Soil Disturbance by Invertebrates in a Semi-arid Eucalypt Woodland: Effects of Grazing Exclusion, Faunal Reintroductions, Landscape and Patch Characteristics

Soil disturbing invertebrates are common elements of arid and semi-arid landscapes. Disturbances such as burrows, nest entrances, emergence holes and mounds of ejecta soil have large, but often poorly understood, effects on ecosystem properties and processes as broad as pedogenesis, soil movement and water infiltration. We examined disturbances created by a range of invertebrates in a semi-arid eucalypt woodland in eastern Australia in relation to three levels of disturbance varying from areas currently grazed by domestic herbivores to those where domestic herbivores have been removed, with and without the reintroduction of locally-extinct omnivorous native mammals. Overall, the tunnels and ejecta soil from ant nests comprised 80% of all invertebrate disturbances across all sites and treatments. There were significantly more invertebrate disturbances at sites where domestic herbivores had been excluded, more disturbances on dunes and in the swales than on plains, and more under shrubs than under trees. The cover of disturbances by invertebrates tended to increase with increasing cover of disturbance by native vertebrates, but only under exclosure where no locally-extinct native mammals had been reintroduced. Our results indicate that invertebrate-created disturbances are a common feature of semi-arid woodland soils, and that management activities, such as grazing and the reintroduction of locally-extinct vertebrates, will affect their density, potentially influencing a range of ecosystem processes

Soil Disturbance by Invertebrates in a Semi-arid Eucalypt Woodland: Effects of Grazing Exclusion, Faunal Reintroductions, Landscape and Patch Characteristics

. Soil disturbance by invertebrates in a semiarid eucalypt woodland: effects of grazing exclusion, faunal reintroductions, landscape and patch characteristics. Proceedings of the Linnean Society of New South Wales 134, A11-A18. Soil disturbing invertebrates are common elements of arid and semi-arid landscapes. Disturbances such as burrows, nest entrances, emergence holes and mounds of ejecta soil have large, but often poorly understood, effects on ecosystem properties and processes as broad as pedogenesis, soil movement and water infi ltration. We examined disturbances created by a range of invertebrates in a semi-arid eucalypt woodland in eastern Australia in relation to three levels of disturbance varying from areas currently grazed by domestic herbivores to those where domestic herbivores have been removed, with and without the reintroduction of locally-extinct omnivorous native mammals. Overall, the tunnels and ejecta soil from ant nests comprised 80% of all invertebrate disturbances across all sites and treatments. There were signifi cantly more invertebrate disturbances at sites where domestic herbivores had been excluded, more disturbances on dunes and in the swales than on plains, and more under shrubs than under trees. The cover of disturbances by invertebrates tended to increase with increasing cover of disturbance by native vertebrates, but only under exclosure where no locally-extinct native mammals had been reintroduced. Our results indicate that invertebrate-created disturbances are a common feature of semi-arid woodland soils, and that management activities, such as grazing and the reintroduction of locally-extinct vertebrates, will affect their density, potentially infl uencing a range of ecosystem processes

Improvement of local budget filling

This chapter describes the biological removal of sulphur compounds from gas streams. First, an overview is given of the toxicity of sulphur compounds to animals and humans whereafter biological and industrial formation routes for (organic) sulphur compounds are given. Microbial degradation routes of volatile organic sulphur compounds under both aerobic and anaerobic conditions are presented. Finally, the most commonly applied processes for sulphur removal from gaseous streams are discussed and an overview is given of operating experiences for biological gas treatment systems. The chapter concludes with some remarks on future developments

New controls investigated for vine mealybug

The vine mealybug is a newly invasive pest that has spread throughout California's extensive grape-growing regions. Researchers are investigating new control tools to be used in combination with or as an alternative to standard organophosphate insecticide controls. Insect growth regulators and nicotine-based insecticides provide good alternative pesticides for use in some vineyards. Ongoing studies on the augmentative release of natural enemies and mating disruption also show promise, but commercial products are not yet available to growers

Branching principles of animal and plant networks identified by combining extensive data, machine learning and modelling

Branching in vascular networks and in overall organismic form is one of the most common and ancient features of multicellular plants, fungi and animals. By combining machine-learning techniques with new theory that relates vascular form to metabolic function, we enable novel classification of diverse branching networks-mouse lung, human head and torso, angiosperm and gymnosperm plants. We find that ratios of limb radii-which dictate essential biologic functions related to resource transport and supply-are best at distinguishing branching networks. We also show how variation in vascular and branching geometry persists despite observing a convergent relationship across organisms for how metabolic rate depends on body mass