Kansri Boonpragob

Seasonal variation of elemental status in the lichen Ramalina menziesii Tayl. from two sites in southern California : evidence for dry deposition accumulation

Abstract In southern California the lichen Ramalina menziesii was transplanted from a relatively unpolluted area to a highly polluted area for three periods over a year. During each period multi-element analyses of both water leachable extracts and residual fractions from the leached thallus were analyzed at 2-week intervals. Total concentrations were calculated by adding these two measurements. Total concentration of most elements did not exhibit distinct seasonal patterns but the higher concentrations exceeded background levels by factors of 1.3–3.7, depending on the element. In contrast, the elements in the leachates at the control and the polluted site exhibited distinct seasonal patterns with higher concentrations generally present in summer than in winter. High leachable concentrations were only found during dry periods, and consequently the leachable fraction was assumed to represent primarily dry deposition accumulation, particularly as the magnitude of the differences was higher at the polluted site. These elemental patterns reflected not only atmospheric deposition patterns, but also intracellular release of elements as injury occurred and to a lesser extent accumulation of marine aerosols and soil particulates.

Physiological responses of the lichen Ramalina menziesii Tayl. To the Los Angeles urban environment

Abstract In southern California the lichen Ramalina menziesii was transplanted from a control area to a polluted area for three periods during a year. Net photosynthetic rates, recorded under standard conditions in the laboratory, chlorophyll contents and per cent phaeophytins were measured at 2-week intervals for samples from both sites. Druing summer periods at the polluted site chlorophylls and net photosynthesis declined substantially and per cent phaeophytins increased, but during the winter period no changes in these parameters wereobserved. At the control site little or no change in these parameters was observed during the transplant periods. During the winter there was no difference in net photosynthesis for samples collected from the two sites. During the summers the decline in the lichen at the polluted site was associated with the accumulation of 23 ions. Although not demonstrably toxic, nitrate concentrations alone explained over 75% of the variation of each physiological parameter. Fluoride was the second most important variable and it was probably accumulated to toxic levels.

Using Phylogenetic and Coalescent Methods to Understand the Species Diversity in the Cladia aggregata Complex (Ascomycota, Lecanorales)

The Cladia aggregata complex is one of the phenotypically most variable groups in lichenized fungi, making species determination difficult and resulting in different classifications accepting between one to eight species. Multi-locus DNA sequence data provide an avenue to test species delimitation scenarios using genealogical and coalescent methods, employing gene and species trees. Here we tested species delimitation in the complex using molecular data of four loci (nuITS and IGS rDNA, protein-coding GAPDH and Mcm-7), including 474 newly generated sequences. Using a combination of ML and Bayesian gene tree topologies, species tree inferences, coalescent-based species delimitation, and examination of phenotypic variation we assessed the circumscription of lineages. We propose that results from our analyses support a 12 species delimitation scenario, suggesting that there is a high level of species diversity in the complex. Morphological and chemical characters often do not characterize lineages but show some degree of plasticity within at least some of the clades. However, clades can often be characterized by a combination of several phenotypical characters. In contrast to the amount of homoplasy in the morphological characters, the data set exhibits some geographical patterns with putative species having distribution patterns, such as austral, Australasian or being endemic to Australia, New Zealand or Tasmania.

Seasonal deposition patterns of acidic ions and ammonium to the lichen Ramalina menziesii tayl. in southern California

Abstract Seasonal deposition patterns as indicated by water leachable ions (NO3−, NH42+, SO42−, PO43−, H+, F− and Cl− from the lichen Ramalina menziesii were investigated at 2-week intervals over 50 weeks at a polluted and control site in southern California. During interstorm periods accumulation of leachable ions occurred with the highest levels found at the end of extended summer drought periods. Leachable NO3− was always the ion in highest concentration and the ions NH4+, H+ and Cl−1 were found in intermediate concentration. During summers all ions except Cl−1 were consistently higher at the polluted site than at the control site.

Monitoring Physiological Change in Lichens: Total Chlorophyll Content and Chlorophyll Degradation

Chlorophyll in lichens is very sensitive to changes in environmental factors including air pollution. It degrades into phaeophytin upon exposure to acid deposition and heavy metals [10, 8, 9], Changes in chlorophyll and phaeophytin content can be used to assess changes in air quality [2, 4, 6, 13]. This method can be used to detect early stages of damage prior to responses in growth and morphology of a species, so that preventive and protective measures can be introduced.

Modeling potential changes of forest area in Thailand under climate change

The forest cover of Thailand has been characterized according to the Holdridge Life Zone Classification, a model that correlates climatic features with vegetation distribution. Six Holdridge life zone types of forest cover are found in Thailand: subtropical dry forest, subtropical moist forest, subtropical wet forest, tropical dry forest, tropical moist forest, and tropical wet forest. Climate change scenarios were simulated by three general circulation models: two United Kingdom Meteorological Office models (the low and high resolution versions) and the Goddard Institute for Space Studies model. These scenarios were used to simulate the effects of future climate change on Thai forests. The ratios of precipitation and the absolute values of temperature changes were incorporated into a baseline climate scenario from the International Institute of Applied Systems Analysis. Under the climate change scenarios simulated by the three general circulation models, the subtropical dry forest could potentially disappear, and areas of tropical very dry forest would appear. In general, the area of subtropical life zone would decline from about 50% to 20%–12% of total cover, whereas the tropical life zone would expand its cover from 45% to 80%. All three general circulation model scenarios suggest that the tropical dry forest has the greatest potential to extend into the subtropical moist forest. This analysis suggests that global climate change would have a profound effect on the future distribution and health of Thai forests.

Thelotremoid lichen species recently described from Thailand: a re-evaluation

Twenty-six species recently described from Thailand are revised. Eleven taxa are reduced to synonymy with previously described species, including Leptotrema phaeosporum var. vainiona Räsänen. The following new combinations are proposed: Chapsa calathiformis (Vain.) Lumbsch & Papong, C. laemensis (Homchantara & Coppins) Lumbsch & Papong, Melanotrema melanophthalmum (Homchantara & Coppins) Lumbsch & Papong, Ocellularia albocincta (Hale) Divakar & Mangold, O. guianensis (Sipman) Divakar & Mangold, O. khunantensis (Homchantara & Coppins) Lumbsch & Papong, O. percolumellata (Sipman) Divakar & Mangold, O. subcalvescens (Nyl.) Divakar & Mangold and Ocellularia subgranulosa (Homchantara & Coppins) Lumbsch & Papong.

New species and new records of foliicolous lichens from Thailand

One new species and 71 new records are reported from Thailand. Coenogonium disciforme sp. nov. is distinguished by its disc-shaped, shortly stipitate isidia, which leave perfectly circular holes, almost like punched holes, when detached.

Four new taxa of Chroodiscus (thelotremoid Graphidaceae) from Southeast Asia

Abstract Four new taxa of the lichenized, foliicolous ascomycete genus Chroodiscus are described from Southeast Asia: Chroodiscus defectus Papong & Lücking, Ch. homchantarae Papong & Lücking, Ch. khaolungensis Papong & Lücking and Ch. khaosokensis Papong & Lücking. Chroodiscus argillaceus (Müll. Arg.) Lücking & Papong ( = Chroodiscus parvisporus Kalb & Lücking) is introduced as new combination. The genus as currently circumscribed now includes 14 taxa, which are keyed out here. A short discussion on the putative evolution and taxonomic treatment of species pairs in this genus is included.

A new species and new records of Lecanora ( Lecanoraceae , Ascomycota) from south–east Asia

The new species Lecanora ulrikii from Bhutan and Thailand is described. It belongs to Lecanora s. str. and is characterized by relatively large, orange-brown to brown apothecia that are constricted at the base, a clear to inspersed hymenium, an epihymenium of the glabrata -type, and by the presence of atranorin, usnic acid and the isoarthothelin chemosyndrome. Further, three species, L. arthothelinella, L. austrotropica and L. subimmergens , are reported for the first time from Thailand.