Pub Date : 2024-04-04DOI: 10.1186/s42408-024-00265-z
S. Sydorenko, V. Gumeniuk, F. De Miguel-Díez, O. Soshenskiy, I. Budzinskyi, V. Koren
There is a clearly increasing trend of wildfires that become catastrophic in some countries such as the United States, Australia, Russia, Portugal, Greece, and Spain. Fuel is one of the key components that influences fire behavior and its effects. Assessing the fuel load and distribution of its components in the landscape provides effective fire management treatments in terms of fire prevention campaigns on a scientific basis. This study aims to evaluate the litter, duff, and herb fuels in highly flammable coniferous forest types in Ukrainian Polissia. To estimate relationships between forestry variables that reflect the characteristics of the pine stand (DBH, height of the stand, age, relative density, stock of the plantation etc.) and the load of litter, duff, and herb fuels (CWD, FWD, litter, live grass, etc.), correlation analysis was used. To analyze difference between groups of sampling plots that have different forests, we use generalized linear mixed models including random effects of sampling plot type. Cluster analysis was performed using k-means partitioning method and Calinski-Harabasz criterion. To assess the significance of individual variables on which the variation of forest fuel depends, the random forest algorithm was used; for variable selection, we used two parameters: the percent increase in mean squared error and the Gini impurity index. The research revealed that in the pine forest stands, the stock of litter and duff varies from 15.5 (15 years) to 140 ton/ha (139 years). When modeling, the humidity level of the forest site (soil) significantly affects the dynamics of forest fuel accumulation. In fresh types of forest-growing conditions, the forest litter stock increases to the age of 80–90 years; then, it strongly decreases, while in wet forest types, continuous forest fuel stock accumulation is established during the entire growth period. Moreover, the results showed that the forest fuel load was influenced by the soil fertility. The stock of live and dead herbaceous fuel in fresh and wet conditions is not statistically different, and soil moisture has not had a significant impact. Fine woody debris stocks were more dependent on stand productivity and practically does not depend on the soil fertility index, site moisture content, and its age and ranged from 0.4 to 1.9 t/ha (1 h), from 0.1 to 2.2 t/ha (10 h), and from 0 to 1.6 t/ha (100 h). The obtained results enabled to develop mathematical models for estimating litter and duff stocks in the Polissia forest stands based on stand characteristic and the soil humidity level. Moreover, the results will serve as basis to develop local forest fuel models as well as to determine potential fire hazards and a fire behavior modeling process in coniferous forests of that region. These models constitute the basis for the national set of fuel model development for each nature zone of Ukraine.
{"title":"Assessment of the surface forest fuel load in the Ukrainian Polissia","authors":"S. Sydorenko, V. Gumeniuk, F. De Miguel-Díez, O. Soshenskiy, I. Budzinskyi, V. Koren","doi":"10.1186/s42408-024-00265-z","DOIUrl":"https://doi.org/10.1186/s42408-024-00265-z","url":null,"abstract":"There is a clearly increasing trend of wildfires that become catastrophic in some countries such as the United States, Australia, Russia, Portugal, Greece, and Spain. Fuel is one of the key components that influences fire behavior and its effects. Assessing the fuel load and distribution of its components in the landscape provides effective fire management treatments in terms of fire prevention campaigns on a scientific basis. This study aims to evaluate the litter, duff, and herb fuels in highly flammable coniferous forest types in Ukrainian Polissia. To estimate relationships between forestry variables that reflect the characteristics of the pine stand (DBH, height of the stand, age, relative density, stock of the plantation etc.) and the load of litter, duff, and herb fuels (CWD, FWD, litter, live grass, etc.), correlation analysis was used. To analyze difference between groups of sampling plots that have different forests, we use generalized linear mixed models including random effects of sampling plot type. Cluster analysis was performed using k-means partitioning method and Calinski-Harabasz criterion. To assess the significance of individual variables on which the variation of forest fuel depends, the random forest algorithm was used; for variable selection, we used two parameters: the percent increase in mean squared error and the Gini impurity index. The research revealed that in the pine forest stands, the stock of litter and duff varies from 15.5 (15 years) to 140 ton/ha (139 years). When modeling, the humidity level of the forest site (soil) significantly affects the dynamics of forest fuel accumulation. In fresh types of forest-growing conditions, the forest litter stock increases to the age of 80–90 years; then, it strongly decreases, while in wet forest types, continuous forest fuel stock accumulation is established during the entire growth period. Moreover, the results showed that the forest fuel load was influenced by the soil fertility. The stock of live and dead herbaceous fuel in fresh and wet conditions is not statistically different, and soil moisture has not had a significant impact. Fine woody debris stocks were more dependent on stand productivity and practically does not depend on the soil fertility index, site moisture content, and its age and ranged from 0.4 to 1.9 t/ha (1 h), from 0.1 to 2.2 t/ha (10 h), and from 0 to 1.6 t/ha (100 h). The obtained results enabled to develop mathematical models for estimating litter and duff stocks in the Polissia forest stands based on stand characteristic and the soil humidity level. Moreover, the results will serve as basis to develop local forest fuel models as well as to determine potential fire hazards and a fire behavior modeling process in coniferous forests of that region. These models constitute the basis for the national set of fuel model development for each nature zone of Ukraine.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"115 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140572090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-04DOI: 10.1186/s42408-024-00268-w
Javier Pérez, Cecilia Brand, Alberto Alonso, Alaia Sarasa, Diana Rojo, Francisco Correa-Araneda, Luz Boyero
Wildfires have strong impacts on terrestrial and aquatic ecosystems, whose frequency, severity, and intensity are increasing with climate change. Moreover, the expansion of exotic monoculture plantations, such as those of eucalypts, increases this risk. When wildfires do not cause the disappearance of riparian vegetation, they still imply the fall of leaf litter exposed to the fire (i.e., crown scorch), which consequences for ecosystems are unknown. To explore how these leaf litter inputs may affect stream ecosystem functioning, we conducted a microcosm experiment where we quantified the decomposition of leaf litter from three tree species (alder, oak, and eucalypt) under two conditions (control litter simulating natural entries and litter subjected to 150 °C for 3 h mimicking exposure to fire). We also examined the interaction between this factor and a temperature rise (which is often associated to the loss of riparian vegetation caused by the wildfire) by manipulating water temperature (10, 12.5, and 15 °C). Finally, we explored the effects of these variables on the growth of a common detritivore, the caddisfly Sericostoma pyrenaicum. Control alder presented the highest decomposition rates, which were notably reduced due to fire exposure. On the contrary, eucalypt litter decomposition was even slower than that of oak and hardly showed any effect derived from fire exposure. The different leaf litter types determined detritivore growth, to a greater extent than variation related to warming, which generally had negligible effects. Our study shows the negative effects of wildfires on stream ecosystem functioning even when they only involve brief exposure of leaf litter to the fire. Effects are greater on the most palatable native species, which represents the highest quality input in streams of the study area. Our results highlight the importance of protecting riparian forests, especially those composed of native species, against wildfires.
野火对陆地和水生生态系统有很大影响,随着气候变化,野火的频率、严重程度和强度都在增加。此外,桉树等外来单一种植园的扩张也增加了这一风险。当野火没有导致河岸植被消失时,它们仍意味着暴露在火中的落叶(即树冠焦枯)的掉落,而这对生态系统的影响尚不清楚。为了探索这些落叶的输入会如何影响溪流生态系统的功能,我们进行了一个微观世界实验,在两种条件下(模拟自然进入的对照落叶和模拟火灾暴露的 150 °C 3 小时的落叶)量化了三种树种(赤杨、橡树和桉树)落叶的分解情况。我们还通过调节水温(10、12.5 和 15 °C)研究了这一因素与温度上升(通常与野火造成的河岸植被损失有关)之间的相互作用。最后,我们还探讨了这些变量对一种常见的食腐动物--笛簧片蝇(Sericostoma pyrenaicum)生长的影响。对照组桤木的分解率最高,但由于受到火灾影响,分解率明显降低。相反,桉树落叶的分解速度比橡树还要慢,而且几乎没有受到火灾的影响。不同的落叶类型决定了食腐动物的生长,其影响程度大于与气候变暖有关的变化,后者的影响一般可以忽略不计。我们的研究表明,野火对溪流生态系统的功能有负面影响,即使野火只涉及枯落叶的短暂暴露。对最适口的本地物种的影响更大,而这些物种代表了研究区域溪流中最高质量的投入。我们的研究结果突显了保护河岸森林,尤其是由本地物种组成的河岸森林免受野火影响的重要性。
{"title":"Wildfires alter stream ecosystem functioning through effects on leaf litter","authors":"Javier Pérez, Cecilia Brand, Alberto Alonso, Alaia Sarasa, Diana Rojo, Francisco Correa-Araneda, Luz Boyero","doi":"10.1186/s42408-024-00268-w","DOIUrl":"https://doi.org/10.1186/s42408-024-00268-w","url":null,"abstract":"Wildfires have strong impacts on terrestrial and aquatic ecosystems, whose frequency, severity, and intensity are increasing with climate change. Moreover, the expansion of exotic monoculture plantations, such as those of eucalypts, increases this risk. When wildfires do not cause the disappearance of riparian vegetation, they still imply the fall of leaf litter exposed to the fire (i.e., crown scorch), which consequences for ecosystems are unknown. To explore how these leaf litter inputs may affect stream ecosystem functioning, we conducted a microcosm experiment where we quantified the decomposition of leaf litter from three tree species (alder, oak, and eucalypt) under two conditions (control litter simulating natural entries and litter subjected to 150 °C for 3 h mimicking exposure to fire). We also examined the interaction between this factor and a temperature rise (which is often associated to the loss of riparian vegetation caused by the wildfire) by manipulating water temperature (10, 12.5, and 15 °C). Finally, we explored the effects of these variables on the growth of a common detritivore, the caddisfly Sericostoma pyrenaicum. Control alder presented the highest decomposition rates, which were notably reduced due to fire exposure. On the contrary, eucalypt litter decomposition was even slower than that of oak and hardly showed any effect derived from fire exposure. The different leaf litter types determined detritivore growth, to a greater extent than variation related to warming, which generally had negligible effects. Our study shows the negative effects of wildfires on stream ecosystem functioning even when they only involve brief exposure of leaf litter to the fire. Effects are greater on the most palatable native species, which represents the highest quality input in streams of the study area. Our results highlight the importance of protecting riparian forests, especially those composed of native species, against wildfires.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"22 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140603065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-27DOI: 10.1186/s42408-024-00260-4
Jeanne C. Chambers, Eva K. Strand, Lisa M. Ellsworth, Claire M. Tortorelli, Alexandra K. Urza, Michele R. Crist, Richard F. Miller, Matthew C. Reeves, Karen C. Short, Claire L. Williams
Sagebrush ecosystems are experiencing increases in wildfire extent and severity. Most research on vegetation treatments that reduce fuels and fire risk has been short term (2–3 years) and focused on ecological responses. We review causes of altered fire regimes and summarize literature on the longer-term effects of treatments that modify (1) shrub fuels, (2) pinyon and juniper canopy fuels, and (3) fine herbaceous fuels. We describe treatment effects on fuels, fire behavior, ecological resilience, and resistance to invasive annual grasses. Our review revealed tradeoffs in woody fuel treatments between reducing canopy fuels vs. increasing understory herbaceous vegetation (fuels) and fire behavior. In pinyon-juniper expansion areas, all treatments decreased crown fire risk. Prescribed fire and cut and broadcast burn treatments reduced woody fuels long-term but had higher risk of invasion. Mechanical treatments left understory vegetation intact and increased native perennial plants. However, cut and leave treatments increased downed woody fuel and high-intensity wildfire risk, while cut and pile burn and mastication caused localized disturbances and annual grass invasion. Ecological outcomes depended on ecological resilience; sites with warm and dry conditions or depleted perennial native herbaceous species experienced lower recovery and resistance to invasive annual grasses. In invasive annual grass dominated areas, high-intensity targeted grazing reduced fine fuels but required retreatment or seeding; in intact ecosystems with relatively low shrub cover, dormant season targeted grazing reduced fine fuel and thus fire spread. Preemergent herbicides reduced annual grasses with differing effects in warm and dry vs. cool and moist environments. The information largely exists to make informed decisions on treatments to mitigate effects of wildfire and improve ecological resilience at local, project scales. Primary considerations are the short- vs long-term tradeoffs in fuels and fire behavior and thus fire severity and the likely ecological response.
{"title":"Review of fuel treatment effects on fuels, fire behavior and ecological resilience in sagebrush (Artemisia spp.) ecosystems in the Western U.S.","authors":"Jeanne C. Chambers, Eva K. Strand, Lisa M. Ellsworth, Claire M. Tortorelli, Alexandra K. Urza, Michele R. Crist, Richard F. Miller, Matthew C. Reeves, Karen C. Short, Claire L. Williams","doi":"10.1186/s42408-024-00260-4","DOIUrl":"https://doi.org/10.1186/s42408-024-00260-4","url":null,"abstract":"Sagebrush ecosystems are experiencing increases in wildfire extent and severity. Most research on vegetation treatments that reduce fuels and fire risk has been short term (2–3 years) and focused on ecological responses. We review causes of altered fire regimes and summarize literature on the longer-term effects of treatments that modify (1) shrub fuels, (2) pinyon and juniper canopy fuels, and (3) fine herbaceous fuels. We describe treatment effects on fuels, fire behavior, ecological resilience, and resistance to invasive annual grasses. Our review revealed tradeoffs in woody fuel treatments between reducing canopy fuels vs. increasing understory herbaceous vegetation (fuels) and fire behavior. In pinyon-juniper expansion areas, all treatments decreased crown fire risk. Prescribed fire and cut and broadcast burn treatments reduced woody fuels long-term but had higher risk of invasion. Mechanical treatments left understory vegetation intact and increased native perennial plants. However, cut and leave treatments increased downed woody fuel and high-intensity wildfire risk, while cut and pile burn and mastication caused localized disturbances and annual grass invasion. Ecological outcomes depended on ecological resilience; sites with warm and dry conditions or depleted perennial native herbaceous species experienced lower recovery and resistance to invasive annual grasses. In invasive annual grass dominated areas, high-intensity targeted grazing reduced fine fuels but required retreatment or seeding; in intact ecosystems with relatively low shrub cover, dormant season targeted grazing reduced fine fuel and thus fire spread. Preemergent herbicides reduced annual grasses with differing effects in warm and dry vs. cool and moist environments. The information largely exists to make informed decisions on treatments to mitigate effects of wildfire and improve ecological resilience at local, project scales. Primary considerations are the short- vs long-term tradeoffs in fuels and fire behavior and thus fire severity and the likely ecological response.\u0000","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"128 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140312599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}