Aim This study of contemporary landscape burning patterns in the North Kimberley aims to determine the relative influences of environmental factors and compare the management regimes occurring on Aboriginal lands, pastoral leases, national park and crown land.Location The study area is defined at the largest scale by Landsat Scene 108-70 that covers a total land area of 23,134 km 2 in the North Kimberley Bioregion of north-west Australia, including the settlement of Kalumburu, coastline between Vansittart Bay in the west and the mouth of the Berkeley River in the east, and stretching approximately 200 km inland.Methods Two approaches are applied. First, a 10-year fire history (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999) derived from previous study of satellite (Landsat-MSS) remote sensing imagery is analysed for broad regional patterns. And secondly, a 2-year ground-based survey of burning along major access roads leading to an Aboriginal community is used to show fine-scale burning patterns. anova and multiple regression analyses are used to determine the influence of year, season, geology, tenure, distance from road and distance from settlement on fire patterns.Results Satellite data indicated that an average of 30.8% (±4.4% SEM) of the study area was burnt each year with considerable variability between years. Approximately 56% of the study area was burnt on three or more occasions over the 10-year period. A slightly higher proportion of burning occurred on average in the late dry season (17.2 ± 3.6%), compared with the early dry season (13.6 ± 3.3%). The highest fire frequency occurred on basalt substrates, on pastoral tenures, and at distances 5-25 km from roads. Three-way anova demonstrated that geological substrate and land use were the most significant factors influencing fire history, however a range of smaller interactions were also significant. Analysis of road transects, originating from an Aboriginal settlement, showed that the timing of fire and geology type were the most significant factors affecting the pattern of area burnt. Of the total transect area, 28.3 ± 2.9% was burnt annually with peaks in burning occurring into the dry season months of June, August and September. Basalt uplands (81.2%) and lowlands (30.1%) had greater areas burnt than sandstone (12.3%) and sands (17.7%).Main conclusions Anthropogenic firing is constrained by two major environmental determinants; climate and substrate. Seasonal peaks in burning activity in both the early and late dry season relate to periods of optimal fireweather conditions. Substrate factors (geology, soils and physiognomy) influence vegetation-fuel characteristics and the movement of fire in the landscape. Basalt hills overwhelmingly supported the most frequent wildfire regime in the study

The accounts of explorers and colonists in the Kimberley region ofWestern Australia were searched to find records of landscape burning by Aborigines. Analyses of these records provide estimates of the spatial and temporal patterns of fire across the region in historic times.The seasonality of fire varied across the region. In northern parts of the Kimberley landscape fire was recorded from May to October with peak levels in June and September. In southern parts of the region there are records of burning as early as February and March, through to August but no records of fire were made in late dry season months.Modern fire regimes were compared with historic by superimposing the routes taken by five explorers over a modern fire history map derived from satellite imagery. Tallies of the number of modern fires that intersect the explorer's daily and monthly route were compared with actual observations of fire made by the explorers in historic times. The results indicate an increase in early dry season fires and the overall frequency of fires across the region in modern times.Explorers' accounts were also examined to derive further information regarding Aboriginal landscape burning in different environments and to distinguish landscape burning from other uses of fire such as smoke signals and cooking fires.

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Indigenous landscape burning is practiced around remote communities in the Kimberleys but has been replaced by wildfires across uninhabited areas. A landscape-scale natural experiment was established to investigate the effects of these different fire histories (derived from a 10-year Landsat remote-sensing sequence) on the floristic structure and composition of woody vegetation within and among three of the major vegetation types on three landscape types (sandplain, sandstone and volcanics) near Kalumburu in the North Kimberley bioregion.Substrate factors determine vegetation and associated fire patterns within the landscape such that each landscape type needs to be examined independently. Basalt soils are dominated by an open savanna and tend to have very high fire frequencies. Basalt vegetation showed few significant response variables to fire-history parameters. The total density of woody stems showed no significant relationship to fire-history variables, regardless of size class. The 0–2.0-m size class of Erythrophleum chlorostachys (F.Muell.) Baillon showed significant (P < 0.005) responses to the various interactions involving all three fire-history variables, indicating that seedling density is sensitive to fire.Sandplain is dominated by open woodland, with relatively low fire frequency. Total stem density, shrub density and the densities of Grevillea agrifolia Cunn. Ex R.Br., Canthium sp. A and Stenocarpus cunninghamii R.Br. showed strong positive (P < 0.005) relationships with the total number of fire-free months. In sandstone, the density of all woody stems, acacias and a range of mid-storey trees showed significant positive relationships with the total number of fire-free months. Other species showed strong relationships with the number of late dry season fires. Vegetation thickening was evident in sand environments through the accumulation of woody stems in fire-free years and in sandstone through the promotion of 'fireweeds' such as Acacia gonocarpa F.Muell. after fire events.Mid-storey tree species capable of resprouting after fire showed some evidence of structural suppression in response to frequent fire events, including Planchonia careya (F.Muell.) Knuth, Persoonia falcata R.Br. and Buchanania obovata Engl.Results are discussed in the context of indigenous landscape burning and biodiversity conservation.

Summary  Much of northern Australia’s tropical savannas are subject to annual intense and extensive late dry season wildfires, much of this occurring on Aboriginal land. Based on the successful West Arnhem Land Fire Abatement (WALFA) model, which has resulted in significantly reduced greenhouse gas emissions, fire abatement programmes are planned for other significant regions of northern Australia. This study offers an introduction to the ideas behind a proposed environmental and social benchmarking project that aims to evaluate the potential benefits of expanding the fire abatement program in northern Australia, under the leadership of NAILSMA and its partners. Gaining a better understanding of the biodiversity, social and cultural outcomes of these fire abatement activities is an important component of demonstrating multiple benefits of these programmes. We emphasize the role of both biodiversity and cultural mapping to establish benchmarks and baseline states, with the involvement of Indigenous communities being a key element to optimize social and biodiversity benefits. Consultation with Traditional Owners and ranger groups to establish an agreed set of targets, indicators and sampling protocols and methodologies are critical component of this process. Examples of preliminary work to date are provided.