What happened next? relatively few 'super-highways’ directed the initial peopling of Sahul
Wednesday, 26th February 2020 | Presented by Distinguished Professor Michael Bird|JCU
The peopling of Sahul (the combined landmass of Australia and New Guinea) represents the earliest trans-oceanic migration event in human history. Archaeological data and demographic modelling suggest that the peopling of the continent required substantial populations, occurred within a few thousand years, and encompassed environments ranging from hyper-arid deserts to temperate uplands and tropical rainforests. How this migration through an empty continent occurred, or how humans responded to the physical environment they encountered has, however, remained largely speculative. By constructing a new, fine-scale (250m resolution) digital elevation model for Sahul, coupled with a fine-scale viewshed analysis of landscape prominence for the entire continent, we developed a point process-to-network function whereby the most parsimonious routes these first people likely traversed emerge.
Out of ~125 billion created paths, our analysis revealed a small number of major pathways - super-highways - transecting the continent, validated against archaeological data, suggesting that the early Sahulians adopted a set of fundamental rules for physiological capacity, attraction to landscape features and freshwater distribution to ensure survival and success. This early continental peopling can be described by basic rules of adaptation to local landscape features, with people minimizing the likelihood of failure, even without previous experience of novel landscapes. Results demonstrate the extraordinary cultural plasticity of humans to adapt to novel and challenging environments. Our analyses provide targets for future archaeological investigation, as well as informing current policy makers planning for present day migration as a result of climate disruption, and methods to more robustly interrogate current Out-of-Africa debates.
Mangrove, people and sea level rise: the past as a guide to the future
Wednesday, 4th March 2020 | Presented by A/Prof Kerrylee Rogers |University of Wollongong
Abstract: Mangroves occur at the coast and will be central to any discussion regarding the implications of sea-level rise for coastal communities. As mangrove forests provide crucial ecosystem services for people in coastal communities, there is an immediate and critical need to understand and project the capacity of mangrove forests to adapt to anticipated accelerating sea-level rise. Improved access to spatial data has facilitated the application of spatial models that project changes to mangrove accommodation space with sea-level rise. Scientists presently have relatively good understanding of the behaviour of mangrove forests at millennial timescales, and processes operating at contemporary timescales. However, there is less certainty about the response of mangrove forests at decadal to century timescales. It is now time for mangrove scientists to integrate data across spatial scales and prioritise accuracy over precision when undertaking projections. These challenges are discussed in the context of lessons learnt whilst researching mangrove forests in Australia and elsewhere. This research emphasises the need for cross-disciplinary research projects and international collaboration between physical and social scientists.Watch the recording
Invasive Species and Climate Change: managing the risks
How we manage for biosecurity in the Wet Tropics with a changing climate (Cath Moran)
Increasing temperatures, changing rainfall patterns, rising sea levels and higher levels of carbon dioxide in the atmosphere are changing the conditions that affect the growth and survival of invasive species. These changes benefit some invasive species and disadvantage others. It is likely that increasing climate-driven disturbance will advantage many invasive species, and powerful cyclones, widespread and intense bushfires, and frequent floods are expected to create more opportunities for pest plants and animals to invade new areas. New invasive species are also being dispersed in floodwaters, changing ocean currents and wind patterns and via human population movements. Adapting management of invasive species to the impacts of climate change will involve re-assessing the risk from introduced species under changing conditions, increasing vigilance for emerging problems and possibly re-defining our concept of what is ‘natural’
Invasive ants and climate change—what we know and what we need to know to understand future threats (Lori Lach):
When climate change and invasive species are mentioned together, it is usually in the context of predicting whether a given species would be able to establish in a given area under future climate scenarios. But abiotic suitability as it affects establishment is only one aspect of invasive species ecology that might be affected by climate change. The spread, impact, and management of invasive species will also be affected by changes to temperature and rainfall patterns. Ants are among the most formidable of invasive species, and Australia spends millions of dollars annually attempting to eradicate some of the worst. In my talk, I’ll focus on how current and predicted changes to our climate may affect ant abundance, which underpins both the spread and impact of these invaders. ’ll also describe how increased variability in seasonal weather patterns is already vexing invasive ant management programs, and, overlain with potential changes to ant biology, will make eradication or containment even more challenging. Throughout my talk, I will highlight the many gaps in our knowledge that prevent us from making strong predictions, as well as point out where there is cause for optimism.
The Role of Citizen Science in Invasive Species and Climate Change (Andrew Robinson):
As the impact of climate change increases before our eyes, established scientific practice is struggling even more to protect biodiversity and agriculture from invasive species. Institutional science, weighed down in Australia by 250 years of colonial history, lacks the necessary resource, trust and nimbleness to make meaningful, long-term change in the face of the current climate crisis. A solution lies in a transformation of scientific practice itself - something which is becoming more possible these days due to the latest developments in citizen science practice and the latest technologies being produced right here in Australia. I’ll be talking about how, if we hope to reduce the impact of invasive species and climate change in Australia, it's both necessary and easy to start moving rigorous scientific practice out of traditional science institutions and into the hands of local communities, indigenous scientists, young people and anyone who wishes to be part of saving life on Earth.Watch the recording
‘Bioreactors: protecting aquatic ecosystems downstream of productive agri- and aqua-culture’
Wednesday, 18th March 2020 | Presented by A/Prof Paul Nelson|James Cook University
Efficient production of food entails raising nitrogen concentrations in soil and water above levels found in natural ecosystems. Some nitrogen is inevitably lost from the paddock or pond, especially in high rainfall environments. We are testing the ability of ‘denitrification bioreactors’ to remove nitrogen from water leaving sugarcane and fish farms, in a first for the tropics. We are testing various configurations of bioreactors in various situations, and testing the effects of factors such as nutrient concentration, water salinity and retention time. This talk will present interim results of the research.Watch the recording
Ecological intensification for sustainable agriculture and forestry
Wednesday, 25th March 2020 | Presented by Dr Daniel Montesinos| Senior Research Fellow ATH/JCU
Ecological intensification aims to counter-balance the negative impacts of agriculture and forestry intensification by promoting management interventions that maximize ecosystem services. Ecological intensification is a knowledge intensive process that requires optimal management of nature’s ecological functions and biodiversity to improve agricultural system performance, efficiency and farmers’ and foresters’ livelihoods. This approach intends to harness the benefits of increasing ecosystem services and biodiversity in a way that maximizes production, but minimizes environmental impacts by decreasing, but not excluding, the use of synthetic fertilizers, pesticides, or energy. Ecological intensification is gaining popularity due to its down-to-earth results-based approach, and includes practices that are generally recognized as good practices in both agriculture and forestry, such as: conservation tillage, crop rotation, and mixed cropping.Watch the recording