 |
Adaptation to Environmental Change - program overview
Continuous plankton recorder being deployed from the Aurora Australis. The CPR is used to map plankton communities and monitor the health of the Southern Ocean.
| | The current biological diversity of Earth reflects an evolutionary history of adaptation to environmental changes and the selection of adaptations that allow continued existence, or enhanced survival resulting in species proliferation. The Antarctic harbours many endemic taxa at the limits of their distribution and in a rapidly changing environment. The extreme conditions have led to remarkable biochemical physiological and behavioural adaptations, the study of which is leading to the discovery of useful chemicals and genes. Antarctica offers an unparalleled natural laboratory for investigating the impacts of environmental changes on the structure and function of biological communities and species.
A better understanding of the distribution and abundance of plants, animals and microorganisms, their functional relationships and interactions, their dependence on environmental gradients, particularly latitudinal and altitudinal gradients, and their potential for evolutionary adaptation is required. With this information, models to predict changes in the structure and dynamics of Antarctic ecosystems as a consequence of environmental change can be developed.
Research on Antarctic and sub-Antarctic ecosystems can provide insight into the globally profound, fundamental processes that are frequently obscured by anthropogenic effects at lower latitudes. Studies will focus on a small number of key environments. These will include the photic zone of the Southern Ocean, the terrestrial biota of selected sub-Antarctic islands, the near-shore benthos, terrestrial and aquatic habitats on the Antarctic continent.
Specifically, the program aims to address the following issues:
Mechanisms of adaptation. What are the consequences of Antarctic environmental change and how will/do high latitude ecosystems, communities and species respond to change?
How organisms have responded to past conditions can be gleaned from lake, fjord and coastal sediments as well as relic bird rookeries, peat cores and biogenic constituents in ice cores. Knowledge of such processes as life cycles, physiology and trophic interactions is essential to understand the mechanisms by which organisms respond to changing conditions, indeed whether they are able to do so.
Weddell seal and pup on the sea ice.
| |
The 'feathery' Leptinella plumosa is a vascular plant that was discovered on Heard Island during the 2003/04 season.
| |
Scanning electron mircrograph of Ceratium lineatum a Southern Ocean 'armoured' dinoflagellate, seen here with other cold water microplankton.
| |
Responses to adaptation. What are the consequences of environmental change on biodiversity?
There is a pressing need to improve our knowledge of the present genetic, species and community biodiversity of Antarctica and to ascertain how the past has shaped the present biodiversity. There are many unanswered questions concerning how high latitude organisms and ecosystems respond to environmental change. Among these are fundamental questions about whether gene pools of Antarctic organisms are as disparate as those in lower latitudes because if they are more homogeneous the consequences of even subtle climate change could be quite dramatic. In addition, if gene pools of Antarctic organisms are relatively homogeneous, then the potential for species to adapt to environmental change may be constrained. What changes in biodiversity can be expected is a key issue to be addressed.
What effect will predicted climate change have on natural ecosystems?
A number of predictions of future climate change have been made, and further refinements will be made by the Antarctic Climate and Ecosystems Co-operative Research Centre and the Ice, Oceans, Atmosphere and Climate priority program. Research on natural ecosystems in the Antarctic and the Southern Ocean must be conducted in a manner complementary to that conducted elsewhere so that it is possible to more accurately assess the likely consequences of these predicted changes. The program will assess the impacts of environmental change on the marine micro-organisms that play a critical role in sustaining the marine food web, as well as global biogeochemical cycles. A major concern is how environmental change will affect the invasion by alien species especially when exacerbated by increasing human activity in Antarctica.
|
