Evaluación de la cobertura de la vegetación después de un incendio mediante análisis de mezclas espectrales. Aplicación y comparación de diferentes métodos de caracterización de factores de referencia

The analysis of satellite images allows one to monitor the regeneration of vegetation after a fire. In this work, a methodology for quantifying post fire vegetation cover was developed. The proposed methodology is based on the examination of Landsat 7 ETM+ images by using Spectral Mixture Analysis (SMA) and involves the following steps: a) pre-processing, b) inherent dimensionality image determination c) endmember characterization following two methods that thus lead to different models: traditional method based on the knowledge of the area worked as well as Minimum Noise Fraction and Pixel Purity Index method, d) model inversion and combination, e) comparison between the vegetation cover estimated by each model and that measured in field, and f) selection of the most accurate model and mapping of the vegetation cover for the study area. The cover estimated provided by the different models exhibited a high correlation (Spearman’s correlation coefficient >0.89). The average absolute difference between the estimated and field-measured vegetation cover obtained with the most accurate model for each fire never exceeded 6%.El análisis de imágenes de satélite permite el seguimiento y evaluación de los procesos de restauración post-incendio. En este trabajo se presentan parte de los resultados de una metodología dirigida a la cuantificación de la cobertura de la vegetación después de un incendio. La metodología propuesta se basa en el empleo de imágenes Landsat 7 ETM+ mediante un Análisis de Mezclas Espectrales (SMA) y supone los siguientes procesos: a) pre-procesado de la imagen, b) determinación de la dimensión intrínseca (inherent dimensionality) de la imagen c) selección y caracterización de los factores de referencia (endmember) mediante dos métodos propuestos en la literatura: estudio previo de la zona de trabajo, Minimum Noise Fraction y pixles puros (Pixel Purity Index), d) inversión del modelo y combinación, e) comparación entre la cobertura estimada por cada modelos y las medidas realizadas en el campo, y f) selección del modelo de mayor precisión para la realización de una cartografía de la cobertura de la vegetación en el área de estudio. La cobertura estimada por los diferentes modelos muestran una alta correlación (Coeficiente de correlación de Spearman > 0.89), lo que ha permitido establecer una diferencia entre las medidas de cobertura a través de la imagen y la estimación de campo que en ningún caso han superado el 6% de la cobertura post-inendio

Método cualitativo para la determinación del estatus de conservación de Bulnesia sarmientoi (Zygophyllaceae) en Paraguay con fines de exportación

A qualitative analysis of the reasons why the species Bulnesia sarmientoi is included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has been performed using the methodology proposed by the IUCN. This analysis was supplemented with information related to derivative products commercialization and data concerning growth, phenology, ecology and deforestation in the area occupied by the species. Analyses showed several information gaps, especially quantitative data, to establish the species conservation status. Results indicate that Bulnesia sarmientoi populations are under severe threat such as accelerated habitat loss and unsustainable timber harvesting and derivate products. The study concludes that quantitative population studies should be conducted to determine export quotas, without which it will not be possible to ensure the continuity of the populations of this species.Se realiza un análisis cualitativo, mediante el uso de la metodología propuesta por la UICN, de las causas por las que la especie Bulnesia sarmientoi se encuentra incluida dentro del Apéndice II de la Convención Internacional para el Tráfico de la Vida Silvestre (CITES). Estos datos se complementan con información procedente de la comercialización de los productos derivados, así como de otros datos referentes al crecimiento, la fenología, la ecología y la deforestación del área ocupada por esta especie. Los análisis muestran varios vacíos de información, especialmente de datos cuantitativos, para la determinación de su estado de conservación. Los resultados indican que las poblaciones de Bulnesia sarmientoi se encuentran sometidas a fuertes amenazas, como la pérdida acelerada de su hábitat y a la explotación no sostenible de su madera y de los productos derivados. El estudio concluye que se deberán realizar estudios poblacionales cuantitativos tendentes a la obtención de cupos de exportación, sin los cuales no se podrá garantizar la supervivencia de las poblaciones de la especi

Nursery location and potassium enrichment in Aleppo pine stock 1. Effect on nursery culture, growth, allometry and seedling quality

There is a need for a better understanding of the primary role of macronutrients in Aleppo pine stock quality and for producing larger nutrient-loaded stock, which may be challenging for inland nurseries. The influence of nursery location and fertilization on nursery culture, growth, allometry and seedling quality of Aleppo pine was studied in seedlings cultivated over the 2006 growing year. Fertilization treatments considered how a K enrichment performed over common programs currently being practiced and divided into three levels of K/N ratio: 0.63-0.89 (normal), 1.81-1.89 (high), and 2.25-2.53 (very high). Results showed that fertilization had a minor effect on seedling growth and allometry in comparison with location, which was the governing factor. However, fertilizing treatments significantly affected final seedling attributes, which has its origin on the early treatment differences that were kept up to the end of culture. Higher nutrient supply treatments produced the highest nutrient concentration in seedlings but they were associated with lower fertilization efficiencies. Fertilizer efficiency was approximately twofold in the coastal nursery for the three macronutrients, although concentration was higher in the inland nursery due to lower seedling growth. It is concluded that warmer regions are more suitable for producing large stock more efficiently. © Institute of Chartered Foresters, 2011. All rights reserved.This work was supported by the projects 'Improvement of reforestation in the province of Valencia through the definition of seedling quality standards' (20020995) and 'Establishment of protocols for seedling quality testing in nursery and field' (20080682), directed by the Polytechnic University of Valencia and the Valencian Regional Government (Generalitat Valenciana).Campo García, ADD.; Hermoso De Mena, J.; Ceacero, CJ.; Navarro Cerrillo, RM. (2011). Nursery location and potassium enrichment in Aleppo pine stock 1. Effect on nursery culture, growth, allometry and seedling quality. Forestry. 84(3):221-233. https://doi.org/10.1093/forestry/cpr008S22123384

Influence of dose and route of administration on the outcome of infection with the virulent Neospora caninum isolate Nc-Spain7 in pregnant sheep at mid-gestation

Experimental infections in pregnant sheep have been focused on studying the effect of the time of challenge on the outcome of N. caninum infection, whereas the impact of the dose and route of challenge has not been studied in depth. Therefore, clinical outcome, immune responses, parasite detection and burden, and lesion severity in placental tissues and foetal brains were investigated in 90-day-pregnant sheep inoculated intravenously with 105 (G1), 104 (G2), 103 (G3), or 102 (G4) tachyzoites or subcutaneously with 104 (G5) tachyzoites of the virulent Nc-Spain7 isolate and an uninfected group (G6). Comparing challenge doses, G1 was the only group that had 100% abortion. Likewise, IFN¿ levels in G1 increased earlier than those in other intravenously infected groups, and IgG levels on day 21 post-infection (pi) were higher in G1 than those in other intravenously infected groups. Concerning vertical transmission, G1 shows a higher parasite burden in the foetal brain than did G2 and G3. Comparing routes of administration, no differences in foetal survival rate or parasite load in the foetal brain were found. Although G2 had higher IFN¿ levels than G5 on day 10 pi, no differences were found in humoral immune responses. Because the outcome after intravenous infection with 105 tachyzoites was similar to that observed after intravenous infection with 106 tachyzoites used in a previous work (100% abortion and vertical transmission), we conclude that it may be reasonable to use 105 tachyzoites administered by the intravenous route in further experiments when assessing drugs or vaccine candidates

Influence of dose and route of administration on the outcome of infection with the virulent Neospora caninum isolate Nc-Spain7 in pregnant sheep at mid-gestation

15 páginas, 2 tablas, 7 figuras.Experimental infections in pregnant sheep have been focused on studying the effect of the time of challenge on the outcome of N. caninum infection, whereas the impact of the dose and route of challenge has not been studied in depth. Therefore, clinical outcome, immune responses, parasite detection and burden, and lesion severity in placental tissues and foetal brains were investigated in 90-day-pregnant sheep inoculated intravenously with 10(5) (G1), 10(4) (G2), 10(3) (G3), or 10(2) (G4) tachyzoites or subcutaneously with 10(4) (G5) tachyzoites of the virulent Nc-Spain7 isolate and an uninfected group (G6). Comparing challenge doses, G1 was the only group that had 100% abortion. Likewise, IFN gamma levels in G1 increased earlier than those in other intravenously infected groups, and IgG levels on day 21 post-infection (pi) were higher in G1 than those in other intravenously infected groups. Concerning vertical transmission, G1 shows a higher parasite burden in the foetal brain than did G2 and G3. Comparing routes of administration, no differences in foetal survival rate or parasite load in the foetal brain were found. Although G2 had higher IFN gamma levels than G5 on day 10 pi, no differences were found in humoral immune responses. Because the outcome after intravenous infection with 10(5) tachyzoites was similar to that observed after intravenous infection with 10(6) tachyzoites used in a previous work (100% abortion and vertical transmission), we conclude that it may be reasonable to use 10(5) tachyzoites administered by the intravenous route in further experiments when assessing drugs or vaccine candidates.We gratefully acknowledge Neus Callizo Esteve from Clinical Veterinary Hospital (Complutense University of Madrid, Spain) and Jose Maria Gonzalez (University of Zaragoza, Spain) for their excellent technical assistance. The Animal Experimentation Service (SEA) at the University of Zaragoza is acknowledged for using their facilities to carry out the reproduction programme. Roberto Sanchez Sanchez is supported by a fellowship from the Spanish Ministry of Education, Culture and Sports (MECD) as a part of the Programme of Training of University Teaching Staff (FPU, Grant Number FPU13/03438). This work was supported by the Ministry of Economy and Competitiveness (AGL2016-75935-C2) and Community of Madrid, Spain (PLATESA, S2013/ABI2906).Peer reviewe

Forest and woodland replacement patterns following drought-related mortality

Forest vulnerability to drought is expected to increase under anthropogenic climate change, and drought-induced mortality and community dynamics following drought have major ecological and societal impacts. Here, we show that tree mortality concomitant with drought has led to short-term (mean 5 y, range 1 to 23 y after mortality) vegetation-type conversion in multiple biomes across the world (131 sites). Self-replacement of the dominant tree species was only prevalent in 21% of the examined cases and forests and woodlands shifted to nonwoody vegetation in 10% of them. The ultimate temporal persistence of such changes remains unknown but, given the key role of biological legacies in long-term ecological succession, this emerging picture of postdrought ecological trajectories highlights the potential for major ecosystem reorganization in the coming decades. Community changes were less pronounced under wetter postmortality conditions. Replacement was also influenced by management intensity, and postdrought shrub dominance was higher when pathogens acted as codrivers of tree mortality. Early change in community composition indicates that forests dominated by mesic species generally shifted toward more xeric communities, with replacing tree and shrub species exhibiting drier bioclimatic optima and distribution ranges. However, shifts toward more mesic communities also occurred and multiple pathways of forest replacement were observed for some species. Drought characteristics, species-specific environmental preferences, plant traits, and ecosystem legacies govern post drought species turnover and subsequent ecological trajectories, with potential far-reaching implications for forest biodiversity and ecosystem services.Peer reviewe

Programa nacional de mejora y conservación de los recursos genéticos de la encina y el alcornoque frente a la seca

Como respuesta a la gravedad de los procesos de decaimiento y mortalidad de la encina y el alcornoque, que amenazan la sostenibilidad de sus masas en la Península Ibérica, en el año 2019 se constituyó el subgrupo de trabajo “Mejora genética y fisiológica”, que forma parte del grupo de trabajo “Seca”, coordinado por el MITECO. Este subgrupo incluye a científicos y técnicos de varias administraciones y numerosos centros de investigación y Universidades y una empresa pública, expertos en mejora genética, fitopatología, ecología, propagación vegetativa, bioquímica y biología molecular. El programa tiene como objetivo la selección de genotipos de Quercus ilex y Q. suber tolerantes al estrés hídrico y a la podredumbre radical provocada por Phytophthora cinnamomi. A partir del estudio de 18 poblaciones y de 194 árboles “escape” seleccionados en focos de seca, se espera seleccionar un material apto para restaurar zonas afectadas por problemas de decaimiento. Se presenta una síntesis de las primeras actividades de caracterización e identificación de árboles escape en focos de seca, ensayos de invernadero para el estudio de la variabilidad poblacional en cuanto a vigor y tolerancia al estrés, recogida de muestras vegetales y edáficas para el análisis genético, molecular y de microbioma, identificación de marcadores moleculares asociados a resiliencia y micropropagación del material de mayor valor potencial

Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial

Background: Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment. Methods: This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal. Results: Enrolment began in 2016, and the study is expected to end in 2020. Conclusions: This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission. Clinical trial reference number: EudraCT 2015-001410-1

Early Diagnosis of Vegetation Health From High-Resolution Hyperspectral and Thermal Imagery: Lessons Learned From Empirical Relationships and Radiative Transfer Modelling

[Purpose of Review] We provide a comprehensive review of the empirical and modelling approaches used to quantify the radiation–vegetation interactions related to vegetation temperature, leaf optical properties linked to pigment absorption and chlorophyll fluorescence emission, and of their capability to monitor vegetation health. Part 1 provides an overview of the main physiological indicators (PIs) applied in remote sensing to detect alterations in plant functioning linked to vegetation diseases and decline processes. Part 2 reviews the recent advances in the development of quantitative methods to assess PI through hyperspectral and thermal images.[Recent Findings] In recent years, the availability of high-resolution hyperspectral and thermal images has increased due to the extraordinary progress made in sensor technology, including the miniaturization of advanced cameras designed for unmanned aerial vehicle (UAV) systems and lightweight aircrafts. This technological revolution has contributed to the wider use of hyperspectral imaging sensors by the scientific community and industry; it has led to better modelling and understanding of the sensitivity of different ranges of the electromagnetic spectrum to detect biophysical alterations used as early warning indicators of vegetation health.[Summary] The review deals with the capability of PIs such as vegetation temperature, chlorophyll fluorescence, photosynthetic energy downregulation and photosynthetic pigments detected through remote sensing to monitor the early responses of plants to different stressors. Various methods for the detection of PI alterations have recently been proposed and validated to monitor vegetation health. The greatest challenges for the remote sensing community today are (i) the availability of high spatial, spectral and temporal resolution image data; (ii) the empirical validation of radiation–vegetation interactions; (iii) the upscaling of physiological alterations from the leaf to the canopy, mainly in complex heterogeneous vegetation landscapes; and (iv) the temporal dynamics of the PIs and the interaction between physiological changes.The authors received funding provided by the FluorFLIGHT (GGR801) Marie Curie Fellowship, the QUERCUSAT and ESPECTRAMED projects (Spanish Ministry of Economy and Competitiveness), the Academy of Finland (grants 266152, 317387) and the European Research Council Synergy grant ERC-2013-SyG-610028 IMBALANCE-P.Peer reviewe