Piqueray, Julien; Bottin, Gaëtan; Delescaille, Louis-Marie; Bisteau, Emmanuelle; Mahy, Grégory
L’objectif de ce travail était de réaliser une première évaluation des actions de restauration de pelouses calcicoles effectuées dans les régions de Lesse et Lhomme et du Viroin (Belgique) depuis 15 ans. L’évaluation en terme de structure spatiale a montré que la surface totale de pelouses avait plus que doublé dans ces régions. Cette augmentation était surtout due à l’augmentation de la surface moyenne des pelouses et dans une moindre mesure à l’augmentation du nombre de pelouses présentes s...
Full Text Available The objective of this paper is to (a summarize the results of malacological investigations of the West Carpathian treeless spring fens and (b show how unique sites these fens are. The mollusc communities were studied from several ecological points of view such as: response to the poor-rich mineral gradient, calcicole-calcifuge behaviour, geographical distribution, and historical development. The published or prepared articles concerning above-mentioned topics are cited in the text.
Full Text Available Llavea Lag. is a genus of Cryptogrammoideae (Pteridaceae, whose only species is distributed from southern United States and Mexico to Guatemala and Costa Rica, although it lives mainly in Mesoamerica, inhabiting preferably calcicolous habitats associated with forests and mountains. The genus is easily recognized by the presence of fertile leaves hemi-dimorphic, with the fertile apical portion with longer and narrower segments than the sterile ones, with strongly revolute margin, and rhizome scales bicolorous, shiny, and black. This paper presents a revision of the genus, nomenclatural issues are resolved, and and palynological morphological diversity are reviewed, as well as its distribution, phenology, ecology, and applications, based on field and herbarium specimens studies. In addition, two names related to Llavea, Allosorus karwinskii Kunze and Ceratodactylis osmundioides J. Sm., were lectotypified.
Lichenometric age measured on rock-falls related to historic seismicity affecting Lorca and its surroundings (Murcia, SE Spain); Datacion mediante liquenometria de los desprendimientos rocosos asociados a la sismicidad historica en Lorca (Murcia, SE de Espana)
Perez-Lopez, R.; Martin-Gonzalez, F.; Martinez-Diaz, J. J.; Rodriguez-Pascua, M. A.
During the earthquake at Lorca (Murcia, SE Spain) in 2011 (5.2 Mw, 4km depth) several rock-falls occurred, mobilizing an estimated volume of close to 2,000 m3. All these rock-falls took place within the Estancias and La Tercia mountain ranges, the topography of which is composed of Tortonian calcarenitic sandstones with steep scarps more than 30 m in height. We have conducted a lichenometric study to obtain the age of the ancient rock-falls within the Las Estancias Range. We have assumed an annual growth rate of 0.24 mm for lichen species classified as calcicolous and related to warm climatic conditions. Our aim was to corroborate the hypothesis that seismic events triggered these massive rock-falls. The city of Lorca had experienced two nearfield historic earthquakes (1674 EMS VIII and 1818 EMS VI) and one far-field tremor during the great Lisbon earthquake in 1755 (EMS VI). Results obtained here indicate that the earthquakes of 1674 and 2011 were quite similar, except that the 1674 one mobilised a greater quantity and twenty times the volume of blocks mobilised during the 2011 earthquake. Therefore, we conclude that the size of the earthquake of 1674 was possibly between 6.0 < M < 6.8, assuming similar focal and seismotectonic conditions to those of the instrumentally measured earthquake of 2011. (Author) 34 refs.
Venturas, Martin; Fernández, Victoria; Nadal, Paloma; Guzmán, Paula; Lucena, Juan J; Gil, Luis
The calcifuge and calcicole character of wild plants has been related to nutrient availability shortages, including iron (Fe)-deficiency. Surprisingly, just a few studies examined the relation between root Fe uptake and plant distribution in different soil types. We assessed the root Fe acquisition efficiency of two Ulmus species with calcareous (Ulmus minor) and siliceous (U. laevis) soil distribution patterns in the Iberian Peninsula. Seedlings of both elm species were grown hydroponically with different Fe concentrations during 6 weeks. Plant physiological responses to Fe-limiting conditions were evaluated as were the ferric reductase activity and proton (H(+)) extrusion capacity of the roots. Iron deprived elm seedlings of both species were stunted and suffered severe Fe-chlorosis symptoms. After Fe re-supply leaf chlorophyll concentrations rose according to species-dependent patterns. While U. minor leaves and seedlings re-greened evenly, U. laevis did so along the nerves of new growing leaves. U. minor had a higher root ferric reductase activity and H(+)-extrusion capability than U. laevis and maintained a better nutrient balance when grown under Fe-limiting conditions. The two elm species were found to have different Fe acquisition efficiencies which may be related to their natural distribution in calcareous and siliceous soils of the Iberian Peninsula.
Full Text Available The calcifuge and calcicole character of wild plants has been related to nutrient availability shortages, including iron (Fe-deficiency. Surprisingly, just a few studies examined the relation between root Fe uptake and plant distribution in different soil types. We assessed the root Fe acquisition efficiency of two Ulmus species with calcareous (U. minor and siliceous (U. laevis soil distribution patterns in the Iberian Peninsula. Seedlings of both elm species were grown hydroponically with different Fe concentrations during six weeks. Plant physiological responses to Fe-limiting conditions were evaluated as were the ferric reductase activity and proton (H+ extrusion capacity of the roots. Iron deprived elm seedlings of both species were stunted and suffered severe Fe-chlorosis symptoms. After Fe re-supply leaf chlorophyll concentrations rose according to species-dependent patterns. While U. minor leaves and seedlings re-greened evenly, U. laevis did so along the nerves of new growing leaves. Ulmus minor had a higher root ferric reductase activity and H+-extrusion capability than U. laevis and maintained a better nutrient balance when grown under Fe-limiting conditions. The two elm species were found to have different iron acquisition efficiencies which may be related to their natural distribution in calcareous and siliceous soils of the Iberian Peninsula.
de Groot G Arjen
Full Text Available Abstract Background Previous studies on the reproductive biology of ferns showed that mating strategies vary among species, and that polyploid species often show higher capacity for self-fertilization than diploid species. However, the amount of intraspecific variation in mating strategy and selfing capacity has only been assessed for a few species. Yet, such variation may have important consequences during colonization, as the establishment of any selfing genotypes may be favoured after long-distance dispersal (an idea known as Baker's law. Results We examined intra-and interspecific variation in potential for self-fertilization among four rare fern species, of which two were diploids and two were tetraploids: Asplenium scolopendrium (2n, Asplenium trichomanes subsp. quadrivalens (4n, Polystichum setiferum (2n and Polystichum aculeatum (4n. Sporophyte production was tested at different levels of inbreeding, by culturing gametophytes in isolation, as well as in paired cultures with a genetically different gametophyte. We tested gametophytes derived from various genetically different sporophytes from populations in a recently planted forest colonized through long-distance dispersal (Kuinderbos, the Netherlands, as well as from older, less disjunct populations. Sporophyte production in isolation was high for Kuinderbos genotypes of all four species. Selfing capacity did not differ significantly between diploids and polyploids, nor between species in general. Rather selfing capacity differed between genotypes within species. Intraspecific variation in mating system was found in all four species. In two species one genotype from the Kuinderbos showed enhanced sporophyte production in paired cultures. For the other species, including a renowned out crosser, selfing capacity was consistently high. Conclusions Our results for four different species suggest that intraspecific variation in mating system may be common, at least among temperate calcicole
蒋能; 宁世江; 盘波; 沈晓琳; 黄仕训
In order to understand the wild and shade ornamental plant resources and valuable germplasm hidden in Guangxi,the shade and half shade plant resources in Guangxi were studied by the methods of field investigation and specimen collection identification. The results showed that the five basic characteristics of Guangxi wild shade ornamental plants: rich species(162 families, 485 genera, and 1 309 species) , precious germplasm resources (including 195 species of the valuable and rare plant, and 136 species endemic to Guangxi) , diversity of growth soil texture (the calcicole, the acidophile and the intermediate plant), remarkable of the herbaceous ratio(the herb plants account for about 66. 1%) ,and great disparity of wild resources distribution. The six taxa were as following:Pteridophyte(43 families,240 species) ,Orchidaceae(37 genera,126 species) ,Liliaceae(21 genera,82species) ,Gesneriaceae(17 genera, 63 species) ,Begoniaceae(l genera,43 species) and Araceae(12 genera,30 species). The results would provide a reference for the rational development and u-tilization of wild shade ornamental plant resources.%为了解广西境内蕴藏的野生阴生观赏植物资源及珍贵种质,采取野外实地考察及标本采集鉴定相结合的方法,对广西全境分布的阴生和半阴生观赏植物资源进行研究.结果表明:广西野生阴生观赏植物有5个基本特点:种类丰富(162科485属1 309种)、种质资源珍贵(珍稀植物195种,广西特有植物136种)、生长基质多样(喜钙植物、喜酸植物和中间类型植物)、草本性状比值显著(草本植物约占总种数的66.1％)、野生资源贮藏量的多寡悬殊性.6个主要野生阴生观赏类群为:蕨类植物(43科240种)、兰科(37属126种)、百合科(21属82种)、苦苣苔科(17属63种)、秋海棠科(1属43种)、天南星科(12属30种).研究结果可为合理开发利用广西野生阴生观赏植物资源提供参考.
Full Text Available Structure, flora, ecology and dynamics of submediterranean Thymus vulgaris garrigues (Thymelaeo-Aphyllanthetum monspeliensis are analysed and compared with two groups of calcicolous scrubs, based upon 391 relevés from Navarre (NE Spain. Those submediterranean Thymus vulgaris garrigues are more diverse, have higher proportion of hemicryptophytes than cushion heaths of Genista occidentalis (Genistion occidentalis and show wide ecological differences, as they thrive at lower altitudes, on less inclined slopes with preference for southward exposures. They are distinguished from the more xerophillous somontano-aragonés Thymus vulgaris garrigues (Aphyllanthion by their higher frequency of Atlantic and Eurosiberian taxa, lower proportion of nano-phanerophytes and affinity for more humid climates. There is a gradual change in the flora and structure of those three scrub groups related with the Eurosiberian-mediterranean climatic transition. Thymelaeo-Aphyllanthetum floristic composition has higher frequency of character taxa of Rosmarinetea and Rosmarinetalia than those of Festuco-Ononidetea striatae and Ononidetalia striatae, and this feature together with its structure justify the inclusion of this community in Aphyllanthion alliance, pointing out their relationship with somontano-aragonés Thymus vulgaris garrigues.
Sur la base de 391 rélevés procédant de la Navarre, les auteurs ont analysé les caractères physionomiques, floristiques, dynamiques et écologiques des garrigues subméditérranéennes (Thymelaeo-Aphyllanthetum monspeliensis et ont établi également la comparaison avec d'autres types de matorral basophiles. Ainsi les garrigues du Thymelaeo-Aphyllanthetum se montrent plus diverses et avec un pourcentage d'hemicryptophytes plus élevé que celui de la lande à Genista occidentalis (