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Interactions among wood-decay fungi can have a profound effect on fungal community composition, decay rates and ultimately the chemical composition of the material remaining after the decay process. Interspecific interactions among fungi as they decay wood have been well-studied but almost nothing is known about the effect of intraspecific interactions between individual genets on the decay process. In this study we examine the effect of both intra- and interspecific competition on wood mass-loss for five species of wood-decay fungi: Cerrena unicolor , Fuscoporia gilva , Irpex lacteus , Stereum ostrea and Trametes versicolor. Four of the five species studied showed a significant increase in mass loss when five individual isolates (genets) of the same species simultaneously colonized aspen test wafers in vitro. The dynamics of interspecific interactions were also significantly impacted by the presence of multiple genets of each species. Taken together, these results demonstrate that intraspecific interactions can change the outcome of interspecific interactions and thus the functioning of the overall community. [ABSTRACT FROM AUTHOR]

Invasive alien species are considered one of the main threats to marine biodiversity. We used a BACI design to investigate the changes in rocky reef benthic communities related to the invasion of the octocoral Latissimia ningalooensis in the Southwest Atlantic. Drastic changes in benthic community structure were restricted to the invaded site and associated with the growth of L. ningalooensis on turf algae. Conversely, the zoanthid Palythoa caribaeorum remained stable coverage along the 9-year study period, indicating a greater biotic resistance against the octocoral. Latissimia ningalooensis spread from large and well-established patches to new areas of the reef, increasing turf-octocoral interactions. This study warns of the great invasive potential of the octocoral, due to its high abundance, competitive and expansion ability. The decline in abundance of turf-forming algae following the emergence of L. ningalooensis threatens the structure and functioning of macroalgal-dominated rocky reefs. [Display omitted] • The alien octocoral was largely associated with changes in the benthic community. • Changes were associated with the growth of the invader on turf algae. • Zoanthid cover remained stable indicating a greater biotic resistance. • The invader is spreading through turf-octocoral interactions. • Invasive octocorals threatens macroalgal-dominated rocky reefs. [ABSTRACT FROM AUTHOR]

Over the past few years, an increase in Peruvian Pelican Pelecanus thagus presence has occurred in southern Chile, along the coast of the Los Lagos region, at the southern end of its range. We evaluate the presence of the pelicans in seabird colonies of this region and describe their behavior and interactions with other seabird species. Three colonies were surveyed: San Pedro Bay Islets (40°55'S), Kaikué-Lagartija Island (41°48'S) and Caicura Island (41°42'S). Counts were carried out from boats, and age structure was determined based on plumage color. Pelicans were found to be numerous and included a high proportion of juveniles. With the exception of one pelican egg (unhatched) found at Caicura Island in December 2013. there was no evidence of pelican nesting. Potential competitive interactions between the pelicans and other seabirds were evident. [ABSTRACT FROM AUTHOR]

Abstract: A majority of plant species has roots that are colonized by both arbuscular mycorrhizal (AM) and non-mycorrhizal (NM) fungi. The latter group may include plant mutualists, commensals, parasites and pathogens. The co-occurrence of these two broad groups may translate into competition for root volume as well as for plant-derived carbon (C). Here we provide evidence that the relative availability of soil nitrogen (N) and phosphorus (P) (i.e., soil nutrient stoichiometry) controls the competitive balance between these two fungal guilds. A decrease in the soil available N:P ratio resulted in a lower abundance of AM fungi and a corresponding increase in NM fungi. However, when the same fertilization treatments were applied in a soil in which AM fungi were absent, lowering the soil available N:P ratio did not affect NM fungal abundance. Taken collectively, our results suggest that the increase in NM fungal abundance was not a direct response to soil nutrient stoichiometry, but rather a competitive release from AM fungi responding negatively to higher soil P. We briefly discuss the mechanisms that may be responsible for this competitive release. [Copyright &y& Elsevier]

Abstract: The effects of canola-type rapeseed oil (RSO) on serum lipids, plasma fibrinogen, lipid oxidation and fatty acids were studied in three groups of subjects, two of which had not been consuming fish in their habitual diets. Forty-two volunteers (35 women, 7 men, 16–62 years) replaced fat with RSO for 6 weeks in a parallel design. The average cholesterol and fibrinogen concentrations were 5.0mmol/l and 2.6g/l, respectively. The intake of α-linolenic acid (α-LLA) was doubled. Efficient competitive inhibition by α-LLA was seen as a decrease in long-chain (LC) n-6 PUFA at 3 weeks. Elevated fibrinogen (2.6–3.9g/l) decreased by 0.95g/l at 6 weeks. Docosahexaenoic acid (22:6n-3) in plasma phospholipids increased at low fibrinogen levels only. The associations and changes in plasma C18 and LC PUFA followed the competitive and metabolic principles of the body, and especially in the case of n-3 PUFA according to the recycling pathway. [Copyright &y& Elsevier]

Abstract: The role of lianas (woody vines) in the development and diversity of both tropical and temperate forests under differing management scenarios has not been thoroughly explored. We examined changes in grapevine (Vitis spp.) densities over time in clearcut stands as influenced by manual tending, physiography, and host tree associations. We used data from long-term studies on 66 clearcut stands dominated by temperate deciduous forest tree species on the Hoosier National Forest in south-central Indiana, USA. Fourteen of the stands had grapevines removed manually, approximately during the stem exclusion stage of development. Grapevine densities steadily increased from age 5 until age 15, which coincides with the period of stem exclusion of these stands. Subsequent grapevine mortality may have been related to light competition. Manually treated stands had similar grapevine densities as untreated stands after 20 years across sites, and it appeared that only on the most xeric area was the grapevine treatment effective in reducing grapevine densities. During early stand development, ranging from ages 5 to 17, grapevine density was strongly related to slope position, but as stands developed through the stem exclusion stage, aspect emerged as a stronger factor influencing grapevine density. Black cherry (Prunus serotina Ehrh.), walnut (Juglans spp.), and elm (Ulmus spp.) were the most common grapevine host trees under both treated and untreated scenarios, which may be associated with the crown architecture of these species. Results suggest lianas play a critical role in the early development of disturbed forest sites in temperate deciduous forests. With concerns that lianas are increasing in abundance and distribution in these forest types, understanding their role in forest dynamics, such as host tree associations at different stages of development, competition dynamics on different sites and corresponding influences on tree growth, species composition, and diversity, will be critical to decision-making processes in achieving desired management goals in the future. [Copyright &y& Elsevier]

Abstract: In this article, strategic investment in duopoly where the costs of the two firms are asymmetric is studied based on the option games. First, the expressions of value functions of the firm and the optimal investment thresholds are deduced. Second, this study investigates the strategy equilibriums and their types and existing conditions of both the firms by considering negative externalities and positive externalities, respectively. Third, the effect of uncertainty on investment thresholds and the effect of uncertainty, first-mover advantage, and second-mover advantage on equilibrium results and on investment interval are also discussed. Finally, the existence of optimal perfect Nash equilibrium strategies is proved further by a numerical analysis. [Copyright &y& Elsevier]

Wolf (Canis lupus) packs are generally competitively dominant over Black Bears (Ursus ainericanus); however, less is known about lone Wolf-Black Bear interactions. We report an observation of a lone Wolf and an adult Black Bear at a kill made by the Wolf in northeastern Alberta. In this instance, the bear chased the Wolf from the kill site. Our observation supports the hypothesis that Wolf-Black Bear interactions may fit the pattern of asymmetrical interference competition when the interaction involves a lone Wolf rather than a pack. [ABSTRACT FROM AUTHOR]