DIF-Artículos, capítulos...
http://hdl.handle.net/10396/2311
2024-03-29T13:49:17ZIntegrating dendrochronological and LiDAR data to improve management of Pinus canariensis forests under different thinning and climatic scenarios
http://hdl.handle.net/10396/27587
Integrating dendrochronological and LiDAR data to improve management of Pinus canariensis forests under different thinning and climatic scenarios
Navarro Cerrillo, Rafael M.; Padrón Cedrés, E.; Cachinero-Vivar, Antonio M.; Valeriano, Cristina; Camarero, J. Julio
Thinning focused on achieving growth and diameter management objectives has typically led to stands with reduced climate sensitivity compared to unthinned stands. We integrated dendrochronological with Airborne Laser Scanner (LiDAR) data and growth models to assess the long-term impact of thinning intensity on Canary pine (Pinus canariensis) radial growth. In 1988, 18 permanent treatment units were established in 73-year-old Canary pine plantations and three thinning treatments were applied (C–control-unthinned; 0% basal area removal; MT–moderate thinning: 10% and 15% basal area removal, and HT–heavy thinning: 46% and 45% basal area removal on the windward and leeward slopes, respectively). Dendrochronological data were measured in 2022 and expressed as basal area increment (BAI). The impact of climate on growth was examined by fitting linear regression models considering two different Representative Concentration Pathway (RCP) climate scenarios, RCP 2.6 and RCP 4.5. Finally, LiDAR data were used for standing segmentation to evaluate changes in overall growth under different climatic scenarios. The LiDAR–stand attributes differed between aspects. The BAI of the most recent 20 years (BAI20) after thinning was significantly higher for the moderate and heavy treatments on the leeward plots (F = 47.31, p < 0.001). On the windward plots, BAI decreased after moderate thinning. Considerable thinning treatments resulted in stronger changes in growth when compared to RCP climatic scenarios. From a silviculture perspective, the mapping of canopy structure and growth response to thinning under different climatic scenarios provides managers with opportunities to conduct thinning strategies for forest adaptation. Combining dendrochronological and LiDAR data at a landscape scale substantially improves the value of the separate datasets as forecasted growth response maps allow improving thinning management plans.
2024-01-01T00:00:00ZCompetition modulates the response of growth to climate in pure and mixed Abies pinsapo subsp. maroccana forests in northern Morocco
http://hdl.handle.net/10396/27147
Competition modulates the response of growth to climate in pure and mixed Abies pinsapo subsp. maroccana forests in northern Morocco
Navarro Cerrillo, Rafael M.; Delgado Manzanedo, Rubén; Rodríguez-Vallejo, Carlos; Gazol, Antonio; Palacios Rodríguez, Guillermo; Camarero, J. Julio
The effects of changes in structure and composition on the dynamics and responses of secondary forests to climate change are understudied. Secondary forests of Abies pinsapo var. maroccana are often a mosaic of patches of various development stages showing different stand structures and successional stages. We hypothesise that the structure, species composition and tree-to-tree competition of A. pinsapo stands in Talassemtane National Park (Riff in northern Morocco) modulate the potential response of these secondary forests to climate change. Nine plots representing three species mixtures were established in A. pinsapo-dominated forests, and dendrometric and dendroecological surveys were conducted. The two-parameter Weibull function was used to investigate the diameter distributions of Abies pinsapo, Pinus nigra subsp. mauritanica. Cedrus atlantica, Acer opalus, Juniperus oxycedrus and Quercus ilex for each site along the compositional gradient. We quantified changes in radial growth, response to climate and drought, and components of growth resilience. Finally, the influence of neighbourhood competition on individual tree growth was evaluated using the a competition index. Diameter distributions had an exponential, reverse-J character for A. pinsapo in pure and C. atlantica mixed stands. By contrast, A. pinsapo presented a positively-skewed diameter distribution dominated by small-sized trees in P. nigra mixed stands. There was a significant correlation between tree growth and climate on all forest types, with differing magnitudes per species. Significant precipitation-growth correlations were found for the previous autumn and winter (October, December) in A. pinsapo. Drought events reduced A. pinsapo’s resistance to subsequent droughts when growing in pure and mixed stands with C. atlantica. This decline was statistically significant by the end of the studied period (1999–2005). In contrast, mixed forests showed the highest recovery after drought. Successive drought events consistently reduced A. pinsapo‘s resilience to drought, regardless of species composition. In pure A. pinsapo and in A. pinsapo-C. atlantica mixed forests, competition reduced A. pinsapo’s growth, while in A. pinsapo-P. nigra mixed forests increased competition with P. nigra seemed to have a positive-to-neutral effect on A. pinsapo growth. Here, we showed that the response to climate and resilience of A. pinsapo forests could be severely influenced by structure, species composition, and competition, potentially influencing our expectations of long-term persistence of old-growth coniferous trees in the Riff mountains. Understanding forest resilience and response to changing climate has important implications towards managing and safeguarding the productivity and health of these old growth forests.
2020-01-01T00:00:00ZDrought stress and pests increase defoliation and mortality rates in vulnerable Abies pinsapo forests
http://hdl.handle.net/10396/27143
Drought stress and pests increase defoliation and mortality rates in vulnerable Abies pinsapo forests
Navarro Cerrillo, Rafael M.; González-Moreno, Pablo; Ruiz Gómez, Francisco José; Sánchez-Cuesta, Rafael; Gazol, Antonio; Camarero, J. Julio
Forest ecosystems are increasingly exposed to the combined pressure of climate change and attacks by pests and pathogens. These stress factors can threaten already vulnerable species triggering dieback and rising defoliation and mortality rates. To characterize abiotic (drought, climate warmings) and biotic (pathogens) risks and their spatiotemporal patterns we quantified the recent loss of vitality for the endangered and relict Abies pinsapo forests from Andalusia, south-eastern Spain. Abies pinsapo is an iconic Mediterranean fir showing a high vulnerability to drought stress and also to several pests (Cryphalus numidicus) and root rot fungi (Armillaria mellea). We analyzed a monitoring network dataset of radial growth, defoliation and mortality from 2001 to 2017 including 1025 trees situated in three major mountain ranges (Sierra de Grazalema, Sierra de las Nieves, and Sierra Bermeja). We fitted several statistical models to determine the main drivers of changes in defoliation, a proxy of tree vigor, and mortality. Defoliation and mortality rates were much higher towards the East of the study area, mirroring the gradient from Atlantic to Mediterranean climatic conditions. In the most affected stands tree defoliation increased in response to a combination of long and severe droughts, with attacks by the beetle C. numidicus. Mortality rates increased in response to a higher defoliation rate, a lower relative radial-growth rate, long and severe droughts and a higher incidence of A. mellea. Our findings illustrate the value of monitoring networks recording changes in forest health to quantify and forecast future vulnerability of threatened tree species.
2022-01-01T00:00:00ZIs thinning an alternative when trees could die in response to drought? The case of planted Pinus nigra and P. Sylvestris stands in southern Spain
http://hdl.handle.net/10396/27142
Is thinning an alternative when trees could die in response to drought? The case of planted Pinus nigra and P. Sylvestris stands in southern Spain
Navarro Cerrillo, Rafael M.; Sánchez-Salguero, Raúl; Rodríguez, Carlos; Duque Lazo, Joaquín; Moreno-Rojas, José Manuel; Palacios Rodríguez, Guillermo; Camarero, J. Julio
Previous research has provided insights into the potential response of growth and water use efficiency to thinning in Mediterranean forests, but little is known about the potential benefits of silviculture for plantations under severe drought stress. We selected two stands of Pinus sylvestris L. and P. nigra Arnold., and used dendrochronology and carbon isotopes (δ13C) to understand the growth and functional responses of high-density planted pine forests to thinning in drought-prone areas. Resistance, recovery, and resilience indices were calculated for each species using BAI data. We expected heavy thinning to produce stands that were more resilient to drought, particularly for the more drought-tolerant P. nigra. Differences in the basal area increments (BAI) and intrinsic water-use efficiency (iWUE) were found between the unthinned stand and the thinned stands, for both species. After thinning, BAI decreased as iWUE increased but this relationship was only marginally significant in P. sylvestris. Thinning increased growth resistance, recovery, and resilience following the severe drought of 2012. Our findings suggest that water shortage, linked to recurrent droughts, together with high tree competition, negatively affected tree growth and increased iWUE, which explains the dieback of some of these pine plantations. We evidence the vulnerability of densely planted Mediterranean pines to the forecasted warmer and drier conditions. These results show that a heavy thinning treatment (60% of basal area removed) provides a promising silvicultural framework for the adaptation of these drought-sensitive Mediterranean mountain pine forests to the potential risks of climate change.
2019-01-01T00:00:00Z