rosamond), Tyystjärvi, V. A. (Vilna A.), Ueyama, M. (Masahito), Ujházy, K. (Karol), Ujházyová, M. (Mariana), Uogintas, D. (Domas), Urban, A. V. (Anastasiya V.), Urban, J. (Josef), Urbaniak, M. (Marek), Ursu, T.-M. (Tudor-Mihai), Vaccari, F. P. (Francesco Primo), Van De Vondel, S. (Stijn), Van Den Brink, L. (Liesbeth), Van Geel, M. (Maarten), Vandvik, V. (Vigdis), Vangansbeke, P. (Pieter), Varlagin, A. (Andrej), Veen, G. F. (G. F.), Veenendaal, E. (Elmar), Venn, S. E. (Susanna E.), Verbeeck, H. (Hans), Verbrugggen, E. (Erik), Verheijen, F. G. (Frank G. A.), Villar, L. (Luis), Vitale, L. (Luca), Vittoz, P. (Pascal), Vives-Ingla, M. (Maria), Von Oppen, J. (Jonathan), Walz, J. (Josefine), Wang, R. (Runxi), Wang, Y. (Yifeng), Way, R. G. (Robert G.), Wedegärtner, R. E. (Ronja E. M.), Weigel, R. (Robert), Wild, J. (Jan), Wilkinson, M. (Matthew), Wilmking, M. (Martin), Wingate, L. (Lisa), Winkler, M. (Manuela), Wipf, S. (Sonja), Wohlfahrt, G. (Georg), Xenakis, G. (Georgios), Yang, Y. (Yan), Yu, Z. (Zicheng), Yu, K. (Kailiang), Zellweger, F. (Florian), Zhang, J. (Jian), Zhang, Z. (Zhaochen), Zhao, P. (Peng), Ziemblińska, K. (Klaudia), Zimmermann, R. (Reiner), Zong, S. (Shengwei), Zyryanov, V. I. (Viacheslav I.), Nijs, I. (Ivan), Lenoir, J. (Jonathan), Lembrechts, J. J. (Jonas J.), van den Hoogen, J. (Johan), Aalto, J. (Juha), Ashcroft, M. B. (Michael B.), De Frenne, P. (Pieter), Kemppinen, J. (Julia), Kopecky, M. (Martin), Luoto, M. (Miska), Maclean, I. M. (Ilya M. D.), Crowther, T. W. (Thomas W.), Bailey, J. J. (Joseph J.), Haesen, S. (Stef), Klinges, D. H. (David H.), Niittynen, P. (Pekka), Scheffers, B. R. (Brett R.), Van Meerbeek, K. (Koenraad), Aartsma, P. (Peter), Abdalaze, O. (Otar), Abedi, M. (Mehdi), Aerts, R. (Rien), Ahmadian, N. (Negar), Ahrends, A. (Antje), Alatalo, J. M. (Juha M.), Alexander, J. M. (Jake M.), Allonsius, C. N. (Camille Nina), Altman, J. (Jan), Ammann, C. (Christof), Andres, C. (Christian), Andrews, C. (Christopher), Ardo, J. (Jonas), Arriga, N. (Nicola), Arzac, A. (Alberto), Aschero, V. (Valeria), Assis, R. L. (Rafael L.), Assmann, J. J. (Jakob Johann), Bader, M. Y. (Maaike Y.), Bahalkeh, K. (Khadijeh), Barancok, P. (Peter), Barrio, I. C. (Isabel C.), Barros, A. (Agustina), Barthel, M. (Matti), Basham, E. W. (Edmund W.), Bauters, M. (Marijn), Bazzichetto, M. (Manuele), Marchesini, L. B. (Luca Belelli), Bell, M. C. (Michael C.), Benavides, J. C. (Juan C.), Benito Alonso, J. L. (Jose Luis), Berauer, B. J. (Bernd J.), Bjerke, J. W. (Jarle W.), Bjork, R. G. (Robert G.), Bjorkman, M. P. (Mats P.), Bjornsdottir, K. (Katrin), Blonder, B. (Benjamin), Boeckx, P. (Pascal), Boike, J. (Julia), Bokhorst, S. (Stef), Brum, B. N. (Barbara N. S.), Bruna, J. (Josef), Buchmann, N. (Nina), Buysse, P. (Pauline), Camargo, J. L. (Jose Luis), Campoe, O. C. (Otavio C.), Candan, O. (Onur), Canessa, R. (Rafaella), Cannone, N. (Nicoletta), Carbognani, M. (Michele), Carnicer, J. (Jofre), Casanova-Katny, A. (Angelica), Cesarz, S. (Simone), Chojnicki, B. (Bogdan), Choler, P. (Philippe), Chown, S. L. (Steven L.), Cifuentes, E. F. (Edgar F.), Ciliak, M. (Marek), Contador, T. (Tamara), Convey, P. (Peter), Cooper, E. J. (Elisabeth J.), Cremonese, E. (Edoardo), Curasi, S. R. (Salvatore R.), Curtis, R. (Robin), Cutini, M. (Maurizio), Dahlberg, C. J. (C. Johan), Daskalova, G. N. (Gergana N.), Angel de Pablo, M. (Miguel), Della Chiesa, S. (Stefano), Dengler, J. (Juergen), Deronde, B. (Bart), Descombes, P. (Patrice), Di Cecco, V. (Valter), Di Musciano, M. (Michele), Dick, J. (Jan), Dimarco, R. D. (Romina D.), Dolezal, J. (Jiri), Dorrepaal, E. (Ellen), Dusek, J. (Jiri), Eisenhauer, N. (Nico), Eklundh, L. (Lars), Erickson, T. E. (Todd E.), Erschbamer, B. (Brigitta), Eugster, W. (Werner), Ewers, R. M. (Robert M.), Exton, D. A. (Dan A.), Fanin, N. (Nicolas), Fazlioglu, F. (Fatih), Feigenwinter, I. (Iris), Fenu, G. (Giuseppe), Ferlian, O. (Olga), Fernandez Calzado, M. R. (M. Rosa), Fernandez-Pascual, E. (Eduardo), Finckh, M. (Manfred), Higgens, R. F. (Rebecca Finger), Forte, T. G. (T'ai G. W.), Freeman, E. C. (Erika C.), Frei, E. R. (Esther R.), Fuentes-Lillo, E. (Eduardo), Garcia, R. A. (Rafael A.), Garcia, M. B. (Maria B.), Geron, C. (Charly), Gharun, M. (Mana), Ghosn, D. (Dany), Gigauri, K. (Khatuna), Gobin, A. (Anne), Goded, I. (Ignacio), Goeckede, M. (Mathias), Gottschall, F. (Felix), Goulding, K. (Keith), Govaert, S. (Sanne), Graae, B. J. (Bente Jessen), Greenwood, S. (Sarah), Greiser, C. (Caroline), Grelle, A. (Achim), Guenard, B. (Benoit), Guglielmin, M. (Mauro), Guillemot, J. (Joannes), Haase, P. (Peter), Haider, S. (Sylvia), Halbritter, A. H. (Aud H.), Hamid, M. (Maroof), Hammerle, A. (Albin), Hampe, A. (Arndt), Haugum, S. V. (Siri, V), Hederova, L. (Lucia), Heinesch, B. (Bernard), Helfter, C. (Carole), Hepenstrick, D. (Daniel), Herberich, M. (Maximiliane), Herbst, M. (Mathias), Hermanutz, L. (Luise), Hik, D. S. (David S.), Hoffren, R. (Raul), Homeier, J. (Juergen), Hörtnagl, L. (Lukas), Hoye, T. T. (Toke T.), Hrbacek, F. (Filip), Hylander, K. (Kristoffer), Iwata, H. (Hiroki), Jackowicz-Korczynski, M. A. (Marcin Antoni), Jactel, H. (Herve), Jarveoja, J. (Jarvi), Jastrzebowski, S. (Szymon), Jentsch, A. (Anke), Jimenez, J. J. (Juan J.), Jonsdottir, I. S. (Ingibjorg S.), Jucker, T. (Tommaso), Jump, A. S. (Alistair S.), Juszczak, R. (Radoslaw), Kanka, R. (Robert), Kaspar, V. (Vit), Kazakis, G. (George), Kelly, J. (Julia), Khuroo, A. A. (Anzar A.), Klemedtsson, L. (Leif), Klisz, M. (Marcin), Kljun, N. (Natascha), Knohl, A. (Alexander), Kobler, J. (Johannes), Kollar, J. (Jozef), Kotowska, M. M. (Martyna M.), Kovacs, B. (Bence), Kreyling, J. (Juergen), Lamprecht, A. (Andrea), Lang, S. I. (Simone, I), Larson, C. (Christian), Larson, K. (Keith), Laska, K. (Kamil), Maire, G. I. (Guerric Ie), Leihy, R. I. (Rachel, I), Lens, L. (Luc), Liljebladh, B. (Bengt), Lohila, A. (Annalea), Lorite, J. (Juan), Loubet, B. (Benjamin), Lynn, J. (Joshua), Macek, M. (Martin), Mackenzie, R. (Roy), Magliulo, E. (Enzo), Maier, R. (Regine), Malfasi, F. (Francesco), Malis, F. (Frantisek), Man, M. (Matej), Manca, G. (Giovanni), Manco, A. (Antonio), Manise, T. (Tanguy), Manolaki, P. (Paraskevi), Marciniak, F. (Felipe), Matula, R. (Radim), Clara Mazzolari, A. (Ana), Medinets, S. (Sergiy), Medinets, V. (Volodymyr), Meeussen, C. (Camille), Merinero, S. (Sonia), Guimaraes Mesquita, R. d. (Rita de Cassia), Meusburger, K. (Katrin), Meysman, F. J. (Filip J. R.), Michaletz, S. T. (Sean T.), Milbau, A. (Ann), Moiseev, D. (Dmitry), Moiseev, P. (Pavel), Mondoni, A. (Andrea), Monfries, R. (Ruth), Montagnani, L. (Leonardo), Moriana-Armendariz, M. (Mikel), di Cella, U. M. (Umberto Morra), Moersdorf, M. (Martin), Mosedale, J. R. (Jonathan R.), Muffler, L. (Lena), Munoz-Rojas, M. (Miriam), Myers, J. A. (Jonathan A.), Myers-Smith, I. H. (Isla H.), Nagy, L. (Laszlo), Nardino, M. (Marianna), Naujokaitis-Lewis, I. (Ilona), Newling, E. (Emily), Nicklas, L. (Lena), Niedrist, G. (Georg), Niessner, A. (Armin), Nilsson, M. B. (Mats B.), Normand, S. (Signe), Nosetto, M. D. (Marcelo D.), Nouvellon, Y. (Yann), Nunez, M. A. (Martin A.), Ogaya, R. (Roma), Ogee, J. (Jerome), Okello, J. (Joseph), Olejnik, J. (Janusz), Olesen, J. E. (Jorgen Eivind), Opedal, O. H. (Oystein H.), Orsenigo, S. (Simone), Palaj, A. (Andrej), Pampuch, T. (Timo), Panov, A. V. (Alexey V.), Pärtel, M. (Meelis), Pastor, A. (Ada), Pauchard, A. (Aníbal), Pauli, H. (Harald), Pavelka, M. (Marian), Pearse, W. D. (William D.), Peichl, M. (Matthias), Pellissier, L. (Loïc), Penczykowski, R. M. (Rachel M.), Penuelas, J. (Josep), Petit Bon, M. (Matteo), Petraglia, A. (Alessandro), Phartyal, S. S. (Shyam S.), Phoenix, G. K. (Gareth K.), Pio, C. (Casimiro), Pitacco, A. (Andrea), Pitteloud, C. (Camille), Plichta, R. (Roman), Porro, F. (Francesco), Portillo-Estrada, M. (Miguel), Poulenard, J. (Jérôme), Poyatos, R. (Rafael), Prokushkin, A. S. (Anatoly S.), Puchalka, R. (Radoslaw), Pușcaș, M. (Mihai), Radujković, D. (Dajana), Randall, K. (Krystal), Ratier Backes, A. (Amanda), Remmele, S. (Sabine), Remmers, W. (Wolfram), Renault, D. (David), Risch, A. C. (Anita C.), Rixen, C. (Christian), Robinson, S. A. (Sharon A.), Robroek, B. J. (Bjorn J. M.), Rocha, A. V. (Adrian V.), Rossi, C. (Christian), Rossi, G. (Graziano), Roupsard, O. (Olivier), Rubtsov, A. V. (Alexey V.), Saccone, P. (Patrick), Sagot, C. (Clotilde), Sallo Bravo, J. (Jhonatan), Santos, C. C. (Cinthya C.), Sarneel, J. M. (Judith M.), Scharnweber, T. (Tobias), Schmeddes, J. (Jonas), Schmidt, M. (Marius), Scholten, T. (Thomas), Schuchardt, M. (Max), Schwartz, N. (Naomi), Scott, T. (Tony), Seeber, J. (Julia), Segalin De Andrade, A. C. (Ana Cristina), Seipel, T. (Tim), Semenchuk, P. (Philipp), Senior, R. A. (Rebecca A.), Serra-Diaz, J. M. (Josep M.), Sewerniak, P. (Piotr), Shekhar, A. (Ankit), Sidenko, N. V. (Nikita V.), Siebicke, L. (Lukas), Siegwart Collier, L. (Laura), Simpson, E. (Elizabeth), Siqueira, D. P. (David P.), Sitková, Z. (Zuzana), Six, J. (Johan), Smiljanic, M. (Marko), Smith, S. W. (Stuart W.), Smith-Tripp, S. (Sarah), Somers, B. (Ben), Sørensen, M. V. (Mia Vedel), Souza, J. J. (José João L. L.), Souza, B. I. (Bartolomeu Israel), Dias, A. S. (Arildo Souza), Spasojevic, M. J. (Marko J.), Speed, J. D. (James D. M.), Spicher, F. (Fabien), Stanisci, A. (Angela), Steinbauer, K. (Klaus), Steinbrecher, R. (Rainer), Steinwandter, M. (Michael), Stemkovski, M. (Michael), Stephan, J. G. (Jörg G.), Stiegler, C. (Christian), Stoll, S. (Stefan), Svátek, M. (Martin), Svoboda, M. (Miroslav), Tagesson, T. (Torbern), Tanentzap, A. J. (Andrew J.), Tanneberger, F. (Franziska), Theurillat, J.-P. (Jean-Paul), Thomas, H. J. (Haydn J. D.), Thomas, A. D. (Andrew D.), Tielbörger, K. (Katja), Tomaselli, M. (Marcello), Treier, U. A. (Urs Albert), Trouillier, M. (Mario), Turtureanu, P. D. (Pavel Dan), Tutton, R. (Rosamond), Tyystjärvi, V. A. (Vilna A.), Ueyama, M. (Masahito), Ujházy, K. (Karol), Ujházyová, M. (Mariana), Uogintas, D. (Domas), Urban, A. V. (Anastasiya V.), Urban, J. (Josef), Urbaniak, M. (Marek), Ursu, T.-M. (Tudor-Mihai), Vaccari, F. P. (Francesco Primo), Van De Vondel, S. (Stijn), Van Den Brink, L. (Liesbeth), Van Geel, M. (Maarten), Vandvik, V. (Vigdis), Vangansbeke, P. (Pieter), Varlagin, A. (Andrej), Veen, G. F. (G. F.), Veenendaal, E. (Elmar), Venn, S. E. (Susanna E.), Verbeeck, H. (Hans), Verbrugggen, E. (Erik), Verheijen, F. G. (Frank G. A.), Villar, L. (Luis), Vitale, L. (Luca), Vittoz, P. (Pascal), Vives-Ingla, M. (Maria), Von Oppen, J. (Jonathan), Walz, J. (Josefine), Wang, R. (Runxi), Wang, Y. (Yifeng), Way, R. G. (Robert G.), Wedegärtner, R. E. (Ronja E. M.), Weigel, R. (Robert), Wild, J. (Jan), Wilkinson, M. (Matthew), Wilmking, M. (Martin), Wingate, L. (Lisa), Winkler, M. (Manuela), Wipf, S. (Sonja), Wohlfahrt, G. (Georg), Xenakis, G. (Georgios), Yang, Y. (Yan), Yu, Z. (Zicheng), Yu, K. (Kailiang), Zellweger, F. (Florian), Zhang, J. (Jian), Zhang, Z. (Zhaochen), Zhao, P. (Peng), Ziemblińska, K. (Klaudia), Zimmermann, R. (Reiner), Zong, S. (Shengwei), Zyryanov, V. I. (Viacheslav I.), Nijs, I. (Ivan), and Lenoir, J. (Jonathan)

Abstract

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km² resolution for 0‐5 and 5‐15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1‐km² pixels (summarized from 8519 unique temperature sensors) across all the world’s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10° degrees C (mean = 3.0 +/‐ 2.1° degrees C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 +/‐2.3° degrees C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (‐0.7 +/‐ 2.3° degrees C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological

Published
2022

9. Increased Vegetation in Mountainous Headwaters Amplifies Water Stress During Dry Periods

Author

Vicente‐Serrano, S. M., primary, Domínguez‐Castro, F., additional, Murphy, C., additional, Peña‐Angulo, D., additional, Tomas‐Burguera, M., additional, Noguera, I., additional, López‐Moreno, J. I., additional, Juez, C., additional, Grainger, S., additional, Eklundh, L., additional, Conradt, T., additional, Azorin‐Molina, C., additional, and Kenawy, A., additional

Published
2021
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10. Global maps of soil temperature

Author

Lembrechts, JJ, van den Hoogen, J, Aalto, J, Ashcroft, MB, De Frenne, P, Kemppinen, J, Kopecký, M, Luoto, M, Maclean, IMD, Crowther, TW, Bailey, JJ, Haesen, S, Klinges, DH, Niittynen, P, Scheffers, BR, Van Meerbeek, K, Aartsma, P, Abdalaze, O, Abedi, M, Aerts, R, Ahmadian, N, Ahrends, A, Alatalo, JM, Alexander, JM, Nina Allonsius, C, Altman, J, Ammann, C, Andres, C, Andrews, C, Ardö, J, Arriga, N, Arzac, A, Aschero, V, Assis, RL, Johann Assmann, J, Bader, MY, Bahalkeh, K, Barančok, P, Barrio, IC, Barros, A, Barthel, M, Basham, EW, Bauters, M, Bazzichetto, M, Belelli Marchesini, L, Bell, MC, Benavides, JC, Luis Benito Alonso, J, Berauer, BJ, Bjerke, JW, Björk, RG, Björkman, MP, Björnsdóttir, K, Blonder, B, Boeckx, P, Boike, J, Bokhorst, S, Brum, BNS, Brůna, J, Buchmann, N, Buysse, P, Luís Camargo, J, Campoe, OC, Candan, O, Canessa, R, Cannone, N, Carbognani, M, Carnicer, J, Casanova‐Katny, A, Cesarz, S, Chojnicki, B, Choler, P, Chown, SL, Cifuentes, EF, Čiliak, M, Contador, T, Convey, P, Cooper, EJ, Cremonese, E, Curasi, SR, Curtis, R, Cutini, M, Johan Dahlberg, C, Daskalova, GN, Angel de Pablo, M, Della Chiesa, S, Dengler, J, Deronde, B, Descombes, P, Di Cecco, V, Di Musciano, M, Dick, J, Dimarco, RD, Dolezal, J, Dorrepaal, E, Dušek, J, Eisenhauer, N, Eklundh, L, Erickson, TE, Erschbamer, B, Eugster, W, Ewers, RM, Exton, DA, Fanin, N, Fazlioglu, F, Feigenwinter, I, Fenu, G, Ferlian, O, Rosa Fernández Calzado, M, Fernández‐Pascual, E, Finckh, M, Finger Higgens, R, Forte, TGW, Freeman, EC, Frei, ER, Fuentes‐Lillo, E, García, RA, García, MB, Géron, C, Gharun, M, Ghosn, D, Gigauri, K, Gobin, A, Goded, I, Goeckede, M, Gottschall, F, Goulding, K, Govaert, S, Jessen Graae, B, Greenwood, S, Greiser, C, Grelle, A, Guénard, B, Guglielmin, M, Guillemot, J, Haase, P, Haider, S, Halbritter, AH, Hamid, M, Hammerle, A, Hampe, A, Haugum, SV, Hederová, L, Heinesch, B, Helfter, C, Hepenstrick, D, Herberich, M, Herbst, M, Hermanutz, L, Hik, DS, Hoffrén, R, Homeier, J, Hörtnagl, L, Høye, TT, Hrbacek, F, Hylander, K, Iwata, H, Antoni Jackowicz‐Korczynski, M, Jactel, H, Järveoja, J, Jastrzębowski, S, Jentsch, A, Jiménez, JJ, Jónsdóttir, IS, Jucker, T, Jump, AS, Juszczak, R, Kanka, R, Kašpar, V, Kazakis, G, Kelly, J, Khuroo, AA, Klemedtsson, L, Klisz, M, Kljun, N, Knohl, A, Kobler, J, Kollár, J, Kotowska, MM, Kovács, B, Kreyling, J, Lamprecht, A, Lang, SI, Larson, C, Larson, K, Laska, K, le Maire, G, Leihy, RI, Lens, L, Liljebladh, B, Lohila, A, Lorite, J, Loubet, B, Lynn, J, Macek, M, Mackenzie, R, Magliulo, E, Maier, R, Malfasi, F, Máliš, F, Man, M, Manca, G, Manco, A, Manise, T, Manolaki, P, Marciniak, F, Matula, R, Clara Mazzolari, A, Medinets, S, Medinets, V, Meeussen, C, Merinero, S, de Cássia Guimarães Mesquita, R, Meusburger, K, Meysman, FJR, Michaletz, ST, Milbau, A, Moiseev, D, Moiseev, P, Mondoni, A, Monfries, R, Montagnani, L, Moriana‐Armendariz, M, Morra di Cella, U, Mörsdorf, M, Mosedale, JR, Muffler, L, Muñoz‐Rojas, M, Myers, JA, Myers‐Smith, IH, Nagy, L, Nardino, M, Naujokaitis‐Lewis, I, Newling, Emily, Nicklas, L, Niedrist, G, Niessner, A, Nilsson, MB, Normand, S, Nosetto, MD, Nouvellon, Y, Nuñez, MA, Ogaya, R, Ogée, J, Okello, J, Olejnik, J, Eivind Olesen, J, Opedal, Ø, Orsenigo, S, Palaj, A, Pampuch, T, Panov, AV, Pärtel, M, Pastor, A, Pauchard, A, Pauli, H, Pavelka, M, Pearse, WD, Peichl, M, Pellissier, L, Penczykowski, RM, Penuelas, J, Petit Bon, M, Petraglia, A, Phartyal, SS, Phoenix, GK, Pio, C, Pitacco, A, Pitteloud, C, Plichta, R, Porro, F, Portillo‐Estrada, M, Poulenard, J, Poyatos, R, Prokushkin, AS, Puchalka, R, Pușcaș, M, Radujković, D, Randall, K, Ratier Backes, A, Remmele, S, Remmers, W, Renault, D, Risch, AC, Rixen, C, Robinson, SA, Robroek, BJM, Rocha, AV, Rossi, C, Rossi, G, Roupsard, O, Rubtsov, AV, Saccone, P, Sagot, C, Sallo Bravo, J, Santos, CC, Sarneel, JM, Scharnweber, T, Schmeddes, J, Schmidt, M, Scholten, T, Schuchardt, M, Schwartz, N, Scott, T, Seeber, J, Cristina Segalin de Andrade, A, Seipel, T, Semenchuk, P, Senior, RA, Serra‐Diaz, JM, Sewerniak, P, Shekhar, A, Sidenko, NV, Siebicke, L, Siegwart Collier, L, Simpson, E, Siqueira, DP, Sitková, Z, Six, J, Smiljanic, M, Smith, SW, Smith‐Tripp, S, Somers, B, Vedel Sørensen, M, João L. L. Souza, J, Israel Souza, B, Souza Dias, A, Spasojevic, MJ, Speed, JDM, Spicher, F, Stanisci, A, Steinbauer, K, Steinbrecher, R, Steinwandter, M, Stemkovski, M, Stephan, JG, Stiegler, C, Stoll, S, Svátek, M, Svoboda, M, Tagesson, T, Tanentzap, AJ, Tanneberger, F, Theurillat, J, Thomas, HJD, Thomas, AD, Tielbörger, K, Tomaselli, M, Albert Treier, U, Trouillier, M, Dan Turtureanu, P, Tutton, R, Tyystjärvi, VA, Ueyama, M, Ujházy, K, Ujházyová, M, Uogintas, D, Urban, AV, Urban, J, Urbaniak, M, Ursu, T, Primo Vaccari, F, Van de Vondel, S, van den Brink, L, Van Geel, M, Vandvik, V, Vangansbeke, P, Varlagin, A, Veen, GF, Veenendaal, E, Venn, Susanna, Verbeeck, H, Verbrugggen, E, Verheijen, FGA, Villar, L, Vitale, L, Vittoz, P, Vives‐Ingla, M, von Oppen, J, Walz, J, Wang, R, Wang, Y, Way, RG, Wedegärtner, REM, Weigel, R, Wild, J, Wilkinson, M, Wilmking, M, Wingate, L, Winkler, M, Wipf, S, Wohlfahrt, G, Xenakis, G, Yang, Y, Yu, Z, Yu, K, Zellweger, F, Zhang, J, Zhang, Z, Zhao, P, Ziemblińska, K, Zimmermann, R, Zong, S, Zyryanov, VI, Nijs, I, Lenoir, J, Lembrechts, JJ, van den Hoogen, J, Aalto, J, Ashcroft, MB, De Frenne, P, Kemppinen, J, Kopecký, M, Luoto, M, Maclean, IMD, Crowther, TW, Bailey, JJ, Haesen, S, Klinges, DH, Niittynen, P, Scheffers, BR, Van Meerbeek, K, Aartsma, P, Abdalaze, O, Abedi, M, Aerts, R, Ahmadian, N, Ahrends, A, Alatalo, JM, Alexander, JM, Nina Allonsius, C, Altman, J, Ammann, C, Andres, C, Andrews, C, Ardö, J, Arriga, N, Arzac, A, Aschero, V, Assis, RL, Johann Assmann, J, Bader, MY, Bahalkeh, K, Barančok, P, Barrio, IC, Barros, A, Barthel, M, Basham, EW, Bauters, M, Bazzichetto, M, Belelli Marchesini, L, Bell, MC, Benavides, JC, Luis Benito Alonso, J, Berauer, BJ, Bjerke, JW, Björk, RG, Björkman, MP, Björnsdóttir, K, Blonder, B, Boeckx, P, Boike, J, Bokhorst, S, Brum, BNS, Brůna, J, Buchmann, N, Buysse, P, Luís Camargo, J, Campoe, OC, Candan, O, Canessa, R, Cannone, N, Carbognani, M, Carnicer, J, Casanova‐Katny, A, Cesarz, S, Chojnicki, B, Choler, P, Chown, SL, Cifuentes, EF, Čiliak, M, Contador, T, Convey, P, Cooper, EJ, Cremonese, E, Curasi, SR, Curtis, R, Cutini, M, Johan Dahlberg, C, Daskalova, GN, Angel de Pablo, M, Della Chiesa, S, Dengler, J, Deronde, B, Descombes, P, Di Cecco, V, Di Musciano, M, Dick, J, Dimarco, RD, Dolezal, J, Dorrepaal, E, Dušek, J, Eisenhauer, N, Eklundh, L, Erickson, TE, Erschbamer, B, Eugster, W, Ewers, RM, Exton, DA, Fanin, N, Fazlioglu, F, Feigenwinter, I, Fenu, G, Ferlian, O, Rosa Fernández Calzado, M, Fernández‐Pascual, E, Finckh, M, Finger Higgens, R, Forte, TGW, Freeman, EC, Frei, ER, Fuentes‐Lillo, E, García, RA, García, MB, Géron, C, Gharun, M, Ghosn, D, Gigauri, K, Gobin, A, Goded, I, Goeckede, M, Gottschall, F, Goulding, K, Govaert, S, Jessen Graae, B, Greenwood, S, Greiser, C, Grelle, A, Guénard, B, Guglielmin, M, Guillemot, J, Haase, P, Haider, S, Halbritter, AH, Hamid, M, Hammerle, A, Hampe, A, Haugum, SV, Hederová, L, Heinesch, B, Helfter, C, Hepenstrick, D, Herberich, M, Herbst, M, Hermanutz, L, Hik, DS, Hoffrén, R, Homeier, J, Hörtnagl, L, Høye, TT, Hrbacek, F, Hylander, K, Iwata, H, Antoni Jackowicz‐Korczynski, M, Jactel, H, Järveoja, J, Jastrzębowski, S, Jentsch, A, Jiménez, JJ, Jónsdóttir, IS, Jucker, T, Jump, AS, Juszczak, R, Kanka, R, Kašpar, V, Kazakis, G, Kelly, J, Khuroo, AA, Klemedtsson, L, Klisz, M, Kljun, N, Knohl, A, Kobler, J, Kollár, J, Kotowska, MM, Kovács, B, Kreyling, J, Lamprecht, A, Lang, SI, Larson, C, Larson, K, Laska, K, le Maire, G, Leihy, RI, Lens, L, Liljebladh, B, Lohila, A, Lorite, J, Loubet, B, Lynn, J, Macek, M, Mackenzie, R, Magliulo, E, Maier, R, Malfasi, F, Máliš, F, Man, M, Manca, G, Manco, A, Manise, T, Manolaki, P, Marciniak, F, Matula, R, Clara Mazzolari, A, Medinets, S, Medinets, V, Meeussen, C, Merinero, S, de Cássia Guimarães Mesquita, R, Meusburger, K, Meysman, FJR, Michaletz, ST, Milbau, A, Moiseev, D, Moiseev, P, Mondoni, A, Monfries, R, Montagnani, L, Moriana‐Armendariz, M, Morra di Cella, U, Mörsdorf, M, Mosedale, JR, Muffler, L, Muñoz‐Rojas, M, Myers, JA, Myers‐Smith, IH, Nagy, L, Nardino, M, Naujokaitis‐Lewis, I, Newling, Emily, Nicklas, L, Niedrist, G, Niessner, A, Nilsson, MB, Normand, S, Nosetto, MD, Nouvellon, Y, Nuñez, MA, Ogaya, R, Ogée, J, Okello, J, Olejnik, J, Eivind Olesen, J, Opedal, Ø, Orsenigo, S, Palaj, A, Pampuch, T, Panov, AV, Pärtel, M, Pastor, A, Pauchard, A, Pauli, H, Pavelka, M, Pearse, WD, Peichl, M, Pellissier, L, Penczykowski, RM, Penuelas, J, Petit Bon, M, Petraglia, A, Phartyal, SS, Phoenix, GK, Pio, C, Pitacco, A, Pitteloud, C, Plichta, R, Porro, F, Portillo‐Estrada, M, Poulenard, J, Poyatos, R, Prokushkin, AS, Puchalka, R, Pușcaș, M, Radujković, D, Randall, K, Ratier Backes, A, Remmele, S, Remmers, W, Renault, D, Risch, AC, Rixen, C, Robinson, SA, Robroek, BJM, Rocha, AV, Rossi, C, Rossi, G, Roupsard, O, Rubtsov, AV, Saccone, P, Sagot, C, Sallo Bravo, J, Santos, CC, Sarneel, JM, Scharnweber, T, Schmeddes, J, Schmidt, M, Scholten, T, Schuchardt, M, Schwartz, N, Scott, T, Seeber, J, Cristina Segalin de Andrade, A, Seipel, T, Semenchuk, P, Senior, RA, Serra‐Diaz, JM, Sewerniak, P, Shekhar, A, Sidenko, NV, Siebicke, L, Siegwart Collier, L, Simpson, E, Siqueira, DP, Sitková, Z, Six, J, Smiljanic, M, Smith, SW, Smith‐Tripp, S, Somers, B, Vedel Sørensen, M, João L. L. Souza, J, Israel Souza, B, Souza Dias, A, Spasojevic, MJ, Speed, JDM, Spicher, F, Stanisci, A, Steinbauer, K, Steinbrecher, R, Steinwandter, M, Stemkovski, M, Stephan, JG, Stiegler, C, Stoll, S, Svátek, M, Svoboda, M, Tagesson, T, Tanentzap, AJ, Tanneberger, F, Theurillat, J, Thomas, HJD, Thomas, AD, Tielbörger, K, Tomaselli, M, Albert Treier, U, Trouillier, M, Dan Turtureanu, P, Tutton, R, Tyystjärvi, VA, Ueyama, M, Ujházy, K, Ujházyová, M, Uogintas, D, Urban, AV, Urban, J, Urbaniak, M, Ursu, T, Primo Vaccari, F, Van de Vondel, S, van den Brink, L, Van Geel, M, Vandvik, V, Vangansbeke, P, Varlagin, A, Veen, GF, Veenendaal, E, Venn, Susanna, Verbeeck, H, Verbrugggen, E, Verheijen, FGA, Villar, L, Vitale, L, Vittoz, P, Vives‐Ingla, M, von Oppen, J, Walz, J, Wang, R, Wang, Y, Way, RG, Wedegärtner, REM, Weigel, R, Wild, J, Wilkinson, M, Wilmking, M, Wingate, L, Winkler, M, Wipf, S, Wohlfahrt, G, Xenakis, G, Yang, Y, Yu, Z, Yu, K, Zellweger, F, Zhang, J, Zhang, Z, Zhao, P, Ziemblińska, K, Zimmermann, R, Zong, S, Zyryanov, VI, Nijs, I, and Lenoir, J

Published
2021

11. Increased Vegetation in Mountainous Headwaters Amplifies Water Stress During Dry Periods

Author

Vicente‐Serrano, S. M., Domínguez‐Castro, F., Murphy, C., Peña‐Angulo, D., Tomas‐Burguera, M., Noguera, I., López‐Moreno, J. I., Juez, C., Grainger, S., Eklundh, L., Conradt, T., Azorin‐Molina, C., El Kenawy, A., Vicente‐Serrano, S. M., Domínguez‐Castro, F., Murphy, C., Peña‐Angulo, D., Tomas‐Burguera, M., Noguera, I., López‐Moreno, J. I., Juez, C., Grainger, S., Eklundh, L., Conradt, T., Azorin‐Molina, C., and El Kenawy, A.

Abstract

The dynamics of blue and green water partitioning under vegetation and climate change, as well as their different interactions during wet and dry periods, are poorly understood in the literature. We analyzed the impact of vegetation changes on blue water generation in a central Spanish Pyrenees basin undergoing intense afforestation. We found that vegetation change is a key driver of large decreases in blue water availability. The effect of vegetation increase is amplified during dry years, and mainly during the dry season, with streamflow reductions of more than 50%. This pattern can be attributed primarily to increased plant water consumption. Our findings highlight the importance of vegetation changes in reinforcing the decrease in water resource availability. With aridity expected to rise in southern Europe over the next few decades, interactions between climate and land management practices appear to be amplifying future hydrological drought risk in the region.

Published
2021

12. Increased Vegetation in Mountainous Headwaters Amplifies Water Stress During Dry Periods

Author

Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comisión Interministerial de Ciencia y Tecnología, CICYT (España), European Commission, Ministerio de Economía y Competitividad (España), Irish Government, Vicente Serrano, Sergio M., Domínguez-Castro, Fernando, Murphy, C., Peña-Angulo, Dhais, Tomás-Burguera, Miquel, Noguera, Iván, López-Moreno, Juan I., Juez, Carmelo, Grainger, S., Eklundh, L., Conradt, T., Azorín-Molina, César, Kenawy, A. El, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comisión Interministerial de Ciencia y Tecnología, CICYT (España), European Commission, Ministerio de Economía y Competitividad (España), Irish Government, Vicente Serrano, Sergio M., Domínguez-Castro, Fernando, Murphy, C., Peña-Angulo, Dhais, Tomás-Burguera, Miquel, Noguera, Iván, López-Moreno, Juan I., Juez, Carmelo, Grainger, S., Eklundh, L., Conradt, T., Azorín-Molina, César, and Kenawy, A. El

Abstract

The dynamics of blue and green water partitioning under vegetation and climate change, as well as their different interactions during wet and dry periods, are poorly understood in the literature. We analyzed the impact of vegetation changes on blue water generation in a central Spanish Pyrenees basin undergoing intense afforestation. We found that vegetation change is a key driver of large decreases in blue water availability. The effect of vegetation increase is amplified during dry years, and mainly during the dry season, with streamflow reductions of more than 50%. This pattern can be attributed primarily to increased plant water consumption. Our findings highlight the importance of vegetation changes in reinforcing the decrease in water resource availability. With aridity expected to rise in southern Europe over the next few decades, interactions between climate and land management practices appear to be amplifying future hydrological drought risk in the region.

Published
2021

15. EUROSPEC: At the interface between remote-sensing and ecosystem CO2 flux measurements in Europe

Author

Porcar Castell, A, Mac Arthur, A, Rossini, M, Eklundh, L, Pacheco Labrador, J, Anderson, K, Balzarolo, M, Martín, M, Jin, H, Tomelleri, E, Cerasoli, S, Sakowska, K, Hueni, A, Julitta, T, Nichol, C, Vescovo, L, Vescovo, L., ROSSINI, MICOL, JULITTA, TOMMASO, Porcar Castell, A, Mac Arthur, A, Rossini, M, Eklundh, L, Pacheco Labrador, J, Anderson, K, Balzarolo, M, Martín, M, Jin, H, Tomelleri, E, Cerasoli, S, Sakowska, K, Hueni, A, Julitta, T, Nichol, C, Vescovo, L, Vescovo, L., ROSSINI, MICOL, and JULITTA, TOMMASO

Abstract

Resolving the spatial and temporal dynamics of gross primary productivity (GPP) of terrestrial ecosystems across different scales remains a challenge. Remote sensing is regarded as the solution to upscale point observations conducted at the ecosystem level, using the eddy covariance (EC) technique, to the landscape and global levels. In addition to traditional vegetation indices, the photochemical reflectance index (PRI) and the emission of solar-induced chlorophyll fluorescence (SIF), now measurable from space, provide a new range of opportunities to monitor the global carbon cycle using remote sensing. However, the scale mismatch between EC observations and the much coarser satellite-derived data complicate the integration of the two sources of data. The solution is to establish a network of in situ spectral measurements that can act as a bridge between EC measurements and remote-sensing data. In situ spectral measurements have already been conducted for many years at EC sites, but using variable instrumentation, setups, and measurement standards. In Europe in particular, in situ spectral measurements remain highly heterogeneous. The goal of EUROSPEC Cost Action ES0930 was to promote the development of common measuring protocols and new instruments towards establishing best practices and standardization of these measurements. In this review we describe the background and main tradeoffs of in situ spectral measurements, review the main results of EUROSPEC Cost Action, and discuss the future challenges and opportunities of in situ spectral measurements for improved estimation of local and global estimates of GPP over terrestrial ecosystems.

Published
2015

16. High resolution mapping of vegetation dynamics from Sentinel-2

Author

Eklundh, L., Sjöström, M., Jonas Ardö, and Jönsson, P.

Subjects
Naturvetenskap, Natural Sciences
Abstract

The aim of this work is to develop and test a method for generation of information on vegetation dynamics from high-spatial resolution data, such as Sentinel-2. In order to accomplish this, Sentinel-2 data were simulated from existing SPOT HRG and HRVIR scenes over Sweden. We used TIMESAT, a well-tested computer package for generating smooth seasonal profiles and generation of seasonality parameters, like start and end, length, amplitude, integrated values, seasonal maximum, derivatives, etc. The processing works on a pixel-by-pixel basis and is resistant to clouds and noise. Data gaps are handled, and quality information can be included to increase the fidelity of the fits. The pilot study demonstrated that TIMESAT was successful in fitting smooth model functions to the data, and generating seasonality parameters for the test area at 10 x 10 m resolution. We conclude that TIMESAT will be useful for generating vegetation dynamics data from high-spatial resolution data such as Sentinel-2. The smooth seasonal profiles will be extremely useful for driving high-resolution biophysical vegetation models, and the seasonality parameters will be excellent for change detection, and for studying trends in vegetation productivity and seasonality.

Published
2012

17. EUROSPEC: at the interface between remote-sensing and ecosystem CO<sub>2</sub> flux measurements in Europe

Author

Porcar-Castell, A., primary, Mac Arthur, A., additional, Rossini, M., additional, Eklundh, L., additional, Pacheco-Labrador, J., additional, Anderson, K., additional, Balzarolo, M., additional, Martín, M. P., additional, Jin, H., additional, Tomelleri, E., additional, Cerasoli, S., additional, Sakowska, K., additional, Hueni, A., additional, Julitta, T., additional, Nichol, C. J., additional, and Vescovo, L., additional

Published
2015
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20. Towards operational remote sensing of forest carbon balance across Northern Europe

Author

Olofsson, P., Lagergren, F., Lindroth, A., Lindström, J., Klemedtsson, L., Eklundh, L., and EGU, Publication

Subjects
[PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.STU] Sciences of the Universe [physics]/Earth Sciences, [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph], [SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces, environment
Abstract

Monthly averages of ecosystem respiration (ER), gross primary production (GPP) and net ecosystem exchange (NEE) over Scandinavian forest sites were estimated using regression models driven by air temperature (AT), absorbed photosynthetically active radiation (APAR) and vegetation indices. The models were constructed and evaluated using satellite data from Terra/MODIS and measured data collected at seven flux tower sites in northern Europe. Data used for model construction was excluded from the evaluation. Relationships between ground measured variables and the independent variables were investigated. It was found that the enhanced vegetation index (EVI) at 250 m resolution was highly noisy for the coniferous sites, and hence, 1 km EVI was used for the analysis. Linear relationships between EVI and the biophysical variables were found for both coniferous and deciduous data: correlation coefficients ranged from 0.91 to 0.79, and 0.85 to 0.67, respectively. Due to saturation, there were no linear relationships between normalized difference vegetation index (NDVI) and the ground measured parameters found at any site. APAR correlated better with the parameters in question than the vegetation indices. Modeled GPP and ER were in good agreement with measured values, with more than 90% of the variation in measured GPP and ER being explained by the coniferous models. The site-specific respiration rate at 10°C (R10) was needed for describing the ER variation between sites. Even though monthly NEE was modeled with less accuracy than GPP, 61% and 75% (dec. and con., respectively) of the variation in the measured time series was explained by the model. These results are important for moving towards operational remote sensing of forest carbon balance across Northern Europe.

Published
2007

23. Ground-Based optical measurements at European flux sites: A review of methods, instruments and current controversies

Author

Balzarolo, M., Anderson, K., Nichol, C., Rossini, M., Vescovo, L., Arriga, N., Wohlfahrt, G., Calvet, J-C, Carrara, A., Cerasoli, S., Cogliati, S., Daumard, F., Eklundh, L., Elbers, J.A., Evrendilek, F., Handcock, R.N., Kaduk, J., Klumpp, K., Longdoz, B., Matteucci, G., Meroni, M., Montagnani, L., Ourcival, J-M, Sánchez-Cañete, E.P., Pontailler, J-Y, Juszczak, R., Scholes, B., Martín, M.P., Balzarolo, M., Anderson, K., Nichol, C., Rossini, M., Vescovo, L., Arriga, N., Wohlfahrt, G., Calvet, J-C, Carrara, A., Cerasoli, S., Cogliati, S., Daumard, F., Eklundh, L., Elbers, J.A., Evrendilek, F., Handcock, R.N., Kaduk, J., Klumpp, K., Longdoz, B., Matteucci, G., Meroni, M., Montagnani, L., Ourcival, J-M, Sánchez-Cañete, E.P., Pontailler, J-Y, Juszczak, R., Scholes, B., and Martín, M.P.

Abstract

This paper reviews the currently available optical sensors, their limitations and opportunities for deployment at Eddy Covariance (EC) sites in Europe. This review is based on the results obtained from an online survey designed and disseminated by the Co-cooperation in Science and Technology (COST) Action ESO903—“Spectral Sampling Tools for Vegetation Biophysical Parameters and Flux Measurements in Europe” that provided a complete view on spectral sampling activities carried out within the different research teams in European countries. The results have highlighted that a wide variety of optical sensors are in use at flux sites across Europe, and responses further demonstrated that users were not always fully aware of the key issues underpinning repeatability and the reproducibility of their spectral measurements. The key findings of this survey point towards the need for greater awareness of the need for standardisation and development of a common protocol of optical sampling at the European EC sites.

Published
2011

24. An optical sensor network for vegetation phenology monitoring and satellite data calibration

Author

Eklundh, L., Jin, H., Schubert, P., Heliasz, M., Guzinski, Radoslaw, Eklundh, L., Jin, H., Schubert, P., Heliasz, M., and Guzinski, Radoslaw

Abstract

We present a network of sites across Fennoscandia for optical sampling of vegetation properties relevant for phenology monitoring and satellite data calibration. The network currently consists of five sites, distributed along an N-S gradient through Sweden and Finland. Two sites are located in coniferous forests, one in a deciduous forest, and two on peatland. The instrumentation consists of dual-beam sensors measuring incoming and reflected red, green, NIR, and PAR fluxes at 10-min intervals, year-round. The sensors are mounted on separate masts or in flux towers in order to capture radiation reflected from within the flux footprint of current eddy covariance measurements. Our computations and model simulations demonstrate the validity of using off-nadir sampling, and we show the results from the first year of measurement. NDVI is computed and compared to that of the MODIS instrument on-board Aqua and Terra satellite platforms. PAR fluxes are partitioned into reflected and absorbed components for the ground and canopy. The measurements demonstrate that the instrumentation provides detailed information about the vegetation phenology and variations in reflectance due to snow cover variations and vegetation development. Valuable information about PAR absorption of ground and canopy is obtained that may be linked to vegetation productivity.

Published
2011

25. Ground-Based Optical Measurements at European Flux Sites: A Review of Methods, Instruments and Current Controversies

Author

Balzarolo, M, Anderson, K, Nichol, C, Rossini, M, Vescovo, L, Arriga, N, Wohlfahrt, G, Calvet, J, Carrara, A, Cerasoli, S, Cogliati, S, Daumard, F, Eklundh, L, Elbers, J, Evrendilek, F, Handcock, R, Kaduk, J, Klumpp, K, Longdoz, B, Matteucci, G, Meroni, M, Montagnani, L, Ourcival, J, Sanchez Canete, E, Pontailler, J, Juszczak, R, Scholes, B, Martin, M, Calvet, JC, Elbers, JA, Handcock, RN, Ourcival, JM, Sanchez Canete, EP, Pontailler, JY, Martin, MP, ROSSINI, MICOL, COGLIATI, SERGIO, Balzarolo, M, Anderson, K, Nichol, C, Rossini, M, Vescovo, L, Arriga, N, Wohlfahrt, G, Calvet, J, Carrara, A, Cerasoli, S, Cogliati, S, Daumard, F, Eklundh, L, Elbers, J, Evrendilek, F, Handcock, R, Kaduk, J, Klumpp, K, Longdoz, B, Matteucci, G, Meroni, M, Montagnani, L, Ourcival, J, Sanchez Canete, E, Pontailler, J, Juszczak, R, Scholes, B, Martin, M, Calvet, JC, Elbers, JA, Handcock, RN, Ourcival, JM, Sanchez Canete, EP, Pontailler, JY, Martin, MP, ROSSINI, MICOL, and COGLIATI, SERGIO

Abstract

This paper reviews the currently available optical sensors, their limitations and opportunities for deployment at Eddy Covariance (EC) sites in Europe. This review is based on the results obtained from an online survey designed and disseminated by the Co-cooperation in Science and Technology (COST) Action ESO903—“Spectral Sampling Tools for Vegetation Biophysical Parameters and Flux Measurements in Europe” that provided a complete view on spectral sampling activities carried out within the different research teams in European countries. The results have highlighted that a wide variety of optical sensors are in use at flux sites across Europe, and responses further demonstrated that users were not always fully aware of the key issues underpinning repeatability and the reproducibility of their spectral measurements. The key findings of this survey point towards the need for greater awareness of the need for standardisation and development of a common protocol of optical sampling at the European EC sites.

Published
2011

26. Exploring the potential of MODIS EVI for modeling gross primary production across African ecosystems

Author

Sjöström, M, Ardö, J, Arneth, A, Boulain, N, Cappelaere, B, Eklundh, L, de Grandcourt, A, Kutsch, WL, Merbold, L, Nouvellon, Y, Scholes, RJ, Schubert, P, Seaquist, J, Veenendaal, EM, Sjöström, M, Ardö, J, Arneth, A, Boulain, N, Cappelaere, B, Eklundh, L, de Grandcourt, A, Kutsch, WL, Merbold, L, Nouvellon, Y, Scholes, RJ, Schubert, P, Seaquist, J, and Veenendaal, EM

Abstract

One of themost frequently appliedmethods for integrating controls on primary production through satellite data is the light use efficiency (LUE) approach, which links vegetation gross or net primary productivity (GPP or NPP) to remotely sensed estimates of absorbed photosynthetically active radiation (APAR). Eddy covariance towers provide continuousmeasurements of carbon flux, presenting an opportunity for evaluation of satellite estimates of GPP. Here we investigate relationships between eddy covariance estimated GPP, environmental variables derived fromflux towers,Moderate Resolution Imaging Spectroradiometer (MODIS) enhanced vegetation index (EVI) and GPP across African savanna ecosystems.MODIS GPP was found to underestimate GPP at themajority of sites, particularly at sites in the Sahel. EVIwas found to correlate well with estimated GPP on a site-by-site basis. Combining EVI with tower-measured PAR and evaporative fraction (EF, ameasure ofwater sufficiency) improved the direct relationship betweenGPP and EVI at themajority of the sites. The slope of this relationshipwas strongly related to site peak leaf area index (LAI). These results are promising for the extension of GPP through the use of remote sensing data to a regional or even continental scale. © 2011 Elsevier Inc.

Published
2011

27. Estimation of diurnal air temperature using MSG SEVIRI data in West Africa

Author

Stisen, Simon, Sandholt, Inge, Nørgaard, Anette, Fensholt, Rasmus, Eklundh, L.., Stisen, Simon, Sandholt, Inge, Nørgaard, Anette, Fensholt, Rasmus, and Eklundh, L..

Abstract

Spatially distributed estimates of evaporative fraction and actual evapotranspiration are pursued using a simple remote sensing technique based on a remotely sensed vegetation index (NDVI) and diurnal changes in land surface temperature. The technique, known as the triangle method, is improved by utilizing the high temporal resolution of the geostationary MSG-SEVIRI sensor. With 15 min acquisition intervals, the MSG-SEVIRI data allow for a precise estimation of the morning rise in land surface temperature which is a strong proxy for total daytime sensible heat fluxes. Combining the diurnal change in surface temperature, dTs with an interpretation of the triangular shaped dTs - NDVI space allows for a direct estimation of evaporative fraction. The mean daytime energy available for evapotranspiration (Rn - G) is estimated using several remote sensors and limited ancillary data. Finally regional estimates of actual evapotranspiration are made by combining evaporative fraction and available energy estimates. The estimated evaporative fraction (EF) and actual evapotranspiration (ET) for the Senegal River basin have been validated against field observations for the rainy season 2005. The validation results showed low biases and RMSE and R2 of 0.13 [-] and 0.63 for EF and RMSE of 41.45 W m- 2 and R2 of 0.66 for ET.

Published
2007

37. EUROSPEC: at the interface between remote-sensing and ecosystem CO2 flux measurements in Europe.

Author

Porcar-Castell, A., Mac Arthur, A., Rossini, M., Eklundh, L., Pacheco-Labrador, J., Anderson, K., Balzarolo, M., Martín, M. P., Jin, H., Tomelleri, E., Cerasoli, S., Sakowska, K., Hueni, A., Julitta, T., Nichol, C. J., and Vescovo, L.

Subjects
PHOTOCHEMISTRY, CHLOROPHYLL spectra, VEGETATION & climate, CARBON cycle, PRIMARY productivity (Biology), CARBON dioxide & the environment, REMOTE sensing
Abstract

Resolving the spatial and temporal dynamics of gross primary productivity (GPP) of terrestrial ecosystems across different scales remains a challenge. Remote sensing is regarded as the solution to upscale point observations conducted at the ecosystem level, using the eddy covariance (EC) technique, to the landscape and global levels. In addition to traditional vegetation indices, the photochemical reflectance index (PRI) and the emission of solarinduced chlorophyll fluorescence (SIF), now measurable from space, provide a new range of opportunities to monitor the global carbon cycle using remote sensing. However, the scale mismatch between EC observations and the much coarser satellite-derived data complicate the integration of the two sources of data. The solution is to establish a network of in situ spectral measurements that can act as a bridge between EC measurements and remote-sensing data. In situ spectral measurements have already been conducted for many years at EC sites, but using variable instrumentation, setups, and measurement standards. In Europe in particular, in situ spectral measurements remain highly heterogeneous. The goal of EUROSPEC Cost Action ES0930 was to promote the development of common measuring protocols and new instruments towards establishing best practices and standardization of these measurements. In this review we describe the background and main tradeoffs of in situ spectral measurements, review the main results of EUROSPEC Cost Action, and discuss the future challenges and opportunities of in situ spectral measurements for improved estimation of local and global estimates of GPP over terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Published
2015
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46. Satellites reveal an increase in gross primary production in a greenlandic high arctic fen 1992-2008.

Author

Tagesson, T., Mastepanov, M., Tamstorf, M. P., Eklundh, L., Schubert, P., Ekberg, A., Sigsgaard, C., Christensen, T. R., and Ström, L.

Subjects
PRIMARY productivity (Biology), WETLANDS, CARBON cycle, CLIMATE change, ATMOSPHERIC carbon dioxide
Abstract

Arctic wetlands play a key role in the terrestrial carbon cycle. Recent studies have shown a greening trend and indicated an increase in CO2 uptake in boreal and sub- to low-arctic areas. Our aim was to combine satellite-based normalized difference vegetation index (NDVI) with ground-based flux measurements of CO2 to investigate a possible greening trend and potential changes in gross primary production (GPP) between 1992 and 2008 in a high arctic fen area. The study took place in Rylekaerene in the Zackenberg Research Area (74°28' N 20°34' W), located in the National park of North Eastern Greenland. We estimated the light use efficiency (ϵ) for the dominant vegetation types from field measured fractions of photosynthetic active radiation (FAPAR) and ground-based flux measurements of GPP. Measured FAPAR were correlated to satellite-based NDVI. The FAPAR-NDVI relationship in combination with ϵ was applied to satellite data to model GPP 1992-2008. The model was evaluated against field measured GPP. The model was a useful tool for up-scaling GPP and all basic requirements for the model were well met, e.g., FAPAR was well correlated to NDVI and modeled GPP was well correlated to field measurements. The studied high arctic fen area has experienced a strong increase in GPP between 1992 and 2008. The area has during this period also experienced a substantial increase in local air temperature. Consequently, the observed greening trend is most likely due to ongoing climatic change possibly in combination with CO2 fertilization, due to increasing atmospheric concentrations of CO2. [ABSTRACT FROM AUTHOR]

Published
2010
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47. Disentangling the effects of climate and people on Sahel vegetation dynamics.

Author

Seaquist, J. W., Hickler, T., Eklundh, L., Ardö, J., and Heumann, B. W.

Subjects
VEGETATION dynamics, ENVIRONMENTAL degradation, DROUGHTS, ECOLOGICAL research, HERDING, GRAZING
Abstract

The Sahel belt of Africa has been the focus of intensive scientific research since the 1960s, spurred on by the chronic vulnerability of its population to recurring drought and the threat of long-term land degradation. But satellite sensors have recently shown that much of the region has experienced significant increases in photosynthetic activity since the early 1980s, thus re-energizing long-standing debates about the role that people play in shaping land surface status, and thus climate at regional scales. In this paper, we test the hypothesis that people have had a measurable impact on vegetation dynamics in the Sahel for the period 1982-2002. We compare potential natural vegetation dynamics predicted by a process-based ecosystem model with satellite-derived greenness observations, and map the agreement between the two across a geographic grid at a spatial resolution of 0.5°. As aggregated data-model agreement is very good, any local differences between the two could be due to human impact. We then relate this agreement metric to state-of-the-art data sets on demographics, pasture, and cropping. Our findings suggest that demographic and agricultural pressures in the Sahel are unable to account for differences between simulated and observed vegetation dynamics, even for the most densely populated areas. But we do identify a weak, positive correlation between data-model agreement and pasture intensity at the Sahel-wide level. This indicates that herding or grazing does not appreciably affect vegetation dynamics in the region. Either people have not had a significant impact on vegetation dynamics in the Sahel or the identification of a human "footprint" is precluded by inconsistent or subtle vegetation response to complex socio-environmental interactions, and/or limitations in the data used for this study. [ABSTRACT FROM AUTHOR]

Published
2008
Full Text
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48. Evaluation of satellite based indices for primary production estimates in a sparse savanna in the Sudan.

Author

Sjöström, M., Ardö, J., Eklundh, L., El-Tahir, B. A., El-Khidir, H. A. M., Pilesjö, P., and Seaquist, J.

Subjects
INDEX use studies, SPECTROPHOTOMETERS, ECOLOGICAL research, VEGETATION surveys
Abstract

One of the more frequently applied methods for integrating controls on primary production through satellite data is the Light Use Efficiency (LUE) approach. Satellite indices such as the Enhanced Vegetation Index (EVI) and the Shortwave Infrared Water Stress Index (SIWSI) have previously shown promise as predictors of primary production in several different environments. In this study, we evaluate EVI and SIWSI derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor against in-situ measurements from central Sudan in order to asses their applicability in LUE-based primary production modelling within a water limited environment. Results show a strong correlation between EVI against gross primary production (GPP), demonstrating the significance of EVI for deriving information on primary production with relatively high accuracy at similar areas. Evaluation of SIWSI however, reveal that the fraction of vegetation apparently is to low for the index to provide accurate information on canopy water content, indicating that the use of SIWSI as a predictor of water stress in satellite data-driven primary production modelling in similar semi-arid ecosystems is limited. [ABSTRACT FROM AUTHOR]

Published
2008

49. Development of a method for monitoring of insect induced forest defoliation – limitation of MODIS data in Fennoscandian forest landscapes

Author

Olsson, Per-Ola, Kantola, Tuula, Lyytikäinen-Saarenmaa, Päivi, Jönsson, Anna, and Eklundh, Lars

Subjects
Forestry, SD1-669.5
Abstract

We investigated if coarse-resolution satellite data from the MODIS sensor can be used for regional monitoring of insect disturbances in Fennoscandia. A damage detection method based on z-scores of seasonal maximums of the 2-band Enhanced Vegetation Index (EVI2) was developed. Time-series smoothing was applied and Receiver Operating Characteristics graphs were used for optimisation. The method was developed in fragmented and heavily managed forests in eastern Finland dominated by Scots pine ( L.) (pinaceae) and with defoliation of European pine sawfly ( Geoffr.) (Hymenoptera: Diprionidae) and common pine sawfly ( L.) (Hymenoptera: Diprionidae). The method was also applied to subalpine mountain birch ( N.I. Orlova) forests in northern Sweden, infested by autumnal moth (Borkhausen) and winter moth ( L.). In Finland, detection accuracies were fairly low with 50% of the damaged stands detected, and a misclassification of healthy stands of 22%. In areas with long outbreak histories the method resulted in extensive misclassification. In northern Sweden accuracies were higher, with 75% of the damage detected and a misclassification of healthy samples of 19%. Our results indicate that MODIS data may fail to detect damage in fragmented forests, particularly when the damage history is long. Therefore, regional studies based on these data may underestimate defoliation. However, the method yielded accurate results in homogeneous forest ecosystems and when long-enough periods without damage could be identified. Furthermore, the method is likely to be useful for insect disturbance detection using future medium-resolution data, e.g. from Sentinelâ2.Pinus sylvestrisNeodiprion sertiferDiprion piniBetula pubescensssp. Czerepanovii Epirrita autumnata Operophtera brumata

Published
2016
Full Text
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50. Disentangling the effects of climate and people on Sahel vegetation dynamics

Author

Seaquist, J. W., Eklundh, L., Ardö, J., Heumann, B. W., and Hickler, T.

Subjects
2. Zero hunger, 13. Climate action, 15. Life on land
Abstract

The Sahel belt of Africa has been the focus of intensive scientific research since the 1960s, spurred on by the chronic vulnerability of its population to recurring drought and the threat of long-term land degradation. But satellite sensors have recently shown that much of the region has experienced significant increases in photosynthetic activity since the early 1980s, thus re-energizing long-standing debates about the role that people play in shaping land surface status, and thus climate at regional scales. In this paper, we test the hypothesis that people have had a measurable impact on vegetation dynamics in the Sahel for the period 1982-2002. We compare potential natural vegetation dynamics predicted by a process-based ecosystem model with satellite-derived greenness observations, and map the agreement between the two across a geographic grid at a spatial resolution of 0.5 degrees. As aggregated data-model agreement is very good, any local differences between the two could be due to human impact. We then relate this agreement metric to state-of-theart data sets on demographics, pasture, and cropping. Our findings suggest that demographic and agricultural pressures in the Sahel are unable to account for differences between simulated and observed vegetation dynamics, even for the most densely populated areas. But we do identify a weak, positive correlation between data-model agreement and pasture intensity at the Sahel-wide level. This indicates that herding or grazing does not appreciably affect vegetation dynamics in the region. Either people have not had a significant impact on vegetation dynamics in the Sahel or the identification of a human "footprint" is precluded by inconsistent or subtle vegetation response to complex socio-environmental interactions, and/or limitations in the data used for this study. We do not exclude the possibility of a greater human influence on vegetation dynamics over the coming decades with changing land use.

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