Austral Ecology最新文献

Nothofagus is a genus of 37 species of tree distributed across the Southern Hemisphere and has long been considered a taxon of fundamental importance for understanding the evolution and ecology of the forest ecosystems of the Southern Hemisphere. Using quantitative text analysis, we evaluated 65 years of research on this iconic genus. Since 1960, research publications about the Nothofagus have steadily increased. Network analysis and structural topic models indicate that over this period, research activity has been concentrated on three broad themes: (i) long-term vegetation history and palaeoecology, (ii) forest ecology and management, with the latter becoming more prevalent over time, and (iii) the taxonomy and ecology of species associated with Nothofagus. Efforts to understand the long-term evolution, dispersal, and history of the group continue to inform debates about the biogeography of the Southern Hemisphere. Over time, there have been changes in the geographic patterns of research activity, with it becoming increasingly concentrated in South America since around 2000, with a commensurate decline in Australia and Aotearoa-New Zealand. This change in geographic activity is also associated with a shift in focus. Research in South America has increasingly addressed applied questions, including the potential response of forests with a Nothofagus component to climate change and questions associated with the silvicultural use of the group. Some outstanding research gaps remain, especially regarding our understanding of the ecology of the 19 tropical members of the genus, most of which are scarcely mentioned in the literature. A number of these tropical Nothofagus are of conservation concern, making this lack of basic ecological and distributional information alarming.

The management and conservation of Australia's native forests has been highly contested for many decades. Since the 1970s, there have been major changes in the science underpinning and general perspectives on relationships between logging and forest biodiversity conservation. Science has quantified the impacts of logging operations on biodiversity at a range of scales – from the tree to stand, landscape, and ecosystem levels. It has also highlighted deficiencies in the protection of forest biodiversity, resulting in an expansion of the protected area network in forests, as well as changes in the way forests are managed. In this paper, I briefly discuss some of the changes in the understanding of logging impacts on biodiversity over the past ~50 years, particularly in terms of the array of contributions made by the esteemed ecologist Jamie Kirkpatrick. These include his contributions to the following: (1) the development of new ways of identifying the most important areas as places to reserve; (2) assessments of the conservation values, including world heritage values, of particular areas; (3) forest management change via his rigorous scientific appraisals of forest policies and legislative instruments such as Regional Forest Agreements (RFAs). Just as there have been enormous changes in the management and conservation of Australia's native forests over the past 50+ years, there will likely also be large changes in the coming 10–50 years. On that basis, I conclude with some commentary on future prospects for forest biodiversity conservation in Australia.

Large erect bryozoan colonies significantly enhance habitat complexity and associated biodiversity. Globally, bryozoan habitats are rare and at risk from anthropogenic disturbance. This paper presents two newly described bryozoan habitats in Western Port (~70 km south-east of Melbourne, Australia) and further expands our current knowledge of bryozoan habitats in other parts of the bay. These previously unknown bryozoan habitats discovered in the North and Western Arms of Western Port are comprised of laminar forms that develop erect plates, growing large (up to 1 m in circumference and vertical relief) robust colonies and structure on cobble and shelly sand substrates in areas of high current and moderate wave energy. These bryozoan habitats are composed of two main species: Adeonellopsis sulcata (Milne Edwards, 1836) and Celleporaria foliata (MacGillivray, 1888). Colonies of A. sulcata and C. foliata were in approximately equal proportional abundance at the North Arm site, while A. sulcata dominated the Western Arm site. These bryozoan habitats support a variety of marine life, with sponges, ascidians, molluscs, echinoderms, fishes, cnidarians, smaller, non-habitat-forming bryozoan species and macroalgae recorded. The North and Western Arm bryozoan habitats differ from previously described bryozoan reefs in the Eastern Arm, which are dominated by fenestrate species forming erect rounded foliose colonies arranged in continuous linear rows and patch reefs in shallower areas of the bay. The new findings add to an emerging understanding of bryozoan habitats in Western Port (a Ramsar site of international significance), which are unique in their ecophysical setting and one of only four known such habitats in Australia. Further research is needed to determine the extent of these habitats in Western Port, the biodiversity of associated species and ecological function.

The freshwater catfish Tandanus tandanus, a species with riverine populations listed as endangered in the Murray–Darling Basin, faces significant conservation challenges. Knowledge about early life stage dispersal remains limited, yet recent larval netting over two spawning seasons in the Macquarie River and adjoining irrigation channels fed by river pumps has revealed important insights. Freshwater catfish exhibited actipassive larval drift dispersal during a short spawning and nesting period in late austral spring to early summer (October–December), coinciding when water temperatures exceeded 21°C. Larvae (9.3–23.9 mm in standard length) were sampled in drifting ichthyoplankton nets set in the main flow of the river, as well as in adjacent irrigation channels. Sporadic low catch rates during the second season, likely due to flooding events, suggest potential disruption of nesting and spawning. Most freshwater catfish larvae were collected in overnight drift samples, indicating that drifting may be a nocturnal dispersal method. No larvae were captured in the still water areas using overnight light traps, further underscoring the potential importance of drift as a dispersal mechanism. The detection of frequent loss of larval individuals at unscreened pumps highlights a previously undocumented threat to the species during the larval life stage. Downstream larval drift contributes to the dispersal of early life stages of this species, but also increases susceptibility to entrainment at pump intakes and water diversions, which often operate at peak capacity during the larval drift period. Threats may be particularly pronounced in lowland rivers, where long reaches and higher levels of water extraction are likely to increase the risk of larval entrainment. This reinforces the need for modern fish protection screens at water diversions to mitigate this risk and help safeguard the future of freshwater catfish in the Murray–Darling Basin.

Kelp removes carbon from the oceans as it grows, with the potential for long-term removal of this ‘blue carbon’ through the sequestration of kelp detritus in deep offshore sediments and waters. However, understanding the magnitude of kelp's blue carbon potential requires more detailed information about kelp growth, biomass production, and detrital production through erosion and mortality. Here, hole punch growth measurements were conducted on tagged kelp plants to quantify these factors at multiple sites and in each season across 7° of latitude in New South Wales (NSW), Australia. Kelp biomass production varied among sites and among seasons, being higher over winter and spring than in summer and autumn and higher at Port Stephens than at Coffs Harbour, Batemans Bay and Eden. However, detrital production per plant, from kelp erosion and mortality, did not vary significantly among sites or seasons, although detrital production per unit area varied among sites with differences in kelp density. Overall, kelp growth and biomass and detrital production in NSW were comparable to those previously recorded in South Australia and Western Australia, although erosion was generally lower and mortality rates were generally higher than in Western Australia. This has important implications for management; the relatively uniform growth, biomass and detrital production across Australia indicates that, to maximise the blue carbon potential of kelp forests across Australia's Great Southern Reef, management should focus on preserving large, high-density kelp forests with high levels of detrital transport into deep offshore waters.

Understanding species responses to environmental changes is vital for effective conservation, especially in vulnerable regions like the Uruguayan Savannah in South America. This study focused on two often overlooked species: the South American coati (Nasua nasua) and Molina's hog-nosed skunk (Conepatus chinga). We deployed 90 camera traps across 15 sites in both Brazilian and Uruguayan sectors of the ecoregion to investigate the effects of land cover types (forests, grasslands, farmland and silviculture) and human density on species occupancy. Using occupancy models, we assessed activity patterns and landscape transition histories, generating innovative occupancy maps to inform conservation policies. The South American coati occupancy is positively correlated with forest areas but negatively with grasslands and crop farming (p < 0.05). In contrast, Molina's hog-nosed skunk exhibited a positive response to grasslands and crop farming, but a negative response to forests (p < 0.05). Estimated occupancy for coatis was 0.141 (0.041–0.420), while for skunks, it was 0.377 (0.200–0.610). Coatis were found only in seemingly pristine areas, whereas skunks adapted to previously human-used areas. Our findings highlight the urgent need for targeted conservation efforts for coatis while recognising the skunk's resilience to landscape alterations. This research provides critical insights for guiding conservation strategies in threatened ecoregions.