Craig R. Nitschke

University of Melbourne | MSD · School of Ecosystem and Forest Sciences

In an era where global climate change is shifting plant phenology, global meta-analyses of multiple species are required more than ever. Common language or references for enhanced data compatibility are key for such analyses. Although the Plant Phenology Ontology (PPO) addresses this challenge, it does not capture several relevant reproductive stru...

With large wildfires becoming more frequent1,2, we must rapidly learn how megafires impact biodiversity to prioritize mitigation and improve policy. A key challenge is to discover how interactions among fire-regime components, drought and land tenure shape wildfire impacts. The globally unprecedented3,4 2019–2020 Australian megafires burnt more tha...

This study explores the social, economic and environmental dimensions of human‐wildlife conflict (HWC) in four districts of Bhutan. Looking beyond the common unidimensional approach to the evaluation of HWCs, it documents the multifaceted nature of HWCs through a social‐ecological system (SES) lens. We carried out a mixed method analysis of HWC bas...

Background Chir pine ( Pinus roxburghii Sarg.) forests are distributed in the dry valleys of Bhutan Himalaya. In the past, these forests have been heavily influenced by human activities such as grazing, burning, resin tapping, and collection of non-timber forest products. Bhutan’s Forest Act of 1969, which shifted forest management from local commu...

Background Tree hollows are an important habitat resource used by arboreal fauna for nesting and denning. Hollows form when trees mature and are exposed to decay and physical damage. In the absence of excavating fauna, hollow formation can take up to 200 years in Australian temperate Eucalyptus forests, making tree hollows a critical but slow formi...

Many plant species are well-adapted to historical fire regimes. An increase in the severity, frequency, and extent of wildfires could compromise the regenerative capacity of species, resulting in permanent shifts in plant diversity. We surveyed extant vegetation and soil seed banks across two forest types with contrasting historical fire regimes—Sh...

Old-growth forests provide many ecosystem services and benefits. However, they are becoming increasingly rare and thus are an urgent priority for conservation. Accurately mapping old-growth forests is a critical step in this process. Here, we used LiDAR, an improved individual tree crown delineation algorithm for broadleaved forests, Gaussian mixtu...

In vertebrates, gliding evolved as a mode of energy‐efficient locomotion to move between trees. Gliding vertebrate richness is hypothesised to increase with tree height and decrease with tree density but empirical evidence for this is scarce, especially at a global scale. Here, we test the ability of tree height and density to explain species richn...

Background: Chir pine (pinus roxburghii Sarg.) forests are distributed in the dry valleys of Bhutan Himalaya. These forests are heavily influenced by biotic activities such as grazing, resin tapping and NWFP (non-wood forests produce) collection. Understanding the relationship between past and present climate and the frequency and severity of fores...

A fundamental requirement of sustainable forest management is that stands are adequately regenerated after harvesting. To date, most research has focused on the regeneration of the dominant timber species and to a lesser degree on plant communities. Few studies have explored the impact of the regeneration success of dominant tree species on plant c...

Extreme fire events have increased across south-eastern Australia owing to warmer and drier conditions driven by anthropogenic climate change. Fuel reduction burning is widely applied to reduce the occurrence and severity of wildfires; however, targeted assessment of the effectiveness of this practice is limited, especially under extreme climatic c...

Protected areas (PA) to conserve wildlife are the cornerstone of biodiversity conservation but they can also result in increased human-wildlife conflict (HWC), which poses a serious challenge to jointly achieving sustainable development goals of food security and biodiversity conservation, particular in regions with high conservation values and sub...

Structural features of the overstorey in managed and unmanaged forests can significantly influence plant community composition. Native Acacia species are common in temperate eucalypt forests in southeastern Australia. In these forests, intense disturbances, such as logging and wildfire, lead to high densities of regenerating trees, shrubs, and herb...

Monitoring provides crucial information to help understand species distribution and abundance, the condition of ecosystems and changes induced by disturbances such as fire, and to evaluate and enhance actions to conserve and recover species and ecological communities. However, biodiversity monitoring in Australia is patchy, has poor taxonomic cover...

Sustainable Development Goals (SDGs) are part of 2030 Agenda for Sustainable Development (SD) that aim to eradicate poverty, achieve economic prosperity, gender equality, ensure social well-being, promote sustainable management and use of natural resources, and protect the Earth’s natural ecosystems. However, the occurrence of human–wildlife confli...

Predictive vegetation mapping is an essential tool for managing and conserving high conservation-value forests. Cool temperate rainforests (Rainforest) and cool temperate mixed forests (Mixed Forest, i.e., rainforest spp. overtopped by large remnant Eucalyptus trees) are threatened forest types in the Central Highlands of Victoria. Logging of these...

Indirect impacts of Human Wildlife Conflict (HWC) are largely ignored, poorly understood, and scantly reported in the literature on HWC. Subsistence farmers in the Himalayan kingdom of Bhutan experience an increasing intensification of HWC impacts. Working across four districts representing different geographic regions of the country, we explored t...

Our understanding of how environmental heterogeneity shapes plant community dynamics is largely based on above-ground diversity despite the importance of seed banks as reservoirs of genetic and taxonomic diversity that buffer plant populations and influence vegetation following disturbance. Using a plant functional trait approach, this study examin...

Climate projections indicate that dangerous fire weather will become more common over the coming century. We examine the potential of a network of temperature- and moisture-sensitive tree-ring sites in southeastern Australia to reconstruct the number of high fire-danger days for the January–March season. Using the Forest Fire Danger Index (FFDI), w...

Aim: The increasing availability of regional and global climate data presents an opportunity to build better ecological models; however, it is not always clear which climate dataset is most appropriate. The aim of this study was to better understand the impacts that alternative climate datasets have on the modelled distribution of plant species, an...

Quantifying mean annual tree seed production is important for conservation and forestry applications, but its estimation remains a substantial challenge. Interspecies variation in seed production is often expressed as a trade-off between seed size and seed number, forming a key component of established models of mean annual seed production in fores...

As wildfires become more frequent and severe, there are concerns regarding their impacts on water yield from forested catchments. While there are many studies in Australia about the effects of individual wildfires on streamflow at fine scales (<1 km²) in specific geographic settings, the effects of wildfire regimes on streamflow at broad spatial sc...

Land-use change has progressed rapidly throughout the Indonesian archipelago and is now intruding into western New Guinea (Tanah Papua), one of the world’s last wilderness areas with extensive tracts of pristine and highly diverse tropical rainforests. Tanah Papua has reached a crossroads between accelerating environmental degradation and sustainab...

Forests play a key role in mitigating global climate change through carbon storage and sequestration. Wildfire affects forest carbon through combustion and by influencing forest mortality and regrowth, which are also influenced by a forest’s growth environment. Wildfires are becoming more severe and frequent in many temperate regions but the impact...

Leadbeater’s possum (Gymnobelideus leadbeateri) is a critically endangered arboreal marsupial found primarily in the mountain ash forests of Victoria’s Central Highlands in southeastern Australia. It has two very specific and well-known habitat requirements: a dense, connected lower stratum of Acacia spp. for foraging and movement within the forest...

Links between climate variability modes, rainfall, and streamflow are important for understanding the trajectories of change and dynamics in water availability. In this study, we examined the influence of the El Nino Southern Oscillation, Indian Ocean Dipole, Southern Annular Mode, and Interdecadal Pacific Oscillation modes on interannual variation...

Herbivore foraging decisions are closely related to plant nutritional quality. For arboreal folivores with specialized diets, such as the vulnerable greater glider (Petauroides volans), the abundance of suitable forage trees can influence habitat suitability and species occurrence. The ability to model and map foliar nitrogen would therefore enhanc...

In the forested landscapes of southeastern Australia, bushfires and timber harvesting are the primary catalysts for regeneration in Eucalyptus regnans, E. delegatensis, and high elevation mixed species (HEMS) forests. Quantifying the role of climate, topography and edaphic conditions on plant regeneration is important for understanding current and...

Wildlife can persist in a range of landscape configurations, but population densities can vary due to resource availability. Resources and environmental conditions shaping habitat suitability may be spatially dispersed or clumped, which can drive habitat availability. We explored how spatial configuration and aggregation of favorable feeding resour...

Rural communities in the Himalayan Kingdom of Bhutan are dependant on natural capital for their livelihoods. Climate change impacts on ecosystem could have serious consequences for these communities but little research has been done to explore these potential impacts. In this study, we used Boosted Regression Tree (BRT) models to model current and...

In southeast Australia, fire regimes are changing. Conserving species into the future under these changing fire regimes will require understanding their recruitment and growth dynamics following historical fires. Where monitoring is absent, dendroecology provides a tool for reconstructing and quantifying these dynamics. The use of dendroecology in...

Extreme weather can have significant impacts on plant species demography; however, most studies have focused on responses to a single or small number of extreme events. Long‐term patterns in climate extremes, and how they have shaped contemporary distributions, have rarely been considered or tested. BIOCLIM variables that are commonly used in corre...

Dead wood, including dead standing trees (DST) and coarse woody debris (CWD), is a critical component of forest ecosystems that provides habitat and refugia for fauna, flora, and microbial communities and plays a key role in carbon and nutrient cycling. However, few studies have modelled the long-term dynamics of dead wood, limiting our ability to...

Increasing impacts of climatic change and anthropogenic disturbances on natural ecosystems are leading to population declines or extinctions of many species worldwide. In Australia, recent climatic change has caused population declines in some native fauna. The projected increase in mean annual temperature by up to 4°C by the end of the 21st centur...

Vulnerability to climate change is a function of exposure, sensitivity and adaptive capacity. Econometric and indicator-based approaches have been used to assess vulnerability at regional, national and global scales. However, these approaches often fail to capture how vulnerability varies within regions and communities. Within regions there is ofte...

ContextEffective conservation planning for species depends on vegetation models that can capture the dynamics of habitat elements across both spatial and temporal domains. Incorporating these dynamics at landscape scales is essential for understanding the impact of natural disturbance, management, and climate change on habitat availability and stab...

Soil organic carbon (SOC) stocks in Australia’s temperate forests have been overlooked in national soil databases and in global SOC analyses of natural ecosystems despite the importance of temperate forests to the global terrestrial carbon balance. This limits the potential to both predict change in SOC stocks in temperate Australia and to identify...

Habitat fragmentation imperils the persistence of many functionally important species, with climate change a new threat to local persistence due to climate‐niche mismatching. Predicting the evolutionary trajectory of species essential to ecosystem function under future climates is challenging but necessary for prioritizing conservation investments....

Aim Forest carbon storage is the result of a multitude of interactions among biotic and abiotic factors. Our aim was to use an integrative approach to elucidate mechanistic relationships of carbon storage with biotic and abiotic factors in the natural forests of temperate Australia, a region that has been overlooked in global analyses of carbon‐bio...

Context: Multi-species native forests are an important source of habitat for many plant and animal species. The dynamics of these forests are shaped by species-specific differences in growth, shade tolerance, life span, and other life-history traits, which lead to complex development patterns. Whether a particular forest stand is suitable habitat f...

In this study, we examined the associations between field-assessed floristic and structural habitat values for mature forest and GIS-derived variables to assess whether high conservation value forests could be predicted for strategic reservation at a landscape scale. We investigated the Eucalyptus regnans forests of the Victorian Central Highlands...

Modern approaches to predictive ecosystem mapping (PEM) have not thoroughly explored the use of ‘characteristic’ gradients, which describe vegetation structure (e.g., light detection and ranging (lidar)-derived structural profiles). In this study, we apply a PEM approach by classifying the dominant stand types within the Central Highlands region of...

Growth‐stage optimization (GSO) offers a new approach to biodiversity conservation in fire‐prone regions by estimating the optimal distribution of vegetation growth stages that maximize a species diversity index. This optimal growth‐stage structure provides managers an operational goal explicitly linked to a positive conservation outcome but does n...

Ecosystem services (ES) are increasingly recognized as a means to facilitate adaption to environmental change. However, the provisions of ES are likely to be impacted by changes in climate and/or changes in land use. In developing countries, where people are typically dependent on these services for their livelihoods, these impacts are of concern;...

Daily (Jan 1981 - Jul 2014), monthly and mean monthly (1981-2010) surfaces of minimum temperature (approx. 1.2 m from ground) across Victoria at a spatial resolution of 9 seconds (approx. 250 m). Surfaces are developed using trivariate splines (latitude, longitude and elevation) with partial dependence upon a topographic index of relative elevation...

Daily (Jan 1981 - Jul 2014), monthly and mean monthly (1981-2010) surfaces of maximum temperature (approx. 1.2 m from ground) across Victoria at a spatial resolution of 9 seconds (approx. 250 m). Surfaces are developed using ordinary trivariate splines (full spline dependence upon latitude, longitude and elevation). Dataset is available on the CSIR...

Daily (Jan 1981 - Jul 2014), monthly and mean monthly (1981-2010) surfaces of minimum temperature (approx. 1.2 m from ground) across Victoria at a spatial resolution of 9 seconds (approx. 250 m). Surfaces are developed using bivariate splines (latitude and longitude) with partial dependence upon elevation. Dataset is available on the CSIRO data acc...

Daily (Jan 1981 - Jul 2014), monthly and mean monthly (1981-2010) surfaces of maximum temperature (approx. 1.2 m from ground) across Victoria at a spatial resolution of 9 seconds (approx. 250 m). Surfaces are developed using trivariate splines (latitude, longitude and elevation) with partial dependence upon standardised day time MODIS land surface...

Daily (Jan 1981 - Jul 2014), monthly and mean monthly (1981-2010) surfaces of minimum temperature (approx. 1.2 m from ground) across Victoria at a spatial resolution of 9 seconds (approx. 250 m). Surfaces are developed using trivariate splines (latitude, longitude and elevation) with partial dependence upon a topographic index of relative elevation...

Managers of public forests are required to balance multiple values of forests. Developing policies to represent these can be impeded by uncertainty regarding how to understand and describe values relevant to forests. This paper addresses one source of ambiguity by examining forest values at two levels of abstraction: Core values of people (principl...

Tree ferns are slow-growing and long-lived components of temperate forests; however, these characteristics make determining size-age and population dynamics through mensuration approaches problematic while den-droecological approaches cannot be used. In this study, we use radiocarbon (14 C) dating of Cyathea australis and Dicksonia antarctica to (1...

Epicormic and basal resprouting promote tree survival and persistence in fire-prone regions worldwide. However, little is known about limits to resprouting effectiveness when severe wildfires increase in frequency. In the extensive fire-tolerant mixed-eucalypt forests of temperate Australia, we examined the effects of one and two high-severity wild...

Ecosystem services (ES) are critical to human well-being, especially in developing countries. Improved understanding of the status of ES is required to help people improve their quality of life. The status of ES is largely unknown in many regions of Nepal. This study was carried out in one of Nepal’s biodiversity hotspots, the Panchase Mountain Eco...

Questions Are factors influencing plant diversity in a fire‐prone Mediterranean ecosystem of southeast Australia scale dependent?. Location Heathy‐woodland in the Otways region of Victoria, southeast Australia. Methods We measured patterns of above‐ground and soil‐seedbank vegetation diversity and associated them with climatic, biotic, edaphic, t...

Rural mountain communities in developing countries are considered particularly vulnerable to environmental change, including climate change. Forests and agriculture provide numerous ecosystem goods and services (EGS) to local communities and can help people adapt to the impacts of climate change. There is however poor documentation on the role of E...

Context Self-thinning is fundamental to modern density-based forest management. The process of self-thinning arises from the dynamic interaction of stand growth and mortality at equilibrium conditions. However, despite the dynamic basis for the self-thinning process, it is typically modeled using static size-density data. Material and methods We te...

This is a brief tutorial to accompany functions we have written to facilitate estimating the intercept and slope of the self-thinning line from mortality data and models.

Context Australia’s temperate forest landscapes encompass broad topographic and edaphic ranges, and are regularly disturbed by fire. Nonetheless, relative contributions of environmental heterogeneity, disturbance regimes, and dispersal limitations to plant species turnover remain poorly understood. Objectives To evaluate the relative influences of...

Question Frequent severe wildfires have the potential to alter the structure and composition of forests in temperate biomes. While temperate forests dominated by resprouting trees are thought to be largely invulnerable to more frequent wildfires, empirical data to support this assumption are lacking. Does frequent fire erode tree persistence by inc...

The recent decline in the health of the City of Melbourne’s deciduous tree species to a recent drought event has led to concerns about the vulnerability of the city’s trees to future climate change. Understanding the response of tree growth to past climate is critical for determining the likely impacts of climate change on future growth and can pro...

Criteria and indicators (C & I) have proven an essential tool for managers implementing sustainable forest management, but have been less effective for communication with the wider community. We demonstrate a new bottom-up approach to developing socially relevant C & I using social analysis and psychology-based concepts and methods. Our conceptual...

We studied urban vegetation at the landscape scale for one hundred cities and its relation to sociodemographic and climate • The landscape metrics best describing urban vegetation structure: amount, fragmentation and distribution of green cover • The climate and socioeconomic context relates to the degree of fragmentation and amount of urban vegeta...

Spatial climate datasets currently available for Bhutan are limited by weather station data availability, spatial resolution, or interpolation methodology. This paper presents new datasets for monthly maximum temperature, minimum temperature, precipitation and vapour pressure climate normals interpolated for the 1986-2015 reference period using tri...