Burn Site Research Articles

Influence of disturbance on transpiration and evaporation in tropical peat swamp forests

Disturbances in tropical peat swamp forests greatly impact water transport into the atmosphere through evapotranspiration (ET). However, transpiration (T) and evaporation (E) are affected by disturbances in different manners. Based on eddy fluxes and meteorological data, we used three methods to estimate T and E separately at three tropical peat swamp forest sites with different degrees of disturbance. Each method utilizes the i) water use efficiency, ii) linear relationship between ET and gross primary production, and iii) conductance of T and E in each. The results showed that the conductance method was the most reasonable for estimating T and E. The other two methods could not be applied because of the large variance in the water use efficiency and lack of a strong relationship between ET and gross primary production, among other reasons. Inter-site comparisons suggested that lowering the groundwater level (GWL) reduced T, but T subsequently recovered. This was likely because the trees acclimated to the dry environment. There was no clear difference in E among the three sites under conditions of lower GWLs. The mean T/ET in the almost undisturbed forest (0.60) was greater than that at the burned site with sparse vegetation (0.21). Overall, El Niño events decreased both T and E during the dry season at all sites. In the almost undisturbed forest, T and E decreased by 1.14 and 0.27 mm day−1, respectively. During El Niño events, precipitation decreased to near zero, fire sizes increased, and the downward photosynthetic photon flux density decreased. The decreases in T and E were mainly due to attenuation of incoming radiation by the fire-induced haze. In addition, significant soil desiccation due to lowered GWL impaired root water uptake, resulting in decreased T. In addition, E was decreased by soil surface drying. However, the direct effect of further atmospheric drying on E and T was small during the dry season. Our results show that both drainage and El Niño events reduced T and E in different manners.

Engineered Superinfective Pf Phage Prevents Dissemination of Pseudomonas aeruginosa in a Mouse Burn Model.

Pf is a filamentous bacteriophage integrated in the chromosome of most clinical isolates of Pseudomonas aeruginosa. Under stress conditions, mutations occurring in the Pf genome result in the emergence of superinfective variants of Pf (SI-Pf) that are capable of circumventing phage immunity; therefore, SI-Pf can even infect Pf-lysogenized P. aeruginosa. Here, we identified specific mutations located between the repressor and the excisionase genes of Pf4 phage in the P. aeruginosa PAO1 strain that resulted in the emergence of SI-Pf. Based on these findings, we genetically engineered an SI-Pf (eSI-Pf) and tested it as a phage therapy tool for the treatment of life-threatening burn wound infections caused by PAO1. In validation experiments, eSI-Pf was able to infect PAO1 grown in a lawn as well as biofilms formed in vitro on polystyrene. eSI-Pf also infected PAO1 present in burned skin wounds on mice but was not capable of maintaining a sustained reduction in bacterial burden beyond 24 h. Despite not lowering bacterial burden in burned skin tissue, eSI-Pf treatment completely abolished the capability of P. aeruginosa to disseminate from the burn site to internal organs. Over the course of 10 days, this resulted in bacterial clearance and survival of all treated mice. We subsequently determined that eSI-Pf induced a small-colony variant of P. aeruginosa that was unable to disseminate systemically. This attenuated phenotype was due to profound changes in virulence determinant production and altered physiology. Our results suggest that eSI-Pf has potential as a phage therapy against highly recalcitrant antimicrobial-resistant P. aeruginosa infections of burn wounds. IMPORTANCE Pseudomonas aeruginosa is a major cause of burn-related infections. It is also the most likely bacterial infection to advance to sepsis and result in burn-linked death. Frequently, P. aeruginosa strains isolated from burn patients display a multidrug-resistant phenotype necessitating the development of new therapeutic strategies and prophylactic treatments. In this context, phage therapy using lytic phages has demonstrated exciting potential in the control P. aeruginosa infection. However, lytic phages can present a set of drawbacks during phage therapy, including the induction of bacterial resistance and limited bacteria-phage interactions in vivo. Here, we propose an alternative approach to interfere with P. aeruginosa pathogenesis in a burn infection model, i.e., by using an engineered superinfective filamentous phage. Our study demonstrates that treatment with the engineered Pf phage can prevent sepsis and death in a burn mouse model.

Clinical application of functional near-infrared spectroscopy for burn assessment.

Significance: Early assessment of local tissue oxygen saturation is essential for clinicians to determine the burn wound severity. Background: We assessed the burn extent and depth in the skin of the extremities using a custom-built 36-channel functional near-infrared spectroscopy system in patients with burns. Methods: A total of nine patients with burns were analyzed in this study. All second-degree burns were categorized as superficial, intermediate, and deep burns; non-burned skin on the burned side; and healthy skin on the contralateral non-burned side. Hemodynamic tissue signals from functional near-infrared spectroscopy attached to the burn site were measured during fNIRS using a blood pressure cuff. A nerve conduction study was conducted to check for nerve damage. Results: All second-degree burns were categorized into superficial, intermediate, and deep burns; non-burned skin on the burned side and healthy skin on the contralateral non-burned side showed a significant difference distinguishable using functional near-infrared spectroscopy. Hemodynamic measurements using functional near-infrared spectroscopy were more consistent with the diagnosis of burns 1 week later than that of the degree of burns diagnosed visually at the time of admission. Conclusion: Functional near-infrared spectroscopy may help with the early judgment of burn extent and depth by reflecting differences in the oxygen saturation levels in the skin.

Effects of prescribed burning on rodents in an East African woodland ecosystem

AbstractThe name “miombo” is a vernacular term for the forests in central, southern, and eastern Africa that are dominated by the closely related legume family genera Brachystegia, Julbernardia and/or Isoberlinia. Prescribed burning is a common management practice in most miombo woodland in protected areas that highly influences vegetation structure and composition which in turn influences small mammals' distribution and abundance. This practice if not checked might significantly affect the ecosystems. We investigated the effects of prescribed burning on rodent's ecology in the miombo woodland ecosystem in the Selous game reserve, Tanzania, between July 2018 and June 2020. A total of 473 individuals comprising six rodent species; Acomys ngurui (31.50%), Aethomys chrysophilus (28.96%), Mastomys natalensis (18.82%), Lemniscomys rosalia (14.16%), Mus minutoides (2.33%), Paraxerus flavovittis (0.85%) and two insectivorous shrew species; Petrodromus tetradactylus (3.17%) and Crocidura hitra (0.21%) were captured during 14,112 trap nights. There were no statistically significant differences in the abundance of A. ngurui between burnt and unburnt areas but its abundance was statistically significantly different between seasons. M. natalensis abundance was not statistically significantly different between burnt and unburnt areas or across seasons. The burnt sites had the highest species diversity than the unburnt in both wet and dry seasons. A. ngurui and M. natalensis survival and recruitment between burnt and unburnt sites were not statistically significantly different. The study shows that prescribed burning has an effect on specific species and demographic characteristics both positive and negative.

Influence of wildfire on the rapidly changing features of patchy permafrost, Northeast China

AbstractAs an active ecological agent in the boreal forest, wildfires have many important impacts on the underlying permafrost. However, investigations of post‐fire changes in the features of ecosystem‐protected permafrost are extremely limited in the patchy permafrost regions, Northeast China. Additionally, the impacts of wildfires on patchy permafrost are complicated in this region. In this paper, based on field surveys and observations, permafrost features and their influencing factors were analyzed in the area burned in 2006. The results showed notably lower soil temperatures in shrub‐wetland (NWH1, unburned and NWH2, light burn) in comparison with those in the birch‐larch forest (NWH3, light burn and NWH4, moderate burn). Changes in shallow ground temperatures (0–4 m in depth) were significant. Mean annual soil temperatures (MAST) and annual maximum soil temperature at the light‐burn NWH2 site were 0.3–5.2°C higher than those of unburned NWH1, but annual minimum soil temperatures, 0.3–2.1°C lower. MASTs at the moderately burned NWH4 were 0.6–1.6°C higher than those at the light‐burn NWH3. The active layer thickness (ALT) was greater at burned sites, and; at the moderately burned site, only seasonal frost was found when 13 years after the burn. The contents of soil organic carbon and total nitrogen were the highest at the unburned NWH1 from 0.0 to 0.4 m in depth, followed by those at the lightly‐burned NWH2 and NWH3, and the lowest at the moderately‐burned NWH4. Climate warming, forest fires, and changing local factors (e.g., soil moisture contents, snow cover, soil texture and drainage conditions) worked together to increase ground temperature and ALT. These research results could provide important scientific basis for the protection of boreal forest and wetlands and the ecosystem‐protected permafrost under a warming climate.

Characterization of Gaseous and Particulate Phase Polycyclic Aromatic Hydrocarbons Emitted During Preharvest Burning of Sugar Cane in Different Regions of Kwa-Zulu Natal, South Africa.

Biomass burning is a significant anthropogenic source of air pollution, including the preharvest burning of sugar cane. These burn events result in atmospheric emissions, including semivolatile organic compounds, that may have adverse impacts on air quality and human health on a local, regional, and even a global scale. Gaseous and particulate polycyclic aromatic hydrocarbon (PAH) emissions from various sugar cane burn events in the province of Kwa-Zulu Natal in South Africa were simultaneously sampled using a portable denuder sampling technology, consisting of a quartz fiber filter sandwiched between two polydimethylsiloxane multichannel traps. Total gas and particle phase PAH concentrations ranged from 0.05 to 9.85 µg m-3 per individual burn event, and nine PAHs were quantified. Over 85% of all PAHs were found to exist in the gas phase, with smaller two- and three-ring PAHs, primarily naphthalene, 1-methyl naphthalene, and acenaphthylene, being the most dominant and causing the majority of variance between the burn sites. The PAH profiles differed between the different burn events at different sites, emphasizing the significant influence that the crop variety, prevailing weather conditions, and geographical location has on the type and number of pollutants emitted. The potential carcinogenicity of the PAH exposure was estimated based on toxic equivalency factors that showed varying risk potentials per burn event, with the highest value of 5.97 ng m-3 . Environ Toxicol Chem 2023;42:778-792. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Abundance and detection of feral cats decreases after severe fire on Kangaroo Island, Australia

AbstractPredation by feral cats (Felis catus) has caused the extinction of many native species in Australia and globally. There is growing evidence that the impacts of feral cats can be amplified in post‐fire environments, as cats are drawn to hunt in or around recently burnt areas and are also more effective hunters in open habitats. In 2018–2019, we established arrays of camera traps to estimate the abundance of feral cats on Kangaroo Island, South Australia. Much of the island (including five of our seven survey sites) was subsequently burnt in a severe wildfire (December 2019–February 2020). We re‐sampled the sites 3–8 months post‐fire (seven sites) and 11–12 months post‐fire (three sites). At two unburnt sites sampled post‐fire, it was possible to produce density estimates of cats using a spatially explicit capture–recapture approach. Where estimating density was not possible (due to low detections or individual cats not being distinguishable), the number of individuals and percentage of trap nights with detections was compared between the sampling periods. Some low‐level cat control occurred within 2 km of three of the seven arrays (all within the burn scar) within 3 months of the fire. Across the five burnt sites, there was a decline in cat detections post‐fire (including those without post‐fire cat control). At 3–8 months post‐fire, there was, on average, a 57% reduction in the number of individual cats, and a 65% reduction in the number of nights with cat detections, relative to pre‐fire levels. Although cat detections declined following the fire, reduced population sizes of prey species and reduced cover as a result of the fire might still mean that cat predation is a threat to some surviving prey species. Management that reduces feral cat predation pressure on wildlife following wildfire should enhance the likelihood of post‐fire wildlife persistence and recovery.

Impacts of fire suppression on above‐ground carbon stock and soil properties in Borana rangelands, southern Ethiopia

AbstractBackgroundFire is a natural disturbance that releases carbon back into the atmosphere. Pastoralists have used fire for many thousands of years for rangeland management. The use of fire in the Borana rangelands of southern Ethiopia was a common practice to improve the productivity of the rangelands. However, the use of fire as a tool to manage rangeland was prohibited by government policy in the early 1970s.MethodsIn this study, we assessed the long‐term impacts of fire suppression on aboveground carbon stocks of woody and herbaceous biomass, soil organic carbon stocks, and total nitrogen stocks at burned versus adjacent unburned areas in the Borana rangelands of southern Ethiopia. The investigation was conducted in two locations: Dikale and Sanke. The upland location was represented by Dikale, while the bottomland location was represented by Sanke. Each study site was replicated three times, with burned versus adjacent unburned areas representing each replicate. Soil samples were collected in three soil depths (0–5, 5–15, and 15–30 cm), while vegetation attributes were collected from 60 plots within three burned and three adjacent unburned sites in each landscape.ResultsThe soil organic carbon stock and pooled carbon stock between burned and unburned sites across the two landscapes showed minimal variation. The above‐ground carbon biomass accumulation for woody and herbaceous plants did not show any significant difference between burned and unburned sites both at the bottomland and upland areas. The total nitrogen contents recorded at uplands in burned sites were significantly (p < 0.05) higher than the total nitrogen stocks for the unburned adjacent sites.ConclusionsBurned areas accumulated relatively more carbon stocks in terms of herbaceous biomass (3.27 ± 0.43 Mg ha−1) than the adjacent unburned areas (0.98 ± 0.43 Mg ha−1). The results of the current study suggest that burning improved the carbon sequestration potential of herbaceous plants in arid savanna ecosystems.

Human health risk associated with metal exposure at Agbogbloshie e-waste site and the surrounding neighbourhood in Accra, Ghana

Agbogbloshie in Accra, Ghana, was a center for informal e-waste recycling until it was closed recently. This study investigated the potential health risks of toxic metals (including As, Cd, Cu, Ni, Pb, Sb, and Zn) found in the surface soils based on their concentrations and in vitro bioaccessibility. Mean concentrations at the burning sites were As: 218; Cd: 65; Cr: 182; Cu: 15,841; Ni: 145; Pb: 6,106; Sb: 552; and Zn: 16,065 mg/kg while the dismantling sites had mean concentrations of As: 23; Cd: 38; Cr: 342; Cu: 3239; Ni: 96; Pb: 681; Sb: 104; and Zn: 1658 mg/kg. The findings confirmed the enrichment of potentially toxic metals at the dismantling and burning sites, exceeding international environmental soil quality guidelines. Based on the total metal concentrations, bioaccessibility, and calculated risk indices, the risks associated with incidental ingestion of soil-borne metal contaminants at the dismantling and burning sites were very high. Despite evidence of higher metal concentrations in the communities near the burning and dismantling sites, the human health risk associated with soil ingestion was significantly lower in the surrounding neighborhood.

Short-term impact of a wildfire on the homeostasis of Tropidurus oreadicus lizards.

Wildfires cause significant changes in natural habitats and can impact lizard populations. Through changes in the thermal environment, reduced prey availability, and increased exposure to parasite vectors, wildfires affect lizard physiology, immunity, and health. We sampled 56 Tropidurus oreadicus lizards from Cerrado savannas of Brazil living in two adjacent sites: one burned 14 days before the study, and the other unburned for 6 years. We logged the air temperatures of those sites throughout fieldwork. We assessed the short-term possible homeostatic imbalances caused by the fires via measuring body mass, circulating levels of corticosterone (CORT), leukocytes profile changes in heterophile-lymphocyte ratios (HLRs), innate immunity using the bacterial killing assay (BKA), and the diagnosis of hemoparasites using molecular techniques. The air temperature was significantly higher in the burned site. There was no difference in lizard body mass between the two sites, suggesting that prey availability was not affected by the wildfire. While parasite presence was seemingly not affected by fire, the timing of initial parasite infection for animals in the study was unknown, so we also evaluated parasitism as an independent variable relative to the other metrics. Our results showed that parasitic infections lead to reduced bactericidal capacity and body mass in lizards, suggesting clinical disease and depletion of innate immune resources. Moreover, we observed increased HLR with fire and parasitic infections and a strong negative correlation with BKA. These findings suggest that the increased environmental temperature following wildfires may lead to increased CORT and decreased BKA.

Recent fire in a Mediterranean ecosystem strengthens hoverfly populations and their interaction networks with plants.

Fire affects many critical ecological processes, including pollination, and effects of climate change on fire regimes may have profound consequences that are difficult to predict. Considerable work has examined effects of fire on pollinator diversity, but relatively few studies have examined these effects on interaction networks including those of pollinators other than bees. We examined the effects of a severe wildfire on hoverfly pollinators in a Mediterranean island system. Using data collected over 3 consecutive years at burnt and unburnt sites, we documented differences in species diversity, abundance, and functional traits, as well as hoverfly interactions with flowering plants. Hoverfly abundance and species richness peaked during the first post-fire flowering season (year 1), which coincided with the presence of many opportunistic species. Also in year 1, hoverfly pollination networks were larger, less specialized, more nested, and less modular at burnt (vs. unburnt) sites; furthermore, these networks exhibited higher phylogenetic host-plant diversity. These effects declined over the next 2 years, with burnt and unburnt sites converging in similarity to hoverfly communities and interaction networks. While data obtained over 3 years provide a clear timeline of initial post-fire recovery, we emphasize the importance of longer-term monitoring for understanding the responses of natural communities to wildfires, which are projected to become more frequent and more destructive in the future.

Sentinel-1 Response to Canopy Moisture in Mediterranean Forests before and after Fire Events

This study investigates the sensibility of Sentinel-1 C-band backscatter to the moisture content of tree canopies over an area of about 500 km2 in north-western Portugal, with specific analysis over burnt areas. Sentinel-1 C-VV and C-VH backscatter values from 276 images acquired between January 2018 and December 2020 were assigned to five classes depending on the Drought Code (DC) scenario over several unburned and burned sites with total (>90%) forest canopy cover. Confounding variables such as tree cover and incidence angle were accounted for by masking using specific thresholds. The following results are discussed: (a) C-VV and C-VH backscatter values are inversely correlated (R2 = 0.324 to 0.438 −p < 0.001) with local incidence angle over canopies; (b) correlation is significantly stronger over very wet scenarios (DC class = 0 to 1); (c) C-VV and C-VH backscatter values can discriminate wet to dry forest environments, but they are less sensitive to the transition between dry (DC classes = 1 to 10, 10 to 100) and extremely dry environments (DC classes = 100 to 1000); (d) C-VH is more sensible than C-VV to capture burnt canopy; and (e) the C-VH polarization captures post-fire recovery after an average minimum period of 360 days after the fire event, although with less distinction for extremely wet soils. We conclude that C-band VH backscatter intensity decreases from wet to dry canopy conditions, that this behavior of the backscatter signal with respect to canopy dryness is lost after a fire event, and that after one year it is recovered.

Epidemiological features and management of eye burn patients in Wuxi, China

BackgroundThe current study aimed to analyse epidemiological data on eye burns in Wuxi, China, for the years 2015–2021, and to provide insight into the development of appropriate prevention strategies.MethodsA retrospective...

Expansion potential of novel skin grafts simulants with I-shaped auxetic incisions

Skin grafts play an important role in treatment of severe burn injuries. Split-thickness skin grafting is one of the most common grafting technique, in which, parallel incision patterns are projected onto a small portion of excised skin for generating expansions and covering a larger burn site. However, to date, expansions reported through experiments on such grafts, have been much lower than claimed, which inhibits their application in severe burn injury mitigation. In this work, novel skin graft simulants were developed to study the expansion potential of skin grafts with I-shaped auxetic incision patterns. A range of I-shape dimensional parameters were tested, and the effective Poisson's effect, meshing ratios, and generated stresses, biaxial deformation and stress were estimated across all skin graft simulants, with strain loadings up to 200%. High spacing between I-shaped unit cells, was found to generate high negative Poisson's ratio and meshing ratio (MR). With high spacing, lowest stresses were generated for the maximum edge lengths of the I-shape. Maximum negative Poisson's ratio of -1.12 and meshing ratio of 3.84 were produced by the skin graft simulants, indicating expansions much higher than traditional skin grafts. Such results have not been realized with skin grafts to date, which would be indispensable for further research into skin graft expansions and treatment of severe burn injuries.

Histopathological changes of experimental burns in rabbits treated with Berberine nano gel

Berberin, isolated from Coscinium fenestratum and some plants in the family Ranunculaceae, has been shown to have healing effects on wounds, burns. Study to determine the effect of treatment of superficial burns in rabbits on the pathophysiology of burns of berberine nano gel produced by the National Burn Hospital.The study was conducted on 45 rabbits, creating circular burns with a diameter of 4cm on both sides of the rabbit's back skin; rabbits were divided into 3 groups (15 rabbits, 30 burns/group), study group (A): Treated site by Berberin nano gel; control group (B): Treatment with SSD; Standard group (C): Treatment with Natri Chloride 0.9%. Follow-up histopathology at the rabbit burn site until the end of the study. Results: Group A burns had a lower number of inflammatory cells and a higher number of fibroblasts and blood vessels than group B and C burns. Conclusion: Berberin nano gel for treatment of superficial burns has been shown to have anti-inflammatory effects and stimulate wound healing.

Mainland broad-toothed rat (Mastacomys fuscus mordicus) recovery after wildfire

Wildfires are considered a major risk to the threatened broad-toothed rat (Mastacomys fuscus mordicus), a native murid rodent. Kosciuszko National Park is an important stronghold for the species, raising concern regarding the impact of the 2019–20 fires on populations occurring in this area. Sixty-two burnt sites known to be occupied by the species in 2016–17 were revisited. One year after the fires, little evidence of the broad-toothed rat was found, with its distinctive scats located at just 8% of sites. All these sites had some unburnt vegetation present. In contrast, 80.4% of 51 unburnt sites had evidence of the broad-toothed rat in both the pre- and post-fire surveys. Two years following the fire, scats were found at 42% of burnt sites, predominantly occurring within grassland (n = 23), with three in forested habitat. Three years following the fire, the scats were detected in 66% of sites, comprising 30 in grassland, 11 in forested gully and the first in lower slope shrubland. Based on the recovery trajectory, it is likely that in subsequent years (with the absence of fire or the adequate management of other competing threats) all remaining previously occupied sites may be re-populated.

Old Man Saltbush mortality following fire challenges the resilience of post‐mine rehabilitation in central Queensland, Australia

SummaryLandscape rehabilitation following mining is required to be resilient to disturbance impacts such as fire, drought and disease. As mining companies undergo the process of rehabilitation certification and mine closure, there are notable knowledge gaps on the ecological risks associated with mature rehabilitated landscapes, based largely on the assumption that rehabilitation is analogous to reference communities. However, the response to fire disturbance across a range of landscapes remains largely untested and in particular there is limited understanding of recovery traits of plant species that occur naturally or are commonly seeded into rehabilitation. In August 2018, a controlled fire was applied to 37 hectares of 12‐year‐old coal‐mine rehabilitation in central Queensland, Australia. We used a combination of (i) ground plot surveys and (ii) drone imagery to compare the vegetation response of burnt woody species to unburnt controls prior to, and for, two years following the fire. The survival of the most dominant shrub species found on the rehabilitation site was significantly impacted by the fire. Old Man Saltbush (Atriplex nummularia Lindl. subsp. nummularia) recorded significant post‐fire mortality, with ground surveys recording an average reduction of 89% of stems per hectare across the burnt site, while unburnt controls remained unchanged. The plot data analysis was supported with high spatial and temporal resolution drone imagery, classified using a Random Forest machine‐learning approach. Change analysis of these maps showed a significant decline of 82% in Old Man Saltbush plant density and 92% reduction in foliage cover following the fire. In addition, the mean canopy area of individual Old Man Saltbush shrubs reduced significantly from a pre‐fire mean of 11.3 to 4.8 m2 two years following the fire. A spatial proximity analysis showed that those individuals that survived the fire were located significantly closer to unburnt areas and bare spoil, indicating that discontinuous ground fuel loads can greatly improve the survivability of individuals. This study provides new evidence on the contested fire sensitivity of Old Man Salt bush and demonstrates the risk that future climate‐driven extreme events may have on the resilience of novel ecosystems.

Effects of a large wildfire on the community composition of medium and large mammals in a neotropical savannah

Background The Cerrado is a neotropical savannah with high mammalian diversity where wildfires are rather common and highly relevant to its ecological patterns and processes. The effects of fire on Cerrado mammals, however, are poorly understood. Aims We investigated the effects of an unplanned large wildfire (burned area ~66 000 ha) on medium and large mammals in a Cerrado area in Brazil, focusing on fire-driven changes in community composition up to 3 years after fire. Methods We evaluated burned and unburned sites before and after the wildfire, using 54 camera traps between 2017 and 2020. Total trap effort was 6334 days (unburned areas) and 7670 days (burned areas). Key results We recorded 25 species in burned and 19 in unburned areas. Fire markedly affected the community up to 3 years after burning. A canonical correspondence analysis indicated that herbivores (tapirs and pampas deer) were common in the burned areas, with an increase in the relative abundance of carnivores the second year after fire. Conclusions Community-level responses were complex, with guild-dependent changes and effects still detected 3 years after fire. Implications Management strategies that include patch mosaic burns (with areas unburned and burned 1 and 2 years earlier) could contribute to maintenance of local mammal diversity.

IN VIVO ИССЛЕДОВАНИЕ РАНОЗАЖИВЛЯЮЩЕЙ АКТИВНОСТИ ПОЛИСАХАРИДНОГО ГЕЛЯ С ИНКАПСУЛИРОВАННЫМ ОБЛЕПИХОВЫМ МАСЛОМ (HIPPOPHAE RHAMNOIDES)

Objective: To study the morphophysiological features of burn wound healing in rats using a polysaccharide gel form based on pectin and polysaccharide from apricot gum with encapsulated sea buckthorn oil. Methods: The study was carried out on two groups of laboratory rats with 18 animals in each group. A skin burn injury was inflicted in both groups (for 5 seconds at a temperature of 150°C). In the main group, in order to facilitate regeneration, a new gel form based on a polysaccharide composite with encapsulated sea buckthorn oil was applied to the burn site. In the control group, instead of the gel, a 3% hydrogen peroxide solution was applied to the surface of the wound. The skin, subcutaneous tissue, and muscles were sampled for morphological studies, sample size being 2×2 cm. The tissue was sampled within unchanged skin and processed for histological examination. Histological slides were stained with hematoxylin-eosin and viewed under Axiostar PLUS microscope (Carl Zeiss, Germany). Results: In the control group, physiological wound healing took place which corresponds to incomplete healing (reparative regeneration) and the formation of scars. In the main group after the gel treatment, the formation of granulation tissue within the epidermis, dermis, and subcutaneous fat was accelerated. It was noted that the use of the proposed gel limited destructive changes, and contributed to the steady maturation of young connective tissue, ensuring the process of re-epithelialization and complete closure of the defect Conclusion: The proposed polysaccharide gel with encapsulated sea buckthorn oil has great potential for use as a dressing for burn wounds to expedite their healing. Keywords: Burn wound, wound healing, polysaccharide gel, pectin, apricot gum, sea buckthorn oil (Hippophae rhamnoides).

Comparison of open and closed burn wound dressing applications with tissue culture sampling.

Secondary infections are the leading cause of death in burn patients. The purpose of this study is to evaluate the effects of open and closed burn dressings on the development of secondary infections. Tissue cultures were obtained from the burn sites of 56 patients between the ages of 18 and 65 who were admitted to our burn unit between December 2022 and January 2023, on days 3 and 7. The impact of the demographic features of the patients, the characteristics of the burn wound, the dressing type, and the first intervention strategies given to the burn wound on the development of wound infection were evaluated. There was no statistically significant difference between the open- and closed-dressing groups in terms of cultural positiv-ity (P>0.05). A statistically significant difference (P=0.019) was found between the groups in terms of culture positivity among those whose wounds were cleansed with warm water as the initial intervention after a burn and those whose wounds were not. Even though the main impacts of the patient's variables on the development of a wound infection are recognized, it has been found that the appropriate and successful first intervention in a burn wound is also quite important.