Low Woodland Research Articles

Collaborative anthracology and cultural understandings of wood charcoal in Marra Country (northern Australia)

This paper presents results from the first collaborative anthracological (archaeological wood charcoal analysis) study in northern Australia’s southwest Gulf of Carpentaria region. The analysis focused on charcoal from a Late Holocene combustion feature and surrounding dispersed charcoal on a buried floor surface. The results suggest that the combustion feature likely functioned as a ground oven associated with a potential specific function, with the majority of fuel wood coming from wakuwaku/marnunggurrun (Callitris columellaris or White Cypress Pine) and Myrtaceae species. These species are found in low woodlands associated with hilly and freshwater springs settings, and their abundance and dispersal are influenced by fire regimes (e.g., Aboriginal fire regimes). Information provided by members of the Marra Aboriginal community about our findings focused on the social and cultural significance of wakuwaku/marnunggurrun, with particular emphasis around its role in past and present wood collection strategies (fire-making and transport, high value timber etc.). By exploring how anthracology and cultural knowledge intersect to generate new understandings about the relational qualities of wood (charcoal), we aim to highlight how collaborative archaeobotany can help reorient research questions in the discipline, providing an opportunity to make such specialised analyses meaningful to communities.

BREEDING SITES CHARACTERISTICS AND MOSQUITO ABUNDANCE IN SOME SELECTED LOCATIONS WITHIN KADUNA METROPOLIS

Natural or artificial collection of water serves as an optimum habitat that supports mosquito’s breeding, while savannah, grasslands or shady low woodlands supports their resting activities, swarming and mating. Samples were collected from breeding sites within some selected locations from January to June. Five hundred and thirty two mosquito larvae belonging to 3 genera Culex, Anopheles and Aedes were collected and seven species of mosquitoes were identified comprising; Culex quinquefasciatus 102 (19.17%), Aedes aegypti 345(64.84%), Culex decens 8 (1.50%), Aedes vittatus 49 (9.21%) Culex simpsoni 8(1.50%), Culex tigripes 17 (3.20%) and Anopheles gambiae 3(0.50%). Aedes aegypti was common in all the locations. Water samples were collected from seven different major breeding sites such as abandoned tyres 155(50.82%), Concrete gutters 50(16.39%), Pools 10 (3.27%) ponds 4 (1.31%), Plastic containers50 (16.39%), Potholes 6 (1.97%) and Metallic containers30 (9.84%) totaling 305 sampled breeding sites. The characteristics of breeding sites noted were the movement of water in the breeding places, the consistency of the presence of water in the breeding places, the existence of vegetation on the breeding and types of predators. Correlation analysis showed abundance of mosquitoes decreased with increase in physicochemical parameters. In conclusion, the common house mosquito (Aedes aegypti) was most abundant and occurring in abandoned tyres; while the physico-chemical parameters were all within the acceptable limits for mosquito breeding.

Habitat‐contingent responses to disturbance: impacts of cattle grazing on ant communities vary with habitat complexity

Predicting community responses to disturbance is a major challenge for both ecology and ecosystem management. A particularly challenging issue is that the same type and intensity of disturbance can have different impacts in different habitats. We investigate how habitat contingency influences ant community responses to disturbance in arid Australia, testing the hypothesis that disturbance has a greater impact in more complex habitats. We also assess the effectiveness of a highly simplified ant assessment protocol that considers larger species only. We sampled ants at 46 sites from two habitats (Chandler, low chenopod shrubland; and mulga, low woodland) with contrasting complexity, using distance from water as a surrogate for variation in grazing intensity. We assessed variation in habitat structural variables (basal area of perennial grass, and cover of herbs, litter, and bare ground) and ant communities in relation to habitat and distance from water, first using data from the entire ant community and then for larger ants (>4mm body length) only. Site species richness was almost twice as high in mulga, the more structurally complex habitat, than in Chandler, and ant communities in mulga showed far more variation in relation to distance from water. Litter cover was the key environmental variable associated with the interaction between grazing and habitat: it increased with increasing distance from water in mulga and was virtually absent from Chandler. Analysis of only larger species revealed the same patterns of variation in ant abundance, species richness and composition in relation to habitat and grazing as shown by entire ant communities. Our findings support the hypothesis that disturbance impacts on faunal communities increase with increasing habitat complexity. An appreciation of such habitat contingency is important for a predictive understanding and therefore effective management of disturbances such as rangeland grazing. Our findings also show that simplified assessment can provide robust information on the responses of highly diverse ant communities to disturbance, which enhances their feasibility for use as bio-indicators in land management.

Floral resource pulse decreases bumble bee foraging trip duration in central Wisconsin agroecosystem

1. Resource pulses, narrow periods of high resource availability, can elicit strong behavioural responses across diverse taxa. Mass‐flowering agricultural crops are an example of a resource pulse that insect pollinators exploit. However, the underlying mechanism behind changes in pollinator behaviour associated with mass‐flowering crops is still relatively unexplored.2. The present study quantified the behavioural response of bumble bees, an important wild pollinator, to commercial cranberry bloom, an important mass‐flowering crop in Wisconsin, U.S.A. Over a 2‐year period, foraging trip duration was measured using radio frequency identification at 14 farms situated across landscape contexts, ranging from high to low natural area (woodland amount). Using transect surveys, floral resource abundance at a landscape scale was estimated.3. It was found that bumble bees were highly sensitive to temporal changes in landscape‐level resource abundance associated with the onset of cranberry bloom, during which they decreased foraging trip duration by 22% and increased the number of foraging trips during bloom by 24% on average relative to the period before and after bloom. This phenomenon was consistent across colonies, individual bees, and landscape contexts, despite a higher abundance of flowers in low woodland landscapes. Bumble bee colonies growing in low‐ and high‐woodland landscapes exhibited a similar performance.4. As mass‐flowering crops are probably a factor influencing bumble bee foraging behaviour in agricultural regions, investigations should continue into how variable resource landscapes, particularly those offering resource pulses, affect wild pollinators and the pollination services they provide.

Temporal changes in species composition, diversity, and woody vegetation structure of savannas in the Cerrado-Amazon transition zone

ABSTRACT Vegetation in the transition between tropical forest and savanna is hyperdynamic and there is evidence that in the absence of fire, forest advances over savanna. Between 2008 and 2013 we evaluated changes in species composition and diversity and in the structure of the woody vegetation of savanna physiognomies in the transition between the Cerrado and Amazon biomes that were fire free for 11 years. The physiognomies form a gradient from savanna woodland (Typical Cerrado - TC), to low woodland (Dense Cerrado - DC), to woodland (locally called Cerradao - CO). We hypothesise that: 1) the more open physiognomies (TC and DC) are more dynamic compared to the closed physiognomy (CO); and 2) in the absence of fire vegetation tends to become more forested. We found that: 1) TC was more dynamic (e.g. greater increases in richness, diversity, and abundance of plants and basal area) than CO and DC; 2) The three physiognomies experienced an increase in basal area and abundance of individuals, but only certain key species contributed to these increases. These results indicate that the open physiognomies were more dynamic than the closed physiognomies, and in the absence of fire the savanna physiognomies became more forested and accumulated biomass.

Changes in floristic composition and physiognomy are decoupled along elevation gradients in central Argentina

AbstractQuestionsMost vegetation descriptions tacitly assume that floristic composition and physiognomy are tightly linked. However, the two vegetation properties may not respond in a similar way to environmental and disturbance gradients, leading to uninformed management planning and difficulties when attempting to restore degraded ecosystems. In this context, we addressed two main questions: (1) how close are relations between floristic and physiognomic types as defined by numerical vegetation classification in mountain ecosystems; and (2) how are floristic and physiognomic types distributed along the elevation gradient?LocationCentral mountains of Argentina, between 500 and 1700 m a.s.l.MethodsWe selected 437 sites where we performed complete floristic and physiognomic relevés. We classified eight physiognomic and eight floristic types. We tested the relationship between the two classifications through a chi square analysis. We tested the association between elevation and each physiognomic and floristic type with random permutations.ResultsIn general, floristic types were significantly and positively associated with more than one physiognomic type and vice versa. Physiognomic and floristic types responded differently to the elevation gradient. Floristic types were restricted to different sections of the gradient, although having large overlap among them. In contrast, seven out of the eight physiognomic types did not show elevation restriction, being distributed along the complete elevation gradient. The open low woodland with shrubs was the only restricted physiognomy, significantly absent from the upper part of the gradient.ConclusionsWe highlight the importance of considering the two vegetation properties independently when characterizing vegetation patterns in heterogeneous systems, since they show decoupled responses to environmental gradients. We note that the assumption of a direct link between floristic composition and physiognomy may induce bias into the understanding of vegetation patterns and processes. Hence, we encourage managers and restoration practitioners to consider the complete range of possible physiognomic types under each floristic type.

Relative vulnerability to climate change of trees in western North America

Many recent changes in tree species distributions, mortality, and growth rates have been linked to changes in climate. Managing forests in the face of climate change will require a basic understanding of which tree species will be most vulnerable to climate change and in what ways they will be vulnerable. We assessed the relative vulnerability to climate change of 11 tree species in western North America using a multivariate approach to quantify elements of sensitivity to climate change, exposure to climate change, and the capacity to adapt to climate change. Our assessment was based on a combination of expert knowledge, published studies, and projected changes in climate. Of the 11 species, Garry oak (Quercus garryana) was determined to be the most vulnerable, largely because of its relatively high sensitivity. Garry oak occupies some of the driest low woodland and savanna sites from British Columbia to California and is highly dependent on disturbances, such as periodic, low intensity fire. Big leaf maple (Acer macrophyllum) was determined to be the least vulnerable, largely because of its adaptive capacity. Big leaf maple can reproduce quickly after disturbances and its seeds can disperse long distances potentially allowing it to move in response to a changing climate. Our analyses provide a framework for assessing vulnerability and for determining why some species will likely be more vulnerable than others. Such information will be critical as natural resource managers and conservation practitioners strive to address the impacts of climate change with limited funds.

Through the eye of a butterfly: Assessing biodiversity impacts of cashew expansion in West Africa

The cultivation of perennial cash crops is fast expanding in the tropics, but for most crops and regions there is very limited understanding about their biodiversity impacts. This is the case of cashew nut cultivation, which is occupying ever larger areas, particularly in West Africa. Here we investigated the impacts of cashew cultivation on biodiversity using butterfly assemblages sampled across a gradient of cashew expansion in Guinea-Bissau (West Africa). The overall species richness and abundance of butterflies were only slightly lower in cashew orchards than in native woodland habitats, but whereas the former were dominated by generalist species, the latter showed a much higher richness and abundance of trophic and habitat specialists. The landscape context significantly affected butterfly assemblages, with reduced richness and abundance of generalist species recorded within woodland habitats in heterogeneous landscapes with low woodland cover. Increases in land cover by cashew cultivation were associated with reduced abundance of specialist species within woodland habitats, and reduced abundance of generalist species within cashew orchards. Overall, our study provides the first evidence that cashew expansion may have serious negative consequences for biodiversity in West Africa, suggesting that this is an unfolding conservation problem that needs to be fully evaluated. Retaining woodland patches within production landscapes might help reducing the negative impacts of cashew expansion on biodiversity.

Vatnahverfi: A Green and Pleasant Land? Palaeoecological Reconstructions of Environmental and Land-use Change

Accounts describing the Vatnahverfi region of Greenland are almost always effusive in their praise for the rich and bountiful nature of the landscape. Whether it was the dense scrub and woodlands, or the freshwater lakes and fertile green pastures, this landscape—contrary to elsewhere in the Eastern Settlement—is frequently assumed to have been an excellent location for Norse pastoral farming. Nevertheless, these observations are merely anecdotal in nature and based on the perceptions of archaeologists, or others who have visited the region. This paper asks whether Vatnahverfi was really the green and pleasant land that the literature would suggest, while exploring the rationale behind settlement in this region. Pollen-analytical data and associated proxies are deployed here in an attempt to assess whether the pre-landnám landscape was an attractive location for settlement, and to investigate vegetation and land-use changes consequent upon settlement. Pollen analysis allows an assessment of the natural capital of the pre-landnám (initial settlement) environment, which suggests that the central valley of northwest Vatnahverfi supported substantial Betula-Salix scrub or low woodland prior to landnám. The presence of woodland at landnám indicates the availability of a key resource (for fuel, building materials, or as fodder for livestock), and a cluster of early landnám-era dates have been returned on pollen sequences from farms in the center of Vatnahverfi. Data from pollen influx and coprophilous fungal spores associated with grazing animals also point towards this landscape having been particularly suitable for pastoralism. Poaceae (grass) pollen influx values, for instance, are often double those of farms in the Qassiarsuk region, suggesting higher hay yields with the potential to support larger numbers of domesticates. Radiocarbon age-depth modelling of pollen sequences suggests that abandonment of farms in the region may have begun from the mid-13th century AD, culminating in the 14th century.

An Intensity Analysis of land-use and land-cover change in Karatu District, Tanzania: community perceptions and coping strategies

Land-use and land-cover changes (LULCCs) are the result of complex interactions between the human (cultural, socio-economic and political) and the biophysical environment at different spatial scales. The present study assessed the spatial distribution of LULC (1976–2008) in the high and low altitude zones in the northern highlands of Karatu, Tanzania, using both qualitative (in-depth interviews and focus group discussions) and quantitative techniques (Intensity Analysis). The qualitative approach was used to elicit information on the coping strategies adopted by land users as transitions occurred with time and the Intensity Analysis was used to assess the systematic land losses, gains and persistence of the various land categories with time. The results of the Intensity Analysis show that overall land transformation is decelerating in both agro-ecological zones across the two time intervals. In the low altitude zone, woodland, settlements and bushland are active categories unlike cultivated and grassland, which are dormant. In the low altitude zone, grassland systematically loses to cultivated areas during both time intervals. However, in the high altitude zone, forest systematically loses to woodland during both time intervals. In both agro-ecological zones, land change was rapid during the first interval and slowed during the second. We suggest that the fast change in land during the first interval may be attributed to the villagization policy in the 1970s that sought to drive the population towards rural settlements.

The establishment and distribution of feral wild boar (Sus scrofa) in England

Until recently, geographic isolation has protected Britain from the widespread increases in wild boar populations seen elsewhere in Europe, but following the development of wild boar farming in the 1980s a number of escapes and releases have occurred, resulting in the re-establishment of the species in the wild in England. The present study monitored the establishment and presence of wild boar in England by collating reports of escapes or releases and ground-truthing evidence of animals in the wild. This data is used to give an up-to-date indication of the distribution of the species in England. In the twenty years from 1989/90 to 2008/9 an average of one to two escape/release incidents occurred each year, with individual incidents involving from one to more than 50 individuals. These have resulted in the establishment of at least four distinct populations, the largest of which probably has a pre-breeding population in excess of 200 animals. None of the escapes or releases involving five or fewer individuals is believed to have led to establishment of a population. Based on the availability of woodland, there is potential for a total population in England of around 30,000 – 40,000 animals. However, future development of local populations is likely to be constrained over much of the country because of low woodland cover and culling pressure, and it is likely to take many years for a population of this size to develop, if at all.

Inter- and intra-specific variation in phyllode size and growth form among closely related Mimosaceae Acacia species across a semiarid landscape gradient

The mulga complex (Acacia aneura F. Muell ex Benth and closely related species) consists of woody trees and shrubs, and is distributed across 20% of the Australian continent. A. aneura is renowned for a wide variety of phyllode shapes and growth forms, which may co-occur at any one site. We examined the intra- and inter-specific variation in growth form and phyllode shape in four species of the mulga complex, including A. aneura, across topographic gradients in semiarid north-west Australia. We measured 792 trees across 28 sites stratified into six discrete landscape positions; upper slope, lower slope, low open woodland, banded woodland, low woodland, and drainage line. Dominance of phyllode shapes was strongly related to landscape position. A. aneura with terete phyllodes were dominant on the hill slopes, whereas broad phyllodes were most common on A. aneura in all valley woodlands. Trends in growth form were less distinct, although single-stemmed forms were more common on hills, whereas the valleys had more multi-stemmed forms. The quantification of growth form and phyllode shape variability within the mulga complex provides a basis for the quantitative determination of functional links between morphology and environmental conditions at both the site and landscape level.

Small-scale patterns of species richness and floristic composition in relation to microsite variation in herb-rich woodlands

Non-riverine Eucalyptus camaldulensis (red gum) woodlands with herbaceous understoreys in southern Australia have been recognised as botanically significant due to their high small-scale species richness, but little is known about the factors that underpin these patterns. To examine the influence of local environmental variation (microsites) on small-scale vegetation patterns, we sampled vegetation under trees, away from trees, and in depressions and hummocks in three herb-rich woodlands. Trees influenced both the composition and richness of the ground-layer vegetation, with reductions in species richness found under trees in sites where incident light availability was reduced by >40%. Species composition and richness differed between microsites, indicating that spatial heterogeneity is an important factor affecting species distribution patterns. Patchiness in relation to abiotic factors creates environmentally and compositionally distinct patterns. Indicator species analysis found that all microsites could be distinguished by character species with some evidence for microsite limitation for only a few species, lending weak support for a niche-based model of community assembly for herb-rich woodlands. A more plausible explanation for extremely high small-scale species richness is the lack of dominant species in these low productivity woodlands.

Is coppice a potential for urban forestry? The social perspective

After years of decline and neglect, low woodland types based on coppice management experience renewed interest. Substantial research has demonstrated the potentials of coppice for biomass production and for nature conservation, and coppices are increasingly being suggested for urban situations. Yet, our understanding of the more social aspects of coppice woodlands in modern urban situations is limited. Against this background, this contribution classifies coppice management systems as a basis for identification of social aspects of coppices and their potential use in contemporary urban forestry. Based on this classification, the social perspectives and potential niches for urban coppices are discussed, while lines of research are suggested which will support the development of a thorough and up-to-date knowledge base, against which the social merits of urban coppice woodlands can be critically evaluated.

Past and present vegetation ecology of Laetoli, Tanzania

We are attempting to set up a new protocol for palaeoecological reconstruction in relation to the fossil hominin site Laetoli, Tanzania. This is based on the premise that habitat variability in the past was at least as great as at present; that this variability at the landscape level is a function of variations in geology, soils, and topography rather than climate; and that vegetation type at the landscape level can be reconstructed from these environmental variables. Measurable variation in climate in tropical Africa today occurs over distances of at least 100 km, so that ranges of habitat variation within the limited area of Laetoli today can be reconstructed in relation to soils and topography, and the effects of climate changes are then estimated in relation to these other factors. In order to document the modern vegetation, we have made voucher collections of plants in the Laetoli region, recorded distributions of plants by habitat, climate, soil, and topography, and mapped the vegetation distributions. Results show that areas of low relief have soils with impeded drainage and dense Acacia drepanolobium woodland, having low canopies when disturbed by human action, higher when not; shallow brown soils on volcanic lavas have four woodland associations, two dominated by Acacia species, two by Combretum- Albizia species; shallow volcanic soils to the east have a woodland association with Croton-Dombeya-Albizia species; elevated land to the east on volcanic soils has two associations of montane-edge species, one with Croton-Celtis-Lepidotrichilia, and the other with Acacia lahai; the eastern highlands above 2,750 m have montane forest; seasonal water channels flowing from east to west have three Acacia riverine woodland associations; three deep valleys to the north of the area have dense riverine woodland with Celtis, Albizia, Euclea, Combretum, Acacia spp.; emergence of springs at Endulen feed a perennial stream with closed gallery forest with Ficus-Croton-Lepidotrichilia; and, finally, recent ash falls have produced immature alkaline soils with calcrete formation and short grass vegetation. All of these vegetation associations have been modified by human disturbance to greater or lesser degrees, and we have attempted to allow for this both by basing the associations on the least modified areas and by predicting how the associations, or parts of associations, have been altered by human action. Past land forms at Laetoli have been based on the geology and geomorphology of the area. Past vegetation patterns were estimated by superimposing present distributions of plant associations on equivalent landforms in the past, assuming similar climate to the present. This indicates the overall pattern of vegetation at Laetoli to have been a mosaic of low and tall deciduous woodlands and with riverine woodland and forest associations along water courses. Low woodlands would have been dominated by Acacia species, and tall woodlands by Combretum-Albizia species, with increasing increments of montane species, such as Croton species, to the east of the area. Riverine woodlands would have been dominated by Acacia-Euclea species, with wetter associations (downriver or linked with spring activity) supporting gallery forest with Ficus, Celtis, and Croton species. These are all species associations common in the area today, and with landforms little changed in the past, and assuming similar climate, there is every reason to predict that they would have been present in the past. Moreover, Pliocene environments lack the human disturbance that has destroyed much of the present day vegetation. Presence of woodlands is supported by fossil wood attributed to several of the tree species present in the area today and by similarities in the mammalian community structure between past and present. Having established the pattern for Pliocene vegetation based on climatic variables existing today, we then predict the effects of past variations in climate.

Distinctiveness, Use, and Value of Midwestern Oak Savannas and Woodlands as Avian Habitats

AbstractOak savannas and woodlands historically covered millions of hectares in the midwestern United States but are rare today. We evaluated the ecological distinctiveness and conservation value of savannas and woodlands by examining bird distributions across a fire-maintained woody-vegetation gradient in northwest Indiana encompassing five habitats—open habitats with low canopy cover, savannas, woodlands, scrublands, and forests—during migration, breeding, and overwintering. Savannas and woodlands were significantly different in overall bird species composition from open and forest habitats but were often intermediate between open and forest in guild densities. Few bird species were consistently and highly concentrated in savannas or woodlands, and the Red-headed Woodpecker (Melanerpes erythrocephalus) was the only species significantly more abundant in savannas and woodlands than in open, scrub, and forest habitats. Fire frequency over a 15-year interval was a significant predictor of bird community composition and was positively related to species diversity, spring transient migrant density, and density of the most threatened species. Each habitat type had characteristics potentially important for avian conservation. Scrub had the highest density of transient migrants, which suggests it plays an important role as migration stopover habitat. More species were significantly concentrated in open or forest habitats than in the other habitats. Lack of species concentration and intermediate community composition suggested that birds experienced savannas and woodlands more as ecotones than as habitats distinct from forests or grasslands. However, this intermediate character can benefit conservation, as evidenced by savannas and woodlands having the highest density of the most threatened species along this woody-vegetation gradient.Características Únicas, Uso y Valor de las Sabanas y Bosques Abiertos de Roble del Oeste Central como Hábitats para las Aves

DISTINCTIVENESS, USE, AND VALUE OF MIDWESTERN OAK SAVANNAS AND WOODLANDS AS AVIAN HABITATS

Abstract Oak savannas and woodlands historically covered millions of hectares in the midwestern United States but are rare today. We evaluated the ecological distinctiveness and conservation value of savannas and woodlands by examining bird distributions across a fire-maintained woody-vegetation gradient in northwest Indiana encompassing five habitats—open habitats with low canopy cover, savannas, woodlands, scrublands, and forests—during migration, breeding, and overwintering. Savannas and woodlands were significantly different in overall bird species composition from open and forest habitats but were often intermediate between open and forest in guild densities. Few bird species were consistently and highly concentrated in savannas or woodlands, and the Red-headed Woodpecker (Melanerpes erythrocephalus) was the only species significantly more abundant in savannas and woodlands than in open, scrub, and forest habitats. Fire frequency over a 15-year interval was a significant predictor of bird community c...

Fuel modelling and fire hazard assessment based on data from the Portuguese National Forest Inventory

Fire management activities can greatly benefit from the description of wildland fuel as a fire behaviour predictor. A forest typology developed from the Portuguese National Forest Inventory that combines cover type (the dominant overstorey species) and forest structure defined as a combination of generic stand density (closed or open) and height (low or tall) was translated into fuel models. Fire behaviour simulations that accounted for the fire environment modification induced by stand structure resulted in an objective and quantitative fire hazard classification for 19 forest types. We found that potential fire behaviour is primarily driven by stand structure, rather than by cover type. The results reveal four basic fire hazard groups. Surface fire spread rate is low to moderate, surface fire intensity is low and the crown fire hazard is insignificant in the open and tall forest types, as well as in dense and tall Quercus suber and diverse forests. Moderate surface fire potential and high to very high crowning potential characterizes dense and low woodland of deciduous oaks, Quercus suber and diverse forests, closed and tall Pinus pinaster stands, and open and low eucalypt stands. Open and low types of P. pinaster, Q. suber and Q. rotundifolia have very high or extreme spread and crowning potential, while surface fire intensity ranges from high to very high. In closed and low stands of P. pinaster, eucalypts and acacias, spread rate is moderate, but fireline intensity varies from high to extreme, and the potential for crowning is extreme. Practical applications for the hazard classification are suggested and exemplified.

Birds of Iwokrama Forest

Abstract This paper is an abridged version of an earlier report describing field work on birds of Iwokrama Forest (IF) between March 1996 and September 1997. The avifauna of IF is discussed in terms of habitat heterogeneity, seasonailty and ongoing monitoring. Avian species richness in IF is similar to other tropical forest localities that have been studied with similar intensity with 476 species having been recorded furing the work reported here. Distinctive habitats such as Humiria-dominated low woodland and scrub with little or no grass cover that grows on areas with nutrient-poor sandy surface soil (Muri scrub) and pre-montane (foothill) forests are also found within IF and both of these habitats contribute significantly to total diversity of IF. IF has relatively high densities of larger frugivorous birds such as cracids, cotingas, and parrots.

The use of SPOT VEGETATION data in a classification tree approach for burnt area mapping in Australian savanna

An algorithm to map burnt areas has been developed for SPOT VEGETATION (VGT) data in Australian woodland savannas. A time series of daily VGT images (15 May to 15 July 1999) was composited into 10-day periods by applying a minimum value criterion to the near-infrared band (0.78-0.89 @m). The algorithm was developed using a classification tree methodology that was confirmed as a powerful means of image classification. This methodology allowed the identification of three classes of burnt surfaces that appear to be differentiated by the proportion of the pixel that is burnt, the intensity of the fire and the density of the tree layer. The performance of the algorithm was assessed by classification of one VGT composite image (31 May-9 June) using, as representative of the ground truth, burnt areas extracted from two Landsat TM scenes (9 June). We randomly extracted 30 windows (each of ∼14 km by 14 km) for which we compared the percentage of area burnt as derived from TM and VGT. The estimated mean absolute deviation in the percentage of the area burnt in each window is - 6.3%. In the area common to the two datasets a total amount of 6473 km 2 was estimated to be burnt in the VGT classification against 7536 km 2 that was burnt according to TM images. The accuracy of the classification was found to vary with the vegetation type being the most accurate estimate in low woodland with an underestimation error of 8.6%. These results show that VGT could be a very useful sensor for burnt area mapping over large woodland areas, although the low spatial resolution and the lack of a thermal band can be a limitation in certain conditions (e.g. understorey burns). The same methodology will be applied to map burnt areas for the entire Australian continent.