Spatial ecology of an apex predator over an urban to forest gradient

This research focused on predicting habitat suitability for the Powerful Owl over an urbanization gradient. Zones along the gradient provided different proportions of habitat for this species and tied in with availability of key resources. Urban environments provided limited habitat for the Powerful Owl and may potentially be acting as ecological traps.

Forest of gestures : video installation and performance work

Invitation to contribute to Alexander Harrisions' program 'What's Coming' resulted in 'Forest of Gestures' a 3 channel video projection and installation with a live feed component

Under the forest and Ladyswamp ( a radio play and a sonic poem)

'Under the Forest'  and 'Ladyswamp' are audio recordings created in collaboration with musician/ sound artist Tom Kazas. As the first outputs of the ongoing Lyrebird project (fully documented at writingfix.com.au) both works reinvent history in artistic form. At the same time they consider the aftermath of inappropriate farming techniques, representing the sense of disconnection the settlers immediately have from any historical continuity or indigenous relationship to land. In focussing on a regional area in Victoria and the stories that emerge from here, this practice-led research has implications for all other regional areas in countries throughout a world in a time of climate change. The two pieces, linked by the flow of water from the upper catchment of the Tarwin River, to the river flats near the South Gippsland coast, embody the presence of location via poetic means; the flow is from erosion to silt: of land becoming water, becoming land. In the sound design the locations are also represented poetically without losing the actuality of their haunting geography.
The two audio works were first presented at the Double Dialogues Conference: 'The 21st century - The Event, The Subject, The Artwork', Fiji, 2012, and are published in In/Stead, Issue 4, 2013 alongside a discursive article, ‘Under the forest & Ladyswamp: a radio play & a sonic poem’. Extracts of the audio appear on Youtube. The process of ‘Ladyswamp’ appears on an educational video currently in production by Deakin University.

Urban to forest gradients: suitability for hollow bearing trees and implications for obligate hollow nesters

 Resource availability is a limiting factor influencing the distribution and composition of faunal communities. Globally, hollow bearing trees are a resource required by wildlife at all trophic levels, and are used for a diverse range of ecological functions. In the northern hemisphere avian species act as primary hollow excavators, whereas the southern hemisphere must rely on complex interactions between stochastic events, and eventual decay. Hollow formation is therefore a slow process in the southern hemisphere. In contrast, hollow loss is quite rapid and influenced greatly by anthropogenic impacts.To identify the ecological characteristics driving hollows over an urban to forest gradient as a resource for the powerful owl (Ninox strenua) and its prey we used presence-only modelling. The potential for an area to support tree hollows suitable for powerful owls and their prey was linked to the density of ephemeral rivers, land cover, tree cover and distance from riparian vegetation. The potential for large hollows throughout the landscape, suitable for the powerful owl, was also influenced by density of permanent rivers. Potential habitat for tree hollows, capable of supporting powerful owls and their prey was greatest in forested environments, declining with increased urbanization. However the urban region still supported some smaller tree hollows suitable for arboreal marsupials. Managing for urban dwelling species, is not as simple as retaining old hollow producing trees or providing alternate nesting structures. We also need to mitigate increased mortality associated with built environments (e.g. electrocution, collisions).

Understanding the effects of the invasive plants on rural forest-dependent communities

Most of the studies on invasive species are disproportionately focused on their ecological effects and more investigations are needed to understand the effects of invasive plants on rural livelihoods. This study assesses the effects of the invasion of Mikania micrantha-an invasive vine-on the livelihoods of the buffer zone community forest users of Chitwan National Park, Nepal. In this study, the invasive plants are categorized based on their life-form (woody and non-woody) and mode of introduction (accidental or deliberate). The focus is on accidentally transported non-woody species. A household survey revealed that the invasion disproportionately affects the livelihoods of forest-dependent households. In addition, the livelihood effects of invasive plants are particularly determined by the suitability of the invasive plants to produce locally important forest products. © 2014 Steve Harrison, John Herbohn.

Reforestation with native mixed-species plantings in a temperate continental climate effectively sequesters and stabilizes carbon within decades.

Reforestation has large potential for mitigating climate change through carbon sequestration. Native mixed-species plantings have a higher potential to reverse biodiversity loss than do plantations of production species, but there are few data on their capacity to store carbon. A chronosequence (5-45 years) of 36 native mixed-species plantings, paired with adjacent pastures, was measured to investigate changes to stocks among C pools following reforestation of agricultural land in the medium rainfall zone (400-800 mm yr(-1) ) of temperate Australia. These mixed-species plantings accumulated 3.09 ± 0.85 t C ha(-1)  yr(-1) in aboveground biomass and 0.18 ± 0.05 t C ha(-1)  yr(-1) in plant litter, reaching amounts comparable to those measured in remnant woodlands by 20 years and 36 years after reforestation respectively. Soil C was slower to increase, with increases seen only after 45 years, at which time stocks had not reached the amounts found in remnant woodlands. The amount of trees (tree density and basal area) was positively associated with the accumulation of carbon in aboveground biomass and litter. In contrast, changes to soil C were most strongly related to the productivity of the location (a forest productivity index and soil N content in the adjacent pasture). At 30 years, native mixed-species plantings had increased the stability of soil C stocks, with higher amounts of recalcitrant C and higher C : N ratios than their adjacent pastures. Reforestation with native mixed-species plantings did not significantly change the availability of macronutrients (N, K, Ca, Mg, P, and S) or micronutrients (Fe, B, Mn, Zn, and Cu), content of plant toxins (Al, Si), acidity, or salinity (Na, electrical conductivity) in the soil. In this medium rainfall area, native mixed-species plantings provided comparable rates of C sequestration to local production species, with the probable additional benefit of providing better quality habitat for native biota. These results demonstrate that reforestation using native mixed-species plantings is an effective alternative for carbon sequestration to standard monocultures of production species in medium rainfall areas of temperate continental climates, where they can effectively store C, convert C into stable pools and provide greater benefits for biodiversity.