Abstract:
Metadata record for data from AAS (ASAC) Project 3117
See the link below for public details on this project.
Public
Climate change and feral animals are having profound effects on Macquarie Island, threatening its World Heritage values. Through the use of lake sediments and peat deposits we will examine how the climate has changed in the past, what it was like before feral animals were
... introduced, and the rate and extent of changes since. This essential information will ensure successful future conservation and restoration and provide a series of measures to assess the recovery of Macquarie Island once the feral animals have been removed.
Project Objectives:
Macquarie Island is a key site for understanding both Southern Hemisphere and global climate and ecosystem changes as it is one of the few landmasses in the Southern Ocean and one of the few sub-Antarctic islands between 45 degrees and 60 degrees S. Furthermore, it has World Heritage status and is a UNESCO Biosphere Reserve (the only Biosphere Reserve in the sub-Antarctic biogeographic region). Macquarie Island is therefore of considerable global ecological and conservation significance.
In order to understand environmental changes occurring on Macquarie Island and to make realistic predictions about future scenarios, it is critical to determine and quantify natural and human-induced causes of change and variability. This can only be achieved by understanding the long term magnitude and direction of natural environmental change, establishing the 'baseline' status of the environment prior to human impacts, and then use this information to separate subsequent natural from human-induced change.
This project seeks to:
Objective 1
Quantify high resolution long term environmental (climate and ecosystem) change on Macquarie Island over the last 10,000 years in terms of:
(i) Temperature and precipitation (using established Macquarie Island diatom transfer functions and in-situ reflectance spectroscopy of lake sediments)
(ii) Vegetation assemblages (by pollen, plant macrofossil and DNA analyses of lake and peat sediments)
(iii) Abundance, presence and absence of selected fauna, including non-indigenous species (using lacustrine invertebrate microfossils and DNA analyses of lake sediments)
(iv) Erosion rates (by measuring sedimentation and accumulation rates in lakes using radioisotope dating).
Objective 2
Quantify changes in all of the above variables during the period of human impact (1810-present) to identify ecological anomalies (i.e., changes outside the range of natural variability). In particular, changes attributable to recent shifts in climate and/or the impacts of rabbits will be measured.
Objective 3
Integrate changes in each of the above parameters to provide a multiproxy quantification of the effects of long term climate and ecosystem changes on Macquarie Island and an assessment of the impact of feral animals, in particular rabbits. This will provide a framework and set of tools for measuring the extent to which environmental change has occurred due to natural vs. human causes and consequently, the extent to which management targets have been achieved. These tools will consist of straightforward analyses of material incorporated into sediments (e.g., sediment traps) and other records of environmental change (e.g., surface sediments and peat development).
Taken from the 2009-2010 Progress Report:
Progress against objectives:
Objective 1:
The last 12 months have primarily involved planning and undertaking fieldwork. We had two field trips to Macquarie Island in 2009/2010. This involved the collection of sediment cores from 9 lakes with the additional lake sediment and water sampling of a further 40 lakes on Macquarie Island. This has provided the samples needed to address Objective 1.
Objectives 2 and 3:
Progress towards objectives 2 and 3 will follow completion of Objective 1. 
