2,4-Di-tert-butylphenol or 2,4-bis(1,1-dimethylethyl)-phenol (2,4-DTBP) is a common toxic secondary metabolite produced by various groups of organisms. The biosources and bioactivities of 2,4-DTBP have been well investigated, but the phenol has not been systematically reviewed. This article provides a comprehensive review of 2,4-DTBP and its analogs with emphasis on natural sources and bioactivities. 2,4-DTBP has been found in at least 169 species of bacteria (16 species, 10 families), fungi (11 species, eight families), diatom (one species, one family), liverwort (one species, one family), pteridiphyta (two species, two families), gymnosperms (four species, one family), dicots (107 species, 58 families), monocots (22 species, eight families), and animals (five species, five families). 2,4-DTBP is often a major component of violate or essential oils and it exhibits potent toxicity against almost all testing organisms, including the producers; however, it is not clear why organisms produce autotoxic 2,4-DTBP and its analogs. The accumulating evidence indicates that the endocidal regulation seems to be the primary function of the phenols in the producing organisms.

The spatial expansions of invasive organisms in the novel range are generally expected to follow an isolation-by-distance relationship (IBD) if the invasion is biologically driven; however, many invasions are facilitated anthropogenically. This research focused on the extant expansion patterns of cogongrass (Imperata cylindrica). Cogongrass is a widespread invasive species throughout the southern United States (US). Patterns of infestation vary among US states. Cogongrass is pyrogenic, and its invasion threatens softwood (Pinus spp.) plantations, a substantial economic market for this US region. Over 600 individuals were sampled from seven invaded US states, using amplified fragment length polymorphisms (AFLPs) to assess genetic diversity and population structure. We suspected that differences in historical management efforts among US states influenced differences in genetic diversity and structure. We detected two genetic lineages at the highest level of analysis. One genetic lineage was locally restricted, whereas the other was found throughout the study region. Admixed individuals were found in all US states and consistently co-occurred with the dominant lineage, suggesting that secondary contact and hybridization may have facilitated expansion. The widespread prevalence of only one of the two detected genetic lineages suggests a primary genetic lineage responsible for on-going population expansion in the US.

The initial processes for successful biological invasions are transport, introduction, and establishment. These can be directly influenced or completely avoided through activities that reduce the number and frequency of entering nonnative propagules. Economic and environmental benefits through preventative monitoring programs at early stages of invasion far outweigh the long-term costs associated with mitigating ecological and economic impacts once nonnative species establish and spread. In this study, we identified 30 taxa of hitchhiking plant propagules on the air-intake grilles of refrigerated shipping containers arriving into a United States seaport from a port on the Pacific coast of South America. The four monocotyledonous taxa with the highest number of seeds collected were analyzed; we estimated propagule pressure, germination, and survivorship of these taxa, and we used the estimates to determine likelihood of establishment. At the levels of propagule pressure estimated here, non-zero germination and survival rates resulted in high establishment probabilities even when escape rates from shipping containers were modelled to be exceedingly low. Our results suggest high invasion risk for nonnative taxa including Saccharum spontaneum L., a listed Federal Noxious Weed. Currently, not all shipping containers arriving at USA ports are thoroughly inspected due to limited personnel and funding for biological invasion prevention. Our results indicate that there is a significant risk from only a few propagules escaping into the environment from this source, and we propose possible solutions for reducing this risk.

To control non-native species, resource managers may import and introduce biocontrol agents. Like accidentally introduced insects, biocontrol agents must overcome several abiotic and biotic obstacles to establish successfully. They can also have varying efficacy and negative or positive impacts on native species and ecosystems. Given the similarities between accidentally introduced insects and biocontrol agents, researchers studying these organisms can more effectively communicate and actively link data to improve overall understanding and management of non-native species within the framework(s) of invasion theory. To assess interdisciplinarity between invasion ecologists and biocontrol practitioners that study insects in forests, we identified 102 invasion ecology and 90 biocontrol articles published from 2006 to 2018. These articles helped us determine which broad disciplines (invasion ecology, biocontrol, other control, other ecological, and nonecological) and publication formats (e.g., journals and books) the authors cited most. We found 1) invasion ecologists primarily cite other invasion ecology research; 2) biocontrol researchers cite biocontrol and invasion ecology research; 3) both disciplines primarily cited peer-reviewed journal articles; and 4) there was 65–70% overlap in the top 20 journals cited in primary invasion ecology and biocontrol literature. Though we found some cross-communication, it is currently mostly unidirectional, whereby invasion ecology informs biocontrol. We identify and discuss three areas—1) ecological principles governing success or failure of introduced species, 2) the invasion process, and 3) negative impacts on native species—for which the disciplines possess substantial overlap to demonstrate that biocontrol agents can provide invasion ecologists with an unconventional model to study the mechanisms of species invasion.