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Biosphere reserves have among their functions to support scientific research, education, training and monitoring. In the Cape Horn Biosphere Reserve (RBCH), created in 2005, these functions have been accomplished with the creation of the Omora Ethnobotanical Park in 2000, and its implementation in 2008 as a co-founder site of the Chilean Network of Studies Long-term Socio-Ecological (LTSER-Chile). In 2016, this network has been strengthened with the addition of the new Cape Horn Long-Term Socio-Ecological Research Network (LTSER-Cape Horn). The latter includes the Omora Ethnobotanical Park, and three new sites added to the monitoring of the sub-Antarctic Magellanic ecoregion of South America. From south to north, the four sites are: (1) Gonzalo Island (56°31’S; 68°43’O), at the southern end of the Diego Ramirez archipelago, with sub-Antarctic vegetation dominated by grasses and cryptogams, devoid of woody species; (2) Horn Island (55°58’S; 67°13’O), at the southern end of the Cape Horn Islands archipelago, hosting the southernmost forest ecosystems on the planet, which are dominated by Magellan’s coigue (Nothofagus betuloides); (3) Omora Ethnobotanical Park (54°56’S; 67’40’O), Navarino Island, an ideal site for studies on climate change and its impact on biota and sub-Antarctic ecosystems, since it protects a watershed that includes a representative mosaic of characteristic habitats of the RBCH in an altitudinal gradient with a thermal decrease analogous to that which occurs with increases in latitude; and (4) Caleta 2 de Mayo Site (54°52’S; 68’41’O), Yendegaia Bay, in an ecotonal zone between evergreen and deciduous forests (product of the local climate gradient), at a site that will be central to future connectivity between Continental Chile, Tierra del Fuego, Navarino Island, and the RBCH. In 2015, UNESCO approved the Report of the First Periodic Review of the RBCH that proposed the protection of the Diego Ramirez Archipelago and the creation of the Diego Ramirez Islands Marine Park-Drake Pass (creation decree published in the Diario Oficial of Chile in January 2019). In this context, the new LTSER-Cape Horn network acquires great local, national and global relevance. At the local scale, it covers a representative environmental heterogeneity of the great diversity of landscapes and terrestrial, freshwater and marine ecosystems of the RBCH and the sub-Antarctic Magellanic ecoregion. At the national scale, it incorporates sub-Antarctic monitoring sites, located at the southern end of South America, to LTSER-Chile and to the Monitoring Network of the Ministry of the Environment. On a global scale, the terrestrial ecosystems of the LTSER-Cape Horn network stands out for two main reasons: (1) these sub-Antarctic ecosystems lack a geographical replicate in the southern hemisphere, and (2) high latitude ecosystems are especially sensitive to global climate change. Thus, the LTSER-Cape Horn network helps to overcome critical geographical gaps in the implementation of the International Network for Long-Term Ecological Research (ILTER). In order to articulate these four sites and strengthen the training of technical capacities and knowledge transfer to decision makers in the area of special interest tourism and other sustainable economic activities, the LTSER-Cape Horn network will be managed locally from the new Cape Horn Sub-Antarctic Center (Cape Horn Center) that will be inaugurated in Puerto Williams in 2020. The implementation of the LTSER-Cape Horn network is based on a close collaboration with various actors: Ministry of National Assets, Ministry of Environment, Subsecretary of Fisheries and Aquaculture of the Ministry of Economy Development and Tourism, National Forestry Corporation (CONAF), General Water Directorate of the Ministry of Public Works, Navy of Chile, Chilean Police (Carabineros), Municipality of Cape Horn, Provincial Government of Chilean Antarctica, and the Regional Government of Magallanes and Chilean Antarctica. In the following phases, the LTSER-Cape Horn network and the Cape Horn Center aim to strengthen the participation of the local community, especially the Yahgan Indigenous Community of Bahia Mejillones, artisanal fisheries, tour operators, and the educational community, including private actors. Located at the “southern summit” of the Americas, Puerto Williams, capital of the Chilean Antarctic Province emerges as a global hub for transdisciplinary sub-Antarctic research, equipped with a new center and network of long-term socio-ecological studies. Collaboration with regional, national and international actors will allow the LTSER-Cape Horn network and the Cape Horn Center to: (i) provide critical data, which will open up new opportunities for monitoring climate change and its impact on biodiversity and ecosystems in sub-Antarctic latitudes; (ii) consolidate long-term monitoring, which is an essential component to effectively design mitigation and adaptation actions; (iii) strengthen a local sustainable development model that, associated with the Cape Horn Biosphere Reserve, contributes from the south of the world, to a biocultural conservation model that meets the needs of socio-economic well-being and environmental sustainability at multiple regional and planetary scales.

Biodiversity is vital in the functioning of ecosystems, but it’s permanently being threatened by anthropic impacts derived from productive activities. Thus, conservation has become a global challenge. In Chile, the dissociation between economic activities and conservation has triggered numerous socio-environmental conflicts in recent decades. This work explores how different projects that give rise to these conflicts can represent an underestimated threat to biodiversity. We identified socio-environmental conflicts in Chile and their associated projects by carrying out an online review of 1035 news articles published between 2004 and 2018 using the key words “environmental conflict”. We selected articles describing a socio-environmental conflict between parties caused by a project or productive sector. Conflict-generating projects were classified by productive sector and capital origin. In addition, their geographical distribution with respect to High Conservation Value Areas (HCVAs, protected areas and priority sites for conservation) was determined. A total of 283 projects were identified from 14 different productive sectors, most of them related to energy and mining, which threaten biodiversity and human well-being mainly due to pollution and habitat destruction. Chilean companies finance most of the projects, but international companies finance over half of the energy and mining projects. Moreover, 37 % of the projects were located within HCVAs either for the establishment of future protected areas or where protected areas are currently established. As countries make new efforts to maintain and recover biodiversity, it is contradictory not to consider the threats posed by conflict-generating projects to key areas for conservation, both in public policies and in spatial planning instruments.

The COVID-19 pandemic has caused a pause in people's activities and a socio-economic crisis worldwide due to confinement. This situation is an unprecedented opportunity to understand how these changes may impact biodiversity and its conservation, as well as to study human-nature interaction. Biodiversity plays an essential role in conservation and economic activities, and in countries with greater inequality and low gross domestic product (GDP), biodiversity could have a low priority. Moreover, how biodiversity is prioritized in a society impacts how the citizens view it, and digital news tends to shape biodiversity narratives. The aim of this work was to determine the main trends in biodiversity-related news categories during the COVID-19 pandemic in countries with terrestrial and marine hotspots and relate them to the socioeconomic and public health context of each country. For this, we searched for news on biodiversity and Covid-19 in the first 6 months of the pandemic and related them to GDP, Gini-index, deaths, and infections by Covid-19. Results showed that conservation, public policies, and use of natural resources stood out as the main news categories across countries, with a positive narrative and mostly related to terrestrial rather than marine environments. On the other hand, the socio-economic and public health characteristics of each country had an influence on which aspect of the biodiversity was reflected in the media. For example, countries with greater inequality were associated with tourism news, additionally, countries with low GDP, high cases, and deaths by Covid-19 were associated with news about cultural diversity. In contrast, countries with high GDP and low inequality were associated with news about zoonosis, research and development, public policies, and alien and invasive species.

During the last two decades, online media have played an increasing role in modeling modern societies. However, their role to shape public perception of biodiversity conservation and their alignment with conservation policies have received little attention so far. We conducted an extensive qualitative assessment of the interest in biodiversity in online media in the case-study of Chile in order to identify the main topics that are covered and how they vary across time and geographic scale. We also compared national trends of biodiversity interest in Chile and other countries as a first assessment of the international situation. Regarding Chilean digital media, our results highlight that there is a diversification of the biodiversity-related topics in news articles when reducing geographic scale. Overall, regardless of the considered scale, conservation policies, biodiversity loss, environmental education and citizen participation represented over 60% of the topics covered by digital news articles. Regarding the 8 selected countries, biodiversity interest in digital media followed two contrasting inter-annual trends equally: on the one side, a growing coverage of biodiversity topics (Brazil, Colombia, France and Spain), and on the other side, a constant or decreasing interest in the other countries (Australia, Chile, Costa Rica and South Africa). Our analysis also indicates that national media interest in biodiversity is multifactorial and may strongly depend on the link a country has between its economy and natural resources, its political influence on the media and the holding of major environmental summits coupled with concrete political actions. Apparent disconnection of media and public interest observed on a continuous scale may indicate that other factors are prone to shape the public interest in biodiversity. This first assessment calls for further research, especially about the underlying processes driving changes in biodiversity interest, in order to implement effective conservation actions. It also invites conservation managers to diversify their conservation targets, taking into consideration biodiversity interest transmitted by media to wide audiences.

El genero Prosopis (Mimosoideae, Leguminosae) constituye un importante recurso genetico de ambientes aridos y semiaridos. Prosopis chilensis (Molina) Stuntz es una especie multiproposito nativa de America del Sur que presenta una gran variabilidad fenotipica. En Chile, esta especie crece en la region semiarida, a lo largo de lechos de rios de los valles transversales. En este trabajo se estudio la diversidad genetica y la estructura genetica de poblaciones de P. chilensis en los tres valles transversales de la Region de Coquimbo (29o-32oS) mediante un analisis de diversidad genetica de 182 individuos con cuatro marcadores de microsatelites nucleares y uno de cloroplasto. Utilizando un analisis espacial de componentes principales (sPCA), se detecto una clara estructura genetica jerarquica. Este analisis revelo la existencia de siete grupos geneticos distintos en la region estudiada. Ninguno de los grupos geneticos detectados se superpuso entre los valles. Esto sugiere que las cadenas montanosas que separan los tres valles transversales pueden haber ejercido un efecto de barrera. Sin embargo, aunque significativa, la diferenciacion genetica de la poblacion fue baja y la mayor parte de la variacion genetica se encontro dentro de los grupos. Estos resultados sugieren que un alto flujo genico podria estar contrarrestando y desdibujando el efecto de factores de estructuramiento. Este es el primer estudio de genetica de poblaciones en P. chilensis en Chile y los datos geneticos obtenidos pueden ser de utilidad para la conservacion de esta especie arborea vulnerable y multiproposito.

In the southern Andes mountains (27-39◦S) Azorella madreporica and Laretia acaulis, two Apiaceae cushion plant species commonly known as yaretas, conform a well-established altitudinal vegetation belt along the lower Andean zone. These species have been considered as fundamental components of several ecological dynamics within their communities; however, high mountain ecosystems are increasingly threatened worldwide by natural and anthropogenic pressures and the southern Andes are not the exception. Recognizing that genetic information is crucial for the success of any conservation or restoration initiative inwild populations, we developed and cross-amplified 28 specifically designed microsatellite markers (14 in A. madreporica and 14 in L. acaulis), and also tested the cross amplification of 25 markers from the related species Azorella selago. In a region which is particularly vulnerable to global change trends, this new polymorphic microsatellite loci will be useful in the study of the genetic diversity of these high-mountain cushion plants, which are pivotal in the structuring of their native ecosystems.

Countries that are signatories of the Convention of Biological Diversity are committed to the goal of protecting 17% of their natural ecosystems by 2020. The lack of an up-to-date, operational classification and cartography of regional ecosystems seriously limits the assessment of progress towards this goal. Here, we present a broad ecosystem framework, which combines land use, functional traits of dominant plant species, and climatic factors for the classification of terrestrial ecosystems and apply this framework to classify Chilean terrestrial ecosystems. This new classification is consistent with the recently proposed IUCN framework to assess ecosystem conservation status. Using this framework, we identified and described 30 Chilean terrestrial ecosystems, including land units of natural and anthropogenic origin. We also provide a cartographic representation of ecosystems for land planning purposes and an overall assessment of their conservation status. We evaluated the representation of the 30 ecosystems in the Chilean National System of Protected Areas (NSPA) and in Private Protected Areas (PPA), identifying 15 ecosystems underrepresented (below the 17% target) in the NSPA, in contrast to only 11 when the area of NSPA+PPA was considered. The proposed classification can be broadly applicable to assess the conservation status of ecosystems elsewhere, using similar conceptual and methodological tools. The development of functional ecosystem classifications for different countries must be encouraged to facilitate monitoring of global conservation targets.

Plant facilitation is now recognized as an important process in severe environments. However, there is still no agreement on how facilitation changes as conditions become increasingly severe. The classic stress gradient hypothesis (SGH) predicts a monotonic increase in facilitation, which rises in frequency as conditions approach the extreme end of the environmental gradient. However, few studies have evaluated the validity of the SGH at the community level, the level at which it was formulated. Moreover, few studies have tested the SGH at either extreme of the gradient, and very few have excluded the effect of livestock on community response to stress. In line with the SGH, we hypothesized that several spatial pattern summary statistics would change monotonically from the least to the most arid sites, indicating increasingly aggregated patterns. In this study, we performed an evaluation of the SGH both within communities of shrub species and across a large portion of the Atacama Desert, and we isolated the abiotic component of the SGH. Our environmental gradient covered an extreme aridity gradient (

Understanding the regeneration niche of species may allow us to gain insight into how communities are structured. In deserts, the regeneration niche is usually related to spaces beneath shrubs where shade cast by shrubs creates microenvironments that benefit seedlings and where even small amounts of rain may favour germination and establishment. Shade and water may also interact with different types of soils. However, species may have different requirements for germination and seedling survival. We could expect that shrub species with different drought tolerances exhibit different responses to the combination of these factors. We ask if responses of dominant species of the Atacama Desert to abiotic factors (shade, water and soil type) are related to their drought tolerance, a topic not exhaustively explored in shrubs growing in true deserts. We conducted two factorial experiments. The first one was designed to evaluate how shade (microhabitat) in combination with water may affect germination (emergence) and early survival. In the second experiment, we assessed the influence of shade in relation to soil type. Each species responded distinctively to the three variables under study, but in general, their emergence responses were more influenced by water (more water, greater emergence) than by microhabitat or soil type. Survival was influenced both by microhabitat and by water and was higher under shade and abundant water. Soil type affected only one of our species in terms of emergence. Species responses in general depended on their tolerance to stress. In one species, there was indication of a seed–seedling conflict. Our results show similar species responses to environmental constraints but also more or less unique responses that are related to their tolerance to drought and which may ultimately permit species coexistence. We found that shade may not be important for germination but may be crucial for survival in dry years.

Models of plant–plant interactions suggest that nurse plants are critical for the maintenance of biodiversity and ecosystem functions in arid and semiarid lands. At the community scale, however, empirical support of this idea is limited and context-dependent. Following on a preliminary work which suggested that a dominant shrub in north-central Chile ( Porlieria chilensis ) had nurse plant effects, we tested the effects of this and two other shrubs ( Adesmia bedwellii and Proustia cuneifolia ) on community biomass production, species density, and species composition of ephemeral plants in the semiarid scrub of the Bosque Fray Jorge National Park (Chile) over four consecutive years. We tested for main and interactive effects of shrubs and precipitation on total biomass production and species density of ephemeral plant communities using Generalized Linear Mixed Models (GLMM). To analyze the effects of shrubs and precipitation on species composition we used Canonical Correspondence Analysis (CCA) and t-value biplot analysis. Total biomass production increased significantly with precipitation and was consistently lower beneath shrub canopies, particularly under A. bedwellii and P. chilensis . Although ephemeral plant species density generally was higher in open areas, differences between open and shrub canopy samples diminished with increasing precipitation. Finally, despite significant differences in ephemeral plant species composition between open areas and shrub canopies, we found no evidence of shrub species-specific effects. In conclusion, our results do not support a classical nurse plant syndrome in the semiarid scrub of the Bosque Fray Jorge National Park although shrubs can increase local diversity by favoring some ephemeral plant species that are absent in open areas.

In the winter-rain southern Atacama Desert of the Coquimbo Region of Chile, El Niño - Southern Oscillation (ENSO) events modulate primary productivity. In this region, there are important changes in water availability between La Niña (dry) and El Niño (rainy) years. Using inter-annual comparisons of LANDSAT images from 30° to 31° S latitude, we observed changes in primary productivity between dry and rainy years at the regional level. There were also significant, negative correlations between productivity and elevation, with changes occurring first at low elevation during rainy years. The limiting factors to dryland vegetation primary productivity is different in regard to elevation. Rain during an El Niño year is the main factor that explains the increase in primary productivity at low elevation, while lower temperatures reduce and delay the net primary productivity at mid elevation.

El estado de conservación de la flora nativa a una escala administrativa como la regional es útil para implementar medidas que reduzcan la pérdida de biodiversidad a nivel local. En este trabajo se clasifica la flora nativa de las regiones de Arica-Parinacota y de Tarapacá según su estado de conservación, utilizando una base de datos de 7.432 registros geo- referenciados que corresponden a 717 especies vasculares nativas. La clasificación se realizó utilizando principalmente los criterios de distribución geográfica de UICN (versión 3.1). Un 27,6% de las especies nativas presentes en estas regiones presentan problemas de conservación (3,2% En Peligro y 24,4% Vulnerable). En la Región de Arica y Parinacota las especies amenazadas alcanzarían el 34,4% de la flora nativa y el 24,3% en la Región de Tarapacá. La flora nativa de estas dos regiones tiene un grado de amenaza mayor que los encontrados en las regiones de Antofagasta, Atacama o Coquimbo. Esto se explica parcialmente por distribuciones restringidas (bajas extensiones de la presencia y/o áreas de ocupación) sumado a una disminución en la calidad de su hábitat.

In stressful environments, nurse elements, such as shrubs or rocks, facilitate plant recruitment by providing less severe environments for seed germination and seedling survival. As seedlings develop, however, they may compete for resources with their nurse when it is a plant instead of a rock. We examined the role of conspecific plants and rocks as nurses of an endangered Atacama-Desert shrub. Establishment was highest under conspecific plants, revealing that in stressful environments plants can facilitate establishment of their own species. Our study contrasts findings from other environments where recruitment is lowest near plants of the same species., Harsh environmental conditions in arid ecosystems limit seedling recruitment to microhabitats under nurse structures, such as shrubs or rocks. These structures, however, do not necessarily afford the same benefits to plants because nurse rocks provide only physical nurse effects, whereas nurse plants can provide both physical and biological nurse effects. Nevertheless, if the nurse plant is a conspecific, the benefits it provides may be outweighed by higher mortality due to negative density-dependent processes; consequently, negative density-dependence is expected to limit plants from acting as nurses to their own seedlings. The degree to which an abiotic nurse may be more beneficial than a conspecific one remains largely unexplored. Here, we examine the role and elucidate the mechanisms by which conspecific plants and rocks promote plant establishment in a hyper-arid desert. For 4 years, we examined establishment patterns of Myrcianthes coquimbensis (Myrtaceae), a threatened desert shrub that recruits solely in rock cavities and under conspecific shrubs. Specifically, we characterized these microhabitats, as well as open interspaces for comparison, and conducted germination, seed removal and seedling survival experiments. Our results revealed that conspecific shrubs and nurse rocks modified environmental conditions in similar ways; soil and air temperatures were lower, and water availability was higher than in open interspaces. We found no evidence on negative density-dependent recruitment: seed removal was lowest and seedling emergence highest under conspecific plants, moreover seedling survival probabilities were similar in rock cavities and under conspecific plants. We conclude that the probability of establishment was highest under conspecific plants than in other microhabitats, contrasting what is expected under the Janzen–Connell recruitment model. We suggest that for species living in stressful environments, population regulation may be a function of positive density-dependence and intraspecific facilitation may be a process that promotes the persistence of some plant species within a community.

Connectivity between populations plays a key role in the long-term persistence of species in fragmented habitats. This is of particular concern for biodiversity preservation in drylands, since water limited landscapes are typically characterized by little suitable habitat cover, high habitat fragmentation, harsh matrices, and are being rapidly degraded at a global scale. In this study, we modelled landscape connectivity between 11 guanaco Lama guanicoe populations in Chile's arid Norte Chico, a region that supports the last remnant coastal populations of this emblematic herbivore indigenous to South America. We produced a habitat suitability model to derive a regional surface resistance map, and used circuit theory to map functional connectivity, investigate the relative isolation between populations, and identify those that contribute most to the patch connectivity network. Predicted suitable habitat for L. guanicoe represented about 25% of the study region (i.e. 29,173 km2) and was heterogeneously distributed along a continuous stretch along the Andes, and discontinuous patches along the coast. As a result, we found that high connectivity current flows in the mid and high Andes formed a wide, continuous connectivity corridor, enabling connectivity between all high Andean populations. Coastal populations, in contrast, were more isolated. These groups demonstrate no inter-population connectivity between themselves, only with higher altitude populations, and for two of them, animal movement was linked to the effectiveness of wildlife crossings along the Pan-American highway. Our results indicate that functional connectivity is an issue of concern for L. guanicoe in Chile’s Norte Chico, implying that future conservation and management plans should emphasize strategies aimed at conserving functional connectivity between coastal and Andean populations, as well as the protection of habitat patches likely to act as stepping stones within the connectivity network. The raw material it is composed of three folders: 1. Maxent_products folder contains the main results and analysis of Maxent model results plus ocurrences data used for modelling.2. ResistanceSurf folder: this folder show the final landscape resistance used to build the connectivity model by using Circuitscape program. 3. Circuitscape matrix folder: contains the resistance matrix generated by circuitscape as from logistic output of maxent model.This study has been sumitted to PeerJ journal.

In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This interaction could be crucial in burrowing birds, which depend heavily on the availability of suitable nesting locations. One representative of this group is the burrowing parrot, Cyanoliseus patagonus that breeds on specific ravines and forms large breeding colonies. At a particular site, breeding aggregations require the concentration of adequate environmental elements for cavity nesting, which are provided by within ravine characteristics. Therefore, intrinsic ravine characteristics should be more important in determining nest site selection compared to landscape level characteristics. Here, we assess this hypothesis by comparing the importance of ravine characteristics operating at different scales on nest-site selection and their interrelation with reproductive success. We quantified 12 characteristics of 105 ravines in their reproductive habitat. For each ravine we quantified morphological variables, distance to resources and disturbance as well as nest number and egg production in order to compare selected and non-selected ravines and determine the interrelationship among variables in explaining ravine differences. In addition, the number of nests and egg production for each reproductive ravine was related to ravine characteristics to assess their relation to reproductive success. We found significant differences between non-reproductive and reproductive ravines in both intrinsic and extrinsic characteristics. The multidimensional environmental gradient of variation between ravines, however, shows that differences are mainly related to intrinsic morphological characteristics followed by extrinsic variables associated to human disturbance. Likewise, within reproductive ravines, intrinsic characteristics are more strongly related to the number of nests. The probability of producing eggs, however, was related only to distance to roads and human settlements. Patterns suggest that C. patagonus mainly selects nesting sites based on intrinsic morphological characteristics of ravines. Scale differences in the importance of ravine characteristics could be a consequence of the particular orography of the breeding habitat. The arrangement of resources is associated to the location of the gullies rather than to individual ravines, determining the spatial availability and disposition of resources and disturbances. Thus, nest selection is influenced by intrinsic characteristics that maximize the fitness of individuals. Scaling in nest-selection is discussed under an optimality approach that partitions patch selection based on foraging theory.

Aims Plant functional traits determine how plants respond to environmental factors and influence ecosystem processes. Among them, root traits and analyses of relations between above and below-ground traits in natural communities are scarce. We characterized a set of above- and below-ground traits of three dominant shrub species in a semiarid shrub-steppe that had contrasting leaf phenological habits (deciduous, semideciduous and evergreen). We analysed if there was coordination among above- and below-ground resource economics patterns: i.e. patterns of biomass allocation, construction costs and lifespan. Important Findings Above- and below-ground traits and their resource economics relations pointed to species-specific functional strategies to cope with drought and poor soils and to a species ranking of fast to slow whole-plant strategies in terms of resource uptake, biomass construction costs and turnover. The deciduous shrub, Proustia cuneifolia, had relatively deep and even distribution of roots, and high proportion of short-lived tissues of low C construction costs: it had high fine to coarse root and high leaf-to-stem biomass ratios, high specific leaf area (SLA), and stems of low wood density. This strategy allows Proustia to maximize and coordinate above- and belowground resources uptake as long as the most limiting factor (water) is available, but at the cost of having relative high plant biomass turnover. The evergreen Porlieria chilensis, instead, displayed a more conservative and slow strategy in terms of resource economics. It had ~80% of the roots in the 40 cm topsoil profile, low proportion of fine compared with coarse roots and low leaf-to-stem ratios, low SLA and stems of high wood density, i.e. it invested in C costly tissues that, overall, persist longer but probably at the cost of having lower plant resource uptake rates. Traits in the semideciduous Adesmia bedwellii were in between these two functional extremes. Our results revealed high functional diversity and aboveand below-ground complementarity in resource economics among these three codominant species in the Chilean coastal desert.

The definition of a common vision that includes social and environmental goals, ecosystem services and/or biodiversity features that people are interested in maintaining or restoring is a great challenge for marine protected areas (MPAs). Recent initiatives have promoted broadening the focus from biodiversity conservation alone to the conservation of both ecosystem services and biodiversity, indicating that this integration should improve support and compliance from stakeholders. Using a Multiple-Use Coastal Marine Protected Area recently proposed in northern Chile, we investigated (i) stakeholders’ perceptions of the valuation of ecosystem services, threats to their provision, and the prioritization of ecosystem services, biodiversity features, and uses in a planning scenario, and (ii) stakeholders’ expectations for the establishment of a new MPA. The perceptions of different groups of stakeholders were compared and statistically analyzed, and the relationships among prioritizations were studied using a network approach. Stakeholders identified and valued 13 ecosystem services, 28 biodiversity features, 20 uses and activities, and 22 threats. Significant differences among the valuations and prioritizations of different stakeholder groups were attributable principally to artisanal fishermen's perceptions of some components that are directly related to their activities and livelihoods. High expectations of benefits from a new MPA implementation were observed for all categories of stakeholders. To relate the different valuated components, we proposed a network-based conceptual model that reduces complexity, and also as a strategy to communicate relationships and trade-offs occurring in this particular social–ecological system to the several stakeholders. We strongly recommend early stakeholder engagement so as to understand the variability in environmental perceptions and then reflect that variation in the planning and management actions of MPAs, thus improving support for their implementation and achieving conservation and societal goals. Our findings indicate that stakeholders’ perceptions and prioritizations of ecosystem services, biodiversity features and uses should be used as the basis for starting the MPA implementation and planning process.

The ecology of macroinvertebrate communities in arid regions is still poorly understood. Here we examined how the community structure varied at spatial and temporal scales in streams and tributaries of the Huasco River in semi-arid region of Northern Chile. We expected that macroinvertebrate distribution may be responding to natural processes of mineralization described for Chilean semiarid basins. The relationships among biotic and abiotic variables were assessed through multivariate techniques (principal component analysis, non-metric multidimensional scaling, canonical correspondence analysis), and a two-way analysis of similarity was used to evaluate differences between basins and years (2007, 2008, and 2009). Significant differences in community structure and physical–chemical variables between basins (Del Carmen and Del Transito) were found, but not between years. Altitude, Mn, Al, Ca, Na, HCO3, and dissolved oxygen were the variables that best accounted for the communities distribution. In particular, high metals concentration in El Transito basin should determine low density and diversity of macroinvertebrates. Chironomidae, Ephydridae, and Glossiphoniidae were associated to waters with high metals content and acidic pH, whereas Baetidae, Hydroptilidae, and Blephariceridae were associated to sites with more favorable physical–chemical conditions. These results contribute to understand the ecological patterns of macroinvertebrates in arid regions and should lead to conservation and monitoring plans for this remote place.

La perdida de la biodiversidad producida por el crecimiento demografico, la demanda por recursos y la actividad productiva es contradictoria con el reconocimiento de su importancia. En ecosistemas terrestres, el Sistema Nacional de Areas Protegidas del Estado (SNASPE) contiene cerca del 19 % del territorio de Chile continental; aunque no representa todos los ecosistemas con especies amenazadas, puede ser complementado implementando nuevas areas protegidas publicas (AP) y privadas (APP). El desarrollo de areas marinas protegidas (AMP) es incipiente, y algunas iniciativas comparten la responsabilidad de conservacion con los usuarios locales. En Chile, un conjunto de reglamentos, normas legales y tratados internacionales promueven distintas oportunidades de conservacion en ecosistemas terrestres y marinos costeros, de las cuales emergen nuevos desafios. Entre estos destacan, estandarizar la clasificacion de especies segun categorias de conservacion en un protocolo internacional y optimizar las metodologias para seleccionar areas prioritarias, ambos criterios indispensables para decidir que y donde conservar. Otro desafio es integrar el valor intrinseco de la biodiversidad con los servicios ecosistemicos que presta para instaurar una cultura participativa. Esto mejoraria la efectividad de las distintas estrategias de proteccion y uso sustentable de la biodiversidad al incorporar la educacion y la participacion ciudadana desde una perspectiva biocultural. La educacion fomenta la conservacion de la naturaleza al hacernos conscientes de nuestro entorno; mientras que la participacion involucra a los ciudadanos como un actor mas en la toma de decisiones, procurando la aplicacion efectiva de las estrategias de conservacion de la biodiversidad.

El aumento de la demanda energética chilena en los últimos años ha promovido la creación de una gran cantidad de proyectos de generación eléctrica. La posible instalación de tres centrales termoeléctricas a carbón al norte de la Región de Coquimbo y en las inmediaciones de áreas definidas como claves para la conservación y manejo de la biodiversidad marina (e.g., reservas marinas, áreas de manejo y explotación de recursos bentónicos) y terrestre (e.g., reserva nacional, sitios prioritarios), ha generado conflictos sociales y controversias sobre su ubicación y compatibilidad con los usos propuestos para el área. El presente comentario plantea el conflicto que se origina entre la necesidad de cubrir los requerimientos energéticos de Chile y la implementación de iniciativas de conservación y manejo de recursos naturales. Se describe la importancia y relevancia ecológica y económica del área de posible instalación de las termoeléctricas y se revisan los principales impactos reportados para este tipo de tecnología sobre la salud humana y ecosistémica. Finalmente, se proponen enfoques y herramientas que pueden asistir en la toma de decisiones y en la resolución de conflictos.In recent years, Chilean increasing energy needs have promoted the creation of many initiatives to generate electricity. The possible installation of three coal-fired power plants in the coastal area north of the Region of Coquimbo and close to areas identified as key to the conservation and management of marine (e.g., marine reserves, management and exploitation areas for benthic resources) and terrestrial (e.g., national reserve, priority sites) biodiversity, has generated social conflicts and raised concerns about the location and compatibility with others proposed uses for the area. This commentary proposes the conflict that arises between the need to cope with Chile's energy needs and the implementation of conservation and management of natural resources initiatives. We describe the ecological and economic significance and importance of the area of possible installation of power plants and the main impacts reported for this type of technology on human and ecosystem health. Finally, we suggest approaches and tools that can help in decision-making and conflicts resolution.

The abundance of exotic plants is thought to be limited by competition with resident species (including plants and generalist herbivores). In contrast, observations in semiarid Chile suggest that a native generalist rodent, the degu (Octodon degus), may be facilitating the expansion of exotic annual plants. We tested this hypothesis with a 20-year data set from a World Biosphere Reserve in mediterranean Chile. In this semiarid environment, rainfall varies annually and dramatically influences cover by both native and exotic annual plants; degu population density affects the composition and cover of exotic and native annual plants. In low-rainfall years, cover of both native and exotic herbs is extremely low. Higher levels of precipitation result in proportional increases in cover of all annual plants (exotic and native species), leading in turn to increases in degu population densities, at which point they impact native herbs in proportion to their greater cover, indirectly favoring the expansion of exotic plants. We propose that bottom-up control of consumers at our site results in top-down indirect facilitation of invasive annual herbs, and that this pattern may be general to other semiarid ecosystems.

A partir de 1985 comienzan los esfuerzos del Estado de Chile, con el apoyo de especialistas, para generar listas de especies de plantas (1985) y animales (1987) con altos a moderados riesgos de extinción en el corto plazo producto de actividades antrópicas (i.e., especies amenazadas). Las siete categorías de amenazas utilizadas para la fauna coinciden con las empleadas por la Unión Internacional para la Conservación de la Naturaleza (UICN) en 1982; para la flora hubo coincidencia en solo cinco de las categorías utilizadas. En el año 1994, la Ley 19300 de Bases del Medio Ambiente estableció seis categorías de estados de conservación. El Reglamento para la Clasificación de Especies Silvestres, promulgado el 2005, definió estas seis categorías haciendo una combinación entre lo propuesto por la UICN en 2001 y 1982. La generación de este sistema híbrido que no era comparable con el utilizado ampliamente en el mundo, restringió severamente la posibilidad de clasificar a las especies con amenaza inferior al nivel de Vulnerable. Complicaciones adicionales se generaron con la inclusión de categorías de conservación en la Ley 19473 de Caza (1996), la Ley 20283 sobre Recuperación del Bosque Nativo y Fomento Forestal (2008), y sus respectivos reglamentos. La Ley 20417 (publicada el 26 de enero 2010) modificó la ley 19300 e incorporó las categorías recomendadas por la UICN. Ahora el Estado requiere adecuar varios cuerpos legales para avanzar en el conocimiento del estado de conservación de la flora y la fauna nacional, y consecuentemente, asegurar la implementación de medidas efectivas de protección de la biodiversidad.Since 1985, the Chilean government with the participation and support of different specialists in plant and animal conservation, started the publication of checklists (i.e. red books) of plant (1985) and animal species (1987) with high to modérate risk of extinction due to human activities (i.e. threatened species). The seven categories of threats used in these publications matched those used by the International Unión for the Conservation of Nature (IUCN) in 1982; nonetheless, for the flora there was matching only in five of the categories used. In 1994, the Law 19300 on the General Bases of the Environment established six categories of conservation status. The regulations for the classification of the wild species in Conservation categories, enacted in 2005, defined these six categories, which resulted from a combination of those proposed by the IUCN in 2001 and 1982. The generation of this hybrid system, which is not fully comparable with that of the IUCN (2001) and widely used in the rest of the world, has severely restricted the possibility of classifying species with a threat level lower than "Vulnerable". Further complications were generated due to the definition of conservation categories that appeared in the Laws 19473 (1996) regulating the hunting activity and 20283 (2008) supporting the native forest recovery and forestry development. The Law 20417 (enacted in January 26, 2010) modified the Law 19300 and incorporated the categories recommended by IUCN. Currently, the State requires adapting several legal bodies to advance in the knowledge of the conservation status of the nation's flora and fauna, and consequently, ensure the implementation of effective efforts to protect our biodiversity.

Questions: (1) What is the water threshold for shrub seedling establishment in arid scrubland? (2) How do seedling root growth morphological traits affect the water threshold required for seedling establishment? Location: Arid scrubland, Atacama Desert, north-central Chile. Methods: We conducted a field experiment with nine native shrub species under a gradient of simulated rainfall to test if species with deep root architecture have higher seedling survival rates and establish more successfully during water pulses. Results: Seedling survival rate was very low; only 2% of the 12150 planted seedlings survived the first summer drought. Seedling survival required at least 206mm of water, which is twice the average rainfall and roughly equivalent to the precipitation during an ENSO (El Ni˜ no Southern Oscillation) event in this region. Seedling survival at the onset of the summer drought was best explained by leaf habit, root length and initial seedling size. However, only Senna cumingii seedlings survived through the first year. S. cumingii seedlings had distinctively longer roots than the other shrub species, enabling them to reach moister soil layers. Conclusions: Water conditions resembling rainy years enhance shrub seedling establishment in the Atacama Desert, but the effects of higher water availability are strongly dependent on the shrub species. Rapid and deep rooting appears to be a very important functional trait for successful first-year survival in this arid system where water availability is highly episodic.

La producción de carbón vegetal a partir de arbustos leñosos es una de las principales amenazas para la vegetación nativa en zonas áridas. En este trabajo se estima la producción de carbón en la provincia de Huasco, al sur de la Región de Atacama, y se identifican las principales especies utilizadas en este proceso. Se detectaron 21 puntos de venta de carbón nativo en el área de estudio. En cada uno de ellos se recolectaron muestras del carbón comercializado, las que fueron posteriormente comparadas con muestras de referencia. Se realizaron 28 entrevistas a vendedores, productores de carbón nativo e informantes claves, para estimar el volumen de producción anual. Se identificaron 4 sitios productivos en la zona de estudio, tres de ellos entre Vallenar y El Tránsito, y uno en Incahuasi-Tres Cruces. Se estimó para el año 2007 una producción total de carbón vegetal de 281 toneladas para la provincia de Huasco, lo que equivale a una extracción anual de arbustos en un área de entre 573 y 1.112 hectáreas. Los principales arbustos nativos utilizados corresponden a Fabiano imbricata (Solanaceae), Balsamocarpon brevifolium (Fabaceae) y Adesmia hystrix (Fabaceae).Charcoal production from woody shrubs is one of the main threats to native vegetation in arid zones. The aim of this investigation was to estimate the production of charcoal produced in Huasco province, southern of Atacama Región, and to identify the main species used in this process. Twenty one points of sale of native charcoal were detected in the study área. In each point, samples of the commercialized charcoal were collected and subsequently compared with reference samples. Twenty eight sellers, charcoal producers, and key informants were interviewed to estimate the volume of annual production. Four places of production were identified in the study área, three of them between Vallenar and El Tránsito, and one of them in Incahuasi-Tres Cruces. For 2007, a total production of 281 tons of charcoal was estimated in Huasco province, which is equivalent to an annual extraction of shrubs between 573 y 1,112 hectares. The main native shrubs used for the production of charcoal are Fabiana imbricata (Solanaceae), Balsamocarpon brevifolium (Fabaceae) and Adesmia hystrix (Fabaceae).

La produccion de carbon vegetal a partir de arbustos lenosos es una de las principales amenazas para la vegetacion nativa en zonas aridas. En este trabajo se estima la produccion de carbon en la provincia de Huasco, al sur de la Region de Atacama, y se identifican las principales especies utilizadas en este proceso. Se detectaron 21 puntos de venta de carbon nativo en el area de estudio. En cada uno de ellos se recolectaron muestras del carbon comercializado, las que fueron posteriormente comparadas con muestras de referencia. Se realizaron 28 entrevistas a vendedores, productores de carbon nativo e informantes claves, para estimar el volumen de produccion anual. Se identificaron 4 sitios productivos en la zona de estudio, tres de ellos entre Vallenar y El Transito, y uno en Incahuasi-Tres Cruces. Se estimo para el ano 2007 una produccion total de carbon vegetal de 281 toneladas para la provincia de Huasco, lo que equivale a una extraccion anual de arbustos en un area de entre 573 y 1.112 hectareas. Los principales arbustos nativos utilizados corresponden a Fabiano imbricata (Solanaceae), Balsamocarpon brevifolium (Fabaceae) y Adesmia hystrix (Fabaceae).

Premise of the study Drought is the most limiting factor for plant growth and recruitment in arid environments. For widespread species, however, plant responses to drought can vary across populations because environmental conditions can vary along the range of the species. Here, we assessed whether plants of Encelia canescens from different populations along an aridity gradient in the Atacama Desert respond differently to water-deficit conditions. Methods We conducted a common-garden experiment using plants grown from seeds from three populations distributed along an aridity gradient to test for differences in relative growth rate (RGR), biomass, root to shoot ratios, and photosynthesis between watered and water-deficit plants. Additionally, we examined the relationship between root to shoot ratios with RGR and total plant biomass along the gradient. Key results Water deficit affected root to shoot ratios, biomass, and RGR, but not photosynthesis. Populations varied in RGR and biomass; plants from the most arid population had higher RGRs, but lower biomass than those from the least arid population. In watered conditions, root to shoot ratios did not vary with RGR or biomass. Conversely, with the water deficit, root to shoot ratios were negatively and positively related to biomass and RGR, respectively. Conclusions Response to water deficit differed among E. canescens populations; plants from the lowest rainfall environment adjusted root to shoot ratios, which may have allowed for equal biomass production across treatments. In contrast, plants from the wettest population did not adjust root to shoot ratios, but were reduced in biomass. These morphological and physiological changes to water availability showed that populations can use different strategies to cope with water deficit.

BACKGROUND: Seed loss to predators is a common phenomenon across plant communities and an important determinant of plant recruitment. Although seed predators commonly destroy the entire seed, partial seed consumption has been reported for many species; however, the degree to which seed mass loss affects germination dynamics and survival of new individuals has been poorly documented. We simulated seed damage in natural conditions to examine how different levels of cotyledonary reserve removal affect germination dynamics and seedling performance of Myrcianthes coquimbensis (Myrtaceae), a threatened Atacama Desert shrub. The experiment combined two levels of seed maturity with three levels of seed mass loss. RESULTS: Removal of the cotyledon reserves and seed maturity negatively affected the odds and the temporality of seedling emergence; nonetheless, seedlings were able to emerge from seed fragments, of either mature or immature seeds, that lost up to 75% of their original mass. Removal of cotyledonary reserves had negative effects on seedling size but no effect on root:shoot ratios. CONCLUSIONS: Our findings indicate that the loss of cotyledonary reserves in M. coquimbensis seeds is not necessarily lethal. Moreover, we posit that tolerance to partial seed consumption is likely a key reproductive strategy, which enables recruitment in this species.

Feces-based population genetic studies have become increasingly popular. However, polymerase chain reaction (PCR) amplification rates from fecal material vary depending on the species, populations, loci, and extraction protocols. Here, we assessed the PCR amplification success of three microsatellite markers and a segment of the mitochondrial control region of DNA extracted from field-collected feces of guanaco (Lama guanicoe) using two protocols - Qiagen DNA Stool Kit and 2 cetyltrimethylammonium bromide/phenol:chloroform:isoamyl alcohol (2CTAB/PCI) method. Chelex resin treatment to remove inhibitors was also tested. Our results show that the mitochondrial locus was the most difficult to amplify. PCR success rates improved for all markers after Chelex treatment of extracted DNA, and 2CTAB/PCI method (95.83%) appeared to perform slightly better than stool kit (91.67%) for the nuclear markers. Amplification success was significantly influenced by the extraction method, Chelex treatment, and locus (P0.001) but not by the freshness of the feces (fresh vs old, P = 0.17). The repeatability levels were high without Chelex treatment (0.89), but they decreased slightly after treatment for amplification of nuclear markers and markedly after treatment for amplification of the mitochondrial control region. Thus, we showed that Chelex treatment gives high PCR success, especially for nuclear markers, and adequate DNA extraction rates can be achieved from L. guanicoe feces even from non-fresh fecal material. Although not significant, 2CTAB/PCI method tended to provide higher successful amplification rates on a whole set of samples, suggesting that the method could be particularly useful when using small sample sizes.

The understanding of the water cycle is one of the key elements to evaluate the present and long-term primary productivity in arid ecosystems. This study uses hydrogeological and isotope tools to evaluate the recharge mechanisms in a coastal unconfined gravel and sand aquifer located in the arid zone of north-central Chile. The main water sources in the study area, fog, rain and groundwater, were isotopically characterized over a decade. The isotope data confirm previous studies based on fog capture, that fog does not play any role in groundwater recharge. The water table and isotope data showed that during low water conditions (dry periods), the aquifer is maintained primarily by water recharged in the higher part of the Romeral basin. During high water table conditions (wet periods), recharge associated with local precipitation becomes a significant source of groundwater recharge. The water table data showed that the aquifer responded very fast to rains with amounts over the average level for precipitation and the fastest response was observed during the El Nino year of 1997. No recharge was detected with precipitation events lower than the average value for precipitation. The aquifer recharge pattern in the coastal area of the Romeral Basin has significant implications for functional groups of plants characterized by deep root systems that have low capacity to respond directly to precipitation and consequently use groundwater as their main water source for new plant growth and reproduction. The recharge pattern can also influence the behavior of other functional groups characterized by a dimorphic root systems than can perform hydraulic redistribution. Part of the fast recharge of the aquifer could be related to this water redistribution. This study also shows that wetlands near the coast are fed mainly by groundwater associated with regional groundwater systems linked to recharge areas located in the high part of the Elqui River Basin.

While climatic extremes are predicted to increase with global warming, we know little about the effect of climatic variability on biome distribution. Here, we show that rainy El Nino Southern Oscillation (ENSO) events can enhance tree recruitment in the arid and semiarid ecosystems of north-central Chile and northwest Peru. Tree-ring studies in natural populations revealed that rainy El Nino episodes have triggered forest regeneration in Peru. Field experiments indicate that tree seedling recruitment in Chile is much less successful than in Peru due mostly to larger mortality caused by herbivores. The dramatic impact of herbivores in Chile was derived from the combined result of slower plant growth and the presence of exotic herbivores (European rabbits and hares). The interplay of herbivory and climatic effects we demonstrated implies that rainy ENSO events may represent 'windows of opportunity' for forest recovery if herbivore pressure is minimized at the right moment.

There is an exceptional group of alpine peatlands in the world situated in the arid grasslands of the central Andes. The peatlands in northern Chile occur in the most arid part of their range. Members of the Juncaceae are the primary peat-forming plant species. Fresh and mildly saline groundwaters originate from glaciers, snowmelt and rain are the water sources for the northern Chile peatlands. Paleoecological investigations suggest that some peatlands are recent features of the landscape having developed within the last three thousand years or less. These peatlands are unique, extremely fragile water features sensitive to climate changes and human disturbances such as regional mining activity. Much more work is required to develop scientifically based sound management and conservation programs for the rare plants and animals that live in them and to ensure the future livelihoods of the indigenous peoples who depend on themExiste un grupo excepcional de turberas (bofedales) de alta montaña en el mundo situados en la estepa árida de los Andes centrales. Los bofedales en el norte de Chile están presentes en la parte más árida de su rango. Las principales especies de plantas responsables de la formación de turba corresponden a miembros de Juncaceae. El agua fresca y medianamente salina de los bofedales proviene de agua subterránea asociada a riachuelos proveniente de glaciares, derretimiento de nieve y lluvia. Investigaciones paleoecológicas sugieren que algunos bofedales son integrantes recientes del paisaje, habiéndose desarrollado durante los últimos tres mil años o menos. Estos bofedales son entidades únicas, extremadamente frágiles por su dependencia del agua, sensibles a los cambios climáticos y vulnerables a la alteración humana tal como la actividad minera en la región. Se requiere mucho más trabajo para desarrollar programas de manejo y conservación, con sólidas bases científicas, de las plantas y animales que viven en ellos, y para asegurar la capacidad futura de pastoreo de la cual dependen los pueblos indígenas

Fundamentally, El Niño Southern Oscillation (ENSO) is a climatic and oceanographic phenomenon, but it has profound effects on terrestrial ecosystems. Although the ecological effects of ENSO are becoming increasingly known from a wide range of terrestrial ecosystems (Holmgren et al., 2001), their impacts have been more intensively studied in arid and semiarid systems. In this brief communication, we summarize the main conclusions of a recent symposium on the effects of ENSO in these ecosystems, which was convened as part of the First Alexander von Humboldt International Conference on the El Niño Phenomenon and its Global Impact, in Guayaquil, Ecuador, from 16–20 May 2005. Participants in the symposium shared results and perspectives from research conducted in North and South America and Australia, regions where the ecological effects of ENSO have been studied in depth. Although the reports covered a wide array of organisms and ecological systems (Fig. 1), a recurring theme was the strong increase in rainfall associated with ENSO events in dry ecosystems (during the El Niño phase of the oscillation in the Americas and the La Niña phase in Australia). Because inter-annual variability in precipitation is such a strong determinant of productivity in arid and semiarid ecosystems, increased ENSO rainfall is crucial for plant recruitment, productivity and diversity in these ecosystems. Several long-term studies show that this pulse in primary productivity causes a subsequent increase in herbivores, followed by an increase in carnivores, with consequences for changes in ecosystem structure and functioning that can be quite complex.

Aim Colliguaja odorifera Mol., a Euphorbiaceous shrub of central Chile, inhabits the matorral formation, growing at low altitudes on both Andean and coastal mountain range slopes. In the recent geological past, this region was subjected to climatic changes and geological disturbances that most probably caused population shrinkages on the Andean mountain slopes. This study tested the hypothesis that under such a scenario, existing populations should show lower genetic diversity in the Andean than in the coastal areas; these coastal populations being the potential source populations for recolonization. Location The study was carried out in central Chile by comparing the genetic diversity between the Andean and coastal areas, each represented by five localities distributed from 32°30′ S to 34° S. Methods Genetic diversity was estimated by DNA analysis using 18 dominant multilocus Random Amplified Polymorphic DNA (RAPD) loci, characterizing 73 genetic phenotypes. Results The comparison of the two matorral areas showed that Andean populations of C. odorifera have a subset of the genetic diversity found in the coastal populations. Andean populations also show a consistently lower genetic diversity, lower genetic distances and higher genetic structure, coincident with expectations based on the Pleisto-Holocenic perturbation regime. Main conclusions This first genetic analysis for South American mediterranean populations confirms the findings of previous floristic and palynological studies that identified refuge zones in the coastal mountain range of central Chile, a situation analogous with that occurring during periods of inter-glacial northward migration in Southern Europe. Resumen Objetivo Colliguaja odorifera Mol., arbusto euforbiaceo de Chile central, habita una formacion de matorral creciendo a bajas altitudes tanto en pendientes de las cordilleras de Los Andes como de la costa. En el pasado reciente esta region fue sometida a cambios climaticos y perturbaciones geologicas que muy probablemente condujeron a reducciones de las poblaciones andinas. Este estudio somete a prueba la hipotesis que bajo tal escenario las poblaciones actuales deberian tener menor diversidad genetica en las areas andinas que en las costeras, siendo estas las potenciales fuentes de recolonizacion. Ubicacion El estudio se llevo a cabo en Chile central comparando la diversidad genetica entre las areas andinas y costeras representadas cada una por cinco localidades distribuidas entre las latitudes 32°30′ S y 34° S. Metodos La diversidad genetica fue estimada por analisis del ADN usando 18 alelos multilocus de tipo RAPD (Random Amplified Polymorphic DNA) caracterizando 73 fenotipos geneticos. Resultados La comparacion de las dos areas de matorral mostraron que las poblaciones andinas de C. odorifera poseen un subconjunto de la diversidad genetica encontrada en las poblaciones costeras. Las poblaciones andinas muestran tambien una consistente menor diversidad genetica, menores distancias y alta estructura genetica, coincidentes con las espectativas basadas en un regimen de perturbaciones pleisto-holocenico. Conclusiones principales Este primer analisis genetico para poblaciones mediterraneas confirma estudios previos de tipo floristico y palinologico que revelan zonas de refugio en la cordillera de la costa de Chile central, en analogia a lo que ocurrio en el Sur de Europa durante los periodos de migracion interglacial hacial el Norte.

Seed predation and seed dispersal are important ecological processes with antagonistic effects on plant recruitment. In the southern edge of the Atacama Desert in Chile, Myrcianthes coquimbensis is an endangered, large-seeded, vertebrate-dispersed shrub that in the present-day has no known dispersers. Native rodents hoard and eat the seeds of M. coquimbensis but leave viable seed fragments at the hoarding sites; soil interspaces within rock outcrops where seedlings recruit. Here we examined whether rodents act as effective dispersers of M. coquimbensis by discarding viable seed fragments in sites suitable for recruitment. We simulated different levels of endosperm loss to determine if seedlings could develop from seed fragments. We assessed how frequently rodents discarded fragments, and the probability that these fragments produced seedlings. Finally, we compared emergence and seedling survival at the hoarding sites and in two other habitats where seeds arrive to evaluate the suitability of the hoarding sites. Seeds of M. coquimbensis developed seedlings even after 87% of their storage tissue was removed. Rodents left seed fragments in more than 50% of the trials; almost 60% of the discarded fragments produced seedlings. Seedlings did not emerge from open ground habitats, and emergence was higher under M. coquimbensis shrubs than in rock habitats. Survival of two-year-old seedlings was higher in rock habitats than under conspecific adult shrubs. Our results suggest that rodents may play a dual role in the recruitment dynamics of M. coquimbensis, acting simultaneously as seed predators and effective dispersers. Therefore, though seed predators impose costs, their net effect on plant fitness in this system—where dispersers of large-seeded species have been lost—is likely positive.

El agua es el factor más importante que afecta a la productividad primaria y la estructura de la vegetación en ecosistemas áridos. Dado que las especies de plantas pueden diferir en sus capacidades de utilizar distintas fuentes de agua, el conocimiento de estos aspectos es fundamental para los planes de conservación, manejo y restauración ecológica. En un estudio realizado en el secano costero del norte-centro de Chile (29" 43' S, 71" 14' O, 300 msnm), se compararon los mecanismos de utilización de distintas fuentes de agua por las especies arbustivas, en dos a1'íos con precipitaciones contrastantes. En este trabajo se incluyen antecedentes de estudios fenológicos; arquitectura radical y fuentes de agua utilizadas por arbustos mediante el uso de isótopos estables. Para e l sistema estudiado se reconocen 6 grupos funcionales basados en la obtención y utilización del agua. Los grupos funcionales fueron definidos con base en su hábito (caducifolios y siempre verdes), sus sistemas radicales (superficial, dimórfico o profundo) y la capacidad de utilizar distintas fuentes de agua (superficial y/ o profunda). Debido al impacto diferencial sobre los distintos grupos funcionales, se postula que el sobre pastoreo con caprinos resultaría en una menor utilización de aguas superficiales. Un plan de manejo y/o restauración debería maximizar la utilización de todas las fuentes de agua disponibles para recuperar la productividad primaria y la estabilidad del sistema. Esto se lograría a través de reforzar los grupos funcionales más afectados y a las especies facilitadoras. Estos planes deben considerar además el escenario futuro, que incluye desde las tendencias climáticas (e.g., disminución de las precipitaciones) y cambios socio-culturales (e.g., promoción de la crianza intensiva del ganado caprino en lugar de extensiva).