Cork Oak Forests Research Articles

Remotely sensed indicators of forest conservation status: Case study from a Natura 2000 site in southern Portugal

The successful implementation of habitat conservation measures demands regular and spatially explicit monitoring and reporting on conservation status at a range of scales, based on indicators of both habitat range and condition (structure and functions required for long-term maintenance). Such is the case with the Natura 2000 protected areas in Europe. Focusing on the cork oak (Quercus suber) forests of one such area, the Serra de Monchique in southern Portugal, we test the complementarity and joint effectiveness of airborne multispectral and laser scanning (lidar) in providing robust indicators of conservation status. Principal forest types and other land covers are mapped to an accuracy of up to 70% (11 land cover classes) and 81% (5 classes) by fusing the two remote sensing datasets, results that are superior to using either one alone. Using previously tested relationships between lidar height metrics, forest vegetation structure and species diversity, we develop a map predicting areas of high (22% of area), medium (25%) and low (53%) condition. We recommend the further development and testing of remotely sensed range and condition indicators of conservation status for their application in important forested sites across Europe and beyond.

EVSItalia Database of Evergreen Mediterranean Forests

A database of the Evergreen Mediterranean Forests of peninsular Italy is presented (EVSItalia Database of Evergreen Mediterranean Forests, GIVD ID EU-IT-014). The database stores 1,266 releves from published certified phytosociological sources, belonging to the syntaxa of Quercion ilicis. Specifically, Quercus ilex forest of Viburno-Quercetum ilicis and the cork oak forest in the syntaxa of Viburno-Quercetum ilicis suberetosum (according to a centralMediterranean classical interpretation). Q. suber stands are a variant of the Q. ilex forests, although the continued exploitation of cork and grazing activities in the cork forests, do not allow a precise analysis of the true spatial limits of the two biocoenoses. All the releves are uploaded to TURBOVEG; a related ArcGIS Database stores information about localization: Operational Geographic Units (OGU), corresponding to the quadrates of the Italian floristic grid, precise GPS or toponym information as well as descriptive records of locations extracted from geographical information systems are stored. The data-set aims to support reviews based on large data-sets for the classification of Italian vegetation types, classification of communities and their parameterization over larger areas by geostatistical analysis, the exploration geographic changes in community distribution along topographical gradients and to test changes along geographical gradients. A different insight in the patterns of synonymy and reassessment among syntaxa on the basis of a geographical approach is expected.

Distribution of Coraebus undatus (Coleoptera: Buprestidae) in cork oak forests of southern Spain

Coraebus undatus is a beetle which excavates galleries in the cork tissue, leading to important economic reductions in quantity and quality of cork that can be harvested from cork oak Quercus suber. Andalusia (southern Spain) produces around 14% of the world's cork supplies and leads the way in cork production in Spain. By analysing distribution patterns and infestation levels of C. undatus in different cork oak forests of southern Spain, useful information for implementing sustainable management of the pest can be obtained. We recorded the level of beetle infestation in cork oak forests by observing the traces left by larval galleries in trees that had recently been de-corked. Our results reveal a widespread distribution for C. undatus and a high percentage of infested oaks (>70%) in almost all cork oak forests in southern Spain. The most damaged forests were located in the areas with the highest density of cork oak forests and a dominant understory.

Forecasting infestation by Coraebus undatus (Coleoptera, Buprestidae) in cork oak forests

Larvae of the buprestid beetle Coraebus undatus feed on the cork-generating layer of cork oaks, seriously affecting cork quality and reducing the monetary value of cork plank which is used by the wine industry. The galleries of C. undatus are only observable after cork bark has been removed; therefore if, prior to harvesting, trees that have a high likelihood of having been infested can be identified, control measures can be applied to good effect, thus reducing the cost of insecticide applications. Here, we identify the variables that can provide reliable information on infestations. Prominent among these is the presence of chlorotic spots, as it provides direct information on presence of C. undatus galleries. Other useful variables are the degree of defoliation and, as regards ants, the absence of Crematogaster scutellaris and the presence of Camponotus cruentatus.

The impact of the common rabbit on cork oak regeneration in SW Spain

Seed predation has traditionally been considered as simply a progressive loss of seeds. However, partial consumption of tree seeds may actually assist regeneration. We quantified partial consumption of acorns by the common rabbit (Oryctolagus cuniculus) in a cork oak forest in southwest Spain (Donana Natural Park). To examine the effects of partial consumption on germination and seedling emergence, we simulated two different levels of acorn predation (30 and 50 % cotyledon loss, representing light and heavy partial consumption, respectively). One-third of the sampled acorns presented evidence of consumption but most of the damage caused by partial consumption did not affect the acorn embryo (damage was mainly to non-vital parts of the propagule). Partial consumption caused more rapid germination and emergence than that was observed in intact acorns, but germination and emergence rate was unaffected. Heavy consumption of the acorn caused differences in root and shoot biomass as a consequence of cotyledon loss. In this greenhouse study, partial consumption was non-lethal to the acorns, and cotyledon biomass loss did not decrease the probability of successful establishment. Partially consumed seeds can therefore contribute significantly to the natural regeneration of Quercus coccifera, although it would be beneficial to conduct long-term studies focusing on seed traits and animal behaviour under field conditions.

Changes in soil organic carbon and climate change – Application of the RothC model in agro-silvo-pastoral Mediterranean systems

Due to the complexity of soil organic carbon (SOC), models have proved very useful in helping to improve our understanding of the soil–plant–atmosphere system. In this study we used the Rothamsted carbon model (RothC), which considers the effect of climate (temperature, rainfall and evaporation), soil texture (clay content) and crop management on the decomposition processes, to predict changes in SOC under different land uses and the different climate that may occur in the future.SOC turnover was evaluated in land uses under different levels of agricultural intensification. The agriculture of the study-area is mainly extensive and markedly agro-silvo-pastoral, and is typical of north-eastern Sardinia (Italy) and similar areas of the Mediterranean basin. The following land uses were considered: vineyards, hay crops, pastures, semi-natural systems (formerly vineyards) and cork oak forests. Since the study-area is characterized by the same soil type (Haplic Endoleptic Cambisols, Dystric) derived from granitic rocks and potential native vegetation (Quercus suber L.), this was considered as the model baseline to study soil organic carbon dynamics. Climate change scenarios for 90yr were generated from the baseline climate with two Global Climate Models: GISS (Goddard Institute of Space Studies, USA), and HadCM3 (Met Office, Hadley Centre, UK), for two of the Intergovernmental Panel on Climate Change (IPCC) emission scenarios (SRES A2 and B2).Land uses at low cropping intensity were more efficient than intensive agricultural systems in terms of SOC storage in the order: hay crop>pasture>cork oak forest>semi-natural systems. Land use change to vineyards decreased the carbon balance significantly between 0.09 and 0.15tCha−1yr−1. However, former vineyards have almost recovered from soil disturbance following the establishment of the vineyards.

Environmental analysis of raw cork extraction in cork oak forests in southern Europe (Catalonia – Spain)

Cork oak grows endemically in a narrow region bordering the western Mediterranean, and especially in the Iberian Peninsula. The importance of cork agro-forestry systems lies in the fact that a natural and renewable raw material – cork – can be extracted sustainably without endangering the tree or affecting biodiversity. This paper describes an environmental analysis of the extraction of raw cork in cork oak forests in Catalonia, using data from five representative local forest exploitations. The evaluation was carried out using life cycle assessment (LCA) methodology, and all the forestry management required to obtain a tonne of raw cork was included. The aim of the study was to evaluate the environmental impacts – in terms of global warming, acidification, eutrophication, human toxicity, and so on – caused by cork extraction and determine the carbon dioxide balance of these forestry systems, with a tree lifespan of about 200 years.During the life cycle extraction of cork in Catalonia, 0.2 kg of CO2 eq. was emitted per kg of raw cork extracted. Moreover, cork cannot be extracted without the tree, which will be fixing carbon dioxide throughout its technological useful life (200 years), despite the fact that the bark is removed periodically: every 13–14 years. If the emission from extraction and the carbon contained in the material is discounted, the carbon dioxide balance indicates that 18 kg of CO2 are fixed per kg of raw cork extracted. Therefore, cork is a natural, renewable and local material that can replace other non-renewable materials, at local level, to reduce the environmental impacts of products, and particularly to reduce their carbon footprint.

Use of an Airborne Lidar System to Model Plant Species Composition and Diversity of Mediterranean Oak Forests

Airborne lidar is a remote-sensing tool of increasing importance in ecological and conservation research due to its ability to characterize three-dimensional vegetation structure. If different aspects of plant species diversity and composition can be related to vegetation structure, landscape-level assessments of plant communities may be possible. We examined this possibility for Mediterranean oak forests in southern Portugal, which are rich in biological diversity but also threatened. We compared data from a discrete, first-and-last return lidar data set collected for 31 plots of cork oak (Quercus suber) and Algerian oak (Quercus canariensis) forest with field data to test whether lidar can be used to predict the vertical structure of vegetation, diversity of plant species, and community type. Lidar- and field-measured structural data were significantly correlated (up to r= 0.85). Diversity of forest species was significantly associated with lidar-measured vegetation height (R(2) = 0.50, p < 0.001). Clustering and ordination of the species data pointed to the presence of 2 main forest classes that could be discriminated with an accuracy of 89% on the basis of lidar data. Lidar can be applied widely for mapping of habitat and assessments of habitat condition (e.g., in support of the European Species and Habitats Directive [92/43/EEC]). However, particular attention needs to be paid to issues of survey design: density of lidar points and geospatial accuracy of ground-truthing and its timing relative to acquisition of lidar data.

Short communication. Isolation of Aeromonas hydrophila in piglets

The production of Alentejano breed pig started a recovery two decades ago due to increasing demand for gourmet products. These pigs are raised in rotational semi-extensive or extensive outdoor production systems in the “Montado” (green and cork oak forest), grazing and feeding acorns and other associated food resources. Bacteria of the genus Aeromonas are considered as emerging pathogens of importance for man and animals, but its involvement in swine is not well documented. In the context of a study made at the University of Évora to assess the specific diseases of Alentejano swine, diseased piglets from two farms were submitted for pathological and bacteriological examinations. Pathological examinations revealed changes characteristic of septicemia, and Aeromonas hydrophila was isolated in pure culture from multiple organs of piglets from both farms. Antibiotic sensitivity tests showed that the isolates from one of the farms were susceptible to gentamicin, oxitetracycline, neomycin, enrofloxacin, colistin sulfate, trimethoprim, ceftiofur, and amoxicillin plus clavulanic acid. In contrast, the A. hydrophila isolated in the other farm was resistant to all drugs tested but enrofloxacin. This is the first report in the world showing the relationship between septicemia and A. hydrophila infection in piglets. The importance of this finding is further reinforced by the fact that these bacteria can be highly resistant to antimicrobial agents.

Unravelling Soil Fungal Communities from Different Mediterranean Land-Use Backgrounds

BackgroundFungi strongly influence ecosystem structure and functioning, playing a key role in many ecological services as decomposers, plant mutualists and pathogens. The Mediterranean area is a biodiversity hotspot that is increasingly threatened by intense land use. Therefore, to achieve a balance between conservation and human development, a better understanding of the impact of land use on the underlying fungal communities is needed.Methodology/Principal FindingsWe used parallel pyrosequencing of the nuclear ribosomal ITS regions to characterize the fungal communities in five soils subjected to different anthropogenic impact in a typical Mediterranean landscape: a natural cork-oak forest, a pasture, a managed meadow, and two vineyards. Marked differences in the distribution of taxon assemblages among the different sites and communities were found. Data analyses consistently indicated a sharp distinction of the fungal community of the cork oak forest soil from those described in the other soils. Each soil showed features of the fungal assemblages retrieved which can be easily related to the above-ground settings: ectomycorrhizal phylotypes were numerous in natural sites covered by trees, but were nearly completely missing from the anthropogenic and grass-covered sites; similarly, coprophilous fungi were common in grazed sites.Conclusions/SignificanceData suggest that investigation on the below-ground fungal community may provide useful elements on the above-ground features such as vegetation coverage and agronomic procedures, allowing to assess the cost of anthropogenic land use to hidden diversity in soil. Datasets provided in this study may contribute to future searches for fungal bio-indicators as biodiversity markers of a specific site or a land-use degree.

Nutritional status of Quercus suber populations under contrasting tree dieback

Summary ‘Los Alcornocales’ Natural Park (southwest Spain), one of the most important Mediterranean cork oak (Quercus suber) forests in Europe, has experienced a substantial tree dieback in the past decades. We hypothesize that areas experiencing high eutrophication should exhibit higher leaf nitrogen (N) concentrations and lower N resorption efficiency and proficiency indices than areas under lower environmental stress, and this could be related with forest functioning and tree mortality rates. To test this hypothesis, we collected leaf and soil samples from four plots in the southern part of the park, near a polluted industrial area, and four plots in the northern part of the park, far from this pollution source. N and phosphorus (P) in green and senescent leaves and soil NH4 1 -N, NO3 2 -N and PO4 3− -P were analysed. Foliar N and the leaf N:P ratio were significantly higher in the southern plots (high-mortality plots) than in the northern plots. The resorption efficiency was significantly higher for P than for N in all southern and northern plots. The values of resorption proficiency indicated incomplete resorption for N and complete resorption for P in all plots. Our results suggest that oak populations showing high-mortality rates may be associated with tree N and P imbalance.

Pathways for resilience in Mediterranean cork oak land use systems

Abstract Context Loss of woodlands and degradation of vegetation and soil have been described for all Mediterranean-type ecosystems worldwide. In the Western Iberian Peninsula, overexploitation of evergreen cork oak land use systems has led to soil erosion, failures in oak recruitment, and loss of forests. Degraded and dry sites are quickly colonised by pioneer heathland rockrose (Cistus spp.) shrubs forming highly persistent patches. Aims Although traditionally shrublands have been considered as a transient successional state, we present evidence that they can represent persistent alternative states to former cork oak forests. Review trends and conclusions We first describe how Mediterranean vegetation evolved in the Iberian Peninsula and the role of fire and long-term human management as main disturbances. We then discuss alternative pathways through state-and-transition models indicating the ecological and land use variables that halt cork oak regeneration and recruitment and drive vegetation transitions towards persistent shrublands. Unless concerted management actions and restoration programmes are undertaken, the cork oak land use systems will not be sustainable.

Distribution review, habitat suitability and conservation of the endangered and endemic Moroccan spadefoot toad (Pelobates varaldii)

The Moroccan spadefoot toad (Pelobates varaldii) has received little scientific attention since its discovery. Currently, P. varaldii is listed as Endangered on the IUCN Red List due to a multitude of threats, while its distribution is partially unknown and fragmented. The current study addresses distribution, threats and the potential niche using ecological niche modelling, while emphasizing conservation strategies and immediate actions. The distribution of P. varaldii can be divided into four disjunct areas, at least two of which consist of small populations. The largest threats to P. varaldii include the transformation of habitat and breeding ponds into agricultural and industrial areas, the pollution of breeding ponds due to extensive livestock pasturing and the possible expansion of Procambarus sp. into the Mamora cork oak forest. Additional threats constitute a reduction of gene flow and loss of genetic variability as a result of habitat fragmentation. The ecological niche models (ENMs) of P. varaldii revealed fundamental environmental conditions along parts of the northeast Moroccan Atlantic and Mediterranean coastline. The species mainly inhabits well vegetated areas upon Quaternary soils at low altitudes. Proposed conservation actions include the development of a biannual monitoring program, identification and designation of protected areas within the distribution and development of a management plan for Mamora forest.

Aspectos ecológicos y efectos del manejo forestal en una población de tortuga mediterránea (Testudo hermanni hermanni) en Cataluña (España)

The aim of this research was to evaluate the effects of forestry works on Testudo hermanni hermanni, and to establish ecological parameters useful for habitat management. This study took place in the northeast of Spain, in the Albera Mountains, where one of the last natural populations of Hermann’s tortoises lives. Twenty-one tortoises were weekly monitored using radiotracking during six months, between July 2009 and January 2010. Between October 2009 and January 2010, forestry works took place at the study site. The impact of the forestry works and the associated damages were estimated using two approaches: the displacements of the monitored tortoises and the use of plaster models resembling tortoises, which were placed in similar locations and conditions to live tortoises. Radiotracking results showed that 30% of the tortoises were found on open areas (pastures and sparse cork oak forest), whereas 70% corresponded to dense forests and heath scrubland locations. The analysis of the effect of forestry works showed that tortoises were affected by the works in 45% of the cases, even during hibernation period. The simulation results of the impact of the forestry works based on plaster models showed that 4% of the models were seriously damaged when using manual works (brush cutters and clearing saws), whereas mechanized works (chain tractor) were responsible for an estimation of 22% mortality and 6% serious damages.

Contribution of cork oak plantations installed after 1990 in Portugal to the Kyoto commitments and to the landowners economy

Cork oak stands are a part of the agroforestry ecosystem in Portugal, characterized by a low crown cover from cork oak trees, managed towards cork production, and sometimes in combination with grazing. In recent years, European Union policies gave impetus to a large area of new cork oak plantations, which have been established mainly for cork production purposes, and consequently with higher stand density than traditional agroforestry systems. These plantations are important not only for cork production but also for the carbon sequestered by these slow growing forests that won't be harvested for wood production. Thinning operations will be needed to avoid excessive inter-tree competition and wood extracted from these thinning may also provide income for the owners. In the present study, carbon sequestered and wood volumes resulting from thinning were estimated for the next 70years. Three scenarios of different annual afforestation rates and different site indexes were tested. The resulting values for the considered scenarios show that, if the plantation rates are maintained, new cork oak plantations will have an important contribution to the Portuguese commitments to providing CO2 offsets under the Kyoto protocol. Additionally, due to the increasing values of initial density in new cork plantations, cork oak forests will produce a significant volume of wood that may become an important contribution to the landowners' income.

Environmental analysis of the production of champagne cork stoppers

Champagne cork stoppers are a product made basically from cork, a natural and renewable resource extracted from cork oak forests in western Mediterranean regions. Each stopper is made up of an agglomerated cork body and two natural cork discs. In 2009, 60% of the world’s champagne cork stoppers were produced in Catalonia, due to the importance of cava, champagne and other sparkling wines in neighbouring areas. The aim of this research was to provide environmental reference data on champagne cork stoppers production, and identify the industrial stages and operations that made the greatest impact. This research was carried out using life cycle assessment (LCA) methodology, and five of the most representative producers were analysed. The system considered all the processes involved in production after the forest management stage and one million champagne cork stoppers were taken as a functional unit (FU). Results showed that 53,886 kg of CO 2 eq. were emitted to produce the FU. It was observed that the champagne cork stopper manufacture stage represented between 57 and 67% of the environmental impact, depending on the category. Specifically, between 25 and 47% of the environmental impacts associated with this stage were caused by the body agglomeration operation, and between 21 and 29% were caused by the gluing of discs. On the other hand, some of the production stages such as the transport of raw cork and intermediate products, cork slab preparation or end of life stages represented a very small part of the total environmental impact of the product, less than 2%. Furthermore, it was observed that a champagne cork stopper produced by the most impacting company presented a higher impact, between 10 and 27% above the sector average, depending on the impact category; while the least impacting company presented between 12 and 32% less impact. These differences indicate that some companies can improve their production by adopting technology and production practices that some of their competitors have already put in place.

Scale-dependent segregation of seeders and resprouters in cork oak (Quercus suber) forests

Recent studies showed that disturbances and water availability determine the richness among plants with different post-fire strategies of Mediterranean-type ecosystems. The aim of this study was to determine whether or not the scale of analysis has an influence on the effects of these factors and, therefore, on the segregation of the dominant post-fire strategies, obligate seeders and obligate resprouters, and facultative species. We recorded all woody species and geographical features on 94 (75 m(2)) plots of cork oak woodlands in the southern Iberian Peninsula. For each regenerative type (resprouters, seeders and species with both traits--facultative species), we tested the relationship between the number of species and the predictors using a generalised linear mixed model. The fixed predictor considered at the large scale was altitude, and fixed predictors considered at the local scale were aspect (north/south) and disturbance (fire and clearing by heavy machinery; yes/no). The random predictor was the factor of site. When this factor did not have significant effect for some regenerative types, these relationships was tested using a generalised linear model. Resprouting species were most represented at lower altitudes and in undisturbed sites, while seeders were also at lower altitudes but mostly on south-facing slopes, especially south-facing disturbed sites. For facultative species, site is the most important variable. The proportion of seeders from the total species is not related to altitude, but it is related to disturbance and aspect. These results suggest that there is no segregation of the richness of seeders and resprouters at the large scale (altitudinal gradient). Differences appeared at the local scale (aspect and disturbance).

Effects of soil management on structure and activity of denitrifying bacterial communities

The influx of carbon sources and energy into the grossly oligotrophic soil system is a major driving force in biogeochemical cycles. Differences in these inputs due to the ground-covering plants and agriculture practices, likely influence the activity of the microbial communities. Previously, we have shown that the extent and degree of active bacterial diversity in soils are clearly affected by the type of management. In the present study we have evaluated the effects of different soil managements (tilled vineyard, grass-covered vineyard, temporary grassland, pasture, cork oak forest) on the diversity and activity of denitrifying bacterial species. Total DNA and RNA were directly extracted from soil sampled in two different seasons, spring and autumn. Genes and transcripts for two nitrite reductases ( nirS and nirK), nitric oxide reductases ( qnorB) and nitrous oxide reductase ( nosZ) were used as PCR targets of denitrifying bacteria. Denaturing Gradient Gel Electrophoresis (DGGE) results showed a high abundance and wide distribution of bacterial denitrifiers in soil, while denitrifying gene expression was detected in few species or groups of species. A distinct seasonal shift was evident in denitrifying active communities, that also showed a significant variation depending on soil variables such as texture, pH and organic carbon. DGGE band sequence analysis revealed similarities between sequences found in our soil and those belonging mainly to α and β- Protebacteria division. However, several sequences were not related to any known denitrifying species. The applied RT-nested PCR approach has proven to have the potential to provide information on diversity of active denitrifying bacterial communities and on where and when these bacteria express their ability within the soil.

Drinking and Protecting: A Market Approach to the Preservation of Cork Oak Landscapes

With the availability of new techniques to close wine bottles avoiding the risk of ‘corky’ taste, the tradition of closing wine bottles with cork stoppers is on the retreat. As a consequence, the Mediterranean cork oak forests with their rich biodiversity are endangered, since their cultivation is not profitable anymore. This paper explores the viability of a market approach to the preservation of these ecologically valuable landscapes. In an internet-based contingent valuation survey, we assess wine consumers' willingness to pay (WTP) a higher price for wine bottles closed with high-quality cork stoppers (with a low risk of tainting the wine) instead of buying wine bottles with alternative stoppers in order to preserve the cork oak landscapes. We find that though many wine consumers have experience with tainted wine, they are, nevertheless, willing to buy wine with high-quality cork stoppers at higher prices. Their average WTP is, however, not sufficient to cover the additional costs of these stoppers. Thus, we propose a financing mix of market returns and government subsidies for preserving the cork oaks. As a precondition for this market approach to be successful, bottles with high-quality cork stoppers must be clearly identifiable in the shops, and consumers must be informed about the ecological consequences of supporting the cork production.

Long-term understory recovery after mechanical fuel reduction in Mediterranean cork oak forests

In the Euro-Mediterranean region, mechanical fuel reduction is increasingly used in response to the mounting occurrence of catastrophic wildfires, yet their long-term ecological effects are poorly understood. Although Mediterranean vegetation is resilient to a range of disturbances, it is possible that widespread fuel management at short intervals may threaten forest structural complexity and the persistence of some plant species and functional types, with overall negative consequences for biodiversity. We used a chronosequence approach to infer woody vegetation changes in the first 70 years after understory clearing in upland cork oak (Quercus suber) forests, and to assess how these are affected by treatment frequency. Across the chronosequence there was a shift between plant communities with contrasting composition, structure and functional organization. Understory cover increased quickly after disturbance and a community dominated by pioneer seeder and dry-fruited shrubs (Cistus ladanifer, C. populifolius, Genista triacanthos, and Lavandula stoechas) developed during about 15 years, but this was slowly replaced by a community dominated by resprouters and fleshy-fruited species (Arbutus unedo, Erica arborea) >40 years after disturbance. During the first 15 years there were rapid increases in woody species richness, vertical structural diversity, cover by Q. suber juveniles and saplings, and shrub cover at <1.5m strata, which levelled off or slightly declined thereafter. In contrast, tree species richness, tree density and density of arboreal A. unedo and E. arborea, vertical structural evenness, and cover at >1.5m strata increased slowly for >50 years. Treatment frequency showed strongly negative relationships with species richness, structural diversity and evenness, and horizontal and vertical understory cover, particularly that of slowly recovering species. These findings suggest that fuel reduction programs involving widespread and recurrent understory clearing may lead to the elimination at the landscape scale of stands with complex multi-layered understory occupied by large resprouters and fleshy-fruited species, which take a long time to recover after disturbance. Fuel management programs thus need to balance the dual goals of fire hazard reduction and biodiversity conservation, recognizing the value of stands untreated for >50 years to retain ecological heterogeneity in Mediterranean forest landscapes.