Plant regeneration from an endangered valuable cork oak tree by somatic embryogenesis.

Among the several applications of in vitro tissue culture techniques, the conservation of plant germplasm is one of the most widely used. The cork oak is one of the principal tree species in the Western Mediterranean regi��n. Within this ��rea, the Balearic Islands are considered to be a glacial refuge, and therefore a reservoir of genetic resources. A singular tree has been found in the small Minorca Island population. The haplotype of this tree is of Tyrrhenian origin, showing a past link between Minorca and Sardinia. Moreover, this tree do not bear a deletion within an ITS from ribosimic nuclear DNA, which is fairly common in many populations of this species, and indicates that ir may be the descendant of a very ancient population. This tree is currently in a precarious condition, and it has not produced acorns in the last years. Hence there is a clear need of vegetative propagation to conserve this genotype. We have previously developed methods to clone adult cork oak tres by somatic embryogenesis, and therefore the aim of the present work was to clone this singular tree. There braches from the corwn were collected in November 2004, and methods previously described were carried out. By February 2005 somatic embryogenesis was obtained from leaves of the tree with percentages on induction ranging from 17 to 54% depending on the branch, which may show a novel source of variation that requires further study. Spontaneously matured somatic embryos germinated at 46% in average, and the first somatic seedlings from the Alfavaret's cork oak tree were obtained. Therefore, this study shows one of the most relevant applications of somatic embryogenesis: the plant regeneration of valuable genotypes for the in situ and ex situ conservation of forest genetic resources.

Census, reproductive biology, and germination of Astragalus gines-lopezii (Fabaceae), a narrow and endangered endemic species of SW Spain

Astragalus gines-lopezii Talavera, Podlech, Devesa & F.M.V��zquez (Fabaceae) is a threatened endemic species with a distribution restricted to a very small area in Badajoz Province (Extremadura Region, SW Spain) and only 2 populations are known. This species was catalogued in the ?Endangered? category in the 2008 Red List and the 2010 Threatened Spanish Vascular Flora List. Despite its status as an endangered species, at present very little is known about the distribution, census, and reproductive biology of this species. In this study we have carried out an exhaustive census of A. gines-lopezii , and we have evaluated the production of flowers, fruits, and seeds and the existence or not of intra- and interpopulation variability in seed germination. Results have highlighted the high reproductive capacity of this species on the basis of a high production of flowers, fruits, and seeds. Mechanical scarification of seeds was effective for increasing germination. Thus, initial germination (22%?60%) was increased to 97%?99% when seeds were rubbed with sandpapers. A high intra- and interpopulation variability in seed germination was found in this species. A. gines-lopezii produces seeds with different degrees of physical dormancy, varying this grade among different individuals within a population.

Conservation of endangered Lupinus mariae-josephae in its natural habitat by inoculation with selected, native Bradyrhizobium strains

Lupinus mariae-josephae is a recently discovered endemism that is only found in alkaline-limed soils, a unique habitat for lupines, from a small area in Valencia region (Spain). In these soils, L. mariae-josephae grows in just a few defined patches, and previous conservation efforts directed towards controlled plant reproduction have been unsuccessful. We have previously shown that L. mariae-josephae plants establish a specific root nodule symbiosis with bradyrhizobia present in those soils, and we reasoned that the paucity of these bacteria in soils might contribute to the lack of success in reproducing plants for conservation purposes. Greenhouse experiments using L. mariae-josephae trap-plants showed the absence or near absence of L. mariae-josephae-nodulating bacteria in ������terra rossa������ soils of Valencia outside of L. mariaejosephae plant patches, and in other ������terra rossa������ or alkaline red soils of the Iberian Peninsula and Balearic Islands outside of the Valencia L. mariae-josephae endemism region. Among the bradyrhizobia able to establish an efficient symbiosis with L. mariae-josephae plants, two strains, LmjC and LmjM3 were selected as inoculum for seed coating. Two planting experiments were carried out in consecutive years under natural conditions in areas with edapho-climatic characteristics identical to those sustaining natural L. mariae-josephae populations, and successful reproduction of the plant was achieved. Interestingly, the successful reproductive cycle was absolutely dependent on seedling inoculation with effective bradyrhizobia, and optimal performance was observed in plants inoculated with LmjC, a strain that had previously shown the most efficient behavior under controlled conditions. Our results define conditions for L. mariae-josephae conservation and for extension to alkaline-limed soil habitats, where no other known lupine can thrive.

Census, reproductive biology, and germination of Astragalus gines-lopezii (Fabaceae),a narrow and endangered endemic species of SW Spain.

Astragalus gines-lopezii Talavera, Podlech, Devesa & F.M.Vazquez (Fabaceae) is a threatened endemic species with a distribution restricted to a very small area in Badajoz Province (Extremadura Region, SW Spain) and only 2 populations are known.This species was catalogued in the "Endangered" category in the 2008 Red List and the 2010 Threatened Spanish Vascular Flora List. Despite its status as an endangered species, at present very little is known about the distribution, census, and reproductive biology of this species. In this study we have carried out anexhaustive census of A. gines-lopezii, and we have evaluated the production of flowers, fruits, and seeds and the existence or not of intra- and interpopulation variability in seed germination. Results have highlighted the high reproductive capacity of this species on the basis of a high production of flowers, fruits, and seeds. Mechanical scarification of seeds was effective for increasing germination. Thus, initial germination (22%-60%) was increased to 97%-99% when seeds were rubbed with sandpapers. A high intra- and interpopulation variability in seed germination was found in this species. A. gines-lopezii produces seeds with different degrees of physical dormancy, varying this grade among different individuals within a population.

Riparian woodland encroachment following flow regulation: a comparative study of Boreal and Mediterranean streams

Water development accompanying mankind development has turned rivers into endangered ecosystems. Improving the understanding of ecological responses to river management actions is a key issue for assuring sustainable water management. However, few studies have been published where ecological metrics have been quantified in response to various degrees of flow alteration. In this work, changes in natural distribution of trees and shrubs within the riparian corridor (as indicator of the ecological status of the fluvial ecosystem) were quantified at multiple sites along a flow alteration gradient (as indicator of impact) along two regulated river reaches, one Boreal and the other Mediterranean, each downstream of a dam. Based on the obtained relationships we evaluated differences in response trends related to local physico-climatic factors of the two biomes and regarding to differing life-forms. Woody vegetation establishment patterns represented objective indicators of ecological responses to flow alteration. We found different responses between life-forms. Both trees and shrubs migrated downwards to the channel after dam closure, but shrubs were most impacted under higher degrees of flow alteration in terms of lateral movement. In addition, our results show clear longitudinal recovery trends of natural patterns of tree and shrub distribution corresponding to a decrease in intensity of hydrologic alteration in the Boreal river. However, vegetation encroachment persisted along the entire Mediterranean study reach. This may result from a relatively low gradient of decrease of hydrologic alteration with distance from the dam, coupled with other overlapping pressures and the mediating effect of physico-climatic characteristics on vegetation responses.

Is it appropriate protective figure "Plant Micro-Reserves" to protect tree species? The example of Betula pendula subsp. fontqueri in "La Garganta de los Caballeros" (��vila)

The figure of protection "micro-reserves" was created in the Region of Valencia (ANONYMOUS, 1994) with the aim of protecting endangered plant species. This is one of the areas of greatest floristic richness and uniqueness of the western Mediterranean. In this area rare, endemic or threatened vascular flora has a peculiar distribution: they appear to form small fragments spread over the entire region (LAGUNA, 1994; LAGUNA, 2001) The protection of every these small populations of great scientific value has significant challenges. It doesn��t try to protect every species that set out in Annex IV of the by then existing Law 4 / 1989 (repealed in 2007), or to protect to the most ecological level with the creation of Natural Protected Area but an intermediate level: the plant community of small size. According to the decree: ���as Micro-Reserve will be declared the natural parcels of land under 20 hectares that contain a high concentration of rare plants, endemic, threatened or of high scientific interest��� (ANONYMOUS, 1994) . Of course, the statement of an area as micro-reserve carries certain prohibitions that are harmful to the vegetal community

Morphological and germination response variability in seeds of wild yellow gentian (Gentiana lutea L.) accessions from northwest Spain

Gentiana lutea L. (yellow gentian, Gentianaceae) is an important medicinal plant under protection as endangered species in most European countries. The aim of this work was to evaluate variation in seed mass, seed water content, and seed germination among 56 wild accessions of G. lutea. The effect of gibberellic acid (GA3), putrescine, moist chilling, and level of ripeness of seeds on subsequent germination was also investigated. Seeds of G. lutea showed physiological dormancy (final germination percentages ranged from 0% to 11%, depending on the accession) and GA3 enhanced seed germination drastically in all the accessions. The highest germination (99%) of GA3-treated seeds was reached at 15 ��C. Final germination percentage and germination rate (as expressed by mean germination time), as well as seed mass and seed water content, varied significantly among accessions. In general, 1 year moist chilling did not significantly enhance G. lutea seed germination. For most accessions, no significant differences were found between fully ripe seeds and less ripe seeds for seed water content, seed mass, and seed germination. Applications of GA3 were always most effective than those of putrescine for increasing seed germination.

Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species.

Estudio de la ecolog��a de Ulmus laevis Pallas en la Pen��nsula Ib��rica

Esta tesis doctoral pretende profundizar en el conocimiento de la ecolog��a de Ulmus laevis Pallas, especie aut��ctona en peligro de extinci��n en la Pen��nsula Ib��rica, con el fin de proponer medidas adecuadas para su conservaci��n. Se ha estudiado la distribuci��n natural de la especie atendiendo a aspectos ed��ficos. Los resultados muestran que U. laevis presenta menor capacidad de acidificaci��n de la rizosfera, menor actividad de la reductasa f��rrica y menor homeostasis que U. minor Mill. cuando crecen en sustratos con una disponibilidad de hierro limitada. Estas diferencias ayudan a comprender la distribuci��n de ambas especies en la Pen��nsula Ib��rica: U. laevis se ve restringido a suelos ��cidos o moderadamente ��cidos, mientras que U. minor es capaz de habitar tanto suelos ��cidos como b��sicos. Se han analizado las propiedades hidr��ulicas y anat��micas de U. laevis, constatando que sus caracter��sticas son favorables en ambientes con gran disponibilidad h��drica y que se trata del olmo ib��rico m��s vulnerable a la cavitaci��n por estr��s h��drico, por lo que la aridificaci��n del clima y la p��rdida de los fre��ticos supone un riesgo para sus poblaciones. Para evaluar la capacidad de recuperaci��n de la especie se han estudiado la diversidad y estructura gen��tica espacial de las dos mayores poblaciones espa��olas. Los resultados evidencian que estas poblaciones mantienen niveles de diversidad equiparables o ligeramente superiores a los europeos, pese a haber sufrido un cuello de botella prolongado durante las glaciaciones y a las reducciones poblacionales recientes. En la actualidad la endogamia no representa un riesgo para estas poblaciones. Tambi��n se ha analizado la producci��n, dispersi��n y predaci��n de semillas en Valdelatas (Madrid). Los resultados han mostrado que el viento dispersa las s��maras a corta distancia (<30 m) y que los a��os no veceros las probabilidades de establecimiento de regenerado son bajas. Adem��s, la producci��n de s��maras vanas puede tratarse de un car��cter adaptativo que aumenta la eficiencia biol��gica de la especie, ya que favorece la supervivencia de las semillas embrionadas disminuyendo sus tasas de predaci��n pre- y post-dispersi��n. La modificaci��n del h��bitat de esta especie como consecuencia de las actividades humanas afecta de manera negativa al establecimiento del regenerado. La conservaci��n de esta especie a largo plazo requiere la recuperaci��n de los niveles fre��ticos y de reg��menes hidrol��gicos que permitan avenidas, ya que estas crean las condiciones adecuadas para el establecimiento de regenerado al eliminar la vegetaci��n preexistente y depositar barro. ABSTRACT Ulmus laevis Pallas is an endangered species in the Iberian Peninsula. Therefore, in order to be able to propose adequate management guidelines for its conservation, this PhD Thesis intends to advance the knowledge on the species ecology in the region. Firstly, the species natural distribution was studied in relation to soil nature. Results show that U. minor Mill. had a higher root ferric reductase activity and proton extrusion capability than U. laevis, and maintained a better nutrient homeostasis when grown under iron limiting conditions. These differences in root Fe acquisition efficiencies proved helpful to understand the distribution of these species in the Iberian Peninsula, where U. laevis is restricted to acid or moderately acid soils, whereas U. minor can grow both in acid and basic soils. Secondly, we studied Ulmus laevis��� xylem anatomy and hydraulic traits. These proved favourable for growing under high water availability, but highly susceptible to drought-stress cavitation. Therefore, this species is vulnerable to the Iberian Peninsula���s aridification. Spatial genetic structure and diversity were evaluated in two of the biggest U. laevis populations in Spain in order to evaluate their recovery capabilities. These populations maintain similar or slightly higher diversity levels than European populations, despite having undergone an ancestral genetic bottleneck and having suffered recent population size reductions. No inbreeding problems have been detected in these populations. Seed production, dispersal and predation were assessed in Valdelatas��� elm grove (Madrid). Despite U. laevis samaras being winged nuts, wind dispersed them short distances from the mother tree (<30 m). The seed shadow models show that non-mast years provide very few chances for the stand to regenerate due to their low full seed flux. Empty samaras deceive pre- and post-dispersal predators increasing full seed survival probabilities. Therefore, empty fruit production might be an adaptive trait that increases plant fitness. Finally, human-induced changes in water-table levels and river regulation may affect U. laevis seed dispersal and regeneration establishment negatively. The long-term conservation and expansion of this species in the Iberian Peninsula requires the recovery of water-tables and of natural hydrological regimes, as flooding eliminates vegetation, creating open microhabitats and deposits mud, creating the ideal conditions for seedling establishment.

Estudio de viabilidad para almacenamiento de CO2 en la cuenca del Guadalquivir

El objetivo de este proyecto es investigar la viabilidad del almacenamiento de CO2 en un acu��fero salino profundo ubicado en el margen suroccidental de la Cuenca del Guadalquivir. Este proyecto est�� destinado a una operaci��n industrial con tasas de emisi��n de CO2 superiores a medio mill��n de toneladas anuales. Se ha construido un modelo geol��gico de la formaci��n almac��n en Petrel y se ha simulado la inyecci��n utilizando la versi��n composicional de ECLIPSE. El objetivo es inyectar CO2 manteniendo una tasa de inyecci��n constante durante 30 a��os, el m��ximo periodo permitido por la legislaci��n espa��ola sobre almacenamiento geol��gico de CO2. La cantidad de CO2 inyectada en cada uno de los casos ha sido determinada. Los resultados parecen indicar que la inyecci��n de CO2 a escala industrial podr��a ser viable, aunque la viabilidad del proyecto podr��a verse comprometida por la escasa profundidad a la que se encuentra el contacto entre la formaci��n almac��n y el sello lateral. Antes de seguir adelante con el desarrollo del proyecto ser��a conveniente determinar mejor la continuidad lateral de la formaci��n almac��n y sus condiciones de sello. ABSTRACT The aim of this project is to investigate the feasibility of CO2 geological storage in a deep saline aquifer located onshore in the southwestern margin of Guadalquivir Basin. The project is addressed for an industrial scale operation with CO2 emission rates higher than half a million tons per year. A geological model of the target reservoir was built in Petrel and injection simulations were performed with the compositional version of ECLIPSE. The purpose is to inject CO2 at constant rate during 30 years, the maximum period allowed by the Spanish law on carbon dioxide geological storage. The amount of CO2 injected in each studied scenario has been determined. Results suggest that CO2 injection at industrial scale could be viable, but the project feasibility could be endangered by the shallow depth of the contact between the target reservoir and the lateral seal. Prior to injection, further work should include ascertaining the reservoir���s lateral continuity and better determination of its sealing conditions

Cole��pteros Saprox��licos de los Bosques de Monta��a en el Norte de la Comunidad de Madrid

La fauna saprox��lica ha cobrado mucha relevancia en los ��ltimos a��os. Por una parte, debido a los m��ltiples papeles que juega en la ecolog��a de los bosques y por otra, por encontrarse muchas especies de ese grupo amenazadas como consecuencia de la intensificaci��n de las actividades forestales. Se supone que los bosques de Europa meridional albergan una fauna saprox��lica rica y variada. Sin embargo apenas se han realizado estudios que permitan conocer la composici��n de las biocenosis saprox��licas, as�� como el estatus y grado de amenaza a que est�� sometida cada especie. En esta tesis se han muestreado de forma sistem��tica las comunidades de cole��pteros saprox��licos de cuatro montes del norte de la Comunidad de Madrid, muy diferentes a pesar de su cercan��a: Dehesa Bonita de Somosierra, Hayedo de Montejo, Dehesa de Madarcos y Pinar de La Maleza. Para llevar a cabo la recogida de muestras se defini�� una estaci��n de muestreo tipo, compuesta por cuatro trampas a��reas con cebo oloroso, dos trampas de ventana y una trampa de embudos. En los dos primeros montes mencionados se desplegaron seis estaciones de muestreo, por s��lo tres en los otros dos. El primer objetivo de esta tesis fue conocer las especies de cole��pteros que constituyen la fauna de los cuatro montes estudiados. Los muestreos sistem��ticos reportaron la presencia de un total de 357 especies de cole��pteros saprox��licos, siendo el Hayedo de Montejo el bosque con la diversidad m��s alta, 220 especies; le siguen la Dehesa de Madarcos con 116; el pinar de La Maleza con 115; y la Dehesa de Somosierra con 109, si bien la fauna de este ultimo bosque podr��a ser mucho m��s variada dado que la interferencia del ganado con algunos dispositivos de captura hizo que se perdiera parte del material all�� recolectado. Se han encontrado nueve especies nuevas para la fauna de la Pen��nsula Ib��rica, y otras muchas desconocidas previamente en el centro peninsular. Un total de 50 especies se encuentran incluidas en la Lista Roja Europea de cole��pteros saprox��licos. El segundo objetivo fue estimar la riqueza de fauna de cole��pteros saprox��licos en cada bosque. Partiendo de los datos de los respectivo muestreos se calcularon diferentes estimadores, param��tricos y no param��tricos, y se elaboraron las curvas de rarefacci��n para cada bosque y para el conjunto. El bosque con m��s biodiversidad ha resultado ser el Hayedo de Montejo, que albergar��a entre 254 y 332 especies. En el Pinar de la Maleza se encontrar��an de 132 a 223; de 128 a 205 en la Dehesa de Somosierra; y entre 134 y 188 en la Dehesa de Madarcos. Para el conjunto del ��rea se estim�� la presencia de entre 411 y 512 especies. El tercer objetivo fue evaluar la influencia de algunos factores como la especie arb��rea dominante y la cantidad de madera muerta en la riqueza y diversidad de cole��pteros saprox��licos. El estudio se realiz�� en el Hayedo de Montejo, encontrando una alta correlaci��n positiva entre cantidad y calidad de madera muerta, y diversidad y riqueza de especies de cole��pteros saprox��licos. El cuarto objetivo fue evaluar la eficacia y complementariedad de los diferentes tipos de dispositivos de captura empleados en los muestreos. El m��s eficaz result�� ser la trampa de ventana, seguido por la trampa a��rea con cebo oloroso, y finalmente la trampa de embudos. La mayor complementariedad se encontr�� entre trampas de ventana y a��reas con cebo oloroso. No obstante, si se quiere optimizar la exhaustividad del inventario no se debe prescindir de ninguno de los sistemas. En cualquier caso, puede afirmarse que la efectividad de los tres tipos de dispositivos de captura utilizados en los muestreos fue baja, pues para la gran mayor��a de especies presentes se captur�� un n��mero de ejemplares realmente bajo. El bajo rendimiento de captura implica un bajo impacto sobre las poblaciones de las especies muestreadas, y esto supone una importante ventaja desde el punto de vista de la conservaci��n. Finalmente, se dejan algunas recomendaciones de manejo a aplicar en cada uno de los montes con el fin de preservar o mejorar los h��bitats utilizables por la fauna saprox��lica que garanticen el mantenimiento y mejora de dichas comunidades. ABSTRACT The saproxylic fauna has become increasingly important in recent years. It has been due, on the one hand, to the multiple roles they play in the forest ecosystems and, on the other, because of the large proportion of endangered saproxylic species as a result of the intensification of forestry. It is generally assumed that southern Europe forests are home to a rich and diverse saproxylic fauna. However, there are hardly any studies leading to reveal the composition of saproxylic biocenosis, or the stage and extent of the threat each species is suffering. For the purpose of this thesis the communities of saproxylic beetles of four mountain forests in northern Comunidad de Madrid have been systematically sampled: Dehesa Bonita de Somosierra, Hayedo de Montejo, Dehesa de Madarcos and Pinar de La Maleza. They are very different from each other in spite of not being too far apart. In order to carry out sample collection, a standard sampling station was defined as follows: four smelly bait aerial traps, two window traps and one funnel trap. Six sampling stations were deployed in each of the first two forests mentioned above; put only three in each of the other two. The first aim of this thesis was to determine the composition of saproxylic beetles fauna inhabiting each of the four forests studied. Systematic sampling reported the presence of a total of 357 species of saproxylic beetles. Hayedo de Montejo, with 220 species, is the forest with the highest diversity, followed by Dehesa de Madarcos, 116; Pinar de La Maleza, 115, and Dehesa de Somosierra, 109. The fauna of the latter forest, however, could be much more varied, since cattle interference with some capture devices caused the loss of part of the material collected there. Nine new species in the fauna of the Iberian Peninsula were found, and many others previously unknown in the center of the Peninsula. A total of 41 of those species are included in the European Red List of saproxylic beetles. The second aim was to estimate the richness of saproxylic (beetle) fauna in each forest. From the data of the respective sampling, different parametric and nonparametric estimators were calculated, and rarefaction curves for each forest, as well as for the four of them together, were drawn. The most biodiverse forest turned out to be Hayedo de Montejo, which houses between 254 and 332 species. In Pinar de La Maleza, between 132 and 223 species were found; between 128 and 205 in Dehesa de Somosierra, and between 134 and 188 in Dehesa de Madarcos. The estimated diversity of species for the whole area ranges from 411 to 512. The third aim was to evaluate the influence of such factors as the dominant tree species and the amount of dead wood in the richness and diversity of saproxylic beetles. The study was conducted at Hayedo de Montejo, finding a high positive correlation between quantity and quality of coarse woody debris and diversity and richness of saproxylic beetle species. The fourth aim was to evaluate the effectiveness and complementarity of the different sampling methods used in this research work. The most effective proved to be the window trap, followed by the smelly bait aerial trap and the funnel trap, in that order. The greater complementarity was found between window and aerial traps. However, in order to optimize the completeness of the inventory, neither of the systems should be discarded. Nevertheless, the effectiveness of the three types of capture devices used in this piece of research was on the whole rather low, since for the vast majority of species, a significant low number of specimens were captured. Poor trapping performance implies a low impact on the populations of the sampled species, and this is an important advantage in terms of conservation. Finally, this thesis gives some recommendations with regard to the management of each of those four forests, leading to preserve and improve the habitats of the saproxylic wildlife and so ensure the maintenance and growth of their communities.

Ficciones urbanas vern��culas dise��adas seg��n principios art��sticos. Permanencia y poder simb��lico del ideal urbano tradicional

The theoretical contributions of John Ruskin, the analysis and proposals in Camillo Sitte?s City Planning According to Artistic Principles or the urban environment defense by Gustavo Giovannoni involved important restrictions on the destruction of this heritage and on the progressive Haussmanization of many European cities. But this interest on the endangered traditional city also caused the birth of a wide range of urban proposals which aimed at recreating or reproducing an ideal model of it. Erected under different circumstances and with multiple purposes, they did not only define new urban developments, but also succeeded in the context of the mentioned international fairs and exhibitions, appearing a whole family of them in diverse countries.

Native bradyrhizobial symbionts of Lupinus mariae-josephae, a unique endemism thriving in alkaline soils in Eastern Spain

Lupinus mariae-josephae (Lmj) es una especie de lupino end��mica de una peque��a y espec��fica ��rea de Comunidad Valenciana (Este de Espa��a), donde prospera en suelos alcalinoscalc��reos, un h��bitat singular para los altramuces, que crecen preferentemente en suelos ��cidos o neutros. Esto hace de Lmj una especie de lupino ��nica. Cuando se inici�� este trabajo, la extensi��n conocida de este endemismo abarcaba unos 700 kil��metros cuadrados, confinados en la provincia de Valencia. En esta ��rea, Lmj prospera en peque��as poblaciones aisladas que contienen un n��mero reducido de plantas por lo que se la consider�� una especie en peligro de extinci��n. Todos los esfuerzos, utilizando estrategias cl��sicas dirigidas a ampliar el ��rea de crecimiento de Lmj y garantizar su conservaci��n, han tenido un ��xito limitado. El trabajo que se presenta est�� dirigido a mejorar el conocimiento de la ecolog��a de Lmj, en particular la interacci��n simbi��tica que establece con bacterias del suelo denominadas rizobios y se centra en la caracterizaci��n fenot��pica, filogen��tica y gen��mica de esos rizobios. Tambi��n se investiga la posible contribuci��n de la simbiosis en mejorar la conservaci��n de Lmj. Para este fin, se han estudiado diferentes aspectos que se describen a continuaci��n. El primero objetivo se centr�� en aislar y estudiar de la diversidad gen��tica de las bacterias endosimbi��ticas de Lmj. . Se realiz�� un an��lisis filogen��tico de genes esenciales que mostr�� que las cepas de Lmj pertenecen al g��nero Bradyrhizobium y que presentan una gran diversidad con caracter��sticas fenot��picas y simbi��ticas diferentes de cepas de Bradyrhizobium que nodulan otras especies de lupinos nativos de Espa��a (cepas ISLU). Las cepas estudiadas se dividieron en dos grupos (Clado I y Clado II). El Clado I, incluye a las cepas Lmj, definiendo un nuevo linaje, filogen��ticamente relacionado con otras especies de Bradyrhizobium, como B. jicamae y B. elkanii. El Clado II contiene cepas ISLU relacionadas con cepas de B. canariense y B. japonicum que establecen simbiosis con lupinos de suelos ��cidos. Otro an��lisis filogen��tico basado en genes simbi��ticos, distribuy�� las cepas de Lmj en s��lo dos grupos diferentes. La singularidad y gran diversidad de estas cepas en una peque��a ��rea geogr��fica, hacen de este, un atractivo sistema para el estudio de la evoluci��n y adaptaci��n de las bacterias simbi��ticas a su respectiva planta hu��sped. Adicionalmente, se estudio la presencia de bacterias capaces de nodular Lmj en suelos b��sicos de Chiapas, M��xico. Sorprendentemente, estos suelos contienen bacterias capaces establecer interacciones simbi��ticas eficientes con Lmj en ensayos de invernadero. A continuaci��n se investig�� la taxonom��a de los endosimbiontes de Lmj analizando la secuencia de cuatro genes esenciales (16S rRNA, recA, glnII y atpD) y el promedio de identidad de nucle��tidos de genomas completos de algunas cepas representativas de la diversidad (ANIm). Se identificaron nuevas especies de Bradyrhizobium dentro del Clado I y se defini�� una de ellas: 'Bradyrhizobium valentinum' sp. nov (cepa tipo LmjM3T = CECT 8364T, LMG 2761T). Tambi��n se abord�� c��mo conservar Lmj en su h��bitat natural mediante inoculaci��n con alguna de las cepas aisladas. Se demostr�� la ausencia de bacterias capaces de nodular Lmj en suelos rojos alcalinos o ������terra rossa������ de la Pen��nsula Ib��rica y Baleares. Dos cepas, altamente eficientes en cuanto a la fijaci��n de nitr��geno, LmjC y LmjM3T, fueron seleccionadas para ser empleadas como inoculantes. Dos experimentos de campo llevados a cabo en a��os consecutivos en ��reas con caracter��sticas edafoclim��ticas similares a las que presentan las poblaciones de Lmj, lograron la reproducci��n exitosa de la planta. Se concluy�� que un ciclo reproductivo exitoso de Lmj es absolutamente dependiente de la inoculaci��n con sus simbiontes naturales y que la simbiosis debe ser considerada un factor esencial en estrategias de conservaci��n de leguminosas en peligro. La obtenci��n de varias secuencias gen��micas de cepas aisladas de Lmj y de otras cepas de Bradyrhizobium revel�� una alta similitud entre los genomas de las cepas del Clado I, y permiti�� la identificaci��n de cinco posibles nuevas especies. Adem��s, se estudiaron tres agrupaciones de genes relacionados con la simbiosis (nod, nif y fix) definiendo un nuevo linaje para las cepas de Lmj, diferente del symbiovar ���genistearum��� de B. canariense y B. japonicum. La baja diversidad encontrada en el an��lisis filogen��tico de los genes simbi��ticos contrasta con la gran diversidad asociada a genes esenciales. La presencia de pl��smidos en cepas del g��nero Bradyrhizobium ha sido descrita en muy pocas ocasiones, sin embargo el an��lisis de la secuencia gen��mica de la cepa ISLU101, aislada de Lupinus angustifolius, revel�� la presencia de un origen de replicaci��n extracromos��mico hom��logo al oper��n repABC, presente en el pl��smido de Bradyrhizobium sp BTAi1. Gracias a esta secuencia se identificaron genes hom��logos en 19 de 72 cepas ISLU. Filogen��ticamente, las secuencias de repABC se agruparon en un grupo monofil��tico con las de pBTAi1 y separadas de los rizobios de crecimiento r��pido. Finalmente, se identificaron sistemas de secreci��n de prote��nas de tipo III (T3SS) en nueve genomas de cepas de Lmj. Los T3SS pueden inyectar prote��nas efectoras al interior de c��lulas vegetales. Su presencia en rizobios se ha relacionado con la gama de hospedador que pueden nodular y puede tener un efecto beneficioso, neutro o perjudicial en la simbiosis. Los T3SS de las cepas de Lmj codifican para una prote��na efectora similar a NopE, un efector dependiente de T3SS descrito en B. diazoefficiens USDA 110T. La prote��na NopE de la cepa LmjC se ha caracterizado bioqu��micamente. ABSTRACT Lupinus mariae-josephae (Lmj) is a lupine species endemic of a unique small area in Valencia region (Eastern Spain) where the lupine plants thrive in alkaline-limed soils, which preferentially grow in acid or neutral soils. This is the type of soils native lupines of Spain. When this work was initiated, the extension of the endemic area of Lmj was of about 700 squared kilometers confined to the Valencia province. In this area, Lmj thrives in small, isolated patches containing a reduced number of plants, and points to an endemism that can easily became endangered or extinct. Consequently, the Valencia Community authorities gave a ������microreserve��� status for conservation of the species. All efforts, using classical strategies directed to extend the area of Lmj growth and ensure its conservation have been so far unsuccessful. The work presented here is directed to improve our knowledge of Lmj ecology and it is centered in the characterization of the rhizobial symbiosis by phenotypic, phylogenetic and genomic analysis as well as in investigate the potential contribution of the symbiosis to improve its conservation. To this end, five different topics have been studied, and results are briefly described here. Extensive details can be followed en the attached, published articles. The first topic deals with the indigenous rhizobial symbionts of the Lmj endemism, and its genetic diversity was investigated. The Lmj root symbionts belong to the Bradyrhizobium genus, and phylogenetic analysis based on core genes identified a large diversity of Bradyrhizobium strains with phenotypic and symbiotic characteristics different from rhizobia nodulating other Lupinus spp. native of Spain. The strains were split in two clades. Clade II contained strains close to classical B. canariense and B. japonicum lineages that establish symbioses with lupines in acid soils of the Mediterranean area. Clade I included Lmj strains that define a new lineage, close to other Bradyrhizobium species as B. jicamae and B. elkanii. The phylogenetic analysis based on symbiotic genes identified only two distinct clusters. The singularity and large diversity of these strains in such a small geographical area makes this an attractive system for studying the evolution and adaptation of the rhizobial symbiont to the plant host. Additionally, the presence of bacteria able to nodulate Lmj in basic soils from Chiapas, Mexico was investigated. Surprisingly, these soils contain bacteria able to effectively nodulate and fix nitrogen with Lmj plants in greenhouse assays. In the second topic, the taxonomic status of the endosymbiotic bacteria of Lmj from Valencia endemism and Chiapas was investigated. Results from phylogenetic analysis of core genes and Average Nucleotide Identity (ANIm) using draft genomic sequences identified new Bradyrhizobium species within strains of Clade I of Lmj endosymbiotic bacteria. Only one of these potentially new species has been defined, meanwhile the others are under process of characterization. The name ���Bradyrhizobium valentinum��� sp. nov. was proposed for the defined species (type strain LmjM3T= CECT 8364T, LMG 2761T). The third topic was directed to conservation of endangered Lmj in its natural habitat. The relevant conclusion of this experimentation is that the symbiosis should be considered as a relevant factor in the conservation strategies for endangered legumes. First, we showed absence of bacteria able to nodulate Lmj in all the inspected ������terra rossa������ or alkaline red soils of the Iberian Peninsula and Balearic Islands. Then, two efficient nitrogen fixing strains with Lmj plants, LmjC and LmjM3T, were selected as inoculum for seed coating. Two planting experiments were carried out in consecutive years under natural conditions in areas with edapho-climatic characteristics identical to those sustaining natural Lmj populations, and successful reproduction of the plant was achieved. The relevant conclusion from these assays was that the successful reproductive cycle was absolutely dependent on seedling inoculation with effective bradyrhizobia The forth topic deep into the analysis of the genomic of Lmj representative strains. To this end, draft genomic sequences of selected Lmj strains and type strains of Bradyrhizobium spp. were assembled. The comparison analysis of the draft genomic sequences of Lmj strains and related Bradyrhizobium species grouped in Clade I, revealed a high genomic homology among them, and allowed the definition of five potentially new species of Lmj nodulating bacteria. Also, based on the available draft genomic sequences, only three clusters of nod, fix and nif genes from Lmj strains were identified and showed to define a new symbiotic lineage, distant from that of B. canariense and B. japonicum bv. genistearum. The low diversity exhibited by the phylogenetic analysis of symbiotic genes contrast with the large diversity of strains as regards the housekeeping genes analyzed. Besides, the genomic analysis of a Lupinus angustifolius strain ISLU101, revealed the presence of an extrachromosomal replication origin homologous to repABC cluster from plasmid present in Bradyrhizobium spp BTAi1. This repABC cluster gene sequence allowed the identification of extrachromosomic replication origin in 19 out of 72 Bradyrhizobium strains from Lupinus spp., a highly significant result since the absence of plasmids in the Bradyrhizobium genus was traditionally assumed. The repABC gene sequences of these strains grouped them in a unique monophyletic group, related to B. sp. BTAi1 plasmid, but differentiated from the repABC gene cluster of plasmids in fast growing rhizobium strains. The last topic was focused on characterization of type III secreted effectors present in Lmj endosymbiotic bacteria. Type III secretion systems (T3SS) are specialized protein export machineries which can deliver effector proteins into plant cells. The presence of T3SS in rhizobia has frequently been related to the symbiotic nodulation host-range and may have a beneficial or detrimental effect on the symbiosis with legumes. In this context, the presence of T3SS in genomes of nine Lmj strains was investigated, and it was shown the presence of clusters encoding NopE type III-secreted protein similar to the NopE1 and NopE2 of B. diazoefficiens USDA 110T. The putative NopE protein of LmjC strain is at present being characterized regarding its structure and function.

Metodolog��a para la estimaci��n de indicadores armonizados a partir de los inventarios forestales nacionales europeos con especial ��nfasis en la biodiversidad forestal

Durante las ��ltimas d��cadas el objetivo principal de la silvicultura y la gesti��n forestal en Europa ha pasado de ser la producci��n de madera a ser la gesti��n sostenible de los ecosistemas, por lo que se deben considerar todos los bienes y servicios que proporcionan los bosques. En consecuencia, es necesario contar con informaci��n forestal peri��dica de diversos indicadores forestales a nivel europeo para apoyar el desarrollo y la implementaci��n de pol��ticas medioambientales y que se realice una gesti��n adecuada. Para ello, se requiere un seguimiento intensivo sobre el estado de los bosques, por lo que los Inventarios Forestales Nacionales (IFN), (principal fuente de informaci��n forestal a gran escala), han aumentado el n��mero de variables muestreadas para cumplir con los crecientes requerimientos de informaci��n. Sin embargo, las estimaciones proporcionadas por los diferentes pa��ses no son f��cilmente comparables debido a las diferencias en las definiciones, los dise��os de muestreo, las variables medidas y los protocolos de medici��n. Por esto, la armonizaci��n de los datos que proporcionan los diferentes pa��ses es fundamental para la contar con una informaci��n forestal s��lida y fiable en la Uni��n europea (UE). La presente tesis tiene dos objetivos principales: (i) establecer el dise��o de una metodolog��a para evaluar la biodiversidad forestal en el marco del Inventario forestal nacional de Espa��a teniendo en cuenta las diferentes iniciativas nacionales e internacionales, con el objetivo de producir estimaciones comparables con las de otros pa��ses de la UE y (ii) armonizar los indicadores m��s relevantes para satisfacer los requerimientos nacionales e internacionales. Como consecuencia del estudio realizado para alcanzar el primer objetivo, la metodolog��a dise��ada para estimar la biodiversidad fue adoptada por el Tercer Inventario forestal nacional. ��sta se compon��a de indicadores agrupados en: cobertura del suelo, composici��n de ��rboles y especies de arbustos, riqueza de especies herb��ceas y helechos, especies amenazadas, estructura, madera muerta, y l��quenes ep��fitos. Tras el an��lisis del dise��o metodol��gico y de los datos proporcionados, se observ�� la conveniencia de modificarla con el fin de optimizar los costes, viabilidad, calidad y cantidad de los datos registrados. En consecuencia, en el Cuarto Inventario Forestal Nacional se aplica una metodolog��a modificada, puesto que se elimin�� el muestreo de especies herb��ceas y helechos, de l��quenes ep��fitos y de especies amenazadas, se modificaron los protocolos de la toma de datos de estructura y madera muerta y se a��adi�� el muestreo de especies invasoras, edad, ramoneo y grado de naturalidad de la masa. En lo que se refiere al segundo objetivo, se ha avanzado en la armonizaci��n de tres grupos de variables considerados como relevantes en el marco de los IFN: los indicadores de vegetaci��n no arb��rea (que juegan un papel relevante en los ecosistemas, es donde existe la mayor diversidad de plantas y hasta ahora no se conoc��an los datos muestreados en los IFN), la determinaci��n de los ��rboles a��osos (que tienen un importante papel como nicho ecol��gico y su identificaci��n es especialmente relevante para la evaluaci��n de la biodiversidad forestal) y el bosque disponible para el suministro de madera (indicador b��sico de los requerimientos internacionales de informaci��n forestal). Se llev�� a cabo un estudio completo de la posible armonizaci��n de los indicadores de la vegetaci��n no arb��rea en los IFN. Para ello, se identificaron y analizaron las diferentes definiciones y dise��os de muestreo empleados por los IFN, se establecieron definiciones de referencia y se propusieron y analizaron dos indicadores que pudiesen ser armonizados: MSC (mean species cover) que corresponde a la media de la fracci��n de cabida cubierta de cada especie por tipo de bosque y MTC (mean total cover). Se estableci�� una nueva metodolog��a que permite identificar los ��rboles a��osos con los datos proporcionados por los inventarios forestales nacionales con el objetivo de proporcionar una herramienta eficaz para facilitar la gesti��n forestal considerando la diversidad de los sistemas forestales. Se analiz�� el concepto de "bosque disponible para el suministro de madera" (FAWS) estudiando la consistencia de la informaci��n internacional disponible con el fin de armonizar su estimaci��n y de proporcionar recomendaciones para satisfacer los requerimientos europeos. Como resultado, se elabor�� una nueva definici��n de referencia de FAWS (que ser�� adoptada por el proceso paneuropeo) y se analiza el impacto de la adopci��n de esta nueva definici��n en siete pa��ses europeos. El trabajo realizado en esta tesis, puede facilitar el suministrar y/o armonizar parcial o totalmente casi la mitad de los indicadores de informaci��n forestal solicitados por los requerimientos internacionales (47%). De ��stos, pr��cticamente un 85% tienen relaci��n con los datos inventariados empleando la metodolog��a propuesta para la estimaci��n de la biodiversidad forestal, y el resto, con el establecimiento de la definici��n de bosque disponible para el suministro de madera. No obstante, y pese a que esta tesis supone un avance importante, queda patente que las necesidades de informaci��n forestal son cambiantes y es imprescindible continuar el proceso de armonizaci��n de los IFN europeos. ABSTRACT Over the last few decades, the objectives on forestry and forest management in Europe have shifted from being primarily focused on wood production to sustainable ecosystem management, which should consider all the goods and services provided by the forest. Therefore, there is a continued need for forest indicators and assessments at EU level to support the development and implementation of a number of European environmental policies and to conduct a proper forest management. To address these questions, intensive monitoring on the status of forests is required. Therefore, the scope of National Forest Inventories (NFIs), (primary source of data for national and large-area assessments), has been broadened to include new variables to meet these increasing information requirements. However, estimates produced by different countries are not easily comparable because of differences in NFI definitions, plot configurations, measured variables, and measurement protocols. As consequence, harmonizing data produced at national level is essential for the production of sound EU forest information. The present thesis has two main aims: (i) to establish a methodology design to assess forest biodiversity in the frame of the Spanish National Forest Inventory taking into account the different national and international initiatives with the intention to produce comparable estimates with other EU countries and (ii) to harmonize relevant indicators for national and international requirements. In consequence of the work done related to the first objective, the established methodology to estimate forest biodiversity was adopted and launched under the Third National Forest Inventory. It was composed of indicators grouped into: cover, woody species composition, richness of herbaceous species and ferns, endangered species, stand structure, dead wood, and epiphytic lichens. This methodology was analyzed considering the provided data, time costs, feasibility, and requirements. Consequently, in the ongoing Fourth National Forest Inventory a modified methodology is applied: sampling of herbaceous species and ferns, epiphytic lichens and endangered species were removed, protocols regarding structure and deadwood were modified, and sampling of invasive species, age, browsing impact and naturalness were added. As regards the second objective, progress has been made in harmonizing three groups of variables considered relevant in the context of IFN: Indicators of non-tree vegetation (which play an important role in forest ecosystems, it is where the highest diversity of plants occur and so far the related sampled data in NFIs were not known), the identification of old-growth trees (which have an important role as ecological niche and its identification is especially relevant for the assessment of forest biodiversity) and the available forest for wood supply (basic indicator of international forestry information requirements). A complete analysis of ground vegetation harmonization possibilities within NFIs frame was carried on by identifying and analyzing the different definitions and sampling techniques used by NFIs, providing reference definitions related to ground vegetation and proposing and analyzing two ground vegetation harmonized indicators: ���Mean species cover��� (MSC) and ���Mean total cover��� (MTC) for shrubs by European forest categories. A new methodology based on NFI data was established with the aim to provide an efficient tool for policy makers to estimate the number of old-growth trees and thus to be able to perform the analysis of the effect of forest management on the diversity associated to forest systems. The concept of ���forest available for wood supply��� (FAWS) was discussed and clarified, analyzing the consistency of the available international information on FAWS in order to provide recommendations for data harmonization at European level regarding National Forest Inventories (NFIs). As a result, a new reference definition of FAWS was provided (which will be adopted in the pan-European process) and the consequences of the use of this new definition in seven European countries are analyzed. The studies carried on in this thesis, can facilitate the supply and/or harmonization partially or fully of almost half of the forest indicators (47%) needed for international requirements. Of these, nearly 85% are related to inventoried data using the proposed methodology for the estimation of forest biodiversity, and the rest, with the establishment of the definition of forest available for wood supply. However, despite this thesis imply an important development, forest information needs are changing and it is imperative to continue the process of harmonization of European NFIs.

Deforestaci��n y P��rdida de h��bitat en Bosques de monta��a en la Cuenca alta del R��o Zamora (Loja, Ecuador)

Los bosques h��medos de monta��a se encuentran reconocidos como uno de los ecosistemas m��s amenazados en el mundo, llegando inclusive a ser considerado como un ���hotspot��� por su alta diversidad y endemismo. La acelerada p��rdida de cobertura vegetal de estos bosques ha ocasionado que, en la actualidad, se encuentren restringidos a una peque��a fracci��n de su ��rea de distribuci��n hist��rica. Pese a esto, los estudios realizados sobre cual es efecto de la deforestaci��n, fragmentaci��n, cambios de uso de suelo y su efecto en las comunidades de plantas presentes en este tipo de vegetaci��n a��n son muy escuetos, en comparaci��n a los realizados con sus similares amaz��nicos. En este trabajo, el cual se encuentra dividido en seis cap��tulos, abordaremos los siguientes objetivos: a) Comprender cu��l es la din��mica que han seguido los diferentes tipos de bosques montanos andinos de la cuenca del Rio Zamora, Sur de Ecuador durante entre 1976 y 2002. b) Proveer de evidencia de las tasas de deforestaci��n y fragmentaci��n de todos los tipos diferentes de bosques montanos andinos presentes en la cuenca del Rio Zamora, Sur de Ecuador entre 1976 y 2002. c) Determinar qu�� factores inducen a la fragmentaci��n de bosques de monta��a en la cuenca alta del r��o Zamora entre 1976 y 2002. d) Determinar cu��les son y c��mo afectan los factores ambientales y socioecon��micos a la din��mica de la deforestaci��n y regeneraci��n (p��rdida y recuperaci��n del h��bitat) sufrida por los bosques de monta��a dentro de la zona de estudio y e) Determinar si la deforestaci��n y fragmentaci��n act��an sobre la diversidad y estructura de las comunidades de tres tipos de organismos (comunidades de ��rboles, comunidades de l��quenes ep��fitos y comunidades de hep��ticas ep��fitas). Este estudio se centr�� en el cuenca alta del r��o Zamora, localizada al sur de Ecuador entre las coordenadas 3�� 00�� 53��� a 4�� 20�� 24.65��� de latitud sur y 79�� 49��58��� a 78�� 35�� 38��� de longitud oeste, que cubre alrededor de 4300 km2 de territorio situado entre las capitales de las provincias de Loja y Zamora-Chinchipe. Con objeto de predecir la din��mica futura de la deforestaci��n en la regi��n de Loja y c��mo se ver��n afectados los diferentes tipos de h��bitat, as�� como para detectar los factores que m��s influyen en dicha din��mica, se han construido modelos basados en la historia de la deforestaci��n derivados de fotograf��as a��reas e im��genes satelitales de tres fechas (1976, 1989 y 2002). La cuantificaci��n de la deforestaci��n se realiz�� mediante la tasa de inter��s compuesto y para la caracterizaci��n de la configuraci��n espacial de los fragmentos de bosque nativo se calcularon ��ndices de paisaje los cuales fueron calculados utilizando el programa Fragstats 3.3. Se ha clasificado el recubrimiento del terreno en forestal y no forestal y se ha modelado su evoluci��n temporal con Modelos Lineales Generalizados Mixtos (GLMM), empleando como variables explicativas tanto variables ambientales espacialmente expl��citas (altitud, orientaci��n, pendiente, etc) como antr��picas (distancia a zonas urbanizadas, deforestadas, caminos, entre otras). Para medir el efecto de la deforestaci��n sobre las comunidades modelo (de ��rboles, l��quenes y hep��ticas) se monitorearon 11 fragmentos de vegetaci��n de distinto tama��o: dos fragmentos de m��s de cien hect��reas, tres fragmentos de entre diez y noventa ha y seis fragmentos de menos de diez hect��reas. En ellos se instalaron un total de 38 transectos y 113 cuadrantes de 20 x 20 m a distancias que se alejaban progresivamente del borde en 10, 40 y 80 m. Nuestros resultados muestran una tasa media anual de deforestaci��n del 1,16% para todo el per��odo de estudio, que el tipo de vegetaci��n que m��s alta tasa de destrucci��n ha sufrido, es el p��ramo herb��ceo, con un 2,45% anual. El an��lisis de los patrones de fragmentaci��n determin�� un aumento en 2002 de m��s del doble de fragmentos presentes en 1976, lo cual se repite en el an��lisis del ��ndice de densidad promedio. El ��ndice de proximidad media entre fragmentos muestra una reducci��n progresiva de la continuidad de las ��reas forestadas. Si bien las formas de los fragmentos se han mantenido bastante similares a lo largo del per��odo de estudio, la conectividad entre estos ha disminuido en un 84%. Por otro lado, de nuestros an��lisis se desprende que las zonas con mayor probabilidad de deforestarse son aquellas que est��n cercanas a zonas previamente deforestadas; la cercan��a a las v��as tambi��n influye significativamente en la deforestaci��n, causando un efecto directo en la composici��n y estructura de las comunidades estudiadas, que en el caso de los ��rboles viene mediado por el tama��o del fragmento y en el caso del componente ep��fito (hep��ticas y l��quenes), viene mediado tanto por el tama��o del fragmento como por la distancia al borde del mismo. Se concluye la posibilidad de que, de mantenerse esta tendencia, este tipo de bosques desaparecer�� en corto tiempo y los servicios ecosist��micos que prestan, se ver��n seriamente comprometidos. ABSTRACT Mountain rainforests are recognized as one of the most threatened ecosystems in the world, and have even come to be considered as a ���hotspot��� due to their high degree of diversity and endemism. The accelerated loss of plant cover of these forests has caused them to be restricted today to a small fraction of their area of historic distribution. In spite of this, studies done on the effect of deforestation, fragmentation, changes in soil use and their effect on the plant communities present in this type of vegetation are very brief compared to those done on their analogues in the Amazon region. In this study, which is divided into six chapters, we will address the following objectives: a) To understand what the dynamic followed by the different types of Andean mountain forests in the Zamora River watershed of southern Ecuador has been between 1976 and 2002. b) To provide evidence of the rates of deforestation and fragmentation of all the different types of Andean mountain forests existing in the upper watershed of the Zamora River between 1976 and 2002. c) To determine the factors that induces fragmentation of all different types of Andean mountain forests existing in the upper watershed of the Zamora River between 1976 and 2002. d) To determine what the environmental and anthropogenic factors are driving the dynamic of deforestation and regeneration (loss and recuperation of the habitat) suffered by the mountain forests in the area of the study and e) To determine if the deforestation and fragmentation act upon the diversity and structure of three model communities: trees, epiphytic lichens and epiphytic liverworts. This study is centered on the upper Zamora River watershed, located in southern Ecuador between 3�� 00�� 53��� and 4�� 20�� 24.65 south latitude and 79�� 49�� 58��� to 78�� 35�� 38��� west longitude, and covers around 4,300 km2 of territory located between Loja and Zamora-Chinchipe provinces. For the purpose of predicting the future dynamic of deforestation in the Loja region and how different types of habitats will be affected, as well as detecting the environmental and socioeconomic factors that influence landscape dynamics, models were constructed based on deforestation history, derived from aerial photographs and satellite images for three dates (1976, 1989 and 2002). Quantifying the deforestation was done using the compound interest rate; to characterize the spatial configuration of fragments of native forest, landscape indices were calculated with Fragstats 3.3 program. Land cover was classified as forested and not forested and its evolution over time was modeled with Generalized Linear Mixed Models (GLMM), using spatially explicit environmental variables (altitude, orientation, slope, etc.) as well as anthropic variables (distance to urbanized, deforested areas and roads, among others) as explanatory variables. To measure the effects of fragmentation on three types of model communities (forest trees and epiphytic lichen and liverworts), 11 vegetation fragments of different sizes were monitored: two fragments of more than one hundred hectares, three fragments of between ten and ninety ha and six fragments of fewer than ten hectares . In these fragments, a total of 38 transects and 113 20 x 20 m quadrats were installed at distances that progressively moved away from the edge of the fragment by 10, 40 and 80 m. Our results show an average annual rate of deforestation of 1.16% for the entire period of the study, and that the type of vegetation that suffered the highest rate of destruction was grassy paramo, with an annual rate of 2.45%. The analysis of fragmentation patterns determined the number of fragments in 2002 more than doubled the number of fragments present in 1976, and the same occurred for the average density index. The variation of the average proximity index among fragments showed a progressive reduction of the continuity of forested areas. Although fragment shapes have remained quite similar over the period of the study, connectivity among them has diminished by 84%. On the other hand, it emerged from our analysis that the areas of greatest probability of deforestation were those that are close to previously deforested areas; proximity to roads also significantly favored the deforestation causing a direct effect on the composition of our model communities, that in the case of forest trees is determined by the size of the fragment, and in the case of the epiphyte communities (liverworts and lichens), is determined, by the size of the fragment as well as the distance to edge. A subject under discussion is the possibility that if this tendency continues, this type of forest will disappear in a short time, and the ecological services it provides, will be seriously endangered.