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• The structure of gnaphosid assemblages was primarily determined by elevation. • Abundance decreased and diversity increased with increasing grazing intensity. • Overgrazing favours sparse populations of mostly rare, opportunistic species. • Overgrazing causes low temporal co-occurrence probably due to resource limitation. • Ground spiders are good indicators of grazing on species and assemblage level. The phryganic and maquis shrublands form the most typical vegetal formations in the Eastern Mediterranean that since thousands of years have been subject to various types of anthropogenic disturbance, including grazing. We studied the impact of sheep and goat grazing on 50 assemblages of ground spiders (Araneae: Gnaphosidae) in phryganic, maquis and forest habitats from zero to 2000 m elevation on Crete, Greece using pitfall traps for one year at each sampling site. In total, 58 gnaphosid species and 16,592 individuals were collected. Cretan endemic Gnaphosidae were negatively affected by intensive grazing and, contrary to findings on other taxa studied on the island, they were sparse and rare throughout the study area. The species composition of gnaphosid assemblages was primarily determined by elevation. Trachyzelotes lyonneti , Urozelotes rusticus , Zelotes scrutatus , Anagraphis pallens and Berinda amabilis proved to be significant indicators of overgrazing. The vast majority of spiders belonging to synanthropic and nationally red-listed species were found in overgrazed sites. Despite theoretical expectations, while the average activity density decreased, the number of species, evenness, rarity, taxonomic, temporal and functional diversity (FRic) indices increased with increasing grazing intensity. This was mainly due to the nature of disturbance itself, which probably allows equibalanced low abundances of indigenous or synanthropic species, rather than overdominance of few, thus partly refuting the opportunistic species hypothesis (OSH). Ground spider assemblages in overgrazed sites comprised sparse populations of mostly rare, opportunistic species with different combinations of life-history traits that partly replace other species more commonly found in the less degraded sites. Species of these assemblages shorten their phenologies to minimize temporal co-occurrence with each other due to resource limitation. These distinct community patterns highlight ground spiders as good indicators of grazing pressure on Crete, on species and assemblage level. To conserve the indigenous and potentially endangered invertebrate fauna, the spatiotemporal discontinuity of grazing including rested patches is important in order to maintain spatial variability and possibly lead to habitat restoration. [ABSTRACT FROM AUTHOR]

The Israeli Mediterranean ecosystem has a distinctive flora with high levels of plant diversity. Previous studies of soil microbial ecology from the region have paid little attention to the possibility of distinctive soil bacterial communities associated with particular habitats. This study looked at bacterial communities present in the bulk soil from the closed canopy of four indigenous plants – Quercus ithaburensis, Calicotome villosa, Sarcopoterium spinosum , and Rhamnus puncata . Soil DNA was amplified for the 16S rRNA gene and sequenced using MiSeq Illumina platform. Results indicated that the bacterial communities differed between open and closed canopy with no significant difference in community structure within closed canopy, with soil moisture and organic matter content significantly influenced the community. Only the relative abundance of Gemmatimonadetes varied significantly with the open canopy having the highest abundance, and the relative abundance of Spartobacteri a and Saprospirae was unusually high compared to other Mediterranean soils. There was no difference in OTU richness between plant species. Additionally, this study revealed that open canopy community between plants was nested within closed canopy bacterial community implying that open canopy community potentially serves as a source for the closed canopy. It is then possible that the rhizospheric influence extends beyond the root-soil interface and to the surrounding bulk soil. Overall, this study indicates that in Israeli Mediterranean ecosystems native plants extend a selection beyond the rhizosphere, and like other studies from Mediterranean ecosystems pH does not seem to play an integral role in structuring bacterial communities. [ABSTRACT FROM AUTHOR]

Maquis, which provides numerous ecosystem services and constitutes an integral part of the Mediterranean ecosystem, is highly heterogeneous. However, despite its importance and heterogeneity, maquis is generally mapped as a single class, while forests are mapped for management purposes. Detailed mapping of the maquis formations is necessary to understand their ecology and manage them sustainably. This study presents a method that generates alliance-level maps of the maquis ecosystems through satellite images using various machine learning techniques with different feature combinations and evaluates the proposed approach in the Mediterranean region of Southern Turkey, which has an area of 95,000 km2. Multi-temporal images extract information from vegetation phenology, while topographic and meteorological data are used to improve the classification. Cross-validation is performed using a ground-truth data set of approximately 7500 polygons. Results show that cost-effective and accurate maquis classification at the alliance level is possible using a combination of environmental features, multi-spectral, and multi-temporal satellite images. Adding environmental features to remotely sensed classification has improved the accuracy by 18%. The Random Forest (RF) algorithm improves classification accuracy by 7.3% and 14.6% relative to Support Vector Machine and Quadratic Discriminant Analysis algorithms, respectively. With the help of newly introduced features, we have succeeded in mapping 11 alliances with 64.2–82.7% overall accuracy. We believe the proposed classification approach will help improve the mapping of the shrubland ecosystems, which will significantly affect natural resource management, conservation, and adaptation to climate change. • Maquis is classified in alliance level at regional scale (30 m resolution). • New spectro-temporal features are proposed for vegetation classification. • RF algorithm is superior to SVM and QDA in classification of maquis formations. • Combination of environmental features and satellite images led to higher accuracy. • Mapping maquis formations will help sustainable use and ecosystem conservation. [ABSTRACT FROM AUTHOR]

New Caledonia (NC) is a biodiversity hotspot sheltering terrestrial ecosystems of high ecological and conservation value including tropical dry forests, rainforests, and maquis. However, uncontrolled bushfires threaten this exceptional biodiversity. A science-based fire management policy could reduce the impact of unwanted fires and help facing climate change. However, to date, data on the location, extent, causal factors and spatial patterns of fires had not been collected. We compiled a 13-year-long (1999–2011) spatially-explicit fire database for NC using MODIS and Landsat data. Using boosted regression trees we disentangled the role of anthropogenic factors, physiography, weather and vegetation on fire activity. We also characterized the location of fires and the vegetation composition at the fire edges, in order to determine which ecosystems were especially vulnerable. Fire size distribution was typically asymmetric with many small fires (<10 ha) and very few large fires (>500 ha). Ignitions were preferentially located close to villages, cities or roads, at low elevation and linked to high values of fire weather index. Fires were larger at the end of the dry season and during El Niño events. Most fires were bushfires burning in savannas, thickets and maquis, while rainforests were rather ‘avoided’ by fire. However, bushfires generally propagated towards forests of high-conservation value, thus increasing the potential for forest edge erosion. As savanna-forest and maquis-forest mosaics are dominant in the landscape, we discuss the extent to which NC could become a ‘fire trap’ where fire cannot be easily extirpated. Based on our spatially-explicit information on fire activity, we make recommendations for a sustainable forest and fire management policy which would balance the traditional use of fire and the conservation of the most valuable ecosystems. In particular, it may help by reducing the damages of large and destructive bushfires ignited during drought peaks. [ABSTRACT FROM AUTHOR]

Abstract: We examined the effects of fire recurrence on a mosaic structure of Quercus suber and Erica-Cistus shrubland communities of Southeastern France in order to improve the understanding of fire-vegetation interplay. Plant communities that were similar in 1959 (woodlands on shrublands called maquis on acidic soils) were compared along a gradient of fire recurrence, from 0 to 4 fires, with different time intervals between fires. The results showed that understory cover increased roughly with fire recurrence, whereas tree height, cover, density, stand basal area and litter depth decreased. Different fire recurrences along the past decades led to different vegetation types. High fire recurrence corresponded to maquis and sparse cork-oak woodlands while pure oak woodlands established in the absence of fire during the same period. In all, the diversity of tree diameter decreased with fire recurrence. High fire recurrence (3 or 4 fires in 50years) led to a simple vertical structure of vegetation with a mono-layered shrub cover and few Quercus suber trees. In contrast, spatial connections between plants were maximal at longer time intervals, leading to a multi-layered vegetation. We finally discuss the potential implications of past fires on the behavior of future fires in the perspective of a sustainable management of these Mediterranean ecosystems. [Copyright &y& Elsevier]

Abstract: Soil microbial activities and chemical properties related to the N cycle were investigated in function of variations in plant cover type in a Mediterranean area of Southern Italy. Several biological (microbial biomass, soil respiration, protease activity, degradation of 7 amino acids, net N mineralization, net nitrification, potential net nitrification and denitrification) and chemical properties (water content, pH, organic C, total and mineral N, C/N ratio) were determined in soil samples collected in spring and early autumn under three plant cover types (high maquis, low shrub community and meadow) epitomizing distinct successional stages following disturbance. Water content, organic C and C/N ratio were higher in soil from high maquis than in soils from the other plant cover types; in contrast, no difference was generally observed between the three soil types as for total and mineral N content. Likewise, no clear-cut difference was recorded for most of the tested biological parameters if these were expressed per unit of soil dry weight, with the exception of protease activity and soil respiration, which were significantly higher in the high maquis. However, when biological data were expressed per unit of organic C, meadow soil showed higher values of microbial biomass, asparagine degradation (only in spring), net mineralization and net nitrification (only in autumn) compared to the other soils. Statistical analysis pointed to seasonal fluctuation of water availability as an important limiting factor for microbial biomass and activity, with the exceptions of net N mineralization, net nitrification, glutamine and glutamic acid degradation activities which appeared to be mainly driven by organic matter content in soils. Overall, the results suggest that, in the investigated Mediterranean environment, variations in plant community ranging from meadow to high maquis produce little changes in soil biological activities linked to the N cycle, these being primarily affected by the availability of water and soil organic matter during the annual cycle. [Copyright &y& Elsevier]

Abstract: Maquis is a dense evergreen shrub layer which, in semi-arid Mediterranean lands, is commonly linked to the presence of well-conserved soils with large contents of mineralizable substrates. It was our aim to test whether: (i) maquis promotes soil microbial biomass and activity, and (ii) mature pine plantations without a shrubby understory support microbial biomass and activity levels comparable to those of stands with maquis. Surface soil samples were taken in four sites that sustain pine plantations (PP), maquis with pines (MP), maquis (MQ) and grasslands (GS). Microbial biomass was inferred from the C content in the soil microbiota. The ATP content in fresh samples and the CO2–C production from incubated samples were used to assess microbial activity, as was the activity of β-glucosidase and alkaline phosphatase. Topsoils under maquis (MP and MQ) were the most fertile, both chemically (high organic carbon contents) and physically (low bulk density, high aggregate stability) and showed by far the largest levels of microbial biomass and activity. These levels in soils under PP, which sustained a successful plantation in terms of tree canopy density but lacked the shrubby understory, were significantly smaller than those of the adjacent shrubland with pines (MP). Redundancy analysis extracted a main axis explaining 67% of the variation of the microbiological soil properties, which was interpreted as an environmental gradient of soil fertility. Along this axis, the samples were separated according to the presence or absence of a maquis dominated by late-successional species; other factors such as soil type, slope position and aspect were less influential. The effects of afforestation practices on the detritus-based system should be considered in the design of future forest restoration strategies in desertification-threatened lands. [Copyright &y& Elsevier]

Abstract: This case study on the Sifnos island, Greece, assesses the main factors controlling vegetation succession following crop abandonment and describes the vegetation dynamics of maquis and phrygana formations in relation to alternative theories of secondary succession. Field survey data were collected and analysed at community as well as species level. The results show that vegetation succession on abandoned crop fields is determined by the combined effects of grazing intensity, soil and geological characteristics and time. The analysis determines the quantitative grazing thresholds that modify the successional pathway. Light grazing leads to dominance by maquis vegetation while overgrazing leads to phryganic vegetation. The proposed model shows that vegetation succession following crop abandonment is a complex multi-factor process where the final or the stable stage of the process is not predefined but depends on the factors affecting succession. An example of the use of succession models and disturbance thresholds as a policy assessment tool is presented by evaluating the likely vegetation impacts of the recent reform of the Common Agricultural Policy on Sifnos island over a 20–30-year time horizon. [Copyright &y& Elsevier]

Abstract: Basic soil parameters of Kozlar high plateau in Mut (Mersin) have been investigated. Soil samples were collected from the eroded, maquis and forest habitats of the research area in January, October, April and July between 2000 and 2002. The average values for soil moisture, CaCO3, saturation percentage, field capacity, salinity, conductivity, pH, total carbon and total nitrogen were found in the range of 4.0–19.7%, 25.0–33.3%, 39.7–72.1%, 22.0–56.0%, 0.027–0.074dS/m, 0.80–1.2μS/cm, 7.5–8.1, 0.82–5.50%, and 0.10–0.58%, respectively. Generally, despite no significant differences among the soil parameters of the three habitats, only three parameters, saturation percentages, amount of total carbon and of carbon mineralization differed significantly. [Copyright &y& Elsevier]

A series of 25 experimental fires was carried out in a maquis fuel type in southwestern Turkey. The fires were conducted under a range of weather and fuel conditions to gather quantitative data on fire spread, fuel consumption and fire intensity, and develop fire behavior prediction models for fire management purposes. Of the fire behavior characteristics, rate of spread and fire intensity were related to both fuel loading and wind speed, whereas fuel consumption was related to fuel loading and fuel moisture. Regression models developed using the data gathered are able to predict fire behavior in terms of wind speed, fuel loading and fuel moisture. Results obtained in this study should be invaluable in overall fire management practices. But its use should be restricted to the range of conditions within which the data were gathered. [Copyright &y& Elsevier]

The water use by a stand of Quercus calliprinos Webb. maquis, growing on Mount Carmel Israel, was estimated by means of the heat pulse method. Hourly heat pulse velocity (HPV) measurements on eight or 16 trunks, each being the main trunk in its stool, were done continuously for between 96 and 240 h, approximately every 3 weeks. The measured trunks were selected to represent the circumference distribution of the 240 trunks at the site. The HPV was measured with a probe carrying six thermistors along its axis, 8 mm apart. The six-thermistor probe was inserted into a hole drilled radially into the trunk exactly 15 mm above the heater, and the reference probe into a hole drilled at least 100 mm lower and aside from the heater. This kind of a probe facilitates measurement of the decline in the pulse velocity with the depth under the bark. Hourly and daily sap flow rates, i.e., transpiration were calculated by means of known procedures and equations.The highest average daily transpiration rate of about 28.1 l per tree per day occurred in May, and the lowest, of 5.0 l per tree per day in October. The estimated total yearly transpiration of the 0.1 ha plot containing 240 oak trunks in 47 stools ranged between 44 and 75% of the preceding winter rainfall, i.e., between 234 and 358 mm. In drier years the trees had used a higher proportion of the annual rainfall than in wetter years. The estimated water consumption by the oak trees in the early years after thinning which left only the 47 main trunks, one per stool, was only 13–20% of the preceding annual rainfall. Thinning caused increased transpiration of the single main trunk, but the estimated overall water use by the remaining trees (47 out of 240) was very much reduced. Thinning of most of the trunks in several stools enhanced the growth rate of the remaining trunks. The circumferences of the trunks in the thinned stools increased to 115.4% of their initial value in 3 years compared with to only 107% by those of the trunks in the non-thinned stools. [Copyright &y& Elsevier]

The endemic conifer species Araucaria laubenfelsii forms a characteristic component of the various forest and non-forest vegetation assemblages present on Mont Do, New Caledonia. It is the only tree species in the landscape to be found in both maquis (shrubland) and forest patches. Adult density ranges from zero in some parts of the maquis to extremely high in others, forming an Araucaria woodland. The current landscape structure on Mont Do appears to be the result of recurrent disturbance, especially by fire. However, it is uncertain whether this structure is the result of recent changes in the fire regime (as a result of Melanesian and European phases of human colonisation of New Caledonia) and is therefore transient, or represents a more stable formation. A spatially explicit grid-based model was developed to explore some of these issues. The model is primarily concerned with understanding how alterations to the disturbance regime (past and future) may influence the landscape structure and, in particular, whether the current landscape pattern is a result of increased fire frequencies over the last century and whether certain unusual vegetation assemblages in the landscape, such as maquis with emergent Araucaria, are likely to persist in the long-term. The ecological context of the spatial landscape model is described as is a simple sensitivity analysis of the model and an example of its use under ‘baseline’ conditions. [Copyright &y& Elsevier]

• Modeled species distributions differ, when test and training region are exchanged. • Edaphic specialists can be better extrapolated than edaphic generalists. • Relief and climatic variables are suitable for extrapolation. • Geological data impair performance of models extrapolated between regions. This study aims to test the extrapolation effects of species distribution models (SDM) using three groups of predictor variables: climate, relief and geology (bedrock type). We highlight potential ecological differences for selected taxa, regarding both generalists and specialists in terms of edaphic conditions. We used distributional data of 12 woody species shared by two large Mediterranean islands (Crete and Sicily) to calibrate Maxent models of their potential distribution. We trained models with data from Crete and extrapolated to Sicily and vice versa. We tested ten proxies for the three variable groups and compared AUC values as a measure of model performance. Extrapolation of SDMs worked fairly well across species and islands for those models including climatic and relief data, while those including geological information performed worse for the tested species. Edaphic generalists performed less well compared to edaphic specialists. The latter performed best with climate data included in models and more poorly with only geological data. This may be due to differences in bedrock type affinities of species between the two islands. [ABSTRACT FROM AUTHOR]