Landcover degradation analysis of Mediterranean forest by means of hyperplanes obtained from mixture linear algorithms (MLA)

The percentage alteration of the Mediterranean forest landscape is one of the primary indicators for its degradation. In this sense, the land cover abundances change analysis by using mixture linear algorithms (MLA), is presented like a good alternative to study this degradation. This research analyzes the use of two information sources like Remote Sensing (Landsat-ETM+) and Field Radiometry (GER 1500) to obtain mixture hyperplanes. These are calculated by models based on least square estimations, assuming that each pure land cover (endmember) belonging to any geographic area, behaves as a random variable which distribution function is known. The mixture hyperplanes provide spectral signatures with a suitable correlation level with regard to the supplied from remote satellite sensors once corrected, for the same geographical zone. These established hyperplanes can be used in future researches about Mediterranean forest landscape changes, because they can represent the different levels of its degradation. In this sense, it is proposed that they will feed a land cover spectral library with free accessibility

Polarimetry SAR detectors for monitoring Mediterranean forest fires events

Over the past decades, the great technological advances made in airborne and space sensors have led to a significant improvement of the remote sensing methods and techniques used for studying worldwide natural ecosystem disturbances. Generally, optical sensors are chosen for investigating landscapes transformation, however, this technology requires certain technical and environmental conditions (sunlight, no cloud-coverage) which are problematic for monitoring some regions of the world. In response to this challenge, this research aims to highlight the capabilities of Synthetic Aperture Radar - SAR satellite sensors for detecting disturbances in Mediterranean forests due to fire events. We are exploring three different methodologies: 1. Monitoring image intensity changes in dense time series of radar data; 2. We are investigating soil moisture changes after the fire that can be detected in intensities of radar images; 3. We are testing novel polarimetric SAR change detectors that are able to extract more information from polarimetric data (intensities and cross-correlations between polarimetric channels). All the procedures in this project were developed by using Co & Cross polarised radar satellite data acquired by the ESA-Sentinel-1 system in C-band, using the Doñana national park (Spain) forest fire event in June-July 2017 as a case study

A Comparative Analysis of Phytovolume Estimation Methods Based on UAV-Photogrammetry and Multispectral Imagery in a Mediterranean Forest

Management and control operations are crucial for preventing forest fires, especially in Mediterranean forest areas with dry climatic periods. One of them is prescribed fires, in which the biomass fuel present in the controlled plot area must be accurately estimated. The most used methods for estimating biomass are time-consuming and demand too much manpower. Unmanned aerial vehicles (UAVs) carrying multispectral sensors can be used to carry out accurate indirect measurements of terrain and vegetation morphology and their radiometric characteristics. Based on the UAV-photogrammetric project products, four estimators of phytovolume were compared in a Mediterranean forest area, all obtained using the difference between a digital surface model (DSM) and a digital terrain model (DTM). The DSM was derived from a UAV-photogrammetric project based on the structure from a motion algorithm. Four different methods for obtaining a DTM were used based on an unclassified dense point cloud produced through a UAV-photogrammetric project (FFU), an unsupervised classified dense point cloud (FFC), a multispectral vegetation index (FMI), and a cloth simulation filter (FCS). Qualitative and quantitative comparisons determined the ability of the phytovolume estimators for vegetation detection and occupied volume. The results show that there are no significant differences in surface vegetation detection between all the pairwise possible comparisons of the four estimators at a 95% confidence level, but FMI presented the best kappa value (0.678) in an error matrix analysis with reference data obtained from photointerpretation and supervised classification. Concerning the accuracy of phytovolume estimation, only FFU and FFC presented differences higher than two standard deviations in a pairwise comparison, and FMI presented the best RMSE (12.3 m) when the estimators were compared to 768 observed data points grouped in four 500 m2 sample plots. The FMI was the best phytovolume estimator of the four compared for low vegetation height in a Mediterranean forest. The use of FMI based on UAV data provides accurate phytovolume estimations that can be applied on several environment management activities, including wildfire prevention. Multitemporal phytovolume estimations based on FMI could help to model the forest resources evolution in a very realistic way

The “Mediterranean Forest”: A Perspective for Vegetation History Reconstruction

Starting from the multifaceted meaning of “Mediterranean”, this thematic review wishes to reconnect the palaeobotanical with the phytogeographical approach in the reconstruction of the Mediterranean Forest of the past. The use of the term “Mediterranean” is somewhat ambiguous in its common use, and has not an unequivocal meaning in different research fields. In botany, geographical-floristic studies produce maps based on the distribution of the plant species; floristic-ecological studies, produce maps that deal with the distribution of the plant communities and their relationships with different habitats. This review reports on the different use of the term “Mediterranean” in geographical or floristic studies, and on the way climate and plant distributions are used to define the Mediterranean area. The Mediterranean Forest through the palynological records is then shortly reported on. Pollen analysis may be employed to reconstruct the Mediterranean Forest of the past but a number of problems make this a difficult task: low pollen preservation, lack of diagnostic features at low taxonomical level, and low pollen production of species which form the Mediterranean Forests. Variable images of this vegetation are visible in different landscapes, but the Mediterranean Forest often remains a sort of “ghost forest” in pollen spectra from the Mediterranean Region

Abrupt climate changes of the last deglaciation detected in a Western Mediterranean forest record

Abrupt changes in Western Mediterranean climate during the last deglaciation (20 to 6 cal ka BP) are detected in marine core MD95-2043 (Alboran Sea) through the investigation of high-resolution pollen data and pollen-based climate reconstructions by the modern analogue technique (MAT) for annual precipitation (Pann) and mean temperatures of the coldest and warmest months (MTCO and MTWA). Changes in temperate Mediterranean forest development and composition and MAT reconstructions indicate major climatic shifts with parallel temperature and precipitation changes at the onsets of Heinrich stadial 1 (equivalent to the Oldest Dryas), the Bölling-Allerød (BA), and the Younger Dryas (YD). Multi-centennial-scale oscillations in forest development occurred throughout the BA, YD, and early Holocene. Shifts in vegetation composition and (Pann reconstructions indicate that forest declines occurred during dry, and generally cool, episodes centred at 14.0, 13.3, 12.9, 11.8, 10.7, 10.1, 9.2, 8.3 and 7.4 cal ka BP. The forest record also suggests multiple, low-amplitude Preboreal (PB) climate oscillations, and a marked increase in moisture availability for forest development at the end of the PB at 10.6 cal ka BP. Dry atmospheric conditions in the Western Mediterranean occurred in phase with Lateglacial events of high-latitude cooling including GI-1d (Older Dryas), GI-1b (Intra-Allerød Cold Period) and GS-1 (YD), and during Holocene events associated with high-latitude cooling, meltwater pulses and N. Atlantic ice-rafting. A possible climatic mechanism for the recurrence of dry intervals and an opposed regional precipitation pattern with respect to Western-central Europe relates to the dynamics of the westerlies and the prevalence of atmospheric blocking highs. Comparison of radiocarbon and ice-core ages for well-defined climatic transitions in the forest record suggests possible enhancement of marine reservoir ages in the Alboran Sea by 200 years (surface water age 600 years) during the Lateglacial

From failure to value: Economic valuation for a selected set of products and services from Mediterranean forests

Aim of study: the paper estimates the economic value of a selected range of forest products and services, i.e. roundwood, nonwood forest products (NWFPs), and carbon-related services. Area of study: the research covers 21 Mediterranean countries, distinguished into four sub-regions. Material and methods: data have been gathered from official statistical sources (e.g. FAOSTAT), scientific literature and technical reports. Different estimation approaches based on market-price have been used for different products/services. Main results: the estimated value ranges between \u20ac10,512 and \u20ac11,158 million (M). Wood products represent more than 85% of the total value. Within them, industrial timber is the most relevant component (65%). Figures for NWFPs are likely to be underestimated because data are available only for some products and countries. When using alternative estimates for pine nuts, pine resin and cork, figures show a \u20ac36.8-572 M increase. In geographical terms, the economic value of Mediterranean forests is highly concentrated: North-West Mediterranean countries account for 70%, and nearly 90% is in just four countries (France, Spain, Turkey and Italy). Research highlights: enhancing the offer of Mediterranean forest products and increasing their role in the rural economy could help to reduce the costs of forest protection: a well-structured forest economy ensuring stable flows of incomes can provide a fundamental set of public non-market services and social values to both local people and the whole community. Understanding the true value of natural resources, then, is an essential step for promoting their protection and sustainable use

Physiological drought responses improve predictions of live fuel moisture dynamics in a Mediterranean forest.

The moisture content of live fuels is an important determinant of forest flammability. Current approaches for modelling live fuel moisture content typically focus on the use of drought indices. However, these have mixed success partly because of species-specific differences in drought responses. Here we seek to understand the physiological mechanisms driving changes in live fuel moisture content, and to investigate the potential for incorporating plant physiological traits into live fuel moisture models. We measured the dynamics of leaf moisture content, access to water resources (through stable isotope analyses) and physiological traits (including leaf water potential, stomatal conductance, and cellular osmotic and elastic adjustments) across a fire season in a Mediterranean mixed forest in Catalonia, NE Spain. We found that differences in both seasonal variation and minimum values of live fuel moisture content were a function of access to water resources and plant physiological traits. Specifically, those species with the lowest minimum moisture content and largest seasonal variation in moisture (Cistus albidus: 49–137% and Rosmarinus officinalis: 47–144%) were most reliant on shallow soil water and had the lowest values of predawn leaf water potential. Species with the smallest variation in live fuel moisture content (Pinus nigra: 96–116% and Quercus ilex: 56–91%) exhibited isohydric behaviour (little variation in midday leaf water potential, and relatively tight regulation of stomata in response to soil drying). Of the traits measured, predawn leaf water potential provided the strongest predictor of live fuel moisture content (R2 = 0.63, AIC = 249), outperforming two commonly used drought indices (both with R2 = 0.49, AIC = 258). This is the first study to explicitly link fuel moisture with plant physiology and our findings demonstrate the potential and importance of incorporating ecophysiological plant traits to investigating seasonal changes in fuel moisture and, more broadly, forest flammability.This study was made possible thanks to the collaboration of and the staff from the Natural Park of Poblet, P Sopeña, and the technical staff from MedForLab. This study was funded by the Spanish Government (RYC-2012-10970, AGL2015-69151-R). R. H. Nolan was supported with funding from the New South Wales Office of Environment and Heritage, via the Bushfire Risk Management Research Hub. We benefitted from critical comments from J Voltas, JM Moreno and L Serrano and instrument loans from R Savín

Floristic Features, Distribution, and Ethnobotany of Plants Gathered and Used by Local People from the Mediterranean Forest in Northern Jordan

Understanding the distribution and floristic features of native forest plants, as well as the reasons that lead local people to collect them, is of great value for planning and implementing forest conservation and rehabilitation projects in the Mediterranean forest involving local communities. The aims of this study were to (1) investigate the distribution pattern, (2) analyze the floristic features, and (3) investigate the main uses of plants gathered from three Mediterranean forest ecosystems in Northern Jordan. We sampled 14 villages that were selected according to their location on the edge and within the three Mediterranean forest types in Northern Jordan. Three hundred informants were interviewed face to face using a semi-structured questionnaire. The data obtained included a list of plants collected and their uses. A Detrended Correspondence Analysis (DCA) was carried out to investigate the distribution of plant species collected from the three forest types. Also, important indices were calculated including Informant Consensus Factor (ICF), Fidelity Level (FL%), and uses totaled. The DCA showed that there are common plant species gathered intensively from all three forest types, namely Origanum syriacum L., Malva parviflora L., and Arum palaestinum Boiss., and that some plant species are collected from a particular forest type. The main uses of the collected plants are food and medicine. The study results suggest value in taking into account the behavior of people who collect native forest plants when designing fragile forest ecosystem restoration programs. These programs should be community-based in order to achieve ecosystem sustainability and prevent biodiversity erosion

Suitability assessment of olive plantations for Iberian Lynx habitat restoration

This study adopts a twofold methodological approach to assessing the suitability of agricultural areas for wildlife habitat restoration. Embedding expert judgements through an Analytic Hierarchy Process (AHP) and Geographical Information Systems (GIS) about the effect of specific elements of the landscape on Iberian lynx (Lynx pardinus) habitat restoration potentiality as an indicator of selection of the most suitable agricultural areas to be transformed to the natural state (Mediterranean forest and scrublands). The case study is the olive (Olea europaea L.) plantations of the mountain areas of Andalusia (Spain) which, because of their low yield, are likely to be abandoned after the decoupling of the EU olive oil subsidies. The results suggest that the edge of major agricultural areas (mostly olive groves), the natural vegetation and areas adjacent to Natural Park with oaks would be most suitable for wildlife habitat restoration. These results are in agreement other studies carried out by other researchers on biodiversity, based on either individual or groups of species.analytic hierarchy process (AHP), GIS, Lynx pardinus, habitat restoration, Spain, Resource /Energy Economics and Policy,