Do tropical savanna skink assemblages show a short-term response to low-intensity fire?

2006 ◽  
Vol 33 (4) ◽  
pp. 331 ◽  
Author(s):  
Evelyn Nicholson ◽  
Alan Lill ◽  
Alan Andersen
Keyword(s):  
Fire Regimes ◽  
Reproductive Activity ◽  
Dry Season ◽  
Tropical Savanna ◽  
Weather Variables ◽  
Fire Event ◽  
Low Intensity ◽  
Before And After ◽  
High Degree ◽  
Term Response

The composition of skink assemblages at a tropical savanna site in northern Australia was documented immediately before and after low-intensity, experimental fires in the early dry season (June), and compared with the composition in neighbouring unburnt plots. The composition of the assemblage of captured skinks was not significantly affected by fire, and no change in total abundance of skinks was recorded. Arthropods constitute the principal food of the skinks and the composition of the captured arthropod samples on the treatment plots was significantly affected by the fires, with spiders, beetles and hemipterans increasing in numbers during the immediate post-fire period. Seasonal changes in captured skink assemblage composition, unrelated to the fire event, occurred between the wet–dry season transition and the early dry season. These changes were associated with variation in four weather variables and were possibly also related to seasonal reproductive activity. Our study demonstrates a high degree of resilience of savanna skinks to individual fire events; however, the longer-term effect of different fire regimes requires further investigation.

scholarly journals A reconstruction of the recent fire regimes of Majete Wildlife Reserve, Malawi, using remote sensing

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Willem A. Nieman ◽  
Brian W. van Wilgen ◽  
Alison J. Leslie
Keyword(s):  
Remote Sensing ◽  
Fire Management ◽  
Fire Regime ◽  
Fire Regimes ◽  
Dry Season ◽  
Annual Rainfall ◽  
Vegetation Types ◽  
Local Evidence ◽  
Hot Dry Season ◽  
Wildlife Reserve

Abstract Background Fire is an important process that shapes the structure and functioning of African savanna ecosystems, and managers of savanna protected areas use fire to achieve ecosystem goals. Developing appropriate fire management policies should be based on an understanding of the determinants, features, and effects of prevailing fire regimes, but this information is rarely available. In this study, we report on the use of remote sensing to develop a spatially explicit dataset on past fire regimes in Majete Wildlife Reserve, Malawi, between 2001 and 2019. Moderate Resolution Imaging Spectroradiometer (MODIS) images were used to evaluate the recent fire regime for two distinct vegetation types in Majete Wildlife Reserve, namely savanna and miombo. Additionally, a comparison was made between MODIS and Visible Infrared Imager Radiometer Suite (VIIRS) images by separately evaluating selected aspects of the fire regime between 2012 and 2019. Results Mean fire return intervals were four and six years for miombo and savanna vegetation, respectively, but the distribution of fire return intervals was skewed, with a large proportion of the area burning annually or biennially, and a smaller proportion experiencing much longer fire return intervals. Variation in inter-annual rainfall also resulted in longer fire return intervals during cycles of below-average rainfall. Fires were concentrated in the hot-dry season despite a management intent to restrict burning to the cool-dry season. Mean fire intensities were generally low, but many individual fires had intensities of 14 to 18 times higher than the mean, especially in the hot-dry season. The VIIRS sensors detected many fires that were overlooked by the MODIS sensors, as images were collected at a finer scale. Conclusions Remote sensing has provided a useful basis for reconstructing the recent fire regime of Majete Wildlife Reserve, and has highlighted a current mismatch between intended fire management goals and actual trends. Managers should re-evaluate fire policies based on our findings, setting clearly defined targets for the different vegetation types and introducing flexibility to accommodate natural variation in rainfall cycles. Local evidence of the links between fires and ecological outcomes will require further research to improve fire planning.

scholarly journals A late-Holocene multiproxy fire record from a tropical savanna, eastern Arnhem Land, Northern Territory, Australia

The Holocene ◽  
2021 ◽  
pp. 095968362098803
Author(s):  
Emma Rehn ◽  
Cassandra Rowe ◽  
Sean Ulm ◽  
Craig Woodward ◽  
Michael Bird
Keyword(s):  
Isotope Composition ◽  
Fire Regimes ◽  
Northern Territory ◽  
Ecosystem Dynamics ◽  
Optical Methods ◽  
Fire Intensity ◽  
Tropical Savanna ◽  
Anthropogenic Fire ◽  
Pyrogenic Carbon ◽  
Arnhem Land

Fire has a long history in Australia and is a key driver of vegetation dynamics in the tropical savanna ecosystems that cover one quarter of the country. Fire reconstructions are required to understand ecosystem dynamics over the long term but these data are lacking for the extensive savannas of northern Australia. This paper presents a multiproxy palaeofire record for Marura sinkhole in eastern Arnhem Land, Northern Territory, Australia. The record is constructed by combining optical methods (counts and morphology of macroscopic and microscopic charcoal particles) and chemical methods (quantification of abundance and stable isotope composition of pyrogenic carbon by hydrogen pyrolysis). This novel combination of measurements enables the generation of a record of relative fire intensity to investigate the interplay between natural and anthropogenic influences. The Marura palaeofire record comprises three main phases: 4600–2800 cal BP, 2800–900 cal BP and 900 cal BP to present. Highest fire incidence occurs at ~4600–4000 cal BP, coinciding with regional records of high effective precipitation, and all fire proxies decline from that time to the present. 2800–900 cal BP is characterised by variable fire intensities and aligns with archaeological evidence of occupation at nearby Blue Mud Bay. All fire proxies decline significantly after 900 cal BP. The combination of charcoal and pyrogenic carbon measures is a promising proxy for relative fire intensity in sedimentary records and a useful tool for investigating potential anthropogenic fire regimes.

Dry season water use patterns underGuiera senegalensisL. shrubs in a tropical savanna

1998 ◽  
Vol 40 (1) ◽  
pp. 53-67 ◽  
Author(s):  
Stephen R Gaze ◽  
Joost Brouwer ◽  
Lester P Simmonds ◽  
John Bromley
Keyword(s):  
Water Use ◽  
Dry Season ◽  
Tropical Savanna ◽  
Use Patterns ◽  
Water Use Patterns

Responses of the bovine teat to machine milking: measurement of changes in thickness of the teat apex

1988 ◽  
Vol 55 (3) ◽  
pp. 331-338 ◽  
Author(s):  
Jörn Hamann ◽  
Graeme A. Mein
Keyword(s):  
Positive Pressure ◽  
Vacuum Level ◽  
Machine Milking ◽  
Before And After ◽  
The Mean ◽  
High Degree

SummaryChanges in the teat apex before and after different milking treatments were measured with a spring-loaded caliper device known as a cutimeter which could detect changes in thickness of the tissues of the teat end, presumably due to congestion and/or oedema, with a high degree of accuracy (± 2%) and repeatability (r = 0·99). Teat end thickness increased with increasing vacuum level. The mean increase immediately after milking with a conventional cluster was 2% for 24 teats milked at 30 kPa, 8% at 50 kPa and 21% at 70 kPa. At these vacuum levels, the mean increases for the same teats milked with an unconventional (PKME) teatcup were 10, 18 and 25% respectively. Cyclic application of 35 kPa positive pressure to the pulsation chamber of a conventional teatcup operating at 50 kPa reduced teat end thickness by 8% compared with the mean premilking value. Although most teats returned to within ± 2% of their premilking thickness values by 1 h after milking, differences were apparent between different milking systems for up to 4 h postmilking.

scholarly journals The influence of prescribed fire on the extent of wildfire in savanna landscapes of western Arnhem Land, Australia

2012 ◽  
Vol 21 (3) ◽  
pp. 297 ◽  
Author(s):  
Owen F. Price ◽  
Jeremy Russell-Smith ◽  
Felicity Watt
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Prescribed Fire ◽  
Fire History ◽  
Prescribed Burning ◽  
Landsat Imagery ◽  
Fire Regimes ◽  
Dry Season ◽  
Gas Emissions ◽  
Arnhem Land

Fire regimes in many north Australian savanna regions are today characterised by frequent wildfires occurring in the latter part of the 7-month dry season. A fire management program instigated from 2005 over 24 000 km2 of biodiversity-rich Western Arnhem Land aims to reduce the area and severity of late dry-season fires, and associated greenhouse gas emissions, through targeted early dry-season prescribed burning. This study used fire history mapping derived mostly from Landsat imagery over the period 1990–2009 and statistical modelling to quantify the mitigation of late dry-season wildfire through prescribed burning. From 2005, there has been a reduction in mean annual total proportion burnt (from 38 to 30%), and particularly of late dry-season fires (from 29 to 12.5%). The slope of the relationship between the proportion of early-season prescribed fire and subsequent late dry-season wildfire was ~–1. This means that imposing prescribed early dry-season burning can substantially reduce late dry-season fire area, by direct one-to-one replacement. There is some evidence that the spatially strategic program has achieved even better mitigation than this. The observed reduction in late dry-season fire without concomitant increase in overall area burnt has important ecological and greenhouse gas emissions implications. This efficient mitigation of wildfire contrasts markedly with observations reported from temperate fire-prone forested systems.

The Flash Technique in a Low-Intensity Group Trauma Intervention for Healthcare Providers Impacted by COVID-19 Patients

2021 ◽  
pp. EMDR-D-20-00053
Author(s):  
Philip E. Manfield ◽  
Lewis Engel ◽  
Ricky Greenwald ◽  
David G. Bullard
Keyword(s):  
Group Intervention ◽  
Healthcare Providers ◽  
Preliminary Evidence ◽  
Effect Sizes ◽  
Traumatic Memories ◽  
Low Intensity ◽  
Before And After ◽  
Flash Technique ◽  
Rapid Relief

The flash technique (FT) is a low-intensity individual or group intervention that appears to rapidly lessen the distress of disturbing and traumatic memories. This paper reports on the safety and effectiveness of group FT with 77 healthcare providers and 98 psychotherapists impacted by working with COVID-19 patients. One-hour webinars included 30 minutes of psychoeducation and two guided 15-minute FT interventions, focused on participants’ most distressing pandemic-related memory. Before and after each 15-minute FT intervention, they rated that memory using the 11-point zero-to-ten subjective units of disturbance (SUD) scale. Results from both interventions were highly significant with large effect sizes (p < .001, Hedges’ g = 2.01, Hedges’ g = 2.39). No adverse reactions were reported. For 35 participants who processed the same memory in both interventions, the pre–post SUD scores from the beginning of intervention #1 to the end of intervention #2 showed a significant reduction with a large effect size (p < .001, Hedges’ g = 3.80). For this group, both intervention #1 and intervention #2 showed significant reductions with large effect sizes (p < .001, Hedges’ g = 2.00) (p < .001, Hedges’ g = 1.18). Follow-up SUD scores were obtained from 58 participants, with the mean disturbance level showing a significant further decrease. These findings provide preliminary evidence that group FT appears to safely provide rapid relief from disturbing memories. FT merits further research.

Neural tissue reactions to low-intensity laser radiation

1998 ◽  
Vol 79 (3) ◽  
pp. 204-210
Author(s):  
Yu. A. Chelyshev ◽  
K. I. Sitekulov
Keyword(s):  
Laser Radiation ◽  
Pain Relief ◽  
Neural Tissue ◽  
Low Intensity ◽  
The Past ◽  
Tissue Reactions ◽  
High Degree ◽  
Intensity Laser

Over the past 25 years, laser radiation has found wide application in various fields of medicine, including neurology, mainly as a means of pain relief [17]. A high degree of specificity of the photobiological action is determined by its unique properties: monochromaticity, selective focus and coherence.

scholarly journals Toward a Country-Based Prediction Model of COVID-19 Infections and Deaths Between Disease Apex and End: Evidence From Countries With Contained Numbers of COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
Tianshu Gu ◽  
Lishi Wang ◽  
Ning Xie ◽  
Xia Meng ◽  
Zhijun Li ◽  
...  
Keyword(s):  
Real Data ◽  
Control Measures ◽  
Actual Number ◽  
The Public ◽  
The Us ◽  
Multiple Regression Models ◽  
Before And After ◽  
Using Data ◽  
High Degree ◽  
The Relationship

The complexity of COVID-19 and variations in control measures and containment efforts in different countries have caused difficulties in the prediction and modeling of the COVID-19 pandemic. We attempted to predict the scale of the latter half of the pandemic based on real data using the ratio between the early and latter halves from countries where the pandemic is largely over. We collected daily pandemic data from China, South Korea, and Switzerland and subtracted the ratio of pandemic days before and after the disease apex day of COVID-19. We obtained the ratio of pandemic data and created multiple regression models for the relationship between before and after the apex day. We then tested our models using data from the first wave of the disease from 14 countries in Europe and the US. We then tested the models using data from these countries from the entire pandemic up to March 30, 2021. Results indicate that the actual number of cases from these countries during the first wave mostly fall in the predicted ranges of liniar regression, excepting Spain and Russia. Similarly, the actual deaths in these countries mostly fall into the range of predicted data. Using the accumulated data up to the day of apex and total accumulated data up to March 30, 2021, the data of case numbers in these countries are falling into the range of predicted data, except for data from Brazil. The actual number of deaths in all the countries are at or below the predicted data. In conclusion, a linear regression model built with real data from countries or regions from early pandemics can predict pandemic scales of the countries where the pandemics occur late. Such a prediction with a high degree of accuracy provides valuable information for governments and the public.

scholarly journals Unges dialektbrug i bygden Sandur på Færøerne

2021 ◽  
Vol 11 (2) ◽  
pp. 173-187
Author(s):  
Jógvan í Lon Jacobsen
Keyword(s):  
Young Generation ◽  
Faroe Islands ◽  
State Of Health ◽  
Future Scenario ◽  
Person Plural ◽  
Stability And Change ◽  
Before And After ◽  
Underwater Tunnel ◽  
The University ◽  
High Degree

In this article, dialect changes and variation among young schoolchildren in the island of Sandoy in the Faroe Islands are discussed. The fieldwork was made by a group of students at the University of the Faroe Islands in November 2019 under the guidance of this article’s author. The informants are two groups of 10 and 15 year old schoolchildren. By examining the young generation, we can get information about the ‘state of health’ of the dialect. Here three dialectal variables are examined: (i) The variation of definite and indefinite form of words for family members, for instance the dialectal form mamman ‘the mother’ and the Central Faroese form mamma ‘mother’; (ii) Personal and possessive pronouns in 1st and 2nd person plural in oblique case, for instance the dialect form [o:gʊn] ‘us’ and the Central Faroese form [ɔʰk:ʊn] ‘us’; (iii) The pronunciation of short ó with the dialectal variant [ɔ] and the Central Faroese form [œ], for instance [fɔlk] resp. [fœlk] ‘people’. The first variable shows clearly a tendency towards dialect change in the young generation: the indefinite forms are much more frequent than the dialect counterpart. The use of the pronouns shows a relatively high degree of variation: the dialect forms are more frequently used by the 10 than the 15 year old pupils. The pronunciation of short ó shows variation to a large extent. Here we see the same pattern as we saw for variable 2: the youngest pupils are more likely to use the dialect¬al form [ɔ] than the older ones. On the other hand, variation is much more common in the group of 15 year old pupils. This study shows both stability and change in the dialect of children in Sandoy: Stability in use of the dialectal forms of the personal and possessive pro¬nouns, and variation and change in the two other variables. In a couple of years an underwater tunnel will connect the island of Sandoy with the central part of the islands. In a future scenario this dialect study opens the possibility for comparative studies of the dialect of Sandoy before and after the opening of the tunnel.

Responses of lizards to three experiments fires in the savanna forests of Kakadu National Park

1994 ◽  
Vol 21 (2) ◽  
pp. 131 ◽  
Author(s):  
CR Trainor ◽  
JCZ Woinarski
Keyword(s):  
National Park ◽  
Habitat Type ◽  
Detrended Correspondence Analysis ◽  
Fire Regimes ◽  
Direct Effects ◽  
Short Term ◽  
Lizard Species ◽  
Savanna Communities ◽  
Induced Changes ◽  
Term Response

A species-rich lizard community responded variably to a range of experimental fire regimes in a tropical savanna. Heteronotia binoei was the only lizard species that showed a short-term response to fire, decreasing in abundance directly after the early- and late-burns. H. binoei and Diporiphora bilineata were significantly more abundant in early-burn treatments. Carlia amax was more abundant in unburnt and early-burn treatments. C. munda was more abundant in unburnt and early-burn sites. Differences in the relative abundance of species between treatments is attributed to site differences in vegetation structure, and fire-induced changes to the structure of habitat. Early-burn sites were significantly richer in lizard species (P< 0.05); however, overall lizard abundance, Shannon-Wiener diversity and Detrended Correspondence Analysis (DCA) 1 and DCA 2 scores were not significantly different, suggesting that habitat partitioning has a stronger influence than the direct effects of fire. Many lizards were associated with a direct gradient of moisture availability, including a seepage assemblage, with Carlia gracilis and Sphenomorphus darwiniensis correlated with increased moisture, a well-developed canopy and abundant leaf litter. An assemblage associated with the drier end of the gradient included Carlia triacantha, Ctenotus kurnbudj, Diporiphora magna and D. bilineata. The lizard composition of most quadrats was intermediate along the moisture gradient and was associated with typical eucalypt savanna communities. Lizard species that largely are restricted to the moist seepage zones may be particularly sensitive to late dry-season fires which alter this habitat type.

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