Influencia de la fecha de plantación, la preparación del terreno y la calidad de planta en repoblaciones forestales de pino piñonero (Pinus pinea L.) y encina (Quercus ilex L.) en ámbito mediterráneo

Son múltiples los factores que afectan a la respuesta al establecimiento de las plántulas en una repoblación forestal en ámbito mediterráneo, los cuales, en su conjunto, deben condicionar la calidad de la planta y la técnica repobladora a emplear. Las condiciones ambientales tras la plantación, el manejo realizado de la planta, así como su morfología y fisiología, son considerados como los factores más determinantes para el establecimiento de una repoblación forestal. Entre estos factores que pueden influir en el establecimiento de las repoblaciones forestales en ámbito mediterráneo, este trabajo de investigación ha planteado como objetivo general estudiar el efecto que la fecha de plantación, los tratamientos de preparación del terreno utilizados y la calidad de planta, ejercen en la supervivencia y el desarrollo de las repoblaciones forestales tras su establecimiento. Para ello, se ha analizado la influencia relativa de cada uno de los factores estudiados, controlando el efecto del resto de variables, y estableciendo así la importancia relativa que cada uno de ellos presenta sobre el establecimiento definitivo de plantaciones forestales en ámbito mediterráneo. El estudio se centró en dos especies mediterráneas de alto valor ambiental y socioeconómico, como son la encina (Quercus ilex L.) y el pino piñonero (Pinus pinea L.). Para abordar el objetivo general, este trabajo ha planteado una serie de hipótesis a contrastar, centradas en a) determinar si los tres factores analizados (fecha de plantación, preparación del terreno y calidad de planta) ejercen la misma influencia en la supervivencia y crecimiento de plantaciones de Q. ilex y P. pinea realizadas en medio mediterráneo, b) analizar si el valor o característica de cada uno de los factores estudiados condiciona la respuesta al establecimiento respecto al resto de factores, existiendo, por tanto, interacciones entre ellos, y c) determinar la posible respuesta diferencial en términos de estrategias fisiológicas y morfológicas entre Q. ilex y P. pinea para la superación del estrés hídrico inicial en repoblaciones forestales mediterráneas. El ensayo fue realizado en condiciones reales en una repoblación forestal ubicada en el término municipal de Aznalcóllar (Sevilla), estableciendo 3 fechas de plantación (temprana – media – tardía), 2 tratamientos de preparación del terreno (ahoyado manual – subsolado mecánico) y 2 calidades de planta (alta – baja), con una muestra de 1200 plantas por especie estudiada. Para el análisis de los datos se acudió a técnicas estadísticas paramétricas (ANOVA multivariante) y no paramétricas (regresión logística), con objeto de poder analizar las interacciones existentes entre los factores estudiados. Los resultados de este trabajo han confirmado que la fecha de plantación, los tratamientos de preparación del terreno y la calidad de planta determinan la respuesta al establecimiento de Q. ilex y P. pinea en repoblaciones realizadas bajo condiciones mediterráneas, si bien es necesaria la consideración de las interacciones existentes entre ellos para analizar cómo estos factores afectan a la supervivencia y al crecimiento de las plántulas. La fecha de plantación es la variable que más influye en el establecimiento de plantaciones de Q. ilex y P. pinea en medios mediterráneos, siendo las fechas tempranas (noviembre) y medias (enero) las más adecuadas, en tanto...Many factors affect the seedlings establishment response in Mediterranean reforestations, which, should determine the quality of the plant and the reforestation technique selected. Environmental conditions after planting, plant management and its morphology and physiology, are considered as the most important factors for the establishment of reforestations. Among the factors that may influence the establishment of reforestations in Mediterranean area, this research has raised overall objective to study the effect of planting date, the site preparation treatments and the plant quality have on survival and development of the reforestation after its establishment. The relative influence of each of the factors studied, controlling for the other variables, have been analyzed, establishing the relative importance of each one on the final establishment of Mediterranean reforestations. The study focused on two Mediterranean species with high environmental and socio-economic value, such as Mediterranean holm oak (Quercus ilex L.) and stone pine (Pinus pinea L.). To address the overall objective, this work has raised a number of hypotheses to be tested, focused on a) determining whether the three factors analyzed (planting date, soil preparation and plant quality) exert the same influence on survival and growth of Q. ilex and P. pinea plantations conducted in Mediterranean environments, b) analyzing whether the value or characteristic of each factor studied conditions the response to the establishment over other factors existing, therefore, interactions between them, c ) determine the possible differential response in terms of physiological and morphological strategies between Q. ilex and P. pinea to overcome the initial water stress in Mediterranean afforestation. The trial was conducted under real conditions in a reforestation located in the municipality of Aznalcóllar (Sevilla), establishing three planting dates (early - mid - late), 2 treatments of soil preparation (manual holing – mechanical subsoiling) and 2 plant qualities (high - low), with a sample of 1,200 plants per each specie tested. Data analysis was attended by parametric (multivariate ANOVA) and nonparametric (logistic regression) statistical techniques in order to be able to analyze the interactions between the factors studied. Results have confirmed that planting date, soil preparation treatments and plant quality determine the establishment response of Q. ilex and P. pinea in reforestations conducted under Mediterranean conditions, although consideration of the interactions between them is needed to analyze how these factors affect the survival and growth of seedlings. The planting date is the most influential variable in establishing Q. ilex and P. pinea plantations in Mediterranean environments, being the most appropriate early dates (November) and mid-dates (January), while the water supply after planting is more likely. Late planting dates (March) limit the ability of root growth after planting, because plants have a shorter growing season for roots development, which compromises their survival and growth. Mechanical soil preparations by subsoiling or ripping provide a greater volume of soil to be explored by the roots of the plant, increasing the availability of water after the establishment facing to manual holing, thereby increasing the chances of success of reforestation. Q. ilex and P. pinea have..

Land Suitability for Biological Wastewater Treatment in Lebanon and the Litani River Basin Using Fuzzy Logic and Analytical Hierarchy Process

Biological wastewater treatment (BWWT) has been demonstrated to be a suitable procedure to degrade organic pollutants by utilizing natural processes. This paper presents a validated model to map land suitability for BWWT systems under the climatic conditions of Lebanon and the Litani River basin, using the Geographic Information System (GIS) and a machine learning approach for the Litani River Basin and Lebanon. The model was validated using fuzzy theory and the analytic hierarchy process (AHP) modeling theory, and a final suitability map was created in Lebanon that combined potential areas for Biological Wastewater Treatment (BWWT) based on particular criteria. Results show that spatial distribution of the suitable areas for BWWT sites differs for each of the criteria and the total extent of these potential areas is 162.94 km2 all over Lebanon and 42.62 km2 in the Litani basin areas. This area covers around 1.55% of the Lebanese areas and can help more than 30 regions while the total number of beneficiaries can reach a minimum of 60,000 and a maximum of 180,000 which represents between 1.5% and 3.75% of the total population. These potential areas are identified through land suitability classes to sustain the remaining BWWT areas and can contribute to the riparian forest ecosystem and mitigate the impact of climate change

Relación de la ejecución presupuestal y calidad del gasto de inversión de la Municipalidad Distrital de Castilla, 2019

La investigación buscó relacionar la ejecución presupuestal y la calidad del gasto de inversión en la Municipalidad Distrital de Castilla, 2019. Se planteó bajo el paradigma positivista y una metodología cuantitativa; fue de nivel descriptivo y tipo correlacional. Se usó como instrumento la encuesta para las variables ejecución presupuestal y calidad del gasto de inversión, la misma que fue sometida a prueba de confiabilidad y validez. Se aplicó a una población de 65 servidores públicos de las Gerencias de Planificación y Presupuesto, Desarrollo Urbano y Administración y Finanzas, la variable ejecución presupuestal se dimensionó en Compromiso, Devengado y Pagado, mientras que la variable calidad del gasto de inversión se dimensionó en cumplimiento de objetivos y logro de eficiencia y eficacia. Los resultados obtenidos en la investigación, reportan que existe una relación significativa y positiva entre las variables satisfacción de la ciudadanía y la gestión pública, con un valor p= 0,013, así mismo las relaciones con sus dimensiones son: La relación entre el nivel de ejecución presupuestal y la calidad del gasto de inversión es directa y de nivel medio 0,461, comprobándose la hipótesis existe una relación entre las variables ejecución presupuestal y la calidad del gasto de inversión, en tanto a las dimensiones el compromiso y la calidad del gasto, tienen una relación directa y de nivel alta 0,616, el devengado y calidad de gasto es directa y de nivel medio 0,461 y el pagado y la calidad del gasto, es directa y de nivel alto 0,607, sobre los resultados obtenidos, los servidores públicos de las gerencias en estudio deben de seguir los lineamientos de ejecución presupuestal determinados por la normativa peruana que permita tener un mayor una mayor información, sinterización de actividades y control para obtener un buen resultado de calidad del gasto de inversión en un determinado ejercicio

Deforestation and Biomass Production in Miombo Forest in Huambo (Angola): A Balance between Local and Global Needs

Miombo is one of the most widely distributed ecosystems in Angola, with a great social and environmental value. Thus, the rural population uses the biomass as fuel and miombo provides important ecosystem services, such as its carbon sequestration capacity. The objectives of this work were (i) to assess deforestation in miombo forest in Huambo province (Angola) during the last 20 years, (ii) to evaluate carbon storage capacity of miombo, and (iii) to calculate the charcoal productive capacity of those forests. From 2000 to 2019, 359,130 ha (12.96%) were deforested in Huambo province. Thirty-six woody species were identified as major components of miombo forest, the most frequent being Albizia anthunesiana, Brachystegia spiciformis, Julbernardia paniculata, Monote spp., Brachystegia boemii, Isoberlinea angolensis, Anisophyllea boehmii, Syzygium guineense, and Erythrophleum africanum. The total biomass estimated in miombo forest was 195.05 Mg ha−1 (55.02 Mg ha−1 radical and 140.04 Mg ha−1 area), with a total wood volume of 78.57 m3 ha−1. This represents values of 91.67 Mg ha−1 of accumulated carbon and 336.13 Mg ha−1 of CO2 equivalent. The potential charcoal productivity was 15,359.9 kg ha−1, corresponding to 24.78 trees ha−1. The Annual Allowable Cutting Volume was 10.77 m3 ha−1 year−1, 14.13 m3 ha−1 year−1, 21.17 m3 ha−1, and 32.85 m3 ha−1 year−1 for rotation lengths of 55, 40, 25, and 15 years, respectively, corresponding to a potential annual charcoal productivity of 2107.08 Kg ha−1 year−1, 2762.96 Kg ha−1 year−1, 4139.21 Kg ha−1, and 422.56 Kg ha−1 year−1. However, deforestation rates in the last 19 years and low charcoal productive capacity could compromise the sustainability of the Miombo ecosystem and its value as an ecosystem service provider in the province if appropriate management strategies are not developed

Comparison of Errors Produced by ABA and ITC Methods for the Estimation of Forest Inventory Attributes at Stand and Tree Level in Pinus radiata Plantations in Chile

Airborne laser scanning (ALS) technology is fully implemented in forest resource assessment processes, providing highly accurate and spatially continuous results throughout the area of interest, thus reducing inventory costs when compared with traditional sampling inventories. Several approaches have been employed to estimate forest parameters using ALS data, such as the Area-Based Approach (ABA) and Individual Tree Crown (ITC). These two methodologies use different information processing and field data collection approaches; thus, it is important to have a selection criterion for the method to be used based on the expected results and admissible errors. The objective of this study was to compare the prediction errors of forest inventory attributes in the functioning of ABA and ITC approaches. A plantation of 500 ha of Pinus radiata (400–600 trees ha−1) in Chile was selected; a forest inventory was conducted using the ABA and ITC methods and the accuracy of both methods was analyzed. The ITC models performed better than the ABA models at low tree densities for all forest inventory attributes (15% MAPE in tree density—N—and 11% in volume—V). There was no significant difference in precision regarding the volume and basal area (G) estimations at medium densities, although ITC obtained better results for density and dominant height (Ho). At high densities, ABA performed better for all the attributes except for height (6.5% MAPE in N, 8.7% in G, and 8.9% in V). Our results showed that the precision of forest inventories based on ALS data can be adjusted depending on tree density to optimize the selected approach (ABA and ITC), thus reducing the inventory costs. Hence, field efforts can be greatly decreased while achieving better prediction accuracies

Thinning Effect of C Sequestration along an Elevation Gradient of Mediterranean Pinus spp. Plantations

Forests are key elements in mitigating the effects of climate change due to the fact of their carbon sequestration capacity. Forest management can be oriented to optimise the carbon sequestration capacity of forest stands, in line with other productive objectives and the generation of ecosystem services. This research aimed to determine whether thinning treatments have a positive influence on the growth patterns of some of the main Mediterranean pine species and, therefore, on their Carbon (C) fixation capacity, both in terms of living biomass and soil organic carbon. The results obtained show that C sequestration capacity (biomass and SOC) increased at higher thinning intensities due to the induced alterations in tree growth patterns. We observed almost a 1.5-fold increase in P. nigra and P. sylvestris, respectively, and over a two-fold increase in P. pinaster under heavy thinning treatments; SOC stocks were affected by the intensity of the thinning treatments. These results can contribute to improving silvicultural practices aimed at C sequestration in forest plantations located in dry areas of the Mediterranean

Linkages between Climate, Radial Growth and Defoliation in Abies pinsapo Forests from Southern Spain

Systematic forest networks of health monitoring have been established to follow changes in tree vigor and mortality. These networks often lack long-term growth data, but they could be complemented with tree ring data, since both defoliation and radial growth are proxies of changes in tree vigor. For instance, a severe water shortage should reduce growth and increase tree defoliation in drought-prone areas. However, the effects of climatic stress and drought on growth and defoliation could also depend on tree age. To address these issues, we compared growth and defoliation data with recent climate variability and drought severity in Abies pinsapo old and young trees sampled in Southern Spain, where a systematic health network (Andalucía Permanent Plot Network) was established. Our aims were: (i) to assess the growth sensitivity of old and young A. pinsapo trees and (ii) to test if relative changes in radial growth were related with recent defoliation, for instance, after severe droughts. We also computed the resilience indices to quantify how old and young trees recovered growth after recent droughts. Wet-cool conditions during the prior autumn and the current early summer improved the growth of old trees, whereas late-spring wet conditions enhanced the growth of young trees. Old trees were more sensitive to wet and sunny conditions in the early summer than young trees. Old and young trees were more responsive to the Standardized Precipitation-Evapotranspiration Index drought index of June–July and July–August calculated at short (one–three months) and mid (three–six months) time scales, respectively. Old trees presented a higher resistance to a severe drought in 1995 than young trees. A positive association was found between stand defoliation and relative growth. Combining monitoring and tree ring networks is useful for the detection of early warning signals of dieback in similar drought-prone forests

Cumulative Drought Stress Leads to a Loss of Growth Resilience and Explains Higher Mortality in Planted than in Naturally Regenerated Pinus pinaster Stands

The assessment of the long-term impacts of drought on tree growth decline using tree-ring analyses may be used to test if plantations are more vulnerable to warming after successive droughts, leading to a “cumulative stress” effect. We selected 76 Pinus pinaster trees (declining and non-declining trees), and basal area increments over the last 20 years (BAI20) were calculated to build the chronologies for the stand types and vigor classes. Resistance, recovery and resilience indices were calculated. Pearson correlations, analyses and Partial Least-Squares regression were used to analyze the relationships among the response and environmental variables. We found a negative and significant relationship between mean temperature for May and June of the current year and growth in the naturally regenerated stands. This negative effect on growth under warm spring conditions was more noticeable in plantations than in naturally regenerated stands. A negative trend along time was found for the resilience index in planted stands. Evapotranspiration, maximum temperature and annual radiation showed significant and negative correlations with the growth of declining trees from planted stands, indicating they are susceptible to drought stress. Declining trees in planted stands showed a loss of growth resilience, specifically a negative trend after successive droughts

Improvement of Remote Sensing-Based Assessment of Defoliation of Pinus spp. Caused by Thaumetopoea pityocampa Denis and Schiffermüller and Related Environmental Drivers in Southeastern Spain

This study used Landsat temporal series to describe defoliation levels due to the Pine Processionary Moth (PPM) in Pinus forests of southeastern Andalusia (Spain), utilizing Google Earth Engine. A combination of remotely sensed data and field survey data was used to detect the defoliation levels of different Pinus spp. and the main environmental drivers of the defoliation due to the PPM. Four vegetation indexes were also calculated for remote sensing defoliation assessment, both inside the stand and in a 60-m buffer area. In the area of study, all Pinus species are affected by defoliation due to the PPM, with a cyclic behavior that has been increasing in frequency in recent years. Defoliation levels were practically equal for all species, with a high increase in defoliation levels 2 and 3 since 2014. The Moisture Stress Index (MSI) and Normalized Difference Infrared Index (NDII) exhibited similar overall (p < 0.001) accuracy in the assessment of defoliation due to the PPM. The synchronization of NDII-defoliation data had a similar pattern for all together and individual Pinus species, showing the ability of this index to adjust the model parameters based on the characteristics of specific defoliation levels. Using Landsat-based NDII-defoliation maps and interpolated environmental data, we have shown that the PPM defoliation in southeastern Spain is driven by the minimum temperature in February and the precipitation in June, March, September, and October. Therefore, the NDII-defoliation assessment seems to be a general index that can be applied to forests in other areas. The trends of NDII-defoliation related to environmental variables showed the importance of summer drought stress in the expansion of the PPM on Mediterranean Pinus species. Our results confirm the potential of Landsat time-series data in the assessment of PPM defoliation and the spatiotemporal patterns of the PPM; hence, these data are a powerful tool that can be used to develop a fully operational system for the monitoring of insect damage

Assessment of the Carbon Stock in Pine Plantations in Southern Spain through ALS Data and K-Nearest Neighbor Algorithm Based Models

Accurate estimation of forest biomass to enable the mapping of forest C stocks over large areas is of considerable interest nowadays. Airborne laser scanning (ALS) systems bring a new perspective to forest inventories and subsequent biomass estimation. The objective of this research was to combine growth models used to update old inventory data to a reference year, low-density ALS data, and k-nearest neighbor (kNN) algorithm Random Forest to conduct biomass inventories aimed at estimating the C sequestration capacity in large Pinus plantations. We obtained a C stock in biomass (Wt-S) of 12.57 Mg·ha−1, ranging significantly from 19.93 Mg·ha−1 for P. halepensis to 49.05 Mg·ha−1 for P. nigra, and a soil organic C stock of the composite soil samples (0–40 cm) ranging from 20.41 Mg·ha−1 in P. sylvestris to 37.32 Mg·ha−1 in P. halepensis. When generalizing these data to the whole area, we obtained an overall C-stock value of 48.01 MgC·ha−1, ranging from 23.96 MgC·ha−1 for P. halepensis to 58.09 MgC·ha−1 for P. nigra. Considering the mean value of the on-site C stock, the study area sustains 1,289,604 Mg per hectare (corresponding to 4,732,869 Mg CO2), with a net increase of 4.79 Mg·ha−1·year−1. Such C cartography can help forest managers to improve forest silviculture with regard to C sequestration and, thus, climate change mitigation