Inappropriate fire-regimes brought about by patterns of human settlement and land-use threaten plant diversity in Mediterranean-type climate (MTC) regions. In south-west Western Australia (SWWA), where there are many threatened plant species distributed across a range of human-modified landscapes, there is a need for approaches to identify where the threat is greatest. This requires knowledge of contemporary fire regimes, how they vary across landscapes, and the sensitivity of threatened species to these regimes. Currently, this information is lacking, and this limits strategic fire management. In this study we compiled fire response information for SWWA’s threatened plant species and undertook a bioregional assessment of variation in fire interval over the last 40 years. We determined the fire response traits of 242 (60%) of the region’s 401 extant threatened species. Over half of the 242 species were obligate seeders and will therefore have population dynamics particularly sensitive to fire interval. Our study highlights large differences in fire interval across nine bioregions in SWWA. The differences were greatest for the heavily cleared and fragmented bioregions compared with more continuously vegetated bioregions. We discuss how variations in the frequency of fire life-history traits and fire interval interact to determine the nature and relative level of threat posed by fire in these landscapes. Survival of many populations of threatened flora in this biodiversity hotspot will depend on developing appropriate fire regimes that match the regeneration requirements of each species.

The structure and ultrastructure on floral nectaries of Heliocarpus popayanensis Kunth. and Luehea divaricata Mart (Malvaceae-Grewioideae) were investigated for the first time. The floral nectaries of the analysed species are structured (can be recognised macroscopically and microscopically) and of trichomatic type. Significant morphological differences were observed between the nectaries of perfect and pistillate flowers of H. popayanensis, as well as between nectaries of this species and those of the related species, Triumfetta rhomboidea Jacq. The volume of nectar produced in the perfect and pistillate flowers of H. popayanensis and in the perfect flowers of L. divaricata presents significant differences that could be related to the rewards offered to flower visitors. No differences were observed in ultrastructure features of the glandular trichomes between H. popayanensis and L. divaricata. Nectar accumulation occurs between the wall and the cuticle. The predominant floral visitors in perfect and pistillate flowers of H. popayanensis were bees, and less frequently flies; whereas for L. divaricata were wasps, bumblebees, butterflies and beetles. Our results support the inclusion of each genus in different tribes according to the recent tribal classification based on molecular and morphological data of the subfamily Grewioideae.

Ornithophily is a widespread pollination syndrome that has evolved independently several times along the evolution of plants. It is reported in sixty-five plant families, including Gesneriaceae. One of the most diverse genera within gesneriads is Sinningia, which comprises species pollinated by bees, hummingbirds and bats. However, little is known about the reproduction biology of either species or on pollinator specificity in this genus. Based on investigations on flowering phenology, flower morpho-anatomy, volume and concentration of floral nectar, pollinators, and breeding system, this paper reports the reproduction and the pollinator specificity of Sinningia douglasii and Sinningia araneosa in natural areas in Brazil. Both species offer nectar as a resource and are exclusively pollinated by a single species of hermit hummingbird. Nectar is produced by glands around the ovary. Pollen is deposited between the base of the beak and the head feathers. Both species are self-compatible and pollinator-dependent. In both Sinningia species, the combination of protandry, pollinator specificity, due to long corolla tubes that exclude the visitation of short-billed hummingbirds. The presence of particular flower features influence the occurrence of pollination by specific pollen vectors, such as hermit hummingbirds, in deterrence of illegitimate visitors (i.e. territorial hummingbirds), protection against vigorous foraging, and accurate placement of pollen on legitimate pollinators. In addition, the foraging of Phaethornis on flowers of Sinningia is independent of relative humidity and air temperature, whereas the main factor influencing hummingbird visits is the luminosity.

The first account of the lichen flora of the Cape York Peninsula bioregion is provided with 423 lichen taxa from 47 families and 127 genera recorded. The tropical savannas of Cape York Peninsula, which experience annual or biennial ground fires, are generally a harsh environment for lichen establishment and growth. The majority of eucalypts and Melaleuca viridiflora Sol. ex Gaertn. trees that dominate much of Cape York Peninsula vegetation regularly shed their bark and do not generally provide a suitable habitat for lichen establishment and persistence. However, even in these savanna habitats, some tree species provide suitable fire-safe substrates for lichens. The rainforest, riparian and coastal vegetation lichen flora is much more diverse, primarily because of the lack of fire but also because of more mesic conditions and persistent thin bark types. Most of the lichens (413 lichen species) survive on a number of bark types, while there are 51 species on rock substrates (10 exclusively on rocks). The diverse lichen flora is dominated by pantropical species, many of which are shared with New Guinea, Thailand and the Northern Territory. However, eleven lichen species are only known from Cape York Peninsula.

The fine-scale effects of fire and the consequences for seed survival are poorly understood, especially in the Cerrado (Brazilian savannas). Thus, we investigated whether vegetation gaps (bare soil patches) influence the survival of exposed seeds during fire events in the Cerrado by serving as safe sites. We performed field fire experiments in Central Brazil to examine how gap size (% of bare soil) influences fire heat (fire temperatures and residence time) and seed survival (Experiment 1) and to determine how seed survival is affected by fixed conditions: gaps vs grass tussocks during fires (Experiment 2). We used seeds of two common Cerrado legumes, Mimosa leiocephala Benth. and Harpalyce brasiliana Benth. Seed survival was analysed using GLMMs with a binomial distribution. In Experiment 1, seeds survived (38 and 35% for M. leiocephala and H. brasiliana respectively) only when the gaps had >40% of bare soil. In Experiment 2, all seeds under grass tussocks died when exposed to fire, whereas up to 40% of seeds survived in vegetation gaps, relative to their respective controls. Because vegetation gaps influence fire heat, they are important as safe sites for seed survival in the Cerrado, allowing a significant proportion of seeds to survive when exposed at the soil surface.

The subtropical rainforests of South East Queensland are relatively understudied but their importance for conservation has recently been highlighted, with the Sunshine Coast region identified as an area of high diversity, second to the Border Ranges. We measured phylogenetic diversity at a fine scale to identify areas of high diversity and dissimilarity across the Sunshine Coast, within the Forest of East Australia biodiversity hotspot. Edaphic and climatic influences were incorporated in the analysis to test their relevance to diversity in the region, and to aid the identification of local diversity hotspots. The Sunshine Coast was found to be phylogenetically even overall and had a high proportion of even sites (91 out of 109), consistent with the identification of refugia at a larger scale. The Blackall Range was identified as a local centre of diversity but it has been extensively cleared. Contrary to expectation, coastal lowland sites were phylogenetically even, suggesting potential localised stability or strong connectivity to refugia. These results reiterate the high conservation value of the region in general, particularly for the remnant areas of rainforest on the Blackall Range.

Eucalyptus delegatensis R.T. Baker subsp. delegatensis is an interval-sensitive, fire-killed eucalypt that dominates large tracts of montane forest in the Australian Alps. Although it has been widely accepted in forest management that E. delegatensis takes 20 years to flower and fruit after stand-replacing fire events, recent observations after high intensity fires in the Australian Alps have shown that early flowering and fruiting is occurring from what can be termed ‘precocious’ individuals in some areas. In some instances, early flowering and fruit set is occurring within 6 years after stand-replacing fire. One historical study in the Australian Capital Territory had noted that such seed was viable, but we found no reported experiments documenting this or detailing the degree of viability. Here we discuss the results of a germination experiment undertaken on seed collected from Namadgi National Park from early-maturing alpine ash trees. Although at the low end of known viability estimates for E. delegatensis, seed from these individuals was nonetheless found to be viable, with a mean of 455 (s.d. = 139) germinants per 10 g of chaff and seed mix. We discuss this result in relation to fire management in the Australian Alps and suggest further research that needs to be undertaken to better document and understand the phenomenon.

The root anatomy of bromeliad Nidularium minutum Mez was studied and the efficiency of root system in contributing to the growth, development and mineral uptake of the species evaluated. To accomplish this analysis, four treatments were applied as follows: (i) control plants with 5 mL H2O on substrate and 5 mL H2O into tank; (ii) plants supplied with nutrients to the tank with 5 mL H2O on substrate and 5 mL Hoagland and Arnon solution into tank; (iii) plants supplied with nutrients to the roots with 5 mL HA on substrate and 5 mL H2O into tank; and (iv) plants supplied with nutrients to the tank and roots with 5 mL HA on substrate and 5 mL HA into tank. Biometric variables and biomass were measured. Contents of macro- and micronutrients were evaluated in leaves, and the anatomical structure of roots was analysed. Structurally, the roots possess multiseriate epidermis, termed velamen, which is typical in Orchidaceae and other families for taking up water and nutrients. Plants supplied with nutrients to the roots had higher values than control plants for fresh and dry mass of stems, leaves and total (leaves + stems + roots), besides being more efficient than plants supplied with nutrients to the tank for nitrogen uptake. These results indicate that root system of N. minutum is very efficient for nutrients uptake when compared with the tank contributing to plant growth and development, most likely assisted by the presence of velamen.

Nitrogen resorption (NR) from senescing leaves enhances nutrient conservation in plants. Leaf area in lianescent aroid vines increases dramatically as the plant ascends vertically on its host. In Rhodospatha oblongata Schott, the largest leaves have up to 35 times the area and 50 times the N content of the smallest. We hypothesised that despite the costs of reallocating nitrogen within the plant, the huge increase in nitrogen cost to produce larger new leaves in R. oblongata should lead to increased NR from large leaves, mitigating the high demands on N acquisition from primary sources. The amount of veins available per unit leaf area may however constrain the ability to reutilise nitrogen within the plant. It was found that N concentration was 2–3% in green and 1–2% in senescent leaves, independent of leaf area, whereas vein density increased with leaf area. N use efficiency, resorption efficiency, and proficiency were not affected by leaf area; however, results indicate that R. oblongata does not have a conservative use of N despite occurring in oligotrophic soils. The absence of increased N resorption indicates that R. oblongata may have the capacity to acquire large amounts of soil and aerial N to produce new larger leaves, which after leaf fall may positively affect litter decomposition.

Bird pollination is particularly common and widespread in the southern regions of Australia. Despite some eucalypts being heavily frequented by birds, they are usually considered to have a generalist pollination system because of their apparently unspecialised floral morphology. A few species possess protandrous anthers that dehisce within a tightly furled dome of filaments. We hypothesised that this facilitates pollen transport via the brush tongues of lorikeets. Using Eucalyptus leucoxylon F.Muell. and five captive rainbow lorikeets (Trichoglossus hematodus) as a model, we demonstrated that lorikeets remove significant quantities of pollen from flowers with inflexed filaments in a short time (30 min), compared with bagged control flowers (Mann–Whitney U test, Z = 165.4, d.f. = 29, P = 0.008). Some of this pollen is deposited on stigmas by the tongue, which is the organ that most regularly and reliably contacts stigmas. The mean number of pollen grains deposited on stigmas by each bird was as high as 121.2. Adhesive tape contacted by the tongue during foraging removed up to 2104 pollen grains, which was significantly greater than for uncontacted control tape (Mann–Whitney U test, Z = 110, d.f. = 21, P < 0.001). Scanning electron micrograph imaging of a lorikeet tongue showed many pollen grains that had been transferred onto its keratin papillae, which is likely to have contributed to high carryover rates by retaining pollen for a substantial amount of time. Minimal pollen is available for generalist pollination once the filaments unfurl. It appears highly unlikely that insects are able to access pollen from these male-phase flowers and inflexed filaments may therefore fulfil an exclusionary role.