Showing papers in "Pacific Conservation Biology in 2001"

Abundance and Decline of Isolated Trees in the Agricultural Landscapes of Central New South Wales, Australia

Abstract: Prior to this study, isolated trees were largely isolated from research. This study has provided a methodology, rigorous assessment of isolated tree density and distribution, and identified the potential ecological, social and economic importance of isolated trees, in a relatively small, but probably typical area of the wheat-sheep zone of eastern Australia. The abundance and decline of isolated native trees was measured by line-intersect sampling in the highly fragmented agricultural landscapes of the mid-Lachlan Valley of central New South Wales, Australia. A total of 7 000 trees were sampled along 5 678 km of transect on 441 aerial photographs. An isolated tree was defined as having no neighbouring tree within 25 m. The density of trees outside of remnants patches is low (0.3/ha) and has generally declined by 20% since the 1960s. The 1990s density of isolated trees equates to 275 000 trees across 830 000 ha of agricultural land not occupied by remnant vegetation patches larger than about 10 ha. The density of isolated trees was found to vary with land use with consistently fewer trees in cultivated areas compared to areas with no traces of cultivation. The isolated trees that remain within the agricultural landscape are not uniformly scattered. They exist as widely spaced clusters of isolated trees with 50% of trees having a nearest neighbouring tree within 25-49 m and less than 10% of trees had a nearest neighbour within a distance class greater than 100 m. Compared to the 1960s, isolated trees are now more isolated - the nearest neighbour distance has increased. The mean diameter of isolated tree crowns has significantly increased from 15 m in the 1960s to 18 m in the 1990s. The total canopy cover of isolated trees from the 1990s samples was 0.8% of the total study area below 400 m asl. A reversal in isolated tree decline will only occur if trees are replanted, or existing trees fenced to promote regeneration. Otherwise, isolated trees are dieing relicts of 150 years of clearing and intensive agriculture. This is of concern considering that we do not fully understand their value. We speculate on some of the ecological, economic and social values of these trees.

The reproductive biology and diet of sea snake bycatch of prawn trawling in northern Australia: characteristics important for assessing the impacts on populations

Abstract: Trawlers catch up to 17 species of sea snake as bycatch in the Northern Prawn Fishery (NPF) in northern Australia. We examined the biological characteristics of 660 sea snakes caught by research, scientific observer and commercial vessels between 1986 and 1998 as part of a project to assess their vulnerability. Three species accounted for more than 75% of the total sea snakes caught. Hydrophis species were more common in unstructured habitats close to prawn trawling grounds, while Aipysurus species were the dominant species in areas having reef structure. Sea snakes were caught more frequently at night on commercial trawlers and even more were caught during the day by research trawling. Female sea snakes were caught more often than males for 10 out of 13 species examined. The proportion of mature sea snakes in trawl catches was high (67% males, 89% females). Juvenile sea snakes of most species are not caught suggesting there is little impact of trawling on recruits. We found all species breed annually, producing a few large young after a gestation period of 6-7 months. Litter size varied between 1 to 20 and young of most species were born during the NPF closed season (Nov-Mar). Except for Aipysurus duboisii, Disteira major and Hydrophis ornatus, pregnant females of most species were not more catchable by prawn trawls than non-pregnant females. The relative clutch mass had little effect on the catchability of pregnant females. Most sea snake species had a specialized diet, feeding on one to four benthic fish species and did not appear to be attracted into trawl grounds by the increased availability of discarded bycatch. Their reproductive characteristics mean that populations of many species caught by trawlers in northern Australia are potentially vulnerable.

Conservation of Vertebrate Fauna Using Hollows in Forests of South-West Western Australia: Strategic Risk Assessment in Relation to Ecology, Policy, Planning, and Operations Management

Abstract: Forty-two vertebrate species use hollows in live standing trees in the forests of south-west Westem Australia. We determined the reliance of each of these species on hollows in standing trees, assessed the relative frequency of occurrence of suitable hollows (based on the size of hollow and hollow entry), and further categorized species by the size of their home range and their current dependence on publicly-owned forest. No species was identified as being at high or immediate risk of decline. Eight species (6 bird, 2 mammal) were identified as excellent candidates for monitoring, with one species (Trichosurus vulpecula) most likely to provide the earliest indication of any critical reduction in the long-term supply of large hollows at small spatial scales. Past impacts of Aborigines and Europeans on populations of the larger species are likely to have been substantial, as these were hunted for food and trapped for fur. Hollow-using species are considered at present to be adequately safeguarded by: extensive areas of forest reserved from logging; science-based prescriptions mandating the retention of trees in Jarrah Eucalyptus marginata forest available for timber harvesting; a forest-wide baiting program to reduce predation by the introduced Red fox Vulpes vulpes; and a 70 year tradition of adaptive forest management. The recovery of populations of medium-sized mammal species following control of foxes will provide an opportunity to re-assess the adequacy of current hollow-management strategies. Future research should include modelling of stand structure, determining the home range of priority species, and assessing the extent of overlap of home ranges. Monitoring of indicator hollow-using species should take place at landscape scales.

Testing for food limitation in reintroduced Hihi populations: contrasting results for two islands

Abstract: The Hihi Notiomystis cincta, a New Zealand honeyeater (Aves: Meliphagidae), became extinct everywhere except one offshore island following European colonization, Attempts to establish Hihi on additional islands in the 1980s had poor success, and this was attributed to food limitation. These islands had all been modified by human use, and had a lower diversity of natural carbohydrate (fruit and nectar) sources than the source island, particularly in winter. When Hihi were released on two additional islands, Mokoia and Tiritiri Matangi, we used supplementation experiments to test whether condition and survival of birds were limited by availability of carbohydrate food. Sugar water was provided on an on-off basis from autumn through spring in the year after the release. Birds were weighed at the beginning and end of fed periods, and survival for fed and unfed periods was estimated using mark-recapture analysis on sighting data. Armstrong and Perrott (2000) reported that supplementary feeding had no effect on condition or survival on Mokoia, and annual survival was about 40%, both in the year of the experiment and in subsequent years when food was supplied continuously. This paper reports contrasting results for Tiritiri Matangi. Supplementary feeding on Tiritiri Matangi increased both condition and survival, and overall survival was substantially higher than on Mokoia - 66% in the year of the experiment and 76% the following year when food was supplied continuously. It therefore appears that supplementary feeding can be used to improve survival of Hihi on Tiritiri Matangi, whereas survival is constrained to a low level by other factors on Mokoia. These results emphasize the value of habitat manipulation experiments for developing appropriate management strategies for reintroduced populations.

The Pied Currawong's role in avian nest predation: A predator removal experiment

Abstract: Pied Currawongs Strepera graculina have been implicated as a major threat to the persistence of small passerines in urban and rural landscapes through their intense nest predation while raising their young. Pied Currawongs have recently increased in abundance and colonized new areas, due to the planting of exotic berry-bearing trees and shrubs. In association with habitat fragmentation, this may have intensified their predatory impact. We measured the rate of predation on 416 artificial nests, using quail and plasticine eggs, in a 240 ha remnant of eucalypt woodland. Nests were placed in one grid from which Pied Currawongs were removed and in one control grid. The level of predation was monitored before and after Pied Currawong removal. Overall, nest predation was extremely high with 91 % of all nests preyed upon in seven days. Moreover, nest predation decreased significantly following Pied Currawong removal, thus identifying them as significant nest predators. However, imprint evidence from plasticine eggs and the remains of real eggs indicate that other animals, particularly other birds, are also important predators. If this high level of nest predation is reflected in real nests and occurs over a number of years, it may lead to low recruitment of open-nesting birds at this site. If it occurs regionally, it could contribute to long term declines of these species. Our findings suggest that even quite large woodland fragments may be too small to sustain many declining bird species.

Community survey of the distribution of Lumholtz's Tree-kangaroo on the Atherton Tablelands, north-east Queensland

Abstract: Lumholtz's Tree-kangaroo Dendrofagus lumholtzi is endemic to the rainforests of north Queensland, Australia. Most records of D. lumholtzi are from upland forests on the Atherton Tablelands, an area -extensively cleared for agriculture. In 1997, residents of the Tablelands formed the Tree Kangaroo and Mammal Group Inc. (TKMG) with the aim of promoting the conservation of the species. The first project of TKMG was an intensive community-based survey of the distribution of D. fumholtzi. Residents of all postal districts encompassing areas of upland rainforest within the range of D. lumholtzi were sent a written questionnaire seeking details of tree-kangaroo sightings. The Malanda postal district was surveyed in 1998 while all other postal districts were surveyed in 1999. In total, 10 122 questionnaires were distributed in the survey. Nearly BOO responses were received to the survey, providing 2 36B Sighting records of D. lumholtzi. Of these, 367 records were of dead tree-kangaroos, mostly road-kills." The survey has provided a much more comprehensive account of the distribution of the species than was previously available. Most records of D. lumholtz; obtained in the survey were from upland forests between Atherton and Ravenshoe, particularly remnant forests in the central and western Tablelands. Although the survey methodology is biased towards areas frequented by humans, these patterns are consistent with independent surveys. The conservation of D. lumholtzi on the Tablelands would benefit from the protection of remnant forests, the restoration of habitat and a reduction in the incidence of road-kills and dog attacks on tree-kangaroos.

How grassland plants are distributed over five human-created habitats typical of eucalypt woodlands in a variegated landscape

Abstract: A sample of 212 quadrats in grassland vegetation was collected in eucalypt woodlands in sub-tropical Queensland. These included roadside (53 sites), native pasture (109), riparian zone (20), sown pasture (16) and crop (14) habitats. A total of 350 species and subspecies was recorded of which 89 species were identified as being locally rare (native species of <3% frequency, not specialists of other habitats). Forty-three species were collected in addition to the quadrat records. Multivariate analysis indicated the major difference in floristic composition was between roadsides and native pastures, versus the other three habitats. The second axis separated roadside from native pasture vegetation, and the third axis separated riparian sites from all the rest. Crop and sown pasture habitats were the most similar in composition. The grazing practices in this region have enabled the persistence of grasslands that are of national significance in conservation terms. The variegated nature of the landscape is demonstrated by the occurrence of native grassland species across all the human-created habitats, including native species that were unique to intensive land uses. However, our results also show that intensive land uses (cropping, sown pastures) are more of a threat to the conservation status of grasslands than is cattle grazing, even at commercial levels of stocking. Species at most immediate risk are those that are sensitive to commercial cattle grazing and to intensive land uses such as crops and sown pastures.

Understanding the impacts of recreation in Australian protected areas: Quantifying damage caused by horse riding in D'Entrecasteaux National Park, Western Australia

Abstract: There is presently very little published quantitative information on the environmental impacts of recreational horse riding. Particularly in Western Australia the lack of "hard evidence" concerning the environmental impacts of horse riding hinders objective judgement of damage caused by horse riding in national parks. This paper presents data on horse riding impacts in a Western Australian (D'Entrecasteaux) national park. The research measured vegetation and soil impacts caused by horse use in un-tracked areas with the specific aim of relating the amount of horse use to degree of environmental impact. Horse riding altered plant species composition, increased the area of bare ground and decreased height and cover of vegetation. Significant impacts occurred after only low levels of horse use. The findings indicate the need for a database on horse riding impact in Australia so that, where horse riding is allowed, impacts can be properly assessed and effectively managed.

The canopy, bark, soil and litter invertebrate fauna of the Darling Plateau and adjacent woodland near Perth, Western Australia, with reference to the diversity of forest and woodland invertebrates

Abstract: This paper tables and reports on pooled taxonomic data from three separate research projects involving aspects of eucalypt invertebrate ecology: canopy invertebrates in jarrah and marri forest; bark invertebrates on four eucalypt species in forest and woodland; and soil and litter fauna in jarrah and marri forest. The data support the concept of a high invertebrate biodiversity on and under southwestern eucalypts, with 1 234 adult morphospecies of invertebrates being collected from the bark alone. Despite different trapping methods used in each of the three studies, we were able to find a high degree of overlap at the family level between bark and canopy fauna (126 families were found on both bark and in the canopy representing 79.2% of 159 canopy families). Eighty identified genera were also found on both bark and canopy, which represents 46.2% of the 173 identified canopy genera. The soil and litter fauna data are not complete (a taxonomic inventory of Acarina and Formicidae is not available) but appears to be more distinctive, sharing only 24 families (= 60% of the 40 identified soil-litter families) with bark, and 17 families (= 42.5% of the soil-litter families) with the canopy. At the generic level, only seven identified genera (= 8.6% of 22 soil-litter genera) were shared between soil-litter and bark, and five genera (= 6.2% of soil-litter genera) were shared between soil-litter and the canopy. An examination of the trophic guilds reveals that fungivores-decomposers were very diverse in soil and litter (accounting for approximately 50% of the biodiversity in these substrates). This guild was much less diverse on the canopy (21.6% of the canopy diversity) and the bark (16.9% of bark diversity). Sap-sucking organisms were more diverse in soil (13.9%) and litter (12.8%) than on the canopy (5.3%) or on bark (5.9%). The canopy result is surprising, and suggests that not many invertebrate species are able to feed on the sap of southwestern eucalypts, the sap of which may contain a high proportion of toxic compounds. Predators were more diverse on the canopy and on bark (?19-23% of total taxa) than in soil and litter (? 9-9.5%), as were parasitoids (18.7% and 22.5% compared with 10.5% and 14.8%). Epiphyte grazers and phytophages were not very diverse (=11 %) on any of the substrates, and representatives of other guilds or organisms whose diet was unknown accounted for less than 2.5% of the total diversity. Tourist species were not recognised among the soil and litter fauna, though they were found in the canopy and on bark, and ants were not quantified for soil and litter.

Conservation of Wetlands in the Paroo and Warrego River Catchments in Arid Australia

Abstract: Irrigation proposals to divert water from the Paroo and Warrego Rivers in arid Australia will affect their aquatic ecosystems. These two are the last of 26 major rivers in the Murray-Darling Basin without large dams and diversions. Knowledge of the extent of their biodiversity value is critical to assessing likely impacts. During the 1990 flood, 1.73 million ha of wetlands, or 12.5% of the land surface of the Paroo and Warrego River catchments, were flooded. Flooded wetland area in the respective catchments was 781 330 ha and 890 534 ha. Most of the wetland area (97%) was floodplain, with 37 freshwater lakes (>50 ha) occupying 2.5% of the wetland area and 177 salt lakes covering 0.8%. A high diversity and abundance of biota depend on these wetlands. Only 7% of the wetland area, all in the Paroo catchment, is in conservation reserves. New South Wales has a high proportion of the wetland area on the Paroo (60%) and a substantial proportion of the wetland area on the Warrego River (23%). Queensland, the upstream state, will influence the ecology of the entire catchment areas of both river systems through its proposed water management plan. Any resulting extraction practices will have detrimental ecological consequences within a decade. Conservation of wetlands is usually site-focused and reflects a paradigm of conservation based on reservation of parcels of land. However, wetlands are dependent on water that is seldom adequately protected. Intergovernment co-operation should protect the entire catchment of the Paroo River from major diversions and stop further development on the Warrego River. This would do more for the conservation of wetlands than the formal reservation of small parts of their catchments.

Ecological attributes and conservation of dasyurid marsupials in New South Wales, Australia

Abstract: This paper outlines the status of dasyurid marsupials in New South Wales, Australia, and then compares the ecological attributes of threatened and non-threatened species. Of the 21 species recorded in the state since European settlement, eight are protected but not threatened, 10 are listed or proposed for listing as vulnerable or endangered, and three are presumed extinct. Status was not related to diet, habit or habitat. However, species weighing <35 g are less likely to be threatened than heavier species, while species occupying a single region are more likely to be threatened than species occurring in two or more regions. All vulnerable and endangered species occur at least partly in reserves and other areas of protected land, but are likely to be affected by one or more threatening processes. These processes differ regionally, with larger species (=175 g) being affected by a greater range of threats than very small species (<15 g). We propose a programme of survey, research, management and education to promote and sustain recoveries.

Doing Science Design, Analysis and Communication of Scientific Research

Abstract: THE growing number of people interested in science has created a need for an introductory book linking the actual research with the communication of the results. Doing Science is a book that attempts to do this without losing the essentials of each stage of the scientific method. It aims to show that these stages are not separate topics, but a combined unit setting the framework for scientific work.

The conflict between animal welfare and conservation

Abstract: IT is a measure of a civilized society that its inhabitants are concerned about the welfare of animals. Furthermore, there has been increasing concern about conservation, especially of threatened species. In many countries, including Australia, there is now extensive legislation to cover both animal welfare and the protection of many native species. Whereas welfare deals with individuals, conservation is concerned with populations. Thus, researchers must always weigh potential gains in knowledge against the consequences of their activities (see Gaunt and Oring 1997). Ironically, management for conservation often involves the killing of individuals of one species, typically predators or competitors, for the good of the population of another species. In Australia many of the animals that are killed are feral (e.g., foxes and rabbits). As some feral species also have major impacts on agriculture, the need to control their numbers is generally accepted and attracts little attention. However, there is mounting evidence that a number of native species may pose threats to declining or endangered native species. For instance, Pied Currawongs Strepera graculina are known to be nest predators and Noisy Miners Manorina rnelanocephala are known to drive most other small birds from the vicinity of their colonies. Many woodlarid birds are experiencing long-term decline and it has been hypothesized that Pied Currawongs and Noisy Miners contribute to this decline (Ford et al. 2001). We set out to test experimentally the hypothesis that Pied Currawongs are major nest predators.

Seasonal and landscape differencesin the foraging behaviour of the Rufous Treecreeper Climacteris rufa

Abstract: The insectivorous Rufous Treecreeper Climacteris rufa has declined in abundance in the agricultural regions of southwestern Australia. Examining its foraging behaviour is fundamental to identifying important foraging resources and how landscape change (e.g., fragmentation and disturbance) may affect foraging effectiveness. We studied seasonal and landscape differences in the foraging behaviour of the treecreeper in the wheatbelt of Western Australia. Foraging data were collected in autumn and winter in a large, unfragmented landscape and in a highly modified agricultural landscape (winter only) with grazed and ungrazed woodland patches. The ground layer was the most common foraging location used by the species, although there were seasonal differences in foraging behaviour in the unfragmented landscape. In autumn, treecreepers foraged primarily on trees (56% of observations) with a shift to mostly ground foraging in winter (72-74%). The species also preferentially foraged on larger trees. Foraging behaviour differed between the two landscapes within the same season. Treecreepers foraged less on the ground in the agricultural landscape (52%), but this difference is attributed mainly to the low percentage of ground foraging in ungrazed (43%) compared to grazed (60%) patches. In winter and early spring, the ground layer is an important foraging substrate for the Rufous Treecreeper and other woodland birds. Changes to the ground layer and associated invertebrate communities through habitat disturbance (e.g., weed invasion) may be detrimental to the foraging effectiveness of ground-foraging insectivores. This is a potential contributing factor to the decline of these species in the agricultural regions of southern Australia.

Temperate Eucalypt Woodlands in Australia: Biology, Conservation, Management and Restoration

Abstract: TEMPERATE Eucalypt Woodlands in Australia provides a comprehensive account of the biology, conservation and management and rehabilitation of one of the most important broad-vegetation types in Australia. The book is divided into four sections, the distribution and status of woodlands, threats, processes and management, regeneration and repair and finally socio-economic issues. Chapters cover a wide range of issues including tree decline, the role of soil fungi, the impacts and opportunities of fuel wood extraction and the attitude of landholders to environmental issues. The characteristics and current status of the temperate woodlands in each state are separately covered in individual chapters. Contributions are included from many different authors and from sources across Australia and for the first time students, researchers or the general public can access information on this fascinating subject. Extensive bibliographies attached to each chapter will enable the reader to pursue topics in greater detail.

The influence of recent changes in public sector management on biodiversity conservation

Abstract: Over the last 15 years increasing emphasis has been placed worldwide on biodiversity conservation. During the same period, the public sector which carries much of the responsibility for biodiversity conservation has experienced, in OECD countries, a revolution in management practices. Managerialism has emerged, modeled on private sector philosophies including economic efficiency and accountability. Managerialism and an increased emphasis on biodiversity conservation have occurred over the same period, however, the links have not been investigated. This paper explores the influences of managerialism on biodiversity conservation in three Western Australian state public sector agencies: the Department of Conservation and Land Management; Water and Rivers Commission; and Water Corporation. Each of the agencies has embraced managerialism in a different way, modifying elements to match organizational mandates. All have become conscious of managing political risk. Other managerialist influences include increased emphases on contracting, strategic planning and performance reporting. Understanding managerialism helps managers and researchers manage the socio-political environment to achieve desired outcomes, in this case biodiversity conservation. Managerial skills such as diplomacy, administration, decision making and leadership are essential if managers and researchers are to influence decision making and progress through agencies, given that technical expertise is no longer sufficient.

Impacts of Agricultural Land Use on the Floristics, Diversity and Life-form Composition of a Temperate Grassy Woodland

Abstract: This opportunistic study examines the impacts of cropping and grazing management on a eucalypt grassy woodland in northern Victoria. The woodland is an area of uniformity in abiotic attributes, and with significant anecdotal similarity in pre-European floristic composition and abundance. Permanent vegetation quadrats were established within the now named Dookie Bushland Reserve, a 270 ha remnant of White and Grey Box grassy woodland located at Dookie College in northern Victoria. Density and cover for all species, as well as life form type, were evaluated within quadrats in 1992, when agricultural land uses ceased and conservation management was instigated. Results indicate that agricultural impact over a 27 year period had contributed to significant declines in the number and cover of indigenous species, and had resulted in the significant increase in the number and cover of introduced species. The loss of shrub species, juvenile eucalypts, and the dominance of tussock-forming indigenous grasses with increased agricultural impact was observed. Individual species responded differently to increased agricultural impacts. Some species, particularly non-tussock forming indigenous grasses and introduced annuals, were promoted in establishment and cover by increased impact, while others, most notably Orchidaceae and Liliaceae, were intolerant of any impact. Certain groups of indigenous species, particularly the Asteraceae and tussock forming indigenous grasses, were reduced significantly in cover by increasing impact. Grazing increased proportions of therophytic (annuals) and/or hemicryptophytic (rosette-forming) forbs, while lesser impacted sites contained a greater diversity of forbs, greater evenness across life form types, and greater proportions of perennial phanerophytes, chamaephytes and cryptophytes, and with fewer therophytes.

A direct comparison of trapping and spotlight searches for capturing Brown Tree Snakes on Guam

Abstract: Brown Tree Snake populations on Guam are controlled in the vicinities of cargo staging and transport areas to prevent their dispersal from Guam, and their populations are controlled in areas where endangered species are to be reintroduced. Trapping and night-time spotlight searches of fences are the two primary Brown Tree Snake population reduction methods used on Guam. We conducted a three month study comparing Brown Tree Snake captures by spotlighting fences to captures by trapping. Traps were placed either on the edge of the forest paralleling the fences, or they were hung on the fences. Applications of each capture method followed the standard practices used within the operational programme charged with deterring the spread of Brown Tree Snakes from Guam. We found captures by trapping to exceed those by spotlighting each month, but the captures by trapping decreased substantially over time, while those by spotlighting did not. We detected no differences statistically between numbers of captures taken by traps hung on the forest edge versus those hung on the fences. We found no differences in sizes of Brown Tree Snakes captured by spotlighting and trapping, based on average snout-vent length (SVL) or the distribution of SVLs. We feel that the two capture methods complement each other in an integrated pest management programme.

Case history studies of the effects of vegetation succession and fire on the moth Fraus simulans (Lepidoptera, Hepialidae) and its food plant, the sedge Ecdeiocolea monostachya (Ecdeiocoleacea) in the Western Australian Wheatbelt: implications for retenti

Abstract: Field observations of the effects of succession of vegetation, grazing by the moth Fraus simulans on the sedge Ecdeiocolea monostachya in a long unburnt area, the post-fire survival and regeneration of established tussocks and the survival of seedlings germinating in the first winter following burning are presented. There was considerable post-fire mortality of the established tussocks and in only one of the three areas burnt did any of the seedlings survive successive summer droughts. Surviving seedlings did not replace the tussocks killed by the burning. The possible effects of fire, drought and insect grazing on the biotic composition of small reserves are discussed. It is suggested that the information presented provides a basis for a formal decision process for risk assessment when managing reserves for retention of biodiversity and fire hazard reduction.

Cattle, mining or fire? The historical causes of recent contractions of open forest in the wet tropics of Queensland through invasion by rainforest

Abstract: Changes to Aboriginal fire regimes since European occupation are thought to have affected the range and demographic structure of many vegetation communities. This study shows a contraction by 49% of the area of fireprone open forest through rainforest invasion between 1945 and 1991-94 in the northern wet tropics of Queensland, Australia. Relative Growth Rates (RGR) for open forest areas varied from -0.112 to -0.005. Collaborative historical research with the Aboriginal traditional owners, the Kuku-Yalanji people, investigated possible linkages with alterations to their fire practices. A multiplicity of human impacts is associated with the measured vegetation change, including clearing for agriculture and mining, logging for timber and firewood, and the introduction of cattle and horses. Some rainforest expansion since 1945 represents a recovery following clearing from earlier mining operations. Contraction of open forest through rainforest invasion was most rapid (RGR = -0.124) where there was a continuation of Aboriginal fire management with cattle grazing. The contraction of open forest was nine times slower in an ungrazed area (RGR = -0.005) than in a nearby area grazed by horses (RGR = -0.045). Aboriginal fire regimes may act synergistically with cattle or horse grazing to accelerate the invasion of rainforest into open forest. Management prescriptions currently focus on active fire management to prevent further open forest contraction. However, fire management may have unexpected outcomes when rainforest-open forest dynamics are complicated by recent historical factors such as cattle grazing, logging, and tin mining, and possible synergies between these factors and fire regimes. Managers need to understand the histories of particular sites when formulating plans, and monitor the consequences of their actions to enable an adaptive approach.

Abundance and management of Mariana Fruit Bats and feral ungulates on Anatahan, Mariana Islands

Abstract: A survey of Mariana Fruit Bats Pteropus mariannus and feral ungulates was conducted on Anatahan, Mariana Islands, in July 1995. We estimated that a population of 1 902-2 136 bats persists on the island, based on a combination of direct colony counts, departure counts, and station counts of non-colonial animals. Our data suggest that bat numbers have declined since the last surveys were made in 1983 and 1984. We located seven colonies, which held approximately 85-92% of the total population. Most colonies and foraging animals were associated with native forest or isolated native trees in other habitats. Bats fed on five species of plants, with the fruit of Pandanus tectorius eaten most frequently. Anatahan supports a very large Feral Goat Capra hircus population estimated at roughly 5 000-6 000 animals. Feral Pigs Sus scrofa are less common. Both species cause severe damage to plant communities of the island. We recommend that a legal hunting programme for fruit bats be deferred until 1) population censuses on neighbouring islands are completed and it is determined that bat populations can sustain harvesting, 2) habitat degradation is reversed through the control of feral animals, and 3) illegal hunting is curtailed.

Biodiversity of canopy arthropods in Jarrah forest of south-west Western Australia: review of ecological theory and conservation management

Abstract: A theory proposed in 1996 by Recher, Majer and Ganesh linking biodiversity of forest canopy arthropods to site productivity is analysed. Available evidence from Jarrah Eucalyptus marginata forest is inconsistent with this model. We instead propose that increased habitat variety and temperature and rainfall clines are the major environmental factors that determine canopy arthropod species richness. Biodiversity gradients for mammal, landbird and reptile species across south-west Western Australia appear to provide an appropriate model for forest insect faunas. These gradients predict that the most diverse canopy fauna should occur in the eastern Jarrah and Wandoo forests. Precautionary forest management policies and procedures currently in place to conserve the poorly collected and inadequately known arthropod fauna of tree crowns in Jarrah forest are summarized and discussed. In essence, these maximize habitat diversity at landscape scales. Major conservation threats are considered to be factors that reduce leaf area at large spatial (Phytophthora infection) and temporal scales (summer wildfire and defoliating insect outbreaks). Logging is not considered significant because it is constrained to small spatial scales (10 ha for the most extreme treatment) and long return times (2-3 decades).

Are economic instruments the saviour for biodiversity on private land

Abstract: IT is the year 2020. Farmers have broken the record for the number of threatened species recorded on private property in a single year. Five species of woodland bird are removed from threatened species lists. The area of private land managed for biodiversity now exceeds the area of public land managed for biodiversity. Farm income from biodiversity is greater than wheat. The Biodiversity Growers Association calls for the environment levy on Australian taxpayers to be increased. Drought relief payments are at an all time low. Retiring head of government conservation agency described as "visionary" by farmers' representatives.

Culture, commerce, and international co-operation in the global recovery of Polar Bears

Abstract: About thirty years ago, Polar Bears were considered to be severely depleted over most of their international range. In 1973, the five range states signed an international treaty that allowed continued hunting and sale of skins by some customary users whose subsistence had historically involved commercial trade in the products of the hunt. There have been multiple benefits associated with this continued consumptive use, including Polar Bear population recovery throughout the species extensive range, enhanced international research and management co-operation, progressive involvement of the user communities in management initiatives, and excellent regulatory compliance. This successful regional and international conservation programme provides a model for managing other highly migratory (and difficult to monitor), culturally and commercially valuable species.

Prostanthera junonis Conn (LAMIACEAE); is recovery possible?

Abstract: Prostanthera junonis is an endangered plant from the Somersby plateau west of Gosford, New South Wales. Most populations occur in sites modified by clearing or adjacent to developments. This paper examines the current status and recovery efforts for this species in the light of research to date. Studies undertaken indicate that the species has the reproductive ecology expected of a colonising species. Autogamy, a low pollen/ovule ratio, higher seed set in open sites compared with densely vegetated sites, clonal growth, a long flowering period and flowering by young plants were recorded for the species. It is predicted that these reproductive traits should help the population recover from clearing. Comments on recovery planning are made.

You are the Earth

Abstract: THE communication of basic environmental principles to children should begin at an early age to solidly embed the awareness of human connectivity to the Earth. Everyone is connected to the Earth by the air, the water, and the food they consume. Thus when we degrade the earth, we inevitably degrade ourselves. This is Suzuki and Vanderlinden's strongest message.

Bryophytes and the morphospecies concept: a comparison of novice and expert sorting

Abstract: The exclusion of bryophytes (mosses, liverworts and hornworts) from the majority of impact assessment and monitoring studies is probably due to key characters being microscopic and difficult to work with given limited resources. Coarse morphological groups have been used in rangeland monitoring where a level of identification accessible to amateurs successfully separated different soil crust groups. However, there has been only one study of the feasibility of using a morphospecies approach for bryophytes. In this study, I investigate a different environment with a level of species richness that is more typical of many dry sclerophyll forests. Novices collected the specimens as well as sorted, which is a realistic replication of the task facing biologists when undertaking biodiversity surveys or establishing monitoring studies. Here I compare the efforts of 65 novices (second-year biogeography students) and myself in sampling an area of sub-alpine Tasmania. I was interested quantifying the abilities of this group rather than a smaller, more experienced group because a range of interests and abilities were represented. The results is informative as to the feasibility of including bryophytes in monitoring projects where the focus of the project may be on other groups and the field officer has little experience with bryophytes.

Community characteristics, species diversity and management of middle-mountain moist evergreen broad-leaved forest in the Ailao Mountains, Southwestern China

Abstract: Middle-mountain, moist, evergreen broad-leaved forest is an important forest type of Yunnan Province, SW China. Species composition, vegetation structure, physiognomy, diversity and phenology of this forest in Ailao Mountain were surveyed. The forest has characteristics common to subtropical, evergreen broad-leaved forest elsewhere in China. It also has local features associated with the middle-mountain location at lower latitude and higher altitude, including relatively high humidity and mild temperatures all year. The forest is dominated by species unique to Yunnan. There is a well-developed bamboo layer, fewer megaphanerophytes, more microphylls, more lianas and more epiphytes than in other subtropical evergreen broad-leaved forests. Floristically, elements of tropical, temperate and endemic flora comprise 54, 43 and 3% of the genera, while tropical, temperate and endemics account for 22, 38 and 40% of the species in the forest. Two-thirds of the trees and shrubs have leaves with drip tips in varying degree. The phenological rhythm of the forest is similar to that of a tropical forest, with plants flowering and bearing fruits almost throughout the year. Species diversity is richer than that of other evergreen broad-leaved forests in central Yunnan. Some management strategies and priorities for this forest are suggested.

Veterinary Conservation Biology

Abstract: IN July, I attended the symposium at Taronga Zoo on "Wildlife Health and Management in Australasia" organized by the Australian Association of Veterinary Conservation Biologists, the World Association of Wildlife Veterinarians, the Wildlife Disease Association: Australasian Section, and the Wildlife Society of the New Zealand Veterinary Association. It is worth listing all these, not just because they organized a great symposium, but because I had never heard of any of them before and suspect I may not be alone. Comprehensively, these veterinary associations are concerned about conservation biology, as was the symposium. The symposium, the Proceedings of which will be reviewed in a later edition of Pacific Conservation Biology, had sections on "conservation biology in Australasia", "sustainable utilization of wildlife", "wildlife translocation", "marine wildlife" and "wildlife health", all of which embraced issues that are topical among non-veterinary conservation biologists in the Pacific Region. However, the spin was different and, for me, eye-opening.

Conservation of relict potato Solanum tuberosum cultivars within Maori communities in New Zealand

Abstract: It is generally accepted by scholars that potatoes were first introduced to New Zealand in the late 18th century by Captain James Cook and the French explorer, Marion du Fresne. Further introductions of potatoes from a variety of sources including possible direct introductions from South America, followed into the 19th century. Maori were quick to recognize the advantages that these new introductions had over their traditional food crops including kumara (sweet potato) Ipomoea batatas and Taro Colocasia esculentum both of which they introduced from east Polynesia some 800-100 years previously. Potatoes soon became a staple item in the Maori diet and an important trade commodity and by the mid-19th century they were growing thousands of hectares of potatoes for that purpose. The various cultivars that were introduced were given Maori names and many of these early types are still grown by Maori, having been passed down through families for many generations. With their deep set eyes, often knobbly irregular shape, "open" leaves and colourful tubers these "Maori Potatoes" are quite distinctive in appearance from modern potatoes and some retain many of the features of Solanum tuberosum subsp. andigena types. This paper discusses the adoption of the potato by Maori, the effects it had on Maori society and the perpetuation of the early cultivars within Maori families and communities. This examination of an introduced crop plant and its intersection with an indigenous people is essentially an ethnobotanical study which in addition to its botanical and anthropological foci includes elements of Matauranga Maori (traditional Maori knowledge) history, geography and horticulture. The preservation of these old potato cultivars by generations of Maori people has made a valuable contribution to conservation of biological diversity.