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Mountain ecosystems are, however, fragile and particularly vulnerable to the adverse impacts of climate change, deforestation and forest degradation, land-use change, land degradation and natural disasters. [ABSTRACT FROM PUBLISHER]

Global change is leaving a fingerprint on the appearance, structure and productivity of the treeline ecotone, modifying patterns of mountain ecosystems. In order to implement correct policies for managing natural resources, we examine how climate change interrelated with land-use abandonment could shape mountain forests at their upper limit in a Mediterranean environment, and how patterns of tree growth and periods of tree establishment guide the interpretation of global change effects on treeline dynamics. We reconstructed the population dynamics of mountain pine (Pinus mugoTurra spp.mugo) in the subalpine belt of the Majella National Park (Italy). In a test area of 14,440 ha, proposed as a pilot study site for long-term ecological monitoring, temporal and spatial mountain pine distribution were examined since 1954 by historical aerial ortophotos. Multitemporal maps documented the expansion upwards (1 m/year) and downwards (3 m/year) of mountain pine. Mountain pine started to expand upwards into the formerly tree-free grassland in early 1900s, in association with a decline of the local human population and livestock. Land-use change was the major driving force of vegetation dynamics at the treeline in the Majella massif. [ABSTRACT FROM PUBLISHER]

Recent attempts to mitigate global change have brought forestry-based carbon (C) sequestration into sharp focus due to its potential to absorb CO2 from the atmosphere. However, the consequences of actual forest management practices on C storage capacity are still controversial to a certain extent. Under such a perspective, a distinctive relevant issue concerns the management of forest ecosystems within areas specifically designated for nature conservation. From the analysis of biomass data from forests in the National Parks of Italy, we found that the average forest C stock and sink per unit area is relatively higher within National Parks (81.21 and 2.18 tons ha−1, respectively) than on the overall national territory (76.11 and 1.12 tons ha−1 year−1, respectively). The analysis confirms the influence of ecological conditions and management approach on C sequestration capacity. Although the results of the proposed assessment approach have to be considered as rough estimates, the trial proves interesting, given the relative lack of specific information, at least on a large scale, about C stocks and sinks within forest areas designated for nature conservation, and the direct comparison with those forest areas not designated to such an end. The C storage capacity can be enhanced by increasing the productivity of forests, minimizing the disturbance to stand structure and composition. Extending conservation strategies adopted in National Parks to other forest areas of the national territory would allow the restoration of C sequestration potential, where unsustainable management practices have degraded relatively large stocks of biomass. [ABSTRACT FROM PUBLISHER]

In this study, silver fir – European beech forest types were examined in their structure and tree species composition. Two study areas, one in the Molise Region in Italy (Abeti Soprani) and one in the Dinaric Mountains in Slovenia (Leskova dolina), were compared in their dynamics and present structure. The aim of the study was to assess if a standardized field survey protocol can supply indicators related to forest structure and composition, and deadwood amount in two different Natura 2000 sites. The present structure and composition were evaluated on a 1-ha plot in each area. All live trees, standing and downed dead trees, snags, stumps, and lying coarse woody debris were censed. For each individual tree, the position within the plot, the species, diameter at breast height, height or length, crown structure and height, and decay level (only for deadwood) were recorded. The forest structure was influenced by past management, modifying the tree density, the amount of deadwood and the growth trends. The spatial distribution of trees and their vertical stratification show pluristratified stands with a mainly horizontal random pattern. The assessment of forest parameters in large plots could be an opportunity to evaluate the best choices for a nature-based silvicultural approach. [ABSTRACT FROM PUBLISHER]

The maintenance of certain levels of old forest represents a cornerstone of the EU's biodiversity management strategy. A consensus on a single general ecological definition of old-growth is particularly difficult in Mediterranean Europe. The present paper deals with old-growth forests and persistent woodlands in the Cilento and Vallo di Diano National Park (PNCVD) to give an ecological understanding of forest complexity and dynamics under a multiscale and multidisciplinary perspective. The multiscale approach ranged from the identification and mapping of potential old-growth stands at landscape scale to a two-level field review of forest stand features. Field sampling involved a multidisciplinary team of researchers in forest structure, pedologic environment, soil microbial activity, flora and vegetation and deadwood components. The research provided sound knowledge about old-growthness features in the PNCVD that constitutes a unique case study in the whole Mediterranean basin. The integration of results allowed to: identify main ecosystem functions and the related services of the old-growth forests in the study area; distinguish persistent woodlands, multi-aged stands with old trees deriving from nineteenth-century management practices, from old-growth forests sensu strictu; recognize indicators of direct and indirect impacts of human activities; suggest effective practices for sustainable management in the Mediterranean context. [ABSTRACT FROM AUTHOR]

Olive is a drought-tolerant species and it is known that it responds efficiently to any additional water up to a limit. A field experiment was planned with the following aims: to provide estimates of crop evapotranspiration (ETc) to improve water use efficiency during the growing season; to present guidelines for efficient management of irrigation scheduling; and to characterize the relationship between plant water status and optimum fruit yield. These relationships were monitored during four years by analysing the influence of deficit irrigation strategies on mature modern-trained olive trees of cultivars Frantoio and Leccino. Treatments were a non-irrigated control (rain-fed) and three treatments that received a seasonal water amount equivalent to 33, 66 and 100% of ETc, from the beginning of pit hardening to early fruit veraison. Results of the relationship between leaf water potential and maximum stomatal conductance (Ψpd vs. gsmax) showed that the stomatal apparatus in Frantoio was more sensitive to water deficit than that of Leccino. Differences in yield between treatments were mainly related to mean fruit weight, indicating that water availability might have affected growing conditions before flowering or during the early stages of fruit growth rather than later in the summer season. Vegetative development was a function of water available to plants. Frantoio achieved the highest crop production per unit of water consumption. Oil quality was scarcely affected by deficit irrigation. Regulated deficit irrigation of olive trees after pit hardening could be recommended, at least under the experimental conditions of this study. Given the different long-term watering response of Frantoio and Leccino, a cultivar-specific irrigation scheduling is advisable. [ABSTRACT FROM AUTHOR]

The response of mature olive (Olea europaea L.) trees to both regulated deficit irrigation and fertigation was studied for some consecutive years in sub-humid (Italy) and semi-arid conditions (Spain). All cultivars tested in these experiments were preferentially for table olive consumption (pickling and double-aptitude). Data from these long-term studies on field-grown, mature trees are summarized for assessing common effects of water and nutrient supply on plant behaviour and fruit yield. Seasonal yield variations were observed, and showed that the effect of irrigation treatments was somewhat more gradual in the "on" than in the "off" year. Differences amongst cultivars were always marked. Dry matter accumulation in pulp and pit was positively affected by progressively increasing the amount of water supplied to plants, regardless of years and cultivars. The ratio between pulp and pit fresh weight was negatively affected by irrigation, while fruit size was positively influenced by the gradual increase of irrigation water. Average nitrogen levels in leaves were generally above the deficiency threshold at both experimental plantations. Crop yield was not consistently increased by addition of soil nutrients. The effect of fertigation treatments was relatively uninfluential on oil accumulation in fruits. However, polyphenols in oil samples decreased progressively as the addition of nutrients increased. Critical aspects and strategic decisions in modern olive growing are the selection of cultivar, the supply of water, the option of fertilization, together with other orchard management practices. In this paper we outline various aspects of long-term studies in experimental olive plantations with the aim of highlighting inter-regulatory processes, involving plant growth and crop yield, which must be taken into account when planning future field research and modelling exercises. [ABSTRACT FROM AUTHOR]