Forest diversity plays a key role in determining the stand carbon stocks of Mexican forests

Arasa-Gisbert, R., Vayreda, J., Román-Cuesta, R.M., Villela, S.A., Mayorga, R., Retana, J. (2018) Forest diversity plays a key role in determining the stand carbon stocks of Mexican forests. Forest Ecology and Management. 415-416: 160-171.
Link
Doi: 10.1016/j.foreco.2018.02.023

Abstract:

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

Hudson, L.N., Newbold, T., Contu, S., Hill, S.L.L., Lysenko, I., De Palma, A., Phillips, H.R.P., Alhusseini, T.I., Bedford, F.E., Bennett, D.J., Booth, H., Burton, V.J., Chng, C.W.T., Choimes, A., Correia, D.L.P., Day, J., Echeverría-Londoño, S., Emerson, S.R., Gao, D., Garon, M., Harrison, M.L.K., Ingram, D.J., Jung, M., Kemp, V., Kirkpatrick, L., Martin, C.D., Pan, Y., Pask-Hale, G.D., Pynegar, E.L., Robinson, A.N., Sanchez-Ortiz, K., Senior, R.A., Simmons, B.I., White, H.J., Zhang, H., Aben, J., Abrahamczyk, S., Adum, G.B., Aguilar-Barquero, V., Aizen, M.A., Albertos, B., Alcala, E.L., del Mar Alguacil, M., Alignier, A., Ancrenaz, M., Andersen, A.N., Arbeláez-Cortés, E., Armbrecht, I., Arroyo-Rodríguez, V., Aumann, T., Axmacher, J.C., Azhar, B., Azpiroz, A.B., Baeten, L., Bakayoko, A., Báldi, A., Banks, J.E., Baral, S.K., Barlow, J., Barratt, B.I.P., Barrico, L., Bartolommei, P., Barton, D.M., Basset, Y., Batáry, P., Bates, A.J., Baur, B., Bayne, E.M., Beja, P., Benedick, S., Berg, Å., Bernard, H., Berry, N.J., Bhatt, D., Bicknell, J.E., Bihn, J.H., Blake, R.J., Bobo, K.S., Bóçon, R., Boekhout, T., Böhning-Gaese, K., Bonham, K.J., Borges, P.A.V., Borges, S.H., Boutin, C., Bouyer, J., Bragagnolo, C., Brandt, J.S., Brearley, F.Q., Brito, I., Bros, V., Brunet, J., Buczkowski, G., Buddle, C.M., Bugter, R., Buscardo, E., Buse, J., Cabra-García, J., Cáceres, N.C., Cagle, N.L., Calviño-Cancela, M., Cameron, S.A., Cancello, E.M., Caparrós, R., Cardoso, P., Carpenter, D., Carrijo, T.F., Carvalho, A.L., Cassano, C.R., Castro, H., Castro-Luna, A.A., Rolando, C.B., Cerezo, A., Chapman, K.A., Chauvat, M., Christensen, M., Clarke, F.M., Cleary, D.F.R., Colombo, G., Connop, S.P., Craig, M.D., Cruz-López, L., Cunningham, S.A., D'Aniello, B., D'Cruze, N., da Silva, P.G., Dallimer, M., Danquah, E., Darvill, B., Dauber, J., Davis, A.L.V., Dawson, J., de Sassi, C., de Thoisy, B., Deheuvels, O., Dejean, A., Devineau, J.-L., Diekötter, T., Dolia, J.V., Domínguez, E., Dominguez-Haydar, Y., Dorn, S., Draper, I., Dreber, N., Dumont, B., Dures, S.G., Dynesius, M., Edenius, L., Eggleton, P., Eigenbrod, F., Elek, Z., Entling, M.H., Esler, K.J., de Lima, R.F., Faruk, A., Farwig, N., Fayle, T.M., Felicioli, A., Felton, A.M., Fensham, R.J., Fernandez, I.C., Ferreira, C.C., Ficetola, G.F., Fiera, C., Filgueiras, B.K.C., Fırıncıoğlu, H.K., Flaspohler, D., Floren, A., Fonte, S.J., Fournier, A., Fowler, R.E., Franzén, M., Fraser, L.H., Fredriksson, G.M., Freire, G.B., Frizzo, T.L.M., Fukuda, D., Furlani, D., Gaigher, R., Ganzhorn, J.U., García, K.P., Garcia-R, J.C., Garden, J.G., Garilleti, R., Ge, B.-M., Gendreau-Berthiaume, B., Gerard, P.J., Gheler-Costa, C., Gilbert, B., Giordani, P., Giordano, S., Golodets, C., Gomes, L.G.L., Gould, R.K., Goulson, D., Gove, A.D., Granjon, L., Grass, I., Gray, C.L., Grogan, J., Gu, W., Guardiola, M., Gunawardene, N.R., Gutierrez, A.G., Gutiérrez-Lamus, D.L., Haarmeyer, D.H., Hanley, M.E., Hanson, T., Hashim, N.R., Hassan, S.N., Hatfield, R.G., Hawes, J.E., Hayward, M.W., Hébert, C., Helden, A.J., Henden, J.-A., Henschel, P., Hernández, L., Herrera, J.P., Herrmann, F., Herzog, F., Higuera-Diaz, D., Hilje, B., Höfer, H., Hoffmann, A., Horgan, F.G., Hornung, E., Horváth, R., Hylander, K., Isaacs-Cubides, P., Ishida, H., Ishitani, M., Jacobs, C.T., Jaramillo, V.J., Jauker, B., Hernández, F.J., Johnson, M.F., Jolli, V., Jonsell, M., Juliani, S.N., Jung, T.S., Kapoor, V., Kappes, H., Kati, V., Katovai, E., Kellner, K., Kessler, M., Kirby, K.R., Kittle, A.M., Knight, M.E., Knop, E., Kohler, F., Koivula, M., Kolb, A., Kone, M., Kőrösi, Á., Krauss, J., Kumar, A., Kumar, R., Kurz, D.J., Kutt, A.S., Lachat, T., Lantschner, V., Lara, F., Lasky, J.R., Latta, S.C., Laurance, W.F., Lavelle, P., Le Féon, V., LeBuhn, G., Légaré, J.-P., Lehouck, V., Lencinas, M.V., Lentini, P.E., Letcher, S.G., Li, Q., Litchwark, S.A., Littlewood, N.A., Liu, Y., Lo-Man-Hung, N., López-Quintero, C.A., Louhaichi, M., Lövei, G.L., Lucas-Borja, M.E., Luja, V.H., Luskin, M.S., MacSwiney G, M.C., Maeto, K., Magura, T., Mallari, N.A., Malone, L.A., Malonza, P.K., Malumbres-Olarte, J., Mandujano, S., Måren, I.E., Marin-Spiotta, E., Marsh, C.J., Marshall, E.J.P., Martínez, E., Martínez Pastur, G., Moreno Mateos, D., Mayfield, M.M., Mazimpaka, V., McCarthy, J.L., McCarthy, K.P., McFrederick, Q.S., McNamara, S., Medina, N.G., Medina, R., Mena, J.L., Mico, E., Mikusinski, G., Milder, J.C., Miller, J.R., Miranda-Esquivel, D.R., Moir, M.L., Morales, C.L., Muchane, M.N., Muchane, M., Mudri-Stojnic, S., Munira, A.N., Muoñz-Alonso, A., Munyekenye, B.F., Naidoo, R., Naithani, A., Nakagawa, M., Nakamura, A., Nakashima, Y., Naoe, S., Nates-Parra, G., Navarrete Gutierrez, D.A., Navarro-Iriarte, L., Ndang'ang'a, P.K., Neuschulz, E.L., Ngai, J.T., Nicolas, V., Nilsson, S.G., Noreika, N., Norfolk, O., Noriega, J.A., Norton, D.A., Nöske, N.M., Nowakowski, A.J., Numa, C., O'Dea, N., O'Farrell, P.J., Oduro, W., Oertli, S., Ofori-Boateng, C., Oke, C.O., Oostra, V., Osgathorpe, L.M., Otavo, S.E., Page, N.V., Paritsis, J., Parra-H, A., Parry, L., Pe'er, G., Pearman, P.B., Pelegrin, N., Pélissier, R., Peres, C.A., Peri, P.L., Persson, A.S., Petanidou, T., Peters, M.K., Pethiyagoda, R.S., Phalan, B., Philips, T.K., Pillsbury, F.C., Pincheira-Ulbrich, J., Pineda, E., Pino, J., Pizarro-Araya, J., Plumptre, A.J., Poggio, S.L., Politi, N., Pons, P., Poveda, K., Power, E.F., Presley, S.J., Proença, V., Quaranta, M., Quintero, C., Rader, R., Ramesh, B.R., Ramirez-Pinilla, M.P., Ranganathan, J., Rasmussen, C., Redpath-Downing, N.A., Reid, J.L., Reis, Y.T., Rey Benayas, J.M., Rey-Velasco, J.C., Reynolds, C., Ribeiro, D.B., Richards, M.H., Richardson, B.A., Richardson, M.J., Ríos, R.M., Robinson, R., Robles, C.A., Römbke, J., Romero-Duque, L.P., Rös, M., Rosselli, L., Rossiter, S.J., Roth, D.S., Roulston, T.H., Rousseau, L., Rubio, A.V., Ruel, J.-C., Sadler, J.P., Sáfián, S., Saldaña-Vázquez, R.A., Sam, K., Samnegård, U., Santana, J., Santos, X., Savage, J., Schellhorn, N.A., Schilthuizen, M., Schmiedel, U., Schmitt, C.B., Schon, N.L., Schüepp, C., Schumann, K., Schweiger, O., Scott, D.M., Scott, K.A., Sedlock, J.L., Seefeldt, S.S., Shahabuddin, G., Shannon, G., Sheil, D., Sheldon, F.H., Shochat, E., Siebert, S.J., Silva, F.A.B., Simonetti, J.A., Slade, E.M., Smith, J., Smith-Pardo, A.H., Sodhi, N.S., Somarriba, E.J., Sosa, R.A., Soto Quiroga, G., St-Laurent, M.-H., Starzomski, B.M., Stefanescu, C., Steffan-Dewenter, I., Stouffer, P.C., Stout, J.C., Strauch, A.M., Struebig, M.J., Su, Z., Suarez-Rubio, M., Sugiura, S., Summerville, K.S., Sung, Y.-H., Sutrisno, H., Svenning, J.-C., Teder, T., Threlfall, C.G., Tiitsaar, A., Todd, J.H., Tonietto, R.K., Torre, I., Tóthmérész, B., Tscharntke, T., Turner, E.C., Tylianakis, J.M., Uehara-Prado, M., Urbina-Cardona, N., Vallan, D., Vanbergen, A.J., Vasconcelos, H.L., Vassilev, K., Verboven, H.A.F., Verdasca, M.J., Verdú, J.R., Vergara, C.H., Vergara, P.M., Verhulst, J., Virgilio, M., Vu, L.V., Waite, E.M., Walker, T.R., Wang, H.-F., Wang, Y., Watling, J.I., Weller, B., Wells, K., Westphal, C., Wiafe, E.D., Williams, C.D., Willig, M.R., Woinarski, J.C.Z., Wolf, J.H.D., Wolters, V., Woodcock, B.A., Wu, J., Wunderle, J.M., Yamaura, Y., Yoshikura, S., Yu, D.W., Zaitsev, A.S., Zeidler, J., Zou, F., Collen, B., Ewers, R.M., Mace, G.M., Purves, D.W., Scharlemann, J.P.W., Purvis, A. (2017) The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project. Ecology and Evolution. 7: 145-188.
Link
Doi: 10.1002/ece3.2579

Abstract:

Multiscale scenarios for nature futures

Rosa, I.M.D., Pereira, H.M., Ferrier, S., Alkemade, R., Acosta, L.A., Akcakaya, H.R., Den Belder, E., Fazel, A.M., Fujimori, S., Harfoot, M., Harhash, K.A., Harrison, P.A., Hauck, J., Hendriks, R.J.J., Hernández, G., Jetz, W., Karlsson-Vinkhuyzen, S.I., Kim, H., King, N., Kok, M.T.J., Kolomytsev, G.O., Lazarova, T., Leadley, P., Lundquist, C.J., García Márquez, J., Meyer, C., Navarro, L.M., Nesshöver, C., Ngo, H.T., Ninan, K.N., Palomo, M.G., Pereira, L.M., Peterson, G.D., Pichs, R., Popp, A., Purvis, A., Ravera, F., Rondinini, C., Sathyapalan, J., Schipper, A.M., Seppelt, R., Settele, J., Sitas, N., Van Vuuren, D. (2017) Multiscale scenarios for nature futures. Nature Ecology and Evolution. 1: 1416-1419.
Link
Doi: 10.1038/s41559-017-0273-9

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Changes in forest structure and composition after fire in tropical montane cloud forests near the Andean treeline

Oliveras I., Malhi Y., Salinas N., Huaman V., Urquiaga-Flores E., Kala-Mamani J., Quintano-Loaiza J.A., Cuba-Torres I., Lizarraga-Morales N., Roman-Cuesta R.-M. (2014) Changes in forest structure and composition after fire in tropical montane cloud forests near the Andean treeline. Plant Ecology and Diversity. 7: 329-340.
Link
Doi: 10.1080/17550874.2013.816800

Abstract:

Background: In tropical montane cloud forests (TMCFs) fires can be a frequent source of disturbance near the treeline. Aims: To identify how forest structure and tree species composition change in response to fire and to identify fire-tolerant species, and determine which traits or characteristics are associated with fire tolerance. Methods: Shifts in forest structure and diversity were assessed on 15 paired plots in burnt and unburnt (control) forests, along a fire chronosequence. Species were classified as fire-sensitive, fire survivors or fire thrivers, using a fire tolerance index. Regression and tree analyses were used to determine which traits contributed to the fire tolerance of species. Results: There were more small- and medium-sized trees in the burnt plots independent of time since the last fire. There were shifts in family importance value and in species diversity among the plots. Of the 73 species analysed there were 39 fire-sensitive species, 19 fire survivors and 14 fire thrivers. Sprouting ability and biomass showed a positive relationship with the fire tolerance of species. Conclusions: There were immediate as well as long-term (up to 15 years) effects of fire on forest structure and species composition, suggesting that TMCFs take more than 15 years to regenerate from a fire. Long-term studies are needed to fully understand regeneration patterns of TMCFs after fires. © 2014 Copyright 2013 Botanical Society of Scotland and Taylor & Francis.

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Synchronous fire activity in the tropical high Andes: An indication of regional climate forcing

Roman-Cuesta R.M., Carmona-Moreno C., Lizcano G., New M., Silman M., Knoke T., Malhi Y., Oliveras I., Asbjornsen H., Vuille M. (2014) Synchronous fire activity in the tropical high Andes: An indication of regional climate forcing. Global Change Biology. 20: 1929-1942.
Link
Doi: 10.1111/gcb.12538

Abstract:

Global climate models suggest enhanced warming of the tropical mid and upper troposphere, with larger temperature rise rates at higher elevations. Changes in fire activity are amongst the most significant ecological consequences of rising temperatures and changing hydrological properties in mountainous ecosystems, and there is a global evidence of increased fire activity with elevation. Whilst fire research has become popular in the tropical lowlands, much less is known of the tropical high Andean region (>2000masl, from Colombia to Bolivia). This study examines fire trends in the high Andes for three ecosystems, the Puna, the Paramo and the Yungas, for the period 1982-2006. We pose three questions: (i) is there an increased fire response with elevation? (ii) does the El Niño- Southern Oscillation control fire activity in this region? (iii) are the observed fire trends human driven (e.g., human practices and their effects on fuel build-up) or climate driven? We did not find evidence of increased fire activity with elevation but, instead, a quasicyclic and synchronous fire response in Ecuador, Peru and Bolivia, suggesting the influence of high-frequency climate forcing on fire responses on a subcontinental scale, in the high Andes. ENSO variability did not show a significant relation to fire activity for these three countries, partly because ENSO variability did not significantly relate to precipitation extremes, although it strongly did to temperature extremes. Whilst ENSO did not individually lead the observed regional fire trends, our results suggest a climate influence on fire activity, mainly through a sawtooth pattern of precipitation (increased rainfall before fire-peak seasons (t-1) followed by drought spells and unusual low temperatures (t0), which is particularly common where fire is carried by low fuel loads (e.g., grasslands and fine fuel). This climatic sawtooth appeared as the main driver of fire trends, above local human influences and fuel build-up cyclicity. © 2014 John Wiley & Sons Ltd.

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Pacific and Atlantic oceanic anomalies and their interaction with rainfall and fire in Bolivian biomes for the period 1992–2012

Roman-Cuesta R.M., Rejalaga-Noguera L., Pinto-Garcia C., Retana J. (2014) Pacific and Atlantic oceanic anomalies and their interaction with rainfall and fire in Bolivian biomes for the period 1992–2012. Climatic Change. : 0-0.
Link
Doi: 10.1007/s10584-014-1246-5

Abstract:

Bolivia is located at the crossroad of the major climatic influences of Northern and Southern-South America, which turns this country into a natural laboratory to investigate the interactions between ocean-climate and fire variability. We chose two oceanic indices: MEI (multivariate ENSO Index) and AMO (Atlantic Multidecadal Oscillation) to select the three most representative years for four oceanic conditions: El Niño, La Niña, AMO, and standard years (understood as years with little ocean influences), for the period 1992–2012. We investigated how i) rainfall (dry vs wet seasons) and ii) fire responded in five Bolivian biomes (Tropical Moist Forests, Tropical Dry Forests, Tropical Grasslands, Tropical Montane, and Seasonally Flooded ecosystems) under these oceanic conditions. Bolivia showed a strong rainfall increase in El Niño years in both seasons (wet/dry), while AMO showed the strongest droughts in both seasons. La Niña showed a bipolar response with rainfall increases in the wet season and a very marked rainfall decrease in the dry season. Drought significantly increased fire numbers in AMO years, being the most significant fire condition and suggesting a larger fire influence of the Atlantic than the Pacific at the national level. Surprisingly, the amount of fire was very large under normal years (STD) and similar to fire levels under La Niña, suggesting generalized fire conditions in the country, except for El Niño years that bring rainfall excess and little fire. The most fire-affected biomes were the seasonally flooded and dry forests, followed by the grassland/savannah biome. Montane areas showed the least fire, but satellite fire omission is well known in the Andean region.

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Comparison of burnt area estimates derived from satellite products and national statistics in Europe

Loepfe L., Lloret F., Román-Cuesta R.M. (2012) Comparison of burnt area estimates derived from satellite products and national statistics in Europe. International Journal of Remote Sensing. 33: 3653-3671.
Link
Doi: 10.1080/01431161.2011.631950

Abstract:

Burnt area maps based on satellite observations are frequently used in calculations related to fire regime, such as those of carbon dioxide emissions. Nevertheless, burnt area estimates between products vary widely, and validation against independent data is scarce, especially for Europe. Here we compare two active fire maps (the ATSR World Fire Atlas and the Moderate Resolution Imaging Spectroradiometer (MODIS) Active Fire Product) and two fire scars maps (the L3JRC and the MODIS Burned Area Product) to independent national statistics taken from 22 European countries between 1997 and 2008. We also tested the coincidence between satellite products derived by calculation of the fraction of active fires that were confirmed by a subsequent drop in reflectance. As a large proportion of fire pixels (between 40% and 66%, depending on the product) is located on urban land or crop fields, filtering out fires located on these land uses greatly improves the agreement between satellite-based burnt area estimates and national statistics and it also improves the coincidence between satellite products. The MODIS Active Fire Product appears to be most suitable for use as a proxy for burnt area patterns, showing a high correlation to national statistics (R 2 = 0.9), relatively low spatial and temporal heterogeneity and only a slight underestimation of the total burnt area (19 000 ha year -1). Unfiltered products show cases of substantial wildfire overestimation in all products, mainly attributable to anthropogenic activity, in the case of active fire products, and drought-induced vegetation dieback, in that of fire scar maps. Thus, filtering out fires on anthropogenic land uses seems to be essential when analysing patterns of forest fires from satellite observations. However, if agricultural fires are to be included, a combination of MODIS Active Fire and MODIS Burned Area products is recommended. We obtained that such combination shows low temporal and spatial heterogeneity and the highest coincidence between satellite products (25%), although the correlation to national statistics is not very high (R 2 = 0.67) and clearly underestimates the total burnt area (187 000 ha year -1). © 2012 Copyright Taylor and Francis Group, LLC.

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Characterising fire spatial pattern interactions with climate and vegetation in Colombia

Armenteras-Pascual D., Retana-Alumbreros J., Molowny-Horas R., Roman-Cuesta R.M., Gonzalez-Alonso F., Morales-Rivas M. (2011) Characterising fire spatial pattern interactions with climate and vegetation in Colombia. Agricultural and Forest Meteorology. 151: 279-289.
Link
Doi: 10.1016/j.agrformet.2010.11.002

Abstract:

Vegetation burning in tropical countries is a threat to the environment, causing not only local ecological, economic and social impacts, but also large-scale implications for global change. The burning is usually a result of interacting factors, such as climate, land-use and vegetation type. Satellite-derived monthly time series datasets of rainfall, burned area and active fire detections between December 2000 and 2009 were used in this study. A map of vegetation types was also used to determine these factors' spatial and temporal variability and interactions with the total amount of burned area and active fires detected in Colombia. Grasslands represented the vegetation most affected by fires every year in terms of burned area (standardised by their total area), followed by secondary vegetation, pasture and forests. Grasslands were also most affected by active fires, but followed closely by pasture, agricultural areas, secondary vegetation and forests. The results indicated strong climate and fire seasonality and marked regional difference, partly explained by climatic differences amongst regions and vegetation types, especially in the Orinoco and Caribbean regions. The incidence of fire in the Amazon and Andes was less influenced by climate in terms of burned area impacted, but the strength of the ENSO phenomenon affected the Orinoco and the Andes more in terms of burned area. Many of the active fires detected occurred in areas of transition between the submontane and lowland Andes and the Amazon, where extensive conversion to pasture is occurring. The possible high impact of small fires on the tropical rainforest present in this transition area and the Amazonian rainforest deserves more attention in Colombia due to its previous lack of attention to its contribution to global change. © 2010 Elsevier B.V.

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Using learning networks to understand complex systems: A case study of biological, geophysical and social research in the Amazon

Barlow J., Ewers R.M., Anderson L., Aragao L.E.O.C., Baker T.R., Boyd E., Feldpausch T.R., Gloor E., Hall A., Malhi Y., Milliken W., Mulligan M., Parry L., Pennington T., Peres C.A., Phillips O.L., Roman-Cuesta R.M., Tobias J.A., Gardner T.A. (2011) Using learning networks to understand complex systems: A case study of biological, geophysical and social research in the Amazon. Biological Reviews. 86: 457-474.
Link
Doi: 10.1111/j.1469-185X.2010.00155.x

Abstract:

Developing high-quality scientific research will be most effective if research communities with diverse skills and interests are able to share information and knowledge, are aware of the major challenges across disciplines, and can exploit economies of scale to provide robust answers and better inform policy. We evaluate opportunities and challenges facing the development of a more interactive research environment by developing an interdisciplinary synthesis of research on a single geographic region. We focus on the Amazon as it is of enormous regional and global environmental importance and faces a highly uncertain future. To take stock of existing knowledge and provide a framework for analysis we present a set of mini-reviews from fourteen different areas of research, encompassing taxonomy, biodiversity, biogeography, vegetation dynamics, landscape ecology, earth-atmosphere interactions, ecosystem processes, fire, deforestation dynamics, hydrology, hunting, conservation planning, livelihoods, and payments for ecosystem services. Each review highlights the current state of knowledge and identifies research priorities, including major challenges and opportunities. We show that while substantial progress is being made across many areas of scientific research, our understanding of specific issues is often dependent on knowledge from other disciplines. Accelerating the acquisition of reliable and contextualized knowledge about the fate of complex pristine and modified ecosystems is partly dependent on our ability to exploit economies of scale in shared resources and technical expertise, recognise and make explicit interconnections and feedbacks among sub-disciplines, increase the temporal and spatial scale of existing studies, and improve the dissemination of scientific findings to policy makers and society at large. Enhancing interaction among research efforts is vital if we are to make the most of limited funds and overcome the challenges posed by addressing large-scale interdisciplinary questions. Bringing together a diverse scientific community with a single geographic focus can help increase awareness of research questions both within and among disciplines, and reveal the opportunities that may exist for advancing acquisition of reliable knowledge. This approach could be useful for a variety of globally important scientific questions. © 2010 The Authors. Biological Reviews © 2010 Cambridge Philosophical Society.

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Factors influencing the formation of unburned forest islands within the perimeter of a large forest fire

Román-Cuesta R.M., Gracia M., Retana J. (2009) Factors influencing the formation of unburned forest islands within the perimeter of a large forest fire. Forest Ecology and Management. 258: 71-80.
Link
Doi: 10.1016/j.foreco.2009.03.041

Abstract:

Large forest fires have recently increased in frequency and severity in many ecosystems. Due to the heterogeneity in fuels, weather and topography, these large fires tend to form unburned islands of vegetation. This study focuses on a large forest fire that occurred in north-eastern Spain in 1998, which left large areas of unburned vegetation within its perimeter. Based on a satellite post-fire severity map we searched for the relative influence of biotic and abiotic factors leading to unburned island formation. We divided the area of the fire into individual units we called "slopes" which were meant to separate the differential microclimatic effects of contrasted aspects. The number of unburned islands and their areas were related to 12 variables that influence their formation (i.e. land cover composition, aspect, steepness, forest structure, two landscape indices and weather variables). We hypothesized that unburned vegetation islands would concentrate on northern aspects, in less flammable forests (i.e. broadleaf species) and higher fragmentation to interrupt the advance of fire. While north and western aspects did have a higher presence of unburned vegetation islands, our study suggests greater presence of islands in slopes that are larger (i.e. more continuous areas with relatively homogeneous aspect), with greater proportions of forest cover, with higher wood volumes and with lower proportions of broadleaf species. Climate also played a role, with relative humidity and wind speed positively and negatively correlated to island formation, respectively. Unburned vegetation was more frequent on slopes with lower diversity of land covers and higher dominance of one land cover in the slope. Since slopes with only one land cover (i.e. forests) had more islands than slopes with multiple cover types, we infer that under severe meteorological conditions, fragmented forests can be more affected by wind and by water stress, thus burning more readily than forests that are protected from this edge phenomenon. These results would reinforce forest management strategies that avoid linear features (fire-lines and fire-breaks), to enhance fuel treatments that focus on areas and minimize fragmentation. © 2009 Elsevier B.V. All rights reserved.

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