The impact of feral pigs (Sus scrofa) on an Australian lowland tropical rainforest

2011 ◽  
Vol 38 (5) ◽  
pp. 437 ◽  
Author(s):  
D. L. Taylor ◽  
L. K.-P. Leung ◽  
I. J. Gordon

Context Feral pigs are thought to damage tropical rainforests, but long-term impact has not yet been quantified. Aims This study aimed to determine the impact of feral pigs on soil, soil biota and vegetation in a lowland tropical rainforest in Daintree, north-eastern Australia, and the recovery following exclusion of feral pigs for 12 years. Methods Three types of plots were established in 1994: damaged plots were fenced in areas where severe damage had already occurred (‘fenced damaged’); undamaged plots were fenced in areas showing no evidence of damage (‘fenced undamaged’); and unfenced plots were randomly placed and remained at risk of damage (‘unfenced’). Key results In 2006, feral pigs had caused significant declines in seedling density, soil macroinvertebrate density and leaf litter cover, but not in soil pH, soil conductivity, invertebrate diversity, vegetation diversity, tree density, canopy cover or fallen log cover. Mean seedling density was lower in the fenced damaged plots than the fenced undamaged plots in 1994 but not in 2006. Other response variables also did not differ significantly between these two plot types, indicating that any damage caused by feral pigs to soil, soil biota or vegetation before 1994 was fully recovered within 12 years. Conclusions Our findings suggest that reductions in soil invertebrate density, seedling density, and leaf litter cover should be monitored regularly to inform feral pig management programs, and that these variables should be measured for objective assessment of the outcome of any feral pig control program. These declines may continue and be translated into the decline of trees and other keystone species or processes into the future. Implications The efficacy of feral pig control programs can be assessed using the quantitative analysis of the aforementioned variables. The results of such monitoring programs, in conjunction with baseline data, can provide an indication of ecosystem recovery and therefore the level of success achieved by the applied control measures.


Author(s):  
Amanda , E. Elledge ◽  
Clive , A. McAlpine ◽  
Peter , J. Murray ◽  
Iain , J. Gordon


2005 ◽  
Vol 32 (4) ◽  
pp. 297 ◽  
Author(s):  
Peter B. S. Spencer ◽  
Steve J. Lapidge ◽  
Jordan O. Hampton ◽  
John R. Pluske

In Australia, the feral pig (Sus scrofa) is a significant vertebrate pest that has an impact on agricultural production, public health and ecosystem integrity. Although feral pigs are controlled throughout much of their range, little is known about the impact that these control programs have had on the social biology, structure and the dispersal of pigs. To begin to address this, we collected demographic data and genetic samples from 123 feral pigs culled during a regional aerial shooting program over 33 pastoral properties in the semi-arid rangelands of southern Queensland, Australia. Sampling was carried out after two years of extensive control efforts (aerial 1080-baiting) and the samples therefore represented a controlled, persecuted population with a bias towards young animals. The analysis of 13 microsatellite loci suggested that females will accept multiple matings, females form loose mobs that appear to be highly dynamic social groups, and males will travel large distances between mobs. These data indicate that feral pigs in this population had a high level of social contact and form a single open population with no evidence of genetic (population) structuring. Such information may be important to integrate into management strategies, particularly the development of contingency plans regarding the spread of wildlife diseases.



2020 ◽  
Vol 41 (2) ◽  
pp. 309-324
Author(s):  
Meghdad Jourgholami ◽  
Masoumeh Ahmadi ◽  
Farzam Tavankar ◽  
Rodolfo Picchio

Ground-based skidding operations can lead to soil compaction and displacement, which could cause negative effects on forest soil. Hence, some efforts such as forestry best management practices (BMPs) must be implemented in the prone area to mitigate these possible impacts. Several materials and treatments have been adopted to suppress these adverse effects by increasing the ground cover. However, the effects of mulch treatments on runoff and sediment yield are inconclusive with a diverse range of effectiveness. For these reasons, in this research mulch treatments were tested as to determine how the application of organic mulch amendments such as straw and leaf litter and contour-felled logs would alleviate the runoff and sediment yield on machine operating trails and ensure successful hillslope stabilization. The aims of the study were to analyse and compare the effectiveness of leaf litter (LM) and straw mulch (SM) rate and different distances of contour-felled logs (CFL) to mitigate the runoff and sediment yield, and examine the impact of rainfall intensity on effectiveness of litter mulch, straw mulch, and contour-felled logs. Totally, 30 bounded runoff plots in the machine operating trails and four treatments including litter mulch (LMR1: 0.62, LMR2: 1.24, and LMR3: 1.86 kg m-2), straw mulch (SMR1: 0.45, SMR2: 0.92, and SMR3: 1.34 kg m-2), contour-felled logs (CFL10: 10, CFL20: 20, and CFL30: 30 m), and untreated area were established in triplicate with 4 m width and 100 m length. During the study period, the runoff and sediment yield in the untreated trails (U) were 2.36 mm and 11.84 g m-2. Straw (from 41.5 to 60.6%) and litter mulch (from 38.1 to 55.1%), and contour-felled logs treatments (from 70.8 to 88.1%) significantly decreased the runoff, compared to U treatment. Results show that mulch treatments with three different levels of Litter Mulch Rate, LMR1, LMR2, and LMR3 decreased mean sediment by 46.6, 64.0 and 71.8%, in the treatments with three different levels of Straw Mulch Rate, SMR1, SMR2, and SMR3 decreased mean sediment by 42.9, 62.1, and 69.9%, and in the treatments with three different distances of Contour-Felled Logs, CFL10, CFL20, and CFL30 decreased mean sediment by 90.6, 94.7 and 88.3% comparing to U, respectively. The relationships of the runoff and sediment responses to increasing mulching rate of litter and straw followed as negative logarithmic curves, but the decreasing-increasing trends were observed in runoff and sediment yield as the distance between contour-felled logs increased from 10 to 30 m. Polynomial regression equations were developed for predicting the runoff and sediment yield as a function of the application rate of litter and straw mulch and the distance between contour-felled logs, and rainfall intensity. We concluded that contour-felled logs treatment was more effective than both litter and straw mulch to mitigate the runoff, runoff coefficient, and sediment yield on machine operating trails. As a management measure, it could be possible to propose that the contour-felled logs with a distance of 20 m be prescribed to protect the machine operating trails from the negative effects of surface waterflow.



2006 ◽  
Vol 33 (5) ◽  
pp. 427 ◽  
Author(s):  
Brendan D. Cowled ◽  
Eddie Gifford ◽  
Michelle Smith ◽  
Linton Staples ◽  
Steven J. Lapidge

Conservative population declines of 73% were recorded in three independent feral pig populations in Welford National Park, Queensland, when PIGOUT® baits containing 72 mg of sodium fluoroacetate were used in a baiting program following prefeeding. Declines were measured using a prebaiting population census with remote cameras, followed by carcass recovery. The knockdown of susceptible feral pigs may have been higher than this, since any carcasses not recovered reduced the recorded efficacy. In addition, feral pigs know to have left the baiting area after trapping and telemetry-tagging, and subsequently not exposed to toxic baits, were included in the analysis. The use of remote cameras and carcass recovery appears to be a relatively accurate means of recording localised declines in feral pig populations. This method is applicable only when carcass recovery is possible, such as in open areas in the semi-arid rangelands. A decline of 86% of radio-tagged feral pigs attending bait stations was also recorded. Camera observations revealed no non-target consumption of baits. Measurement of sodium fluoroacetate–contaminated tissues from feral pigs showed that residues were too low to present a significant risk to recorded scavenging animals in the area. Some feral pigs vomited before death, with vomitus containing sodium fluoroacetate poison at high concentrations. No vomitus was consumed by non-target species. Almost all feral pigs were killed relatively rapidly after ingestion of sodium fluoroacetate and the signs observed in a small number of poisoned feral pigs did not indicate a significant welfare concern.



2000 ◽  
Vol 31 (3-4) ◽  
pp. 288-293 ◽  
Author(s):  
J. Dighton ◽  
A.S. Morale Bonilla ◽  
R. A. Jimînez-Nûñ ◽  
N. Martînez


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2984
Author(s):  
Hyeonju Lee ◽  
Min-Ho Koo ◽  
Byong Wook Cho ◽  
Yong Hwa Oh ◽  
Yongje Kim ◽  
...  

Hydraulic structures have a significant impact on riverine environment, leading to changes in stream–aquifer interactions. In South Korea, 16 weirs were constructed in four major rivers, in 2012, to secure sufficient water resources, and some weirs operated periodically for natural ecosystem recovery from 2017. The changed groundwater flow system due to weir operation affected the groundwater level and quality, which also affected groundwater use. In this study, we analyzed the changes in the groundwater flow system near the Geum River during the Baekje weir operation using Visual MODFLOW Classic. Groundwater data from 34 observational wells were evaluated to analyze the impact of weir operation on stream–aquifer interactions. Accordingly, the groundwater discharge rates increased from 0.23 to 0.45 cm/day following the decrease in river levels owing to weir opening, while the hydrological condition changed from gaining to losing streams following weir closure. The variation in groundwater flow affected the groundwater quality during weir operation, changing the groundwater temperature and electrical conductivity (EC). Our results suggest that stream–aquifer interactions are significantly affected by weir operation, consequently, these repeated phenomena could influence the groundwater quality and groundwater use.



2019 ◽  
Vol 6 (6) ◽  
pp. 1728-1739 ◽  
Author(s):  
Gaozhong Pu ◽  
Danjuan Zeng ◽  
Ling Mo ◽  
Wen He ◽  
Longwu Zhou ◽  
...  

The negative effect of AgNP on leaf litter decomposition was alleviated by artificial light at night (ALAN).



2013 ◽  
Vol 4 (1) ◽  
pp. 141-153
Author(s):  
Julia Miller

In 1963 Sydneysiders, having suffered four dismal summers in a row and wetter than usual weather during the 1950s, looked back to those lazy, hazy days of the summers of a distant past where the sky arched blue over the gleaming golden sand of the quintessential Australian beach. City dwellers in the dying months of 1963, worried by persistent rain and cool temperatures, concluded that soggy weather had become the established norm. More recent experiences of wet summers in Sydney have blamed this on La Niña—a short-term climate driver that brought heavy rains and flooding to many districts of eastern Australia. This article examines the impact of natural climate cycles on attitudes to weather in Sydney. It shows how an investigation of the cultural interface of weather and climate can illuminate attitudes that impact on our ability to plan for climate change into the future.



1999 ◽  
Vol 47 (2) ◽  
pp. 157 ◽  
Author(s):  
D. J. Eldridge ◽  
J. F. Leys

A field-based wind tunnel was used to assess threshold wind velocities required to initiate movement of the vagant lichen Chondropsis semiviridis (F.Muell. ex Nyl.) Nyl. in a semi-arid eastern Australian woodland. Threshold wind velocities were lowest on bare surfaces (21 km h-1) and highest on surfaces covered with the needle-like litter of Casuarina cristata Miq. trees (58 km h-1). Examination of wind speed data suggests that threshold wind velocities for movement on litter-covered surfaces occur about 1% of the time in summer. The extensive litter cover in the groves, and the tendency of C. semiviridis to firmly attach to this litter, probably explains the concentration of C. semiviridis in the groves and the low rates of migration and emigration during most years. It is hypothesised that migration of C. semiviridis between timbered groves would only occur during extreme droughts when pasture and litter cover are sparse.



2006 ◽  
Vol 46 (8) ◽  
pp. 993 ◽  
Author(s):  
S. M. Robertson

The impact of different management strategies on production and profit can be evaluated with knowledge of how sheep production responds to changes in the available feed base and sheep or pasture management. This study aimed to quantify on-farm pasture and sheep production in mixed sheep and cropping systems in the Victorian Mallee of south-eastern Australia (325 ± 50 mm annual rainfall) as a prelude to computer simulation modelling. During 2001 (average rainfall) and 2002 (extreme drought) pasture production, the feed base and sheep production were monitored in 15 paddocks on 5 properties located across the region. Crop stubbles were the major source of feed for 6 months of the year, enabling ewes to maintain liveweight. There was more variation in pasture parameters between paddocks at the 1 location than between locations. The botanical composition, plant density, soil fertility and management were key variables associated with between-paddock variation in pasture production. Variation in pasture production between years was larger than within-year differences. In contrast, stocking rates were not much lower in the drought year of 2002 than in 2001. This study suggests there is potential for management to improve pasture production, and demonstrates the importance of feed sources other than annual pasture for sheep production in environments where the annual pasture growing season is short.



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