RISING TO THE CHALLENGE

CHIEF SCIENTIST AND DIRECTOR SCIENCE, EDUCATION AND CONSERVATION, PROFESSOR BRETT SUMMERELL, REPORTS ON A VITAL EXPEDITION TO DOCUMENT BIODIVERSITY IN AUSTRALIA'S HIGHEST MOUNTAIN RANGE.

The Australian Alps are one of the most amazing environments in Australia. Part of the Great Dividing Range, they include the highest peaks on the continent and several significant national parks – among them Kosciuszko National Park in New South Wales and the Alpine National Park in Victoria. Within the Alps is an enormous diversity of plants and environmental conditions. Given the sparsity of truly alpine areas in Australia, many species are endemic to the region, and highly adapted and dependent on the conditions that occur there, especially in those areas above the tree line and covered by snow during winter. The ecosystems of the Alps face a huge number of challenges. The first and most obvious is the impact of climate change – as temperatures rise, species adapted to an alpine environment are less likely to survive and reproduce. Added to this is the more frequent risk of extreme events such as prolonged drought, flooding and bushfires (large areas were burnt in the 2019/20 Black Summer). Invasive species – weeds, disease and feral animals – are also severely affecting large areas and increasing the risk of species extinction. As such, it is more vital than ever that we collect baseline data on species occurrence.

The Bush Blitz program was established in 2010 to document Australia’s biodiversity and it is our country’s largest nature discovery program. It is a unique multi-million-dollar partnership between the Australian Federal Government, Parks Australia, BHP and Earthwatch Australia to record plants and animals across Australia. As part of the program, herbaria, botanic gardens, museums and universities send along scientists and horticulturists to survey, document and collect all forms of life – enhancing our knowledge of diversity and ensuring there are records and permanent collections in these institutions.

In February 2023 a team from the Gardens joined staff from the Australian Museum, CSIRO, Royal Botanic Gardens Victoria, Museums Victoria and various state national parks to survey locations throughout the Alps. While the aim of these expeditions is to ultimately discover species that have not been scientifically described, it is equally important to document what species are where, supplement collections (especially in areas that have not been surveyed previously) and provide the essential data needed to enable monitoring of inevitable changes. The Gardens has been involved in a number of Bush Blitz expeditions over the past 13 years at locations in NSW, Queensland and the Northern Territory.

A wonderful component of these expeditions is the coordination and collaboration of different experts, the support in terms of meal preparations and logistics, and the opportunity to use helicopters to access remote (and sometimes otherwise inaccessible) areas. This ensures that the maximum amount of effort is directed towards exploring and collecting specimens and getting them back to the home base, then on to the various gardens and herbarium. The weather conditions the team experienced on the Australian Alps Bush Blitz was typically extreme, with snow (even in February!), rain and sunny weather following each other with the sort of unpredictability that is a feature of life in these ecosystems.

The team made approximately 450 collections, which included new populations of a number of threatened species, new records of species for NSW, and several collections of potentially unique species new to science that will need to be researched over the coming months and years. Our colleagues working on insects and spiders found a number of species that haven’t been described before – highlighting how much Australian biodiversity is still poorly understood.

A unique aspect of the expedition was its focus on collecting propagation material to be used in horticultural displays in the Gardens. A number of species are now safely in the mist houses in the nursery at the Australian Botanic Garden Mount Annan. These species will eventually be planted in suitable locations at the Gardens (particularly the Blue Mountains Botanic Garden Mount Tomah) and some have great potential for use in horticulture. Unfortunately, our team observed large numbers of feral horses, deer and other invasive animals – and the damage they cause. The impact of feral horses on fragile biodiverse swamp and riverine environments was significant and a serious cause of concern. These environments contain many rare species and are at great risk from the damage caused by these feral species. It is clear that enhanced efforts are needed to control population numbers in order to properly protect the unique environments and the plants and animals that make them their home. Weeds and diseases like Phytophthora root rot are also common, and need to be managed and controlled to prevent further spread and allow regeneration of native species.

As these threats become more common and intense, it is increasingly important that greater efforts are made to collect and document species so that we can understand the changes to biodiversity that result. Unless we have accurate baseline data, and information on how ecosystems are changing, it will be difficult to assess the effects of a changing climate and how to mitigate them. In this context it becomes more important than ever for our scientific teams to spend more time in the bush collecting, documenting and highlighting their concerns – all backed up by the best scientifically collected information.