Natural Microcosms Research Articles

Deciphering the ecological impact of azo dye pollution through microbial community analysis in water-sediment microcosms.

The uncontrolled release of untreated dyeing wastewater into aquatic ecosystems poses global environmental risks. It alters native microbial communities and associated ecological processes, often going unnoticed. Therefore, the influence of acid orange 7dye (AO7) contamination on the natural microbial community was investigated using a water-sediment microcosm. Compared to sterile microcosms, complete dye decolourization in natural microcosms showed microbial communities' significance in combating xenobiotic contamination. Proteobacteria dominated the water community, whereas Firmicutes dominated the sediment. AO7 exposure induced notable shifts in the structural composition of the bacterial community in both water and sediment. Niveispirillum exhibited a marked decrease, and Pseudomonas demonstrated a notable increase. The - 9.0 log2FC in Niveispirillum, a nitrogen-fixing bacterium, from 24.4% in the control to 0.1% post-treatment, may disrupt nutrient balance, plant growth, and ecosystem productivity. Conversely, elevated levels of Pseudomonas sp. resulting from azo dye exposure demonstrate its ability to tolerate and bioremediate organic pollutants, highlighting its resilience. Functional profiling via KEGG pathway analysis revealed differential expression patterns under AO7 stress. Specifically, valine, leucine, and isoleucine degradation pathways in water decreased by 52.2%, and cysteine and methionine metabolism ceased expression entirely, indicating reduced protein metabolism and nutrient bioavailability under dye exposure. Furthermore, in sediment, glutathione metabolism ceased, indicating increased oxidative stress following AO7 infusion. However, C5-branched dibasic acid metabolism and limonene and pinene degradation were uniquely expressed in sediment. Decreased methane metabolism exacerbates the effects of global warming on aquatic ecosystems. Further, ceased-butanoate metabolic pathways reflect the textile dye wastewater-induced adverse impact on ecological processes, such as organic matter decomposition, energy flow, nutrient cycling, and community dynamics that help maintain self-purification and ecological balance in river ecosystems. These findings underscore the critical need for more comprehensive environmental monitoring and management strategies to mitigate ecological risks posed by textile dyes in aquatic ecosystems, which remain unnoticed.

Interactive effects of drought and deforestation on multitrophic communities and aquatic ecosystem functions in the Neotropics-a test using tank bromeliads.

Together with the intensification of dry seasons in Neotropical regions, increasing deforestation is expected to exacerbate species extinctions, something that could lead to dramatic shifts in multitrophic communities and ecosystem functions. Recent studies suggest that the effects of habitat loss are greater where precipitation has decreased. Yet, experimental studies of the pure and interactive effects of drought and deforestation at ecosystem level remain scarce. Here, we used rainshelters and transplantation from rainforest to open areas of natural microcosms (the aquatic ecosystem and microbial-faunal food web found within the rainwater-filled leaves of tank bromeliads) to emulate drought and deforestation in a full factorial experimental design. We analysed the pure and interactive effects of our treatments on functional community structure (including microorganisms, detritivore and predatory invertebrates), and on leaf litter decomposition in tank bromeliad ecosystems. Drought or deforestation alone had a moderate impact on biomass at the various trophic level, but did not eliminate species. However, their interaction synergistically reduced the biomass of all invertebrate functional groups and bacteria. Predators were the most impacted trophic group as they were totally eliminated, while detritivore biomass was reduced by about 95%. Fungal biomass was either unaffected or boosted by our treatments. Decomposition was essentially driven by microbial activity, and did not change across treatments involving deforestation and/or drought. Our results suggest that highly resistant microorganisms such as fungi (plus a few detritivores) maintain key ecosystem functions in the face of drought and habitat change. We conclude that habitat destruction compounds the problems of climate change, that the impacts of the two phenomena on food webs are mutually reinforcing, and that the stability of ecosystem functions depends on the resistance of a core group of organisms. Assuming that taking global action is more challenging than taking local-regional actions, policy-makers should be encouraged to implement environmental action plans that will halt habitat destruction, to dampen any detrimental interactive effect with the impacts of global climate change.

Empirical Evidence for the Rescue Effect from a Natural Microcosm.

Ecological theory predicts that populations which receive immigrants are less vulnerable to extinction than those that do not receive immigrants (the "rescue effect"). A parallel but opposite process may also exist, where emigration increases the risk of local extinction (the "abandon-ship effect"). Using a natural microcosm of plant-specialist frogs from Madagascar, empirical evidence for both processes is provided. Populations receiving immigrants were less extinction-prone than those without immigration, and those populations losing individuals through emigration were more extinction-prone than those in which no emigration occurred. The number of immigrants and emigrants was also elevated and depressed (respectively) in patches that did not go extinct. These data provide some of the first definitive empirical evidence for the rescue effect and provide suggestive initial data on the abandon-ship effect. Both of these processes may be important to understanding the dynamics of populations.

Bromeliad phytotelmata: the first scientometric study

Some representatives of this family have the ability to form phytotelma environments through the accumulation of water and organic matter, serving as substrate and food for a variety of organisms. Here, a scientometric analysis was carried out to show trends in scientific work on bromeliad phytotelmata and the importance of these microcosms for the maintenance of biodiver¬sity. The papers were analyzed using the Thomson Reuters, Scopus and Scielo databases between the years 1970 and 2021. Information was sought on the years of publications, geographic regions, countries, article design (descriptive, predictive, ex¬perimental, review), focus (ecological, biological, molecular), and ecological level of study (organism, population, community and ecosystem). South America presented the highest number of works developed with the subject and also with researchers involved. Most studies presented predictive designs focusing on community ecology. Insecta, followed by Crustacea and Anu¬ra, were the most studied groups of organisms. The results contribute to a better understanding of biodiversity in bromeliad phytotelmata, pointing out gaps and trends in research directed at these natural microcosms.

Design and Development of Fluorinated and Biocide-Free Sol-Gel Based Hybrid Functional Coatings for Anti-Biofouling/Foul-Release Activity.

Biofouling has destructive effects on shipping and leisure vessels, thus producing severe problems for marine and naval sectors due to corrosion with consequent elevated fuel consumption and higher maintenance costs. The development of anti-fouling or fouling release coatings creates deterrent surfaces that prevent the initial settlement of microorganisms. In this regard, new silica-based materials were prepared using two alkoxysilane cross-linkers containing epoxy and amine groups (i.e., 3-Glycidyloxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane, respectively), in combination with two functional fluoro-silane (i.e., 3,3,3-trifluoropropyl-trimethoxysilane and glycidyl-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorononylether) featuring well-known hydro repellent and anti-corrosion properties. As a matter of fact, the co-condensation of alkoxysilane featuring epoxide and amine ends, also mixed with two opportune long chain and short chain perfluorosilane precursors, allows getting stable amphiphilic, non-toxic, fouling release coatings. The sol–gel mixtures on coated glass slides were fully characterized by FT-IR spectroscopy, while the morphology was studied by scanning electron microscopy (SEM), and atomic force microscopy (AFM). The fouling release properties were evaluated through tests on treated glass slides in different microbial suspensions in seawater-based mediums and in seawater natural microcosms. The developed fluorinated coatings show suitable antimicrobial activities and low adhesive properties; no biocidal effects were observed for the microorganisms (bacteria).

Degradation profile and dioxygenase activity of Carnobacterium gallinarum (mt350233) and Enterococcus faecalis (mt345788) isolated from landfill soil in Benin City

Landfill is a potential microbial hub of hydrocarbon (HC) degrading bacterial population owing to nutrient availability and continuous enrichment by organic materials. The degradation and dioxygenase activity of Carnobacterium gallinarum and Enterococcus faecalis isolated from landfill soil in Benin City was investigated. Soil samples were collected from a Government approved landfill in Benin City at a depth of 0 to 10 cm. Standard microbiological and molecular methods were followed for the isolation and characterization of bacterial population. Bacterial isolates were standardized for degradation using spectrophotometer optical density (OD) 0.08 at 600 nm (equivalent to 1×108cfu/ml). The gas chromatography with flame ionization detector (GC-FID) method was used to determine the total petroleum hydrocarbon (TPH) of waste engine oil (WEO) containing samples. The spectrophotometric methods were used for the assay of catechol 1,2-dioxygenase (C12O) and catechol 2,3-dioxygenase (C23O) activity. The result of the 16S rRNA analyses of the bacterial isolates confirmed the identity of Carnobacterium gallinarum as 98.71 % and Enterococcus faecalis as 100 %. The degradation profile of Carnobacterium gallinarum and Enterococcus faecalis at varied concentrations (20, 40, 60, 80 and 100 mg/L) of WEO showed significant decline in optical density (OD) values from day 1 to day 7. The decline in OD is an indication of utilization of Polycyclic Aromatic Hydrocarbons (PAHs) present in the WEO. The result of the gas Chromatography with Flame Ionization Detector (GC-FID analyses) of degraded WEO containing samples revealed the absence of low molecular weight and high molecular weight PAHs after the 7-days degradation study. The presence of HC degrading enzyme in the bacterial isolates was confirmed by the production of C12O and C23O as a result of the formation of cis, cis muconic acid and 2-hydroxymuconic semi-aldehyde respectively. This study revealed that the landfill soil is a potential natural microcosm for WEO degrading bacteria and possesses biologically active HC degrading bacteria population such as Carnobacterium gallinarum and Enterococcus faecalis.

Vertical Stratification of Insect Species Developing in Water-Filled Tree Holes

Forest ecosystems have a distinct vertical dimension, but the structuring of communities in this three-dimensional space is not well understood. Water-filled tree holes are natural microcosms structured in metacommunities. Here, we used these microcosms as model systems to analyze how insect communities and the occurrence and abundance of individual species are influenced by biotic and abiotic microhabitat characteristics, the vertical position of the tree hole, and stand-scale habitat availability. We found that both the characteristics of water-filled tree holes and their insect communities differ significantly between canopy and ground level. Individual insect species showed contrasting responses to the vertical position of the tree holes when important environmental factors at the stand and the tree-hole scale were considered. While some species, such as the mosquito Aedes geniculatus and the beetle Prionocyphon serricornis, decreased in abundance with increasing tree-hole height, the biting midge Dasyhelea sp., the non-biting midge Metriocnemus cavicola and the hoverfly Myiatropa florea increased in abundance. Our results suggest that vertical stratification in forests is most likely driven not only by variation in tree-hole microhabitat properties, i.e., niche separation, but also by individual species traits, such as adult dispersal propensity, food preferences and mating behavior of adult stages, and interspecific competition of larval stages. Therefore, communities of insect species developing in tree holes are likely structured by competition–colonization trade-offs predicted by metacommunity theory.

Ecology of Tree-Holes and Diversity of Insect Larvae in Tree-Hole Water in Mayiladuthurai Taluk

Tree holes are produced due to environmental factors as well as biotic pressure.  It is a unique habitat for insect breeding and survival. Water-filled tree-holes or their analogs are natural microcosms because of their relative simplicity in habitat structure, small size, discrete boundaries, and naturally replicated nature.  The present investigation was carried out with aim of the ecology of tree holes from the different tree species with diversity and distribution of insect larvae.

On Hating the Provinces

On Hating the Provinces Carl Van Doren [End Page 185] From A Roving Critic, "Nooks and Fringes" Emerson lived in Concord and took villages for granted, as natural microcosms in any one of which a sage might study the world. Whitman lived in Manhattan and sent his imagination on strong flights over the entire body of his land, and to the remotest regions, neither denying nor rejecting whatever signs of life he saw. Lincoln in Springfield, whitherto by no means all the philosophies had come and little enough of culture in any composition, mastered not only an incomparable wisdom but an incomparable style. To no one of these men could it have been quite understandable that a second or third generation after them would begin to display among certain of its intellectual leaders that restless and intense hatred of the provinces which marks, for example, the critics of Paris and the professors of Berlin. Yet something of precisely this sort has come to pass. Voice after voice is added to the regiments of criticism being raised against suburban Philistia and the villatic bourgeoisie. That is to say, a reaction is commencing against the frontier which has had so large a hand in making us. It is no longer a natural device to put critical sagacity in the mouth of a rural sage. When Lowell created Hosea Biglow he did so with the brash originality of a young man who was taking venturesome shots at his age; no young American of Lowell's scholarship would think a second time of such a device today. Josh Billings and Artemus Ward to all but a few have come to seem "old stuff." Even Mr. Dooley is not a crossroads loafer but a native son of the city streets. In return for a long course of ridicule from rustic philosophers a new order of philosophes is striking back. We need not wonder, perhaps, that the riposte is often acrimonious; the weight of all this village ridicule has often been heavy. We need not feel too much distressed at the look of snobbishness which some of the critics of our frontier somewhat too continually wear; nothing ought to be so easy to forgive as a zeal for enlightenment. It is important to remember, however, that there is a point of vantage a little above this particular critical melee from which the battle appears less crucial than it doubtless appears to those who wage it. That point of vantage is the artist's, at least so far as the artist is concerned with the reproduction of life without the Puritan's anxiety to make it—or to make it out—the kind of life he thinks it ought to be. The moralist condemns the "bad" people and the wit condemns the dull; but these are phases of argument. With argument the dramatist or novelist is much less concerned. His task is first [End Page 186] of all a representation of what he finds, and his obligation ends—though he may decide to do more—when he has represented it. At his lowest level he yields himself wholly to the manners of his society and sets them forth with implied approbation, as if they were the laws of God. At a higher level, he turns violently against its prejudices and assails them as if they were the sins of Satan. But there is a level higher still, from which, as he looks upon his community, he sees it as men and women involved in the exercises of life, and he makes his record of them without either uncritical admiration or vexed recrimination. Those novelists and dramatists who now hate our provinces most are nearly all dissatisfied men lately escaped from stodginess and devoted to getting their revenges. In this fashion the heretic, while his wounds smart, lashes back at the doctrines which oppressed him. But the truly emancipated spirit no longer has time for recrimination or revenge. He goes, as artist, about his proper business, accepting stupidity as his material as well as intelligence, vice as well as virtue, gentleness as well as cruelty. In every community, he knows, all the types and tendencies of...

Bisphenol A attenuation in natural microcosm: Contribution of ecological components and identification of transformation pathways through stable isotope tracing

Residues of bisphenol A (BPA) are ubiquitously detected in the surface water due to its widespread usage. This study systematically investigated the dissipation and kinetics of BPA under simulated hydrolysis, direct and indirect photolysis, bacterial degradation, microbial degradation and natural attenuation in microcosm. Structural equation modeling (SEM) by using partial least square method in path coefficient analysis suggested that the microbial degradation was the major factor involved in the natural attenuation of BPA. The potential transformation products were identified by using liquid chromatography high-resolution mass spectrometry (LC-HRMS) and stable isotope tracing technique by simultaneous performing gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) and gas chromatography mass spectrometry (GC–MS). A total of fourteen including three novel transformation products of BPA were identified to indicate five possible pathways. An increased yield of labeled (δ13C) CO2 and detection of 13C-labeled phospholipid fatty acids (PLFAs) indicated the mineralization of BPA and possible utilization of BPA or its transformation products by microbes for cellular membrane synthesis, respectively.

Biomass and abiotic variables change in phytotelmic environment in the tank-bromeliad Nidularium longiflorum Ule in tropical forest

Abstract Aim Phytotelm plays an important role in plant growth and ecosystem functioning, but this natural aquatic microcosm is poorly known. We evaluated the seasonal (dry and rainy seasons) and spatial variations (forest trail and stream sites) of the phytotelm in Nidularium longiflorum, bromeliad that occurs in the Atlantic Forest. Methods Abiotic and biotic variables were measured in tank-bromeliad phytotelms. The biomass was analyzed by ash-free dry mass and chlorophyll-a concentration. Results Abiotic variables measured in the phytotelmic environment of bromeliads varied between sampling sites and seasons. Temperature, electrical conductivity and total nitrogen values were significantly different between seasons and sites. Chlorophyll-a and ash-free dry mass (organic matter) in phytotelm were significantly different between sampling sites. Eleven genera of algae in the phytotelm were identified. PCA axis 1 ordination evidenced the seasonal variation of environmental conditions. Conclusions Our findings suggest that environmental and micro-environmental conditions do not favor the development of algal community in the phytotelm. Biomass and abiotic variables in phytotelm of Nidularium longiflorum change seasonally, however biomass accumulation was strongly influenced by site characteristics.

English

A study on ecological preference of breeding sites of Anopheles gambiae compared to other mosquito species were carried out in small natural microcosms. A total of sixteen small ponds, four each from North, South, East and West of Maiduguri Metropolitan were surveyed for the breeding and non-breeding sites for mosquitoes. In each pond mosquito larvae samples were collected by dip method after identifying species by their angular positions and later confirmed by Polymerase Chain Reaction (PCR). Water samples from which collection of A. gambiae and non-Anopheles gambiae larvae were also collected and analyzed for physico-chemical properties following the standard laboratory procedures. The results revealed that, preference of breeding site of A. gambiae is dependent on the physico-chemical nature of water habitat. Of a total of 30 parameters analyzed, pairwise comparison using SPSS software revealed that 11of the physico-chemical parameters significantly varied (P<0.05) between A. gambiae and non-A. gambiae breeding sites. These parameters include Turbidity, pH, Conductivity, Temperature, Suspended solid, Sodium, Chloride, Sulphate, Calcium, Magnesium, Total hardness and Magnesium hardness. The proportion of A. gambiae in larval habitats were significantly (P<0.05) and positively correlated to these parameters. However, of the eleven parameters, PH (r = 0.429, P = 0.001), temperature (r = 0.269, P = 0.050), calcium(r = 0.256, P = 0.048) and turbidity (r = 0.515, P = 0.000), were found to be the most influential parameters that determine habitat selection for breeding. Key words: Arid zone, ecological preference, physico-chemical, Anopheles gambiae, distribution.

Island Biogeography of Cryoconite Hole Bacteria in Antarctica's Taylor Valley and Around the World

Cryoconite holes are holes in a glacier’s surface caused by sediment melting into the glacier. These holes are self-contained ecosystems that include abundant bacterial life within their sediment and liquid water, and have recently gained the attention of microbial ecologists looking to use cryoconite holes as “natural microcosms” to study microbial community assembly. Here, we explore the idea that cryoconite holes can be viewed as “islands”, in the same sense that an island in the ocean is an area of habitat surrounded by a barrier to entry. In the case of a classic oceanic island, the ocean is a barrier between islands, but in the case of cryoconite holes, the ocean is comprised of impermeable solid ice. We test two hypotheses, born out of island biogeographic theory, that can be readily applied to cryoconite hole bacteria. First, we ask to what extent the size of a cryoconite hole is related to the amount of bacterial diversity found within it. Second, we ask to what extent cryoconite holes exhibit distance decay of similarity, meaning that geographically close holes are expected to harbor similar bacterial communities, and distant holes are expected to harbor more different bacterial communities. To test the island size hypothesis, we measured the sizes of cryoconite holes on three glaciers in Antarctica’s Taylor Valley and used DNA sequencing to measure diversity of bacterial communities within them. We found that for two of these glaciers, there is a strong relationship between hole size and bacterial phylogenetic diversity, supporting the idea that cryoconite holes on those glaciers are “islands.” The high biomass dispersing to the third glacier we measured could explain the lack of size-diversity relationship, remaining consistent with island biogeography. To test the distance decay of similarity hypothesis, we used DNA sequence data from several previous studies of cryoconite hole bacteria from across the world. Combined with our Taylor Valley data, those data showed that cryoconite holes have strong spatial structuring at scales of one to several hundred kilometers, also supporting the idea that these dirty holes on glaciers are really islands in the cryosphere.

Finding flies in the mushroom soup: Host specificity of fungus-associated communities revisited with a novel molecular method.

Fruiting bodies of fungi constitute an important resource for thousands of other taxa. The structure of these diverse assemblages has traditionally been studied with labour-intensive methods involving cultivation and morphology-based species identification, to which molecular information might offer convenient complements. To overcome challenges in DNA extraction and PCR associated with the complex chemical properties of fruiting bodies, we developed a pipeline applicable for extracting amplifiable total DNA from soft fungal samples of any size. Our protocol purifies DNA in two sequential steps: (a) initial salt-isopropanol extraction of all nucleic acids in the sample is followed by (b) an extra clean-up step using solid-phase reversible immobilization (SPRI) magnetic beads. The protocol proved highly efficient, with practically all of our samples-regardless of biomass or other properties-being successfully PCR-amplified using metabarcoding primers and subsequently sequenced. As a proof of concept, we apply our methods to address a topical ecological question: is host specificity a major characteristic of fungus-associated communities, that is, do different fungus species harbour different communities of associated organisms? Based on an analysis of 312 fungal fruiting bodies representing 10 species in five genera from three orders, we show that molecular methods are suitable for studying this rich natural microcosm. Comparing to previous knowledge based on rearing and morphology-based identifications, we find a species-rich assemblage characterized by a low degree of host specialization. Our method opens up new horizons for molecular analyses of fungus-associated interaction webs and communities. Fruiting bodies of fungi constitute an important resource for thousands of other taxa. The structure of these diverse assemblages has traditionally been studied with labour-intensive methods involving cultivation and morphology-based species identification, to which molecular information might offer convenient complements. To overcome challenges in DNA extraction and PCR associated with the complex chemical properties of fruiting bodies, we developed a pipeline applicable for extracting amplifiable total DNA from soft fungal samples of any size. Our protocol purifies DNA in two sequential steps: (a) initial salt-isopropanol extraction of all nucleic acids in the sample is followed by (b) an extra clean-up step using solid-phase reversible immobilization (SPRI) magnetic beads. The protocol proved highly efficient, with practically all of our samples-regardless of biomass or other properties-being successfully PCR-amplified using metabarcoding primers and subsequently sequenced. As a proof of concept, we apply our methods to address a topical ecological question: is host specificity a major characteristic of fungus-associated communities, that is, do different fungus species harbour different communities of associated organisms? Based on an analysis of 312 fungal fruiting bodies representing 10 species in five genera from three orders, we show that molecular methods are suitable for studying this rich natural microcosm. Comparing to previous knowledge based on rearing and morphology-based identifications, we find a species-rich assemblage characterized by a low degree of host specialization. Our method opens up new horizons for molecular analyses of fungus-associated interaction webs and communities.

Environmental change and predator diversity drive alpha and beta diversity in freshwater macro and microorganisms.

Global biodiversity is eroding due to anthropogenic causes, such as climate change, habitat loss, and trophic simplification of biological communities. Most studies address only isolated causes within a single group of organisms; however, biological groups of different trophic levels may respond in particular ways to different environmental impacts. Our study used natural microcosms to investigate the predicted individual and interactive effects of warming, changes in top predator diversity, and habitat size on the alpha and beta diversity of macrofauna, microfauna, and bacteria. Alpha diversity (i.e., richness within each bromeliad) generally explained a larger proportion of the gamma diversity (partitioned in alpha and beta diversity). Overall, dissimilarity between communities occurred due to species turnover and not species loss (nestedness). Nevertheless, the three biological groups responded differently to each environmental stressor. Microfauna were the most sensitive group, with alpha and beta diversity being affected by environmental changes (warming and habitat size) and trophic structure (diversity of top predators). Macrofauna alpha and beta diversity was sensitive to changes in predator diversity and habitat size, but not warming. In contrast, the bacterial community was not influenced by the treatments. The community of each biological group was not mutually concordant with the environmental and trophic changes. Our results demonstrate that distinct anthropogenic impacts differentially affect the components of macro and microorganism diversity through direct and indirect effects (i.e., bottom-up and top-down effects). Therefore, a multitrophic and multispecies approach is necessary to assess the effects of different anthropogenic impacts on biodiversity.

Nectar yeasts: a natural microcosm for ecology.

The species of yeasts that colonize floral nectar can modify the mutualistic relationships between plants and pollinators by changing the chemical properties of nectar. Recent evidence supporting this possibility has led to increased interest among ecologists in studying these fungi as well as the bacteria that interact with them in nectar. Although not fully explored, nectar yeasts also constitute a promising natural microcosm that can be used to facilitate development of general ecological theory. We discuss the methodological and conceptual advantages of using nectar yeasts from this perspective, including simplicity of communities, tractability of dispersal, replicability of community assembly, and the ease with which the mechanisms of species interactions can be studied in complementary experiments conducted in the field and the laboratory. To illustrate the power of nectar yeasts as a study system, we discuss several topics in community ecology, including environmental filtering, priority effects, and metacommunity dynamics. An exciting new direction is to integrate metagenomics and comparative genomics into nectar yeast research to address these fundamental ecological topics.

The role of landscape connectivity in resistance, resilience, and recovery of multi-trophic microarthropod communities.

There is a need to find generalizable mechanisms supporting ecological resilience, resistance, and recovery. One hypothesized mechanism is landscape connectivity, a habitat configuration that allows movement of biotic and abiotic resources between local patches. Whether connectivity increases all or only one of resistance, resilience, and recovery has not been teased apart, however, and has been difficult to test at large scales and for complex trophic webs. Natural microcosms offer a complex system that can be manipulated to test questions at a landscape-scale relative to the community of study. Here, we test the role of connectivity in altering resistance, resilience, and recovery to a gradient of heating disturbance in moss microcosms. To test across trophic levels, we focused on community composition as our metric of response and applied three connectivity treatments - isolation, connected to an equally disturbed patch, and connected to an undisturbed patch. We found that connectivity between equally disturbed patches boosted resistance of communities to disturbance. Additionally, recovery was linear and rapid in communities connected to undisturbed landscapes, hump shaped when connected to equally disturbed landscapes, and linear but slow in isolated communities. We did not find thresholds on the disturbance gradient at which disturbed communities exhibited zero or increasing dissimilarity to controls through time, so were unable to draw conclusions on the role of connectivity in ecological resilience. Ultimately, isolated communities exhibited increasingly variable composition and slow recovery patterns even in control communities when compared with connected treatments.

Messy Communities: Editor's Note

Editor's Note: In this edition of the Paper Trail, an outsider might surmise that the state of community ecology is vanity of vanities with enough theories to make one's head spin. Local vs. regional, deterministic vs. stochastic, and the list goes on. However, two individuals and an entire field would beg to differ and rightly so. Community ecology has a history of being very messy, yet patterns and trends soon emerge when a different view is taken based on a level of understanding and the use of research tools that perhaps the up and coming and established ecologists’ predecessors did not have in their day. Now, instead of opposition, these two researchers have been studying these earlier theories and have gone on to dig deeper through, for example, a Bromeliad Working Group and long-term natural microcosms. And, along the way, they are asking many more questions that will continue to stir up, stimulate, and help advance the messy field of community ecology.

Natural Heritage as a Structure for Urban Regeneration: Case of the El Harrach River

Discredited for a long time, the El Harrach River is extremely pollut­ed today, exceeding by 30 times the accepted standards and by 400 times the WHO standards. Indeed, it crosses over its last nine kilometers to its outfall, an important urban and industrial zone. Nonetheless, the river pollution threatens the bay of Algiers. Being a main part of the urban structure and the natural grid of the city, at 67km-long it starts in the Blida Atlas and flows into the Mediterranean in the middle of the Bay of Algiers. Relatively modest operations have been undertak­en to try to absorb the pollution. Recently, the government launched rigorous decontamination work as a part of the new redevelopment plan of Algiers by 2029. The river is considered an important ecological axis and a natural regen­erative of the urban structure. This article analyses the strategy of reinstatement of this urban and natural microcosm through five segments as a green heritage and generator of the city of tomorrow, with a special focus on the impact of the river redevelopment on these different slices, in relation to the protection of ecosystems, channelling axis of urbanization, for the medium and the long terms.

Chaos and Cosmos: Literary Roots of Modern Ecology in the British Nineteenth Century by Heidi C. M. Scott

Heidi C. M. Scott. Chaos and Cosmos: Literary Roots of Modern Ecology in the British Nineteenth Century. University Park, Pennsylvania: Pennsylvania State University Press. 2014. Pp. 224. $64.95. Chaos and Cosmos is an authoritative, truly interdisciplinary book that turns the usual impulse of Romantic studies on its head: instead of sketching out a literary ecocriticism, to paraphrase Jonathan Bate's famous phrase, Scott ambitiously sets out to find the origins of contemporary ecological methods in Romantic and Victorian literature. Each of the structures of thought of the book's title is connected both to a nineteenth-century literary genre, and to a practice or principle in the work of modern ecological scientists. Chaos refers both to the formal features of nonlinear prose narrative in Romantic and Victorian speculative fictions by Mary Shelley, Richard Jefferies, and H. G. Wells, and also to the unpredictable and cataclysmic environmental phenomena of our contemporary natural world--which Scott argues would be more accurately charted through narrative ecological modeling. Cosmos, by contrast, is related to a Romantic notion of the mind as natural microcosm in nineteenth-century lyric poetry, and to the experimental model of microcosm that modern ecologists continue to use to study nature's activities in a balanced, controlled form--a scientific procedure that, Scott contends, is inherited from lyrical poetic practices familiar to readers of Wordsworth and Keats. Prose and poetry; cataclysm and balance; Scott brings together these bald dichotomies under the banners of chaos and cosmos to make an argument about the practice of ecological science today, in relation both to its poetic inheritance and its potential narrative future. While these are no doubt heterogeneous ideas yoked together forcefully, nature and art prove to be connected by more than comparison and allusion. Scott argues that the disciplines of contemporary ecology and Romantic literature (and, by implicit extension, literary studies) are mutually discursive: The seed of imagination that would enable a scientist to study a lake as a microcosm at the formal, empirical level was sown by poets of the nineteenth century who consciously drew a sphere around small-scale nature in order to make sense of spots of time and place amid the increasingly chaotic global, industrial modern world (4). With readings of both Romantic and Victorian texts, the book addresses itself to literary scholars, but as inset chapters on Scientific Nonfiction and Today's Scientific Modeling reveal, Scott also intends to reach ecologists an ambition confirmed by her ultimate objective to extrapolate literary methods into ecological science, both by acknowledging the indebtedness of post-Darwinian ecology to poetic microcosm, and by revealing the usefulness of narrative in charting the progress of environmental unpredictability. real goal of the book to extend outside of literary studies can sometimes mean that its tone becomes unevenly empiricist (155)> as Scott strives to make studying the nineteenth century relevant to her implied ecologist reader. A reading of George Eliot's lyric poetry is interrupted by an invective on Disney's Imagineering (137); the final section of the book, a Case Study of Keats, is introduced with the sentence, Detailed data collected from this exemplary poet reveal underlying principles that apply more generally (155). This possibly estranging language is an unavoidable and minor consequence of Scott's admirable cross-disciplinary fluency, and her book's argument will have the reach beyond Romanticism to be both impactful and sustainable in ecological studies. There is no question that this book will impact both Romanticism and literary ecocriticism more generally. Scott's first two chapters, which address anticipations of today's climate change in Romantic and Victorian prose, are wonderfully original. …