The influence of vegetation structure and composition on invasibility by Pinus radiata in the Blue Mountains, NSW

The exotic tree species Pinus radiata D. Don (in the family Pinaceae) has successfully spread from commercial plantations into adjacent vegetation in southeastern Australia. Identifying factors facilitating spread will aid the control of current invasions and the prediction of future invasion events. The structure and composition of vegetation can have an important role in determining community resilience to invasion. Two dry eucalypt sclerophyll woodlands in the Blue Mountains west of Sydney known to be invaded by Pinus radiata were surveyed to investigate the influence of eucalypt presence, species diversity, species composition and vegetation cover on the extent and density of invasion. Relationships between community characteristics and the level of pine invasion were weak and variable. Pines were found growing in plots with 0–70% understorey cover and 5–90% ground cover, and in areas of both high and low eucalypt diversity and presence, illustrating the high invasion potential of Pinus radiata

Editorial: Fire regimes in desert ecosystems: Drivers, impacts and changes

Although not commonly associated with fire, many desert ecosystems across the globe do occasionally burn, and there is evidence that fire incidences are increasing, leading to altered fire regimes in this biome. The increased prevalence of megafires (wildfires \u3e 10,000 ha in size and typically damaging) in most global biomes is linked to climate change, although those occurring in deserts have received far less attention, from both a research and policy perspective, than that of forested ecosystems (Linley et al., 2022). Understanding the drivers of desert fires, from climate to landscape patterns of hydrology and soil, and how these may be changing in the face of anthropogenic pressures, such as invasive species, livestock grazing, and global climate change, is imperative. This Research Topic has published nine papers addressing these drivers, how they have changed, and their impacts on desert biodiversity

Variation in dormancy among populations of the fire-ephemeral flannel flower, Actinotus helianthi

Dormancy is a necessary mechanism to prevent seeds from germinating during unfavourable external environmental conditions. For the Sydney Flannel Flower (Actinotus helianthi Labill.) it is not clear how the environment influences the erratic variation experienced in published germination trials. This study examined differences in dormancy and viability between several wild populations of Actinotus helianthi. Mature seeds were collected from four populations across the Greater Sydney region. Germination of seeds was assessed at 15oC and seeds were pre-treated with deionised water or 1% smoke water (1% has been previously demonstrated to improve germination in Actinotus leucocephalus). Poor viability ranging from 40% to 58% was identified across all populations, producing low numbers of germinated seeds. Significant variation in germination percentage between populations was exhibited in seeds treated with smoke water. Seed from Flannel Flower populations should be collected, stored and germinated separately. The variability recorded between populations is most likely an adaptive response to the fire history of the area, giving varying levels of smoke sensitivity

Episodic population fragmentation and gene flow reveal a trade-off between heterozygosity and allelic richness

In episodic environments like deserts, populations of some animal species exhibit irregular fluctuations such that populations are alternately large and connected or small and isolated. Such dynamics are typically driven by periodic resource pulses due, for example, to large but infrequent rainfall events. The repeated population bottlenecks resulting from fragmentation should lower genetic diversity over time, yet species undergoing these fluctuations appear to maintain high levels of genetic diversity. To resolve this apparent paradox, we simulated a metapopulation of constant size undergoing repeat episodes of fragmentation and change in gene flow to mimic outcomes experienced by mammals in an Australian desert. We show that episodic fragmentation and gene flow have contrasting effects on two measures of genetic diversity: heterozygosity and allelic richness. Specifically, fragmentation into many, small subpopulations, coupled with periods of infrequent gene flow, preserves allelic richness at the expense of heterozygosity. In contrast, fragmentation into a few, large subpopulations maintains heterozygosity at the expense of allelic richness. The strength of the trade-off between heterozygosity and allelic richness depends on the amount of gene flow and the frequency of gene flow events. Our results imply that the type of genetic diversity maintained among species living in strongly fluctuating environments will depend on the way populations fragment, with our results highlighting different mechanisms for maintaining allelic richness and heterozygosity in small, fragmented populations

Effective ecosystem monitoring requires a multi-scaled approach

Ecosystem monitoring is fundamental to our understanding of how ecosystem change is impacting our natural resources and is vital for developing evidence-based policy and management. However, the different types of ecosystem monitoring, along with their recommended applications, are often poorly understood and contentious. Varying definitions and strict adherence to a specific monitoring type can inhibit effective ecosystem monitoring, leading to poor program development, implementation and outcomes. In an effort to develop a more consistent and clear understanding of ecosystem monitoring programs, we here review the main types of monitoring and recommend the widespread adoption of three classifications of monitoring, namely, targeted, surveillance and landscape monitoring. Landscape monitoring is conducted over large areas, provides spatial data, and enables questions relating to where and when ecosystem change is occurring to be addressed. Surveillance monitoring uses standardised field methods to inform on what is changing in our environments and the direction and magnitude of that change, whilst targeted monitoring is designed around testable hypotheses over defined areas and is the best approach for determining the causes of ecosystem change. The classification system is flexible and can incorporate different interests, objectives, targets and characteristics as well as different spatial scales and temporal frequencies, while also providing valuable structure and consistency across distinct ecosystem monitoring programs. To support our argument, we examine the ability of each monitoring type to inform on six key types of questions that are routinely posed for ecosystem monitoring programs, such as where and when change is occurring, what is the magnitude of change, and how can the change be managed? As we demonstrate, each type of ecosystem monitoring has its own strengths and weaknesses, which should be carefully considered relative to the desired results. Using this scheme, scientists and land managers can design programs best suited to their needs. Finally, we assert that for our most serious environmental challenges, it is essential that we include information from each of these monitoring scales to inform on all facets of ecosystem change, and this is best achieved through close collaboration between the scales. With a renewed understanding of the importance of each monitoring type, along with greater commitment to monitor cooperatively, we will be well placed to address some of our greatest environmental challenges

Extending the boundaries of non-Indigenous science to embrace the cultural curriculum by creating a living compendium of practice

BACKGROUND Embedding cultural competence (CC) into science curricula is key to the University of Sydney’s commitment to producing students with skills and knowledge to work in cross-cultural settings. Within the Faculty of Science, there are eight disciplinary schools who have, to some extent, endeavoured to introduce CC into their delivery and content to ensure students achieve this graduate outcome. Cultural competence inclusion was initiated by the Wingara Mura-Bunga Barrabugu program, with a focus on integration of Indigenous knowledge systems (IKS) into non-Indigenous science. PLAN In 2018, we initiated a CC compendium to act as a bridging space between academics, to share content and explore collaborations laterally across the faculty. ACTIONS This paper documents the process of interviewing academic staff and collating the compendium by gathering teaching materials and CC teaching approaches, highlighting the points of highest resonance within each discipline. Academics are using creative and innovative ways to extend their disciplinary boundaries, are embracing personal and professional growth by taking on this challenge and are carving out new pathways in science. REFLECTION These boundary-pushing efforts are however, marginal, and are largely being introduced by non-Indigenous academics, which raises questions about IKS inclusion as a pathway for generating CC. ACKNOWLEDGEMENTS We thank the Wingara Mura-Bunga Barrabugu, Deputy Vice-Chancellor Indigenous Strategy and Services for funds for this project

Making ecological monitoring successful: Insights and lessons from the Long Term Ecological Research Network

Ecological monitoring allows us to track changes in the environment and helps us see how our actions affect the environment. Long-term monitoring is particularly important, yielding valuable insights that are not possible from shorter-term investigations. We consider successful ecological monitoring to be monitoring that generates knowledge that is useful to others, and can be valuable in adaptive and effective environmental management. Any effective monitoring program requires a number of fundamental considerations, and additional factors should be considered in the design of a long-term monitoring program. This booklet describes what we consider to be the key characteristics of successful ecological monitoring, including long-term monitoring.All these characteristics work together. For example, good project design cannot meet its objectives without long-term funding; data management must be matched by good communication; and good partnerships must be maintained through succession and project planning. In discussing these characteristics and our recommendations for how they may be achieved, we present a series of stories and quotes. These insights are based on the collective experience of research leaders of the 12 plot networks within the Long Term Ecological Research Network, along with other professionals associated with the network. These stories highlight just how difficult it is to do long-term ecological research in Australia. They also illustrate the unique value of this kind of research for helping to understand and manage the Australian environment. We hope that this booklet will support the development of more effective and influential long-term ecological projects in Australia.LTERN is a facility within the Terrestrial Ecosystem Research Network (TERN). TERN is supported by the Australian Government through the National Collaborative Research Infrastructure Strategy

The power of forecasts to advance ecological theory

Ecological forecasting provides a powerful set of methods for predicting short- and long-term change in living systems. Forecasts are now widely produced, enabling proactive management for many applied ecological problems. However, despite numerous calls for an increased emphasis on prediction in ecology, the potential for forecasting to accelerate ecological theory development remains underrealized. Here, we provide a conceptual framework describing how ecological forecasts can energize and advance ecological theory. We emphasize the many opportunities for future progress in this area through increased forecast development, comparison and synthesis. Our framework describes how a forecasting approach can shed new light on existing ecological theories while also allowing researchers to address novel questions. Through rigorous and repeated testing of hypotheses, forecasting can help to refine theories and understand their generality across systems. Meanwhile, synthesizing across forecasts allows for the development of novel theory about the relative predictability of ecological variables across forecast horizons and scales. We envision a future where forecasting is integrated as part of the toolset used in fundamental ecology. By outlining the relevance of forecasting methods to ecological theory, we aim to decrease barriers to entry and broaden the community of researchers using forecasting for fundamental ecological insight

Bioclimatic transect networks: Powerful observatories of ecological change

Transects that traverse substantial climate gradients are important tools for climate change research and allow questions on the extent to which phenotypic variation associates with climate, the link between climate and species distributions, and variation in sensitivity to climate change among biomes to be addressed. However, the potential limitations of individual transect studies have recently been highlighted. Here, we argue that replicating and networking transects, along with the introduction of experimental treatments, addresses these concerns. Transect networks provide cost-effective and robust insights into ecological and evolutionary adaptation and improve forecasting of ecosystem change. We draw on the experience and research facilitated by the Australian Transect Network to demonstrate our case, with examples, to clarify how population- and community-level studies can be integrated with observations from multiple transects, manipulative experiments, genomics, and ecological modeling to gain novel insights into how species and systems respond to climate change. This integration can provide a spatiotemporal understanding of past and future climate-induced changes, which will inform effective management actions for promoting biodiversity resilience