Widespread Communities Research Articles

Sacred sites in north‐western Morocco – naturalness of their vegetation and conservation value for vulnerable plant species

The vegetation and flora of 86 sacred sites (surroundings of tombs of local saints, cemeteries) in NW Morocco was studied to assess their conservation value for undisturbed Mediterranean evergreen forests and vulnerable plants. Habitats were mapped, based on life form, maximum height and cover value, and classified according to naturalness. Vascular plants were classified according to pre‐defined risk factors like stenochory or grazing sensitivity. Naturalness index and refugial value were calculated for each site. Only 20% of the mapped site area was closed forest. On many places, human impact had created a vegetation mosaic. Most of the vulnerable plants were mesophilous forest species or grazing sensitive taxa. Endemic species occurred only rarely. The occurrence of vulnerable plants and the naturalness of the vegetation were positively correlated. Sacred site extension had no significant effect on the number of vulnerable species. Results indicate a limited relevance of sacred sites in northern Morocco for the protection of intact forests and vulnerable plants. However, these localities can play an important role as stepping stones in agricultural landscapes. They protect plants, sensitive to opening of the tree layer, to deforestation and to intense grazing. Certain formerly widespread forest communities survived exclusively on sacred sites.

Victim entrepreneurs doing well by doing good: Venture creation and well-being in the aftermath of a resource shock

Venture creation generates value in a variety of forms both for the entrepreneur him or her-self and the venture's stakeholders. Recent research explores entrepreneurial action as a vehicle for personal transformation and development for the individual, especially as it pertains to overcoming adversity. We build on this emerging literature by exploring victims creating new ventures in the aftermath of a disaster event, where widespread adversity threatens entire communities. Following the disaster, some victim resources are destroyed (e.g., property) while others remain (e.g., human capital) at varying levels. We build on organizational emergence and conservation of resources theories and use structural equation modeling to test a victim entrepreneur model of functioning through the creation of ventures to alleviate others' suffering. We find that venture creation mediates the positive relationship between human capital and functioning and that for those who do not create ventures, human capital is negatively related to functioning—highlighting the important role of venture creation for the victim-actor following a disaster event. Implications of these findings for literature on venture creation and responses to adversity are discussed.

The Last Possible Outposts for Life on Mars.

The evolution of habitable conditions on Mars is often tied to the existence of aquatic habitats and largely constrained to the first billion years of the planet. Here, we propose an alternate, lasting evolutionary trajectory that assumes the colonization of land habitats before the end of the Hesperian period (ca. 3 billion years ago) at a pace similar to life on Earth. Based on the ecological adaptations to increasing dryness observed in dryland ecosystems on Earth, we reconstruct the most likely sequence of events leading to a late extinction of land communities on Mars. We propose a trend of ecological change with increasing dryness from widespread edaphic communities to localized lithic communities and finally to communities exclusively found in hygroscopic substrates, reflecting the need for organisms to maximize access to atmospheric sources of water. If our thought process is correct, it implies the possibility of life on Mars until relatively recent times, perhaps even the present.

A Note from the Editor

A Note from the Editor Gwendolyn Alker Over the last few weeks I have been thinking about the proverbial claim of academia as an “ivory tower”—supposedly free from the turbulence of the outside world. To a certain extent there are economic, social, and political buffers between academia and other milieus, at least in the United States. And certainly some universities are more buttressed from the economic realities of this moment than others. But what my editing of this current issue reminded me of is how we academics, and particularly those who deal with theatre and performance, are intertwined with and have certain responsibilities to our local communities. Indeed, as art-makers and as theorists of our art form, we not only interact with and comment on that which goes on around us, but are also engaged with the creation, and re-creation, of our cultural moment. Scholarship that moves gracefully between theory and practice must also move ethically and intelligently among the communities that create the ideas and the work. I have come to think of Theatre Topics as a place to support strategies and create insights on such movement. Put into disciplinary terms, I see this through our commitment to pedagogy, devising, and dramaturgy, but also in our engagement with applied and community-based theatre. The definition and purview of such terms are complex. I invoke one recently offered in Theatre for Change by Robert Landy and David Montgomery: “Applied Theatre is a simple idea—this is a theatre for change that exists to question and challenge the given order” (130). Perhaps we can then say that what TT as a whole does is to ask what changes for whom, and why. As theatre artists and scholars (including those who identify as both, and those who look toward the other half of this duality for inspiration and support), theatre can become a bridge among higher education, the professional performance world, and the many other worlds that surround us. In this issue of TT such exchanges take place within communities as specific as one prison or one farm, or in more widespread communities based around a racial or ethnic identity in a certain geographic region. Thus it is with considerable pride that I offer the following essays and notes from the field, almost all of which question how theatre creates ethical change within specific communities. This issue begins with a timely look back at the way that theatre has engaged with the overwhelmingly theatrical event that was and is 9/11. Facing the fifteenth anniversary of this tragedy, authors Elliot Leffler and Michael Mellas ask how theatre can be a place for maintaining complex and divergent views. Their reflection offers a hopeful engagement on how theatre can spatially, compositionally, and politically allow for a “dramaturgy of divergence,” while maintaining a culture of respect for those present in the theatre. With the hindsight that we now have regarding 9/11 and the subsequent turn in the mediation of news and its reception, the multiplicity of such theatrical experiences seems relevant and timely. Catherine Ming T’ien Duffly continues the issue with “Farms and Fables: Cultivating Difference in Community-based Theatre.” Taking an applied theatre project in which members of the Open Waters Theater Company worked with various farmers in Maine, she points out the difficulties of bringing community-based theatre to those who may or may not be willing or able to participate. Such honest challenges for theatre professionals working with divergent communities is revisited in three brief, but powerful notes later in this volume: Monica Prendergast’s description of her project with the William Head on Stage company in British Columbia; Paul Maunder’s far-reaching experiences as a “journeyman writer” in New Zealand/Aotearoa; and Fadi Fayad Skeiker’s interview [End Page ix] with Alexander Schroeder as he seeks to bring therapeutic theatre experiences to the Syrian refugee populations who are, as we go to press, still fleeing a devastating civil war in their home country. Other fascinating convergences arise with our next essay, Lisa Jackson-Schebetta’s “Worlds of More Than One,” and the final peer-reviewed essay in the print version of this issue, Lisa Quoresimo...

Best management practices to face degraded territories occupied by Cistus ladanifer shrublands – Portugal case study

Land degradation in the Mediterranean Basin is clearly connected to the resilience of perturbed ecosystems, contributing to land abandonment, recurrent fires and biodiversity loss, with the prevalence of secondary shrublands that tend to occupy large areas. This is the case of Cistus ladanifer shrublands, one of the most widespread shrub communities in the Iberian Peninsula and a poor, uniform and resilient system. Here, we analyse the impact of several management practices in the recovery of territories largely occupied by this shrubland. We tested “non-intervention”, “cut”, “fire”, “mechanical mobilisation” and “pasture” in 100-m2 plots of Cistus ladaniferus L., in Central Portugal, and followed them from 1993. Flora were analysed using Braun–Blanquet's methodology and the plots were compared with hierarchical cluster analysis and principal component analysis. An analysis of variance was also performed to investigate differences in management practices, both between plots and between two periods of time. The results show that extensive grazing or continuous cut have a high impact on plant diversity and community structure, with extensive grazing being the best way to improve plant diversity in a short period of time, using fewer resources.

Effect of temperature and pH on the early stages of interaction of compatible partners of the lichen Cladonia rangiferina (Cladoniaceae)

Reindeer lichens (such as Cladonia rangiferina) are important winter forage for caribou and reindeer and are widely distributed in northern ecosystems. Widespread lichen communities may be explained by dispersal from thallus fragments or by fungal ascospores interacting with algal cells. Since three early stages of interactions between symbionts of the lichen C. rangiferina have already been established, this study investigated the effect of three temperatures (5, 20, and 35 °C) and pH levels (4.5, 6.5, and 8.5) on the early interaction of C. rangiferina by quantifying morphological differences for three fungal (internode length, number of lateral branches, number of appressoria) and one algal (cell diameter) characters using Scanning Electron Microscopy. The results showed that the fungal characters were significantly altered by the extreme temperatures (5 and 35 °C) and the pH level produced differences in the fungal characters at pH 8.5. The alga was more tolerant of the wide temperature range than the fungus while the fungus was more tolerant of pH changes than the alga. An interaction effect by temperature and pH on the symbiont characters was also observed. The study raises questions regarding the range of conditions tolerated by other species of lichens and their symbionts.

Constellations of Cultural Practices across Generations: Indigenous American Heritage and Learning by Observing and Pitching In

This article argues that a generational approach focusing on changing constellations of cultural practices helps to understand culture. We contrast this approach with the “box approach,” which categorizes individuals by racial or ethnic ancestry. The article focuses on the survival, disappearance, and transformation of constellations of cultural practices related to Learning by Observing and Pitching In to activities of the family and community (LOPI) in Indigenous communities of the Americas, across time and place. We illustrate the importance of considering constellations of cultural practices by showing connections among schooling, urban/rural residence, occupations, Indigenous birthing and spiritual practices, and LOPI across three cultural communities in a Mexican metropolis across three generations. We argue that a constellation of practices, including the cultural tradition of Learning by Observing and Pitching In to family and community endeavors, links widespread communities with Indigenous practices of the Americas.

Anaerobic methanotrophic community of a 5346‐m‐deep vesicomyid clam colony in the Japan Trench

Vesicomyidae clams harbor sulfide-oxidizing endosymbionts and are typical members of cold seep communities where active venting of fluids and gases takes place. We investigated the central biogeochemical processes that supported a vesicomyid clam colony as part of a locally restricted seep community in the Japan Trench at 5346 m water depth, one of the deepest seep settings studied to date. An integrated approach of biogeochemical and molecular ecological techniques was used combining in situ and ex situ measurements. In sediment of the clam colony, low sulfate reduction rates (maximum 128 nmol mL−1 day−1) were coupled to the anaerobic oxidation of methane. They were observed over a depth range of 15 cm, caused by active transport of sulfate due to bioturbation of the vesicomyid clams. A distinct separation between the seep and the surrounding seafloor was shown by steep horizontal geochemical gradients and pronounced microbial community shifts. The sediment below the clam colony was dominated by anaerobic methanotrophic archaea (ANME-2c) and sulfate-reducing Desulfobulbaceae (SEEP-SRB-3, SEEP-SRB-4). Aerobic methanotrophic bacteria were not detected in the sediment, and the oxidation of sulfide seemed to be carried out chemolithoautotrophically by Sulfurovum species. Thus, major redox processes were mediated by distinct subgroups of seep-related microorganisms that might have been selected by this specific abyssal seep environment. Fluid flow and microbial activity were low but sufficient to support the clam community over decades and to build up high biomasses. Hence, the clams and their microbial communities adapted successfully to a low-energy regime and may represent widespread chemosynthetic communities in the Japan Trench. In this regard, they contributed to the restricted deep-sea trench biodiversity as well as to the organic carbon availability, also for non-seep organisms, in such oligotrophic benthic environment of the dark deep ocean.

Растительность города Салавата (Республика Башкортостан). V. Естественная и полуестественная травяная растительность (классы Molinio-Arrhenatheretea, Festuco-Brometea и Thero-Salicornietea)

The big cities are ecosystems where the most of the planet population is concentrated. The urban environment is characterized by essential changes of substances circulation, energy flow and the ecological conditions important for vegetation growing (Vladimirov, 1986; Odum, 1986; Burda, 1991; Goryshina, 1991; Berezutski, 2007 etc.). At present, urbanized territories of the world occupy only 5% of the entire land, and about 3 billion people live there., Increase of urbanization forces us to study the vegetation cover of the cities. Within city line, two main variants of vegetation communities are distinguished. The first is anthropogenic. It includes man-planted vegetation and widespread communities of synanthropic species. The second variant represents the remains of natural communities ecotopes on the urban territory. Native and semi-native herb vegetation of Salavat town (classes Molinio-Arrhenatheretea, Festuco-Brometea and Thero-Salicornietea) is classified to 6 orders, 9 unions, 10 associations, 1 subassociation, 7 variants and 6 communities. Among them 3 associations (Elytrigio repentis–Bromopsidetum inermis, Sedo acris–Festucetum pseudovinae, Astragalo austriacae–Stipetum pulcherrimae), 1 subassociation (F. v.–C. f. poetosum angustifoliae) and 5 communities (derivate community Solidago canadensis [Arrhenatheretalia], basal community Poa angustifolia [Cynosurion/Onopordetalia acanthii], derivate community Lolium perenne [Cynosurion] and communities of Geranium sibiricum and Suaeda corniculata) are described for the first time in the South Urals. Grassland communities of the class Molinio-Arrhenatheretea maintaining some trampling and pasture (in the city suburbs) are most widespread. They are rather diverse due to a wide range of ecological characteristics of the habitats (disturbance, moistening, and characteristics of substratum). The steppe vegetation of the class Festuco-Brometea is remained on the southern and eastern slopes of the uplands. The class Thero-Salicornietea communities on habitats with technogenic salinification occur locally. When building the city most of natural vegetation communities were destroyed, or they were transformed in semi-natural phytocoenosis with a high number of synanthropic species in floristic structure. The remained fragments of natural vegetation make an essential contribution, both to city flora, and to urban vegetation. They are refuges of many plant species, including rare and endemic species of the plants. Among endemic species — 1 species (Astragalus wolgensis). Two species (Stipa pulcherrima, S. pennata) are included in the Red List of the Russian Federation and also 2 species from the Red List of Bashkortostan Republic (Stipa korshinskyi and Tulipa biebersteiniana) were revealed. The rare plant species were described in steppe communities and the steppe meadows. These ecosystems need to be protected urgently.

Habitat Re-Creation (Ecological Restoration) as a Strategy for Conserving Insect Communities in Highly Fragmented Landscapes.

Because of their vast diversity, measured by both numbers of species as well as life history traits, insects defy comprehensive conservation planning. Thus, almost all insect conservation efforts target individual species. However, serious insect conservation requires goals that are set at the faunal level and conservation success requires strategies that conserve intact communities. This task is complicated in agricultural landscapes by high levels of habitat fragmentation and isolation. In many regions, once widespread insect communities are now functionally trapped on islands of ecosystem remnants and subject to a variety of stressors associated with isolation, small population sizes and artificial population fragmentation. In fragmented landscapes ecological restoration can be an effective strategy for reducing localized insect extinction rates, but insects are seldom included in restoration design criteria. It is possible to incorporate a few simple conservation criteria into restoration designs that enhance impacts to entire insect communities. Restoration can be used as a strategy to address fragmentation threats to isolated insect communities if insect communities are incorporated at the onset of restoration planning. Fully incorporating insect communities into restoration designs may increase the cost of restoration two- to three-fold, but the benefits to biodiversity conservation and the ecological services provided by intact insect communities justify the cost.

Forest herb layer response to long-term light deficit along a forest developmental series

Temperate deciduous forest communities are slow-changing systems, with herbaceous understorey communities displaying a delayed response to overstorey canopy and light dynamics. While light availability constrains herbaceous understorey diversity and composition in space and time, its response in the long-term absence of light has seldom been quantified, particularly as it is often confounded by covariation in soil conditions. We studied a developmental high-forest series in two widespread NW-European temperate deciduous forest communities with different dominant canopy tree species: Stellario-Carpinetum (Oak-hornbeam canopy) and Milio-Fagetum (Beech canopy). All plots had soil conditions which were not significantly different, enabling investigation into the direct effects of the long-term absence of light on the herbaceous understorey, disentangled from the confounding effects of soil variation.Plant species richness measures declined with canopy cover continuity in the herb layer of the oak-hornbeam stands, whereas richness in the herb layer of the beech stands displayed a unimodal response. Nonetheless, in both plant communities, species richness and closed-forest species richness were negatively affected by the extended absence of light in stands with the longest period of continuous canopy cover. The long-term limitation or decline in quantitative and qualitative light availability as a result of extended periods of canopy cover was shown to be the primary driver behind losses in alpha-diversity, community composition turn-over and individual species dynamics. Heliophilous species were lost from both communities, while closed-forest species also declined, as a direct consequence of the prolonged period without ample light on the forest floor. This study demonstrates how the herb layer is affected by the absence of light on the forest floor mediated by long periods of continuous canopy cover. Despite different temporal responses in herb layer richness and composition between different shade-casting canopy species, the eventual outcome in the prolonged absence of light is independent of dominant canopy species.

A Functional Framework for Improved Management of Western North American Aspen (Populus tremuloides Michx.)

Quaking or trembling aspen (Populus tremuloides Michx.) forests occur in highly diverse settings across North America. However, management of distinct communities has long relied on a single aspen-to-conifer successional model. We examine a variety of aspen-dominated stand types in the western portion of its range as ecological systems, avoiding an exclusive focus on seral dynamics or single-species management. We build a case for a large-scale functional aspen typology based on the existing literature. Aspen functional types are defined as aspen communities that differ markedly in their physical and biological processes. The framework presented here describes two “functional types” and seven embedded “subtypes”: seral (boreal and montane), stable (parkland, Colorado Plateau, elevation and aspect limited, and terrain isolated), and a crossover seral-stable subtype (riparian). The assessment hinges on a matrix comparing proposed functional types across a suite of environmental characteristics. Differences among functional groups based on physiological and climatic conditions, stand structures and dynamics, and disturbance types and periodicity are described herein. We further examine management implications and challenges, such as human alterations, ungulate herbivory, and climate futures, that affect the functionality of these aspen systems. The functional framework lends itself well to stewardship and research that seek to understand and emulate ecological processes rather than combat them. We see advantages of applying this approach to other widespread forest communities that engender diverse functional adaptations.

Outbreaks by canopy-feeding geometrid moth cause state-dependent shifts in understorey plant communities.

The increased spread of insect outbreaks is among the most severe impacts of climate warming predicted for northern boreal forest ecosystems. Compound disturbances by insect herbivores can cause sharp transitions between vegetation states with implications for ecosystem productivity and climate feedbacks. By analysing vegetation plots prior to and immediately after a severe and widespread outbreak by geometrid moths in the birch forest-tundra ecotone, we document a shift in forest understorey community composition in response to the moth outbreak. Prior to the moth outbreak, the plots divided into two oligotrophic and one eutrophic plant community. The moth outbreak caused a vegetation state shift in the two oligotrophic communities, but only minor changes in the eutrophic community. In the spatially most widespread communities, oligotrophic dwarf shrub birch forest, dominance by the allelopathic dwarf shrub Empetrum nigrum ssp. hermaphroditum, was effectively broken and replaced by a community dominated by the graminoid Avenella flexuosa, in a manner qualitatively similar to the effect of wild fires in E. nigrum communities in coniferous boreal forest further south. As dominance by E. nigrum is associated with retrogressive succession the observed vegetation state shift has widespread implications for ecosystem productivity on a regional scale. Our findings reveal that the impact of moth outbreaks on the northern boreal birch forest system is highly initial-state dependent, and that the widespread oligotrophic communities have a low resistance to such disturbances. This provides a case for the notion that climate impacts on arctic and northern boreal vegetation may take place most abruptly when conveyed by changed dynamics of irruptive herbivores.Electronic supplementary materialThe online version of this article (doi:10.1007/s00442-013-2648-1) contains supplementary material, which is available to authorized users.

Bursting the bubble on bacterial biofilms: a flow cell methodology

The flow cell biofilm system is an important and widely used tool for the in vitro cultivation and evaluation of bacterial biofilms under hydrodynamic conditions of flow. This paper provides an introduction to the background and use of such systems, accompanied by a detailed guide to the assembly of the apparatus including the description of new modifications which enhance its performance. As such, this is an essential guide for the novice biofilm researcher as well as providing valuable trouble-shooting techniques for even the most experienced laboratories. The adoption of a common and reliable methodology amongst researchers would enable findings to be shared and replicated amongst the biofilm research community, with the overall aim of advancing understanding and management of these complex and widespread bacterial communities.

Reconstructing Community Assembly in Time and Space Reveals Enemy Escape in a Western Palearctic Insect Community

How geographically widespread biological communities assemble remains a major question in ecology. Do parallel population histories allow sustained interactions (such as host-parasite or plant-pollinator) among species, or do discordant histories necessarily interrupt them? Though few empirical data exist, these issues are central to our understanding of multispecies evolutionary dynamics. Here we use hierarchical approximate Bayesian analysis of DNA sequence data for 12 herbivores and 19 parasitoids to reconstruct the assembly of an insect community spanning the Western Palearctic and assess the support for alternative host tracking and ecological sorting hypotheses. We show that assembly occurred primarily by delayed host tracking from a shared eastern origin. Herbivores escaped their enemies for millennia before parasitoid pursuit restored initial associations, with generalist parasitoids no better able to track their hosts than specialists. In contrast, ecological sorting played only a minor role. Substantial turnover in host-parasitoid associations means that coevolution must have been diffuse, probably contributing to the parasitoid generalism seen in this and similar systems. Reintegration of parasitoids after host escape shows these communities to have been unsaturated throughout their history, arguing against major roles for parasitoid niche evolution or competition during community assembly.

Benthic bacterial diversity from freshwater tufas of the Iberian Range (Spain)

Aiming to characterize the bacterial diversity of modern tufa systems of the Iberian Range (Spain), we surveyed the 16S rRNA gene sequence diversity from 24 sites within three rivers (Añamaza, Mesa and Piedra). These tufas record substantial calcareous growth under different physicochemical conditions and are part of an important, regional landscape-building system. The bacterial community structure and composition, richness and diversity were quantified from denaturing gradient gel electrophoresis fingerprints. Retrieved DNA sequences could be assigned to 10 bacterial phyla and included a variety of phototrophic and heterotrophic groups. Cyanobacteria, mainly filamentous taxa, constituted 43% of all the retrieved sequences, followed by Firmicutes (11%), Gammaproteobacteria (10%), Alphaproteobacteria (7%), Acidobacteria (6%), Bacteroidetes (5%), Betaproteobacteria (4%), Planctomycetes (4%), Actinobacteria (3%) and Deltaproteobacteria (2%). Diatom and Xanthophyceae chloroplast sequences were also detected. Physicochemical variables measured at each site were modelled with multivariate statistics. Principal component analyses yielded the highest variance for salinity-related variables (conductivity; Na(+) , Cl(-) and SO4(2-) concentrations), which correlated negatively and significantly with diversity indices. However, the highest variance explained by individual principal components was relatively low (< 34%). Overall, we show that these young fluvial tufas are inhabited by a large variety of bacteria in diverse and widespread communities.

The Effect of Plant Inbreeding and Stoichiometry on Interactions with Herbivores in Nature: Echinacea angustifolia and Its Specialist Aphid

Fragmentation of once widespread communities may alter interspecific interactions by changing genetic composition of interacting populations as well as their abundances and spatial distributions. In a long-term study of a fragmented population of Echinacea angustifolia, a perennial plant native to the North American prairie, we investigated influences on its interaction with a specialist aphid and tending ants. We grew plant progeny of sib-matings (I), and of random pairings within (W) and between (B) seven remnants in a common field within 8 km of the source remnants. During the fifth growing season, we determined each plant's burden of aphids and ants, as well as its size and foliar elemental composition (C, N, P). We also assayed composition (C, N) of aphids and ants. Early in the season, progeny from genotypic classes B and I were twice as likely to harbor aphids, and in greater abundance, than genotypic class W; aphid loads were inversely related to foliar concentration of P and positively related to leaf N and plant size. At the end of the season, aphid loads were indistinguishable among genotypic classes. Ant abundance tracked aphid abundance throughout the season but showed no direct relationship with plant traits. Through its potential to alter the genotypic composition of remnant populations of Echinacea, fragmentation can increase Echinacea's susceptibility to herbivory by its specialist aphid and, in turn, perturb the abundance and distribution of aphids.

Microbial geomorphology: A neglected link between life and landscape

Whilst recognition is increasing that life and landscapes are intimately related, as evidenced by growing research into ecosystem engineering, biogeomorphology and allied topics, the microbial contribution to such interactions has been relatively neglected. A revolution in environmental microbiology, based on molecular techniques, is now driving a reconsideration of the role of microbial processes in geomorphology at all scales. Recent research illustrates the hitherto unknown microbial diversity present in many extreme geomorphic environments, such as hyperarid deserts, subglacial lakes, hot springs, and much richer microbial life than previously suspected within the soils and sediments that blanket most other landscapes. Such microbial communities have been found to play important geomorphic roles across a wide range of environments, notably in weathering, precipitation of minerals and protecting surfaces from erosion. These geomorphic roles can also be conceptualised as examples of ecosystem engineering, and can pave the way for further plant-geomorphology and zoogeomorphology processes. Three key aspects which emerge from a review of microbial influences on Earth surface processes are a) that microbes play roles on a continuum from full control to passive involvement, b) that complex and widespread communities of microorganisms are involved and c) that microbial activity usually affects several Earth surface processes at once. Examples of the contribution of microbial life to geomorphology over long, medium and short timescales suggest that microorganisms play key geomorphological roles in two major situations; on the cusp between stable states, and in extreme environments where higher plant and animal life is limited and many abiotic processes are also constrained. The dominant link between microbial life and geomorphology appears to take on different forms depending on the timescale under consideration, with a stabilising microbial role apparent over short timescales being replaced by a denudational role over longer timescales. Further research involving microbiologists and geomorphologists is now needed to address three main questions, i.e. under what conditions are microbial and geomorphological processes most closely linked?, what scale issues surround links between microbes and geomorphology? And how do microbiological processes underpin broader biogeomorphological interactions?

Tropospheric ozone effects on chemical composition and decomposition rate of Quercus ilex L. leaves

We determined the effects of tropospheric ozone on the chemical composition of Quercus ilex L. leaves and their decomposition, with a view to assessing the influence of ozone on nutrient cycling and the sustainability of Mediterranean holm oak forests. Forming one of the most widespread thermophilous vegetation communities in the area, Q. ilex is a dominant and widespread evergreen oak in the Mediterranean, where concentrations of tropospheric ozone are particularly high. The dynamics of carbon, nitrogen, lignin and cellulose concentrations were monitored for six months during the decomposition of leaves from plants subjected to controlled ozone exposure in open-top chambers. Ozone-exposed leaves, compared to unexposed leaves, showed no significant differences in C, N, lignin and cellulose concentrations prior to the incubation in mesocosms. However, during decomposition, leaves from plants exposed to ozone lost C significantly more slowly and showed a higher C/N ratio than unexposed leaves. Ozone exposure significantly slowed down the decomposition rate, indicating a negative effect of tropospheric ozone on nutrient cycling, which may reduce long-term sustainability of the holm oak forest.

Teratomorphs of broad-leaved cattail Typha latifolia L. in Vozhe Lake

Morphological anomalies such as hypogenesia, dystopia, and polymerization have been found and classified in communities of the broad-leaved cattail Typheta latifoliae in the specific species Typha latifolia L. in technogenically disturbed habitats of Vozhe Lake. Anomalies have also been found in other specific species in the most widespread communities of Vologda Poozer’e, such as Phramitetum australis subpurum and Typheta angustifoliae subpurum. This testifies to the deep changes in hydrophilic flora under anthropogenic influences. The tendency to teratological speciation appears in natural conditions in pure communities of Phramitetum australis, Typheta angustifoliae, and Typheta latifoliae on the northern border of coenotic and ecological areals.