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In this paper, we analyse the long-run equilibrium demand of the peer-to-peer sharing economy. Our panel data demand model relates occupancy rates to relative prices of Airbnb and HomeAway listings, prices of competitors (hotels and apartments) and a proxy for income of tourists visiting the Canary Islands (Spain). We use a fractional heterogeneous panel data model which allows for a more general persistence and cointegration relationship and incorporates individual and interactive fixed effects. We find some evidence for (fractional) cointegration in P2P at the listing level. Regarding elasticities, classic cointegration methods give larger estimates for individual slopes and mean group coefficients than the fractional integrated heterogeneous model. Finally, own-price elasticities are inelastic, and the cross-price elasticity indicates that P2P listings and hotels are substitute goods. Income elasticity is lower than 1 and is not statistically significant, indicating that the demand for tourism in the Canary Islands is not sensitive to the economic conditions in the origin countries. [ABSTRACT FROM AUTHOR]

This paper draws inference on the effect of changes in indirect taxation on household spending on cinema and performing arts using data from the Spanish household expenditure survey. As of September 2012, value-added tax (VAT) on cinema and performing arts in Spain was raised 13 percent points, with the exception of the Canary Islands which are not part of the Spanish VAT territory. Indirect taxation levied on cinema and performing arts through the General Indirect Tax of Canary Islands (Impuesto General Indirecto de Canarias, IGIC) had changed in July 2012 by only 2 percent points. Such an uneven raise in the tax rates is the source of exogenous variation used for identification in this paper. As the sample of treated households (exposed to the VAT rise) is much larger than the sample of untreated households (exposed to the IGIC rise), we use causal inference methods to estimate the average treatment effect of the VAT rise on the untreated households. We find that the average household expenditure on cinema and performing arts of the untreated households would not have changed significantly, had untreated households been exposed to the VAT rise. However, this average treatment effect would not have been homogeneous, as we identify an average treatment effect conditional on participation of 52.37 euros. Thus, the tax rise would have increased the annual expenditure of those households that spend on cinema and performing arts regularly. [ABSTRACT FROM AUTHOR]

The location, size, and structure of the farmlands and hydraulic systems built by the Indigenous inhabitants of Gran Canaria, Canary Islands, Spain, remain unknown. This hampers our ability to understand how they organized agricultural production and how European settlers transformed local landscapes to build commercial plantations in the late fifteenth century. This paper combines an analysis of archival sources with the study of agricultural landscapes and practices to identify and describe the fields that were employed by the first colonists of Agüimes and Temisas, and to derive information about the location, design, and management of the pre-Hispanic farmlands. [ABSTRACT FROM AUTHOR]

Rockfalls are frequent and damaging phenomena that occur on steep or vertical slopes, in coastal areas, mountains and along coastal cliff. Water, in different forms, is the most common triggered factor of rockfalls. Consequently, we can consider that precipitation is the most influential factor for slope instabilities and it influences almost all other water parameters. Besides, the specific geology of the Anaga nature reserve in the volcanic island of Tenerife, together with its steep landscape, contributes to the instability of the slopes and frequent rockfalls. Recently, due to climate change and global warming, the annual precipitation/rainfall has declined but the number of heavy storms, associated with intense rainfall and strong winds, events that exceed precipitation thresholds in a brief period has increased which triggers slope movements. This paper describes the analysis of information on rainfall-induced rockfalls in Anaga, Tenerife (Canary Islands), to forecast rock failures of social significance and to improve the capability to respond and emergency decision making. To define reliable thresholds for a certain area, we analized information during the period 2010–2016, reconstructed the rockfall events, and statistically analyzed the historical rainfall conditions that led to landslides. The summary graph correlating precipitation to the probability of occurrence of an event was plotted. Statistical and probability graphs were made with the direct relationship between the number of rockfall events and total rainfall in that period by examining the maximum daily precipitation, not only on the day of the event but up to 3 days before. Hence, the results of this study would serve as a guide for the possible forecasting of rainfall-induced rockfalls, especially for road maintenance services, so that they can be on alert or mobilize the necessary resources in advance depending on the intensity of the expected rainfall. Highlights: We have determined the correlation between the probability of occurrence of a rockfall event in a natural reserve (Anaga, island of Tenerife, Canary Islands) and the expected rainfall intensity. We have observed the time delay between the occurrence of rainfall and rock falls, corroborated by experience in this area, between the day of the event and the day of the maximum rainfall associated with it. We have provided a tool to be used by the Civil Protection and Emergency and Road Maintenance and Conservation Services of the island of Tenerife as part of their management to mobilise the necessary resources or means or to adopt traffic limitations or restrictions depending on the level of alert decreed for adverse meteorological phenomena related to rainfall. [ABSTRACT FROM AUTHOR]

The literature on the water–energy–food nexus has repeatedly signaled the need for transdisciplinary approaches capable of weaving the plurality of knowledge bodies involved in the governance of different resources. To fill this gap, Quantitative Story-Telling (QST) has been proposed as a science for adaptive governance approach that aims at fostering pluralistic and reflexive research processes to overcome narrow framings of water, energy, and food policies as independent domains. Yet, there are few practical applications of QST and most run on a pan-European scale. In this paper, we apply the theory of QST through a practical case study regarding non-conventional water sources as an innovation for water and agricultural governance in the Canary Islands. We present the methods mixed to mobilize different types of knowledge and analyze interconnections between water, energy, and food supply. First, we map and interview relevant knowledge holders to elicit narratives about the current and future roles of alternative water resources in the arid Canarian context. Second, we run a quantitative diagnosis of nexus interconnections related to the use of these resources for irrigation. This analysis provides feedback to the narratives in terms of constraints and uncertainties that might hamper the expectations posed on this innovation. Thirdly, the mixed analysis is used as fuel for discussion in participatory narrative assessment workshops. Our experimental QST process succeeded in co-creating new knowledge regarding the water–energy–food nexus while addressing some relational and epistemological uncertainties in the development of alternative water resources. Yet, the extent to which mainstream socio-technical imaginaries surrounding this innovation were transformed was rather limited. We conclude that the potential of QST within sustainability place-based research resides on its capacity to: (a) bridge different sources of knowledge, including local knowledge; (b) combine both qualitative and quantitative information regarding the sustainable use of local resources, and (c) co-create narratives on desirable and viable socio-technical pathways. Open questions remain as to how to effectively mobilize radically diverse knowledge systems in complex analytical exercises where everyone feels safe to participate. [ABSTRACT FROM AUTHOR]

Kudoid myxozoans have been reported causing serious chronic problems in marine fisheries, by reducing the market value of infected fish through pathological damage to the host musculature. We report here the overall prevalence of a Kudoa species in 84/277 (30.3%) fishes from 20 different species of high commercial value captured between October 2011 and December 2013 from the United Nations Food and Agriculture Organization (FAO) 34 commercial fishing area, near the coast of the Canary Islands (Spain). Macroscopic examination showed myxozoan-like cysts in skeletal muscle from 5 of the 20 fish species examined, with the following prevalences: Pagellus acarne (86.7%), Pagellus erythrinus (46.5%), Serranus cabrilla (27.8%), Spondyliosoma cantharus (19.4%), and Sarpa salpa (28.6%). Infection intensity was determined based on spore counts following muscle tissue digestion. Morphometric studies to characterize the species and DNA sequence analysis results suggest that these infections are attributable to a Kudoa species closely related to Kudoa trachuri. This paper reports the first study on a multivalvulidan species to be identified from the Canary Islands. Furthermore, this is the first report of Kudoa parasites in all of the hosts mentioned above, with the exception of P. acarne. [ABSTRACT FROM AUTHOR]

There are three species of Phoenix (Arecaceae) in the territory of the European Union, P. canariensis, P. dactylifera and P. theophrasti, found in wild-native populations, feral, planted and intermediate states, accounting each for thousands of individuals. The EU Habitats Directive has addressed the conservation of P. theophrasti and P. canariensis under the habitat type 9370, ‘Palm groves of Phoenix,’ but neglected to include the wild-growing populations of P. dactylifera palms in southern Spain. In this paper, we survey the habitats and status of both representative native and naturalized populations of Phoenix, in total 103, through fieldwork, image analysis and review of literature. We underline the significance of feral populations and palms originating from ancient abandoned plantations, existing in protected areas as a reservoir of genetic variation. We conclude that, in order to improve their conservation status by adequate protection and conservation management, the concept of Phoenix palm groves in the Habitats Directive should be redefined to include the western group of P. dactylifera and the various habitats of P. canariensis and P. theophrasti that do not appear in the current definition. [ABSTRACT FROM AUTHOR]

The introduction of the rotary quern into the Iberian Peninsula during the Iron Age represents a great technological innovation with regard to processing cereals. These mechanisms arrived several centuries later in the Canarian archipelago with the first North African colonists. Contacts with the African continent appear to have either been cut off or minimised a short time later, obliging the colonists to subsist autonomously and adapt to the features of the new territory. Moreover, the archipelago's volcanic character does not offer minerals that could be transformed into metals obliging the new populations to resort to stone tools, an adaptation evidenced by the manufacture of rotary querns. Currently few technological studies of these querns have combined experimental work with hypotheses stemming from archaeological evidence. This article presents two experimental programs that have attempted to reconstruct the operational sequence (chaîne opératoire) of the two main types of rocks exploited for querns in the Canary Islands: volcanic tuff and vesicular basalt. [ABSTRACT FROM AUTHOR]

Island archaeology is a well-established field within the wider discipline, but African contributions to it remain scarce. The Canary Islands are unusual in the broader African context for their relatively long history of occupation (~2000 years) and the intensity with which archaeological research has been, and is, undertaken there. Much of that research, however, has focused on specifically Canarian issues, including efforts to demonstrate connections between the islands' initial settlement and the Classical Mediterranean world. Relatively little of it has been conducted within the broader comparative framework that an island archaeology perspective provides. Additionally, much of the Canarian literature is not directly accessible to non-Hispanophones. In response, I synthesize what is currently known about the archaeology of the Canary Islands, focusing on determining when, how, and by whom they were first settled; the impacts of human settlement on their environments; inter-island variability in precolonial subsistence, social, and political trajectories; and the record left by European contact and subsequent colonization, which began in the 14th century AD. As well as pointing to further opportunities for research within the archipelago, I simultaneously map out several areas where archaeological work there could contribute to wider debates in island archaeology as a whole. [ABSTRACT FROM AUTHOR]

At many dormant volcanoes, magmatic gases are not channeled through preferential degassing routes as fumaroles and only percolate through the flanks of the volcano in a diffuse way. This type of volcanic gas emission provides valuable information, even though the soil matrix contains an important atmospheric component. This study aimed to demonstrate that chemical ratios such as He/CO2 in soil gases provide excellent information on the evolution of volcanic unrest episodes and help forecast the volcanic eruption onset. Before and during the occurrence of the October 2011–March 2012 submarine of El Hierro, Canary Islands, more than 8500 soil He analyses and diffuse CO2 emission measurements were performed. The results show that the soil He/CO2 emission ratio began increasing drastically one month before eruption onset, reaching the maximum value 10 days before. During the eruptive period, this ratio also showed a maximum value several days before the period with the highest magma emission rate. The He/CO2 ratio was also helpful in forecasting the eruption onset. We demonstrate that this tool can be applied in real-time during volcanic emergencies. Our results also encourage a reevaluation of the global He emission from the subaerial volcanism. [ABSTRACT FROM AUTHOR]

The Canary Islands are one of the main destinations for mass tourism in the European context, characterized by the absence of seasonality in tourist activity. Moreover, the level of activity increases during the winters, coinciding with a greater probability of extreme rainfall events, whose danger seems to be increasing as a result of climate change. Owing to its pronounced orography, the southern coast of the island of Gran Canaria houses several tourist settlements built along ravines and steeply sloping terrain. This scenario presents considerable risk because of spatial probability of landslide occurrence. The case of San Agustín, especially, serves to test the model of tourist urbanization along the hillside, demonstrating its high fragility in the face of extreme rainfall events. Especially owing to its importance in providing assistance in emergency situations, its vulnerability has been analyzed with regard to accessibility, which is entirely dependent on road mobility. The growth model of San Agustín serves as an example of mass tourism in small islands, allowing urban planners and designers to assess corrective measures based on managing its existing road infrastructure and open spaces right from the planning stage. [ABSTRACT FROM AUTHOR]

Parliamentary websites have become one of the most important windows for citizens and media to follow the activities of their legislatures and to hold parliaments to account. Therefore, most parliamentary institutions aim to provide new multimedia solutions capable of displaying video fragments on demand on plenary activities. This paper presents a multimedia system for parliamentary institutions to produce video fragments on demand through a website with linked information and public feedback that helps to explain the content shown in these fragments. A prototype implementation has been developed for the Canary Islands Parliament (Spain) and shows how traditional parliamentary streaming systems can be enhanced by the use of semantics and computer vision for video analytics. The semantic web technologies used make search capabilities on parliamentary websites available to users to retrieve video fragments on demand with accurate and timely information. In addition, video analytic techniques enable the automation of identifying representative keyframes to be annotated by parliamentary experts. As a result, parliaments are able to enhance citizens' access to information and ensure that these institutions are more open and accountable on their websites and; at the same time, the labor-intensive tasks of parliamentary experts are considerably reduced. [ABSTRACT FROM AUTHOR]

The Canary Islands consist of seven basaltic shield volcanoes whose submerged portion is much more voluminous than the subaerial part of each island. Like so many other volcanic oceanic islands, the indicative deposits of explosive felsic volcanism are not a common feature on the Canary archipelago. Hitherto, they have only been documented from the central islands of Gran Canaria and Tenerife, which are the largest volcanic complexes of the islands. On the other Canary Islands, the presence of felsic rocks is mostly restricted to intrusions and a few lava flows, generally within the succession in the oldest parts of individual islands. In this paper, we present a detailed stratigraphic, lithological and sedimentological study of a significant felsic pumice deposit on the island of El Hierro, referred here as the Malpaso Member, which represents the only explosive episode of felsic volcanism found on the Canary Islands (outside of Gran Canaria and Tenerife). The products of the eruption indicate a single eruptive event and cover an area of about 15 km. This work provides a detailed stratigraphic and chronological framework for El Hierro, and four subunits are identified within the member on the basis of lithological and granulometric characteristics. The results of this study demonstrate the importance of an explosive eruption in a setting where the activity is typified by effusive basaltic events. Given the style and the spatial distribution of the Malpaso eruption and its products, a future event with similar characteristics could have a serious impact on the population, infrastructure and economy of the island of El Hierro. [ABSTRACT FROM AUTHOR]

Injuries to the dentofacial region caused by third parties can affect physiological, sensory and esthetic functions with legal repercussions. The personal and social circumstances generated by Covid-19 and the governmental measures taken to control it, have increased the risk factors for violence and with it, the resulting injury rate. The aim of the present investigation was to compare the amount of civil liability for dental injury crimes agreed by Spanish courts, in certain Autonomous Communities, before and during the pandemic situation caused by Covid-19. For this purpose, a analytic cross-sectional study was carried out by analyzing sentences from the database of the Judicial Documentation Center. A comparison of means (one-way ANOVA) was used on the amount of compensation between the different years, and between the Autonomous Communities of Madrid, Catalonia Cataluña, Andalusia, the Canary Islands and the Valencian Community. It was observed that the year 2020 stood out for the increase in the number of cases of dental injury offenses. For its part, the Autonomous Community of Andalusia showed the highest amount of compensation during the pandemic, although the highest number of cases corresponded to the Community of Madrid. The statistical analysis yielded a probability of more than 0.05, which eliminated the possibility of significant differences in each of the comparisons. [ABSTRACT FROM AUTHOR]

La Palma island is located in the NW of the Canary Islands and is one of the most volcanically active of the archipelago, therefore the existence of geothermal resources on the island is highly probable. The main objective of this work is to detect velocity anomalies potentially related to active geothermal reservoirs on La Palma island, by achieving a high-resolution seismic velocity model of the first few kilometres of the crust using Ambient Noise Tomography (ANT). The obtained ANT model is merged with a recent local earthquake tomography model. Our findings reveal two high-velocity zones in the island's northern and southern parts, that could be related to a plutonic intrusion and old oceanic crust materials. Conversely, four low-velocity zones are imaged in the southern part of the island. Two of them can be related to hydrothermal alteration zones located beneath the Cumbre Vieja volcanic complex. This hypothesis is reinforced by comparing the S-wave velocity model with the seismicity recorded during the pre-eruptive phase of the 2021 Tajogaite eruption, which revealed an aseismic volume coinciding with these low-velocity zones. Another low-velocity zone is observed in the southern part of the island, which we interpret as highly fractured rocks which could favour the ascent of hot fluids. A last low-velocity zone is observed in the central part of the island and associated with loose deposits generated by the Aridane valley mega landslide. [ABSTRACT FROM AUTHOR]

The recent eruption of the Cumbre Vieja Volcanic Ridge in La Palma started on September 19, 2021, after a series of seismic swarms and lasted 85 days. Seismic swarms showed a large variability but could be grouped in two categories: long-term swarms located at subcrustal depth, showing b-values close to 2.2 and low rates (from 4.1 to 56 events/hour) and short-term swarms located at very shallow depths, showing moderate b-values [0.9, 1.6] and high rates (from 58 to 460 events/hour). Magma ascent velocity within the 0–10 km depth range varied between 0.03 and 0.21 km/h. Spatial and temporal characterization of the b-values for the entire magmatic process during the selected study period also indicated three distinct dynamics during a preparation phase starting from at least October 2017–August 2021, the eruptive phase from September 2021–December 2021 and a post-eruption process from the end of the eruption in December 2021–May 2022. These stages with clearly different values reflect two scenarios: one corresponding to the time before the eruption with magma ascending from a 39-km depth to the surface, and a second stage corresponding to the eruption itself which includes two seismicity concentrations within the 30–40 km depth interval and a shallow concentration from 0–20 km, corresponding to the crustal reservoir and movement towards the surface. [ABSTRACT FROM AUTHOR]

Climate models project an increase in drought and aridity in many regions in response to greenhouse gas concentrations in the atmosphere. In areas with complex topography, such as the Canary Islands, elevation gradients may play an important role in future changes. Convection-permitting climate simulations driven by data from three global climate models included in the Coupled Model Intercomparison Project (CMIP5) have been performed for the Canary Islands. A significant increase in the duration and severity of drought is projected by the end of the twenty-first century (2070–2099), relative to the recent past (1980–2009), under intermediate and high emissions scenarios. In addition, the percentage of land affected by droughts, on average, would increase considerably, covering up to 96% in the higher elevations, in the business-as-usual scenario. These changes and the increase in aridity are more pronounced at higher altitudes due to a clear dependence of temperature rise as a function of elevation and a substantial decrease in precipitation. [ABSTRACT FROM AUTHOR]

The seven-spotted ladybug is a widespread species in the Palearctic, and also acclimated in the Nearctic. It has been classified into different species on the basis of certain morphological characteristics, the geographical origin, and the genitalia structure of both sexes. The morphotypes of North Africa and the Canary Islands are separated, under the name of Coccinella algerica Kovář, 1977, from the rest of the Palearctic and Nearctic populations of Coccinella septempunctata Linnaeus, 1758. In this study, we investigated, on one hand, whether potential reproductive barriers have been established during evolution between the geographically isolated North African and the European seven-spotted ladybugs by performing reciprocal crosses. On the other hand, we assessed their cuticular hydrocarbon (CHC) divergence by GC–MS. The 33 CHCs indentified are with a skeleton of 23 to 32 carbon atoms. These CHCs are linear alkanes (24.9 ± 3.6%) and methyl-branched alkanes (75.1 ± 3.6%) including monomethylalkanes (48.8 ± 2.4%), dimethylalkanes (24.6 ± 4.0%) and trimethylalkanes (2.0 ± 1.0%). Although all the CHC compounds identified are present in the two seven-spotted ladybugs and their F1 and F2 hybrids, their profiles diverged significantly. However, these chemical divergences have not altered the sexual communication to cause reproductive isolation. The two ladybugs interbreed and leave viable and fertile offspring, with even a heterosis effect on reproductive performances, without phenotypic degradation after the F1 generation. So, these chemical differences are just an intraspecific variability in response to heterogeneous environments. The two types of ladybugs can be considered as two different races of the same species with reduced genetic divergence. [ABSTRACT FROM AUTHOR]

In this work, a regional-scale strategy to characterize the radon activity levels in the Canary Islands (Spain) is described. The main objectives of this strategy consisted of (1) studying the likely relationship between radon concentration and lithology of the rock matrix through the lithological data of 247 samples from volcanic rocks of the Canary Islands and (2) implementing a series of monitoring sites in the form of boreholes and wells to study the evolution of radon-in-air activity on a daily to yearly timescale. [ABSTRACT FROM AUTHOR]

The holotype of the Tenerife (Canary Islands) giant rat, Canariomys bravoi, an almost complete cranium from the Late Pleistocene site of Cueva de las Palomas, is described for the first time. This species is characterized by its large size, robust skull with a short rostrum, dorsal inflation at the level of the infraorbital foramen, and moderately high-crowned upper molars which develop partial stephanodonty at advanced wear stages. Canariomys tamarani from Gran Canaria Island, the only other species of this genus known so far, is slightly smaller and further differs in its higher crowned molars with cusps arranged in a lamellar pattern. However, their crania are remarkedly similar and present a distinctive anatomy of the zygomatic plate, which is very high on the rostrum, so that its dorsal border is nearly on level with the zygomatic process of the maxilla instead of considerably below it as usually seen in murines. This is also observed in other insular, often large-sized, murines but certainly evolved in parallel as an adaptation to herbivory. Molar morphology is congruent with recent analyses of ancient molecular data of C. bravoi which place it in the tribe Arvicanthini (mostly African murines), more concretely within the Arvicanthis niloticus species complex. Even though genetic data indicate that both species diverged very recently, just 650,000 years ago, cranial and dental anatomy of C. bravoi are very derived. Conversely, C. tamarani presents a molar morphology reminiscent of that of A. niloticus albeit associated with a similarly highly derived cranial anatomy. [ABSTRACT FROM AUTHOR]

The White-faced Storm Petrel (WFSP) Pelagodroma marina has a widespread distribution, although virtually nothing is known about their feeding ecology and distributions at-sea. To describe their foraging areas, a total of 77 birds were equipped with 1 g-GPS loggers on Selvagem Grande, Madeira, Portugal (30° 09′ N, 15° 52′ W), during the 2018 and 2019 breeding seasons. We also assessed the diet of WFSP by analysing 17 faecal samples from chicks and 1 regurgitation from an adult using DNA metabarcoding techniques. Additionally, we collected body feathers from ten WFSP chicks to determine mercury concentration. WFSP fed mainly in deep oceanic waters, travelling up to 400 km from the colony, and did not concentrate in any well-defined, population-level foraging hotspots. Some individuals foraged along the edge of the shelf, near the African coast and the Canary Islands, especially during chick rearing. The duration of foraging trips and the total distance travelled, were, on average, 5.1 days and 723 km during the incubation period and 3.0 days and 578 km during chick rearing. The diet of WFSP was dominated by fish and cephalopods (crustacean prey were not detected), with Myctophidae (FO = 71%) representing the main fish family. WFSP often consume mesopelagic fish, in line with their preference for deep oceanic waters and with a small difference in at sea behavior (i.e., travel speed) between the diurnal and nocturnal period. The relatively high concentrations of mercury accumulated in body feathers of WFSP chicks (3.45 ± 1.44 mg kg−1 dry weight; range 1.68–6.01 mg kg−1) support the idea that WFSP raise their chicks mostly on mesopelagic prey from deep pelagic areas. [ABSTRACT FROM AUTHOR]

This paper shows a new multidisciplinary interpretation approach to the internal structure of Tenerife Island. The central core of this work is the determination of the three-dimensional attenuation structure of the region using P-waves and the coda normalization method. This study has been performed using 45,303 seismograms recorded at 85 seismic stations from an active experiment (air gun shots) conducted in January 2007. The interpretation of these new results is done combining the new images with previous studies performed in the area such as seismic velocity tomography, magnetic structure, magnetotelluric surveys or gravimetric models. Our new 3D images indicate the presence of seismic attenuation contrasts, with areas of high and low seismic attenuation patterns. High seismic attenuation zones are observed both in shallow and in deeper areas. The shallowest area of Las Cañadas caldera complex (1-3 km thick) is dominated by high attenuation behavior, and it is interpreted as the combined effect of sedimentary and volcanoclastic deposits, multifracture systems and the presence of shallow aquifers. At the same time, the deeper analyzed area, more than 8 km below sea level, is dominated by a high attenuation pattern, and it is interpreted as the consequence of the effect of high-temperature rocks in the crustal-mantle boundary. This interpretation is compatible and confirmed by previous models that indicate the presence of underplating magma in this region. On the contrary, some low attenuation bodies and structures have been identified at different depths. A deep low attenuation central body is interpreted as the original central structure associated with the early stage of Tenerife Island. At shallower depths, some low attenuation bodies are compatible with old intermediate magmatic chambers postulated by petrological studies. Finally, in the north of the island (La Orotava valley) we can interpret the low attenuation structure as the headwall of this valley, supporting the idea that Las Cañadas caldera and this valley resulted from two different destructive processes. [ABSTRACT FROM AUTHOR]

Populations of some zoantharian species (Cnidaria: Anthozoa) have been able to proliferate in locations where abiotic conditions hinder scleractinian corals' survival. One of the contributing factors might be the advantageous host-symbiont associations that could lead holobionts to be more resilient to environmental variation, even in marginal-environments. However, few studies have addressed these Zoantharia–Symbiodiniaceae associations, especially little is known about their nature and distribution in the Atlantic Ocean. In this study, we use the large ribosomal subunit (LSU-rDNA) and Internal Transcribed Spacer 2 (ITS2) to examine the biodiversity and distribution of Symbiodiniaceae species within zoantharians that inhabit along the latitudinal gradient Madeira (40ºN)—Cape Verde (16ºN). Moreover, we determine the number of different endosymbionts genera inhabiting the same specimen, in order to estimate their ability to face alterations in the environment. The results showed that Symbiodiniaceae diversity increases towards the tropics, with a total of six ITS2 types belonging to Symbiodinium and Cladocopium, the latter being the most frequent genus. Furthermore, we have found a possible undescribed species inhabiting P. aff. clavata collected at Madeira Island, the northernmost limit of brachycnemic zoantharian distributions in the East Atlantic. These results, combined with the literature reviewed, constitute the first mention of the genus Symbiodinium in a species host that is not Zoanthus spp and for the archipelago of the Canary Islands. An appendix summarizing Zoantharia–Symbiodiniaceae distributions around the Atlantic is included to facilitate future research on these holobiont associations. [ABSTRACT FROM AUTHOR]

Climate change is expected to enhance weather conditions prone to wildfires. Climate regionalized projections for the Canary Islands were performed, using as boundary conditions some of the results provided by the Coupled Model Intercomparison Project (CMIP5) initiative, and covering the recent past (1980–2009) and future (2070–2099) periods, under two Representative Concentration Pathways, 4.5 and 8.5. All fire risk indicators derived from the Canadian Forest Fire Weather Index (FWI) are foreseen to worsen by the end of the century. The fire season could increase its length up to 75 days per year, being more noticeable as altitude increases. The extreme risk days (FWI > 60) show an average increase of 58%, reaching 12 days a year, and the area with high risk could increase by 44%. Analyzing the contribution of the different meteorological variables, it is observed that the main parameter in the fire danger index result is the temperature (currently weights 46%). However, in the future, the importance of precipitation will increase, since the rainfall reduction in some areas could reach 41%. The high dependence of the expected changes on land height, and the small size of the islands, demonstrates the necessity of using high-resolution climate regionalizations. [ABSTRACT FROM AUTHOR]

In this study, we define a local magnitude scale for earthquakes occurring in the Canary Islands during the 2003–2020 period. We used data corresponding to 696 earthquakes (excluding those associated with the 2011–2015 El Hierro eruption), which consisted of 9267 observations in a hypocentral distance in the range of 10–500 km. Amplitudes were obtained by deconvolving the original recordings with the instrument response and then convolving the recording with the Wood-Anderson response. The amplitudes were inverted simultaneously to obtain the distance correction terms and station corrections. We found that the amplitude for this set of data is linearly attenuated. However, this is not the case for the seismicity recorded during the 2011 El Hierro eruption, which is the reason for excluding data for that case. We obtain a local magnitude of ML = log A + 0.967 log (R/40) + 0.00142 (R − 40) + 2.445 + S, where A is the maximum amplitude in millimeters of the S wave for the horizontal components of the simulated Wood-Anderson instrument (WA), R is the hypocentral distance in kilometers, and S is the station correction for each component at every station. This relationship indicates that seismic waves at this island volcano setting are less attenuated than those in crustal continental settings, such as across the Iberian Peninsula or in California. [ABSTRACT FROM AUTHOR]

Hourly data usually exhibit complex seasonal variations characterized by yearly, monthly, weekly or daily seasonal patterns. Each seasonal variation is modelled by using an evolving spline function in such a way that a seasonal effect at a proportion of the seasonal period is defined as a non-fixed parametric formulation of this proportion. Subsequently, the areas under the splines are proposed as a useful tool to measure the changes in the magnitude of seasonal variations over time, and to compare the relevance of seasonal variations with different seasonal periods. Furthermore, two indexes are suggested to compare seasonal variations with the same seasonal period in different time series: a dissimilarity index accounts for the area between the splines corresponding to the seasonal variation for each series, whereas a complementarity index accounts for this area when seasonal effects have opposite signs. The proposal is illustrated by applying it to hourly series of energy demand in Canary Islands. [ABSTRACT FROM AUTHOR]

Oceanic islands have long been considered engines of differentiation and speciation for terrestrial organisms. Here we investigated colonisation and radiation processes in the Madeira Archipelago and the Canary Islands of the Andrena wollastoni group of bees (subgenus Micrandrena), which comprises six endemic species and five endemic subspecies on the islands. Mitochondrial COI sequences support the monophyly of the four species of the Canary Islands and the two species of the Madeira Archipelago and suggest a relatively young age for all taxa. The data do not support a simple stepping-stone model (eastern-western colonisation from the mainland, with splitting into new taxa), but suggest Andrena gomerensis (extant on La Gomera and La Palma) or its ancestor as the basal lineage from which all other taxa evolved. Andrena lineolata (Tene-rife) or its putative ancestor (A. gomerensis) is sister to A. dourada (Porto Santo), A. catula (Gran Canaria), and A. acuta (also Tenerife). Andrena dourada (Porto Santo) and A. wollastoni (Madeira Island) are sister species. Morphologically and morphometrically defined subspecies were not distinguishable with COI DNA sequences. Colonisation likely led from the Canary Islands to the Madeira Archipelago and not from the mainland directly to the latter. [ABSTRACT FROM AUTHOR]

The biology, including accompanying ectoparasitic fauna, remains unstudied for several elasmobranchs off the Canary Islands in spite of concerns over their conservation. Within this region, this is the first report of copepod associations with these fishes. Twenty smooth hammerhead sharks, Sphyrna zygaena, and one common stingray, Dasyatis pastinaca, were inspected for symbionts on their body surface. Symbiotic siphonostomatoids were collected from 18 S. zygaena hosts and represent two different species, i.e., Alebion crassus (Caligidae) and Pandarus cranchii (Pandaridae). A high prevalence of 90% and a mean infection of 8.3 individuals per infected host were exhibited by A. crassus, while only a single P. cranchii was collected. Both these findings represent new geographical records. Additionally, one free-ranging common stingray Dasyatis pastinaca was opportunistically inspected and 11 Pseudocharopinus pillaii (Lernaeopodidae) collected which constitutes a new host record and a new geographical record. A re-description with detail regarding the morphology of the appendages is provided for the first time. Due to the morphological similarity between P. pillaii and P. malleus, a molecular analysis of the partial mitochondrial DNA cytochrome oxidase I gene was done in an attempt to determine if there is molecular divergence between the two species. This provided an estimate of the phylogenetic relationships amongst four Pseudocharopinus species (P. bicaudatus, P. pteromylaei, P. malleus, and P. pillaii) with Charopinus dubius as an outgroup as an alternative hypothesis to compare with the previous morphological topology estimated for all Pseudocharopinus species. [ABSTRACT FROM AUTHOR]

This work presents the results of a hydrogeochemical study conducted in two galleries on the island of Tenerife: Fuente del Valle and San Fernando, during a 2-year period with weekly sampling (July 2016 to July 2018). Groundwater temperature, pH, and electrical conductivity exhibited stable values throughout the study period, while significant temporal variations were observed in the total alkalinity, SO42−/Cl− ratio (in meq·L−1), and isotopic composition (δ18O and δD). δ13CTDIC values showed an endogenous signature for both galleries, while δ18O and δD values indicated a meteoric origin with interaction with endogenous gases, mainly CO2. Changes in isotopic ratios coincided with variations observed in alkalinity and SO42−/Cl− ratio. On October 2, 2016, a seismic swarm of long-period events was recorded on Tenerife followed by a general increase of the seismic activity in and around the island. A correlation was observed between some hydrogeochemical parameters in the groundwaters of the galleries related to observed changes of the seismic activity. [ABSTRACT FROM AUTHOR]

Characterizing genetic diversity and structure of populations is essential for the effective conservation of threatened species. Orchis patens sensu lato is a narrowly distributed tetraploid species with a disjunct distribution (i.e., Northern Italy, North Africa and the Canary Islands), which is facing a severe decline. In this study, we evaluated levels of genetic diversity and population structuring using 12 new nuclear microsatellite markers. Our analyses of genetic differentiation based on multiple approaches (Structure analysis, PCA analysis, and F-statistics using the ploidy-independent Rho-index) showed that gene flow is low across the range of O. patens s.l., particularly in the Canary Islands. Clear differences in allele frequencies between Italy, Algeria and the Canary Islands underlie the genetic differentiation retrieved. Our study provides support for the recognition of O. canariensis as a sister species to O. patens and the separation of the Italian populations as a new subspecies of O. patens. Despite the high heterozygosity values found in all populations (ranging from 0.4 to 0.7), compatible with the tetraploid status of the species, small population sizes and reduced gene flow will be likely detrimental for the different populations in the long term, and we recommend immediate conservation actions to counteract further fragmentation and population decline. [ABSTRACT FROM AUTHOR]

The Canarian date palm, Phoenix canariensis, is one of the most representative endemic plant species of the Canary Islands, although it is better known for its significant horticultural interest because it is one of the most appreciated ornamental trees of the subtropical and tropical worlds for its ability to grow on a wide range of site types. The naturally-occurring Canarian palm groves are the most important genetic reservoir of the species. This review aims to bring together the most important advances reached in the past three decades relative to the distribution, genetics and reproductive biology patterns of this species. Currently, P. canariensis palm groves are experiencing conservation problems such as the high pressure of human activities, and invasive pests, so it is appropriate to summarize all the current knowledge to make it available for incorporation into conservation strategies. [ABSTRACT FROM AUTHOR]

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Invasive alien species and climate change are two of the main current threats to conservation of biodiversity worldwide. Their effects have been extensively studied individually, but we know less about their combined effect. This study analyzes the population changes in the plant community of the high mountain legume shrub habitat of Tenerife over 10 years (between 2009 and 2018), using alien herbivore exclusion plots distributed over two sectors with different patterns of climate. Our outcomes show contrasting effects of herbivory and climate in plant communities, with significant shifts in community composition. The dominant species, Teide broom (Spartocytisus supranubius), is negatively affected by both climate and alien herbivores, leading to a regression of its abundance. In contrast, a formerly rare species, Pterocephalus lasiospermus, is benefiting from warmer temperatures and from herbivore presence owing to its low palatability. Simultaneously, some thermal native species from the neighboring pine forest are invading the alpine ecosystem. We conclude that the alpine habitat is changing very quickly and differently according to whether it is in warmer or colder sectors of the summit of Tenerife. This work reveals the need to simultaneously consider multiple drivers to understand the response of mountain ecosystems to global change. [ABSTRACT FROM AUTHOR]

Actinomycetes are a wide group of Gram positive prokaryotes, the soil being their most characteristic habitat, where they play important ecological functions. Their immense biotechnological potential as producers of bioactive molecules of great commercial and industrial interest is exemplified by most antibiotics for clinical use being derived from this group of bacteria. In this work several methodologies and culture media were tested for the isolation of actinomycetes in soils from three different edafoclimatic areas of Tenerife (Canary Islands, Spain): an arid zone of the southeast coast of the island, a humid area in the laurel forest and the Canary high mountain. The results of this work evidenced that just an air drying of the sample during 7 days (pretreatment) produces high counts of actinomycetes versus non-actinomycetes in the three soils and in any of the culture media studied, making unnecessary post physical and chemical treatments. However, the only method that produced an exclusive isolation of actinomycetes was the use of 0.22-μm filters as a physical barrier, and hence being a tool of unquestionable utility to estimate actinomycetes populations in soil. The analysis by BOX rep-PCR determined that the richness and genetic diversity of the isolates of these localities are very high. The greatest similarities were, with one exception, found between strains from the same locations. Izaña was one that obtained the highest diversity. Regarding the biotecnology potential as antibiotic produces isolates from Güimar soils are the most promising as 7 out of 10 isolates showed some antibiotic activity. [ABSTRACT FROM AUTHOR]

Terrestrial records of the last geomagnetic reversal often have few age constraints. Chronostratigraphy using suborbital-scale paleoceanic events during marine isotope stage 19 may contribute to solving this problem. We applied the method to an 8 m long, high-resolution paleomagnetic record from a loess sequence in China and revealed millennial-to-sub-centennial scale features of the Matuyama–Brunhes (MB) transition. All samples were subjected to progressive thermal demagnetization with 14–15 steps up to 650–680 °C. As a result, 96% of the samples yielded a high-quality remanent magnetization. The MB transition terminated with a 75 cm thick zone with nine polarity flips. The polarity flip zone, dated at about 779–777 ka, began between the warm events "I" and "J" and terminated at the end of the cooling event coincident with the lowest axial-dipole strength interval. Most polarity flips occurred within 70 years. The virtual geomagnetic poles (VGPs) in the upper polarity flip zone clustered in the SW Pacific region, where the MB transitional VGPs from lavas of the Hawaiian and Canary Islands and lacustrine deposits of Java also clustered. These sites were probably dominated by dipolar fields. The absence of transitional fields across polarity flips implies a short time span for averaging fields due to a thin loess-magnetization lock-in zone. The reverse-to-normal polarity reversal dated at about 778 ka in Lingtai occurred at the end of the SW Pacific VGP zone, an important key bed for MB transition stratigraphy. The reversal is a good candidate for the main MB boundary. We found an excursion at about 766 ka spanning about 1 ka. [ABSTRACT FROM AUTHOR]

Coastal geomorphological systems have undergone major changes in recent decades as a result of both natural and anthropic phenomena, with the growth of urban tourism having one of the biggest impacts. This has been the case of Las Palmas de Gran Canaria city (Canary Islands, Spain), which has expanded considerably since the late nineteenth century. The objective of this work is to identify the coastal landforms that existed in the city environment before 1879 and evaluate the extent to which they have been preserved or lost because of urban expansion on five dates (1879, 1954, 1966, 1981 and 2018). This evaluation was made possible through the integration, in a geographic information system, of information from historical and current documents, both cartographic and photographic, and from oral sources and field data. The results of the study reveal that 848.1 ha of the initial coastal landforms have been lost, with only 16.7% of the area they occupied remaining. The landforms that have experienced the most losses have been the aeolian sedimentary systems, which have totally disappeared since 1981. The least altered have been calcarenitic reefs, coastal active cliffs and sandy beaches. The land uses of the occupied coastal landforms, from highest to lowest, are: residential and tourist, road infrastructure, public spaces and green areas, port, facilities and industrial. The academic, social, educational and urban planning interests of this research are addressed in the discussion. Highlights • Identification of the coastal landforms that existed in LPGC city before 1879. • Evaluation of preserved vs. lost landforms areas because of urban expansion. • Loss of 848.1 ha (83.2%) of the initial coastal landforms. • Preservation of 170.2 ha (16.7%) of the original landforms. • Results of interest for academic, social, educational and urban planning. [ABSTRACT FROM AUTHOR]

The Walker and Syers model predict that phosphorus (P) availability decreases with time leading to a final stage known as retrogression. We tested the validity of the Walker and Syers model in the Canary Islands, a soil chronosequence ranging from 300 years to 11 million years under recurrent episodes of atmospheric dust-containing P inputs. In particular, we compared our results with those from the volcanic soil chronosequences described in the Hawaii Islands and in Arizona, as they share key biological and/or geological characteristics. In three islands of the Canarian Archipelago, we selected 18 independent sites dominated by mature Pinus canariensis forests and grouped them into six age classes. For each site, soil samples were analyzed for known proxies of soil nitrogen (N), P and cations availability. We also analyzed the P. canariensis needles for N, P and cation contents. We found tendencies similar to those observed in other soil chronosequences: maximum N and P concentrations at intermediate ages and lower P concentrations in the older soils. The nutrient dynamics suggested that the older sites may indeed be approaching the retrogression stage but at lower rates than in other similar chronosequences. Differences from other chronosequences are likely due to the drier Canarian climate, the higher P deposition rates originating from the nearby Sahara Desert and the top soil horizon studied. Our results confirm the validity of the Walker and Syers model for the Canary Islands despite the influence that the high P deposition rates and the seasonally dry climate may have on soil development and P pools in P. canariensis ecosystems. [ABSTRACT FROM AUTHOR]

Navaea phoenicea (Malvaceae) is a flagship shrub species endemic to Tenerife Island in the Canary archipelago and is included as Endangered on the Spanish Red List. We conducted a comprehensive census and monitored the structure of eight accessible populations over 10 years to develop a stage-based demographic matrix model and performed deterministic and stochastic projections. To determine the longevity of individuals, we conducted a dendrochronological study on ten collected dry samples. The censuses showed a clear, gradual decline, and the total population was around half that in previous studies. The yearly finite growth rate was strongly correlated with annual rainfall. Survival rates of seedlings were low, and high elasticity values were allocated to the larger, reproductive individuals, which showed the highest survival rates. The age of the oldest individual was 32 years, while the average age inferred from dendrochronology was 18 years. These results point to a lower longevity of individuals with respect to the values calculated by demographic models. The findings of this study suggest the importance of the preservation of reproductive individuals and their habitat, as well as the need to re-adopt legal measures of greater protection for the species. [ABSTRACT FROM AUTHOR]

The main goal of this study was to investigate the contribution of transcription skills to written composition in Spanish beginning writers. For this purpose, we tested models by pen and keyboard modes in which handwriting/typing and spelling were specified to correlate with each other against models in which these two skills were specified to load on a higher-order transcription factor. The study sample consisted of 1124 beginning writers of Spanish (i.e., grades 1–2) from 11 schools in the Canary Islands. We used structural equation modeling to test the contribution of transcription and its specific components to these Spanish pupils' written text production. This analysis revealed that in pen mode, handwriting fluency and spelling directly contributed to writing fluency in free composition at the sentence level, with handwriting fluency contributing less than spelling and spelling contributing both to narrative writing and writing fluency. As regards writing by keyboard, typing fluency and spelling, both taken together and separately, contributed to writing fluency. [ABSTRACT FROM AUTHOR]

In Tenerife there are a vast number of sub-horizontal blind water mines, called "galleries". Seven air and soil temperatures and CO2 concentration profiles in air were carried out inside the Río de Guía gallery (hereinafter RdG). An anomalous stable maximum temperature point (hereinafter MTP) was found around 2000 m from the entrance. During the warm period, a clear CO2 stagnation was detected before MTP, showing concentrations up to 14,000 ppm. In order to study gas emission and its dynamics inside the gallery, four stations were deployed around MTP. All stations recorded air and soil temperatures, and CO2 and Rn concentration in air from November 2009 to January 2011. After analyzing this dataset, it was possible to characterize the influence of MTP. This thermal anomaly divided the gallery into two sections. In the cold period, the outer section located outwards from MTP became colder while the inner section warmed up owing to a less heat transfer into the deepest part of the gallery. There were several short periods when variations in barometric pressure created an advection movement that was able to temporally change the gas behavior inside the gallery. Two soil gas samples were taken around MTP and their δ13C (CO2) ratios suggested a magmatic origin. All data were combined to create a model for the gas and thermal dynamics inside the gallery. This model, together with identification of background levels in each parameter, allows to identify any anomalous signal that could be elated with changes in volcanic activity. [ABSTRACT FROM AUTHOR]

In this study, we estimate the emissions in terms of category of hotel, with the data of a sample of 12 hotels of 5, 4 and 3 stars in the Canary Islands (Spain), located in the most arid eastern islands of the archipelago, Fuerteventura and Lanzarote, where there are a total of 122 hotels and this sampling represents 10% of the hotels of these islands where water for consumption comes from desalination plants using seawater reverse osmosis (SWRO), which was chosen. Water consumption was measured not considering consumption due to irrigation and swimming pools and comparing the generation of water by means of desalination plants of the hotels or external plant centralized with public distribution. Considering the energy and water consumption of the hotels in the study, their carbon footprints, scope 1 and 2 and obtaining average values of emissions between 14.23 kg CO2/person night (CO2/p) for hotels with own SWRO and 15.16 CO2/p for hotels with external water distribution. These data were compared to hotels with the same characteristics and consumptions in mainland Spain, proving that average emissions from the islands for the energy are 1.27 higher and for water production are 3.89 higher for own SWRO and 7.87 superior for distribution by centralized external SWRO. The Canary Islands, as a sensitive and vulnerable tourist destination, with their external energy dependence, their great ecological value, and their need for water desalination, make for a good laboratory to test the application of measures and improvements in the systems of industrial water generation, and in the conservation of energy in buildings, to try to turn these establishments into nearly zero energy buildings (nZEB). [ABSTRACT FROM AUTHOR]

Digital videos of parliamentary activity play an important role in enhancing transparency and accountability for open e-government. The rapid growth in these videos and the lack of semantic annotations and relationships between video and knowledge resources make it increasingly difficult to find accurate video clips with contextual information for content understanding. To overcome this problem, we highlight the need for building multimedia systems based on a semantic vision. With this aim, we focus on (1) how to address the knowledge representation for automatic extraction of contextual information for video content understanding; (2) how to link the parliamentary knowledge structures within video resources to provide accurate video clips retrieval; and (3) how to perform semantic annotation on video resources. The methodology applied is focused on a systematic approach that uses techniques from ontology engineering. This approach is based on the definition of two models: the semantic model and the reference architecture. The semantic model is composed of a reference ontology and a semantic video annotation framework. The ontology provides the support for video content understanding and the semantic vocabulary for annotating video resources. The video annotation framework is based on an RDF-powered semantic video annotation to effectively relate low- and mid-level visual features, corresponding to speakers' interventions, to high-level parliamentary concepts. To evaluate the proposed system, a prototype for the Canary Islands Parliament (Spain) has been carried out. The results show how semantic enhancement is a key enabler for improved video retrieval on parliamentary multimedia content. [ABSTRACT FROM AUTHOR]

Asteraceae have the most endemic species of any flowering plant family in oceanic archipelagos, and these insular endemics display a higher frequency of self-compatibility (SC) compared to mainland composites. However, little attention has focused on the evolution of selfing in situ in islands. The genus Tolpis (Asteraceae) in the Macaronesian archipelagos consists predominantly of self-incompatible (SI) or pseudo-self-compatible plants, with one documented occurrence of the origin of self-compatibility (SC) in the Canary Islands. This study reports SC in two small populations of T. succulenta on Graciosa Island in the Azores. Progeny from the two populations exhibit high self-seed set. Segregation in F2 hybrids between SC and SI T. succulenta indicates that one major factor is associated with breeding system, with SC recessive to SI. Molecular phylogenetic analyses show that SC T. succulenta is sister to SI T. succulenta in the Azores, suggesting that SC originated from SI T. succulenta in the Azores. Plants on Graciosa are morphologically distinct from SI populations of T. succulenta on other islands in the Azorean archipelago, with smaller capitula and lower pollen-ovule ratios, both indicative of the selfing syndrome. The factors that may have favored selfing in these populations are discussed, as are the conservation implications of SC. Finally, the issue of whether the two SC populations are cryptic species worthy of taxonomic recognition is discussed. [ABSTRACT FROM AUTHOR]

Volcanic island inception applies large stresses as the ocean crust domes in response to magma ascension and is loaded by eruption of lavas. There is currently limited information on when volcanic islands are initiated on the seafloor, and no information regarding the seafloor instabilities island inception may cause. The deep sea Madeira Abyssal Plain contains a 43 million year history of turbidites among which many originate from mass movements in the Canary Islands. Here, we investigate the composition and timing of a distinctive group of turbidites that we suggest represent a new unique record of large-volume submarine landslides triggered during the inception, submarine shield growth, and final subaerial emergence of the Canary Islands. These slides are predominantly multi-stage and yet represent among the largest mass movements on the Earth's surface up to three or more-times larger than subaerial Canary Islands flank collapses. Thus whilst these deposits provide invaluable information on ocean island geodynamics they also represent a significant, and as yet unaccounted, marine geohazard. [ABSTRACT FROM AUTHOR]

Snakes introduced to islands can be devastating to naïve native fauna. However, introduced populations must establish before range expansion (invasion) can occur. The factors that can determine successful invasion are those associated with the introduction event (e.g., characteristics of the founding population), the location (e.g., suitable environment and prey availability) and the species (e.g. life history characteristics). Here, we collected morphometric, ecological and genetic data on the recently introduced California Kingsnake ( Lampropeltis californiae) in Gran Canaria. We found that snakes occurring at two locations a few 10 s of km apart do not represent the same population. Genetic analyses confirmed significant genetic difference ( F = 0.184; D = 0.341), and that despite being inbred ( F = 0.245-0.257) the populations had high levels of diversity ( H = 0.485-0.490; allelic richness = 4.875-6.364). Snakes at the different Gran Canaria locations were significantly different in morphology (colouration, mass, length and age), fitness (egg production) and diet (rodents, skinks, lizards and geckos), supporting a hypothesis of separate founding groups in combination with local environmental heterogeneity leading to variation between these populations. We concluded that one population was more successful than the other in reproduction and recruitment, and may be having a greater impact on endemic reptiles. We recommend greater eradication effort for this population, as well as monitoring of local fauna at all locations to access the impact of predation. [ABSTRACT FROM AUTHOR]

Genetic data could be considered irrelevant to the conservation of species in imminent danger, and that habitat protection and ex situ conservation strategies should be carried out regardless of the existence of estimates of genetic diversity. However, genetic data are needed to determine the current state of diversity of the species, the genetic structure and the genetic differentiation between populations and therefore to establish the most suitable management strategy. We compared genetic diversity and differentiation estimated from allozymes and random amplified polymorphic DNA (RAPD) in the three known natural populations of the critically endangered endemism from the Island of Tenerife (Canary Islands) Helianthemum juliae Wildpret. There were discrepancies in levels and structuring of genetic diversity measured with both molecular markers due to genome sampling. So, whereas allozymes allele frequency revealed a low genetic differentiation between natural populations ( F = 0.034), the presence/absence of RAPD data matrix showed a considerable level of genetic differentiation ( F = 0.397) between these populations. Genetic data identify 20 unique genotypes distributed within H. juliae populations, which supposes an important finding for conservation management of this endangered species. Considering that the three populations showed unique genotypes, management strategies should be focused on strengthening these genotypes in the whole of the species. So, although considerable genetic differentiation has been detected between the natural populations, bearing in mind the high extinction probabilities described for the species, genetic data would support the establishing of new localities with individuals from different natural populations in a conservation genetics strategy. [ABSTRACT FROM AUTHOR]

The volcanic unit of Montaña Reventada on the island of Tenerife (Canary Islands, Spain) is an example of magma mingling and mixing in which the eruptive process was triggered by an intrusion of basanite into a phonolite magma chamber. The eruption started with emplacement of a basanitic scoria deposit followed by emplacement of a phonolitic lava flow characterized by the presence of mafic enclaves. These enclaves represent approximately 1 % of the outcrop and are basanitic, phono-tephritic and tephri-phonolitic in composition. The morphology of each enclave is different, varying from rounded to complex finger-like structures usually with cuspate terminations. In this study we quantified textural heterogeneity related to the enclaves generated by the mixing process and thus provided a new perspective on the 1100 Ad Montaña Reventada eruption. The textural study was performed by use of fractal geometry methods and the results show that the logarithm of the viscosity ratio between the phonolitic magma and the enclaves ranges between 0.39 and 0.81, with a mode at 0.49. This enables us to infer the water content is 2-2.5 wt% for the phonolitic magma and 1.5-2 wt% for the basanitic magma and the enclaves. [ABSTRACT FROM AUTHOR]

Oceans are becoming warmer due to climate change processes. Marine invertebrates live within a limited range of body temperatures, and functional constraints result at temperature extremes. Furthermore, interactions between temperature and other environmental stressors have the potential to narrow the thermal windows of species. This study assessed the interactive effects of current and predicted conditions of temperature and food availability on the survival, growth, and development of the sea urchin Paracentrotus lividus. Samples were collected from the Canary Islands (28°24′N, 16°18′W) in March 2011. Nine two-factor treatments of temperature (19, 20.5 and 22.5 °C) and food level (2000, 1000 and 500 cells mL) were tested in laboratory experiments. The temperature and food-level treatments were chosen based on current oceanographic data for seawater off the studied region and from values predicted for the next century in the subtropical eastern Atlantic region. Our results indicated that P. lividus larvae survival could be affected by increasing seawater temperatures, in ranges expected to occur over the next century. The negative effects of decreasing food availability on the development of P. lividus larvae will be significantly modulated, however, by increasing seawater temperature. These results show that surviving sea urchin larvae are capable of shifting their energy budget to successfully grow and develop under the stressful conditions presented by the combined effects of environmental factors. [ABSTRACT FROM AUTHOR]

In the Canary Islands, a number of old Andean potato introductions have been maintained by farmers and are cultivated there since the sixteenth century. Genetic resistance is an inexpensive way to control the main pests and diseases of potato and avoids the use of phytochemicals or other costly protective measures. In this study, we have analysed eight Solanum tuberosum subsp. andigena and S. tuberosum subsp. tuberosum accessions, representing old potato varieties from Tenerife Island, for their resistance levels to Phytophthora infestans, Globodera rostochiensis, Globodera pallida and Pectobacterium atrosepticum. New resistance sources against P. infestans in leaves and P. atrosepticum were found, as well as partial resistance to both nematode species. The results suggest the potential exploitation of the cultivar Venezolana Negra in breeding programmes in order to improve pest and disease resistance of potato. [ABSTRACT FROM AUTHOR]