18 research outputs found
Nebenbestimmungen bei der Zulassung von Abfallentsorgungsanlagen unter besonderer Berücksichtigung des Instruments der Sicherheitsleistung
No full textSoftcover, 17x24Gegenstand der Arbeit sind die Nebenbestimmungen bei der Zulassung von Abfallentsorgungsanlagen, die einerseits die begehrte Erlaubnis einschränken, andererseits oftmals ihren Erlass überhaupt erst ermöglichen. Den Schwerpunkt der Arbeit bildet eine eingehende Betrachtung der Sicherheitsleistung, die in dem Gefüge von Nebenbestimmungen eine Sonderrolle einnimmt. Es wird untersucht, inwieweit die Regelungen zur Sicherheitsleistung bei der Zulassung von Abfallentsorgungsanlagen im BImSchG und KrWG einen angemessenen Ausgleich der widerstreitenden Interessen im Spannungsverhältnis von Ökonomie und Umweltschutz ermöglichen. Dabei werden auch die Historie, der Gestaltungsspielraum bei der behördlichen Anordnung der Sicherheitsleistung und die verfassungsrechtlichen Implikationen näher beleuchtet. Zudem werden die Spezifika von Abfallentsorgungsanlagen aufgezeigt, die es rechtfertigen, dass die Regelungen der Sicherheitsleistung für die übrigen Anlagenarten des BImSchG grundsätzlich keine Anwendung finden.The subject of the work is the ancillary provisions for the licensing of waste management facilities, which on the one hand restrict the requested permission, but on the other hand often make it possible to issue it in the first place. The main focus of the work is a detailed examination of the security aspects, which play a special role in the structure of collateral clauses. It will be examined to what extent the regulations on security in the licensing of waste management facilities in the BImSchG and KrWG allow an appropriate balance of conflicting interests in the tension between economy and environmental protection. In this context, the history, the scope for action in the official order of the security aspects and the constitutional implications are also examined in more detail. In addition, the specifics of waste management facilities are shown which justify the fact that the regulations of security for the other types of facilities of the BImSchG are generally not applicable
Nebenbestimmungen bei der Zulassung von Abfallentsorgungsanlagen unter besonderer Berücksichtigung des Instruments der Sicherheitsleistung
No full textThe subject of the work is the ancillary provisions for the licensing of waste management facilities, which on the one hand restrict the requested permission, but on the other hand often make it possible to issue it in the first place. The main focus of the work is a detailed examination of the security aspects, which play a special role in the structure of collateral clauses. It will be examined to what extent the regulations on security in the licensing of waste management facilities in the BImSchG and KrWG allow an appropriate balance of conflicting interests in the tension between economy and environmental protection. In this context, the history, the scope for action in the official order of the security aspects and the constitutional implications are also examined in more detail. In addition, the specifics of waste management facilities are shown which justify the fact that the regulations of security for the other types of facilities of the BImSchG are generally not applicable
Nebenbestimmungen bei der Zulassung von Abfallentsorgungsanlagen unter besonderer Berücksichtigung des Instruments der Sicherheitsleistung
No full textThe subject of the work is the ancillary provisions for the licensing of waste management facilities, which on the one hand restrict the requested permission, but on the other hand often make it possible to issue it in the first place. The main focus of the work is a detailed examination of the security aspects, which play a special role in the structure of collateral clauses. It will be examined to what extent the regulations on security in the licensing of waste management facilities in the BImSchG and KrWG allow an appropriate balance of conflicting interests in the tension between economy and environmental protection. In this context, the history, the scope for action in the official order of the security aspects and the constitutional implications are also examined in more detail. In addition, the specifics of waste management facilities are shown which justify the fact that the regulations of security for the other types of facilities of the BImSchG are generally not applicable
Efficacy of prescribed fire as a fuel reduction treatment in the Colorado Front Range
No full textPrescribed fires are an important management tool for reducing fuels and returning fire to the landscape. However, rarely are changes in fuels fully quantified using pre to post prescribed fire measurements and those studies that do exist show variable results. In the southern Rockies little literature exists on the impacts of prescribed fires, thus we examined multiple prescribed fires in northern Colorado to understand fire effects and changes in fuel complexes. Most prominently, prescribed fires influenced litter, duff, and rotten coarse woody debris but did not influence other surface fuels. Crown base height increased and tree density decreased, while basal area was relatively unimpacted. Season of burning impacted fire effects as substrate burn severity, bole char, and crown volume scorched were highest in summer and fall. Continued monitoring of prescribed fires is critical to understand the influence of prescribed fire on wildfires and ultimately improve prescribed fire outcomes.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Prior wildfires influence burn severity of subsequent large fires
No full textWith longer and more severe fire seasons predicted, incidence and extent of fires is expected to increase in western North America. As more area is burned, past wildfires may influence the spread and burn severity of subsequent fires, with implications for ecosystem resilience and fire management. We examined how previous burn severity, topography, vegetation, and weather influenced burn severity on four wildfires, two in Idaho, one in Washington, and one in British Columbia. These were large fire events, together burning 330,000 ha and cost $165 million USD in fire suppression expenditures. Collectively, these four study fires reburned over 50,000 ha previously burned between 1984 and 2006. We used sequential autoregression to analyze how past fires, topography, vegetation, and weather influenced burn severity. We found that areas burned in the last three decades, at any severity, had significantly lower severity in the subsequent fire. Final models included maximum temperature, vegetation cover type, slope, and elevation as common predictors. Across all study fires and burning conditions within them, burn severity was reduced in previously burned areas, suggesting that burned landscapes mitigate subsequent fire effects even with the extreme fire weather under which these fires burned.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
The effects of post-fire logging on microclimate and surface fuels
No full text2021 Spring.Includes bibliographical references.Wildfire is increasing in size and severity in forests of the western US, driven by climate change and land management practices during the 20th century. Altered fire regimes have resulted in a greater need for knowledge on best practices for managing burned landscapes, especially in instances where a return to a previous forested ecosystem is desired. Our study location was the Spring Creek Fire in the Rockies of Colorado, where we examined soil moisture, soil temperature, and soil disturbance as well as surface fuel loading and understory vegetation recovery in areas that burned at low and high severity, a subset of which received post-fire logging treatments. Two years post-fire, we found no difference in understory vegetation response; however, logged sites demonstrated lower daily average and minimum soil moisture and higher fuel loading across most fuel size classes, and were more likely to show evidence of compaction, erosion, and rutting. This suggests that post-fire logging may create unfavorable conditions for tree regeneration while increase short term site susceptibility to reburns. Careful consideration should be taken when conducting post-fire logging to prevent detrimental ecological effects
The ecological effects of multiple disturbances on subalpine forest structure and recovery in a changing climate
No full text2020 Fall.Includes bibliographical references.Due to the shifting global climate, the severity, size, and frequency of climate-driven disturbances are increasing, inevitably causing disturbances to interact in time and space. Bark beetle epidemics and wildfires have historically shaped the disturbance regimes of western North American forests. Their interactive effects on stand dynamics and recovery are inadequately studied in Engelmann spruce (Picea engelmannii)- subalpine fir (Abies lasiocarpa) dominant forests; understanding these interactions is imperative to the management and health of forested ecosystems. Tree seedling densities and species composition, surface fuel loading, and stand structure characteristics were compared across 80 sites that experienced either high tree mortality from epidemic spruce beetle outbreaks (>50% affected basal area), high-severity wildfire (>90% tree mortality), post-outbreak high-severity wildfire (1-3 years post-outbreak), or no disturbance (control) in northern Colorado and southern Wyoming. The beetle-affected sites span multiple years post-outbreak from 1996-2017, ultimately comprising a chronosequence of beetle-affected stands. Structural changes in subalpine stands following spruce beetle outbreaks include species compositional shifts in overstory trees, and significant increases in fuel loading over time-since-outbreak. Tree seedling densities among outbreak and control sites differ significantly from burned areas, indicating that wildfires override the effects of repeated disturbances on regeneration. While a cursory assessment of post-outbreak regeneration based on height resulted in the appearance of consistent and stable forest recovery, subsequent aging techniques shed additional light on the drivers of subalpine tree establishment. Subalpine tree regeneration may remain suppressed in the understory for over a century; post-outbreak recovery dynamics cannot be fully understood through the use of height as a proxy for seedling age. Given the strong correlation between Engelmann spruce and subalpine fir establishment with cool and moist growing conditions, there remains significant uncertainty about post-disturbance recovery and the persistence of spruce-fir forests in a warming and drying world. It is critical to understand post-disturbance fuel dynamics and stand recovery to identify hazards for subsequent fire suppression, implement treatments to enhance forest resilience, and to understand the potential consequences of climate-induced shifts in disturbance regimes on forest health
Disturbance promotes native bee biodiversity in a southwestern ponderosa pine forest
No full text2021 Summer.Includes bibliographical references.Native bees are critical components of ecosystems where they provide an estimated 85% of pollination services. In recent decades, reports of global decline in bee populations have drawn concern from conservationists, compelling the need for further research on the drivers and mechanisms influencing the diminishment of native bee populations. In ponderosa pine ecosystems, land management tactics of the late 19th and early 20th century, particularly fire suppression policies, promoted dense stand structures with closed canopies, a suppressed understory, and increased surface fuel loadings. Forest restoration practices including thinning of stands and re-introduction of fire are utilized as a technique to restore historical ecosystem structures, and restoration goals in southwestern ponderosa pine forests may align with conservationists' goals of creating desirable habitat for bees by promoting resource patch connectivity, growth of understory floral species, and landscape heterogeneity. However, despite the widespread implementation of ecological restoration tactics in western forests, the effects of restoration and disturbance in general on native bee communities are not understood but could have important consequences for ecosystem function. To address this knowledge gap, the objectives of this thesis are: (1) describe the response of native bee communities to ecological disturbance, including wildfire, managed fire, and forest density reduction treatments, (2) identify structural components of ponderosa pine forests associated with site occupancy by native bees, and (3) inventory and describe the native bee fauna present in a common forest type of the Colorado Front Range. In two separate studies, native bee communities were sampled within lower-montane ponderosa pine forest systems along the Colorado Front Range over a 2-year period. Sites were representative of various wildfire severities (high and low) and forest management treatments (prescribed fire and mechanical thinning). I quantified bee α- and β-diversity and compared diversity metrics to variation in forest structure, foraging resources (floral abundance and richness), and nesting habitat (woody material). In total, 2,177 bee specimens were collected. Overall γ-diversity consisted of 5 families (Andrenidae, Apidae, Colletidae, Halictidae, and Megachilidae), 25 genera, and at least 57 species. Four main findings emerged: (1) bee species richness and diversity varied across disturbance types and were highest within 1-year post-fire and high-severity wildfire stands, (2) unique bee community compositions were associated with different disturbance types but also varied across the growing season, (3) treatment type (non-treated, thinned, or burned) was associated with differences in bee functional variation, especially nesting behavior, and (4) floral resource abundances and richness were associated with increased bee abundance, richness, and α-diversity, though stand basal area was negatively correlated with bee abundance and species richness. These collective findings have implications for forest management and indicate structural elements of ecosystems that can be managed for enhancing bee biodiversity. The data presented in this thesis provide evidence that fire-disturbed forest stands generally promote bee site occupancy compared to non-burned control stands, but this effect is likely to peak shortly after fires and then decline. In addition, distinct bee assemblages were found in stands that experienced different disturbances (e.g., thinned vs. burned vs. non-disturbed), indicating that a mosaic of disturbance histories is likely to support the greatest bee biodiversity at a landscape-scale. Further, findings here elucidate habitat structural components, specifically stand basal area and floral resource richness, that can be targeted by land managers to facilitate site occupancy by bees. Accordingly, I conclude that forest restoration practices including thinning and prescribed fire use, as well as natural fire disturbances, likely promote pollinator abundance and diversity (and ostensibly pollination services) in semi-arid ponderosa pine forests of the southwestern United States
Post-fire vegetation and bird habitat use in piñon-juniper woodlands
No full text2022 Spring.Includes bibliographical references.Global climate change has caused fire activity and behavior to shift from historical norms due to hotter and drier conditions. Although the ecological effects of changing fire regimes have been explored in many systems, the resilience of some forest types, such as piñon-juniper, are often overlooked. Piñon-juniper is a dominant forest type in the western US and provides breeding habitat for many obligate or semi-obligate bird species. Similarly, this system is supported by a critical mutualism, where the regeneration and infilling of these trees is reliant on several bird species that disperse piñon pine and juniper seeds. This study aimed to assess woodland resilience by evaluating post-fire forest structure and the associated avian communities one-year and 20+ years post-fire. More specifically, seedling regeneration and the habitat use of piñon-juniper obligate bird species, semi-obligates, piñon seed dispersers, and juniper seed dispersers were compared across burned, refugia, and unburned patches. Replicate patches of each habitat type were selected within three fire locations, and 3-4 bird point count stations and 1 forest inventory plot were established in each patch. No tree regeneration was observed 1-year post-fire, and after 25 years, there were few juniper seedlings and no piñon seedlings observed in burned plots. Seedling regeneration and forest structure in refugia and unburned plots were not different, regardless of fire age. Results from occupancy models indicated that Woodhouse's Scrub-jay, a piñon seed disperser, used all habitats equally. American Robin had the highest habitat use in the recent burned patches. Obligate and semi-obligate bird species had differing responses to habitat types, with the habitat use of Ash-throated Flycatcher and Spotted Towhee not differing across habitat types, Virginia's Warbler having the highest habitat use in old burn and refugia patches, the Gray Vireo, Black-throated Gray Warbler, and Gray Flycatcher having highest habitat use in unburned, refugia, and recent burn patches, and the Blue-grey Gnatcatcher having the highest habitat use in the old burn. While there is a need for longer term studies, our work highlights that even 25 years post-fire, little tree recovery is observed and the associated bird species continue to differ, emphasizing the potential transition or long recovery time in these sensitive areas
