Mapping and characterizing social-ecological land systems of South America

Humans place strong pressure on land and have modified around 75% of Earth’s terrestrial surface. In this context, ecoregions and biomes, merely defined on the basis of their biophysical features, are incomplete characterizations of the territory. Land system science requires classification schemes that incorporate both social and biophysical dimensions. In this study, we generated spatially explicit social-ecological land system (SELS) typologies for South America with a hybrid methodology that combined data-driven spatial analysis with a knowledge-based evaluation by an interdisciplinary group of regional specialists. Our approach embraced a holistic consideration of the social-ecological land systems, gathering a dataset of 26 variables spanning across 7 dimensions: physical, biological, land cover, economic, demographic, political, and cultural. We identified 13 SELS nested in 5 larger social-ecological regions (SER). Each SELS was discussed and described by specific groups of specialists. Although 4 environmental and 1 socioeconomic variable explained most of the distribution of the coarse SER classification, a diversity of 15 other variables were shown to be essential for defining several SELS, highlighting specific features that differentiate them. The SELS spatial classification presented is a systematic and operative characterization of South American social-ecological land systems. We propose its use can contribute as a reference framework for a wide range of applications such as analyzing observations within larger contexts, designing system-specific solutions for sustainable development, and structuring hypothesis testing and comparisons across space. Similar efforts could be done elsewhere in the world

Modeling unobserved variables in dendrochronological age structures improves inferences about population dynamics.

The loss of evidence poses a major challenge to historical ecology. For example, dendroecological studies aiming at relating tree establishment with past climate should consider the possibility that many plants might not survive to be recorded at the date of the study. A standard approach to deal with this data loss consists in fitting an exponential decay curve to the observed age structure and using the residuals of this fit as a proxy of tree establishment. Here we show that Hierarchical Bayesian analysis (HBA) where tree establishment is modeled as a latent variable can outperform the standard approach. We illustrate the use of HBA with a simulation study where the goal is to infer population dynamics from dendrochronological age-structures. Both methods are also used to analyze empirical data from expanding alder forests in northwestern Argentina. The simulation study showed that the standard approach underestimated the association between rainfall and tree establishment. The HBA was unbiased and had narrower uncertainty around estimates. In the empirical study, the HBA detected effects of rainfall on tree establishment, which were deemed not significant by the standard approach. Besides these advantages, the flexibility of HBA should allow the analysis of more complex (and realistic) models. La perte d'éléments de preuve pose un défi pour l'écologie historique. Par exemple, des études dendroécologiques concernant la relation entre l'établissement des arbres et le climat passé devraient envisager la possibilité de que nombreuses plantes pourraient ne pas survivre à la date de l'étude. Une méthode standard pour traiter ce problème consiste à ajuster une courbe de décroissance exponentielle à la structure d'âge observée et utiliser les résidus comme un indicateur d'établissement. Nous montrons que l'analyse Bayésienne hiérarchique (ABH), où l'établissement est modélisé comme une variable latente peut surpasser la méthode standard. Nous illustrons l'utilisation d'ABH avec une étude de simulation où le but est déduire la dynamique des populations à partir des structures d'âge dendrochronologiques. Les deux méthodes sont aussi utilisées pour analyser données empiriques de l'expansion des forêts d'aulnes dans le nord-ouest de l'Argentine. L'étude de simulation a montré que l'approche standard sous-estime l'association entre les précipitations et l'établissement. Le ABH l'a estimée sans biais et avec moins incertitude. Dans l'étude empirique, l'ABH a détecté des effets des précipitations sur l'établissement, qui ont été jugé non significatifs par la méthode standard. Outre ces avantages, la flexibilité de l'ABH permet l'analyse des modèles plus complexes (et réalistes).The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Climate and human impact during the past 2000 years as recorded in the Lagunas de Yala, Jujuy, northwestern Argentina

210Pb, 137Cs and 14C dated sediments of two late Holocene landslide lakes in the Provincial Park Lagunas de Yala (Laguna Rodeo, Laguna Comedero, 24°06′S, 65°30′W, 2100 m asl, northwestern Argentina) reveal a high-resolution multi-proxy data set of climate change and human impact for the past ca. 2000 years. Comparison of the lake sediment data set for the 20th century (sediment mass accumulation rates MARs, pollen spectra, nutrient and charcoal fluxes) with independent dendroecological data from the catchment (fire scars, tree growth) and long regional precipitation series (from 1934 onwards) show that (1) the lake sediment data set is internally highly consistent and compares well with independent data sets, (2) the chronology of the sediment is reliable, (3) large fires (1940s, 1983/1984–1989) as documented in the local fire scar frequency are recorded in the charcoal flux to the lake sediments and coincide with low wet-season precipitation rates (e.g., 1940s, 1983/1984) and/or high interannual precipitation variability (late 1940s), and (4) the regional increase in precipitation after 1970 is recorded in an increase in the MARs (L. Rodeo from 100 to 390 mg cm−2 yr−1) and in an increase in fern spores reflecting wet vegetation. The most significant change in MARs and nutrient fluxes (Corg and P) of the past 2000 years is observed with the transition from the Inca Empire to the Spanish Conquest around 1600 AD. Compared with the pre-17th century conditions, MARs increased by a factor of ca. 5 to >8 (to 800 +130, −280 mg cm−2 yr−1), PO4 fluxes increased by a factor of 7, and Corg fluxes by a factor of 10.5 for the time between 1640 and 1930 AD. 17th to 19th century MARs and nutrient fluxes also exceed 20th century values. Excess Pb deposition as indicated by a significant increase in Pb/Zr and Pb/Rb ratios in the sediments after the 1950s coincides with a rapid expansion of the regional mining industry. Excess Pb is interpreted as atmospheric deposition and direct human impact due to Pb smelting

Histology of the storage organ of wild maca, Lepidium meyenii (Brassicaceae), and comparison of the cultivated maca

Samples of the underground reserve organ of wild maca (Lepidium meyenii) from Cumbres Calchaquíes (Tucumán), were fixed in FAA and embedded in paraffin in order to study their anatomy. The underground structure was compared with the storage organ of cultivated maca observed in a previous study. The storage organ of wild maca is a contractile root with normal secondary growth. Peridermis arises from outer cortical parenchymatic cells. Cortex and star shaped pith constituted by amiliferous parenchyma with myrosin ideoblasts. Secondary phloem and xylem with abundant parenchymatous rays. Tissue from contractile area reflects the shortening of the root caused by vertical contraction and radial expansion of the inner cortical parenchyma. The contraction mechanism is discussed.Se estudió la anatomía del órgano de reserva subterráneo de la maca silvestre proveniente de Cumbres Calchaquíes (Tucumán) a partir de muestras fijadas en FAA y empleando la técnica de inclusión en parafina. Se comparó esta estructura con la observada en la maca cultivada en un trabajo previo. El órgano reservante de la maca silvestre es una raíz contráctil con crecimiento secundario normal que presenta peridermis diferenciada a partir de células del parénquima cortical externo, cortex y médula de forma estrellada constituidos por parénquima amilífero con idioblastos de mirosina. Floema y xilema secundario con abundantes radios parenquimáticos. Los tejidos de la región contráctil reflejan el acortamiento de la raíz, causado por la contracción vertical y expansión radial del parénquima cortical interno. Se discute el mecanismo de contracción.Fil: Chain, Fernando Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Mercado, Maria Ines. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Coll Araoz, Maria Victoria. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Catalan, Cesar Atilio Nazareno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Grau, A.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales E Instituto Miguel Lillo. Instituto de Ecología Regional; ArgentinaFil: Ponessa, Graciela I.. Universidad Nacional de Tucuman. Facultad de Cs.naturales E Instituto Miguel Lillo. Departamento de Morfologia Fisiologia y Taxonomia Vegetal; Argentin

Domesticación de plantas productoras del azul y el rojo, obtención de sus tinturas y difusión de estas metodologías para un desarrollo

Los artesanos que trabajan la lana, encuentran en las tinturas naturales un recurso promisorio para dar un valor agregado a su producto y permanecer en el medio rural. Sin embargo, desconocen o tienen a disposición muy pocos colores, provenientes de un acotado número de especies, entre los que no figuran el rojo y el azul, colores de difícil obtención. La domesticación de los recursos naturales nativos es un elemento básico para emprender iniciativas de desarrollo agroindustrial. El objetivo de este proyecto fue domesticar plantas productoras de azul y de rojo, obtener sus tinturas y difundir estas metodologías para un desarrollo sustentable. Para ello se mejoró el cultivo de 6 especies herbáceas tintóreas, se desarrollaron y/o ajustaron 45 metodologías de extracción de los colores más importantes, (rojo: 34 recetas y azul: 11 recetas), en 9 especies. Se logró teñir utilizando polvo de añil, reducido con dióxido de thiourea, sin utilizar método con orina o fermentación. Se introdujeron al cultivo en la Pampa de Oláen nuevas plantaciones de Indigofera kurtzii e Isatis tinctoria, permitiendo el desarrollo de Talleres de transferencia a la cooperativa de dicho lugar, y se realizó un Jardín Tintóreo con 9 especies en esta gama de colores en el Jardín Botánico de la ciudad de Córdoba para que constituya una verdadera transferencia educativa. Se recolectaron materiales de tinción y de multiplicación en los ecosistemas de Córdoba, en laboratorio se ajustaron las metodologías de obtención de estos tintes y a los mismos se los evaluó y probó para confirmar la capacidad tintórea. Se identificaron las especies botánicamente, para confirmar su identidad. Se realizaron talleres participativos, donde se capacitaron a docentes y alumnos de diversos niveles, artesanos y público en general, en conocimientos sobre la reproducción de las especies que producen estos tintes y en las metodologías de obtención y teñido. Las lanas teñidas en los talleres completaron el muestrario exhibido en el Museo Antropológico y en la Biblioteca de la FCA-UNC. Se creó una página web en donde se publicaron los avances obtenidos, para que el público tenga acceso a ellos. Se efectuó también una transferencia educativa -reforzando la currícula en colegios primarios y secundarios-, en las temáticas de Vivero Forestal, Tecnología de Productos y en Talleres de Plástica. Todas estas actividades contribuyeron a que los actores conozcan las especies tintóreas, las conserven y las valoren

Mapping and characterizing social-ecological land systems of South America

Humans place strong pressure on land and have modified around 75% of Earth’s terrestrial surface. In this context, ecoregions and biomes, merely defined on the basis of their biophysical features, are incomplete characterizations of the territory. Land system science requires classification schemes that incorporate both social and biophysical dimensions. In this study, we generated spatially explicit social-ecological land system (SELS) typologies for South America with a hybrid methodology that combined data-driven spatial analysis with a knowledge-based evaluation by an interdisciplinary group of regional specialists. Our approach embraced a holistic consideration of the social-ecological land systems, gathering a dataset of 26 variables spanning across 7 dimensions: physical, biological, land cover, economic, demographic, political, and cultural. We identified 13 SELS nested in 5 larger social-ecological regions (SER). Each SELS was discussed and described by specific groups of specialists. Although 4 environmental and 1 socioeconomic variable explained most of the distribution of the coarse SER classification, a diversity of 15 other variables were shown to be essential for defining several SELS, highlighting specific features that differentiate them. The SELS spatial classification presented is a systematic and operative characterization of South American social-ecological land systems. We propose its use can contribute as a reference framework for a wide range of applications such as analyzing observations within larger contexts, designing system-specific solutions for sustainable development, and structuring hypothesis testing and comparisons across space. Similar efforts could be done elsewhere in the world