Lichen Growth Forms Research Articles

Functional traits of epiphytic lichen communities in a Temperate-Mediterranean fragmented landscape: Importance of patch size, tree diameter and summer rainfall

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 levels in a Temperate-Mediterranean area dominated by Quercus forests. At fragment level, patch size and summer rainfall positively contributed to richness in most of the traits, while tree diameter and slope were the most important drivers, especially for the type of reproduction and growth form at plot scale. High coverage of growth forms especially sensitive to fragmentation were indicative of high values of total species richness, while early-colonizers indicated the opposite. These results provide important information on how lichen traits respond to environmental conditions in an ecotone area where a shift towards a drier climate is more likely to occur.

The response of lichen growth forms to fire frequency: a case study in oak forests of the southern Russian Far East

Epiphytic lichens are used as sensitive indicators of environmental changes. Lichen growth forms are related to biotic and abiotic factors. In the present study, we investigate the response of lichen growth form diversity to fire frequency. In the oak forests of the southern Primorsky Krai, we established 43 sampling plots of 25 m x 25 m each. All plots were assigned to four fire history regimes defined by the combination of fire marks. A total of 168 epiphytic lichen species were recorded. They were classified into 12 groups of growth forms. The linear regression model demonstrated that the taxonomic diversity of epiphytic lichens and the growth form diversity were highly and positively correlated. Increasing fire frequency resulted in limited damage to growth form diversity of the epiphytic lichen communities, whereas species diversity drastically decreased with increasing fire frequency. The diversity of most growth form groups were connected with the gradient of fire frequency. Diversity of growth forms tolerant to a wide environmental variety, such as foliose species with narrow lobes, crustose granular verrucose, and compact crustose, drastically decreased under regular fire events. In contrast, growth forms adapted to sheltered and humid environments, such as foliose gelatinous, foliose inflated, and foliose with broad lobes, were absent on the plots with regular and frequent fire events. Thus, due to the close relationship between morphological traits and specific environmental conditions, certain groups of growth forms can be used as indicators of fire regimes of forests.

Remarkable cases of parallel evolution of the placodioid thallus growth form in theLecanographaceae(Arthoniales) with the description of a new species ofAlyxoriafrom Mexico

AbstractThe new speciesAlyxoria sierramadrensisis described from Mexico where it inhabits limestone rocks. The lichen developing from this fungus is characterized by a placodioid to subfoliose thallus with a white pruinose surface; rounded to shortly elongated ascomata with a black epruinose margin and a widely exposed, white pruinose hymenial disc; hyaline, 3-septate ascospores, 17–25 × 7–9 μm; the presence of anthraquinones rendering the medulla orange. Phylogenetic analyses of nuLSU, mtSSU andRPB2sequences place this species in the genusAlyxoria(Lecanographaceae). This generic affiliation is surprising because all knownAlyxoriaspecies have a crustose thallus.Lecanographaceaemainly includes species without a thallus (lichenicolous taxa) or with a thin crustose thallus, the only exception beingSimonyella variegatawith a fruticose thallus. The new species belongs to theAlyxoria ochrocheilasubgroup, which includes lichens also frequently known to have anthraquinones, white pruinose hymenial discs and 3-septate ascospores. Phylogenetic analyses further determined the systematic position of the monotypic genusPhoebus. This genus, considered as anArthonialesof uncertain family affiliation, is shown to belong to theLecanographaceae. With its placodioid thallus, it is another example of a lichenized fungus with a deviating morphology in thallus structure for the family, increasing the number of remarkable cases of parallel evolution of lichen growth forms within theArthoniales.Phoebus hydrophobiusis newly recorded for Mexico.

Detecting the drivers of functional diversity in a local lichen flora: a case study on the extinct volcano of Roccamonfina (southern Italy).

Current strategies for conservation reportedly suffer from an inadequate awareness of the drivers affecting lichen diversity, pointing to the need to fully develop a functional approach to lichen ecology. This study is an attempt to detect the drivers affecting functional diversity in the lichen flora of a volcanic Mediterranean area. Data on epiphytic lichen distribution were correlated with information coming from a GIS analysis. Species richness, functional diversity and indicator values of lichens species were analyzed as a function of altitude, bioclimatic patterns and land use patterns. Both taxonomic and functional diversity were found to increase with altitude, peaking at 600m a.s.l. and slightly decreasing at higher elevations. A filtering effect of altitude on lichen growth-forms was detected at increasing altitude, with foliose isidiate lichens replacing crustose lichens with sexual reproduction, cyanobacteria replacing Trentepohlia as photobiont, and oligotrophic species linked to partially shaded environments gradually replacing species indicating eutrophic conditions. Forest stations impacted by low impact traditional agriculture tended to express higher lichen diversity compared to either undisturbed broadleaved forests or intensive orchards. These data demonstrate the need to integrate traditional low-impact agricultural practices in protected areas. Moreover, they provide the evidence that reanalyzing past and recent lichenological censuses with the proposed analytical tools may help previewing and driving the evolution of endangered ecosystems.

The weight of the crust: Biomass of crustose lichens in tropical dry forest represents more than half of foliar biomass

AbstractIn recent years, our ecological knowledge of tropical dry forests has increased dramatically. However, the functional contributions of whole ecosystem components, such as lichens, remain mostly unknown. In these forests, the abundance of epiphyte crustose lichens is responsible for the characteristic white bark on most woody plants, conspicuous during the dry season, but the amount of resources that the lichen component represents remains unexplored. We estimated lichen biomass in a Mexican tropical dry forest using the bark area of trees, the dry mass of lichens per unit area and the percentage of bark covered by lichens, together with previously known tree densities. The lowest 2.5 m of the forests main trunks contained 188 kg/ha of lichen biomass, with lichens covering 85% of the available bark for trees <12 cm DBH and 38% for trees >12 cm. Total epiphytic lichen biomass was 1.34–1.99 Mg/ha. Lichen biomass represented 61% of the foliar biomass in the forest. To our knowledge, this is the first time that a lichen biomass estimate is provided for an ecosystem in which crustose lichens are the dominant lichen growth form. Crustose lichens are typically considered to contribute little to the total lichen biomass and to be difficult to include in ecological analyses. The high lichen biomass in this ecosystem implies a significant ecological role which so far is unexplored. We suggest the crustose lichen component should not be underestimated a priori in ecological studies, especially in ecosystems with abundant lichen cover.Abstract in Spanish is available with online material.

Corticolous lichen species as indicators of disturbed/undisturbed vegetation types in the central mountains of Sri Lanka

AbstractCorticolous lichens in the central mountains of Sri Lanka differ with vegetation type, disturbance and climate. All growth forms of lichens were studied in 42 plots (six plots × seven vegetation types), yielding 124 species. Lichen species diversity varied with number of tree species per plot (correlations) and differed with disturbance group, vegetation type and climate zone (general linear models). Lichen community composition (estimated cover of 74 species each at ≥ 3 plots) varied along two ordination gradients secondarily correlated with disturbance (nonmetric multidimensional scaling, NMS). Undisturbed and disturbed plots (mostly grouped by vegetation type) were divided along NMS axis 1, correlating with distance to undisturbed forest. Longest-disturbed plots differed from all others along NMS axis 2 and were correlated with canopy cover. Climate was weakly reflected on the ordination as the proximity of two plot clusters in montane vegetation types. Indicator species analyses (ISA) of lichen cover by plot identified 60 strong indicator species (indicator value ≥ 50%, P < 0.015). Fifty-seven species were indicators for individual vegetation types (28 of them for undisturbed types); three were for a disturbance group only; 11 were also for a disturbance group or climate zone. Most species strongly driving ordination patterns were also ISA indicators. Most lichens were crustose (39, with 24 in the Graphidaceae). Each vegetation type had at least one indicator with trentepohliod algae (increasing for undisturbed plots) and one with chlorococcoid algae. Two visually distinct indicator species, three genera and two multi-genus groups will be useful to parataxonomists in forest evaluation.

Estimation of physiological responses using two growth forms of lichens around coal-based Tanda Thermal Power Plant, Ambedkar Nagar district of Uttar Pradesh, India

Estimation of physiological responses using two growth forms of lichens around coal-based Tanda Thermal Power Plant, Ambedkar Nagar district of Uttar Pradesh, India

A new measurement tool to consider for airborne pollutants evaluations using lichens.

An important factor affecting acquisition of pollution elements could be the lichen growth form. The Brunauer-Emmett-Teller theory approach has been used to determinate the specific area surface (BET-area) of solids by gas multilayer adsorption. Taking this standard method as a new tool, we measure the specific thallus area in foliose and fruticose lichens to evaluated area/volume relation for bioaccumulation prospects. Some preliminary results of elemental contents such as REEs (La, Sc, Sr) and pollutants (Cd, Co, Pb) were also measured to support the importance to use for the analysis of these thallus attributes.

Using Growth Forms to Predict Epiphytic Lichen Abundance in a Wide Variety of Forest Types

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 assessment methods need to be extrapolated throughout the world. This study correlated lichen growth forms and total epiphytic abundance across 119 forests located in Europe and Central-South America. A total of 54 papers were selected from specific databases focused on lichens. Additionally, data from several unpublished ecological studies were included. Linear regression models showed that epiphytic lichen abundance was highly and positively correlated with the number of growth forms at all geographical levels considered (i.e., Central-South American and European forests, and the combination of both). Thus, the use of growth forms may provide an alternative and complementary way to evaluate epiphytic diversity because most growth forms have cosmopolitan distribution and are easily recognizable.

Lichens and lichenicolous fungi of Serranía de Ronda (Málaga-Cádiz), south Spain

As a result of a field trip organised by the Spanish Lichen Society in Serranía de Ronda, south Spain, a catalogue of 360 taxa is presented (336 lichens, 24 lichenicolous fungi). The list includes three new records for the Iberian Peninsula: Arthonia paretinaria, Micarea myriocarpa and Niesslia keissleri, 51new ones for the Autonomous Andalusian Community, and three and 81 new ones for the province of Cádiz and of Málaga, respectively. After these results, the total updated number of the province of Málaga rises to 556 lichens and lichenicolous fungi. The best represented lichen genus is Cladonia (18) with the most species, unlike Lecanora (15), Pertusaria (12), Physconia (12) and Collema (9). As regard habitat, most lichen species are mainly corticolous (55%), as opposed to saxicolous (24%), terricolous (14%) as the species growing on other lichens as lichenicolous fungi (7%). The percentages of lichen growth forms are mainly foliose (50%) and crustose (31%), while fruticose (7%), crustose squamulose (6%) and dimorphic (6%) are less represented. The lichen wit

Lichens on the Hudson Bay Lowlands: a long-term survey in Wapusk National Park, Manitoba

AbstractWapusk National Park is part of the Hudson Bay Lowlands in Manitoba and covers 11 475 km2. Lichen surveys were initiated in 2002 but none have reported all species incorporating broad habitat types or a baseline on which to make management decisions. The objectives of this study were: 1) to determine species diversity, including species richness and evenness of the lichens present; 2) to explore species distributions; and 3) to compare lichen growth form and substratum relationships among physiographic regions. Fifty-six locations in four habitat types (physiographic regions: open coastal beach ridge, forested coastal beach ridge, boreal transition forest, and peat plateau bog) and three burned locations were visited over nine years and specimens were collected at each location. A total of 276 species and subspecies were collected. One species is new to Canada (Buellia uberior Anzi) and ten species are new to Manitoba. Species diversity, evenness, and richness were highest in the coastal beach ridge. The open coastal beach ridge, boreal transition forest, and peat plateau bogs formed separate clusters in the non-metric multidimensional scaling (NMS) but the forested coastal beach ridge overlapped with the open coastal beach ridge. Unique species in each region may serve as indicators to monitor long-term changes. While the coastal beach ridge facilitates travel along the coast, it also represents the region with the highest need for intervention to conserve species diversity.

Lichen-Associated Fungal Community in Hypogymnia hypotrypa (Parmeliaceae, Ascomycota) Affected by Geographic Distribution and Altitude.

Lichen-associated fungal species have already been investigated in almost all the main growth forms of lichens, however, whether or not they are homogeneous and constant within each lichen species are still inconclusive. Moreover, the related ecological factors to affect and structure the fungal composition have been poorly studied. In order to answer these questions, we took Hypogymnia hypotrypa as a model to study the relationship between the lichen-associated fungal composition and two ecological factors, i.e., site and altitude, using the method of IlluminaMiSeq sequencing. Four different sites and two levels of altitude were included in this study, and the effects of site and altitude on fungal community composition were assessed at three levels, i.e., operational taxonomic unit (OTU), class and phylum. The results showed that a total of 50 OTUs were identified and distributed in 4 phyla, 13 classes, and 20 orders. The lichen-associated fungal composition within H. hypotrypa were significantly affected by both site and altitude at OTU and class levels, while at the phylum level, it was only affected by altitude. While the lichen associated fungal communities were reported to be similar with endophytic fungi of the moss, our results indicated the opposite results in some degree. But whether there exist specific OTUs within this lichen species corresponding to different sites and altitudes is still open. More lichen species and ecological factors would be taken into the integrated analyses to address these knowledge gaps in the near future.

A survey method for assessing the richness of epiphytic lichens using growth forms

The species richness of epiphytic lichens is continuously decreasing by degradation and loss of habitat. Considering that taxonomic identification of all species is time and resource consuming, rapid assessment methods to extrapolate the total number of species are needed for practical conservation. This paper describes an alternative method using the correlation between lichens growth forms and species richness. The study was conducted in 406 forest stands located in Central Spain, covering a wide range of mediterranean-climate ecosystem regions, management intensity levels, canopy cover conditions, and tree sizes. The presence/absence of epiphytic lichens was determined in 6090 trees, which were dominated by oak species (Quercus ilex, Q. faginea, and Q. pyrenaica). In all type of forests, the diversity of growth forms was positively correlated with the total epiphytic lichen richness. In all cases, species richness increased in non-managed forest stands with dense canopies. Thus, we propose the use of lichen growth forms as a helpful surrogate of species richness to detect potentially conservation priority areas in the Mediterranean region.

Tree Species Composition Predicts Epiphytic Lichen Communities in an African Montane Rain Forest

AbstractThe ecology of many tropical rain forest organisms, not the least in Africa, remains poorly understood. Here, we present a detailed ecological study of epiphytic lichens in the equatorial montane rain forest of Bwindi National Park (331 km2), Uganda. We evaluated all major lichen growth forms, including selected groups of crustose lichens. In 14 transects at elevations of 1290 m to 2500 m, we sampled 276 trees belonging to 60 species. We recorded all lichen species on each tree trunk between ground level and 2 m above the ground, yielding 191 lichen species in 67 genera, with a mean of 4.7 species per tree. We used non‐metric multi‐dimensional scaling to separate epiphytic lichen assemblages according to tree species composition and elevation. Structural equation modeling indicated that elevation influenced tree species composition and that tree species composition largely determined lichen species composition. Thus, elevation acted indirectly on the lichen assemblages. Further studies examining factors such as bark properties and lichen colonization ecology may clarify what determines the association between tree species and lichen assemblages. The link between lichen assemblages and large‐scale elevation patterns, as well as disturbance and regrowth histories, warrants further study. An analysis of lichen species composition on individual tree species that occur over large elevation ranges would distinguish the effect of tree species on lichen assemblages from the effect of elevation and thus climate. Our study highlights the limited extent of our knowledge of tropical epiphytic lichens.

Epiphytic lichen diversity along elevational gradients: biological traits reveal a complex response to water and energy

AbstractAimPatterns of epiphytic lichen diversity along elevational gradients covering the range of Norway spruce forests were analysed. The roles of water and energy variables in shaping the observed species–elevation relationship were tested, as well as how growth form and photobiont type distribution varied along the gradient.LocationSouth Tyrol, northern Italy.MethodsEight sites were selected spanning the elevational range of spruce forests (900–1900 m a.s.l.) and the regional rainfall gradient. At each site, a pair of forest stands (one mature even‐aged and one multilayered) was selected at three elevation steps. Epiphytic lichens were surveyed according to European guidelines for lichen diversity monitoring. Explanatory variables indicative of both forest structure and climate were included in the models.ResultsA positive relationship was found between number of species and elevation. This reflected the physiological response of epiphytic lichens to the main climatic factors, trait selection being the mechanism that determined the response at community level. Nonlinear species–temperature and trait–temperature relationships predicted that major changes may be expected in the intermediate part of the gradient. Lichens with a Trentepohlia algal partner were more frequent at lower elevations and proved to be sensitive to environmental factors indicative of forest structure. Lichen growth forms had contrasting patterns related to temperature, crustose species richness being enhanced by increasing values, and alectorioid and foliose lichens by decreasing values. Alectorioid lichens were also negatively influenced by rainfall.Main conclusionsIn a climate change scenario, lichen diversity in alpine regions will probably not benefit from an increase in air temperature in the same way as flowering plants. Monitoring variations in the proportions of growth form and photobiont type may represent a tool for detecting the effects of climate change on lichen species.

Influence of macro-scale environmental variables on diversity and distribution pattern of lichens in Badrinath valley, Western Himalaya

Morphological growth forms confer ecological adaptability to lichens species and are indicators of habitat conditions and various climatic as well as zooanthropogenic pressures. Lichens samples from six sites in two locations of Badrinath valley were studied in order to assess the influence of macro-scale environmental variables (i.e. altitude, relative humidity and temperature) on diversity and distribution of lichens, using ordination (PCA and hierarchical clustering) and correlation analysis. The study recorded 106 lichen species in the valley. Parmeliaceae was a dominant family. Lichen species constitution in sites resulted in different groups, which were determined by the dominant growth forms and substrate preferences. Lichen growth form distribution was significantly correlated with studied macro-scale environment variables. On rock (saxicolous) substrate was the main substrate of lichen inhabitancy in the valley. The study concluded that macro-scale environmental variables play determining role in lichen community constitution of alpine habitats in Himalayas.

Rain, dew, and humid air as drivers of morphology, function and spatial distribution in epiphytic lichens

AbstractThis review is a first attempt to combine and compare spatial distribution of the three main water sources, rain, dew and humid air, with water-related traits of mainly epiphytic macrolichens in a conceptual and functional model. By comparing climatic and lichenological knowledge, various effects of dewfall, rainfall and humid air on epiphytic lichen morphology and function are analyzed to search for traits and patterns. Although dew, rain and humid air cause lichen hydration and activate photosynthesis, these atmospheric hydration sources influence and shape lichens differently. In order to visualize hydration patterns, dew, rain and humid air are shown as corners in a triangle exhibiting the various combinations of these hydration sources. The sources of hydration vary on temporal scales, and on the spatial scales: regional, landscape, stand and tree. Lichen growth form, photobiont type, water-holding capacity (WHC) and suprasaturation depression show clear patterns within the hydration triangle. For most lichen species, one average pre-dawn dewfall approximately fills their average internal WHC. This suggests that lichens are optimally designed to utilize dew rather than rain, consistent with literature emphasizing dew as a driver for annual C-assimilation in chlorolichens. However, rain is needed to fill their external WHC and to fully hydrate most cyanolichens. Including the sources of hydration and internal lichen variables, such as water-holding capacity, will improve modelling of local and global future scenarios on lichen distribution and biomass production.

A radical shift in the taxonomy of Lepraria s.l.: Molecular and morphological studies shed new light on the evolution of asexuality and lichen growth form diversification

A combination of molecular phylogenetic analyses of ITS and mtSSU sequences, morphological and chemical analyses were used to investigate the lineages nominally included in the sterile lichen genus Lepraria. A core group (Lepraria s. str.) was resolved as sister to Stereocaulon. Species producing the secondary compounds argopsin, pannarin and usnic acid were found to belong to other lineages of lichen-forming ascomycetes. Study of Leprocaulon revealed that all species, except the type, likely represent members of Lepraria s. str. that have evolved a fruticose growth form. The correct name for the type species of Leprocaulon is shown to be L. quisquiliare, not L. microscopicum, and the genus is redefined to include several species previously placed in Lepraria. Leprocaulon quisquiliare is also shown to comprise two morphologically convergent species. The name is lectotypified and epitypified on material from the type region (Germany) and its application restricted to Old World populations. New World populations of L. quisquiliare are described as L. americanum. Leprocaulon, in its revised sense, is recognized in a new family (Leprocaulaceae) and order (Leprocaulales) sister to the Caliciales and including the genus Halecania. A new genus of Pilocarpaceae, Nelsenium, is introduced to accommodate Lepraria usnica. The status of Lepraria ecorticata is discussed in the context of usnic acid-producing Lecanora species. These nomenclatural novelties are proposed: (i) transfers from Leprocaulon to Lepraria: Lepraria albicans comb. nov., L. arbuscula comb. nov., L. congestum comb. nov., L. gracilescens comb. nov., L. pseudoarbuscula comb. nov., L. subalbicans comb. nov., L. tenellum comb. nov.; (ii) transfers from Lepraria to Leprocaulon: Leprocaulon adhaerens comb. nov., L. coriense, L. santamonicae comb. nov., L. terricola comb. nov. and L. textum comb. nov.; (iii) new taxa: Leprocaulales ord. nov., Leprocaulaceae fam. nov., Nelsenium gen. nov., Leprocaulon americanum sp. nov. and L. knudsenii sp. nov.

The conservation of ground layer lichen communities in alvar grasslands and the relevance of substitution habitats

Semi-natural calcareous grasslands (alvars) are biodiversity hotspots in Northern Europe, particularly for herb layer plants. In the last century, traditional management has ceased, and the area of grasslands has declined due to extensive encroachment. We were interested in the drivers of ground layer (alias terricolous or epigeic) lichen communities. Our survey consisted of 86 habitat fragments in western Estonia, covering four types of historic alvar grasslands and three types of alvar-like habitats. We found that the ground lichen communities were primarily soil-type-specific, but were also affected by historic disturbances and land use change. In contrast to knowledge about herb layer communities, for which shrub encroachment has been shown to be main driver, the increased density of the herb layer and the reduced diversity of microhabitats were major drivers for the ground layer lichen community. These drivers caused a decrease in species richness, but only within the species of conservation value, and also led to a shift in the composition of lichen growth form from the dominance of squamulose and crustose towards fruticose lichens. We conclude that the traditional practice of restoring alvars by cutting shrubs is insufficient to maintain ground layer lichen biodiversity. Alvar maintenance practices should include grazing, which creates various small-scale ground disturbances and increases microhabitat heterogeneity. Alvar-like habitats originating from large-scale historic disturbances appeared to be suitable for calcicolous epigeic lichens, and can therefore be considered to be temporary substitution habitats, i.e. refugia for the regional species pool.

Uporaba epifitskih lišajev kot kazalnikov kakovosti zraka ob izbranih testnih odsekih cest v Sloveniji

For the assessment of air quality at locations along selected road sections with different traffic density, epiphytic lichens were used as passive reactive bioindicators. With the mapping at different distances from the roadside at each location, the trafficrelated pollution impact area was assessed. Two different mapping methods were used, specifically the simple assessment of air quality, based on the assessment of frequency and coverage of different lichen growth forms (the SI method), and more demanding one, based on mapping of lichen species (the VDI method). We conclude that at locations with moderate traffic density (average daily traffic < 20,000) the traffic-related emissions have an influence on air quality as well, except that the impact is limited to a narrow zone along the roads (< 100 m). The epiphytic lichen species composition, the number of different lichen species, as well as calculated indexes of air purity according to two different methods indicate influence of traffic-pollution in the first mapping zone (adjacent to roads), with the impact level decreasing with the distance from the roads.