Aportaciones de la paleobotánica a la interpretación del área natural de 'Pinnus nigra' Arn. ssp. 'sazmanni' en las Sierras Béticas (Sureste de España)

En este trabajo se ha analizado la cartografía del área natural de Pinus nigra Arn. ssp. salzmannii en las Sierras Béticas (sureste de España) a partir del Mapa Forestal de España en su versión digital y se han descrito las características geológicas y litológicas de las zonas que ocupa utilizando para ello la cartografía correspondiente. El área natural de la especie se ha comparado con los Mapas de Series de Vegetación más utilizados. Posteriormente se ha realizado una búsqueda bibliográfica seleccionando las citas significativas de yacimientos holocenos en el Sureste peninsular en los que se han encontrado evidencias paleoecológicas (pólenes, madera, carbón, etc.) de la presencia de Pinus nigra en estos enclaves. A partir de los datos obtenidos se ha discutido acerca de la presencia natural de Pinus nigra Arn. en las Sierras Béticas y su difícil encaje en los modelos fitosociológicos más utilizados, aportando datos ecológicos y paleoecológicos que inciden en la importancia de elaborar modelos más complejos que consideren factores más allá de la climatología y el suelo para explicar la dinámica vegetal. Se confirman o elaboran hipótesis acerca de la presencia de pino salgareño durante el Holoceno en dos zonas en las que actualmente se encuentra extinguido: la Sierra de Gádor (Almería) y las Sierras Subbéticas de Córdoba, y acerca de su mayor presencia en épocas pasadas. Como consecuencia de los resultados se incide en la importancia que tiene en la gestión forestal la consideración y conservación de las poblaciones de pino salgareño.This paper develops a map of the natural area of Pinus nigra Arn. ssp. salzmanni in the Beticas Mountain Range based on the Digital version of the Forestry Vegetation Map of Spain. This map has been compared with the most commonly used Potential Vegetation, Geology and Lithology maps. A bibliographic research has been carried out with a selection of Holocene deposits where Pinus nigra pollen, wood or charcoal has been found. With this information collected, a discussion about the natural distribution of Pinus nigra at the Béticas Mountain Range and the difficulty of matching this distribution within the most common phytosociological models has been posed. Ecological and palaeoecological data have been given to stress the importance of developing more complex models, considering factors beyond climate and soil, to explain the forest dynamics. It has been confirmed the hypothesis about the existence of Pinus nigra in the Holocene in two Andalousian Mountain Range (Gádor in the province of Almeria and Sierras Sub-Béticas in the province of Córdoba), where this species are currently extinguished. Considering all these data it is emphasized the interest and importance of conservation of natural salzmann pine forests in this area

SilvAdapt.Net: A Site-Based Network of Adaptive Forest Management Related to Climate Change in Spain

Adaptive forest management (AFM) is an urgent need because of the uncertainty regarding how changes in the climate will affect the structure, composition and function of forests during the next decades. Current research initiatives for the long-term monitoring of impacts of silviculture are scattered and not integrated into research networks, with the consequent losses of opportunities and capacity for action. To increase the scientific and practical impacts of these experiences, it is necessary to establish logical frameworks that harmonize the information and help us to define the most appropriate treatments. In this context, a number of research groups in Spain have produced research achievements and know-how during the last decades that can allow for the improvement in AFM. These groups address the issue of AFM from different fields, such as ecophysiology, ecohydrology and forest ecology, thus resulting in valuable but dispersed expertise. The main objective of this work is to introduce a comprehensive strategy aimed to study the implementation of AFM in Spain. As a first step, a network of 34 experimental sites managed by 14 different research groups is proposed and justified. As a second step, the most important AFM impacts on Mediterranean pines, as one of the most extended natural and planted forest types in Spain, are presented. Finally, open questions dealing with key aspects when attempting to implement an AFM framework are discussed. This study is expected to contribute to better outlining the procedures and steps needed to implement regional frameworks for AFMA.J. Molina is beneficiary of an “APOSTD” fellowship (APOSTD/2019/111) funded by the Generalitat Valenciana. M. Moreno-de las Heras is beneficiary of a Serra Hunter fellowship (UB-LE-9055) funded by the Generalitat de Catalunya. F.J. Ruiz-Gómez is supported by a postdoctoral fellowship of the Junta de Andalucía (Sevilla, Spain), and the European Social Fund 2014–2020 Program (DOC_0055). The authors received national and international funding through the following projects: SILVADAPT.NET (RED2018-102719-T), ESPECTRAMED (CGL2017-86161-R), Life-FOREST CO2 (LIFE14 CCM/ES/001271), ALTERACLIM (CGL2015-69773-C2-1-P), INERTIA (PID2019-111332RB-C22-BDV), CEHYRFO-MED (CGL2017-86839-C3-2-R), DEHESACLIM (IB16185), RESILIENTFORESTS (LIFE17 CCA/ES/000063), Rhysotto (PID2019-106583RB-I00), AGL2017-83828- C2-2-R, RTI2018-096884-B-C31, ESPAS (CGL2015-65569-R), and caRRRascal (RTI2018-095037-B-I00) : We thank the financial support from the “Ministerio de Ciencia e Innovación -Redes de Investigación 2018, Programa Estatal de Generación de Conocimiento y Fortalecimiento Científico y Tecnológico del Sistema de I + D + I

Growth trends and sensitivity to climate of declining Mediterranean open woodlands exhibiting widespread mortality in Southern Spain

We present two chronologies of dead and weakened Quercus ilex trees from declining open woodlands of Southern Andalusia and discuss climate's implication in the current widespread mortality in these ecosystems. Basal area increments were used to find out periods of growth decline preceding death. Absent rings became frequent since the 1970s, coinciding with increasing drought. Negative pointer years matched dry years and became more pronounced in the last decades. Growth was correlated with the annual Palmer Drought Severity Index and precipitations from previous October to May. Mean sensitivity increased recently, ranging between high values (0.35-0.5). Correlations with spring temperatures turned from positive to negative, positive correlations with current autumn precipitation arose whereas significant positive correlations with summer precipitations were no longer observed. These changes could suggest modifications on tree phenology. Intensively-used Mediterranean open woodlands of Southern Andalusia are vulnerable and the current dying process suggests that they are unlikely to overcome increasing stress climatic conditions

Climate change-controlled dendroecological signal in Pinus pinea in Southern Spain

Researching the dynamic response to climatic variability of Mediterranean pine forests is a basic issue when evaluating the vulnerability of these ecosystems to climate change-induced abiotic stress. Tree-rings can provide valuable information to approach this purpose. We established five Pinus pinea ring-width chronologies in SW Spain. Tree-growth variability was analyzed using principal component analysis (PCA) for the period 1935-2011. A common climatic signal expressed by the first principal component (PC1) was found. Considering the PC1 scores as a regional chronology, significant correlations with meteorological data were found: correlation was positive for winter-spring precipitation and winter minimum temperatures, and negative for spring maximum temperatures. The PCA, the PC1-climate correlations and the inter-annual ringwidth variability (sensitivity) were computed for successive intervals to check whether the variance explained by the PC1, the climate-growth relationships and the intensity of growth response to climate varied over time. Both sensitivity and shared variance increased over the last decades. The correlation with winter precipitation and temperatures became stronger, spring precipitations lost significance and negative correlation with spring temperatures was enhanced. This indicates that climate became more limiting and a major force controlling growth in the recent decades. In agreement with our findings, meteorological series showed an increase of maximum temperatures in the warmer months, a decrease of minimum temperatures in winter and a marked increase of precipitation variability. Finally, running-interval correlations were performed between PC1 and three P. pinea reference chronologies from Central Spain: correlation increased significantly since the 1970s, indicating an enhanced common macroclimatic signal. Our study highlights the sensitivity of P. pinea to more restrictive climatic conditions and the synchronizing effect of climate change on P. pinea forest growth patterns at regional scale

Identification of Old-Growth Mediterranean Forests Using Airborne Laser Scanning and Geostatistical Analysis

The protection and conservation of old-growth forests (OGFs) are becoming a global concern due to their irreplaceability and high biodiversity. Nonetheless, there has been little research into the identification and characterization of OGFs of the oldest tree species in Mediterranean areas. We used forest inventory data, low-density airborne laser scanning (ALS) metrics, and geostatistical analysis to estimate old-growth indices (OGIs) as indicators of old-growth forest conditions. We selected a pilot area in European black pine (Pinus nigra subsp. salzmannii) ecosystems where the oldest known living trees in the Iberian Peninsula are found. A total of 756 inventory plots were established to characterize standard live tree and stand attributes. We estimated several structural attributes that discriminate old growth from younger age classes and calculated different types of OGI for each plot. The best OGI was based on mean tree diameter, standard deviation of tree diameter, and stand density of large trees (diameter > 50 cm). This index is useful for assessing old-growthness at different successional stages (young and OGFs) in Mediterranean black pine forests. Our results confirm that the estimation of OGIs based on a combination of forest inventory data, geostatistical analysis, and ALS is useful for identifying OGFsThis work was supported by the following projects: “Iberian Heritage Project”, funded by the Netherlands Organization for Scientific Research (NWO, project number 236-61-001), National Geographic Society-Waitts Grant Program (“Millennia old black pines and Andalusian Cultural Heritage to unravel human-environment interactions in the Western Mediterranean”, W329-14), the Biodiversity Foundation of the Ministry of Agriculture and Fisheries, Food and Environment (“Bosques viejos frente al cambio climático. Vulnerabilidad, capacidad adaptativa e implicaciones frente a la gestión forestal”, PRCV00433) and Ministry of Economy, Industry and Competitiveness (MINECO) (“El final del ciclo envejecimiento, mortalidad y regeneración en pinares mediterráneos, y su papel en la adaptación ante un ambiente en cambio (OLDPINE), AGL2017-83828-C2-2-R). The Ministry of Agriculture and Environment of the Regional Government of Andalusia provided the AF forest inventory data. AH have been supported by PinCaR project (UHU-1266324, FEDER Funds, Andalusia Regional Government, Consejería de Economía, Conocimiento, Empresas y Universidad 2014-2020). We thank the Forest Service at Cazorla, Segura y Las Villas Natural Park, for providing the forest inventory data and for their interest in the project. Debería de ser más completo: We are grateful to Teresa Moro from the Natural Park, and Valentin Badillo from the Cazorla, Segura and Las Villas Natural Park, for their interest and support. The forestry engineering students Raúl García-Raga and Carlos Maeztu (University of Huelva), and Alex Boninsegna (University of Padova) contributed to the fieldwork as part of their final thesis undergraduate studie

Dendroclimatic signal in managed Mediterranean forests : a case study in SW Spain

Spanish Ministry of Economy and Competitiveness, the European Union (FEDER funds), Spanish National Agriculture Research Institute (project ref: RTA2013-00011-C02-02

Efectos del clima sobre las variaciones diarias del radio del tronco y el crecimiento diametral de la encina durante siete años en una dehesa del suroeste de España (Huelva)

En el presente estudio se han analizado mediante dendrómetros electrónicos puntuales de alta resolución las variaciones diarias del radio del tronco de 9 encinas y los efectos del clima en sus patrones de crecimiento intraanual durante un periodo de 7 años (2005-2012). Nuestros resultados muestran ciclos diarios de expansión-contracción del tronco estrechamente relacionados con cambios en procesos ecofisiológicos a nivel intradiario. A nivel intraanual la encina presenta dos fases de crecimiento. La primera fase sucede generalmente durante el final del invierno y la primavera; y la segunda durante finales del verano y el otoño. Entre estas fases aparecen dos periodos de bajo crecimiento, parada o incluso contracciones del tronco, que se producen generalmente durante finales de la primavera y el verano, y durante finales del otoño y el invierno. La evapotranspiración de referencia afectó negativamente al incremento del tronco durante todo el año. La precipitación tuvo un efecto positivo solo durante las dos fases intraanuales de crecimiento. Las altas temperaturas tuvieron un efecto negativo, excepto en el periodo de meses más fríos. Las variaciones diarias del contenido de agua extraíble relativa tuvieron un efecto positivo, excepto durante el periodo de parada y contracción de final de la primavera y verano

Características hidráulicas de ramillas de "Quercus ilex ssp." ballota y sus efectos sobre la producción de bellota en una dehesa de la provincia de Huelva, suroeste de España

Durante tres años consecutivos, se estudiaron las características hidráulicas de ramillas de Quercus ilex ssp. ballota en una dehesa de la provincia de Huelva, suroeste de España, sometida a tratamientos de suelo (laboreo, laboreo-siembra y un testigo sin tratar). La producción de bellota de cada período se determinó mediante el método de contenedores dispuestos bajo la copa de los árboles. Cada 5-6 semanas, se determinó el potencial hídrico xilemático (Ψ) mediante metodología estándar con cámara de presión. En el mismo momento se tomaron muestras para determinar en laboratorio la conductividad hidráulica en ramillas (K). Asimismo, se obtuvo el diámetro y densidad de vasos xilemáticos, realizando cortes histológicos de secciones transversales de los ramillas, variables que se correlacionaron positivamente con la producción de bellotas, aunque sin significación estadística. Los parámetros con resultados más concluyentes fueron la conductividad específica xilemática (Ks) y la conductividad específica por área foliar (Kl). La producción de bellota presentó gran variabilidad entre individuos y se correlacionó con los valores de los parámetros hidráulicos durante los períodos secos, situación que reflejó la estrecha relación entre óptimas condiciones hidráulicas en períodos de estrés hídrico y producción de semillas de la especie

Influencia de la poda en la producción de la bellota y el crecimiento en dehesas de la provincia de Huelva

Las dehesas son sistemas agrosilvopastorales de gran importancia económica ecológica y social en la provincia de Huelva. Su gestión debe considerarse de forma integral sin olvidar las buenas prácticas selvícolas, en un momento en que muchas de estas formaciones están sufriendo la influencia del fenómeno de la “seca”, que afecta de forma dramática al estado sanitario de estas formaciones y a su supervivencia. En este trabajo se evalúa la influencia de las podas, uno de los tratamientos más frecuentes en las dehesas, en la producción de bellota y en el crecimiento diamétrico de los pies. De acuerdo con los resultados obtenidos se realizan recomendaciones de gestión referentes a este tratamiento._________________________________The “dehesas” are agro-silvicultural systems with a huge economical, ecological and social interest for the province of Huelva. Its management must be considered in a global way without forgetting the good silvicultural practices, specially when this forests are dramatically affected by the oak decline. In this paper the influence of pruning on acorn production and diametric growing is evaluated, and starting from the obtained results, management options in relation with pruning are discussed

Tree rings reflect growth adjustments and enhanced synchrony among sites in Iberian stone pine (Pinus pinea L.) under climate change

Key Message We used tree ring analysis to assess the response of Pinus pinea to climate change in South Iberia. Climate – growth relationships changed over time, with greater sensitivity in recent years due to increasing aridity. A common dendroclimatic signal among sites was found, suggesting that climate change is the main responsible for the observed variation in tree growth. & Context Understanding the response of Mediterranean for- ests to climate change is required to assess their vulnerability and to develop measures that may limit the impact of future climate change. & Aims We analyzed the sensitivity of several populations of Pinus pinea (Stone pine) in Southern and Central Spain and Portugal to climate and identified some responses to climate change. & Methods We constructed tree ring chronologies and studied the dendroclimatic signal over the last century. & Results There were similarities in tree ring growth and response to climate among sites. Growth was enhanced after precipitation during the previous autumn and the current spring and was limited by water shortage. In recent decades, aridity incr easedinthestudyregion andthesensitivityoftreeringgrowthtowateravail- ability increased at all study sites. We also observed an enhanced growth synchrony among chronologies as well as an increase in ring width variability during the last decades. & Conclusion The radial growth of P. pinea indicated strong effects of climate change. The climatic signal in tree ring chronologies suggested a plastic growth response to climate of this species, although the enhanced growth synchrony and variability in recent years suggest the presence of conditions that are limiting for growth. This study provides the first as- sessment of the responses of Iberian populations of P. pinea toSpanish Ministry of Economy and Competitiveness, European Union (FEDER funds), Spanish National Agriculture Research Institute (project ref:RTA2013-00011575C02-02), Department of Innovation, Science and Business of the Regional Government of Andalusia, Spain (project ref: P07RNM02688), International Campus of Excellence for Environment, Biodiversity and Global Change (CeiCambio)This study was supported by the Spanish Ministry of Economy and Competitiveness, the European Union (FEDER funds), the Spanish National Agriculture Research Institute (project ref: RTA2013-00011575 C02-02), the Department of Innovation, Science and Business of the Regional Government of Andalusia, Spain (project ref: P07RNM02688), and the International Campus of Excellence for Environment, Biodiversity and Global Change (CeiCambio