Physical Sciences and Mathematics Commons^™

Natural Regeneration Of Severely Degraded Terrestrial Arid Ecosystems Needs More Than Just Removing The Cause Of The Degradation, M. Louhaichi, M. Gamoun, N. Al Hashash, F. Al-Ameer, D. Alrashedi, A. Redha, F. Alkandari, A. Niane

IGC Proceedings (2001-2023)

Rangelands cover over 75% of Kuwait’s total land area. Most of these rangelands are severely degraded because of overgrazing, poor anthropic utilization, and mismanagement. Restoring natural rangelands is a way to increase forage productivity, enhance biodiversity, and achieve sustainable development. When degradation has not reached the point of irreversibility, natural restoration through resting is one of the best low-cost restoration techniques. This study evaluated the effect of natural restoration on vegetation cover and species richness in the desert rangelands of Kuwait. The studied rangeland was a completely fenced area of 1 km2. The percent of vegetation was measured using the …

Do Species And Functional Diversity Indices Reflect Changes In Grazing Regimes And Climatic Conditions In Northeastern Spain?, F. De Bello, J. Leps, M. T. Sebastià

IGC Proceedings (2001-2023)

Understanding the mechanisms that maintain biodiversity in various ecosystems enables the development of management practices that prevent degradation (Canals & Sebastia, 2000). Each diversity index reflects some compositional properties and could be influenced differently by stress and disturbance factors (Magurran, 2004). In this study, we aim to reveal 1) which management practices and environmental factors affect biodiversity in rangelands of northeastern Spain and 2) the relationship between species diversity and functional diversity (SD and FD).

Do Species And Functional Diversity Indices Reflect Changes In Grazing Regimes And Climatic Conditions In Northeastern Spain?, F. De Bello, J. Leps, M. T. Sebastià

IGC Proceedings (2001-2023)

Understanding the mechanisms that maintain biodiversity in various ecosystems enables the development of management practices that prevent degradation (Canals & Sebastia, 2000). Each diversity index reflects some compositional properties and could be influenced differently by stress and disturbance factors (Magurran, 2004). In this study, we aim to reveal 1) which management practices and environmental factors affect biodiversity in rangelands of northeastern Spain and 2) the relationship between species diversity and functional diversity (SD and FD).

River Response To Sediment Supply: The Sand Bed Case, Christina M. Leonard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effective management of in-channel and floodplain habitat requires an ability to forecast river response to changes in water and sediment supply. These changes may result from dam construction/decommissioning, changes in reservoir operations, or changes in grazing or forestry practices. If a change in water and sediment supply causes sediment to be delivered faster than the channel’s capacity to transport it, sediment will accumulate in the reach, leading to changes in channel form and increasing the potential for flooding. A decrease in sediment supply relative to transport capacity can lead to channel incision. The extent and timing of sediment accumulation or …

Disturbance, Vegetation Co-Occurrence, And Human Intervention As Drivers Of Plant Species Distributions In The Sagebrush Steppe, Fiona Claire Schaus Noonan

Boise State University Theses and Dissertations

Changes in fire regimes, invasive species dynamics, human land use, and drought conditions have shifted important plant species in the Northern Great Basin (NGB)—including big sagebrush (Artemisia tridentata ssp.), conifers (e.g., Juniperus spp.) and invasive annual grasses (e.g., Bromus tectorum). Characterizing how these overlapping disturbances influence species distributions is critical for land management decision-making. Previous research has explored the individual effects of drought, wildfire, restoration, and invasive species on sagebrush steppe communities, but the specific effects of these disturbances in context with one another remain poorly understood at a landscape scale. To address this …

Interacting Effects Of Disease And Weather Variability On Rangeland Biodiversity Associated With Black-Tailed Prairie Dog (Cynomys Ludovicianus) Colonies, Courtney J. Duchardt, J. D. Hennig, D. Pellatz

IGC Proceedings (2001-2023)

Rangeland ecosystems worldwide are experiencing novel pressures during the Anthropocene, including land conversion, disease dynamics, non-native species, and climate change. These issues can be compounded in rangelands occupied by burrowing rodents. Often considered keystone species important for maintaining rangeland biodiversity, these species often experience widespread control efforts because of their potential to reduce forage for livestock. We examined the effects of climatic variation and disease on bird communities associated with a North American burrowing rodent, the black-tailed prairie dog (Cynomys ludovicianus). Following an outbreak of sylvatic plague (Yersinia pestis) in the prairie dog population, we observed …

Dataset For: Mapping Fire History And Quantifying Burned Area Through 35 Years Of Prescribed Fire History At An Illinois Tallgrass Prairie Restoration Site Using Gis, Erin G. Rowland-Schaefer, Elizabeth M. Bach, Bill P. Kleiman, Holly P. Jones

Research Datasets

Fire was important to pre-colonization prairies. In today’s remnant and reconstructed prairies, managers frequently employ prescribed fire, a historical management practice that limits woody encroachment, suppresses non-native species, and promotes nutrient cycling. However, few long-term prescribed fire spatial datasets are available for study. We used archived images of prescribed fire maps and hand-drawn fire records to generate a geospatial record of the prescribed fire history at Nachusa Grasslands, a combination remnant and restored preserve in northern Illinois. This record contains maps of the prescribed fire history of the preserve across the entirety of its 35-year history. We used the maps …

Grassland Bird Responses To Bison And Prescribed Fire Disturbances At Nachusa Grasslands And Kankakee Sands, Antonio Del Valle

Graduate Research Theses & Dissertations

Grazing from native herbivores such as bison (Bison bison), in combination with prescribed fire, are applied to tallgrass prairies by managers to recreate important disturbance patterns in this ecosystem. Bird communities may be indirectly impacted by these disturbances through their direct impact on plants that provides critical breeding habitat for grassland birds. The objectives of this research are to determine the impacts that bison and prescribed fire have on grassland breeding birds in two tallgrass prairie preserves, Kankakee Sands and Nachusa Grasslands. Birds, vegetation structure, and bison activity were surveyed systematically at these two preserves in 2020 and 2021. Prescribed …

Biodiversity And Fire In Shortgrass Steppe, Paulette L. Ford

IGC Proceedings (2001-2023)

Effects of fire at two levels of intensity on beetle diversity in shortgrass steppe were examined. The experimental design was completely randomized, with 3 treatments and 4 replicates per treatment. Treatments were two levels of fire 1) dormant-season fire (relatively hot), and 2) growing-season fire (relatively cool), and unburned plots. The response variables were arthropod species richness and abundance. The intermediate disturbance hypothesis predicts that maximum species richness occurs at intermediate levels of disturbance. Data obtained in this study support that prediction. Species richness was higher on plots of intermediate fire intensity than the more intensely burned plots, and almost …

Informing Wetland Management With Waterfowl Movement And Sanctuary Use Responses To Human-Induced Disturbance, Fiona Mcduie, Austen A. Lorenz, Robert C. Klinger, Cory T. Overton, Cliff L. Feldheim, Joshua T. Ackerman, Michael L. Casazza

Faculty Research, Scholarly, and Creative Activity

Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors, such as human-induced disturbance, can cause behavioral changes which may influence movement and resource needs, driving variation that affects management efficacy. To better understand the relationship between human-based disturbance and animal movement and habitat use, and their potential effects on management, we GPS tracked 15 dabbling ducks in California over ~4-weeks before, during and after the start of a recreational hunting season in October/November 2018. We recorded locations at 2-min intervals across three separate 24-h tracking phases: Phase 1) two …

Diversity Of Desert Rodent Communities Under Different Disturbances And Scales In Alashan Desert, Inner Mongolia, Heping Fu, Xiaodong Wu, Fushun Zhang

IGC Proceedings (2001-2023)

No abstract provided.

Overcoming An “Irreversible” Threshold: A 15-Year Fire Experiment, Christine H. Bielski, Rheinhardt Scholtz, Victoria Donovan, Craig R. Allen, Dirac Twidwell

School of Natural Resources: Faculty Publications

A key pursuit in contemporary ecology is to differentiate regime shifts that are truly irreversible from those that are hysteretic. Many ecological regime shifts have been labeled as irreversible without exploring the full range of variability in stabilizing feedbacks that have the potential to drive an ecological regime shift back towards a desirable ecological regime. Removing fire from grasslands can drive a regime shift to juniper woodlands that cannot be reversed using typical fire frequency and intensity thresholds, and has thus been considered irreversible. This study uses a unique, long-term experimental fire landscape co-dominated by grassland and closed-canopy juniper woodland …

Model-Based Control For Second-Order Piezo Actuator System With Hysteresis Intime-Delay Environment, Saikat Kumar Shome, Sandip Jana, Arpita Mukherjee, Partha Bhattacharjee

Turkish Journal of Electrical Engineering and Computer Sciences

Piezo actuated systems are promising solutions for precision positioning applications. In this paper, a piezoelectric actuator is modeled as a second-order system using the Dahl hysteresis model and the system parameters have been identified from experimental data. The modified internal model control (M-IMC) approach is presented, which not only improves control performance but also reduces associated controller hardware resources. System dead time is approximated using first-order Padé expansion and the proposed Smith predictor-based M-IMC for piezoelectric actuators is seen to offer satisfactory stable control response even for plants with large dead time. The control performance of the M-IMC has been …

Does Invasion Science Encompass The Invaded Range? A Comparison Of The Geographies Of Invasion Science Versus Management In The U.S., Lara Munro

Masters Theses

Biases in invasion science lead to a taxonomic focus on plants, particularly a subset of well-studied plants, and a geographic focus on invasions in Europe and North America. Geographic biases could also cause some branches of invasion science to focus on a subset of environmental conditions in the invaded range, potentially leading to an incomplete understanding of the ecology and management of plant invasions. While broader, country-level geographic biases are well known, it is unclear whether these biases extend to a finer scale and thus affect research within the invaded range. This study assessed whether research sites for ten well-studied …

The Impact Of Overgrazing On Needlegrass‐Peashrub‐Forbs Community, D. Bolormaa, B. Avaadorj, B. Enkhmaa, Ts. Altanzul

IGC Proceedings (2001-2023)

No abstract provided.

Application Of Model Prediction Control In Ship Dynamic Positioning Simulator, Xiaobin Qian, Yin Yong, Xiufeng Zhang, Xiaofeng Sun

Journal of System Simulation

Abstract: According to the requirement of ship Dynamic Positioning simulator control simulation system, a model predictive control scheme was proposed for DP simulator with the proportional integrator. Ship Dynamic Positioning simulator was mainly used for training and competency assessment of DP operator. At present, DP Simulator mainly depends on imports and there is no domestic DP simulator with independent intellectual property rights. Dynamic Positioning controller is one of the key technologies, which determines the performance of DP simulator. Considering the unknown slowly-varying marine environment disturbance and vessel constraints, a dynamic positioning controller was designed based on the model predictive control …

Impact Of Disturbance Regimes On Community And Landscape Biodiversity In Atlantic Coastal Pine Barren Ecoregion Streams, Sean T. Mccanty

Graduate Doctoral Dissertations

Streams are dynamic systems shaped by geographic location, hydrology, riparian vegetation, and in-stream habitat. Furthermore, ecosystem disturbance plays a major role in structuring stream communities and ecosystem processes. Disturbances include natural occurrences, such as flooding, drought, and fire events and anthropogenic disturbances such as land use changes, damming, and pollution. Agricultural use acts as a press disturbance regime, homogenizing the surrounding landscape and simplifying in-stream habitat, leaving legacy effects after farming ceases. Active restoration is intended to ameliorate these effects by reintroducing variation, with the goal of shifting the ecosystem into a more diverse and natural state. The act of …

Biogeochemical Cycling Of Nutrients And Carbon In Subtropical Wetlands, Lauren N. Griffiths

USF Tampa Graduate Theses and Dissertations

As human development intensifies, ecosystems around the word are being exponentially destroyed and degraded. Wetlands have the capacity to mitigate some of the possible problems by retaining nutrients and carbon, keeping them from harming downstream ecosystems or being released into the atmosphere. This project focuses on the processes that make wetlands successful by studying two unique ecosystems: 1) a created urban stormwater treatment wetland and 2) mangrove wetlands in Florida and Puerto Rico that were affected by hurricanes in 2017.

The first phase of this study investigates the role of sedimentation and vegetative and algal uptake of nutrients to retain …

Root System Ecology Of Shrubs In Qilian Mountains Alpine Rhododendron Shrubland, Wenxia Cao, Degang Zhang, Fuzeng Hong

IGC Proceedings (2001-2023)

No abstract provided.

Unravelling The Mechanisms Behind The Invasion Of An Introduced And Now Undesirable Grass Species, Jennifer Firn, Yvonne Buckley

IGC Proceedings (2001-2023)

No abstract provided.

Characterizing The Impacts Of The Invasive Hemlock Woolly Adelgid On The Forest Structure Of New England, Peter Brehm Boucher

Graduate Doctoral Dissertations

Climate change is raising winter temperatures in the Northeastern United States, both expanding the range of an invasive pest, the hemlock woolly adelgid (HWA; Adelges tsugae), and threatening the survival of its host species, eastern hemlock (Tsuga canadensis). As a foundation species, hemlock trees underlie a distinct network of ecological, biogeochemical, and structural systems that will likely disappear as the HWA infestation spreads northward. Remote sensing can offer new perspectives on this regional transition, recording the progressive loss of an ecological foundation species and the transition of evergreen hemlock forest to mixed deciduous forest over the course of the infestation. …

Effects Of Wild Pig Disturbance On Forest Vegetation And Soils, Steven M. Gray, Gary J. Roloff, Daniel B. Kramer, Dwayne R. Etter, Kurt C. Vercauteren, Robert A. Montgomery

USDA Wildlife Services: Staff Publications

In North America, wild pigs (Sus scrofa; feral pigs, feral swine, wild boars) are a widespread exotic species capable of creating large‐scale biotic and abiotic landscape perturbations. Quantification of wild pig environmental effects has been particularly problematic in northern climates, where they occur only recently as localized populations at low densities. Between 2016 and 2017, we assessed short‐term (within ~2 yrs of disturbance) effects of a low‐density wild pig population on forest features in the central Lower Peninsula of Michigan, USA. We identified 16 8‐ha sites using global positioning system locations from 7 radio‐collared wild pigs for sampling.Within each …

Historical Land Use Influence On Fine-Grained Sedimentation In Channel And Floodplain Deposits In A Forested Missouri Ozark Watershed, Katy Nicole Reminga

MSU Graduate Theses

Hydrologic disturbances due to land use and climate effects can disrupt river form and increase sediment transport. Ozark streams have been experiencing the effects of accelerated channel erosion on coarse sediment delivery and gravel bar deposition since the onset of early European settlement in the late 1800’s. Little attention has focused on understanding the fate of fine-grained sediment released by upland soil and headwater channel erosion and the potential for storage as legacy deposits on floodplains. Legacy deposits are attributed to human disturbances as the result of land clearing and agriculture that increase runoff, soil erosion, flooding, and sediment supply …

Spatial And Temporal Trends In The Xestospongia Muta (Giant Barrel Sponge) Population On The Southeast Florida Reef Tract, Alanna D. Waldman

HCNSO Student Theses and Dissertations

Xestospongia muta, the giant barrel sponge, is a key component of coral reef benthic communities in Southeast Florida and the Caribbean. Xestospongia muta increases habitat complexity and stability, and filters large volumes of water, enhancing water quality and facilitating nutrient cycling. Therefore, it is important to investigate trends in the X. muta population on Southeast Florida reefs in response to anthropogenic stressors, changing environmental conditions and acute disturbances and how these events affect its ecological role in the benthic community. This study identified trends in X. muta population density, volume, and size class distribution over time and across reef …

Riparian Resilience In The Face Of Interacting Disturbances, Alexa S. Whipple

2019 Symposium

Riparian systems of the dryland western United States provide critical ecosystem functions such as diverse habitat for numerous species, flood attenuation and essential water storage in water-limited environments. These systems have experienced long term disturbance from anthropogenic activities including the grazing of livestock in dryland riparian systems and near extirpation of a keystone riparian species, Castor canadensis (beaver). However, increasing frequency of large-scale wildfires and climate change driven weather is altering the severity and scale of riparian disturbance. Beaver restoration has been gaining use to address long term riparian disturbances, yet little is understood regarding the impact of restored beaver …

Northern Bottlenose Whales In A Pristine Environment Respond Strongly To Close And Distant Navy Sonar Signals, Paul J. Wensveen, Saana Isojunno, Rune R. Hansen, Alexander M. Von Benda-Beckmann, Stacy L. Deruiter

University Faculty Publications and Creative Works

Impact assessments for sonar operations typically use received sound levels to predict behavioural disturbance in marine mammals. However, there are indications that cetaceans may learn to associate exposures from distant sound sources with lower perceived risk. To investigate the roles of source distance and received level in an area without frequent sonar activity, we conducted multi-scale controlled exposure experiments ( n = 3) with 12 northern bottlenose whales near Jan Mayen, Norway. Animals were tagged with high-resolution archival tags ( n = 1 per experiment) or medium-resolution satellite tags ( n = 9 in total) and subsequently exposed to sonar. …

Wildfire Alters Spatial Patterns Of Available Soil Nitrogen And Understory Environments In A Valley Boreal Larch Forest, Jianjian Kong, Jian Yang, Bo Liu, Lin Qi

Forestry and Natural Resources Faculty Publications

Wildfire, a primary natural disturbance in many forests, affects soil nutrient availability and spatial distributions of forest plants. However, post-fire changes in soil nutrients and spatial patterns of understory environments at fine scales are poorly understood. Here, we characterized spatial patterns of soil nitrogen availability and site characteristics at a 3-year-post-fire and an unburned site in a valley boreal larch forest. We also examined the relationship between soil nitrogen availability and site characteristics. The results showed that the burned site had higher NO₃⁻ and lower NH₄⁺ than the control. The herb, litter and coarse wood debris …

Historical Data Modeling Based On State Observation, Dong Ze, Erxin Yin

Journal of System Simulation

Abstract: Aiming at the problem that the conventional historical data modeling method can not overcome the influence of disturbance on modeling accuracy, a historical data modeling method based on state observation is proposed. In this method, the data with the characteristic from dynamic to steady state are selected from the historical data as the modeling data, which is subjected to zero initialization processing based on the final steady state value. The processed data is then divided into two segments. The first segment is used to track the state of the prediction model, and the final observed state is used as …

Recolonization Of Mollusc Assemblages In Mangrove Plantations Damaged By Typhoon Chan-Hom In The Philippines, Severino G. Salmo Iii, Ian R. Tibbetts, Norman C. Duke

Environmental Science Faculty Publications

We investigated the effects of a catastrophic typhoon on mollusc assemblages of damaged mangrove plantations of different ages. Molluscs were sampled from infaunal, epifaunal and arboreal assemblages of mangrove stands in Lingayen Gulf, northwest Philippines, and compared with assemblages of un-impacted areas. Prior to the occurrence of the typhoon, there were clear shifts in the species diversity (H’) and composition of mollusc assemblages with stand age of mangrove forests. This was observed in species composition through the succession in dominance from pioneer to seral or putative climax species, and assemblage type (as arboreal, epifaunal and infaunal). However, severe damage to …

Identifying The Effects Of Land Use And Policy On Disturbance Regimes In The Teanaway Community Forest, Washington, Savannah Bommarito

All Master's Theses

The historic fire regime of the forests of the Eastern Cascades, Washington, has been described as one of high-frequency, low-severity fires using fire scar analysis. Over the past few centuries, the historically open, park-like ponderosa pine-dominated stands have been significantly altered due to Euro-American land use change such as fire exclusion, grazing, mining, and logging. The eventual encroachment of shade-tolerant species has resulted in a high-density forest structure that promotes rare, but extreme fire behavior and heightened susceptibility to insect attacks. As a result, the current disturbance regime is significantly less frequent and of higher severity, posing risks to forest …