The past distribution of pinus nigra arnold in northern iberia. Contribution from its macroremains.

The presence of Pinus nigra in central Spain, where its natural populations are very rare, has led to different interpretations of the current vegetation dynamics. Complementary to the available palynological evidence, macroremains provide local information of high taxonomic resolution that helps to reconstruct the palaeobiogeography of a given species. Here we present new macrofossil data from Tubilla del Lago, a small palaeolake located at the eastern part of the northern Iberian Meseta. We identified 17 wood samples and 71 cones on the basis of their wood anatomy and morphology, respectively. S ome of the fossil samples were radiocarbon dated (~4.230-3210 years cal BP). The results demonstrate the Holocene presence of P. nigra in the study area, where it is currently extinct. This evidence, together with other published palaeobotanical studies, indicates that the forests dominated by P. nigra must have had a larger importance on the landscape prior to the anthropogenic influence on the northern Iberian Meseta.

Onomástica, ecología y territorio. La toponimia de La Rioja como indicador biogeográfico y de la dinámica del paisaje forestal

Se presenta un trabajo de investigación toponímica en La Rioja con enfoque geobotánico. La premisa de partida es que la toponimia relacionada con especies y agrupaciones vegetales, productos forestales y usos del suelo proporciona información valiosa sobre la corología y la dinámica de la vegetación al ser clasificada y analizada con criterios biogeográficos y ecológicos. Se ha elegido la región riojana como zona piloto, al concurrir distintos tipos fisonómicos de vegetación y un conjunto muy diverso de comunidades vegetales representativas del paisaje peninsular. Se añade una larga historia de usos agrícolas en la llanura del Ebro que contrasta con la predominante actividad forestal en las zonas montañosas, en particular la potenciación de los pastos para ganadería trashumante. La Rioja tiene carácter de encrucijada no sólo fitocorológica: es también tierra de fronteras políticas y transiciones lingüísticas. En el léxico y la toponimia conviven variantes puras del castellano, rasgos del romance navarro-aragonés, elementos genuinos de una variante medieval riojana, palabras mozárabes y un numeroso y significativo elenco de topónimos de origen vasco. El trabajo se inicia con unas consideraciones epistemológicas. Se establece un planteamiento de la Toponimia como ciencia interdisciplinar, la etiología de los nombres geográficos, así como su valor apelativo descriptor de los atributos del paisaje. Se enumeran los condicionantes metodológicos de la investigación toponímica y se desarrolla una reflexión sobre las particularidades de la toponimia geobotánica. Se dedica un epígrafe a reseñar estudios precedentes de toponimia botánica y ecológica y el estado actual de conocimientos sobre la toponimia de La Rioja. La delimitación superficial de los parajes designados por los nombres geográficos es clave para un análisis orientado a detectar la correspondencia entre los elementos aludidos por el topónimo y las especies y comunidades vegetales. Las áreas de distribución y presencia, así como las transformaciones del paisaje, quedan definidas en superficies acotadas territorialmente. La metodología seguida se basa en la revisión exhaustiva de fuentes toponímicas ya existentes; destacadamente, los datos procedentes de la cartografía del Castro de Rústica, adscritos a polígonos con dimensión espacial. Las denominaciones de las parcelas catastrales se han complementado con los nombres geográficos del Diccionario de Toponimia Actual de La Rioja (DTALR) (González Blanco, 1987), el nomenclátor NomGeo del IGN, y algunas recopilaciones toponímicas municipales. De la base de datos conjunta se han seleccionado los topónimos con significado geobotánico. Se propone una taxonomía de grupos semánticos basada en categorías de estructura (arbolado, matorral, cubiertas herbáceas y áreas de vegetación escasa o rala) y en la adscripción a tipos de vegetación potencialmente dominantes, ordenados según una escala de higrofilia decreciente). También se reseñan topónimos referentes a usos y aprovechamientos en el medio rural: dehesas, ganadería, productos forestales y algunos cultivos agrícolas. El trabajo reúne en un repertorio sistemático los datos toponímicos, acopiados por comarcas y términos municipales. Se incluye la relación de nombres geográficos encontrados por campos nocionales y se comentan los nombres vernáculos que les han dado origen y su etimología. Quedan señalados los topónimos georreferenciados y asignados a entidades superficiales en la cartografía digital catastral, que se ha superpuesto a mapas forestales a escalas 1:200.000 y 1:50.000, en cuya elaboración participamos. El análisis ha permitido definir “topónimo externo” como el recinto catastral en que la especie o agrupación aludida no tiene presencia en la vegetación actual, al menos como dominante. Los topónimos externos más significativos de cada grupo han sido analizados describiendo la cubierta vegetal actual correspondiente, lo que permite interpretar, junto con las características fisiográficas del paraje, las causas posibles de ausencia del elemento aludido, teniendo en cuenta criterios generales de mesología, de dinámica de la vegetación y de la historia de la acción humana. El trabajo se cierra con un capítulo de conclusiones generales, conceptuales y metodológicas, así como una relación de líneas de profundización de la investigación que quedan apuntadas. Se completa con una relación de fuentes y referencias bibliográficas fundamentales. ABSTRACT This paper presents a study of the toponymy of La Rioja with a specific focus on place names reflecting the region’s geobotany. Its underlying premise is that the toponymy associated with plant species and communities, forest products and land uses can provide valuable information about the chorology and vegetation dynamics when classified and analysed using biogeographical and ecological criteria. La Rioja has been chosen for this pilot study because it concentrates vegetation types of distinct physiognomy and a highly diverse set of plant communities that can be considered representative of the vegetation of the peninsula’s landscapes. This combines with a long history of different agricultural uses on the Ebro plain that contrast with the predominance of forestry activity in the more mountainous areas, in particular the promotion of pasture for livestock transhumance. Indeed, La Rioja is not only a crossroads in terms of its phytochorology, but it is also a land of political boundaries and language transitions. Coexisting in its lexicon and toponymy, we find pure Castilian variants, features from the Romance language of Navarro-Aragonese, genuine elements of the medieval variant of the Riojan dialect, words of Mozarabic and a large and significant list of place names of Basque origin. The paper begins by outlining a number of epistemological considerations and establishes an interdisciplinary approach to toponymy, the aetiology of geographical names, and their value in the descriptive naming of the features of a landscape. It continues by enumerating the methodological determinants of toponymic research and reflects on the specific characteristics of geobotanical toponyms. The next section is dedicated to examining previous studies of botanical and ecological place names and providing a state-of-the-art review of the toponymy of La Rioja. Delimiting the sites designated by the geographical names is essential to any analysis designed to detect the correspondence between the elements alluded to by the toponyms and plant species and communities. These areas of distribution and presence, as well as the landscape changes, are defined in terms of spatially delimited surface areas. The methodology adopted involves an exhaustive review of existing toponymic sources; in particular, data obtained from the maps of the Rustic Cadastre, assigned to spatial polygons. The names of these cadastral parcels are complemented by the geographical names taken from the Diccionario de Toponimia Actual de La Rioja (DTALR) (González Blanco, 1987); the gazetteer – NomGeo, published by Spain’s Instituto Geográfico Nacional; and, various municipal list of toponyms. Place names with a geobotanical meaning were then selected from this joint database. The paper proposes a taxonomy of semantic groups based on structural categories (namely wooded areas, brushland, grassy areas and areas of scanty or sparse vegetation) and assignment to the potentially dominant type of vegetation (ordered on a scale of decreasing hygrophilic trends). Place names referring to land uses and practices in rural areas – including, pasture, livestock, forest products and some agricultural crops – are also described. The study produces a systematic list of toponyms ordered by counties and municipalities. The geographical names are organised by notional fields and the vernacular names that have given rise to them and their etymology are discussed. The toponyms are georeferenced and assigned to surface elements on the digital cadastral map, superimposed on forest maps at scales of 1:200,000 and 1:50,000, in the production of which the authors participated. The analysis has allowed us to define “external toponyms” as those cadastral parcels in which the plant species or group alluded to is no longer present in the vegetation, at least as the dominant type. The most significant external toponyms in each group have been analysed by describing the corresponding, present-day vegetation cover, which allows us to interpret, along with the physiographic features of the site, the possible causes of the absence of the aforementioned element, bearing in mind general criteria of mesology, vegetation dynamics and the history of human action. The paper finishes by offering a number of general conceptual and methodological conclusions, and a list of areas that future research can usefully examine. The study is supplemented with a list of sources and key references.

Diversité floristique du peuplement à Pistacia atlantica Desf. dans la région de Béchar (Sud-ouest algérien)

La conservation des groupements à Pistacia atlantica dans la région de Béchar est actuellement menacée par une forte pression humaine et animale. Ce travail consiste à proposer une analyse phyto-écologique fine en se basant sur la dynamique de végétation et les inventaires floristiques. Les explications sont étayées par une analyse statistique (AFC) afin de mieux cerner les facteurs écologiques prépondérants. Nous savons très bien que Pistacia atlantica est une espèce d’avenir pour l’Algérie occidentale, son adaptation au stress écologique lui permet une dynamique et une remontée biologique certaine. Cette espèce peut vivre dans des endroits très secs, de 700 à 1200m d’altitude où la pluviométrie ne dépasse guère les 100 mm/an, avec une température maximale de 42°C et un quotient pluviothermique (Q2) supérieur à 7. La diversité floristique du groupement à Pistacia atlantica est très particulière du fait de sa caractérisation biologique, systématique et phytogéographique. Cet examen fait ressortir l’importance des espèces Saharienne-Endémiques grâce à une adaptation et une résistance plus favorables sous bioclimat typiquement saharien.

PLANT MACROFOSSIL METHODS AND STUDIES | Treeline Studies

Macrofossil series from mountainous and polar areas such as the Alps, the Scandes, and the Rocky Mountains provide useful information about the late Quaternary course of treelines. Reconstructions of past treeline positions and compositions after the Ice Age can be used to infer paleoclimatic information or to study treeline ecosystem responses to (rapid) climatic change. Both approaches are illustrated by study cases. In addition to these paleoclimatic and paleoecological issues, macrofossil records can be used to validate dynamic treeline vegetation models. An example from the Alps shows the high potential of such a procedure towards applying forest-succession models for assessing future vegetation dynamics at treeline.

Pollen profile of sediment core Dethlingen, Germany

To better understand the environmental variability during the Holsteinian interglacial, we have palynologically analyzed a new core from Dethlingen, northern Germany, at a decadal resolution. Our data provide insights into the vegetation dynamics and thus also climate variability during the meso- to telocratic forest phases of the interglacial. Temperate mixed forests dominated the regional landscape throughout the Holsteinian. However, changes in the forest composition during the younger stages of the interglacial suggest a climatic transition towards milder conditions in winter. The strong presence of boreal floral elements during the older stages of the Holsteinian interglacial suggests a high seasonality. In contrast, during the younger stages the development of sub-Atlantic and Atlantic floral elements suggests increasingly warm and humid climatic conditions. Peak warming during the younger stage of the Holsteinian is marked by the maximum pollen abundances of Buxus, Abies, and Quercus. Although the vegetation dynamics suggest a general warming trend throughout the Holsteinian interglacial, abrupt as well as gradual changes in the relative abundances of temperate plants indicate considerable climatic variability. In particular, two marked declines in temperate taxa leading to the transient development of boreal and sub-temperate forests indicate short-term climatic oscillations that occurred within full interglacial conditions. The palynological signatures of these two regressive phases in vegetation development differ with regard to the expansion of pioneer trees, the abundances and rates of change of temperate taxa, and the presence of frost-sensitive taxa. These differences point to different mechanisms responsible for the individual regressive phases. Assuming a correlation of the interglacial at Dethlingen with Marine Isotope Stage (MIS) 11, our data suggest that temperate forests prevailed in northern Germany during the younger parts of MIS 11c.

(Figure 2) Mean discharge per day (total and baseflow part) of the San Francisco River and daily precipitation at station ECPL (Planta), in 2007

We investigated controls on the water chemistry of a South Ecuadorian cloud forest catchment which is partly pristine, and partly converted to extensive pasture. From April 2007 to May 2008 water samples were taken weekly to biweekly at nine different subcatchments, and were screened for differences in electric conductivity, pH, anion, as well as element composition. A principal component analysis was conducted to reduce dimensionality of the data set and define major factors explaining variation in the data. Three main factors were isolated by a subset of 10 elements (Ca2+, Ce, Gd, K+, Mg2+, Na+, Nd, Rb, Sr, Y), explaining around 90% of the data variation. Land-use was the major factor controlling and changing water chemistry of the subcatchments. A second factor was associated with the concentration of rare earth elements in water, presumably highlighting other anthropogenic influences such as gravel excavation or road construction. Around 12% of the variation was explained by the third component, which was defined by the occurrence of Rb and K and represents the influence of vegetation dynamics on element accumulation and wash-out. Comparison of base- and fast flow concentrations led to the assumption that a significant portion of soil water from around 30 cm depth contributes to storm flow, as revealed by increased rare earth element concentrations in fast flow samples. Our findings demonstrate the utility of multi-tracer principal component analysis to study tropical headwater streams, and emphasize the need for effective land management in cloud forest catchments.

Pollen and dinoflagellate cyst counts on sediment core M72/5_628-1 (MD72/5-25-GC1) from the Black Sea

High-resolution pollen and dinoflagellate cyst records from sediment core M72/5-25-GC1 were used to reconstruct vegetation dynamics in northern Anatolia and surface conditions of the Black Sea between 64 and 20 ka BP. During this period, the dominance of Artemisia in the pollen record indicates a steppe landscape and arid climate conditions. However, the concomitant presence of temperate arboreal pollen suggests the existence of glacial refugia in northern Anatolia. Long-term glacial vegetation dynamics reveal two major arid phases ~64-55 and 40-32 ka BP, and two major humid phases ~54-45 and 28-20 ka BP, correlating with higher and lower summer insolation, respectively. Dansgaard-Oeschger (D-O) cycles are clearly indicated by the 25-GC1 pollen record. Greenland interstadials are characterized by a marked increase in temperate tree pollen, indicating a spread of forests due to warm/wet conditions in northern Anatolia, whereas Greenland stadials reveal cold and arid conditions as indicated by spread of xerophytic biomes. There is evidence for a phase lag of ~500 to 1500 yr between initial warming and forest expansion, possibly due to successive changes in atmospheric circulation in the North Atlantic sector. The dominance of Pyxidinopsis psilata and Spiniferites cruciformis in the dinocyst record indicates brackish Black Sea conditions during the entire glacial period. The decrease of marine indicators (marine dinocysts, acritarchs) at ~54 ka BP and increase of freshwater algae (Pediastrum, Botryococcus) from 32 to 25 ka BP reveals freshening of the Black Sea surface water. This freshening is possibly related to humid phases in the region, to connection between Caspian Sea and Black Sea, to seasonal freshening by floating ice, and/or to closer position of river mouths due to low sea level. In the southern Black Sea, Greenland interstadials are clearly indicated by high dinocyst concentrations and calcium carbonate content, as a result of an increase in primary productivity. Heinrich events show a similar impact on the environment in the northern Anatolia/Black Sea region as Greenland stadials.

(Tables 1-3) Water chemistry of cloud forest streams at baseflow conditions, Rio San Francisco, Ecuador

We investigated controls on the water chemistry of a South Ecuadorian cloud forest catchment which is partly pristine, and partly converted to extensive pasture. From April 2007 to May 2008 water samples were taken weekly to biweekly at nine different subcatchments, and were screened for differences in electric conductivity, pH, anion, as well as element composition. A principal component analysis was conducted to reduce dimensionality of the data set and define major factors explaining variation in the data. Three main factors were isolated by a subset of 10 elements (Ca2+, Ce, Gd, K+, Mg2+, Na+, Nd, Rb, Sr, Y), explaining around 90% of the data variation. Land-use was the major factor controlling and changing water chemistry of the subcatchments. A second factor was associated with the concentration of rare earth elements in water, presumably highlighting other anthropogenic influences such as gravel excavation or road construction. Around 12% of the variation was explained by the third component, which was defined by the occurrence of Rb and K and represents the influence of vegetation dynamics on element accumulation and wash-out. Comparison of base- and fast flow concentrations led to the assumption that a significant portion of soil water from around 30 cm depth contributes to storm flow, as revealed by increased rare earth element concentrations in fast flow samples. Our findings demonstrate the utility of multi-tracer principal component analysis to study tropical headwater streams, and emphasize the need for effective land management in cloud forest catchments.

Pollen distribution of sediment core MD96-2048 from the Western Indian Ocean

Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a pollen record of the marine core MD96-2048 retrieved by the Marion Dufresne from the Indian Ocean ~120 km south of the Limpopo River mouth. The sedimentation at the site is slow and continuous. The upper 6 m (spanning the past 342 Ka) have been analysed for pollen and spores at millennial resolution. The terrestrial pollen assemblages indicate that during interglacials, the vegetation of eastern South Africa and southern Mozambique largely consisted of evergreen and deciduous forests. During glacials open mountainous scrubland dominated. Montane forest with Podocarpus extended during humid periods was favoured by strong local insolation. Correlation with the sea surface temperature record of the same core indicates that the extension of mountainous scrubland primarily depends on sea surface temperatures of the Agulhas Current. Our record corroborates terrestrial evidence of the extension of open mountainous scrubland (including fynbos-like species of the high-altitude Grassland biome) for the last glacial as well as for other glacial periods of the past 300 Ka.

Influência das condições ambientais no verdor da vegetação da caatinga frente às mudanças climáticas

The Caatinga biome, a semi-arid climate ecosystem found in northeast Brazil, presents low rainfall regime and strong seasonality. It has the most alarming climate change projections within the country, with air temperature rising and rainfall reduction with stronger trends than the global average predictions. Climate change can present detrimental results in this biome, reducing vegetation cover and changing its distribution, as well as altering all ecosystem functioning and finally influencing species diversity. In this context, the purpose of this study is to model the environmental conditions (rainfall and temperature) that influence the Caatinga biome productivity and to predict the consequences of environmental conditions in the vegetation dynamics under future climate change scenarios. Enhanced Vegetation Index (EVI) was used to estimate vegetation greenness (presence and density) in the area. Considering the strong spatial and temporal autocorrelation as well as the heterogeneity of the data, various GLS models were developed and compared to obtain the best model that would reflect rainfall and temperature influence on vegetation greenness. Applying new climate change scenarios in the model, environmental determinants modification, rainfall and temperature, negatively influenced vegetation greenness in the Caatinga biome. This model was used to create potential vegetation maps for current and future of Caatinga cover considering 20% decrease in precipitation and 1 °C increase in temperature until 2040, 35% decrease in precipitation and 2.5 °C increase in temperature in the period 2041-2070 and 50% decrease in precipitation and 4.5 °C increase in temperature in the period 2071-2100. The results suggest that the ecosystem functioning will be affected on the future scenario of climate change with a decrease of 5.9% of the vegetation greenness until 2040, 14.2% until 2070 and 24.3% by the end of the century. The Caatinga vegetation in lower altitude areas (most of the biome) will be more affected by climatic changes.