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Methods for characterizing the composition, biomass, and accumulation rates of harvestable epiphytic bryophytes in the understory of temperate forests have recently been developed, but have yet to be implemented in a much wider geographical area and adapted to provide estimates at the individual mat level. In response to regulatory need, we modified and implemented these methods in 27 50 yr-old upland and riparian forest stands below 915 m to: a) characterize the composition of harvestable epiphytic bryophytes in central western Oregon, b) evaluate the compositional changes immediately following harvest, and c) retrospectively estimate minimum simple accumulation rates for harvestable bryophyte mats. Twenty-two bryophyte species, two lichens, and one vascular plant were found in a total of 433 sampled mats, dominated by Isothecium myosuroides, Neckera douglasii, Antitrichia curtipendula, Frullania tamarisci subsp. nisquallensis, and Porella navicularis. Harvest brought on significant shifts in the relative abundance of species primarily through the disproportionate removal of these species, which are commonly found in harvestable bryophyte mats throughout western Oregon. The minimum simple accumulation rate for bryophyte mats from 13 of these stands, calculated as the oven-dried mat mass per unit surface area divided by the stem age, was 22.4 (std 15.5) g/m2/yr and is approximately comparable to that previously observed in the Coast and Cascade Ranges of northwestern Oregon. This accumulation rate translates into a commercial harvest rotation period of at least 21 (std. 12) yr. This long rotation time, coupled with the scarcity of sites supporting harvestable mats, leads to our recommendation that commercial bryophyte harvest be prohibited in the study region.
Chaenotheca Th. Fr. is associated with four different genera of photobionts, Dictyochloropsis, Stichococcus, Trebouxia, and Trentepohlia. The species of Chaenotheca consistently harbor only one photobiont genus. A molecular phylogeny based on their ITS1-5.8-ITS2 sequences of 16 species is presented. It contains five well supported clades. In two clades the species were only associated with Stichococcus, and one only with Trebouxia. In the other two clades two or three photobiont genera were present. Thus there is a partial congruence between photobiont association and cladogenesis in the genus. Section Cystophora, characterized by its association with Trebouxia, and sect. Allodium, with Stichococcus, are polyphyletic in the molecular phylogeny. The subgenera Chaenotheca and Cystophora are characterized by ascus shape and secondary chemistry. Two distinctive clades in the molecular phylogeny contain species referred to subg. Chaenotheca and two other distinctive clades contain species referred to subg. Cystophora. However, one of the two clades containing species of subg. Chaenotheca has a clade of species belonging to subg. Cystophora as sister group, and the other one has all the other species as sister group. These relationships, although only have weak support.
According to cpDNA trnLUAA intron and partial nrDNA ITS2 sequences, the Slovakian endemic Ochyraea tatrensis Váňa (formerly Hypnobartlettiaceae) is closely related to Hygrohypnum smithii (Amblystegiaceae), which grows nearby at the type locality of Ochyraea. The sequences of both species are identical (trnLUAA intron) or differ only in two substitutions (ITS2). It is concluded that the monospecific Ochyraea, like Hypnobartlettia fontana itself, does not deserve being segregated into a separate family, but belongs to the Amblystegiaceae. The genus Ochyraea should be maintained, first with regard to the gametophytic differences between O. tatrensis and Hygrohypnum, and second because Hygrohypnum, and in particular H. smithii, might be not monophyletic according to the molecular data.
Lecanora pseudargentata, L. rhodi, and L. stenotropa are reported new for North America, and three other poorly known North American lichens, Aspicilia moenium, L. minutella, and L. ochraceorubescens, are also discussed. Lecanora rhodi and L. ochraceorubescens cannot be confused with any other lichens in North America, so the limited number of collections of these species probably indicate that they are uncommon or rare. The spotty specimen distributions of A. moenium, L. minutella, L. pseudargentata, and L. stenotropa, however, are probably the result of misidentification or oversight. An informed search of both herbaria and the field is recommended to improve our understanding of their geographic ranges.
We examined biotic soil crust cover and composition at nine shrub-steppe sites in central and eastern Oregon, U.S.A. One pair of livestock-grazed and excluded transects was established at each site. Data were collected on the cover of biotic soil crust and vascular plant species, soil surface pH and electrical conductivity, and other environmental variables.
Using gradient analysis, we found that differences in community composition among sites were most strongly related to soil pH, electrical conductivity (EC), and Calcareous Index Value (CIV; a scale representing the relative calcium carbonate content of soils). Other important variables included precipitation, elevation, aspect, and temperature. We found total crust cover to be highest at sites with lower pH, EC, and CIV. Dominant species differed markedly between the more calcareous sites with higher pH, and the less calcareous, lower pH sites. Livestock exclusion was not an important gradient in the ordination of these data, being overshadowed by the strong soil chemistry and climate gradients. However, overall community composition of soil crust species was different between grazed and long-ungrazed sites (p = 0.02, Blocked Multi-Response Permutation Procedure). Comparison of grazed and long-ungrazed sites revealed lower cover of biotic crusts, nitrogen-fixing lichens, crust-dominated soil surface roughness, and lower species richness in the grazed transects. There was more bare ground in the grazed transects, on average (p ≤ 0.02 for all, two-tailed paired t-tests). Our results suggested that total bunchgrass cover was higher within exclosures, but conclusive evidence was lacking (p = 0.1, two-tailed paired t-test). Vascular plant composition, cover, richness, shrub cover, electrical conductivity, and pH were not different between the grazed and livestock-excluded transects. Thus, livestock-related reductions in cover and richness of biotic soil crusts were apparent while significant impacts to vascular plants were not obvious. We conclude that 1) biotic soil crusts are sensitive indicators of disturbance and 2) there are strong compositional differences in shrub steppe crust communities of Oregon, which are correlated with regional soil and climate gradients.
Cladonia lacryma sp. nov., a previously overlooked species from north coastal California and adjacent Oregon, is characterized by the teardrop-like shape of its podetium. The unusual shape develops when the indistinct, immature cup is deformed by the vertical growth of a single proliferation along its margin. Cladonia lacryma is similar to other species in section Cladonia, which are characterized by closed cups and the presence of fumarprotocetraric acid. The pattern of growth dynamics of C. lacryma suggests its affinity with C. prolifica, which grows on similar soil types in California.
This study is the first attempt to review the Usnea fragilescens complex in Mexico. Morphological, anatomical, and chemical characters, as well as distribution are described for nine species. The updated distribution of U. dasaea Stirt. in Mexico is provided. A discriminant analysis of the CMA of the most common species is used to show the reliability of the correlation of anatomical, morphological, and chemical characters in their separation. Usnea brasiliensis (Zahlbr.) Motyka, U. esperantiana Clerc, U. fragilescens Lynge var mollis (Vain.) Clerc, U. jamaicensis Ach., and U. ramillosa Motyka s.str. are new records for Mexico. Usnea brasiliensis is a new record for North America. A key for the U. fragilescens group in Mexico is provided.
Two new species are described: Erioderma glabrum (from the Antillean region and Ecuador) and Parmeliella conopleoides(from Brazil, Venezuela, and Costa Rica). Both species are unusual in their respective genera. Erioderma glabrum is the only glabrous species in the genus Erioderma, with no obvious close relations, while P. conopleoides is a species of the Parmeliella pannosa group and the first species in this genus known to have gymnidia.
A new moss species, Orthotrichum underwoodii F. Lara, Garilleti & Mazimpaka, is described from material kept in the New York Botanical Garden Herbarium. The new taxon is included in subgenus Pulchella (Schimp.) Vitt, and characterized by leaf cells pluripapillose; capsule immersed, cylindric, abruptly contracted to the seta whose apical part is hidden in a hollow; operculum conic-convex; stomata cryptopore and located in the lower capsule half; capsule with 8 short exothecial bands, comprising 2(3) cell rows; exostome with 16 whitish teeth recurving irregularly; and endostome with 16 segments uniseriate. Orthotrichum underwoodii is taxonomically close to O. handiense F. Lara, Garilleti & Mazimpaka recently described from the Canary Islands (Spain). Differences of the two mosses and possible confusion of the new species with others are discussed.
The Pacific Northwest tall shrub Acer circinatum (vine maple) can host diverse and abundant epiphyte communities. A chronosequence approach revealed that these communities gradually shift in composition as the shrub progresses through its life cycle. Different epiphytic life forms occupy different spatial and temporal niches on shrub stems. These life forms generally shift upwards along the shrub stem as the stem ages and develops, in accordance with the similar gradient hypothesis. We postulate the following sequence of events. An initial wave of colonization occurs as new substrate is laid down. Over time, superior competitors gradually engulf and overgrow competitively inferior primary colonizers. Concurrently, shrub stem microclimate changes as shrub stems grow, age, and layer, causing the processes of competition and colonization to shift in favor of different epiphytic life forms during different life stages of the shrub stem. We define four separate shrub stem life stages: life classes 1–4 describe, respectively, young upright ‘whips’; vigorous, upright, mature stems; declining stems beginning to bend towards the forest floor; and horizontal, decadent stems. As space on the shrub stem is filled through growth and colonization, interspecific competition intensifies. Successful competitors persist and spread, while poor competitors are increasingly restricted to the stem tips, where interspecific competition is less intense. In these forests, Usnea, green-algal foliose lichens, and moss tufts excel as the primary colonizers and become common on the outer portions of shrub stems over time, as long as the overstory is not too dense. Moss mats are also good primary colonizers, but excel as secondary colonizers, often coming to dominate decadent shrub stems. Although all life forms can be primary colonizers, the remaining forms (cyanolichens, liverworts, and Antitrichia curtipendula) are effective secondary colonizers. Liverworts are also effective competitors, but less so than the moss mats on the most decadent stems. Cyanolichens appear to benefit from the aging and decline of shrub stems. The ability of vine maple to continually generate new young stems through basal sprouting and layering make it a varied and dynamic substrate for epiphytes. Such shrubs may act as epiphyte dispersal agents, with the potential to affect epiphyte continuity within forest stands that have experienced large disturbances.
Observations of the gemmae of 135 specific and subspecific taxa of Calymperes, Mitthyridium, and Syrrhopodon reveal that the gemmae of most taxa have a generalized morphology. However, the morphologies of some of the gemmae differ among species and species-groups, revealing evolutionary divergence at the levels of genus and subgenus, in which gemmae vary in shape, color, surface texture, appendages, and in average size (from about 75 μm long in S. orientalis to more than 1,600 μm long in S. helicophyllus). Divergence from the generalized gemma morphology reflects the ecological life styles of the taxa, as for example in Syrrhopodon subg. Pseudocalymperes, in which filiform or moniliform gemmae borne in splashcups correlate with the commonly ramicolous habitat.
Two Sphagnum species are reported for Hawaii: S. palustre L. (section Sphagnum) and S. wheeleri C. Müll. (section Rigida). Sphagnum henryense Warnst. (section Sphagnum) is excluded. Additional evidence supporting the exclusion of Sphagnum vitjianum Schimper and S. perichaetiale Hampe (both in section Sphagnum) is also presented. The type of S. lonchocladum C. Müll. is shown to be a Hillebrand collection (in section Sphagnum) from Hawaii and not a Kirk collection (in section Rigida) from New Zealand. The description of S. palustre is revised, in large part to reflect the incorporation of S. japonicum Warnst., S. pseudocymbifolium C. Müll, and S. sulphureum Warnst.
Vezdaea acicularis Coppins is reported growing on soil under hydroelectric transmission lines in Quebec, Canada. It is new to the North American lichen flora. Vezdaea leprosa (P. James) Vězda was found twice in the Ottawa region and is a new lichen for Canada. Steinia geophana (Nyl.) Stein was growing with the V. leprosa and is new for Ontario and Quebec.
World-wide, 15 taxa (11% of the 137 studied) of the three traditional genera of Calymperaceae (s.s.) regularly produce gemmae sequentially on multicellular stalk-like foliar structures referred to here as gemmipars. Individual gemmiferous leaves give rise to few to many gemmipars, each of which is capable of producing gemmae continuously during the functional life of the leaf. In the remainder of the gemmiferous species of Calymperaceae, the gemmae are produced and matured simultaneously on each gemmiferous leaf, and after abscission of their gemmae the gemmiferous leaves play no further role in asexual reproduction. Syrrhopodon, seemingly the least specialized genus of the family, has only about half the frequency of occurrence of gemmipars (7% of the 82 taxa studied) as that of Calymperes (17% of 35 taxa) and Mitthyridium (15% of 20 taxa). Gemmipars are species-specific in the Calymperaceae and thus potentially useful in systematics. The taxon-limited occurrence of gemmipars in the Calymperaceae and their role in enhancing asexual reproduction suggest that this method of asexual reproduction has ecological and evolutionary implications.
A new moss species, Ptychomitrium yulongshanum Cao & Guo, is described from fruiting material collected from Yunnan province, in southwestern China. The ovate, cucullate leaves with obtuse apices; small, smooth, upper and median leaf cells; oblong-ovate capsules; and mitrate calyptra covering only half the capsule are distinguishing traits of the new species.
Lethocolea naruto-toganensis is described as a new species from central Honshu of Japan. It is closely allied to L. congesta (Lehmann) S. W. Arnell from South Africa, L. javanica (Schiffn.) Grolle from Indonesia, and L. pansa (Taylor) G. A. M. Scott & K. Beckm. from Australia in having multicellular discoid gemmae. However, L. naruto-toganensis is distinguished from these species by purple-red rhizoids, ovate leaves, smooth cell surfaces, small trigones, and short marsupia.