Recent publications in Zoology and Ecology
Problem solving is important for survival, allowing animals to access novel food resources or escape from predators. It was originally thought to rely on an animal’s intelligence; however, studies examining the relationship between individual cognitive ability and problem solving performance show mixed results, and studies are often restricted to only one cognitive and one problem solving task. We investigated the relationship between general cognitive ability and problem solving across multiple tasks in the fawn-footed mosaic-tailed rat Melomys cervinipes. We measured general cognitive ability across different domains (memory in an odour learning association task, recognition in a novel object recognition task, size discrimination using different sized pieces of food, and learning across multiple presentations of a food-baited activity board). We also measured problem solving across different contexts (food-baited puzzle boxes in home cage, obstruction task, and food-baited activity board in a novel arena). Mosaic-tailed rats showed a general cognitive ability, with average problem solving latency, memory ability, and learning in the tile task being correlated. As such, individuals that were able to remember an association and learned to solve the tile task solved the problems faster than individuals that could not remember or learn. Our results suggest that problem solving in mosaic-tailed rats likely relies on some forms of simple cognition, particularly memory, but could also depend on other traits, such as an individual’s persistence.
Cernusak, Lucas A., and De Kauwe, Martin G. (2022) Red light shines a path forward on leaf minimum conductance. New Phytologist, 233 (1). pp. 5-7.
Leaf minimum conductance sounds like a leaf trait that might not be very important – it is the minimum of something known to be positively associated with plant productivity. In other words, the higher the stomatal conductance, the faster the photosynthetic rate, because stomatal opening facilitates diffusion of CO2 into the leaf interior, and ultimately into chloroplasts. So why should we be concerned about the leaf minimum conductance, when it is most strongly associated with photosynthetic inactivity? The leaf minimum conductance comprises two diffusional pathways operating in parallel: the cuticular conductance, through the waxy cuticle that covers epidermal cells, and the residual stomatal conductance, through imperfectly closed stomata. As it turns out, there is a plethora of reasons why leaf minimum conductance is squarely on the radar of plant scientists.
Pike, Kyana N., Blake, Stephen, Cabrer, Freddy, Gordon, Iain J., and Schwarzkopf, Lin (2022) Body size, sex and high philopatry influence the use of agricultural land by Galapagos giant tortoises. Oryx, 56 (1). pp. 16-25.
As agricultural areas expand, interactions between wild animals and farmland are increasing. Understanding the nature of such interactions is vital to inform the management of human-wildlife coexistence. We investigated patterns of space use of two Critically Endangered Galapagos tortoise species, Chelonoidis porteri and Chelonoidis donfaustoi, on privately owned and agricultural land (hereafter farms) on Santa Cruz Island, where a human-wildlife conflict is emerging. We used GPS data from 45 tortoises tracked for up to 9 years, and data on farm characteristics, to identify factors that influence tortoise movement and habitat use in the agricultural zone. Sixty-nine per cent of tagged tortoises used the agricultural zone, where they remained for a mean of 150 days before returning to the national park. Large male tortoises were more likely to use farms for longer periods than female and smaller individuals. Tortoises were philopatric (mean overlap of farmland visits = 88.7 ± SE 2.9%), on average visiting four farms and occupying a mean seasonal range of 2.9 ± SE 0.3 ha. We discuss the characteristics of farm use by tortoises, and its implications for tortoise conservation and coexistence with people.
Ruaro, Renata, and Laurance, William F. (2022) Pending bill could devastate Brazil’s Serra do Divisor National Park. Nature Ecology & Evolution, 6. pp. 120-121.
The pending bill could also jeopardize commodity-export markets in Brazil that increasingly value environmental sustainability and Indigenous rights. Brazil has little justification for approving this pending legislation and an array of compelling reasons to defeat it.
Cartaxo-Pinto, Simone, Jackes, Betsy R., Marinho, Elysiane de Barros, Gonçalves-Esteves, Vania, and Mendonça, Cláudia Barbieri Ferreira (2022) Pollen analysis of representatives of the tribes Ampelopsideae, Cayratieae and Parthenocisseae and evolutionary history of Vitaceae genera. Palynology, 46 (2). 1998240. (In Press)
The family Vitaceae has a wide distribution, occurring in temperate, subtropical, and tropical climates. Vine members of the family thrive in different types of vegetation. Currently, the family includes five recognized tribes: Ampelopsideae, Cisseae, Cayratieae, Parthenocisseae, and Viteae. This study describes the pollen morphology of representatives of Ampelopsideae, Cayratieae, and Parthenocisseae. The other tribes are not described because they have been the subject of previous studies. The aim was to assess the relationships among the five tribes using multivariate analysis and to reconstruct the evolution of pollen characters using existing phylogenetic hypotheses. Specimens representing the three tribes were obtained from herbaria, treated by the acetolysis method, measured, photographed, and described using light and scanning electron microscopy. Results showed that pollen grains are medium (25–50 mm) in size, isopolar, tricolporate, and subprolate to prolate. Ornamentation varies between species. Multivariate analysis was based on quantitative characters, of which pollen diameters, apocolpium side, and polar area index were the most significant. Tracing of pollen characters showed that size, shape, and ornamentation are an evolutionary trend within the family. This investigation expands the palynological knowledge on representatives of Vitaceae tribes, contributing to future palynotaxonomic and evolutionary studies.
Cartaxo-Pinto, Simone, Paulo, Gabriel Henrique Cardoso, Jackes, Betsy, Gonçalves-Esteves, Vania, and Mendonça, Claudia Barbieri F. (2022) A palynological perspective on the tribe Viteae of the grape family (Vitaceae). Grana, 61 (1). pp. 27-44.
The tribe Viteae comprises about 200 species and is represented by the genera Vitis and Ampelocissus. Vitis is the most studied genus within the grape family (Vitaceae) because of the global economic importance of its fruits and derived products. This study examined the palynology of Ampelocissus and Vitis species belonging to the tribe Viteae to identify pollen characters that may contribute to the taxonomic and morphological characterisation of Ampelocissus. Pollen specimens were obtained from herbaria, treated by the acetolysis method, measured, photographed, and described using light and scanning electron microscopy. In the analysed species, pollen grains were isopolar or heteropolar, medium-sized, tricolporate, oblate spheroidal to subprolate. Ornamentation patterns differed among species, with examples of bireticulate, microreticulate, perforate, reticulate, and rugulate sexine. These characters were used for the development of a pollen key to the genera. Principal component analysis revealed that quantitative pollen characters were the most important for group discrimination. This study contributes to the palynological knowledge of some undescribed species and provides novel palynotaxonomic information on the family Vitaceae.
Binks, Oliver, Cernusak, Lucas A., Liddell, Michael, Bradford, Matt, Coughlin, Ingrid, Carle, Hannah, Bryant, Callum, Dunn, Elliot, Oliveira, Rafael, Mencuccini, Maurizio, and Meir, Patrick (2022) Forest system hydraulic conductance: partitioning tree and soil components. New Phytologist, 233 (4). pp. 1667-1681.
Soil–leaf hydraulic conductance determines canopy–atmosphere coupling in vegetation models, but it is typically derived from ex-situ measurements of stem segments and soil samples. Using a novel approach, we derive robust in-situ estimates for whole-tree conductance (ktree), ‘functional’ soil conductance (ksoil), and ‘system’ conductance (ksystem, water table to canopy), at two climatically different tropical rainforest sites. Hydraulic ‘functional rooting depth’, determined for each tree using profiles of soil water potential (Ψsoil) and sap flux data, enabled a robust determination of ktree and ksoil. ktree was compared across species, size classes, seasons, height above nearest drainage (HAND), two field sites, and to alternative representations of ktree; ksoil was analysed with respect to variations in site, season and HAND. ktree was lower and changed seasonally at the site with higher vapour pressure deficit (VPD) and rainfall; ktree differed little across species but scaled with tree circumference; rsoil (1/ksoil) ranged from 0 in the wet season to 10× less than rtree (1/ktree) in the dry season. VPD and not rainfall may influence plot-level k; leaf water potentials and sap flux can be used to determine ktree, ksoil and ksystem; Ψsoil profiles can provide mechanistic insights into ecosystem-level water fluxes.
Lach, Lori, Case, Dylan, Yeeles, Peter, and Hoskin, Conrad J. (2022) Invasive ants reduce abundance of small rainforest skinks. Biodiversity and Conservation, 31. pp. 739-755.
Invasive ants are among the world's most damaging invasive species, often directly or indirectly affecting native fauna. Insecticidal baits are the main method for suppressing or eradicating invasive ant populations, but their use must be considered against potential for unintended effects on native organisms. The invasive yellow crazy ant (Anoplolepis gracillipes) is widespread in the tropics, particularly on islands, where they have displaced a range of invertebrates. Effects of this ant on vertebrates, and in continental ecosystems generally, are less studied. We investigated the effects of yellow crazy ants and bait application on rainforest skinks and their invertebrate prey. We compared skink and skink prey abundance across four replicated rainforest site categories: high and low yellow crazy ant sites had both been baited but differed in yellow crazy ant activity; control sites had never had yellow crazy ants or been baited; and buffer sites had never had yellow crazy ants but had been baited. We recorded significantly lower abundance of two small skink species (Lygisaurus laevis and Saproscincus tetradactylus) in high yellow crazy ant sites compared to all other site categories. The differences persisted even after baiting reduced yellow crazy ant activity by 97.8% +/- 0.04% (mean +/- SD). A larger rainforest skink species (Carlia rubrigularis) was not negatively affected by yellow crazy ant invasion. Skink prey abundance was significantly lower in high yellow crazy ant sites compared to control sites and low yellow crazy ant sites, but not compared to buffer sites. These differences did not persist following baiting. We found no evidence that baiting negatively affects skinks or their invertebrate prey. Our data suggest that yellow crazy ants, but not the bait used to treat them, pose a direct threat to small rainforest skinks.
Zhang, Mingxi, Yang, Xihua, Cleverly, Jamie, Huete, Alfredo, Zhang, Hong, and Yu, Qiang (2022) Heat wave tracker: a multi-method, multi-source heat wave measurement toolkit based on Google Earth Engine. Environmental Modelling and Software, 147. 105255.
Under ongoing global warming due to climate change, heat waves in Australia are expected to become more frequent and severe. Extreme heat waves have devastating impacts on both terrestrial and marine ecosystems. A multi-characteristic heat wave framework is used to estimate historical and future projected heat waves across Australia. A Google Earth Engine-based toolkit named heat wave tracker (HWT) is developed, which can be used for dynamic visualization, extraction, and processing of complex heat wave events. The toolkit exploits the public long-term high-resolution climate datasets to developed nine heat wave datasets across Australia for extreme heat wave value analysis. To examine climate change on heat waves and how they vary in time and space, we also explore the probability and return periods of extreme heat waves over a period of 100 years. The datasets, toolkit and findings we developed contribute to global studies on heat waves under accelerated global warming.
Ma, Xiaolin, Deng, Zhixiong, Blair, David, Bi, Yonghong, Hu, Wei, and Yin, Mingbo (2022) Cyanobacterial bloom associated with a complete turnover of a Daphnia population in a warm-temperate eutrophic lake in Eastern China. Freshwater Biology, 67 (3). pp. 508-517.
The effect of cyanobacterial blooms on aquatic ecosystems has received wide attention, yet little is known about their impacts on zooplankton genetic structure. For 26 months (April 2012–May 2014), we monitored zooplankton in a warm-temperate ice-free lake in Eastern China, with an emphasis on seasonal population dynamics of the cladoceran, Daphnia galeata. There was a seasonal succession in the zooplanktonic community (composed of Cladocera, Copepoda, and Rotifera). Genetic analysis (based on 14 microsatellite loci) of the 21 monthly samples in which D. galeata was present demonstrated that several clones could successfully overwinter and/or persist for many months. However, all clones, including these long-lived clones, were completely replaced by new ones after October 2013, probably due to cyanobacteria blooms in that summer. A high clonal richness coupled with high turnover rate was observed in the D. galeata population overall, suggesting frequent sexual reproduction. Daphnia galeata experimentally fed with a diet of Microcystis aeruginosa (the most abundant toxic cyanobacterial species in the lake) had a substantially reduced survivorship, consistent with the field observations. Our findings highlight the changes of zooplanktonic population dynamics in terms of both community and clonal structure in a warm-temperate ice-free lake, and call for further investigation on ecological responses of zooplankton to cyanobacterial blooms.
Geyle, Hayley M., Hoskin, Conrad J., Bower, Deborah S., Catullo, Renee, Clulow, Simon, Driessen, Michael, Daniels, Katrina, Garnett, Stephen T., Gilbert, Deon, Heard, Geoffrey W., Hero, Jean-Marc, Hines, Harry, Hoffmann, Emily P., Hollis, Greg, Hunter, David A., Lemckert, Frank, Mahony, Michael, Marantelli, Gerry, McDonald, Keith R., Mitchell, Nicola J., Newell, David, Roberts, J. Dale, Scheele, Ben C., Scroggie, Michael, Vanderduys, Eric, Wassens, Skye, West, Matt, Woinarski, John C.Z., and Gillespie, Graeme R. (2022) Red hot frogs: identifying the Australian frogs most at risk of extinction. Pacific Conservation Biology. (In Press)
More than a third of the world’s amphibian species are listed as Threatened or Extinct, with a recent assessment identifying 45 Australian frogs (18.4% of the currently recognised species) as ‘Threatened’ based on IUCN criteria. We applied structured expert elicitation to 26 frogs assessed as Critically Endangered and Endangered to estimate their probability of extinction by 2040. We also investigated whether participant experience (measured as a self-assigned categorical score, i.e. ‘expert’ or ‘non-expert’) influenced the estimates. Collation and analysis of participant opinion indicated that eight species are at high risk (>50% chance) of becoming extinct by 2040, with the disease chytridiomycosis identified as the primary threat. A further five species are at moderate–high risk (30–50% chance), primarily due to climate change. Fourteen of the 26 frog species are endemic to Queensland, with many species restricted to small geographic ranges that are susceptible to stochastic events (e.g. a severe heatwave or a large bushfire). Experts were more likely to rate extinction probability higher for poorly known species (those with <10 experts), while non-experts were more likely to rate extinction probability higher for better-known species. However, scores converged following discussion, indicating that there was greater consensus in the estimates of extinction probability. Increased resourcing and management intervention are urgently needed to avert future extinctions of Australia’s frogs. Key priorities include developing and supporting captive management and establishing or extending in-situ population refuges to alleviate the impacts of disease and climate change.
Rifai, Sami W., De Kauwe, Martin G., Ukkola, Anna M., Cernusak, Lucas A., Meir, Patrick, Medlyn, Belinda E., and Pitman, Andy J. (2022) Thirty-eight years of CO2 fertilization has outpaced growing aridity to drive greening of Australian woody ecosystems. Biogeosciences, 19 (2). pp. 491-515.
Climate change is projected to increase the imbalance between the supply (precipitation) and atmospheric demand for water (i.e., increased potential evapotranspiration), stressing plants in water-limited environments. Plants may be able to offset increasing aridity because rising CO2 increases water use efficiency. CO2 fertilization has also been cited as one of the drivers of the widespread "greening" phenomenon. However, attributing the size of this CO2 fertilization effect is complicated, due in part to a lack of long-term vegetation monitoring and interannual- to decadalscale climate variability. In this study we asked the question of how much CO2 has contributed towards greening. We focused our analysis on a broad aridity gradient spanning eastern Australia's woody ecosystems. Next we analyzed 38 years of satellite remote sensing estimates of vegetation greenness (normalized difference vegetation index, NDVI) to examine the role of CO2 in ameliorating climate change impacts. Multiple statistical techniques were applied to separate the CO2-attributable effects on greening from the changes in water supply and atmospheric aridity. Widespread vegetation greening occurred despite a warming climate, increases in vapor pressure deficit, and repeated record-breaking droughts and heat waves. Between 1982-2019 we found that NDVI increased (median 11.3 %) across 90.5 % of the woody regions. After masking disturbance effects (e.g., fire), we statistically estimated an 11.7 % increase in NDVI attributable to CO2, broadly consistent with a hypothesized theoretical expectation of an 8.6 % increase in water use efficiency due to rising CO2. In contrast to reports of a weakening CO2 fertilization effect, we found no consistent temporal change in the CO2 effect. We conclude rising CO2 has mitigated the effects of increasing aridity, repeated record-breaking droughts, and record-breaking heat waves in eastern Australia. However, we were unable to determine whether trees or grasses were the primary beneficiary of the CO2-induced change in water use efficiency, which has implications for projecting future ecosystem resilience. A more complete understanding of how CO2-induced changes in water use efficiency affect trees and non-tree vegetation is needed.
Xie, Qiaoyun, Cleverly, Jamie, Moore, Caitlin E., Ding, Yanling, Hall, Christopher C., Ma, Xuanlong, Brown, Luke A., Wang, Cong, Beringer, Jason, Prober, Suzanne M., Macfarlane, Craig, Meyer, Wayne S., Yin, Gaofei, and Huete, Alfredo (2022) Land surface phenology retrievals for arid and semi-arid ecosystems. ISPRS Journal of Photogrammetry and Remote Sensing, 185. pp. 129-145.
Land surface phenology (LSP) plays a critical role in the regulation of photosynthesis, evapotranspiration, and energy fluxes. Significant progress has been made in extracting LSP information over large areas using satellite data, yet LSP retrievals remain a challenge over vast arid and semi-arid ecosystems because of sparse greenness, high variability and the lack of distinct annual patterns; for example, the MODerate Imaging Spectrometer (MODIS) Land Cover Dynamics Product MCD12Q2 that provides LSP metrics globally often failed to provide LSP information in these ecosystems. In this study, we used a modified threshold algorithm to extract LSP timing metrics, including the start, peak, and end of growing seasons, using the 16-day composite Enhanced Vegetation Index (EVI) time series from MODIS data. We applied this regionally customized algorithm across all arid and semi-arid climate regions of Australia (75% of the continental land area) encompassing shrublands, grasslands, savannas, woodlands, and croplands, extracting LSP metrics annually from 2003 to 2018, with up to two (phenology) seasons accounted for in each year. Our algorithm yielded an average of 64.9% successful rate of retrieval (proportion of pixels with retrieved LSP metrics) across 16 years in Arid and Semi-arid AUStralia (AS-AUS), which was a significant increase compared to the 14.5% rate of retrieval yielded in our study area by the global product and the major cause of the different performances between these two approaches was the different EVI amplitude restrictions utilized to avoid spurious peaks (i.e. EVI amplitude ≥ 0.1 used by the global product and peak EVI ≥ time series average EVI used by our algorithm). Gross primary productivity (GPP) measurements at OzFlux eddy covariance (EC) tower sites were used to cross-compare with the presence/absence of growing seasons detected by our algorithm, and 97% of our retrieved seasons matched with those extracted using EC data. Preliminary tests at five OzFlux sites showed that our algorithm was robust to view angle-induced sensitivity of the input data and showed similar performance when using EVI data calculated using MODIS Nadir BRDF-Adjusted Reflectance product. Our retrieved LSP metrics revealed that vegetation growth in arid ecosystems is highly irregular and can occur at any time of the year, more than once in a year, or can skip a year. The proportion of pixels with two growing seasons was found to be correlated with the average annual precipitation of the study area (p < 0.01), providing an estimation approach of LSP via rainfall. Our study improves the detection and measurement of vegetation phenology in arid and semi-arid regions by improving the spatial extend of LSP retrievals, which contributes to studies on LSP variations and dryland ecosystem resilience to climate change. More evaluation is planned for future work to assess and further improve the accuracy of the retrieved LSP metrics.
Poorter, Hendrik, Knopf, Oliver, Wright, Ian J., Temme, Andries A., Hogewoning, Sander W., Graf, Alexander, Cernusak, Lucas A., and Pons, Thijs L. (2022) A meta-analysis of responses of C3 plants to atmospheric CO2: dose–response curves for 85 traits ranging from the molecular to the whole-plant level. New Phytologist, 233 (4). pp. 1560-1596.
Generalised dose–response curves are essential to understand how plants acclimate to atmospheric CO2. We carried out a meta-analysis of 630 experiments in which C3 plants were experimentally grown at different [CO2] under relatively benign conditions, and derived dose–response curves for 85 phenotypic traits. These curves were characterised by form, plasticity, consistency and reliability. Considered over a range of 200–1200 µmol mol−1 CO2, some traits more than doubled (e.g. area-based photosynthesis; intrinsic water-use efficiency), whereas others more than halved (area-based transpiration). At current atmospheric [CO2], 64% of the total stimulation in biomass over the 200–1200 µmol mol−1 range has already been realised. We also mapped the trait responses of plants to [CO2] against those we have quantified before for light intensity. For most traits, CO2 and light responses were of similar direction. However, some traits (such as reproductive effort) only responded to light, others (such as plant height) only to [CO2], and some traits (such as area-based transpiration) responded in opposite directions. This synthesis provides a comprehensive picture of plant responses to [CO2] at different integration levels and offers the quantitative dose–response curves that can be used to improve global change simulation models.
Brodie, Sheryn, Towsey, Michael, Allen-Ankins, Slade, Roe, Paul, and Schwarzkopf, Lin (2022) Using a novel visualization tool for rapid survey of long-duration acoustic recordings for ecological studies of frog chorusing. Frontiers in Ecology and Evolution, 9. 761147.
Continuous recording of environmental sounds could allow long-term monitoring of vocal wildlife, and scaling of ecological studies to large temporal and spatial scales. However, such opportunities are currently limited by constraints in the analysis of large acoustic data sets. Computational methods and automation of call detection require specialist expertise and are time consuming to develop, therefore most biological researchers continue to use manual listening and inspection of spectrograms to analyze their sound recordings. False-color spectrograms were recently developed as a tool to allow visualization of long-duration sound recordings, intending to aid ecologists in navigating their audio data and detecting species of interest. This paper explores the efficacy of using this visualization method to identify multiple frog species in a large set of continuous sound recordings and gather data on the chorusing activity of the frog community. We found that, after a phase of training of the observer, frog choruses could be visually identified to species with high accuracy. We present a method to analyze such data, including a simple R routine to interactively select short segments on the false-color spectrogram for rapid manual checking of visually identified sounds. We propose these methods could fruitfully be applied to large acoustic data sets to analyze calling patterns in other chorusing species.
Fourcade, Yoan, Winsor, Leigh, and Justine, Jean-Lou (2022) Hammerhead worms everywhere? Modelling the invasion of bipaliin flatworms in a changing climate. Diversity and Distributions, 28 (4). pp. 844-858.
Aim: Alien species introduced into new ecosystems occasionally predate upon or outcompete native species. Land planarians (Geoplanidae) are a family of carnivorous Platyhelminthes among which several species are found outside their native range. Specifically, hammerhead flatworms originate from Asia and Madagascar but have now reached many new locations worldwide through the transport of exotic plants. Because they are predators of earthworms and snails, they are considered a potential threat to native ecosystems. In this context, to anticipate their potential impacts and to inform early preventative actions, it is necessary to know where these species could spread to in future, or where they might already be present but undetected. Location: Worldwide. Methods: Here, we used occurrence records from online databases and climatic and soil variables to model the potential distribution of five hammerhead flatworm species (Bipalium adventitium, B. kewense, B. pennsylvanicum, B. vagum and Diversibipalium multilineatum) that are known to occur outside their native range. Results: We demonstrate that precipitation is an important factor determining their distribution, which is in accordance with their known affinity for humidity. We show that some areas have the potential to be invaded by all five species, including regions that are relatively spared so far. This includes the River Plate basin in South America, which already harbours a diverse fauna of native terrestrial flatworms and which appears to also be a potential hotspot for the establishment of alien hammerhead flatworms. According to scenarios of future climate change, two species (B. kewense and B. vagum) that currently have the largest observed global range are predicted to further increase their potential distribution. Main conclusions: The results we report can be used to provide guidance for monitoring the potential sources of introduction of alien hammerhead flatworms in regions that are suitable, but which are not yet colonized.
Allen-Ankins, Slade, and Schwarzkopf, Lin (2022) Using citizen science to test for acoustic niche partitioning in frogs. Scientific Reports, 12. 2447.
The acoustic niche hypothesis proposes that to avoid interference with breeding signals, vocal species should evolve to partition acoustic space, minimising similarity with co-occurring signals. Tests of the acoustic niche hypothesis are typically conducted using a single assemblage, with mixed outcomes, but if the process is evolutionarily important, a pattern of reduced acoustic competition should emerge, on average, over many communities. Using a continental-scale dataset derived from audio recordings collected by citizen scientists, we show that frogs do partition acoustic space. Differences in calls were predominately caused by differences in spectral, rather than temporal, features. Specifically, the 90% frequency bandwidths of observed frog assemblages overlapped less than expected, and there was greater distance between dominant frequencies than expected. To our knowledge, this study is the first to use null models to test for acoustic niche partitioning over a large geographic scale.
Legge, Sarah, Rumpff, Libby, Woinarski, John C.Z., Whiterod, Nick S., Ward, Michelle, Southwell, Darren G., Scheele, Ben C., Nimmo, Dale G., Lintermans, Mark, Geyle, Hayley M., Garnett, Stephen T., Hayward-Brown, Brittany, Ensbey, Miki, Ehmke, Glenn, Ahyong, Shane T., Blackmore, Caroline J., Bower, Deborah S., Brizuela-Torres, Diego, Burbidge, Allan H., Burns, Phoebe A., Butler, Gavin, Catullo, Renee, Chapple, David G., Dickman, Christopher R., Doyle, Katherine E., Ferris, Jason, Fisher, Diana, Gallagher, Rachael, Gillespie, Graeme, Greenlees, Matt J., Hohnen, Rosie, Hoskin, Conrad J., Hunter, David, Jolly, Chris, Kennard, Mark, King, Alison, Kuchinke, Diana, Law, Brad, Lawler, Ivan, Lawler, Susan, Loyn, Richard, Lunney, Daniel, Lyon, Jarod, MacHunter, Josephine, Mahony, Michael, Mahony, Stephen, McCormack, Rob B., Melville, Jane, Menkhorst, Peter, Michael, Damian, Mitchell, Nicola, Mulder, Eri, Newell, David, Pearce, Luke, Raadik, Tarmo A., Rowley, Jodi J.L., Sitters, Holly, Spencer, Ricky, Valavi, Roozbeh, West, Matt, Wilkinson, David P., and Zukowski, Sylvia (2022) The conservation impacts of ecological disturbance: Time-bound estimates of population loss and recovery for fauna affected by the 2019-2020 Australian megafires. Global Ecology and Biogeography. (In Press)
Aim: After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019-2020 Australian megafires, we estimated population losses and recovery in fire-affected fauna, to inform conservation status assessments and management. Location: Temperate and subtropical Australia. Time period 2019-2030 and beyond. Major taxa: Australian terrestrial and freshwater vertebrates; one invertebrate group. Methods: From > 1,050 fire-affected taxa, we selected 173 whose distributions substantially overlapped the fire extent. We estimated the proportion of each taxon's distribution affected by fires, using fire severity and aquatic impact mapping, and new distribution mapping. Using expert elicitation informed by evidence of responses to previous wildfires, we estimated local population responses to fires of varying severity. We combined the spatial and elicitation data to estimate overall population loss and recovery trajectories, and thus indicate potential eligibility for listing as threatened, or uplisting, under Australian legislation. Results: We estimate that the 2019-2020 Australian megafires caused, or contributed to, population declines that make 70-82 taxa eligible for listing as threatened; and another 21-27 taxa eligible for uplisting. If so-listed, this represents a 22-26% increase in Australian statutory lists of threatened terrestrial and freshwater vertebrates and spiny crayfish, and uplisting for 8-10% of threatened taxa. Such changes would cause an abrupt worsening of underlying trajectories in vertebrates, as measured by Red List Indices. We predict that 54-88% of 173 assessed taxa will not recover to pre-fire population size within 10 years/three generations. Main conclusions We suggest the 2019-2020 Australian megafires have worsened the conservation prospects for many species. Of the 91 taxa recommended for listing/uplisting consideration, 84 are now under formal review through national processes. Improving predictions about taxon vulnerability with empirical data on population responses, reducing the likelihood of future catastrophic events and mitigating their impacts on biodiversity, are critical.
Riedel, Jendrian, and Schwarzkopf, Lin (2022) Variation in density, but not morphology, of cutaneous sensilla among body regions in nine species of Australian geckos. Journal of Morphology, 283 (5). pp. 637-652.
Skin sense organs, cutaneous sensilla, are a well-known feature of the integument of squamate reptiles and particularly geckos. They vary widely in morphology among species and are thought to be mechanosensitive, associated with prey capture and handling, tail autotomy and placement of the adhesive toepads in pad-bearing species. Some authors suggest that they may also sense abiotic environmental features, such as temperature or humidity. Here, we describe the morphology and distribution of cutaneous sensilla among body regions of nine Australian gecko species, in four genera. We hypothesised that if sensilla morphology was distinct, or sensilla density high, around the mouth, on the tail and on extremities, sensilla were likely used for these direct tactile functions. We found that sensilla morphology was uniform among body regions within species, but varied among species, while sensilla densities varied among species and body regions. In all species studied, sensilla density was highest on the labials and the dorsal tail scales and low on the feet, head and body, providing strong support for the hypothesis that sensilla serve tactile mechanoreceptive functions for prey capture and handling and for predator avoidance, but not for toepad placement. We suggest sensilla density may be explained by mechanoreception, whereas structure may be influenced by other factors.
Leng, Song, Huete, Alfredo, Cleverly, Jamie, Gao, Sicong, Yu, Qiang, Meng, Xianyong, Qi, Junyu, Zhang, Rongrong, and Wang, Qianfeng (2022) Assessing the impact of extreme droughts on dryland vegetation by multi-satellite solar-induced chlorophyll fluorescence. Remote Sensing, 14 (7). 1581.
Satellite-estimated solar-induced chlorophyll fluorescence (SIF) is proven to be an effective indicator for dynamic drought monitoring, while the capability of SIF to assess the variability of dryland vegetation under water and heat stress remains challenging. This study presents an analysis of the responses of dryland vegetation to the worst extreme drought over the past two decades in Australia, using multi-source spaceborne SIF derived from the Global Ozone Monitoring Experiment-2 (GOME-2) and TROPOspheric Monitoring Instrument (TROPOMI). Vegetation functioning was substantially constrained by this extreme event, especially in the interior of Australia, in which there was hardly seasonal growth detected by neither satellite-based observations nor tower-based flux measurements. At a 16-day interval, both SIF and enhanced vegetation index (EVI) can timely capture the reduction at the onset of drought over dryland ecosystems. The results demonstrate that satellite-observed SIF has the potential for characterizing and monitoring the spatiotemporal dynamics of drought over water-limited ecosystems, despite coarse spatial resolution coupled with high-retrieval noise as compared with EVI. Furthermore, our study highlights that SIF retrieved from TROPOMI featuring substantially enhanced spatiotemporal resolution has the promising capability for accurately tracking the drought-induced variation of heterogeneous dryland vegetation.
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