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Plant invasion in forest ecosystems is a serious ecological and economic issue, deserving attention by researchers, managers and policy-makers worldwide. Many invasive plants have been reported as early successional species able to colonize disturbed areas following abrupt changes in microhabitat and resource availability. We investigated disturbance effects of a severe windstorm generated by a wet microburst (hail and rain at 160 mm h -1 ) remarkably affecting the canopy cover of an old-growth Quercus ilex urban forest in Southern Italy. This stand-replacing disturbance produced a mosaic of 103 gaps, 5.6 to 1632 m 2 in size, over an area of 1.53 ha, uprooting 76% of the trees and decreasing thereby 85% of the standing above-ground dry biomass into the gaps. By intensive monitoring we compared above-and below-ground microclimate, soil moisture and mineral N availability in paired disturbed and control areas of the study forest. Within newly formed gaps we observed a seasonally consistent 70% higher content of nitrate nitrogen, 29% and 47% decreases of ammonia nitrogen in summer and autumn, respectively, and a higher moisture in topsoil, in addition to different above-and below-ground microclimatic conditions, with canopy cover mitigating extreme temperatures. One year after the windstorm, the microhabitat shift promoted the establishment in gaps of 15 native and 10 alien taxa previously absent in both disturbed and control plots. In such conditions, the rarefaction of the dominant Q. ilex canopy cover and the occurrence of empty niches prone to invasion could dramatically affect the local community structure and diversity. Our data indicate that stand-replacing windstorm can transiently transform the studied urban evergreen forest to an early allogenic successional community dominated, in the medium and large gaps, by annual and perennial non-native species. This is particularly relevant under a perspective of possible increasing frequency of windstorm events in the Mediterranean region in the near future.

Forests are part of a complex landscape mosaic and play a crucial role for people living both in rural and urbanized spaces. Recent progresses in modelling and Decision Support System (DSS) applied to the forestry sector promise to improve public participative forest management and decision-making in planning and conservation issues. However, most DSS are not open-source systems, being in many cases software designed for site-specific applications in forest ecosystems. Furthermore, some of these systems often miss challenging the integration of other land uses within the landscape matrix, which is a key issue in modern forestry planning aiming at linking recent developments in open-source Spatial-DSS systems to sectorial forest knowledge. This paper aims at demonstrating that a new type of S-DSS, developed within the Life+ project SOILCONSWEB over an open-source Geospatial Cyber-Infrastructure (GCI) platform, can provide a strategic web-based operational tool for forest resources management and multi-purpose planning. In order to perform simulation modelling, all accessible via the Web, the GCI platform supports acquisition and processing of both static and dynamic data (e.g., spatial distribution of soil and forest types, growing stock and yield), data visualization and computer on-the-fly applications. The DSS forestry tool has been applied to a forest area of 5,574 ha in the southern Apennines of Peninsular Italy, and it has been designed to address forest knowledge and management providing operational support to private forest owners and decision-makers involved in management of forest landscape at different levels. Such a geospatial S-DSS tool for supporting integrated forest knowledge at landscape represents a promising tool to implement sustainable forest management and planning. Results and output of the platform will be shown through a short selection of practical case studies.

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