Macrolichen Species Richness Research Articles

Forest fuel extraction does not affect macrolichens on deadwood substrates, but only if coarse woody debris is not collected

AbstractThe increasing use of forest fuels poses risks to biodiversity. Lichens that grow on deadwood may be affected as fuel extraction removes their substrates. We surveyed deadwood and macrolichens on deadwood in two types of clearcuts: sites in which forest fuels, stumps and slash, had been extracted, and standard clearcut sites, i.e. control sites with no fuel extraction. Extraction sites had 52% lower deadwood volume (44.3 m³/ha vs. 21.4 m³/ha) and 36% less deadwood surface area. However, the negative impact of fuel extraction on macrolichen species richness was low: 21.4 and 16.9 species on average were found in control and extraction sites, respectively. We found a clear positive relationship between macrolichen species richness and the surface area of logs, which are usually not targeted by forest fuel extraction. Species composition varied more among extraction sites than control sites and differed between all the studied deadwood types. Species of Cladonia were associated with stumps, while species in the family Parmeliaceae were associated with logs. Slash was of negligible importance to macrolichens. Stumps may hold value, particularly if large-sized deadwood is otherwise not available. Thus, we conclude that the extraction of slash poses no threat to macrolichen diversity, whereas extensive extraction of stumps can cause losses in lichen diversity. The loss of coarse woody debris during forest fuel extraction has negative effects on lichen diversity and should be avoided.

Recovery kinetics of epiphytic lichen diversity after dieback during a continuously wet season

Epiphytic lichens are considered sensitive indicators of environmental change. Excess water is known to depress their photosynthesis, but the effect of long-lasting rain on species richness of epiphytic lichens is rarely reported. By annually repeated records of macrolichen species richness on tree trunks over a period of 33 years that included one long rainy season in year 2000, a strong decline in macrolichen richness on tree trunks was detected after the unusually wet autumn. Afterwards, the lichen richness slowly recovered, but had not yet fully recovered 19 years after the dieback. Thereby, long rainy periods can cause lasting depression in epiphytic lichen richness, and continuous rain should be considered a possible threat to lichens in regions like northern Europe where global change predicts enhanced rainfall frequency.

Growth form matters – Crustose lichens on dead wood are sensitive to forest management

Lichens have a vital role in forest ecosystems and they are a threatened group in boreal forests. However, the conservation ecology of the total lichen community has very rarely been studied. Here we studied lichen species and communities, including macrolichens (=foliose and fruticose growth forms) and rarely studied crustose lichens, on decaying wood in boreal spruce-dominated forests in Finland. We also studied obligate lignicoles that grow only on dead wood and are mostly crustose in growth form. Species richness and community composition were examined on decaying logs and natural or cut stumps of Picea abies at different decay stages (2–5) in 14 stands, half of which were natural or seminatural and half recently managed. We used thorough search to yield a species list as close to complete as possible. Our study questions were: 1) Are species richness and lichen communities different in natural and managed forests, and if so, are there differences between macrolichens, crustose lichens and obligate lignicoles in how they respond to forest management? 2) How does the decay stage and dead wood type affect the lichens, i.e. are there differences between stumps and logs? We found a total of 127 lichen species. Most (75 %) of the recorded lichen species were crustose. With a generalized linear model we found that crustose lichens and obligate lignicoles had a higher species richness in natural than managed forests, but macrolichen richness was not significantly affected by forest management. Utilizing non-metric multidimensional scaling we discovered that site level community composition of macrolichens, crustose lichens and obligate lignicoles was also significantly different between natural and managed forests. We found that on dead wood unit level the decay stage had a significant effect on species richness and community composition, so that the species richness of all studied groups declined during the decay process. The dead wood type (stump vs log) had a significant effect on species richness of macrolichens and obligate lignicoles, both for which species richness was higher on logs than on stumps, as well as on the communities of crustose lichens.

SPECIES RICHNESS OF MACROLICHENS IN MT. SAPINIT, SITIO DAGULOS, LA ROXAS, MARAMAG, BUKIDNON

The species richness of macrolichens in Mt. Sapinit, SitioDagulos, and MaramagBukidnon was investigated. The main objective of the study is to determine the species richness of macrolichens in the vicinity of Mt. Sapinit. Transect walk and quadrat sampling were carried out in the collection of macrolichens. The gathering and identification of specimens collected was based on standard taxonomical procedure. Results of the study revealed a total of 20 species classified into 7 genera and 13 families. The most family-rich species belong to the family Lobariaceae, and the least family-rich belong to Ramalinaceae, Collemataceae, and Dictyonemaceae. Most of the epiphytic macrolichens belong to the family Parmeliaceae, which dominates the entire montane forest. The distribution of macrolichens across the area occurs in the bark of the tree, logs and twigs, and in tree branches.Elevation also have impact to the growth of lichen species. Higher elevations appear to provide suitable condition for many lichen species to thrive. Thus, the need to preserve the forest ecosystem is essential in order to conserve the lichen communities.

Species richness and \u03b2-diversity patterns of macrolichens along elevation gradients across the Himalayan Arc

Understanding the species richness and β-diversity patterns along elevation gradients can aid in formulating effective conservation strategies particularly in areas where local anthropogenic stresses and climate change are quite significant as in the Himalaya. Thus, we studied macrolichen richness and β-diversity along elevational gradients at three sites, namely Kashmir (2200 to 3800 m a.m.s.l), Uttarakhand (2000–3700 m a.m.s.l) and Sikkim (1700 to 4000 m a.m.s.l) which cover much of the Indian Himalayan Arc. In all, 245 macrolichen species belonging to 77 genera and 26 families were collected from the three sites. Only 11 species, 20 genera and 11 families were common among the three transects. Despite the differences in species composition, the dominant functional groups in the three sites were the same: foliose, fruticose and corticolous forms. The hump-shaped elevation pattern in species richness was exhibited by most of the lichen groups, though an inverse hump-shaped pattern was also observed in certain cases. β-diversity (βsor) based on all pairs of comparisons along an elevation gradient varied from 0.48 to 0.58 in Kashmir, 0.03 to 0.63 in Uttarakhand and 0.46 to 0.77 in Sikkim. The contribution of turnover to β-diversity was more than nestedness at all the three transects. Along elevation β-diversity and its components of turnover and nestedness varied significantly with elevation. While species turnover increased significantly along the elevation in all the three transects, nestedness decreased significantly in Kashmir and Sikkim transects but increased significantly in the Uttarakhand transect. Except for the Kashmir Himalayan elevation transect, stepwise β-diversity and its components of turnover and nestedness did not vary significantly with elevation. The present study, the first of its kind in the Himalayan region, clearly brings out that macrolichen species richness, β-diversity, and its components of turnover and nestedness vary along the elevation gradients across the Himalayan Arc. It also highlights that contribution of turnover to β-diversity is higher in comparison to nestedness at all the three transects. The variations in species richness and diversity along elevation gradients underpin the importance of considering elevational gradients in planning conservation strategies.

Effects of elevation and disturbances on the associations between the diversities of bryophyte and macrolichen functional-taxonomic groups on Madeira Island

Biodiversity varies with elevation and is affected by disturbances. However, little is known about how the associations between the diversities of different bryophyte and macrolichen functional-taxonomic groups are altered along elevational gradients and by disturbances. Knowledge on the associations between these functional-taxonomic groups might be of importance in practical conservation biology, as identifying indicator taxa which are easy to monitor could be useful in estimating a wider biodiversity. We sampled the species richness of bryophytes and macrolichens in 92 plots distributed in disturbed and undisturbed stands along elevational gradients in the laurel forest of Madeira. We then calculated a matrix of correlations for all pairwise combinations of 18 different functional-taxonomic bryophyte and macrolichen groups and tested for average differences in correlations with elevation and disturbance history and whether particular functional-taxonomic groups can be used to estimate the richness of other taxa. Associations between the diversities of functional-taxonomic groups within the bryophyte group and within the macrolichen group were always positive and mainly strong. Although changes in elevation and disturbance history changed the associations between the different bryophyte and macrolichen functional-taxonomic groups, we found the species richness of mosses or liverworts to be suitable for predicting overall bryophyte species richness and the species richness of green-algae macrolichens to be reliable for estimating overall macrolichen species richness. Associations between diversities of bryophyte and macrolichen groups were generally weak, suggesting that the two groups have different ecological requirements and do not share the same environmental drivers. The fact that no single bryophyte taxon can be used to predict the richness of any macrolichen group, and vice versa, points to the need to study both bryophytes and lichens. However, we found indicator taxa that are relatively easy to monitor and therefore could be used to estimate the wider biodiversity.

Species richness of multiple functional groups peaks in alpine tundra in subarctic Alaska

AbstractClimate warming has initiated changes to vegetation across subarctic North America with potential to dramatically alter the distribution of biodiversity of vascular plants, mosses, and macrolichens. However, landscape‐scale studies of the patterns and drivers of species richness in this region are scarce, raising the possibility that dramatic changes to biodiversity could occur undetected over a wide area with serious consequences for ecosystem integrity and conservation. We used a hierarchical, systematic design to compile a uniquely large and comprehensive diversity dataset for our study area in subarctic North America. We utilized a unified sampling frame at the landscape scale to record diversity of vascular plants, mosses, and macrolichens as the three primary components of vegetation species richness. We applied Bayesian hierarchical modeling techniques to identify site attributes associated with richness of the three functional groups. We also examined whether richness of groups was positively or negatively inter‐correlated across multiple spatial scales. Our goal was to quantify the fundamental relationships of species richness with site attributes across this landscape to better understand the possible responses of species richness to habitat changes forecast to occur in the subarctic as a result of a warming climate and other stressors. Moss, vascular plant, and terricolous macrolichen species richness were strongly inter‐correlated, due to an underlying marked positive association of each with increasing elevation into the alpine zone across multiple spatial scales. Our results further reveal varying influences of factors such as soil pH, disturbance, and plant canopy cover on diversity in these physiologically different functional groups. Taken together, the patterns revealed by our work provide a new framework to consider how predicted habitat changes wrought by warming climates in interior Alaska may affect fundamental diversity patterns of primary producers in the future, with important implications for ecosystem function and conservation.

Lichen traits and species as indicators of vegetation and environment

Abstract Lichens in the Arctic play important ecological roles. They also face the threats of increasing fire and shrub and tree expansion, exacerbated or caused by climate change. These forces may lead to changes not only in lichen community composition but also in the abundance, diversity and distribution of lichen functional traits. We sought to connect landscape-scale patterns of lichen community composition and traits to environmental gradients to both monitor lichen communities and clarify community-trait-environment relationships. We measured lichens throughout one of the largest and most remote U.S. National Parks within the Arctic. We then analyzed lichen community composition and species richness within ecologically informative lichen trait groups along environmental and vascular vegetation gradients. Macrolichen species richness in 0.4 ha plots averaged 41 species with a total landscape level observed gamma diversity of 262 macrolichen species. Jackknife estimators placed the landscape level ma...

Dynamics of epiphytic macrolichen abundance, diversity and composition in boreal forest

Summary Epiphytic macrolichen lichens are important components of forest ecosystems, but their responses to stand‐replacing fire and multiple successional pathways of the canopy tree layer are poorly understood. We examined the dynamics of epiphytic macrolichens following wildfire and tested the independent and interactive effects of time since fire and overstorey composition on epiphytic macrolichen abundance, diversity and composition in boreal forests of Canada. Epiphytic macrolichens were sampled in 51 stands of conifer, mixed‐wood and broadleaf overstorey types ranging from 7 to 209 years since fire. Macrolichen abundance estimated as percentage cover continuously increased with stand age with highest cover in 209‐year‐old stands for all overstorey types. Mixed‐wood and conifer stands had higher macrolichen abundance than broadleaf stands in all age classes except similarly low abundances in stands ≤15 years old for all overstorey types. Species richness of epiphytic macrolichens reached peaks in 98‐ or 146‐year‐old stands. Mixed‐wood stands had higher macrolichen species richness than broadleaf and conifer stands at 98 years old, but not at other age classes. Multivariate analysis indicated that the macrolichen communities were compositionally distinct for all age classes and overstorey types. Synthesis and applications. Epiphytic macrolichen abundance continuously increases with time since fire. Our results also show that macrolichen diversity peaks at intermediate stand ages with highest diversity in mixed‐wood stands. Our findings of distinct macrolichen communities supported by each age class and overstorey compositional type suggest that conservation of epiphytic macrolichen diversity would require forest managers to maintain a diverse age structure and overstorey composition in forest landscapes.

Relative effects of vehicle pollution, moisture and colonization sources on urban lichens

Summary Lichens are sensitive to pollution and have therefore been used as air quality indicators. While the distribution of lichens within cities may reflect the distribution of traffic pollution, other factors affecting urban lichens are correlated with this pollution – particularly moisture and the presence of lichen colonization sources. Our objective was to determine the relative importance of these three factors – vehicle pollution, moisture and colonization sources – in determining lichen distribution within a city. We surveyed macrolichen richness and cover on 420 trees within 84 sites across urban Ottawa, Canada. The sites were selected to minimize correlations among vehicle pollution, moisture and colonization sources. Model‐averaged standardized regression coefficients were used to compare the relative effects of these three variables on macrolichen richness and cover. We found that macrolichen cover was most strongly related to vehicle pollution and that this effect occurred within 300 m of a site. However, macrolichen species richness responded more strongly to both moisture (at the site centre) and colonization sources (within 1000 m of the site) than to vehicle pollution. Synthesis and applications. Our results suggest that macrolichen cover, but not macrolichen species richness, can be used as an indicator of urban traffic pollution. Our results also suggest that, to promote urban macrolichen diversity, it would be more effective to increase the availability of lichen colonization sources (nearby trees) than to control traffic pollution.

Temporal Changes in Lichen Species Richness and Elemental Composition on a Pennsylvania Atmospheric Deposition Gradient

Abstract. In 1988 the macrolichen species richness and elemental concentrations in Hypogymnia physodes thalli were surveyed at four equally-spaced study areas along a 160-km west-to-east atmospheric deposition gradient in north-central Pennsylvania. There was significantly lower lichen species richness in the western, higher deposition half of the gradient and significantly higher elemental concentrations at the western study areas. The same study sites were revisited in 2004 to determine if spatial-temporal changes in lichen richness and elemental concentrations had occurred in the ensuing 16 years. By 2004 lichen richness had increased in the western portion of the gradient to be nearly equal that of the eastern portion of the gradient. Lichen elemental concentrations generally decreased at all study sites, with the greatest reduction in the western sites. These changes are likely a response to air quality improvements resulting from the Clean Air Act Amendments of 1990. Lichens are useful indicators of...

Diversity and vertical distribution of epiphytic macrolichens in lowland rain forest and lowland cloud forest of French Guiana

Abstract Recent work on bryophyte diversity in lowland forests of northern South America has suggested the existence of a new type of cloud forest, the “tropical lowland cloud forest” (LCF). LCF occurs in river valleys with high air humidity and radiation fog, and is rich in epiphytes. We explored the lichenological characteristics of putative LCF in a lowland area (200–400 m a.s.l.) near Saul, central French Guiana, using macrolichens (including large crustose species) as indicator taxa. We analyzed macrolichen diversity on 16 trees in two 1 ha plots, in LCF and in lowland rain forest without fog (LRF). Sampling efficiency was ca. 80% in both forest types. Canopies of both LRF and LCF were richer in lichen species than understory trunks. Species richness of macrolichens was rather similar in the two forest types but species composition was significantly different. Cyanolichen richness in LCF was ca. 2.5 times higher than in LRF; in contrast, LRF had 4 times more species of green-algal Parmeliaceae. Our study suggests that cyanolichens except for Coccocarpiaceae serve as indicators of LCF. We explain the detected diversity patterns by differences in water availability due to fog precipitation and higher humidity. This is indicated by the higher relative air humidity in the lowland cloud forest, which was >6% higher than in the rain forest.

Habitat associations of macrolichens on a boreal island in the Bay of Fundy, New Brunswick, Canada

Compared to the mainland, boreal oceanic islands would be expected to have a depauperate lichen biota because of their isolation, small area, exposure to salt spray and structurally simple habitats. We surveyed the macrolichens (non-crustose lichens) and quantified habitat associations on Kent Island, an 80-hectare island that lies at the mouth of the Bay of Fundy, New Brunswick, Canada. A total of 43 species in 13 genera were identified, which represents 19% of the macrolichen species richness of Fundy National Park on the mainland coast of New Brunswick. Cyanolichens were not found on Kent Island. Nearly 75% of Kent Island's macrolichen species had boreal biogeographical affinities, despite the island's temperate latitude (44°35′N) and low elevation, due to the chilling influence of the locally upwelling Labrador Current. Multi-response Permutation Procedures and Indicator Species Analysis demonstrated non-random habitat associations among Kent Island's macrolichen species and moderate but significant differences in lichen communities among five forest types on the island.

Macrolichen diversity in Noatak National Preserve, Alaska

We sampled macrolichens in Noatak National Preserve to help address the need to document lichen biodiversity in Arctic ecosystems and to initiate regional-scale monitoring in the face of climate change and air pollution. We used a stratified random sample to allow unbiased park-wide diversity estimates, along with an intensive sample in a limited area. The purpose of the intensive sample was to allow us to calculate a correction from diversity estimates based on a single person in a time-constrained method to a value that more closely approximates the “true” diversity of a plot. Our 88, 0.38-ha plots averaged 26 species of macrolichens in the sample, while our best estimate of the true average was 42 species per plot. Our raw estimate of gamma diversity (park-wide macrolichen species richness) was 209 species, with jackknife estimates adjusting this to 255 or 290 species, depending on the estimator. Overall beta diversity was rather high at 7.1, reflecting the considerable variation in lichen communities among topographic positions, rock chemistry, substrate pH, climate, and vegetation. The richest lichen communities were in conifer forests, low birch/ericaceous vegetation, dwarf shrub, and talus lichen cover. Sparse vegetation was the cover type with lowest lichen species richness, reflecting the frequency of bare rock in that cover type. The herbaceous cover type was the most heterogeneous in lichen communities, having a high gamma diversity, high beta diversity, but averaging rather low alpha diversity. Several notable species are among the 364 taxa reported here. Leucocarpia biatorella is reported as new to the American Arctic. Cladonia libifera and C. jacutica are newly reported for North America. A second location for Rhizocarpon cumulatum beyond the type locality was found. The range of Parmelia squarrosa is extended ca. 1500 km north of coastal southeast Alaska. The high landscape-level diversity and high beta diversity in Noatak National Preserve provide a rich biotic tapestry for detecting future changes in macrolichen communities.

Epiphytic lichens along gradients in topography and stand structure in western Oregon, USA

Epiphytic macrolichen communities were compared among forest stand types in the Blue River watershed of western Oregon. Stand types were defined by stand structure, according to age classes of the younger tree cohort and remnant tree retention. Remnant trees were those in an older cohort that remained following a stand disturbance that initiated tree regeneration, such as a timber harvest or natural forest fire. Stands were located in upland and riparian forests of two vascular plant series (western hemlock and true fir). Presence and abundance of all epiphytic macrolichen species were sampled in a 0.4 ha circular plot in 117 stands. Nonmetric multidimensional scaling (NMS) ordination revealed that the strongest differences in lichen community composition were related to elevation, which was correlated with vascular plant series. Cyanolichens were largely limited to lower elevation forests (470 – 950 m) of the western hemlock series, while matrix lichens and forage lichens with green-algal photobionts dominated high elevation stands (950 – 1470 m) of the true fir series. Lichen communities differed with stand age. In even-aged young stands, lichen communities were species poor and lichen community composition differed from all other stand types. In general, macrolichen species richness varied little among stand types. However, cyanolichen species were most diverse in old-growth and mature stands at lower elevations. Lichen communities in young stands (< 20 yr) with remnants differed from those in even-aged young forests in both plant series. As a stand develops, the presence of remnant trees may accelerate the development of the lichen community towards those found in older stands. We infer that remnant trees serve as refugia for lichens through a disturbance and provide lichen inoculum to younger trees. Hardwood patches were hotspots for lichen diversity, particularly cyanolichens that are infrequent on conifers. Hardwood patches were most prevalent along perennial streams. To maintain and enhance lichen communities at a landscape level, forest managers must consider the importance of features such as late-successional stands, remnant trees, hardwoods, and riparian areas to lichen communities. These features are especially important to retain in or near regenerating forests to promote colonization by dispersal-limited lichens.

Epiphytic macrolichens in managed and natural forest landscapes: a comparison at two spatial scales

To maintain biodiversity in managed forests we must understand how forestry affects various organisms across a wide range of spatial and temporal scales. We compared landscape structure, forest structure, and species richness and abundance of epiphytic macrolichens in three pairs of natural and managed boreal forest landscapes. Study landscapes (2500 ha) were located within and adjacent to three of the largest forest reserves in Sweden (Reivo, Muddus, Jelka). The structural heterogeneity within landscapes was higher in managed forests whereas within‐stand structural heterogeneity was higher in natural landscapes. Species richness of macrolichens at the stand level (sample plot) was 23% higher in natural forests but there was no difference at the landscape level. Most (86%) of the common species were more frequent in natural landscapes. Lichen abundance (estimated by lichen litter) was two times higher in natural than in managed landscapes, 5.6 and 2.7 kg ha‐1 forest (pooled data), respectively. Both species richness and abundance were negatively related to cutting level (number and basal area of cut stumps) and positively related to stand variables (stand age, stem density and basal area). Lichen‐rich forest stands were more numerous but covered a smaller area and were more isolated in managed landscapes. This may in turn have important consequences for dispersal of lichen propagules to second‐growth forests. In conclusion, the results suggest that effects of forestry on epiphyte diversity and abundance are strongly related to the spatial scale (stand or landscape). To enhance biodiversity in managed forests we must increase structural heterogeneity at the whole range of spatial and temporal scales.