Modeling spatiotemporal dynamics of outbreaking species: influence of environment and migration in a locust.

Future climate change likely to reduce the Australian plague locust (Chortoicetes terminifera) seasonal outbreaks

Locusts and grasshoppers cause considerable economic damage to agriculture worldwide. The Australian Plague Locust Commission uses multiple pesticides to control locusts in eastern Australia. Avian exposure to agricultural pesticides is of conservation concern, especially in the case of rare and threatened species. The aim of this study was to evaluate the probability of pesticide exposure of native avian species during operational locust control based on knowledge of species occurrence in areas and times of application. Using presence-absence data provided by the Birds Australia Atlas for 1998 to 2002, we developed a series of generalized linear models to predict avian occurrences on a monthly basis in 0.5 degrees grid cells for 280 species over 2 million km2 in eastern Australia. We constructed species-specific models relating occupancy patterns to survey date and location, rainfall, and derived habitat preference. Model complexity depended on the number of observations available. Model output was the probability of occurrence for each species at times and locations of past locust control operations within the 5-year study period. Given the high spatiotemporal variability of locust control events, the variability in predicted bird species presence was high, with 108 of the total 280 species being included at least once in the top 20 predicted species for individual space-time events. The models were evaluated using field surveys collected between 2000 and 2005, at sites with and without locust outbreaks. Model strength varied among species. Some species were under- or over-predicted as times and locations of interest typically did not correspond to those in the prediction data set and certain species were likely attracted to locusts as a food source. Field surveys demonstrated the utility of the spatially explicit species lists derived from the models but also identified the presence of a number of previously unanticipated species. These results also emphasize the need for special consideration of rare and threatened species that are poorly predicted by presence-absence models. This modeling exercise was a useful a priori approach in species risk assessments to identify species present at times and locations of locust control applications, and to discover gaps in our knowledge and need for further focused data collection.

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Processed Landsat multispectral data were used to determine areas in the Riverina region of New South Wales, Australia, in which eggs were likely to have been laid by swarms of the Australian plague locust ( Chortoicetes terminifera (Walker)), which invaded the region at the end of March 1987. A map was produced from the processed data with potential eggbed areas highlighted, which could be used for field survey purposes in the spring and summer when hatching started. The results showed that > 95 per cent of all nymphal band targets were in the areas defined by a normalized difference vegetation index as being those where vegetation growth had resulted from rain during March. Furthermore, a maximum-likelihood classification using a known eggbed location as a training area, produced an excellent correlation with locusts hatching in September/October 1987. The results are discussed in relation to the future operational use of such techniques by the Australian Plague Locust Commission.

BackgroundThe northern part of India harbours a great diversity of medicinal plants due to its distinct geography and ecological marginal conditions. The traditional medical systems of northern India are part of a time tested culture and honored still by people today. These traditional systems have been curing complex disease for more than 3,000 years. With rapidly growing demand for these medicinal plants, most of the plant populations have been depleted, indicating a lack of ecological knowledge among communities using the plants. Thus, an attempt was made in this study to focus on the ecological status of ethnomedicinal plants, to determine their availability in the growing sites, and to inform the communities about the sustainable exploitation of medicinal plants in the wild.MethodsThe ecological information regarding ethnomedicinal plants was collected in three different climatic regions (tropical, sub-tropical and temperate) for species composition in different forest layers. The ecological information was assessed using the quadrate sampling method. A total of 25 quadrats, 10 × 10 m were laid out at random in order to sample trees and shrubs, and 40 quadrats of 1 × 1 m for herbaceous plants. In each climatic region, three vegetation sites were selected for ecological information; the mean values of density, basal cover, and the importance value index from all sites of each region were used to interpret the final data. Ethnomedicinal uses were collected from informants of adjacent villages. About 10% of inhabitants (older, experienced men and women) were interviewed about their use of medicinal plants. A consensus analysis of medicinal plant use between the different populations was conducted.ResultsAcross the different climatic regions a total of 57 species of plants were reported: 14 tree species, 10 shrub species, and 33 herb species. In the tropical and sub-tropical regions, Acacia catechu was the dominant tree while Ougeinia oojeinensis in the tropical region and Terminalia belerica in the sub-tropical region were least dominant reported. In the temperate region, Quercus leucotrichophora was the dominant tree and Pyrus pashia the least dominant tree. A total of 10 shrubs were recorded in all three regions: Adhatoda vasica was common species in the tropical and sub-tropical regions however, Rhus parviflora was common species in the sub-tropical and temperate regions. Among the 33 herbs, Sida cordifolia was dominant in the tropical and sub-tropical regions, while Barleria prionitis the least dominant in tropical and Phyllanthus amarus in the sub-tropical region. In temperate region, Vernonia anthelmintica was dominant and Imperata cylindrica least dominant. The consensus survey indicated that the inhabitants have a high level of agreement regarding the usages of single plant. The index value was high (1.0) for warts, vomiting, carminative, pain, boils and antiseptic uses, and lowest index value (0.33) was found for bronchitis.ConclusionThe medicinal plants treated various ailments. These included diarrhea, dysentery, bronchitis, menstrual disorders, gonorrhea, pulmonary affections, migraines, leprosy. The ecological studies showed that the tree density and total basal cover increased from the tropical region to sub-tropical and temperate regions. The species composition changed with climatic conditions. Among the localities used for data collection in each climatic region, many had very poor vegetation cover. The herbaceous layer decreased with increasing altitude, which might be an indication that communities at higher elevations were harvesting more herbaceous medicinal plants, due to the lack of basic health care facilities. Therefore, special attention needs to be given to the conservation of medicinal plants in order to ensure their long-term availability to the local inhabitants. Data on the use of individual species of medicinal plants is needed to provide an in-depth assessment of the plants availability in order to design conservation strategies to protect individual species.

The impact of climatic variations on peritoneal dialysis (PD)-related peritonitis has not been studied in detail. The aim of the current study was to determine whether various climatic zones influenced the probability of occurrence or the clinical outcomes of peritonitis. Using ANZDATA registry data, the study included all Australian patients receiving PD between 1 October 2003 and 31 December 2008. Climatic regions were defined according to the Köppen classification. The overall peritonitis rate was 0.59 episodes per patient-year. Most of the patients lived in Temperate regions (65%), with others residing in Subtropical (26%), Tropical (6%), and Other climatic regions (Desert, 0.6%; Grassland, 2.3%). Compared with patients in Temperate regions, those in Tropical regions demonstrated significantly higher overall peritonitis rates and a shorter time to a first peritonitis episode [adjusted hazard ratio: 1.15; 95% confidence interval (CI): 1.01 to 1.31]. Culture-negative peritonitis was significantly less likely in Tropical regions [adjusted odds ratio (OR): 0.42; 95% CI: 0.25 to 0.73]; its occurrence in Subtropical and Other regions was comparable to that in Temperate regions. Fungal peritonitis was independently associated with Tropical regions (OR: 2.18; 95% CI: 1.22 to 3.90) and Other regions (OR: 3.46; 95% CI: 1.73 to 6.91), where rates of antifungal prophylaxis were also lower. Outcomes after first peritonitis episodes were comparable in all groups. Tropical regions were associated with a higher overall peritonitis rate (including fungal peritonitis) and a shorter time to a first peritonitis episode. Augmented peritonitis prophylactic measures such as antifungal therapy and exit-site care should be considered in PD patients residing in Tropical climates.

Recent studies have used occupancy models (OM) and ecological niche models (ENM) to provide a better understanding of species’ distributions at different scales. One of the main ideas underlying the theoretical foundations of both OM and ENM is that they are positively related to abundance: higher occupancy implies higher density and more suitable areas are likely to have more abundant populations. Here, we analyze the relationship between habitat use measured in terms of occupancy probabilities from OM and environmental suitability derived from ENM in three different Neotropical mammal species: Leopardus wiedii, Cuniculus paca, and Dasypus novemcinctus. For ENM, we used climatic and vegetation cover variables and implemented a model calibration and selection protocol to select the most competitive models. For OM, we used a single-species, single-season model with site covariates for camera-trap data from six different sites throughout the Neotropical realm. Covariates included vegetation percentage, normalized difference vegetation index, normalized difference water index, and elevation. For each site, we fit OM using all possible combinations of variables and selected the most competitive (ΔAICc < 2) to build an average OM. We explored relationships between estimated suitability and occupancy values using Spearman correlation analysis. Relationships between ENM and OM tended to be positive for the three Neotropical mammals, but the strength varied among sites, which could be explained by local factors such as site characteristics and conservation status of areas. We conjecture that ENM are suitable to understand spatial patterns at coarser geographic scales because the concept of the niche is about the species as a whole, whereas OM are more relevant to explain the distribution locally, likely reflecting transient dynamics of populations resulting from many local factors such as community composition and biotic processes.

Monitoring studies often use marked animals to estimate population abundance at small spatial scales. However, at smaller scales, occupancy sampling, which uses detection/nondetection data, may be useful where sites are approximately territories, and occupancy dynamics should be strongly correlated with population dynamics. Occupancy monitoring has advantages in that it is less expensive and invasive, and marked animals are not needed. Here, we used empirical data to determine whether and when change in occupancy is a good proxy for population change for a territorial species. As part of this overall goal, we also compared maximum‐likelihood estimates using a model‐averaging approach with a Bayesian MCMC approach. We used field data collected from 1993 to 2013 on three study areas for California spotted owls (Strix occidentalis occidentalis), a territorial species. Although correlations for trajectories of realized population change (Δt) between territory occupancy and Pradel models were moderate to high for Bayesian MCMC‐based estimates and high for model‐averaged estimates, magnitudes of the trajectories were different with the Pradel model reporting greater magnitudes of change. For the two areas showing a decline, Δt for the Pradel model was approximately 20–30% lower than for the occupancy model, and 25% higher in the area showing an increase. These differences can arise because the occupancy model is less sensitive, in that if two owls share a territory, the loss of one may be reflected in survival and, consequently in Δt by the Pradel model, but because the territory remains occupied it is not reflected by the occupancy model. Bayesian MCMC‐based and model‐averaged estimates of Δt were in close agreement in pattern (correlation ≥0.74) and magnitude (relative differences of last Δt were ≤5%) for both occupancy and mark–resight models. Results from the Pradel model may lead to conservation actions necessary to avoid high extinction or extirpation risk for small populations, while results from the territory occupancy model may result in status quo management. We found both Bayesian MCMC‐based and model‐averaged estimates of Δt robust approaches to evaluate population trends. However, we recommend the Bayesian MCMC approach for estimating risk (e.g., probability of declines) for retrospective analyses.

Predicting the distribution of Invasive alien species (IAS) using species distribution models is promising for conservation planning. To achieve accurate predictions, it is essential to explore species niche dynamics. New approaches are necessary for bringing this analysis to real conservation management needs. Using multi-site comparisons can provide great useful insights to better understand invasion processes. Exploring the fine-scale niche overlap between IAS and native species sharing a location can be a key tool for achieving the implementation of local species conservation actions, which can play a fundamental role in the global management of IAS. This can also increase society’s awareness of the threat of IAS. In this context, here, we explored two key research demands. First, we studied the large-scale niche dynamics of the invasive species Paraserianthes lophantha (Willd.) I.C. Nielsen’s considering different invaded areas. The analysis compared niches of the native range (South Western Australia) with the Australian invaded range (eastern Australia); the native range with the European invaded range, and its full Australian range (native plus invaded range) with the European invaded range. Second, we perform a fine-scale niche overlap analysis at landscape scale in Spain. We studied the niche overlap between P. lophantha and a species with remarkable conservation interest (Quercus lusitanica Lam). All the niche analyses were realized following a well-established ordination (principal component analysis) approach where important methodological aspects were compared and analyzed. Our multi-site study of P. lophantha large-scale niche dynamics detected niche shifts between the Australian ranges demonstrating that the species is labile and may potentially adapt to further European climate conditions and spread its invasive range. Comparative analysis between the European and the full Australian ranges supports that calibrate models including the Australian invasive information is promising to accurate predict P. lophantha European potential distribution. The fine-scale study of niche overlap further explained the potential of this IAS and can be used as a model example of how these local studies can be used to promote the implementation of conservation actions in situ as a complement to large-scale management strategies.

Determinations of environmental factors on interactive soil properties across different land-use types on the Loess Plateau, China

Rabbit populations were sampled regularly during 1962-64 at four sites in different climatic regions (subalpine, mediterranean, subtropical, and semi-arid) in eastern Australia. A total of 2981 rabbits were taken by shooting at night. Oocysts in the faeces were identified as Eimeria stiedae, E. media, E. perforans, E. irresidua, E. magna, E. piriformis, and E. exigua. Infections were highest and most frequent at the subalpine site, less at the sites with mediterranean and subtropical climates, and were not common at the semi-arid site. Regular seasonal fluctuations occurred at the subalpine and mediterranean sites, with troughs occurring in summer. Multiple regression analysis of oocyst count on several anatomical and climatic measurements showed that, except at the semi-arid site, oocyst count was significantly related to measurements highly correlated with host age, and to evaporation (during the preceding 8 weeks); at the semi-arid site rainfall was the only really significant factor. Differences between species of coccidia were small compared with the differences between sites.

Seasonal patterns in climatic conditions affect the life cycles and temporal patterns in the abundance of most temperate insect species. In tropical regions where there is no winter season, the situation may be different. For a better understanding of the evolution of seasonal life cycles, and the dynamics affecting temporal patterns in abundance of tropical insect populations and assemblages, it is important to study the life cycles of tropical insects and the presence or absence of seasonality in relation to climatic conditions. By reviewing studies on temporal patterns of abundance, this article examines the patterns of seasonality in adult tropical forest insects and discusses the variation in such patterns in various forest types. Seasonal and aseasonal patterns were found to be common in tropical dry and wet regions, respectively. In wet regions, which lack a distinctive dry season, there exists a wide variety of temporal patterns in addition to aseasonal patterns: distinctively seasonal and supra‐annual fluctuations in some insect species. Some of the problems of hidden ecological mechanisms underlying seasonal patterns in abundance are discussed, and the definition of seasonality in temporal patterns of insect abundance at a particular stage in the life cycle is considered. Methodological problems are also discussed.

The absence of chronic toxicity data for tropical marine waters has limited our ability to derive appropriate water quality guideline values for metals in tropical regions. To aid environmental management, temperate data are usually extrapolated to other climatic (e.g., tropical) regions. However, differences in climate, water chemistry, and endemic biota between temperate and tropical systems make such extrapolations uncertain. Chronic nickel (Ni) toxicity data were compiled for temperate (24 species) and tropical (16 species) marine biota and their sensitivities to Ni compared. Concentrations to cause a 10% effect for temperate biota ranged from 2.9 to 20 300 µg Ni/L, with sea urchin larval development being the most sensitive endpoint. Values for tropical data ranged from 5.5 to 3700 µg Ni/L, with copepod early–life stage development being the most sensitive test. There was little difference in temperate and tropical marine sensitivities to Ni, with 5% hazardous concentrations (95% confidence interval) of 4.4 (1.8–17), 9.6 (1.7–26), and 5.8 (2.8–15) µg Ni/L for temperate, tropical, and combined temperate and tropical species, respectively. To ensure greater taxonomic coverage and based on guidance provided in Australia and New Zealand, it is recommended that the combined data set be used as the basis to generate a jurisdiction‐specific water quality guideline of 6 µg Ni/L for 95% species protection applicable to both temperate and tropical marine environments. Environ Toxicol Chem 2020;39:2540–2551. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Schemes to produce permanent inland water surfaces in central Australia to ameliorate the climate in agricultural areas have been suggested since the late 19th century. A thorough examination of the expected meteorological response to such an imposed water expanse was undertaken by Warren (1945) and the general conclusion was that there would be limited change to the climate. Here we use data and techniques not available to Warren (1945) to assess the likely impact of large permanent inland water surfaces on Australian rainfall. Studies of the rainfall response to extensive areas of irrigation in other countries generally conclude that there is little discernible difference in the rainfall amount, and the rainfall pattern does not change. Inland Australia is arid, with strong potential evaporation and only intermittent rainfall from modifications to the large-scale flow, often linked with positive phases of the El Niño – Southern Oscillation (ENSO). ENSO is also strongly linked with rainfall in eastern Australia, most likely swamping any signal from an inland water source. The large-scale interaction between the atmosphere and the land surface in central Australia is weak, and is not affected by whether large lakes such as Lake Eyre are full. Both mesoscale and global climate models show that large water expanses do have local effects including a large local increase in surface latent heat flux and a decrease in temperature. In some cases this reduces rainfall over the water surface. The variable-resolution version of the CSIRO conformal cubic atmospheric model, with a fine grid of approximately 60 km over Australia, and the Melbourne University General Circulation Model are both used to assess the wider response to a large inland water expanse. Away from the imposed water expanse there is no consistent or significant response in rainfall anywhere in Australia. We conclude, as did Warren (1945) that there is no evidence that large-scale permanent water surfaces in inland Australia would result in widespread climate amelioration.

A WIDESPREAD outbreak of the migrating grasshopper, Chortoicetes terminifera, Walk., occurred in Australia during 1933–35. Reports show that, in South Australia, small, local swarms appeared during the summer 1932–33 in certain districts in the pastoral country about 150 miles north of the 10 in. annual isohyet (see Fig. 1). During 1933–34 swarms were widely distributed and in some areas extended about 100 miles south of this rainfall line. During 1934–35 they became generally distributed southwards over the agricultural areas of the State. These widespread invasions develop only at irregular intervals of several years; the presence of the insects in numbers, in the southern areas of the State, is temporary. Restricted outbreaks occur more frequently in certain areas situated immediately north of the 10 in. isohyet; in some instances the swarms may extend southwards into the wheat belt.