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Proje??o diam?trica com base em dados observados antes e ap?s o desbaste em povoamentos de eucaliptoLacerda, Talles Hudson Souza 16 February 2017 (has links)
?rea de concentra??o: Manejo florestal e silvicultura. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-06-09T22:52:32Z
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Previous issue date: 2017 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O objetivo desse trabalho foi avaliar, do ponto de vista estat?stico e biol?gico, simula??es
realizadas por dois modelos de distribui??o diam?trica, ajustados pelos m?todos de
aproxima??o linear e m?xima verossimilhan?a, em planta??es de eucalipto submetidos a
desbaste. Os dados foram provenientes de um povoamento h?brido de Eucalyptus grandis x
Eucalyptus urophylla, sob regime de desbaste, localizado no nordeste da Bahia, vinculados ?
empresa BAHIA SPECIALTY CELLULOSE. Os dados utilizados neste estudo foram obtidos
nas idades 27, 40, 50, 61, 76, 87, 101, 112, 122, 137, 147, 158 e 165 meses. Esse povoamento
foi submetido a tratamentos de remo??o seletiva de 20%, 35% e 50%, nas idades 58 e 142
meses. Utilizou-se dois modelos de distribui??o diam?trica, empregando bases de dados
observadas aos 27 meses (antes do primeiro desbaste), aos 61 meses (ap?s o primeiro
desbaste) e aos 147 meses (ap?s o segundo desbaste). Por meio dos modelos gerou-se tr?s
sistemas, os quais se diferiram no m?todo de ajuste da fun??o Weibull. No sistema 1 os
par?metros da fun??o Weibull foram ajustados pelo m?todo de aproxima??o linear. No
sistema 2 e no sistema 3, os par?metros foram ajustados pelo m?todo da m?xima
verossimilhan?a. As proje??es realizadas pelos sistemas foram confrontadas com as
distribui??es diam?tricas observadas, por meio do teste de ader?ncia Kolmogorov-Smirnov a
1% de signific?ncia, e pelo teste F de Graybill, com n?vel de signific?ncia de 5%. Os tr?s
sistemas proporcionaram distribui??es diam?tricas projetadas estatisticamente semelhantes ?s
observadas, antes e ap?s o desbastes. O sistema 2 apresentou um maior percentual de
proje??es n?o significativas para os dois testes estat?sticos empregados. As simula??es
realizadas pelos modelos apresentaram realismo estat?stico e tend?ncia do crescimento da
distribui??o de di?metros para diferentes porcentagens de desbaste. Houve maior efici?ncia
dos modelos ao se utilizar distribui??es diam?tricas observadas em idades imediatamente
antes do desbaste. As proje??es das distribui??es diam?tricas, empregando-se como base
inicial as distribui??es observadas antes do primeiro desbaste e imediatamente ap?s os
desbastes (simula??es 1, 2 e 3), foram mais precisas do que as proje??es obtidas quando
foram utilizadas somente as distribui??es diam?tricas observadas antes do primeiro desbaste
como base inicial para as proje??es e, em seguida, simulados os desbastes nas idades previstas
e, por ?ltimo, realizadas as proje??es empregando-se a distribui??o estimada remanescente do
desbaste como base inicial para projetar as distribui??es para idades subsequentes (simula??es
4, 5 e 6). / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The objective of the study was evaluated from the statistical and biological point of view,
simulations performed by two models of diametric distribution, adjusted by linear
approximation and maximum likelihood methods, in eucalyptus plantations submitted to
thinning. The data were found in a hybrid settlement of Eucalyptus grandis x Eucalyptus
urophylla, under thinning regime, located in the northeast region of Bahia, linked to the
company BAHIA ESPECIALIDADE CELULOSE. The data used in this study 27, 40, 50, 61,
76, 87, 101, 112, 122, 137, 147, 158 and 165 months. This population was submitted to
treatments of selective removal of 20%, 35% and 50%, in the ages 58 and 142 months. Two
diametric distribution models were used, using data bases observed at 27 months (before the
first thinning), at 61 months (after the first thinning) and at 147 months (after the second
thinning). By means of the models three systems were generated, the channels did not differ
any method of adjustment of the Weibull function. No system 1 of the Weibull function
parameters were adjusted by the linear approximation method. In system 2 and in system 3
the parameters were adjusted by the maximum likelihood method. As the projections
performed by the systems were compared with the observed diametric distributions, using the
Kolmogorov-Smirnov test at 1% significance, by the Graybill F test, with a significance level
of 5%. The three systems provided by the statistically projected diametric distributions for
observations, before and after the deviations. System 2 presents a higher percentage of nonsignificant
projections for the two statistical tests used. As simulations of model execution
demonstrated statistical realism and tendency of growth of the distribution of diameters for
different percentages of thinning. There was greater efficiency of the models of use of
diametric distributions observed in ages before thinning. As the projections of the diametric
distributions, using as an initial basis as distributions observed before the first thinning and
after the slabs (simulations 1, 2 and 3), were more accurate than the projections obtained
when only diametric distributions observed before the first Thinning as the initial basis for the
projections and then simulated the lagging at the predicted ages and finally performed as
projections using an estimated remnant distribution of the thinning as the initial basis for
designing as distributions for subsequent ages (simulations 4, 5 and 6).
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Understanding Patterns of Bird Species Distribution in the Western GhatsVijayakumar, Sneha January 2015 (has links) (PDF)
Macroecology is the study of relationships between organisms and the environment at large spatial and temporal scales. This field of research examines patterns in species abundance, distribution and diversity. Understanding patterns in species distribution and richness can contribute significantly to our knowledge of community assembly and macroecological patterns, as well as to the effective conservation of threatened species and habitats. Although there have been a plethora of studies on birds in India over the years, there is a critical need to accurately delineate species distributions and understand patterns of richness. The focus of this study was to understand the factors (abiotic and biotic) that influence the distribution and composition of bird species in the Western Ghats, as well as to explore patterns in their geographic range sizes. The objectives of this study were addressed at the scale of the entire Western Ghats using a combination of field surveys, secondary data collection and species distribution modeling. The specific approaches to address these questions and the findings are outlined below.
Chapter 2: Bird species in the Western Ghats – Patterns in composition and richness
Fine-scale data on species presence and abundance are essential for exploring patterns in species distribution and richness. Despite the fact that birds have been extensively studied in the Western Ghats, systematic data collection and compilation of information over the entire mountain range has not been carried out, especially for the purpose of testing macroecological questions. This chapter describes patterns in bird species presence, abundance, composition and richness within the Western Ghats. The study area, site selection protocol and the sampling technique have also been described in detail. This dataset establishes a baseline of information about birds in the Western Ghats and subsets of this larger dataset will be used to address various questions in the following chapters.
Chapter 3: Predicting bird species distribution in the Western Ghats
Detailed knowledge of species’ ecological and geographical distributions is fundamental for conservation, as well as for understanding ecological and evolutionary determinants of spatial patterns of biodiversity. However, occurrence data for a vast majority of species are sparse, resulting in information about species distributions that is inadequate for many purposes. Species distribution models attempt to provide detailed predictions of distributions by relating presence or abundance of species to environmental predictors.
In this chapter, we describe the usage of Maxent, a species distribution modelling technique based on presence-only data, to predict the distributions of bird species within the Western Ghats. For this purpose, we put together primary locations of bird species presence along with a published dataset. Using a number of important environmental layers, predicted species distribution maps were derived for 98 bird species, including 13 endemics, in the Western Ghats. Additionally, we calculated predicted range sizes for each of these species and obtained percentage contributions of important environmental predictors to each species’ distribution. This is the first study to develop species distribution models for bird species within the Western Ghats.
Chapter 4: Patterns of range size among bird species
Understanding large-scale patterns of variation in species geographic range size is fundamental to questions in macroecology and conservation biology. In general, range is believed to be influenced by a combination of environmental factors, evolutionary history and biotic interactions, mediated by species specific traits. These patterns need to be examined even for well-studied taxa like birds, especially within biodiversity hotspots faced by persistent degradation due to anthropogenic activities such as the Western Ghats.
In this chapter, we use a dataset of 98 bird species within the Western Ghats to examine trends in range sizes, measured as latitudinal extent of occurrence and predicted range size from species distribution models. We show a significant relationship between latitude and range size for these bird species, supporting Rapoport’s rule. As far as we know, this relationship has never been tested at such low latitudes for birds. We also find that species traits such as body size, mean abundance and diet do not seem to show any discernable effect on patterns of range size. Additionally, we found that widely-used bird species range maps (in this case, from BirdLife International) are inaccurate representations of species ranges in comparison to the predicted species distribution maps that were derived in the previous chapter. We quantitatively demonstrated that these expert-drawn maps need to re-evaluated, especially since they are used to make conservation decisions. This is the first study to quantify species range sizes of birds within the Western Ghats and assess such range maps that are used to determine conservation status of species.
Chapter 5: Environmental predictors of bird species distribution
One of the major goals in ecology is to understand patterns and processes that determine species diversity. The drivers of global species richness gradients have been studied, especially in the case of birds, in terms of contemporary and historical factors. Such broad scale processes may not always reflect the processes affecting richness and distribution at smaller scales. Therefore, understanding the factors that influence individual species distributions is the first step towards this larger goal.
In this chapter, we examined the environmental predictors that contributed to the predicted distribution of bird species observed in the Western Ghats, using the variable importance contribution values derived in Chapter 3. We found that a large proportion of the 98 bird species studied were influenced by normalized differential vegetation index, annual precipitation and elevation. The predictors did not differ among birds of different diet guilds and body size classes. Using Prinicipal components analysis, we observed that all 98 bird species are spread out across the environmental ordination space depicted by the PC axes 1 and 2. These axes are governed by measures of habitat heterogeneity and water-energy related variables, consistent with other tropical studies. The insectivorous guild seemed to occupy a variety of environmental niches across this space and other guilds seemed to be nested within the insectivorous guild. Similarly, larger sized birds were spread across the entire environmental ordination space, with species of smaller sizes nested within. This is the first step in trying to understand environmental predictors acting on birds in the Western Ghats. Further detailed studies need to be carried out to come to definite conclusions.
Chapter 6: Relative roles of floristics and vegetation structure on bird species composition
On the basis of the hierarchical model of habitat selection, it is known that birds select suitable habitats based on vegetation structure (physiognomy) at coarse biogeographic scales, and plant species composition (floristics) at more local scales. This chapter examines the relative influence of tree species composition and vegetation structure on bird species composition in the Western Ghats. These relationships were specifically assessed across the entire Western Ghats, within regions of the Western Ghats as well as within specific forest types.
We found that floristics had a strong association with bird species composition across the Western Ghats and within evergreen and mixed deciduous habitat types. This association seems to be independent of the structural variation in the region. There was a decrease in association strength from the southern to the northern Western Ghats, in terms of both floristics and structure. We did not find an association between vegetation structure and insectivore composition, whereas phytophage composition did show a stronger association with floristics than structure. This is the first study at the scale of the entire Western Ghats to test the relative roles of floristics and vegetation structure.
Taken as a whole, this dissertation examines large-scale macroecological questions regarding species distribution, range size and patterns of composition using primary data at the scale of the Western Ghats. The findings of this study have established a foundation that will help further our understanding of species distribution and richness in the Western Ghats, and aid in the decision making for conservation strategies in the future.
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Estimativa da vulnerabilidade dos corais brasileiros / Assessing the vulnerability of Brazilian coralsAndrade, André Felipe Alves de 26 February 2016 (has links)
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Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Coral reefs are of extreme importance to both nature and society, due to being
responsible for several services and harbouring hundreds of species. Despite such critical
importance, reef corals current suffered heavy losses since the Anthropocene, with 20% of
world´s corals damaged beyond recovery due to human pressure and coastal development. This
scenario is even worse, since corals are especially vulnerable to climate change and the entire
ecosystem could go extinct by 2050. In this study we focus on comparing the already
established impacts from human development and the yet happen losses from climate change
on Brazilian corals, a unique fauna that still have gaps in knowledge. We created environmental
suitability models for 24 species and quantified individual losses from both climate change and
human activities. From the individual results we derived an overall pattern, in which we found
out that future losses from climate alteration are equivalent to current losses from human
activities. We then used the spatial distribution of those activities and key areas for
conservation, determined with software Zonation, to select six areas in the Brazilian exclusive
economic zone where proactive and reactive conservation strategies should be implanted, given
its importance to biodiversity and concentrated anthropogenic impacts. Overall suitability
losses were of approximately 30% for both sources and 60% of the areas will continue to be
suitable in the future. Therefore, Brazilian corals will experience heavy losses from climate,
especially the loss of highly suitable areas, which are compared to effects from human
economic activities. Coral situation is likely to be even worse, if we were to consider bleaching,
ocean acidification and diseases, events expected to increase with the rising temperature. / Ecological Niche Modelling (ENM) is widely used for conservation purposes, predicting
species invasion, evolutionary aspects and a whole array of applications. However, for most
cases, evaluating the efficiency of those models poses as problematic, as commonly used
methods (i.e. random methods) do not assure the required independence between data used to
create the model and data used to evaluate the model. We developed a new transferabilitybased
framework that ensures the much-needed independence between subsets. We created an
alternate approach that geographically splits occurrence datasets, while intrinsically controls
issues related to previous transferability approaches, such as overfitting, extrapolation and
sampling bias. We used 26 Atlantic coral species to perform three different geographical
divisions quantifying the effect of different splits on model predictive efficiency. We
demonstrate that transferability should be used as an effective method to evaluate ENMs.
Geographical split of the area in deciles proved as a reliable evaluation method, assuring
independence between datasets and being less prone to common transferability issues. Our
odds-and-evens framework provides improvements to the ongoing debate of ENMs evaluating
by its transferability. This new method corrects the issue of artificiality causing sampling bias
and overfitting, common in previous methodologies, while also is less prone to extrapolation
issues, a common problem in transferability approaches. Moreover, the framework appears as
a feasible and useful alternative to the problematic and commonly used random partition of
datasets evaluation.
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Multivariate approaches in species distribution modelling: Application to native fish species in Mediterranean RiversMuñoz Mas, Rafael 01 December 2018 (has links)
This dissertation focused in the comprehensive analysis of the capabilities of some non-tested types of Artificial Neural Networks, specifically: the Probabilistic Neural Networks (PNN) and the Multi-Layer Perceptron (MLP) Ensembles. The analysis of the capabilities of these techniques was performed using the native brown trout (Salmo trutta; Linnaeus, 1758), the bermejuela (Achondrostoma arcasii; Robalo, Almada, Levy & Doadrio, 2006) and the redfin barbel (Barbus haasi; Mertens, 1925) as target species. The analyses focused in the predictive capabilities, the interpretability of the models and the effect of the excess of zeros in the training datasets, which for presence-absence models is directly related to the concept of data prevalence (i.e. proportion of presence instances in the training dataset). Finally, the effect of the spatial scale (i.e. micro-scale or microhabitat scale and meso-scale) in the habitat suitability models and consequently in the e-flow assessment was studied in the last chapter. / Esta tesis se centra en el análisis comprensivo de las capacidades de algunos tipos de Red Neuronal Artificial aún no testados: las Redes Neuronales Probabilísticas (PNN) y los Conjuntos de Perceptrones Multicapa (MLP Ensembles). Los análisis sobre las capacidades de estas técnicas se desarrollaron utilizando la trucha común (Salmo trutta; Linnaeus, 1758), la bermejuela (Achondrostoma arcasii; Robalo, Almada, Levy & Doadrio, 2006) y el barbo colirrojo (Barbus haasi; Mertens, 1925) como especies nativas objetivo. Los análisis se centraron en la capacidad de predicción, la interpretabilidad de los modelos y el efecto del exceso de ceros en las bases de datos de entrenamiento, la así llamada prevalencia de los datos (i.e. la proporción de casos de presencia sobre el conjunto total). Finalmente, el efecto de la escala (micro-escala o escala de microhábitat y meso-escala) en los modelos de idoneidad del hábitat y consecuentemente en la evaluación de caudales ambientales se estudió en el último capítulo. / Aquesta tesis se centra en l'anàlisi comprensiu de les capacitats d'alguns tipus de Xarxa Neuronal Artificial que encara no han estat testats: les Xarxes Neuronal Probabilístiques (PNN) i els Conjunts de Perceptrons Multicapa (MLP Ensembles). Les anàlisis sobre les capacitats d'aquestes tècniques es varen desenvolupar emprant la truita comuna (Salmo trutta; Linnaeus, 1758), la madrilla roja (Achondrostoma arcasii; Robalo, Almada, Levy & Doadrio, 2006) i el barb cua-roig (Barbus haasi; Mertens, 1925) com a especies objecte d'estudi. Les anàlisi se centraren en la capacitat predictiva, interpretabilitat dels models i en l'efecte de l'excés de zeros a la base de dades d'entrenament, l'anomenada prevalença de les dades (i.e. la proporció de casos de presència sobre el conjunt total). Finalment, l'efecte de la escala (micro-escala o microhàbitat i meso-escala) en els models d'idoneïtat de l'hàbitat i conseqüentment en l'avaluació de cabals ambientals es va estudiar a l'últim capítol. / Muñoz Mas, R. (2016). Multivariate approaches in species distribution modelling: Application to native fish species in Mediterranean Rivers [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/76168 / TESIS
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MODELING THE POTENTIAL FOR GREATER PRAIRIE-CHICKEN AND FRANKLIN’S GROUND SQUIRREL REINTRODUCTION TO AN INDIANA TALLGRASS PRAIRIEZachary T Finn (11715284) 22 November 2021 (has links)
<p>Greater prairie-chickens (<i>Tympanuchus cupido pinnatus</i>; GPC) have
declined throughout large areas in the eastern portion of their range. I used
species distribution modeling to predict most appropriate areas of
translocation of GPC in and around Kankakee Sands, a tallgrass prairie in
northwest Indiana, USA. I used MaxEnt for modelling the predictions based on
relevant environmental predictors along with occurrence points of 54 known lek
sites. I created four models inspired by Hovick et al. (2015): Universal,
Environmental, Anthropogenic-Landcover, and Anthropogenic-MODIS. The Universal,
Environmental, and Anthropogenic-MODIS models possessed passable AUC scores
with low omission error rates. However, only the Universal model performed
better than the null model according to binomial testing. I created maps of all
models with passing AUC scores along with an overlay map displaying the highest
predictions across all passing models. MaxEnt predicted high relative
likelihoods of occurrence for the entirety of Kankakee Sands and many areas in
the nearby landscape, including the surrounding agricultural matrix. With implementation
of some management suggestions and potential cooperation with local farmers,
GPC translocation to the area appears plausible.</p>
<p>Franklin’s ground squirrels (<i>Poliocitellus franklinii</i>; FGS) have
declined throughout a large portion of the eastern periphery of their range.
Because of this, The Nature Conservancy is interested in establishing a new
population of these animals via translocation. The area of interest is
tallgrass prairie in northwest Indiana, USA: Kankakee Sands and the surrounding
landscape. Species distribution modelling can help identify areas that are
suitable for translocation. I used MaxEnt, relevant environmental variables,
and 44 known occurrence points to model the potential for translocation of FGS
to Kankakee Sands and the surrounding area. I created four models inspired by
Hovick et al. (2015): Universal, Environmental, Anthropogenic-Landcover, and
Anthropogenic-MODIS. I created maps of models with passing AUC scores. The
final map was an overlay map displaying the highest relative likelihood of
occurrence predictions for the area in all passing models. Only the Universal
and Anthropogenic-MODIS models had passable AUC scores. Both had acceptable
omission error rates. However, none of the models performed better than the
null model (p < 0.05). MaxEnt predicted that a few areas in and outside of Kankakee
Sands possess high relative likelihoods of occurrence of FGS in both the
Universal and Anthropogenic-MODIS models. However, MaxEnt predicted high
relative likelihoods in the surrounding agricultural matrix in the Universal
Model. FGS prefer to cross through agricultural areas via unmowed roadside
instead of open fields (Duggan et al. 2011). Because of this, high predictions
in agricultural matrices in the Universal model are irrelevant. High relative
likelihood predictions for linear sections that are obviously roads are
disregardable in the context of my modeling efforts. Because of my low sample
size, none of the models are really reliable in predicting relative likelihoods
of occurrence for this area. Despite high relative likelihood predictions, the
appropriateness of a translocation effort to the area is inconclusive.</p>
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Distribution of Particle Image Velocimetry (PIV) Errors in a Planar JetHowell, Jaron A. 01 May 2018 (has links)
Particle Image Velocimetry (PIV) is an optical fluid measurement technique used to obtain velocity measurements. Two PIV systems were used to capture data simultaneously and measurement error for the MS PIV system is calculated. An investigation of error distribution is performed to determine when uncertainty estimations fail for the CS PIV-UQ method. Investigation of when results from multi pass PIV processing are achieve were performed so that reliable uncertainty estimations are produced with the CS method. An investigation was also performed which determined that error distributions in PIV systems are correlated with flow shear and particle seeding density. Correlation of random errors in space was also performed at the jet core and shear regions of the flow.
It was found that in flow regions with large shear that error distributions were non-Gaussian. It was also found in regions of large shear that CS uncertainty results did not match the error. For multi-pass PIV processing with 50% and 75% IW overlap it was found that 4 and 6 passes should be used, respectively, in order for CS uncertainty estimations to be reliable. It was also found that the correlation of random errors in space is much larger in shear regions of the jet flow than in the jet core.
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<b>MONITORING CRYPTIC MAMMALIAN SPECIES IN INDIANA USING COMMUNITY-INFORMED MODELING AND ENCLOSED CAMERA TRAPPING</b>Carsten L White (18422673) 23 April 2024 (has links)
<p dir="ltr">Mammalian mesocarnivores contribute greatly to a proper functioning ecosystem by exerting top-down population control on prey species. While many of these species can be legally trapped or hunted in Indiana, given their responsibilities in the ecosystem, continuous monitoring of Gray fox (Urocyon cinereoargenteus) and Long-tailed weasel (Neogale frenata) by researchers is important to identify potential signs of decline and produce specific management plans. Both U. cinereoargenteus and N. frenata populations are suspected to be declining based on reduced frequencies of observations and harvest. However, each species displays cryptic behaviors that can make observation and effective surveying difficult, which may make the development of accurate assessments of population health unfeasible. To enable better monitoring of populations of these species, I developed a model for potential U. cinereoargenteus habitat and build upon camera trapping survey methods for N. frenata in this project. I used community surveying tools in a presence-only software (e.g., MaxEnt) to develop a consensus model for U. cinereoargenteus potential habitat. I identified five landscape-based covariates (distance to mixed and evergreen forest, distance to low urban cover, distance to shrub/scrub cover, and percent total forest cover per km2 ) that contributed the greatest to predicting the presence of the species. The top models in my project indicated a positive relationship between predicted U. cinereoargenteus presence and forested land cover. Additionally, predicted presence was high when the distance to low urban and shrub/scrub cover was low. In the Southern portion of Indiana predicted areas of presence occurred where larger forest patches exist. This differed from the Central and Northern portions of the state where smaller fragmented forest patches exist. In these areas, predicted areas of presence predominantly occurred near shrub/scrub or low urban cover. These findings will allow researchers to target specific areas for effective surveying and develop species conservation strategies. I also evaluated the ability of three enclosed camera trapping systems (AHDriFT system, Mostela system, and MoHDriFT system) to detect N. frenata. These camera systems have been designed to detect N. frenata and potential prey items, doing so successfully in past studies. I deployed trapping systems in three sites throughout Northeast Indiana from February to November 2023. Camera systems collected data during the project period during unbaited and baited (using sardines) survey periods. During my project, I observed three unique detections of N. frenata, all 9 of which were in the AHDriFT system during unbaited survey periods (P = 0.99; Z = -0.005). During these survey periods when N. frenata were detected, the AHDriFT system accounted for greater prey visitation and prey species abundance than the other two trapping systems (P < 0.01; F = 12). The ability to attract large amounts of prey species while successfully detecting N. frenata in this project may point to the AHDriFT system as the best camara trapping system suited for monitoring this cryptic species. The results from my project provide researchers and state agencies with input for monitoring these two cryptic species. With both species in suspected declines, the research conducted in the two chapters can contribute to portions of future species management plans. By targeting specific areas with predicted suitable habitat for U. cinereoargenteus, agencies can better allocate funds and conduct more extensive species research in Indiana. Likewise, by deploying the AHDriFT system, researchers in Indiana can cost-effectively monitor, not only N. frenata populations, but also small mammal and herp communities with ease. The research in this project provides researchers and state agencies in Indiana with new tools and insights in monitoring these cryptic species that are critical mesocarnivores in the state’s ecosystem.</p>
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Estimation cohérente de l'indice de surface foliaire en utilisant des données terrestres et aéroportées / Consistent forest leaf area index retrieval using ground and airborne dataHu, Ronghai 27 August 2018 (has links)
L’indice de surface foliaire (Leaf Area Index, LAI), défini comme la moitié de la surface foliaire par unité de surface de sol, est un paramètre clé du cycle écologique de la Terre, et sa précision d'acquisition a toujours la nécessité et la possibilité d'amélioration. La technologie du scanner laser actif offre une possibilité d'obtention cohérente du LAI à plusieurs échelles, car le scanner laser terrestre et le scanner laser aéroporté fonctionnent sur le même mécanisme physique. Cependant, les informations tridimensionnelles du scanner laser ne sont pas complètement explorées dans les méthodes actuelles et les théories traditionnelles ont besoin d'adaptation. Dans cette thèse, le modèle de distribution de longueur de trajet est introduit pour corriger l'effet d’agrégation, et il est appliqué aux données du scanner laser terrestre et du scanner laser aéroporté. La méthode d'obtention de la distribution de longueur de trajet de différentes plates-formes est étudiée et le modèle de récupération cohérent est établi. Cette méthode permet d’améliorer la mesure du LAI des arbres individuels dans les zones urbaines et la cartographie LAI dans les forêts naturelles, et ses résultats sont cohérents à différentes échelles. Le modèle devrait faciliter la détermination cohérente de l'indice de surface foliaire des forêts à l'aide de données au sol et aéroportées. / Leaf Area Index (LAI), defined as one half of the total leaf area per unit ground surface area, is a key parameter of vegetation structure for modeling Earth's ecological cycle and its acquisition accuracy always has the need and opportunity for improvement. Active laser scanning provides an opportunity for consistent LAI retrieval at multiple scales because terrestrial laser scanning (TLS) and airborne laser scanning (ALS) have the similar physical mechanism. However, the three-dimensional information of laser scanning is not fully explored in current methods and the traditional theories require adaptation. In this thesis, the path length distribution model is proposed to model the clumping effect, and it is applied to the TLS and ALS data. The method of obtaining the path length distribution of different platforms is studied, and the consistent retrieval model is established. This method is found to improve the individual tree measurement in urban areas and LAI mapping in natural forest, and its results at consistent at different scales. The model is expected to facilitate the consistent retrieval of the forest leaf area index using ground and airborne data.
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Adequabilidade ambiental dos biomas brasileiros à ocorrência do lobo-guará (Chrysocyon brachyurus) e efeitos da composição da paisagem em sua ecologia espacial, atividade e movimentação / Environmental Suitability of the Brazilian biomes to the occurrence of the maned wolf (Chrysocyon brachyurus) and the effects of landscape structure on its spatial ecology, activity, and movementsPaula, Rogério Cunha de 03 May 2016 (has links)
O lobo-guará é uma espécie de ampla distribuição na América do Sul, tendo no Brasil sua maior área de ocorrência. No entanto, as modificações das áreas naturais principalmente destinadas à agropecuária tornam a espécie vulnerável à extinção. A investigação objetivou conhecer em larga escala a área de distribuição potencial gerada por atributos ambientais favoráveis e áreas adequadas à sua ocorrência nos biomas brasileiros e investigar como a espécie responde à estrutura da paisagem, avaliando os efeitos de ambientes modificados pelo homem na sua ecologia espacial, nos padrões de atividade e na movimentação. Modelos de distribuição de espécie foram gerados pelo Maxent, utilizando uma base de pontos de localização de presença a partir de 2000 para o Cerrado (Ce), Pantanal (Pa), Mata Atlântica (MA) e Pampas (Pp) e um conjunto de onze variáveis ambientais não correlacionadas (topográficas, climáticas e paisagísticas). Para análises de ecologia espacial, das atividades e de movimentação, utilizou-se localizações de telemetria (GPS) de animais habitantes de áreas protegidas (AP), e indivíduos em paisagens modificados (AM). Análises de áreas de vida (AV) foram realizadas utilizando o estimador AKDE e associadas com classificação da paisagem local. Os modelos de distribuição do lobo-guará apresentaram uma área de distribuição potencial de 78% do total dos biomas. Apesar de possuírem grandes proporções de áreas adequadas (Ce, 90%; Pa, 93%; MA, 65% e Pp, 6%), somente um pequeno percentual (4,4% do Ce e 4,7% da MA) possui adequabilidade ambiental acima de 50%. Dos atributos que favorecem sua presença, a altitude (para todos os biomas), a precipitação (Ce e Pa), diferenças de temperatura e uso e cobertura do solo (Ma e Pp) foram os mais importantes. Em nível local, animais apresentaram média de AV de 90Km2 em AP e 41Km2 em AM, uma diferença significativa (p<0,01) com áreas diretamente proporcionais ao percentual de áreas naturais na paisagem. Ainda, apesar dos padrões regulares de atividade não mostrarem grandes mudanças, o período de repouso foi significativamente maior (p<0,01) entre os animais AM (46% do dia) que em animais AP (25% do dia). Lobos-guarás de AP e AM não apresentaram grandes diferenças no deslocamento diário com média geral de 14km caminhados por dia, com comprimentos de passos de 1Km. Diferenças no comprimento de passo foram relacionadas à composição da diversidade de contato de classes da paisagem com a proporção de ambientes naturais no passo (quanto maior as variáveis, maior o passo). Passos menores refletem menor persistência de movimento interferindo no deslocamento diário. Com os resultados desse estudo identificou-se a MA e Pa muito importantes, mas o Ce como bioma mais adequado à espécie. Foram encontrados indícios de que a estrutura de suas AV, o uso da paisagem, as atividades e movimentação são afetados pela paisagem modificada. Isso pode comprometer a viabilidade populacional, interferindo na presença em uma área e refletindo no seu potencial de distribuição. As estratégias de manejo de uso do solo, e a recuperação e conexão de áreas adequadas são urgentes e necessárias para que o lobo-guará permaneça presente e funcional nas paisagens dos biomas brasileiros. / The maned wolf has an extensive distribution range throughout South America with Brazil holding the largest portion of this area. However, the species is presently under a vulnerable status due to natural habitats alteration especially from farming and ranching. This study aimed to observe in large scale the potential distribution area indicated by favorable environmental attributes and suitable habitats to its presence within the Brazilian biomes and further to investigate how the species respond to the landscape structure, evaluating the effects of human-modified landscapes on its spatial ecology, activity patterns and movements. Species distribution models were generated using Maxent with a database of presence-only locations from 2000 though 2015, of the Cerrado (Ce), Pantanal (Pa), the Atlantic Forest (AF), and the Pampas (Pp) biomes, and eleven uncorrelated environmental variables (topographic, climatic, and landscape-based). As for the spatial ecology, activity and movement analysis, GPS-based telemetry locations were used from animals inhabiting protected (PAs) and disturbed areas (DAs). Home range (HR) analysis was performed using the AKDE estimator and then associated with the landscape-classified image. The distribution models for the maned wolf showed a potential distribution area of 78% of the total biomes range. Despite the high proportion of suitable areas (Ce, 90%; Pa, 93%; AF, 65%, and Pp, 6%), only a small percentage of the biomes (4.4% for Ce and 4.7% for AF) presented values over 50% suitable. Concerning the attributes that favor its presence, the altitude (for all the biomes), the precipitation (Ce and Pa), the temperature differences and land use (AF and Pp) were the most important. At the local scale, maned wolves showed HR sizes (average) with significant differences (p<0.01) between the 90Km2 (PA) and 41Km2 (DA) with HR size directly related to the proportion of natural areas. Although the general activity patterns were not considerably different between PA and DA, the resting periods of DA\'s animals (46% of the day) were significantly different (p<0.01) than the period of PA\'s wolves (46% of the day). Animals did not show changes on the daily movement patterns, accounting with 14km in general average and 1km of average step length (no major differences as well). The variation on the step length was related to the association of the diversity of contacts between landscape classes with the proportion of natural classes at each step (as bigger the variable values, bigger the step). As a consequence of smaller steps, constancy of movement decreases. Considering the results, the AF and Pa outstand as very important biomes, however the Ce was indicated as the most suitable biome. Furthermore, the research indicated signs that the HR structure and the landscape use, besides the activity patterns and the movement are affected by altered landscapes. This might compromise the population viability, interfering directly on its presence in an area and affecting the species distribution. Thus, a proper land use management aiming the recovering of degraded habitats is an important strategy tor the maned wolf conservation, so the species can long last survive across the Brazilian biomes.
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Spatial analysis of invasive alien plant distribution patterns and processes using Bayesian network-based data mining techniquesDlamini, Wisdom Mdumiseni Dabulizwe 03 1900 (has links)
Invasive alien plants have widespread ecological and socioeconomic impacts throughout many parts of the world, including Swaziland where the government declared them a national disaster. Control of these species requires knowledge on the invasion ecology of each species including how they interact with the invaded environment. Species distribution models are vital for providing solutions to such problems including the prediction of their niche and distribution. Various modelling approaches are used for species distribution modelling albeit with limitations resulting from statistical assumptions, implementation and interpretation of outputs.
This study explores the usefulness of Bayesian networks (BNs) due their ability to model stochastic, nonlinear inter-causal relationships and uncertainty. Data-driven BNs were used to explore patterns and processes influencing the spatial distribution of 16 priority invasive alien plants in Swaziland. Various BN structure learning algorithms were applied within the Weka software to build models from a set of 170 variables incorporating climatic, anthropogenic, topo-edaphic and landscape factors. While all the BN models produced accurate predictions of alien plant invasion, the globally scored networks, particularly the hill climbing algorithms, performed relatively well. However, when considering the probabilistic outputs, the constraint-based Inferred Causation algorithm which attempts to generate a causal BN structure, performed relatively better.
The learned BNs reveal that the main pathways of alien plants into new areas are ruderal areas such as road verges and riverbanks whilst humans and human activity are key driving factors and the main dispersal mechanism. However, the distribution of most of the species is constrained by climate particularly tolerance to very low temperatures and precipitation seasonality. Biotic interactions and/or associations among the species are also prevalent. The findings suggest that most of the species will proliferate by extending their range resulting in the whole country being at risk of further invasion.
The ability of BNs to express uncertain, rather complex conditional and probabilistic dependencies and to combine multisource data makes them an attractive technique for species distribution modeling, especially as joint invasive species distribution models (JiSDM). Suggestions for further research are provided including the need for rigorous invasive species monitoring, data stewardship and testing more BN learning algorithms. / Environmental Sciences / D. Phil. (Environmental Science)
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