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[Background] The global human footprint has fundamentally altered wildfire regimes, creating serious consequences for human health, biodiversity, and climate. However, it remains difficult to project how long-term interactions among land use, management, and climate change will affect fire behavior, representing a key knowledge gap for sustainable management. We used expert assessment to combine opinions about past and future fire regimes from 99 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300., [Results] Respondents indicated some direct human influence on wildfire since at least ~ 12,000 years BP, though natural climate variability remained the dominant driver of fire regime change until around 5,000 years BP, for most study regions. Responses suggested a ten-fold increase in the frequency of fire regime change during the last 250 years compared with the rest of the Holocene, corresponding first with the intensification and extensification of land use and later with anthropogenic climate change. Looking to the future, fire regimes were predicted to intensify, with increases in frequency, severity, and size in all biomes except grassland ecosystems. Fire regimes showed different climate sensitivities across biomes, but the likelihood of fire regime change increased with higher warming scenarios for all biomes. Biodiversity, carbon storage, and other ecosystem services were predicted to decrease for most biomes under higher emission scenarios. We present recommendations for adaptation and mitigation under emerging fire regimes, while recognizing that management options are constrained under higher emission scenarios., [Conclusion] The influence of humans on wildfire regimes has increased over the last two centuries. The perspective gained from past fires should be considered in land and fire management strategies, but novel fire behavior is likely given the unprecedented human disruption of plant communities, climate, and other factors. Future fire regimes are likely to degrade key ecosystem services, unless climate change is aggressively mitigated. Expert assessment complements empirical data and modeling, providing a broader perspective of fire science to inform decision making and future research priorities.

Recent geomorphological, paleoenvironmental, and chronological evidence allows for a reconstruction of the coasts of southwest Iberia during the first millennium BCE that accords with descriptions of the region offered by authors of antiquity, most notably the description by the fourth-century CE Roman writer R. F. Avienus in his poem Ora Maritima. This poem contains information that appears to date from the sixth century BCE regarding, for instance, the pre-Roman polity of Tartessos. The reliability of this work as a historical source has been questioned for decades. Critics argue that the information is pertinent to our understanding of the literary, rather than historiographical, context of the Late Roman Empire. However, philological as well as historical analyses reveal no clear cause to doubt the documentary value of the Ora Maritima. Furthermore, geomorphological research makes it possible to identify most place-names in the poem; for example, the city embraced by the river Tartessos, apparently the political and trade center of the realm, may likely have stood on the present-day spit of La Algaida, which was an isle in the first millennium BCE. While this hypothesis has been advanced elsewhere, this article offers an entirely new set of evidences to support it.

The global human footprint has fundamentally altered wildfire regimes, creating serious consequences for human health, biodiversity, and climate. However, it remains difficult to project how long-term interactions among land use, management, and climate change will affect fire behavior, representing a key knowledge gap for sustainable management. We used expert assessment to combine opinions about past and future fire regimes from 99 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300.

The area of Prados del Cervunal (PC) is an intra-morainic topographic depression located at 1800 m asl in the divide or interfluve between Garganta de Gredos and Garganta del Pinar valleys (Central Gredos; Iberian Central System, ICS). Both valleys, along with the adjacent Hoya Nevada, were occupied by glaciers during the Upper Pleistocene, leading to the development of the Prados del Cervunal moraine complexes studied in this work. Using cartographic methods and morphostratigraphic analysis, the three main glacial formations established in the Regional Chrono-Evolutionary Pattern for the ICS, Peripheral Deposits (PD), Principal Moraine (PM) and Internal Deposits (ID), have been identified and mapped in this area. The chronology of these formations has been implemented by Cosmic Ray Exposure (CRE) techniques using 10Be (new data) and 26Cl (previous data, recalculated in this work) in samples from morainic boulders. With these data, the following chrono-evolutionary sequence has been established: (stage 1) local-Maximum Ice Extent (MIE), dated in 25.0 ± 1.4 ka and corresponding to the maximum age obtained in these paleoglaciers; (stage 2) period of oscillations around the MIE, corresponding to the development of the PD Formation between ∼25 ka and ∼21 ka; (stage 3) period of readvance and stabilisation, dated after ∼21 ka (average age obtained for the PD moraines attached to PM moraines) and previous to ∼18 (minimum age obtained for a main crest of the PM formation); and (stage 4) onset of deglaciation dated around to ∼18 ka (average of ages obtained for the first main crest of the ID formation). During the stages of maximum ice expansion, these three glaciers formed an Ice field whose tongues were interconnected on the PC flat by an ice transfluence system (stages 1 and 2, Plateau Glacier Period). In later stages, the ice masses were partitioned, giving rise to valley glaciers and large moraines forming morainic complexes like those of PC (stages 2, 3 and 4, Valley

Understanding ecosystem resilience requires long data series provided by palaeoecological studies, the best tool for reconstructing vegetation dynamics. Here, we analyzed a continuous and well-dated record of pollen, non-pollen palynomorphs, macrocharcoal remains, loss-on-ignition and magnetic susceptibility from one of the most singular peatlands in the Toledo Mountains (central Spain), in order to delineate the anthropogenic and/or climate impact on the peatland and the ecosystem’s response. La Ventilla mire is an isolated site of birch woodland dominated by Betula pubescens subsp. celtiberica (Rothm. & Vasc.) Rivas Mart. This mire, acting as a refugium for this species, is located in Cabañeros National Park and is recognized as ‘Special Area of Conservation’ according to Habitats Directive of the Natura 2000 network. We describe major patterns and trends in the development of this palaeorefugium since the mid-Holocene (∼ 6145 cal BP) and provide historical context for some natural and/or human-induced dynamics. Around 1500 cal BP, the lotic depositional environment with slow moving backwaters developed into a minerotrophic mire. Until the Middle Ages, macroclimate and autogenic succession appear to have been the main drivers of both local and regional development of vegetation. Between 1500 and 500 cal BP, an abrupt decline in birch cover started, coincident with the Visigothic period. The pronounced peaks in the coprophilous fungi record ca. 1000 and 150 cal BP reflect extensive pastoral activities in the area. This study shows how palaeoecological knowledge helps to explain present patterns in the composition of a valuable protected site, which may be used in prioritizing conservation.

In order to provide a better framework for the interpretation of fossil pollen records, a set of 49 modern pollen samples collected across different habitats of SW Iberia, categorised by context and sample type (soil vs moss), were selected to explore pollen–vegetation relationships by multivariate analysis and identify possible biases in pollen representativeness. The distribution of both samples and pollen taxa in the plots is successfully explained according to specific environmental variables in some clusters (A, B and E) in which plant communities depend on certain environmental conditions. On the other hand, other clusters (C, D and F) are better explained by opposition to some variables and suggest a wider range of adaptability of their floristic communities. The classification of samples by context consistently explains their differences in vegetal and environmental terms. However, some discrepancies seem to be better explained by sample type (soil vs moss), which raises some questions on how taphonomic factors may cause biases in both modern and fossil pollen samples.

The study was conducted in the southern part of the lower Strymon valley, in northern Greece, and revealed up to 25 m of fluvio-lacustrine sediments deposited over the last seven millennia. This sedimentary record represents a significant opportunity for high-resolution palaeoenvironmental studies of the period from 6 to 3 ka cal BP linked to land use and climate change. The results of geophysical investigations, multi-proxy sedimentological (grain size, magnetic susceptibility, loss-on-ignition), pollen and NPP analyses, based on high-precision radiocarbon dating enabled reconstruction of past landscapes as well as a comprehensive discussion of anthropogenic responses and their impact on the vegetation cover, especially during periods with well-known Holocene Rapid Climate Change events (5.6, 4.2 and 3.2 ka cal BP)., During the 7–5.7 ka cal BP corresponding to the Late and Final Neolithic, wet conditions created an extended lake surrounded by the densely wooded Strymon watershed, followed by a shift to a shallower lake environment that lasted until ca. 4.5 ka cal BP. The continuous presence of anthropogenic taxa suggests the persistence of human activities even in the absence of formally recognized sites, suggesting the relocation of settlements. The first signs of human disturbance of the landscape at regional scale occurred toward 5.2 ka cal BP (onset of the Early Bronze Age). The so-called « 4.2 ka BP event », which coincided with the end of the Early Bronze Age and the transition to the Middle Bronze Age, is divided into three distinct periods (4.35–4.1, 4.1–3.95 and 3.95–3.75 ka cal BP). The first corresponds to gradual aridification before a period with severe dry conditions that marks a tipping point toward wetland contraction. From this period on, diversification, and multiplication of anthropogenic species including Olea, Juglans and Castanea reflect a global trend toward cultural landscapes. The later periods are characterized by dramatic climatic change around 3.2–3 ka cal BP, at the end of Late Bronze Age, and increasing impacts of agro-pastoral activities and forest clearing starting at the beginning of Antiquity, around 2.8 ka cal BP (Thracian period). After the 4.2 ka cal BP event and we suggest that climatic adversity may have acted as a stimulus to innovation and relocation rather than retarding societal development in the region. To conclude, environmental factors in the lower Strymon valley were not sufficient on their own to trigger a social crisis similar to that mentioned in the Middle East.

High-mountain peatlands are essential ecosystems for habitats, biodiversity, water, and carbon cycling, but there is little comprehensive information in central Iberia. We present results of research concerning the distribution, geormorphology, floristic,geobotany, and habitat diversity of peatlands in the Gredos Regional Park (Iberian Central System). We identified 72 peatlands covering 117 ha and ranging in size from 0.01 to 17.34 ha. Peatlands occur primarily in the upper orosubmediterranean bioclimatic belt at 1775–2230 m asl. From a geomorphological point of view, 9 different peatland typologies have been defined. Multivariate analyses (agglomerative cluster analysis and principal component analysis) of 103 relevés allowed us to classify the sampled peatland stands into 7 plant communities and 4 European habitats that formed along complex hydrogeomorphic conditions, and to propose a new subassociation of other community previously described (Caricetum echinato-nigrae lycopodielletosum inundatae). The main threat to Gredensean peatlands is pastoral pressure, which affects 15 of them intensively, mainly between the upper supramediterranean and the lower orosubmediterranean bioclimatic belts (~1314–1700 m asl). Seven bryophytes and three vascular plants documented in the Gredos Regional Park peatlands are included in the IUCN Red List. From the point of view of conservation priority, the most threatened correspond to transition mires communities (Habitat 7140) growing in oligotrophic and minerotrophic peatlands (Caricion nigrae vegetation). Particularly, the Iberian Central System endemic Sedo lagascae-Eriophoretum latifolii association is the one that has achieved the highest score in the five criteria considered in this regard because Meesia triquetra, a species with the category of “critically endangered”, inhabits it

The La Janda wetland record allows to expand the knowledge of the evolution of a restricted estuary since the Last Glacial Maximum. Multiproxy analysis of the sediments (facies, geochemistry, pollen, fossils) reveals that this system exhibits a classic incised valley sequence but differences with the adjacent estuaries can be established. The La Janda sedimentary infill can be split in four main sequences: (1) the Falling Stage Systems Tract (>20.6 ka BP) and (2) the Lowstand Systems Tract (16.7–20.6 ka BP) deposits record fluvial sedimentation in a narrow and incised valley, here seminally identified in the Gulf of Cádiz estuarine system; and (3) the Transgressive Systems Tract (7–16.7 ka BP), ending with the Holocene marine flooding surface at 7 ka BP, is composed of estuarine and marine basin deposits infilling a still steep and narrow topography coupled with the fast retreat of the river mouths. The (4) Highstand Systems Tract (0–7 ka BP) is composed of estuarine basin deposits with fluvial and tidal currents deposits in a wide a gentle sloped estuarine valley and it records the transformation of the basin into a terrestrial one. Comparison to other areas in the Gulf of Cádiz allows to correlate the different estuaries and to distinguish between open and restricted ones by the development of spit systems during the Highstand Systems Tract. But further work is needed to clarify the stratigraphy of the present eustatic cycle in the Gulf of Cádiz as the scarcity of data does not allow to determine the evolution of its estuaries during the last fall and rise of sea level. Such knowledge is crucial to disentangle the role of climate and tectonics in the future evolution of our coasts and design measures to adapt to sea level rise.

A multiproxy study (pollen, non-pollen palynomorphs, sedimentology, and geochemistry) was carried out in two cores drilled in La Janda basin (SW Iberia) to trace the environmental evolution and human impact on the landscape. An incised fluvial valley existed in the basin during the Late Pleistocene, followed by a transitional environment characterized by the development of saltmarsh vegetation affected by the increased marine influence ca. 10/8.7 ka cal BP. During this period comprising the Upper Palaeolithic and Mesolithic (>∼7.8 ka cal BP), the impact of hunter-gatherer groups on the landscape was rather low according to palynological and geochemical records. A restricted estuary connected to the sea was identified in La Janda between ca. 10/8.7-3.5/3.3 ka cal BP, coinciding with a predominance of saltmarsh vegetation developing on saline shore soils and the punctual presence of foraminifera and dynoflagellate cysts. The anthropogenic pressure was progressively increasing during the Neolithic, especially from ca. 7 ka cal BP, with markers suggesting herding/livestock activities prior to the punctual presence of cereals, which is only confirmed by the archaeological record ca. 6 ka cal BP. Human pressure become more noticeable throughout the Chalcolithic and Bronze Age (∼5-3 ka cal BP), period during which a new transitional phase is recorded in La Janda (ca. 3.5/3.3-1.3 ka cal BP), culminating in the terrestrialization of the area. The predominance of freshwater taxa and decrease of saltmarsh vegetation is observed during this period, and the transformation of the landscape for agricultural activities over the last centuries is reflected in the local presence of cereals and markers of erosive processes.

The European flat oyster (Ostrea edulis) is a native species that was consumed as a luxurious product by the Romans. In the Strait of Gibraltar area, between southwest Iberia and North Africa, numerous oyster shells have been found in Roman archaeological sites located in both, the Atlantic Ocean and the Mediterranean Sea. The origin of these oysters is unknown, as so if they were farmed or harvested in the wild and/or even imported for consumption. This study presents the results of pollen analysis of oyster shells from six archaeological sites in the Strait of Gibraltar area dated between the 1st and 6th centuries AD. This is the first time that such research is undertaken in the Iberian Peninsula and North Africa; the second worldwide for a discipline rarely known until now: conchopalynology. Our study suggests that differences observed in pollen spectra could be used to identify the origin of the consumed specimens, i.e. where they were grown or harvested, discriminating whether oyster shells originated from the Mediterranean Sea or the Atlantic Ocean coastline

[En] In this paper we present our analysis of the agrarian uses of a landscape located in the Baetic systems within the southeastern quadrant of the Iberian Peninsula. We have addressed the identification of agricultural practices from a comprehensive multidisciplinary strategy. Multi-proxy analyzes have had positive results in two areas of the Jutia valley (Nerpio-Yeste, Albacete), by obtaining stratigraphic, geochronological, pollen, chemical and carpological evidence of its cultivation in a wide diachrony that spans the 1st millennium BC. These results allow us to identify crops and consider the possibility of agricultural infrastructures, thus providing novel data to the study of agricultural landscapes in the long term. This data about agricultural practices in mountain landscapes allows us to question certain recurrent apriorisms and provide arguments about the possible existence of a mixed and diversified model of exploitation in a landscape integrated into the regional dynamics of the western Mediterranean., [ES] En este trabajo presentamos nuestro análisis de los usos agrarios de un paisaje ubicado en las estribaciones de los sistemas béticos dentro del cuadrante suroriental de la península Ibérica. Hemos abordado la identificación de las prácticas agrarias a partir de una estrategia integral de carácter multidisciplinar. Los análisis multi-proxy han tenido resultados positivos en dos zonas del valle de Jutia (Nerpio-Yeste, Albacete), al lograr evidencias estratigráficas, geocronológicas, polínicas, químicas y carpológicas de su cultivo en una amplia diacronía que abarca el I milenio ane. Estos resultados nos permiten identificar cultivos y plantear la posibilidad de infraestructuras agrarias, aportando así datos novedosos al estudio de los paisajes agrarios a largo plazo. Este mayor conocimiento de las prácticas agrarias en paisajes de montaña nos permite cuestionar ciertos apriorismos recurrentes y aportar argumentos sobre la posible existencia de un modelo de explotación mixto y diversificado en un paisaje integrado en las dinámicas regionales del occidente mediterráneo.

Se describen las comunidades edafoxerófilas dominadas por Juniperus oxycedrus subsp. badia en la Sierra de Gredos, tanto en cuanto a su composición florística como biogeografía.

[EN] The palynological study of four samples from the archaeological site of Camino de las Yeseras contributes to the characterization of the landscape in the Henares corridor in the second half of the 3rd millennium cal BC. The main results indicate the existence of open Holm oak woodlands, together with riparian vegetation and clear evidence of anthropization derived from the agro-pastoral activities developed by the Chalcolithic communities., [ES] El estudio palinológico de cuatro muestras procedentes del yacimiento arqueológico de Camino de las Yeseras contribuye a la caracterización del paisaje en el corredor del Henares en la segunda mitad del III milenio cal BC. Los principales resultados indican la existencia de formaciones abiertas de encinas, junto con vegetación riparia y claras evidencias de antropización derivadas de las actividades agropastoriles desarrolladas por las comunidades calcolíticas.

En el presente trabajo se lleva a cabo una recopilación de la historia de la vegetación de la sierra de Gredos (Sistema Central), entre el Neolítico y la Edad Media, a partir de registros polínicos procedentes de yacimientos arqueológicos y turberas. Los principales factores que intervienen en dicha historia son la diacronía del impacto humano, la variabilidad climática y, particularmente, los cambios climáticos abruptos, la recurrencia de los incendios y las rutas trasterminantes y trashumantes del pastoreo

The settlement of cold and arid environments by Pleistocene hunter-gatherers has been a heated topic in Paleolithic Archaeology and the Quaternary Sciences for years. In the Iberian Peninsula, a key area for studying human adaptations to such environments is composed by the large interior and upland regions of the northern and southern plateaus (Mesetas) and bordering areas. As, traditionally, these regions have been relatively under-investigated compared to the ecologically more favored coastal areas of the peninsula, our knowledge of the human settlement of the whole Iberian hinterland remains scarce for the Last Glacial. In this paper we present the discovery and first geoarcheological, paleoenvironmental and chronometric evidence obtained at Charco Verde II, a new site close to the southwestern foothills of the Iberian system range (Guadalajara province, Spain), bearing a sequence of Magdalenian human occupations starting at least at 20.8–21.4 ka cal BP during the Last Glacial Maximum, and covering Greenland Stadial 2 until ∼15.1–16.6 ka cal BP, including Heinrich stadial 1. As this site is located in an upland region which today faces one of the harshest climates in Iberia, such occupation sequence, occurred during some of the coldest and most arid phases of the Last Glacial, has relevant implications for our understanding of human-environment-climate interactions and population dynamics in Iberia and Western Europe. These findings support the hypothesis that the Iberian hinterland was not avoided by Upper Paleolithic hunter-gatherers due to ecological constraints, but it hosted a complex and relatively dense settlement at least in some areas, even during cold periods. This suggest, one more time, that the historical scarcity of Upper Paleolithic sites in inland Iberia is, to a significant extent, an artifact of research bias.

[ES] El estudio fitosociológico de tres comunidades arbustivas y una arbórea en el valle del Tiétar (sur de la sierra de Gredos), en las provincias de Ávila y Madrid, nos permite proponer dos nuevos sintaxones, la subasociación Pyro bourgaeanae-Quercetum rotundifoliae celtidetosum australis, y la asociación Arbuto unedonis-Myrtetum communis perteneciente a la alianza Ericion arboreae, cuya distribución se circunscribe, en ambos casos, al piso mesomediterráneo inferior del distrito biogeográfico Verato del sector Cordillerano Oretano-Tagano de la subprovincia Lusa-Extremadurense de la provincia Mediterránea Ibérica Occidental. Además, se aportan datos sobre dos asociaciones hasta ahora no citadas en dicha comarca: Santolino rosmarinifoliae-Cistetum laurifolii y Lavandulo sampaioanae-Cistetum albidi, pertenecientes a las alianzas Cistion laurifolii y Ulici argentei-Cistion ladaniferi, respectivamente., [EN] The phytosociological study of three shrubland and one tree communities in the Tiétar valley (south of the Gredos Mountain Range), in the provinces of Avila and Madrid, allows us to propose two new syntaxa, the subassociationPyro bourgaeanae-Quercetum rotundifoliae celtidetosum australis, and the associationArbuto unedonis-Myrtetum communis belonging to the allianceEricion arboreae, whose distribution is limited, in both cases, to the lower mesomediterranean bioclimatic belt of the Vera biogeographical district of the Oretana Range and Tajo sector of the Lusitania and Extremadura subprovince of the West Iberian Mediterranean province. In addition, data are provided on two previously unpublished associations in this region: Santolino rosmarinifoliae-Cistetum laurifolii andLavandulo sampaioanae-Cistetum albidi, belonging to the alliancesCistion laurifolii and Ulici argentei-Cistion ladaniferi, respectively