Michael J. Lawes

• PhD
• Professor at University of KwaZulu-Natal

Context Macropods are very susceptible to stress during capture. Capture methods for macropods fall into two categories: trapping and darting. Trapping by nets or a triggered trap mechanism is commonly used for small macropods. Darting is most often used for large macropods that are more prone to stress and capture myopathy when caught in traps. Ai...

In the tropical savannas of northern Australia, many native mammal species are experiencing rapid and ongoing declines due to multiple interacting threats. These mostly arboreal and semi-arboreal mammals are reliant on tree hollows for shelter, which may be contributing to their decline. We monitored 198 nestboxes over three years across a 100-km t...

The age and parity of female primates could reflect their physical condition and reproductive experience. Consequently, the individual age-parity dependent condition of mothers and the survival of their offspring represents a fitness tradeoff. This reproductive tradeoff is expressed in the individual birth sex ratio, offspring mortality and interbi...

Extensive oil palm plantations worldwide are dependent on insect pollination, specifically by introduced African weevils (Elaidobius spp.). The effectiveness of these weevils has been questioned following poor pollination and yield loss in Malaysia. Indigenous thrip (Thysanoptera) species, and moths (Lepidoptera) in the genus Pyroderces, may also b...

The age and parity of female primates reflects their physical condition and reproductive experience. Individual age-parity dependent condition of females and the survival of their offspring represents a fitness tradeoff. This reproductive tradeoff is expressed in the individual birth sex ratio, offspring mortality and interbirth interval (IBI). Thu...

Successful cost-effective reforestation plantings depend substantially on maximising sapling survival from the time of planting, yet in reforestation programs remarkably little attention is given to management of saplings at the planting stage and to planting methods used. Critical determinants of sapling survival include their vigour and condition...

Rubber bush (Calotropis procera), a perennial invasive milkweed, infests large swathes of pastoral land in northern Australia and Queensland, diminishing pasture productivity. The seeds of rubber are small with fluffy pappi that confer buoyancy during wind dispersal. Long-distance seed dispersal (LDD) by wind is dependent in part on seed terminal v...

Invasive plants adversely affect native communities by altering ecosystem function and disrupting natural regeneration. We investigate the effect of invasive Lantana camara L. (Verbenaceae) on forest regeneration in Kibale National Park, Uganda. We appraise the efficacy of cutting and uprooting Lantana for promoting native tree recruitment. Sample...

The extensive coastal forests in eastern southern Africa persist as a putative alternative stable state in an open ecosystem mosaic that includes grassland and savanna. We examine two current hypotheses of the state-transition origins of these forests: (1) facilitation—where light-demanding pioneer cohorts facilitate establishment by species that t...

In Africa, most protected forests are in densely human‐dominated landscapes where human–wildlife conflict is intense. We documented farmer perceptions and responses to crop‐raiding wildlife from Kibale National Park, Uganda. Crop raiding was mostly (95%) by baboons ( Papio anubis ) and elephants ( Loxodonta africana ). While the financial loss caus...

Tree species of Eurasian broadleaved forest possess two divergent trait syndromes with contrasting patterns of resource allocation adapted to different selection environments: short-stature basal resprouters that divert resources to a bud bank adapted to frequent and severe disturbances such as fire and herbivory, and tall trees that delay reproduc...

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we...

Many of the world’s most biodiverse regions are found in the poorest and second most populous continent of Africa; a continent facing exceptional challenges. Africa is projected to quadruple its population by 2100 and experience increasingly severe climate change and environmental conflict—all of which will ravage biodiversity. Here we assess conse...

Positive bark allometry (hyperallometry), characterised by rapid early bark growth, is expected where fire selects for thicker bark to resist cambial damage and topkill. We examine this prediction for 52 Australian eucalypt species. An effective bark allometric coefficient (α) was estimated from the first segment of breakpoint regression, which inc...

Postfire resprouting (R+) and recruitment from seed (S+) are common resilience traits in Australian ecosystems. We classified 2696 woody Australian taxa as R+ or not (R−) and as S+ or not (S−). The proportions of these traits in Australian ecosystems were examined in relation to fire regimes and other ecological correlates, and by trait mapping on...

With open-access publishing authors often pay an article processing charge and subsequently their article is freely available online. These charges are beyond the reach of most African academics. Thus, the trend towards open-access publishing will shift the business model from a pay-wall model, where access to literature is limited, to a pay-to-pub...

Background Tropical forests are repositories of much of the world’s biodiversity and are critical for mitigation of climate change. Yet, the drivers of forest dynamics are poorly understood. This is in large part due to the lack of long-term data on forest change and changes in drivers. Methodology We quantify changes in tree abundance, diversity,...

With open-access publishing authors pay an article processing charge and subsequently their article is freely available online. These charges are beyond the reach of most African academics. Thus, the trend towards open access publishing will shift the business model from a pay-wall model, where access to literature is limited, to a pay-to-publish o...

Context Invasive predators are a key threat to biodiversity worldwide. In Australia, feral cats are likely to be responsible for many extinctions of native mammal species in the south and centre of the continent. Aims Here we examine the effect of feral cats on native rodent populations in the second of two translocation experiments. Methods In a...

Half-butt eucalypts (genera: Eucalyptus and Corymbia) have both thick outer bark at the stem base (half-butt) conferring resistance to surface fire, and thin photosynthetic canopy bark that reduces moisture stress. Here we examine how the functional ecology of dual outer bark types influences the wide distribution of Australian half-butt species. W...

Background: Tropical forests are repositories of much of the world’s biodiversity and are critical for mitigation of climate change. Yet, the drivers of forest dynamics are poorly understood. This is in large part due to the lack of longitudinal data on forest change and changes in drivers. Methodology: We quantify changes in tree abundance, divers...

Bark contributes approximately 20% to the total above‐ground biomass of trees, yet bark is not properly accounted for when estimating carbon sequestered by trees. Current allometric functions estimate tree volume from diameter measured over the bark, and derive bark density and carbon content from estimates for wood. As the bark density of hardwood...

Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and...

Aim: Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) an...

Northern Australia's savannas are among the most fire‐prone biomes on Earth and are dominated by eucalypts (Eucalyptus and Corymbia spp.). It is not clear what processes allow this group to dominate under such extreme fire frequencies and whether a superior ability to compete for nutrients and water might play a role. There is evidence that eucalyp...

Terminalia ferdinandiana Exell., also known as the Kakadu plum, is an important food plant endemic to northern Australia. The fruit has substantial commercial demand as it contains sought-after antioxidants and the greatest concentration of ascorbic acid of any fruit known worldwide. Better knowledge of its reproductive biology is required to incre...

Although conventional wisdom considers knowledge of threatened species' ecology and status essential for conservation , few studies demonstrate this in a quantitative way across many species and within the same political entity. Here, we evaluated the impacts of scientific research against conservation interventions (including funding) and species-...

The Gouldian finch (Erythrura gouldiae, Gould 1844) is a threatened grass finch (Estrildidae) endemic to the tropical savannas of northern Australia. Current fire regimes, consisting of frequent and extensive fire across these savanna grasslands, affect the type and availability of grass seed for granivores. Gouldian finches are particularly affect...

Seeds of native grasses are an important food source for granivorous finches throughout the tropical savannas of northern Australia. The iconic Gouldian finch (Erythrura gouldiae), a threatened species endemic to these savanna grasslands, relies almost exclusively on the grass seeds of annual Sorghum spp. when breeding, and appears to time breeding...

In much of the tropics, the proportion of the land covered by regenerating forest surpasses than in primary forest, thus protecting regenerating forest could offer a valuable conservation opportunity, but only if those lands promote faunal recovery. Chapman et al. documented the recovery of populations of six primate species over up to 45 years in...

Understanding the role that the vast north Australian savannas play in the continental carbon cycle requires reliable quantification of their carbon stock at landscape and regional scales. LiDAR remote sensing has proven efficient and accurate for the fine-scale estimation of above-ground tree biomass (AGB) and carbon stocks in many ecosystems, but...

Significance Identifying and explaining regional differences in tropical forest dynamics, structure, diversity, and composition are critical for anticipating region-specific responses to global environmental change. Floristic classifications are of fundamental importance for these efforts. Here we provide a global tropical forest classification tha...

From analysis of results from 93 studies on the frequency of occurrence of birds in cat dietary samples, and a recently published assessment of the population size of feral cats in largely natural landscapes, we estimate and map the number of birds killed annually in Australia by feral cats. We show that average rates of predation on birds by cats...

Ecosystem restoration can help reverse biodiversity loss, but whether faunal communities of forests undergoing restoration converge with those of primary forest over time remains contentious. There is a need to develop faunal indicators of restoration success that more comprehensively reflect changes in biodiversity and ecosystem function. Ants are...

Ecological restoration is increasingly applied in tropical forests to mitigate biodiversity loss and recover ecosystem functions. In restoration ecology, functional richness, rather than species richness, often determines community assembly, and measures of functional diversity provide a mechanistic link between diversity and ecological functioning...

Biodiversity is declining at an alarming rate, especially among vertebrates. Disease is commonly ignored or dismissed in investigations of wildlife declines, partly because there is often little or no obvious clinical evidence of illness. We argue that disease has the potential to cause many species declines and extinctions and that there is mounti...

Conflict between Top End livestock producers and high densities of Agile Wallabies (Macropus agilis) on pastoral land has been ongoing for decades. In recent years, wallaby numbers and densities on pastoral lands have increased dramatically. In some agricultural situations wallaby densities are 1,000 times greater than the natural density (<0.5 ani...

Afrotemperate forests situated in the Drakensberg mountains of South Africa are characteristically small (1–10 s ha) and widely dispersed in a vast fire-prone grassland. Compared with lowland forests, they are typically species poor with low levels of endemism and species turnover, patterns that are to date unexplained. Here we show that the richne...

Reforestation and restoration offer critical contributions to addressing climate change and biodiversity decline. Enabling carbon credits to be derived from these activities is important for reforestation, particularly since reforestation does not come cheaply. Australia’s Carbon Farming Initiative is a world-leading policy that allows carbon credi...

Fire is a pervasive feature of the tropical savannas of northern Australia. Increasingly extensive and intensive fires have had an adverse effect on grass layer diversity. Reduced grass species diversity and abundance are important correlates of the decline of granivores in these tropical savannas. The Gouldian finch (Erythrura gouldiae), an endang...

Plant invasions are threats to biodiversity and ecosystem processes that have far reaching ecological and economic impacts. Understanding the mechanisms of invasion essentially helps in developing effective management strategies. Rubber bush (Calotropis procera) is an introduced milkweed that invades Australian beef production rangelands. Its estab...

Tropical landscapes are changing rapidly as a result of human modifications; however, despite increasing deforestation, human population growth, and the need for more agricultural land, deforestation rates have exceeded the rate at which land is converted to cropland or pasture. For deforested lands to have conservation value requires an understand...

Fruit ripeness can be indicated through changes in chromaticity, luminance, odor, hardness, and size to attract seed dispersing animals. We quantified these attributes for both ripe and unripe fruits of 31 lemur-dispersed plant species in Ankarafantsika National Park, a tropical dry forest in northwestern Madagascar. We used spectroscopy, gas-chrom...

Plant succession theory underpins the development of strategies for the conservation and regeneration of native communities. Current theory has been based largely on space-for-time rather than long-term monitoring data, which have known limitations. There is general consensus that more site-specific studies are needed to corroborate existing hypoth...

Calotropis procera (Ait.) R.Br. (Apocynaceae), an invasive woody milkweed, has expanded its range in northern Australia affecting rangeland and pastoral productivity. While self-compatibility should enhance the species range expansion, spread of C. procera is limited by the availability of larger wasp and bee species that are able to vector its sol...

Seed-dispersal ecology in tropical montane forests (TMF) differs in some predictable ways from tropical lowland forests (TLF). Environmental, biogeographic and biotic factors together shape dispersal syndromes which in turn influence forest structure and community composition. Data on diaspore traits along five elevational gradients from forests in...

Woody plant demographics provide important insight into ecosystem state-shifts in response to changing fire regimes. In Australian tropical savannas, the switch from patchy landscape burning by Aborigines to unmanaged wildfires within the past century has been implicated in biodiversity declines including the fire-sensitive conifer, Callitris intra...

Relative bark thickness (RBT; bark thickness/stem diameter; cm cm−1) is a widely used species-specific plant trait, especially in the context of fire ecology. We consider several problems with its measurement and suggest that (1) it should be measured as bark thickness (BT)/bole diameter and not BT/stem diameter; (2) its measurement should be restr...

Many long-distance migratory shorebirds are threatened. Anthropogenic disturbance at roost sites on their non-breeding grounds might exacerbate other threats by leading to depletion of fat reserves and forcing birds away from traditional sites. We measured the response (occurrence of alarm flight and resettlement time) of roosting shorebirds knots...

Although bark thickness and fire-activity are correlated in many ecosystems worldwide, substantial data-gaps remain, especially for dryland biomes, preventing generalisation of this relationship at the global scale. We examined bark thickness trends in trees and shrubs across a large-scale fire-rainfall gradient from desert to dry savanna in northe...

In this special issue of Plant Ecology celebrating the research contributions of the late Peter J. Clarke, we review advances in understanding of interactions between fire and vegetation, and the role of these interactions in shaping the evolution of plant species. The research presented here reviews the measurement of fire severity and plant respo...

In subtropical coastal dune forests of South Africa, the microenvironment of tree seedlings is largely influenced by a pervasive understorey woody herb, Isoglossa woodii. We examined whether the additional shading by I. woodii explains the competitive response of tree seedlings from these forests. Seedlings of four common mid- to late-successional...

Conservation can be achieved only if sustainability is embraced as core to organizational cultures. To test the extent to which the related concepts of sustainability, conservation, response to climate change, poverty alleviation and gender equity have been incorporated into organizational culture, we compared mission statements in the period 1990–...

The potential spread of any invasive plant is a central concern in weed risk assessment. Calotropis procera is wind dispersed and forms extensive monospecific stands that reduce the productivity of pastoral land, but its potential distribution and drivers of its spread are not well known. Using maximum entropy methodology, we modelled current and f...

s Inter- and intra-specific comparisons were made between several co-occurring populations of two Banksia species growing in Eastern Australian dry sclerophyll open woodland that experiences a grass-fueled surface-fire regime. The two species differ in life-history from a short basal resprouter (B. Neoanglica) to a tall fire-survivor (B. integrifol...

Understanding the seed biology of the introduced weed rubber bush (Calotropis procera (Aiton, W.T.Aiton)) is critical to its management in northern Australia. We examined the numbers of seeds produced and the effects of environmental temperature and water stress on germination performance (germinability G; mean germination time MGT) of rubber bush...

Carbon markets afford potentially useful opportunities for supporting socially and environmentally sustainable land management programs but, to date, have been little applied in globally significant fire-prone savanna settings. While fire is intrinsic to regulating the composition, structure and dynamics of savanna systems, in north Australian sava...

GIS files for Litchfield Landscape Units. (ZIP)

Calculating fire metrics and carbon credits. (DOCX)

GIS files for Kakadu Landscape Units. (ZIP)

GIS files for Nitmiluk Landscape Units. (ZIP)

GIS files for WALFA Landscape Units. (ZIP)

We (Murphy et al., 2013; Clarke et al., 2015) have recently developed a framework to understand the spatial distribution of fire regimes and plant fire-response traits at large spatial scales. We integrated a range of data sources to create a continental-scale overview of Australian pyromes from which to infer pyrogeographic drivers. Gosper et al....

Premise of the study: In fire-prone ecosystems, variation in bark thickness among species and communities has been explained by fire frequency; thick bark is necessary to protect cambium from lethal temperatures. Elsewhere this investment is deemed unnecessary, and thin bark is thought to prevail. However, in rain forest ecosystems where fire is r...

The Eastern Curlew (Numenius madagascariensis) has recently been uplisted to Critically Endangered under Australian Government legislation due to an ongoing decline of the species population on its non-breeding grounds. Declines have been reported from nearly all monitored sites along the coastline of Australia and at some, local extinction is pred...

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approx...

Australia has experienced dramatic declines and extinctions of its native rodent species over the last 200 years, particularly in southern Australia. In the tropical savanna of northern Australia significant declines have occurred only in recent decades. The later onset of these declines suggests that the causes may differ from earlier declines in...

Mangrove habitats are under severe land use pressure throughout the world and Australia is no exception. Here we describe the heterogeneity of mangrove habitat and its relationship with mangrove bird diversity. We examined the role of mangrove habitat complexity in determining the richness of avian mangrove dependent species (MDS) and interior spec...

Plant resprouting after disturbance confers community resilience because individuals persist through trade-offs in resources for buds versus those required to produce seeds. However, repeated disturbance may deplete bud banks, and population persistence may become increasingly reliant on regeneration from seed. Theory predicts a shift in community...

Conflict between Top End livestock producers and high densities of Agile Wallabies (Macropus agilis) on pastoral land has been ongoing for decades. In recent decades wallaby numbers and densities on pastoral lands have increased dramatically. In some agricultural situations wallaby densities are 1000 times greater (>5 animals ha-1) than the natural...

Few measurements for carbon sequestration, ratio of above-ground to below-ground biomass and wood density exist for young trees. Current allometric models are mostly for mature trees, and few consider trees at the sapling stage. Over four years we monitored the growth rates, from seedling to the sapling stage, of 490 trees (five native species) in...

Postfire resprouting and recruitment from seed are key plant life-history traits that influence population dynamics, community composition and ecosystem function. Species can have one or both of these mechanisms. They confer resilience, which may determine community composition through differential species persistence after fire. To predict ecosyst...

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approx...

Introduction: Recent studies at sites in northern Australia have reported severe and rapid decline of several native mammal species, notwithstanding an environmental context (small human population size, limited habitat loss, substantial reservation extent) that should provide relative conservation security. All of the more speciose taxonomic group...

Introduction: Recent studies at sites in northern Australia have reported severe and rapid decline of several native mammal species, notwithstanding an environmental context (small human population size, limited habitat loss, substantial reservation extent) that should provide relative conservation security. All of the more speciose taxonomic group...

Small mammal (<2 kg) numbers have declined dramatically in northern Australia in recent decades. Fire regimes, characterised by frequent, extensive, late-season wildfires, are implicated in this decline. Here, we compare the effect of fire extent, in conjunction with fire frequency, season and spatial heterogeneity (patchiness) of the burnt area, o...

Land-clearing represents the first step in agricultural development and signals a shift in landscape function towards provisioning ecosystem services, in particular food production. In the process, other types of ecosystem services are often unintentionally lost as illustrated by the associated decline in biodiversity, increased soil erosion and em...

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approx...

The recent commentary by Woinarski (2014, Global Ecology and Biogeography, doi: 10.1111/geb.12165) disagreed with our conclusions on the correlates of decline in the marsupials of tropical Australia (Fisher et al., 2014, Global Ecology and Biogeography, 23, 181–190). We compared traits of species that were associated with range decline in southern...

Different land use practices often influence the distribution and abundance of wildlife. This can lead to uncontrolled population growth by native species, causing substantial economic and ecological impacts to the landscape. In this scenario, assessment of the extent of these effects and possible management responses needs to be achieved within ti...

While overall numbers of African elephant have declined dramatically in recent times, some populations are now confined to protected areas and are locally overabundant-an undesirable situation for both biodiversity conservation and elephants. In forested protected areas, options to manage elephants are limited because it is difficult to safely appr...

Conflict between Top End pastoralists and agile wallabies has been ongoing for decades. In 2009, Katherine Pastoral Industry Advisory Committee (KPIAC) reported a dramatic increase in wallaby numbers since the late 1990’s, and requested that the NT government survey populations and allow large culls around farmland. The NT government requested that...

Conflict between Top End producers and high densities of Agile Wallabies (Macropus agilis) on pastoral land has been ongoing for decades. In recent decades wallaby numbers and densities on pastoral lands have increased dramatically. In some agricultural situations wallaby densities are 1000 times greater (>5 animals ha-1) than the natural density....

Different land use practices often influence the distribution and abundance of wildlife. This can lead to uncontrolled population growth by native species, causing substantial economic and ecological impacts to the landscape. In this scenario, assessment of the extent of these effects and possible management responses needs to be achieved within ti...

Small mammal species are declining across northern Australia. Predation by feral cats Felis sylvestris catus is one hypothesised cause. Most evidence of cat impacts on native prey comes from islands, where cat densities are often high, but cats typically occur at low densities on mainland Australia. We conducted a field experiment to measure the ef...