Open Access
Significant increase in ecosystem C can be achieved with sustainable forest management in subtropical plantation forests
(Public Library of Science, 2014) Wei, Xiaohua; Blanco Vaca, Juan Antonio; Ciencias del Medio Natural; Natura Ingurunearen Zientziak
Subtropical planted forests are rapidly expanding. They are traditionally managed for intensive, short-term goals that often lead to long-term yield decline and reduced carbon sequestration capacity. Here we show how it is possible to increase and sustain carbon stored in subtropical forest plantations if management is switched towards more sustainable forestry. We first conducted a literature review to explore possible management factors that contribute to the potentials in ecosystem C in tropical and subtropical plantations. We found that broadleaves plantations have significantly higher ecosystem C than conifer plantations. In addition, ecosystem C increases with plantation age, and reaches a peak with intermediate stand densities of 1500–2500 trees ha-1. We then used the FORECAST model to simulate the regional implications of switching from traditional to sustainable management regimes, using Chinese fir (Cunninghamia lanceolata) plantations in subtropical China as a study case. We randomly simulated 200 traditional short-rotation pure stands and 200 sustainably-managed mixed Chinese fir – Phoebe bournei plantations, for 120 years. Our results showed that mixed, sustainably-managed plantations have on average 67.5% more ecosystem C than traditional pure conifer plantations. If all pure plantations were gradually transformed into mixed plantations during the next 10 years, carbon stocks could rise in 2050 by 260.22 TgC in east-central China. Assuming similar differences for temperate and boreal plantations, if sustainable forestry practices were applied to all new forest plantation types in China, stored carbon could increase by 1,482.80 TgC in 2050. Such an increase would be equivalent to a yearly sequestration rate of 40.08 TgC yr-1, offsetting 1.9% of China’s annual emissions in 2010. More importantly, this C increase can be sustained in the long term through the maintenance of higher amounts of soil organic carbon and the production of timber products with longer life spans.
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 - IMAB
Droughts 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.
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
Propuesta de rehabilitación ambiental del Lago Uru Uru
(Instituto de Investigaciones Mineras, Universidad Técnica de Oruro (Bolivia), 2021) Zamora Echenique, Gerardo; Blanco Vaca, Juan Antonio; Ciencias; Zientziak
Durante varios siglos, la industria minera y de procesamiento de minerales ha sido la base de la economía del departamento de Oruro en Bolivia, y aparentemente, continuará siéndolo en un futuro previsible. Estas labores, a lo largo de muchos años, han hecho un considerable daño al medio ambiente. En concreto, en el presente trabajo de investigación, se presenta los efectos de la contaminación por metales pesados y las aguas residuales urbanas en la calidad de las aguas, suelos, sedimentos y especies vegetales del lago Uru Uru; así como, las posibilidades para su recuperación a través de la fitoremediación vegetal. En ese contexto, en principio se describen las características tanto físicas como químicas de los ecosistemas del lago Uru Uru, y después se hace una descripción detallada de la vegetación de la zona, tanto de los diferentes ecosistemas existentes, como de las asociaciones vegetales. Por otra parte, se describe la situación actual de la zona, mostrando los diferentes problemas que afectan al suelo y a la vegetación (contaminación por metales pesados, salinidad propia del lago, explotación excesiva de los recursos vegetales, compactación del suelo, etc.) y las consecuencias que las acciones humanas tienen sobre estos elementos del ecosistema. Posteriormente, se describen detalladamente las cinco especies vegetales (thola, quinua, totora, milenrama y kauchi), que por sus características ecológicas de adaptación, pueden ser usadas en la fitoremediación. Finalmente, se establecen las diferentes acciones que deben ser tomadas en cuenta para mejorar la calidad del agua (control en las descargas de las aguas residuales de Oruro y de las aguas de mina de San José; además de un adecuado manejo del caudal de ingreso de las aguas al lago, en especial cuando se generen incrementos en las pérdidas por evaporación, que pueden ser compensadas con la descarga de aguas domésticas adecuadamente tratadas), el uso de enmiendas en el suelo para su descontaminación por fito- adsorción y estabilización (uso de materia orgánica, yeso y caliza), sobre el aire (control de las emisiones de la Empresa Metalúrgica de Vinto); y finalmente, el incremento de la población vegetal de las cinco especies seleccionadas, con el propósito de mejorar la calidad de las aguas, además de incrementar la biodiversidad de la zona del lago Uru Uru, y sin olvidar la de promover la necesidad de la población local de utilizar sus recursos.
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; Zientziak
Noticia 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'.
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 - IMAB
Isolating 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.
Open Access
Long-term carbon sequestration in pine forests under different silvicultural and climatic regimes in Spain
(MDPI, 2022) Navarro Cerrillo, Rafael M.; Ruiz Gómez, Francisco Javier; Camarero, Jesús Julio; Castillo, Víctor M.; Barberá, Gonzalo G.; Palacios Rodríguez, Guillermo; Navarro, Francisco B.; Blanco Vaca, Juan Antonio; Imbert Rodríguez, Bosco; Cachinero Vivar, Antonio M.; Molina, Antonio J.; Campo, Antonio D. del; Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB; Ciencias
Proactive silviculture treatments (e.g., thinning) may increase C sequestration contributing to climate change mitigation, although, there are still questions about this effect in Mediterranean pine forests. The aim of this research was to quantify the storage of biomass and soil organic carbon in Pinus forests along a climatic gradient from North to South of the Iberian Peninsula. Nine experimental Pinus spp trials were selected along a latitudinal gradient from the pre-Pyrenees to southern Spain. At each location, a homogeneous area was used as the operational scale, and three thinning intensity treatments: unthinned or control (C), intermediate thinning (LT, removal of 30–40% of the initial basal area) and heavy thinning (HT, removal of 50–60%) were conducted. Growth per unit area (e.g., expressed as basal area increment-BAI), biomass, and Soil Organic Carbon (SOC) were measured as well as three sets of environmental variables (climate, soil water availability and soil chemical and physical characteristics). One-way ANOVA and Structural Equation Modelling (SEM) were used to study the effect of thinning and environmental variables on C sequestration. Biomass and growth per unit area were higher in the control than in the thinning treatments, although differences were only significant for P. halepensis. Radial growth recovered after thinning in all species, but it was faster in the HT treatments. Soil organic carbon (SOC10, 0–10 cm depth) was higher in the HT treatments for P. halepensis and P. sylvestris, but not for P. nigra. SEM showed that Pinus stands of the studied species were beneficed by HT thinning, recovering their growth quickly. The resulting model explained 72% of the variation in SOC10 content, and 89% of the variation in silvicultural condition (basal area and density) after thinning. SOC10 was better related to climate than to silvicultural treatments. On the other hand, soil chemical and physical characteristics did not show significant influence over SOC10- Soil water availability was the latent variable with the highest influence over SOC10. This work is a new contribution that shows the need for forest managers to integrate silviculture and C sequestration in Mediterranean pine plantations
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 Zientziak
Our 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.
Open Access
Importancia de la caracterización de la biomasa de raíces en la simulación de ecosistemas forestales
(Asociación Española de Ecología Terrestre, 2013) Gárate Bienzobas, Mikel; Blanco Vaca, Juan Antonio; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; Gobierno de Navarra / Nafarroako Gobernua
Los análisis de sensibilidad son una herramienta importante para comprender el funcionamiento de los modelos ecológicos, así como para identificar los parámetros más importantes en su funcionamiento. Además, los análisis de sensibilidad pueden utilizarse para diseñar de forma más efectiva planes de muestreo de campo dirigidos a calibrar los modelos ecológicos. En los estudios de ecosistemas forestales, el análisis cuantitativo de la parte subterránea es mucho más costoso y complicado que el estudio de la parte aérea, en especial el estudio de la dinámica de producción y descomposición de raíces gruesas y finas de los árboles. En este trabajo se muestra un ejemplo de análisis de sensibilidad del modelo forestal FORECAST a parámetros que definen la biomasa, longevidad y concentración de nitrógeno en las raíces de los árboles. El modelo se calibró para simular dos rodales de pino silvestre (Pinus sylvestris) en los Pirineos de Navarra. Los resultados indican que la tasa de renovación de raíces finas es el parámetro más influyente en las estimaciones del modelo de crecimiento de los árboles, seguida de la concentración de N en las mismas, siendo la relación biomasa subterránea/total el parámetro al cual el modelo es menos sensible. Además, el modelo es más sensible a los parámetros que definen el componente subterráneo de la biomasa arbórea cuando simula un sitio de menor capacidad productiva y mayor limitación por nutrientes.
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 Zientziak
We 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.