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In many parts of the world, achieving a target of 30% of land managed for conservation under the Kunming‐Montreal Global Biodiversity Framework will require the protection of land with a long history of management for production. In newly protected forests, past logging practices will have impacted key aspects of stand structure, including hollow‐bearing trees that provide critical habitat for vertebrate fauna. The impacts of past silvicultural practices on hollow density, distribution, type and longevity may necessitate targeted ameliorative actions. We investigated tree hollows in the largest river red gum (Eucalyptus camaldulensis Denh.) forest in the world, which had undergone logging‐induced woody thickening prior to being converted to a conservation reserve in 2010. We recorded stem diameters and hollows in living and dead trees in 66 two‐hectare plots. Our sites sampled two productivity states and a wide range of total tree densities. On all sites, we found that hollow‐bearing tree densities were lower than reference values for unlogged stands and average density had halved relative to reference values. We found no relationship between the density of hollow‐bearing trees and total tree density, but we did find a weak positive relationship with site productivity. Larger trees had more hollows, bigger hollows and a greater diversity of hollow sizes. However, of the 1254 hollow‐bearing trees recorded, 43% were dead, 48% of the dead trees had been ringbarked. The proportion of hollow‐bearing trees that were dead was positively correlated with tree size, with 60% of trees in the largest quartile (>105 cm) recorded as dead. The prevalence of dead hollow‐bearing trees suggests that the density and diversity of hollows will continue to decline and ameliorative actions should be considered. These results highlight the need to consider the legacy of past silvicultural practices in the management of newly created conservation reserves. [ABSTRACT FROM AUTHOR]

The global trend in offsetting for no‐net‐loss (NNL) is increasing, focusing on protecting high‐condition habitats and restoring degraded ones. Australia's New South Wales (NSW) Biodiversity Offset Scheme (BOS) promotes active restoration (AR; reconstruction of missing ecosystem properties, AR) on offset sites. We examined (1) the adoption of AR under the BOS, and (2) practical constraints and attitudes toward AR. Records of management actions on 138 proposed offset sites revealed that AR was proposed for 19.3% (12,180 ha) of the total offset area (67,310 ha). For areas with a low‐moderate condition score (26,528 ha), AR was proposed for only 27.3% (7248 ha), despite these being the areas where it would be most likely to be necessary. A survey of 111 individuals involved in offsetting policy and restoration revealed that while 76% agreed AR was necessary for NNL, financial constraints were seen as a major barrier. A structural equation model indicated that positive attitudes toward AR rules and AR as a social imperative were strongly linked to agreement on the necessity of AR for NNL outcomes. Our results indicate that attitudes could influence the adoption of AR on offset sites, even in cases where policies are explicitly designed to provide financial incentives for AR, as exemplified in the context of NSW. [ABSTRACT FROM AUTHOR]

Summary: Vegetation condition metrics are often used as a surrogate of biodiversity to support management decisions, conservation regulations and biodiversity markets. Vegetation condition metrics, which aggregate multiple attributes, are often criticised for simplifying the complexity of biodiversity. A particular challenge is substitution when high‐scoring attributes compensate for those with low scores (e.g. high vegetation cover compensating for low growth from diversity). The geometric mean is often suggested for aggregation to reduce these effects. In New South Wales, Australia, the Vegetation Integrity metric, calculated as the geometric mean of Composition, Structure and Function sub‐indices, measures the losses and gains in biodiversity values within the NSW Biodiversity Offsets Scheme. However, concern has been raised that Vegetation Integrity underestimates conservation values of derived native grasslands when the Function sub‐index (primarily tree‐related attributes) approaches zero. We explore this issue using two datasets and compare the current Vegetation Integrity metric with aggregation using the arithmetic mean, adopting a minimum value of 10/100 for the Function sub‐index and use of a grassland benchmark for derived native grasslands. Our evaluation draws on a large‐scale expert elicitation of conservation values in Critically Endangered Box‐gum Grassy Woodlands and 4018 Vegetation Integrity estimates undertaken during development assessments. We find that Vegetation Integrity underestimates conservation values of derived native grasslands and that the problem is widespread. Although evidence most strongly supports aggregation using the arithmetic mean, this change could be disruptive to the Biodiversity Offsets Scheme. Alternatively, a sub‐index minimum of 10/100 eliminates underestimation of derived native grasslands without substantial impacts in other circumstances. We found little evidence to support the use of a grassland benchmark, which tended to overestimate conservation values. This study highlights the need for sufficient flexibility in biodiversity policies and regulations to accommodate ongoing metric evaluation and revision to support more robust biodiversity outcomes. [ABSTRACT FROM AUTHOR]

Oxidative stress within the vascular endothelium, due to excess generation of reactive oxygen species (ROS), is thought to be fundamental to the initiation and progression of the cardiovascular complications of type 2 diabetes mellitus. The term ROS encompasses a variety of chemical species including superoxide anion (O2•−), hydroxyl radical (OH−) and hydrogen peroxide (H2O2). While constitutive generation of low concentrations of ROS are indispensable for normal cellular function, excess O2•− can result in irreversible tissue damage. Excess ROS generation is catalysed by xanthine oxidase, uncoupled nitric oxide synthases, the mitochondrial electron transport chain and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidases. Amongst enzymatic sources of O2•− the Nox2 isoform of NADPH oxidase is thought to be critical to the oxidative stress found in type 2 diabetes mellitus. In contrast, the transcriptionally regulated Nox4 isoform, which generates H2O2, may fulfil a protective role and contribute to normal glucose homeostasis. This review describes the key roles of Nox2 and Nox4, as well as Nox1 and Nox5, in glucose homeostasis, endothelial function and oxidative stress, with a key focus on how they are regulated in health, and dysregulated in type 2 diabetes mellitus.

Analyses of diverse aboveground and belowground indicators should underpin assessments of ecosystem recovery, yet monitoring many indicators is costly and their integration is challenging. Our objective was to combine indicators through a Bayesian hierarchical model to provide a comprehensive assessment of ecosystem status and identify a cost‐effective subset of indicators to provide an accurate estimate of ecosystem recovery. We assessed 59 aboveground–belowground indicators, classified into nine components of composition, structure, and function, to estimate the ecosystem status of restored rock spoils and reference forests in south‐eastern Australia. Overall ecosystem status, which integrates across ecosystem components and supporting indicators, was lower within restored forests but positively correlated with forest age. Reference forests had greater aboveground and belowground biotic structure, organic matter supply, and soil carbon stability, and trends were consistent among all of their supporting indicators. A subset of organic matter quality and nutrient cycling indicators were greater within restored forests, suggesting high ecosystem process rates, but that soil carbon may be more vulnerable to loss. Aboveground biotic structure was correlated with organic matter supply and quality, stability of soil carbon, the cycling of nutrients, and belowground biotic structure, providing evidence of aboveground–belowground coupling. A combination of four indicators representing belowground biotic structure, soil carbon stability, organic matter supply, and aboveground composition, provided a good estimate of ecosystem status at a third of the cost. Although ecosystem status can be monitored with a small set of indicators, a diversity of aboveground–belowground indicators provide a robust and comprehensive assessment of recovery. [ABSTRACT FROM AUTHOR]