Francisco Gómez Mercado

The endemic flora in the south of the Iberian Peninsula: taxonomic composition, biological spectrum, pollination, reproductive mode and dispersal

Summary The taxonomical composition and four ecological characteristics (life form, seed-dispersal, pollination and reproductive mode) of the 553 endemic species occurring in the south of the Iberian Peninsula have been investigated. A comparative analysis of the results reveals that this endemic flora does not comply with the general patterns previously observed in local floras, Mediterranean regional floras and floras of temperate latitudes. Predominant life forms are chamaephytes (45%) and hemicryptophytes (33%). By contrast, therophytes (11%) and phanerophytes (1%) are relatively infrequent. This spectrum of life forms mirrors the altitudinal distribution of the endemic species, their seed-dispersal strategy and the type of phytocoenoses in which they occur. As far seed-dispersal is concerned, 44% of the endemic species lack any noteworthy adaptive feature. However, the results clearly suggest that this limitation in their disseminative potential has only encouraged endemicity among the therophytes inhabiting lowlands. Among chamaephytes and hemicryptophytes of medium and high altitude, there is a relatively high frequency of exozoochory and anemochory, an adaptation that has contributed to the survival of small plant populations. 91% of the endemic species are pollinated by animals (insects), and only 3 species are dioecious. The dichotomies that the above mentioned characteristics produce (herbaceous vs woody life form, animal-assisted vs abiotic seed-dispersal, animal-assisted vs abiotic pollination and dioecious vs hermaphrodite reproductive mode), have been used to plot statistically significant associations. These are three: Pollination mode is linked with the seed-dispersal strategy, life form with pollination mode, and pollination mode with the reproductive mode. These associations contrast distinctly with results of previous surveys on whole floras, a contrast which makes the singularity of the endemic flora of the Southern Iberian peninsula even more remarkable.

Análisis de la flora vascular de la Sierra de Gádor (Almería, España)

Se lleva a cabo un estudio de la flora vascular de la Sierra de Gador (SW Almeria), analizandose la composicion taxonomica, biotipos dominantes y el caracter endemico de los taxones representados. Del analisis del catalogo floristico, que consta de 1540 taxones se obtiene que el 80% de la flora estudiada pertenece al grupo de dicotiledoneas, con las Asteraceas y Fabaceas como familias dominantes, del 14% que representan las monocotiledoneas, Poaceas es la familia dominante. Se compara el espectro biologico con otras areas peninsulares y del norte de Africa. El alto grado de mediterraneidad se refleja en la dominancia de terofitos (38,6%) seguido por los hemicriptofitos (23%) y camefitos (16,4%). Del analisis corologico se extrae que mas del 10% de la flora es endemica de la Peninsula Iberica. Entre los elementos iberonorteafricanos (9%) representados en el area de estudio destacan algunos con distribucion en la Peninsula unicamente en este territorio, como es el caso de Polycarpon policarpoides subsp. herniarioides e Hypericum robertii. Existen 7 endemismos exclusivos de la Sierra de Gador, seis pertenecen al sector Alpujarreno-Gadorense, provincia Betica ( Alyssum gadorense,Seseli intricatum, Astragalus tremolsianus, Coronopus navasii, Centaurea kunkelii y Barliorchis x almeriensis ) y uno al sector Almeriense, provincia Murciano-Almeriense ( Teucrium intricatum ).

Soil Requirements of Four Salt Tolerant Species in Two Saline Habitats

In this paper we investigated the response to some edaphic factors of the guiding species in two habitats of interest for the European Union (Habitats Directive 92/43/EEC). For the priority habitat 1510 (Mediterranean salt steppes, Limonietalia), we chose Limonium cossonianum. For habitat 1420 (Mediterranean and thermo-Atlantic halophilous scrubs, Sarcocornietea fruticosi), we chose Arthrocnemum macrostachyum, Sarcocornia fruticosa, and Sarcocornia perennis subsp. alpini. We studied four coastal wetlands in the bay of Almería (southeast of Spain), where we set up a grid of sampling plots. In each of these plots we related the presence of these species with a series of edaphic variables measured at specific times of the year for two years. Habitat 1510 is made up of moderately halophilous species that grow on soils that are saturated only in very wet weather conditions and cannot tolerate flooding for long periods of time. By contrast, the species of habitat 1420 are genuinely halophilous and the soils they grow on are often saturated and subject to frequent and prolonged flooding. The differences between these species are mainly rooted in different levels of tolerance to flooding-drying cycles (anoxia). Our results could be used as a criterion for the restoration of the habitats mentioned in the Habitats Directive, such as degraded salt marshes, and abandoned salt works, among others.

Estimación de los rangos de tolerancia a los factores ambientales de diversas especies mediterráneas de interés ecológico-forestal

En este trabajo se analiza el comportamiento de un grupo de especies vegetales relevantes desde el punto de vista paisajistico y por tanto potencialmente utilizables en tareas de restauracion. El area de trabajo en donde se enmarca el estudio es el Corredor Verde del Guadiamar, una estrecha franja de terreno que va desde Entremuros a Aznalcollar (Sevilla). El objetivo principal es delimitar con la mayor precision posible los limites de tolerancia de dichas especies a los diversos factores ambientales que controlan su dinamica y condicionan su distribucion. Para ello hemos seleccionado 12 especies: Quercus suber y Q. rotundifolia entre los grandes elementos forestales; Olea europaea var. sylvestris, Quercus coccifera, Chamaerops humilis, Arbutus unedo y Pistacia lentiscus representan a los arbustos del sotobosque de encinares y alcornocales. Cistus ladanifer, Genista hirsuta, Rosmarinus officinalis, Cistus monspeliensis y Thymbra capitata , son las especies del matorral heliofilo o matorral serial. Algunas de las conclusiones mas relevantes fueron que Q. suber y Arbutus unedo aparecen siempre en suelos con muy baja presencia de calcio, districos, con muy bajo porcentaje de carbonatos y pH menor de 6,7. En el otro extremo de valores de la mayoria de las variables estudiadas se encuentra Thymbra capitata , la unica especie que se presenta solo en suelos eutricos, con niveles muy bajos de carbono organico, valores muy altos de calcio o con valores muy altos en el porcentaje de carbonato calcico equivalente. Quercus rotundifolia , en cambio, destaca por presentar rangos de tolerancia muy amplios para casi todas las variables estudiadas.

Ecological behaviour of some Mediterranean plant species: scientific grounds for restoration

Abstract As a basis for the restoration of degraded areas we propose vegetal restoration with indigenous species peculiar to the immediate environment of the area, taking into account their ecological requirements. By doing this, we will be able to foresee their future behaviour, improve their chances of success and cut the costs and guarantee adequate environmental management. For this purpose we took a number of samples in nearby sites which maintain well preserved shrub or forest vegetal communities, and in each of them we carried out a relevé of flowering plant species and estimated the values of 20 environmental variables. The PCA reveals the existence of two clearly distinct environments: hygrophilous and non-hygrophilous. We will concentrate on the non-hygrophilous. In this group, the most significant variables were topo—climatic gradient on the one hand and edapho—chemical gradient on de other hand. In conclusion, we mention the most suitable tree and shrub species for the restoration of each of the large environments of the study area.

Comunidades vegetales de las balsas de la Sierra de Gádor (Almería)

Se describe la microserie supra y oromediterraneo de las balsas gadorenses, como resultado del estudio de las comunidades vegetales acuaticas y semiacuaticas que se desarrollan en ellas, integrado por 7 comunidades vegetales, una de las cuales ( Lepidioni petrophili- Coronopodetum navasii ) se describe como nueva.

Edaphic behaviour of several species of Cistus in the Green Corridor of Guadiamar (Spain) .

Las especies del genero Cistus son arbustos lenosos que tienen interes en restauracion forestal y que se han utilizado con frecuencia como especies caracteristicas de distintas unidades sintaxonomicas de alto rango. Por todo ello consideramos interesante conocer sus limites de tolerancia y condiciones optimas de desarrollo con respecto a diversos factores edaficos. El trabajo de campo se desarrollo en los terrenos del Corredor Verde del Guadiamar, un largo pasillo que pone en contacto dos grandes territorios protegidos, el Parque Natural y Parque Nacional de Donana y los Parques Naturales de Aracena y Picos de Aroche y la Sierra Norte de Sevilla en Andalucia. Trabajamos con seis especies (C. albidus, C. ladanifer, C. monspeliensis, C. populifolius, C. crispus y C. salviifolius) detectadas en 14 localidades. En cada una de ellas se tomo una muestra de suelo y un inventario fitosociologico. Las variables edaficas analizadas fueron calcio de cambio, magnesio de cambio, sodio de cambio, potasio de cambio, carbonatos totales, humedad de saturacion y pH. C. albidus es la especie mas tolerante a la presencia de calcio y carbonatos de las muestreadas. En cuanto al pH se encuentra preferentemente en suelos proximos a la neutralidad o moderadamente basicos. Sin embargo, no se trata de una especie calcicola estricta, sino que su capacidad de competencia se ve favorecida en estos medios. C. crispus aparece en los suelos que presentan los mas bajos valores del muestreo en bases de cambio, carbonatos totales, pH y humedad de saturacion. De C. ladanifer puede destacarse el bajo nivel de carbonatos totales. C. populifolius es la que presenta la humedad de saturacion mas elevada. C. monspeliensis es la especie que tiene el mayor rango de tolerancia, sobre todo a los valores de pH y una las mas xerofilas. C. salviifolius presenta un comportamiento intermedio con respecto a la mayor parte de las variables, con una preferencia por los ambientes moderadamente acidofilos, aunque tampoco de manera estricta.

Syntaxonomical review of the Omphalodion commutatae alliance (class Helianthemetea)

Abstract The syntaxa of Omphalodion commutatae (Trachynietalia distachyae, Helianthemetea) are examined as regards to their floristic, ecological and biogeographical characteristics, and the new association Sileno lasiostylae-Arenarietum tenuis is described. A correspondence analysis (CA) has been carried out and, as a result of it, the relationships between the different syntaxa in the alliance are reviewed.

Rupicolous communities of the southeast of the Iberian Peninsula

Abstract We have studied the rupicolous communities of the SE of the Iberian Peninsula (Alpujarreño-Gadorense sector and Almeriense Occidental district). Using both our own relevés and those available in bibliography, we have carried out a Detrended Correspondence Analysis (DCA) and a phytosociological review. As a result, we propose two new taxa and consider two other taxa as, so far regarded as distinct, as one. Finally, we propose including the new taxa in annex I of the Habitats Directive, as a means for preserving them.

Novedades florísticas para la sierra de Gádor (Almería, España)

We comment on twelve taxa of floristic and chorological interest collected in the Gador Mountains (Almeria). All of them are new records for the Alpujarra-Gador sector. We highlight the new records for Serratula baetica subsp. baetica and Potentilla reuteri in Almeria province.