Above-ground biomass equations for Pinus radiata D. Don in Asturias

Aim of the study: The aim of this study was to develop a model for above-ground biomass estimation for Pinus radiata D. Don in Asturias. Area of study: Asturias (NE of Spain). Material and methods: Different models were fitted for the different above-ground components and weighted regression was used to correct heteroscedasticity. Finally, all the models were refitted simultaneously by use of Nonlinear Seemingly Unrelated Regressions (NSUR) to ensure the additivity of biomass equations. Research highlights: A system of four biomass equations (wood, bark, crown and total biomass) was develop, such that the sum of the estimations of the three biomass components is equal to the estimate of total biomass. Total and stem biomass equations explained more than 92% of observed variability, while crown and bark biomass equations explained 77% and 89% respectively.This study was funded by the Asturian Energy Foundation (FAEN) and the Regional Ministry of Rural Environment and Fisheries (Government of the Principality of Asturias) through the project CN-06-007 "Production of biomass in several forestry species in Asturias"S

Willow short rotation coppice trial in a former mining area in Northern Spain: Effects of clone, fertilization and planting density on yield after five years

A willow short rotation coppice (SRC) trial was conducted on former mining land in northern Spain over a period of five years, with the purpose of evaluating the effects on yield of two planting densities (9876 and 14,815 cuttings ha−1), three treatments (control, two levels of nitrogen, phosphorus and potassium compound fertilizer (NPK) plus weed control) and three willow clones (Björn, Inger, Olof). The area was subsoiled, ploughed, harrowed and fertilized with NPK before trial establishment. A randomized block design was applied, with three replications of each treatment in a total of 54 plots, each of an area of 400 m2. The effects of the interactions between the various factors on yield and other growth parameters were also studied. The clone factor significantly affected the number of shoots per stool (greatest for the Inger clone) and the Olof clone, which showed the lowest mortality rate and produced the largest trees and largest quantity of biomass. The combined application of fertilizer and herbicide also significantly increased the values of all response variables considered, except the mortality rate. The planting density did not significantly affect the response variables. Clone × treatment interactions were significant for the shoots per stool, height, diameter and biomass variables, and the Olof clone displayed the highest height and diameter growth and yield. The results obtained in the first rotation indicate that the Olof clone adapted well to the trial conditions and therefore would be appropriate for producing biomass in abandoned mine land in Asturias. These findings will help in the development of strategies for the establishment and management of SRC on marginal land

Effect of replacing conventional Italian ryegrass by organic nitrogen source systems on chemical soil properties

Aim of study: To evaluate agronomic performance and changes on soil chemical properties in two types of managements: conventional or sustainable.Area of study: Principality of Asturias, Spain.Material and methods: On a sandy-clay-loam texture soil, three winter forage legumes (faba bean, red clover and white lupin), in monoculture or mixed with Italian ryegrass and with organic fertilization (sustainable management) versus Italian ryegrass in monoculture and inorganic fertilization (conventional management) were evaluated during three consecutive years. After the harvest in spring, the rotations were completed with maize crop with the purpose to evaluate the effect of the sustainable management on forage yield and soil chemical parameters.Main results: The results showed that faba bean and red clover in monoculture and mixed with Italian ryegrass had better edaphic quality than Italian ryegrass in monoculture, and white lupin in monoculture or mixed with Italian ryegrass. Faba bean in monoculture and mixed with Italian ryegrass, both with organic fertilization, could be competitive crops since both had yields comparable to Italian ryegrass in monoculture with inorganic fertilization.Research highlights: Current agricultural practice could be changed for a more sustainable management system, including organic fertilization and legume crops

Phytoremediation potential depends on the degree of soil pollution: a case study in an urban brownfield

Phytoremediation is a cost-effective nature-based solution for brownfield reclamation. The choice of phytoextraction or phytostabilization strategies is highly relevant when planning full-scale treatments. A suitable approach to identify such species involves the evaluation of plants that grow spontaneously on the contaminated sites. Here, we sought to determine the phytoremediation potential of three spontaneous plant species, namely the trees Acer pseudoplatanus L (A. pseudoplatanus) and Betula celtiberica Rothm. & Vasc (B. celtiberica), and the shrub Buddleja davidii Franch (B. davidii), for the recovery of an urban brownfield. To determine the response of the species to the degree of contamination, we conducted soil and vegetation sampling inside and outside the site. The concentrations of As, Cu, and Zn in soil and plant samples were measured, and then various indexes related to phytoremediation were calculated. The translocation factor and transfer coefficient indicated that vegetation outside the brownfield had phytoextraction capacity while the same plants inside the brownfield revealed phytostabilization properties. Given our results, we propose that the selected species are suitable for phytostabilization strategies in areas with high concentrations of contaminants, whereas they could be used for phytoextraction only in soils with low or moderate levels of pollution.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was partially funded by the European Commission project LIFE I + DARTS (LIFE11ENV/ES/000547)

Impact of Old Pb Mining and Metallurgical Production in Soils from the Linares Mining District (Spain)

[EN] Mineral processing and metallurgy production centers may leave a far-reaching fingerprint of soil contamination. This scenario is particularly relevant in the mining district of Linares (Southern Spain), where former industrial sites are now dedicated to other land uses. Within this context, we selected five sectors of concern in Linares region, which are currently used as agricultural and residential areas. The study began with an edaphic characterization, including grain-size fractioning and soil chemical analyses, which were complemented by mineralogical and sequential extraction information. Anomalous soil concentrations of As, Cd, Cu, Pb, and Zn were found, with higher values than the admissible regional guideline limits. Moreover, chemical speciation indicated that in general, Pb, Zn, and Cd were highly available and bound mainly to the carbonate fraction. In addition, health risk assessment evidenced potential threats by Pb and As. Regarding remediation approaches, we observed that, in soils affected by mining and ore dressing activities, the clay and silt size fractions contained the highest pollution load, making them suitable for a size classification treatment. By contrast, in areas affected by metallurgical activity, pollutants were prone to be evenly distributed among all grain sizes, thereby complicating the implementation of such remediation strategies

Xeric grasslands of the inner-alpine dry valleys of Austria - new insights into syntaxonomy, diversity and ecology

Aims: We studied the syntaxonomic position, biodiversity, ecological features, nature conservation value and current status of dry grasslands investigated by Josias Braun-Blanquet more than 60 years ago. Study area: Inner-alpine valleys of Austria. Methods: We sampled 67 plots of 10 m2, following the standardized EDGG methodology. We subjected our plots to an unsupervised classification with the modified TWINSPAN algorithm and interpreted the branches of the dendrogram syntaxonomically. Biodiversity, structural and ecological characteristics of the resulting vegetation units at association and order level were compared by ANOVAs. Results: All the examined grasslands belong to the class Festuco-Brometea. From ten distinguished clusters, we could assign four clusters to validly published associations, while the remaining six clusters were named tentatively. We classified them into three orders: Stipo-Festucetalia pallentis (Armerio elongatae-Potentilletum arenariae, Phleo phleoidis-Pulsatilletum nigricantis, Medicago minima-Melica ciliata community, Koelerio pyramidatae-Teucrietum montani), Festucetalia valesiacae (Sempervivum tectorum-Festuca valesiaca community); Brachypodietalia pinnati (Astragalo onobrychidis-Brometum erecti, Agrostis capillaris-Avenula adsurgens community, Anthericum ramosum-Brachypodium pinnatum community, Ranunculus bulbosus-Festuca rubra community, Carduus defloratus-Brachypodium pinnatum community). Conclusions: The ten distinguished dry grassland communities of the Austrian inner-alpine valleys differ in their ecological affinities as well as their vascular plant, bryophyte and lichen diversity. We point out their high nature conservation importance, as each of them presents a unique habitat of high value

Screening of Pioneer Metallophyte Plant Species with Phytoremediation Potential at a Severely Contaminated Hg and As Mining Site

Phytoremediation of mine soils contaminated by potentially toxic elements (PTEs) requires the use of tolerant plants given the specific conditions of toxicity in the altered soil ecosystems. In this sense, a survey was conducted in an ancient Hg-mining area named “El Terronal” (Asturias, Spain) which is severely affected by PTE contamination (As, Hg, Pb) to obtain an inventory of the spontaneous natural vegetation. A detailed habitat classification was performed and a specific index of coverage was applied after a one-year quadrat study in various sampling stations; seven species were finally selected (Agrostis tenuis, Betula celtiberica, Calluna vulgaris, Dactylis glomerata, Plantago lanceolata, Salix atrocinerea and Trifolium repens). A total of 21 samples (3 per plant) of the soil–plant system were collected and analyzed for the available and total concentrations of contaminants in soil and plants (roots and aerial parts). Most of the studied plant species were classified as non-accumulating plants, with particular exceptions as Calluna vulgaris for Pb and Dactylis glomerata for As. Overall, the results revealed interest for phytoremediation treatments, especially phytostabilization, as most of the plants studied were classified as excluder metallophytes

Agromorphological characterization and dollar spot fungus susceptibility in accessions of common bent

Fourteen Agrostis capillaris accessions collected in northern Spain were characterized in a trial with a lowfertilization regime, carried out in two successive years (2004 and 2005). The commercial cultivar �Golfin�was included in the study as a control. All accessions and the commercial cultivar were evaluated for 11 agromorphological characteristics and susceptibility to dollar spot disease, caused by Sclerotinia homoeocarpa F.T. Bennet. The data obtained were reduced to five principal components that cumulatively explained 85.4% of the total variance. Cluster analysis was useful in identifying four groups of accessions that described 50% of the phenotypic variation among accessions. Cluster 1 consisted of four accessions with the highest resistance to dollar spot, dark green colour, late heading date and high autumn turf quality. Cluster 2 included the two earliest heading accessions, dark green colour, intermediate tolerance to dollar spot and low autumn turf quality. Cluster 3 comprised six accessions with the latest heading date, dark green colour and low tolerance to dollar spot. Cluster 4 consisted of two accessions and the �Golfin� cultivar, with lightest green colour, low autumn turf quality and the poorest tolerance to dollar spot. The results of this study suggest the potential value of some of these common bent accessions collected in northern Spain for turf and forage improvement.Catorce accesiones de Agrostis capillaris procedentes del norte de España se caracterizaron en un régimen de baja fertilización durante dos años (2004 y 2005) en un diseño de bloques completos al azar con dos repeticiones de 15 plantas por accesión (en total 30 plantas por accesión). El cultivar comercial �Golfin� se incluyó como control en el estudio. Todas las accesiones y el cultivar �Golfin� se evaluaron mediante 11 caracteres agromorfológicos y la susceptibilidad a la enfermedad fúngica «dollar spot» (Sclerotinia homoeocarpa F.T. Bennet). Los datos obtenidos se redujeron a cinco componentes principales que explicaron el 85,4% de la varianza total. Mediante una clasificación jerárquica se identificaron cuatro grupos, que describen el 50% de la variación fenotípica entre las accesiones. El grupo 1 incluyó cuatro accesiones con la mayor resistencia al «dollar spot», color verde oscuro, espigado tardío y muy buena calidad de césped en el otoño. El grupo 2 incluyó las dos accesiones más precoces de espigado, tolerancia intermedia al «dollar spot» y mala calidad de césped en el otoño. El grupo 3 comprendió seis accesiones tardías de espigado, color verde oscuro y baja tolerancia al «dollar spot». El grupo 4 incluyó dos accesiones y el cultivar �Golfin� con color verde más claro, baja calidad otoñal de césped y la menor tolerancia al dollar spot. Los resultados de este estudio muestran el potencial de algunas de las accesiones de agrostis común procedentes del norte de España para uso en mejora de céspedes y forrajes