Creating tools to manage the rainforest

April 2002

The Wet Tropics World Heritage Area The information unfolding from the Centre’s tists believe that certain species of (WTWHA) encompasses nearly 900,000 multidisciplinary research is being used in a frog might be prone to decline be- hectares of tropical rainforest between number of ways. In particular, it is being cause of their habitat specialisation. Cooktown and Townsville. In 1988, in used to develop tools to assist with the man- recognition of their unique biological agement of Wet Tropics World Heritage Area. Recently, Centre scientists discovered treasures, these forests were designated a means of monitoring frog as a World Heritage Area, granting spe- Management is of key interest to government populations for signs of impending cial protection to the forests to ensure and native custodians as well as the commu- declines. ‘Fluctuating asymmetry’ is their survival for future generations. nities and industries which use the rainfor- the term used to describe size differ- est. Tools which have been created range ences between the appendages on One of the primary reasons the Wet from monitoring techniques for endangered both sides of the body of an animal Tropics rainforests were selected for species to computer models which can pre- and is a symptom of environmental world heritage listing is their superla- dict future patterns of rainforest distribution. stress experienced during develop- tive natural values. These extraordinary Some of these are described here. ment. Scientists examined specimens forests are well known for their evolu- of Litoria nanotis and Litora tionary history, rich biological diversity genimaculata, whose high evaluation and large number of unique species. populations disappeared in the early While information about the plants and 1990s. They found that levels of fluc- animals in the rainforests is vital, pre- tuating asymmetry increased dra- serving the integrity of rainforest ecosys- matically the year before the tems requires managing for natural populations declined and were linked changes as well as human activities. to periods of increased environmen- tal stress. The challenges of managing such a large area are as complex and diverse as the This finding has led to a new moni- forests themselves. These ecosystems toring technique being used by the experience natural and human induced Queensland Department of Environ- changes which may affect individual ment and the species, habitats, and specific forests. In Disappearing Frogs frog recovery program. Its applica- addition, the Wet Tropics is subject to a tion could signal the approach of im- range of land tenures with more than 700 Several frogs, native to the Wet Tropics, are minent declines. Advanced warning different land owners within the world suffering the same mysterious disappearance will then give scientist a chance to heritage boundaries. Activities occur- which is affecting frogs around the world. Six monitor for the sources of environ- ring in and around the Wet Tropics are species of frogs that breed in high elevation mental stresses and establish captive varied, including residential develop- rainforest streams have drastically declined breeding programs if necessary. ments, agriculture, tourism and forestry, in numbers since 1990. Despite intensive and can sometimes present conflicting monitoring, searches, and surveys, three spe- Modelling the past to predict the demands on the rainforests. Managing cies have not been seen since 1994. future for the future requires strategic planning and decision makers need high quality The Centre’s timely research on frog behav- Centre researchers have uncovered information. The Centre has a strong iour, such as how far they travel from their evidence that the Wet Tropics rainfor- portfolio of research directed specifically preferred habitat during different periods of ests have been expanding since the for this purpose. their life, has provided critical information last ice-age. By identifying and car- about these disappearing frogs. Some scien- bon-dating charcoal fragments found in rainforest soils, they have found that current patterns of diversity and the To address these problems, a financial large areas of the current rainforest processes which created them. This in- model, using a simple EXCEL landscape were once covered by dry formation is being used to create com- spreadsheet, was developed to predict eucalypt woodlands. Around 13,000 puter models with the aid of artificial potential financial returns of small-scale years ago when the climate was cooler neural networks to help unearth the native species plantations. The model and drier, rainforests retreated to only origins of rainforest flora and fauna and allows for the prediction of the internal the wettest locations, usually along peer into the future to forecast future rate of return and the net present value creeks and rivers. As the climate be- rainforest distributions. Knowing how for mixed species plantations incorpo- came wetter, rainforests began reclaim- rainforests are likely to change can in- rating up to five rainforest species. ing their old territory. The reservoirs dicate how forests might recover from of flora and fauna which survived in deforestation and climate change. This Centre scientists have also been work- these ‘refugia’ provided the source of knowledge will help scientists and land ing to understand the physiological at- today’s diversity. managers with conservation planning tributes and ecological requirements of and design of reserves. plantation species suitable for north At the same time, scientists have been Queensland plantations. Combining using molecular technology to examine Reviving the timber industry information on the financial aspects how different species, which were iso- with biological information of native lated by the rainforest’s retreat, have Since its World Heritage listing, logging trees will help farm foresters maximize responded to the forest’s return. DNA activities within the Wet Tropics have their plantation investments. A suite of analysis revealed significant genetic ceased. However, high quality rainfor- the most promising trees has been se- differences between populations of sev- est timber is still in strong demand. lected for both upland and lowland eral species of birds and lizards on ei- Government sponsored programs such sites, based on their growth in planta- ther side of what is known as the Black as the Community Rainforest Reforesta- tion field trials and their timber qual- Mountain Barrier (BMB) – a large rift tion Program have been established to ity. Current research is exploring site- of dry forest created when the rainfor- encourage native timber plantations on species relationship at a finer, landscape ests contracted during the last ice-age. private holdings to meet these demands scale, which takes into consideration and create sources of quality timber in geological and topographic variations. This finding points to the presence of the future. However, government ef- two very different evolutionary line- forts to establish plantations have been For more information ages within these narrowly distributed minimal because landowners need species. Now that the rainforest has sound information on ecological, For more information about these and returned to the BMB, scientists believe silvicultural and economic aspects of other research projects of the Tropical that the once isolated populations are growing rainforest trees for timber. Rainforest CRC please contact: again mixing or ‘hybridising’ into new species. This has significant conserva- Socio-economic research undertaken by Professor Nigel Stork tion implications, as the disappearance Centre researchers has pinpointed a Director of species from one rainforest patch major impediment in the growth of CRC for Tropical Rainforest Ecology could represent the loss of significant farm-forestry. There is an apparent un- And Management evolutionary diversity rather than just willingness of many farmers to invest PO Box 6811 a local extinction. in farm-forestry because of the uncer- Cairns QLD 4870 tainty of the returns. It is also very dif- Tel: (07) 4042 1246 The carbon-dating and genetic research, ficult for land agents to estimate the Fax: (07) 4042 1247 when considered together, are giving added value of reforestation without Web site: http://www.crctrem.edu.au scientists a better understanding of the dependable information.