Terricolous Lichen Communities Research Articles

Water-energy relationships shape the phylogenetic diversity of terricolous lichen communities in Mediterranean mountains: Implications for conservation in a climate change scenario

Lichens are symbiotic organisms sensitive to climate change and susceptible to a severe decline in diversity, especially in high elevation environments that are already threatened. In this study, we focused on water-energy relationships derived from climatic variables and phylogenetic diversity indices of terricolous lichen communities occurring on a representative Mediterranean mountain. We hypothesized that the variation of precipitation and temperature and their interaction along the altitudinal gradient will shape the phylogenetic diversity and structure of lichen communities. Our results reveal that dry and arid conditions lead to a strong loss in phylogenetic diversity with consequent impoverishment of high elevation lichen communities under a climate change scenario. The interaction between variables, reflecting water-energy relationships with phylogenetic and community diversity patterns, suggests that in a future climate change scenario, the novel climatic conditions may reduce the capability of the species to survive harsher conditions, and Mediterranean mountains may face a severe loss of genetic diversity in a climate change scenario.

Factors at multiple scales influence the composition of terricolous lichen communities in temperate semi-arid sandy grasslands

AbstractInland dune ecosystems are rich in terricolous lichen species. However, these communities are sensitive to human activities, both locally and globally. Since terricolous lichens have a dominant role in semi-arid sandy grasslands, it is important to explore the composition of their communities and the environmental factors affecting them. We studied the structure of the terricolous lichen assemblages of calcareous grassland in an inland duneland ecosystem by comparing the lichen communities of arid and humid dune sides on two sites with different disturbance histories. Microcoenological data were collected according to the Braun-Blanquet method. Environmental variables include the cover of bare soil, moss, litter, herb cover and height of herbs. We investigated the relationship of these variables and the presence and absence data of terricolous lichen species to sites and dune side. We found that the site had a significant effect on species richness that might reflect the different types and severity of previous disturbance events at the studied sites. On a smaller, ‘dune’ scale, in general lower herb cover and height and a higher moss cover were characteristic of arid dune sides. Most of the frequent species were negatively affected by higher moss cover. Some lichen species were more abundant (e.g. Cladonia furcata) or found only (e.g. Xanthoparmelia subdiffluens, Gyalolechia fulgens) on arid dune sides, while others preferred (e.g. C. pyxidata) or occurred only on (e.g. Peltigera species, C. rei) humid sides. It was observed that the impact of the dune side on several variables differed between sites. The diverse microhabitat types, microclimate and landscape structure, results in species-rich and valuable terricolous lichen communities forming in inland dune ecosystems.

Morphological and Chemical Traits of Cladonia Respond to Multiple Environmental Factors in Acidic Dry Grasslands.

Terricolous lichen communities in lowlands occur especially in open dry habitats. Such communities are often dominated by species of the genus Cladonia, which are very variable in morphology, reproduction strategies, and secondary metabolites. In this work, we investigated traits-environment relationships considering vegetation dynamics, substrate pH, disturbance, and climate. A total of 122 plots were surveyed in 41 acidic dry grasslands in the western Po Plain (Northern Italy). Relationships between Cladonia traits and environmental variables were investigated by means of a model-based Fourth Corner Analysis. Thallus morphology and metabolites responded to vegetation dynamics, substrate pH, disturbance, and climate, whereas reproduction strategies responded only to vegetation dynamics. Traits’ correlations with vegetation dynamics elucidate their colonization patterns in open dry habitats or suggest biotic interactions with bryophytes and vascular plants. In addition, correlations between metabolites and environmental factors support interpretations of their ecological roles. Our results also stress the importance of studying traits’ relationships with climatic factors as an alert towards lichen reactions to climate change.

Terricolous lichen communities in Thero-Airion dry grasslands of the Po Plain (Northern Italy): syntaxonomy, ecology and conservation value.

Terricolous lichen communities in Thero-Airion dry grasslands of the Po Plain (Northern Italy): syntaxonomy, ecology and conservation value.

Life on sand dunes from lichens point of view – effect of microclimate and seasonality on activity of terricolous lichen communities

Life on sand dunes from lichens point of view – effect of microclimate and seasonality on activity of terricolous lichen communities

Plot Sizes Used for Phytosociological Sampling of Bryophyte and Lichen Micro-Communities

Berg, C., Schwager, P., Pöltl, M. & Dengler, J. 2016. Plot sizes used for phytosociological sampling of bryophyte and lichen micro-communities. — Herzogia 29: 654–667.To study the ecology of bryophytes and lichens, a plot-based approach in the tradition of phytosociology is widely used in Europe. Plot size has a crucial influence on the outcome of various analyses. Vegetation-environment analyses, biodiversity studies and vegetation classifications can be strongly biased if different plot sizes are compared or combined. For this reason, standard plot sizes have been recommended repeatedly. We collected 122 articles from eight international journals to analyse which plot sizes they used for sampling bryophyte and lichen communities. We found 11,573 relevés from 19 European countries, with German data and bryophyte communities being prevailing. Overall plot sizes ranged from 0.0002 to 30 m2. The medians of plots sizes of saxicolous, corticolous, terricolous and lignicolous communities were all in the range of 0.04 to 0.09 m2. Much smaller plots were used for bird casts and for epiphyllous micro-communities, with the smallest plots being only 2.1 cm2 in size. The largest plots exceeded 1m2 and were mostly used for terricolous lichen communities, in which most authors also recorded vascular plants. The most frequently used plot sizes in all data were 0.04, 0.01 and 0.03 m2, while differences between the substrate types and among the two taxa were of subordinate importance. To replace the former vague criteria used to determine the plot size, like minimum area, representativeness and homogeneity, we recommend the use of a standard plot size for future studies of cryptogam micro-communities. To achieve best-possible compatibility with former studies, 0.04m2 (20cm × 20 cm) appears as a good option. If cryptogam-rich vegetation types regularly cover many square metres or even hectares, we recommend to analyse them not only as micro-communities, but, including the co-occurring vascular plants and using plot sizes of 4–16 m2, also as part of the normal system of complete plant communities, where such types typically had been neglected. Finally, we emphasize the fundamental difference between complete phytocoenoses, which alone should be considered in conventional syntaxonomy, and partial communities (merocoenoses, synusia), which better should be treated in a parallel classification system with its own ranks. Plot size can be considered as strong circumstantial evidence, whether a record refers to a complete phytocoenosis or to a synusia. We recommend assuming for plot sizes below 1 m2 that they are either synusiae or incomplete records of phytocoenoses, thus in either case not suitable for conventional syntaxonomy. Syntaxa based on such micro-plots should generally be considered as invalid.

Short-term response of Cladonia lichen communities to logging and fire in boreal forests

Fire is the major disturbance agent in boreal forests that initiates forest regeneration and succession, and plays a major role in determining the composition of terricolous lichen communities. In recent decades however, logging has become an important disturbance agent in boreal forests. In this context, growing concerns about logging effects on endangered species such as woodland caribou (Rangifer tarandus caribou) has emerged and drawn attention on how reindeer lichens (i.e. Cladonia arbuscula, Cladonia mitis, Cladonia rangiferina, Cladonia stellaris, and Cladonia stygia) respond to logging and fire given their importance as winter forage for caribou. We compared critical lichen habitat factors (i.e., forest floor thickness, tree height, and canopy closure) between fire and logged sites and evaluated how Cladonia lichen species richness, biomass, and ground cover were related to these habitat factors in the first decades following disturbance. We found no significant differences in habitat factors and no significant differences in lichen species richness or ground cover between logged and fire sites. However, Cladonia lichen biomass was significantly higher following logging. These results support the hypothesis that Cladonia lichens can persist following logging and suggest that forestry practices that include in their toolbox winter harvesting or machinery traffic restricted to specific trails are likely to preserve undisturbed forest floor habitat conditions with source populations of lichens.

Contrasting responses of epiphytic and terricolous lichens to variations in forest characteristics in northern boreal ecosystems

The main environmental factors that drive lichen communities are still poorly known in northern boreal ecosystems. This study compares the effects of forest stand characteristics (height, canopy cover, and age) on fruticose epiphytic and terricolous lichen communities across a large region located at the interface between closed-crown boreal forests and northern open woodlands in the province of Quebec (Canada). The dataset consists of 875 plots spread across a 242 000 km2 territory that ranges from the eastern to the western extremities of the province. The biomass of fruticose epiphytic lichens (Alectoria, Bryoria, Evernia, and Usnea) was evaluated at the branch, tree, and plot levels, and terricolous lichen cover (Cladonia spp.) was evaluated at the plot level. The results indicate that epiphytic and terricolous lichens respond significantly but differently to variations in forest characteristics. At the plot level, epiphytic lichen biomass was highest in the oldest stands (>100 years) and lowest in stand with low canopy cover (<25%) or in stands dominated by relatively short trees (<7 m). By contrast, terricolous lichen cover was highest in stands dominated by short (<7 m) or mid-sized (7–12 m) trees and lowest in stands with a relatively high canopy cover (>40%) or stands of intermediate age (60 to 100 years old). Species composition of epiphytic communities was also examined, and some species or genera exhibit a strong association with older stands (Alectoria sarmentosa (Ach.) Ach., Bryoria spp.) or with specific regions along the ca. 1500 km east–west gradient (Evernia mesomorpha Nyl. in the western part, Bryoria spp. in the central part, and A. sarmentosa in the eastern part). In terms of conservation, these results indicate that epiphytic lichens communities are potentially sensitive to the preferential logging of older stands. Both epiphytic and terricolous lichen communities are also potentially sensitive to expected climate change effects such as increased fire frequencies or increased forest growth.

Influence of Time since Fire and Micro-Habitat Availability on Terricolous Lichen Communities in Black Spruce (Picea mariana) Boreal Forests

Terricolous lichens are an important component of boreal forest ecosystems, both in terms of function and diversity. In this study, we examined the relative contribution of microhabitat characteristics and time elapsed since the last fire in shaping terricolous lichen assemblages in boreal forests that are frequently affected by severe stand-replacing fires. We sampled 12 stands distributed across five age classes (from 43 to >200 years). In each stand, species cover (%) of all terricolous lichen species and species richness were evaluated within 30 microplots of 1 m2. Our results show that time elapsed since the last fire was the factor that contributed the most to explaining terricolous lichen abundance and species composition, and that lichen cover showed a quadratic relationship with stand age. Habitat variables such as soil characteristics were also important in explaining lichen richness. These results suggest that the presence of suitable substrates is not sufficient for the conservation of late-successional terricolous lichen communities in this ecosystem, and that they also need relatively long periods of times for species dispersal and establishment.

Terricolous lichen communities of Plain Crimea (Ukraine)

Terricolous lichen communities of Plain Crimea (Ukraine)

Terricolous lichens as indicators of nitrogen deposition: Evidence from national records

Large areas of Great Britain currently receive nitrogen (N) deposition at rates which exceed the thresholds above which there is risk of damage to sensitive components of the ecosystem (critical loads for nutrient nitrogen and critical levels for ammonia), and are predicted to continue to do so. Excess N can damage semi-natural ecosystems. Lichens are potentially sensitive to air quality because they directly utilise nutrients deposited from the atmosphere thus may be good indicators of air quality. We used data from the British Lichen Society (BLS) database, which records the presence of all lichen taxa growing in Britain at 10km resolution. The probability of presence of a taxa at a given level of N deposition was analysed together with driver data for climate, change in sulphur deposition, land-use and N deposition using generalised additive models (GAMs). Many taxa showed negative responses to N deposition with reductions in the probability of presence as N deposition increased. In all of the habitats, there were a mix of terricolous taxa which showed negative or no significant relationship with N deposition. Most of the taxa with negative relationships with N deposition started to decline in prevalence at the lowest levels of deposition found in this study. Levels of deposition over which a negative response apparently occurs are lower than those at which critical loads have been set for some habitats. These findings suggest that some terricolous lichen taxa are sensitive to atmospheric N deposition and even low levels of nitrogen deposition could be damaging terricolous lichen communities making then potentially good indicators of N deposition.

Terricolous alpine lichens are sensitive to both load and concentration of applied nitrogen and have potential as bioindicators of nitrogen deposition

The influence of applied nitrogen (N) concentration and load on thallus chemistry and growth of five terricolous alpine lichen species was investigated in a three-month N addition study. Thallus N content was influenced by both concentration and load; but the relative importance of these parameters varied between species. Growth was most affected by concentration. Thresholds for effects observed in this study support a low critical load for terricolous lichen communities (<7.5 kg N ha −1 y −1) and suggest that concentrations of N currently encountered in UK cloudwater may have detrimental effects on the growth of sensitive species. The significance of N concentration effects on sensitive species also highlights the need to avoid artificially high concentrations when designing N addition experiments. Given the sensitivity of some species to extremely low loads and concentrations of N we suggest that terricolous lichens have potential as indicators of deposition and impact in northern and alpine ecosystems.

Ecology of soil lichens from Pliocene clay badlands of central Italy in relation to geomorphology and vascular vegetation

The terricolous lichen communities occurring under a temperate sub-arid to sub-humid climate (mean annual rainfall about 750 mm) on Pliocene clay soils of southern Tuscany (central Italy) are similar to those reported for arid or sub-arid areas, with mean annual rainfall around 200 mm. The distribution of these communities is influenced by the availability of bare soil and percentage cover of vascular plants. Where vascular communities are more important and pedogenetic processes lead to the development of more structured and evolved soils, pioneer lichen communities of the Toninio-Psoretum decipientis are replaced by communities such as that of Cladonietum convolutae, which are more capable of competing for light and nutrients with dense communities of tall grasses such as Bromus erectus. The distribution patterns of Artemisia cretacea and B. erectus among vascular plants, and Fulgensia fulgens and Cladonia rangiformis among lichens, account for most of the variability in vascular and lichen communities, respectively.

Lichens of the Blair Atholl limestone

Abstract: Saxicolous and terricolous lichen communities associated with the Blair Atholl limestone are described by reference to two main sites—the Meall Breac area and Tulach Hill (including Creag Odhar). Several rare arctic-alpine lichens occur in the Meall Breac area, including the first population of Cetraria nivalis to be found outside acidic lichen-moss heaths in Great Britain. Tulach Hill and Creag Odhar, in contrast, are at relatively low altitudes and more sheltered, supporting a range of species not normally seen in the Highlands. These communities, most of which lie in the anthropogenic zone that was formerly covered by woodland, are compared with those of major montane calcareous sites in Scotland that have always been above the tree line.

Effect of Land-Use on Terricolous Lichens

AbstractThe limestone plateau of Derbyshire is intensively farmed but supports terricolous lichens associated with unimproved grazing, derelict lead mining ground and modern fluorspar working. The assemblages identified include a number of relict species now very rare in central England. Reworking mine waste for fluorspar can result in the development of communities containing particularly interesting lichens. Land-use is now the chief determinant of terricolous lichen communities in the area studied.

Simplification of the Blue Mountain Lichen Communities near a Zinc Factory

In Lehigh Water Gap near a zinc factory, species diversities of corticolous, saxicolous, lignicolous, and terricolous lichen communities are markedly reduced compared to the species diversities of lichen communities in Delaware Water Gap. Nine lichen species were found in Lehigh Water Gap; 84 in Delaware Water Gap. Foliose, fruticose, and crustose species, respectively, are increasingly more tolerant of the conditions around the zinc factory. The effect of the zinc factory on the Blue Mountain lichen flora is discernible up to 6 km to the west of Lehigh Water Gap and 15 km to the east. Located at the northern base of Blue Mountain in Palmerton, Carbon County, Pennsylvania, New Jersey Zinc Company's factory is composed of two divisions situated approximately 1 km to the east and west, respectively, of Lehigh Water Gap (Fig. 1). Results from a preliminary reconnaissance of Lehigh Water Gap suggested that its lichen communities are simplified. To ascertain the depauperateness of the Lehigh Water Gap lichen communities, I sampled the lichens of Lehigh Water Gap, and those of Delaware Water Gap, approximately 50 km ENE of Lehigh Water Gap. Delaware Water Gap is an adequate control area for Lehigh Water Gap because both gaps have similar topography, geologic history, soils, and historical use by man (except for the installation of New Jersey Zinc Company's factory at Lehigh Water Gap). The Lehigh River flows through Lehigh Water Gap at 118 m above sea level; the Delaware River, at 98 m through Delaware Water Gap. The mountains on either side of the gap rise to 430-475 m, and their axes of orientation are similar (ENE-WSW). The predominant substrate in both areas is Silurian Shawangunk conglomerate, which has a siliceous matrix. During the Mesozoic the two mountains were part of the Schooley peneplain. Erosion during the Cretaceous and Tertiary formed the two water gaps, exposed the conglomerate, and left the mountains as the dominant topographic feature in the area (Widmer, 1964). Soils in both gaps are very stony loams, and most of the soil in each of the gaps belongs to the Dekalb Series (U.S. Dept. Agric., 1962; U.S. Dept. Agric., unpublished data). Today, four-lane highways and railroads pass through both gaps. In the 1800's, canals were built through the gaps for coal transport, and both mountains were logged extensively. The gaps are now covered by a second- ary forest composed primarily of Quercus rubra, Q. prinus, and Betula lenta.