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Context: Human action has a direct impact on vegetation. Numerous studies use different indicators to evaluate this human influence in different regions. However, there are fewer studies that analyse in detail anthropisation causes, and the degree of protection that is being given to the best-preserved patches of vegetation. Objectives: This study firstly determines human alteration of vegetation through a synanthropisation index. Then, it responds to two questions: What contribution do different human activities have on vegetation synanthropisation? Do protected areas adequately preserve vegetation with reduced synanthropisation? Methods: The study area included six provinces of Central Spain. A global synanthropisation index (ISG) including flora and vegetation, and six anthropisation indicators (population, agriculture, forestry, livestock, mining and reservoirs) were established, conducting a statistical treatment. Areas with the lowest ISG were overlaid with protected areas to determine their degree of inclusion. The proposed methodology can be applied in other geographical regions, and is integrative, allowing the incorporation of other similar indices and indicators. Results: Average ISG value was 0.673; 58% of the area had high synanthropisation, 26% medium and 16% low. Multiple regression of ISG with anthropisation indicators was extremely significant. Agriculture would explain 63.7% of synathropisation, population 11.2%, forestry 8.8%, livestock 7.6%, dams 4.6% and mining 4.4%. Environmental protected areas included only 46.7% of vegetation plots with reduced synathropisation. Conclusions: The main cause of vegetation synanthropisation was agriculture. Vegetation with low synathropisation should be preserved, but almost half of the detected plots were outside protected areas. The synanthropisation of vegetation should be considered in decision-making on territorial planning and environmental assessment. [ABSTRACT FROM AUTHOR]

Piping is an important land degradation process that occurs in almost all climatic zones. This study analyses for the first time the frequency-size distribution of different types of pipe collapses (PCs): sinkholes and compound depressions related to the coalescence of sinkholes (compound sinkholes and elongated blind gullies). Exploring the frequency-size relationships of PCs provides critical morphometric information about this hazardous erosion and ground-stability process, as well as its impact on hillslope denudation, hillslope-channel coupling and landscape development. The analysis has been performed with field-based inventories of PCs from five catchments located in two different morphoclimatic environments: one in the semi-arid Ebro Depression, NE Spain (Valpalmas catchment), and four in the humid Bieszczady Mts., SE Poland. In total, 724 PCs were mapped, among which 335 PCs in Valpalmas and 389 PCs in the Bieszczady Mts. The morphometric analyses were based on the major axis (the maximum length or width) and area of the PCs. Despite differences between study areas from NE Spain and SE Poland (related to climate conditions, rainfall regime, soil water storage capacity, spatial pattern of pipe networks, vegetation cover and land use), empirical cumulative frequency curves of PCs show similar patterns in all study sites indicating similar overall effects of piping erosion. The size distribution of the inventoried PCs can be modelled satisfactorily with logarithmic functions with high goodness of fit values (R2 ≥ 0.93) for each type of PC and the combined set of PCs (sinkholes and compound sinkholes/blind gullies) mapped in each area and in the five catchments together. The PCs mapped in Valpalmas are displaced towards larger dimensions attributable to local factors. The applicability and limitations of frequency-size relationships of PCs for geomorphological studies and hazard assessment are discussed. Frequency-size distribution of pipe collapses in SE Spain and SE Poland Unlabelled Image • The frequency-size distribution of pipe collapses (PCs) is presented for the first time. • Analyses were based on the major axis (maximum length or width) and area of PCs. • Size distribution of PCs was modelled satisfactorily with logarithmic functions (R2 ≥ 0.93). • Cumulative frequency curves of PCs show similar patterns in semi-arid Spain and humid Poland. • PCs mapped in Valpalmas are displaced towards larger dimensions attributable to local factors. [ABSTRACT FROM AUTHOR]

The deposits of the As Pontes Basin in north-west Spain yield extraordinarily well-preserved microfloral assemblages that have unmatched diversity within the European Oligocene. The comprehensive examination of 300 miospore taxa has led to the discovery of two new fossil pollen genera, Eucommiopsispollenites gen. nov. and Pistaciapollenites gen. nov., as well as seven new species: Eucommiopsispollenites compactus sp. nov., Eucommiopsispollenites gracilis sp. nov., Nymphaeapollenites asponticus sp. nov., Nymphaeapollenites perforatus sp. nov., Pistaciapollenites heteroporatus sp. nov., Punctilongisulcites cryptornatus sp. nov. and Symplocoipollenites diktyotos sp. nov. Moreover, the botanical affinity and geographic distribution of 13 additional species of particular interest are discussed in detail, because these are either recorded for the first time anywhere within the Paleogene (Lythraceaepollenites bavaricus, Myrtaceidites myrtiformis, Punctilongisulcites punctiechinatus, Rhuspollenites ornatus and Vitispollenites tener), in the Iberian Peninsula (Aglaoreidia pristina, Diospyrospollenites ovalis, Pseudospinaepollis pseudospinosus, Reevesiapollis reticulatus and Tricolporopollenites vancampoae), or are studied for the first time using scanning electron microscopy (SEM) (Pentapollenites regulatius, Polycolpites helmstedtensis and Triporopollenites robustus). SEM analysis has enabled the conclusive botanical assignment of two species: Polycolpites helmstedtensis, with affinity to the extant tropical genus Eriandra, and Triporopollenites robustus, related to Myricaceae. In view of these affinities, new combinations are proposed accordingly: Polygalacidites helmstedtensis comb. nov. and Myricipites robustus comb. nov. The results of this study carry significant biostratigraphic and palaeobiogeographic implications at a regional and wider, continental scale. Firstly, the similarities of the As Pontes microflora with other Oligocene assemblages located various thousands of kilometres apart indicates the spread of a relatively homogenous broadleaved evergreen flora in Europe and allows for the recognition of Myricipites robustus and the genus Pentapollenites as key biostratigraphic index taxa across the continent. Secondly, the last occurrence datums of thermophilous taxa that became extinct in the Eocene in more northern latitudes indicates that the Iberian Peninsula functioned as a refuge area for thermic vegetation at least since the early Oligocene. [ABSTRACT FROM AUTHOR]

Piping is a soil erosion process that occurs in almost all morphoclimatic zones and in a widevariety of sediment types. It plays a considerable role in badlands evolution. Pipes(subsurface tunnels) and the associated internal mechanical erosion transfer sedimentfrom hillslopes to channels providing subsurface slope–channel connectivity. Tothe best of our knowledge, this process is not included in soil erosion models andit is not considered in sedimentary budget assessments. However, soil loss ratesrelated to piping may reach significant values, ranging from below 1 t ha−1 y−1, asreported in the US, to 33 t ha−1 y−1 in the Loess Plateau, China, and with a maximumof 550 t ha−1 y−1 in Spain. Therefore, there is a need to better understand thisprocess. This study explores the frequency-size distribution of pipe collapses (PCs) through theconstruction of empirical cumulative frequency curves. The analysis has been performed withfield-based inventories of PCs from two different morphoclimatic environments: one area inthe semi-arid Ebro Depression, NE Spain and 4 areas in the temperate BieszczadyMts., SE Poland. This morphometric study allows us to check for the first time iffrequency–size relationships of PCs follow a power-law as it is proven for many naturalphenomena. PCs developed when the upward propagation of cavity roofs by collapse processes(i.e., stoping) reached the surface, resulting in collapse sinkholes with vertical ornearly vertical walls. There was only subsurface connection between them and theassociated gully/valley systems. These landforms are initiated by piping erosion andthe foundering of the undermined pipe roofs. However, PCs may have a complexmulti-episodic evolution. Once a PC is formed, it may change its size and geometry bymass-wasting processes acting on their walls and by coalescence with adjacent holes. Intotal, more than 720 PCs were analyzed (335 in Spain and 389 in Poland). Thefrequency–size relationships were based on the major axis (m) and area (m2) ofPCs. The cumulative frequency curves of empirical data in the different areas show a similarpattern and high goodness of fit (R2: 0.91-0.98). The cumulative frequency-size distributionfollows a negative power-law for medium-size PCs. However, some differences can be noted.For instance, PCs in NE Spain show larger dimensions suggesting that mechanical factorssuch as the strength of the sediments play a decisive role, controlling the minimum size ofthe collapses (geomorphic threshold) and the frequency-size distribution of eacharea. Exploring the magnitude-frequency relationships of PCs provides relevant informationabout the impact of piping on hillslope denudation and landscape evolution. It also offerscritical quantitative data for subsidence hazard assessment. The study is supported by the National Science Centre, Poland within the first author’sproject SONATINA 1 (DEC-2017/24/C/ST10/00114) and by the Institute of Geography andSpatial Management of the Jagiellonian University in Kraków, Poland (K/DSC/005466). [ABSTRACT FROM AUTHOR]

This paper focuses on pollen, spores, non-pollen palynomorphs (NPPs) and certain geochemical elements from the ombrotrophic blanket bog of Zalama (Basque-Cantabrian Mountains, northern Iberian Peninsula), with the support of a robust chronology based on 17 AMS 14C dates. The main results related to the last 8000 years show that, during the early middle Holocene, pines and deciduous forests were the most extensive tree formations. At the beginning of the succession, pines reach 44%, showing regional presence, whereas after 7600 cal. a BP, deciduous forests were particularly abundant. From c. 6500 cal. a BP the pollen diagram constructed from our samples shows the first anthropogenic evidence, linked with the new economic practices related to the Neolithic of the Basque-Cantabrian Mountains. From 3300 cal. a BP the expansion of Fagus sylvatica is particularly clear, and has since then become one of the dominant forest species in this region. We also discuss the Holocene evolution of other noteworthy plant communities in southwestern Europe, such as Taxus baccata, Juglans and shrublands. [ABSTRACT FROM AUTHOR]

This report describes for the first time a part of the Middle and Upper Devonian conodont sequence of the Sierra Negra Subfacies in the Aragonian Pyrenees (Spain), establishing the basis for further sound correlations both across the distinct Pyrenean facies and subfacies and on other relevant world areas. The description of 20 conodont taxa and their stratigraphical distribution permits recognition of two separate time intervals. The older one corresponds to the lower Upper Givetian (Middle Devonian), hermanni to cristatus ectypus zones. The younger interval is uppermost Lower Frasnian to lower Middle Frasnian (Upper Devonian) and is equivalent to MN4-MN6 zones. The combination of litho- and conodont biofacies supports the distinction between the Sierra Negra and Renanué Subfacies. Conodont biofacies for the studied interval are partially close to the ones from the Compte Subfacies, but lithofacies are clearly different. This faunal similarity fosters accurate correlation between subfacies and stimulates further research aiming at Devonian Pyrenean basin(s) reconstruction. Additionally, this faunal sequence permits direct comparison with regions located in northern Gondwana and in the Russian platform for part of the interval. Comparison with Laurasia, mainly with the Northwest Territories of Canada and the north-western United States, is also provided. Some taxa are also common with eastern and central Asia (China, Siberia, Tadzhikistan, Afghanistan), Australia and western USA (Nevada). [ABSTRACT FROM AUTHOR]

The main goal of the present study was to provide a detailed analysis of olive pollen transport dynamics in the province of Córdoba (south-western Spain) by applying back-trajectory analysis. Pollen data from 2006 and 2007 were analysed at four monitoring sites: Córdoba city in the centre of the province, Baena and Priego de Córdoba located in the south, and El Cabril reserve (Hornachuelos Natural Park) in the north. Particular attention was paid to nine episodes of high pollen counts. Synoptic surface maps were used, and kinematic back-trajectories (3D) were computed using the hybrid single particle Lagrangian integrated trajectory model (HYSPLIT) at 500 m above ground level, run with a time-step of 6 h over a period of 36 h. Findings were analysed in conjunction with daily and bi-hourly airborne pollen data, field phenological data and hourly surface meteorological data recorded at nearby stations: temperature, relative humidity, rainfall, wind direction and wind speed. The results identified two pollen source areas over the Córdoba province, the largest one located in the south, affecting Baena, Priego de Córdoba and Córdoba city, and one smaller located in the west, which determines mainly the pollen cycle over the north of the province, El Cabril. In addition, two air mass circulations were found, one coming from the south and crossing the main olive pollen sources very close to the surface and being frequently associated with higher pollen counts, and the other coming from the west and, in the episodes investigated, influencing mainly the north of the province. [ABSTRACT FROM AUTHOR]

Abstract  Temporal variation of airborne bracken (Pteridium aquilinum) spores concentration in Salamanca during 10 years from January 1998 to December 2007 were studied by using a Burkard spore trap, and correlations with some meteorological parameters were analyzed. The number of spores that were counted was very low, due probably to the distance between the spore trap and the main bracken populations which were located 70 km away from the city. Long-range transport caused by winds coming from the Second Quadrant (IIQ) is supposed to be responsible for the appearance of bracken spores in Salamanca. The season period from August to late October shows the most intense spore dispersal process, with an early morning distribution along the day. Years 2002 and 2007 with a low quantity of airborne spores were also characterized by low mean temperatures, always under 18°C from May to June. Daily spore concentration shows positive correlation with temperature and sun hours but negative with IVQ winds and with relative humidity. No correlation between daily spore concentration and rainfall was found. Also, a positive correlation between number of spores and IIQ winds was observed during the main spore season (MSS) and prepeak period (PRE). [ABSTRACT FROM AUTHOR]

Climate change is increasing the vulnerability of Mediterranean coniferous plantations. Here, we integrate a Landsat time series with a physically-based distributed hydrological model (Watershed Integrated Management in Mediterranean Environments—WiMMed) to examine spatially-explicit relationships between the mortality processes of Pinus pinaster plantations and the hydrological regime, using different spectral indices of vegetation and machine learning algorithms. The Normalized Burn Ratio (NBR) and Moisture Stress Index (MSI) show the highest correlations with defoliation rates. Random Forest was the most accurate model (R2 = 0.79; RMSE = 0.059), showing a high model performance and prediction. Support vector machines and neural networks also demonstrated a high performance (R2 > 0.7). The main hydrological variables selected by the model to explain defoliation were potential evapotranspiration, winter precipitation and maximum summer temperature (lower Out-of-bag error). These results show the importance of hydrological variables involved in evaporation processes, and on the change in the spatial distribution of seasonal rainfall upon the defoliation processes of P. pinaster. These results underpin the importance of integrating temporal remote sensing data and hydrological models to analyze the drivers of forest defoliation and mortality processes in the Mediterranean climate. [ABSTRACT FROM AUTHOR]