Slash Pile Burning Effects on Soil Biotic and Chemical Properties and Plant Establishment: Recommendations for Amelioration

Ponderosa pine forest restoration consists of thinning trees and reintroducing prescribed fire to reduce unnaturally high tree densities and fuel loads to restore ecosystem structure and function. A current issue in ponderosa pine restoration is what to do with the large quantity of slash that is created from thinning dense forest stands. Slash piling burning is currently the preferred method of slash removal because it allows land managers to burn large quantities of slash in a more controlled environment in comparison with broadcast burning slash. However burning slash piles is known to have adverse effects such as soil sterilization and exotic species establishment. This study investigated the effects of slash pile burning on soil biotic and chemical variables and early herbaceous succession on burned slash pile areas. Slash piles were created following tree thinning in two adjacent approximately 20‐ha ponderosa pine (Pinus ponderosa) restoration treatments in the Coconino National Forest near Flagstaff, Arizona. We selected 30 burned slash pile areas and sampled across a gradient of the burned piles for arbuscular mycorrhizal (AM) propagule densities, the soil seed bank, and soil chemical properties. In addition, we established five 1‐m² plots in each burned pile to quantify the effect of living soil (AM inoculum) and seeding amendments on early herbaceous succession in burned slash pile areas. The five treatments consisted of a control (no treatment), living soil (AM inoculum) amendment, sterilized soil (no AM inoculum) amendment, seed amendment, and a seed/soil (AM inoculum) amendment. Slash pile burning nearly eliminated populations of viable seeds and AM propagules and altered soil chemical properties. Amending scars with native seeds increased the cover of native forbs and grasses. Furthermore adding both seed and living soil more than doubled total native plant cover and decreased ruderal and exotic plant cover. These results indicate that seed/soil amendments that increase native forbs and grasses may enhance the rate of succession in burned slash pile areas by allowing these species to outcompete exotic and ruderal species also establishing at the site through natural regeneration.     

Alteration and Recovery of Slash Pile Burn Sites in the Restoration of a Fire‐Maintained Ecosystem

Restoration practices incorporating timber harvest (e.g. to remove undesirable species or reduce tree densities) may generate unmerchantable wood debris that is piled and burned for fuel reduction. Slash pile burns are common in longleaf pine ecosystem restoration that involves hardwood removal before reintroduction of frequent prescribed fire. In this context, long‐lasting effects of slash pile burns may complicate restoration outcomes due to unintended alterations to vegetation, soils, and the soil seed bank. In this study, our objectives were to (1) examine alterations to the soil seed bank, soil physical and chemical characteristics, and initial vegetation recolonization following burn and (2) determine the rate of return of soil and vegetation characteristics to pre‐burn conditions. We found that burning of slash piles (composed of scores of whole trees) results in elevated nutrient levels and significant impacts on vegetation and the soil seed bank, which remain evident for at least 6 years following burn. In this ecosystem, formerly weakly acidic soils become neutral to basic and levels of P remain significantly higher. Following an initial decrease after burn, total soil N increases with time since burn. These changes suggest that not only does pile burning create a fire scar initially devoid of biota, but it also produces an altered soil chemical environment, with possible consequences for long‐term ecosystem restoration efforts in landscapes including numerous fire scars. To facilitate restoration trajectories, further adaptive management to incorporate native plant propagules or suppress encroaching hardwoods within fire scars may be warranted in fire‐dependent ecosystems.     

Avian Response to Mechanical Aspen Restoration in Sierra Nevada Coniferous Forest

Using mechanical treatments to mimic natural disturbances is becoming a standard management and restoration approach. In the Sierra Nevada, as throughout much of western North America, much of aspen habitat is in poor health. Because of the high ecological value of healthy aspen, and its limited extent on the landscape, restoration to reverse the decline and improve stand health has become a management priority in the region. To evaluate the ecological effects of mechanically removing competing conifers to restore aspen in the Sierra Nevada, we compared vegetation characteristics and bird abundance in treated and untreated aspen stands on the Lassen National Forest before and up to 13 years after mechanical conifer removal. Treatments reduced total canopy cover and increased herbaceous cover and the number of aspen stems, while shrub and overstory aspen covers were unchanged. Of 10 aspen focal bird species, 7 increased in abundance following treatment relative to controls, including all species associated with early seral aspen habitat and cavity nesting species; none declined. In contrast, of the six conifer focal species, the four associated with denser conifer habitat declined as a result of the treatments. The two species associated with conifer edges and understory cover increased. Our results demonstrate mechanical conifer removal treatments can provide ecologically meaningful changes in habitat for the avian community and are an effective tool for restoring ecological values of degraded aspen habitat for birds in the Sierra Nevada.     

Competition and regeneration in quaking aspen–white fir (Populus tremuloides–Abies concolor) forests in the Northern Sierra Nevada,USA

Question: How does competition between quaking aspen (Populus tremuloides) and white fir (Abies concolor) affect growth and spatial pattern of each species? Location: The northern Sierra Nevada, California, USA. Methods: In paired plots in mixed aspen‐ (n=3) or white fir‐dominated (n=2) stands, we mapped trees and saplings and recorded DBH, height, species, and condition and took increment cores. We tallied seedlings by species. Tree ring widths were used as a measure of basal area change over the last decade, and canopy openness was identified using hemispherical photographs. Linear mixed models were used to relate neighborhood indices of competition, stand, and tree‐level variables to diameter increment. Spatial patterns of stems were identified using the Neighborhood Density Function. Results: White fir radial growth was higher in aspen‐ than white fir‐dominated plots. Individual‐level variables were more important for white fir than for aspen growth, while variables representing competitive neighborhood were important only for aspen. The forest canopy was more open in aspen‐ than white fir‐dominated stands, but ample aspen seedlings were observed in all stands. Canopy stems of aspen and white fir were randomly distributed, but saplings and small trees were clumped. Aspen saplings were repelled by canopy aspen stems. Conclusions: Variation in canopy openness explained more stand–stand variation in white fir than aspen growth, but high light levels were correlated with recruitment of aspen seedlings to the sapling class. Radial growth of aspen was predicted by indices of neighborhood competition but not radial growth of white fir, indicating that spacing and stem arrangement was more important for aspen than white fir growth. Fire suppression has removed a major disturbance mechanism that promoted aspen persistence and reduced competition from encroaching conifers, and current forests favor species that regenerate best by advance regeneration (white fir).     

Natural Regeneration of Trees in Three Types of Afforested Stands in the Taihang Mountains,China

Natural regeneration is the natural process by which plants replace themselves. It is a cost-effective way to re-establish vegetation, and it helps to preserve genetic identity and diversity. In this study, we investigated the natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China, which were dominated by Robinia pseudoacacia (black locust), Quercus variabilis (Chinese cork oak) and Platycladus orientalis (Chinese arborvitae) respectively. A consistent pattern was found among the three types of stands, being that the density of seedlings was positively correlated with the overstory canopy cover and negatively correlated with the covers of shrub, herb and litter layers. While a positive correlation between the density of seedlings and stand age was found for the conifer stands, negative correlations were found for the two types of broadleaf stands. Correlations between the density of saplings and the stand attributes were not consistent among the three types of stands. The two types of broadleaf stands had higher densities of seedlings and saplings than the conifer stands. While the broadleaf stands had adequate recruits for regeneration, the conifer stands did not have enough recruits. Our findings suggest that the overstory canopy should be prevented from being disturbed, any reduction of the canopy cover will decrease the recruits and affect the regeneration.     

Influence of Post‐Clearing Treatment on the Recovery of Herbaceous Plant Communities in Amazonian Secondary Forests

Secondary forests are an increasingly common feature in tropical landscapes worldwide and understanding their regeneration is necessary to design effective restoration strategies. It has previously been shown that the woody species community in secondary forests can follow different successional pathways according to the nature of past human activities in the area, yet little is known about patterns of herbaceous species diversity in secondary forests with different histories of land use. We compared the diversity and abundance of herbaceous plant communities in two types of Central Amazonian secondary forests—those regenerating on pastures created by felling and burning trees and those where trees were felled only. We also tested if plant density and species richness in secondary forests are related to proximity to primary forest. In comparison with primary forest sites, forests regenerating on non‐burned habitats had lower herbaceous plant density and species richness than those on burned ones. However, species composition and abundance in non‐burned stands were more similar to those of primary forest, whereas several secondary forest specialist species were found in burned stands. In both non‐burned and burned forests, distance from the forest edge was not related to herbaceous density and species richness. Overall, our results suggest that the natural regeneration of herbaceous species in secondary tropical forests is dependent on a site's post‐clearing treatment. We recommend evaluating the land history of a site prior to developing and implementing a restoration strategy, as this will influence the biological template on which restoration efforts are overlaid.     

Increase in nonnative understorey vegetation cover after nonnative conifer removal and passive restoration

Nonnative conifers are widespread in the southern hemisphere, where their use as plantation species has led to adverse ecosystem impacts sometimes intensified by invasion. Mechanical removal is a common strategy used to reduce or eliminate the negative impacts of nonnative conifers, and encourage native regeneration. However, a variety of factors may preclude active ecological restoration following removal. As a result, passive restoration – unassisted natural vegetation regeneration – is common following conifer removal. We asked, ‘what is the response of understorey cover to removal of nonnative conifer stands followed by passive restoration?' We sampled understorey cover in three site types: two‐ to ten‐year‐old clearcuts, native forest and current plantations. We then grouped understorey species by origin (native/nonnative) and growth form, and compared proportion and per cent cover of these groups as well as of bare ground and litter between the three site types. For clearcuts, we also analysed the effect of time since clearcut on the studied variables. We found that clearcuts had a significantly higher average proportion of nonnative understorey vegetation cover than native forest sites, where nonnative vegetation was nearly absent. The understorey of clearcut sites also averaged more overall vegetation cover and more nonnative vegetation cover (in particular nonnative shrubs and herbaceous species) than either plantation or native forest sites. Notably, 99% of nonnative shrub cover in clearcuts was the invasive nonnative species Scotch broom (Cytisus scoparius). After ten years of passive recovery since clearcutting, the proportion of understorey vegetation cover that is native has not increased and remains far below the proportion observed in native forest sites. Reduced natural regeneration capacity of the native ecosystem, presence of invasive species in the surrounding landscape and land‐use legacies from plantation forestry may inhibit native vegetation recovery and benefit opportunistic invasives, limiting the effectiveness of passive restoration in this context. Abstract in Spanish is available with online material.     

Fire Interval Effects on Successional Trajectory in Boreal Forests of Northwest Canada

Although succession may follow multiple pathways in a given environment, the causes of such variation are often elusive. This paper describes how changes in fire interval mediate successional trajectory in conifer-dominated boreal forests of northwestern Canada. Tree densities were measured 5 and 19 years after fire in permanent plots and related to pre-fire vegetation, site and fire characteristics. In stands that were greater than 75 years of age when they burned, recruitment density of conifers was significantly correlated with pre-fire species basal area, supporting the expectation of stand self-replacement as the most common successional pathway in these forests. In contrast, stands that were under 25 years of age at the time of burning had significantly reduced conifer recruitment, but showed no change in recruitment of trembling aspen (Populus tremuloides). As a result, young-burned stands had a much higher probability of regenerating to deciduous dominance than mature-burned stands, despite the dominance of both groups by spruce (Picea mariana and Picea glauca) and pine (Pinus contorta) before the fire. Once initiated, deciduous-dominated stands may be maintained across subsequent fire cycles through mechanisms such as low on-site availability of conifer seed, competition with the aspen canopy, and rapid asexual regeneration of aspen after fire. We suggest that climate-related increases in fire frequency could trigger more frequent shifts from conifer to deciduous-dominated successional trajectories in the future, with consequent effects on multiple ecosystem processes.     

Return of Fire as a Restoration Tool: Long‐Term Effects of Burn Severity on Habitat Use by Mexican Fox Squirrels

After decades of suppression, fire is returning to forests of the western United States through wildfires and prescribed burns. These fires may aid restoration of vegetation structure and processes, which could improve conditions for wildlife species and reduce severe wildfire risk. Understanding response of wildlife species to fires is essential to forest restoration because contemporary fires may not have the same effects as historical fires. Recent fires in the Chiricahua Mountains of southeastern Arizona provided opportunity to investigate long‐term effects of burn severity on habitat selection of a native wildlife species. We surveyed burned forest for squirrel feeding sign and related vegetation characteristics to frequency of feeding sign occurrence. We used radio‐telemetry within fire‐influenced forest to determine home ranges of Mexican fox squirrels, Sciurus nayaritensis chiricahuae, and compared vegetation characteristics within home ranges to random areas available to squirrels throughout burned conifer forest. Squirrels fed in forest with open understory and closed canopy cover. Vegetation within home ranges was characterized by lower understory density, consistent with the effects of low‐severity fire, and larger trees than random locations. Our results suggest that return of low‐severity fire can help restore habitat for Mexican fox squirrels and other native wildlife species with similar habitat affiliations in forests with a historical regime of frequent, low‐severity fire. Our study contributes to an understanding of the role and impact of fire in forest ecosystems and the implications for forest restoration as fire returns to the region.     

Does forest restoration using taungya foster tree species diversity? The case of Afram Headwaters Forest Reserve in Ghana

The taungya agro‐forestry system is an under‐researched means of forest restoration that may result in high tree diversity. Within a forest reserve in Ghana, the forest core and its surrounding Teak‐ and Cedrela‐taungya on logged, cropped and burned land were mapped with ALOS satellite imagery. Native trees, seedlings and saplings were enumerated in 70 random, nested plots, equally divided between forest and taungya. The native tree regeneration was assessed by species richness (SR), Shannon‐Wiener Index (SWI), Shannon Evenness Index (SEI) and species density (SeD) for seedlings, saplings and trees separately and combined and subsequently correlated with canopy covers (CC) in taungya. As anticipated, the taungya diversity was lower than the forest diversity but higher than reported from nontaungya exotic plantations. In the forest, the diversity of native trees increased from seedlings through saplings to trees. The reverse was found in the taungya. Taungya seedling diversity was not significantly different from the forest, while the sapling and tree diversity were significantly lower. Weak correlations of CC with SR, SWI, SEI and SeD were found. Our results suggest the need for treatment to maintain the tree diversity beyond the seedling stage in the taungya.     

Vegetation Recovery in Slash‐Pile Scars Following Conifer Removal in a Grassland‐Restoration Experiment

A principal challenge to restoring tree‐invaded grasslands is the removal of woody biomass. Burning of slash piles to reduce woody residues from forest restoration practices generates intense, prolonged heating, with adverse effects on soils and vegetation. In this study, we examined vegetation responses to pile burning following tree removal from conifer‐invaded grasslands of the Oregon Cascades. We quantified the longevity and magnitude of fire effects by comparing ground conditions and the cover and richness of plant species in burn‐scar centers (higher‐intensity fire) and edges (lower‐intensity fire) with adjacent unburned vegetation 7 years after treatment. We interpreted patterns of recovery through the responses of species with differing growth forms, habitat affinities, and clonality. Cover of bare ground remained elevated at the centers, but not at the edges of scars; however, much of this effect was due to gopher disturbance. Total plant cover, consisting entirely of native species, was comparable in and adjacent to scars. However, richness remained depressed at the scar centers. Cover of grass, meadow, and non‐clonal species was comparable in and adjacent to scars, but cover of forb, sedge, residual forest, and clonal species was reduced at the centers. Although scar centers had a simpler community structure (fewer but more abundant species) than the adjacent vegetation, they remained free of exotics and recovered quickly, aided by the soil‐disturbing activities of gophers and the regenerative traits of native, disturbance‐adapted species. Pile burning can be a viable and efficient approach to fuel reduction in the absence of exotics.     

Post‐fire succession and 20th century reduction in fire frequency on xeric southern Appalachian sites

Abstract. We document post‐fire succession on xeric sites in the southern Appalachian Mountains, USA and assess effects of 20th century reduction in fire frequency on vegetation structure and composition. Successional studies over 18 yr on permanent plots that had burned in 1976–1977 indicate that tree mortality and vegetation response varied with fuel load and fire season. In the first three years after fire, hardwood sprouts dominated tree regeneration. On sites where summer and autumn fires reduced litter depth to less than 1 cm, densities of shade‐intolerant Pinus seedlings increased steadily over this period. 4 to 8 yr after fire, large numbers of newly established seedlings and sprouts had grown to 1 – 10 cm DBH. By year 18 growth of these saplings led to canopy closure on most sites. Herbaceous cover and richness peaked in the first decade after fire, then declined. On similar sites that had not burned in more than 50 yr, regeneration of shade‐intolerant Pinus spp. and mean cover and richness of herbs were considerably lower than those observed on recently burned plots. Reconstructions of landscape conditions based on observed post‐fire succession and 20th century changes in fire regime suggest that reductions in fire frequency circa 1940 led to substantial changes in forest structure and decreases in cover and richness of herbaceous species.     

Roller Chopping Effectively Reduces Shrub Cover and Density in Pine Flatwoods

Changes to fire regimes have resulted in excessive shrub growth and declines in the species rich herbaceous ground layer of pyric savanna and grassland systems worldwide, including the pine flatwoods of the Southern Coastal Plain of the United States. Prescribed burning and roller chopping during growing (April–October) and dormant (November–March) seasons are management practices promoted to reduce shrub invasion and increase herbaceous plant growth in flatwoods. However, relatively little is known about the seasonal effects these activities have on shrubs and herbaceous vegetation. We assessed the effects of prescribed burning and roller chopping on herbaceous and shrub characteristics in pine flatwoods and explored how grazing may mediate these treatments. We used a paired design, with comparison made between sampling locations randomly located within treated (e.g. burned) and adjacent untreated areas. Growing season burning was more effective at reducing shrub cover and height than dormant season burning. However, shrub re‐growth occurred the second year post‐burn. Roller chopping and roller chopping/burning combinations led to decreases in shrub cover and height for 2 years post‐treatment. Decreases in shrub density were seen on sites subject to growing season roller chopping and grazing. Decreases in herbaceous vegetation were observed following all treatments, possibly the result of grazing. If reductions in shrub density are required, growing season roller chopping in combination with grazing may be the only effective treatment. However, initial deferment from grazing following burning and roller chopping treatments may be necessary to permit re‐establishment and growth of forbs and graminoids.     

Effects of Prescribed Fires on Young Valley Oak Trees at a Research Restoration Site in the Central Valley of California

Woodland restoration sites planted with Quercus lobata (valley oak) often have serious invasions of nonnative annual grasses and thistles. Although prescribed fire can effectively control these exotics, restoration managers may be reluctant to use fire if it causes substantial mortality of recently planted saplings. We studied the effects of prescribed fires on the survival and subsequent growth of 5‐ and 6‐year‐old valley oak saplings at a research field near Davis, California. One set of blocks was burned in summer 2003 at a time that would control yellow star thistle, a second set of blocks was burned in spring 2004 at a time that would control annual grasses, and a third set was left unburned. Very few oaks died as a result of either fire (3–4%). Although a large proportion was top‐killed (66–72%), virtually all these were coppiced and most saplings over 300 cm tall escaped top‐kill. Tree height, fire temperature, and understory biomass were all predictive of the severity of sapling response to fire. Although the mean sapling height was initially reduced by the fires, the growth rates of burned saplings significantly exceeded the growth rates of unburned control trees for 2 years following the fires. By 2–3 years after the fires, the mean height of spring‐ and summer‐burned saplings was similar to that of the unburned control saplings. The presence of valley oak saplings does not appear to preclude the use of a single prescribed burn to control understory invasives, particularly if saplings are over 300 cm tall.     

Removal of Encroaching Conifers to Regenerate Degraded Aspen Stands in the Sierra Nevada

Aspen is considered a keystone species, and aspen communities are critical for maintaining biodiversity in western landscapes. Inventories of aspen stand health across the Eagle Lake Ranger District (ELRD), Lassen National Forest, California, U.S.A., indicate that 77% of stands are in decline and at risk of loss as defined by almost complete loss of mature aspen with little or no regeneration. This decline is due to competition from conifers establishing within aspen stands as a result of modification of natural fire regimes coupled with excessive browsing by livestock. Restoration treatments were implemented in four aspen stands in 1999 using mechanical equipment to remove competing conifers to enhance the growth environment for aspen. Recruitment and establishment of aspen stems were measured in treated stands (removal of competing conifers) and non‐treated stands (control) immediately prior to treatment and 2 and 4 years post‐treatment. There was a significant increase in total aspen stem density and in two of three aspen regeneration size classes for treated stands compared to controls. Pre‐treatment total aspen density was positively associated with total aspen density and density in all size classes of aspen (p < 0.001). The results demonstrate that mechanical removal of conifers is an effective treatment for restoring aspen.     

塔河林业局林火对植被的影响

针对大兴安岭地区塔河林业局不同林型下,不同火烧强度的火烧迹地的森林植被更新及恢复情况进行了调查研究。结果表明：（1）针叶林过火迹地上,落叶松幼苗较少,阔叶树萌条更新强度同火烧程度成正比;火烧前生长有白桦、赤杨的林地上,火烧后阔叶树成为主导树种,林相完全发生变化。（2）重度火烧下有利于天然更新,促使白桦、山杨萌生。中度火烧最初形成以杨桦为优势树种的阔叶林,后逐渐演变为针阔混交林。轻度火烧有利于针叶林的更新。（3）火烧后不同林型下灌木草本植被种类变化不同。从盖度方面来看,杜鹃落叶松林型中林下灌木草本更新最为良好。     

Short‐term bryoid and vascular vegetation response to reforestation alternatives following wildfire in conifer plantations

Question: How are dynamics of early‐seral post‐fire vascular plant and bryoid (terrestrial mosses, lichens, and fungi) vegetation impacted by reforestation activities, particularly manual vegetation removal and planting density? Does the relationship between vegetation dynamics and vegetation removal differ between harsh (west‐facing) and moderate (east‐facing) aspects? Location: Five high‐severity burn plantation forests of Pseudotsuga menziesii in southwestern Oregon, USA. Methods: Plantations severely burned in a recent wildfire were planted with conifer seedlings as a four‐species mixture or a monoculture, at two different densities, with and without manual vegetation removal. A subset of plots was also planted on a contrasting aspect within each plantation. The contrasting aspects differed in potential solar insolation and were indicative of moderate (eastern exposure) and harsh (western exposure) site conditions. Covers of shrub, herbaceous and bryoid vegetation layers were measured during reforestation activities 2–4 yr after the fire. Dynamics of structural layer cover and community composition were compared among treatments with analysis of variance and multivariate analyses (non‐metric multidimensional scaling and blocked multi‐response permutation procedure). Results: Structural layer cover and community composition differed between areas that received reforestation treatments and untreated areas. However, variability within treatments in a plantation was greater than variability within treatments across plantations. Effects of vegetation removal on composition and structure were more evident than effects of planting or altering planting density. Vegetation removal decreased cover of tall and low shrub and the bryoid layer, and increased herbaceous layer cover. Bryoid community and low shrub structural layer responses were more pronounced on moderate aspects than on harsh aspects. Vegetation removal shifted vascular plant community composition towards exotic and annual species. Conclusions: These reforestation treatments may be implemented without substantially altering early‐seral vegetation community composition dynamics, especially in areas with harsh site conditions. Site conditions, such as aspect, should be evaluated to determine need and potential effects of reforestation before implementation. Monitoring for exotic species establishment should follow reforestation activities.     

Shrub Cover Influence on Seedling Growth and Survival Following Logging of a Tropical Forest

Logging in tropical forests may create large canopy openings. These gaps provide suitable conditions for some opportunistic shrubs and herbs to take advantage of the surge in resources and rapidly colonize disturbed sites. This dense plant cover may limit forest regeneration by interfering with tree seedling establishment, growth, and survival by altering the light and nutrients available to seedlings, modifying herbivore behavior, or a number of other factors. In Kibale National Park (Uganda), old logging sites are mainly covered by dense stands of Acanthus pubescens Engl., which appear to inhibit tree regeneration. We wanted to identify the ecological processes underlying this regeneration collapse. To do so, we designed a factorial experiment to evaluate the influences of herbivory and vegetation cover on the growth and survival of tree seedlings. We compared the survival and growth of transplanted tree seedlings in A. pubescens stands and logged forests, in the presence or absence of the understory vegetation layer (logged forest) or vegetation cover (A. pubescens), and with or without herbivory. We found no evidence to support the hypothesis that herbivory is significantly higher under dense A. pubescens cover. Seedling survival was not influenced by the environment. Seedling growth, however, was positively influenced by the removal of A. pubescens, suggesting that changes in resource availability associated with the presence of A. pubescens, may be important for regeneration. Our results suggest that sustained cutting of A. pubescens cover could foster the growth of established seedlings and could lead to tree regeneration and habitat restoration.     

Effects of heterogeneity of pre-fire forests and vegetation burn severity on short-term post-fire vegetation density and regeneration in Samcheok,Korea

This study investigated the combined effects of heterogeneity of pre-fire forest cover and vegetation burn severity on post-fire vegetation density and regeneration at an early stage in Samcheok, Korea. To measure the spatial heterogeneity of pre-fire forests, spatial pattern metrics at a landscape level and class level were adopted, and a regression tree analysis for post-fire vegetation density and regeneration was used to avoid spatial autocorrelation. Two regression tree models were estimated for post-fire vegetation density and post-fire vegetation regeneration with the same independent variable sets, including heterogeneity of pre-fire forest cover and vegetation burn severity. The estimated model suggested that the percentage of Japanese red pine and burn severity were the most significant variables for post-fire vegetation density and regeneration, respectively. The compositional and spatial heterogeneity of pre-fire forest and burn severity, as well as the degree of burn severity, was found to have significant impacts on post-fire vegetation density and regeneration. Overall, more rapid vegetation regeneration can be expected in more severely burned areas. However, this rapid vegetation regeneration at an early stage is due mostly to perennials and shrubs, not to the sprouting or regrowth of trees. The study results strongly indicated that a susceptible forest cover type and its spatial patterns directly influence the heterogeneity of burn severity and early vegetation density and regeneration. Hence, the management of susceptible forest cover types is particularly critical for establishing more fire-resilient forests and for post-fire forest restoration.