26 results on '"Camarero, Jesús Julio"'
Search Results
2. Forests synchronize their growth in contrasting Eurasian regions in response to climate warming.
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Shestakova TA, Gutiérrez E, Kirdyanov AV, Camarero JJ, Génova M, Knorre AA, Linares JC, Resco de Dios V, Sánchez-Salguero R, and Voltas J
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- Linear Models, Siberia, Spain, Species Specificity, Time Factors, Climate Change, Forests, Trees growth & development
- Abstract
Forests play a key role in the carbon balance of terrestrial ecosystems. One of the main uncertainties in global change predictions lies in how the spatiotemporal dynamics of forest productivity will be affected by climate warming. Here we show an increasing influence of climate on the spatial variability of tree growth during the last 120 y, ultimately leading to unprecedented temporal coherence in ring-width records over wide geographical scales (spatial synchrony). Synchrony in growth patterns across cold-constrained (central Siberia) and drought-constrained (Spain) Eurasian conifer forests have peaked in the early 21st century at subcontinental scales (∼ 1,000 km). Such enhanced synchrony is similar to that observed in trees co-occurring within a stand. In boreal forests, the combined effects of recent warming and increasing intensity of climate extremes are enhancing synchrony through an earlier start of wood formation and a stronger impact of year-to-year fluctuations of growing-season temperatures on growth. In Mediterranean forests, the impact of warming on synchrony is related mainly to an advanced onset of growth and the strengthening of drought-induced growth limitations. Spatial patterns of enhanced synchrony represent early warning signals of climate change impacts on forest ecosystems at subcontinental scales.
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- 2016
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3. Facilitation drives tree seedling survival at alpine treelines.
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Chen, Wensheng, Li, Jiangrong, Camarero, Jesús Julio, Ding, Huihui, Fu, Fangwei, Li, Yueyao, Zheng, Xiangyu, Li, Xiaoxia, Shen, Wei, Sigdel, Shalik Ram, Leavitt, Steven W, and Liang, Eryuan
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TREE seedlings ,TIMBERLINE ,SOLAR radiation ,ENVIRONMENTAL monitoring ,CLIMATE change ,SEAGRASSES - Abstract
Alpine treelines are considered ecological monitors recording the impacts of climate change on trees and forests. To date, most treeline research has focused on how climate change drives treeline dynamics. However, little is known about how biotic interactions mediate treeline shifts, particularly in the case of tree recruitment, a bottleneck of treeline dynamics. We hypothesized that inter- and intraspecific facilitation determined the establishment and survival of tree seedlings at alpine treelines. To test this hypothesis, 630 Abies georgei var. smithii seedlings with different ages (4–6, 7–9 and 10–15 years old) were transplanted into three growth habitats (canopy-in, canopy-out and meadow) across the alpine treeline ecotone (4300–4500 m) in the Sygera Mountains, on the southeastern Qinghai-Tibetan Plateau. Microclimate, height growth, mortality rates and leaf functional traits of transplanted seedlings were measured over 3 years. We found that the variations in leaf functional traits were driven by microclimate. After the transplantation, the leaf concentrations of soluble sugars and starch and C:P ratio increased, whereas leaf size decreased. The resource use of seedlings gradually shifted to a more conservative strategy as indicated by changes in non-structural carbohydrates and nutrient concentrations. Radiation, temperature and moisture conditions, mediated by plant interactions, influenced seedling mortality and annual growth by affecting leaf morphological traits. Our findings illustrate how facilitation plays a crucial role in altering solar radiation and leaf trait functioning, determining seedling survival and growth at alpine treelines. We provide new insights into the underlying mechanisms for tree establishment and alpine treeline shifts in response to climate change. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Tree-Level Climate Sensitivity Reveals Size Effects and Impending Growth Decline in Silver Fir Affected by Dieback.
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Crespo-Antia, Juan Pablo, González de Andrés, Ester, Gazol, Antonio, Camarero, Jesús Julio, and Linares, Juan Carlos
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SILVER fir ,CLIMATE change ,TREE mortality ,WATER shortages ,FOREST declines ,DROUGHTS ,CLIMATE sensitivity - Abstract
Worldwide studies have related recent forest decline and mortality events to warmer temperatures and droughts, as well as pointing out a greater vulnerability to climate changes in larger trees. Previous research performed on silver fir (Abies alba Mill.) suggest an increasing decline and mortality, mainly related to rising water shortages. Here, we investigate these die-off events in two silver fir populations at the rear edge of the species in the western Pyrenees. We used dendrochronology to investigate tree age, size (diameter) and individual climate sensitivity (climate–growth relationships) as predisposing factors related to growth patterns and drought resilience indexes in canopy-level declining and non-declining trees. The regional climate was also investigated, including temperature trends, quantile regression in precipitation and frequency of extreme events in drought indexes (SPEI). The regional climate was characterized by an increase in mean temperatures and a higher frequency of extreme drought events in recent decades, without a decrease in total precipitation. Larger trees were more sensitive to temperature and prone to decline. Declining trees presented decreasing growth trends years ago, providing a robust predisposing trait. Both populations were not different in mean growth, despite the contrasting local climate and management legacies, although we identified a higher resilience to drought in the eastmost stand. A significant regression was found between growth trends and climate sensitivity, supporting that declining trees are more sensitive to warmer temperatures and drought. Hence, the results support a contrasting climate sensitivity related to tree size (but not to tree age), suggesting impending decline and mortality in large trees with higher temperature sensitivity (negative temperature–growth correlations). Nonetheless, contributing factors, such as the legacy of previous logging, should also be accounted for. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Tree Rings Elucidate Differential Drought Responses in Stands of Three Mexican Pines.
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Vivar-Vivar, Eduardo Daniel, Pompa-García, Marín, and Camarero, Jesús Julio
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PINE ,TREE growth ,CLIMATE change ,TREE-rings ,TREE mortality ,TEMPERATURE effect ,DROUGHTS - Abstract
Knowledge regarding the growth of trees is essential to understanding their response to predicted warmer and drier climate scenarios. We used the annual rings of three Mexican pines (Pinus montezumae Lamb., Pinus oocarpa Schiede ex Schltdl., and Pinus monophylla Torr. & Frém) to explore their drought responses. Correlation analyses showed that hydroclimatic factors differentially impact tree species in terms of the intensity and temporality. The negative influence of the maximum temperature and positive effect of the precipitation on the growth indices were notable, with P. montezumae being the most responsive species, followed by P. oocarpa and P. monophylla. The climate–growth relationships were specific and driven by the differential hydrothermal conditions across the study areas. SPEI analyses indicated that P. monophylla is better able to tolerate drought than P. montezumae or P. oocarpa, especially in recent years. The lower resilience of P. montezumae and P. oocarpa could predispose them to a higher mortality risk if warming and drying rates increase. Our findings strengthen the understanding of the responses of tree growth to seasonal drought, which is critical considering the biogeographic shifts that will potentially be experienced by these forests in the future. This knowledge improves the understanding of young Mexican stands and could contribute to the design of management strategies in the face of predicted climatic variations. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Spatiotemporal Variability in Tree Growth in the Central Pyrenees: Climatic and Site Influences
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Tardif, Jacques, Camarero, Jesús Julio, Ribas, Montse, and Gutiérrez, Emilia
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- 2003
7. Species interactions slow warming-induced upward shifts of treelines on the Tibetan Plateau
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Liang, Eryuan, Wang, Yafeng, Piao, Shilong, Lu, Xiaoming, Camarero, Jesús Julio, Zhu, Haifeng, Zhu, Liping, Ellison, Aaron M., Ciais, Philippe, and Peñuelas, Josep
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- 2016
8. Assessing Forest Vulnerability to Climate Change Combining Remote Sensing and Tree-Ring Data: Issues, Needs and Avenues.
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Italiano, Santain S. P., Camarero, Jesús Julio, Colangelo, Michele, Borghetti, Marco, Castellaneta, Maria, Pizarro, Manuel, and Ripullone, Francesco
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CLIMATE change ,FOREST microclimatology ,HEAT waves (Meteorology) ,REMOTE sensing ,CLIMATE extremes ,DROUGHTS ,GLOBAL warming - Abstract
Forests around the world are facing climate change. Increased drought stress and severe heat waves in recent decades have negatively impacted on forest health, making them more vulnerable and prone to dieback and mortality phenomena. Although the term vulnerability is used to indicate an increased susceptibility of forests to climate change with a worsening of their vigour status that can compromise their ability to respond to further climate extreme events, there are still uncertainties on how to evaluate it. Indeed, evaluation of forest vulnerability is complex both because of some critical issues in the estimation methods used and because of the multiple factors influencing the response of forests to ongoing climate change. A way to assess the vulnerability to environmental stresses is by combining remote sensing and dendroecological data. However, these two approaches entail multiple uncertainties, including growth/photosynthetic relationships, carbon allocation dynamics, biases of tree-ring data and noisy remote sensing data, which require further clarification for proper monitoring of pre- and post-drought forest trajectories. Our review aims to create an overview of the current literature and knowledge to understand the critical issues, needs and possible solutions that forest vulnerability research is addressing. We focus on Mediterranean forests located in a climate warming hotspot and showing a high vulnerability to increased aridification. [ABSTRACT FROM AUTHOR]
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- 2023
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9. Inconsistent Growth Responses of Alpine Rhododendron Shrubs to Climate Change at Two Sites on the Eastern Tibetan Plateau.
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Wang, Ya-Lei, Wang, Ya-Feng, and Camarero, Jesús Julio
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RHODODENDRONS ,SHRUBS ,MOUNTAIN ecology - Abstract
Evidence is accumulating that the radial growth of high-elevation Rhododendron shrubs has high dendrochronological potential. However, it remains unclear if the growth responses of alpine Rhododendron shrubs to climate are contingent on site conditions. Herein, the climate–growth relationships of alpine Rhododendron przewalskii Maxim. shrubs were investigated at two sites (NQ, LWQ) at an elevation of 4300 m on the eastern Tibetan Plateau. We collected ring-width data from 53 Rhododendron shrubs. Well-replicated 111-year-old and 51-year-old long shrub ring-width chronologies were built for NQ and LWQ, respectively. Mean shrub growth did not differ between the two study sites. Mean maximum temperature in September of the previous year was significantly negatively correlated with shrub ring-width indices in site NQ, whereas the August minimum temperature of the current year showed a strong negative association with shrub growth indices in site LWQ. Random effects with the shrub level condition exerted a certain influence on shrub radial growth. Results of previous studies in other forest regions across the Tibetan Plateau, along with this study, revealed the diverse responses of radial growth of alpine Rhododendron shrubs to climate change. Thus, both climatic and local-scale variables should be considered when conducting shrub-based dendrochronological studies. A warmer and drier climate in the future could further reduce Rhododendron shrub growth in particular sites and threaten the survival of alpine shrub ecosystems on the eastern Tibetan Plateau. [ABSTRACT FROM AUTHOR]
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- 2023
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10. Response of vegetation to drought time-scales across global land biomes
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Vicente-Serrano, Sergio M., Gouveia, Célia, Camarero, Jesús Julio, Beguería, Santiago, Trigo, Ricardo, López-Moreno, Juan I., Azorín-Molina, César, Pasho, Edmond, Lorenzo-Lacruz, Jorge, Revuelto, Jesús, Morán-Tejeda, Enrique, and Sanchez-Lorenzo, Arturo
- Published
- 2013
11. Alpine Shrubification: Juniper Encroachment into Tundra in the Ural Mountains.
- Author
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Grigoriev, Andrey A., Shalaumova, Yulia V., Balakin, Dmitriy S., Erokhina, Olga V., Abdulmanova, Svetlana Yu., Moiseev, Pavel A., and Camarero, Jesús Julio
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JUNIPERS ,TUNDRAS ,SNOW accumulation ,COLD regions ,MOUNTAIN ecology ,SHRUBS ,WINTER ,SNOW cover - Abstract
Snow cover is one of the most important factors affecting the regeneration and growth of shrubs in cold arctic and alpine ecosystems. In many of these cold regions, climate change in the last century is manifested not only in a rapid rise of temperature, but also in an increase in winter precipitation. For instance, in the Ural Mountains, winter turned warmer and more humid during the past century, leading to higher snow accumulation. We investigated how the change trends in the cold season (November to March) climate conditions affected the recruitment of the shrub Juniperus sibirica Burgsd., the most widespread shrub conifer in mountains of this region where it is dominant in treeless areas. Specifically, we considered seven sites located in the Southern and Northern Urals that are subjected to lower and higher continentality, respectively. We assessed how juniper recruitment changed along altitudinal gradients going from the open forest to the alpine tundra and passing by the transition zone. We found that juniper shrubs recruited at higher elevations during the 20th century in most sites, with a rapid shrub encroachment into alpine tundra (shrubification) after the 1990s. This process was especially intensive in the last decades at the uppermost parts of convex slopes where the snowpack is shallow. We found positive associations between juniper recruitment and cold-season precipitation or temperature in the Northern and Southern Urals, respectively. Shrubification is following upward treeline shifts in the Southern Urals. Our findings indicate that juniper shrubs will tend to colonize sites with low snowpack depth if winter conditions keep warm and wet enough and the snowpack allows the effective protection of shrubs. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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12. Competition modulates the adaptation capacity of forests to climatic stress: insights from recent growth decline and death in relict stands of the Mediterranean fir Abies pinsapo
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Linares, Juan Carlos, Camarero, Jesús Julio, and Carreira, José Antonio
- Published
- 2010
13. Heterogeneous Responses of Alpine Treelines to Climate Warming across the Tibetan Plateau.
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Wang, Yafeng, Li, Daihan, Ren, Ping, Ram Sigdel, Shalik, and Camarero, Jesús Julio
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TIMBERLINE ,PLATEAUS ,CONTINUOUS distributions ,TREE growth ,TREE height ,CLIMATE change - Abstract
The Tibetan Plateau hosts a continuous distribution of alpine treelines from the Qilian Mountains to the Hengduan Mountains and the Himalaya Mountains. However, not much is known about the broadscale alpine treeline dynamics and their responses to climate warming across the Tibetan Plateau. Herein, we collected a total of 59 treeline sites across different forest regions of the Tibetan Plateau and the related field data (i.e., upward advance magnitude, tree recruitment and height growth), expansion potential (i.e., elevational difference between the current treeline and the tree species line (EP)) and vegetation TI (an index of species interactions) from the published references. Site characteristics (e.g., elevation, slope and aspect) and the related environmental factors were used to analyze the relationships between treeline shifts and environmental variables. Despite increases in the recruitment and growth of trees at most treeline sites, alpine treeline positions showed heterogeneous responses to climate warming. Most treelines advanced over the last century, while some treelines showed long-term stability. EP was significantly and positively linked to the summer warming rate and treeline shifts, suggesting that the position of current tree species line is of crucial importance in evaluating treeline dynamics under climate change. In addition, warming-induced treeline advances were modulated by plant–plant interactions. Overall, this study highlighted the heterogeneous responses of regional-scale alpine treelines to climate warming on the Tibetan Plateau. [ABSTRACT FROM AUTHOR]
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- 2022
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14. Stand-structural effects on Heterobasidion abietinum-related mortality following drought events in Abies pinsapo
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Linares, Juan Carlos, Camarero, Jesús Julio, Bowker, Matthew A., Ochoa, Victoria, and Carreira, José Antonio
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- 2010
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15. Iberian oaks coping with global change: Ecological processes and management strategies
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Marañón, Teodoro, Pérez-Ramos, Ignacio Manuel, Villar Montero, Rafael, Acácio, Vanda, Aranda, Ismael, Camarero, Jesús Julio, de la Riva, Enrique G., Domínguez, María Teresa, Fernández Rebollo, Pilar, Quero, José L., Ramírez Valiente, José A., Rodríguez Calcerrada, Jesús, Valbuena Carabaña, María, Ministerio de Ciencia e Innovación (España), Marañón, Teodoro, Pérez-Ramos, Ignacio Manuel, Domínguez, María Teresa, de la Riva, Enrique G., Villar Montero, Rafael, Marañón, Teodoro [0000-0002-7751-9316], Pérez-Ramos, Ignacio Manuel [0000-0003-2332-7818], Domínguez, María Teresa [0000-0002-7348-9543], de la Riva, Enrique G. [0000-0002-3393-8375], and Villar Montero, Rafael [0000-0002-3895-9984]
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Quercus ilex ,Dehesas ,Quercus suber ,Resilience ,Regeneration ecology ,Climate change ,Ecosystem services ,Growth ,Functional diversity ,Mediterranean ,Hybridization ,Genetic diversity - Abstract
Capítulo de libro monográfico sobre el género Quercus, Iberian oak forests and woodlands are vital providing a variety of ecosystem services. They provide raw materials like cork, wood and fuel, and fodder (acorns) for wild and domestic animals. Oak trees provide a climate regulating service by their capacity to sequester carbon and therefore to mitigate the effects of climatic change. There is an increasing demand for cultural services provided by oak woodlands, mainly for recreation and ecotourism. However, some global-change drivers are negatively affecting oak forests, therefore diminishing their ecosystem services and in consequence undermining human well-being. The main drivers affecting Iberian oaks are: land use changes, introduction of exotic pathogens, air and soil pollution deteriorating oak health, and climatic change, in particular the combined reduction of rainfall and the rise in temperature. In this chapter we focus on the ecology of Iberian oaks and how they are affected by global change. Firstly, we introduce a literature overview of the research conducted on Quercus, analysed by species, countries and topics. Secondly, we review the main biological processes related with the oak responses to global change: i) genetic diversity, climatic refuges and adaptation to climatic change; ii) ecophysiological responses to stress and disturbance, functional diversity, growth patterns, and scaling up from leaf to ecosystem; iii) demographic responses, causes of regeneration failures, spatial patterns of recruitment, drivers of decline and dieback. Thirdly, we review the management strategies in three case studies: the agro-silvo-pastoral systems (dehesas and montados), the cork oak woodlands, and the afforestation of a polluted-land for phytostabilization of contaminants.
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- 2020
16. Tree‐to‐tree interactions slow down Himalayan treeline shifts as inferred from tree spatial patterns.
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Sigdel, Shalik Ram, Liang, Eryuan, Wang, Yafeng, Dawadi, Binod, and Camarero, Jesús Julio
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TIMBERLINE ,TREE-rings ,BIRCH ,TREES ,FOREST density ,FIR - Abstract
Aim: The spatial patterns of tree populations reflect multiple ecological processes. However, little is known on whether these patterns mediate responses to climate in marginal tree populations such as those forming alpine tree lines. We examined the influence of tree‐to‐tree interactions on the responsiveness of tree lines to climate warming. Location: Central Himalayas. Taxon: Betula utilis; Abies spectabilis. Methods: We analysed a network of 17 tree line sites located across the central Himalayas, encompassing a wide longitudinal gradient characterized by increasing precipitation eastwards. We quantified the changes in density and the spatial patterns of three 50‐year age classes of the two main tree species found at the tree line (Betula utilis and Abies spectabilis), and related them to reconstructed shifts in tree line elevation. Results: Younger trees showed clustering near the tree line, while older trees tended to show random spatial distribution. Clustering decreased as climate conditions ameliorated, that is, in the wetter eastern sites. Lower rate of tree line elevation change was observed at the sites with higher clustering intensity. Main Conclusions: Our study indicates that tree aggregation weakens tree line responsiveness to climate warming, and thus warming‐induced drought stress tends to lower tree line shift rates by enhancing clustering. It also highlights the complexity and contingency of site‐dependent tree line responses to climate. Hence, to advance our understanding of tree line processes, we should consider both direct and indirect influences of relevant biotic (tree‐to‐tree interactions) and abiotic (climate) drivers of tree line dynamics. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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17. Last-century forest productivity in a managed dry-edge Scots pine population: the two sides of climate warming.
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Marqués, Laura, Madrigal‐González, Jaime, Zavala, Miguel A., Camarero, Jesús Julio, and Hartig, Florian
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FOREST productivity ,SCOTS pine ,TREE populations ,GLOBAL warming ,DROUGHTS ,CLIMATE change - Abstract
Climate change in the Mediterranean, associated with warmer temperatures and more frequent droughts, is expected to impact forest productivity and the functioning of forests ecosystems as carbon reservoirs in the region. Climate warming can positively affect forest growth by extending the growing season, whereas increasing summer drought generally reduces forest productivity and may cause growth decline, trigger dieback, hamper regeneration, and increase mortality. Forest management could potentially counteract such negative effects by reducing stand density and thereby competition for water. The effectiveness of such interventions, however, has so far mostly been evaluated for short time periods at the tree and stand levels, which limits our confidence regarding the efficacy of thinning interventions over longer time scales under the complex interplay between climate, stand structure, and forest management. In this study, we use a century-long historical data set to assess the effects of climate and management on forest productivity. We consider rear-edge Scots pine ( Pinus sylvestris) populations covering continental and Mediterranean conditions along an altitudinal gradient in Central Spain. We use linear mixed-effects models to disentangle the effects of altitude, climate, and stand volume on forest growth and ingrowth (recruitment and young trees' growth). We find that warming tends to benefit these tree populations, warmer winter temperature has a significant positive effect on both forest growth and ingrowth, and the effect is more pronounced at low elevations. However, drought conditions severely reduce growth and ingrowth, in particular when competition (stand volume) is high. We conclude that summer droughts are the main threat to Scots pine populations in the region, and that a reduction of stand volume can partially mitigate the negative impacts of more arid conditions. Mitigation and adaptation measures could therefore manage stand structure to adopt for the anticipated impacts of climate change in Mediterranean forest ecosystems. [ABSTRACT FROM AUTHOR]
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- 2018
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18. Evaluando los efectos del cambio global sobre el funcionamiento de los abetos ibéricos
- Author
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Linares, Juan Carlos and Camarero, Jesús Julio
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Water-use efficiency ,Dendrochronology ,Dendrocronología ,Drought ,Climate change ,Cambio climático ,Eficiencia en el uso del agua ,Stress ,Sequía ,Estrés - Abstract
17 páginas, 8 figuras, 1 tabla., [EN]: Assessing the effects of global change on the performance of Iberian firs using carbon isotopes analyses in tree rings. Drought is the main tree-growth limiting factor in the Mediterranean basin. It has been suggested that, in water-limited ecosystems, the global atmospheric CO2 rise might to compensate an increasing drought-induced stomatal closure, without a significant drop in the production rates. In this paper we show data of secondary growth and intrinsic water use efficiency (WUEi) for Abies alba and A. pinsapo trees. We compared populations with and without external decline symptoms. Since the early eighties of the 20th century, the rate of WUEi increase has declined in the sites with decline symptoms, being currently below the rate of CO2 increase. Our data show a good relationship between the time the rate of WUEi increase falls below the CO2 increase, the regional mean temperature increase, the occurrence of several extreme droughts, and generalised radial growth decline., [ES]: Evaluando los efectos del cambio global sobre el funcionamiento de los abetos ibéricos mediante análisis de isótopos de carbono en los anillos de crecimiento. La sequía es el principal factor limitante del crecimiento en las especies forestales de la cuenca mediterránea. Se ha propuesto que en ecosistemas limitados por el agua, el incremento global de CO2 atmosférico puede compensar el mayor cierre estomático inducido por la sequía sin reducirse notablemente las tasas de producción. En este trabajo se muestran las tasas de crecimiento secundario y la eficiencia intrínseca de uso de agua (WUEi) de poblaciones de Abies alba y A. pinsapo. Se han comparado poblaciones con y sin síntomas externos de decaimiento. Desde comienzos de los años ochenta del pasado siglo la tasa de incremento de la WUEi en los sitios que presentan síntomas de decaimiento ha descendido hasta colocarse por debajo de la tasa de incremento de CO2. Nuestros datos muestran una buena correlación entre el momento en que el incremento de WUEi cae por debajo del incremento del CO2, el incremento regional de la temperatura media, la ocurrencia de varias sequías extremas, y la reducción de crecimiento radial.
- Published
- 2010
19. La respuesta del crecimiento de 'Pinus Uncinata' al clima en poblaciones relictas del sistema ibérico
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Camarero, Jesús Julio and Gutiérrez, Emilia
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Iberian System ,NAO ,Cambio climático ,Sistema Ibérico ,Climate change ,Dendroecología ,Dendroecology - Abstract
[ES] El clima controla el crecimiento radial de las especies arbóreas pero dichas relaciones no son estables en el tiempo e interaccionan con los cambios de uso del bosque. En el caso de poblaciones relictas de área restringida debe evaluarse si su persistencia dependerá de su respuesta de crecimiento al cambio climático y si esta respuesta va a diferir de la observada en el área principal de distribución de la especie. Para responder a estas preguntas, cuantificamos y comparamos la relación crecimiento-clima y su variabilidad temporal mediante métodos dendrocronológicos en dos poblaciones relictas ibéricas de Pinus uncinata (Castillo de Vinuesa, Soria- La Rioja; Sierra de Gúdar, Teruel) y en poblaciones del área principal de distribución más próxima (Pirineos). Las series de crecimiento radial de Soria y Teruel mostraron tendencias similares de crecimiento ya sea aumentos (1850-1860, 1950-1960, 1960-1970) o descensos (1830-1840, 1930-1940, 1950-1960). Desde aproximadamente 1970 las dos poblaciones mostraron un crecimiento divergente ya que aumentó en Soria y descendió en Teruel. Las relaciones crecimiento-clima de las poblaciones relictas ibéricas durante el año de formación del anillo difirieron de las observadas en poblaciones pirenaicas ya que la población de Teruel respondió de manera positiva a la precipitación de junio-agosto del año de crecimiento y la de Soria mostró una asociación positiva con la temperatura de julio-agosto. Todas las poblaciones mostraron una respuesta negativa/positiva a las temperaturas de septiembre/noviembre en el año previo al de formación del anillo y respuestas positivas a la temperatura de mayo durante el año de crecimiento. Las relaciones entre clima y crecimiento fueron claramente inestables en ambas poblaciones: la temperatura de septiembre del año previo al de formación del anillo ha mostrado relaciones cada vez más negativas con el crecimiento a lo largo del siglo XX, y las relaciones cada vez más positivas con las temperaturas de mayo del año de crecimiento sugieren un inicio cada vez más temprano de la estación de crecimiento. La respuesta al clima de poblaciones relictas ibéricas de P. uncinata difiere de la observada en el área principal pirenaica por lo que su persistencia y viabilidad futura dependerá de la dirección del cambio climático y de la respuesta del crecimiento al clima que caracteriza cada población., [EN] The climate controls the radial growth of tree species but climate-growth relationships are unstable and they interact with land-use changes. In the case of relict tree populations with restricted distribution area it should be assessed if (i) their persistence will depend on the growth response to climatic change, and (ii) if the climate-growth response will differ between relict restricted- area populations and stands from the main distribution area. To answer these questions, we quantified and compared the climate-growth relationships and their temporal variability using dendrochronological methods in two relict Pinus uncinata populations located in the Iberian System (Castillo de Vinuesa, Soria; Sierra de Gúdar, Teruel) and in populations located in the closest main distribution area (Pyrenees). The radial-growth series of Soria and Teruel showed similar ascending (1850-1860, 1950-1960, 1960- 1970) or descending (1830-1840, 1930-1940, 1950-1960) trends. Since ca. 1970 both populations showed a divergent growth since growth increased in the Soria site but decreased in the Teruel site. The climate-growth relationships of both relict Iberian populations were different from those observed in Pyrenean populations for the year of tree-ring formation. The Teruel population showed a positive response to current June-August precipitation but growth in the Soria population was positively associated with current July-August temperature. All sites showed a negative/positive response to September/ November temperature during the year before tree-ring formation and positive responses to current May temperature. The climate-growth relationships were clearly unstable in both relict populations since previous September temperature showed declining negative relationships throughout the 20th century, whereas current May temperatures showed increasingly positive relationships with growth which suggests an earlier growth onset. The growth response to climate in relict Iberian P. uncinata populations differed from that observed in the main Pyrenean distribution area. Thus, the persistence and future viability of these relict populations will depend on the direction of climatic change and on the characteristic growth response of each population to climate.
- Published
- 2008
20. Earlywood and Latewood Widths of Picea chihuahuana Show Contrasting Sensitivity to Seasonal Climate.
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Cabral-Alemán, Citlalli, Pompa-García, Marín, Acosta-Henández, Andrea C., Zúñiga-Vásquez, José M., and Camarero, Jesús Julio
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WOOD ,SPRUCE ,ENDANGERED plants ,EFFECT of temperature on plants ,CLIMATE change - Abstract
The existence of endangered tree species in Mexico necessitates an understanding of their vulnerability to the predicted climate changes (warming and drying trends). In this study, the sensitivity to climate of earlywood (EW) and latewood (LW) widths of the threatened Picea chihuahuana was determined. The response of EW and LW to climate variables (maximum temperature, minimum temperature, precipitation, evaporation, and a drought index) was analyzed by means of correlation analysis using dendrochronology over the period of 1950-2015. EW and LW production were enhanced by cool and wet conditions during winter prior to the start of growing season. During the growing season, EW and LW production increased in response to cool spring and summer conditions, respectively; temperatures and year-round evaporation, excluding summer and the previous drought in the period prior to the growing season. EW was sensitive to seasonal drought, which is a concern considering the predicted aridification trends for the study area. These results provide further knowledge on the dendroecological potential of Picea chihuahuana. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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21. Species interactions slow warming-induced upward shifts of treelines on the Tibetan Plateau.
- Author
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Eryuan Liang, Yafeng Wang, Shilong Piao, Xiaoming Lu, Camarero, Jesús Julio, Haifeng Zhu, Liping Zhu, Ellison, Aaron M., Ciais, Philippe, and Peñuelas, Josep
- Subjects
TIMBERLINE ,CLIMATE change research ,COMPETITION (Biology) ,POPULATION biology - Abstract
The alpine treeline is commonly regarded as being sensitive to climatic warming because regeneration and growth of trees at treeline generally are limited by low temperature. The alpine treelines of the Tibetan Plateau (TP) occur at the highest elevations (4,900 m above sea level) in the Northern Hemisphere. Ongoing climatic warming is expected to shift treelines upward. Studies of treeline dynamics at regional and local scales, however, have yielded conflicting results, indicating either unchanging treeline elevations or upward shifts. To reconcile this conflict, we reconstructed in detail a century of treeline structure and tree recruitment at sites along a climatic gradient of 4 °C and mean annual rainfall of 650 mm on the eastern TP. Species interactions interacted with effects of warming on treeline and could outweigh them. Densification of shrubs just above treeline inhibited tree establishment, and slowed upward movement of treelines on a time scale of decades. Interspecific interactions are major processes controlling treeline dynamics that may account for the absence of an upward shift at some TP treelines despite continued climatic warming. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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- View/download PDF
22. Age, competition, disturbance and elevation effects on tree and stand growth response of primary Picea abies forest to climate.
- Author
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Primicia, Irantzu, Camarero, Jesús Julio, Janda, Pavel, Čada, Vojtĕch, Morrissey, Robert C., Trotsiuk, Volodymyr, Bače, Radek, Teodosiu, Marius, and Svoboda, Miroslav
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PLANT growth ,NORWAY spruce ,CLIMATE change ,TREE height ,FOREST management ,COMPETITION (Biology) - Abstract
Stands and trees may exhibit different climate–growth responses compared to neighbouring forests and individuals. The study of these differences is crucial to understanding the effects of climate change on the growth and vulnerability of forests and trees. In this research we analyse the growth responsiveness of primary Norway spruce forests to climate as a function of different stand (elevation, aspect, slope, crowding, historic disturbance regime) and tree (age, tree-to-tree competition) features in the Romanian Carpathians. Climate–growth relationships were analysed using Pearson correlation coefficients between ring-width indices (RWIs) and climate variables. The influence of stand and tree characteristics on the RWI responses to climate were investigated using linear mixed-effects models. Elevation greatly modulated the climate–growth associations and it frequently interacted with competition intensity or tree age to differentially influence growth responsiveness to climate. Old trees were more sensitive to climate than young trees, but while old tree’s response to climate highly depended on elevation (e.g. positive influence of summer temperature on old trees’ RWIs at high elevations, but negative effect at low elevations), differences of the young trees’ response across the elevation gradient were less evident. The severity of the past disturbance also modified the climate–growth associations because of contrasting canopy structures. Our results suggest that although an increase in temperature might enhance growth at high elevations, it may also induce growth declines due to drought stress at lower elevations, particularly for old trees or trees growing under high levels of competition, which may increase their vulnerability to disturbances. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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23. Seeing the trees for the forest: drivers of individual growth responses to climate in Pinus uncinata mountain forests.
- Author
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Galván, Juan Diego, Camarero, Jesús Julio, Gutiérrez, Emilia, and Zuidema, Pieter
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- *
MOUNTAIN forests , *FOREST plants , *MUGO pine , *DENDROCHRONOLOGY , *CLIMATE change , *TREE growth - Abstract
Individual trees, not forests, respond to climate. Such an individual-scale approach has seldom been used to retrospectively track the radial growth responses of trees to climate in dendrochronology. The aim of this study was to adopt this individual view to retrospectively assess tree sensitivity to climate warming, and to evaluate and compare the potential drivers of tree growth responses to climate acting at species, site and individual scales., Following a dendroecological framework, we sampled a network of 29 Pinus uncinata forests in NE Spain and obtained tree-ring widths series from 642 trees. Individual features as northness, elevation, slope, basal area, sapwood area, tree height and tree age were used to evaluate the potential drivers of tree growth responses to climate. The analysed data set includes diverse ecological and biogeographical conditions. The tree growth responses to climate were assessed by relating growth indices to climatic variables using linear-mixed effects models., Maximum November temperatures during the year prior to tree-ring formation enhanced P. uncinata growth mainly in mid-elevation sites, whereas at higher elevations growth was more dependent on the positive effect of warmer minimum May temperatures during the year of tree-ring formation. Current June precipitation was the positive main climatic driver of growth in sites prone to water deficit such as the southernmost limit of the species distribution area or very steep sites. Elevation was the main factor controlling how much growth variability is explained by climate at the site and tree scales. Climate warming was more intense during the early 20th century, when the importance of elevation as an indirect modulator of growth declined as compared with the late 20th century., Synthesis. The individual-scale approach taken in this study allowed detecting that trees growing at southern and low-elevation sites were the most negatively affected by warm and dry summer conditions. Our results emphasize that both (i) an individual-scale approach to quantify tree growth responses to climate and (ii) a detailed evaluation of the potential biotic and abiotic drivers of those individual responses are necessary to understand climate sensitivity of trees. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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24. Upward Treeline Shifts in Two Regions of Subarctic Russia Are Governed by Summer Thermal and Winter Snow Conditions.
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Grigoriev, Andrey A., Shalaumova, Yulia V., Vyukhin, Sergey O., Balakin, Dmitriy S., Kukarskikh, Vladimir V., Vyukhina, Arina A., Camarero, Jesús Julio, and Moiseev, Pavel A.
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TIMBERLINE ,TREE-rings ,INFLUENCE of altitude ,SCOTS pine ,NORWAY spruce ,TUNDRAS - Abstract
Climate warming impacts on alpine treeline dynamics. However, we still lack robust assessments of the long-term impacts of climate on tree recruitment at the treeline, particularly in remote areas such as the subarctic regions of Russia subjected to different climate influences. We expected that the treelines in two regions may have different features and dynamics patterns. We analyzed climate variables and assessed treeline dynamics by quantifying recruitment using the tree rings of ca. 7000 trees of four species (Betula pubescens Ehrh. ssp. tortuosa, Pinus sylvestris L., Picea abies Ledeb. ssp. obovata, Larix gmelinii Rupr.) along 14 altitudinal transects (series of study plots). We compared the Khibiny Massif (Kola Peninsula) and the western Putorana Plateau, subjected to oceanic and continental influences, respectively. In both regions, summers became warmer, and winters became snowier during the past century. At the low part of the treeline ecotone, tree recruitment has slowly increased since the mid-18th century at the Putorana Plateau and the mid-19th century at the Khibiny but accelerated in the early 20th century at both regions and reached a maximum peak in the second half of the past century. Treeline encroachment intensified in the 1930s at the Khibiny and the 1950s at the Putorana Plateau. Trees encroached in the tundra leading to upward treeline shifts in the late 20th century. The slope exposure affected the rates of treeline shift with higher upward advances on southern-oriented slopes. Tree recruitment and early-winter precipitation were positively correlated. The differences in species composition, treeline altitude and influences of slope orientation on treeline dynamics can be explained primarily by differences in the degree of continentality. The abundance of saplings in both regions allows the future encroachment of trees into tundra and further treeline upward shifts to be forecast. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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25. Increasing Drought Sensitivity and Decline of Atlas Cedar (Cedrus atlantica) in the Moroccan Middle Atlas Forests.
- Author
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Linares, Juan C., Taïqui, Lahcen, and Camarero, Jesús Julio
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EFFECT of drought on plants ,ATLAS cedar ,CLIMATE change ,TREE growth ,FOREST conservation - Abstract
An understanding of the interactions between climate change and forest structure on tree growth are needed for decision making in forest conservation and management. In this paper, we investigated the relative contribution of tree features and stand structure on Atlas cedar (Cedrus atlantica) radial growth in forests that have experienced heavy grazing and logging in the past. Dendrochronological methods were applied to quantify patterns in basal-area increment and drought sensitivity of Atlas cedar in the Middle Atlas, northern Morocco. We estimated the tree-to-tree competition intensity and quantified the structure in Atlas cedar stands with contrasting tree density, age, and decline symptoms. The relative contribution of tree age and size and stand structure to Atlas cedar growth decline was estimated by variance partitioning using partial-redundancy analyses. Recurrent drought events and temperature increases have been identified from local climate records since the 1970s. We detected consistent growth declines and increased drought sensitivity in Atlas cedar across all sites since the early 1980s. Specifically, we determined that previous growth rates and tree age were the strongest tree features, while Quercus rotundifolia basal area was the strongest stand structure measure related to Atlas cedar decline. As a result, we suggest that Atlas cedar forests that have experienced severe drought in combination with grazing and logging may be in the process of shifting dominance toward more drought-tolerant species such as Q. rotundifolia. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
26. Synergistic effects of past historical logging and drought on the decline of Pyrenean silver fir forests.
- Author
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Camarero, Jesús Julio, Bigler, Christof, Linares, Juan Carlos, and Gil-Pelegrín, Eustaquio
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SILVER fir ,LOGGING ,FOREST declines ,ECOLOGY ,CLIMATE change ,VEGETATION & climate ,TREE growth ,EFFECT of drought on plants ,EFFECT of stress on plants - Abstract
Abstract: The causal factors and effects of forest declines are not well understood in temperate conifer forests. Most studies have focused on climatic and environmental stressors and have obviated the potential role of historical forest management as a predisposing factor of decline. Here, we assess if the recent silver fir (Abies alba) decline observed in the Spanish Pyrenees was predisposed by historical logging and incited by warming-induced drought stress. We analysed a dataset of environmental, structural, and historical variables at the tree and stand level including 32 sites with contrasting degrees of defoliation distributed over 5600km
2 . We followed a dendroecological approach to reconstruct historical logging and to infer the effects of warming-induced drought stress on growth. The silver fir decline was more severe and widespread in western low-elevation mixed forests dominated by trees of small size and slow growth. These sites were subject to higher water deficits than eastern sites, where late-summer rainfall as the key climatic variable controlling silver fir growth was higher. Declining sites showed more frequent growth releases induced by historical logging than non-declining sites. Historical logging and warming-induced drought acted as long-term predisposing and short-term inciting factors of silver fir decline in the Pyrenees, respectively. We suggest that biomass increases caused by past intense logging affected the vulnerability of silver fir against late-summer water deficit. Future research in declining temperate conifer forests should consider the interacting role of predisposing historical management and inducing climatic stressors such as droughts. [Copyright &y& Elsevier]- Published
- 2011
- Full Text
- View/download PDF
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