Showing papers by "National University of Comahue published in 2014"

From research to action: Enhancing crop yield through wild pollinators

Abstract: Recent evidence highlights the value of wild-insect species richness and abundance for crop pollination worldwide. Yet, deliberate physical importation of single species (eg European honey bees) into crop fields for pollination remains the mainstream management approach, and implementation of practices to enhance crop yield (production per area) through wild insects is only just beginning. With few exceptions, studies measuring the impacts of pollinator-supporting practices on wild-insect richness and pollination service success – particularly in relation to long-term crop yield and economic profit – are rare. Here, we provide a general framework and examples of approaches for enhancing pollinator richness and abundance, quantity and quality of pollen on stigmas, crop yield, and farmers' profit, including some benefits detected only through long-term monitoring. We argue for integrating the promotion of wild-insect species richness with single-species management to benefit farmers and society.

Conflicting values: ecosystem services and invasive tree management

Abstract: Tree species have been planted widely beyond their native ranges to provide or enhance ecosystem services such as timber and fibre production, erosion control, and aesthetic or amenity benefits. At the same time, non-native tree species can have strongly negative impacts on ecosystem services when they naturalize and subsequently become invasive and disrupt or transform communities and ecosystems. The dichotomy between positive and negative effects on ecosystem services has led to significant conflicts over the removal of non-native invasive tree species worldwide. These conflicts are often viewed in only a local context but we suggest that a global synthesis sheds important light on the dimensions of the phenomenon. We collated examples of conflict surrounding the control or management of tree invasions where conflict has caused delay, increased cost, or cessation of projects aimed at invasive tree removal. We found that conflicts span a diverse range of taxa, systems and countries, and that most conflicts emerge around three areas: urban and near-urban trees; trees that provide direct economic benefits; and invasive trees that are used by native species for habitat or food. We suggest that such conflict should be seen as a normal occurrence in invasive tree removal. Assessing both positive and negative effects of invasive species on multiple ecosystem services may provide a useful framework for the resolution of conflicts.

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Abstract: Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species Existing global databases of species’ threat status or population time series are dominated by charismatic species The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines We describe and assess a new database of more than 16 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – wwwpredictsorguk) We make site-level summary data available alongside this article The full database will be publicly available in 2015

A memory-based foraging tactic reveals an adaptive mechanism for restricted space use.

Abstract: The restricted area of space used by most mobile animals is thought to result from fitness-rewarding decisions derived from gaining information about the environment. Yet, assessments of how animals deal with uncertainty using memory have been largely theoretical, and an empirically derived mechanism explaining restricted space use in animals is still lacking. Using a patch-to-patch movement analysis, we investigated predictions of how free-ranging bison (Bison bison) living in a meadow-forest matrix use memory to reduce uncertainty in energy intake rate. Results indicate that bison remembered pertinent information about location and quality of meadows, and they used this information to selectively move to meadows of higher profitability. Moreover, bison chose profitable meadows they had previously visited, and this choice was stronger after visiting a relatively poor quality meadow. Our work demonstrates a link between memory, energy gains and restricted space use while establishing a fitness-based integration of movement, cognitive and spatial ecology.

Invasive belowground mutualists of woody plants

Abstract: Most plants require mutualistic associations to survive, which can be an important limitation on their ability to become invasive. There are four strategies that permit plants to become invasive without being limited by a lack of mutualists. One is to not be dependent on mutualists. The other three strategies are to form novel mutualisms, form associations with cosmopolitan species, or co-invade with mutualists from their native range. Historically there has been a bias to study mutualisms from a plant perspective, with little consideration of soil biota as invasive species in their own right. Here we address this by reviewing the literature on belowground invasive mutualists of woody plants. We focus on woody invaders as ecosystem-transforming plants that frequently have a high dependence on belowground mutualists. We found that co-invasions are common, with many ectomycorrhizal plant species and N-fixing species co-invading with their mutualists. Other groups, such as arbuscular mycorrhizal plants, tend to associate with cosmopolitan fungal species or to form novel associations in their exotic range. Only limited evidence exists of direct negative effects of co-invading mutualists on native mutualist communities, and effects on native plants appear to be largely driven by altered environmental conditions rather than direct interactions. Mutualists that introduce novel ecosystem functions have effects greater than would be predicted based solely on their biomass. Focusing on the belowground aspects of plant invasions provides novel insights into the impacts, processes and management of invasions of both soil organisms and woody plant species.

Beta diversity of plant-pollinator networks and the spatial turnover of pairwise interactions.

Abstract: Interactions between species form complex networks that vary across space and time. Even without spatial or temporal constraints mutualistic pairwise interactions may vary, or rewire, across space but this variability is not well understood. Here, we quantify the beta diversity of species and interactions and test factors influencing the probability of turnover of pairwise interactions across space. We ask: 1) whether beta diversity of plants, pollinators, and interactions follow a similar trend across space, and 2) which interaction properties and site characteristics are related to the probability of turnover of pairwise interactions. Geographical distance was positively correlated with plant and interaction beta diversity. We find that locally frequent interactions are more consistent across space and that local flower abundance is important for the realization of pairwise interactions. While the identity of pairwise interactions is highly variable across space, some species-pairs form interactions that are locally frequent and spatially consistent. Such interactions represent cornerstones of interacting communities and deserve special attention from ecologists and conservation planners alike.

New Age Constraints for the Salamanca Formation and Lower Río Chico Group in the Western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene Extinction Recovery and Land Mammal Age Correlations

Abstract: The Salamanca Formation of the San Jorge Basin (Patagonia, Argentina) preserves critical records of Southern Hemisphere Paleocene biotas, but its age remains poorly resolved, with estimates ranging from Late Cretaceous to middle Paleocene. We report a multi-disciplinary geochronologic study of the Salamanca Formation and overlying Rio Chico Group in the western part of the basin. New constraints include (1) an 40Ar/39Ar age determination of 67.31 ± 0.55 Ma from a basalt flow underlying the Salamanca Formation, (2) micropaleontological results indicating an early Danian age for the base of the Salamanca Formation, (3) laser ablation HR-MC-ICP-MS (high resolution-multi collector-inductively coupled plasma-mass spectrometry) U-Pb ages and a high-resolution TIMS (thermal ionization mass spectrometry) age of 61.984 ± 0.041(0.074)[0.100] Ma for zircons from volcanic ash beds in the Penas Coloradas Formation (Rio Chico Group), and (4) paleomagnetic results indicating that the Salamanca Formation in this area is entirely of normal polarity, with reversals occurring in the Rio Chico Group. Placing these new age constraints in the context of a sequence stratigraphic model for the basin, we correlate the Salamanca Formation in the study area to Chrons C29n and C28n, with the Banco Negro Inferior (BNI), a mature widespread fossiliferous paleosol unit at the top of the Salamanca Formation, corresponding to the top of Chron C28n. The diverse paleobotanical assemblages from this area are here assigned to C28n (64.67–63.49 Ma), ∼2–3 million years older than previously thought, adding to growing evidence for rapid Southern Hemisphere floral recovery after the Cretaceous-Paleogene extinction. Important Peligran and “Carodnia” zone vertebrate fossil assemblages from coastal BNI and Penas Coloradas exposures are likely older than previously thought and correlate to the early Torrejonian and early Tiffanian North American Land Mammal Ages, respectively.

When to be discrete: the importance of time formulation in understanding animal movement

Abstract: Animal movement is essential to our understanding of population dynamics, animal behavior, and the impacts of global change. Coupled with high-resolution biotelemetry data, exciting new inferences about animal movement have been facilitated by various specifications of contemporary models. These approaches differ, but most share common themes. One key distinction is whether the underlying movement process is conceptualized in discrete or continuous time. This is perhaps the greatest source of confusion among practitioners, both in terms of implementation and biological interpretation. In general, animal movement occurs in continuous time but we observe it at fixed discrete-time intervals. Thus, continuous time is conceptually and theoretically appealing, but in practice it is perhaps more intuitive to interpret movement in discrete intervals. With an emphasis on state-space models, we explore the differences and similarities between continuous and discrete versions of mechanistic movement models, establish some common terminology, and indicate under which circumstances one form might be preferred over another. Counter to the overly simplistic view that discrete- and continuous-time conceptualizations are merely different means to the same end, we present novel mathematical results revealing hitherto unappreciated consequences of model formulation on inferences about animal movement. Notably, the speed and direction of movement are intrinsically linked in current continuous-time random walk formulations, and this can have important implications when interpreting animal behavior. We illustrate these concepts in the context of state-space models with multiple movement behavior states using northern fur seal (Callorhinus ursinus) biotelemetry data.

Physical and Functional Properties of Blackberry Freeze- and Spray-Dried Powders

Abstract: The aim of the present work was to develop two products from blackberry juice by freeze and spray drying with potential use as food colorants or healthy ingredients. A characterization of the physical and functional properties of the powdered juices was done. Maltodextrin or a mixture of trehalose and maltodextrin were assessed as carrier matrices. Freeze-dried, maltodextrin-containing powders presented the best retention of bioactive compounds and antiradical activity; however, they showed a narrow relative humidity range for storage in the glassy state. Spray-dried powders showed better physical properties, bearing higher glass transition temperature and lower molecular mobility than freeze-dried formulations.

Extremely frequent bee visits increase pollen deposition but reduce drupelet set in raspberry

Abstract: Summary 1. Production of many flowering crops often benefits from elevated pollinator diversity and abundance. Nevertheless, the opposite relationship may arise if bees impair fruit or seed production and/or quality by damaging flowers during visitation, despite transferring pollen. 2. We assessed pollination and drupelet set (i.e. the number of drupelets per fruit) in 16 raspberry Rubus idaeus fields along a gradient of bee abundance in north-west Patagonia, Argentina. Using pollen supplementation, we also tested whether drupelet set was pollen limited in a subset of six fields. 3. Managed Apis mellifera and the invasive bumblebee Bombus terrestris accounted for 50% and 45% of all bee visits, respectively, to raspberry flowers. Pollen loads on stigmas increased with visit frequency of all bees combined and particularly with visitation by A. mellifera, but not by B. terrestris. Drupelet set was not pollen limited along the gradient of bee abundance. 4. Instead, drupelet set decreased with the proportion of damaged styles, which varied more strongly with the frequency of visits by B. terrestris than by A. mellifera. In fields with the highest bee frequency of visits ( � 300 visits flower � 1 day � 1 ), � 80% of styles were damaged in flowers and these developed into fruits with � 30% fewer drupelets compared to flowers in fields with the lowest bee visitation rates ( � 4 visits flower � 1 day � 1 ). 5. Synthesis and applications. Extreme bee visitation, particularly by Bombus terrestris, damaged the styles of raspberry flowers, precluding ovule fertilization by deposited pollen and limiting crop production by reducing drupelet set. Only a few bee visits are required to maximize fruit production in raspberry plants, therefore, pollinator management in north-west Patagonia should focus principally on reducing the abundance of the invasive bumblebee B. terrestris and secondarily controlling the number of honeybee hives in nearby cultivated fields. Although mainstream pollinator management relies on the assumption that more visits enhance fruit set, high bee visitation rates can be detrimental for fruit development and, consequently, for crop yield.

Competition, predation, and migration: Individual choice patterns of Serengeti migrants captured by hierarchical models

Abstract: Large-herbivore migrations occur across gradients of food quality or food abundance that are generally determined by underlying geographic patterns in rainfall, elevation, or latitude, in turn causing variation in the degree of interspecific competition and the exposure to predators. However, the role of top-down effects of predation as opposed to the bottom-up effects of competition for resources in shaping migrations is not well understood. We studied 30 GPS radio-collared wildebeest and zebra migrating seasonally in the Serengeti-Mara ecosystem to ask how predation and food availability differentially affect the individual movement patterns of these co-migrating species. A hierarchical analysis of movement trajectories (directions and distances) in relation to grass biomass, high-quality food patches, and predation risk show that wildebeest tend to move in response to food quality, with little attention to predation risk. In contrast, individual zebra movements reflect a balance between the risk of predation and the access to high-quality food of sufficient biomass. Our analysis shows how two migratory species move in response to different attributes of the same landscape. Counterintuitively and in contrast to most other animal movement studies, we find that both species move farther each day when resources are locally abundant than when they are scarce. During the wet season when the quality of grazing is at its peak, both wildebeest and zebra move the greatest distances and do not settle in localized areas to graze for extended periods. We propose that this punctuated movement in high-quality patches is explained by density dependency, whereby large groups of competing individuals (up to 1.65 million grazers) rapidly deplete the localized grazing opportunities. These findings capture the roles of predation and competition in shaping animal migrations, which are often claimed but rarely measured.

When mutualism goes bad: density‐dependent impacts of introduced bees on plant reproduction

Abstract: Summary Invasive, alien plants and pollinators have varying effects on their interaction partners, ranging from highly beneficial to strongly detrimental. To understand these contrasting impacts, we review the benefits and costs associated with plant–pollinator interactions and enquire as to how the presence of abundant invaders affects the benefit–cost balance. We provide a conceptual framework that predicts that mutualism shifts to antagonism when invaders increase disproportionally in abundance relative to their interaction partners. This outcome is illustrated by an empirical example of a crop in which flower damage and an associated reduction in fruit quality represent interaction costs of intense visitation by invasive bees. More generally, the extremely high density of invasive flower visitors, such as Apis mellifera and Bombus terrestris, might have population- and community-level consequences by hampering reproduction of native plants while promoting reproduction of alien plants. Furthermore, modification of the structure of pollination networks resulting from intense visitation of native plants by superabundant alien flower visitors in highly invaded communities could predict accentuated interaction costs for many native plants. Owing to their high density and the exclusion of native pollinators, invasive bees, originally introduced for honey production and crop pollination, may negatively impact both the native biota and agriculture.

Saccharomyces eubayanus and Saccharomyces uvarum associated with the fermentation of Araucaria araucana seeds in Patagonia

Abstract: Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by Mapuche communities. The main goal of the present study was to identify and characterize the yeast microbiota responsible of Mudai fermentation as well as from A. araucana seeds and bark from different locations in Northern Patagonia. Only Hanseniaspora uvarum and a commercial bakery strain of Saccharomyces cerevisiae were isolated from Mudai and all Saccharomyces isolates recovered from A. araucana seed and bark samples belonged to the cryotolerant species Saccharomyces eubayanus and Saccharomyces uvarum. These two species were already reported in Nothofagus trees from Patagonia; however, this is the first time that they were isolated from A. araucana, which extends their ecological distribution. The presence of these species in A. araucana seeds and bark samples, led us to postulate a potential role for them as the original yeasts responsible for the elaboration of Mudai before the introduction of commercial S. cerevisiae cultures. The molecular and genetic characterization of the S. uvarum and S. eubayanus isolates and their comparison with European S. uvarum strains and S. eubayanus hybrids (S. bayanus and S. pastorianus), allowed their ecology and evolution us to be examined.

Selection and characterization of a Patagonian Pichia kudriavzevii for wine deacidification

Abstract: Fil: del Monaco, Silvana Maria. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Patagonia Norte. Instituto de Investigacion y Desarrollo En Ingenieria de Procesos, Biotecnologia y Energias Alternativas; Argentina. Universidad Nacional del Comahue. Facultad de Ingenieria; Argentina

Time is of the essence: direct and indirect effects of plant ontogenetic trajectories on higher trophic levels

Abstract: Physiological and morphological constraints during plant ontogeny affect the expression of numerous plant traits relevant to higher trophic levels, such as nutritional content and physical and chemical defenses. Yet we know little about how temporal variation in these traits can directly and/or indirectly mediate tri-trophic interactions, such as those between plants, their herbivores, and herbivore natural enemies. Using four distinct ontogenetic stages of Plantago lanceolata (Plantaginaceae) and the specialist herbivore Junonia coenia (Lepidoptera, Nymphalidae), we evaluated how ontogenetic changes in plant quality can: (1) directly alter plant–herbivore interactions through butterfly oviposition choice and caterpillar performance assays, and (2) indirectly alter herbivores' susceptibility to higher trophic levels through caterpillars' iridoid glycoside sequestration and immune defenses. Results showed that plant defensive traits increased over P. lanceolata development, with leaf tissues becoming tougher and plant allelochemicals (iridoid glycosides) occurring in higher amounts. Conversely, plant nutritional quality (water and nitrogen content) decreased as plants aged. These ontogenetic trajectories strongly altered both direct and indirect interactions between plants and higher trophic levels. Buckeye butterflies showed a stronger oviposition preference for younger developmental stages of P. lanceolata, laying on average 60% more eggs on juvenile than on reproductive plants. Feeding experiments with caterpillars showed that larvae feeding on juvenile plants showed faster relative growth rate and increased digestive efficiency compared with those feeding on plants in the reproductive stage. These individuals, however, acquired lower levels of sequestered chemical defenses than did those feeding on older P. lanceolata plants, potentially rendering them more susceptible to predation. Finally, host plant age altered the ability of a caterpillar to mount an immune response against simulated parasitoid eggs. Specifically, caterpillars reared on older plant life stages, and thus with higher levels of sequestered iridoid glycosides, showed a compromised immune response compared to those feeding on younger plant age classes. This study exemplifies how ontogenetic trajectories in plant traits can scale up to directly or indirectly alter tri-trophic interactions, which may have key implications for understanding temporal shifts in herbivore population and community structure.

Can model species be used to advance the field of invasion ecology

Abstract: Hypotheses for explaining plant invasions have focused on a variety of factors that may influence invasion success, including propagule pressure, interactions of the introduced species with the biotic, abiotic, or disturbance properties of the new ecosystem, or the genetic characteristics of the invader itself. Evaluating the relative importance of these factors has been difficult because for most invaders key information about the introduced population or the introduction event is not available. We propose that natural experiments using model species is an important tool to test multiple invasion hypotheses at the same time, providing a complementary approach to meta-analysis and literature review. By focusing on a single candidate species, Pinus contorta, we explore several attributes that we propose constitute a good model, including: (a) intentional and relatively well documented introduction into a wide range of environments and countries across the world during the past century, where invasion success or failure has already occurred, (b) conspicuous growth form that simplifies assessment of growth rates, and comparisons across native and introduced ecosystems around the world, and, (c) documented and replicated variability of introduction intensity, genetic characteristics of the introduced populations, contrasting biotic communities present at sites of introduction, and abiotic conditions within and across introduced ecosystems. We propose that identifying model species with these characteristics will provide opportunities to disentangle the relative importance of different mechanisms hypothesized to influence invasion success, and thereby advance the field of invasion ecology.

Medicinal plants in the cultural landscape of a Mapuche-Tehuelche community in arid Argentine Patagonia: an eco-sensorial approach

Abstract: The taste and smell of medicinal plants and their relation to the cultural landscape of a Mapuche-Tehuelche community in the Patagonian steppe was investigated. We assume that the landscapes as a source of therapeutic resources is perceived, classified and named according to different symbolic, ecological and utilitarian criteria which are influenced by chemosensorial appearance of medicinal plants which are valued by inhabitants. Information relating to the cultural landscape experienced by 18 inhabitants, all representing 85% of the families, in terms of medicinal plants, knowledge of species and their organoleptic perception was obtained through participant observation, interviews and free listing. The data were examined using cualitative and quantitative approach, including discourse analysis and non-parametric statistics. Informants use 121 medicinal species, obtained from both wild and non-wild environments, most of which (66%) present aroma and/or taste. It was found that the plants with highest use consensus used for digestive, respiratory, cardio-vascular, analgesic-anti-inflammatory, obstetric-gynaecological and genito-unrinary complaints, have the highest frequencies of cites reporting flavor; and those with the highest frequencies relating to digestive, analgesic-anti-inflammatory and cultural syndromes present the highest frequencies of aroma. Flavor and/or aroma are interpreted as strong or soft, and the strongest are associated with treatment of supernatural ailments. Also, taste is a distinctive trait for the most of the species collected in all natural units of the landscape, while aroma is more closely associated with species growing at higher altitudes. The local pharmacopeia is also enriched with plants that come from more distant phytogeographical environments, such as the Andean forest and the Patagonian Monte, which are obtained through barter with neighboring populations. Herbal products are also obtained in regional shop. The practices of barter and purchase extend the limits of the landscape as a provider of therapeutic resources, improving the dynamics of its functions and structure, leading to more effective solutions to the various health needs that arise in the community. Herbal landscape perceived by the community exhibits notable eco sensorial and spatial heterogeneity. Local inhabitants’ sensorial interpretations play a role as heuristic tools in the recreation and redefinition of old and new available resources.

Unraveling fission-fusion dynamics: how subgroup properties and dyadic interactions influence individual decisions

Abstract: Many species show fission-fusion group dynamics because it has clear advantages for flexibly exploiting heterogeneous environments. However, the mechanisms by which these dynamics arise are not well known. We used a hierarchical Bayesian model to disentangle the different influences on spider monkey (Ateles geoffroyi) individual fissions and fusions, including the three dimensions of fission-fusion dynamics (subgroup size, dispersion, and composition). Furthermore, we considered the influences of other individuals also leaving or joining a subgroup at the same time. We found that the most important influence on individual fissions and fusions is whether other individuals are also doing the same. Subgroup size and dispersion did not have clear effects on the probability that an individual fissioned or fusioned, while individuals tended to leave subgroups that were biased toward the opposite sex and to join subgroups that were biased toward their own sex. The networks constructed by the inter-individual influences during fissions and fusions were cohesive and did not show assortativity by sex or by degree. Individuals had a similar degree in both networks and each was influenced by a different set of individuals, suggesting a high fluidity in the social networks. We suggest that these networks reflect the way in which information about the environment flows as individuals follow one another during fissions and fusions.

Stabilization process in Saccharomyces intra- and interspecific hybrids in fermentative conditions

Abstract: Summary. We evaluated the genetic stabilization of artificial intra- ( Saccharomyces cerevisiae) and interspecific ( S. cerevisiae × S. kudriavzevii) hybrids under wine fermentative conditions. Large-scale transitions in genome size and genome reorganizations were observed during this process. Interspecific hybrids seem to need fewer generations to reach genetic stability than intraspecific hybrids. The largest number of molecular patterns recovered among the derived clones was observed for intraspe cific hybrids, particularly for those obtained by rare-mating. Molecular marker analyses revealed that unstable clones could change during the industrial process to obtain active dry yeast. When no changes in molecular markers and ploidy were observed after this process, no changes in genetic composition were confirmed by comparative genome hybridization, consid ering the clone as a stable hybrid. According to our results, under these conditions, fermentation steps 3 and 5 (30–50 generations) would suffice to obtain genetically stable interspecific and intraspecific hybrids, respectively . [Int Microbiol 2014; 17(4):213-224]

Shifts in food quality for herbivorous consumer growth: multiple golden means in the life history.

Abstract: Consumer growth can be affected by imbalances between the nutrient content of the consumer and its food resource. Although ontogenetic-driven changes in animal composition are well documented, their potential consequences for the organism's sensitivity to food quality constraints have remained elusive. Here we show that the potential growth response of the copepod Mixodiaptomus laciniatus (as %RNA and RNA:DNA ratio) to the natural gradient of seston carbon (C) : nutrient ratio is unimodal and stage specific. Solution of the equation given by the first derivative function provided the optimum C : nutrient ratio for maximum stage-specific growth, which increased during ontogeny. The peakedness of the function indicated that animal vulnerability to suboptimal food quality decreased as juveniles reached adulthood. Consistent with these results, a field experiment demonstrated that potential consumer growth responded to variations in seston C : phosphorus ratio, and that early life stages were particularly vul...

Retracing the evolutionary history of Nothofagus in its geo-climatic context: new developments in the emerging field of phylogeology.

Abstract: Phylogeographic studies have made a significant contribution to the interpretation of genetic lineage distribution in response to climate changes, such as during glaciation events of the Neogene. However, the effects of ancient landscapes associated with global sea level rises, tectonic processes, and climatology driving lineage evolution have been largely overlooked. These effects can be tested in widespread lineages of cold-tolerant species that have endured cooling, and thus, phylogeographic patterns may reflect large-scale processes that were not reset by the ice ages. We hereby combine geological evidence from marine sedimentary basins, Andean orogeny, and climatology with molecular dating and statistical phylogeography to infer how geological and climatic processes affected the distribution of lineages in cold-tolerant Nothofagus species during the Cenozoic. A total of 239 populations along the entire range of all species within the genus Nothofagus (N. antarctica, N. betuloides, N. dombeyi, N. nitida, and N. pumilio) were sampled and analyzed by sequencing three non-coding regions of the chloroplast. We found 30 chloroplast DNA haplotypes that were geographically structured. Molecular dating calibrated with fossils revealed that ancestral lineages appeared in Eocene/Oligocene, whereas most divergences took place during the Miocene; in turn, Bayesian skyline plots showed that population expansion occurred in the Early Pleistocene (1.5–1 million years ago). Lineage divergence from all wide-ranging Nothofagus was spatially and temporally concordant with episodic marine transgressions and warmer times in Patagonia during Eocene/Miocene Epochs. Long-lasting stable raised areas preserved haplotype diversity throughout Patagonia, from where cold-tolerant taxa expanded their ranges during pre-Quaternary times. The detailed study of such ancient divergences is novel and allows us to infer the effects of geological processes on distribution patterns of ancient lineages, that is, phylogeology.