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; Zientziak
Las 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.
Open Access
Pinus sylvestris L. and Fagus sylvatica L. effects on soil and root properties and their interactions in a mixed forest on the Southwestern Pyrenees
(Elsevier, 2021) Yeste Yeste, Antonio; Blanco Vaca, Juan Antonio; Imbert Rodríguez, Bosco; Zozaya Vela, Helena; Elizalde Arbilla, Martín; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB; Ciencias
Tree species alter soil properties, potentially modifying forest nutrients cycling. In the current management context in which mixed species forests are favoured over monocultures due to their biodiversity and productivity-related advantages, the assessment of species effects on soils, as well as their interactions with other species, gains increasing relevance. In this study, the effects of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) on soil properties were evaluated. Fine roots were paid special attention, measuring their biomass, functional traits (specific root length, root tissue density) and vertical distribution in order to discern the direction of these species interaction, either complementary or competitive. The research was carried out in the Southwestern Pyrenees (northern Spain), in an originally Scots pine stand transformed nowadays into a mixed forest by European beech natural regeneration. Soil and root samples were taken close to pine trees surrounded by other pines in areas that remain similar to pine monospecific stands, and close to pine and beech trees surrounded by both species in mixed areas. A lower C/N ratio was found in the soil close to beech stems. This suggests better quality in mixed litter in comparison to pine litter, leading to higher decomposition rates. Higher fine root biomass was found in the mixed areas mainly due to beech fine roots great abundance, which correlated positively with microbial biomass. Fine roots functional traits such as specific root length and diameter did not vary depending on their proximity to different tree species, though Scots pine fine root biomass decreased sharply when close to beech trees. This reduction, together with the already more abundant fine root biomass of beech, with higher specific root length and root tissue density than pine, lead to a competitive interaction in which European beech tends to dominate the soil at all depths. In this case, no complementarity effect at belowground level, strong enough to allow Scots pines to cope with beech soil colonization, was found under natural conditions.
Open Access
Nuevas citas de insectos en las albuferas de Adra (Almería, España), y otros datos de interés para el sur de la Península Ibérica (arthropoda, insecta)
(Asociacion española de Entomología, 2020) Gómez de Dios, Miguel Ángel; Barranco, Pablo; Hódar, José Antonio; Yeste Yeste, Antonio; Santa, Mauricio; Paracuellos, Mariano; Rodríguez Luque, Francisco; Rodríguez Lozano, Borja; Tarifa, Rubén; Ciencias; Zientziak
Las albuferas de Adra son uno de los humedales mejor conocidos a escala nacional en diversas disciplinas, no obstante, existe un gran vacío de información en lo que se refiere a la entomofauna Terrestre. Tratando de paliar esta situación, en febrero de 2017 se inició un muestreo de la artropodofauna en la vegetación circundante a las principales lagunas del complejo palustre, las albuferas Nueva y Honda. De las 114 especies identificadas hasta el momento (marzo de 2020), cabe destacar cuatro por constituir nuevas citas para la provincia de Almería. Se añade además el registro de una especie de interés, capturada en trampas de caída.
Open Access
Soil C/N ratios cause opposing effects in forests compared to grasslands on decomposition rates and stabilization factors in southern European ecosystems
(Elsevier, 2023) Blanco Vaca, Juan Antonio; Durán Lázaro, María; Luquin, Josu; San Emeterio Garciandía, Leticia; Yeste Yeste, Antonio; Canals Tresserras, Rosa María; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Ciencias; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Soils store an important amount of carbon (C), mostly in the form of organic matter in different decomposing stages. Hence, understanding the factors that rule the rates at which decomposed organic matter is incorporated into the soil is paramount to better understand how C stocks will vary under changing atmospheric and land use conditions. We studied the interactions between vegetation cover, climate and soil factors using the Tea Bag Index in 16 different ecosystems (eight forests, eight grasslands) along two contrasting gradients in the Spanish province of Navarre (SW Europe). Such arrangement encompassed a range of four climate types, elevations from 80 to 1420 m.a.s.l., and precipitation (P) from 427 to 1881 mm year–1. After incubating tea bags during the spring of 2017, we identified strong interactions between vegetation cover type, soil C/N and precipitation affecting decomposition rates and stabilization factors. In both forests and grasslands, increasing precipitation increased decomposition rates (k) but also the litter stabilization factor (S). In forests, however, increasing the soil C/N ratio raised decomposition rates and the litter stabilization factor, while in grasslands higher C/N ratios caused the opposite effects. In addition, soil pH and N also affected decomposition rates positively, but for these factors no differences between ecosystem types were found. Our results demonstrate that soil C flows are altered by complex site-dependent and site-independent environmental factors, and that increased ecosystem lignification will significantly change C flows, likely increasing decomposition rates in the short term but also increasing the inhibiting factors that stabilize labile litter compounds.
Open Access
Sensitivity of long-term productivity estimations in mixed forests to uncertain parameters related to fine roots.
(Elsevier, 2024) Yeste Yeste, Antonio; Seely, Brad; Imbert Rodríguez, Bosco; Blanco Vaca, Juan Antonio; Ciencias; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB
Forest growth models are increasingly being used in forestry and ecology research as predictive tools to help developing practical guidelines and to improve understanding of the drivers of forest ecosystem functioning. Models are usually calibrated using parameters directly obtained or estimated from empirical field observation, and hence are subject to uncertainty. Thus, output accuracy depends on input parameters precision and on how influential is each parameter on model behaviour. Hence, it is important to analyse parameter-related uncertainty and its effects on model outputs. This can be done by performing sensitivity analyses, which allow to explore the influence of one or several calibration parameters on model outputs. As studies on tree root parameters are particularly scarce, the aim of the present work was to evaluate the influence of parameters related to fine roots on estimations of long-term forest growth patterns in pure and mixed forests, using FORECAST (a hybrid forest growth model) as a virtual lab. The fine root parameters assessed were biomass, turnover rate, and nitrogen content. The analysis was performed by simulating monospecific stands of two contrasting species (Pinus sylvestris L. and Fagus sylvatica L.), and mixed stands formed by both species. In all cases, FORECAST showed good capability to contain uncertainty propagation during the first and middle stages of stand development (<40 years). After that moment, model output uncertainty steadily increased, but it reached different maximum uncertainty levels depending on stand type. Simulations of the less nutrient demanding P. sylvestris manifested very little sensitivity when growing in monospecific stands. However, F. sylvatica monospecific stands showed intermediate sensitivity, but significant species interactions occurred in mixed stands that determined the biggest impact detected of uncertainty related to fine root parameters over model outputs. All things considered, FORECAST displayed an interesting capability to capture some of the interspecific interactions that are key in mixed forests functioning. Our results suggest an acceptable model performance under uncertain parameterization but also caution against expecting accurate quantitative estimations of forest growth, especially when considering long-term scenarios in complex mixed stands.
Open Access
Synergies between climate change, biodiversity, ecosystem function and services, indirect drivers of change and human well-being in forests
(Springer, 2021) Imbert Rodríguez, Bosco; Blanco Vaca, Juan Antonio; Candel Pérez, David; Lo, Yueh-Hsin; González de Andrés, Ester; Yeste Yeste, Antonio; Herrera Álvarez, Ximena; Rivadeneira Barba, Gabriela; Liu, Yang; Chang, Shih-Chieh; Ciencias; Zientziak
Climate change is having impacts on the biodiversity and structure of many ecosystems. In this chapter, we focus on its impacts on forests. We will focus on how the potential climate change impacts on forest biodiversity and structure will have a reflection on the ecosystem services provided by forests, and therefore on the capacity of these ecosystems to support the Sustainable Development Goals set by the United Nations. The chapter will be organized in three sections, considering boreal, temperate, and tropical forests along each section. The first section will deal with the synergies or interactions between climate change, biodiversity, and ecosystem function with emphasis not only on plants but also on fungi, animals, and prokaryotes. Synergies between climate change and ecosystem services will be described and analyzed in the second section. To better link the first two sections, we will explore the relationships between ecosystem function, species traits, and ecosystem services. Finally, case studies for boreal, Mediterranean, and tropical forests will be presented, emphasizing the synergies between the above factors, the indirect drivers of change (demographic, economic, sociopolitical, science and technology, culture and religion), and human well-being (basic materials for a good life, health, good social relations, freedom of choice and actions) in forests.