The objective of this thesis is to examine the relationship between CAIX (a biomarker for insufficient oxygen in tumor microenvironment) and CD8+ T cells (the immune cells for killing cancer cells) for ovarian cancer. We approach the problem from two perspectives. The first approach is to set up count models such as Poisson, negative binomial, and zero-inflated Poisson models to examine the cell counts between CAIX and CD8+ T cells in the tumor microenvironment. The second approach is to apply the cross-K function, which is a second-order property of the point pattern process. We find that the tissue microarray (TMA), which is a technique to assemble hundreds of tissue samples on one TMA block, has a fixed effect on the CD8+ T cell counts. There are two TMA blocks A2 and B1. The relationship between CAIX and CD8+ T cells highly depends on TMAs. On TMA B1 stroma, a negative relationship between CAIX and CD8+ T cell counts is observed in the negative binomial models. When taking the spatial domain into account and comparing the estimated cross-K function of CAIX and CD8+ T cells to the simulated envelopes generated by a homogeneous Poisson process, we find that CAIX and CD8+ T cells are regulated and repel each other on TMA B1. Tissue category also plays an influential role in analyzing the relationship. The estimated cross-K function of CAIX and CD8 + T cells is more dispersed on tumors than on stroma. / Graduate

Public and private conservation areas are becoming increasingly important to the continued survival of the gopher tortoise, making it imperative that land managers know the specific habitat requirements of juvenile gopher tortoises because recruitment is key to species persistence. Little is currently known about environmental factors that underlie hatchling and juvenile survival and recruitment in gopher tortoise populations. Because of the short duration and distance of juvenile tortoise foraging journeys, food availability, thermoregulatory conditions, and refugia near the burrow may considerably affect juvenile growth and survival. This two-year study of a central Florida sandhill examines the spatial relationship between juvenile gopher tortoise burrows and the surrounding habitat. Gopher tortoise burrow positions, activity, and width were recorded in four complete surveys of the 4-hectare study area. Coincident with three of the burrow surveys, vegetation and structural habitat characteristics, such as forb and canopy cover, were surveyed in a uniform grid design. Vegetation cover was reclassified using habitat suitability functions (HSFs) derived from qualitative literature values and combined into habitat suitability indices (HSIs) to model the relationships between habitat variables and the likelihood of juvenile gopher tortoise presence. Chi-squared tests and spatial point pattern analysis were used to validate and identify well-forming models. In general, the best performing HSI models for the juvenile gopher tortoise were those that incorporated all three gopher tortoise life requisites in a compensatory relationship (geometric mean): thermoregulation (total high canopy, bare ground, or litter), predation (oak mid-canopy), and food (forb or wiregrass). The models could be improved by using the observed relative abundance of juvenile burrows in each vegetation cover class to modify the HSFs. These methods will help identify habitat characteristics associated with active juvenile gopher tortoise burrows that can be used by public and private land managers to improve existing tortoise habitat and to identify high-quality habitat for future preserves.

Here we present a bioarchaeological analysis of a Postclassic (ca. A.D. 950-1524) Maya mass grave from the site of Zacpetén in northern Guatemala. Osteological and spatial analyses (including a Ripley's K function) found evidence of cutting, drilling, and grinding of long bones and teeth as well as the intentional removal and manipulation of skeletal elements based on the left or right sides of the body. The remains were enveloped in layers of cut blocks and fist-sized chunks of white limestone and were placed in a depression on the western side of the ceremonial core of the site. The western orientation of the depression was explicitly associated with the underworld in contrast with the temple on the eastern side of the ceremonial core. The grave was the product of exhumation and violation of enemies' bodies, sacrifice, or the burial of war dead (or some combination thereof) and was created when the Kowoj group emerged as a political force in the Petén lakes region. It served to symbolically rupture the past inhabitants' links to the site and to create an enduring symbol of their defeat.

Point processes are common in many physical applications found in engineering and biology. These processes can be observed in one-dimension as a time series or two-dimensions as a spatial point pattern with extensive amounts of literature devoted to their analyses. However, if the observed process is a hybrid of spatial and temporal point process, very few practical methods exist. In such cases, practitioners often remove the temporal component and analyze the spatial dependencies. This marginal spatial analysis may lead to misleading results if time is an important factor in the process. In this dissertation we extend the current analysis of spatial point patterns to include a temporal dimension. First- and second-order intensity measures for analyzing spatiotemporal point patterns are explicitly defined. Estimation of first-order intensities are examined using 3-dimensional smoothing techniques. Conditions for weak stationarity are provided so that subsequent second-order analysis can be conducted. We consider second-order analysis of spatiotemporal point patterns first in the space-time domain through an extension of Ripley's Κ-function. An alternative analysis is given in the frequency domain though construction of a spatiotemporal periodogram. The methodology provided is tested through simulation of spatiotemporal point patterns and by analysis of a real data set. The biological application concerns the estimation of the homerange of groups of the endangered red-cockaded woodpecker in the Fort Bragg area of North Carolina. Monthly or bimonthly point patterns of the bird distribution are analyzed and integrated over a 23 month period. / Ph. D.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-08-31T20:02:18Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) denise_souza_batista.pdf: 2389253 bytes, checksum: 7d5cc01bdcaca35f20d644bb71a22d7e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-09-04T17:18:29Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) denise_souza_batista.pdf: 2389253 bytes, checksum: 7d5cc01bdcaca35f20d644bb71a22d7e (MD5) / Made available in DSpace on 2017-09-04T17:18:29Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) denise_souza_batista.pdf: 2389253 bytes, checksum: 7d5cc01bdcaca35f20d644bb71a22d7e (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O objetivo deste trabalho ? entender os processos ecol?gicos que orientam a distribui??o espacial e estrutura vegetacional da esp?cie Vellozia ramosissima e tamb?m analisar a anatomia foliar, a nutri??o e a ecofisiologia, inter-relacionados com a an?lise do solo, para reconhecer a plasticidade desta esp?cie em ?reas de Complexos Rupestres Quartz?ticos (CRQs) e Ferruginosos (CRFs). A coleta de dados foi baseada na amostragem de uma parcela de 50x50m em quatro ?reas em Complexos Rupestres: duas ?reas localizadas em afloramentos quartz?ticos e duas em ferruginosos. Nas parcelas, todos os indiv?duos com altura maior ou igual a um metro foram mapeados, o padr?o de distribui??o espacial foi avaliado utilizando a fun??o K de Ripley. O m?todo de Sturges foi utilizado para defini??o do n?mero de classes diam?tricas e de altura. As an?lises de solos avaliaram: pH, teores de P, K+, Ca2+, Mg2+ e Al3+; acidez potencial (H+Al), CTC a pH 7,0 (T); CTC efetiva (t), soma de bases (SB), satura??o por bases (V%), satura??o por alum?nio (m%), areia (fina e grossa), silte, argila e equivalente de umidade (EU). Para anatomia foliar foram estimados a ?rea foliar e cortes anat?micos foliares (fotomicrografias). Para cada imagem foram mensurados os par?metros anat?micos: espessura da cut?cula, da epiderme (nas faces adaxial e abaxial), do par?nquima pali??dico e lacunoso, da extens?o da bainha voltada para o feixe vascular (hipoderme), da hipoderme voltada para fenda e altura da fenda estom?tica. O material coletado para a nutri??o foliar e de raiz foi processado e determinados os nutrientes: N; P; K+; Ca2+; Mg2+; Zn2+; Fe2+; Mn2+; Cu; C; H+ e Al3+. O fluor?metro port?til modulado MINI-PAM, foi utilizado para fazer as medi??es pontuais das vari?veis: fotorrespira??o e rendimento qu?ntico efetivo. Nas quatro ?reas foram levantadas o total de 2542 indiv?duos com a seguinte distribui??o: 158 indiv?duos na ?rea CRQ1, 682 na ?rea CRQ2, 39 em CRF1e 1663 em CRF2. A fun??o K de Ripley calculada para as quatro ?reas rejeitaram a hip?tese de completa aletoriedade espacial, demonstrando, no geral, um padr?o de distribui??o agregado. A estrutura diam?trica e de altura das quatro ?reas seguem um aumento gradativo da frequ?ncia de indiv?duos nas quatro primeiras classes, exceto para ?rea CRF1. As an?lises de solos demonstram baixa fertilidade e textura arenosa com baixa capacidade de reten??o de umidade, al?m de toxidade por metais como: Mn2+ e Al3+, para as ?reas CRF2 e CRQ2, respectivamente. H? uma similaridade na organiza??o estrutural da anatomia foliar, nas quatro popula??es, com caracter?sticas t?picas de esp?cies de ambientes xerom?rficos, como: presen?a de cut?cula espessa, fibras subepid?rmicas, hipoderme aqu?fera e sistema vascular bem desenvolvidos, al?m de fendas estom?ticas. Em termos nutricionais a esp?cie apresenta baixos n?veis de requerimentos, foram observados altos concentra??es de metais pesados (Mn2+ e Al3+) nas folhas e ra?zes da esp?cie. As vari?veis ambientais: altitude, temperatura, umidade relativa do ar e radia??o influenciam diretamente na atividade de fotoss?ntese que ? complexa e sujeita a influ?ncias regulat?rias, internas e ambientais. Foram observadas caracter?sticas funcionais como plasticidade representada pela resposta morfo-anat?mica e ecofisiol?gica nesta esp?cie. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / The objective of this work is to understand the ecological processes that guide the spatial distribution and vegetative structure of the species Vellozia ramosissima and also to analyze leaf anatomy, nutrition and ecophysiology, interrelated with soil analysis, to recognize the plasticity of this species in Areas of Quartzite Rock Complexes (CRQs) and Ferruginous Complexes (CRFs). Data collection was based on the sampling of a 50x50 m plot in four areas in Rock Complexes: two areas located in quartzitic outcrops and two in ferruginous outcrops. In the plots, all individuals with height greater than or equal to one meter were mapped, the spatial distribution pattern was evaluated using the Ripley's K function. The Sturges method was used to define the number of diametric and height classes. Soil analyzes evaluated: pH, levels of P, K+, Ca2+, Mg2+ and Al3+; Potential acidity (H + Al), CTC at pH 7.0 (T); effective CTC (t), base saturation (SB), base saturation (V%), saturation by aluminum (m%), sand (fine and coarse), silt, clay and moisture equivalent (EU). Leaf anatomy and foliar anatomical sections (photomicrographs) were estimated for leaf anatomy. For each image, the anatomical parameters were measured: cuticle thickness, epidermis (on the adaxial and abaxial sides), palisade and lacunar parenchyma, extension of the sheath facing the vascular bundle (hypodermis), hypodermis facing the Stomatal cleft. The material collected for leaf and root nutrition was processed and the nutrients determined: N; P; K+; Ca2+; Mg2+; Zn2+; Fe2+; Mn2+; Cu; C; H+ and Al3+. The portable MINI-PAM modulating fluorometer was used to make point measurements of the variables: photorespiration and effective quantum yield. In the four areas, a total of 2.542 individuals with the following distribution were surveyed: 158 individuals in the CRQ1 area, 682 in the CRQ2 area, 39 in CRF1 and 1663 in CRF2. The Ripley's K function calculated for the four areas rejected the hypothesis of complete spatial randomness, generally showing an aggregate distribution pattern. The diameter and height structure of the four areas follow a gradual increase of the frequency of individuals in the first four classes, except for CRF1 area. Soil analyzes show low fertility and sandy texture with low moisture retention capacity, as well as toxicity by metals such as: Mn2+ and Al3+, for the areas CRF2 and CRQ2, respectively. There is a similarity in the structural organization of the leaf anatomy, in the four populations, with typical characteristics of species of xeromorphic environments, such as: presence of thick cuticle, subepidermal fibers, well developed hypodermis and vascular system, and stomatal cracks. In nutritional terms, the species presented low levels of requirements, high concentrations of heavy metals (Mn2+ and Al3+) were observed in the leaves and roots of the species. The environmental variables: altitude, temperature, relative air humidity and radiation directly influence the activity of photosynthesis that is complex and subject to regulatory, internal and environmental influences. Functional characteristics were observed as plasticity represented by the morpho-anatomical and echophysiological response in this species.

Stochastic point processes and associated methodology provide a means for the statistical analysis and modeling of the spatial point pattern formed from forest tree stem locations. Stochastic Gibbs point processes were explored as models that could simulate short-range clustering arising from reproduction of trees by stump sprouting, and intermediate-range inhibition of trees that may result from competition for light and growing space. This study developed and compared three pairwise interaction processes with parametric models for 2nd-order potentials and three triplets processes with models for 2nd- and 3rd-order potentials applied to a mixed-species hardwood forest in the Southern Appalachian Mountains of western North Carolina. Although the 2nd-order potentials of both the pairwise interaction and triplets processes were allowed to be purely or partially attractive, the proposed Gibbs point process models were demonstrated to be locally stable. The proposed Gibbs point processes were simulated using Markov Chain Monte Carlo (MCMC) methods; in particular, a reversible-jump Metropolis-Hastings algorithm with birth, death, and shift proposals was utilized. Parameters for the models were estimated by a Bayesian inferential procedure that utilizes MCMC methods to draw samples from the Gibbs posterior density. Two Metropolis-Hastings algorithms that do this sampling were compared; one that estimated ratios of intractable normalizing constants of the Gibbs likelihood by importance sampling and another that introduced an auxiliary variable to cancel the normalizing constants with those in the auxiliary variable's proposal distribution. Results from this research indicated that attractive pairwise interaction models easily degenerate into excessively clustered patterns, whereas triplets processes with attractive 2nd-order and repulsive 3rd-order interactions are more robust against excessive clustering. Bayesian inference for the proposed triplets models was found to be very computationally expensive. Slow mixing of both algorithms used for the inference combined with the long iteration times limited the practicality of the Bayesian approach. However the results obtained here indicate that triplets processes can be used to draw inference for and simulate patterns of mixed-species Appalachian hardwood forests. / Ph. D.

O padrão espacial de espécies em florestas nativas pode fornecer evidências sobre a estrutura da comunidade vegetal. Fatores ambientais podem influenciar o padrão espacial das espécies, como as características edáficas e processos que dependem da densidade, como competição intra e interespecífica. Desse modo, a pesquisa da relação entre as características ambientais e o padrão espacial de espécies florestais pode ajudar a entender a dinâmica de florestas. O objetivo deste estudo foi empregar técnicas da análise de processos pontuais para verificar o efeito de fatores ambientais sobre a ocorrência de espécies florestais. A área de estudo foi a Estação Ecológica de Assis (EEA), da unidade de Conservação do Estado de São Paulo em parcelas permanentes, dentro do projeto \"Diversidade, dinâmica e conservação em florestas do Estado de São Paulo: 40 ha de parcelas permanentes\" do programa Biota da FAPESP. A descrição do padrão espacial das espécies mais abundantes na área de estudo foi avaliada pela função K proposta por Ripley e suas extensões para processo não homogêneos, por meio das coordenadas geográficas das espécies com circunferência na altura do peito igual ou superior a 15 cm. Modelos do Processo Poisson Homogêneo, Processo Poisson Não Homogêneos e do Processo Log Gaussiano de Cox foram ajustados para cada espécie. Foi utilizado o critério de AIC para selecionar o modelo que melhor se ajusta aos dados. Testes de diagnósticos dos modelos foram feitos utilizando a função K não homogênea sob a hipótese de Completa Aleatoriedade Espacial. Os resultados indicaram que as espécies mais abundantes na EEA apresentam um padrão de distribuição agregado, ou seja, o número esperado de indivíduos próximos de um evento qualquer é maior do que esperado para uma distribuição aleatória. Conforme esperado, os fatores ambientais desempenharam um importante papel para explicar a distribuição espacial das espécies, porém, os resultados indicaram que existe uma variação espacialmente estruturada que não foi incluída na análise que é imprescindível para um bom ajuste dos modelos. Portanto os resultados sugerem que outros fatores não incluídos nos modelos e dados disponíveis podem estar determinando os padrões espaciais além das (co)variáveis medidas. / The spatial pattern of species in native forests may provide evidence on the structure of the plant community. Environmental factors may influence the species\' spatial patterns, as well as soil characteristics and processes which depend on the density, as intraspecific and interspecific competition. Therefore, researching the relationship among the environmental features and the spatial pattern of the forest species may aid in understanding forest dynamics. The goal of this study was to apply point process techniques to verify the effect of environmental factors on the occurence of forest species. The study area was the \"Assis\'s Ecological Station\" (AES), of the \"Unit of conservation of the state of São Paulo in permanent plots\". The data was collected as part of the project entitled \"Diversity, dynamics and conservation in forests of São Paulo state: 40 ha of permanent plots\", from FAPESP\'s Biota program. The description of the spatial pattern of the most abundant species in the study area was assessed using Ripley\'s K function, using the species\' geographic coordinates with circumference at chest height equal or larger than 15 cm. Homogeneous and Non-Homogeneous Poisson Process models, as well as Cox Log Gaussian Process models were fitted to each species. Model selection was made using the Akaike information criterion. Diagnostics tests were made using the non-homogeneous K function under the hypothesis of complete spatial randomness. Results suggested that the most abundant species in the AES present an aggregate distribution pattern, i.e., the expected number of individuals next to any event is larger than the expected by a random distribution. As it was expected, environmental factors played a major role in explaining the spatial distribution of the species. However, results suggested that there is a spatially structured variation that was not included in the analysis and is needed to a good model fit. Therefore, further studies are needed to assess which environmental feature which was not considered in this study presents an effect on the occurence of these forest species

In this thesis, the basic tools of spatial statistics and time series analysis are applied to the case study of the earthquakes in a certain geographical region and time frame. Then some of the existing methods for joint analysis of time and space are described and applied. Finally, additional research questions about the spatial-temporal distribution of the earthquakes are posed and explored using statistical plots and models. The focus in the last section is in the relationship between number of events per year and maximum magnitude and its effect on how clustered the spatial distribution is and the relationship between distances in time and space in between consecutive events as well as the distribution of the distances.

Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-25T22:37:17Z No. of bitstreams: 1 DISS_2014_Alexandre Ebert.pdf: 1748514 bytes, checksum: d9c571963613083829534e6c841c99ff (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-05-16T14:25:20Z (GMT) No. of bitstreams: 1 DISS_2014_Alexandre Ebert.pdf: 1748514 bytes, checksum: d9c571963613083829534e6c841c99ff (MD5) / Made available in DSpace on 2018-05-16T14:25:20Z (GMT). No. of bitstreams: 1 DISS_2014_Alexandre Ebert.pdf: 1748514 bytes, checksum: d9c571963613083829534e6c841c99ff (MD5) Previous issue date: 2014-02-25 / CAPES / Os distúrbios causados pela antropização de áreas naturais causam fortes alterações na estrutura original da floresta, aumentam o grau de isolamento entre indivíduos afetando o sistema reprodutivo das populações. Diversos processos estão relacionados à distribuição espacial dos indivíduos de uma população, sendo que estes processos refletem na diversidade genética da população. Do ponto de vista genético qualquer alteração no ambiente poderá influenciar nos padrões da estrutura genética, sendo que a extinção de uma espécie é etapa final de um longo processo de declínio ecológico que passa pela perda da diversidade genética. No presente estudo avaliaram-se os padrões espaciais pontuais não homogêneos e a diversidade genética dentro de uma população natural fragmentada de Mezilaurus itauba, buscou-se estabelecer os objetivos de modo que se conclui com a afirmação da hipótese de que as alterações dos padrões de distribuição espacial de indivíduos exercem influência direta na estrutura genética da população. A avaliação dos padrões de distribuição espacial para a espécie foi testada através da função K proposta por Ripley e buscou-se associar a diversidade genética através de análise de agrupamentos estatísticos. Os resultados indicam que a população estudada apresenta padrões de distribuição aleatório com tendência a agregado para as árvores adultas, e de completa aleatoriedade espacial para as árvores jovens. Na análise genética verificou-se uma distribuição da diversidade entre os indivíduos jovens e adultos, porém alelos observados entre as árvores adultas não foram observados entre as árvores jovens, o que indica que na exploração das espécies adultas alelos importantes poderão ser perdidos. O trabalho conclui a afirmação de que estudos da diversidade genética de população são de suma importância para a definição de estratégias de conservação das espécies exploradas economicamente na Amazônia meridional brasileira. / The disturbances caused by human disturbance of natural areas cause strong changes in the original structure of a forest, increase the degree of isolation between individuals affecting the reproductive system of populations. Several processes are related to the spatial distribution of individuals in a population, and that these processes reflect the genetic diversity of the population. From a genetic perspective any changes in the environment may influence the patterns of genetic structure, and the extinction of a species is the final step in a long process of ecological decline that passes through the loss of genetic diversity. In the present study evaluated the inhomogeneous spatial point patterns and genetic diversity within a natural population of fragmented Mezilaurus itauba, we sought to establish the objectives so that concludes with the statement of the hypothesis that changes in the patterns of spatial distribution individuals exert direct influence on the genetic structure of the population . The evaluation of the spatial distribution of the species was tested by K function proposed by Ripley and sought to associate genetic diversity through analysis of statistical groupings. The results indicate that the studied population presents patterns of random distribution with a tendency to aggregate for adult trees, and complete spatial randomness for the young trees. In genetic analysis showed a distribution of diversity among young people and adults, but alleles observed among adult trees were not observed between the young trees, which indicate that the operation of adult species important alleles may be lost. The paper concludes the statement that studies the genetic diversity of the population is of paramount importance for the development of strategies for the conservation of species exploited economically in the southern Brazilian Amazon.

O padrão espacial de espécies em florestas nativas pode fornecer evidências sobre a estrutura da comunidade vegetal. Fatores ambientais podem influenciar o padrão espacial das espécies, como as características edáficas e processos que dependem da densidade, como competição intra e interespecífica. Desse modo, a pesquisa da relação entre as características ambientais e o padrão espacial de espécies florestais pode ajudar a entender a dinâmica de florestas. O objetivo deste estudo foi empregar técnicas da análise de processos pontuais para verificar o efeito de fatores ambientais sobre a ocorrência de espécies florestais. A área de estudo foi a Estação Ecológica de Assis (EEA), da unidade de Conservação do Estado de São Paulo em parcelas permanentes, dentro do projeto \"Diversidade, dinâmica e conservação em florestas do Estado de São Paulo: 40 ha de parcelas permanentes\" do programa Biota da FAPESP. A descrição do padrão espacial das espécies mais abundantes na área de estudo foi avaliada pela função K proposta por Ripley e suas extensões para processo não homogêneos, por meio das coordenadas geográficas das espécies com circunferência na altura do peito igual ou superior a 15 cm. Modelos do Processo Poisson Homogêneo, Processo Poisson Não Homogêneos e do Processo Log Gaussiano de Cox foram ajustados para cada espécie. Foi utilizado o critério de AIC para selecionar o modelo que melhor se ajusta aos dados. Testes de diagnósticos dos modelos foram feitos utilizando a função K não homogênea sob a hipótese de Completa Aleatoriedade Espacial. Os resultados indicaram que as espécies mais abundantes na EEA apresentam um padrão de distribuição agregado, ou seja, o número esperado de indivíduos próximos de um evento qualquer é maior do que esperado para uma distribuição aleatória. Conforme esperado, os fatores ambientais desempenharam um importante papel para explicar a distribuição espacial das espécies, porém, os resultados indicaram que existe uma variação espacialmente estruturada que não foi incluída na análise que é imprescindível para um bom ajuste dos modelos. Portanto os resultados sugerem que outros fatores não incluídos nos modelos e dados disponíveis podem estar determinando os padrões espaciais além das (co)variáveis medidas. / The spatial pattern of species in native forests may provide evidence on the structure of the plant community. Environmental factors may influence the species\' spatial patterns, as well as soil characteristics and processes which depend on the density, as intraspecific and interspecific competition. Therefore, researching the relationship among the environmental features and the spatial pattern of the forest species may aid in understanding forest dynamics. The goal of this study was to apply point process techniques to verify the effect of environmental factors on the occurence of forest species. The study area was the \"Assis\'s Ecological Station\" (AES), of the \"Unit of conservation of the state of São Paulo in permanent plots\". The data was collected as part of the project entitled \"Diversity, dynamics and conservation in forests of São Paulo state: 40 ha of permanent plots\", from FAPESP\'s Biota program. The description of the spatial pattern of the most abundant species in the study area was assessed using Ripley\'s K function, using the species\' geographic coordinates with circumference at chest height equal or larger than 15 cm. Homogeneous and Non-Homogeneous Poisson Process models, as well as Cox Log Gaussian Process models were fitted to each species. Model selection was made using the Akaike information criterion. Diagnostics tests were made using the non-homogeneous K function under the hypothesis of complete spatial randomness. Results suggested that the most abundant species in the AES present an aggregate distribution pattern, i.e., the expected number of individuals next to any event is larger than the expected by a random distribution. As it was expected, environmental factors played a major role in explaining the spatial distribution of the species. However, results suggested that there is a spatially structured variation that was not included in the analysis and is needed to a good model fit. Therefore, further studies are needed to assess which environmental feature which was not considered in this study presents an effect on the occurence of these forest species