Soil amelioration induced by nurse shrubs in coal mines reclaimed to pastures and their synergistic effects with grazing

Producción CientíficaNative shrubs facilitate the establishment of oak seedlings in the opencast coal mines rehabilitated to pastures in Northern Spain, under a Mediterranean sub-humid climate. We evaluate soil changes as one of the possible facilitative effects of nurse shrubs. We hypothesize that nurse shrubs on mining soils can improve edaphic properties directly and indirectly by reducing the negative effects of trampling and grazing by ungulates. Thus, we assessed the combined effects of nurse shrubs (plots with vs without shrubs) and grazing (plots with vs without a fence for preventing browsing and trampling) upon soil properties in a reclaimed coal mine. Chemical properties such as electrical conductivity, K+, cation exchange capacity, and C/N ratio reached higher values beneath shrubs’ canopies, so did total organic matter, total N, total organic C, total P, available P, and Mg2+ under shrubs but only with grazing. In contrast, pH was higher outside the shrubs; also Ca2+, though only in the absence of grazing. With grazing, Na+ decreased under shrubs. Among physical properties, bulk density increased and porosity decreased only in grazed plots, whereas sand content increased under shrubs in the grazed plots, and clay decreased in such locations. Water holding capacity and available water were the highest in ungrazed areas. Overall, we found that shrubs have a positive direct effect on soil fertility, especially relevant in grazed areas because nurse shrubs and grazing have synergistic effects, and a positive indirect effect on physical properties because they attenuate negative effects of grazing, particularly soil compaction, by reducing livestock and wild ungulates trampling. Therefore, these results demonstrate how nurse shrubs contribute to soil amelioration, helping to facilitate plant establishment in reclaimed mines, which has relevant restoration implications for pasture and forest recovery.Junta de Castilla y León (VA035G18)Universidad de Valladolid (CONVREC-2021–11) y (113–2019PREUVA27

Effect of the forest-mine boundary form on woody colonization and forest expansion in degraded ecosystems

[ENG]We evaluated the ecological significance of the boundary form between two patches with contrasting vegetation (mine grassland and adjacent forest) on woody colonization and forest expansion in open-cast coal mines in Northern Spain. Woody colonization and browsing traces were measured on three mine sites, along 24 transects that were laid out perpendicular to the forest-mine boundary and classified according to their shape (concave, convex, straight). Mine sites were colonized from the close forest by woody species, whose colonization intensity depends on the boundary form. The overall colonization intensity decreased with increasing distance to the forest and differed depending on the boundary form. The more intense colonization was found in concave boundaries and the strongest decrease in convex boundaries close to the forest, whereas straight boundaries showed an intermediate colonization pattern. Concave boundaries reached higher woody cover in the basal strata of the mines than convex (up to 2 m) or straight boundaries (up to 1 m) from 11 m to the forest edge, mainly by the presence of dense patches of Cytisus scoparius (L.) Link, with a scattered overstory of Genista florida L. These shrubs might reduce the browsing intensity and act as nurse plants facilitating the establishment of Quercus petraea (Matt.) Liebl. in mine areas at greater distances from the forest edge. The forest-mine boundary form does not affect the forest vertical structure that is homogenous and does not help explain the woody colonization pattern in the mines. We conclude that edge characteristics have a strong potential to be used in the restoration of native forests based on natural processes. The implications of our results for sessile oak (Quercus petraea (Matt.) Liebl.) forest expansion along edges in fragmented Mediterranean forest landscapes were discussed

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Servicios ecosistémicos de masas mixtas de pino albar y pino resinero: conservación de la biodiversidad y secuestro de carbono

Many studies highlight the role of mixed vs monospecific forests to supply ecosystem services. Most reports of positive mixture effects focus on mixtures that combine tree species with contrasting traits, but little is known on the effect of mixing species that are expected to behave quite similarly as they belong to the same genus. This thesis assessed the effect of mixed vs monospecific stands of Scots pine (Pinus sylvestris L.) and Maritime pine (Pinus pinaster Aiton.) (I) on the carbon storage and exchangeable cations along the soil profile; (II) on the understory richness and life-forms composition and its relationship with the soil status; (III) on the main tree species regeneration and understory species composition; and (IV) on the overstory productivity at two spatial scales (small-scale and stand-level), its relationship with soil moisture and fertility, and its repercussion on the understory.Doctorado en Conservación y Uso Sostenible de Sistemas Forestale

¿Cómo elaborar un buen informe de prácticas?

Se explican aspectos básicos para la elaboración de un buen informe de prácticas

Influencia de la heterogeneidad edáfica y de la topografía en la composición de especies vegetales sobre escombreras mineras de carbón del norte de España

La restauración de escombreras mineras es un reto para los profesionales de este campo y comprender sus limitaciones ecológicas es un requisito para garantizar una restauración exitosa, por ello se plantea evaluar la influencia de la heterogeneidad edáfica y topográfica en la composición de especies vegetales en una ladera de una mina de carbón restaurada, donde se distinguieron dos comunidades vegetales (pastizal-matorral) y se compararon con una comunidad forestal vecina. Se encontraron diferencias en composición de especies entre el bosque y las otras comunidades, siendo la capacidad de retención de agua (CRA) la variable más relacionada con la dinámica de la vegetación hacia etapas maduras. Se observó un gradiente altitudinal en la distribución de las comunidades de la ladera restaurada, ocupando el pastizal la parte más alta de la ladera, donde el C fácilmente oxidable fue más alto, y el matorral la más baja, donde la CRA fue más alta.Producción Vegetal y Recursos forestalesMáster en Investigación en Ingeniería para la Conservación y Uso Sostenible de Sistemas Forestale

Restauración en laderas mineras: una oportunidad para estudiar la sucesión ecológica en procesos de pendiente

In the restoration of coal mine slopes, a high edaphic heterogeneity that determines important differences in the plant community is generated. A greater knowledge about the involved ecological processes is essential to guarantee the success of revegetation in degraded environments. This work evaluates the influence of the spatial variability of soil and topographic parameters on the distribution of vegetation on a hillside of a restored coal mine. The steep slope, located in Guardo (Palencia), was hydroseeded in October 2000. In the spring of 2011, six transects were established parallel to the topographic gradient, three in a grassland community and three in a scrubland community. Soils and vegetation were characterized along the topographic gradient. The vegetation is classified by families and by life cycle. A gradient in vegetation distribution was observed in response to altitude, increased water holding capacity and soil thickness, and a decrease in the easily oxidizable carbon / total carbon ratio. The pasture occupied the highest part of the slope and the scrub was in the lowest. The response of the vegetation along the altitudinal gradient was modeled. Woody and leguminous dominated the lower parts of the slope while the higher parts were occupied by grasses and annuals. The results suggest that the design of the hillsides for revegetation should consider the local topographic conditions.En restauración de los taludes de minas de carbón se genera una elevada heterogeneidad edáfica que determina importantes diferencias en la comunidad vegetal. Un mayor conocimiento sobre los procesos ecológicos involucrados es indispensable para garantizar el éxito de la revegetación en ambientes degradados. Este trabajo evalúa la influencia de la variabilidad espacial de parámetros edáficos y topográficos sobre la distribución de la vegetación en una ladera de una mina de carbón restaurada. La ladera, con fuerte pendiente y ubicada en Guardo (Palencia), se hidrosembró en octubre de 2000. En primavera de 2011 se establecieron seis transectos paralelos al gradiente topográfico. Tres en una comunidad de pastizal y tres en otra de matorral. Se caracterizaron los suelos y la vegetación a lo largo del gradiente topográfico. La vegetación se clasifico por familias y por ciclo de vida. Se observó un gradiente en la distribución de la vegetación en respuesta a la altitud, al aumento de la capacidad de retención de agua y del espesor del suelo, y a la disminución de la ratio carbono fácilmente oxidable/carbono total. El pastizal ocupó la parte más alta de la ladera y el matorral la más baja. Se modelizó la respuesta de la vegetación a lo largo del gradiente altitudinal, y se observó que leñosas y leguminosas dominaban las partes bajas de la ladera mientras que las partes más elevadas estaban ocupadas por gramíneas y anuales. Los resultados sugieren que el diseño de las laderas para la revegetación debe considerar las condiciones topográficas locales

Can mixed pine forests conserve understory richness by improving the establishment of understory species typical of native oak forests?

13 Pág.Key message: A positive effect of mixed pine forests (Pinus sylvestrisL. andPinus pinasterAit.) on the understory richness and tree regeneration was observed with respect to monospecific stands. Understory species typical of the native Pyrenean oak forests in the Iberian Peninsula contribute to maintaining high understory richness in such mixed pine forests. Context: The influence of stands characteristics on the understory in mixtures that combine coniferous tree species of the same genus deserves more study since they are frequent in Spain. Aims: To assess the effect of mixed versus monospecific stands of Pinus sylvestris L. and Pinus pinaster Ait. on the main tree species regeneration and understory species composition. Methods: Tree regeneration and understory species composition were inventoried in eighteen forest plots (6 triplets) in North-Central Spain. Each triplet consisted of two plots dominated either by Scots pine or Maritime pine and one mixed plot that contained both species. Results: The basal area (%) of both Pinus species was the only characteristic of the stands that significantly influenced the understory composition and tree regeneration. Characteristic species of humid and temperate zones, including P. sylvestris regeneration, dominated in Scots pine stands, and typical species of well-drained Mediterranean areas, including P. pinaster regeneration, dominated in Maritime pine stands. In mixed stands, the highest regeneration of the native Pyrenean oak with respect to monospecific stands was accompanied by understory species typical of native oak forests that share the same regeneration niche. Conclusion: Mixed pine forests allow the development of understory species better than monospecific forests.This research was funded by a predoctoral grant to DLM (BES-2015-072852) and the Project FORMIXING (AGL2014-51964-C2-1-R) from the Ministry of Economy and Competitiveness of the Spanish Government.Peer reviewe

Los arbustos nodriza en la restauración forestal de minas de carbón del noroeste de Palencia : caso práctico IV

[ES]En las últimas décadas, se ha producido un giro en la percepción de las formaciones de matorral y en el enfoque de la investigación forestal sobre ellas. En concreto, se ha puesto de manifiesto la capacidad de numerosas especies de arbustos para modificar el entorno y favorecer el establecimiento de otras especies, con frecuencia arbóreas, mediante el proceso de facilitación. En este capítulo se presentan, como caso de estudio, los trabajos de seguimiento de las labores de restauración realizados durante los últimos 20 años en minas de carbón del norte de Palencia, en un entorno forestal de roble albar y roble melojo. El interés de este sistema de estudio radica en que permite ilustrar los efectos (positivos/negativos) de las plantas nodriza en situaciones que combinan tres factores limitantes clave para la regeneración forestal en general en la península ibérica: i) suelos poco desarrollados, ii) sequía estival y iii) alta presión de herbívoros. En estas condiciones, los matorrales nodriza han favorecido el reclutamiento, supervivencia y crecimiento de las especies arbóreas que se refugian bajo ellos (Torroba-Balmori et al. 2015; Alday et al. 2016). Por tanto, las conclusiones obtenidas pueden ser fácilmente extrapolables a áreas similares en las que actúen los tres factores individualmente o en interacción

Soil carbon stocks and exchangeable cations in monospecific and mixed pine forests

Many studies highlight the role of mixed versus monospecific forests to supply numerous ecosystem services. Most reports of positive mixture effects on carbon storage focus on mixtures that combine tree species with contrasting traits, but little is known on the effect of mixing species that are expected to behave quite similarly as they belong to the same genus. In this study, we assessed the effect of mixed versus monospecific stands of Pinus sylvestris and P. pinaster on carbon storage and exchangeable cations along the soil profile, based on research with six triplets in the northern Iberian Peninsula (Spain). One soil pit of at least 40 cm depth was dug at each plot for organic and mineral horizons characterization. Two trends were found: in the topsoil, higher values of carbon stock and total organic carbon were found in P. sylvestris stands, lower in P. pinaster stands and intermediate in mixed stands; this pattern was related to the C/N ratio of the forest floor. In the intermediate soil layers, it tends to be higher in mixed stands and is related to percentage of fine roots and to the greater thickness of the first mineral horizon. Differences in soil exchangeable cations among stands were related to the total organic carbon content. These results improve our understanding of the mechanisms underlying soil carbon accumulation in mixed stands and emphasize the use of mixtures as a strategy to combat climate change, due to the advantage in the accumulation of carbon in the subsoil layers