Red spruce is a shade-tolerant conifer whose distribution and abundance reflect Quaternary climate history as well as natural and anthropogenic disturbances. This species once extended further south than its present localities, because of natural and anthropogenic disturbances such as logging, windthrow, and fire. Little is known about the disturbance regime of this species, because long term stand dynamics are difficult to obtain. This-long lived species is hypothesized to be suffering a decline in radial growth, density and abundance at the present time. Recent research suggests pollution, biotic stresses, climate change and natural stand dynamics are the driving forces behind these decreases. The purpose of this study is to investigate the influence of fire in a mesic ecosystem, specifically a high-elevation red spruce (Picea rubens Sarg.) forest on Whitetop Mountain in the southern Appalachian Mountains. Six plots were established in a high elevation red spruce stand to characterize the stand composition. Tree ring data were collected to investigate radial growth relations to inter-annual climatic variability and cross-sections were used to investigate fire history. Red spruce continued to establish throughout the 19th century until a severe fire occurred in 1919 and caused a new cohort of yellow birch (Betula alleghaniensis Britt.) to establish within the stand. Logging and fire caused high mortality in the stand, yet many spruce remain that outdate the past disturbances. Red spruce saplings continue to persist in the stand, showing regeneration despite the abundant hardwoods. Moisture was the main contributing factor to red spruce growth in the dendroclimatic analysis. Red spruce radial growth was significantly correlated to high precipitation and low temperatures of the previous growing season, which is similar to recent research results. This study collaborates the current literature on red spruce growth along with the results found here in creating a model to represent the growth characteristics of red spruce when inter-mixed with hardwoods after a severe disturbance.

I investigated spatial and temporal winter behavior and behavioral responses of 5 territorial whooping crane families to human activities at Aransas National Wildlife Refuge during winters 2003-2004 and 2004-2005. Adult and juvenile cranes spent the majority of the day foraging (63% and 66%, respectively). Alert behavior comprised 15% of the cranes' time-activity budgets; preening or resting, and movement each constituted approximately 7% of the time-activity budget. Adults were more alert than juveniles in Jan-Feb. The proportion of time spent in other behaviors did not differ by age. Over-winter use of territories varied spatially and temporally. Flight occurrence was highest in Nov-Dec, coinciding with establishment of territorial boundaries upon arrival at the wintering grounds. Movement velocity (meters traveled/min) also tended to be highest in Nov-Dec, which may be due to territorial defense and foraging activities. Use of land, open water, and edge habitats (land and water interface) within territories appeared to fluctuate with primary food item availability. Disproportionate use of land habitat by several crane families coincided with peak production of wolfberry (Lycium carolinianum) fruit, which occurs in Nov-Dec. Edge habitat was used disproportionately to its availability throughout the winter, most likely because this habitat type provided refuge for blue crabs (Callinectes sapidus), an important food item for whooping cranes. Several families also used open water disproportionately to its availability. Behavioral responses of whooping cranes to human activities were limited. Responses to varying frequency and intensity of human stimuli were evaluated. Most stimuli did not elicit a response. Two crane families decreased the proportion of time spent foraging during periods of high-intensity stimuli; one family increased movement during such times. Foraging behavior of one family was significantly higher when stimuli frequency was high; alert behavior significantly declined as stimuli frequency increased. The mixed responses of territorial families to varying levels of human stimuli paired with the overall high level of reproductive success of the entire population led to my conclusion that current levels of human activities are not having a detrimental impact on the Aransas-Wood Buffalo whooping crane population.

Open coastlines are dynamic environments which experience seasonal and long-term physical changes. Sandy beaches line much of this coastline. As part of the requirements for Ph.D., I conducted a study examining intertidal macrofaunal and sedimentological features along the upper Texas coastal from 2007-2009. Four sites near Sabine Pass, High Island, Jamaica Beach, and Surfside Beach were selected. Beach transects were established at each site with six intertidal stations identified for collecting macrofaunal sediment core samples. Although sandy beaches are low in species diversity, the taxa found survive under dynamic and harsh conditions. In disturbance dominated environments, sandy beach fauna tended to be influenced by physical factors, instead of biologically controlled ones. The taxa found in this study include primary and secondary successional organisms which are adapted to handle disturbances. 98% of the benthic specimens identified belonged to six taxa with 92% from two taxa, Scolelepis squamata (38%) and Haustoriidae (54%). Macrofaunal zonation varied between sites because of beach geomorphology. On September 13, 2008, Hurricane Ike made landfall on the upper Texas coast causing extensive damage and erosion. Roughly 0.5 m of vertical height was lost at each beach post-storm. Total macrofaunal abundance declined by 87% from pre-storm counts. During the recovery the dominant two taxa, Haustoriidae and Scolelepis squamata, made up 82.78% of the total benthic specimens identified with haustoriids making up 68% of the total benthic taxa. The beach community remained dominated by four of the previously identified, six most common and abundant taxa. Recovery of sandy beaches often was hindered by increased vehicular traffic, sand removal and cleaning. Beach ecosystems have shown a high natural ecological resilience, but do not preclude the possibilities of habitat extinction and/or catastrophic community regime shift. Beaches are highly susceptible to human exploitation and global climate change, such as sea level rise. Knowledge of beach macrofaunal diversity along the Texas coast, such as haustoriids, could be used to estimate beach health and better evaluate the upward effects of natural disturbance, pollution and human uses on an integral part of the coastal ecosystem.

SAS has become an increasingly important public-health problem in recent years. It can abversely affect neurocognitive, cardiovascular, respiratory diseases and can also cause behavior disorder. Moreover, up to 90¢H of these cases are obstructive sleep apnea (OSA). Therefore, it is important that how to diagnose, detect and treat OSA. The respiratory disturbance index is one parameter of estimating OSA. Polysomnography can monitor the OSA with relatively fewer invasive techniques. However, polysomnography-based sleep studies are expensive and time-consuming because they require overnight evaluation in sleep laboratories with dedicated systems and attending personnel. Based on the digital oximetry, this work introduces the estimating respiratory disturbance index. In particular, via signal processing, feature parameters and artificial intelligence, this thesis describes an off-line SpO2-based RDI estimating system.

¡@¡@Taiwan is surrounded by sea, there are coral reefs at both south and north ends, and also at off-shore islands. Coral reef offers habitat and resources for marine animals, that are attracted to in numbers, however due to the limited resources, competitions and conflicts are common among animals. In order to defend the territory on intimidate intruder, some fishes develop vocal mechanism that certain sounds are generated at encounter. The sounds of common Holocendridae fishes at coral reef were studied before, but the sound characteristics of sound were not fully investigated. In this research, sound samples were recorded from Neoniphon sammara, Myripristis murdjan, and Sargocentron spinosissimum(Holocentridae) in an indoor water tank, to understand more about their specific features of sounds generated at disturbance. The identification system of this study was based on Matlab, which extracted the characteristic parameters from the sounds, so the database for comparison can be formed. The sounds can be classified into single pulse and pulse train, and the parameters used are dominant frequency, band width, duration, and pulse repetition rate. As the result, Neoniphon sammara has single pulse frequency of 428.0¡Ó95.0 Hz (mean ¡Ó standard deviation), pulse train frequency of 449.8¡Ó92.4 Hz, Myripristis murdjan has single pulse and pulse train frequency of 375.2¡Ó96.3 Hz and 369.2¡Ó96.0 Hz, and Sargocentron spinosissimum has single pulse and pulse train frequency of 377.6¡Ó93.5 Hz and 387.8¡Ó97.1 Hz. The similarity of sounds between Neoniphon sammara and Myripristis murdjan is 81.3%, between Myripristis murdjan and Sargocentron spinosissimum is 83.6%, and between Neoniphon sammara and Sargocentron spinosissimum is 90.3%. Finally, the identification accuracy of Neoniphon sammara is 78.9%, Myripristis murdjan is 71.4%, and Sargocentron spinosissimum is 38.4%. The low identification accuracy of Sargocentron spinosissimum is due to the high similarity of sounds with Myripristis murdjan, and the number of sound samples is not sufficient.

Ecological communities – groups of interacting species – are subject to a variety of disturbances. Understanding responses to these disturbances is a primary goal of community ecology. The structural complexity of the community and the traits of the community’s constituent species are both known to have a significant impact on a community’s response to a disturbance. In this thesis, we investigated how these two scales – the community level and the species level – interactively affected community responses to both short and long term disturbances. Our first hypothesis was that interaction strength would be weaker in species with many interactions when compared to species with fewer interactions. To test this hypothesis, we used simulated food webs and found that, in locally stable food webs, species with many interactions tended predominantly to have interactions with predators or with prey. While these many predator or prey interactions were weak, they tended to be balanced by a few interactions of the opposite type (with prey or predators) which were stronger than average. The structure of the network, where species had predominantly one type of interaction, was essential for this relationship between the number and strength of interactions to arise. Our second study investigated how food webs of varying size and connectance respond to press and pulse disturbances. Many studies of food web stability only focus on the response to short term or “pulse” disturbances, however, as anthropogenic impacts on food webs increase, it is important to increase our understanding of food web responses to long term or “press” disturbances and determine whether they follow the same pattern as pulse disturbances. We found that more species rich and connected food webs were less stable to both types of disturbance and the more stable a food web was to a pulse disturbance, the more stable it was to a press disturbance as well. We also found that the traits – trophic level and number of interactions – of the disturbed species impacted a food web’s resistance to a press disturbance. Food webs were less resistant to the disturbance of species with many interactions or low trophic level than species with few interactions or high trophic level. The strength of species’ effects on stability was also moderated by the structural complexity of the food web. Together the work that makes up this thesis suggests that, to understand the stability of food webs to any kind of disturbance, we should consider both the structure of the network and the traits of the species embedded within it. While we found that networks were more vulnerable to disturbance of certain species than others, this observation also depended on the structure and complexity of the community they existed in. This has important implications for communities subject to disturbances, especially those disturbances which alter the way in which communities are structured and species interact.

Wind turbines are a cleaner alternative to non-renewable energy, such as fossil fuels, and therefore help to decrease deleterious climate change.[1] Species protection is needed to preserve biodiversity, which is important to all species.[2] It is claimed, how­ever, that between these interests there is a contradiction. Climate change kills birds, but so do wind turbines. According to some, the expansion of wind power is at risk, being hindered by the rules on protected birds, incorrectly interpreted in art­skyddsförordningen[3], the Swedish counterpart to international species conventions and the EU Birds directive[4].[5] The Birds directive and artskyddsförordningen prohibits activi­ties that deliberately kill, capture or disturb migratory birds in the EU (art. 5 Birds directive and 4 § artskyddsförordningen). Mark- och miljööverdomstolen has for some years made the assessment that the establishment and operation of wind turbines may be prohibited by reason of the protection of species, even though the purpose of wind power is to produce electricity and not to kill birds.[6] Due to the legal uncertainty, this essay seeks to find out whether wind energy can fall within art­skyddsförordningens prohibitions and if so, when. This is done through a legal dog­matic method, complemented with a comparative section. The legal situation is not clear, but after a thorough examination of the origin of the Birds directive, previous case law, new disputed ruling by Mark- och miljööver­domstolen, Danish and German case law, ECJ rulings and guidance documents from the European Commission, in total it seems that an inappropriate placement of wind farms or plants can and sometimes should be seen as a deliberate act in respect of the Birds directive and consequently artskyddsförordningen. That is, unless it is possible to under­take precautionary measures, which neutralizes the act. It also appears that art­skyddsförordningen still is to be applied within chapter 2 miljöbalken[7], in the case of species protection. [1] SOU 1999:75, s. 29 f. [2] SOU 2004:37, s. 189. [3] Artskyddsförordningen (2007:845). [4] Directive 2009/147/EC of the European parliament and of the council of 30 November 2009 on the conservation of wild birds. [5] Mark- och miljööverdomstolen har klargjort att vindkraft inte innebär ett avsiktligt dödande eller störande enligt artskyddsförordningen – kommentar av Magnus Fröberg och Hedvig Ekdahl, 2015-01-23, JP Infonet. [6] Se exempelvis MÖD 2013:13. [7] Miljöbalken (1998:808).

Arctic ecosystems are experiencing rapid changes as a result of climate warming and more frequent natural and human-caused disturbances. Disturbances can have particularly large effects on high-latitude ecosystems because ecosystem structure and function is controlled by strong feedbacks between soil conditions, vegetation, and ground thermal regime. My MSc. research used fieldwork and broad-scale GIS data to investigate post-disturbance ecosystem recovery along roads in two permafrost zones (discontinuous and continuous). In the first of two case studies, I focussed on tall shrub proliferation along the Dempster Highway at the Peel Plateau, NT. To explore the drivers of tall shrub proliferation and to quantify shrub expansion in this region of continuous permafrost, greyscale air photos (1975) and Quickbird satellite imagery (2008) were used to map landcover change within a 1.2 km buffer next to the road and inside a buffer 500 m away from the road. Extensive tall shrub proliferation in the study area indicates that warming air temperatures and disturbance both facilitate vegetation change in tundra environments. My findings also indicate that accelerated shrub expansion adjacent to the road was caused by increased soil moisture. Tall shrub proliferation adjacent to the road occurred at lower elevation sites characterized by wetter soils with thicker organic layers. Areas that resisted tall shrub encroachment were located at higher elevations and had drier soils with thin organic layers. These observations also support previous work that illustrates that tall shrub expansion next to the highway promotes strong positive feedbacks to ongoing shrub growth and proliferation. In a second case study I examined ecosystem recovery in an area of discontinuous permafrost 30 years after construction and abandonment of a winter access road in Nahanni National Park Reserve. Ecosystem recovery was studied by comparing disturbed (road) and undisturbed (adjacent to the road) sites in spruce muskeg, black spruce parkland, deciduous forest, and alpine treeline terrain. Field data showed that disturbances to discontinuous permafrost terrain can lead to large and persistent changes to ecosystem composition and structure. In spruce muskeg, permafrost thaw triggered by road construction dramatically increased soil moisture and facilitated a transition from spruce muskeg to sedge wetland. At alpine treeline the removal of stabilizing vegetation and organic soil during construction slowed subsequent ecosystem recovery. These findings are consistent with resilience theory that predicts that changes to key environmental factors will increase the likelihood of regime shifts. In terrain types where disturbance fundamentally alters ecosystem processes, the management of disturbance impacts in NNPR will be extremely difficult. Overall, this thesis contributes to our understanding of effects of disturbance on vegetation and abiotic conditions, and provides insight into the future of high-latitude ecosystems in a warmer climate with increased disturbance. / Graduate

Forest disturbance is expanding in rate and extent and is affecting many montane catchments critical to water resources. Western North America is experiencing an epidemic of mountain pine beetle (MPB) that has affected 20 million hectares of forest in Canada and the United states. This epidemic may have long-lasting consequences for coupled cycles of water, energy, and biogeochemicals. While impacts of forest disturbance by fire and harvest have been studied for more than a half-century, insect-driven mortality differs from these events in the timing and accompanying biophysical impacts. In this work, we quantified catchment hydrologic and hydrochemical response to severe MPB infestation in a lodgepole pine ecosystem. Observations were organized laterally in a nested fashion from soil observations to nested headwater catchments. Vertical observations encompassed what is often termed the critical zone, from atmospheric interactions at the top of the forest through the ground surface and the rooting zone to the interface with groundwater. We quantified responses manifest in snowpack, the primary hydrologic input to this montane ecosystem, in water partitioning between vapor flux and streamflow, and in biogeochemical patterns across the landscape. Key findings of this study include 1) Loss of shelter from the atmosphere caused compensatory sublimation of snowpack to offset decreased interception losses after MPB-driven canopy loss; 2) Vaporization at multiple scales increased over time and in comparison to control forest, reducing water available for streamflow; 3) Nitrogen (N) concentrations were elevated in hillslope groundwater, but attenuation in the riparian zone protected streams from major N influx; and 4) headwater streams rapidly attenuated dissolved carbon (C) and N inputs. Collectively these results demonstrate compensatory negative feedbacks which help explain the lack of strong response to streamflow and stream chemistry observed in the recent MPB epidemic.

Forest disturbance is expanding in rate and extent and is affecting many montane catchments critical to water resources. Western North America is experiencing an epidemic of mountain pine beetle (MPB) that has affected 20 million hectares of forest in Canada and the United states. This epidemic may have long-lasting consequences for coupled cycles of water, energy, and biogeochemicals. While impacts of forest disturbance by fire and harvest have been studied for more than a half-century, insect-driven mortality differs from these events in the timing and accompanying biophysical impacts. In this work, we quantified catchment hydrologic and hydrochemical response to severe MPB infestation in a lodgepole pine ecosystem. Observations were organized laterally in a nested fashion from soil observations to nested headwater catchments. Vertical observations encompassed what is often termed the critical zone, from atmospheric interactions at the top of the forest through the ground surface and the rooting zone to the interface with groundwater. We quantified responses manifest in snowpack, the primary hydrologic input to this montane ecosystem, in water partitioning between vapor flux and streamflow, and in biogeochemical patterns across the landscape. Key findings of this study include 1) Loss of shelter from the atmosphere caused compensatory sublimation of snowpack to offset decreased interception losses after MPB-driven canopy loss; 2) Vaporization at multiple scales increased over time and in comparison to control forest, reducing water available for streamflow; 3) Nitrogen (N) concentrations were elevated in hillslope groundwater, but attenuation in the riparian zone protected streams from major N influx; and 4) headwater streams rapidly attenuated dissolved carbon (C) and N inputs. Collectively these results demonstrate compensatory negative feedbacks which help explain the lack of strong response to streamflow and stream chemistry observed in the recent MPB epidemic.