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The impacts of wildfire on vegetation and soil erosion have been studied for decades aiming to bring back ecosystems after fire perturbance. However, the influence of fires on above and belowground biodiversity remains far less understood. Biodiversity is critical for supporting ecosystem function, and this data scarcity is hampering managers in adopting effective practices for a proper restoration of burned ecosystems. This limitation could be overcome by future research that should focus post-fire diversity of plants and soil biota, by (i) analysing the environmental factors driving post-fire evolutionary trends; (ii) exploring their interrelations across different spatial and temporal scales; (iii) identifying the variability across fires of different severities and frequency; (iv) ascertaining the post-fire response of individual plant species and soil taxa to fire with or without application of post-fire restoration actions.

The multidimensional dynamics of biodiversity and ecosystem function during the rewilding of Mediterranean forests remain poorly understood, limiting our capacity to predict how future restoration efforts may help mitigate climate change. Here, we investigated the changes in multiple dimensions of biodiversity and ecosystem services in a 120-year forest succession after harvest to identify potential trade-offs in multiple dimensions of ecosystem function, and further assess the link between above and below-ground biodiversity and function. We found a positive influence of successional age on not only multiple dimensions of biodiversity and function but also some important trade-offs. Two ecosystem axes of function explained nearly 75.4% of functional variation during ecosystem rewilding. However, while the first axis increased with successional age promoting plant productivity and element stocks, the second axis followed a hump-shaped relationship with age supporting important reductions in nutrient availability and pathogen control in old forests. Our study further revealed a significant positive relationship between plant and soil biodiversity with multiple elements of multifunctionality as forests develop. Moreover, the influence of plant and soil biodiversity were especially important to support a high number of function working at high levels of functioning. Our work provides new insights on the patterns and functional trade-offs in the multidimensional rewilding of forests and further highlights the importance of biodiversity for long-term Mediterranean rewilding.

Overstorey biodiversity is known to drive multiple ecosystem functions in mature forests. However, the role of understorey biodiversity in regulating the soil microbiome and ecosystem multiservices of these ecosystems is virtually unknown. Here, we collected vegetation and soil data from mature plantation Mediterranean pine forests (100 years old) with different combinations of tree and understorey plant species to explore the contri-bution of overstorey and understorey biodiversity for explaining soil microbiomes and ecosystem multiservices. We found that while overstorey diversity is important for supporting soil-borne pathogen control, forest understorey biodiversity is critical for explaining soil nutrient availability, tree production, and soil-plant mutualistic relationships. Our results highlight the importance of understorey biodiversity for maintaining ecosystem multiservices in mature forests, which should be considered in forest management programs.

Eco-engineering techniques are generally effective at reducing soil erosion and restore vegetal cover after wildfire. However, less evidence exists on the effects of the post-fire eco-engineering techniques to restore plant diversity. To fill this knowledge gap, a standardized regional-scale analysis of the influence of post-fire eco-engineering techniques (log erosion barriers, contour felled log debris, mulching, chipping and felling, in some cases with burning) on species richness and diversity is proposed, adopting the Iberian Peninsula as case study. In general, no significant differences in species richness and diversity (Shannon) were found between the forest treated with different post-fire eco-engineering techniques, and the burned and non-treated soils. Only small significant differences were found for some sites treated with log erosion barriers or mulching. The latter technique increased species richness and diversity in some pine species and shrublands. Contour felled log debris with burning slightly increased vegetation diversity, while log erosion barriers, chipping and felling were not successful in supporting plant diversity. This research will help forest managers and agents in Mediterranean forest to decide the best postfire management option for wildfire affected forest, and in the development of more effective post-fire strategies.

Artificial Neural Networks (NNs) have been recognized as a powerful tool for automatically learning complex relationships in data. In this paper, we propose to apply such a tool for modeling forest regeneration, a possibility not yet investigated in the literature. In order to evaluate the capability of NNs to simulate initial recruitment of pine species in Mediterranean forests, a feed-forward multi-layer neural network has been applied to seed germination and seedling survival of four pine species under three soil conditions, with or without seed protection, in Castilla La Mancha (Central-Eastern Spain). The experimental campaign has shown good performance in predicting the two pine initial recruitment stages. The proposed approach may help to predict the success of natural regeneration in Mediterranean pine forests under different basal areas and management strategies.

Forest are highly vulnerable to global change drivers, such as an increase in wildfire events. Learning more about how and why different post-fire management strategies regulate the ability of forest ecosystem properties (e.g. plant diversity and function) to simultaneously recover after wildfire and provide multiple ecosystem functions is of critical importance. This study aims to evaluate how unburned, burned managed and burned unmanaged plots regulate the responses of multiple forest ecosystem properties (e.g. plant diversity, nutrient cycling, soil carbon stocks, water regulation, decomposition and wood production) and overall multifunctionality to wildfires. In September 2017, we selected two post-fire management strategies in a 3-km2 watershed previously affected by a wildfire in July 2012: contour-felled log debris (CFD), log erosion barriers area (LEB), and also unburned and unmanaged plots (BNA). We randomly distributed 12 plots among the three post-fire management strategies (three plots per treatment) and unburned. The results showed that multiple forest ecosystem properties were significantly affected by wildfire and that specific post-fire management treatment (e.g. LEB and CFD) can be used to efficiently support plant diversity and ecosystem functioning. Our results revealed that the general indicators of ecosystem functions decreased in Mediterranean forests after wildfires and post-fire management strategies (LEB and CFD) significantly helped to recover the ecosystems’ short-term community-level properties and ecosystem functions (5 years after a wildfire event) to pre-fire levels. Synthesis and applications. These findings demonstrate that multiple ecosystem functions are affected by wildfires in Mediterranean forests and show that post-fire management treatments can promote multifunctionality and plant diversity. Our results unfold the potential of log erosion barriers (LEB) and contour-felled log debris (CFD) as effective strategies for recovering

[EN]: Soil biodiversity, organic carbon, and their interactions, play critical roles for the maintenance and regulation of ecosystem services in drylands, including soil fertility and food production, among others. Climate change and anthropogenic impacts can result in soil carbon and biodiversity decreases, which can cause alterations of the carbon cycle and the loss of essential ecosystem functions. It is therefore crucial to advance our knowledge on the complex soil biological diversity, and its interactions with the soil organic carbon in drylands. This information will allow us to design effective strategies for carbon sequestration, thus contributing to reverse desertification. In this review, we discuss the importance of the soil biodiversity and organic carbon in drylands in a global change context and underline their interactions and their responses to climate change and degradation. We also highlight the use of novel techniques recently developed, including genomics, and effective soil management practices for promoting soil biodiversity and enhancing soil carbon levels, to ultimately, halt degradation and desertification., [ES]: La biodiversidad y el carbono orgánico del suelo, así como la interacción entre ambos, juegan papeles esenciales en el mantenimiento y regulación de los servicios ecosistémicos de las zonas secas, desde la fertilidad del suelo a la producción de alimentos. El cambio climático y los impactos antrópicos pueden provocar pérdidas en la biodiversidad y carbono del suelo, lo cual puede resultar en alteraciones de los ciclos del carbono y la funcionalidad de los ecosistemas derivando en procesos acelerados de desertificación. Es necesario, por tanto, mejorar nuestro conocimiento sobre la compleja diversidad biológica del suelo, así como su interacción con el carbono orgánico en las zonas secas. Esto nos permitirá diseñar estrategias efectivas para promover el secuestro de carbono en el suelo, contribuyendo así a revertir los procesos de degradación y desertificación. En esta revisión discutimos la importancia de la biodiversidad y el carbono orgánico del suelo de las zonas secas en un contexto de cambio global, definiendo la relación entre ambos y su respuesta a factores climáticos y degradación. También destacamos el uso de herramientas avanzadas tales como la genómica, y practicas relevantes de manejo del suelo que nos permitan incrementar los contenidos de carbono y mejorar la diversidad y funcionalidad de suelo en las zonas secas, con el fin último de prevenir y revertir la desertificación.

Expertos en prevención y gestión de incendios forestales explican en esta tribuna las claves para anticiparse a los efectos devastadores del fuego y aplicar las medidas de restauración de los ecosistemas quemados. Noches asfixiantes en zonas donde nunca lo habían sido, vientos extremadamente cálidos, intenso olor a humo, tensión en el ambiente mientras los vecinos tratan de organizarse para evitar que el fuego devore sus hogares. En el mejor de los casos, los bomberos ya están por la zona y se oyen aviones anfibios y helicópteros sobrevolando; en otros, hasta las medidas para apagar el fuego llegan más tarde de lo que sería deseable. Esta escena se está repitiendo en multitud de municipios en España este verano. Los datos de la superficie quemada ya otorgan a 2022 el triste récord de ser el año en el que más hectáreas de bosque se han quemado en los últimos 30 años. A 12 de agosto superamos las 240 000 hectáreas, una extensión mayor que la provincia de Guipúzcoa. Esta pérdida de masa forestal supone un aumento directo de las emisiones de CO₂, ya que el fuego libera el carbono almacenado en plantas y suelos. También supone perder biodiversidad y los servicios ecosistémicos de los que nos provee el bosque, que van desde la obtención de madera o setas hasta la recuperación del agua y el suelo o la obtención de aire para respirar. Eso sin contar lo más importante: los dramas personales, que incluyen la muerte de personas y los daños materiales, además de la pérdida de esperanza de quienes viven en las zonas rurales y llevan décadas advirtiendo de lo que iba a pasar, la población de la España que han vaciado muchos años de políticas enfocadas en lo urbano.

Few experiences of Artificial Neural Networks (ANNs) for hydro-logical predictions in forest soils after wildfire and post-fire treatments are available in literature. To fill this gap, an ANN model has been adapted to predict surface runoff and soil erosion in Mediterranean burned pine forests (Central Spain), and tested against hydro-logical observations at plot scale throughout 2 years. The model gave very accurate runoff and erosion predictions in burned and non-burned soils as well as for all soil treatments (mulching and/or logging or not). Although further experimental tests are needed to validate the ANN applicability to soils in burned and treated forests in other ecosystems, the use of ANN may be useful for landscape planners as decision support system for the integrated assessment and management of forests.

Droughts chronically alter resource availability in forest ecosystems. The increased frequency and severity of such extreme climate events challenge the acclimation potential of tree species especially across the drought-prone Mediterranean region. Pinus nigra is a widely distributed tree species in the Mediterranean region and considered vulnerable to extreme droughts. We used a 1000 km latitudinal gradient from northern Morocco to north-eastern Spain incorporating four regions (Edge-South, Core-South, Core-North and Edge-North) and including different P. nigra provenances. We aim to identify the climate and forest structure related drivers that influence tree radial growth (BAI, basal area increment). We developed statistical models for BAI by incorporating the potential effects of climate and forest structure (diameter and age distributions). Then, we forecasted the future growth of P. nigra forests during the 21st century considering the emission scenario A2 with an expected increase of +2.7 °C at the end of this century. Our results showed large variability across P. nigra populations in terms of environmental conditions, forest structure, and growth. The northernmost P. nigra populations, subjected to wetter and cooler conditions were those presenting the lowest BAI (4.9 cm2), whereas the southernmost P. nigra populations subjected to drier and warmer conditions presented the highest BAI values (11.5 cm2). Pinus nigra growth was enhanced by high spring precipitation, but this positive effect was probably modulated by forest structure. Temperature explained a higher proportion of the BAI variance than precipitation, with warmer summer conditions decreasing growth. Growth projections forecasted a decline in BAI (from 9.6 to 7.0 cm2) across all ecological regions starting around the mid-21st century but being lower in Edge-North populations compared to the other populations. Our study provides quantitative knowledge related to how P. nigra populations have been g

La biodiversidad y el carbono orgánico del suelo, así como la interacción entre ambos, juegan papeles esenciales en el mantenimiento y regulación de los servicios ecosistémicos de las zonas secas, desde la fertilidad del suelo a la producción de alimentos. El cambio climático y los impactos antrópicos pueden provocar pérdidas en la biodiversidad y carbono del suelo, lo cual puede resultar en alteraciones de los ciclos del carbono y la funcionalidad de los ecosistemas derivando en procesos acelerados de desertificación. Es necesario, por tanto, mejorar nuestro conocimiento sobre la compleja diversidad biológica del suelo, así como su interacción con el carbono orgánico en las zonas secas. Esto nos permitirá diseñar estrategias efectivas para promover el secuestro de carbono en el suelo, contribuyendo así a revertir los procesos de degradación y desertificación. En esta revisión discutimos la importancia de la biodiversidad y el carbono orgánico del suelo de las zonas secas en un contexto de cambio global, definiendo la relación entre ambos y su respuesta a factores climáticos y degradación. También destacamos el uso de herramientas avanzadas tales como la genómica, y practicas relevantes de manejo del suelo que nos permitan incrementar los contenidos de carbono y mejorar la diversidad y funcionalidad de suelo en las zonas secas, con el fin último de prevenir y revertir la desertificación., Soil biodiversity, organic carbon, and their interactions, play critical roles for the maintenance and regulation of ecosystem services in drylands, including soil fertility and food production, among others. Climate change and anthropogenic impacts can result in soil carbon and biodiversity decreases, which can cause alterations of the carbon cycle and the loss of essential ecosystem functions. It is therefore crucial to advance our knowledge on the complex soil biological diversity, and its interactions with the soil organic carbon in drylands. This information will allow us to design effective strategies for carbon sequestration, thus contributing to reverse desertification. In this review, we discuss the importance of the soil biodiversity and organic carbon in drylands in a global change context and underline their interactions and their responses to climate change and degradation. We also highlight the use of novel techniques recently developed, including genomics, and effective soil management practices for promoting soil biodiversity and enhancing soil carbon levels, to ultimately, halt degradation and desertification.

Restoration of degraded drylands is urgently needed to mitigate climate change, reverse desertification and secure livelihoods for the two billion people who live in these areas. Bold global targets have been set for dryland restoration to restore millions of hectares of degraded land. These targets have been questioned as overly ambitious, but without a global evaluation of successes and failures it is impossible to gauge feasibility. Here we examine restoration seeding outcomes across 174 sites on six continents, encompassing 594,065 observations of 671 plant species. Our findings suggest reasons for optimism. Seeding had a positive impact on species presence: in almost a third of all treatments, 100% of species seeded were growing at first monitoring. However, dryland restoration is risky: 17% of projects failed, with no establishment of any seeded species, and consistent declines were found in seeded species as projects matured. Across projects, higher seeding rates and larger seed sizes resulted in a greater probability of recruitment, with further influences on species success including site aridity, taxonomic identity and species life form. Our findings suggest that investigations examining these predictive factors will yield more effective and informed restoration decision-making.

In the version of this Article originally published, the surname of author Tina Parkhurst was incorrectly written as Schroeder. This has now been corrected.

Biocrusts are an essential soil surface cover at drylands where ecosystems are especially fragile to soil degradationprocesses due to climatic peculiarities. In the present work, (micro)biological and physicochemical properties indic-ative of soil functionality were studied in two different biocrust types dominated byDipolschistes diacapsisandLepraria isidiataand in underlying soil at two different depths (SL1, soil layer right below the biocrusts, and SL2,soil layer underlying SL1) at the Tabernas desert (southeast Spain). The influence of climatic factors (rainfall andtemperature) and general soilproperties on the (micro)biological properties were also analyzed in different envi-ronmental (climatic) conditions over a period of two years. PERMANOVA analyses showed significant statisticaldifferences (Pseudo-F = 63.9; P (perm) = 0.001) among biocrust and soil layers. Throughout the study period, en-zyme activities involved in C, N, and P cycles; microbial biomass-C; basal respiration; and several properties directlyrelated to ecosystem productivity (total organic carbon, total nitrogen, concentration of ammonium and nitrate)were higher in both biocrust types than in the underlying soil layers, showing that biocrusts improved soil functionsrelated to nutrient cycling. These properties progressively diminished in successive soil layers under the biocrusts(biocrusts > SL1 > SL2). Biocrusts showed greater similarity to each other and to SL1 than to SL2 in (micro)biologicalproperties. A distance-based linear model analysis showed that total organic carbon, rainfall, pH, mineralized N-NH4+, and total nitrogen were the most important variables for predicting (micro)biological soil properties inbiocrusts. Different biochemical behavior between the biocrusts and successive underlying soil layers has beenfound in wet periods. After rainfall periods, the biocrusts showed important peaks in basal soil respiration and in en-zyme activities involved in C and P cycles. Nevertheless

Adaptive forest management (AFM) is an urgent need because of the uncertainty regarding how changes in the climate will affect the structure, composition and function of forests during the next decades. Current research initiatives for the long-term monitoring of impacts of silviculture are scattered and not integrated into research networks, with the consequent losses of opportunities and capacity for action. To increase the scientific and practical impacts of these experiences, it is necessary to establish logical frameworks that harmonize the information and help us to define the most appropriate treatments. In this context, a number of research groups in Spain have produced research achievements and know-how during the last decades that can allow for the improvement in AFM. These groups address the issue of AFM from different fields, such as ecophysiology, ecohydrology and forest ecology, thus resulting in valuable but dispersed expertise. The main objective of this work is to introduce a comprehensive strategy aimed to study the implementation of AFM in Spain. As a first step, a network of 34 experimental sites managed by 14 different research groups is proposed and justified. As a second step, the most important AFM impacts on Mediterranean pines, as one of the most extended natural and planted forest types in Spain, are presented. Finally, open questions dealing with key aspects when attempting to implement an AFM framework are discussed. This study is expected to contribute to better outlining the procedures and steps needed to implement regional frameworks for AFM.

Aim of study Designing adequate silvicultural systems for natural regeneration of a forest species requires sound knowledge of the underlying ecological subprocesses flowering and fruiting, seed dispersal and predation, seed germination, seedling emergence and seedling survival. The main objective of the present work is to carry out a review on the current knowledge about the different subprocesses governing the regeneration process for the main Iberian Pinus species, in order to propose scientifically based management schedules. Area of study The review focuses on the five main native Pinus species within their most representative areas in the Iberian Peninsula Pinus nigra in Cuenca mountains, Pinus sylvestris in Sierra de Guadarrama, Pinus pinaster and Pinus pinea in the Northern Plateau and Pinus halepensis in Catalonia. Material and methods Firstly, currently available information on spatiotemporal dynamics and influential factors is introduced for each subprocess and species. Secondly, current regeneration strategies are characterized and the main bottlenecks are identified. Finally, alternative silvicultural practices proposed on the light of the previous information are presented. Main results Different climate-mediated bottlenecks have been identified to limit natural regeneration of the Iberian pine species, with seed predation and initial seedling survival among the most influential. New approaches focusing on more gradual regeneration fellings, extended rotation periods, prevent big gaps and program fellings on mast years are presented. Research highlights Natural regeneration of the studied species exhibit an intermittent temporal pattern, which should be aggravated under drier scenarios. More flexible management schedules should fulfil these limitations. © 2017 INIA.

Prescribed fire has been widely used as a fuel reduction tool and silvicultural treatment in Mediterranean forest ecosystems. However, other than the fact that fire may alter microsite conditions, little is known about the impact of prescribed burning on the natural regeneration of Spanish black pine (Pinus nigra Arn. ssp. salzmanii). In this study, we compared the effects of post dispersal seed predation, prescribed burning and vegetation treatment (brushing) on initial recruitment of Spanish black pine in both pure and mixed (with maritime pine, Pinus pinaster Ait.) stands during one year (2014) in the Cuenca Mountains (central-eastern Spain). Seedling recruitment in both pure and mixed stands was negatively affected by prescribed burning but was improved by the vegetation treatment. Post dispersal seed protection was an important factor for seed emergence and early survival success. Prescribed burning must be carefully planned in forest management aimed at regeneration. The influence of fire on natural regeneration should be taken into account for developing guidelines for the management of black pine forests, mainly in the Mediterranean Basin. © 2016 Elsevier B.V.