Southern hemisphere plants show more delays than advances in flowering phenology

Shifts in flowering phenology have been studied in detail in the northern hemisphere and are a key plant response to climate change. However, there are relatively fewer data on species' phenological shifts in the southern hemisphere. We combined historic field data, data from herbarium specimens dating back to 1842 and modern field data for 37 Australian species to determine whether species were flowering earlier in the year than they had in the past. We also combined our results with data compiled in the southern and northern hemispheres, respectively, to determine whether southern hemisphere species are showing fewer advances in flowering phenology through time. Across our study species, we found that 12 species had undergone significant shifts in flowering time, with four species advancing their flowering and eight species delaying their flowering. The remaining 25 species showed no significant shifts in their flowering phenology. These findings are important because delays or lack of shifts in flowering phenology can lead to mismatches in trophic interactions between plants and pollinators or seed dispersers, which can have substantial impacts on ecosystem functioning and primary productivity. Combining our field results with data compiled from the literature showed that only 58.5% of southern hemisphere species were advancing their flowering time, compared with 81.6% of species that were advancing their flowering time in the northern hemisphere. Our study provides further evidence that it is not adequate for ecologists to assume that southern hemisphere ecosystems will respond to future climate change in the same way as ecosystems north of the Equator. Synthesis. Field data and data from the literature indicate that southern hemisphere species are showing fewer advances in their flowering phenology through time, especially in comparison to northern hemisphere species

Guidelines for quantifying leaf chlorophyll content via non-destructive spectrometry

Premise: Leaf chlorophyll is a fundamental bioindicator used in several fields. However, we lack clear guidelines for optimizing sampling efforts and produce comparable studies. Methods: We estimated chlorophyll for ten plant species content using spectrometry. We stored half of the leaves at 4°C and half at room temperature to assess the role of storage in chlorophyll degradation rate. Results: Refrigerated mature leaves maintain chlorophyll content within 5% of the original value for ~1.5 d, while unrefrigerated mature leaves need to be measured within 4 h. When refrigerated, expanding leaves remained within 5% of their original chlorophyll content for at least 5 d, but we suggest analysing them within 3 d. In mature leaves, 73% of the variation in chlorophyll content lies at the species level, 15% between individuals, and variation within leaves is negligible (< 1%). Measuring one mature leaf each from eight individuals is enough to provide a species chlorophyll estimate within 5% of the true value at least 80% of the time. Discussion: We advise researchers to prioritise sampling more individuals rather than repeating measures within leaves or individuals. Our findings will help researchers to optimise their time and research efforts, and to obtain more robust ecological data

A novel method for single sample multi-axial nanoindentation of hydrated heterogeneous tissues based on testing great white shark jaws.

Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the great white shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of great white shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable to a variety of hydrated biological materials whether soft or hard

Code used in "Does the strength of enemy release vary based on abiotic factors?"

R Code used in data analysis for manuscript titled "Does the strength of enemy release varybased on abiotic factors?". Code analyses existing data using R version 4.2.3 and additional packages specified in associated manuscript.The enemy release hypothesis is the understanding that the process of moving to a new place allows introduced species a chance to experience reduced pressure from predators anddisease. We considered whether the strength of enemy release caused observed onintroduced species populations across the world varies based on latitude, landmass size or climate by fitting linear models based on relationships that we hypothesised would exist from ecological theory.</p

<b>Conservation implications of isotopic variation in nails and blood with wetland quality in three species of Australian freshwater turtle</b>

1. Australian freshwater turtles are declining, reflecting global turtle trends. Understanding variation in turtle diets and habitat requirements can guide protection and restoration of ecosystems. Diet and niche overlap were investigated in three co-existing species of turtle, the broad-shelled turtle, Chelodina expansa, the eastern long-necked turtle, C. longicollis, and the Macquarie turtle, Emydura macquarii, across three rivers in the Murray–Darling Basin, Australia, in relation to environmental variables.2. Dietary variation in relation to water quality (salinity) and macrophyte cover was revealed using stable isotope analyses (δ15N and δ13C) of turtle tissues (plasma, red blood cell, whole blood and nail) representing food assimilation over different antecedent periods. These stable isotope results were consistent with current dietary understanding based on stomach flushing, indicating isotope analyses are a non-invasive method for obtaining dietary information.3. There were temporal dietary differences, with strong shifts between spring and summer sampling periods. Intraspecific variation in diets reflected in δ15N and δ13C related to body size. There was evidence of high dietary overlap among the three species, potentially creating competition, particularly when they co-occur or resources might be limited.4. Continued degradation of turtle habitats and water quality affects turtle diet and reduces habitat availability, forcing the three species of turtle to coexist in diminishing refugia, increasing interspecific competition for food. Protecting and restoring freshwater ecosystems, including maintaining freshwater refugia is essential to conserve already declining populations of the three Australian freshwater turtle species.</p

Analysis of Awarded Australian Grants by Gender

Examining temporal trends in the award of research grants in Australia by the Australian Research Council (ARC) and the National Health and Medical Research Council (NHMRC) according to awardee gender

Women are awarded more team grants than solo grants and lead more gender-balanced teams than men

We modelled patterns of collaboration, team gender composition, and funding amounts across awarded Australian government-funded competitive team research grants from 2000–2020. Among mid- and senior-career researchers, the percentage of grants awarded to women was higher for team grants than sole investigator grants compared to men at those levels. Teams led by women tended to have a greater percentage of women co-investigators than teams led by men, but this was below gender parity regardless of team leader gender. Funding amounts per grant did not differ by principal investigator gender and reached parity in 2020 across teams with both high and low representation of women. Since teams tend to be more gender-balanced when led by women, women’s grant leadership may be an important mechanism for shifting overall representation of women in research. We offer public policy measures to address gender equities in the research sector

Research Brief: Grant Leadership is Key to Gender Equity

We modelled patterns of collaboration, team gender composition, and funding amounts across awarded Australian government-funded competitive team research grants from 2000–2020. Among mid- and senior-career researchers, the percentage of grants awarded to women was higher for team grants than sole investigator grants compared to men at those levels. Teams led by women tended to have a greater percentage of women co-investigators than teams led by men, but this was below gender parity regardless of team leader gender. These patterns persisted across all levels of the team leader's career seniority. Funding amounts per grant did not differ by principal investigator gender and reached parity in 2020 across teams with both low and high representation of women, marking a shift from historical trends whereby teams with mostly women received less funding per grant than those with mostly men. Since teams tend to be more gender-balanced when led by women, women’s grant leadership may be an important mechanism for shifting the overall representation of women in research. We offer public policy measures to address gender equities in the research sector

Gender differences in Australian research grant awards, applications, amounts, and workforce participation

Gender differences in the outcomes of competitive grant programs have been detected, though the evidence is mixed. We modelled twenty years (2000–2020) of Australian national competitive grants and funding amounts according to lead investigator gender. We also explored if gender differences in awarded grants mirrored application rates and/or estimates of research workforce participation by gender. The dataset contained 46,912 awarded grants. We incorporated grant application and research workforce data. We found that fewer awarded grants were led by women than men; however, overall success rates of grant applications did not vary according to lead investigator gender. There were fewer women than men in the research workforce. The award rate (awarded grants relative to workforce participation) was slightly higher for women than men. Most of the observed gender differences were largest at senior-career levels. Gender differences in the number of awarded grants reduced over the period of the study, with the strongest temporal trend amongst senior-career researchers. Overall, success rates approximately halved over the 20-year period. The degree of decline varied by career seniority and gender. Gender differences in awarded grants varied by field of research, broadly mirroring differences in application and workforce participation rates within each field of research. Funding amounts per awarded grant did not vary by the gender of the lead investigator. Together these patterns imply that fewer women in the research workforce and leading grant applications have resulted in fewer awarded grants led by women than by men