Gherardo Chirici

Is land abandonment affecting forest dynamics at high elevation in Mediterranean mountains more than climate change

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 mugo Turra 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.

Estimation of Mediterranean forest attributes by the application of k¿NN procedures to multitemporal Landsat ETM+ images

Routine applications of nonparametric estimation methods to satellite data for assisting the creation of forest inventories in Northern European countries are stimulating interest in the possible extension of these methods to more complex Mediterranean areas. This is the subject of the current work, which presents an experiment based on the integration of remotely sensed images and sample field measurements aimed at producing forest attribute maps in central Italy. Testing was carried out in an area where 370 geocoded field plots, sampled on a single‐stage cluster design, were collected to characterize wood and non‐wood forest attributes. These ground data served to apply various k‐Nearest Neighbour (k‐NN) estimation procedures to multitemporal Landsat 7 ETM+ images in order to map major forest attributes (basal area and simulated leaf area index, LAI). More specifically, the investigation focused on evaluating the effects of using satellite images from different periods of the growing season and spectral metrics of increasing complexity. The results achieved by the examined methods are finally discussed in order to provide guidelines for possible operational utilization.

Airborne Laser Scanning to support forest resource management under alpine, temperate and Mediterranean environments in Italy

Abstract This paper aims to provide general considerations, in the form of a scientific review, with reference to selected experiences of ALS applications under alpine, temperate and Mediterranean environments in Italy as case studies. In Italy, the use of ALS data have been mainly focused on the stratification of forest stands and the estimation of their timber volume and biomass at local scale. Potential for ALS data exploitation concerns their integration in forest inventories on large territories, their usage for silvicultural systems detection and their use for the estimation of fuel load in forest and pre-forest stands. Multitemporal ALS may even be suitable to support the assessment of current annual volume increment and the harvesting rates.

Monitoring and assessing old-growth forest stands by plot sampling

Abstract Forest inventories are evolving towards multipurpose resource surveys, broadening their scope by including additional topics such as biodiversity issues. Surprisingly, few quantitative surveys have been devoted to old‐growth forests, even if they constitute the most acknowledged forest biodiversity icons. In this framework, the use of probabilistic sampling may provide an effective as well as rigorous support for monitoring and assessing old‐growth forests. To this purpose, the present paper proposes a two‐phase sampling scheme. In the first phase, a coarse survey of few floristic and stand structural attributes is carried out by means of small plots systematically placed on the study area. Subsequently, in the second phase, a fine assessment of a large number of ecological attributes is performed on a subset of enlarged plots selected among the first‐phase ones by means of simple random sampling without replacement. The proposed sampling scheme is implemented for monitoring and assessing the old forests of Cilento National Park (southern Italy). Results and comments are provided as an exemplicative case study.

Forest ecosystem inventory and monitoring as a framework for terrestrial natural renewable resource survey programmes

ABSTRACT The established practice of forest ecosystem inventory and monitoring is recognised as a main support for terrestrial natural renewable resource survey programmes. Inventory and monitoring programmes focused on an overall assessment of ecosystem attributes evolving into global environmental survey programmes have been devised, but implementation is still quite contradictory. The state-of-the-art is discussed here, with special reference to the European Union and Italy. Topical issues are reviewed, with selective concern to: remote sensing capability, probability sampling, forest type (habitat) classification and landscape ecology, sustainable management indicators. Benefits brought by information technology are highlighted. Its development and the implementation of approaches based on a sound “per habitat” landscape ecological perspective will bring unique benefits, thus leading to an effective integration among sector surveys aimed at global environmental inventory/monitoring.

Airborne laser scanning of forest resources: An overview of research in Italy as a commentary case study

Abstract This article reviews the recent literature concerning airborne laser scanning for forestry purposes in Italy, and presents the current methodologies used to extract forest characteristics from discrete return ALS (Airborne Laser Scanning) data. Increasing interest in ALS data is currently being shown, especially for remote sensing-based forest inventories in Italy; the driving force for this interest is the possibility of reducing costs and providing more accurate and efficient estimation of forest characteristics. This review covers a period of approximately ten years, from the first application of laser scanning for forestry purposes in 2003 to the present day, and shows that there are numerous ongoing research activities which use these technologies for the assessment of forest attributes (e.g., number of trees, mean tree height, stem volume) and ecological issues (e.g., gap identification, fuel model detection). The basic approaches – such as single tree detection and area-based modeling – have been widely examined and commented in order to explore the trend of methods in these technologies, including their applicability and performance. Finally this paper outlines and comments some of the common problems encountered in operational use of laser scanning in Italy, offering potentially useful guidelines and solutions for other countries with similar conditions, under a rather variable environmental framework comprising Alpine, temperate and Mediterranean forest ecosystems.

National Forest Inventories: Contributions to Forest Biodiversity Assessments

1. The need for harmonized estimates of forest biodiversity indicators.- 2. Essential features of forest biodiversity for assessment purposes.- 3. Prospects for harmonized biodiversity assessments using national forest inventory data.- 4. The common NFI database.- 5. Harmonization tests.- 6. Summary and conclusions. Index.

Modeling the influence of alternative forest management scenarios on wood production and carbon storage: A case study in the Mediterranean region.

Forest ecosystems are fundamental for the terrestrial biosphere as they deliver multiple essential ecosystem services (ES). In environmental management, understanding ES distribution and interactions and assessing the economic value of forest ES represent future challenges. In this study, we developed a spatially explicit method based on a multi-scale approach (MiMoSe-Multiscale Mapping of ecoSystem services) to assess the current and future potential of a given forest area to provide ES. To do this we modified and improved the InVEST model in order to adapt input data and simulations to the context of Mediterranean forest ecosystems. Specifically, we integrated a GIS-based model, scenario model, and economic valuation to investigate two ES (wood production and carbon sequestration) and their trade-offs in a test area located in Molise region (Central Italy). Spatial information and trade-off analyses were used to assess the influence of alternative forest management scenarios on investigated services. Scenario A was designed to describe the current Business as Usual approach. Two alternative scenarios were designed to describe management approaches oriented towards nature protection (scenario B) or wood production (scenario C) and compared to scenario A. Management scenarios were simulated at the scale of forest management units over a 20-year time period. Our results show that forest management influenced ES provision and associated benefits at the regional scale. In the test area, the Total Ecosystem Services Value of the investigated ES increases 85% in scenario B and decreases 82% in scenario C, when compared to scenario A. Our study contributes to the ongoing debate about trade-offs and synergies between carbon sequestration and wood production benefits associated with socio-ecological systems. The MiMoSe approach can be replicated in other contexts with similar characteristics, thus providing a useful basis for the projection of benefits from forest ecosystems over the future.

ForestBIOTA data on deadwood monitoring in Europe

Abstract Deadwood is a key ecological factor in forest ecosystems. Its occurrence is fundamental since it represents a microhabitat for hundreds of species of invertebrates, fungi, bryophytes, lichens, amphibians, small mammals and birds. In recent years, deadwood has been recognized as a relevant indicator for the assessment and monitoring of forest biodiversity. In this paper the methodology for surveying woody necromass proposed by the ForestBIOTA project under Regulation (EC) No 2152/2003 (Forest Focus) is described. The amount of deadwood found on 91 Intensive Monitoring Level II plot of the EU and ICP Forest condition monitoring programme range from 0 to 258 m3 ha−1. In the examined areas, total deadwood volume does not differ significantly among forest types, due to the high intra-type variability. On the other hand, its distribution between coarse and fine necromass and among necromass components is highly dependent on forest types.

Combining Remote Sensing and Field Data for Deriving Unbiased Estimates of Forest Parameters over Large Regions

Remote sensing data can be combined with field data to estimate forest variables over large regions. The accuracy of these estimates depends, for example, on how well the field measurements can be linked to satellite images and on how well forest areas can be identified. In practice, it is difficult to delineate forest areas from other land cover classes; this fact might cause biased estimates. In this study, a post-stratification approach was used to combine field data and satellite data to derive unbiased estimates of forest parameters over large regions. Images from Landsat TM and Terra MODIS were used in combination with field data from the National Forest Inventory in Northern Sweden. The results show that the standard deviation for estimates of total stem volume, stem volume for deciduous trees, and dead wood were reduced with 48%, 33%, and 23%, respectively, by using post-stratification based on Landsat TM data instead of field data alone. A significant improvement of the estimation accuracy was obtained also when using MODIS data.