Browsing by Author "Marquet, Pablo A."

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    A 19 Year Analysis of Small Mammals Associated with Human Hantavirus Cases in Chile
    (2019) Torres-Perez, Fernando; Eduardo Palma, R.; Boric-Bargetto, Dusan; Vial, Cecilia; Ferres, Marcela; Vial, Pablo A.; Martinez-Valdebenito, Constanza; Pavletic, Carlos; Parra, Alonso; Marquet, Pablo A.; Mertz, Gregory J.
    Small mammals present in areas where hantavirus cardiopulmonary syndrome (HCPS) cases had occurred in central and southern Chile were captured and analyzed to evaluate the abundance of rodents and seroprevalence rates of antibodies to Andes orthohantavirus (ANDV). Sampling areas ranged from the Coquimbo to Aysen regions (30-45 degrees S approx.) regions. Ninety-two sites in peridomestic and countryside areas were evaluated in 19 years of sampling. An antibody against ANDV was detected by strip immunoassay in 58 of 1847 specimens captured using Sherman traps. Of the eleven species of rodents sampled, Abrothrix olivacea, Oligoryzomys longicaudatus and Abrothrix hirta were the most frequently trapped. O. longicaudatus had the highest seropositivity rate, and by logistic regression analysis, O. longicaudatus of at least 60 g had 80% or higher probability to be seropositive. Sex, age and wounds were significantly related to seropositivity only for O. longicaudatus. Across administrative regions, the highest seropositivity was found in the El Maule region (34.8-36.2 degrees S), and the highest number of HCPS cases was registered in the Aysen region. Our results highlight the importance of long term and geographically extended studies, particularly for highly fluctuating pathogens and their reservoirs, to understand the implications of the dynamics and transmission of zoonotic diseases in human populations.
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    A general theory for temperature dependence in biology
    (2022) Arroyoa, Jose Ignacio; Diez, Beatriz; Kempes, Christopher P.; West, Geoffrey B.; Marquet, Pablo A.
    At present, there is no simple, first principles-based, and general model for quantitatively describing the full range of observed biological temperature responses. Here we derive a general theory for temperature dependence in biology based on Eyring-EvansPolanyi's theory for chemical reaction rates. Assuming only that the conformational entropy of molecules changes with temperature, we derive a theory for the temperature dependence of enzyme reaction rates which takes the form of an exponential function modified by a power law and that describes the characteristic asymmetric curved temperature response. Based on a few additional principles, our model can be used to predict the temperature response above the enzyme level, thus spanning quantum to classical scales. Our theory provides an analytical description for the shape of temperature response curves and demonstrates its generality by showing the convergence of all temperature dependence responses onto universal relationships-a universal data collapse-under appropriate normalization and by identifying a general optimal temperature, around 25.C, characterizing all temperature response curves. The model provides a good fit to empirical data for a wide variety of biological rates, times, and steady-state quantities, from molecular to ecological scales and across multiple taxonomic groups (from viruses to mammals). This theory provides a simple framework to understand and predict the impact of temperature on biological quantities based on the first principles of thermodynamics, bridging quantum to classical scales.
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    Alteration of coastal productivity and artisanal fisheries interact to affect a marine food web
    (2021) Isidora Avila-Thieme, M.; Corcoran, Derek; Perez-Matus, Alejandro; Wieters, Evie A.; Navarrete, Sergio A.; Marquet, Pablo A.; Valdovinos, Fernanda S.
    Top-down and bottom-up forces determine ecosystem function and dynamics. Fisheries as a top-down force can shorten and destabilize food webs, while effects driven by climate change can alter the bottom-up forces of primary productivity. We assessed the response of a highly-resolved intertidal food web to these two global change drivers, using network analysis and bioenergetic modelling. We quantified the relative importance of artisanal fisheries as another predator species, and evaluated the independent and combined effects of fisheries and changes in plankton productivity on food web dynamics. The food web was robust to the loss of all harvested species but sensitive to the decline in plankton productivity. Interestingly, fisheries dampened the negative impacts of decreasing plankton productivity on non-harvested species by reducing the predation pressure of harvested consumers on non-harvested resources, and reducing the interspecific competition between harvested and non-harvested basal species. In contrast, the decline in plankton productivity increased the sensitivity of harvested species to fishing by reducing the total productivity of the food web. Our results show that strategies for new scenarios caused by climate change are needed to protect marine ecosystems and the wellbeing of local communities dependent on their resources.
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    AN OPEN-SYSTEM APPROACH TO COMPLEX BIOLOGICAL NETWORKS
    (2019) Rebolledo, Rolando; Navarrete, Sergio A.; Kefi, Sonia; Rojas, Sergio; Marquet, Pablo A.
    Biological diversity is essential for the maintenance of the ecosystem functions that support life on the planet. Inherent to this diversity is the seemingly endless way in which the biological entities of a natural system interact and affect each other at local and regional scales, conforming complex ecological networks permeable to external forcing. Existing approaches to capture and model such complexity typically make unrealistic or excessively restrictive assumptions. Here we use concepts from open dynamical systems and metacommunity theory to develop a framework in which the system dynamics is a function of both interspecific interactions in the focal system (e.g., a local community of coexisting species) and unobserved biotic and abiotic interactions with the local and regional environment (e.g., the metacommunity). Species in the vital system interact through direct exchanges of biomass (i.e., trophic interactions), as well as through altering the acquisition and/or transformation of biomass by other species (nontrophic interactions). Interactions are affected by environmental fluctuations and by migration and emigration processes, which can take place at different time scales and can be modeled by stochastic differential equations driven by a mixture of continuous and discontinuous processes. In this manner, the proposed framework provides a wider and more flexible representation of the complexity of ecological systems, in comparison with the closed-system paradigm that isolates the system from the environment. Because the core model explicitly recognizes the existence of local and regional processes, it is also a natural starting point to examine spatially structured networks.
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    Analyzing the Spatiotemporal Patterns of Forests Carbon Sink and Sources Between 2000 and 2019
    (2022) Alaniz, Alberto J.; Carvajal, Mario A.; Marquet, Pablo A.; Vergara, Pablo M.; Meneses, Luis; Moreira-Arce, Dario
    Here we present a global time-series of global forest above ground biomass from 2000 to 2019, analyzing spatiotemporal patterns of carbon balance, accounting for losses and gains. We generated a global Above-Ground Biomass (AGB) map for the year 2000 and assessed its correlation with different satellite products. We generated a multi-year analysis of AGB changes at the pixel level was generated, estimating carbon (C) loss and gain. Finally, we estimated the C losses due to forest clearing and wildfires analyzing their trends across biomes and countries. Our results show that the global mean annual loss was 2.88 +/- 0.33 PgC yr(-1), while global mean C gain was 2.95 +/- 0.43 PgC yr(-1), resulting in a neutral to sink behavior of -0.06 +/- 0.58 PgC yr(-1). The mean annual C loss by forest clearing was 1.04 +/- 0.03 PgC yr(-1), with an increasing trend of +0.03 +/- 0.01 PgC yr(-1). Eight biomes and 54 countries showed a significant increasing trend of C loss by forest clearing. Wildfires C losses reached 0.351 +/- 0.02 Pg C yr(-1), representing the 33.71% of forest clearing C losses. Boreal forest presented the highest C losses from wildfires, while significant increasing trends were evidenced in five biomes. We also find increasing trends of wildfire C loss in 20 countries while decreasing trends were identified in 10 countries. Our findings highlight the importance of designing strong policies to halt deforestation as agreed in the recent COP26 and provide information to identify priority areas to start implementing these policies in the short term.
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    Areas of global importance for conserving terrestrial biodiversity, carbon and water
    (2021) Jung, Martin; Arnell, Andy; de Lamo, Xavier; Garcia-Rangel, Shaenandhoa; Lewis, Matthew; Mark, Jennifer; Merow, Cory; Miles, Lera; Ondo, Ian; Pironon, Samuel; Ravilious, Corinna; Rivers, Malin; Schepashenko, Dmitry; Tallowin, Oliver; van Soesbergen, Arnout; Govaerts, Rafael; Boyle, Bradley L.; Enquist, Brian J.; Feng, Xiao; Gallagher, Rachael, V; Maitner, Brian; Meiri, Shai; Mulligan, Mark; Ofer, Gali; Roll, Uri; Hanson, Jeffrey O.; Jetz, Walter; Di Marco, Moreno; McGowan, Jennifer; Rinnan, D. Scott; Sachs, Jeffrey D.; Lesiv, Myroslava; Adams, Vanessa; Andrew, Samuel C.; Burger, Joseph R.; Hannah, Lee; Marquet, Pablo A.; McCarthy, James K.; Morueta-Holme, Naia; Newman, Erica A.; Park, Daniel S.; Roehrdanz, Patrick R.; Svenning, Jens-Christian; Violle, Cyrille; Wieringa, Jan J.; Wynne, Graham; Fritz, Steffen; Strassburg, Bernardo B. N.; Obersteiner, Michael; Kapos, Valerie; Burgess, Neil; Schmidt-Traub, Guido; Visconti, Piero
    To meet the ambitious objectives of biodiversity and climate conventions, the international community requires clarity on how these objectives can be operationalized spatially and how multiple targets can be pursued concurrently. To support goal setting and the implementation of international strategies and action plans, spatial guidance is needed to identify which land areas have the potential to generate the greatest synergies between conserving biodiversity and nature's contributions to people. Here we present results from a joint optimization that minimizes the number of threatened species, maximizes carbon retention and water quality regulation, and ranks terrestrial conservation priorities globally. We found that selecting the top-ranked 30% and 50% of terrestrial land area would conserve respectively 60.7% and 85.3% of the estimated total carbon stock and 66% and 89.8% of all clean water, in addition to meeting conservation targets for 57.9% and 79% of all species considered. Our data and prioritization further suggest that adequately conserving all species considered (vertebrates and plants) would require giving conservation attention to similar to 70% of the terrestrial land surface. If priority was given to biodiversity only, managing 30% of optimally located land area for conservation may be sufficient to meet conservation targets for 81.3% of the terrestrial plant and vertebrate species considered. Our results provide a global assessment of where land could be optimally managed for conservation. We discuss how such a spatial prioritization framework can support the implementation of the biodiversity and climate conventions.
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    Beyond Darwin: On the role of niche construction and self-organization in evolution
    (2009) Marquet, Pablo A.
    In this essay I point out to two processes that can potentially complement the classical view of evolution by natural selection as outlined by Darwin, which captures only part of the processes driving adaptive evolution. This classical view should be complemented with sources of order generated within the biological system itself in response to its own structure and dynamics (i.e. self-organization) and by considering the existence of a fundamental circularity in the interaction between the organism and its environment, such that the action of the organisms modify their selective environment thereby affecting their own evolution. The formalization and inclusion of these two processes (and their interaction) represent major challenges and opportunities for the expansion of evolutionary theory in the Darwinian tradition.
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    Bromeliad growth and stoichiometry: responses to atmospheric nutrient supply in fog-dependent ecosystems of the hyper-arid Atacama Desert, Chile
    (2011) Gonzalez, Angelica L.; Miguel Farina, Jose; Pinto, Raquel; Perez, Cecilia; Weathers, Kathleen C.; Armesto, Juan J.; Marquet, Pablo A.
    Carbon, nitrogen, and phosphorus (C, N, P) stoichiometry influences the growth of plants and nutrient cycling within ecosystems. Indeed, elemental ratios are used as an index for functional differences between plants and their responses to natural or anthropogenic variations in nutrient supply. We investigated the variation in growth and elemental content of the rootless terrestrial bromeliad Tillandsia landbeckii, which obtains its moisture, and likely its nutrients, from coastal fogs in the Atacama Desert. We assessed (1) how fog nutrient supply influences plant growth and stoichiometry and (2) the response of plant growth and stoichiometry to variations in nutrient supply by using reciprocal transplants. We hypothesized that T. landbeckii should exhibit physiological and biochemical plastic responses commensurate with nutrient supply from atmospheric deposition. In the case of the Atacama Desert, nutrient supply from fog is variable over space and time, which suggests a relatively high variation in the growth and elemental content of atmospheric bromeliads. We found that the nutrient content of T. landbeckii showed high spatio-temporal variability, driven partially by fog nutrient deposition but also by plant growth rates. Reciprocal transplant experiments showed that transplanted individuals converged to similar nutrient content, growth rates, and leaf production of resident plants at each site, reflecting local nutrient availability. Although plant nutrient content did not exactly match the relative supply of N and P, our results suggest that atmospheric nutrient supply is a dominant driver of plant growth and stoichiometry. In fact, our results indicate that N uptake by T. landbeckii plants depends more on N supplied by fog, whereas P uptake is mainly regulated by within-plant nutrient demand for growth. Overall, these findings indicate that variation in fog nutrient supply exerts a strong control over growth and nutrient dynamics of atmospheric plants, which are ubiquitous across fog-dominated ecosystems.
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    CAN ECOLOGICAL INTERACTIONS BE INFERRED FROM SPATIAL DATA?
    (2020) Stephens, Christopher R.; Gonzalez-Salazar, Constantino; del Carmen Villalobos-Segura, Maria; Marquet, Pablo A.
    The characterisation and quantification of ecological interactions, and the construction of species distributions and their associated ecological niches, is of fundamental theoretical and practical importance. In this paper we give an overview of a Bayesian inference framework, developed over the last 10 years, which, using spatial data, offers a general formalism within which ecological interactions may be characterised and quantified. Interactions are identified through deviations of the spatial distribution of co-occurrences of spatial variables relative to a benchmark for the non-interacting system and based on a statistical ensemble of spatial cells. The formalism allows for the integration of both biotic and abiotic factors of arbitrary resolution. We concentrate on the conceptual and mathematical underpinnings of the formalism, showing how, using the Naive Bayes approximation, it can be used to not only compare and contrast the relative contribution from each variable, but also to construct species distributions and niches based on arbitrary variable type. We show how the formalism can be used to quantify confounding and therefore help disentangle the complex causal chains that are present in ecosystems. We also show species distributions and their associated niches can be used to infer standard "micro" ecological interactions, such as predation and parasitism. We present several representative use cases that validate our framework, both in terms of being consistent with present knowledge of a set of known interactions, as well as making and validating predictions about new, previously unknown interactions in the case of zoonoses.
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    Coexistence, dispersal and spatial structure in metacommunities: a stochastic model approach
    (2021) Tejo, Mauricio; Quininao, Cristobal; Rebolledo, Rolando; Marquet, Pablo A.
    We propose a stochastic model for interacting species in a metacommunity in order to study the factors affecting the intensity of the competition/colonization trade-off as a coexistence mechanism in metacommunities. We particularly focus on the role of the number of local communities and the number of refuges for the inferior competitor. The stochastic component is associated with the dispersal process and is represented by Poisson random measures. Thus, this stochastic model includes two dynamic scales: a continuous one, which refers to the interactions among species, and a low frequency one, referring to dispersal following a Poisson scheme. We show the well-posedness of the model and that it is possible to study its long-term behavior using Lyapunov exponents; the extinction of a species is associated with a negative slope in the time trajectory of the Lyapunov exponent, otherwise, it is equal to zero. We show that the competition/colonization trade-off is a function of the dispersal rate of the inferior competitor, and that it becomes less intense as the number of local communities increases, while the opposite is true with an increase in the number of refuges for the inferior competitor. We also show that under a priority effect type of scenario, dispersal can reverse priority effects and generate coexistence. Our results emphasize the importance of coexistence mechanisms related to the topology of the system of local communities, and its relationship with dispersal, in affecting the result of competition in local communities.
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    Desalinización: oportunidades y desafíos para abordar la inseguridad hídrica en chile
    (Ministerio de Ciencia, Tecnología, Conocimiento e Innovación, 2022) Vicuña, Sebastián; Daniele, Linda; Farías, Laura; González, Humberto; Marquet, Pablo A.; Palma Behnke, Rodrigo; Stehr, Alejandra; Urquiza, Anahí; Wagemann, Elizabeth; Arenas Herrera, María J.; Bórquez, Rodrigo; Cornejo Ponce, Lorena; Delgado, Verónica; Etcheberry, Gabriel; Fragkou, María Christina; Fuster, Rodrigo; Gelcich, Stefan; Melo, Óscar; Monsalve, Tamara; Olivares, Marcelo; Ramajo, Laura; Ramírez Pascualli, Carlos; Rojas, Carolina; Rojas, Christian; Vilca Salinas, Patricia; Winckler, Patricio; Winckler, Patricio; Lambert, Fabrice
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    Environmental heterogeneity as a driver of terrestrial biodiversity on a global scale
    (2023) Wan, Ji-Zhong; Wang, Chun-Jing; Marquet, Pablo A.
    To improve the effectiveness of biodiversity conservation and risk assessments under global changes, it is necessary to understand the drivers of terrestrial biodiversity on a global scale. Environmental heterogeneity is an important umbrella term for different environmental factors that contribute to species diversity. Previous studies have shown that there are significant relationships between geodiversity and biodiversity on a global scale, and that heterogeneity in geodiversity features and environmental variables, that is indicators of environmental heterogeneity (EH), drive biodiversity at local and regional scales. However, we do not yet know how terrestrial biodiversity is maintained, how well represented are the different taxa, and where would they be more at risks considering their abundances and diversities. In this study, we quantified EH of climate, topography, and land cover. We used four theoretical indexes (i.e., Fisher's alpha, Shannon's H, Hurlbert's PIE, and Good's u) to quantify terrestrial biodiversity based on abundance and diversity. We used regression models to explore the relationships between environmental heterogeneity and terrestrial biodiversity across different organismic groups (ants, bats, birds, butterflies, frogs, ground beetles, mosquitoes, odonates, orthopterans, rodents, scarab beetles, and trees) globally. We found significant relationships between environmental heterogeneity and terrestrial biodiversity, particularly for trees across the three EH components (climate, topography, and land cover), however, the effects of environmental heterogeneity on terrestrial biodiversity may vary among different groups of organisms. Land cover EH could affect the terrestrial biodiversity for ants, bats, birds, butterflies, frogs, mosquitoes, odonates, orthopterans, rodents, and scarab beetles. Furthermore, there were significant relationships between topographic EH and the terrestrial biodiversity for bats, butterflies, ground beetles, odonates, and trees. Climatic EH had significant effects on the terrestrial biodiversity for all organism groups. Our study provides new insights into biodiversity conservation by considering the terrestrial biodiversity based on EH, an indicator of geodiversity.
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    Establishment and formation of fog-dependent Tillandsia landbeckii dunes in the Atacama Desert: Evidence from radiocarbon and stable isotopes
    (2011) Latorre, Claudio; Gonzalez, Angelica L.; Quade, Jay; Farina, Jose M.; Pinto, Raquel; Marquet, Pablo A.
    Extensive dune fields made up exclusively of the bromeliad Tillandsia landbeckii thrive in the Atacama Desert, one of the most extreme landscapes on earth. These plants survive by adapting exclusively to take in abundant advective fog and dew as moisture sources. Although some information has been gathered regarding their modern distribution and adaptations, very little is known about how these dune systems actually form and accumulate over time. We present evidence based on 20 radiocarbon dates for the establishment age and development of five different such dune systems located along a similar to 215 km transect in northern Chile. Using stratigraphy, geochronology and stable C and N isotopes, we (1) develop an establishment chronology of these ecosystems, (2) explain how the unique T. landbeckii dunes form, and (3) link changes in foliar delta N-15 values to moisture availability in buried fossil T. landbeckii layers. We conclude by pointing out the potential that these systems have for reconstructing past climate change along coastal northern Chile during the late Holocene.
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    Azorella Cushion Plants and Aridity are Important Drivers of Soil Microbial Communities in Andean Ecosystems
    (2021) Rodriguez-Echeverria, Susana; Delgado-Baquerizo, Manuel; Morillo, Jose A.; Gaxiola, Aurora; Manzano, Marlene; Marquet, Pablo A.; Gonzalez, Leticia; Cavieres, Lohengrin A.; Pugnaire, Francisco I.; Armas, Cristina
    Cushion plants are specialized keystone species of alpine environments that can have a positive effect on ecosystem structure and function. However, we know relatively little about how cushion plants regulate the diversity and composition of soil microbial communities, major drivers of soil processes and ecosystem functioning. Identifying what factors drive the diversity and composition of soil microbial communities in high-elevation ecosystems is also fundamental to predict how global changes will affect their conservation and the services and functions they provide. Thus, we sampled four sites along the southern Andes following the vegetation belt of Azorella cushion species. The field sites spread along a latitudinal gradient and had contrasting levels of aridity, UV-B radiation, mean temperature and soil properties. Overall, Azorella, as well as aridity and UV-B radiation, were the major drivers of the distribution, composition and diversity of soil microbial communities in the studied ecosystems of the Chilean Andes. UV-B radiation affected particularly soil fungi, while soil properties such as pH, total C and N content, essential predictors of microbial diversity globally, had a much lower effect on the composition of soil microbial communities. Understanding the factors driving the structure and composition of microbial communities, particularly the role of cushion plants and the feedbacks between plant, climate and soil is of uttermost importance for the preservation of the functionality of high-elevation ecosystems threatened by climate change.
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    Insights on fostering the emergence of robust conservation actions from Zimbabwe's CAMPFIRE program
    (2019) Biggs, Duan; Ban, Natalie C.; Castilla, Juan Carlos; Gelcich, Stefan; Mills, Morena; Gandiwa, Edson; Etienne, Michel; Knight, Andrew T.; Marquet, Pablo A.; Possingham, Hugh P.
    One strategy to address threats to biodiversity in the face of ongoing budget constraints is to create an enabling environment that facilitates individuals, communities and other groups to self-organise to achieve conservation outcomes. Emergence (new activities and initiatives), and robustness (durability of these activities and initiatives over time), two related concepts from the common pool resources literature, provide guidance on how to support and enable such self-organised action for conservation. To date emergence has received little attention in the literature. Our exploratory synthesis of the conditions for emergence from the literature highlighted four themes: for conservation to emerge, actors need to 1) recognise the need for change, 2) expect positive outcomes, 3) be able to experiment to achieve collective learning, and 4) have legitimate local scale governance authority. Insights from the literature on emergence and robustness suggest that an appropriate balance should be maintained between external guidance of conservation and enabling local actors to find solutions appropriate to their contexts. We illustrate the conditions for emergence, and its interaction with robustness, through discussing the Communal Areas Management Programme for Indigenous Resources (CAMPFIRE) in Zimbabwe and reflect on efforts at strengthening local autonomy and management around the world. We suggest that the delicate balance between external guidance of actions, and supporting local actors to develop their own solutions, should be managed adaptively over time to support the emergence of robust conservation actions. (C) 2019 Published by Elsevier B.V.
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    Metastatic cells exploit their stoichiometric niche in the network of cancer ecosystems
    (2023) Castillo, Simon P.; Rebolledo, Rolando A.; Arim, Matias; Hochberg, Michael E.; Marquet, Pablo A.
    Metastasis is a nonrandom process with varying degrees of organotropism-specific source-acceptor seeding. Understanding how patterns between source and acceptor tumors emerge remains a challenge in oncology. We hypothesize that organotropism results from the macronutrient niche of cells in source and acceptor organs. To test this, we constructed and analyzed a metastatic network based on 9303 records across 28 tissue types. We found that the topology of the network is nested and modular with scale-free degree distributions, reflecting organotropism along a specificity/generality continuum. The variation in topology is significantly explained by the matching of metastatic cells to their stoichiometric niche. Specifically, successful metastases are associated with higher phosphorus content in the acceptor compared to the source organ, due to metabolic constraints in proliferation crucial to the invasion of new tissues. We conclude that metastases are codetermined by processes at source and acceptor organs, where phosphorus content is a limiting factor orchestrating tumor ecology.
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    Perspectives on the timing of ecosystem collapse in a changing climate
    (2024) Alaniz, Alberto J.; Marquet, Pablo A.; Carvajal, Mario A.; Vergara, Pablo M.; Moreira-Arce, Dario; Muzzio, Miguel A.; Keith, David A.
    Climate change is one of the most important drivers of ecosystem change, the global-scale impacts of which will intensify over the next 2 decades. Estimating the timing of unprecedented changes is not only challenging but is of great importance for the development of ecosystem conservation guidelines. Time of emergence (ToE) (point at which climate change can be differentiated from a previous climate), a widely applied concept in climatology studies, provides a robust but unexplored approach for assessing the risk of ecosystem collapse, as described by the C criterion of the International Union for Conservation of Nature's Red List of Ecosystems (RLE). We identified 3 main theoretical considerations of ToE for RLE assessment (degree of stability, multifactorial instead of one-dimensional analyses, and hallmarks of ecosystem collapse) and 4 sources of uncertainty when applying ToE methodology (intermodel spread, historical reference period, consensus among variables, and consideration of different scenarios), which aims to avoid misuse and errors while promoting a proper application of the framework by scientists and practitioners. The incorporation of ToE for the RLE assessments adds important information for conservation priority setting that allows prediction of changes within and beyond the time frames proposed by the RLE.
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    Phylogeny of the genera Euclidiodes and Hasodima (Lepidoptera: Geometridae) and description of two new species from the Fray Jorge relict forest in northern Chile
    (2009) Parra, Luis E.; Villagran-Mella, Romina; Marquet, Pablo A.
    The Fray Jorge National park contains the northernmost temperate relict forest of Chile (30 degrees 40'S), located over 1000 kilometers north of the rest of the coastal Aextoxicon punctatum (olivillo) communities of southern Chile. In this work we describe two new species of moths in the Fray Jorge relict forest belonging to the genera Hasodima Butler 1882 and Euclidiodes Warren 1895: H. ediliacarmenae Parra sp. nov. and E. frayjorgeana Parra sp. nov. The sister species of these new taxa are distributed in the central-southern zone of Chile, in plant associations where the olivillo is present. We hypothesize that the ancestor from which these species derived was widely distributed in association with coastal "olivillo" forests, which became restricted in distribution during interglacial periods, resulting in the isolation of these insects' populations, and their subsequent speciation.
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    Present-day and future climate over central and South America according to CMIP5/CMIP6 models
    (2021) Ortega, Geusep; Arias, Paola A.; Villegas, Juan Camilo; Marquet, Pablo A.; Nobre, Paulo
    In tropical regions, particularly in Central and South America (CSA), the projections of climate seasonality under climate change are still uncertain. This is especially true for ecologically-relevant variables such as precipitation and temperature. However, assessments of model-based projections of seasonal climate for this region are scarce. We analyzed the simulation of seasonal precipitation and air surface temperature in CSA and six sub-regions within from 49 models included in the Coupled Intercomparison Project Phase 5 (CMIP5) and 33 models from CMIP6. In general, continental patterns and seasonality of both variables are moderately well resembled, while most models show systematic biases over the oceans, producing unrealistic spatial patterns. To quantify how well CMIP5/CMIP6 models simulate these variables, we used Taylor diagrams with respect to TRMM for precipitation and ERA5 for temperature. Precipitation shows the largest spread among models. Conversely, temperature shows a better simulation. CMIP5/CMIP6 models exhibit a better performance simulating both variables during December-January-February and March-April-May than during the other seasons. This is partly due to the reduced model biases in representing the Intertropical Convergence Zone during these two seasons. In general, biases are reduced in the CMIP6 models with respect to CMIP5. Regarding regional evaluations, precipitation patterns for Mesoamerica, Cerrado and Chaco regions are better reproduced compared to TRMM, while the annual cycles for the Andes hotspot, Central Chile and Guianas are not well simulated, mainly during their wet seasons. However, these biases are reduced in CMIP6 models. In regard to precipitation projections, models only agree over most of the regions with decreasing precipitation. Conversely, temperature exhibits a general consensus on persistent warming even during the historical period, with an average increase of 6 degrees C by the end of the century, according to the CMIP6 models.
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    Priority questions for biodiversity conservation in the Mediterranean biome: Heterogeneous perspectives across continents and stakeholders
    (2019) Moreira, Francisco; Allsopp, Nicky; Esler, Karen J.; Wardell-Johnson, Grant; Ancillotto, Leonardo; Arianoutsou, Margarita; Clary, Jeffrey; Brotons, Lluis; Clavero, Miguel; Dimitrakopoulos, Panayiotis G.; Fagoaga, Raquel; Fiedler, Peggy; Filipe, Ana F.; Frankenberg, Eliezer; Holmgren, Milena; Marquet, Pablo A.; Martinez-Harms, Maria J.; Martinoli, Adriano; Miller, Ben P.; Olsvig-Whittaker, Linda; Pliscoff, Patricio; Rundel, Phil; Russo, Danilo; Slingsby, Jasper A.; Thompson, John; Wardell-Johnson, Angela; Beja, Pedro
    The identification of research questions with high relevance for biodiversity conservation is an important step towards designing more effective policies and management actions, and to better allocate funding among alternative conservation options. However, the identification of priority questions may be influenced by regional differences in biodiversity threats and social contexts, and to variations in the perceptions and interests of different stakeholders. Here we describe the results of a prioritization exercise involving six types of stakeholders from the Mediterranean biome, which includes several biodiversity hotspots spread across five regions of the planet (Europe, Africa, North and South America, and Australia). We found great heterogeneity across regions and stakeholder types in the priority topics identified and disagreement among the priorities of research scientists and other stakeholders. However, governance, climate change, and public participation issues were key topics in most regions. We conclude that the identification of research priorities should be targeted in a way that integrates the spectrum of stakeholder interests, potential funding sources and regional needs, and that further development of interdisciplinary studies is required. The key questions identified here provide a basis to identify priorities for research funding aligned with biodiversity conservation needs in this biome.