Non-native Environments Research Articles

Dangerous Liaisons between Detergents and Membrane Proteins. The Case of Mitochondrial Uncoupling Protein 2

The extraction of membrane proteins from their native environment by detergents is central to their biophysical characterization. Recent studies have emphasized that detergents may perturb the structure locally and modify the dynamics of membrane proteins. However, it remains challenging to determine whether these perturbations are negligible or could be responsible for misfolded conformations, altering the protein's function. In this work, we propose an original strategy combining functional studies and molecular simulations to address the physiological relevance of membrane protein structures obtained in the presence of detergents. We apply our strategy to a structure of isoform 2 of an uncoupling protein (UCP2) binding an inhibitor recently obtained in dodecylphosphocholine detergent micelles. Although this structure shares common traits with the ADP/ATP carrier, a member of the same protein family, its functional and biological significance remains to be addressed. In the present investigation, we demonstrate how dodecylphosphocholine severely alters the structure as well as the function of UCPs. The proposed original strategy opens new vistas for probing the physiological relevance of three-dimensional structures of membrane proteins obtained in non-native environments.

An Empirical Study on Multimedia-based Social Constructivist Model in English Vocabulary Acquisition

Basing on the aid of multimedia, this paper aims at investigating the development of students’ controlled and free productive vocabulary through the application of the social constructivist model to a classroom vocabulary empirical study, so as to find out the relationship between FL learners’ vocabulary acquisition and their application of social constructive model with the help of multimedia. On the basis of the results from this study, we attempt to put forward a new vocabulary acquisition model which combines the acquisition with production: combination of input and output, which will help FL learners narrow down the gap between their negative vocabulary and positive vocabulary under non-native environment.

Mosquitofish (Gambusia affinis) responds differentially to a robotic fish of varying swimming depth and aspect ratio

In this study, we explore the feasibility of using bioinspired robotics to influence the behaviour of mosquitofish (Gambusia affinis), a social freshwater fish species that is extensively studied for the ecological issues associated with its diffusion in non-native environments. Specifically, in a dichotomous choice test, we investigate the behavioural response of small shoals of mosquitofish to a robotic fish inspired by mosquitofish in its colouration, shape, aspect ratio, and locomotion. Our results indicate that the swimming depth and the aspect ratio of the robotic fish are both determinants of mosquitofish preference. In particular, we find that mosquitofish are never attracted by a robotic fish whose colouration and shape are inspired by live subjects and that the degree of repulsion varies as a function of the swimming depth and the aspect ratio.

Substrate influence: from spelling pronunciation to pronunciation spelling – a growing trend among university students in Kenya

The development of African varieties of English has been attributed to a variety of factors, and the emergent forms of English spoken in various African countries have been the subject of study for several decades now. Among the factors mentioned as leading to the ‘Africanness’ of African Englishes is the exposure to written language, which tends to lead to the observation of linkages between spelling and pronunciation in some of these varieties of English (Schmied, 1991a, 2006). The argument has been that due to exposure to the written word, second language learners reproduce elements of written language in speech, leading, for example, to the pronunciation of silent letters in words such as ‘heir’, ‘tomb’ etc. This phenomenon of ‘spelling pronunciation’ is more pronounced in some varieties than in others, and the practice may not be confined to non-native environments. In general, spelling pronunciation has been shown to lead to cross-cultural miscommunication and therefore has implications for English as a global language.

English Grammar Automatic Output Model under Non-native Environment

In China, there has been a common phenomenon in English grammar teaching that much emphasis has been laid on the input of students’ English grammatical knowledge while little has been paid on the improvement of their grammatical competence, which directly leads to an obvious gap between students’ English grammatical knowledge and their grammatical competence. According to Anderson’s cognitive theory of ACT, learners will go through three stages (cognitive, associative and automatic stage) from declarative knowledge to procedural knowledge in acquiring the automatic skills. This paper studies the implication of cognitive theory of ACT in English Grammar acquisition, internalization and automatic output. Basing on the integration between explicit grammatical knowledge and implicit grammatical competence in grammar acquisition, we put forward an English grammar automatic output model, aiming at helping foreign language learners narrow down the gap between their grammatical knowledge and grammatical competence under non-native environment.

Rhyme, Rhythm and Rhetoric in Religious Discourse in Nigeria’s ESL Environment

This study documents the ingenious use of the English language in a second language environment, in a way that is making Nigerian preachers who use English as a medium of communication almost becoming more catholic than the Pope. The method used was the researcher’s observation as a participant in the places where the sermons where the data were drawn from were preached. This is in addition to reading various Christian literatures and documenting the observed ingenious use of the English language in a non-native environment. Data gathered were analyzed based on stylistic and pragmatic techniques. The results showed that the English language is gradually taking on a life of its own in Nigeria, especially in the way words are selected, coined and manipulated, in addition to the systematic structural arrangement of points and ideas in sermons to make them rhythmical, rhetorical and memorable. From the way the English language is used as discussed in this study, from both literary and linguistic points of view, making recourse to speech act theories, it is obvious that the English language is becoming a servant in Nigeria. Nigerian second language English users are now showing a mastery of the language and giving it a Nigerian identity, while adopting it to suit their peculiar purpose.

The Double-Edged Sword of RP: the Contrasting Roles of a Pronunciation Model in both Native and Non-native Environments

Received Pronunciation (RP) is often studied as the pronunciation model in Great Britain and non-English-speaking countries separately. What my paper focuses on is the duality with which RP is essentially endowed: the role(s) in which it has to satisfy the needs of both native and non-native speakers of English.
 Whilst the claim that RP has changed recently goes unchallenged, the issue of reflecting these changes in the preferred transcription models is hotly debated. Upton’s model of RP is one that does include several new symbols, motivated by an attempt to ‘ensure that the description of a late twentieth century version the accent […] looks forward to the new millennium rather than back at increasingly outmoded forms’ (2001:352). I discuss the feasibility of adopting Upton’s model of RP as the pronunciation model in non-English speaking countries, where it is desirable to resolve the paradox that ‘most of our teaching is aimed at young people, but the model we provide is that of middle-aged or old speakers’ (Roach 2005: 394).
 The observations I make are largely based on my MA research, which is now being modified for the purposes of my Ph.D. I asked undergraduate students of English in England and the Czech Republic to evaluate seven voices ranging from the clearly regional to the unquestionably RP. The objective was to discover which sounds are considered to fall within the scope of RP by students in both countries, which approach avoids treating RP as though it were to include only the sounds ‘allowed by a preconceived model’ (Upton 2000: 78). Further, the respondents were asked to comment on the most salient features in the recordings: what they opted to comment on reveals a marked difference in the role of RP as a model accent in the given countries. Societies which lack a prestigious non-regional accent are often oblivious to the social connotations RP carries. Whilst it seems technically impossible to replace the model accent in all teaching materials all over the world, creating awareness of the fact that a rather outmoded model of RP found in many textbooks may not always be the best option is a necessary step towards ensuring that non-English speaking students are not only understood but that their speech will attract no adverse judgements.

“We don’t teach English, we teach in English”: teaching non-native English speaking university students.

In this paper we propose a framework designed for more effective teaching of discipline content to non-native English speaking (non-NES) students, extending beyond the boundaries of language itself. While attempts to address the complex issues confronting international students often included language instruction for the learner, less emphasis has been placed on pedagogical issues confronting instructors delivering content to such students. Although students' competency in the language of instruction may still remain of vital importance, our research indicates that there are other factors that need to be addressed in providing competent instruction to non-NES students. This action research study conducted in the United Arab Emirates (UAE) with local Arab students as participants provided a rare opportunity to examine the challenge of teaching non-NES students from a homogeneous ethnic background, rather than consolidating findings from a single but diverse cohort of international students. The findings reflect the interrelationship between non-NES Arab university students and teachers, and positions this within an embedded component model for effective teaching. The conclusions may also have broader implications for teaching students of other ethnic backgrounds in other non-native speaking environments.

Hydraulic traits and water use of Eucalyptus on restored versus natural sites in a seasonally dry forest in southwestern Australia

Eucalyptus is a globally important genus for reforestation but eucalypt growth in non-native environments has uncertain ecohydrological consequences. This study investigated the hydraulic structure and function of juvenile (2.5–10m height) Eucalyptus marginata on restored mine sites and forest sites in a seasonally dry climate in southwestern Australia. We measured sap flow, leaf area, sapwood area, leaf water potential, stomatal conductance and weather variables and applied a simple model of plant water use to examine hydraulic traits across chronosequences of trees (using height as an index of age) in each environment. Younger trees on restored sites grew three times faster and used four times more water per unit leaf area (0.53kgm−2day−1) than forest trees, consistent with greater light, water and nutrient availability on restored sites. To maintain hydraulic homeostasis, trees on restored sites reduced leaf area/sapwood area ratio by 25%, increased sapwood permeability by 20%, and reduced stomatal conductance and transpiration by 50% to counterbalance fourfold increases in height and leaf area. In contrast, forest trees reduced leaf area/sapwood area ratio by 33% but increased sapwood permeability by 100% and stomatal conductance and transpiration by 50% in response to increased water availability, in addition to increased height and leaf area. A linear relationship between leaf area and water use for forest trees was indicative of hydrological equilibrium, whereas a curvilinear relationship for trees on restored sites suggested transition from high to lower water availability. Young eucalypts are likely to develop traits that are hydraulically compatible with their climate and substrate, but they may also adjust their architecture and physiology over time in response to changes in water availability. Trees in reforested landscapes with modified soils and initially abundant soil moisture may develop hydraulic architectures that are more efficient than found in native forests, which may pose risks if they can only access a fixed volume of soil. The long-term sustainability of such systems is likely to depend on trees eventually developing appropriate hydraulic architectures to cope with regimes of water availability more akin to native forests, especially in drought-prone environments.

Elevated size and body condition and altered feeding ecology of the grouper Cephalopholis argus in non-native habitats

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 439:203-212 (2011) - DOI: https://doi.org/10.3354/meps09338 Elevated size and body condition and altered feeding ecology of the grouper Cephalopholis argus in non-native habitats Amanda L. Meyer1,2,*, Jan Dierking1,3,*,** 1Department of Zoology, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA 2Present address: Pacific Reefs National Wildlife Complex, US Fish and Wildlife Service, Honolulu, Hawaii 96850, USA 3Present address: Leibniz Institute of Marine Sciences (IFM-GEOMAR), Evolutionary Ecology of Marine Fishes Group, 24105 Kiel, Germany *The 2 authors contributed equally to this study**Email: jdierking@ifm-geomar.de ABSTRACT: In 1956, the shallow-water grouper Cephalopholis argus was introduced from Moorea (French Polynesia), where grouper diversity (14 species) is high, to the Main Hawaiian Islands (MHI), where only 2 rare native deep-water groupers occur. In this non-native environment, the species has flourished and has become the dominant apex predator on many reefs. In the present study, a comparison of non-native populations of C. argus in the MHI with native populations in Moorea showed that mean total length (32.0 vs. 26.9 cm), mass (722 vs. 326 g), growth, and body condition were each significantly elevated in the MHI. In addition, while an ontogenetic shift towards larger prey occurred in both locations, it was faster and more consistent in Moorea than in the MHI. As a result, while small C. argus of comparable size in the 2 locations consumed similar-sized prey, large C. argus in Moorea consumed significantly longer and deeper-bodied prey than their counterparts in the MHI. This pattern was unrelated to the size distributions of available prey and may thus reflect stronger intra- and interspecific competition for small prey in Moorea. Although ecological release in a broader sense (i.e. a combination of predator release, parasite release, and competitive release) may play a role, the most direct explanation for the observed differences between C. argus in native habitats in Moorea (with many competing grouper species) and non-native habitats in the MHI (few competitors) would be competitive release (here used in the sense of benefits resulting from the reduction of interspecific competition). KEY WORDS: Competitive release · Ecological release · Interspecific competition · Niche shift · Invasive species · Peacock hind · Main Hawaiian Islands · Moorea (French Polynesia) Full text in pdf format PreviousNextCite this article as: Meyer AL, Dierking J (2011) Elevated size and body condition and altered feeding ecology of the grouper Cephalopholis argus in non-native habitats. Mar Ecol Prog Ser 439:203-212. https://doi.org/10.3354/meps09338 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 439. Online publication date: October 20, 2011 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2011 Inter-Research.

Seasonal Variations in the Deoxypodophyllotoxin Content and Yield of Anthriscus sylvestris L. (Hoffm.) Grown in the Field and under Controlled Conditions

Deoxypodophyllotoxin (DPT) is the main lignan in Anthriscus sylvestris . For this study two sets of experiments with 16 plants and seeds, collected from a wide geographical range, were carried out. The DPT content in roots was significantly lower (p < 0.05) when the plants were cultivated in a non-native environment. For field-grown plants the highest DPT content was found in March (second year): 0.15% w/w (dry weight) in roots; 0.03% w/w in aerial parts. For plants grown in the climate room, the highest concentration (0.14% w/w) was observed in April (second year) in the roots and in July (first year) in the aerial parts (0.05% w/w). For the isolation of DPT, roots are the most suitable part. The best harvest times are March (second year) for outdoor plants and April (second year) for indoor plants when height content and adequate biomass give the optimal DPT yield.

Rapid seasonal adaptation of an alien bruchid after introduction: geographic variation in life cycle synchronization and critical photoperiod for diapause induction

Whether alien insects that are introduced into temperate regions adapt to seasonally changing environmental conditions is an important question in evolutionary biology. If rapid evolution has occurred in a non-native environment, a latitudinal cline in critical photoperiod for diapause induction (i.e., the photoperiod at which half of the individuals enter diapause) and in life cycle synchronization with host plant phenology should be evident among locations. The alien bruchid Acanthoscelides pallidipennis (Motschulsky) (Coleoptera: Bruchidae) is native to North America and introduced into Japan with the host plant Amorpha fruticosa L. (Fabaceae) in the late 1940s. To examine whether seasonal adaptation has occurred in A. pallidipennis, we conducted a laboratory experiment and phenological observations using three latitudinally different populations. We bred F1 eggs at 22 °C and five photoperiodic regimens – L:D = 10:14, 13:11, 14:10, 15:9, or 16:8 hours – and examined whether diapause was induced. The estimated critical photoperiod for diapause induction was longest in the most northern population and shortest in the most southern population. Life cycle was found to be synchronized with host phenology in each location. Also voltinism varied geographically, from univoltine in the northern population to bivoltine in the southern populations. These results showed that A. pallidipennis rapidly adapted to seasonal environmental conditions in Japan after its introduction.

Protecting Invaders for Profit

Humans have spread species to nonnative environments for generations. In turn, these species can become invasive, threatening native species. There has been much discussion about the best way to control invasive species and protect native species ([ 1 ][1]). However, one point has been overlooked:

Yeast hexokinase isoenzyme ScHxk2: stability of a two-domain protein with discontinuous domains

The hexokinase isoenzyme 2 of Saccharomyces cerevisiae (ScHxk2) represents an archetype of a two-domain protein with the active site located in a cleft between the two domains. Binding of the substrate glucose results in a rigid body movement of the two domains leading to a cleft closure of the active site. Both domains of this enzyme are composed of discontinuous peptide sequences. This structural feature is reflected in the stability and folding of the ScHxk2 protein. Structural transitions induced by urea treatment resulted in the population of a thermodynamically stable folding intermediate, which, however, does not correspond to a molecule with one domain folded and the other unfolded. As demonstrated by different spectroscopic techniques, both domains are structurally affected by the partial denaturation. The intermediate possesses only 40% of the native secondary structural content and a substantial increase in the Stokes radius as judged by circular dichroism and dynamic light scattering analyses. One-dimensional ¹H NMR data prove that all tryptophan residues are in a non-native environment in the intermediate, indicating substantial changes in the tertiary structure. Still, the intermediate possesses quite a high stability for a transition intermediate of about ΔG = -22 kJ mol⁻¹.

Efficient avian pollination of Strelitzia reginae outside of South Africa

In its native South Africa, endemic birds pollinate the complex flowers of Strelitzia reginae (bird of paradise) through a highly complex method of pollination. The plant is cultivated worldwide in warm-temperated regions but systematic pollination of the ornithophilous species by local birds has not been reported, and, consequently, seed production is rare outside of South Africa. We found that a member of the New World warblers, Geothlypis trichas, efficiently carried out pollination of S. reginae in southern California, thereby supplementing its typical diet of insects with the energy-rich nectar of S. reginae. Only occasionally, seeds were found in plantings not visited by these birds. The pollinator service provided by the warbler increases seed production in an area outside of South Africa. This could lead to adaptive changes in the exotic species, advance species establishment and persistence and possibly promote invasive behavior in a non-native environment.

Departure from naturalized to invasive stage: a disturbance-induced mechanism and associated interacting factors

Aims Within a habitat of multiple plant species, increased resource availabilities and altered species abundances following disturbances create opportunities for exotic species to successfully establish and subsequently naturalize into its non-native environment. Such post-disturbance changes in abiotic and biotic environments may also promote a naturalized exotic species (or invading species) to become invasive through rapid colonization of the habitat sites by reducing the extent and size of resident plant species. By combining species life history traits with that of the disturbance-induced changes in habitat characteristics, we aimed to determine those interacting factors and associated mechanism allowing an exotic invasion to start off. Methods We used a modified version of the classic competition–colonization (CC) model which was formulated first by Hastings (1980) and studied later by Tilman (1994) to explain spatial coexistence of multiple species. Within this model framework, recruitment-limited spatial competition has explicitly been linked with interspecific resource competition without altering the basic assumptions and structure of the original CC model. Important findings The model results showed that at a constant rate of resource supply, invading species can stably coexist with native species via trade-offs between species competitive ability and colonizing ability. On the other hand, the model predicted that with a fluctuating resource condition, invading species can successfully invade a habitat following continuous reductions in the size and extent of native species. Whether or not invading species holds competitive superiority over the native species for limiting resource, we showed that there exists a range of variation in available resource that allows an exotic invasion to start off in post-disturbance habitat. The associated disturbance-induced mechanism promoting invading species to become invasive has been identified. It states that occurrences of disturbances such as fire or clear-cutting influence variation in resource availability, and in addition open up many vacant microsites; given these disturbance-induced changes, invading species with a higher rate of propagule production and with a higher survival rate of adults particularly in low-resource condition recruits microsites at faster rate relative to native competitor species, and with a given range of variation in resource availabilities, it maintains continued expansions following reductions in size and extent of native species. Moreover, we identified those interacting factors and their specific roles that drive this mechanism. These factors include propagule supply, variable resource level and vacant microsite availability. Increased availability of vacant microsites following disturbances creates an opportunity for rapid colonization. Given this opportunity, higher number of propagules supplied by the invading species enhances the rate of colonization success, whereas the resource variation within a range of given thresholds maintains enhanced colonization rate of the invading species while it depresses native competitor species. Owing to the each factor’s invasion regulatory ability, controlling one or all of them may have strong negative impact on the occurrence of exotic invasion.

&lt;em&gt;In-vivo&lt;/em&gt; Centrifugation of &lt;em&gt;Drosophila&lt;/em&gt; Embryos

A major strategy for purifying and isolating different types of intracellular organelles is to separate them from each other based on differences in buoyant density. However, when cells are disrupted prior to centrifugation, proteins and organelles in this non-native environment often inappropriately stick to each other. Here we describe a method to separate organelles by density in intact, living Drosophila embryos. Early embryos before cellularization are harvested from population cages, and their outer egg shells are removed by treatment with 50% bleach. Embryos are then transferred to a small agar plate and inserted, posterior end first, into small vertical holes in the agar. The plates containing embedded embryos are centrifuged for 30 min at 3000g. The agar supports the embryos and keeps them in a defined orientation. Afterwards, the embryos are dug out of the agar with a blunt needle.Centrifugation separates major organelles into distinct layers, a stratification easily visible by bright-field microscopy. A number of fluorescent markers are available to confirm successful stratification in living embryos. Proteins associated with certain organelles will be enriched in a particular layer, demonstrating colocalization. Individual layers can be recovered for biochemical analysis or transplantation into donor eggs. This technique is applicable for organelle separation in other large cells, including the eggs and oocytes of diverse species.

&lt;em&gt;In-vivo&lt;/em&gt; Centrifugation of &lt;em&gt;Drosophila&lt;/em&gt; Embryos

A major strategy for purifying and isolating different types of intracellular organelles is to separate them from each other based on differences in buoyant density. However, when cells are disrupted prior to centrifugation, proteins and organelles in this non-native environment often inappropriately stick to each other. Here we describe a method to separate organelles by density in intact, living Drosophila embryos. Early embryos before cellularization are harvested from population cages, and their outer egg shells are removed by treatment with 50% bleach. Embryos are then transferred to a small agar plate and inserted, posterior end first, into small vertical holes in the agar. The plates containing embedded embryos are centrifuged for 30 min at 3000g. The agar supports the embryos and keeps them in a defined orientation. Afterwards, the embryos are dug out of the agar with a blunt needle. Centrifugation separates major organelles into distinct layers, a stratification easily visible by bright-field microscopy. A number of fluorescent markers are available to confirm successful stratification in living embryos. Proteins associated with certain organelles will be enriched in a particular layer, demonstrating colocalization. Individual layers can be recovered for biochemical analysis or transplantation into donor eggs. This technique is applicable for organelle separation in other large cells, including the eggs and oocytes of diverse species.

Grain Filling Mechanisms in Two Wheat Cultivars, Haruyutaka and Daichinominori, grown in Western Japan and in Hokkaido

Wheat cultivar Haruyutaka, bred in Hokkaido, as a cultivar with improved genetic traits for production in western Japan, had a lower grain yield when grown in Yamaguchi in western Japan than Daichinominori, native to Yamaguchi. We examined the yield and grain growth of these two cultivars in the two areas in 2005/2006, 2006/2007 and 2007/2008 to elucidate theirgrain filling mechanisms under the two environments. When grown in Yamaguchi, Haruyutaka had a lower grain yield due to smaller grains than Daichinominori and when grown in Hokkaido, Daichinominori had a lower grain yield due to smaller grainsthan Haruyutaka. The slower grain growth, especially, at the later period of grain filling was considered to be the major cause of smaller grain in both cultivars, but it was more pronounced in Haruyutaka grown in Yamaguchi. Haruyutaka and Daichinominori ceased total dry mass production earlier when grown in the non-native area, Yamaguchi and Hokkaido, respectively, resulting in less supply of current assimilation products to grain growth. When grown in Yamaguchi, the amount of post-anthesis culm reserves, water soluble carbohydrate (WSC), was smaller in Haruyutaka than in Daichinominori, while they accumulated a similar amount of WSC in Hokkaido. The pattern of remobilization of WSC to grains was similar in both areas. However, the grain filling period was significantly shorter in the non-native area. These results suggested that in the non-native environment, the grain size is decreased due to slower grain growth, mainly due to less current assimilation, and shorter grain filling period.

A diverse assemblage of Botryosphaeriaceae infect Eucalyptus in native and non-native environments

The Botryosphaeriaceae cause endophytic infections of leaves and bark of various trees, including Eucalyptus, and they apparently persist in this state for extended periods of time. Under conditions of stress, these fungi cause many different disease symptoms on Eucalyptus, of which stem and branch cankers and die-back are the most prominent. Given their cryptic, endophytic nature, the Botryosphaeriaceae are easily overlooked when moving seeds and plants around the world. It is, therefore, not surprising to see a growing number of examples of introductions of Botryosphaeriaceae into new environments. In the past, three species were commonly reported from Eucalyptus, namely Botryosphaeria dothidea, Neofusicoccum ribis (reported as B. ribis) and Lasiodiplodia theobromae. It is now known that B. dothidea and N. ribis are generally rare on Eucalyptus, and that Aplosporella yalgorensis, B. mamane, N. parvum, N. eucalyptorum, N. eucalypticola, N. australe, N. macroclavatum, N. andinum, N. mangiferum, Dichomera eucalypti, Dichomera versiformis, Fusicoccum ramosum, Pseudofusicoccum stromaticum, P. adansoniae, P. ardesiarum, P. kimberleyense, Lasiodiplodia crassispora, L. gonubiensis, L. pseudotheobromae and L. rubropurpurea also infect this host. Interestingly, different species dominate on Eucalyptus in different regions of the world, irrespective of whether other species occur in that environment or not. As examples, in parts of eastern Australia, N. eucalyptorum and N. eucalypticola dominate, although N. australe is common on Acacia spp. in this area, while in Western Australia N. australe dominates. In South Africa and Chile N. parvum, N. eucalyptorum and N. eucalypticola are common, despite the presence of N. ribis and N. australe on related hosts such as Syzygium. In Venezuela, there are five other species not common on Eucalyptus elsewhere, but L. theobromae dominates. In Colombia, B. dothidea and N. ribis, and in Uganda and Ethiopia, L. theobromae and N. parvum, are most common. These fascinating patterns of distribution are explored, while their pathogenicity and potential influence on Eucalyptus plantations and surrounding native plant communities are considered.