Crustose Forms Research Articles

Tertiary bioreceptivity of schists from prehistoric rock art sites in the Côa Valley (Portugal) and Siega Verde (Spain) archaeological parks: Effects of cleaning treatments

Schist weathering induced by the presence of lichen is one of the main concerns in the Côa Valley (northeast Portugal) and Siega Verde (northwest Spain) Archaeological Parks. In this study, different types of lichens, including mainly crustose forms (Caloplaca pellodella, Candelariella vitellina, Circinaria hoffmanniana, Diploschistes actinostomus and Lecidea fuscoatra) as well as some foliose forms (Parmelina tiliacea and Xanthoparmelia conspersa), were removed from schistose samples of both lithotypes in different locations. The lichens were removed by treatment with Biotin T® biocide or by laser treatment with the first (1064 nm, IR) and fourth (266 nm, UV) harmonics of a Nd:YAG laser. To assess the effects of the treatments, a recolonization experiment was carried out with biofilm-forming phototrophic microorganisms, and a bioreceptivity index (BI) was calculated for each lithotype and treatment. A water-based treatment (the removal method currently used in both parks) was used as a control cleaning treatment in the bioreceptivity experiment. The study findings show the importance of bioreceptivity studies for evaluating the effectiveness of cleaning treatments. Treatment of the schist samples with the chemical biocide significantly decreased the bioreceptivity (complete inhibition of biofilm formation), whereas laser treatments (especially IR laser) significantly increased the tertiary bioreceptivity. Moreover, the tertiary bioreceptivity of the schists depended on both the treatment applied and the nature of the substrate.

Short Communication: Species diversity of corticolous lichens in the arboretum of Padjadjaran University, Jatinangor, Indonesia

Abstract. Kusmoro J, Mayawatie B, Budiono R, Noer IS, Permatasari RE, Nurwahidah A, Satriawati R, Arum D, Saragih DE, Widya R, Jatnika MF, Makarim A, Partasasmita R. 2019. Short Communication: Species diversity of corticolous lichens in the arboretum of Padjadjaran University, Jatinangor, Indonesia. Biodiversitas 20: 1606-1616. The lichen flora of tropical areas is still much under explored, Java in general and the Arboretum in West Java in particular, are no exceptions. The Arboretum of the main campus of Padjadjaran University, Jatinangor, Sumedang, West Java, Indonesia is representative of a typical man-made lowland tropical rain forest ecosystem in Java. It is planted with peculiar and rare species of plants, such as Antidesma bunius, Syzygium cumini, Durio zibethinus, Caesalpinia pulcherrima, Tectona grandis, Albizzia falcataria, Swietenia mahagoni, Alstonia scholaris, Jatropha multifida, Sterculia foetida, Diospyrus blancoi, Hura crepitans and Rauvolfia serpentina. We explored the lichen flora of this Arboretum using species of corticolous macrolichens as indicator taxa. Lichen survey was performed by exploring the different zones, such as zones for rare species, industrial plants, medicinal plants and fruit plants. Lichen diversity on 23 trees spread in 12 ha area was documented based on morphological and anatomical features, and also chemical tests. A total of 68 species of lichens, distributed in 38 genera and 12 families, were enumerated during the study. The crustose and foliose forms contributed 62% (42 species) and 37% (25 species) of the total species, respectively. Graphidaceae with 28 species and Parmeliaceae with 15 species were the dominant families, which together constituted more than 50% of the lichen populations. Graphis librata and Parmeliopsis sp. were the dominant and co-dominant species and Drinaria picta was another common species.

Molecular data confirm the existence of attached crustose tetrasporangial thalli in Phymatolithon calcareum (Melobesioideae, Hapalidiaceae, Rhodophyta) from the Mediterranean Sea

Phymatolithon calcareum is a species of non-geniculate coralline red algae that commonly forms maërl beds. Tetrasporangial thalli of this species are characterized by unattached growths (rhodoliths), which develop as a branched system without a central nodule, while the attached crustose forms are uncommon and are known only from Brittany (Atlantic coasts of France). In this study we confirm with molecular data the existence of attached crustose tetrasporangial thalli and describe for the first time epilithic, fruticose tetrasporangial specimens from the Mediterranean Sea (Vis Island, Croatia). Since the identification of coralline algal species is difficult due to the high morphological plasticity of the group, molecular analyses based on the nuclear nSSU and the plastidial psbA markers were necessary to correctly identify the specimens. Our study shows that P. calcareum tetrasporangial thalli have the ability to grow both unattached and attached, and we argue this to be in relation to the environmental conditions found at different depths. This ability permits the alga to colonize different habitats of the coastal environment.

DIVERSITY AND ADAPTIVE FEATURES OF CORTICOLOUS LICHENS IN THE HUNDRED ISLANDS, PHILIPPINES

This study is a survey of corticolous lichens in the Hundred Islands, Philippines noting their diversity and morpho-anatomical adaptive features. There were only six islands visited due to accessibility and safety reasons. There are at least thirty-two identified species of lichens; majority is crustose dominated by Graphidaceae lichens followed by pyrenolichens in terms of diversity. Morpho-anatomical features considered to be adaptive include crustose and narrow-lobed foliose growth forms, homiomerous thallus organization, thick upper cortex, and presence of pruina in the cortical or medullary layers. KEYWORDS : Hundred islands; epiphytic lichens; adaptive features

Spatial variability, structure and composition of crustose algal communities in Diadema africanum barrens

Crustose algal communities were studied in Diadema africanum urchin barrens around Tenerife (Canary Islands, NE Atlantic). A hierarchical nested sampling design was used to study patterns of community variability at different spatial scales (sectors, three sides of the island; sites within each sector, 5–10 km apart; stations within each site, 50–100 m apart). Although noncrustose species contributed the most to community richness, cover was dominated by crustose forms, like the coralline algae Hydrolithon farinosum, H. samoense, H. onkodes, Neogoniolithon orotavicum and N. hirtum, and the phaeophycean Pseudolithoderma adriaticum. The structure of these communities showed high spatial variability, and we found differences in the structure of urchin barrens when compared across different spatial scales. Multivariate analysis showed that variability in community structure was related to the five environmental variables studied (wave exposure, urchin density, substrate roughness, productivity and depth). Wave exposure was the variable that contributed most to community variability, followed by urchin density and substrate roughness. Productivity and depth had limited influence. The effects of these variables differed depending on the spatial scale; wave exposure and productivity were the main variables influencing community changes at the largest scale (between different sectors of the island), while D. africanum density, roughness and depth were the most influential at medium and small scales.

동해안 울산 주변의 해조 군집

The marine algal flora and community structure were investigated at three sites in Ulsan on the southeast coast of Korea between August 2005 and July 2006. Ninety-one benthic algae species were identified, including 14 Chlorophyta, 21 Phaeophyta, and 56 Rhodophyta species. Of the 91 seaweeds, 19 species were found throughout the survey period. The wet weight biomass ranged from 310.8 to 2,960.4 g during the study period. The maximum biomass was recorded at Sinri, and the minimum was recorded at Daesong. The R/P, C/P and (R+C)/P values reflecting flora characteristics were 2.67, 0.67, and 3.33, respectively. The flora investigated could be classified into six functional groups: coarsely branched (46.2%), thick leathery (22.0%), filamentous (16.5%), Sheet (7.7%), jointed calcareous (4.4%), and crustose (3.3%) forms. A cluster analysis produced two groups that differed meaningfully: one included the site Sinri-summer and the other included the sites Daesong and Jinha.

태안반도 하계 해조상 및 군집구조

The benthic marine algal flora and community structure were examined at five sites of the Taean Peninsula, Korea, during July-August 2005. Ninety-six algal species were Identified, including 14 green, 21 brown, and 60 red algae, and 1 marine plant. The common species that occurred at the five sites were Sargassum thunbergii, Gelidium divaricatum, Caulacanthus okamurae, Gracilavia vermiculophylla, and Neorhodomela aculeata. Sthunbergii was the dominant species in terms of coverage and biomass at ail of the study sites. The average biomass varied from <TEX>$23.72g/m^2$</TEX> in dry weight at Chaeseokpo to <TEX>$66.43g/m^2$</TEX> at Padori. The species could be divided into six functional groups in terms of morphological characteristics: 41 coarsely branched forms, 25 filamentous forms, 16 sheet forms, 7 thick leathery forms, including the marine plant Phyllospadix iwatensis, 4 crustose forms, and 3 Jointed calcareous forms. The seaweed communities at the five study sites were unstable and the environmental conditions were bad or very bad. Among the five study sites, the ecological evaluation index (EEI) and diversity index (H') were maximal at Padori at 2.29 and 1.98, respectively. By contrast, the dominance index (DI) was minimal at Padori (0.55) and maximal at Baramarae (0.96). Therefore, we conclude that the rocky shore at Padori has the best environment among the five study sites, although the species richness and biomass of seaweeds have declined continuously over the last 10 years.

Análisis ecológico de las comunidades liquénicas de la Catedral de León (España)

Ecological analysis of Leon Cathedral lichen communities (Spain).A study of the lichen communities present on Leon Cathedral showed there to be 39 species present, mainly crustose forms of the Teloschistaceae and Lecanoraceae. Two lichen communities were found on calcareous stonework and on highly nitrified habitats. Species distribution depends mainly on nitrophytism, hygrophytism, photophytism and pH indexes, and to a lesser extent on angle of inclination, exposure and substrate type.

Spatial and temporal variability of macrobenthic communities in tidepools on a rocky shore in Nova Scotia, Canada

Spatial and temporal patterns in the distribution and abundance of macroalgae and macrofauna were measured in 4 pools in each of 3 intertidal zones (mid, high and splash) on a rocky shore near Halifax, Nova Scotia, Canada. Sheets, filamentous, coarsely branched, thick leathery, jointed calcareous, and crustose forms were the most abundant macroalgal functional groups, and mussels, l~ttorinid snails and whelks were the most abundant macroinvertebrates in the pools. Percentage cover of the late-successional macroalgal forms, such as thick leathery and crustose forms, was greatest in the mid pools where environmental fluctuations are smaller and more predictable. Percentage cover of the more opportunistic forms, such as sheets and filamentous algae, was variable among pools in all zones, whereas percentage cover of the other functional forms was most variable among mid pools on most sampling dates. Mussels and whelks were more abundant in mid pools, whereas littonnes were more abundant in the high pools. Macrofaunal abundance also was variable among pools within most zones on most sampling dates. Multiple regressions showed that grazer density, nutrient regime and physical characteristics of the tidepools can consistently explain the variability in percentage cover of late-successional macroalgal functional forms, but not of the more opportunistic forms. The horizontal spatial variability in percentage cover of macroalgae may result from differential recruitment of opportunistic forms, and/or differences in the physical characteristics of the pools which affect slow-growing, late-successional forms. The Shannon D~versity Index for the macroalgal and the macrofaunal assemblages was greatest in mid pools, suggesting that a smaller number of macroalgal and macroinvertebrate species can survive in the higher pools where conditions are harsher. Cluster analyses showed that the macroalgal assemblages were mostly similar among mid pools, and that macrofaunal assemblages of mid pools were similar to high pools, but not splash pools. Our study shows that macrobenthic community structure in tidepools does not vary consistently with the period of tidal isolation and there is large variability among pools within intertidal zones.

Spatial Relationships among Encrusting Marine Organisms in the New England Subtidal Zone

Competition for substratum by encrusting marine organisms usually occurs by direct overgrowth at zones of contact. The documented mechanisms of competitive displacement are numerous, but the relative importance of species in a competing assemblage has been difficult to quantify. This study of the encrusting community on subtidal vertical rock walls in northern Massachusetts used 2 yr of photographic sampling of permanent quadrats to examine the competitive role of each common space occupier. The surface area gained or lost by individuals or colonies of each species in interactions with others was measured over intervals of ≥ 30 d. Four quantitative indices were used to describe competitive roles: the first measured the overgrowth activity of each species within a given assemblage (overgrowth index); the second assessed the relative importance of each species as an overgrowth competitor in the assemblage (weighted overgrowth index); the third described each species' ability to resist overgrowth (resistance index); and the fourth measured each species' growth rate when advancing over other organisms. Analysis of percent cover on subtidal rock walls over a 2—yr period showed that the ascidian Aplidium pallidium, the sponge Halichondria panicea, the octocoral Alcyonium siderium, a red fleshy crustose alga, and a mat of amphipod tubes covered most of the rock surface continuously, although the relative abundances of the species varied across sites and seasons. Several of the common species gained space by overgrowing other species directly or by lateral growth pushing the adjacent species away (lateral movement). This group included several colonial and solitary ascidian species, calcareous tubeworms, and encrusting bryozoans. A few species, including the fleshy red crustose alga and the crustose coralline alga Phymatolithon, gained space from others when an overlying organism receded. The various indices of spatial interaction showed that species which were common and frequent overgrowers in the system were usually not good at resisting overgrowth themselves. Species good at resisting overgrowth were generally large and slow—growing, and were not the most active overgrowers of other species. The interactions among species in this study were basically hierarchical, with the larger thicker colonies and individuals being the winners in competition for space. However, there were a number of reversals of competitive success, especially among the thick crustose forms, and there were numerous "standoffs" where borders did not change during the 30—d interval (19—79% of all encounters, depending on the species involved; 41% overall). The indices of spatial interaction (growth, overgrowth, resistance, overgrowth weighted by abundance) were significantly correlated between exposed and protected sites but were not well correlated between warm and cold seasons. Thus, species tended to have the same competitive roles in slightly different communities but their importance varied as their growth rate changed between warm and cold periods. Overgrowth did not always result in death of the organism overgrown. Species such as the fleshy red crustose alga and the coralline alga Phymatolithon were often encountered alive under invertebrates that had been in position for at least several months. Thus, poor competitors in this system were maintained by two processes: some are early recruits that grow rapidly but later get overgrown, while others are able to withstand overgrowth until predation or some other disturbance removes the overgrower.

Factors influencing algal species assemblages on reef and cobble substrata off Ghana

Subtidal algal assemblages were studied on two substrata, rocky reefs and calcareous cobbles. Although the two occur together at comparable depths, their vegetation differs in species composition and richness, and in patterns of plant size, life form, and longevity. The reef bears a species-rich, patchy cover of small filamentous and crustose forms, with occasional clumps of more robust species. The cobbles support a sparse cover of large leafy and dendritic species in addition to many of the smaller species found on the reef. The floristic separation arises from differential establishment and survival of species under conditions of (1) grazing by fish and urchins (on the reef only), and (2) seasonal physical disturbance during storms leading to the removal of most algae (on the cobbles only). Both substrata show a seasonal floristic cycle, but the trend is more pronounced on cobbles. Species do not depart from randomness in their patterns of co-occurrence on individual cobbles or reef fragments. Interspecific competition appears comparatively unimportant in determining species composition on either substratum.

Microhabitat and Structural Variation in the Aspicilia desertorum Group (Lichenized Ascomycetes)

Fruticose and crustose forms of Aspicilia desertorum (Kremp.) Meresch. are recorded from Western Colorado in microhabitats beneath snow patches and on exposed rock surfaces, respectively. For single populations, microenvironmental variation in substrate, temperature, light intensity and water availability is directly related to continuous morphological variation. Functional variation with habitat is evident in growth form, stage of apothecial development, calcium oxalate pruinosity, anatomical disposition of unidentified crystalline material, cortical anatomy and continuity, numbers of algal cells per unit weight of thallus, medullary anatomy, maximum thallus water content (or water-holding capacity) and relative thickness of hyphal walls. These multivariate relationships define ecomorphological syndromes and a pattern of variation with parallels at a higher phytogeographic level.

MICROHABITAT AND STRUCTURAL VARIATION IN THE ASPICILIA DESERTORUM GROUP (LICHENIZED ASCOMYCETES)

Fruticose and crustose forms of Aspicilia desertorum (Kremp.) Meresch. are recorded from Western Colorado in microhabitats beneath snow patches and on exposed rock surfaces, respectively. For single populations, microenvironmental variation in substrate, temperature, light intensity and water availability is directly related to continuous morphological variation. Functional variation with habitat is evident in growth form, stage of apothecial development, calcium oxalate pruinosity, anatomical disposition of unidentified crystalline material, cortical anatomy and continuity, numbers of algal cells per unit weight of thallus, medullary anatomy, maximum thallus water content (or water‐holding capacity) and relative thickness of hyphal walls. These multivariate relationships define ecomorphological syndromes and a pattern of variation with parallels at a higher phytogeographic level.

The interzooidal communications ofHippothoa sensu lato(Bryozoa) and their value in classification

Summary The interzooidal communications of a number of species of Hippothoa s.l. have been examined. Pore-chambers have a varied morphology. They may be conical or rounded in shape or comprise pocket-shaped or tubular invaginations of autozooidal walls, often flaring distally where they form tubes or otherwise connect with adjacent zooids. Although there are some gradations in the form of the pore-chambers throughout the whole range of Hippothoa species, conical and rounded chambers tend to characterize the strictly uniserial forms and tubular chambers the crustose forms. A consideration of other characters (the ancestrula, early astogeny, polymorphism, anatomy) demonstrates that there are correlated characters to warrent recognition of three generic groupings within Hippothoa s.l.

Factors Determining Various Forms in Cladosiphon zosterae (Phaeophyceae)

The brown alga Cladosiphon zosterae (J. Ag.) Kylin (Chordariaceae) is found to exist in culture in a variety of forms, including filaments, discoid or crustose forms, and two types of erect cylindrical thalli. Asexual spores from plurilocular sporangia of each form can produce any and all forms. Three factors controlling morphological expression in C. zosterae have been identified. These factors include: (1) heteroblasty (formation of filamentous and discoid germlings as a consequence of alternate modes of spore germination), which was independent of all environmental factors tested including temperature, photoperiod, nitrogen source, and general fertility of the growth medium; (2) influence of certain nitrogen sources, notably ammonium, which induce a compact discoid or crustose form; and (3) a morphogenetic factor presumed to be bacterial which determines mode of development and subsequent morphology of the erect Cladosiphon thallus.

FACTORS DETERMINING VARIOUS FORMS IN CLADOSIPHON ZOSTERAE (PHAEOPHYCEAE)

The brown alga Cladosiphon zosterae (J. Ag.) Kylin (Chordariaceae) is found to exist in culture in a variety of forms, including filaments, discoid or crustose forms, and two types of erect cylindrical thalli. Asexual spores from plurilocular sporangia of each form can produce any and all forms. Three factors controlling morphological expression in C. zosterae have been identified. These factors include: (1) heteroblasty (formation of filamentous and discoid germlings as a consequence of alternate modes of spore germination), which was independent of all environmental factors tested including temperature, photoperiod, nitrogen source, and general fertility of the growth medium; (2) influence of certain nitrogen sources, notably ammonium, which induce a compact discoid or crustose form; and (3) a morphogenetic factor presumed to be bacterial which determines mode of development and subsequent morphology of the erect Cladosiphon thallus.

Reproductive strategies in lichens

Lichens employ two divergent strategies of reproduction, a sexual method through spore propagation and a derivative asexual strategy based on systems perpetuating the symbiosis by the dissemination of specialized diaspores. The distribution of these pathways in 24 families in the order Lecanorales is presented. Fruticose and foliose life forms have a greater representation of vegetative diaspores than crustose forms. It is hypothesized that chemical evolution occurred prior to the development of secondary asexual reproductive mechanisms. The derived vegetative morphologies have apparently outlasted their sexual ancestors, although a number of closely related “species pairs” are known, indicating the joint survival of ancestral sexual lines with secondary asexual offspring. Species using a vegetative strategy often have a greater world distribution than their sexual counterparts in foliose and fruticose groups. No clear pattern is apparent in crustose groups. The advantages of vegetative strategies are a greater survival for propagules and rapid invasion of new habitats. The separation of these strategies and the evolution of soredia and isidia represents a gradient in the evolution of taxa.

EFFECTS OF CHRONIC GAMMA IRRADIATION ON LICHEN COMMUNITIES OF A FOREST

Chronic gamma irradiation of an oak‐pine forest on Long Island reduced populations of corticolous and terrestrial lichens in approximate proportion to the rate of irradiation. The decline in species diversity was approximately linearly related to logarithmic increases in daily radiation exposure. While a daily exposure of 2700 R/day was estimated to have reduced diversity to 50% in the first year, a linear extrapolation of diversity, coefficient of community and similarity curves to zero suggested that certain lichens would survive 3 years' exposure at daily rates of 5,000–10,000 R, possibly more. There was an apparent threshold at 300 R/day for radiation effects on the composition of lichen communities; changes in relative density occurred at lower exposures. The crustose forms were more resistant than foliose or fruticose forms, an observation which parallels previous observations that the most radio‐resistant higher plants tend to be of short, stature.