B. Fernández-santos - Academia.edu (original) (raw)
Papers by B. Fernández-santos
Agronomy Journal, 1997
ABSTRACT
Asociación Española de Ecología Terrestre, Apr 1, 2013
Autores. Editado por la AEET. [Ecosistemas no se hace responsable del uso indebido de material su... more Autores. Editado por la AEET. [Ecosistemas no se hace responsable del uso indebido de material sujeto a derecho de autor]
Shrubs are an important source of food for domestic livestock and wildlife in semiarid areas. Thi... more Shrubs are an important source of food for domestic livestock and wildlife in semiarid areas. This is particularly true during dry periods when forage from natural pastures is scarce and its quality is low. Cytisus multiflorus is a leguminous shrub which is endemic to the Northwestern Iberian peninsula. This species occurs in poor soils and in degraded or marginal areas. The objective of this study was to evaluate the potential of near infrared reflectance spectroscopy (NIRS) to determine quality attributes of Cytisus multiflorus as a forage feed. NIRS calibrations were developed for crude protein, neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin, cellulose, hemicellulose, ash, and organic dry matter digestibility (OMD). The sample population used included different plant parts and plants of different ages, and was collected in the Spanish province of Salamanca. Calibration models were accurate for the prediction of crude protein (r 2 = 0.99; Standard...
Forests, 2021
We evaluated the ecological significance of the boundary form between two patches with contrastin... more 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...
Forests, 2021
Research Highlights: The regeneration of Quercus species is usually very difficult in many oak wo... more Research Highlights: The regeneration of Quercus species is usually very difficult in many oak woodlands transformed by livestock farming. Some studies have reported that shrubs can facilitate regeneration. However, the strength of interaction may vary depending on, among other factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are necessary to clarify the relative importance of the two facilitation mechanisms in the same community. Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula (bioclimatic limit) and is present with Quercus pyrenaica Willd and Quercus ilex subsp. ballota Samp trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under a bioclimatic limit....
Environmental Science and Pollution Research, 2015
Informes de la Construcción, 2001
Ecology, 2009
Plant trait information is essential for understanding plant evolution, vegetation dynamics, and ... more Plant trait information is essential for understanding plant evolution, vegetation dynamics, and vegetation responses to disturbance and management. Furthermore, in Mediterranean ecosystems, changes in fire regime may be more relevant than direct changes in climatic conditions, making the knowledge of fire-related traits especially important. Thus the purpose of this data set was to compile the most updated and comprehensive information on fire-related traits for vascular plant species of the Mediterranean Basin, that is, traits related to plant persistence and regeneration after fire. Data were collected from an extensive literature review and from field and experimental observations. The data source is documented for each value. Since life history traits may vary spatially or with environmental conditions, we did not aggregate them by species; i.e., traits and species are repeated in different records if they were observed by different researchers and/or in different locations. Life history traits included in the data set are: life form, resprouting ability (after fire, after clipping, or after other disturbances that remove all the aboveground biomass), resprouting bud source, heat-stimulated germination, other germination cues, seed bank location and longevity, post-fire seedling emergence and survival, maturity age of resprouts and saplings, and seed mass. Several traits are unknown for many species; consequently, the data set reflects the state of the knowledge on the topic. However, since the ability to resprout is a trait of paramount relevance in fire-prone environments, it was considered a core trait in the data set, and thus species whose resprouting capacity was unknown were not included. Life form is also provided for all taxa. The structure of the database allows different levels of information (and accuracy) for each entry, and thus some traits may include different types of data (quantitative, semi-quantitative, or categorical) from different sources. The data set is structured in 8263 records and 11 columns, obtained from 301 published and unpublished sources of information. It includes 952 taxa determined at specific or infraspecific level, which comprise 859 species, 384 genera, and 79 families. Although this is the most comprehensive data set of fire-relevant plant traits for Mediterranean species, there is still a considerable need for observations and experiments, especially in little-studied Mediterranean areas, such as northern Africa.
Ecological Engineering, 2007
The performance of introduced species when interacting with colonising herbs and shrubs from the ... more The performance of introduced species when interacting with colonising herbs and shrubs from the surrounding areas has become an important issue in plant ecology and restoration management. In this paper, we examined the influence of hydroseeding a commercial seed mixture on the revegetation of uranium mine wastes under a semi-arid Mediterranean climate in West-Central Spain. Eight dump slope sites differing two by two in revegetation treatment (hydroseeding or not) and aspect (north/south) were monitored annually during 3 years. There was a combined effect of treatment and aspect on the floristic composition during early succession. Particularly, hydroseeding increased differences in floristic composition between aspects, being the contribution of sown species to these differences small and short. Hydroseeding increased plant cover and diversity significantly only 2 years after its application on the north-facing slopes, favoured the perennial species (mainly hemicryptophytes), and had a different effect depending on the aspect favouring grasses and legumes on the north-and south-facing slopes, respectively. The species mixture was not suitable and the use of local seeds should be tested in future revegetation projects at this zone. The importance of improving natural colonisation for ecological restoration is emphasised.
Studia …, 1993
Acceso de usuarios registrados. Acceso de usuarios registrados Usuario Contraseña. ...
Acta Oecologica, 2005
Comparative plant successional studies on derelict sites are providing significant insights into ... more Comparative plant successional studies on derelict sites are providing significant insights into vegetation dynamics to ensure the success of future revegetation projects in these areas and, in the short-term, by using a space-for-time substitution. In this paper we describe, in relation to site exposure, vegetation development on waste rock materials covered with biologically active soil media, and compare this development with that from a previous study at the same mine (CW Spain) on non-biologically modified waste rock materials. The succession under study is faster on the North slope, as expected, and does not differ significantly from the general pattern of primary revegetation, although it was characterised by its own sequence of plant species. The topsoiling of waste increases richness and diversity from the first year of revegetation, reduces the time required for recovery of a terminal stage, and highlights the influence of slope orientation on vegetation dynamics. A total of 237 plant taxa were recorded, showing one of four patterns of change: (1) 'pioneer', (2) 'intermediate', (3) 'late coloniser' and (4) 'fluctuating'.
Forest Ecology and Management, 2006
The aim of this study was to determine the effect of fire recurrence on the structural characteri... more The aim of this study was to determine the effect of fire recurrence on the structural characteristics, in particular biodiversity, of different communities in Sanabria Natural Park (Castilla y León Region, Spain). Fourteen sites, ten Erica australis heathlands and four Quercus pyrenaica stands, two mature oak forests and two oak shrublands, were chosen. All of them had different levels of fire recurrence and different ages since the last fire. Data on fires occurring in the study area since 1990 are available. Sampling was carried out in July 2005. A 10 x 10 m plot was located in the centre of each site; in each plot, ten 1m 2 quadrats were studied and all the species present were quantified as visual cover percentage. A sampling by layers was also carried out in the same quadrats, estimating total plant cover in each layer. Plant species diversity was measured as richness (number of species). Alpha diversity (diversity/m 2), gamma diversity (diversity/plot), and beta or pattern diversity (S beta = S gamma / mean S alpha) were analysed. Structural diversity was calculated by the Shannon index, using plant cover data in the different layers. An affinity analysis was carried out considering all the species present. The dendrogram showed two groups: Erica australis heathlands and Quercus pyrenaica oak stands. The effect of fire recurrence on species composition was not observed in either case. A PCA was carried out in order to determine whether recurrence or the time elapsed since the last fire had any effect on species diversity or community structural diversity. Differentiation between the oak stands and the heathlands was also observed in this case. There was higher herbaceous species richness and more structural diversity in the oak stands. Stratification was noticeably lower in the heathlands, although they usually had higher woody species richness. No ordination depending on the time elapsed since the previous fire or recurrence was observed. Therefore, changes in community structure caused by fire recurrence in a relatively short period, such as that considered (15 years), are not noticeable in areas adapted to frequent fires. Nevertheless, repeated fire impedes the progress of succession and slows down its initial immature stages. These recover by autosuccession following repeated fire and persist as heathlands or oak shrublands. Although fires occur in mature oak forests, only the understory is affected, thus maintaining greater diversity and structural complexity.
espanolSe estudian los efectos de la quema, corte, arranque, abandono y pastoreo sobre la producc... more espanolSe estudian los efectos de la quema, corte, arranque, abandono y pastoreo sobre la produccion y estructura de un pastizal de dehesa con matorral de Cytisus multiflorus. Se obtienen diferencias significativas entre la biomasa de las herbaceas del pasto y la de los tratamientos si se efectua un corte en Febrero; la mayor produccion total se recoge en la parcela "arrancada", por el contrario, la menor total se detecta en la "abandonada". Entre la parcela quemada y la cortada no se observan diferencias de ningun tipo. Todas las intervenciones, excepto el abandono, producen mayor biomasa herbacea que si no se realiza ninguna de ellas y se mantiene el pastoreo. A los tres anos se observa que los tratamientos no determinan la aparicion de especies distintas sino una reduccion en el numero de estas, menos acentuada en la parcela quemada. La zona con pastoreo tradicional presenta una mayor diversidad y heterogeneidad espacial, ademas de mayor proporcion de legumino...
Se hace un estudio comparativo de los valores de fitomasa subterranea (raices) obtenidos a lo lar... more Se hace un estudio comparativo de los valores de fitomasa subterranea (raices) obtenidos a lo largo de cuatro transecciones transversales de otras tantas vaguadas de pastizales semiaridos, representativas del C-W espanol (Provincias de Avila y Salamanca). Para llevar a cabo el estudio se utilizan: a) los valores totales de fitomasa de cada uno de los perfiles de 30 cm de profundidad y 9 cm de diametro; b) los horizontes, o secciones horizontales de j> en 5 centimetros, en cada transeccion; c) las muestras en que se fracciona cada perfil. Se encuentran en todos los casos trayectorias muy similares que ratifican la repercusion del relieve en la fitomasa subterranea, considerada como sintesis y reflejo de la accion edafoclimatica y antropozoogena que condiciona su desarrollo
Forests, 2021
Research Highlights: The regeneration of Quercus species is usually very difficult in many oak wo... more Research Highlights: The regeneration of Quercus species is usually very difficult in many oak woodlands transformed by livestock farming. Some studies have reported that shrubs can facilitate regeneration. However, the strength of interaction may vary depending on, among other factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are necessary to clarify the relative importance of the two facilitation mechanisms in the same community. Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula (bioclimatic limit) and is present with Quercus pyrenaicaWilld and Quercus ilex subsp. ballota Samp trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under a bioclimatic limit. ...
Ecological Engineering, 2015
ABSTRACT In order to reconcile conventional and emergent goals in restoration ecology, the knowle... more ABSTRACT In order to reconcile conventional and emergent goals in restoration ecology, the knowledge of community assembly during succession at roadsides is crucial. With a chronosequence design, our study assesses the pathway and speed of vegetation succession on roadcuts under different specific site conditions, relating environmental factors to species cover by means of a combination of multivariate analyses and Huisman-Olff-Fresco (HOF) modeling. We want to ascertain to what extent environmental factors control primary colonization, establishment and early dynamics of vegetation on dry Mediterranean roadcuts. We found that changes in floristic composition during natural succession on roadcuts are mostly determined by the species-pool effect at different scales (landscape, regional and local); particular site conditions of roadcuts (slope length, steepness) are also influential factors at a local scale. We also found a shift in the dispersal mode of plant species, from anemochory to zoochory, during succession on tertiary sediments and slates, and a tendency for life-form replacement, from pterophytes to hemicriptophytes, during succession on tertiary sediments. Competitive species are primarily circumscribed to tertiary sediments where succession is not so limited by environmental carrying capacity. Natural colonization is less active on granites, and hence succession is slower. Our results indicate that, in a relatively short time, vegetation communities spontaneously installed under roadcut’s environmental harshness are rich in species whether an adjacent seed source is present in remnant patches of natural vegetation. In particular, surrounding woody vegetation favours zoochory dispersion and the early arrival of late-successional species. Keywords: dry Mediterranean climate; local environmental factors; species-pool effect; surrounding woody vegetation; species colonization patterns; species traits.
Forests, 2021
We evaluated the ecological significance of the boundary form between two patches with contrastin... more 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...
Forest Ecology and Management, 2006
In Sanabria Natural Park (Castilla y León Region, Spain), fires are a frequent occurrence mostly ... more In Sanabria Natural Park (Castilla y León Region, Spain), fires are a frequent occurrence mostly caused by humans. The aim of this study was to determine the effect of fire recurrence on the structural characteristics, in particular biodiversity, of different communities in this area. Fourteen sites, ten heath-lands dominated by Erica australis and four Quercus pyrenaica stands, two mature oak forests and two oak shrublands, were chosen in a total surface area of 30 km 2. All of them had different levels of fire recurrence and different ages since the last fire. Data on fires occurring in the whole study area since 1990 are available. Sampling was carried out in July 2005. A 10 Â 10 m 2 plot was located in the centre of each site; in each plot, ten 1 m 2 quadrats, systematically situated at equal distance from each other, were studied and all the species present were quantified as visual cover percentage. A sampling by layers was also carried out in the same quadrats, estimating total plant cover in each layer (0-0.5 m, 0.5-1 m, 1-2 m, 2-4 m, 4-8 m and >8 m). Plant species diversity was measured as richness (number of species). Alpha diversity, or small-scale diversity (diversity/m 2), gamma diversity (diversity/plot or site), and beta or pattern diversity (S beta = S gamma/mean S alpha) were analysed. Besides total S gamma, annual species number, perennial herbaceous species number and woody species number were also considered. As well as species diversity, structural diversity was calculated by the Shannon index using plant cover data in the different layers. H'alpha, H'gamma and H'beta (H'beta = H'gamma À mean H'alpha) were calculated. An affinity analysis was carried out considering all the species present. The dendrogram showed two groups: Erica australis heathlands and Quercus pyrenaica oak stands. The effect of fire recurrence on species composition was not observed in either case. A PCA was carried out in order to determine whether recurrence or the time elapsed since the last fire had any effect on species diversity or community structural diversity. Differentiation between the oak stands and the heathlands was also observed in this case. There was higher herbaceous species richness and more structural diversity in the oak stands. Stratification was noticeably lower in the heathlands, although they usually had higher woody species diversity. No ordination depending on the time elapsed since the previous fire or recurrence was observed. Therefore, changes in community structure caused by fire recurrence in a relatively short period, such as that considered (15 years), are not noticeable in areas adapted to frequent fires. Nevertheless, repeated fire impedes the progress of succession and slows it down its initial immature stages. These recover by autosuccession following repeated fire and persist as heathlands or oak shrublands. On the other hand, although fires occur in mature oak forests, only the understory is affected, thus maintaining greater diversity and structural complexity.
Agronomy Journal, 1997
ABSTRACT
Asociación Española de Ecología Terrestre, Apr 1, 2013
Autores. Editado por la AEET. [Ecosistemas no se hace responsable del uso indebido de material su... more Autores. Editado por la AEET. [Ecosistemas no se hace responsable del uso indebido de material sujeto a derecho de autor]
Shrubs are an important source of food for domestic livestock and wildlife in semiarid areas. Thi... more Shrubs are an important source of food for domestic livestock and wildlife in semiarid areas. This is particularly true during dry periods when forage from natural pastures is scarce and its quality is low. Cytisus multiflorus is a leguminous shrub which is endemic to the Northwestern Iberian peninsula. This species occurs in poor soils and in degraded or marginal areas. The objective of this study was to evaluate the potential of near infrared reflectance spectroscopy (NIRS) to determine quality attributes of Cytisus multiflorus as a forage feed. NIRS calibrations were developed for crude protein, neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin, cellulose, hemicellulose, ash, and organic dry matter digestibility (OMD). The sample population used included different plant parts and plants of different ages, and was collected in the Spanish province of Salamanca. Calibration models were accurate for the prediction of crude protein (r 2 = 0.99; Standard...
Forests, 2021
We evaluated the ecological significance of the boundary form between two patches with contrastin... more 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...
Forests, 2021
Research Highlights: The regeneration of Quercus species is usually very difficult in many oak wo... more Research Highlights: The regeneration of Quercus species is usually very difficult in many oak woodlands transformed by livestock farming. Some studies have reported that shrubs can facilitate regeneration. However, the strength of interaction may vary depending on, among other factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are necessary to clarify the relative importance of the two facilitation mechanisms in the same community. Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula (bioclimatic limit) and is present with Quercus pyrenaica Willd and Quercus ilex subsp. ballota Samp trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under a bioclimatic limit....
Environmental Science and Pollution Research, 2015
Informes de la Construcción, 2001
Ecology, 2009
Plant trait information is essential for understanding plant evolution, vegetation dynamics, and ... more Plant trait information is essential for understanding plant evolution, vegetation dynamics, and vegetation responses to disturbance and management. Furthermore, in Mediterranean ecosystems, changes in fire regime may be more relevant than direct changes in climatic conditions, making the knowledge of fire-related traits especially important. Thus the purpose of this data set was to compile the most updated and comprehensive information on fire-related traits for vascular plant species of the Mediterranean Basin, that is, traits related to plant persistence and regeneration after fire. Data were collected from an extensive literature review and from field and experimental observations. The data source is documented for each value. Since life history traits may vary spatially or with environmental conditions, we did not aggregate them by species; i.e., traits and species are repeated in different records if they were observed by different researchers and/or in different locations. Life history traits included in the data set are: life form, resprouting ability (after fire, after clipping, or after other disturbances that remove all the aboveground biomass), resprouting bud source, heat-stimulated germination, other germination cues, seed bank location and longevity, post-fire seedling emergence and survival, maturity age of resprouts and saplings, and seed mass. Several traits are unknown for many species; consequently, the data set reflects the state of the knowledge on the topic. However, since the ability to resprout is a trait of paramount relevance in fire-prone environments, it was considered a core trait in the data set, and thus species whose resprouting capacity was unknown were not included. Life form is also provided for all taxa. The structure of the database allows different levels of information (and accuracy) for each entry, and thus some traits may include different types of data (quantitative, semi-quantitative, or categorical) from different sources. The data set is structured in 8263 records and 11 columns, obtained from 301 published and unpublished sources of information. It includes 952 taxa determined at specific or infraspecific level, which comprise 859 species, 384 genera, and 79 families. Although this is the most comprehensive data set of fire-relevant plant traits for Mediterranean species, there is still a considerable need for observations and experiments, especially in little-studied Mediterranean areas, such as northern Africa.
Ecological Engineering, 2007
The performance of introduced species when interacting with colonising herbs and shrubs from the ... more The performance of introduced species when interacting with colonising herbs and shrubs from the surrounding areas has become an important issue in plant ecology and restoration management. In this paper, we examined the influence of hydroseeding a commercial seed mixture on the revegetation of uranium mine wastes under a semi-arid Mediterranean climate in West-Central Spain. Eight dump slope sites differing two by two in revegetation treatment (hydroseeding or not) and aspect (north/south) were monitored annually during 3 years. There was a combined effect of treatment and aspect on the floristic composition during early succession. Particularly, hydroseeding increased differences in floristic composition between aspects, being the contribution of sown species to these differences small and short. Hydroseeding increased plant cover and diversity significantly only 2 years after its application on the north-facing slopes, favoured the perennial species (mainly hemicryptophytes), and had a different effect depending on the aspect favouring grasses and legumes on the north-and south-facing slopes, respectively. The species mixture was not suitable and the use of local seeds should be tested in future revegetation projects at this zone. The importance of improving natural colonisation for ecological restoration is emphasised.
Studia …, 1993
Acceso de usuarios registrados. Acceso de usuarios registrados Usuario Contraseña. ...
Acta Oecologica, 2005
Comparative plant successional studies on derelict sites are providing significant insights into ... more Comparative plant successional studies on derelict sites are providing significant insights into vegetation dynamics to ensure the success of future revegetation projects in these areas and, in the short-term, by using a space-for-time substitution. In this paper we describe, in relation to site exposure, vegetation development on waste rock materials covered with biologically active soil media, and compare this development with that from a previous study at the same mine (CW Spain) on non-biologically modified waste rock materials. The succession under study is faster on the North slope, as expected, and does not differ significantly from the general pattern of primary revegetation, although it was characterised by its own sequence of plant species. The topsoiling of waste increases richness and diversity from the first year of revegetation, reduces the time required for recovery of a terminal stage, and highlights the influence of slope orientation on vegetation dynamics. A total of 237 plant taxa were recorded, showing one of four patterns of change: (1) 'pioneer', (2) 'intermediate', (3) 'late coloniser' and (4) 'fluctuating'.
Forest Ecology and Management, 2006
The aim of this study was to determine the effect of fire recurrence on the structural characteri... more The aim of this study was to determine the effect of fire recurrence on the structural characteristics, in particular biodiversity, of different communities in Sanabria Natural Park (Castilla y León Region, Spain). Fourteen sites, ten Erica australis heathlands and four Quercus pyrenaica stands, two mature oak forests and two oak shrublands, were chosen. All of them had different levels of fire recurrence and different ages since the last fire. Data on fires occurring in the study area since 1990 are available. Sampling was carried out in July 2005. A 10 x 10 m plot was located in the centre of each site; in each plot, ten 1m 2 quadrats were studied and all the species present were quantified as visual cover percentage. A sampling by layers was also carried out in the same quadrats, estimating total plant cover in each layer. Plant species diversity was measured as richness (number of species). Alpha diversity (diversity/m 2), gamma diversity (diversity/plot), and beta or pattern diversity (S beta = S gamma / mean S alpha) were analysed. Structural diversity was calculated by the Shannon index, using plant cover data in the different layers. An affinity analysis was carried out considering all the species present. The dendrogram showed two groups: Erica australis heathlands and Quercus pyrenaica oak stands. The effect of fire recurrence on species composition was not observed in either case. A PCA was carried out in order to determine whether recurrence or the time elapsed since the last fire had any effect on species diversity or community structural diversity. Differentiation between the oak stands and the heathlands was also observed in this case. There was higher herbaceous species richness and more structural diversity in the oak stands. Stratification was noticeably lower in the heathlands, although they usually had higher woody species richness. No ordination depending on the time elapsed since the previous fire or recurrence was observed. Therefore, changes in community structure caused by fire recurrence in a relatively short period, such as that considered (15 years), are not noticeable in areas adapted to frequent fires. Nevertheless, repeated fire impedes the progress of succession and slows down its initial immature stages. These recover by autosuccession following repeated fire and persist as heathlands or oak shrublands. Although fires occur in mature oak forests, only the understory is affected, thus maintaining greater diversity and structural complexity.
espanolSe estudian los efectos de la quema, corte, arranque, abandono y pastoreo sobre la producc... more espanolSe estudian los efectos de la quema, corte, arranque, abandono y pastoreo sobre la produccion y estructura de un pastizal de dehesa con matorral de Cytisus multiflorus. Se obtienen diferencias significativas entre la biomasa de las herbaceas del pasto y la de los tratamientos si se efectua un corte en Febrero; la mayor produccion total se recoge en la parcela "arrancada", por el contrario, la menor total se detecta en la "abandonada". Entre la parcela quemada y la cortada no se observan diferencias de ningun tipo. Todas las intervenciones, excepto el abandono, producen mayor biomasa herbacea que si no se realiza ninguna de ellas y se mantiene el pastoreo. A los tres anos se observa que los tratamientos no determinan la aparicion de especies distintas sino una reduccion en el numero de estas, menos acentuada en la parcela quemada. La zona con pastoreo tradicional presenta una mayor diversidad y heterogeneidad espacial, ademas de mayor proporcion de legumino...
Se hace un estudio comparativo de los valores de fitomasa subterranea (raices) obtenidos a lo lar... more Se hace un estudio comparativo de los valores de fitomasa subterranea (raices) obtenidos a lo largo de cuatro transecciones transversales de otras tantas vaguadas de pastizales semiaridos, representativas del C-W espanol (Provincias de Avila y Salamanca). Para llevar a cabo el estudio se utilizan: a) los valores totales de fitomasa de cada uno de los perfiles de 30 cm de profundidad y 9 cm de diametro; b) los horizontes, o secciones horizontales de j> en 5 centimetros, en cada transeccion; c) las muestras en que se fracciona cada perfil. Se encuentran en todos los casos trayectorias muy similares que ratifican la repercusion del relieve en la fitomasa subterranea, considerada como sintesis y reflejo de la accion edafoclimatica y antropozoogena que condiciona su desarrollo
Forests, 2021
Research Highlights: The regeneration of Quercus species is usually very difficult in many oak wo... more Research Highlights: The regeneration of Quercus species is usually very difficult in many oak woodlands transformed by livestock farming. Some studies have reported that shrubs can facilitate regeneration. However, the strength of interaction may vary depending on, among other factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are necessary to clarify the relative importance of the two facilitation mechanisms in the same community. Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula (bioclimatic limit) and is present with Quercus pyrenaicaWilld and Quercus ilex subsp. ballota Samp trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under a bioclimatic limit. ...
Ecological Engineering, 2015
ABSTRACT In order to reconcile conventional and emergent goals in restoration ecology, the knowle... more ABSTRACT In order to reconcile conventional and emergent goals in restoration ecology, the knowledge of community assembly during succession at roadsides is crucial. With a chronosequence design, our study assesses the pathway and speed of vegetation succession on roadcuts under different specific site conditions, relating environmental factors to species cover by means of a combination of multivariate analyses and Huisman-Olff-Fresco (HOF) modeling. We want to ascertain to what extent environmental factors control primary colonization, establishment and early dynamics of vegetation on dry Mediterranean roadcuts. We found that changes in floristic composition during natural succession on roadcuts are mostly determined by the species-pool effect at different scales (landscape, regional and local); particular site conditions of roadcuts (slope length, steepness) are also influential factors at a local scale. We also found a shift in the dispersal mode of plant species, from anemochory to zoochory, during succession on tertiary sediments and slates, and a tendency for life-form replacement, from pterophytes to hemicriptophytes, during succession on tertiary sediments. Competitive species are primarily circumscribed to tertiary sediments where succession is not so limited by environmental carrying capacity. Natural colonization is less active on granites, and hence succession is slower. Our results indicate that, in a relatively short time, vegetation communities spontaneously installed under roadcut’s environmental harshness are rich in species whether an adjacent seed source is present in remnant patches of natural vegetation. In particular, surrounding woody vegetation favours zoochory dispersion and the early arrival of late-successional species. Keywords: dry Mediterranean climate; local environmental factors; species-pool effect; surrounding woody vegetation; species colonization patterns; species traits.
Forests, 2021
We evaluated the ecological significance of the boundary form between two patches with contrastin... more 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...
Forest Ecology and Management, 2006
In Sanabria Natural Park (Castilla y León Region, Spain), fires are a frequent occurrence mostly ... more In Sanabria Natural Park (Castilla y León Region, Spain), fires are a frequent occurrence mostly caused by humans. The aim of this study was to determine the effect of fire recurrence on the structural characteristics, in particular biodiversity, of different communities in this area. Fourteen sites, ten heath-lands dominated by Erica australis and four Quercus pyrenaica stands, two mature oak forests and two oak shrublands, were chosen in a total surface area of 30 km 2. All of them had different levels of fire recurrence and different ages since the last fire. Data on fires occurring in the whole study area since 1990 are available. Sampling was carried out in July 2005. A 10 Â 10 m 2 plot was located in the centre of each site; in each plot, ten 1 m 2 quadrats, systematically situated at equal distance from each other, were studied and all the species present were quantified as visual cover percentage. A sampling by layers was also carried out in the same quadrats, estimating total plant cover in each layer (0-0.5 m, 0.5-1 m, 1-2 m, 2-4 m, 4-8 m and >8 m). Plant species diversity was measured as richness (number of species). Alpha diversity, or small-scale diversity (diversity/m 2), gamma diversity (diversity/plot or site), and beta or pattern diversity (S beta = S gamma/mean S alpha) were analysed. Besides total S gamma, annual species number, perennial herbaceous species number and woody species number were also considered. As well as species diversity, structural diversity was calculated by the Shannon index using plant cover data in the different layers. H'alpha, H'gamma and H'beta (H'beta = H'gamma À mean H'alpha) were calculated. An affinity analysis was carried out considering all the species present. The dendrogram showed two groups: Erica australis heathlands and Quercus pyrenaica oak stands. The effect of fire recurrence on species composition was not observed in either case. A PCA was carried out in order to determine whether recurrence or the time elapsed since the last fire had any effect on species diversity or community structural diversity. Differentiation between the oak stands and the heathlands was also observed in this case. There was higher herbaceous species richness and more structural diversity in the oak stands. Stratification was noticeably lower in the heathlands, although they usually had higher woody species diversity. No ordination depending on the time elapsed since the previous fire or recurrence was observed. Therefore, changes in community structure caused by fire recurrence in a relatively short period, such as that considered (15 years), are not noticeable in areas adapted to frequent fires. Nevertheless, repeated fire impedes the progress of succession and slows it down its initial immature stages. These recover by autosuccession following repeated fire and persist as heathlands or oak shrublands. On the other hand, although fires occur in mature oak forests, only the understory is affected, thus maintaining greater diversity and structural complexity.