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Until recently, the development of a global geography of floods was challenged by the fragmentation and heterogeneity of in situ data and the high costs of processing large amounts of remote sensing data. Such geography would facilitate the exploration of large-scale drivers of flood extent and timing including wide latitudinal, climate, and topographic effects. Here we used a monthly dataset spanning 30 years (Global Surface Water Extent) to develop a worldwide geographical characterization of slow floods (1-degree grid), weighting the relative contribution of seasonal, interannual, and long-term fluctuations on overall variability, and quantifying precipitation-flooding delays where seasonality dominated. We explored the dominance of different flooding timings across five Köppen-Geiger main climates and seven topography classes derived from modeled water table depths (i.e., hydro-topography) to contribute top-down insight about the outstanding, cross-regional flooding patterns and their likely large-scale drivers. Our results showed that, globally, the mean extent of floods averaged 0.48% of the global land area, predominantly associated with hydro-topography (>2x more extensive in flatter landscapes). Climate drove flood timings, with predictable, seasonally-dominated fluctuations in cold regions, interannual and mixed patterns in temperate climates, and more irregular (higher variability) and unpredictable (less seasonal) patterns in arid regions. Net gains of flooded area dominated temporal variability in 9% of the cells including boreal clusters likely affected by warming trends. We propose that this new geographical perspective of floods can aid different avenues of hydrological research in the upscaling and extrapolation of field studies and the parsimonious representation of floods in hydroclimatic models.

Due to ongoing global warming, seasonal patterns of aboveground net primary production (ANPP) may be altered by temperature trends. Of particular interest is the seasonal association between ANPP and temperature at the beginning of the growing season (the period encompassing minimum to maximum ANPP), where two contrasting mechanisms are in tension. On the one hand, the restrictions exerted by low temperatures in winter may be relaxed, increasing the slope of seasonal association between ANPP and temperature over the years. On the other hand, increases in temperature may increase water demand, reducing the slope over time. Across 543 wetland meadow areas in Patagonia, we estimated ANPP and obtained temperature records on a monthly basis from 2001 to 2019. The seasonal association between ANPP and temperature, tested through linear regression, was statistically significant in 96% of the cases (9921/10317 (543 wetland areas × 19 growing seasons)). The fitted linear models explained, on average, 84% of ANPP seasonal (June–December) variations. Through regression trees, we found out that the two tested mechanisms, the relaxation of temperature restriction and the increase in water demand, showed clear spatial patterns. The relaxation due to temperature increase took place at higher latitudes, but the water-limiting mechanism increased over mid-latitude areas. EEA Esquel Fil: Irisarri, Jorge Gonzalo Nicolás. Rothamsted Research. Net Zero & Resilient Farming Directorate; Reino Unido Fil: Cipriotti, Pablo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Cipriotti, Pablo Ariel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento métodos cuantitativos y sistemas de información; Argentina Fil: Texeira, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Texeira, Marcos. Universidad de Buenos Aires. Facultad de Agronomía. Departamento métodos cuantitativos y sistemas de información; Argentina Fil: Curcio, Matías Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Curcio, Matías Hernán. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agroforestal Esquel; Argentina

Para estudiar, analizar y manejar los agroecosistemas a distintas escalas espaciales y temporales es necesario estimar la evapotranspiración real (ETR). En este trabajo actualizamos los algoritmos de estimación por medio de información espectral del satélite Suomi-NPP; para ello, aplicamos modelos lineales mixtos que consideraron la localidad y el año como factores aleatorios. De esta manera le damos continuidad a los productos de ETR y mejoramos la resolución espacial a ~14 hectáreas. The estimation of the real evapotranspiration (ETR) results in a concrete need for the study, analysis and management of agroecosystems at different spatial and temporal scales. Using spectral information from the Suomi-NPP satellite, we updated the estimation algorithms applying mixed linear models that considered the location and the year as random factors. In this way we give continuity to the ETR products and improve the spatial resolution to ~14 hectares. Instituto de Clima y Agua Fil: Di Bella, Carlos Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Oricchio, Patricio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; Argentina Fil: Gusmerotti, Lucas Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; Argentina Fil: Texeira González, Marcos Alexis. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina

The lack of an organizing conceptual framework to address ecosystem changes reduces our capacity to distinguish biophysical from direct human impacts on grassland dynamics. This is particularly important for subhumid temperate grasslands, one of the world’s most threatened biomes. We identified and mapped 4 functional syndromes of grassland change at the wettest end of its worldwide distribution, the Campos in Uruguay. Syndromes were defined by differences in precipitation use efficiency (PUE, ANPP/precipitation), and in precipitation marginal response (PMR, slope of the linear regression between ANPP and precipitation) between two periods (1981–1995 and 2001–2011). Temporal trends in aboveground net primary production (ANPP, obtained by splicing two sources of NDVI, LTDR and MOD13Q1) were also characterized. To rule out the effect of precipitation we analyzed temporal trends of the residuals from the relationship between ANPP and annual precipitation (RESTRENDS). Functional syndromes associated with increases in seasonality or in the abundance of annual vegetation (ΔPMR > 0, ΔPUE 5000 km2) were the most abundant. ANPP trends were significantly negative in 3.7% of the area (2475 km2) and only positive in 0.3%. However, RESTRENDS were significant in 11% of the area (>7700 km2), and mostly negative (in ∼7200 km2). Most of these negative trends and residual trends were associated to seasonality increase and vegetation loss syndromes. These patterns were consistent with observed changes in the region. We highlight that this conceptual framework is suitable for describing patterns of change and potential causes. Moreover, it provides policymakers with a novel tool to guide management and conservation policies, pointing to sites where intervention (i.e. conservation, restoration) is needed.

Faingerch, Melina. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina. Faingerch, Melina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Grupo de Estudio de Agroecosistemas y Paisajes Rurales. Mar del Plata, Argentina. Vallejos, María. Instituto Nacional de Investigación Agropecuaria (INIA). La Estanzuela, Colonia, Uruguay. Vallejos, María. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información. Buenos Aires, Argentina. Texeira, Marcos. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información. Buenos Aires, Argentina. Texeira, Marcos. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Laboratorio de Análisis Regional y Teledetección (LART). Buenos Aires, Argentina. Texeira, Marcos. CONICET – Universidad de Buenos Aires. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Laboratorio de Análisis Regional y Teledetección (LART) Buenos Aires, Argentina. Texeira, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina. Mastrángelo, Matías Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina. Mastrángelo, Matías Enrique. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Grupo de Estudio de Agroecosistemas y Paisajes Rurales. Mar del Plata, Argentina. Conservation policies often promote land privatization to reduce incentives for deforestation. However, empirical evidence on the relationship between landtenure form and forest conservation outcomes is inconclusive. We combined key informant mapping and geospatial analyses to test the association between the area under tenure and the area deforested by extra-local private and local nonprivate agents in the Argentine Dry Chaco over four decades (1976–2016). The study area is a typical commodity production frontier within a global deforestation hotspot. We found a strong spatial and temporal coupling between the area under tenure and the area deforested by extra-local private agents from 1987 to 2006, when a 59% increase in the former was accompanied by a 508% increase in the latter. Local private agents maintained high levels of forest cover, similarly to local nonprivate agents. Our findings have implications for the adaptive design of the Forest Law in the Argentine Dry Chaco. grafs., tbls., mapas

The temporal trend of aboveground net primary production (ANPP) is frequently used to estimate the effect of humans on ecosystems. In water-limited ecosystems, like most grazing areas in the world, the effect of humans act upon ANPP in combination with environmental variations. Our main objective was to quantify long-term (1981-2012) changes of ANPP and discriminate the causes of these changes between environmental and human at a subcontinental scale, across vast areas of Patagonia. We estimated ANPP through a radiative model based on remote sensing data. Then, we evaluated the relation between ANPP and environmental interannual variations of two hierarchically related factors: El Nino Southern Oscillation (ENSO) through the Southern Oscillation Index (SOI), and precipitation. We described the effect of humans through the shape of the temporal trends of the residuals (RESTREND) of the environmental model and quantified human relative impact through the RESTREND: ANPP trend ratio. ANPP interannual variation was significantly explained by ENSO (through SOI) and precipitation in 65% of the study area. The SOI had a positive association with annual precipitation. The association between ANPP and annual precipitation was positive. RESTREND analysis was statistically significant in 92% of the area where the tested environmental model worked, representing 60% of the study area, and it was mostly negative. However, its magnitude, revealed through the RESTREND: ANPP trend ratio, was relatively mild. Our analysis revealed that most of ANPP trends were associated with climate and that even when human density is low, its incidence seems to be mainly negative.

South America is experiencing profound land use and land cover changes. Their consequences on the Ecosystem Services (ES) supply and human well-being need to be diagnosed and monitored in order to support informed decisions both in management and territorial planning. The ES concept provides a key framework to evaluate human impacts on nature. The use of spatially explicit indicators able to characterize ES supply can turn operative the ES framework, enabling for sustainability assessment. The Ecosystem Services Supply Index (ESSI) is a synoptic indicator that estimates and maps supporting and regulating ES related to water and carbon dynamics from data provided by remote sensors of free access and wide spatial coverage. The ESSI merges two attributes of the Normalized Difference Vegetation Index (NDVI) annual dynamics: the annual average (NDVIMEAN, a proxy of total C gains) and the intra-annual coefficient of variation (NDVICV, an indicator of seasonality). In this article we proposed two objectives: 1) to describe the conceptual foundation of the ESSI and to gather the empirical support that shows its ability to explain the spatial-temporal variation in different ES, and to present a new case of empirical ESSI assessment, and 2) to synthesize the contribution of the ESSI in socio ecosystem diagnosis, monitoring and territorial planning stages in 8 existing cases of application. We also explored the links to the decision-making process by diverse stakeholders including local research and development institutions, NGOs and government agents. Cases corresponded to a wide range of situations from humid and dry forests to grasslands, and from local to subcontinental scales in southern South America. We found that ESSI was successfully applied for diagnosis, planning and monitoring processes which helped to better define interventions in management decisions and also to empower the most vulnerable stakeholders under territorial and environmental conflicts.

Fil: Aguiar, Sebastián. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Laboratorio de Análisis Regional y Teledetección; Argentina. Fil: Texeira, Marcos. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Laboratorio de Análisis Regional y Teledetección; Argentina. Fil: Garibaldi, Lucas A. Universidad Nacional de Río Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; Argentina. Fil: Garibaldi, Lucas A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; Argentina. Fil: Jobbágy, Esteban G. Universidad Nacional de San Luis. Instituto de Matemática Aplicada San Luis. Grupo de Estudios Ambientales; Argentina. Fil: Jobbágy, Esteban G. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Matemática Aplicada San Luis; Argentina. Over the past decades, the choices of farmers and societies regarding what to grow and eat are being reshaped drastically, as suggested by the diversification of crop supply within countries and its simultaneous homogenization across them. Such a trend could be supported by parallel shifts in production (i.e. diversification within countries, homogenization across countries) or by the growing redistribution introduced by international trade which can even mask reductions in production diversity (i.e. specialization) within countries. Here we assessed the spatial and temporal trends in crop production, exports, imports, and supply diversity based on data from the Food and Agriculture Organization (FAO) for 152 countries and 49 crops from 1961 to 2013. Within countries, the diversity of crop supply increased at a faster rate than the diversity of production, which grew only slightly. Both were surpassed by the diversification of trade, which, within countries, involved a much faster diversity growth of imports compared to exports. Across countries, crop production homogenized at slower rates than crop supply, indicating that crop trade was important for explaining this decoupling. Mirroring country-based analyses, a crop-perspective indicates that crops are becoming more geographically ubiquitous for all the components of the food balance. However, this pattern had important exceptions, like oil palm which has increased its production concentrating in a few specialized countries. We evaluate our results in the context of the multiple social-ecological trade-offs related to international trade and the resilience of the global food system.

We present an approach to generate estimates and to map Ecosystem Services (ES) related to C and water dynamics (Soil Carbon sequestration, evapotranspiration and groundwater recharge) and biodiversity (Avian Richness) from remotely sensed data in two ecoregions of South America: the Semiarid Chaco woodlands and the Rio de la Plata grasslands. Two attributes of the seasonal dynamics of the Normalized Difference Vegetation Index (NDVI); the annual mean (NDVI mean), an indicator of light interception and hence of total C gains and the intra-annual Coefficient of Variation of the NDVI (NDVI CV), a descriptor of seasonality; were combined into an ES provision index (ESPI = NDVImean * (1-NDVICV)). The proportion of the variance in ES provision explained by the ESPI varied from 0.484 for avian richness up to 0.662 for C sequestration. A relatively large proportion of the studied area presented changes in ES provision. A 32,4% of the Semiarid Chaco and the Rio de la Plata grasslands presented significant (p < 0.01) trends. Most of the trends (30.2%) were negative, showing a decrease in ESPI. An index like the one proposed here can be used as an aggregated indicator of the status and/or trends of ES supply at large spatial scales (subcontinental in our case). Fil: Paruelo, José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de la República. Facultad de Ciencias; Uruguay Fil: Texeira González, Marcos Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Staiano, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Mastrangelo, Matias Enrique. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Amdan, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Gallego, Federico. Universidad de la República. Facultad de Ciencias; Uruguay

Fil: Baldi, Germán. Universidad Nacional de San Luis. Instituto de Matemática Aplicada San Luis. San Luis, Argentina. Fil: Schauman, Santiago. Universidad Nacional de San Luis. Instituto de Matemática Aplicada San Luis. San Luis, Argentina. Fil: Texeira, Marcos. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información. Buenos Aires, Argentina. Fil: Marinaro, Sofía. Universidad Nacional de Tucumán. Instituto de Ecología Regional. - CONICET - Horco Molle, Horco Molle, Tucumán Fil: Martin, Osvaldo A. Universidad Nacional de San Luis. Instituto de Matemática Aplicada San Luis. San Luis, Argentina. Fil: Gandini, Patricia. Universidad Nacional de la Patagonia Austral. Instituto Ciencias del Ambiente, Sustentabilidad y Recursos Naturales. Santa Cruz, Argentina. Fil: Jobbágy, Esteban G. Universidad Nacional de San Luis. Instituto de Matemática Aplicada San Luis. San Luis, Argentina. Background: South America faces strong environmental transformations due to agriculture and infrastructure expansion and due to demographic growth, demanding immediate action to preserve natural assets by means of the deployment of protected areas.\nCurrently, 7.1% of the (sub)continent is under strict conservation categories (I to IV, IUCN), but the spatial distribution of these 1.3 x 106 km2 is poorly understood.\nWe evaluate protected area representativeness, map conservation priorities and assess demographic, productive or geopolitical causes of the existing protection spatial patterns using a random forest method.\nMethods: We characterized representativeness by two dimensions: the extent and the equality of protection.\nThe first refers to the fraction of a territory under protection, while the second refers to the spatial distribution of this protection along natural conditions.\nWe characterized natural conditions by 113 biogeographical units (specifically, ecoregions) and a series of limited and significant climatic, topographic and edaphic traits.\nWe analyzed representativeness every ten years since 1960 at national and continental levels. In the physical approach, histograms allowed us to map the degree of conservation priorities.\nFinally, we ranked the importance of different productive or geopolitical variables driving the observed distributions with a random forest technique.\nResults: Representativeness was variable across countries in spite of its priority in conservation agendas.\nBrazil, Peru and Argentina underrepresented a significant fraction of their natural diversity, while Bolivia and Venezuela protected their natural diversity equitably under extensive conservation networks.\nAs protected networks increased their extent, so did their equality across countries and within them through time.\nMapping revealed as top continental priorities southern temperate, subhumid and fertile lowland environments, and other country - specific needs (e.g., hot, humid plains of Venezuela). Protection extent was generally driven by a low population density and isolation, while other variables - like distance to frontiers, were relevant only locally (e.g., in Argentina). Discussion: Our description of the spatial distribution can help societies and governments to improve the allocation of conservation efforts, being top continental priorities the southern temperate, subhumid and fertile lowland environments.\nWe identify the main limitations that future conservation efforts will face, as protection was generally driven by the opportunities provided by low population density and isolation.\nFrom a methodological perspective, the complementary physical approach reveals new properties of protection and provides tools to explore nature representativeness at different spatial, temporal and conceptual levels, complementing the traditional ones based on biodiversity or biogeographical attributes. grafs., tbls., mapas

Scopoletin (7-hydroxy-6-methoxychromen-2-one, SC) is a phenolic coumarin commonly found in some medicinal plants. This compound presents relevant literature data demonstrating its anti-inflammatory, antioxidant, antitumor, hypocholesterolemic and hypoglycemic activities. SC was loaded in situ into the Zeolitic Imidazolate Framework-8 (ZIF-8), a slow-releasing material with pharmaceutical application. Both ZIF-8 and SC:ZIF-8 drug delivery systems (DDS) were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), thermogravimetry (TG), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR). The quantification of SC in the solution was performed by high-performance liquid chromatography with diode-array detection (HPLC-DAD) and the release profile at pHs 4.5 and 6.5 was compared under non-sink conditions of SC and SC:ZIF-8 DDS. Expectorant activity was also evaluated. The SC:ZIF-8 DDS showed an encapsulation efficiency of 22.5%. A pH-dependent release profile of SC present in the DDS was observed when compared to the pure SC. The most suitable kinetic model for pure SC at both pHs 4.5 and 6.5 was the Korsmeyer-Peppas model. For SC:ZIF-8 DDS at pH 4.5, the best model was the Korsmeyer-Peppas, but at pH 6.5 it was Peppas-Sahlin. SC also presented expectorant activity at 30 and 100 mg/kg doses, but the system did not show expectorant activity at 10 mg/kg dose.

En un complejo escenario ambiental, productivo y socioeconómico, el 28 de noviembre de 2007 fue sancionada en Argentina la Ley Nacional Nº 26.331 de “Presupuestos Mínimos de Protección Ambiental de los Bosques Nativos" (conocida como "Ley de bosques") con el propósito de proteger los bosques nativos a escala nacional. En este artículo nos proponemos realizar una síntesis crítica de la información disponible acerca de esta ley a diez años de su sanción, con una aproximación que toma en cuenta aspectos ambientales, económicos y sociales. Caracterizamos el desempeño de esta ley en la Región Chaqueña en cuanto a diferentes dimensiones, identificamos sus principales desafíos y describimos una serie de propuestas que desde el sector de Ciencia y Técnica pueden contribuir a su (re)diseño e implementación en el contexto de las actualizaciones de los Ordenamientos Territoriales de Bosques Nativos provinciales. Para ello, integramos información disponible proveniente de distintas fuentes, tales como normativas (nacionales y provinciales), literatura científica, informes de organismos estatales y de ONG y artículos periodísticos. La Ley de Bosques instaló en la opinión pública de nuestro país la problemática vinculada a la pérdida de bosques nativos y se ha posicionado como el principal instrumento de política forestal nacional para su protección. Si bien hubo una reducción en las tasas de deforestación en la región Chaqueña, no existen evidencias certeras de que esta reducción se deba a su aplicación. La Ley de Bosques en la Región Chaqueña presenta una serie de desafíos para mejorar su desempeño en cuanto a su efectividad, equidad y legitimidad social. En este trabajo se presentan diez observaciones que emergen de la revisión realizada. Por otro lado, se esbozan una serie de propuestas de investigación y acción en torno a la ley vinculadas a esas observaciones. In a complex environmental, productive and socioeconomic scenario, on November 28th, 2007, the National Act N°26.331 of “Minimum Standards for the Environmental Protection of Native Forests” (known as the “Forest Law”) was sanctioned in Argentina with the purpose of protecting native forests at the national scale. In this article, we aim to critically synthesize the available information about this law ten years after its sanction from an approach that takes into account environmental, economic and social aspects. In particular, we characterize the performance of this law in the Chaco Region in different dimensions, identify its main challenges and describe a series of proposals that from the science and technology sector can contribute to its (re)design and implementation in the context of the revisions of the Provincial Native Forest Land Use Planning Programs. In order to accomplish these objectives, we integrated information available from different sources, such as laws and regulations (national and provincial), scientific literature, reports from government agencies and NGOs and newspaper articles. The Forest Law installed in the public opinion of our country the problems related to the loss of native forests and has positioned itself as the main national instrument for forest conservation. Although deforestation rates lowered in the Chaco Region, there is no clear evidence that this reduction was due to its application. The Forest Law in the Chaco Region presents a series of challenges to improve its performance in terms of its effectiveness, equity and social legitimacy. In this paper, we present ten observations that emerge from the review carried out. On the other hand, linked to these observations, we outline a series of research and action proposals for enhancing the performance of the law. EEA Balcarce Fil: Aguiar, Sebastián. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Mastrangelo, Matias Enrique. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Grupo de Estudio de Agroecosistemas y Paisajes Rurales; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: García Collazo, María A. Ministerio de Ambiente y Desarrollo Sustentable de la Nación. Dirección Nacional de Bosques; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Camba Sans, Gonzalo H. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Mosso, Clara E. Universidad de Buenos Aires. Facultad de Agronomía. Licenciatura en Ciencias Ambientales; Argentina Fil: Ciuffoli, Lucía. Ministerio de Ambiente y Desarrollo Sustentable de la Nación. Dirección Nacional de Bosques; Argentina. Fil: Schmidt, Mariana. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones Gino Germani. Grupo de Estudios Ambientales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Vallejos, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Langbehn, Lorenzo. Universidad Nacional de Santiago del Estero. Facultad de Humanidades, Ciencias Sociales y de la Salud; Argentina Fil: Brassiolo, Miguel. Universidad Nacional de Santiago del Estero. Facultad de Ciencias Forestales; Argentina Fil: Cáceres, Daniel. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Merlinsky, Gabriela. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones Gino Germani. Grupo de Estudios Ambientales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Paruelo, José María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina. Instituto Nacional de Investigaciones Agropecuarias. INIA La Estanzuela; Uruguay Fil: Seghezzo, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; Argentina Fil: Staiano, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Texeira González, Marcos Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Volante, Jose Norberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina Fil: Veron, Santiago Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina

Fil: Irisarri, Jorge Gonzalo Nicolas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Instituto de Investigaciones Fisiologicas y Ecologicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomia. Instituto de Investigaciones Fisiologicas y Ecologicas Vinculadas a la Agricultura; Argentina

At micro-site scale, the spatial pattern of a plant species depends on several factors including interac- tions with neighbours. It has been seen that unfavourable effects generate a negative association between plants, while beneficial effects generate a positive association. In grasslands, the presence of shrubby species promotes a particular microenvironment beneath their canopy that could affect differently the spatial distribution of plants with different tolerance to abiotic conditions. We measured photosynthetic active radiation, air temperature and wind speed under shrub canopies and in adjacent open sites and analysed the spatial distribution of four grass species (two C3 and two C4) in relation to shrub canopy in a grazed sub-humid natural grassland in southern Uruguay. Radiation, air temperature and wind speed were lower under shrubs than in adjacent open sites. The spatial distribution of grasses relative to the shrub canopy varied depending on the photosynthetic metabolism of grasses. C4 grasses showed a negative association or no correlation with the shrubs, whereas C3 grasses showed a positive association. Our results highlight the importance of the photosynthetic metabolism of the grasses in the final outcome of interactions between grasses and shrubs. Micro-environmental conditions generated underneath shrubs create a more suitable site for the establishment of C3 than for C4 grasses.These results show that facilitation could be more important than previously thought in sub-humid grasslands.

Questions: How do fragment-level characteristics affect remnant grassland functioning in a highly transformed landscape? Are artificial neural networks (ANNs) a better statistical tool to model variations in grassland functioning compared to linear regression models (LRMs)? Location: Tandilia Range, Southern Pampa, Buenos Aires Province, Argentina. Methods: We characterized the dynamics of the vegetation functioning in 60 remnant grasslands using enhanced vegetation index (EVI) data provided by MODIS/Terra images from July 2000 to June 2005. First, we performed a principal components analysis (PCA) on the fragment mean monthly values of EVI in order to obtain synthetic measures (i.e. the PCA axes) of grassland functioning. Grassland fragments were also characterized by size, vegetation structure (abundance of the tall-tussock grass Paspalum quadrifarium) and physical environment (soil type – abundance of litholitic soils – elevation, aspect and slope). The relationship between grassland functioning and these explanatory variables was explored using linear regression models (LRMs) and artificial neural networks (ANNs). Results: The first and second PCA axes were related to the annual integral of EVI (EVI-I) and EVI seasonality (EVI-S), respectively; these explained jointly ca. 80% of total variability in mean EVI values. ANNs captured better than regression models the relationships among the proposed controls and the spatial variability of grassland functioning in Southern Pampa. Results showed that EVI-I variability was related to all independent variables except aspect. While fragment size, litholitic soils and slope were negatively related to EVI-I, the abundance of P. quadrifarium had a positive effect on the spectral index. Grasslands with high seasonality were large and had high slope and aspect, low abundance ofP. quadrifarium and increased abundance of litholitic soils. Conclusions: Our results showed that grassland functioning in Southern Pampa, as estimated by EVI, depends on fragment size, vegetation structure and physical factors (soil type, aspect and slope). Paspalum quadrifarium may have an important functional role in this grassland system.

The dry subtropics are subject to a rapid expansion of crops and pastures over vast areas of natural woodlands and savannas. In this paper, we explored the effect of this transformation on vegetation productivity (magnitude, and seasonal and long-term variability) along aridity gradients which span from semiarid to subhumid conditions, considering exclusively those areas with summer rains (>66%). Vegetation productivity was characterized with the proxy metric "Enhanced Vegetation Index" (EVI) (2000 to 2012 period), on 6186 natural and cultivated sampling points on five continents, and combined with a global climatology database by means of additive models for quantile regressions. Globally and regionally, cultivation amplified the seasonal and inter-annual variability of EVI without affecting its magnitude. Natural and cultivated systems maintained a similar and continuous increase of EVI with increasing water availability, yet achieved through contrasting ways. In natural systems, the productivity peak and the growing season length displayed concurrent steady increases with water availability, while in cultivated systems the productivity peak increased from semiarid to dry-subhumid conditions, and stabilized thereafter giving place to an increase in the growing season length towards wetter conditions. Our results help to understand and predict the ecological impacts of deforestation on vegetation productivity, a key ecosystem process linked to a broad range of services. Fil: Baldi, Germán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentina Fil: Texeira González, Marcos Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Murray, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Jobbagy Gampel, Esteban Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentina

Carbon gains are a key aspect of ecosystem functioning since they represent the energy available for upper trophic levels. Carbon gains (or primary production) are strongly correlated with other ecosystem attributes such as secondary production and they are also the support for the provision of many ecosystem services. Given the documented dependency of primary production on precipitation, we expect that altered precipitation regimes, such as those projected by climate models, will have a significant impact on carbon gains. Land use and land cover changes are also expected to have a significant impact on the dynamics of carbon gains. We generated a spectral database of the fraction of photosynthetically active radiation intercepted by vegetation (fPAR), in order to study long-term trends (i.e., decades) in carbon gains and its spatial and temporal relationships with precipitation and land cover patterns in Uruguay, which is part of the Rio de la Plata Grasslands, one of the largest temperate grasslands biome of the world. We found that carbon gains of native forests and grassland afforestation exhibited the strongest positive spatial response to precipitation, whereas crops and rangelands the weakest. In addition, we found that the temporal response of carbon gains to precipitation was strong and positive for all land uses. Although there were not clear trends in precipitation, we found strong negative trends in carbon gains through time, particularly in rangelands of the "Northern Campos" of Uruguay, where these trends represent a decrease between 10% and 25% of the annual aboveground net primary production. On the other hand, positive trends in carbon gains through time were associated to grassland afforestation and native forests. Therefore, during the period analyzed, land cover had a stronger influence on the observed trends in carbon gains than precipitation. These patterns emerged as a consequence of the interaction among precipitation, temperature, edaphic factors and management. Present trends in the controlling factors of C gains would exacerbate the observed patterns with serious consequences for the provision of ecosystems services. Fil: Texeira González, Marcos Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Oyarzabal, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Piñeiro, Gervasio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Baeza, Santiago. Universidad de la República; Uruguay Fil: Paruelo, José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de la República; Uruguay

Questions: (1) Can above-ground net primary production (ANPP) of Patagonian meadows be estimated from remote sensing? (2) How does ANPP of Patagonian meadows change in space and time? Location: Northwestern Patagonia, meadows embedded in a steppe matrix (39–43°S, 70–72oW; area: 85 000 km 2 ). Methods: For the first question, we contrasted field ANPP measurements with MODIS high-spatial resolution (pixel size: 0.0625 km 2 ) data and developed a model that estimates radiation use efficiency. For the second question, we applied the model to a 6-year MODIS record for 14 meadows whose physiognomic heterogeneity was known from previous work. Results: Up to 77% of the field-based ANPP variation was accounted for by the absorbed photosynthetic radiation, based on a linear transformation of the normalized difference vegetation index derived from MODIS data. Mean radiation use efficiency was 0.54 g dry matter MJ � 1 . ANPP ranged between 610 and 1060 g m � 2 year � 1 , which represents three to 5.3 times the ANPP of the surrounding arid and semi-arid steppes. The inter-annual coefficient of variation of ANPP was 10%, which is higher than other systems of similar productivity, but much lower than the surrounding steppes (33%). At the level of management units (paddock), ANPP spatial variations were mainly related to the proportion of Prairies, a proxy for low topographic position in the landscape, and longitude, a proxy for precipitation. ANPP inter-annual variation was most related to latitude, a proxy for temperature. Conclusion: The model developed and tested can be used to infer ANPP from remote sensing data at a spatial resolution that allows one to detect variability within meadows and management units. Variations at both the physiognomic unit and paddock level were associated with geographic patterns and topography. Meadows were three to five times more productive and less fluctuating than nearby steppes. When compared with other ecosystems, their productivity was high, but more variable inter-annually, likely due to exceptionally high variability of precipitation in Patagonia.

Diversity often increases ecosystem functioning and enhances stability, but this relationship has been evaluated at the community scale and considering, for the most part, only species richness. Here, we explored the relationship between landscape diversity and either the coefficient of variation or the interannual standard deviation of greenness in Pampean grasslands and Patagonian meadows, and tried to elucidate the mechanisms responsible for the resulting patterns. The coefficient of variation decreased with increasing landscape richness in Pampas but remained constant in Patagonia, while the interannual standard deviation of greenness decreased in both regions. The diversity–variability relationship in Pampean grasslands was largely accounted for by the mechanism of statistical averaging, while in Patagonian meadows, it was accounted for by a combination of statistical averaging, mean–variance rescaling and positive covariation of landscape units. There were no cases of negative covariance among landscape units. This is the first demonstration that landscape diversity increases stability of ecosystem functioning.

Environmental variability affects life history and fitness of both animal and plant species. For herbivores in particular, climate can have strong direct and indirect effects on demography, which tend to exacerbate in arid and semiarid environments with highly seasonal weather. We studied the joint effect of forage conditions, plant phenology, and climate on the reproductive performance of a “model” population: domestic sheep in the Patagonian steppe of Argentina. In this region sheep behave as semi-natural populations and relatively good population records are available. Using linear models and artificial neural networks trained by second order back-propagation methods, we demonstrated that reproductive performance, characterized by the marking rate (number of lambs per ewe), was associated to the timing of growing season start and to the primary production (as estimated from remotely sensed data) at mating. An ANN model including these variables explained 73% of the variability of normalized marking rate, and predicted observed marking rates with an accuracy of 63%. Our results highlight the importance of forage availability as opposed to weather regulating the reproductive performance of sheep at Patagonia, suggesting that bottom-up controls are of dominant importance for these populations. Using artificial neural networks, satellite imagery, and historical productive and climatic records, we disentangled the controls of sheep reproductive performance in a region characterized by weak but consistent relationships between environment and sheep dynamics. Our work aims to the development of quantitative tools for the management and planning of sheep herd structure from ranches to regions, especially for those situations in which classical methods (i.e. linear methods) fail.

Persistence and ubiquity of vertically transmitted Neotyphodium endophytes in grass populations is puzzling because infected plants do not consistently exhibit increased fitness. Using an annual grass population model, we show that the problems for matching endophyte infection and mutualism are likely to arise from difficulties in detecting small mutualistic effects, variability in endophyte transmission efficiency and an apparent prevalence of non-equilibrium in the dynamics of infection. Although endophytes would ultimately persist only if the infection confers some fitness increase to the host plants, such an increase can be very small, as long as the transmission efficiency is sufficiently high. In addition, imperfect transmission limits effectively the equilibrium infection level if the infected plants exhibit small or large reproductive advantage. Under frequent natural conditions, the equilibrium infection level is very sensitive to small changes in transmission efficiency and host reproductive advantage, while convergence to such an equilibrium is slow. As a consequence, seed immigration and environmental fluctuation are likely to keep local infection levels away from equilibrium. Transient dynamics analysis suggests that, when driven by environmental fluctuation, infection frequency increases would often be larger than decreases. By contrast, when due to immigration, overrepresentation of infected individuals tends to vanish faster than equivalent overrepresentation of non-infected individuals.

Sheep production is the main agricultural activity in Patagonia. Since the middle of the 20th century, sheep numbers have declined steadly. We used historical records of stock numbers in four ranches to analyze the importance of regional factors so as to explain the decline of the Patagonian sheep flocks. We found that the stocks of all the four ranches declined with a similar trend but fluctuated independently, thus reflecting a complex interaction between regional and local factors. Aboveground net primary production (ANPP) and vegetation physiognomy explained most of the differences in the flocks declining rates. We estimated demographic parameters for two ranches differing in their average annual growth rates. From these demographic parameters, we constructed deterministic and stochastic matrix models to establish the relative contribution of demographic processes to the observed decline. Matrix models projected a faster decline than that observed in the ranch used to calibrate the model. This suggests that the recorded demographic parameters could drive most stocks to extinction in less than 100 years. We concluded that the observed dynamics would be generated by demographic processes, but extinction is delayed or avoided by a continuous intake of animals. Ewe survival was the most important parameter in controlling the growth rate of the flocks. The environmental stochastic model showed that the growth of the stocks was highly sensitive to increases in the frequency of good years (those that produce a positive growth) and in the transition from normal years to bad years. All these evidences point out the existence of biological constraints to sheep production in Patagonia: ANPP and vegetation structure would control flock population dynamics throughout its effects on key demographic parameters, ewe survival and marking rate (a recruitment measure). Our model results suggest that the decline in sheep numbers, and hence the sustainability of the activity, is driven, to a large extent, by the demographic characteristics of the flocks.