Why isn’t the world full of mistletoe? An integrative approach to understanding dispersal, recruitment and distribution of parasitic plants. Parasitic plants are less affected by resource constraints than other plants, but they are characteristically rare in undisturbed habitats?an apparent paradox that challenges current thinking about ecological constraints. To determine which factors limit recruitment and distribution of parasitic plants, we will conduct integrative research on two mistleto ....Why isn’t the world full of mistletoe? An integrative approach to understanding dispersal, recruitment and distribution of parasitic plants. Parasitic plants are less affected by resource constraints than other plants, but they are characteristically rare in undisturbed habitats?an apparent paradox that challenges current thinking about ecological constraints. To determine which factors limit recruitment and distribution of parasitic plants, we will conduct integrative research on two mistletoes and a sandalwood in a structurally simple semi-arid shrubland, combining experimental germination trials and chemical analyses of hosts with ecological studies of seed vectors in a spatially-explicit framework. This study will also yield powerful insights into the general mechanisms underlying the relationships between life-history traits, species distributions and resource availability in dynamic landscapes.Read moreRead less
Mistletoe as a keystone resource---an experimental test. My recent synthesis of known interactions between animals and mistletoe suggests that mistletoe functions as a keystone resource, influencing diversity patterns in forested ecosystems worldwide. This project tests the keystone hypothesis explicitly for woodland communities using landscape-scale manipulation. In 40 woodland remnants, all mistletoes will be removed from 20, with subsequent seasonal censuses of woodland birds, arboreal mars ....Mistletoe as a keystone resource---an experimental test. My recent synthesis of known interactions between animals and mistletoe suggests that mistletoe functions as a keystone resource, influencing diversity patterns in forested ecosystems worldwide. This project tests the keystone hypothesis explicitly for woodland communities using landscape-scale manipulation. In 40 woodland remnants, all mistletoes will be removed from 20, with subsequent seasonal censuses of woodland birds, arboreal marsupials and butterflies. Incorporating data on spatial and temporal variation in fruit, nectar and arthropod availability, this study represents a model system for understanding the ecosystem-wide role of ecological keystones and the influence of resource distribution on diversity patterns in fragmented habitats generally.Read moreRead less
Ecophysiological limitations that affect water and carbon balance within large tree canopies: a comparative investigation. Supply of water to forest canopies is a major control of hydrological, atmospheric and biotic processes that impinge on groundwater stability, catchment yield, the fate of pollutants and plant productivity. Fundamental aspects of water transport and distribution within plant tissues remain obscured by conflicting experimental data and conflicting theoretical models that des ....Ecophysiological limitations that affect water and carbon balance within large tree canopies: a comparative investigation. Supply of water to forest canopies is a major control of hydrological, atmospheric and biotic processes that impinge on groundwater stability, catchment yield, the fate of pollutants and plant productivity. Fundamental aspects of water transport and distribution within plant tissues remain obscured by conflicting experimental data and conflicting theoretical models that describe physiological functioning.
Potential hydraulic constraints to the exchange of water and carbon between leaf and atmosphere require investigation before accurate models and informed decisions can be made with respect to the role of forests in biosphere-atmosphere processes. I will use large trees to investigate physiological and morphological determinants of hydraulic function and consider relationships between tree size, water requirements and water supply.
This project will foster comparative analyses of hydraulic functioning in large angiosperm and conifer species to elucidate universal principles that relate form to function and explain relationships between trees and their environment.
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Is climate change altering the carrying capacity of the world’s forests? Planting trees at a global scale has been proposed as a key strategy to reduce global atmospheric CO2 levels. However, changing climatic conditions threaten the ability of forests to be net CO2 absorbers. In a warmer and drier future, forests may not be able to support as many trees. This project aims to identify how climate will alter
forest carrying capacity across millions of hectares of the world’s forests. By combining ....Is climate change altering the carrying capacity of the world’s forests? Planting trees at a global scale has been proposed as a key strategy to reduce global atmospheric CO2 levels. However, changing climatic conditions threaten the ability of forests to be net CO2 absorbers. In a warmer and drier future, forests may not be able to support as many trees. This project aims to identify how climate will alter
forest carrying capacity across millions of hectares of the world’s forests. By combining recent advances in forest modelling with large-scale and long-term forest inventory data, the project will develop a novel framework to forecast forest dynamics under climate change. It will provide specific guidelines to inform global reforestation strategies and foster climate-smart forest management.Read moreRead less
Devising ecologically sustainable restoration programs for degraded rural landscapes by integrating landscape ecology, genetics and ecophysiology. Concern about tree decline in rural landscape is widespread, and disturbingly climate change is predicted to exacerbate this problem. Past ill-considered tree plantings have proven to be economically wasteful, achieved limited ecological resilience and negligible improvement of biodiversity values. Using Tasmania as a 'model system', we will advance t ....Devising ecologically sustainable restoration programs for degraded rural landscapes by integrating landscape ecology, genetics and ecophysiology. Concern about tree decline in rural landscape is widespread, and disturbingly climate change is predicted to exacerbate this problem. Past ill-considered tree plantings have proven to be economically wasteful, achieved limited ecological resilience and negligible improvement of biodiversity values. Using Tasmania as a 'model system', we will advance this problem by undertaking research to determine how seedling establishment, tree growth, carbon storage and water use are influenced by landscape setting, management history, climate change, species type and local varieties. This research will provide a much needed evidence to devise ecologically sustainable tree-plantings in southern Australia.Read moreRead less
A novel approach for assessing environmental flows using satellite data. This project will determine how ecosystems respond to environmental flow by linking flooding history with vegetation responses, using remote sensing, climate data layers, spatial statistics, models of environmental flows and ecological theory. Beneficiaries will include water and land managers in Australia.
Managing agricultural landscapes to maximise biodiversity gains: the case of the regent parrot. This project provides crucial knowledge to achieve an Environmentally Sustainable Australia (National Research Priority) and meets a principal aim of the National Strategy for Ecologically Sustainable Development-to develop sustainable agriculture while protecting the biological resources on which they depend. We achieve this through a novel approach linking production targets and conservation trade-o ....Managing agricultural landscapes to maximise biodiversity gains: the case of the regent parrot. This project provides crucial knowledge to achieve an Environmentally Sustainable Australia (National Research Priority) and meets a principal aim of the National Strategy for Ecologically Sustainable Development-to develop sustainable agriculture while protecting the biological resources on which they depend. We achieve this through a novel approach linking production targets and conservation trade-offs with agricultural landscape design and management. This information will underpin the development of policies to improve the environmental performance of Australian agriculture, ensure farming enterprises maximise benefits obtained from native ecosystems, and guarantee profitable and viable rural industries.Read moreRead less
Models for biodiversity futures for massively altered agricultural landscapes. Problems with soil and water and declines in native biodiversity have been linked to clearance of native vegetation. We consider future landscapes with substantially more native vegetation than at present to deal with these natural resource problems. Plantings will be slow to mature so optimal planning for landscape revegetation must consider how long it will take for the new vegetation to provide suitable habitat, bo ....Models for biodiversity futures for massively altered agricultural landscapes. Problems with soil and water and declines in native biodiversity have been linked to clearance of native vegetation. We consider future landscapes with substantially more native vegetation than at present to deal with these natural resource problems. Plantings will be slow to mature so optimal planning for landscape revegetation must consider how long it will take for the new vegetation to provide suitable habitat, both at patch and landscape scales. We will develop an optimization framework incorporating models of vegetation maturation and biotic responses to aid designs for placement and scheduling of replantings to give the best outcomes for biodiversity management given constraints on amounts of retired area and costs of implementation.Read moreRead less
Ecohydrologic functioning of ephemeral streams. This project aims to increase understanding of how surface-groundwater interactions sustain vegetation associated with ephemeral streams. One of the biggest problems faced by mining and regional development in arid regions is how to protect ecological and heritage values of ephemeral streams by minimising impacts of water abstraction and surplus discharge. The project will use environmental tracers, coupled with assessment of vegetation water use a ....Ecohydrologic functioning of ephemeral streams. This project aims to increase understanding of how surface-groundwater interactions sustain vegetation associated with ephemeral streams. One of the biggest problems faced by mining and regional development in arid regions is how to protect ecological and heritage values of ephemeral streams by minimising impacts of water abstraction and surplus discharge. The project will use environmental tracers, coupled with assessment of vegetation water use and numerical modelling, to assess resilience of ephemeral streams to changes in flows resulting from mining activities and climate-related shifts in recharge. Expected outcomes of the project include providing appropriate context for evaluating and adapting management to conserve scarce water resources. This project should significantly contribute to the sustainable management of both mineral and groundwater resources.Read moreRead less
Applying macroecology to assist in the management of Kakadu National Park. The ecological integrity of Kakadu National Park is threatened by fires, weeds, and feral animals. To help tackle these problems, we will develop a cost-effective, culturally appropriate, park-wide monitoring system based on changes in the boundaries of closed forests, woodland and grassland. We will gauge the effect of broad-scale land management interventions, and predict the consequences of future change. The findings ....Applying macroecology to assist in the management of Kakadu National Park. The ecological integrity of Kakadu National Park is threatened by fires, weeds, and feral animals. To help tackle these problems, we will develop a cost-effective, culturally appropriate, park-wide monitoring system based on changes in the boundaries of closed forests, woodland and grassland. We will gauge the effect of broad-scale land management interventions, and predict the consequences of future change. The findings of this study will be transferable to other landscape settings in Australia and overseas. It will contribute to debates about the ecological consequences of current land management practices and how these compare with past Aboriginal land management.Read moreRead less