Isabel Martínez

• Dr Biology
• Professor (Full) at Rey Juan Carlos University

Contrary to the assumption that epiphytic lichens, which obtain water and nutrients from the atmosphere, do not exhibit host species preference, this notion is challenged by the limited number of studies that cover a wide geographical range and diverse phorophyte species (hereafter referred to as “host species”). To investigate this assumption, we...

Gypsum soils, despite physico-chemical constraints, harbor a unique biota composed of specialist (gypsophiles) and stress-tolerant non-specialist species (gypsovags). Gypsophily has been addressed in plants, although is important to ask whether lichen communities also contain gypsophile species. Therefore, our main aim is the analysis of the affini...

Specialization remains as a controversial and ambiguous term in ecology. Although it has been usually measured using a dichotomic and simplified classification of specialists and generalists, its nature is by far more complex. In the context of biotic interactions, assigning these two labels is usually based on the number of interacting partners (o...

Lichens are significant components of the biological soil crust communities in gypsum ecosystems and are involved in several processes related to ecosystem functioning, such as water and nutrient cycles or protection against soil erosion. Although numerous studies centered on lichen taxonomy and ecology have been performed in these habitats, global...

A checklist of Lichen-forming, Lichenicolous and Allied Fungi of Ecuador is presented with a total of 2599 species, of which 39 are reported for the first time from the country. The names of three species, Hypotrachyna montufariensis , H. subpartita and Sticta hypoglabra , previously not validly published, are validated. Pertusaria oahuensis , orig...

The ecological success of lichens is related to both myco- and photobionts which condition the physiological limits of the lichen symbioses and thus affect their ecological niches and geographic ranges. A particular type of lichen, called cephalolichen, is characterized by housing both green algal and cyanobacterial symbionts—the latter is restrict...

Specialization, contextualized in a resource axis of an organism niche, is a core concept in ecology. In biotic interactions, specialization can be determined by the range of interacting partners. Evolutionary and ecological factors, in combination with the surveyed scale (spatial, temporal, biological, and/or taxonomic), influence the conception o...

Beech forests are considered one of the most emblematic ecosystems in the temperate deciduous broadleaf forest biome and host a wide variety of specialised cryptogamic organisms such as epiphytic lichens. This checklist is the first compilation focused on the epiphytic lichen diversity occurring on Fagus sylvatica L. trees along Europe. The checkli...

The present paper reports the first record of Diplotomma cedricola (Werner) Etayo in the eastern Mediterranean (Creta Island, Greece), being the nearest record from Corsica (France). This lichen species was found near Iérapreta on decorticated Cupressus sempervirens L. and Pinus brutia Ten. trees. This finding constitutes a great expansion of the d...

Deforestation is the most important cause of biodiversity loss in tropical ecosystems. Epiphytic species, lichens and bryophytes, are very sensitive to environmental changes, including those produced by conversion of primary forests into secondary vegetation. However, little is known about the differences between different secondary forests and pla...

Functional traits have become important tools for evaluating the response of epiphytic lichens to environmental changes. In this study, we evaluated which predictors related to fragmentation, habitat quality and climate were driving the richness and cover of lichen growth form, type of photobiont and reproduction traits, at both fragment and plot l...

Biocrusts are major contributors to dryland diversity, functioning, and services. However, little is known about how habitat degradation will impact multiple facets of biocrust diversity and measurable functional traits. We evaluated changes in taxonomic, functional, and phylogenetic diversity of biocrust‐forming lichens along a habitat degradation...

Water use traits in lichens are important attributes that determine the duration of hydration and metabolically active periods. In this study, the water holding capacity (WHC) and specific thallus mass (STM) were measured for seven macrolichen species (Parmelia sulcata, Parmelina tiliacea, Evernia prunastri, Ramalina farinacea, Lobaria pulmonaria,...

Tropics harbour the greatest biodiversity in the planet but are still largely unknown. Among these remote areas, there are the Tepuyes of Nangaritza Valley, in the Zamora Chinchipe province, southeastern Ecuador. They constitute isolated mountainous systems with great biological importance and high levels of endemicity. Therefore, the main objectiv...

Community ecology has experienced a major transition, from a focus on patterns in taxonomic composition, to revealing the processes underlying community assembly through the analysis of species functional traits. The power of the functional trait approach is its generality, predictive capacity such as with respect to environmental change, and, thro...

Assessing the ecological impacts of environmental change on biological communities requires knowledge of the factors driving the spatial patterns of the three diversity facets along extensive environmental gradients. We quantified the taxonomic (TD), functional (FD), and phylogenetic diversity (PD) of lichen epiphytic communities in 23 beech forest...

Traditional approaches in trait‐based community ecology typically expect that trait filtering across broad environmental gradients is largely due to replacement of species, rather than intraspecific trait adjustments. Recently, the role of intraspecific trait variability has been largely highlighted as an important contributor mediating the ability...

Adopting an integrative approach that explicitly includes the different facets of biodiversity is crucial to assess the response of biological communities to changing environments. The identification of the optimal climatic conditions where communities maximize their functional, phylogenetic and taxonomic diversity is useful to compare whether the...

Characterizing functional trait variation and covariation, and its drivers, is critical to understand the response of species to changing environmental conditions. Evolutionary and environmental factors determine how traits vary among and within species at multiple scales. However, disentangling their relative contribution is challenging and a comp...

Techniques for retrospective analysis of size dynamics at annual resolution remain poorly developed in lichens in general, and fruticose lichens in particular. Only a few attempts in very high latitudes suggested that growth might be studied as a chronosequence of inter-nodal branch elongations. Here we evaluated, for the first time, this hypothesi...

Understanding patterns of habitat natural recovery after human-made disturbances is critical for the conservation of ecosystems under high environmental stress, such as drylands. In particular, the unassisted establishment of nonvascular plants such as biological soil crusts or biocrust communities (e.g., soil lichens, mosses and cyanobacteria) in...

Assessing the response of biological communities to contrasting environmental conditions is crucial to predict the effects of global change drivers. The influence of multiple environmental factors may differ depending on the diversity facet considered, which emphasizes the need to simultaneously evaluate the functional (FD), phylogenetic (PD) and t...

Background and aims: In order to re-establish lichen symbiosis, fungal spores must first germinate and then associate with a compatible photobiont. To detect possible establishment limitations in a sexually reproducing cyanolichen species, we studied ascospore germination, photobiont growth and photobiont association patterns in Pectenia plumbea....

Epiphytic richness is continuously declining due to forest fragmentation, logging, burning, agriculture, and livestock. The rate of species loss caused by habitat degradation and loss is more pronounced in Central and South America. Considering the extreme difficulty and time required to identify the more inconspicuous species, rapid diversity asse...

Context The anthropocene is characterised by global landscape modification, and the structure of remnant habitats can explain different patterns of species richness. The most pervasive processes of degradation include habitat loss and fragmentation. However, a recovery of modified landscape is occurring in some areas. Objectives The main goal is t...

Biological soil crusts (or biocrusts) are widespread, diverse and important components of drylands sometimes threatened by global change drivers. However, their response to fragmentation processes is poorly known. The aim of this study was to assess the effects of changing landscape structure, given by land use change and the presence of linear inf...

Premise of the study: Life history theory predicts that plants in unfavorable habitats for juvenile growth and survival will commence reproduction at smaller sizes and exhibit higher reproductive allocations than those in favorable habitats. The scope of life history theory will increase if these predictions apply to a broad range of organisms. Po...

Background and aims: Onset of reproduction and reproductive allocation patterns are key components of plant reproductive strategies. Life history theory predicts that plants in adverse environments for juvenile performance start reproduction at smaller sizes and exhibit higher reproductive allocation compared to their counterparts in favourable en...

Forest biodiversity is dependent on habitat heterogeneity at several spatial scales. A source of this heterogeneity for forest invertebrates is provided by epiphytic species, including the lichens. Lichens are potentially important refuge and food for many arthropods. However, little is known about how lichens influence invertebrate’s richness and...

Question In order to identify the factors and assembly rules which potentially shape natural lichen communities we asked whether these communities are phylogenetically and functionally structured along an environmental gradient in beech forests in the Iberian Peninsula. Location A climatic gradient in the Iberian Peninsula. Methods We used specie...

There is ample evidence for species distributional changes in response to recent climate change, but most studies are biased toward better known taxa. Thus, an integrated approach is needed that includes the “cryptic diversity” represented partly by lichens, which are among the most sensitive organisms to environmental change due to their physiolog...

Premise of the study: Habitat loss and forest fragmentation affect the dispersal and establishment of species. Furthermore, populations growing far from the species' optimal climate might be less viable because good-quality habitat can be scarce and easily altered by smaller changes. The lichen Pectenia plumbea has oceanic climatic requirements, s...

Many species of lichen-forming fungi are currently threatened by habitat loss, pollution, and climate change. Red Lists represent an important tool for conservation strategies of species and their habitats. To date, no Red List of these organisms is available in Spain and Portugal. Recently, the Spanish Lichen Society (SEL) launched an initiative i...

Species have traditionally been identified and described using morphological characters. Recently, analyses of sequence data have revealed that traditional species delimitation frequently underestimates the diversity of organisms. The main goal of this work was to study species boundaries in the genus Pectenia and elucidate the biogeographic histor...

Context Mediterranean forests have been fragmented intensively over time, thereby yielding small and isolated forest remnants. They host a rich variety of epiphytes, which may be affected by landscape structure. Previous studies have analyzed the influence of habitat quality on these epiphytic communities, but there is little knowledge of the effec...

Detailed knowledge of the habitat requirements of species is required because habitat greatly affects the persistence of species. We investigated the effects of tree species and microhabitat heterogeneity on the population of the locally threatened lichen Lobaria pulmonaria. We studied four L. pulmonaria populations in Central Spain and collected m...

The current genetic diversity and structure of a species plays a marked role in the species' future response to environmental changes. Identification of the factors that might ensure the long-term viability of populations along its distribution area is therefore important for conserving biodiversity. In this work, infraspecific genetic diversity an...

Edge effect involves microclimatic variations (light, temperature and humidity) in the forest edge that become unsuitable for organisms adapted to forest interior conditions. We speculate that under similar edge types (shrubland matrix), the pattern in the response to forest edge might be different and more hostile for epiphytes in south-oriented e...

Reasonable lichen growth rates are required to maintain the important ecosystem functions provided by epiphytic lichen populations. Previously, lichen growth has mainly been quantified in boreal forests. Thus, there is a need for comparable studies from Mediterranean forests. We used reciprocal transplantation to compare relative biomass (RGR) and...

Lobarina scrobiculata (better known as Lobaria scrobiculata ) is a widespread lichen, threatened and Red-Listed in various European countries. Microsatellite markers for the mycobiont of L. scrobiculata were developed in order to investigate its genetic diversity in the Iberian Peninsula and Europe and to design effective conservation strategies. A...

Climate change is expected to cause several impacts at the global scale, and drylands will be amongst the most affected areas. Thus, investigating how these changes will affect the composition, structure and functioning of dryland ecosystems has become a priority. From an ecological indicator point of view, several works have shown that functional...

• Premise of the study: High-quality information about threatened species is required to prevent current global biodiversity losses. Lichens are important components of forest biodiversity and help to maintain ecosystem functioning. The epiphytic cyanolichen Lobarina scrobiculatais red-listed in Europe and North America, but knowledge of its ecolog...

The main factors determining the occurrence, abundance, growth and reproductive capacity of threatened lichens need to be known in order to implement conservation initiatives. The main objective of the present study was to evaluate which factors affect the conservation status of Degelia species-complex in central Spain. We undertook a non-parametri...

Grazing represents one of the most common disturbances in drylands worldwide, affecting both ecosystem structure and functioning. Despite the efforts to understand the nature and magnitude of grazing effects on ecosystem components and processes, contrasting results continue to arise. This is particularly remarkable for the biological soil crust (B...

Understanding functional diversity is critical to manage and preserve biodiversity and ecosystem functioning in the face of global change. However, the efforts to characterize this functional component have been mostly directed to vascular vegetation. We sampled lichen-dominated biological soil crusts (BSCs) in semiarid grasslands along an environm...

Grazing represents one of the most common disturbances in drylands worldwide, affecting both ecosystem structure and functioning. Despite the efforts to understand the nature and magnitude of grazing effects on ecosystem components and processes, contrasting results continue to arise. This is particularly remarkable for the biological soil crust (B...

The current trend of declining epiphytic richness caused by human activities (forest fragmentation, logging, agriculture, and livestock grazing) and the greater efforts required to sample and identify the most inconspicuous species have necessitated the use of indicators of the species richness. In this study, we examined the potential of predictin...

QuestionsEnvironmental factors have been identified as strong modulators of plant community distribution and diversity, especially in arid and semi-arid ecosystems. Despite recent advances in the ecology of biological soil crusts (BSC) from a community perspective, much remains unknown at the species level. Do environmental factors at different sca...

Recent molecular systematic studies have indicated that the traits currently used for generic delimitation in the jelly lichens (Collemataceae s. str.), may not characterize monophyletic groups. Here we reconstruct the phylogeny of Collemataceae using Bayesian and maximum likelihood analyses based on mitochondrial (mtSSU rDNA) and nuclear (nuLSU rD...

Evaluation of the effectiveness of protected areas networks for conserving diversity is a demanding topic in biological conservation. In the last few years, there has been an increasing number of studies on species distribution modelling which can be easily used to test the efficiency of reserve networks. Unfortunately, this effort has been focused...

Observed levels of population genetic diversity are often associated with differences in species dispersal and reproductive strategies. In symbiotic organisms, the genetic diversity level of each biont should also be highly influenced by biont transmission. In this study, we evaluated the influence of the reproductive strategies of cyanolichen spec...

Biological soil crusts (BSCs) are key biotic components of dryland ecosystems worldwide that control many functional processes, including carbon and nitrogen cycling, soil stabilization and infiltration. Regardless of their ecological importance and prevalence in drylands, very few studies have explicitly evaluated how climate change will affect th...

It is necessary to understand how environmental changes affect plant fitness to predict survival of a species, but this knowledge is scarce for lichens and complicated by their formation of sexual and asexual reproductive structures. Are the presence and number of reproductive structures in Lobaria pulmonaria, a threatened lichen, dependent on thal...

The co-occurrence pattern of epiphytic lichen communities was evaluated relative to micro-environmental heterogeneity along an edge-interior forest gradient. We collected data on the occurrence of 57 epiphytic lichen species from 452 plots in a Mediterranean forest remnant. We used two realistic null models to test for non-randomness in the structu...

Latitudinal gradients that involve macroclimatic changes can affect the diversity of several groups of plants and animals. Here we examined the effect of a latitudinal gradient on epiphytic communities on a single host species (Fagus sylvatica) to test the core-periphery theory. The latitudinal span considered, covering two biogeographic regions, i...

Premise of the study: Verrucariaceae is a fascinating lineage of lichenized fungi for which generic and species delimitation is problematic due to the scarcity of discriminating morphological characters. Members of this family inhabit rocks, but they further colonize soils, barks, mosses, and other lichens. Our aim is to contribute to the DNA-base...

Biological soil crusts (BSCs), composed of lichens, cyanobacteria, mosses, liverworts and microorganisms, are key biotic components of arid and semi-arid ecosystems worldwide. Despite they are widespread in Spain, these organisms have been historically understudied in this country. This trend is beginning to change as a recent wave of research has...

Persistence and abundance of species is determined by habitat availability and the ability to disperse and colonize habitats at contrasting spatial scales. Favourable habitat fragments are also heterogeneous in quality, providing differing opportunities for establishment and affecting the population dynamics of a species. Based on these principles,...

Fragmentation represents a serious threat to biodiversity worldwide, however its effects on epiphytic organisms is still poorly understood. We study the effect of habitat fragmentation on the genetic population structure and diversity of the red-listed epiphytic lichen, Lobaria pulmonaria, in a Mediterranean forest landscape. We tested the relative...

Questions: To what degree do biological soil crusts (BSCs), which are regulators of the soil surface boundary, influence associated microbial communities? Are these associations important to ecosystem functioning in a Mediterranean semi-arid environment? Location: Gypsum outcrops near Belmonte del Tajo, Central Spain. Methods: We sampled a total of...

Efectos de la fragmentación de los bosques sobre los líquenes epífitos en la Región Mediterránea. Ecosistemas 20(2-3):54-67. La mayor parte de paisajes forestales en gran parte del planeta se han visto transformados en un mosaico de fragmentos de diferentes tamaños y grado de aislamiento, inmersos en una matriz de vegetación con diferentes estados...

A taxonomic treatment of the genera included in Catapyrenium s. lat. in the Iberian Peninsula and the Balearic Islands is provided, based on study of c . 2000 specimens from both herbaria and fresh material collected by the authors from 2005 to 2009 in numerous localities. A total of 33 species belonging to six of the eight genera included in Catap...

A taxonomic revision of the genus Placidiopsis in the Iberian Peninsula and the Balearic Islands is provided. A total of 500 specimens were studied. A detailed description of the morphology, anatomy, ecology, and distributional rank is presented for each species. Additionally, a key to Placidiopsis species is included. The genus is represented by f...

Spanish holm oak (Quercus ilex subsp. ballota) open woodlands (dehesas) maintain a high diversity of plants and animals compared to other forested Mediterranean habits, but little is known about the responses of epiphytic lichens to different management regimes that are applied to this woodland type. The present study was carried out in central-sou...

Because the number of fungal species (mycobionts) exceeds the number of algae and cyanobacteria (photobionts) found in lichens by more than two orders of magnitude, reciprocal one-to-one specificity between one fungal species and one photobiont across their entire distribution is not expected in this symbiotic system, and has not previously been ob...

Climate change will exacerbate the degree of abiotic stress experienced by semi-arid ecosystems. While abiotic stress profoundly affects biotic interactions, their potential role as modulators of ecosystem responses to climate change is largely unknown. Using plants and biological soil crusts, we tested the relative importance of facilitative-compe...

Family Collemataceae (Peltigerales, Ascomycota) includes species of cyanolichens with foliose to fruticose or crustose thalli, with simple or septate ascospores. The current classification divides this family into two groups on the basis of ascospore types. The objective of this study was to evaluate the phylogenetic relationships within this famil...

The current classification of what used to be called Catapyrenium comprises eight genera belonging to distinct lineages in the Verrucariaceae. Previous phylogenetic studies have shown that the redefined genus Catapyrenium (Catapyrenium s. str.) is monophyletic and sister of Placidiopsis within the Staurothele group, but this relationship was based...

Disjunct species distributions may result from a combination of geologic events and long-distance dispersal. The foliose lichen species complex Leptogium furfuraceum-L. pseudofurfuraceum has an intercontinental disjunction pattern. Populations of this species complex are found in western North America, southern South America, Africa, and southern E...

Destruction and fragmentation of habitats represent one of the most important threats for biodiversity. Here, we examined the effects of fragmentation in Mediterranean forests on the epiphytic lichen Lobaria pulmonaria (Lobariaceae). We tested the hypothesis that not only the level of fragmentation affects L. pulmonaria populations, but also the qu...

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes....

The stress-gradient hypothesis (SGH) predicts a shift from predominant competition to facilitation as abiotic stress increases. Most empirical tests of the SGH have evaluated the interactions between a single or a few pairs of species, have not considered the effects of multiple stress factors, and have not explored these interactions at nested spa...

Anthracocarpon andinum, a new terricolous species, is described from northern Argentina. The most important differences from A. virescens (Zahlbr.) Breuss are in thallus morphology and size and shape of the ascospores. Anthracocarpon andinum develops a squamulose thallus covered by a sulcate epinecral layer. The squamules of A. virescens are smalle...

Ophioparma juniperiicola, a new lignicolous species, is described from eastern Spain. It is closely related with O. rubricosa by the appearance of thallus and apothecia, and the presence of divaricatic and usnic acids. The outstanding differences are in spore size and shape and the pycnospore width. Ophioparma juniperiicola is a lignicolous species...

Lecanora burgaziae, a new epiphytic species, is described from central Spain. It belongs to the Lecanora varia group with amphithecial cortex, and is closely related to L. densa and L. varia by the presence of psoromic acid and a distinctly thickened amphithecial cortex. The major differences are in thallus color, apothecia appearance and shape, an...

Four interesting lichens belonging to Catapyrenium, Placidium and Placopyrenium genera (Verrucariaceae) were collected for the first time in Argentina. Catapyrenium exaratum was only reported from Chile and Perú. Placidium acarosporoides was previously known from North America, Chile and South Africa. Placidium pilosellum, a widespread and common s...

The taxonomy of the Leptogium lichenoides complex is revised here based on a morphological, ecological and molecular phylogenetic study. A phylogenetic analysis of phenotypic characters was compared to a phylogeny based on nrITS and β-tubulin data. Using these phylogenies, we concluded that what was commonly recognized as Leptogium lichenoides s.l....

Question: Are soil lichen communities structured by biotic interactions? Location: Gypsum outcrops located next to Belmonte del Tajo, central Spain. Methods: We sampled a total of 68 (50 cm × 50 cm) plots in gypsum outcrops from central Spain. Each plot was divided into 100 (5 cm × 5 cm) sampling quadrats, and the presence of all lichen species in...

The morphological data with taxonomical value and the distribution maps of ten taxa of the genus Cladonia supergroup Crustaceae is reported from the Iberian Peninsula. With the exception of Cladonia mediterranea and C. ciliata, all of them show an optimal distribution in the Eurosiberian Region with some occurrences in suboceanic territories of the...

Despite advancements in our knowledge on the importance of biological soil crusts (BSC) in arid and semiarid environments, little is known on the effects of specific crust organisms on vascular plant seed emergence. We conducted a growth chamber experiment to evaluate the effects of two BSC-forming lichens (Squamarina lentigera and Diploschistes di...

Question: What are the edge effect responses of epiphytic lichen communities in Mediterranean Quercus pyrenaica forest? Location: Central Spain. Methods: We established ten transects perpendicular to a road dissecting a well conserved remnant of Q. pyrenaica forest into two sections. Transects extended from the forest/road edge to 100 m into the fo...

Question: What are the edge effect responses of epiphytic lichen communities in Mediterranean Quercus pyrenaica forest? Location: Central Spain. Methods: We established ten transects perpendicular to a road dissecting a well conserved remnant of Q. pyrenaica forest into two sections. Transects extended from the forest/road edge to 100 m into the fo...

Several modelling species distribution studies have been developed, in last years, though mainly applied in higher plants, mammals or birds. However, little is known about overlooked taxa like lichens. We have evaluated the potential distribution of eleven threatened lichens in Spain and how the Natura 2000 network contributes to protect them. To o...