Floral biology, pollination vectors and breeding system of Zieria granulata (Rutaceae), an endangered shrub endemic to eastern Australia

Context: Understanding the factors that influence viable-seed production is crucial in the conservation of threatened plant species, yet these factors are often poorly understood. Aims: We investigated the reproductive biology of Zieria granulata C.Moore ex Benth., an endangered Australian endemic with a limited distribution, with the intent of improving conservation and restoration outcomes. Methods: Components of floral biology, including floral ontogeny and nectar production, were quantified to determine the pollination syndrome and the likely breeding system. Flower-visitor surveys (using both digital video recordings and human observations), a manipulative wind-pollination experiment and hand-pollination experiments were conducted to investigate pollination vectors and confirm the breeding system. Key results: Z. granulata flowers were small, white, protandrous and produced highly ornamented pollen grains and small quantities of nectar; these characteristics suggest that the species fits the general entomophily syndrome. All floral visitors were arthropod species and of the 72 visitors observed, predominantly from the Dipteran and Hymenopteran families, 18 could be regarded as potential pollinators. Failure of simulated wind gusts (40 km h-1) to transport pollen ≥5 cm indicated that anemophily is unlikely for this species. Autonomous and manipulative selfing did not result in viable seed set, indicating that this is an obligate outcrossing species. However, fruit and viable-seed production was highly variable within and among some other treatments. Pre-dispersal seed predation was recorded at all study sites. Conclusions: Pre-dispersal seed predation was recorded at all study sites and is a likely factor inhibiting viable-seed production. Implications: This knowledge will be used to improve seed yield for collections used for ex situ conservation and restoration programs for the endangered Z. granulata

Sunlight and red to far-red ratio impact germination of tropical montane cloud forest species

Context: Australia’s tropical montane cloud forests (TMCF) exhibit exceptional species richness and endemism. Determinants of regeneration via seed of these species are next to unknown, limiting our ability to quantify and project their vulnerability to climate change. The ratio of red to far-red light (R:FR) has been shown to influence seed germination of many tropical species.Aims: We investigated germination of six previously unstudied TMCF species in relation to the presence or absence of light (light/dark) and light quality (R:FR). We hypothesised that increased R:FR would lead to increased germination and that small-seeded species would be more likely to have a light requirement and be less sensitive to R:FR compared to larger-seeded species.Methods: Sunlight and polyester filters were used to create a gradient of R:FR ranging from 0.1 to 1.14. Seeds were also sown in constant darkness.Key results: Across species we saw varying germination responses. Three of the four smallest-seeded species exhibited an absolute light requirement for germination and did not discriminate between different R:FR. Germination of the small-seeded TMCF endemic Dracophyllum increased exponentially with increasing R:FR. Germination of the largest-seeded species was inhibited by both low and high R:FR, and germination was higher in constant darkness than diurnal light/dark. All six species were able to germinate at remarkably low R:FR values.Conclusions: Light affects seed germination of Australia’s TMCF plant species in a variety of ways.Implications: The findings of this study provide insights into plant recruitment in situ, and the acclimation potential of these species under reduced R:FR predicted for the future

Understanding seed dormancy and germination aids conservation of rainforest species from tropical montane cloud forest: a case study confirming morphophysiological dormancy in the genus Tasmannia

Context: Seed dormancy is one issue hindering implementation of conservation actions for rainforest species. Aims: We studied dormancy and germination in Tasmannia sp. Mt Bellenden Ker and Tasmannia membranea, two tropical montane rainforest species threatened by climate change, to develop a better understanding of dormancy in the species and the genus. Methods: Dormancy was classified for T. sp. Mt Bellenden Ker on the basis of an imbibition test, analysis of embryo to seed length (E:S) ratios and germination in response to the following four dormancy-breaking treatments: (I) scarification of the seedcoat near the micropylar end; (2) removal of the seedcoat; (3) application of 100 mg L(-1)or (4) 500 mg L-1 gibberellic acid. The most effective treatment was then tested on T. membranea. The requirement for light for germination was also assessed. Key results: Both scarified and intact seeds imbibed water. Initial E:S ratios were <0.22 for both species and increased up to 0.74 after 40 days, just before radicle emergence, for T. sp. Mt Bellenden Ker. Germination proportions were significantly higher in Treatments 1 and 2 than the remaining treatments for T. sp. Mt Bellenden Ker; T. membranea responded similarly well to Treatment 1. Germination under alternating light/dark conditions was slightly, but not significantly, greater than germination in the dark alone. Conclusions: Both species have morphophysiological dormancy and treatments that remove seedcoat resistance to embryo growth facilitate germination. These treatments may improve germination in other species from the genus Tasmannia. Implications: This knowledge will aid the germination of seeds to implement conservation strategies for Tasmannia spp

Reflections on the 'History and Historians' of the black woman's role in the community of slaves: enslaved women and intimate partner sexual violence

Taking as points of inspiration Peter Parish’s 1989 book, Slavery: History and Historians, and Angela Davis’s seminal 1971 article, “Reflections on the black woman’s role in the community of slaves,” this probes both historiographically and methodologically some of the challenges faced by historians writing about the lives of enslaved women through a case study of intimate partner violence among enslaved people in the antebellum South. Because rape and sexual assault have been defined in the past as non-consensual sexual acts supported by surviving legal evidence (generally testimony from court trials), it is hard for historians to research rape and sexual violence under slavery (especially marital rape) as there was no legal standing for the rape of enslaved women or the rape of any woman within marriage. This article suggests enslaved women recognized that black men could both be perpetrators of sexual violence and simultaneously be victims of the system of slavery. It also argues women stoically tolerated being forced into intimate relationships, sometimes even staying with “husbands” imposed upon them after emancipation

Hand-pollination increases seed set in the critically endangered orchid Thelymitra kangaloonica

Thelymitra kangaloonica is a listed Critically Endangered sun-orchid (family Orchidaceae) with a highly restricted distribution. In recent years both individual abundance and capsule set rates have been low in this species. The flowers of Thelymitra kangaloonica possess some traits associated with autogamy (self-fertilisation) and others associated with entomophily (insect-pollination), however the pollination mechanisms have not been explicitly tested. This study compared the capsule set rate of flowers cross-pollinated by hand among individuals, against flowers which received no treatment. We found that capsule set rate in hand cross-pollinated flowers was significantly higher than in flowers receiving no treatment (23.1% versus 4.4%). This suggests that Thelymitra kangaloonica relies primarily on entomogamy to achieve seed set. Hand cross-pollination may assist management of the species by increasing the number of seeds in the soil seed bank and potentially assist in increasing the population size. In addition, it facilitates seed collection for seed banking and development of an ex-situ population for future population augmentation or translocation

Reproductive biology of rainforest Rutaceae : floral biology, breeding systems and pollination vectors of Acronychia oblongifolia and Sarcomelicope simplicifolia subsp. simplicifolia

The conservation of plant species requires an understanding of the factors that affect viable seed production, but often these factors are poorly understood. We investigated the reproductive biology of two Australian endemic rainforest species, Acronychia oblongifolia (A.Cunn. ex Hook.) Endl. ex Heynh and Sarcomelicope simplicifolia (Endl.) T.G.Hartley subsp. simplicifolia, with the intent of improving conservation and restoration outcomes. The floral biology of these species was quantified to provide baseline data and insights into their pollination syndrome. Flower visitor surveys (using both digital recordings and human observations), a manipulative wind pollination experiment, and hand-pollination experiments were carried out to investigate pollination vectors and determine the breeding system. Acronychia oblongifolia and Sarcomelicope simplicifolia subsp. simplicifolia were both found to best fit the general entomophily pollination syndrome. All floral visitors were arthropod species (Acronychia oblongifolia: 31; Sarcomelicope simplicifolia subsp. simplicifolia: 47) and fewer than 30% of the floral visitors identified, predominantly Diptera, Hymenoptera and Coleoptera, were regarded as potential pollinators. Failure of simulated wind gusts (40 km h-1) to transport pollen 50 cm indicated anemophily is unlikely for these species. Autonomous and manipulative selfing treatments produced few (Acronychia oblongifolia: <3%) or no (Sarcomelicope simplicifolia subsp. simplicifolia) viable seed, indicating these are predominantly outcrossing species, although fruit and viable seed production were highly variable within and among all other treatments (open to natural pollinators, pollinator exclusion, pollinator exclusion and manipulative outcross, and pollinator exclusion and manipulative selfing). Pre-dispersal seed predation was recorded for both species, at several study sites. Pre-dispersal seed predation and increased distances between compatible individuals caused by habitat fragmentation, are two factors limiting the production of viable seeds for both species

Sunlight and red to far-red ratio impact germination of tropical montane cloud forest species

Context: Australia’s tropical montane cloud forests (TMCF) exhibit exceptional species richness and endemism. Determinants of regeneration via seed of these species are next to unknown, limiting our ability to quantify and project their vulnerability to climate change. The ratio of red to far-red light (R:FR) has been shown to influence seed germination of many tropical species.Aims: We investigated germination of six previously unstudied TMCF species in relation to the presence or absence of light (light/dark) and light quality (R:FR). We hypothesised that increased R:FR would lead to increased germination and that small-seeded species would be more likely to have a light requirement and be less sensitive to R:FR compared to larger-seeded species.Methods: Sunlight and polyester filters were used to create a gradient of R:FR ranging from 0.1 to 1.14. Seeds were also sown in constant darkness.Key results: Across species we saw varying germination responses. Three of the four smallest-seeded species exhibited an absolute light requirement for germination and did not discriminate between different R:FR. Germination of the small-seeded TMCF endemic Dracophyllum increased exponentially with increasing R:FR. Germination of the largest-seeded species was inhibited by both low and high R:FR, and germination was higher in constant darkness than diurnal light/dark. All six species were able to germinate at remarkably low R:FR values.Conclusions: Light affects seed germination of Australia’s TMCF plant species in a variety of ways.Implications: The findings of this study provide insights into plant recruitment in situ, and the acclimation potential of these species under reduced R:FR predicted for the future

Seed banking is more applicable to the preservation of tropical montane flora than previously assumed: A review and cloud forest case study

The science is clear – significant reductions in tropical montane (TM) habitats are projected to occur by the end of this century. Urgent action is needed to build the resilience of TM flora and understand its adaptive capacity to climate change. Seed banking is the most widely employed ex situ conservation tool, providing insurance against plant species extinction and germplasm for associated research. However, tropical forest floras are grossly under-represented in seed banks due to historic assumptions and generalisations regarding collection, storage and germination of tropical forest seeds. In Australia, the Wet Tropics World Heritage Area of northeast Queensland contains tropical montane cloud forest (TMCF) in which > 70 endemic, seed-bearing species are at high risk of extinction. To mitigate this risk, we synthesised current seed science knowledge from TM plant communities around the world and examined what we know about collection, storage behaviour and germination of TM seeds. Included are our own preliminary investigations into seed banking of Australian TMCF flora. We argue that seed banking is applicable to more TM biodiversity than previously assumed and that a global effort to broaden ex situ conservation to include TM flora is needed. Making use of all the seed/gene banking tools available today, we call for a nationwide coordinated effort to establish a secure network of ex situ germplasm collections of Australian TMCF flora. Seed science research needed to inform and accelerate ex situ conservation of TMCF flora is also discussed

Proceedings of the fourth Resilience Engineering Symposium

These proceedings document the various presentations at the Fourth Resilience Engineering Symposium held on June 8-10, 2011, in Sophia-Antipolis, France. The Symposium gathered participants from five continents and provided them with a forum to exchange experiences and problems, and to learn about Resilience Engineering from the latest scientific achievements to recent practical applications. The First Resilience Engineering Symposium was held in Söderköping, Sweden, on October 25-29 2004. The Second Resilience Engineering Symposium was held in Juan-les-Pins, France, on November 8-10 2006, The Third Resilience Engineering Symposium was held in Juan-les-Pins, France, on October 28-30 2008. Since the first Symposium, resilience engineering has fast become recognised as a valuable complement to the established approaches to safety. Both industry and academia have recognised that resilience engineering offers valuable conceptual and practical basis that can be used to attack the problems of interconnectedness and intractability of complex socio-technical systems. The concepts and principles of resilience engineering have been tested and refined by applications in such fields as air traffic management, offshore production, patient safety, and commercial fishing. Continued work has also made it clear that resilience is neither limited to handling threats and disturbances, nor confined to situations where something can go wrong. Today, resilience is understood as the intrinsic ability of a system to adjust its functioning prior to, during, or following changes and disturbances, so that it can sustain required operations under both expected and unexpected conditions. This definition emphasizes the ability to continue functioning, rather than simply to react and recover from disturbances and the ability to deal with diverse conditions of functioning, expected as well as unexpected. For anyone who is interested in learning more about Resilience Engineering, the books published in the Ashgate Studies in Resilience Engineering provide an excellent starting point. Another sign that Resilience Engineering is coming of age is the establishment of the Resilience Engineering Association. The goal of this association is to provide a forum for coordination and exchange of experiences, by bringing together researchers and professionals working in the Resilience Engineering domain and organisations applying or willing to apply Resilience Engineering principles in their operations. The Resilience Engineering Association held its first General Assembly during the Fourth Symposium, and will in the future play an active role in the organisation of symposia and other activities related to Resilience Engineering