Management Of Mediterranean Forests Research Articles

Exploring climate-smart forestry in Mediterranean forests through an innovative composite climate-smart index

In recent years, Climate-Smart Forestry (CSF) has emerged as an innovative approach to sustainable forest management, aiming to enhance forest resilience and to balance the provision of ecosystem services facing climate-related threats. This study introduces for the first time a new composite climate-smart index (ICSF) to assess CSF. The methodological approach comprises the following steps: (i) the selection and evaluation of CSF indicators; (ii) the weighting of these indicators; and (iii) the assessment of CSF for Mediterranean forests in two distinct periods, specifically 2005 and 2015. Eight indicators were selected from a systematic literature review. The Analytic Hierarchy Process was applied to translate the preferences obtained through an online questionnaire from a network of CSF-expert stakeholders into weights, at both indicators and criteria levels (i.e., adaptation, mitigation, and the social dimension). Results reveals that indicators “tree species composition”, “forest damage”, and “regeneration” are of crucial importance for CSF assessment. The comparison of the CSF value between the years 2005 and 2015, shows a slight increase in CSF ratings. The ICSF serves as a comprehensive index of CSF covering all aspects of that concept, i.e. adaptation, mitigation, and the social dimension (including production). The national-scale analysis provides an overview of the dynamics that involve forest management of Mediterranean forests against climate change. The study offers a practicable method for CSF evaluation with its allover set of indicators, representing a suitable tool for supporting forest managers to mitigate the negative impacts of climate change.

Participatory methods and approaches in the management of Mediterranean forests: a systematic literature review

Participatory methods and approaches in the management of Mediterranean forests: a systematic literature review

Spanish dehesas as heritage: using participatory mapping and archival data to characterise the temporal evolution of an agrosilvopastoral cultural landscape

ABSTRACT Dehesas, together with other private and communal agrarian landscape management enclosures, form part of a managed, sustainable, agrosilvopastoral landscape organisation in Spain. They embody the historic human arrangement of landscape resources in a semi-natural state where equilibrium exists between pasturing, farming and Mediterranean forest management. With their origins in the medieval period, many persist until the present day in different regions of the Iberian Peninsula. Today, dehesas represent a unique form of landscape history and character in the Spanish Portuguese Duero River borderlands. By the twentieth century, many of these historically managed landscapes had been confiscated and sold, resulting in new forms of territorial management. In the Comarca of Sayago, a region located in the south-west of Zamora province, Spain, landscape abandonment and twentyfirst century natural park preservation strategies have contributed to a rise of a more homogenous vegetative landscape that has replaced centuries of the once ecological diverse landscape of which dehesas formed an integral part. With population decline, the memory of the names, use and management of these dehesas is fading. Using three case studies, this research provides a temporal analysis of the dehesas in the Sayago region, their historic use and management, and their importance to the diachronic character, heritage and future sustainability of this region. New cartography is created delineating and characterising historic land use. Our findings demonstrate the importance of integrated, people-centred approaches to recover and valorise endangered landscape history and heritage.

Change of the litter fall, decomposition, and nutrient release in cork oak forest after anthropogenic disturbances in North West of Tunisia.

In Mediterranean forests, anthropogenic disturbances received little interest in regards to their shrub layer induced enlargement. We studied in the cork oak forest of Beni Métir and in undisturbed and disturbed sites, the relative contribution of the tree (LT, DLT) and shrub (LS, DLS) layers to litter fall, litter decomposition, and nutrients dynamic. Our results showed that disturbance significantly (p < 0.001) reduced (-43%) total litter fall in DS in comparison with S (583 g m-2 year-1); the increased (+ 54%) shrub layer contribution to site litter fall did not counterbalance the decreased input by the tree layer. Leaf litter decomposition was negatively affected (p < 0.001) by disturbance, the remaining mass value being after 2 years, approximately 14 and 33%, respectively, for S and DS. This resulted into a gain of above ground soil organic matter 1.3 higher in DS than it was in S whereas the shrub layer contribution to litter fall increased by 50%. The prevailing driver of decomposition was very probably not related to litter quality but rather site-dependent. Indeed, layers of the same site shared the same remaining mass in spite of significant differences (p < 0.05) in initial content of minerals (N, Ca, and Mn) implicated in biological decomposition. In the disturbed site, the nutrient input by the shrub layer increased by more than double, but its low nutrient quality drastically impaired litter decomposition and mineral return at the site level. In conclusion, this study highlighted the importance of shrub layer which must be taken into account when considering any disturbance assessment and management of Mediterranean forests.

Structure and Dynamics of Deadwood in Pine and Oak Stands and their Role in CO2 Sequestration in Lowland Forests of Central Italy

There are many data values describing deadwood in primary forests, however, there is much less information concerning managed forests, particularly in the Mediterranean area. Whole non-living woody biomass (deadwood) is the main component of forest types that plays a vital role in improving and maintaining biodiversity. The dynamics of deadwood and CO2 sequestration by deadwood were examined in three Mediterranean lowland forests: pine forest Pinus pinea L.), evergreen oak forest (Quercus ilex and Quercus suber L.), and deciduous oak forest (Quercus cerris L.). The aim of this study was to carry out a quantitative and qualitative evaluation of the deadwood to gather useful information for the Mediterranean forest management, and to provide some useful data that can be integrated into the methods of estimation for carbon stored in dead components of Mediterranean forest types. The investigations focused on the characterization of the deadwood, to determine which traits are dominant and their potentially functionality within the forest type. Results indicated the deciduous oak type had the highest amount of stand volume (379 m3/ha), deadwood volume (161.8 m3/ha), and C storage (31.43 t/ha). The major component of dead wood was the standing dead trees or snags. There was a higher volume of deadwood in the deciduous oak forest than in the pine and evergreen oak forests. In addition, the deciduous oak forest had a higher snag creation index, a higher fallen log creation index, and a higher past management index compared to pine and evergreen oak forest types. Deadwood volume increased as the decay class in the deciduous oak forest increased, while this trend decreased in the evergreen oak and pine forests. The amount of deadwood was affected by the forest type and forest management regime. Dynamic and past management of deadwood indices indicated that their structure was still in the initial phase of creation and decay in the pine and evergreen oak forests. A comparison with other studies on similar forest types brought out that the variation range of the main parameters for the management of deadwood fell within the variation of the parameters studied. However, the values of these parameters cover a broad range. The population of each forest type is extremely sensitive to the different evolutionary periods of the forest dynamics.

Integration of Fire Risk in a Sustainable Forest Management Model

In Mediterranean areas, forest fires are a considerable risk most years. The seasonality of the climate with a dry summer, high temperatures and low rainfall (which implies increased flammability of materials) is one of the main factors in the ignition and progression of fires. This factor conjugated with more favourable biophysical conditions (e.g., high slopes, aspect) leads to easy propagation and the increasingly destructive power of such phenomena. To prevent and reduce the consequences of forest fires, it is necessary to simulate and forecast the territory use and management, not only focused on forest areas, but also on all land uses and agricultural activities that may coexist there, considering the probability of fire occurrence. The objective of this paper is to present a methodological approach to address the integration of fire risk in integrated Mediterranean forest management models. The methodological approach considers simultaneously the climatic conditions through different times of the year (more or less favourable to forest fire damage) and structural conditions addressed to land uses, aspect, slope, roads and demographic density. The methodological approach was implemented in a management area located in the Algarve, in southern Portugal. The results for the Algarve region showed that the proposed approach is very useful for managers, since it allowed the calculation of fire susceptibility, vulnerability and fire damage, according to several climatic scenarios. It also allowed the incorporation of different paths regarding different fire risk conditions and the minimization of risk due to fire damage through different management responses.

Effects of topsoil treatments on afforestation in a dry Mediterranean climate (southern Spain)

Abstract. Afforestation programs in semiarid areas are associated with a high level of sapling mortality. Therefore, the development of alternative low-cost and low-environmental-impact afforestation methods that ensure the survival of seedlings is crucial for improving the efficiency of Mediterranean forest management. This study assessed the effects of five types of soil amendments on the afforestation success (e.g., plant growth and survival) of a Mediterranean semiarid area. The amendments tested were (i) straw mulch; (ii) mulch containing chipped branches of Aleppo pine (Pinus halepensis L.); (iii) sheep manure compost; (iv) sewage sludge from a wastewater treatment plant; and (v) TerraCottem hydroabsorbent polymer. We hypothesized that in the context of dry Mediterranean climatic conditions, the use of organic amendments would enhance plant establishment and ensure successful afforestation. The results showed that afforestation success varied among the various soil amendment treatments in the experimental plots. The amendments had no effect on soil organic carbon, pH, or salinity, but the results indicated that the addition of mulch or hydroabsorbent polymer can reduce transplant stress by increasing the soil water available for plant growth throughout the hydrological year, and potentially improve the success of afforestation by reducing plant mortality.

Management of Mediterranean forests — A compromise programming approach considering different stakeholders and different objectives

Forest management is a complex issue due to the different type of activities considered in the forest territory and to the criteria involved in the manager's decision: in the last centuries, Mediterranean forests have come under human influence and recently, probably as a consequence of rural depopulation in many of these areas, a decline in the potential of these forests to produce economic and environmental services has been observed. Risk of fire and the resulting economic loss is a common problem in Mediterranean areas, mainly in years when climatic conditions are more unfavorable. Specific strategies for dealing with that risk imply costs, have an impact on biodiversity, and are always implemented following different stakeholders' (landowners/farmers and managers) preferences. Furthermore, this kind of decision always implies a conflict of objectives. Compromise programming represents a very satisfactory way to combine different stakeholders' preferences regarding the criteria considered. The objective of this work is to present a methodology based on the MCDM approach that facilitates the collaborative planning process in the scope of Mediterranean forests, dealing with multiple criteria and multiple stakeholders in a risky situation. This approach was implemented in a Forest Intervention Zone (FIZ) in the Algarve, Southern Portugal.

Shrub biomass accumulation and growth rate models to quantify carbon stocks and fluxes for the Mediterranean region

The importance of shrub formations in the Mediterranean area both in terms of area occupied and carbon sequestered by them is currently being recognized. However, due to the lack of suitable models to estimate biomass accumulation and growth rate in this region, the carbon sequestered by these formations is not included when computing the total carbon stocks in aboveground biomass in Mediterranean forest ecosystems, according to the IPCC guidelines. The aim of the present study is to develop equations to predict biomass accumulation and growth rate for the main shrub formations in the region of Andalusia (Southern Spain), using the fraction of canopy cover (FCCm) and the average height of the shrub formations (Hm) as predictors. To build these models, more than 800 plots were inventoried using destructive sampling; the mean value found in the region for biomass accumulation and annual growth rate being 16.73 Mg ha−1 and 1.14 Mg ha−1 year−1, respectively. Heathers and big-size Cistaceae formations were the ones that presented the highest values of biomass accumulation (24.99 and 21.01 Mg ha−1, respectively), while the highest values for annual growth rate were achieved by Leguminous gorse shrubs and, again, big-size Cistaceae bushes (1.49 and 1.64 Mg ha−1 year−1, respectively). The carbon content for the main shrub species and formations in the area was also obtained. The developed models provide the opportunity to estimate shrub carbon stocks in Mediterranean forest management from easy-to-obtain variables, namely FCCm and Hm. Moreover, the used shrub formations classifications and model structure allow their applicability to compute biomass accumulation and growth rate at regional and national level using as input data from the Spanish National Forest Inventory.

Exploring forest infrastructures equipment through multivariate analysis: complementarities, gaps and overlaps in the Mediterranean basin

The countries of the Mediterranean basin face several challenges regarding the sustainability of forest ecosystems and the delivery of crucial goods and services that they provide in a context of rapid global changes. Advancing scientific knowledge and foresting innovation is essential to ensure the sustainable management of Mediterranean forests and maximize the potential role of their unique goods and services in building a knowledge-based bioeconomy in the region. In this context, the European project FORESTERRA (Enhancing FOrest RESearch in the MediTERRAnean through improved coordination and integration”) aims at reinforcing the scientific cooperation on Mediterranean forests through an ambitious transnational framework in order to reduce the existing research fragmentation and maximize the effectiveness of forest research activities. Within the FORESTERRA project framework, this work analyzed the infrastructures equipment of the Mediterranean countries belonging to the project Consortium. According to the European Commission, research infrastructures are facilities, resources and services that are used by the scientific communities to conduct research and foster innovation. To the best of our knowledge, the equipment and availability of infrastructures, in terms of experimental sites, research facilities and databases, have only rarely been explored. The aim of this paper was hence to identify complementarities, gaps and overlaps among the different forest research institutes in order to create a scientific network, optimize the resources and trigger collaborations.

Factors driving growth responses to drought in Mediterranean forests

We lack information regarding the main factors driving growth responses to drought in tree species with different vulnerability against this stressor and considering sites with contrasting climatic conditions. In this paper, we identify the main drivers controlling growth response to a multi-scalar drought index (Standardized Precipitation Index, SPI) in eight tree species (Abies alba, Pinus halepensis, Quercus faginea, Pinus sylvestris, Quercus ilex, Pinus pinea, Pinus nigra, Juniperus thurifera). We sampled forests growing across a pronounced climatic gradient under Mediterranean conditions in north-eastern Spain. To summarize the patterns of growth responses to drought, we used principal component analysis (PCA). To determine the main factors affecting growth responses to drought, correlation and regression analyses were carried out using a set of abiotic (climate, topography, soil type) and biotic (Normalized Difference Vegetation Index, Enhanced Vegetation Index, tree-ring width, diameter at breast height) predictors and the PCs loadings as response variables. The PCA analysis detected two patterns of growth responses to drought corresponding to xeric and mesic sites, respectively. The regression analyses indicated that growth responses to drought in xeric forests were mainly driven by the annual precipitation, while in mesic sites the annual water balance was the most important driver. The management of Mediterranean forests under the forecasted warmer and drier conditions should focus on the main local factors modulating the negative impacts of drought on tree growth in xeric and mesic sites.

Understory woody vegetation in manmade Mediterranean pine forests: variation in community structure along a rainfall gradient

Natural regeneration that occurs in the understory of Mediterranean pine monocultures provides the basis for the transition of these simply structured systems toward a more complex and sustainable state. However, the course and consequences of this process, and its relationships with environmental and silvicultural variables, are still inadequately understood. We investigated the relationship between rainfall amount and understory woody vegetation (UWV) structure in mature (40–50 year) Pinus halepensis plantations in the Mediterranean zone of Israel, where rainfall ranges from 280 mm/year in the south to 900 mm/year in the north. We measured abundance, diversity and species composition on south- and north-facing slopes, in forest sites distributed along the rainfall gradient. UWV abundance, as measured by cover percentage and height, increased with rainfall amount along the entire gradient (2–113% and 0.1–3.4 m, respectively), more rapidly on north-facing slopes. Species composition varied along the rainfall gradient, with ranges of species occurrences corresponding to those in unforested habitats. The relationship between rainfall and UWV species richness was positive throughout most of the rainfall gradient, possibly with a shift in pattern at the highest rainfall levels. UWV richness increased sharply with increasing abundance, up to a certain point with no further increase in richness as abundance increased further. We concluded that UWV structure in the studied forest environment and climatic range is strongly determined by rainfall and suggested that the design and management of Mediterranean forests should focus more on optimizing water availability for the various components.

Effects of different site preparation treatments on species diversity, composition, and plant traits in Pinus halepensis woodlands

Biodiversity maintenance is a key component of Mediterranean forest management, yet studies on the effects of silvicultural treatments on plant diversity are scarce. Our experiment assessed the impact of five different site preparation treatments on the composition, diversity, ecological traits (life-form, pollination mode, leaf morphology, seed dispersal mode), indicator values (shade tolerance, nutrients demand) of the understory vegetation in a mature thinned Pinus halepensis stand in southern France. The treatments—chopping, chopping followed by scarification in one or two directions, prescribed burning, control—were replicated four times and applied on a total of 40 plots. Vegetation relevés were performed on each plot in the first, second and fourth year following treatment applications. Plant diversity, measured by the species richness or Shannon’s index, increased in the non-control treatment plots in the first year but then decreased through time. Vegetation composition differed between treatments, with the chopping treatment exhibiting composition and ecological trait values more comparable to those of control plots than the other treatments. The burning and scarification treatments led to higher abundance of therophytes, plants with malacophyllous leaves and insect-pollinated plants, and shade-intolerant and nutrient-demanding species. However, these changes were transient in time, the shade-intolerant species remained abundant but the ruderal species decreased while the ligneous species increased indicating a gradual return to a forest vegetation composition. For the Mediterranean area, most of the findings were similar to those in temperate forests subjected to the same site preparation treatments.

Foreste e ciclo dell’acqua

Abstract: Based on a comprehensive literature analysis, a review on factors that control water cycle and water use in Mediterranean forest ecosystems is presented, including environmental variables and silvicultural treatments. This important issue is considered in the perspective of sustainable forest management of Mediterranean forests, with special regard to crucial environmental hazards such as forest fires and desertification risks related to climate change.

Un bel trattato di selvicoltura pubblicato in Spagna

Abstract: A comprehensive textbook of regional and functional silviculture, recently published in Spain by R. Serrada, G. Montero and J. A. Reque (eds.), is presented here as a very useful reference text for all the people who is interested in the management of Mediterranean forests.

Effects of forest composition and structure on bird species richness in a Mediterranean context: Implications for forest ecosystem management

There is a growing need to manage forest ecosystems for biodiversity conservation. However, there is still a lack of knowledge on which forest characteristics have a greater influence on biological diversity, particularly in Mediterranean forests. To provide further insights in this respect, we analyzed how different characteristics related to forest composition and structure (forest area, canopy cover, canopy cover diversity, development stage, development stage diversity, coniferous species percentage, tree species diversity, and mono-specific forest percentage) influence the richness of forest breeding bird species (considering 22 specialist and 31 generalist species) in a large dataset comprising 2923 UTM 1 km × 1 km cells in Catalonia (NE Spain). Bird species richness was estimated through presence/absence data obtained from surveys conducted within the framework of the Catalan Breeding Bird Atlas (1999–2002). Forest characteristics were obtained from the Spanish Forest Map (scale 1:50,000), which was developed within the Third Spanish National Forest Inventory. Best regression models for forest specialists accounted for up to 53% of the variability in species richness, while models for generalist and total species richness accounted for 34% and 49% of total variability, respectively. Species richness was favoured by more developed forest stages and by tree species diversity, but very dense, closed forest canopies (>70%) decreased species richness for both groups. For specialist species richness the percentage of coniferous forest cover had a slightly negative influence, while generalists were favoured by more diverse canopy closure. We discuss the implications of these results for Mediterranean forest management considering the current situation of Catalan forests.

The role of topographic correction in mapping recently burned Mediterranean forest areas from LANDSAT TM images

Operational use of remote sensing as a tool for post‐fire, Mediterranean forest management has been limited by problems of classification accuracy arising from confusion of burned and non‐burned areas. Frequently, this occurs as a result of slope illumination and shadowing effects caused by the complex topography encountered in many forested areas. Cloud shadows can also be a problem. The aim of this work was to investigate how image classification results could be improved by removing the illumination effects of topography from satellite images. This was achieved by applying supervised classification to both uncorrected and topographically corrected LANDSAT TM data for a site on the Greek island of Thasos. The classification methodology included atmospheric and geometric correction, field‐based training, seperability/contingency analysis and maximum likelihood processing. The classification scheme was determined on the basis of consultation with the Greek Forest Service. Overlay of the resulting class maps enabled comparison of the total burned area and its spatial extent using the two different approaches to processing. The results of each approach were compared with the forest perimeter map generated by the Forest Service using traditional survey methods. Accuracy assessment and error analysis clearly indicated that the removal of the topographic effect from the satellite image before its classification resulted in more accurate mapping of the burned area. It is concluded that operational use of satellite remote sensing for forest fire management depends on accurate, robust, widely available and proven techniques. Topographic correction should now be regarded as an essential element of any classification methodology which will be used for operational, post‐fire management of forests in complex Mediterranean landscapes.