Biology subjects

Carle, H.

Publications and source records attributed to Carle, H..

3 recordsLinked to original sources

bioRxiv2026

Climate change drives declines in seed germination potential, particularly in woody species and warmer, drier landscapes of a temperate bioregion

Climate change is accelerating species losses in ecosystems across the world. Seed germination is a critical, climate-dependent phase of the plant life cycle; however, the ecological determinants of germination climate niches within diverse landscapes and across functional types (FTs) are still not well understood. In this study, we characterized seed germination temperature and water availability niches for 28 species that represent different FTs (tree, shrub, grass, forb) and vegetation types (grassy woodland, dry and wet forests) within a temperate bioregion (Sydney, Australia). We tested whether ecological determinants, specifically species climate of origin, seed traits, FT and vegetation type explain germination niches and predicted spatial and temporal patterns of germination potential across the landscape under high and low emission scenarios. We found wide variation in thermal and hydric germination niches among species. Optimal germination temperature (thermal niche) was predicted by FT, climate of origin and seed traits, such that shrubs, cool-origin species, and species with large seeds had significantly cooler optimal temperatures for germination. We also quantified spatial and temporal changes in germination potential to identify vulnerable areas and FTs. We found strong species-specific seasonal patterns in germination potential with future climate shifts affecting FTs differently; germination of woody species declined more than forbs. Future germination potential was predicted by historical climatic conditions, with warmer and drier localities being more vulnerable. Overall, our findings demonstrate that species germination responses to climate change depend on FT, seed traits, and species climate of origin, with woody species and warmer, drier parts of the landscape emerging as being particularly vulnerable to declines in recruitment. Our study provides a mechanistic understanding of germination responses to temperature and water availability, enabling predictions of vulnerable species and areas for conservation under climate change, and inform large-scale ecosystem restoration approaches through improved species selection and sowing times.

plant biology↗

bioRxiv2023

Elevation-dependent patterns of snow-gum dieback are moderated by trait differences between montane and subalpine forests.

Subalpine forests worldwide face the synergistic threats of global warming and increased biotic attack, and the collapse or transition of subalpine forests is predicted in south-eastern Australia under future climates. The recent widespread dieback of subalpine snow gum forests due to increased activity of a native wood-boring longicorn beetle suggests this process may already be underway. We investigated how variation in tree tissue traits and environmental conditions correlated with elevation-dependent spatial patterns of forest mortality. We hypothesised that increased vulnerability of subalpine snow gums to wood-borer-mediated dieback at intermediate elevations was associated with poorly-resolved differences in traits between montane (Eucalyptus pauciflora subsp. pauciflora) and subalpine (E. pauciflora subsp. niphophila) snow-gum subspecies. We first sought to characterise variation and elevation-dependent transitions in 20 structural and drought-related functional traits among 120 healthy trees distributed along a 1000m elevation transect which spanned the subspecies transition zone. Secondly, we surveyed 774 trees across 53 sites between 1280-1980m asl. to explore associations between borer-damage severity, elevation, subspecies, and a subset of traits that differed between subspecies. These snow-gum subspecies exhibited mean differences and/or divergent elevation responses in 25% of traits surveyed, indicating contrasting suites of traits between montane and subalpine subspecies. Increased borer-damage severity across the montane-to-subalpine subspecies transition was correlated with lower bark thickness, whereas reduced borer damage at the highest elevations was associated with greater precipitation and lower temperatures. Our results suggest that due to possessing distinct traits associated with increased borer susceptibility, subalpine snow-gum forests will be subject to increased risk of severe borer-mediated forest dieback under warmer and drier future climates. Identifying traits contributing to species distribution limits and biotic-agent vulnerability remains critical for predicting, monitoring, and possibly mitigating forest and vegetation declines under future climates.

ecology↗

bioRxiv2021

A rapid prototyping approach for intensive field courses to build scientific and professional skills

This paper reports on the design and evaluation of Field Studies in Functional Ecology (FSFE), a two-week intensive residential field course that enables students to master core content in functional ecology alongside skills that facilitate their transition from student to scientist. This paper provides an overview of the course structure, showing how the constituent elements have been designed and refined over successive iterations of the course. We detail how FSFE students: 1. Work closely with discipline specialists to develop a small group project that tests an hypothesis to answer a genuine scientific question in the field; 2. Learn critical skills of data management and communication; and 3. Analyse, interpret and present their results in the format of a scientific symposium. This process is repeated in an iterative cognitive apprenticeship model, supported by a series of workshops that name and explicitly instruct the students in hard and soft skills critical relevant for research and other careers. FSFE students develop a coherent and nuanced understanding of how to approach and execute ecological studies. The sophisticated knowledge and ecological research skills that they develop during the course is demonstrated through high quality presentations and peer-reviewed publications in an open-access, student-led journal. We outline our course structure and evaluate its efficacy to show how this novel combination of field course elements allows students to gain maximum value from their educational journey, and to develop cognitive, affective and reflective tools to help apply their skills as scientists.

scientific communication and education↗