CEAZA
Continuities and discontinuities in the socio-environmental systems of the Atacama Desert during the last 13,000 years
Santoro, C. M., Capriles, J. M., Gayo, E. M., de Porras, M. E., Maldonado, A., Standen, V. G., Latorre, C., Castro, V., Angelo, D., McRostie, V., Uribe, M., Valenzuela, D., Ugalde, P. C., & Marquet, P. A.
Understanding how human societies interacted with environmental changes is a major goal of archaeology and other socio-natural sciences. In this paper, we assess the human-environment interactions in the Pampa del Tamarugal (PDT) basin of the Atacama Desert over the last 13,000 years. By relying on a socio-environmental model that integrates ecosystem services with adaptive strategies, we review past climate changes, shifting environmental conditions, and the continuities and discontinuities in the nature and intensity of the human occupation of the PDT. As a result we highlight the importance of certain key resources such as water, an essential factor in the long-term trajectory of eco-historical change. Without water the outcome of human societies becomes hazardous.
Año: 2017
Palabras claves: Atacama Desert, Pampa del Tamarugal, Climate change, Continuities and discontinuities, Human-environment interaction, Hyperarid environments, Water
Referencia APA: Santoro, C. M., Capriles, J. M., Gayo, E. M., de Porras, M. E., Maldonado, A., Standen, V. G., Latorre, C., Castro, V., Angelo, D., McRostie, V., Uribe, M., Valenzuela, D., Ugalde, P. C., & Marquet, P. A. (2017). Continuities and discontinuities in the socio-environmental systems of the Atacama Desert during the last 13,000 years. Journal of Anthropological Archaeology, 46, 28-39. https://doi.org/10.1016/j.jaa.2016.08.006
A 7000‐year high‐resolution lake sediment record from coastal central Chile (Lago Vichuquén, 34° S): implications for past sea level and environmental variability
Frugone‐Álvarez, M., Latorre, C., Giralt, S., Polanco‐Martínez, J., Bernárdez, P., Oliva‐Urcia, B., Maldonado, A., Carrevedo, M.L., Moreno, A., Delgado-Huertas, A., Prego, R., Barreiro-Lostres, F., & Valero-Garcés, B.
We present a 7‐ka environmental reconstruction based on sedimentological and geochemical data from Lago Vichuquén, a coastal eutrophic lake in central Chile (34°48′S, 72°03′ W, 4 m a.s.l.). A relatively shallow and restricted marine environment with low productivity, high detrital input and dominant anoxic conditions in the Vichuquén Basin occurred from 7.0 to 6.5 cal ka BP. Rapid onset of a Holocene marine transgression at 6.5 cal ka BP favoured deeper and more biologically productive environments that existed until 2.8 cal ka BP. Bioproductivity changes during the mid‐Holocene (6.5–4.2 cal ka BP) were related to upwelling dynamics controlled by the intensity of the South‐east Pacific Anticyclone (SPA). Periods with lower organic productivity and dominant anoxic conditions reflect an increased intensity of SPA (increased upwelling) and decreased precipitation. A shift at ∼4.0 cal ka BP reflects the onset of modern Southern Westerly Winds and El Niño‐Southern Oscillation patterns. Tectonic uplifting and geormorphological activity (dune advancement) are possible reasons behind the Vichuquén Basin closure at ∼1.2 cal ka BP, leading to a low bioproductivity lacustrine environment which has developed until the present.
Año: 2017
Palabras claves: Climate change, Central Chile, Coastal upwelling, Holocene, Sea‐level change, Sedimentology
Referencia APA: Frugone‐Álvarez, M., Latorre, C., Giralt, S., Polanco‐Martínez, J., Bernárdez, P., Oliva‐Urcia, B., Maldonado, A., Carrevedo, M.L., Moreno, A., Delgado-Huertas, A., Prego, R., Barreiro-Lostres, F., & Valero-Garcés, B. (2017). A 7000‐year high‐resolution lake sediment record from coastal central Chile (Lago Vichuquén, 34° S): implications for past sea level and environmental variability. Journal of Quaternary Science, 32(6), 830-844. http://dx.doi.org/10.1002/jqs.2936
The Andes Cordillera. Part I: snow distribution, properties, and trends (1979–2014)
Mernild, S. H., Liston, G. E., Hiemstra, C. A., Malmros, J. K., Yde, J. C., & McPhee, J.
Snow cover presence, duration, properties, and water amount play a major role in Earth's climate system through its impact on the surface energy budget. Snow cover conditions and trends (1979–2014) were simulated for South America – for the entire Andes Cordillera. Recent data sets and SnowModel developments allow relatively high‐resolutions of 3‐h time step and 4‐km horizontal grid increment for this domain. US Geological Survey's Global Multi‐resolution Terrain Elevation Data 2010 topography, Global Land Cover (GlobCover), Randolph Glacier Inventory (v. 4.0) glacier, and NASA modern‐era retrospective analysis for research and applications data sets were used to simulate first‐order atmospheric forcing (e.g. near‐surface air temperature and precipitation, including the fraction of precipitation falling as snow) and terrestrial snow characteristics (e.g. snow cover days, snow water equivalent depth, and snow density). Simulated snow conditions were verified against moderate‐resolution imaging spectroradiometer‐derived snow cover extent and 3064 individual direct observations of snow depths. Regional variability in mean annual air temperature occurred: positive trends in general were seen in the high Andes Cordillera, and negative trends at relatively lower elevations both east and west of the Cordillera. Snow precipitation showed more heterogeneous patterns than air temperature due to the influence from atmospheric conditions, topography, and orography. Overall, for the Cordillera, much of the area north of 23°S had a decrease in the number of snow cover days, while the southern half experienced the opposite. The snow cover extent changed ∼−15% during the simulation period, mostly between the elevations of ∼3000 and 5000 m above sea level (a.s.l.). However, below 1000 m a.s.l. (in Patagonia) the snow cover extent increased. The snow properties varied over short distances both along and across the Andes Cordillera.
Año: 2017
Palabras claves: Andes Cordillera modelling, NASA, MERRA MODIS, SnowModel, Snow, Snow classification, South America
Referencia APA: Mernild, S. H., Liston, G. E., Hiemstra, C. A., Malmros, J. K., Yde, J. C., & McPhee, J. (2017). The Andes Cordillera. Part I: snow distribution, properties, and trends (1979–2014). International Journal of Climatology, 37(4), 1680-1698.http://dx.doi.org/10.1002/joc.4804
Demography and ecology of southern right whales Eubalaena australis wintering at sub-Antarctic Campbell Island, New Zealand
Torres, L. G., Rayment, W., Olavarría, C., Thompson, D. R., Graham, B., Baker, C. S., Patenaude, N., Bury, S.J., Boren, L., Parker, G., & Carroll, E. L.
Since the decimation of the southern right whale Eubalaena australis population in New Zealand by whaling, research on its recovery has focused on the wintering ground at the Auckland Islands, neglecting potentially important wintering habitat at Campbell Island. For the first time in 20 years we conducted an expedition to sub-Antarctic Campbell Island to document and describe E. australis occupying this wintering habitat. We used a variety of methods including photo-identification, genetic and stable isotope analyses of tissue samples, and visual surveys of abundance and distribution, to provide details on the demography, population connectivity and ecology of E. australis wintering at Campbell Island. Our primary findings include (1) a lack of calves observed at Campbell Island, (2) an age-class bias toward sub-adults encountered at Campbell Island, (3) nine photo-identification matches between individuals observed at Campbell Island and previously documented elsewhere in New Zealand, (4) no genetic differentiation between E. australis at Campbell Island and the broader New Zealand population, (5) increased abundance estimates of E. australis at Campbell Island over the last 20 years, and (6) indications that E. australis forage within the sub-Antarctic region based on stable isotope analyses. Our results confirm that the Auckland Islands are currently the only significant calving area for E. australis in New Zealand, and therefore previous abundance estimates based on demographic data from the Auckland Islands are applicable to the entire New Zealand population of E. australis. However, future periodic surveys to Campbell Island are recommended to monitor population recovery and expansion.
Año: 2017
Palabras claves: Age-class, Genetic analysis, Population connectivity, Stable isotope, Sub-Antarctic, Wintering ground, Parentage analysis
Referencia APA: Torres, L. G., Rayment, W., Olavarría, C., Thompson, D. R., Graham, B., Baker, C. S., Patenaude, N., Bury, S.J., Boren, L., Parker, G., & Carroll, E. L. (2017). Demography and ecology of southern right whales Eubalaena australis wintering at sub-Antarctic Campbell Island, New Zealand. Polar Biology, 40(1), 95-106. http://dx.doi.org/10.1007/s00300-016-1926-x
Meroplankton distribution in South Pacific islands, implications for larval connectivity
Meerhoff, E., Ramos, M., Yannicelli, B., Bravo, L., Zambra, D., & Varela, C
The knowledge on the mechanisms of population connectivity through larval stages and its implications across time and spatial scales is crucial to assess possible biological outcomes of marine protected areas (MPA) network designs. We re-analyzed available data on meroplankton distribution in the Rapa Nui ecoregion around Easter Island (27° S, 109°22′ W) and Salas y Gómez Island (26°28′S, 105°21′W) together with in situ and satellite physical and biological information to evaluate its implications for mechanisms of populations connectivity. The geostrophic flow near the coast of Easter Island included vertical and horizontal shears which, combined with vertical migration behavior of the larvae, would promote larval retention. Larval duration in the plankton and a possible effect of connection through seamounts between islands could cause the distribution pattern of ichthyoplankton endemic species between both islands. Finally, we studied the role of sub-mesoscale structures (<10 km) in the distribution of chlorophyll and meroplankton using the finite size Lyapunov exponent (FSLE). Lagrangian coherent structures which are identified as ridges of FSLE were related to higher in situ depth integrated chlorophyll, higher insular and oceanic ichthyoplankton abundances, and explained differences in the ichthyoplankton community structure around Salas y Gómez island.
Año: 2017
Palabras claves:
Referencia APA: Meerhoff, E., Ramos, M., Yannicelli, B., Bravo, L., Zambra, D., & Varela, C. (2017). Meroplankton distribution in South Pacific islands, implications for larval connectivity. Journal of Plankton Research, 40(1), 77-90. https://doi.org/10.1093/plankt/fbx053
Assessment of transboundary river basins for potential hydro-political tensions
De Stefano, L., Petersen-Perlman, J., Sproles, E., Eynard, J., & Wolf, A.
This paper presents a systematic, global assessment of transboundary watersheds that identifies regions more likely to experience hydro-political tensions over the next decade and beyond based upon environmental, political, and economic indicators. The development of new water infrastructure in transboundary basins can strain relationships among fellow riparians as the impacts of new dams and diversions are felt across borders. Formal arrangements governing transboundary river basins, such as international water treaties and river basin organizations, provide a framework for dialogue and negotiation, thus contributing to assuaging potential disputes. Our study examines these two issues in tandem − the stresses inherent in development and the mitigating impact of institutions − and maps the risk of potential hydro-political tensions that exist where basins may be ill-equipped to deal with transboundary disputes triggered by the construction of new dams and diversions. We also consider several factors that could exacerbate those hydropolitical tensions in the near future, including changes in terrestrial water storage, projected changes in water variability, per capita gross national income, domestic and international armed conflicts, and recent history of disputes over transboundary waters. The study points to the vulnerability of several basins in Southeast Asia, South Asia, Central America, the northern part of the South American continent, the southern Balkans as well as in different parts of Africa, where new water infrastructure is being built or planned, but formal transboundary arrangements are absent. Moreover, in some of these regions there is a concomitance of several political, environmental and socioeconomic factors that could exacerbate hydropolitical tensions. This study contributes to the understanding of how the recent proliferation of development accompanied with unfavourable socio-economic and environmental indicators may influence global hydropolitical resilience.
Año: 2017
Palabras claves: Transboundary, Treaty, Assessment, Dispute, Cooperation, Conflict
Referencia APA: De Stefano, L., Petersen-Perlman, J., Sproles, E., Eynard, J., & Wolf, A. (2017). Assessment of transboundary river basins for potential hydro-political tensions. Global Environmental Change, 45, 35-46.
Different sensitivities of snowpacks to warming in Mediterranean climate mountain areas
López-Moreno, J., Gascoin, S., Herrero, J., Sproles, E., Pons, M., Alonso-González, E., Hanich, L., Boudhar, A., Musselman, K.N., Molotch, N.P.
In this study we quantified the sensitivity of snow to climate warming in selected mountain sites having a Mediterranean climate, including the Pyrenees in Spain and Andorra, the Sierra Nevada in Spain and California (USA), the Atlas in Morocco, and the Andes in Chile. Meteorological observations from high elevations were used to simulate the snow energy and mass balance (SEMB) and calculate its sensitivity to climate. Very different climate sensitivities were evident amongst the various sites. For example, reductions of 9%–19% and 6–28 days in the mean snow water equivalent (SWE) and snow duration, respectively, were found per °C increase. Simulated changes in precipitation (±20%) did not affect the sensitivities. The Andes and Atlas Mountains have a shallow and cold snowpack, and net radiation dominates the SEMB; and explains their relatively low sensitivity to climate warming. The Pyrenees and USA Sierra Nevada have a deeper and warmer snowpack, and sensible heat flux is more important in the SEMB; this explains the much greater sensitivities of these regions. Differences in sensitivity help explain why, in regions where climate models project relatively greater temperature increases and drier conditions by 2050 (such as the Spanish Sierra Nevada and the Moroccan Atlas Mountains), the decline in snow accumulation and duration is similar to other sites (such as the Pyrenees and the USA Sierra Nevada), where models project stable precipitation and more attenuated warming. The snowpack in the Andes (Chile) exhibited the lowest sensitivity to warming, and is expected to undergo only moderate change (a decrease of <12% in mean SWE, and a reduction of < 7 days in snow duration under RCP 4.5). Snow accumulation and duration in the other regions are projected to decrease substantially (a minimum of 40% in mean SWE and 15 days in snow duration) by 2050.
Año: 2017
Palabras claves: Snow, Mediterranean mountains, climate warming, snow simulations
Referencia APA: López-Moreno, J., Gascoin, S., Herrero, J., Sproles, E., Pons, M., Alonso-González, E., Hanich, L., Boudhar, A., Musselman, K.N., Molotch, N.P. (2017). Different sensitivities of snowpacks to warming in Mediterranean climate mountain areas. Environmental Research Letters, 12(7), 074006.
First circumglobal assessment of Southern Hemisphere humpback whale mitochondrial genetic variation and implications for management
Rosenbaum H.C., Kershaw F., Mendez M., Pomilla C., Leslie M.S., Findlay K.P., Best P.B., Collins T., Vely M., Engel M.H., Baldwin R., Minton G., Meÿer M., Flórez-González L., Poole M.M., Hauser N., Garrigue C., Brasseur M., Bannister J., Anderson M., Olavarría C., Baker C.S.
The description of genetic population structure over a species’ geographic range can provide insights into its evolutionary history and also support effective management efforts. Assessments for globally distributed species are rare, however, requiring significant international coordination and collaboration. The global distribution of demographically discrete populations for the humpback whale Megaptera novaeangliae is not fully known, hampering the definition of appropriate management units. Here, we present the first circumglobal assessment of mitochondrial genetic population structure across the species’ range in the Southern Hemisphere and Arabian Sea. We combine new and existing data from the mitochondrial (mt)DNA control region that resulted in a 311 bp consensus sequence of the mtDNA control region for 3009 individuals sampled across 14 breeding stocks and subpopulations currently recognized by the International Whaling Commission. We assess genetic diversity and test for genetic differentiation and also estimate the magnitude and directionality of historic matrilineal gene flow between putative populations. Our results indicate that maternally directed site fidelity drives significant genetic population structure between breeding stocks within ocean basins. However, patterns of connectivity differ across the circumpolar range, possibly as a result of differences in the extent of longitudinal movements on feeding areas. The number of population comparisons observed to be significantly differentiated were found to diminish at the subpopulation scale when nucleotide differences were examined, indicating that more complex processes underlie genetic structure at this scale. It is crucial that these complexities and uncertainties are afforded greater consideration in management and regulatory efforts.
Año: 2017
Palabras claves: Humpback whale, International Whaling Commission, Management unit, Population structure, Southern Hemisphere, Arabian Sea
Referencia APA: Rosenbaum H.C., Kershaw F., Mendez M., Pomilla C., Leslie M.S., Findlay K.P., Best P.B., Collins T., Vely M., Engel M.H., Baldwin R., Minton G., Meÿer M., Flórez-González L., Poole M.M., Hauser N., Garrigue C., Brasseur M., Bannister J., Anderson M., Olavarría C., Baker C.S. (2017). First circumglobal assessment of Southern Hemisphere humpback whale mitochondrial genetic variation and implications for management. Endangered Species Research 32: 551–567.
Ancient female philopatry, asymmetric male gene flow, and synchronous population expansion support the influence of climatic oscillations on the evolution of South American sea lion (Otaria flavescens)
Oliveira L.Rd., Gehara M.C.M., Fraga L.D, Lopes F., Túnez J.I., Cassini M.H., Majluf P., Cárdenas-Alayza S., Pavés H.J., Crespo E.A., García N., Loizaga de Castro R., Hoelzel A.R., Sepúlveda M., Olavarría C., Valiati V.H., Quiñones R., Pérez-Alvarez M.J., Ott P.H., Bonatto S.L.
The South American sea lion (Otaria flavescens) is widely distributed along the southern Atlantic and Pacific coasts of South America with a history of significant commercial exploitation. We aimed to evaluate the population genetic structure and the evolutionary history of South American sea lion along its distribution by analyses of mitochondrial DNA (mtDNA) and 10 nuclear microsatellites loci. We analyzed 147 sequences of mtDNA control region and genotyped 111 individuals of South American sea lion for 10 microsatellite loci, representing six populations (Peru, Northern Chile, Southern Chile, Uruguay (Brazil), Argentina and Falkland (Malvinas) Islands) and covering the entire distribution of the species. The mtDNA phylogeny shows that haplotypes from the two oceans comprise two very divergent clades as observed in previous studies, suggesting a long period (>1 million years) of low inter-oceanic female gene flow. Bayesian analysis of bi-parental genetic diversity supports significant (but less pronounced than mitochondrial) genetic structure between Pacific and Atlantic populations, although also suggested some inter-oceanic gene flow mediated by males. Higher male migration rates were found in the intra-oceanic population comparisons, supporting very high female philopatry in the species. Demographic analyses showed that populations from both oceans went through a large population expansion ~10,000 years ago, suggesting a very similar influence of historical environmental factors, such as the last glacial cycle, on both regions. Our results support the proposition that the Pacific and Atlantic populations of the South American sea lion should be considered distinct evolutionarily significant units, with at least two managements units in each ocean.
Año: 2017
Palabras claves: Sea lions, Mitochondrial DNA, Chile (country), Population genetics, Haplotypes, Peru, Argentina, Oceans
Referencia APA: Oliveira L.Rd., Gehara M.C.M., Fraga L.D, Lopes F., Túnez J.I., Cassini M.H., Majluf P., Cárdenas-Alayza S., Pavés H.J., Crespo E.A., García N., Loizaga de Castro R., Hoelzel A.R., Sepúlveda M., Olavarría C., Valiati V.H., Quiñones R., Pérez-Alvarez M.J., Ott P.H., Bonatto S.L. (2017). Ancient female philopatry, asymmetric male gene flow, and synchronous population expansion support the influence of climatic oscillations on the evolution of South American sea lion (Otaria flavescens). PLoS ONE 12(6): e0179442.
Largest baleen whale mass mortality during strong El Niño event is likely related to harmful toxic algal bloom
Häussermann, V., Gutstein, C., Beddington, M., Cassis, D., Olavarria, C., & Dale, A., Valenzuela-Toro, A.M., Valenzuela-Toro, M.J., Sepúlveda, H.H., McConnell, K.M., Horwitz, F.E., Försterra, G.
While large mass mortality events (MMEs) are well known for toothed whales, they have been rare in baleen whales due to their less gregarious behavior. Although in most cases the cause of mortality has not been conclusively identified, some baleen whale mortality events have been linked to bio-oceanographic conditions, such as harmful algal blooms (HABs). In Southern Chile, HABs can be triggered by the ocean–atmosphere phenomenon El Niño. The frequency of the strongest El Niño events is increasing due to climate change. In March 2015, by far the largest reported mass mortality of baleen whales took place in a gulf in Southern Chile. Here, we show that the synchronous death of at least 343, primarily sei whales can be attributed to HABs during a building El Niño. Although considered an oceanic species, the sei whales died while feeding near to shore in previously unknown large aggregations. This provides evidence of new feeding grounds for the species. The combination of older and newer remains of whales in the same area indicate that MMEs have occurred more than once in recent years. Large HABs and reports of marine mammal MMEs along the Northeast Pacific coast may indicate similar processes in both hemispheres. Increasing MMEs through HABs may become a serious concern in the conservation of endangered whale species.
Año: 2017
Palabras claves: Chilean Patagonia, Red tide, El Niño, Sei whales, Drift models, Balaenoptera borealis, Paralytic shellfish poison, Balaenopteridae, Taphonomy, Climate Change
Referencia APA: Häussermann, V., Gutstein, C., Beddington, M., Cassis, D., Olavarria, C., & Dale, A., Valenzuela-Toro, A.M., Valenzuela-Toro, M.J., Sepúlveda, H.H., McConnell, K.M., Horwitz, F.E., Försterra, G. (2017). Largest baleen whale mass mortality during strong El Niño event is likely related to harmful toxic algal bloom. Peerj, 5, e3123.
Pollination Ecology of Polylepis tomentella (Rosaceae), an Andean Anemophilous Tree Presenting a Potential Floral Fungal Infection
Domic, A., Bernhardt, P., Edens-Meier, R., Camilo, G., & Capriles, J.
Premise of research. Anemophily is considered to be a mechanism that evolved to promote pollination success. However, reproductive output can decrease if pollen loads are scarce due to low abundance of compatible mates or floral infections. Here we analyze the effects of breeding system, pollen limitation, and a potential floral fungal infection on the reproductive output of the Andean tree Polylepis tomentella (Rosaceae).
Methodology. We performed pollen supplementation experiments in the field to assess the extent of the effect of pollen limitation on fruit and seed set and to identify any pre- or postzygotic self-incompatibility responses within receptive pistils. Supplementary scanning electron microscopy and epifluorescence microscopy were used to observe the possible effects of a potential floral fungal infection on sexual reproduction.
Pivotal results. Pollen supplementation did not increase fruit and seed set, suggesting weak evidence of pollen limitation. Most stigmas from self- and cross-pollinated flowers showed germinated pollen grains and pollen tubes in the style, indicating that the species exhibits prezygotic self-compatibility. The presence of three Ascomycota genera in stigmas and styles appears to have negatively affected the germination of pollen grains by inhibiting pollen tube growth, but we did not find evidence suggesting that hyphae are able to penetrate the ovary.
Conclusions. This study showed that P. tomentella possesses a prezygotic self-compatible system and that fruit and seed set are not affected by pollen limitation. Therefore, reproductive assurance is achieved through pollen transfer between plants by wind and the role played by self-compatibility that allows selfing in the species. However, it is possible that the potential fungal infection could reduce the fecundity of its tree host, as hyphae are able to penetrate pollen grains.
Año: 2017
Palabras claves: Pollen limitation, Potential floral fungal infection, Prezygotic self-incompatibility, Treeline, Wind pollination.
Referencia APA: Domic, A., Bernhardt, P., Edens-Meier, R., Camilo, G., & Capriles, J. (2017). Pollination Ecology of Polylepis tomentella (Rosaceae), an Andean Anemophilous Tree Presenting a Potential Floral Fungal Infection. International Journal Of Plant Sciences, 178(7), 512-521.
Patterns of composition, richness and phylogenetic diversity of woody plant communities of Quillaja saponaria Molina (Quillajaceae) in the Chilean sclerophyllous forest
Letelier, L., Valderrama, A., Stoll, A., García-Gonzáles, R., & González-Rodríguez, A.
Sclerophyllous forest is among the most representative types of woody plant communities in central Chile where Quillaja saponaria is considered to be one of the most important species. In this study, we analysed the main factors that explain the geographical patterns of variation in composition, richness and phylogenetic diversity of woody plant communities in the Chilean sclerophyllous forest where Quillaja saponaria is present. Vegetation surveys were performed for trees and shrubs in thirty-nine sites from 30° to 38° of latitude South in the Mediterranean biome of Chile. Composition, richness, alfa diversity and phylogenetic diversity metrics of the communities were calculated and associated with spatial (latitude, longitude and altitude), climate (annual mean temperature, annual precipitation, aridity), and disturbance variables (type of adjacent vegetation matrix) using multiple regression models. Sixty taxa were identified, distributed in 29 families, including 23 trees and 37 shrubs. A significant effect of the type of adjacent vegetation matrix (i.e. agricultural land, commercial forestry plantation or natural forest) on diversity and composition of the sampled communities was found. Significant effects of latitude on diversity, and altitude, latitude and annual mean temperature on composition were also found. Metrics of phylogenetic diversity and structure were only associated with altitude and latitude. In conclusion, diversity, composition and phylogenetic structure patterns of sclerophyllous forest communities are associated with spatial and climate variables, and anthropogenic disturbance has also caused important changes in these communities.
Español
El Bosque Esclerófilo es uno de los tipos más representativos de las comunidades de plantas leñosas en el centro de Chile, donde Quillaja saponaria es considerada una de las especies más importantes. En este trabajo se analizaron los principales factores que explican la distribución geográfica de la variación en la composición, riqueza y diversidad filogenética de las comunidades de plantas leñosas del Bosque Esclerófilo de Chile, donde Q. saponaria está presente. Se llevaron a cabo censos de vegetación de árboles y arbustos en treinta y nueve sitios desde los 30° a los 38° de latitud sur en el bioma mediterráneo de Chile. Se calcularon la composición, riqueza, diversidad alfa y la diversidad filogenética de las comunidades y se asociaron con variables espaciales (latitud, longitud y altitud), climáticas (temperatura media anual, precipitación anual, aridez), y variables de perturbación (tipo de matriz de la vegetación adyacente) usando modelos de regresión múltiple. Se identificaron sesenta taxones, distribuidos en 29 familias, incluyendo 23 árboles y 37 arbustos. Se encontró un efecto significativo del tipo de matriz de vegetación adyacente (es decir, tierras agrícolas, plantaciones forestales comerciales o bosques naturales) en la diversidad y composición de las comunidades estudiadas. También se encontraron efectos significativos de la latitud sobre la diversidad; y de la altitud, latitud y temperatura media anual sobre la composición de las comunidades, la diversidad filogenética sólo se asoció con la altitud y la latitud. En conclusión, la diversidad, composición y patrones de estructura filogenética se asocian con variables espaciales y climáticas; y las perturbaciones antropogénicas también han provocado cambios importantes en estas comunidades.
Año: 2017
Palabras claves: Diversity; forest fragmentation; Mediterranean flora; phylogenetic diversity; vegetation matrix
Referencia APA: Letelier, L., Valderrama, A., Stoll, A., García-Gonzáles, R., & González-Rodríguez, A. (2017). Patterns of composition, richness and phylogenetic diversity of woody plant communities of Quillaja saponaria Molina (Quillajaceae) in the Chilean sclerophyllous forest. Gayana. Botánica, (ahead), 0-0.