20 research outputs found
Aproximación a la bibliografía florística básica de la Peninsula Ibérica e Islas Baleares.
MORENO SAuz, J. C. & SAINZ OLLERO, H. 1989. An aproxirnation to the floristic basic bibliography of the Iberian Peninsula and Balearic Islands. BoL ComplutenSis 15: 175-202. A compilation of floristic catalogues from Iberian Península and Balearic Lslands is presented. Tbese works have been sorted out by countries and provinces. A geografical representation of their distribution has been drown in a map.MORENO SÁIZ, £ C. & SAINZ OLLERO, H. 1989. Aproximación a la bibliografía floristica básica de la Península Ibérica e Islas Baleares. Bot Comp/utensis 15: 175202 Se lleva a cabo una recopilación de catálogos floristicos elaborados dentro del territorio de la Península Ibérica e Islas Baleares.Dichos trabajos se han ordenado por países y provincias y representado geográficamente en un mapa de distribucion
Classification and mapping of Spanish Mediterranean mixed forests
Mixed forests play an important role in promoting forest functions and services, and showed better resilience to perturbations than monospecific forests. In the Mediterranean Basin they constitute an important share of the total forest area. However, although mixed forests have been described, classified and mapped in most of the Mediterranean regions around the world, in the Mediterranean Basin they remain neglected, with direct negative consequences for forest management and conservation strategies. Our objective is to present a reliable, uniform classification along with a map of the Spanish Mediterranean Mixed Forests (MMF) as a tool for their management and conservation in Spain. The digital Spanish Forest Map was analyzed to identify MMF. The most frequent tree species combinations were identified and their representativeness in terms of the total forest area was analyzed. In addition, to ensure environmental homogeneity in the proposed classification, the arrangement of each tree species combination within the Spanish Mediterranean ecoregions was evaluated using the Pearson Chi-square test. Based on our results, Spanish MMF currently cover 27.07% of the Mediterranean natural forest area. They were divided into 9 main ecological groups and 23 subtypes. The classification of Spanish MMF and the distribution map represent a first step towards recognizing the importance of mixed forests in the vegetation of the Mediterranean Basin. Together they may provide a valuable basis to improve future forest management, monitoring and conservation strategies both at national and European level
Boletín de la Institución Libre de Enseñanza
Resumen tomado de la publicaciónEl análisis de sedimentos fósiles, especialmente a través de la paleopalinología, está permitiendo profundizar en la evolución de los paisajes vegetales a lo largo del tiempo. Se ofrece una panorámica sintética de los principales resultados obtenidos en la península ibérica en relación con las fluctuaciones climáticas de las últimas fases del Cuaternario.MadridBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5; 28014 Madrid; Tel. +34917748000; [email protected]
Aproximación a la bibliografía florística básica de la Península Ibérica e Islas Baleares
Se lleva a cabo una recopilación de catálogos florísticos elaborados dentro del territorio de la Península Ibérica e Islas Baleares. Dichos trabajos se han ordenado por países y provincias y representado geográficamente en un mapa de distribución
El análisis de semejanza aplicado al estudio de barreras y fronteras fitogeográficas: su aplicación a la corología y endemoflora ibéricas
A method for the analysis and interpretation of phytogeographic limits and barriers is proposed and applied. This method is based on the calculation of marginal coefficients of similarity and on the balance of interchange between the chororological units of a biogeographic sectorization. This method allows for: a) the setting up of different limit patterns according to their permeability; b) the determination of the existence of phytogeographic barriers, migratory pathways, diversity centers, refuges and ecotonal zones. The method is specifically applied to the information obtained from the Iberian-Balearic endemic Magnoliatae. Its application to the territories studied provides new data for their chorological sectorization, quantitatively assessing aspects such as the relationship between the Balearic Archipelago and the Peninsula, the migratory pathways followed by Iberian endemics, the phytogeographical nature of controversial units like the Cadiz-Huelva-Algarve coastline, the Guadalquivir Valley, the Andalusian Mountains, the Cantabrian Range, etc.Se propone y aplica a los territorios ibérico-baleares un método de análisis e interpretación de fronteras y barreras fitogeográficas, basado en el cálculo de coeficientes de similitud marginales y en la definición del balance de intercambio entre las unidades corológicas de una sectorización biogeográfica. El método permite:
a) establecer diferentes modelos de fronteras según su permeabilidad; b) determinar la existencia de barreras fitogeográficas, vías migratorias, centros de diversidad, refugio y zonas ecotónicas. En particular el método se aplica a la información suministrada por las Magnoliatae endémicas ibérico-baleares. Su aplicación a los territorios estudiados aporta nuevos datos a la sectorización corológica de los mismos, valorando de forma cuantitativa aspectos como la relación entre el archipiélago Balear y la Península, las vías migratorias seguidas por el endemismo ibérico, la naturaleza fitogeográfica de unidades controvertidas como el litoral Gaditano-Onubo-Algarviense, el valle del Guadalquivir, las Sierras Béticas, la Cordillera Cantábrica, etc
Contribución a la tipificación de los sabinares albares (Juniperus thurifera L.) en el Sistema Ibérico meridional
Táxones de interés corológico de la cuenca media del Duero (cañón del río Riaza, Segovia)
Se indica la presencia en el cañón del rio Riaza (Segovia) de una serie de táxones entre los que destacan, Isatis platyloba, recientemente incorporado a la flora española, Onopordum acaulon subsp. acaulon, Globularia alypum y Saxifraga cuneata. Se incluyen mapas actualizados de sus áreas de distribución conocidas. Se señalan también otros
táxones colectados en dicha área que ponen de manifiesto, junto con los señalados, la importancia fitogeográfica de este enclave, particularmente a causa del elemento xerotérmico paleógeno.The presence in the canyon of the Riaza river (Segovia) of several taxa is indicated. Among them, the following are outstanding: Isatis platyloba, recently incorporated to the Spanish flora, Onopordum acaulon subsp. acaulon, Globularia alypum and Saxifraga cuneata. Updated maps of their known distribution areas are included. Some other taxa collected in this area are discussed, evidencing, together with those mentioned, the phytogeographic interest of this site, mainly due to its paleogenous xerothermic elements
Yew (Taxus baccata L.) population dynamics in the Iberian Mediterranean Mountains: natural regeneration and expansion in East Central System (Spain)
Aim of study: To evaluate demographical dynamics of yew populations in the Iberian Mediterranean mountains in order to assess population trends and a hypothetical natural regeneration of the species.
Area of study: Ayllón Mountain Range, Eastern end of Central Mountain Range, Spain.
Material and methods: Afield survey was conducted on three yew groves, taking data of altitude, orientation, companion woody species, UTM coordinates, height, perimeter (at breast height, 120cm) and sex. Individuals were classified in four age groups, considering height and trunk perimeter: AgeGroup1, Seedling; AgeGroup2, Juvenile; AgeGroup3, Adult and AgeGroup4, Old. Finally Recruitment rate was calculated for each population.
Main results: Surveyed yew populations include more than 1600 trees, showing elevated Recruitment rates, which indicates that there are more seedling and juvenile individuals (Group1 and Group2) than adult and old ones (Group3 and Group4).
Research highlights: Surveyed yew populations show vigorous regeneration. These results lead us to reconsider the relictic character assigned to the species in the Iberian Mediterranean mountains
Datos sobre las comunidades de caméfitos espinosos en los macizos meridionales galaicos (NW España)
Costa Tenorio, M., Morla Juaristi, C. & Sainz Ollero, H. Datos sobre las comunidades de caméfitos espinosos en los macizos meridionales galaicos (NW España). Lazaroa 13:139-147 (1992). Se describen las comunidades de matorral dominadas por Echinospartum ibericum Rivas-Martínez, Sánchez-Mata & Sancho subsp. pulviniformis (Rivas-Martínez) Rivas-Martínez, que colonizan medios rupícolas en los macizos meridionales del noroeste peninsular. Se discute su posición sintaxonómica y se propone su inclusión en la nueva asociación Festuco graniticolae-Echinospartetum pulviniformis. Se realizan también algunas consideraciones biogeográficas
Hybrid zones between two european oaks: a plant community approach
We present a modelling framework for predicting forest areas. The framework is obtained by integrating a machine learning software suite within the GRASS Geographical Information System (GIS) and by providing additional methods for predictive habitat modelling. Three machine learning techniques (Tree-Based Classification, Neural Networks and Random Forest) are available in parallel for modelling from climatic and topographic variables. Model evaluation and parameter selection are measured by sensitivity-specificity ROC analysis, while the final presence and absence maps are obtained through maximisation of the kappa statistic. The modelling framework is applied at a resolution of 1 km with Iberian subpopulations of Pinus sylvestris L. forests. For this data set, the most accurate algorithm is Breiman's random forest, an ensemble method which provides automatic combination of tree-classifiers trained on bootstrapped subsamples and randomised variable sets. All models show a potential area of P. sylvestris for the Iberian Peninsula which is larger than the present one, a result corroborated by regional pollen analyses