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Science-based sustainable management of agroforestry and silvopastoral systems is essential for their maintenance in a changing world. Using bibliometric and network analyses, we characterized how research is addressing the ecological and socio-economic dimensions of sustainable management of cork oak (Quercus suber) silvo pastoral systems, Mediterranean ecosystems of high nature conservation and socio-economic value. We retrieved publications on cork oak from the Web of Science. More than 60 countries contributed with research on this system. Retrieved papers addressed a great diversity of topics and were published in a variety of journals, highlighting the multidisciplinary character of cork oak research. Research grew exponentially after the 1990's, possibly stimulated by the establishment of the European Forest Ecosystem Research Network. Our analysis shows that most research priorities identified for the Mediterranean region are being well addressed in cork oak systems, although research on the interactions between ecological and socio-economic components remains underrepresented. Less research has been published in North Africa compared to Europe, which is worrisome because it hosts a large area of cork oak that faces major sustainability challenges, often different from those prevailing in Europe. Our study shows that, despite constraints, the global scientific community is contributing to fill relevant knowledge gaps on the sustainability of cork oak systems across their range. Bibliographic and network analyses proved effective to uncover patterns, gaps, and potential constraints on cork oak scientific research and can be easily used to analyze research in other agroforestry and silvopastoral systems worldwide. [ABSTRACT FROM AUTHOR]

Questions Can shrubs ( Cytisus multiflorus) and large herbivore exclusion (fence) facilitate seedling survival and growth of marcescent and sclerophyllous oaks ( Quercus pyrenaica vs Q. ilex subsp. ballota) under a bioclimatic limit in Mediterranean grazed areas? Location Open oak woodlands, central-western Spain. Methods A 2-yr field experiment was conducted by planting 200 seedlings of each Quercus species under four different treatments combining the influence of nurse shrubs and fencing on Quercus seedling survival and growth. Results Cytisus multiflorus enhanced poor Quercus seedling survival found in the study area, at least during the first 2 yr after planting and particularly during the first dry season. The improvement in soil organic matter under the shrub canopy may have contributed to this positive effect, which was more pronounced on Q. pyrenaica seedlings. Seedling herbivory did not seem to be a limitation to survival. Increased seedling growth in both species was also very low, and no growth was recorded 2 yr after planting without shrubs. The positive shrub effect on seedling growth, especially marked in fenced areas, was more important in Q. pyrenaica in the first growing period and in Q. ilex in the second; 2 yr after planting no difference in shrub effect on growth was found in either Quercus species. Seedling herbivory was a limitation to seedling growth in areas without shrubs, mainly in the case of Q. pyrenaica. Conclusions In Mediterranean grazed areas with important summer drought and very sandy soil, shrubby C. multiflorus plants have a clear facilitative effect on seedlings of ecologically contrasted Quercus species. The facilitative effect was found in both marcescent and sclerophyllous oak seedlings, but to a different degree depending on the species considered and the variable measured (survival or growth). In terms of survival, the marcescent species was more favoured by shrub cover than the sclerophyllous one, and this effect was accentuated through time. However, in terms of growth, although Q. pyrenaica was initially more favoured by shrubs, differences between the two species were attenuated after 2 yr. Therefore, C. multiflorus can have a key role in restoration of these oak degraded environments. [ABSTRACT FROM AUTHOR]

Annual Dehesa-type pastures comprise semi-natural vegetation communities dominated by annual species characteristic of the Mediterranean basin areas of Southern Europe. This study analyses all the datasets available on the effects of ozone (O 3 ) on annual pasture species in order to review and propose new exposure- and flux-based O 3 critical levels (CLes) following the methodology of the Convention on Long-Range Transboundary Air Pollution (CLRTAP). Based on the potential effect on pastures main ecosystem services, the availability of data and the statistical significance of the regressions, three variables have been selected for establishing CLes: total above-ground biomass, consumable food value (CFV), as a nutritional quality index, and reproductive capacity based on flower and seed production. New CLes proposed for a 10% loss (with 95% confidence intervals between brackets) of above-ground biomass and reproductive capacity were, respectively, AOT40 = 3.1 (2.6, 3.8) and 2.0 (1.5, 2.8) ppm h and POD1 = 12.2 (8.9, 15.5) and 7.2 (1.1, 13.3) mmol m − 2 . The provisional AOT40- and POD1-based CLes for CFV were 2.3 (1.6, 4.0) ppm h and 4.6 (2.7, 6.5) mmol m − 2 respectively. By using only O 3 -sensitive species for the exposure and dose-response functions, the proposed CLes should be used for risk assessments. Their use for quantifying O 3 damage may lead to an overestimation of the effects. [ABSTRACT FROM AUTHOR]

Two common forms of traditional land use systems in Mediterranean landscapes are dehesa and hedged fields. Both are agroforestry systems in which domestic stock are pastured: amongst parklike trees in dehesa, and in enclosures surrounded by stone walls and woody vegetation in hedged fields. The latter are now tending to be replaced by dehesa due to labour costs. Here, we investigate the boundary layer microclimate and environmental characteristics of these two land uses in order to evaluate the respective differences in relation to climate modification, soil organic carbon, and soil water content. Fraxinus angustifolia -dominated sites were investigated in the Guadarrama mountains, Spain, in high summer with simultaneous sampling under trees in both dehesa and hedgerows and in adjacent open fields. Whilst temperature profiles were similar in both systems, hedgerows had higher soil water content, lower wind speeds, and higher total soil organic carbon compared to dehesa, and moreover these trends also applied to open fields of the respective systems. We conclude that not only do hedged fields have advantages over dehesa for shelter and production, but that the climatic modifications of hedged field systems potentially modify boundary layer climates on a broader scale than both individual fields and dehesa. Thus, the conservation of hedged field systems provides natural capital and broad environmental gains. [ABSTRACT FROM AUTHOR]

Agroforestry ecosystems have a significant social, economic and environmental impact on the development of many regions in the world. On the Iberian Peninsula the Mediterranean agroforestry oak forest known as the dehesa or montado (usually formed by species of the genus Quercus) is considered to be the extreme case of transformation of a Mediterranean forest by human management to provide a wide range of natural resources. The great variability of the Mediterranean climate and the different extensive management practices carried out by humans on the dehesa produces a high spatial and temporal variability in the dynamics of the ecosystem. This leads to a complex pattern of CO exchange between the atmosphere and the ecosystem that can act as a sink or as a source of CO over the years, depending on the various factors interacting with them. It is thus essential to assess the carbon cycle on the dehesa in order to obtain the maximum economic benefits and ensure environmental sustainability. The availability of high-frequency remote sensing time series allows the evolution of an ecosystem to be assessed at different temporal and spatial scales. In this study our overall objective is to assess the gross primary production (GPP) dynamics of a dehesa ecosystem in Central Spain by analysing the time series (2004-2008) of two models: (1) GPP provided by remote sensing images from the MODIS sensor (MOD17A2 product); and (2) GPP estimated by the implementation of a site-specific light-use efficiency model taking into account local ecological and meteorological parameters. Both models were compared to the production provided by an eddy covariance flux tower located in our study area. Dynamic relationships between models of GPP and precipitation and soil water content were investigated by means of cross-correlations and Granger causality tests. Our results indicate that both models of GPP show a typical dehesa dynamic where there are primarily two layers, the arboreal and the herbaceous strata. However, MODIS underestimates the production of the dehesa in a Mediterranean climate, while our site-specific model produced more similar values and dynamics to those of the eddy covariance tower. The analysis of the dynamic relationships corroborated the strong dynamic link between GPP and available water for plant growth. In conclusion, we succeeded in avoiding the main source of underestimation of the MODIS model by the implementation of a site-specific model. It therefore appears that the different ecological and meteorological parameters used in the MODIS model are primarily responsible for this underestimation. Finally, the Granger causality tests indicate that GPP prediction can be improved by including precipitation or soil water in the models. [ABSTRACT FROM AUTHOR]

Mediterranean wooded grasslands are multipurpose systems that support high plant and animal diversity levels and are habitats of European importance (i.e., 6310 – Dehesas with evergreen Quercus spp.). Moreover, these systems offer a number of agro-ecosystem services such as forage production, soil carbon sequestration, nutrient recycling and soil protection. The scattered trees enhance the ecological complexity of grassland influencing the soil properties, the herbaceous layer diversity and composition and the soil communities. Understanding how isolated trees influence the other components of the system is essential to comprehend their role supporting high levels of above and below ground biodiversity and ecosystem services. In the present study, we present a hypothetical framework of the effects of isolated trees on soil properties, plant and soil fauna assemblages, the latter here represented by the class Collembola. The floor litter and the associated input of organic matter to the soil was a key factor linking the components of the tree-soil-biodiversity system in a Mediterranean cork oak wooded grassland. Topsoil C increased by +50% under the tree canopy in comparison with the areas beyond the tree canopy. Plant diversity was lower under tree canopy, but contributed to enhance the total species richness of the grassland. Collembolan diversity was higher under the peculiar conditions beneath the tree canopy. Relationships between plant and collembolan species emerged. The findings of this study suggest that isolated trees have direct and indirect effects on soil properties, plant and collembolan assemblages, hence they can influence the ecological processes of wooded grasslands, with implications for food webs, nutrient cycling and productivity of the agro-ecosystem. [ABSTRACT FROM AUTHOR]

Aims In plants, resource allocation to growth and reproduction may depart from trade-off expectations if (i) investment in growth and reproduction relies on different resource pools, (ii) allocation to reproduction is dependent upon reaching some growth threshold or (iii) reproduction is developmentally linked to growth, both functions relying on the same resource pool. We examined the effects of enhanced resource level on patterns of resource allocation to growth and reproduction in holm oak (Quercus ilex sbsp. ballota), a Mediterranean evergreen tree. Methods In the experimental year (2003), we manipulated the amount of soil nutrients in autumn (to increase nutrient uptake during shoot elongation in the following spring) and soil water in summer (to increase water uptake during acorn growth). Indicators of growth and male and female reproduction were estimated in the pre-experimental (2002), experimental (2003) and post-experimental (2004) years. Important Findings Fertilized trees produced significantly longer shoots, but the number of female flowers per shoot was not affected by treatments. The production of male catkins was also enhanced by fertilization. Irrigation did not affect the production of female flowers or abortion rates. Growth and female reproduction showed no consistent relationship in untreated trees, but resource addition elicited a growth-female reproduction trade-off in the experimental year. The sign of this significant relationship changed in the post-experimental year, indicating the existence of lagged effects of resource manipulation on acorn production. Overall, patterns of allocation to growth and reproduction varied as a function of sex, resource availability and year, a result consistent with extreme allocational plasticity in holm oak. [ABSTRACT FROM PUBLISHER]

Highlights: [•] SOC and TN are compared for Mediterranean Cambisols under dehesas and olive groves. [•] Land use change to olive groves increased SOC and total N under organic management. [•] SOC and total N decreased in depth for both land uses and management options. [•] The stratification ratios for SOC were generally greater than 2. [Copyright &y& Elsevier]

Abstract: The Mediterranean evergreen oak woodland (MEOW-dehesa) is the most widespread agroforestry system in Mediterranean Europe and integrates forestry, agricultural and livestock practices. The MEOW-dehesa is a grazing system with evergreen Quercus ilex spp. ballota. It is characterized by the conservation of forest oaks (Quercus spp.) and provides environmental benefits such as carbon capture and storage in soils. The effect of conventional tillage (CT) and organic tillage (OT) on the distribution of soil organic carbon (SOC), total nitrogen (TN) and C:N ratios has not been well documented in the MEOW-dehesa. The objective of this paper is to study these parameters in the MEOW-dehesa in two soil types (Leptosols and Cambisols) and two management systems, OT for 20 years and CT. The stratification ratio (SR) of SOC, TN and C:N ratio is also evaluated. An analysis is performed on 85 soil profiles over the 2005–2009 period in southern Spain. The SR of SOC in Cambisols was greater under OT than CT, ranging from 1.25 to 1.42 and from 1.3 to 1.6 under CT and OT, respectively. The SR of TN for 0–20.9cm, 20.9–55.5cm and 55.5–102.1cm depth was greater under OT than under CT. The OT also increased the stratification of the C:N ratio compared to CT. [Copyright &y& Elsevier]

Changes in livestock grazing regimes are among the most important drivers of species loss and decrease in functional diversity world-wide. However, taxonomic and functional diversities ( TD and FD) can respond differently to changes in grazing regime or productivity., We surveyed plant communities from 67 sites under different grazing regimes (from heavy grazing to grazing abandonment) in wet and dry habitats, in both wet and dry years. We tested the influence of grazing intensity, habitat type and rainfall on TD, FD and the relationship between them. We also partitioned diversity to examine the effects of grazing on TD and FD across scales (within communities, within grazing levels and between grazing levels)., The effect of grazing within and across communities was modulated by water availability, with grazing showing the strongest effects in dry habitats. The relationship between FD and TD varied between habitat types and years and revealed high functional similarity between species (i.e. redundancy) in dry habitats. TD was reduced in the driest conditions across all the observation levels, contrasting with the high temporal stability of FD, suggesting that FD was decoupled from TD, especially in dry habitats. However, despite the high temporal and spatial stability of FD, results show that under severely limited water availability, high grazing pressure can reduce FD, revealing a convergence in traits under the combined effect of grazing and drought conditions., Synthesis and applications. Results highlight the dependence of functional diversity on the combined effect of water availability and grazing regime. Under severely limited water availability, grazing intensification reduced the functional diversity of these grasslands. Because of the foreseeable reduction in water availability in Mediterranean environments, we recommend the adoption of flexible grazing management schemes that take species and functional diversities into account simultaneously and adapt the level of grazing pressure to water availability. [ABSTRACT FROM AUTHOR]

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The article discusses a study on the foraging behavior, diet and habitat use of Geoffroy's bat, Myotis emarginatus, found in the Mediterranean. The study intends to assist in the assessment of the extent to which habitat use corresponds to differences in habitat availability in various landscapes or if it is a reflection of the lack of selectivity for habitat types, with foraging habitats resulting from dietary preferences. The M. emarginatus foraged mainly in scrubland and pine plantations, occurring near water bodies regardless of main habitat type. The bulk of its diet was constituted by spiders, suited for the hawking foraging style of the M. emarginatus, with an increase in substrates where spiders can build webs in higher vertical vegetation structuring.

Abstract: Modelling ozone (O3) deposition for impact risk assessment is still poorly developed for herbaceous vegetation, particularly for Mediterranean annual pastures. High inter-annual climatic variability in the Mediterranean area makes it difficult to develop models characterizing gas exchange behaviour and air pollutant absorption suitable for risk assessment. This paper presents a new model to estimate stomatal conductance (gs) of Trifolium subterraneum, a characteristic species of dehesa pastures. The MEDPAS (MEDiterranean PAStures) model couples 3 modules estimating soil water content (SWC), vegetation growth and g s. The g s module is a reparameterized version of the stomatal component of the EMEP DO3SE O3 deposition model. The MEDPAS model was applied to two contrasting years representing typical dry and humid springs respectively and with different O3 exposures. The MEDPAS model reproduced realistically the g s seasonal and inter-annual variations observed in the field. SWC was identified as the major driver of differences across years. Despite the higher O3 exposure in the dry year, meteorological conditions favoured 2.1 times higher g s and 56 day longer growing season in the humid year compared to the dry year. This resulted in higher ozone fluxes absorbed by T. subterraneum in the humid year. High inter-family variability was found in gas exchange rates, therefore limiting the relevance of single species O3 deposition flux modelling for dehesa pastures. Stomatal conductance dynamics at the canopy level need to be considered for more accurate O3 flux modelling for present and future climate scenarios in the Mediterranean area. [Copyright &y& Elsevier]