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Using rope techniques for access, we surveyed epiphytes on five Sitka spruce trees up to 92 m tall in an old-growth redwood forest. We quantified epiphyte diversity by sampling 5% of each tree's surface area of axes (branches >5 cm diameter) and branchlets (branches <5 cm diameter, including foliage). Epiphyte communities included 57 macrolichen, 15 crustose lichen, 17 bryophyte, and two fern species. The five most abundant species—Isothecium myosuroides, Polypodium scouleri, Polypodium glycyrrhiza, Lobaria pulmonaria, and Frullania nisquallensis—contributed 42.1, 13.3, 8.4, 6.7, and 4.7% of the total epiphyte biomass, respectively. There was an average of 36.2 kg of bryophytes, 9.9 kg of lichens, 12.7 kg of ferns, and 131 kg of associated dead organic matter per tree. Axes supported 83% of the biomass and 98% of the dead organic matter. At the whole-tree level, bryophyte biomass was 11.3 times higher and lichen biomass was 2.5 times lower on axes than branchlets. Ferns were restricted to axes. Ordination analysis revealed one dominant gradient in epiphyte composition that was positively correlated with height and lichen diversity, and negatively correlated with bryophyte diversity. Chlorolichens dominated the exposed portion of the gradient with equivalent amounts of cyanolichens and bryophytes. Mosses dominated the intermediate portion of the gradient with equivalent amounts of liverworts, cyanolichens, and chlorolichens. There was very little lichen cover in the sheltered portion of the gradient, which was dominated by bryophytes. Extensive bryophyte mats with large quantities of dead organic matter promote biological diversity on Sitka spruce in redwood forest canopies by storing water and serving as habitats for desiccation-sensitive organisms.
Bryophytes may be more appropriate than vascular plants for testing hypotheses relating to plant reproductive biology due to their relatively simple structure. Nevertheless, they have rarely been used for this purpose, and remain poorly known with respect to reproductive biology. It is, for instance, still not known if bryophytes generally exhibit reproductive costs. We addressed the cost of producing reproductive structures in a bryophyte species, the clonal moss Hylocomium splendens, by following a SE Norwegian boreal spruce forest population in which sporophytic female mature segments grew intermingled with segments devoid of sporophytes for five years. By comparing segment sub-populations with and without sporophytes, respectively, we demonstrated that production of sporophytes had significant costs in terms of less favorable size development of daughter segments, lower branching frequency, and higher risk of not producing new annual segments. From the observed patterns of size development and branching, we identify the late phase of sporophyte development (when the capsule expands and ripens, and spores are produced) as the most expensive developmental stage in terms of demands for resources from the source gametophyte segment. Although costs of sexual reproduction have been demonstrated with certainty only for a few bryophytes, it may well turn out to be easier to demonstrate for bryophyte species than for vascular plant species.
There are no standard measures of fungal fitness, and yet descriptions of natural selection in fungi require an understanding of how to compare the success of two individuals. Success, or fitness, is normally understood to be a combination of survival and reproduction. Xanthoparmelia cumberlandia is a sexual, lichenized fungus. By recording the size of, and number of sexual structures on, individual lichens we demonstrate a significant correlation between size and reproductive effort in this species, showing that size is an easily measured surrogate of fitness. Published data of other lichen species, for example Umbilicaria spodochroa or Xanthoria parietina, also show a correlation between size and sexual fecundity, indicating that the correlation may be a general feature of sexual lichens. However, patterns of resource allocation differ between lichen species. Published data collected from U. spodochroa are linear, demonstrating that larger lichens allocate equivalent resources to growth and reproduction. In contrast, the data of X. cumberlandia are curved, indicating that in this species larger lichens allocate a disproportionate share of resources to reproduction.
Five new species are described from the group of Hypogymnia with rimmed holes on the lower surface: H. bulbosa, H. congesta, H. diffractaica, H. laxa, and H. pseudocyphellata. All species in this group are restricted to the Himalayan region, primarily in southwestern China. Four other species in this group have previously been described: H. hengduanensis, H. kangdingensis, H. macrospora, and H. subvittata. Hypogymnia kangdingensis is synonymized with H. hengduanensis and Hypogymnia subvittata is synonymized with H. macrospora. Virensic acid (in H. congesta) and norbarbatic (4′-O-demethylbarbatic acid) are major lichen substances previously unreported from Hypogymnia.
Peatlands cover about 30% of northeastern Alberta and are ecosystems that are sensitive to nitrogen deposition. In polluted areas of the UK, high atmospheric N deposition (as a component of acid deposition) has been considered among the causes of Sphagnum decline in bogs (ombrogenous peatlands). In relatively unpolluted areas of western Canada and northern Sweden, short-term experimental studies have shown that Sphagnum responds quickly to nutrient loading, with uptake and retention of nitrogen and increased production. Here we examine the response of Sphagnum fuscum to enhanced nitrogen deposition generated during 34 years of oil sands mining through the determination of net primary production (NPP) and nitrogen concentrations in the upper peat column. We chose six continental bogs receiving differing atmospheric nitrogen loads (modeled using a CALPUFF 2D dispersion model). Sphagnum fuscum net primary production (NPP) at the high deposition site (Steepbank—mean of 600 g/m2; median of 486 g/m2) was over three times as high than at five other sites with lower N deposition. Additionally, production of S. fuscum may be influenced to some extent by distance of the moss surface from the water table. Across all sites, peat nitrogen concentrations are highest at the surface, decreasing in the top 3 cm with no significant change with increasing depth. We conclude that elevated N deposition at the Steepbank site has enhanced Sphagnum production. Increased N concentrations are evident only in the top 1-cm of the peat profile. Thus, 34 years after mine startup, increased N-deposition has increased net primary production of Sphagnum fuscum without causing elevated levels of nitrogen in the organic matter profile. A response to N-stress for Sphagnum fuscum is proposed at 14–34 kg ha−1 yr−1. A review of N-deposition values reveals a critical N-deposition value of between 14.8 and 15.7 kg ha−1 yr−1 for NPP of Sphagnum species.
While people experienced with lichen field work may easily locate hotspots of lichen diversity, other botanists, ecologists, and land managers may not. We sought to describe lichen hotspots in Pacific Northwest forests in terms of forest structure and environment. Additionally, we describe the varying lichen communities of different hotspot types and how the hotspot communities differ from more typical young and old-growth forest stands. A retrospective, blocked design was used with 17 blocks in the Coast Range and the western Cascades of Oregon. Each block consisted of two young matrix stands, one old-growth stand (age > 200 years), and one diversity hotspot. Most diversity hotspots were in riparian zones, but some upland hardwood gaps and rock outcrops were included. We found 117 lichen species in the 68 plots. There was no difference in the average species richness between matrix and old-growth plots, but hotspots averaged five more species than those plots (blocked ANOVA p = 0.001). Eleven species were associated with old-growth plots, 26 were associated with hotspots, and 28 specifically with hotspots in riparian zones. Most old-growth associates were forage-providing alectorioid lichens while most hotspot and riparian zone associates were nitrogen-fixing cyanolichens. Among the hotspots, stands in riparian zones with a large proportion of hardwood trees were found to be optimal for the conservation of many native lichen species that occur infrequently in typical upland (non-riparian) forests.
Montane coniferous forests in Europe affected by pollutant-caused forest dieback often have a well-developed epiphytic lichen vegetation, including pollution-sensitive species. This phenomenon, apparently contradicting the assumption that acid air pollution is the cause for forest dieback, has been discussed controversially since the 1980s. Studies in Picea abies forests of the Harz Mountains, northern Germany suggest that the high lichen diversity on dieback-affected trees is due to reduced pollutant levels in bark and stemflow. Pollutant-caused needle loss reduces the interception of pollutants from the atmosphere and thus, reduces their concentrations in stemflow. Lower concentrations in stemflow result in lower concentrations in the bark because of reduced absorption. In the Harz Mountains, lower S concentrations in the stemflow of dieback-affected trees are thought to be the main cause for an even higher epiphytic lichen diversity on affected versus healthy trees. In one out of three spruce stands, high Cu concentrations in bark apparently have an additional limiting effect on lichen diversity. In all spruce stands studied in the Harz Mountains, high Mn concentrations in bark and partly also in stemflow limit lichen abundance. In contrast to S and Cu, Mn in bark and stemflow is primarily soil-borne. Lower Mn concentrations found in bark and stemflow of damaged and dead trees are attributed to reduced or lacking element uptake by the tree roots. Experiments to Mn uptake and toxicity in epiphytic lichens support the hypothesis that high Mn levels limit the abundance of epiphytic lichens. Decreasing lichen abundance with increasing Mn concentrations in bark or stemflow found in polluted and remote areas of western and eastern North America suggests that Mn may be an important site factor for epiphytic lichens in coniferous forests in general. Microclimate (including light and water conditions) is apparently of subordinate importance for the high epiphytic lichen diversity in dieback-affected spruce forests of the Harz Mountains. On dieback-affected Picea rubens on Whiteface Mountain, Adirondacks, New York, epiphytic lichen diversity was also found to be higher than on healthy trees. This cannot be attributed to S concentrations in stemflow, as the atmospheric deposition is much lower than in Germany. While Mn concentrations are apparently relevant for a limited number of lichen species on Whiteface Mountain, it is unclear whether lichen diversity might be limited by toxic effects of NO3− from stemflow. On dieback-affected Acer saccharum in Québec more acidophytic and less subneutrophytic lichen species were observed. This suggests that chemical site factors also control epiphytic lichen abundance in this case, however, the mechanisms leading to this effect are not known.
Pretreatment with sucrose or abscisic acid is thought to afford protection for plant tissues during dehydration and freezing by increasing desiccation tolerance. It is possible that the natural desiccation tolerance exhibited by some mosses will provide adequate protection during cryopreservation. The aim of this study was to determine whether three mosses with differing levels of desiccation tolerance would survive and regenerate after cryopreservation without prior encapsulation and pretreatment. The species chosen were Bryum rubens Mitt. (desiccation tolerant), Cyclodictyon laetevirens (Hook. & Tayl.) Mitt. (desiccation intolerant), and Ditrichum cornubicum Paton (limited desiccation tolerance). Encapsulated and non-encapsulated protonemal samples were air dried for 18 days. After desiccation, 100% of B. rubens and 40% of D. cornubicum survived in both non-encapsulated and encapsulated samples. After freezing, 90–100% of B. rubens, and 30–20% of D. cornubicum survived in non-encapsulated and encapsulated samples, respectively, while C. laetevirens did not survive either dehydration or freezing. Cryopreservation reduced the growth rate of D. cornubicum and B. rubens. The reduction in growth rate of B. rubens was temporary, with that of encapsulated protonemata eventually exceeding controls. It was concluded from this study that the natural desiccation tolerance of some mosses would be adequate to allow them to survive cryopreservation without prior pretreatment.
Parsimony analyses of 21 to 29 representatives of the family Bartramiaceae and of six outgroup taxa of Aulacomniaceae, Bryaceae, Plagiomniaceae, Meesiaceae, Rhizogoniaceae, and Timmiaceae were performed. Combined and separate analyses based on morphological data and three chloroplast loci (the genes rbcL and the rps4, and the trnL-trnF gene region) were carried out. Based on the combined analysis, the Bartramiaceae appear to be a monophyletic group including Anacolia, Bartramia, Breutelia, Conostomum, Fleischerobryum, Flowersia, Leiomela, Neosharpiella, Philonotis, and Plagiopus. The same result was also obtained from the analyses of rbcL and morphological data. Catoscopium is excluded from the family.
Genetic and tribal relationships within the hepatic family Lejeuneaceae are problematic. We studied the phylogeny of the family using sequence data from three genomic regions: 1) the internal transcribed spacer 2 sequence between the nuclear genes encoding 26S and 5.8S ribosomal RNA, 2) partial sequences of the chloroplast genes trnL and trnF including the spacer between them, and 3) the partial sequence of the chloroplast gene, rbcL. Seventeen species representing the subfamilies Ptychanthoideae and Lejeuneoideae as well as the tribes Nipponolejeuneae, Lejeuneae, and Cololejeuneae were included. The family as a whole seems to be monophyletic, with the exception of the genus Nipponolejeunea that is closer to the genus Jubula. Our results also support the existence of two main subfamilies, Lejeuneoideae and Ptychanthoideae. The representatives of the genus Cololejeunea are basal in the Lejeuneoideae clade in our tree, supporting tribal, rather than subfamilial position for the Cololejeuneae. The relationships of the Lejeuneaceae, Jubuloideae, and Frullania remain unresolved in our analyses.
Tayloria maidenii Broth. is known only from the type locality in eastern Australia. Examination of the type material reveals that this taxon belongs neither in the genus Tayloria nor in the Splachnaceae. Type material of Tayloria maidenii is referable to Entosthodon laxus (Hook. f. & Wilson) Mitt. (Funariaceae). A lectotype for Tayloria maidenii Broth. is designated.
The only member of the lichen genus Dermiscellum, D. catawbensis, has been found to be synonymous with a name published over a decade earlier by Edward Tuckerman. Thus, in order to correct this case of forgotten priority, Opegrapha oulocheila Tuckerman is placed in the genus Dermiscellum to replace the name D. catawbense. The typification of both names is discussed and the holotype of O. oulocheila is figured for the first time.
The lichen Punctelia semansiana, common and widely distributed in North America and differing from P. hypoleucites by conidial size and substrate ecology, is identical to P. graminicola (B. de Lesd.) Egan, comb. nov. Authentic material of the older epithet, thought to have been destroyed but recently discovered at New Mexico's College of Santa Fe, permits the nomenclatural correction.
North American material of the sorediate Punctelia species has been examined. The presence of four species, Punctelia borreri, P. missouriensis, P. perreticulata, and P. stictica can be confirmed. Specimens named Punctelia subrudecta generally belong to P. perreticulata. Neither of the species most common in Europe, P. subrudecta and P. ulophylla, could be confirmed as occurring in North America.