CSIRO Scientific Computing

ABSTRACT Sustainable Development interventions must deal with rapid and novel changes affecting complex social‐ecological systems, calling for design based on a resilience approach. However, limited analytical attention has been paid to the design settings in which such approaches are deployed. Through two intensive applications of an exemplar resilience tool, we explore its effectiveness in different design settings : a national food security project designed under a Global Environment Facility program and a community‐led project designed locally for agricultural livelihoods. Both cases affirmed the benefits of a resilience approach, opening the eyes of participants to impact pathways and response options that might otherwise be missed. However, the design setting affected the consequences for action systematically: for example, one case was constrained by donor programmatic objectives, whilst the other was not so constrained but lacked assured funding. Four key lessons indicate that donors need a systematic analysis of project design settings to achieve resilience.

Widespread climate-driven increases in background tree mortality rates have the potential to reduce the carbon storage of terrestrial ecosystems, challenging their effectiveness as natural buffers against atmospheric CO2 enrichment with major consequences for the global carbon budget. However, the global extent of trends in tree mortality and their drivers remains poorly quantified. The Australian continent experiences one of the most variable climates on Earth and is host to a diverse range of forest biomes that have evolved high resistance to disturbance, providing a valuable test case for the pervasiveness of tree mortality trends. Here we compile an 83-year tree dynamics database (1941-2023) from >2,700 forest plots across Australia covering tropical savanna and rainforest and warm and cool temperate forests, to explore spatiotemporal patterns of tree mortality and the associated drivers. Over the past eight decades, we found a consistent trend of increasing tree mortality across the four forest biomes. This temporal trend persisted after accounting for stand structure and was exacerbated in forests with low moisture index or a high competition index. Species with traits associated with high growth rate-low wood density, high specific leaf area and short maximum height-exhibited higher average mortality, but the rate of mortality increase was comparable across different functional groups. Increasing mortality was not associated with increasing growth, given that stand basal area increments either declined or remained unchanged over time, but it was associated with increasing temperature over time. Our findings suggest that ongoing climate change has driven pervasive shifts in forest dynamics beyond natural recovery in a range of forest biomes with high resilience to disturbance, threatening the enduring capacity of forests to sequester carbon under current and future climate scenarios.

Polyesters are widely used plastics that persist in the environment due to their resistance to degradation. Microbial polyesterases potentially offer recycling and remediation solutions. However, most polyesterases lack the thermostability and catalytic efficiency required for practical application. Here, we have identified and characterized thermostable bacterial polyesterases from an undercharacterized subfamily of SGNH‐hydrolases (related to PpEST from Pseudomonas oleovorans) and uncovered a previously unreported thermal stabilization mechanism mediated by conformationally flexible N‐terminal regions with features of intrinsically disordered regions. Biochemical assays, structural analysis, small angle X‐ray scattering, X‐ray crystallography, and molecular dynamics simulations suggest that these flexible N‐terminal regions enhance thermal resilience without affecting the catalytic rate or oligomerization in some homologs, while they promote oligomerization and reduce kcat in others. These findings suggest that flexible terminal regions can act as modular stabilizing elements through diverse mechanisms. Our work provides mechanistic insight into an unusual route to protein thermostability, expanding strategies for enzyme engineering, and contributing to the development of robust biocatalysts for polyester degradation.

Abstract Effective water and wetland management for waterbirds during nesting events benefits from knowledge of nesting timing, staging, duration, and associated foraging locations. Such information can inform managers about when, where, and for how long management actions such as environmental watering or predation protection are needed to support specific nesting stages. This is particularly relevant for species nesting in aggregations that are dependent on flooding of key sites to initiate and complete their nesting cycles, such as ibis and spoonbills. These species are frequently targeted for adaptive water and wetland management to support successful breeding events and can be bioindicators of wetland change. However, obtaining on-ground nesting data for highly mobile species in remote or inaccessible sites can be difficult. To solve this problem, we used GPS satellite telemetry to track nesting events for 3 species that frequently nest together in remote wetlands managed with environmental water: Threskiornis spinicollis (Straw-necked Ibis), T. molucca (Australian White Ibis), and Platalea regia (Royal Spoonbill). This is the first time that satellite telemetry for these highly mobile species has been used to analyze: (1) nest stages and nest attendance patterns; (2) distances travelled to forage during nesting; and (3) timing and duration of nesting events. We found both intra- and inter-species variation in nest attendance patterns and foraging distances. There were changes in nest attendance and foraging distance patterns corresponding with transitions between each of the 4 main nest stages: (1) nest establishment; (2) incubation; (3) immobile chicks; (4) mobile chicks. We discuss how this information can be used to implement strategic conservation management of waterbird populations and habitats including environmental watering, nest protection, and predator control.

• Builds on the SEEA EA extended supply and use tables. • Uses real data to populate physical and monetary accounts for the Murray-Darling Basin, Australia. • Separates the use of ecosystem services from the benefits for both industry and households. • Quantifies the contribution of the environment to economic and well-being benefits. • Improves decision making through adequately recognising the economy’s fundamental reliance on the environment. We implement natural capital accounts for ecosystem services (ES) using the System of Environmental-Economic Accounting – Ecosystem Accounting (SEEA EA) framework and a case study from the Murray-Darling Basin, Australia. Extended ES supply-use tables are presented that allow for the simultaneous reporting on multiple intermediate and final ES alongside data already available in traditional national economic accounts. We cover the ES of crop provisioning, grazed biomass provisioning, water supply, soil erosion control, recreational fishing, and carbon sequestration and storage. This study shows that extended ES supply-use tables using physical and monetary measures can provide feasible, although not necessarily complete, links between information recorded in the SEEA EA and traditional national economic accounts. It provides an integration of intermediate ES, final ES and produced goods and services in a single table and helps to distinguish benefits from the inputs that create these benefits. Going forward, more integrated recording of the economy and ecosystems’ contributions to wellbeing is needed to better understand the benefits derived from nature.

Fires disrupt ecosystems, release carbon, and reduce carbon uptake, which increases atmospheric CO2 concentration, warms the atmosphere, and fosters more frequent and intense fires. Quantifying postfire recovery is crucial for understanding the adaptability and resilience of ecosystems to fire disturbances. Observations from satellite-derived active fire (~1-km) and Gross Primary Productivity (GPP) products reveal that Australia experiences extensive fires annually, reducing vegetation productivity. Here we analyze the post-fire GPP recovery trajectories of 1.7 × 106 fire-affected pixels (or 1.5 × 106 km2) in Australia between 2011 and 2019, of which 1.3 × 106 pixels (1.2 × 106 km2) experienced a single fire (single-fire pixels), and 0.4 × 106 pixels (0.3 × 106 km2) experienced two or more fires (multiple-fire pixels). We found that Australia's postfire GPP recovery was strong and rapid. 88% of single-fire pixels recovered to 135% of the prefire level in an average of 2.3 years, whereas 86% of multiple-fire pixels recovered to 115% of the prefire level in an average of 1.2 years. NonForest ecosystems (e.g., grasslands, shrublands, and savannas) exhibited a higher postfire recovery magnitude (138% for single-fire pixels and 115% for multiple-fire pixels) compared to Forest (110% for single-fire pixels and 108% for multiple-fire pixels). This rapid and robust postfire GPP recovery is significantly influenced by postfire precipitation, fire (i.e., fire frequency, intensity) and fire severity (damage, impacts; a metric of resistance of terrestrial ecosystems to fire). Specifically, higher fire severity and higher postfire precipitation have a positive impact on postfire recovery, whereas increased fire frequency has a negative impact. Furthermore, fire dynamics have a smaller role in the long-term interannual continental GPP changes than climate or land-use changes, as strong and rapid GPP recovery offsets the short-term fire-induced GPP losses.

Flow regimes of river ecosystems worldwide have undergone substantial changes because of water resource development, altering the way in which organic matter is generated and cycled throughout entire river catchments. Flow–ecology studies have focused on structural variables measured at small spatial scales. This creates a challenging mismatch when applying adaptive flow management for ecosystem functioning at a catchment or regional scale. Here, we sought to inform flow management by evaluating the drivers of ecosystem metabolism in a regulated river and assessing our ability to predict metabolism at unmonitored locations. We estimated rates of ecosystem metabolism from high-frequency monitoring of dissolved oxygen concentration at eight sites on the Lachlan River of Australia’s Murray–Darling Basin. We then applied a spatio-temporal stream network model to predict metabolism at unmonitored locations using only remotely sensed and gauging station predictor variables. Gross primary productivity (GPP) was higher at sites with lower mean annual discharge, and strong seasonal patterns in rates of productivity tended to be disrupted by rising flows. Similarly, ecosystem respiration (ER) was higher at sites with lower mean annual discharge and lower annual flow variation, but increased slightly in response to higher daily flows. Predictions at validation sites were generally accurate, albeit with substantial site-to-site variation. Our results suggest that flow changes may have altered metabolic rates from conditions prior to water abstraction and dam construction. These findings will assist in managing flows for ecosystem function outcomes and support extrapolation from monitored sites to the broad scales required for evaluating catchment-scale outcomes of river management.

Abstract Managing vegetation to sequester carbon in biomass requires estimates to meet standards for accuracy, with methods that are transparent, verifiable and cost‐effective. Allometric models are commonly used to predict biomass from non‐destructive field inventory data. Although a number of studies have addressed biomass error propagation, none have provided a general set of methods for linking errors all the way from initial allometric model development through to the final site‐based biomass prediction, for both above‐ and below‐ground biomass. Error sources in total biomass (above‐ + below‐ground) were quantified using a combination of analytical and Monte Carlo methods, illustrated with four contrasting case studies using either site‐ and‐species‐specific, species‐specific or generalised allometric models. Sampling error was found to be the most important contributor to site‐level biomass uncertainty, arising from the interaction between spatial variability and the field sampling design. The contribution of allometric model covariance to total error was also quantified, with errors in the determination of moisture content during allometric model development identified as a potentially important yet often overlooked error source. Application of different allometric models to the same inventory data suggested the error from generalised models was no greater than that from site‐ or species‐specific models, with increases in the generalised model prediction error balanced by decreases in other error sources associated with the increased sample size on which generalised models are based. Recommendations for reducing errors in predicted biomass include increasing field survey sample size, adopting field survey designs that ensure spatial representativeness and improving moisture content measurement protocols and increasing the moisture content sample size during allometric model development. To reduce costs while maintaining acceptable accuracy, the use of generalised allometric models is recommended, with the caveat that additional biomass sampling for model validation may be required to limit the potential for biased predictions.

Abstract Intact native forests under negligible large-scale human pressures (i.e. high-integrity forests) are critical for biodiversity conservation. However, high-integrity forests are declining worldwide due to deforestation and forest degradation. Recognizing the importance of high-integrity ecosystems (including forests), the Kunming-Montreal Global Biodiversity Framework (GBF) has directly included the maintenance and restoration of ecosystem integrity, in addition to ecosystem extent, in its goals and targets. Yet, the headline indicators identified to help nations monitor forest ecosystems and their integrity can currently track changes only in (1) forest cover or extent, and (2) the risk of ecosystem collapse using the IUCN Red List of Ecosystems (RLE). These headline indicators are unlikely to facilitate the monitoring of forest integrity for two reasons. First, focusing on forest cover not only misses the impacts of anthropogenic degradation on forests but can also fail to detect the effect of positive management actions in enhancing forest integrity. Second, the risk of ecosystem collapse as measured by the ordinal RLE index (from Least Concern to Critically Endangered) makes it unlikely that changes to the continuum of forest integrity over space and time would be reported by nations. Importantly, forest ecosystems in many biodiverse African and Asian nations remain unassessed with the RLE. As such, many nations will likely resort to monitoring forest cover alone and therefore inadequately report progress against forest integrity goals and targets. We concur that monitoring changes in forest cover and the risk of ecosystem collapse are indeed vital aspects of conservation monitoring. Yet, they are insufficient for the specific purpose of tracking progress against crucial ecosystem integrity components of the GBF’s goals. We discuss the pitfalls of merely monitoring forest cover, a likely outcome with the current headline indicators. Augmenting forest cover monitoring with indicators that capture change in absolute area along the continuum of forest integrity would help monitor progress toward achieving area-based targets related to both integrity and extent of global forests.

Small- to medium-sized shorebirds (< 200 g) can be particularly difficult to track with electronic devices due to their small size and long-distance migrations which place restrictions on device weight and size. A lack of comparative information on suitable tracking devices makes selecting the most appropriate technology time consuming and complex and can result in duplication of effort for each research project. The purpose of this paper is to address this issue by presenting a review of the scientific literature and commercially available devices to help inform device selection as well as options for attachment. The ideal device for tracking small to medium migratory shorebirds would be light weight (< 5% of a bird bodyweight), flat in profile, durable, have high battery longevity, remote data download, easy to attach from a bird welfare perspective, high spatiotemporal resolution and would be low in cost (so that a large enough sample size can be obtained). This ideal device does not yet exist due to the limitations on the weight of the power supply necessary to obtain frequent, high resolution location fixes over long time periods. As a result, the current choice of device depends on the purpose of the study. Platform Transmitter Terminal (PTT) doppler devices are suitable for tracking long distance movement due to their smaller size and lighter weight (around 2 g), but produce lower resolution location data and are expensive. For tracking smaller-scale movements (i.e., tens of kilometres), Global Positioning System (GPS) devices are more suitable, because they produce higher-resolution location data and are often more cost effective but tend to be heavier. Other device options for obtaining movement data include radio telemetry and light-level geolocators, which are generally lighter and cheaper than GPS or Doppler devices but require more effort to retrieve data and often produce lower resolution location data. Attachment methods and materials vary, but the most suitable is usually leg loop harnesses made with soft materials that are likely to degrade (e.g., elastic). Device type and harness design need to be carefully chosen to minimize potential impacts on the animal.