Presence-absence versus abundance data for monitoring threatened species

Effective detection of population trend is crucial for managing threatened species. Little theory exists, however, to assist managers in choosing the most cost-effective monitoring techniques for diagnosing trend. We present a framework for determining the optimal monitoring strategy by simulating a manager collecting data on a declining species, the Chestnut-rumped Hylacola (Hylacola pyrrhopygia parkeri), to determine whether the species should be listed under the IUCN (World Conservation Union) Red List. We compared the efficiencies of two strategies for detecting trend, abundance, and presence-absence surveys, underfinancial constraints. One might expect the abundance surveys to be superior under all circumstances because more information is collected at each site. Nevertheless, the presence-absence data can be collected at more sites because the surveyor is not obliged to spend a fixed amount of time at each site. The optimal strategy for monitoring was very dependent on the budget available. Under some circumstances, presence-absence surveys outperformed abundance surveys for diagnosing the IUCN Red List categories cost-effectively. Abundance surveys were best if the species was expected to be recorded more than 16 times/year; otherwise, presence-absence surveys were best. The relationship between the strategies we investigated is likely to be relevant for many comparisons of presence-absence or abundance data. Managers of any cryptic or low-density species who hope to maximize their success of estimating trend should find an application for our results.

Conservation planning with irreplaceability: does the method matter?

A number of systematic conservation planning tools are available to aid in making land use decisions. Given the increasing worldwide use and application of reserve design tools, including measures of site irreplaceability, it is essential that methodological differences and their potential effect on conservation planning outcomes are understood. We compared the irreplaceability of sites for protecting ecosystems within the Brigalow Belt Bioregion, Queensland, Australia, using two alternative reserve system design tools, Marxan and C-Plan. We set Marxan to generate multiple reserve systems that met targets with minimal area; the first scenario ignored spatial objectives, while the second selected compact groups of areas. Marxan calculates the irreplaceability of each site as the proportion of solutions in which it occurs for each of these set scenarios. In contrast, C-Plan uses a statistical estimate of irreplaceability as the likelihood that each site is needed in all combinations of sites that satisfy the targets. We found that sites containing rare ecosystems are almost always irreplaceable regardless of the method. Importantly, Marxan and C-Plan gave similar outcomes when spatial objectives were ignored. Marxan with a compactness objective defined twice as much area as irreplaceable, including many sites with relatively common ecosystems. However, targets for all ecosystems were met using a similar amount of area in C-Plan and Marxan, even with compactness. The importance of differences in the outcomes of using the two methods will depend on the question being addressed; in general, the use of two or more complementary tools is beneficial.

Sustainable Native Floriculture?

The Centre for Native Floriculture (CNF) commenced in May 2003 at The University of Queensland, Gatton. The CNF is a joint initiative with the Queensland State Government, with funding for an initial 3-year period. The phase-out of bush-picking under the South East Queensland Forests Agreement was a catalyst for the Centres establishment. The CNF vision is: ‘to help create an internationally competitive and environmentally sustainable native floriculture industry that provides significant employment opportunities in Queensland’. The Centre is comprised of three research, development and extension programs. The Value Chain Program assists native floriculture industry groups in developing efficient consumer-orientated production, handling and marketing systems for select high potential species. These value chain systems will serve as models for realizing the market potential of and regional fiscal returns on other native ornamental species identified as crop ideotypes that are sought after by end-users (e.g. florists). The Floriculture Program supports the value chain by working to enhance germplasm for the native floriculture industry through selection and breeding, optimize cultivation protocols and overcome any technical barriers that arise. Such barriers include propagation constraints, disease problems and post-harvest limitations. The Capacity Building Program operates to transfer technology and other skills (e.g. value chain management principles) to industry members, train operatives for the industry and promote native floriculture. Conservation of native flora is encouraged through cultivation and community engagement. Protection of biodiversity is advocated via regional production systems that spare natural areas and educate the public as to the biological, floricultural and aesthetic values of native flora. Eco-agricultural tourism focused on wildflowers both in nature and in cultivation is also advocated by the CNF.

Overview of the conservation status of Australian frogs

A review of the current conservation status of Australian amphibians was recently completed as part of a World Conservation Union (IUCN) sponsored Global Amphibian Assessment (GAA). Fifty of 216 amphibian species (23%) in Australia are now recognized as threatened or extinct in accord with IUCN Red List Categories and Criteria. Here we report on the categories and criteria under which individual species qualified for listing and provide a summary of supporting information pertaining to population and distribution declines. Major threatening processes contributing to listing of species are also reviewed.