Right here, right now: Populations of Actinotus helianthi differ in their early performance traits and interactions

Abstract

Populations across the geographical distribution of a species are shaped by different local environments to produce distinctive patterns of variation in plant traits. Among-population variation is, therefore, important for understanding potential shifts in distributions under changing environments, but is often not included in studies. In particular, critical data on the suitability of local environments for plant traits expressed at different life stages are lacking. To address this we performed two experiments to disentangle the influence of the local environment on multiple plant traits for populations of Actinotus helianthi from across its latitudinal range. A common environment experiment was used to compare early plant traits of germination, early seedling growth and survival for 17 populations of A. helianthi. To examine how biotic interactions vary across populations, we evaluated whether plant traits, including height and number of pseudanthia, influence visitor diversity and abundance, and if insect visitor abundance or diversity was associated with seed set success. We found that populations varied in germination success between 0.2 AE 0.1% and 64.2 AE 2.3%. Seedling growth and early survival varied among populations by as much as a factor of two and 44 respectively. We recorded variation in plant traits across hierarchical spatial scales from the maternal plant to biogeographical regions. The abundance and diversity of insect visitors also varied among populations and seed set was found to be site specific. There was a trend for populations with taller plants and larger floral display sizes to be more frequently visited by pollinators. We also identified a positive linear relationship between the number of visits by flies and seed set success. These results suggest that the local environment has a strong role in directly and indirectly influencing variation in plant traits within populations of A. helianthi, and potentially other perennial species.

Temperature thresholds for germination in 20 short‐range endemic plant species from a Greenstone Belt in southern Western Australia

“…; Emery et al . ). Failure to germinate can have profound consequences for ecosystem processes affecting community composition, species abundance and population dynamics (Walck et al .…”

Nomenclatural notes on New South Wales flannel flowers (Actinotus spp., Umbelliferae/Apiaceae) and Leopold Trattinnick’s other Australian plant-names

“…This fascicle appeared in November 1805, just two months after Labillardière had published Actinotus helianthi in his Novae Hollandiae plantarum specimen. Plants of Actinotus helianthi in Australia can produce flowers in as little as eight months from seed (Worrall et al 2004), but seed viability is reported to be low after 153 days (Emery et al 2017). Naturaliste with Baudin expedition collections left Sydney on 18 November 1802, reaching France in June 1803, so that it is just conceivable that some seeds survived the voyage, the resultant plant(s) flowering in Paris -to be drawn, but then die out completely soon afterwards.…”

Germination of the rarely seen Pink Flannel Flower ('Actinotus forsythii'; Apiaceae)

“…Actinotus helianthi, a closely related fire ephemeral, and have also demonstrated a complex dynamic of germination cues (Emery et al 2011). We aimed to understand the dormancy and germination cues of the Pink Flannel Flower to give insights both for improving its use in cultivation and its ecology in the wild.…”