The Effects Of Urbanization On Cypress (taxodium Distichum) In Central Florida

Urbanization is accelerating in the United States and is contributing to fragmentation of natural habitats, causing changes in species composition and declines in native species. Human population growth in Orlando is typical of growth in the southeastern United States and throughout the range of cypress (Taxodium distichum). Orlando has numerous isolated cypress wetlands, called cypress domes, and many remain among the current urbanized area. This makes Orlando ideal to study the effects of urbanization on cypress domes. Specifically, I tested how urbanization and its effects on fragmentation, hydrology, and fire regime) affected (a) the numbers and spatial pattern of cypress domes in central Florida and (b) the recruitment of cypress within cypress domes. Analysis of historical loss found over 3,000 cypress domes identified in images from1984, of which 26% were lost or degraded (i.e., no longer cypressdominated) by 2004. Due to changed land use, many remaining cypress domes, formerly surrounded by natural lands, have become surrounded by urban lands causing spatial clustering and homogenization. Surprisingly, I found that both natural and urban cypress domes showed lower recruitment than agricultural cypress domes, where the natural fire regime has not been altered. The probability of cypress recruitment in cypress domes urbanized for more than 20 years is very low. Previous to that, cypress tends to recruit on the edge of cypress domes where there is less competition and hydrological conditions are more favorable. I estimate that only ~50% of the current cypress domes are recruiting and the existence of those wetlands are tied to the lifespan of the current adults. By 2104, I estimate that ~89% of the cypress domes currently recruiting will fail to recruit. I believe that reducing urban sprawl and restoring the natural fire iii regime to natural cypress domes will mitigate the current fate of cypress domes. Without this, cypress in isolated wetlands in central Florida, and providing Orlando urbanization is typical, throughout urbanized areas of the range, could be at risk. Cypress in urban areas will be then relegated to riparian zones and with unknown consequences for the species that utilize the former cypress dome habita

The urban regulation of rural land from the perspective of the new Law for the Promotion of Territorial Sustainability in Andalusia (Andalusian Land Law)

Since their inception, various urban planning laws have focused on meeting the growth needs of cities, with urban planning as a discipline paying minimal attention to rural settlement planning. It can, therefore sound clichéd to say that urban planning legislation has been mainly concerned with regulating urban and developable land, with residual or negative status being given to undevelopable or rural land. This has had major territorial impacts that continue to this day. The proposed subject of this paper is considered timely and topical, and its main objective is to analyse whether the planning instruments proposed in the Law for the Promotion of Territorial Sustainability in Andalusia (LISTA, acronym in Spanish) for rural settlements and scattered buildings can help regulate rural land dynamics in Andalusia. To do so, we will first model the patterns of settlement formation and isolated dwellings on rural land using geostatistical methods, and then carry out an analysis of the provisions of these latest rural land management laws, which will affect the planning regulations of this land in the coming years

Modelação geográfica da fragmentação e conectividade de habitats: casos de estudo nos padrões de distribuição local de espécies selvagens

Habitat fragmentation and the resultant reduction in connectivity are process of major importance in the persistence and patterns distribution of wildlife species. This thesis focuses on habitat fragmentation and connectivity, assessing their consequences on the local patterns distribution of wildlife species. The cases studies were published and conducted with monitoring data systematized using a common database. The case studies were located in the Alentejo region between the years of 1995 and 2005. The case studies are supported by examples of local impacts of fragmentation on the habitat connectivity of birds and reptile species patterns distribution. The observed pattern-process interactions are assessing by geographic modeling techniques. Methodologies were developed based on the innovative application of spatial statistical and networks analysis. The results show that the geographic modeling represents an added value to the understanding pattern-process interactions. The findings show how much the local distribution patterns of individuals are affected by habitat disturbances; RESUMO: A fragmentação dos habitats e a conectividade são processos de importância maior na persistência e nos padrões de distribuição das espécies selvagens. Esta tese centra -se na avaliação da fragmentação e conectividade dos habitats nos padrões locais de distribuição de espécies selvagens. Para tal foram realizados casos de estudo, com dados relativos a monitorizações efectuadas no Alentejo entre os anos de 1995 e 2005 e sistematizados numa base dados. Os casos de estudo foram publicados e são suportados por exemplos de impactes locais no padrão de distribuição de espécies de aves e réptil. Foram utilizadas técnicas de modelação geográfica na descrição e avaliação dos processos e padrões observados. Aplicadas e desenvolvidas metodologias inovadoras, com o suporte de técnicas de estatística espacial e análise de redes. Os resultados mostram que a modelação geográfica representa uma maisvalia para a compreensão da dinâmica entre padrões-processos. Os resultados revelam o quanto, os padrões de distribuição local dos indivíduos são afectados pelas alterações nos habitats

Spatio-Temporal Analyses of Cenozoic Normal Faulting, Graben Basin Sedimentation, and Volcanism around the Snake River Plain, SE Idaho and SW Montana

This dissertation analyzes the spatial distribution and kinematics of the Late Cenozoic Basin and Range (BR) and cross normal fault (CF) systems and their related graben basins around the Snake River Plain (SRP), and investigates the spatio-temporal patterns of lavas that were erupted by the migrating Yellowstone hotspot along the SRP, applying a diverse set of GIS-based spatial statistical techniques. The spatial distribution patterns of the normal fault systems, revealed by the Ripley\u27s K-function, display clustered patterns that correlate with a high linear density, maximum azimuthal variation, and high box-counting fractal dimensions of the fault traces. The extension direction for normal faulting is determined along the major axis of the fractal dimension anisotropy ellipse measured by the modified Cantor dust method and the minor axis of the autocorrelation anisotropy ellipse measured by Ordinary Kriging, and across the linear directional mean (LDM) of the fault traces. Trajectories of the LDMs for the cross faults around each caldera define asymmetric sub-parabolic patterns similar to the reported parabolic distribution of the epicenters, and indicate sub-elliptical extension about each caldera that may mark the shape of hotspot’s thermal doming that formed each generation of cross faults. The decrease in the spatial density of the CFs as a function of distance from the axis of the track of the hotspot (SRP) also suggests the role of the hotspot for the formation of the cross faults. The parallelism of the trend of the exposures of the graben filling Sixmile Creek Formation with the LDM of their bounding cross faults indicates that the grabens were filled during or after the CF event. The global and local Moran’s I analyses of Neogene lava in each caldera along the SRP reveal a higher spatial autocorrelation and clustering of rhyolitic lava than the coeval basaltic lava in the same caldera. The alignment of the major axis of the standard deviational ellipses of lavas with the trend of the eastern SRP, and the successive spatial overlap of older lavas by progressively younger mafic lava, indicate the migration of the centers of eruption as the hotspot moved to the northeast

Spatio-Temporal Analyses of Cenozoic Normal Faulting, Graben Basin Sedimentation, and Volcanism around the Snake River Plain, SE Idaho and SW Montana

This dissertation analyzes the spatial distribution and kinematics of the Late Cenozoic Basin and Range (BR) and cross normal fault (CF) systems and their related graben basins around the Snake River Plain (SRP), and investigates the spatio-temporal patterns of lavas that were erupted by the migrating Yellowstone hotspot along the SRP, applying a diverse set of GIS-based spatial statistical techniques. The spatial distribution patterns of the normal fault systems, revealed by the Ripley\u27s K-function, display clustered patterns that correlate with a high linear density, maximum azimuthal variation, and high box-counting fractal dimensions of the fault traces. The extension direction for normal faulting is determined along the major axis of the fractal dimension anisotropy ellipse measured by the modified Cantor dust method and the minor axis of the autocorrelation anisotropy ellipse measured by Ordinary Kriging, and across the linear directional mean (LDM) of the fault traces. Trajectories of the LDMs for the cross faults around each caldera define asymmetric sub-parabolic patterns similar to the reported parabolic distribution of the epicenters, and indicate sub-elliptical extension about each caldera that may mark the shape of hotspot’s thermal doming that formed each generation of cross faults. The decrease in the spatial density of the CFs as a function of distance from the axis of the track of the hotspot (SRP) also suggests the role of the hotspot for the formation of the cross faults. The parallelism of the trend of the exposures of the graben filling Sixmile Creek Formation with the LDM of their bounding cross faults indicates that the grabens were filled during or after the CF event. The global and local Moran’s I analyses of Neogene lava in each caldera along the SRP reveal a higher spatial autocorrelation and clustering of rhyolitic lava than the coeval basaltic lava in the same caldera. The alignment of the major axis of the standard deviational ellipses of lavas with the trend of the eastern SRP, and the successive spatial overlap of older lavas by progressively younger mafic lava, indicate the migration of the centers of eruption as the hotspot moved to the northeast

Identifying and analysing the factors influencing the livelihood strategy choices of rural households

Identifying the influence factors lie behind the livelihood choices of rural households are of crucial significance for improving the sustainable livelihoods of rural households in tourism regions. Five villages in Sa Pa District, Vietnam, were selected in this study, to conduct household surveys and interviews with 180 households. Based on this, a comprehensive approach, which includes multinomial/binary logistic regression, Ripley’s function, and geographical detector, is applied to understand the households’ capital endowment and factors lie behind their livelihood choices. Results show that for rural households, tourism livelihood yields the highest income, but the lack of diversity of livelihood activities may make tourism livelihood household more vulnerable to the external risk and shocks than balanced livelihood households. Different types of households are found to show clustering feature, with clustering degree ranking as: agricultural > balanced > tourism > labour. Households with more natural capital are less likely to choose livelihoods other than agriculture livelihood. And households with more financial capital are less likely to engage in agricultural livelihood. Both financial capital and social capital can facilitate engagement in balanced livelihood. And financial capital is key to tourism livelihood, and a barrier impeding agricultural households to participate in other livelihood activities

Comparing Random and Nonrandom Spatial Patterns of Artifacts within Lithostratigraphic Unit 3 at Cooper’s Ferry, Idaho

Archaeological investigations at the Cooper's Ferry site in Western Idaho have recovered cultural remains dating to 16,000 years ago, suggesting the oldest human occupation recorded in North America. However, many archaeologists have argued the initial peopling of North America occurred no earlier than the opening of an ice-free corridor between the Cordilleran and Laurentide Ice Sheets ~14,800 years ago. This study aims to address concerns that the cultural remains at Cooper's Ferry do not resemble cultural occupations but, instead, are a random distribution of artifacts resulting from post-depositional site transformations. In this study, post-depositional site transformations refer to the unintentional movement of artifacts by biological forces such as fauna or flora and geological processes such as sediment deposition and erosion. To test the hypothesis that the artifacts in LU3 do not resemble human occupation, the artifacts are separated into five distinct archaeological components representing different site activities and organizations. Then, spatio-temporal statistics Ripley's K; Pair Correlation Function; Cross-Correlation) and a K-means analysis test for complete spatial randomness on each component by quantifying and visualizing the extent of artifact distributions. Then, these distributions are compared to currently accepted, culturally intact archaeological assemblages to compare the spatial distribution of artifacts in similar contexts. The results show that each archaeological component contains at least one nonrandom spatial extent and, the components dating from 16,000-14,800 years ago resemble accepted, culturally intact artifact distributions. These results refute the hypothesis that the oldest recorded artifacts at Cooper's Ferry are randomly distributed and do not resemble current models of what human occupation looks like within similar site contexts. On this basis, there is no present reason to reject that Cooper's Ferry captures the oldest human occupation in North America

Dynamics of Forest Structure under Different Silvicultural Regimes in the Acadian Forest

Research plots in many long-term studies of forest ecosystems often cannot be used for spatial modeling because of their small scale and nested inventory design. This has been unfortunate as these plots represent some of the best records of structural development as affected by forest management. I developed methodologies to reconstruct both tree height growth and spatial pattern in these types of plots from historical inventory records and stem-mapped data, and then retrospectively investigated 3-dimensional structural development as affected by five silvicultural and harvesting treatments (unmanaged natural area, commercial clearcut, fixed-diameter limit, 5-year selection, and 3-stage shelterwood— with and without precommercial thinning) in a long-term, USDA Forest Service study in Bradley, ME. In order to capture site variation and account for the hierarchical inventory design, mixed-effects, nonlinear heightdiameter models were developed for the nine most common tree species in 50 stemmapped plots: Abies balsamea (L.) Mill., Acer rubrum L., Betula papyrifera Marsh., B. populifolia Marsh., Picea rubens Sarg., P. mariana (Mill.) B.S.P., Pinus strobus L., Populus tremuloides Michx., and Tsuga canadensis (L.) Carr. Height-diameter models for the remaining species were fit with generalized nonlinear least squares. A morphing algorithmn was developed and then tested on both simulated and actual point patterns, to scale the spatial pattern from nested, sapling subplots (0.020 ha) to the scale of the larger tree plots (0.081 ha). Differences in spatial pattern, species mingling, height differentiation, and relative stand complexity index (rSCI) were compared among treatments. Regeneration events, whether induced through natural stand breakup or by harvesting, increased aggregation in spatial pattern and reduced species mingling. This pattern was heightened when treatments shifted species composition more towards hardwood species. Variation in height differentiation and rSCI was generally highest in the natural areas and 5-year selection compartments, intermediate in commercial clearcut and fixed diameter-limit compartments, and lowest in 3-stage shelterwood compartments. Divergence in spatial structure between the two natural areas reflects natural stand development within this forest and is an appropriate benchmark for management. The reconstruction model developed here can be applied to other long-term studies where the lengthy temporal scale can substitute for small spatial scale

Spatial Genetic Structure of Hatchlings of Cyclura Ricordii (Reptilia: Iguanidae) in Pedernales Province, Dominican Republic is Inconsistent with Natal Philopatry

Cyclura ricordii is an endemic iguana from Hispaniola and is listed as Critically Endangered on the IUCN. The main threats are predation by introduced mammals, habitat destruction and hunting. The present study focused on two nesting areas in Pedernales in the Dominican Republic. The hypothesis tested is that natal philopatry influences dispersal and nest site selection. Monitoring and sampling took place during 2012-2013. Polymorphic markers were used to evaluate whether natal philopatry limits dispersal at multiple spatial scales. Ripley’s K, revealed that nests were significantly clustered. Hierarchical AMOVA revealed that nest site aggregations did not explain a significant portion of genetic variation. However, Mantel’s tests revealed significant positive correlations between genetic and geographic distance. These results indicate that natal philopatry limits dispersal at a course spatial scale, but does not influence nest site selection at a fine spatial scale

Methods for detecting spatial clustering of economic activities using micro-geographic data

This PhD thesis consists of three self-contained but related essays on the topic of empirical assessment of spatial clusters of economic activities within a micro-geographic framework. The tendency of economic activities to be concentrated in a specific territory is well recognized, starting at least from the seminal studies by Alfred Marshall (Marshall, 1920). This spatial behaviour is not fortuitous; by concentrating in some areas firms enjoy a number of advantages, which then have implications for local economic growth and regional disparities and, as a consequence, are object of study in the fields of economics, geography and policy making. It has been recognized, however, that a major obstacle to further comprehension of the agglomeration phenomena of firms is the lack of a method to properly measure their spatial concentration. The most traditional measures employed by economists, indeed, are not completely reliable. Their most relevant methodological limit lies in the use of regional aggregates, which are built by referring to arbitrary definitions of the spatial units (such as provinces, regions or municipalities) and hence introduce a statistical bias arising from the chosen notion of space. This methodological problem can be tackled by using a continuous approach to space, where data are collected at the maximum level of spatial disaggregation, i.e. each firm is identified by its geographic coordinates, say (x, y), and spatial concentration is detected by referring to the distribution of distances amongst economic activities. The main purpose of the dissertation is to contribute to the development of this kind of continuous space-based measures of spatial clustering. The scientific context and motivation are outlined in depth in the first three chapters. Then the first essay introduces the space–time K-function empirical tool, proposed in spatial statistical literature, into economic literature in order to detect the geographic concentration of industries while controlling for the temporal dynamics that characterize the localization processes of firms. The proposed methodology allows to explore the possibility that the spatial and temporal phenomena, producing the observed pattern of firms at a given moment of time, interact to provide space–time clustering. The presence of significant space–time interaction implies that an observed pattern cannot be explained only by static factors but that we should also consider the dynamic evolution of the spatial concentration phenomenon. Indeed, for example, new firm settlements may display no spatial concentration if we look separately at each moment of time and yet they may present a remarkable agglomeration if we look at the overall resulting spatial distribution after a certain time period. In general, without knowing the temporal evolution of the phenomenon under study it is not possible to identify the mechanism generating its spatial structure. As a matter of fact, different underlying space–time processes can lead to resulting spatial patterns which look the same. The methodology is illustrated with an application to the analysis of the spatial distribution of the ICT industries in Rome (Italy), in the long period 1920–2005. The problem of disentangling spatial heterogeneity and spatial dependence phenomena when detecting for spatial clusters of firms is the topic of the second essay, “Measuring industrial agglomeration with inhomogeneous K-function: the case of ICT firms in Milan (Italy)”. Spatial clusters of economic activities can be the result of two distinct broad classes of phenomena: spatial heterogeneity and spatial dependence. The former arises when exogenous factors lead firms to locate in certain specific geographical zones. For instance, firms may group together in certain areas in order to exploit favourable local conditions, such as the presence of useful infrastructures, the proximity to the communication routes or more convenient local taxation systems. The phenomenon of spatial dependence, which is often of direct scientific interest, occurs instead when the presence of an economic activity in a given area attracts other firms to locate nearby. For instance, the presence of firms with a leading role encouraging the settlement of firms producing intermediate goods in the same area or the incidence of knowledge spillovers driving industrial agglomerations. This essay suggests a parametric approach based on the inhomogeneous K-function that allows to assess the endogenous effects of interaction among economic agents, namely spatial dependence, while adjusting for the exogenous effects of the characteristics of the study area, namely spatial heterogeneity. The approach is also illustrated with a case study on the spatial distribution of the ICT manufacturing industry in Milan (Italy). The third paper is titled “Weighting Ripley’s K-function to account for the firm dimension in the analysis of spatial concentration”. In the methodological context of the continuous space-based measures of spatial clustering, firms are identified as dimensionless points distributed in a planar space. In realistic circumstances, however, firms are generally far from being dimensionless and are conversely characterized by different dimension in terms of the number of employees, the product, the capital and so on. This implies that a high level of spatial concentration can occur, for example, because many small firms cluster in space, or few large firms (in the limit just one firm) cluster in space. A proper test for the presence of spatial clusters of firms should thus consider the impact of the firm dimension on industrial agglomeration. For this respect, the third essay develops a methodology based on an extension of the K-function considering firm size as a weight attached to each of the points representing the firms’ locations