Taxonomic evaluation of Galium brockmannii Briq. (Rubiaceae) intraspecific variability

Han sido examinados 13 caracteres morfológicos en 46 individuos de 14 poblaciones de Galium brockmannii Briq. con el objetivo de verificar el estatus taxonómico del presunto endemismo pirenaico G. brockmannii subsp. aterratzense Romo. Mediante un análisis multivariante de la varianza (MANOVA) se ha constatado que las dos subespecies de G. brockmannii no difieren significativamente (W= 0,910, p-valor = 0,259) por lo que respecta a 3 de los principales caracteres considerados diagnósticos en la descripción original de la subsp. aterratzense. No se han encontrado otros caracteres morfológicos que permitan una clara identificación y separación de ambas subespecies. Una representación de los 2 primeros ejes de un Análisis de Componentes Principales (ACP) utilizando los 13 caracteres morfológicos estudiados muestra que la subsp. aterratzense no forma un grupo homogéneo bien caracterizado separable de la subespecie típica. Por otro lado, los 9 individuos de G. idubedae (Pau ex Debeaux) Pau ex Ehrend. estudiados de 5 poblaciones diferentes, utilizados como referencia externa en este análisis, se muestran claramente agrupados y separados de las poblaciones de G. brockmannii. En resumen, todos los dados disponibles sugieren que G. brockmannii subsp. aterratzense debe ser considerado un sinónimo de G. brockmannii.In order to verify the taxonomic status of the presumably endemic Pyrenean Galium brockmannii subsp. aterratzense Romo, 13 morphological characters have been studied in 46 individuals from 14 populations of G. brockmannii. A multivariate analysis of variance (MANOVA) using the 3 main diagnostic characters for subsp. aterratzense showed no significant differences between the two subspecies of G. brockmannii (W= 0.910, p-value = 0.259). No other discriminating morphological characters for the two subspecies have been found. A Principal Components Analysis (PCA) has been performed using the 13 morphological characters, including 9 individuals from 5 populations of G. idubedae (Pau ex Debeaux) Pau ex Ehrend. as an outgroup. The PCA two first axes representation showed that the two species may be clearly distinguished while G. brockmannii subsp. aterratzense does not form a homogeneous, isolated cluster. In conclusion, all available data support G. brockmannii subsp. aterratzense should be considered a synonym of G. brockmannii

Evaluación taxonómica de la variabilidad intraespecífica de Galium brockmannii Briq. (Rubiaceae)

Han sido examinados 13 caracteres morfológicos en 46 individuos de 14 poblaciones de Galium brockmannii Briq. con el objetivo de verificar el estatus taxonómico del presunto endemismo pirenaico G. brockmannii subsp. aterratzense Romo. Mediante un análisis multivariante de la varianza (MANOVA) se ha constatado que las dos subespecies de G. brockmannii no difieren significativamente (W= 0,910, p-valor = 0,259) por lo que respecta a 3 de los principales caracteres considerados diagnósticos en la descripción original de la subsp. aterratzense. No se han encontrado otros caracteres morfológicos que permitan una clara identificación y separación de ambas subespecies. Una representación de los 2 primeros ejes de un Análisis de Componentes Principales (ACP) utilizando los 13 caracteres morfológicos estudiados muestra que la subsp. aterratzense no forma un grupo homogéneo bien caracterizado separable de la subespecie típica. Por otro lado, los 9 individuos de G. idubedae (Pau ex Debeaux) Pau ex Ehrend. estudiados de 5 poblaciones diferentes, utilizados como referencia externa en este análisis, se muestran claramente agrupados y separados de las poblaciones de G. brockmannii. En resumen, todos los dados disponibles sugieren que G. brockmannii subsp. aterratzense debe ser considerado un sinónimo de G. brockmanniiIn order to verify the taxonomic status of the presumably endemic Pyrenean Galium brockmannii subsp. aterratzense Romo, 13 morphological characters have been studied in 46 individuals from 14 populations of G. brockmannii. A multivariate analysis of variance (MANOVA) using the 3 main diagnostic characters for subsp. aterratzense showed no significant differences between the two subspecies of G. brockmannii (W= 0.910, p-value = 0.259). No other discriminating morphological characters for the two subspecies have been found. A Principal Components Analysis (PCA) has been performed using the 13 morphological characters, including 9 individuals from 5 populations of G. idubedae (Pau ex Debeaux) Pau ex Ehrend. as an outgroup. The PCA two first axes representation showed that the two species may be clearly distinguished while G. brockmannii subsp. aterratzense does not form a homogeneous, isolated cluster. In conclusion, all available data support G. brockmannii subsp. aterratzense should be considered a synonym of G. brockmanni

How Fire History, Fire Suppression Practices and Climate Change Affect Wildfire Regimes in Mediterranean Landscapes

Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain). We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape, climate and socioeconomic factors such as fire suppression strategies

Using unplanned fires to help suppressing future large fires in Mediterranean forests

Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire–succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000–2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18–22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are to be achieved, especially in the wider context of climate change.This study was supported by the research projects BIONOVEL (CGL2011-29539/BOS) and MONTES (CSD2008-00040) funded by the Spanish Ministry of Education and Science