El Parque Natural del Carrascal de la Font Roja como laboratorio para investigar el impacto del cambio climático en la vegetación mediterránea

Las proyecciones del cambio climático indican que en el área mediterránea se producirá un aumento en la frecuencia de sequías extremas, lo que causará impactos en sus masas forestales y en los servicios ecosistémicos que estas prestan. En los últimos años se han registrado eventos de decaimiento y mortalidad asociados a fuertes sequías, los cuales se pueden considerar representativos de los previstos por el cambio climático, por lo que su estudio es una oportunidad para comprender y predecir cómo se verán afectados los bosques mediterráneos en el futuro. Este es el principal objetivo del nuevo proyecto de investigación liderado por la Universidad de Alicante y el CEAM y cuyo propósito es profundizar en el conocimiento de estas cuestiones. Para ello se está llevando a cabo el análisis detallado de distintas variables ecohidrológicas y ecofisiológicas en masas forestales de distintas zonas experimentales de la Comunidad Valenciana, dos de las cuales se hallan en el Parque Natural del Carrascal de la Font Roja. En este artículo se presentan los principales objetivos del citado proyecto, así como sus instalaciones experimentales en el Parque Natural.Les projeccions de canvi climàtic indiquen que a l’àrea mediterrània es produirà un augment en la freqüència de sequeres extremes, el que causarà impactes en les seues masses forestals i en els servicis ecosistèmics que aquestes presten. En els últims anys s’han registrat esdeveniments de decaïment i mortalitat associats a fortes sequeres, les quals es poden considerar representatives de les previstes pel canvi climàtic. Per tant, el seu estudi és una oportunitat per a comprendre com es veuran afectats els boscos mediterranis en el futur. Aquest és el principal objectiu d’un nou projecte d’investigació liderat per la Universitat d’Alacant i el CEAM i es tracta d’aprofundir en el coneixement d’aquestes qüestions. Per a això s’està duent a terme l’anàlisi detallat de distintes variables ecohidrológiques i ecofisiológiques en masses forestals de diferents zones experimentals de la Comunitat Valenciana, dues de les quals es troben en el Parc Natural del Carrascal de la Font Roja. En aquest article es presenten els objectius específics de l’esmentat projecte, així com les seues instal·lacions experimentals al Parc Natural.Global change projections point out an increase in the number of severe droughts in the Mediterranean region, which may have a deep impact in forests and in environmental services they provide. In the past years, events of drought-induced decay and plant mortality have been registered in this region, which are considered representative of climatic change consequences. Hence, their study is a good chance to understand and foresee how Mediterranean forests will be affected by climate change in the future. This is the main purpose of the new research project carried out by University of Alicante and CEAM foundation whose main goal is improve our actual knowledge in this topic. To achieve this, an exhaustive study of forest’s ecohydrological and ecophysological variables is being carried out in several experimental sites through the Valencian Communiy, two of them located within kermes oak forest of Font Roja Natural Park. In this paper, we introduce the main project goals and the experimental design of Natural Park’s study sites.Este trabajo que se está desarrollando está financiado dentro del marco de los proyectos Alteraclim (CGL2015-69773-C2-1-P) y Survive-2 (CGL2015-69773-C2-2-P) con fondos del ministerio de Ciencia y Tecnología (MINECO/FEDER)

The main factors that drive plant dieback under extreme drought differ among Mediterranean shrubland plant biotypes

Questions: Knowledge of how extreme drought events induce plant dieback and, eventually, plant mortality, may improve our forecasting of ecosystem change according to future climate projections, especially in Mediterranean drylands. In them, shrublands are the main vegetation communities in transition areas from a subhumid to semi-arid climate. This study analyzed differences in plant dieback after an unusual drought in 2014 and identified their main underlying factors in relation to three groups of explanatory variables: water availability, soil properties and vegetation structure attributes. Location: Four Mediterranean shrublands along a climatic gradient in SE Spain. Methods: At each experimental field site, we sampled a pool of vegetation structure characteristics, soil depth and soil surface properties, and we also determined water availability by continuously monitoring soil moisture and the microclimate conditions. Results: The climatic analysis showed that there was an extreme drought event in 2014, which was below the first percentile of the driest years. Under such conditions, vegetation dieback occurred at all the study sites. However, plant dieback differed between sites and plant biotypes. Subshrubs were the main affected biotype, with diebacks close to 60% at the driest sites, and up to 40% dieback for shrubs depending on their vertical development. Relative extractable water and bare soil surface cover were the best explanatory variables of plant community dieback but changed between plant biotypes. Vegetation structure variables related to plant vertical development (leaf area index [LAI], plant height, phytovolume) were significant explanatory variables of plant dieback in shrubs, subshrubs and grasses. Consecutive dry days fitted the best model to explain subshrub dieback. Conclusions: We found that rainfall pattern rather than total annual rainfall was the climatic factor that best determined water availability for plants in Mediterranean drylands. These results also pointed out the relevance of plant structure and soil properties for explaining ecosystem responses to extreme drought.This research was funded by the Spanish Ministry of Economy and Competitiveness through Projects HYDROMED (PID2019-111332RB-C21) and INERTIA (PID2019-111332RB-C22), and through the IMAGINA projects (PROMETEU/2019/110) and (APOSTD20/2019–-7956) from the Generalitat Valenciana and the European Social Fund. AMR was supported by the scholarship FPU-UA (2015) from the University of Alicante

Extreme drought impacts have been underestimated in grasslands and shrublands globally.

Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought

Extreme drought impacts have been underestimated in grasslands and shrublands globally.

Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought

Extreme drought impacts have been underestimated in grasslands and shrublands globally

Altres Ajuts: Fundación Ramón Areces grant CIVP20A6621Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought

Extreme drought impacts have been underestimated in grasslands and shrublands globally

Climate change is increasing the frequency and severity of short-term (~1 y) drought events—the most common duration of drought—globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function—aboveground net primary production (ANPP)—was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought