Distribution Of Mosses Research Articles

Would You Trust a Bryophyte for Directions? A Field Exercise for Determining the Distribution of Moss on Trees

Every introductory biology course preaches the importance of scientific method, but often students do not have the opportunity to develop and test scientific questions in those very courses. For example, published lab manuals for the traditional survey of the kingdoms course rarely recommend little more than that students observe live and preserved materials and prepared slides in the lab. I designed the following field exercise both to illustrate the ecological requirements of a group of organisms (the mosses) and to allow students to test a hypothesis so popular that it has made its way into folklore: Moss only grows on the north side of The bryophytes, plants such as mosses and liverworts that lack vascular tissue and depend upon water for fertilization, are an excellent subject for study in the field because they are abundant and they are present yearround. One might predict that mosses would be more abundant in moist, shady locations than in dry, sunny habitats because they are tied to water for survival and reproduction. The physiological dependence of mosses on water, coupled with the inclination of the sun in the northern hemisphere underlies the biological explanation for the folklore belief that moss grows only on the north side of trees. In the northern hemisphere, solar radiation strikes south-facing objects directly, while the north-facing objects are shaded from the sun throughout the day. This phenomenon results in hotter, drier microclimates on southfacing structures, and wetter, cooler microclimates on north-facing structures. It has consequences for everything from the location of ski slopes (north facing slopes to avoid snow melt) to the best windows for house plants (south facing because the sun shines on them all day). Does aspect (north or south-facing) also dictate the distribution of moss on trees? In other words, would you trust a bryophyte for directions? Once students have been introduced to key characteristics of a particular group of organisms, it becomes possible to develop hypotheses about the ecological consequences of these characteristics. With rare exceptions, the distribution of a species in nature is inextricably tied to its physiological limitations. In order to train good scientists, we must teach our students to ask research questions and give them practice testing those questions and analyzing the results. In this field exercise, students are challenged to test the hypothesis that moss grows preferentially on the north side of trees. The exercise clearly accomplishes two goals:

Moss distribution in streams of the Quebec Laurentian Mountains

To model the distribution of aquatic mosses, we measured their cover in 33 Quebec streams. The variation in moss cover among streams was explained mostly (42%) by substratum size (percentage >25 cm in diameter). Water pH and depth also explained a significant amount of variation (9 and 10%, respectively). Within a stream, moss cover was again positively correlated to the availability of large substrata and negatively to water depth. There was a strong inverse relationship between covers of moss and of the filamentous cyanobacterium Stigonema, suggesting a competitive interaction. This study confirms previous observations that moss distribution is mainly controlled by substratum size. Chemistry explains part of the among-stream variation. Stigonema-moss competition partly accounts for the patchy distribution within a stream.Key words: aquatic mosses, Fontinalis, streams, Quebec.

Distribution and floristics of moss- and lichen-dominated soil crusts in a patterned Callitris glaucophylla woodland in eastern Australia

The distribution and abundance of soil crust lichens and bryophytes was examined in a patterned Callitris glaucophylla woodland in eastern Australia. Twenty-one lichen species and 26 bryophyte species were collected within thirty quadrats along a sequence of runoff, interception and runoff zones. Crust cover was significantly greatest in the interception zones (79.0 %), followed by the runoff zones (24.0 %), and lowest in the groved, runon zones (6.6 %). Lichens and bryophytes were distributed across all geomorphic zones, and, although there were significantly more moss species in the interception zones (mean = 9.1) compared with either the runoff (4.2) or runon (3.2) zones, the number of lichen species did not vary between zones. Ordination of a reduced data set of 32 species revealed a separation of taxa into distinct groups corresponding to the three geomorphic zones. Canonical correspondence analysis (CCA) of the 32 species and thirteen environmental variables revealed that the most important factors associated with the distribution of species were sheet and scarp erosion, soil stability and coherence, litter cover and crust cover. Surface cracking, microtopography and plant cover were of intermediate importance. The CCA biplot revealed that the timbered runon zones (groves) were dominated by `shade-tolerant' mosses Fissidens vittatus and Barbula hornschuchiana, whilst the heavily eroded runoff zones supported sparse populations of `erosion tolerant' lichens (Endocarpon rogersii) and mosses (Bryum argenteum and Didymodon torquatus). Interception zones supported a rich suite of `crust forming' mosses and lichens capable of tolerating moderate inundation by overland flow. Two other groups of taxa were identified by this analysis: the `pioneer' group, comprising mainly nitrogen-fixing lichens which occupy the zone of active erosion at the lower edge of the groves, and the `opportunists' dominated by liverworts, occupying the shallow depressions or bays at the margins of the groves and the interception zones. This study confirms that the non-vascular lichens and bryophytes in these arid soil crusts, are, like the vascular plants, strongly patterned according to geomorphic zone, being most strongly associated with soil surface and erosional features.

Survival and growth of transplantedFontinalis dalecarlica (Bryophyta) in controlled flow and short-term regulated flow sites in the Perhonjoki River, Western Finland

Impoundment, channelisation and short-term regulation of the Perhonjoki river have caused changes in the distribution and abundance of aquatic mosses. While some moss species have colonised the beds in the channelised and short-term regulated part of the river, Fontinalis spp. are mainly restricted to the sites above the power plant where flow variability is low. Therefore, as a first step towards gaining a better understanding of the factors contributing to the distribution and abundance of Fontinalis dalecarlica (Bruch & Schimp, Fontinalaceae) in the Perhonjoki, a transplant experiment was conducted to test whether short-term flow regulation restricts the survival and growth of this species. Artificial substrates with tufts of F. dalecarlica were transplanted in July 1993 to controlled flow and short-term regulated flow riffles, above and below the Kaitfors power plant, respectively. Survival and growth were monitored for 1 year. F. dalecarlica survived the winter and grew well during the summer in the short-term regulated flow site. Mosses did not grow at the controlled flow site. Effects of channelisation are partly seen in the fate of the substrates. At the controlled flow site, ten of the 30 substrates were lost during the winter, and 67% of the substrates in the mid-channel sub-area and 40% of the substrates in the sub-area near the bank had suffered severely during this experiment. At the short-term regulated flow site, the equivalent percentages were 17, 13 and 27%, respectively. Hygrohypnum spp. attached to the substrates during the summer of 1994. The results indicate that short-term regulation does not prevent the survival and growth of F. dalecarlica and thus does not prevent this species from surviving in the areas below the power plant. Present environmental conditions seem to contribute to the poor colonising capability of this species and thus limit colonisation. However, we suggest that the recovery of F. dalecarlica could be enhanced by moss transplant. Copyright © 1999 John Wiley & Sons, Ltd.

Fissidens crispus from Holocene Deposits in Central Mexico

Through a survey at Salazar Lake, Municipio de Ocoyoacac, State of Mexico, a single stem of Fissidens crispus Mont. was recovered from a depth of 45-50 cm. Radiometric dating indicates an age of 2,420 ? 40 years BP for the sample. This is the first record of a fossil or subfossil moss in Mexico. The distribution of mosses along the Neovolcanic Belt of Mexico has been the subject for research for more than two decades. On the basis of floristic studies, it has been proposed that mosses migrated from other latitudes following the high elevations of the Belt and other continental ranges (Delgadillo 1971). At lower elevations, the Belt has also acted as a barrier to moss dispersal while allowing the floristic exchange across the lowland paths that connect the Mexican Plateau with southern areas (Delgadillo 1985, 1987). The time of floristic displacement has been variously interpreted on the basis of geographical location or geological history, but to date there is no paleobotanical evidence of moss migration in any part of Mexico. In 1996, a preliminary consideration of the physical characteristics of several lakes in central Mexico was made. It was hoped that sedimentation at high elevations in a temperate climate would favor the deposition and preservation of mosses and that the finding of fossil or subfossil fragments would lend support to phytogeographical hypotheses concerning the origin of patterns of distribution of Mexican mosses. The present contribution is the result of the survey of Salazar Lake. Salazar Lake is located in Municipio de Ocoyoacac, State of Mexico, between 19?12'17N and 99029'55W at 2,800 m elevation (INEGI 1993); it is characterized by a temperate climate with a mean annual temperature of 11?C, and a summer rainy season with mean annual rainfall of 1,011 mm. Because of its location along the Las Cruces formation (Delgado & Martin del Pozzo 1992), an early Pliocene-Pleistocene age for the lake basement has been suggested (Mora et al. 1987). Delgado (1986) reports an age between 2.87 + 0.15 my BP and 1.79 + 0.1 my BP (late Pliocene to early Pleistocene).

Floristic corridors for moss distribution across the Neovolcanic Belt of Mexico. III. The Michoacan corridors

The distribution of mosses from four topographic discontinuities or corridors (Tuxpan, Morelia, Patzcuaro and Chapala) suggests that the floristic interchange between northern and southern areas across the Neovolcanic Belt in western Mexico is feasible. Mosses of various phytogeographical affinities are present on either side and in the corridors, but certain other taxa are only represented on one side of the Belt. The tropical species are virtually absent from northern (Plateau) areas indicating a joint barrier effect of the Belt and the Balsas Depression. The sources of the corridor moss flora are heterogeneous; in addition to diverse phytogeographical affinities, the altitudinal distribution shows a close relationship with the upper elevations, including the alpine areas. Bryum capillare var. flaccidum, Entodon sullivantii and Fabronidium guatemalensis are new records for Mexico.

Riparian Bryophytes of the H. J. Andrews Experimental Forest in the Western Cascades, Oregon

The knowledge of the distribution and habitat demands for bryophytes in the Pacific Northwest is scarce, and few published quantitative accounts of the flora are present. The present paper includes habitat description, elevational range, substrate preference, and frequency estimates for more than 130 riparian mosses and liverworts found in old-growth Pseudotsuga-Tsuga forests of the H. J. Andrews Experimental Forest, Oregon. The data are based on 360 samples distributed among 42 sites covering 1st to 5th order streams and 420 to 1250 m. TWINSPAN analysis resulted in 6 sample groups, representing samples from different elevations, geomorphic surfaces, and stream sizes. The most common mosses are Eurhynchium oreganum, Isothecium stoloniferum, Hypnum circinale, and Dicranum fuscescens. Among the hepatics Scapania bolanderi, Cephalozia lunulifolia, and Porella navicularis are the most abundant species. Most species are rare at both site and sample plot level, and this is especially true for acrocarps where more than one-third of the observed species occurred in only one or two sites or/and samples. Four of the occurring species (i.e., Antitrichia curtipendula, Buxbaumia piperi, Douinia ovata, and Ptilidium californicum) are listed for special management and/or regional surveys. Bryophytes constitute an important and conspicuous component of old-growth forests in the Pacific Northwest (Lesica et al. 1991; McCune 1993; Schofield 1988); however, few studies on the abundance and distribution of mosses and liverworts have been conducted. The epiphytic flora, composed of bryophytes and lichens, of old-growth Douglas-fir has been shown to be species rich and influences nutrient dynamics and overall production in old-growth stands (Pike et al. 1975, 1977). Besides these studies, however, there has been until now no published account of factors influencing the distribution of individual species within old-growth forests (see however Peck et al. 1995; Schofield 1976). Dispite this lack of study, many bryophytes are considered to be dependent of old-growth conditions (FEMAT 1993; Soderstrom 1988). Thus, effective management of the bryophyte flora, which is an important forest product of the region (Peck 1990; Schlosser et al. 1992) and a significant part of forest biodiversity, is constrained by lack of knowledge. Riparian zones are thought of as key elements in the forested landscape, and preservation of these is a major goal of forest management (FEMAT 1993). Of the mosses and liverworts considered as vulnerable in the Pacific Northwest (USDA 1994), many occur in riparian areas. This association is dependent on many factors, but the occurrence of a wide range of different substrates, disturbance patterns, and a moist microclimate are important contributors to the diversity in these zones (Glime & Vitt 1987; Vitt et al. 1986). The present paper reports habitats and frequencies of species found in riparian areas of old-growth Pseudotsuga-Tsuga forests in the western Cascades of Oregon. A general treatment of the bryophyte community patterns will be published elsewhere.

Temperature effects on copper uptake and CO2 assimilation by the aquatic moss Rhynchostegium riparioides

Since water temperature is a major factor influencing the development and the geographic distribution of aquatic mosses, experiments were performed to study the influence of temperature on both the physiology and the metal uptake-release ability of the species Rhynchostegium riparioides. Experiments were carried out in the laboratory in a flow-through system contaminated for 12 days by a copper solution with a mean concentration of 80 μg/L and then followed by a post-exposure period of 10 days. Denaturation of chlorophyll pigments was observed at 29°C for both the control and the contaminated organisms. The increase of water temperature from 7 to 29°C led to a decrease in moss vitality measured by CO2 assimilation but did not affect Cu uptake-release kinetics. Therefore the accumulation of Cu is not directly related to photosynthesis. Since Cu uptake by the mosses over the 22 days of exposure was not significantly influenced by water temperature, the results support the use of Rhynchostegium riparioides as an indicator of copper pollution in cases of thermal pollution or during different seasons.

<strong>The Antillean Arc and the distribution of neotropical mosses</strong>

The West Indies have strong continental affinities, but the strongest are with South America, not Central America as was once thought. Moss diversity is the result of migration after the Miocene; the patterns of distribution involving the West Indies and South or North America indicate both migration as well as floristic flows through the Antillean Arc. Speciation due to selective pressures in the changing climate of the Pleistocene gave rise to endemic taxa, but paleoendemics may have resulted in a previous archipelago condition.

<strong>El banco de datos de los musgos neotropicales</strong>

LATMOSS is a data bank for mosses known from the neotropical area. The geographical data contained therein are being used to study phytogeographical patterns and propose explanations to the distribution of neotropical mosses. It currently contains 4129 entries.

Microclimatic Influences on Lichen Distribution and Community Development

AbstractThe distribution of cryptogams and phanerogams and the microclimate of different habitats have been studied. It is shown that a forest community of phanerogams includes an assemblage of different microhabitats inhabited by different lichens and mosses. The distribution of lichens and mosses is governed by factors that are often of little importance to higher plants.

Effects of Disturbance on Stream Moss and Invertebrate Community Structure

Natural occurrence of overturned stones and the distribution of moss with respect to stone size and stability were examined in two North Swedish woodland streams. In total, 16.7% of moss-covered stones had obviously been overturned in the last few years. Moss was rare on small stones except for those that were embedded in the surrounding substrate. On large stones (>12 cm), moss was abundant and embedment did not affect the moss distribution here. It is concluded that the stability of substrates markedly affected the distribution of stream moss. In a field experiment, moss-covered stones were overturned to simulate mild spate effects, and the recovery of moss and invertebrates was followed for 14 mo. The treatment reduced ash free dry weight of moss as well as diversity (H′) and total abundance of invertebrates. Three out of 16 invertebrate taxa increased their density as a result of disturbance, showing peak densities on the moss-covered underside of overturned stones. All other taxa decreased their density upon overturning, and in these taxa peak densities were found on the moss-covered upper side of control stones. Recovery of moss and invertebrates was still weak 14 mo after the stone overturning. I conclude that overturning of stones has severe and prolonged effects on stream moss and, indirectly, on the benthic invertebrate community.

The Floristic Composition and Elevational Distribution of Colombian Mosses

The moss flora of Colombia is examined in terms of the floristic composition of the nearly 900 species. Overall taxonomic diversity is compared between the eastern North American and Colombian moss floras. It is suggested that temperate and tropical moss diversity may not exhibit a strong latitudinal gradient in species richness from high to low latitudes. Species richness increases with elevation in Colombia, at least to near treeline, in the high montane vegetational zone; at 2,600-3,300 m ca. 50% of the total species diversity occurs. The Andean region, covering ca. 20-25% of the Colombian land surface, contains ca. 93% of the total species diversity for the mosses. An appendix provides several new synonyms and additions to the Colombian moss flora. A dramatic increase in research on neotropical bryophytes has occurred in the last two decades. Floristic work based on recent collections, though somewhat limited, has taken place or is continuing in most countries. Checklists for the mosses are available for nearly all neotropical countries. Fur- thermore, these floristic efforts have also led to a number of phytogeographical studies. Although many groups still remain poorly resolved, revision- ary studies have increased significantly, so that now several families and a number of genera have been treated. However, with the exceptions of the pro- ductive ECOANDES project in Colombia (Van der Hammen & Ruiz 1984; see also Gradstein 1982, 1983, 1990) and BRYOTROP project in Peru (Frey 1987), little has been provided recently concerning various aspects of diversity. Probably the fullest ac- count we have for any single country in the Neo- tropics, at least among the Andean countries, is in the publications on Bolivia by Herzog (1910a,b, 1916, 1920, 1923). The present study attempts to characterize, or at least summarize, our understanding offloristic com- position and general trends in elevational distri- bution patterns of the Colombian moss flora. Some generalizations are also presented about levels of diversity. Establishing general trends and patterns of diversity levels can provide a necessary frame- work in attempting to analyze tropical moss floras. Our attempts to understand diversity may be pre- mature, particularly given the number of poorly re- solved taxonomic groups; however, the current rate of deforestation in the tropics faces bryologists with the necessity of addressing all questions about the comparative biology of mosses now, as is true for all groups of organisms occurring in the tropics. There is a paradox in that by the time we have available regional or worldwide revisionary studies for mosses, providing us with a more precise esti- mate of numbers of species for some parts of the world, we may be addressing questions about ecol- ogy and other aspects of biology of these organisms in the past tense. Colombia is experiencing a continued loss of nat- ural vegetation. According to Gentry (1989), the estimate of 38% extant natural forests in Colombia, largely contributed from the region of Amazonia, may be overstated. Although volumes of literature discuss the diversity and deforestation of wet low- land forests in the Neotropics, not a single book and only a few papers address this subject for montane forests. In terms of vascular plant diversity, the montane and premontane vegetational zones are equal to if not richer than the tropical wet lowlands (cf. Balslev 1988; Gentry 1982). The Andean region has felt the impact of human activities that com- menced at least 3,800-2,900 years BP, and that ac- celerated with the conquest and colonization by Europeans in the mid 1500's (Clawson & Crist 1982; Little 1981). In this century, expansion of agricul- ture, particularly coffee production, coupled with rapid population growth centered in the Andes, have accelerated rates of deforestation of the montane vegetation. Given the very high biodiversity of the Andean region, greater emphasis must be accorded to studies of its biotic inventory and ecology, and greater commitment to conservation of the remain- ing montane forests.

Terrestrial and aquatic bryophytes as monitors of environmental contaminants in urban and industrial habitats

The widespread distribution of bryophytes and the tolerance of many species to certain contaminants has led to their use for monitoring purposes. Early this century, changes in the distribution of mosses in urban habitats indicated deteriorating air quality; alterations in species composition in rivers has reflected changing water quality. The main focus in the past 10 to 20 years has been on measuring levels of contaminants in both terrestrial and aquatic bryophytes. Concentrations of metals, organic chemicals, radionuclides and derivatives of acidic gases have been widely reported in species from contaminated and background areas. More rarely, physiological and biochemical parameters are monitored. This paper describes the approaches which have been used and results obtained from monitoring bryophytes in urban and industrial habitats. Data are reviewed from a range of countries illustrating the increasing interest in low cost methods for monitoring contamination.

Moss Distribution and the Phytogeographical Significance of the Neovolcanic Belt of Mexico

Moss distribution suggests that there has been extensive floristic exchange among the major alpine areas of the Neovolcanic Belt of Mexico. Although the large number of shared taxa is a measure of the intensity of the exchange, certain taxa are of limited distribution; several are restricted to the eastern mountains while others are unknown from the higher elevations of the western side. The floristic and age differences among the mountains indicate that moss migration has not been unidirectional nor synchronic. Besides its role as a floristic bridge, the Neovolcanic Belt seems to have limited the dispersal of some mosses in a north-south direction; a barrier effect in a south-north direction is not supported by the known distribution of mosses in Mexico. The moss floras from the southern valleys may have moved northward even before mountain building, but present exchange between northern and southern valleys may take place through corridors across the Neovolcanic Belt.

Globular Mosses

On bare soils, subjected to subarctic climate conditions, lenticular to spherical moss balls have been observed which were completely unattached to the substratum, This article summarized the present knowledge on this unique life-form of foliar mosses, starting with a short treatise on the history of discovery. Then the geographical distribution of globular mosses on the subantarctic islands, the subarctic regions and in the temperate zone is reported. Abundantly, moss balls occur in the alpine zone of high mountains in tropical Africa, especially on Mt. Kenya. A taxonomic approach (Table 1) revealed that globular mosses are representatives of acrocarpous genera which usually form dense hemispherical cushions. As shown by the material from Mt. Kenya [Grimmia ovalis (Hedw.) Lindb.] the globoid shape originates by continual motion either of fragments of moss cushions which have been ruptured by frost or of single moss plants or small aggregations thereof which form a loose carpet on otherwise bare soil. Wind and solifluction which is due to nocturnal needle-ice formation and thawing of the soil in the day time could be demonstrated by two field experiments as moving forces. Structural analysis of the 0.5 to 8cm large balls of Grimmia ovalis showed three zones: The outer layer of living parts is followed by a zone of morphologically intact but dead sections of the plants while the core consists of a peaty material composed of disintegrated leaflets, rhizoids and stems and of minute soil particles as well. The velocities of uptake of water and of methylene blue (as a model substance for cationic nutrients) into a spheroid of Grimmia ovalis has been determined under field conditions.

The distribution of mosses in Nigeria I

The distribution of mosses in Nigeria I

Mosses of the Great Plains VI. The Niobrara River Basin of Nebraska

A total of 68 species are recorded for the Niobrara River basin. Thirtyone species are newly reported for the basin and four species are new state records. The Sorensen Similarity Index is used to compare the species found in the Niobrara River basin with those found in the Black Hills (44%), the Missouri River basin (56%), and the Mississippi River basin (44%). The emphasis of this survey was directed toward both the diversity and the distribution of mosses within the Niobrara River basin of Nebraska. Sixty-eight species of mosses, distributed among 41 genera and 18 families, were recorded for the basin region. These data will be used to test various hypotheses involving the biogeography of the basin and of the Great Plains (Churchill, in preparation). The major portion of the field work for this study was carried out in the Spring of 1976, although limited field work was also conducted in 1975, 1977, and 1978. In all, approximately 300 collections were made from 22 sites throughout the basin (Fig. 1). Several sites were revisited during the course of the investigation. In addition to the original collections made by the author, collections in the Nebraska State Herbarium (NEB) were also examined, as well as those collections cited by Jacobson and Prior (1979) from the University of Nebraska at Omaha (OMA). Previous bryological investigations in the Niobrara River basin had been general studies that merely included the basin area. The Botanical Seminar (1893 and 1901) gave the first reports, and included three mosses from the basin. In a significant early study on the Nebraska mosses, Wolfe (1924) reported a total of 75 species for the state, 15 of these from the Niobrara basin. A study of the family Pottiaceae by Koch (1971) included three species from the basin and, in a later report of additions to the Nebraska mosses, Koch (1975) included two more species. Six species were reported from the basin as new state records by Jacobson and Prior (1979). Studies by Churchill on the state moss flora also added to the number of taxa known from the basin: three (1977a) and nine (1979) species. The present study is This content downloaded from 157.55.39.116 on Sun, 18 Sep 2016 06:10:51 UTC All use subject to http://about.jstor.org/terms

The influence of simulated canopy light on the growth of six acrocarpous moss species

Six moss species were grown in two growth chambers with similar environmental conditions except for their ç ratios (E660:E730). One chamber simulated a sunlit situation the other a subcanopy shade situation. Different growth responses were observed for several species in the two chambers, which were often in the opposite direction to observations made on vascular plants. The ç ratio may be an important factor in regulating the distribution of mosses in the natural environment.

Mineral Cycling and the Niche of Spanish Moss, Tillandsia usneoides L.

On the southeastern coastal plain, the occurrence and abundance of the epiphyte Spanish moss (Tillandsia usneoides L.; Bromeliaceae) are linked to the availability of minerals in the canopy of potential host trees. Trees with high rates of foliar leaching (e.g., cypress and oaks) provide an abundant supply of minerals (Ca, Mg, K, and P) in precipitation collected beneath the canopy. In forests of these species Spanish moss is more abundant and has higher mineral concentrations than in pine forests (e.g., phosphorus 0.04–0.06% dry weight versus 0.03–0.04%). In growth-chamber experiments the growth of Spanish moss increased in response to added phosphorus in the range of concentrations observed in field precipitation collections (0–200 μg/l). In addition to the availability of minerals, the rate of bark sloughing from host trees and allelopathic effects may also control the local distribution of Spanish moss. Light and moisture appear to be less important factors. Thus, within a favorable climatic range, mineral and bark characteristics of host trees may be used to illustrate a niche hypervolume for this species.