Reyes Alejano

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Papers by Reyes Alejano

Caracterización, distribución y manejo de los bosques nativos en el norte de Uruguay

Revista Mexicana de Biodiversidad, 2013

Los bosques del norte de Uruguay sufren de procesos de transformación del territorio y degradació... more Los bosques del norte de Uruguay sufren de procesos de transformación del territorio y degradación, actualmente existe escasa información sobre la estructura y composición florística de las comunidades arbóreas que sirva como base para estudiar su dinámica. Se analizó la distribución, la composición arbórea y el manejo silvícola de los bosques de la región de Rivera, Uruguay. El área de estudio comprende 33 000 ha delimitadas mediante 2 criterios, uno natural (cuenca hidrológica) y otro socioeconómico (ciudad de referencia). La información proveniente de inventarios florísticos y encuestas a productores fue ingresada a un sistema de información geográfica. Los bosques se agruparon de acuerdo al gradiente hídrico asociado con curvas de nivel. La superficie de los bosques ocupa el 13.9% del área de estudio (región de Rivera), cifra que triplica la superficie de bosques existente a nivel nacional. Se registraron 60 especies leñosas. Las familias con mayor frecuencia fueron Anacardiaceae (26.5%) y Euphorbiaceae (14.7%). Las Anacardiaceae son más frecuentes en los bosques subxerófilos y las Euphorbiaceae en los bosques hidrófilos. Todos los bosques son vulnerables debido a la mayor importancia que se concede a la ganadería, sin que exista un manejo integrado de los bosques que contemple la multifuncionalidad de usos (silvicultura y ganadería). Los bosques cercanos a la ciudad están más degradados debido a la presencia de especies exóticas. Palabras clave: bosque nativo, composición florística, modelo hidro-antrópico, SIG.

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Caracterización, distribución y manejo de los bosques nativos en el norte de Uruguay Characterization, distribution and management of native forests in northern Uruguay

Los bosques del norte de Uruguay sufren de procesos de transformación del territorio y degradació... more Los bosques del norte de Uruguay sufren de procesos de transformación del territorio y degradación, actualmente e iste escasa información sobre la estructura y composición orística de las comunidades arbóreas que sirva como base para estudiar su dinámica. Se analizó la distribución, la composición arbórea y el manejo silvícola de los bosques de la región de Rivera, Uruguay. El área de estudio comprende 33 000 ha delimitadas mediante 2 criterios, uno natural (cuenca hidrológica) y otro socioeconómico (ciudad de referencia). La información proveniente de inventarios orísticos y encuestas a productores fue ingresada a un sistema de información geográ ca. Los bosques se agruparon de acuerdo al gradiente hídrico asociado con curvas de nivel. La super cie de los bosques ocupa el 13. del área de estudio (región de Rivera), cifra que triplica la super cie de bosques e istente a nivel nacional. Se registraron 0 especies le osas. Las familias con mayor frecuencia fueron Anacardiaceae (2 .) y Euphorbiaceae (1 .). Las Anacardiaceae son más frecuentes en los bosques sub eró los y las Euphorbiaceae en los bosques hidró los. Todos los bosques son vulnerables debido a la mayor importancia que se concede a la ganadería, sin que exista un manejo integrado de los bosques que contemple la multifuncionalidad de usos (silvicultura y ganadería). Los bosques cercanos a la ciudad están más degradados debido a la presencia de especies exóticas. Palabras clave: bosque nativo, composición orística, modelo hidro-antrópico, SI .

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The role of climate change in the widespread mortality of holm oak in open woodlands of Southwestern Spain

Dendrochronologia, Jun 1, 2016

We obtained robust dendroclimatic signal in Quercus ilex from low latitudes in Iberia.  We repor... more We obtained robust dendroclimatic signal in Quercus ilex from low latitudes in Iberia.  We report massive die-off of Quercus ilex trees in SW Iberia.  Tree growth was strongly controlled by climatic shifts in recent decades.  Warmer climate with longer droughts had a key-role determining the mortality process.

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Silviculture of Eucalyptus globulus Labill

Pruning quantification and biomass production in two holm oak (Quercus ilex L.) dehesas of southwest Spain

This article quantifies the biomass obtained from three pruning treatments (light, moderate and h... more This article quantifies the biomass obtained from three pruning treatments (light, moderate and heavy) carried out in two dehesas in the province of Huelva (south-western Spain). A model based on the index dry weight biomass (kg)/tree diameter (cm) was elaborated to permit us to associate each tree with one of the three pruning types mentioned above. This model will allow us to analyze the influence of the different types of pruning on other parameters such as tree growth, acorn production, physiological state of the tree, etc.

Efecto de la aplicación de podas y tratamientos de suelo en el crecimiento diametral de la encina

Actas De La Iii Reunion Sobre Ecologia Y Suelos Forestales Aportaciones a Y Desde La Gestion Forestal Huelva 9 10 Y 11 De Noviembre De 2011 2013 Isbn 978 84 937964 5 7 Pags 97 104, 2013

[Silviculture of Pinus pinaster Ait. subsp. mesogeensis Fieschi & Gaussen]

Inventario Forestal en la Reserva Natural Comunitaria de Dindefelo (Senegal).�Contribución a la conservación del hábitat de la población más septentrional del chimpancé de África Occidental

La selvicultura mediterránea en Andalucía. Respuestas técnicas ante los objetivos actuales

Ecosistemas, 2003

La selvicultura como ciencia-técnica presenta hoy muchos retos para su aplicación en los montes m... more La selvicultura como ciencia-técnica presenta hoy muchos retos para su aplicación en los montes mediterráneos. En este informe se presentan algunos ejemplos de directrices generales de actuación con aplicación a algunos sistemas forestales de Andalucía. Todas las actuaciones que aquí se describen deben basarse en la conservación y mejora de los sistemas y en el cumplimiento del uso múltiple que la sociedad demanda

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Does the Age of Pinus sylvestris Mother Trees Influence Reproductive Capacity and Offspring Seedling Survival?

Forests

We assess how the age of Pinus sylvestris mother trees influences seed size, seed viability, germ... more We assess how the age of Pinus sylvestris mother trees influences seed size, seed viability, germination capacity and later offspring seedling survival under greenhouse conditions. Thirty trees ranging from 30 to 219 years old were selected in the north facing slopes in the Sierra de Guadarrama, where we could find the oldest Pinus sylvestris trees in central Spain. Forty cones per tree were harvested to study cone and seed characteristics (size and weight), seed viability and germination capacity related to the mother tree age. In addition, 25 germinated seeds per tree were grown in a greenhouse to assess offspring seedling survival during a death trial, where watering was stopped. Significant differences between trees in cone and seed morphological traits were observed. The age of the mother tree had a significant effect on cone size, seed size, and seed weight, but there was no effect on seed germination capacity and seed viability. Seedling survival was mainly affected by the de...

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Efecto de la intensidad de poda en la producción de bellota en dos dehesas del suroeste español

Evolución de la distribución natural de los pinares de pino salgareño (Pinus nigra Arnold) en Andalucía conforme a la arqueología y la historia

Plant water relations and edaphoclimatic conditions affecting acorn production in a holm oak (Quercus ilex L. ssp. ballota) open woodland

Agroforestry Systems, 2009

Acorn production patterns and the annual evolution of water relations parameters of Quercus ilex ... more Acorn production patterns and the annual evolution of water relations parameters of Quercus ilex ssp. ballota (Desf.) Samp. in a dehesa (an open woodland forest) subject to various soil treatments (ploughing, ploughing ? sowing, control) were studied in southwest Spain from June 2006 to December 2008. The effects of soil water holding capacity and effective soil depth on soil and plant water status and acorn production were also investigated. Water parameters showed significant differences between the ploughing treatment and the control, and there were also significant temporal differences. Xylem water potential ranged from-3.4 ± 0.1 to-0.7 ± 0.2 MPa, and cuticular transpiration was 62.4-192.9 mmol H 2 O kg-1 s-1. Acorn production did not differ significantly according to soil treatment, and showed large intra-specific variability. Individual values ranged from 0 to 1,220 g m-2 (fresh weight). Positive relationships were found between xylem water potential, cuticular transpiration and relative water content measured at midsummer, and acorn production during the three studied years. These results suggest that climatic conditions and soil water availability have a strong influence on plant water status, and therefore on acorn development during summer. The results also reflect the ability of this species to adapt to the Mediterranean climate by preserving water during dry periods, which to a large extent can be attributed to stomatal closure at high relative water content levels, and low cuticular transpiration during these periods.

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

Remote Sensing

The protection and conservation of old-growth forests (OGFs) are becoming a global concern due to... more 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...

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Bosques viejos frente al cambio climático: vulnerabilidad, capacidad adaptativa e implicaciones para la gestión forestal

Assessing the relative role of climate on litterfall in Mediterranean cork oak forests

iForest - Biogeosciences and Forestry, 2018

Biogeosciences and Forestry Biogeosciences and Forestry Assessing the relative role of climate on... more Biogeosciences and Forestry Biogeosciences and Forestry Assessing the relative role of climate on litterfall in Mediterranean cork oak forests Enrique Andivia (1) , Jordi Bou (2) , Manuel Fernández (3) , Antonia Caritat (2) , Reyes Alejano (3) , Lluís Vilar (2) , Javier Vázquez-Piqué (3) Litterfall plays a key role in the dynamic of forest ecosystems, ultimately determining forest productivity and carbon and nutrient cycling. Increasing our understanding on the role of structural and environmental factors controlling litterfall amount and seasonality is of paramount importance for modelling and estimating soil carbon sequestration and nutrient cycling under climate change scenarios. However, the effect of climatic conditions on litterfall has been scarcely studied, especially in Mediterranean ecosystems. Here, we used nine years of seasonally collected litterfall data in two contrasting Mediterranean cork oak forests to evaluate the effect of climatic variables on leaf fall and litterfall. First, we isolated the litterfall seasonal trend and the between-sites differences in production by using linear mixed models. Then, we evaluated the effect of climatic variables and whether this effect was site-specific. We found a consistent litterfall seasonal pattern, mainly determined by leaf shedding (70% of litterfall). Leaf fall mainly occurs in spring with a second but much smaller peak in autumn some years. Mean temperature, precipitation and mean wind speed strongly influenced litterfall, but this effect was sitespecific. In the forest site located at higher latitude and altitude, leaf fall increased linearly with temperature and showed a positive quadratic response to precipitation. In the water-limited site, leaf fall was reduced as temperature increased and did not respond to precipitation. These results have implications for modelling and predicting soil carbon sequestration, nutrient cycling, and the forest ecosystem productivity. Specifically, carbon and nutrient cycling models can be improved by incorporating idiosyncratic forest sites responses to climatic variability.

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Do ecological and silvicultural factors influence acorn mass in Holm Oak (southwestern Spain)?

Agroforestry Systems, 2011

The effect of orientation, location, year, and pruning treatment on mean acorn mass in two open w... more The effect of orientation, location, year, and pruning treatment on mean acorn mass in two open woodland experimental locations (Huelva, SouthWestern Spain) of Holm Oak (Quercus ilex L. subsp. ballota [Desf.] Samp.) was analyzed during 2001-2006. Data were analyzed by using a mixed linear model, where the covariates were tree size parameters (circumference at 80 cm height, crown size), topographic position (wet index and flow length), intraspecific competition, total acorn crops per tree (weight and number), and climatic parameters. Average estimated acorn mass was 3.17 g acorn-1 in the Calañas location and 4.12 g acorn-1 in the San Bartolomé location, with significant differences between locations, among individual trees and across years. Acorns from the south sides of trees were significantly heavier than those at other positions. The effect of pruning treatment and the interactions location 9 treatment and treatment 9 year were not significant. Our study provides no evidence that pruning affects acorn mass. None of the analyzed covariates related to tree size, topographic position and intraspecific competition explained the difference among trees, suggesting that heritable factors play an important role. Specific climatic parameters during September, the most important month for acorn growth, may explain the effects of year and location 9 year on acorn mass. In addition, there appeared to be a ''trade-off'' between acorn mass and number of acorns.

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

Forests

Adaptive forest management (AFM) is an urgent need because of the uncertainty regarding how chang... more 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 i...

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The age of black pine (Pinus nigra Arn. ssp. salzmannii (Dunal) Franco) mother trees has no effect on seed germination and on offspring seedling performance

Annals of Forest Science, 2019

We sampled Pinus nigra cones in 29 trees in an age range of 90 to 725 years. The mother tree age ... more We sampled Pinus nigra cones in 29 trees in an age range of 90 to 725 years. The mother tree age did not significantly influence the pinecone or pine seed size, seed germination capacity, or plant size or vigor displayed during the first year of growth in the nursery. Context: Pinus nigra Arn. ssp. salzmannii is a long-lived Mediterranean species, with millenary trees residing in an old-growth forest in the Cazorla Mountain Range in SE Spain which is home to the oldest known trees in the Iberian Peninsula. Aims: This study aimed to assess how the mother tree age in Pinus nigra influences seed viability, germination capacity, and the seedling survival and growth during the first year under nursery conditions. Methods: Twenty-nine trees aged 90 to 725 years were selected and 60 cones were harvested per tree to study the cone characteristics (size and weight), seed viability, and germination capacity in relation to the mother tree age. Eighty germinated seeds per tree were transferred ...

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Evolución temporal del grado de endurecimiento de plantas de vivero de 4 especies forestales españolas cultivadas en localidades con condiciones climáticas distintas

Desde principio del otono hasta principio de primavera se estudio la evolucion de algunos caracte... more Desde principio del otono hasta principio de primavera se estudio la evolucion de algunos caracteres morfo-fisiologicos indicadores de la calidad de las plantas de vivero destinadas a repoblacion forestal (altura, diametro, distribucion de biomasa, nutricion mineral, capacidad de regeneracion de raices y resistencia al frio). Las especies ensayadas fueron Quercus suber, Q. ilex (de dos regiones de procedencia, 11e y 15a), Pistacia lentiscus y Olea europaea var. sylvestris. Todas ellas eran de una savia, procedentes de semillas germinadas en la primavera anterior, crecidas en el mismo tipo de envase (300 cm3) y con el mismo substrato pero cultivadas en dos viveros de localizacion y caracteristicas climaticas diferentes. En cuanto al patron de evolucion temporal de los parametros medidos, se advirtio una alta correlacion con la temperatura ambiente, siendo el vivero de clima con estaciones mas marcadas el que alcanzo con anterioridad su grado maximo de resistencia al frio y el que ret...

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