Role of behaviour in biological invasions and species distributions; lessons from interactions between the invasive Gammarus pulex and the native G-duebeni (Crustacea : Amphipoda)

In attempting to understand the distributions of both introduced species and the native species on which they impact, there is a growing trend to integrate studies of behaviour with more traditional life history/ecological approaches. The question of what mechanisms drive the displacement of the freshwater amphipod Gammarus duebeni by the often introduced G pulex is presented as a case study Patterns of displacement are well documented throughout Europe, but the speed and direction of displacement between these species can be varied. From early studies proposing interspecific competition as causal in these patterns, I review research progress to date. I show there has been no evidence for interspecific competition operating, other than the field patterns themselves, a somewhat tautological argument. Rather, the increased recognition of behavioural attributes with respect to the cannibalistic and predatory nature of these species gave rise to a series of studies unravelling the processes driving field patterns. Both species engage in 'intraguild predation' (IGP), with moulting females particularly vulnerable to predation by congeneric males. G pulex is more able both to engage in and avoid this interaction with G duebeni. However, several factors mediate the strength and asymmetry of this IGP, some biotic (e.g. parasitism) and others abiotic (e.g. water chemistry). Further, a number of alternative hypotheses that may account for the displacement (hybridization; parasite transmission) have been tested and rejected. While interspecific competition has been modelled mathematically and found to be a weak interaction relative to IGP, mechanisms of competition between these Gammarus species remain largely untested empirically. Since IGP may be finely balanced in some circumstances, I conclude that the challenge to detect interspecific competition remains and we require assessment of its role, if any, in the interaction between these species. Appreciation of behavioural attributes and their mediation should allow us to more fully understand, and perhaps predict, species introductions and resultant distributions.

Plant-soil interactions and grassland diversity restoration

Restoration schemes aimed at enhancing plant species diversity of improved agricultural grassland have been a key feature of agri-environmental policy since the mid 1980s. Allied to this has been much research aimed at providing policy makers with guidelines on how best to manage grassland to restore botanical diversity. This research includes long-term studies of the consequences for grassland diversity of management techniques such as different hay cut dates, fertiliser additions, seed introductions and grazing regimes. Studies have also explored the role of introductions of Rhinanthus minor into species-poor swards to debilitate competitive grasses. While these studies have been successful in identifying some management features that control plant species diversity in agricultural grassland, they have taken a largely aboveground perspective on plant community dynamics.

(Table 1) UK research stations, refuges and major depots between 1944 and 2010

Globally, areas categorically known to be free of human visitation are rare, but still exist in Antarctica. Such areas may be among the most pristine locations remaining on Earth and, therefore, be valuable as baselines for future comparisons with localities impacted by human activities, and as sites preserved for scientific research using increasingly sophisticated future technologies. Nevertheless, unvisited areas are becoming increasingly rare as the human footprint expands in Antarctica. Therefore, an understanding of historical and contemporary levels of visitation at locations across Antarctica is essential to a) estimate likely cumulative environmental impact, b) identify regions that may have been impacted by non-native species introductions, and c) inform the future designation of protected areas under the Antarctic Treaty System. Currently, records of Antarctic tourist visits exist, but little detailed information is readily available on the spatial and temporal distribution of national governmental programme activities in Antarctica. Here we describe methods to fulfil this need. Using information within field reports and archive and science databases pertaining to the activities of the United Kingdom as an illustration, we describe the history and trends in its operational footprint in the Antarctic Peninsula since c. 1944. Based on this illustration, we suggest that these methodologies could be applied productively more generally.

The old-spelling Shakespeare: being the works of Shakespeare in the spelling of the best quarto and folio texts;

Issued also with imprint: London, Chatto and Windus; New York, Duffield and company.

English poetry : in three volumes ; with introduction and notes.

Subtitle for v. 2-3: with introductions and notes.

The old-spelling Shakespeare: being the works of Shakespeare in the spelling of the best quarto and folio texts;

Issued also with imprint: New York, Duffield & company; London, Chatto and Windus.

Ecological genetics of Melaleuca quinquenervia (Myrtaceae): Population variation in Florida and its influence on performance of the biological control agent Oxyops vitiosa (Coleoptera: Curculionidae)

Melaleuca quinquenervia (Cav.) Blake (Myrtaceae) was imported into Florida from Australia over a century ago as a landscape plant. A favorable climate and periodic wildfires helped M. quinquenervia thrive; it now occupies about 200,000 hectares in southern Florida. A biological control (i.e., biocontrol) program against M. quinquenervia has been initiated, but not all biocontrol releases are successful. Some scientists have argued that poor biocontrol agent success may relate to genetic differences among populations of invasive weeds. I tested this premise by determining (1) the number and origins of M. quinquenervia introductions into Florida, (2) whether multiple introduction events resulted in the partitioning of Florida's M. quinquenervia populations into discrete biotypes, and (3) whether Oxyops vitiosa, an Australia snout beetle imported to control this weed, might discriminate among putative M. quinquenervia biotypes. Careful scrutiny of early horticultural catalogs and USDA plant introduction records suggested at least six distinct introduction events. Allozyme analyses indicated that the pattern of these introductions, and the subsequent redistribution of progeny, has resulted in geographic structuring of the populations in southern Florida. For example, trees on Florida's Gulf Coast had a greater effective number of alleles and exhibited greater heterozygosity than trees on the Atlantic Coast. Essential oil yields from M. quinquenervia leaves followed a similar trend; Gulf Coast trees yielded nearly twice as much oil as Atlantic Coast trees when both were grown in a common garden. These differences were partially explained by the predominance of a chemical phenotype (chemotype) very rich in the sesquiterpene (E)-nerolidol in M. quinquenervia trees from the Gulf Coast, but rich in a mixture of the monoterpene 1,8-cineole and the sesquiterpene viridiflorol in trees from the Atlantic Coast. Performance of O. vitiosa differed dramatically in laboratory studies depending on the chemotype of the foliage they were fed. Larval survivorship was four-fold greater on the (E)-nerolidol chemotype. Growth was also greater, with adult O. vitiosa gaining nearly 50% more biomass on the (E)-nerolidol plants than on the second chemotype. The results of this study thus confirmed the premise that plant genotype can affect the population dynamics of insects released as weed biocontrols. ^

The state and known impacts of fish species transferred to or within continental Africa

Fish introductions have been made from small fish ponds to the largest lakes in Africa. The primary intent of these introductions has been to sustain or increase fish production, although some introductions have been made to develop sport fisheries and to control unwanted organisms. Some of these introductions have fulfilled their objective in the short term, but several of these "successful" introductions have created uncertainties about their long term sustainability. Lates niloticus, Oreochromis niloticus, O. leucostictus, Tilapia melanopleura and T. zilli were introduced into lakes Victoria and Kyoga in 1950s and early 1960s. By the 1980s O. niloticus and O. niloticus dominated the fisheries of these lakes, virtually eliminating a number of endemic fish species. The loss of genetic diversity of the fish in the worlds second largest lake has also been accompanied by a loss of trophic diversity. The transformation of the fish community has, in Lake Victoria coincided with a profound eutrophication (algal blooms, fish kills, hypolimnetic anoxia) which might be related to alterations of the lake's food-web structure. In contrast, the introduction of a planktivore, Limnothrissa miodon into Lake Kivu and the Kariba reservoir has established highly successful fisheries with little documented effect on the pre-existing fish community or trophic ecology of the lakes. The highly endemised species-rich African Great lakes may be particularly sensitive to species introductions and require special consideration and caution when introductions are contemplated because species extinctions, introgressive hybridization and ecosystem alterations may occur following fish introductions.

Course cohesion : an elusive goal for tertiary education

A program���s development and implementation in a higher education institution is usually launched with great fanfare, goodwill and a huge effort on the part of the whole development team to ensure a worthwhile cohesive set of learning experiences aligned to the desired course learning outcomes. It is often not long before the glue starts to come unstuck arising from staffing changes, subtle migration of course resources, opportunistic inclusions of ���off the shelf��� or unit based innovative teaching and learning approaches, and perhaps general poor attention to detail with regard to the impact of new introductions and electives. This paper presents an initial investigation into the elusive goal of achieving course cohesion. The authors consider building cohesion into a course as it is being designed through identified cohesion factors and in sustaining course cohesion through active leadership.

Worldwide phylogeography of the globally invasive plant: Jatropha gossypiifolia

Dhileepan, Raghu and colleagues recently published their paper 'Worldwide phylogeography of the globally invasive plant: Jatropha gossypiifolia' in Proceedings of the 16th Australian Weeds Conference. They used chloroplast microsatellites to establish patterns of phylogeographic structure in the native and introduced range of Jatropha gossypiifolia, and to determine the origin(s) of introductions and the level of genetic diversity present in native and introduced populations. J. gossypiifolia exhibited limited phylogeographic structure in its native range which was best explained by contemporary movement associated with the ornamental plant trade. Multiple introductions from diverse source locations and no reduction in genetic diversity was found in the introduced range which includes Australia, Africa and Asia. These results have implications for our current biocontrol project.

Lesser auger beetle Heterobostrychus aequalis(Coleoptera: Bostrichidae) in Australia: absent or elusive?

The lesser auger beetle, Heterobostrychus aequalis (Waterhouse), is a serious pest of seasoned hardwood timber throughout the Oriental region and several areas beyond. Some early collection records of H.���aequalis from Australia in the 1950s and 1960s indicated that the insect was present in northern Queensland, but no confirmed breeding population has been found in the past few decades suggesting either that it may have not established permanently or it is difficult to detect. The ambiguity about the breeding status of the pest in Australia has caused confusion for regulating authorities needing to respond to each new post-border detection. We examined records of H.���aequalis in Australian insect collections and from intensive plant pest surveillance activities in Queensland and northern Australia over the past 48���years to resolve this confusion. Until very recently, available evidence suggested that H.���aequalis was not established in Australia, despite multiple introductions and apparently suitable climate and hosts. Collection records of the pest are predominantly linked to intercepted items or are recorded as of unknown origin, and no established populations have been found during many years of targeted surveillance. However, a detection of H.���aequalis in suburban Cairns, north Queensland, in late 2013 and two more in mid-2015 in the same general locality do not appear to be linked to any imported material, indicating that there is at least a tenuously established local population. Investigations are underway to confirm this, but the insect is not widely established in Australia and, if present, remains elusive. Our recommended response to any future detection of H.���aequalis is to fumigate or destroy the infested material, conduct tracing enquiries and limit surveys to the immediate vicinity of the detection.

Deleterious effects of non-native species introduced into Lake Victoria, East Africa

Lake Victoria, in East Africa, has suffered from introductions and invasions of non-native species such as Lates niloticus, various tilapiine species, and Eichornia crassipes since the 1950s. These have had a devastating effect on the natural biological communities. This paper reviews the effects of the introductions on ecology, environment, fisheries and the local human population.

The evolution of the fishery of Oreochromis niloticus (Pisces : Cichlidae) in Lake Victoria

The Lake Victoria ecosystem has experienced changes associated fishing levels, arise in lake level of the 1960s, fish introductions and human activities in the drainage basin. Following the fish introductions of the 1950s and 1960s, niloticus has become the most abundant and commercially important species among the tilapiines. It appears to be the only species which has managed to co-exist with the Nile perch not only in Lake Victoria but also in Lake Kyoga where the two species were also introduced. There is, however, little published information on the biology and ecology of the species in the habitats. It has therefore been found necessary to initiate studies as have been developed for Lates niloticus, especially as the two species have assumed major role in the lake's fisheries.

The efficacy of anti-predator behaviour in the wood fog tadpole (Rana sylvatica) /

Activity has been suggested as an important behaviour that is tightly linked with predator avoidance in tadpoles. In this thesis I examine predator-prey relationships using wood frog tadpoles {Rana sylvaticd) as prey and dragonfly larvae {AnaxJunius) and backswimmers {Notonecta undulatd) as predators. I explore the role of prey activity in predator attack rates, prey response to single and multiple predator introductions, and prey survivorship. The data suggest that Anax is the more successful predator, able to capture both active and inactive tadpoles. In contrast, Notonecta strike at inactive prey less frequently and are seldom successftil when they do. A mesocosm study revealed that the presence of any predator resulted in reduced activity level of tadpoles. Each predator species alone had similar effects on tadpole activity, as did the combined predator treatment. Tadpole survivorship, however, differed significantly among both predator treatments and prey populations. Tadpwles in the combined predator treatment had enhanced risk; survivorship was lower than that expected if the two predators had additive effects. Differences in survivorship among wood frog populations showed that tadpoles from a lake habitat had the lowest survivorship, those from a shallow pond habitat had an intermediate survivorship, and tadpoles from a marsh habitat had the highest survivorship. The frequency of interactions with predators in the native habitat may be driving the population differences observed. In conclusion, results from this study show that complex interactions exist between predators, prey, and the environment, with activity playing a key role in the survival of tadpoles.

Distribuci�� espacial i ��s de l'h��bitat de la comunitat de peixos a l'estany de Banyoles

En el marc d'un projecte m��s ampli sobre la comunitat de peixos de la conca lacustre de Banyoles, s'ha estudiat la distribuci�� espacial de les diferents esp��cies aix�� com l'��s que aquestes fan de l'h��bitat. El poblament pisc��cola de l'estany de Banyoles ��s el resultat d'un llarg historial d'introducci�� d'esp��cies ex��tiques i extinci�� de les poblacions aut��ctones locals. S'ha revisat la seva composici�� actual detectant un total de 18 esp��cies (4 aut��ctones i 14 introdu��des) de les quals nom��s 13 presenten una poblaci�� estable. L'estudi de l'h��bitat s'ha centrat a l'Estany, l'element principal del sistema lacustre, analitzant per separat la zona litoral i la zona limn��tica. En el primer cas s'han realitzat les captures d'individus mitjan��ant pesca el��ctrica des d'una embarcaci�� adaptada per aquesta pr��ctica. La totalitat del litoral ha estat dividida en trams de caracter��stiques homog��nies on s'han obtingut les captures per unitat d'esfor�� per cada esp��cie. El mostreig s'ha desenvolupat entre l'estiu de 1997 i la primavera del 2000 realitzant un total de 10 campanyes de pesca. Les esp��cies m��s abundants al litoral s��n la perca americana (Micropterus salmoides) i el peix sol (Lepomis gibbosus), essent tamb�� presents la perca (Perca fluviatilis), carpa (Cyprinus carpio) i el gard�� (Scardinius erythrophthalmus). S'han capturat altres esp��cies com ara anguila (Anguilla anguilla), bagra (Squalius cephalus), sandra (Sander lucioperca), carp�� (Carassius auratus) i madrilleta vera (Rutilus rutilus), per�� s��n molt menys abundants en nombre. S'ha examinat, per cadascuna de les esp��cies, si existeix selecci�� de l'h��bitat i en cas afirmatiu, quin ��s el preferent en base a la classificaci�� del litoral en sis tipus de vegetaci�� predominant. Les esp��cies m��s abundants, perca americana i peix sol, ocupen tots els h��bitats disponibles per�� amb una densitat diferent. La perca mostra tamb�� una clara selecci�� de l'h��bitat a favor de les zones molt estructurades amb abundant pres��ncia de jonca litoral. Carpa i gard�� seleccionen els ambients m��s fondos amb major pres��ncia de mat��ria org��nica d'origen vegetal procedent del bogar. En general els individus ocupen les zones amb una densitat de vegetaci�� interm��dia, majorit��riament zones de jonca a l'estiu i zones amb mansega a l'hivern, on troben refugi i els recursos tr��fics necessaris. La perca americana, a m��s, presenta una elevada fidelitat a un mateix punt del litoral al llarg de la seva vida. La zona limn��tica ha estat prospectada mensualment mitjan��ant ecosondaci��, realitzant transectes perpendiculars a l'eix principal de l'Estany, cobrint la seva totalitat. La composici�� d'esp��cies s'ha obtingut a partir de les captures fetes amb xarxes (tresmalls) amb periodicitat estacional. L'an��lisi geoestad��stica de la densitat de peixos ha perm��s descriure l'estructura espacial d'aquesta a partir dels variogrames, aix�� com la seva variabilitat tant espacial com temporal, i obtenir els mapes de densitat. A l'hivern, la densitat de peixos a la zona limn��tica assoleix els seus valors m��nims i els individus es troben formant agregats dispersos, pels diferents estrats de fond��ria. A partir de la primavera la densitat augmenta, pel reclutament i la major freq����ncia d'individus que abandonen el litoral; la densitat esdev�� m��s homog��nia a les primer capes de fond��ria. A l'estiu la densitat ��s m��xima i l'estrat m��s homogeni coincideix amb la posici�� de la termoclina. Aquest estructura varia en disminuir la temperatura i barrejar-se la columna d'aigua, tornant a la situaci�� hivernal. La perca i la madrilleta vera s��n les esp��cies predominants en aquest ambient, juntament amb la carpa. La seva distribuci�� no ��s homog��nia i respon a les caracter��stiques limnol��giques de les diferents cubetes de l'Estany. Una particularitat d'aquest, relacionada amb el seu origen c��rstic, es la formaci�� d'una ploma hidrotermal que afecta la distribuci�� dels peixos, probablement en augmentar la terbolesa. S'ha integrat l'��s de l'h��bitat de les esp��cies que ocupen tant la zona limn��tica com la litoral a partir del seguiment d'individus, concretament de perca i bagra. S'ha utilitzat un sistema autom��tic de posicionament que estima la localitzaci�� dels individus marcats amb transmissor de telemetria ac��stica. L'an��lisi dels despla��aments mostra un rang superior per la bagra en comparaci�� amb la perca. Ambdues esp��cies mostren una orientaci�� en els seus despla��aments. La perca ocupa el litoral a la nit i es despla��a a la zona limn��tica de dia, amb un ritme d'activitat marcat per dos m��xims coincidint amb la sortida i posta de sol; en canvi la bagra mostra una major activitat nocturna amb zones de rep��s properes al litoral. S'ha estimat igualment els dominis vital de cada individu marcat.