Browsing by Author "Blanco Vaca, Juan Antonio"
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Publication Open Access 5ª Edición de la Escuela de Verano de Ecología de la UPNA (2019)(Asociación Española de Ecología Terrestre (AEET), 2019) Blanco Vaca, Juan Antonio; Ciencias; ZientziakNoticia de la celebración de la quinta edición de la Escuela de Verano de Ecología de la Universidad Pública de Navarra (UPNA), del 26 al 28 de junio de 2019, en el Museo de Educación Ambiental del Ayuntamiento de Pamplona (Navarra), bajo el título 'Usando la biomasa forestal como fuente de energía renovable'.Publication Open Access 7ª Edición de la Escuela de verano de Ecología de Navarra: 'Biodiversidad, interacciones bióticas y funciones ecosistémicas'(Asociación Española de Ecología Terrestre (AEET), 2021) Rodríguez Pérez, Javier; Blanco Vaca, Juan Antonio; Ciencias; ZientziakNoticia de la celebración de la séptima edición de la Escuela de Verano de Ecología de Navarra, celebrada el 2 de septiembre de 2021, en la que se impartieron cuatro ponencias.Publication Open Access 8ª Edición de la Escuela de verano de Ecología de Navarra: ecólogas/os por un día(Asociación Española de Ecología Terrestre, AEET, 2022) Imbert Rodríguez, Bosco; Blanco Vaca, Juan Antonio; Ciencias; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMABDurante los pasados 23 y 24 de junio tuvo lugar la 8ª edición de la Escuela de Verano de Ecología de Navarra de la Universidad Pública de Navarra (UPNA) con el título ‘Ecólogas/os por un día’. En la jornada se impartieron cuatro ponencias por parte de los miembros del grupo de investigación de Ecología y Medio Ambiente de la Universidad Pública de Navarra, pero la mayor parte del tiempo se dedicó al trabajo de campo en el parque. En dicho trabajo de campo los asistentes pudieron trabajar tres temas diferentes: el estudio de las comunidades vegetales en pastos, el estudio de la estructura de una comunidad arbórea y la observación y estimación de censos de aves. Los trabajos incluyeron la demostración y familiarización de los estudiantes con las distintas técnicas y aparatos para medir variables ambientales como luz ambiental, temperatura del suelo, humedad del suelo, diámetro y altura de árboles, así como las técnicas para realizar inventarios florísticos o de fauna.Publication Open Access Actions for the restoration of the biodiversity of forest ecosystems in Cuba(InTech, 2015) González Izquierdo, Eduardo; Blanco Vaca, Juan Antonio; Geada López, Gretel; Sotolongo Sospedra, Rogelio; González González, Martín; González González, Martín; Ciencias del Medio Natural; Natura Ingurunearen ZientziakThe Earth is threatened daily by the degradation of its ecosystems due to fragmentation. One of the main consequences is biodiversity loss. Despite the economic progress and conservation actions carried out in many countries, the planet is losing genuine tropical forest due to diverse reasons. This chapter presents the results obtained during the restoration of three tropical forests in Cuba: 1) the mesophyll semi-deciduous forest in the western sector of the Biosphere Reserve 'Sierra del Rosario' (BRSR); 2) the riverside forest of the Cuyaguateje River in western Cuba; and 3) the exploited native rainforests of the sector Quibiján-Naranjal of the River Toa in eastern Cuba.Publication Open Access Aplicación del modelo Forecast en dos bosques del Pirineo navarro (Aspurz y Garde): sensibilidad a parámetros del suelo(2014) Gárate Bienzobas, Mikel; Blanco Vaca, Juan Antonio; Escuela Técnica Superior de Ingenieros Agrónomos; Nekazaritza Ingeniarien Goi Mailako Eskola Teknikoa; Ciencias del Medio Natural; Natura Ingurunearen ZientziakEl objetivo general de este trabajo es proporcionar una primera valoración de la sensibilidad del modelo de simulación de ecosistemas forestales FORECAST frente a los parámetros que definen los flujos de nutrientes en la parte subterránea del ecosistema. Esta información proporcionará indicaciones sobre la forma más efectiva para después realizar una calibración del modelo adecuada y eficiente para la simulación del crecimiento de los bosques del Pirineo Navarro. El modelo se calibró para simular el crecimiento de dos rodales de pino silvestre (Pinus sylvestris) en los Pirineos de Navarra, concretamente en Aspurz y Garde. Los datos para calibrar el crecimiento se obtuvieron de la base de datos del Grupo de Ecología y Medioambiente de la UPNA, excepto en el caso de los parámetros relacionados con la biomasa subterránea de los pinos. Los resultados indican que la tasa de renovación de raíces finas es el parámetro más influyente en las estimaciones de crecimiento de los árboles, seguida de la concentración de N en las mismas, siendo la relación biomasa subterránea/total y la tasa de descomposición de humus los parámetros a los cuales el modelo es menos sensible. Además, el modelo es más sensible a los parámetros definidores del componente subterráneo de la masa arbórea y a la tasa de descomposición de humus cuando simula un sitio de menor capacidad productiva y mayor limitación por nutrientes (Garde), Esto se debe a que los cuatro parámetros definen la masa de raíces e influyen en determinar las necesidades nutritivas de los árboles. Si estas necesidades se incrementan al aumentar el valor de cualquiera de los cuatro parámetros analizados, la limitación al crecimiento de los árboles se hace más aguda y la importancia de estos parámetros crece a la hora de estimar el crecimiento final. En conclusión, para llevar a cabo un programa de calibración del modelo eficaz y eficiente, se recomienda centrar los esfuerzos en realizar una adecuada caracterización de las raíces finas en cuanto a su contenido en N y su longevidad.Publication Embargo Belowground forest ecology: an empirical and modelling study on fine roots and their environment in Pinus sylvestris-Fagus sylvatica mixed stands(2023) Yeste Yeste, Antonio; Blanco Vaca, Juan Antonio; Imbert Rodríguez, Bosco; Ciencias; ZientziakLas temáticas principales de este trabajo son la investigación en bosques mixtos, específicamente en rodales de pino silvestre (Pinus sylvestris) y de haya europea (Fagus sylvatica), y la ecología del suelo forestal, evaluando las raíces finas de estas dos especies y las condiciones del suelo. En primer lugar, se llevó a cabo un estudio exploratorio abordando parámetros de raíces finas (biomasa y rasgos funcionales), la interacción de ambas especies a nivel de suelo y su efecto sobre las características químicas del suelo. Posteriormente, se llevó a cabo un experimento de alteración de la disponibilidad de nutrientes para evaluar la plasticidad de cada especie en las respuestas a los cambios en los recursos del suelo. Se establecieron tratamientos de fertilización, control y exclusión de hojarasca. Los estudios se llevaron a cabo en el Suroeste de los Pirineos (Navarra, norte de España). El rodal estudiado se originó en primer lugar con la regeneración natural de pinos silvestres (edad promedio actual ∼58 años) y luego por la regeneración natural de haya (edad promedio actual 43 años). La regeneración de hayas se produjo de forma ∼ heterogénea, por lo que actualmente se pueden encontrar zonas con similitud a monocultivos de pino (donde solo está presente P. sylvestris) y zonas donde ambas especies crecen juntas. Ambos tipos de zonas se ubican a una distancia próxima y mantienen condiciones ambientales similares, creando un buen escenario para la realización de estudios comparativos de cada especie y su mezcla. La biomasa y rasgos funcionales de las raíces finas de cada especie difirieron en gran medida, con valores más altos de biomasa, longitud específica y densidad del tejido radicular en el caso del haya. Además, se observó un efecto negativo sobre la biomasa de raíces finas del pino, disminuyendo cuando éste crecía cerca de un haya. Por lo tanto, aunque se observaron diferencias en términos de morfología de raíces finas, los resultados no sugieren un efecto de complementariedad entre las dos especies. En su lugar, muestran interacción competitiva sobre la colonización del volumen del suelo en la que el haya tiene ventaja sobre el pino silvestre. Esta conclusión es coherente con los resultados obtenidos en el experimento de alteración de la disponibilidad de nutrientes. La biomasa y la morfología de las raíces finas del pino se mostraron muy poco plásticas, sin apenas respuesta a la alteración de los nutrientes del suelo. Por su parte, las hayas aumentaron su biomasa de raíces finas después de aplicar la fertilización y modificaron su morfología, elongándose para explotar aún más el volumen del suelo alcanzando valores más altos de longitud específica y menor densidad del tejido radicular. El tratamiento de fertilización tuvo un mayor impacto sobre los parámetros químicos del suelo que el de exclusión de hojarasca. Los principales cambios después de la fertilización fueron una reducción del pH y del contenido de NH4 + , y un aumento del nitrógeno total del suelo, del fósforo disponible y del fósforo microbiano.Publication Open Access Los bosques españoles como soluciones naturales frente al cambio climático: herramientas de análisis y modelización: reseña(Asociación Española de Ecología Terrestre (AEET), 2021) Blanco Vaca, Juan Antonio; Ciencias; ZientziakReseña del libro que forma parte de la serie de informes sobre el Plan Nacional de Adaptación al Cambio Climático publicada por el Ministerio para la Transición Ecológica y el Reto Demográfico del Gobierno de España.Publication Open Access Bosques, suelo y agua: explorando sus interacciones(Asociación Española de Ecología Terrestre, 2017) Blanco Vaca, Juan Antonio; Ciencias del Medio Natural; Natura Ingurunearen ZientziakMiles de millones de personas sufren los efectos de un acceso inadecuado al agua (Mekonnen y Hoekstra 2016). En muchas regiones del mundo la explotación excesiva de los recursos hídricos disponibles, el mal de uso de los mismos o su contaminación representan una amenaza cada vez mayor para la disponibilidad y la calidad del agua para usos agrícolas, industriales o urbanos (FAO 2009). El cambio climático puede exacerbar la escasez de agua y amenazar la seguridad alimentaria, pudiendo ser una de las causas de migraciones masivas, aumentando la conflictividad social y política (Kelley et al. 2015). Los bosques juegan un papel integral en el suministro de agua de calidad para distintos usos, y también en estabilizar y proteger los suelos de la erosión. La mayoría del agua dulce mundial se proporciona a través de cuencas arboladas, y los bosques protegen muchos embalses y presas del colmatado por sedimentos. Además, los bosques protegen las aguas subterráneas de contaminantes por medio de la labor filtrante de los suelos forestales (FAO 2009). Tanto el suelo como el agua son condicionantes esenciales en el crecimiento y salud de los árboles, y también del resto de organismos que componen los sistemas forestales. Sin embargo, debido a una demanda creciente de agua para usos urbanos, agrícolas e industriales, así como de terreno urbanizable debido a una población humana que aumenta tanto su número como su calidad de vida, los bosques están con frecuencia bajo fuertes presiones. En muchas regiones del mundo estas presiones se exacerbarán debido al cambio climático (IUFRO 2017)Publication Open Access Bringing the natives back: identifying and alleviating establishment limitations of native hardwood species in a conifer plantation(MDPI, 2018) Li, Yu-Tsen; Lo, Yueh-Hsin; Lin, Yi-Ching; Guan, Biing T.; Blanco Vaca, Juan Antonio; You, Chi-How; Ciencias del Medio Natural; Natura Ingurunearen ZientziakTo facilitate the reintroduction of five native late-successional Taiwanese Fagaceae species into Japanese cedar (Cryptomeria japonica (D.) Don) plantations, we experimented with methods to alleviate their establishment limitations. We tested different combinations of tree species, seedling development stages, and site preparation techniques. First, we directly sowed both fresh and germinated acorns under both closed and opened (thinned) canopies. Both fresh and germinated acorns survived only six months at most. Wildlife consumption was the most critical factor hindering their survival. We subsequently experimented with different methods for increasing establishment rates, such as thinning in combination with understory control, applying chemical animal repellents to seeds, using physical barriers against seed predators, and using seedlings of different ages. Among the methods experimented, none was effective. The effects of silvicultural treatments to deter seed consumption lasted only the first few weeks after sowing, whereas the effects of physical barriers were inconsistent. We also tested planting 3-month and 1-year-old seedlings. Seedling survival after 9 months was about 20% on average for 3-month-old seedlings but reached 80% for 1-year-old seedlings. Our results suggest that planting seedlings older than six months or establishing physical obstacles to prevent seed predation will be the most effective strategies to reintroduce late-successional hardwood Fagaceae species into Japanese cedar plantations.Publication Open Access Calculadora de sostenibilidad FIRST-Heat Navarra: generando energía sostenible al reducir el riesgo de incendios forestales en comunidades rurales(Sociedad Española de Ciencias Forestales, 2020) Candel Pérez, David; Blanco Vaca, Juan Antonio; Lo, Yueh-Hsin; Montero, Eduardo; Barrena Figueroa, Ramo; Castillo Martínez, Federico; Ciencias; Zientziak; Gestión de Empresas; Enpresen KudeaketaEl cambio climático, la expansión urbanística o el aumento del uso recreativo en zonas forestales están aumentando la probabilidad de ocurrencia de incendios forestales. Las comunidades rurales pueden afrontar la oportunidad de combinar actividades silvícolas para reducir el riesgo de incendios con el desarrollo energético basado en el aprovechamiento de la biomasa forestal generada. Para demostrar la viabilidad de este tipo de gestión, se ha creado una herramienta informática demostrativa de apoyo a la toma de decisiones. Mediante la modificación y calibración del modelo ecológico FORECAST, se simularon las condiciones de diferentes localidades y especies forestales de Navarra. Sobre dichas simulaciones, se ha desarrollado la interfaz de usuario de esta calculadora (Fire Interface Rural Screening Tool for Heating: FIRST-Heat Navarra), que pretende estimar la sostenibilidad ecológica y socio-económica del uso de la biomasa forestal a nivel local. Esta herramienta se muestra capaz de simular los efectos del cambio en las condiciones de crecimiento del bosque mediante un modelo ecológico dinámico. También presenta la capacidad de integrar, resumir y comunicar de forma efectiva el último conocimiento científico sobre ecología forestal, y el conocimiento técnico, económico y social sobre la tecnología de calefacción de distrito a partir de biomasa.Publication Open Access Carbon density in boreal forests responds non-linearly to temperature: an example from the Greater Khingan Mountains, northeast China(Elsevier, 2023) Liu, Yang; Trancoso, Ralph; Ma, Qin; Ciais, Philippe; Gouvêa, Lidiane P.; Yue, Chaofang; Assis, Jorge; Blanco Vaca, Juan Antonio; Ciencias; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaBoreal forests play a crucial role in the global carbon (C) cycle and in climate stabilization. To better predict global C budgets, it is important to accurately estimate the size of forest C pools, and to identify the factors affecting them. We used national forest inventory data for the Greater Khingan Mountains, northeast China from 1999 to 2018 and 149 additional field plots to estimate C storage and its changes in forest vegetation, excluding C stored in soils, and to calculate the total C density in forest ecosystems. From 1999 to 2018, the vegetation C storage and density increased by 92.22 Tg and 4.30 Mg C ha−1, respectively, while the mean C sink was 4.61 Tg C yr−1. Carbon storage and density showed the same pattern, with the largest stocks in trees, followed by herbs, shrubs, and then litter. Mean C density was higher in mature forests than in young forests. The maximum C density was recorded in Populus davidiana forests, and was 2.2-times larger than in Betula davurica forests (the minimum). The mean (± standard error) total C density of forest ecosystems was 111.3 ± 2.9 Mg C ha−1, including C stored in soils. Mean annual temperature (MAT) controlled total C density, as MAT had positive effects when it was lower than the temperature of the inflection point (-2.1 to -4.6 °C) and negative effects when it was above the inflection point. The rate of change in the total C density depended on the quantile points of the conditional distribution of total C density. Natural and anthropogenic disturbances had weaker effects on C density than temperature and precipitation. In conclusion, our results indicate that there might be a temperature-induced pervasive decrease in C storage and an increase in tree mortality across Eastern Asian boreal forests with future climate warming.Publication Open Access Changes in long-term light properties of a mixed conifer–broadleaf forest in Southwestern Europe(MDPI, 2021) Ruiz de la Cuesta Vela, Ignacio; Blanco Vaca, Juan Antonio; Imbert Rodríguez, Bosco; Peralta de Andrés, Francisco Javier; Rodríguez Pérez, Javier; Ciencias; Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaNatural and anthropogenic factors affect forest structure worldwide, primarily affecting forest canopy and its light properties. However, not only stand-replacing events modify canopy structure, but disturbances of lower intensity can also have important ecological implications. To study such effects, we analyzed long-term changes in light properties of a conifer–broadleaf mixed forest in the Southwestern Pyrenees, placed in the fringe between the Mediterranean and Eurosi- berian biogeographical regions. At this site, a thinning trial with different intensities (0%, 20%, and 30–40% basal area removed) took place in 1999 and 2009, windstorms affected some plots in 2009 and droughts were recurrent during the sampling period (2003, 2005, 2011). We monitored light properties during 14 years (2005–2019) with hemispherical photographs. We applied partial autocorrelation functions to determine if changes between years could be attributed to internal canopy changes or to external disturbances. In addition, we mapped the broadleaf canopy in 2003, 2008, and 2016 to calculate broadleaf canopy cover and richness at the sampling points with different buffer areas of in- creasing surface. We applied generalized linear mixed models to evaluate the effects of light variables on canopy richness and cover. We found that light variables had the most important changes during the period 2008 to 2010, reacting to the changes caused that year by the combined effects of wind and forest management. In addition, we found that an area of 4.0 m radius around the sampling points was the best to explain the relationship between light properties and species richness, whereas a radius of 1.0 m was enough to estimate the relationship between light and canopy cover. In addition, light-related variables such as diffuse light and leaf area index were related to species richness, whereas structural variables such as canopy openness were related to canopy cover. In summary, our study demonstrates that non stand-replacing disturbances such as windstorms, thinning, or droughts can have an important role in modifying structural and light-related canopy properties, which in turn may influence natural processes of stand development and ecological succession.Publication Open Access Climate-forest-water-people relations: seven system delineations(2018) Noordwijk, Meine van; Creed, Irena F.; Jones, Julia A.; Wei, Xiaohua; Gush, Mark; Blanco Vaca, Juan Antonio; Sullivan, Caroline A.; Bishop, Kevin; Murdiyarso, Daniel; Xu, Jianchu; Claassen, Marius; McNulty, Steven G.; Ellison, David; Ciencias del Medio Natural; Natura Ingurunearen ZientziakIn this chapter, we review current scientific understanding and hypotheses at seven system delineations that build up from the level of a ‘tree’ interacting with water, to that of a social-ecological system at the scale of landscapes. A system delineation separates internal entities that interact dynamically from external entities that may have a one-way influence but are not significantly influenced by feedback from within the system boundaries. Each system level has its characteristic outcomes or results.Publication Open Access CO2 fertilization plays a minor role in long-term carbon accumulation patterns in temperate pine forests in the southwestern Pyrenees(Elsevier, 2019) Lo, Yueh-Hsin; Blanco Vaca, Juan Antonio; González de Andrés, Ester; Imbert Rodríguez, Bosco; Castillo Martínez, Federico; Institute for Multidisciplinary Research in Applied Biology - IMABIsolating the long-term fertilization effect of CO 2 from other climate- and site-related effects on tree growth has been proven a challenging task. To isolate long-term effects of [CO2] on water use efficiency at ecosystem level, we used the FORECAST Climate forest model, calibrated for Scots pine (Pinus sylvestris L.) forests in the southwestern Pyrenees, growing at a Mediterranean montane site and at a continental subalpine site. Future climate scenarios (RCP 4.5 and RCP 8.5) were generated using a battery of six climate models to estimate daily values of temperature and precipitation in a 90-year series. A factorial experiment was designed to disentangle the importance on C pools of three growing limiting factors (nitrogen limitation, climate (temperature + precipitation) limitation and atmospheric CO 2 concentration). The relative importance of each factor was quantified by comparing the scenario with the limitation of each individual factor turned on with the non-limitation scenario. Positive CO 2 fertilization due to improvement in water use efficiency was detected by the model, but its quantitative impact improving tree growth was minimum: its average increase in ecosystem C pools ranged from 0.3 to 0.9%. At the site with cooler climate conditions (continental), the main limitation for tree growth was climate. Such limitation will be reduced under climate change and the ecosystem will store more carbon. At the site with milder climate conditions (Mediterranean), N availability was the main limiting factor albeit modulated by water availability. Such limitation could be reduced under climate change as N cycling could accelerate (higher litterfall production and decomposition rates) but also increase if droughts become more frequent and severe. In addition, the magnitude of the uncertainty related to climate model selection was much more important than CO 2 fertilization, indicating that atmospheric processes are more important than tree physiological processes when defining how much carbon could be gained (or lost) in forests under climate change. In conclusion, due to the small changes in forest C pools caused by variation of atmospheric CO 2 concentrations compared to changes caused by other growth limiting factors (nutrients, climate), reducing uncertainty related to climate projections seems a more efficient way to reduce uncertainty in tree growth projections than increasing forest model complexity.Publication Open Access Coarse woody debris' invertebrate community is affected directly by canopy type and indirectly by thinning in mixed scots pine-European beech forests(MDPI, 2020) Herrera Álvarez, Ximena; Blanco Vaca, Juan Antonio; Imbert Rodríguez, Bosco; Álvarez, Willin; Rivadeneira Barba, Gabriela; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB; CienciasResearch Highlights: Thinning and tree species alter the forest floor microclimate by modifying canopy cover, radiation, wind, and humidity. Thus, forest management can directly influence the edaphic mesofauna responsible for decomposing coarse woody debris (CWD). Background and Objectives: This research was carried out in the Southwestern Pyrenees Mountains (Northern Spain) and aimed to determine the influence of forest thinning and canopy type (pure Pinus sylvestris L. or a mix of P. sylvestris and Fagus sylvatica L.) on CWD colonization by edaphic fauna. Materials and Methods: CWD samples were collected belonging to intermediate and advanced decomposition stages, approximately 10 cm long and 5 cm in diameter. Using a design of three thinning intensities (0%, 20%, and 40% of basal area removed), with three replications per treatment (nine plots in total), four samples were taken per plot (two per canopy type) to reach 36 samples in total. Meso- and macrofauna were extracted from CWD samples with Berlese-Tullgren funnels, and individuals were counted and identified. Results: 19 taxonomic groups were recorded, the most abundant being the mesofauna (mites and Collembola). Mixed canopy type had a significant positive influence on richness, whereas advanced decay class had a positive significant influence on total abundance and richness. In addition, there were non-significant decreasing trends in richness and abundance with increasing thinning intensity. However, interactions among thinning intensity, canopy type, and decay class significantly affected mesofauna. Furthermore, some taxonomic groups showed differential responses to canopy type. CWD water content was positively correlated with total invertebrate abundance and some taxonomic groups. Our results suggest that stand composition has the potential to directly affect invertebrate communities in CWD, whereas stand density influence is indirect and mostly realized through changes in CWD moisture. As mesofauna is related to CWD decomposition rates, these effects should be accounted for when planning forest management transition from pure to mixed forests.Publication Open Access Determinants and tools to evaluate the ecological sustainability of using forest biomass as an alternative energy source(2018) Blanco Vaca, Juan Antonio; Candel Pérez, David; Lo, Yueh-Hsin; Ciencias; Zientziak; Gobierno de Navarra / Nafarroako Gobernua, PI037 InFORestForest biomass, the most ancient of fuels, is again in the center of renewable energy production. This chapter provides an introductory view of the main factors that condition the ecological sustainability of this energy source. The basic concepts of ecological sustainability, ecological rotation, and ecological thresholds (among others) are presented. The state of the art on approaches to assess the sustainability of forest biomass production for heat and electricity is discussed, and tools available for decision-makers to evaluate the sustainability of forest biomass production and management are described. This chapter then describes the main advantages and drawbacks of forest certification, growth and yield tables, and ecological models in relationship to their use in sustainable forest management for biomass and energy production.Publication Open Access Determinants of the forest-water relationship(2018) McNulty, Steven G.; Archer, Emma; Gush, Mark; Noordwijk, Meine van; Ellison, David; Blanco Vaca, Juan Antonio; Xu, Jianchu; Bishop, Kevin; Wei, Xiaohua; Vira, Bhaskar; Creed, Irena F.; Mukherji, Aditi; Ciencias del Medio Natural; Natura Ingurunearen ZientziakOur analysis of forest-water relations addresses four important subsystems of a linked planetary social-ecological system: climate, forests, water and people. In this chapter, we consider how each of these subsystems is changing (trend) and what is causing the change (’determinant’). We discuss the critical determinants of change in forests as they relate to water quality and quantity. Chapter 4 then presents the impacts of these changes on water quality and quality.Publication Open Access Determining suitable selection cutting intensities based on long term observations on above-ground forest carbon, growth, and stand structure in Changbai Mountain, Northeast China(Taylor & Francis, 2014) Liu, Yang; Blanco Vaca, Juan Antonio; Wei, Xiaohua; Kang, Xingang; Wang, Weifeng; Guo, Yanrong; Ciencias del Medio Natural; Natura Ingurunearen ZientziakWe studied the effects of different cutting intensities (0%, 5-10%, 15%, and 20% basal area removal) on stand growth, structure, and net carbon storage in spruce-fir (Picea asperata Mast.-Abies fabri Mast. Craib) and broadleaf mixed forests on Changbai Mountain (Northeast China) over 19 years. At this site, inventory-based low-intensity selection cutting was used to maintain a continuous forest canopy. After two cutting events, results showed significant differences in growth, structure, and carbon storage among cutting intensities. When increasing cutting intensity, the growth rate of average diameter, basal area, and volume significantly increased, with the highest increment rates found in the plots with 20% basal area removal. Tree diameters for all plots showed a roughly inverse J-shaped distribution before cutting and a left-skewed unimodal distribution after two cuttings. Volume ratio (the relative amount of volume contained in different diameter classes) for small (6-14 cm), medium (14-26 cm), large (26-36 cm), and very large (>38 cm) diameters remained unchanged in the plots with 5 and 10% basal area removal, but increased in the plots with 15 and 20% basal area removal, reaching approximately a 1:2:3:4 ratio in the plots with 20% basal area removal after two selection cuttings. Net carbon storage increased when increasing cutting intensity, reaching maximum storage in the plots with 20% basal area removal (cutting intensity and net C storage increase: 0%, 7.21 Mg C ha-1, 5-10%: 11.68 Mg C ha-1, 15%: 21.41 Mg C ha-1, 20%: 26.47 Mg C ha-1). Therefore, our results show the potential of low-intensity selection cutting to meet demands of both timber production and maintenance of forest cover for biodiversity values.Publication Open Access Douglas-fir radial growth in interior British Columbia can be linked to long-term oscillations in Pacific and Atlantic sea surface temperatures(NCR Research Press, 2017) Lo, Yueh-Hsin; Blanco Vaca, Juan Antonio; Guan, Biing T.; Ciencias del Medio Natural; Natura Ingurunearen ZientziakA major problem in modern dendrochronology is that the methods traditionally used for linking tree ring growth data to climate records are not well suited to reconstructing low-frequency climatic variations. In this study, we explored the alternative Ensemble Empirical Mode Decomposition to detrend tree-ring records and to extract climate signals without removing low-frequency information. Tree cores of Pseudotsuga menziesii var. glauca (Mayr.) Franco were examined in a semi-arid forest in southern interior British Columbia, western Canada. Ring width data were decomposed into five oscillatory components (intrinsic mode functions, IMFs) of increasingly longer periodicities. IMF 1 was considered white noise, IMF 2 was used to create the first diameter growth index (DGI-1), IMF 3 and IMF 4 were combined to create the second diameter growth index (DGI-2), whereas IMF 5 and the residual term together were considered as the trend term. The highest significant cross-correlations between DGI-1 and the NAOAugust, NIÑO12May, and PDOJanuary indices were found at 1-year lags. DGI-2 had positive and persistent correlations with NAOJune and PDOMay at 0 to 3 years lags, and with NAOMay at 2 and 3 years lags. Our results indicate that periods of slow growth in the tree ring record matched periods of drought in the North American Pacific Northwest. Such water limiting conditions are likely caused by oscillatory patterns in the Pacific Ocean sea surface temperatures that influence precipitation in the Pacific Northwest. These drought events are likely exacerbated by changes in winter precipitation (snowpack) related to oscillations of the Atlantic Ocean sea surface temperatures, highlighting the ecological effects of both oceans on terrestrial ecosystems. Such relationships could not be easily found by traditional tree-ring analysis that remove some of the low-frequency signal, and therefore we suggest Ensemble Empirical Mode Decomposition as an additional tool to establishing tree growth-climate relationships.Publication Open Access Drought limits tree growth more than greenness and reproduction: insights from five case studies in Spain(KeAi Communications, 2025-08-01) Camarero, Jesús Julio; Rubio-Cuadrado, Álvaro; González de Andrés, Ester; Valeriano, Cristina; Pizarro, Manuel; Imbert Rodríguez, Bosco; Lo, Yueh-Hsin; Blanco Vaca, Juan Antonio; Ciencias; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMABDroughts impact forests by influencing various processes such as canopy greenness, tree growth, and reproduction, but most studies have only examined a few of these processes. More comprehensive assessments of forest responses to climate variability and water shortages are needed to improve forecasts of post-drought dynamics. Iberian forests are well-suited for evaluating these effects because they experience diverse climatic conditions and are dominated by various conifer and broadleaf species, many of which exhibit masting. We assessed how greenness, evaluated using the normalized difference vegetation index (NDVI), tree radial growth, and seed or cone production responded to drought in five tree species (three conifers: silver fir (Abies alba), Scots pine (Pinus sylvestris), and stone pine (Pinus pinea); two broadleaves: European beech (Fagus sylvatica) and holm oak (Quercus ilex) inhabiting sites with different aridity. We correlated these data with the standardized precipitation evapotranspiration index (SPEI) using the climate window analysis (climwin) package, which identifies the most relevant climate window. Drought constrained growth more than greenness and seed or cone production. Dry conditions led to high seed or cone production in species found in cool, moist sites (silver fir, beech, and Scots pine). We also found negative associations of cone production with summer SPEI in the drought-tolerant stone pine, which showed lagged growth−cone negative correlations. However, in the seasonally dry holm oak forests, severe droughts constrained both growth and acorn production, leading to a positive correlation between these variables. Drought impacts on greenness, growth, seed, and cone production depended on species phenology and site aridity. A negative correlation between growth and reproduction does not necessarily indicate trade-offs, as both may be influenced by similar climatic factors.