This thesis investigates a resource driven probabilistic cellular automata (PCA) model of plant competition in terms of local interactions, spatial distributions, and invasion. The model also incorporates herbivores and carnivores and examines their effect on plant populations and community structure. Comparisons are drawn between the model, field studies and other mathematical models. Chapter 1 provides a background of relevant concepts from plants and animal ecology, details a number of mathematical models used in this field and describes the model relevant models and results in the literature. It concludes with a comparison of the features of the most germane models and field studies. Chapter 2 primarily focuses on plants, argues for the model we have chosen, recaptures previous results which are similar to some natural phenomena, and makes a preliminary investigation of community behaviour and disturbance. It then describes the effect of introducing biomass for plants on species behaviour, and their spatial distributions. Chapter 3 deals with competition between different species, and aspects of invasion. Coexistence between functionally different plants can occur, join count statistics and measures for patch location on the torus are developed and applied. Chapter 4 derives a generalised probabilistic model for ruderal monocultures, finds numerical solutions for these and investigates models for vegetatively growing species of plants. Chapter 5 examines the population effects of herbivory (i.e. importance of spatial correlation of disturbance) and analogies to competitor-stress tolerator-ruderal (CSR) primary plant types, as well as plant successional rates and factors affecting community composition. Equilibrium species composition corresponded to CSR theory when plant immigration was introduced. Chapter 6 investigates the basic effects of carnivory, and discusses parallels between probabilistic cellular automata and field studies.

Prescribed burning is a commonly used wildlife management tool. While most of the available data have evaluated short term effects of fire on wildlife (< 3 years), the present study addresses longer term effects (0 to 7 years). This enables a more thorough investigation of fire management affects on herpetofaunal communities at the landscape level. Ten sites, stratified by 0 to 7 years post-burn, were randomly selected on Big Oaks National Wildlife Refuge in southeastern Indiana and monitored for 2 field seasons. Within each site, several trapping methods were utilized including a sampling array of drift fences, pitfall traps, single and double ended funnel traps, PVC pipes, and cover boards. Burning caused immediate stand level effects and changed vegetation characteristics, which affected the species assemblages of herpetofauna and small mammals. Data collected identified the spatial and temporal variables that explained the patterns of occurrence and abundance of herpetofaunal species and small mammal species, and how community vegetation characteristics such as structure, resource availability, and plant species assemblages, correlated with and affected those patterns. Burn regimes of 2-5 years were found to be optimal when managing herpetofauna and small mammals. Constrictor coluber priapus and Peromyscus leucopus were captured frequently in the study area and the effects of a properly timed prescribed burn could have positive effects on the numbers of generalist species. Akaike information criterion was used to determine the habitat variables that were most important in habitat selection of the herpetofaunal and small mammal classes and species. While this study was limited to one wildlife refuge, in the central hardwoods its findings may have ramifications for herpetofauna in other areas where prescribed fire can be used as a management tool.

Background : Old fields are abandoned agricultural areas that are undergoing secondary succession. A variety of factors influence the assembly, invasibility, and species turnover during secondary succession in old fields. Old fields are important ecological research locations as an increasing amount of agricultural land is abandoned worldwide. Objectives : 1) To determine if exotic and native "invaders" display differences in invasion success in an old field, and 2) To observe how native and exotic species abundances change over the course of secondary succession under predictable disturbance regimes and resource levels with regards to the Core-Satellite Species (CSS) hypothesis. Methods : An old field located in southern Illinois subject to three levels of fertilization (control, annually fertilized, and fertilized every 5 years) crossed with three levels of mowing treatments (control, spring mowed, and spring/fall mowed) established in 1996 was used to test objectives Seedlings of C3 grasses (native and exotic) were planted within one fertilizer treatment to compare invasion success. Species composition data (species occurrence and abundance at three heights) in all blocks were previously collected from 1996 to 2002 and the sample plots were resampled in 2013. Species sampled in 2013 were assigned to core or satellite categories per the CSS hypothesis. Results : Invading exotic seedlings had higher survivorship than invading native seedlings from the same functional group within the same fertilizer level, and added fertilizer increased seedling survivorship. The number of core and satellite species varied early after experiment establishment in 1996 but has since leveled off, and the ratio of exotic to native species cover at heights <1m ratio was affected by an interaction between mowing treatment and time. The species occupancy distribution of all species in 2013 was not bimodally distributed, but the occupancy distribution of exotic species in 2013 was bimodally distributed.The community composition of the plots varied among blocks, but was affected by an interaction between fertilizer treatment and mowing. Conclusions : Exotic invading grass seedlings in a successional community were relatively more successful than native invading grass seedlings. However, overall survivorship of all invading grass seedlings was low, a typical finding in grasslands. The identity of core and satellite species continued to fluctuate through time following 17 years of secondary succession. Resource availability and disturbance regime affects on community composition throughout secondary succession, and may result in many alternative stable states. This research supports the `CSS' and `parallel dynamics' hypotheses and indicates that presence of exotic species within a community does not necessarily facilitate invasion by new exotic species.

Abstract This thesis operates at two levels of ecological research, describing the effects of withdrawal and re-introduction of management on grasslands. The aim of the community-level survey was to explore the effects of abandonment, mowing and grazing on semi-natural meadows in northern Finland. At the species level, the aim was to evaluate the responses of three monocarpic meadow species to various degrees of simulated grazing under natural growth conditions. The community-level studies suggest that strongly competitive grass species with rapid vegetative growth, especially those forming tussocks, are able to retain or increase their cover in abandoned meadows. However, most species are able to persist in a meadow for a long time after abandonment, even when a group of immigrants arrive. This leads to a temporary increase in species diversity, and it may therefore be used as an indicator of ongoing succession. Nevertheless, abandonment is harmful for the rare archaeophytic species in the long run. Late mowing does not have extensive short-term impacts on grass-dominated semi-natural meadows. Therefore, it is neither an efficient nor a substitutional way of management when the goal is to restore a formerly grazed pasture. Mowing executed early in the season may, however, be a more appropriate way of inducing changes in species composition and enhancing species richness. According to the results of the species-level studies, Erysimum strictum and Rhinanthus minor tolerate well minor apical damage, while more severe damage has a detrimental impact on the performance of both species. The observed differences in regrowth responses between the two species are presumably due to their different habitat requirements in relation to competition. The species-level experiment with two late-flowering populations of field gentian Gentianella campestris ssp. campestris revealed that the southern, Swedish population that has been regularly grazed and mown overcompensated for the intermediate (50%) damage level, whereas the northern, Finnish field gentians growing in unmanaged habitats showed at best partial or full compensation. Regular grazing and mowing have presumably favoured grazing-tolerant plant species, i.e. species with a good regrowth capacity. Herbivory reshapes grassland plant communities in two ways: directly by affecting the survival and reproductive success of individual plants and indirectly by changing the competitive environment. Tall and competitive perennial species suffer relatively more from damage than true grassland species, i.e. small herbs and grasses, which are better able to tolerate regular tissue losses and respond to damage within the ongoing growing season. As a result, certain species benefit from grazing and mowing in the sense that they may gain more through competitive relaxation than they lose in defoliation.

Tidal freshwater forest restoration after dam removal has been unexplored to date. This study elucidated pre-dam forest composition, as well as post-dam edaphic and microtopographical attributes and woody species recruiting along a narrow ecotone of a 29.3-ha tidal freshwater wetland. The ≈65-year-old historical forest (15 species, 200 stems ha-1) and ≈7-year-old contemporary forest (40 species and 11,009 stems ha-) community dominants were dissimilar (Fraxinus spp. vs. Liquidambar styraciflua, respectively). Pre-dam environmental conditions were unknown. Post-dam edaphic water content, organic matter, redox potential and microtopography differed significantly across tidal sites but were less variable in non-tidal sites. Shifts in the contemporary woody community composition and the concomitant increase in stem density and seedling:sapling ratios with elevation likely owed to significant changes in microtopography and edaphic attributes. Developing ecotones that contain variable microtopography may be extremely important for successful natural woody recruitment after dam removal from a tidal freshwater system.

Este trabalho objetivou analisar a dinâmica da regeneração natural de duas áreas de Floresta Ombrófila Densa (FOD) com idades diferentes de regeneração, sendo uma de FOD Submontana de oito anos (A1- Miracatu) e outra FOD das Terras Baixas de 33 anos (A2-Peruíbe), degradadas para implantação da bananicultura. A caracterização da regeneração foi feita por meio de levantamento florístico e fitossociológico realizado pelo método de parcelas, onde em cada área foram implantadas cinco parcelas de 10 x 25 m, totalizando 2.500 m². O material botânico de todos os indivíduos de porte arbustivo-arbóreo 1 m de altura foi coletado e foram registrados a altura e o perímetro do caule a 1,3 m do solo. Após a identificação das espécies foram classificadas as suas síndromes de dispersão, assim como foram estabelecidos os grupos sucessionais aos quais pertenciam. A estrutura florestal foi estudada através do cálculo dos parâmetros de densidade e dominância, tanto absoluta quanto relativa, além do valor de cobertura (VC), realizados com o Fitopac, e também os índices de similaridade de Jaccard (ISj), de diversidade de Shannon (H) e equabilidade (J). Na A1 foram levantados 1.440 indivíduos de 149 espécies e 59 famílias e na A2 foram levantados 1.023 indivíduos de 172 espécies e 56 famílias. As famílias de maiores riquezas de espécies da A1 foram Melastomataceae (29), Myrtaceae (15), Fabaceae (10), Rubiaceae (9) e Asteraceae (6), e na A2 foram Myrtaceae (29), Piperaceae (19), Fabaceae (18), Melastomataceae (13) e Rubiaceae (11), onde na A1 predominaram as espécies pioneiras e secundárias iniciais (36,91%) e na A2 as tardias e de sub-bosque (38,96%) e a síndrome de dispersão predominante em ambas as áreas foi a zoocoria para 54,36% das espécies de A1 e 65,11% em A2. As espécies com maiores valores de VC da A1 foram Tibouchina pulchra, Leandra variabilis, Miconia cinnamomifolia, Piptocarpha macropoda, Vernonanthura discolor e Myrsine coriacea que somaram 64,8% de VC. Na A2 as espécies com os maiores valores de VC foram Euterpe edulis, T. pulchra, Hyeronima alchorneoides, Bathysa australis, Ficus insipida, Cyatheaceae sp.1, Piper gaudichaudianum e Psychotria nuda perfazendo 58,12% do VC. Na A1 as espécies com maiores densidades foram L. variabilis (DeA=2.568 ind./ha e DeR=24,21%), T. pulchra (DeA=1.360 ind./ha e DeR=12,82%), M. cinnamomifolia (DeA=1.088 ind./ha e DeA=10,26%) e H. alchoneoides (DeA=408 ind./ha e DeA=3,85%). A2 possui uma floresta com estrutura mais complexa, apresentou flora similar a quatro estudos realizados nas regiões do Vale do Ribeira e Baixada Santista, e A1 apresentou baixa similaridade. Na A1 as espécies pioneiras destacaram-se na estrutura e na A2 o papel das espécies dos diferentes grupos sucessionais foi mais equilibrada. O componente da vegetação amostrado em A1 apresentou H= 3,330 nat. ind-1 e J = 0,666 e em A2 H= 3,919 nat. ind-1 e J = 0,761. A regeneração natural mostrou-se capaz de promover a erradicação de 95,45% a 100% das bananeiras em A1 enquanto em A2, após 33 anos, nenhuma bananeira remanescente foi observada. / This work aimed to analyze the dynamics of natural regeneration of two areas with physiognomies and different ages of regeneration, with a Dense Ombrophilous Forest (DOF) Submontane (A1-Miracatu-8 years) and another on DOF lowland (A2-Peruíbe-33 years), degraded to deployment of the banana plantation. The characterization of the regeneration was made by using floristic and phytosociological survey, which was performed by methods of plots. Were deployed five 10 x 25 m plots in each area, totaling 2,500 m². The botanical material of all individuals to carry shrub-tree 1 m tall was collected and have been registered, the height and circumference at breast height to 1.3 m above the ground. After the identification of the species have been classified their dispersal syndromes, as well as successional groups to which they belonged were established. The forest structure was studied by calculating the parameters of density and dominance, both absolutely and relative, in addition to the coverage value (VC), performed with the Fitopac, and also the indexes of similarity of Jaccard (ISj), Shannon diversity (H \') and equability (J \'). In A1 were raised 1,440 individuals of 149 species and 59 families and A2 were surveyed 1,023 individuals of 172 species and 56 families. The families of most species richness of A1 were Melastomataceae (29), Myrtaceae (15), Fabaceae (10), Rubiaceae (9) and Asteraceae (6), and A2 were Myrtaceae (29), Piperaceae (19), Fabaceae (18), Melastomataceae (13) and Rubiaceae (11), where the A1 predominated the pioneer and early secondary species (36.91%) and A2 late and understory (38.96%) and predominant dispersion syndrome in both areas was zoochory to 54.36% of the species A1 and 65,11% in A2. The species with the highest values of VC the A1 were Tibouchina pulchra, Leandra variabilis, Miconia cinnamomifolia, Piptocarpha macropoda, Vernonanthura discolor and Myrsine coriacea totaling 64.8% of VC.. In A2 the species with higher VC were Euterpe edulis, T. pulchra, Hyeronima alchorneoides, Bathysa australis, Ficus insipida, Cyatheaceae 1, Piper gaudichaudianum and Psychotria nuda totaling 58,12% of VC. A1 in the species with the highest densities were L. variabilis (DeA = 2.568 ind./ha and DeR = 24.21%), T. pulchra (DeA = 1,360 ind./ha and DeR = 12.82%), M. cinnamomifolia (DeA = 1,088 ind./ha and DeA = 10.26%) and H. alchoneoides (DeA = 408 ind./ha and DeA = 3.85%). A2 has a forest with more complex structure showed similar flora to four studies conducted in regions of the Ribeira Valley and Santos Lowland, and A1 showed low similarity. In A1 pioneer species stood out in the structure and A2 the role of species of different successional groups was more balanced. The vegetation component sampled at A1 presented H\' = 3,330 nat. ind-1 and J\' = 0,666 and A2 H\' = 3,919 nat. ind-1 and J\' = 0.761. Natural regeneration has been shown to promote the eradication of 95.45 to 100% of the banana trees in A1 while in A2 after 33 years, any remaining banana was observed.

Este trabalho objetivou analisar a dinâmica da regeneração natural de duas áreas de Floresta Ombrófila Densa (FOD) com idades diferentes de regeneração, sendo uma de FOD Submontana de oito anos (A1- Miracatu) e outra FOD das Terras Baixas de 33 anos (A2-Peruíbe), degradadas para implantação da bananicultura. A caracterização da regeneração foi feita por meio de levantamento florístico e fitossociológico realizado pelo método de parcelas, onde em cada área foram implantadas cinco parcelas de 10 x 25 m, totalizando 2.500 m². O material botânico de todos os indivíduos de porte arbustivo-arbóreo 1 m de altura foi coletado e foram registrados a altura e o perímetro do caule a 1,3 m do solo. Após a identificação das espécies foram classificadas as suas síndromes de dispersão, assim como foram estabelecidos os grupos sucessionais aos quais pertenciam. A estrutura florestal foi estudada através do cálculo dos parâmetros de densidade e dominância, tanto absoluta quanto relativa, além do valor de cobertura (VC), realizados com o Fitopac, e também os índices de similaridade de Jaccard (ISj), de diversidade de Shannon (H) e equabilidade (J). Na A1 foram levantados 1.440 indivíduos de 149 espécies e 59 famílias e na A2 foram levantados 1.023 indivíduos de 172 espécies e 56 famílias. As famílias de maiores riquezas de espécies da A1 foram Melastomataceae (29), Myrtaceae (15), Fabaceae (10), Rubiaceae (9) e Asteraceae (6), e na A2 foram Myrtaceae (29), Piperaceae (19), Fabaceae (18), Melastomataceae (13) e Rubiaceae (11), onde na A1 predominaram as espécies pioneiras e secundárias iniciais (36,91%) e na A2 as tardias e de sub-bosque (38,96%) e a síndrome de dispersão predominante em ambas as áreas foi a zoocoria para 54,36% das espécies de A1 e 65,11% em A2. As espécies com maiores valores de VC da A1 foram Tibouchina pulchra, Leandra variabilis, Miconia cinnamomifolia, Piptocarpha macropoda, Vernonanthura discolor e Myrsine coriacea que somaram 64,8% de VC. Na A2 as espécies com os maiores valores de VC foram Euterpe edulis, T. pulchra, Hyeronima alchorneoides, Bathysa australis, Ficus insipida, Cyatheaceae sp.1, Piper gaudichaudianum e Psychotria nuda perfazendo 58,12% do VC. Na A1 as espécies com maiores densidades foram L. variabilis (DeA=2.568 ind./ha e DeR=24,21%), T. pulchra (DeA=1.360 ind./ha e DeR=12,82%), M. cinnamomifolia (DeA=1.088 ind./ha e DeA=10,26%) e H. alchoneoides (DeA=408 ind./ha e DeA=3,85%). A2 possui uma floresta com estrutura mais complexa, apresentou flora similar a quatro estudos realizados nas regiões do Vale do Ribeira e Baixada Santista, e A1 apresentou baixa similaridade. Na A1 as espécies pioneiras destacaram-se na estrutura e na A2 o papel das espécies dos diferentes grupos sucessionais foi mais equilibrada. O componente da vegetação amostrado em A1 apresentou H= 3,330 nat. ind-1 e J = 0,666 e em A2 H= 3,919 nat. ind-1 e J = 0,761. A regeneração natural mostrou-se capaz de promover a erradicação de 95,45% a 100% das bananeiras em A1 enquanto em A2, após 33 anos, nenhuma bananeira remanescente foi observada. / This work aimed to analyze the dynamics of natural regeneration of two areas with physiognomies and different ages of regeneration, with a Dense Ombrophilous Forest (DOF) Submontane (A1-Miracatu-8 years) and another on DOF lowland (A2-Peruíbe-33 years), degraded to deployment of the banana plantation. The characterization of the regeneration was made by using floristic and phytosociological survey, which was performed by methods of plots. Were deployed five 10 x 25 m plots in each area, totaling 2,500 m². The botanical material of all individuals to carry shrub-tree 1 m tall was collected and have been registered, the height and circumference at breast height to 1.3 m above the ground. After the identification of the species have been classified their dispersal syndromes, as well as successional groups to which they belonged were established. The forest structure was studied by calculating the parameters of density and dominance, both absolutely and relative, in addition to the coverage value (VC), performed with the Fitopac, and also the indexes of similarity of Jaccard (ISj), Shannon diversity (H \') and equability (J \'). In A1 were raised 1,440 individuals of 149 species and 59 families and A2 were surveyed 1,023 individuals of 172 species and 56 families. The families of most species richness of A1 were Melastomataceae (29), Myrtaceae (15), Fabaceae (10), Rubiaceae (9) and Asteraceae (6), and A2 were Myrtaceae (29), Piperaceae (19), Fabaceae (18), Melastomataceae (13) and Rubiaceae (11), where the A1 predominated the pioneer and early secondary species (36.91%) and A2 late and understory (38.96%) and predominant dispersion syndrome in both areas was zoochory to 54.36% of the species A1 and 65,11% in A2. The species with the highest values of VC the A1 were Tibouchina pulchra, Leandra variabilis, Miconia cinnamomifolia, Piptocarpha macropoda, Vernonanthura discolor and Myrsine coriacea totaling 64.8% of VC.. In A2 the species with higher VC were Euterpe edulis, T. pulchra, Hyeronima alchorneoides, Bathysa australis, Ficus insipida, Cyatheaceae 1, Piper gaudichaudianum and Psychotria nuda totaling 58,12% of VC. A1 in the species with the highest densities were L. variabilis (DeA = 2.568 ind./ha and DeR = 24.21%), T. pulchra (DeA = 1,360 ind./ha and DeR = 12.82%), M. cinnamomifolia (DeA = 1,088 ind./ha and DeA = 10.26%) and H. alchoneoides (DeA = 408 ind./ha and DeA = 3.85%). A2 has a forest with more complex structure showed similar flora to four studies conducted in regions of the Ribeira Valley and Santos Lowland, and A1 showed low similarity. In A1 pioneer species stood out in the structure and A2 the role of species of different successional groups was more balanced. The vegetation component sampled at A1 presented H\' = 3,330 nat. ind-1 and J\' = 0,666 and A2 H\' = 3,919 nat. ind-1 and J\' = 0.761. Natural regeneration has been shown to promote the eradication of 95.45 to 100% of the banana trees in A1 while in A2 after 33 years, any remaining banana was observed.

A estruturação de padrões e processos das comunidades vegetais ocorrem no espaço e no tempo e é mediada pelas adaptações das plantas (características das espécies) às condições bióticas e abióticas a que estão submetidas. Nesse sentido, este estudo usa a identidade das espécies e seus atributos na busca de padrões florístico-estruturais das comunidades e de padrões de convergência (TCAP) e divergência (TDAP) de atributos ao longo do gradiente sucessional. Comunidades espacialmente separadas e com diferentes idades de abandono (substituição espaço-tempo) foram demarcadas para a investigação destes padrões numa região de Mata Atlântica, no Rio Grande do Sul, Brasil. Informantes locais indicaram o histórico de uso do solo e o tempo de regeneração da floresta, o qual variou entre 6 e 45 anos e áreas de referência (sem indicativo de corte raso). O levantamento da vegetação arbórea (DAP !10cm) foi realizado em 28 parcelas constituídas de 3 sub-parcelas de 100m2 cada, compondo a matriz de cobertura das espécies em seus sítios. Variáveis locais de clima, solo e espaço foram levantadas, as quais, juntamente com o tempo de regeneração, compuseram matrizes de variáveis ambientais usadas para identificar a importância do ambiente e do tempo na estruturação das comunidades. De um pool de 96 espécies, aquelas 52 mais frequentes (! 8%) tiveram os seguintes atributos avaliados: conteúdo de nitrogênio (LNC) e fósforo foliar (LPC), a relação entre eles, conteúdo de massa seca da folha, área foliar (LA), a massa foliar por área (LMA), espessura foliar, forma da folha, sazonalidade foliar (SA), altura potencial máxima da espécie, altura máxima das espécies estimada em campo (Ac), densidade da madeira e capacidade de rebrote (Rb). Os resultados indicaram que o tempo de abandono (correlação= 0,38, p= 0,001) tem influência maior sobre a comunidade vegetal do que os outros conjuntos de variáveis ambientais consideradas. As áreas de referência apresentaram-se claramente distintas em relação à composição de espécies das áreas iniciais e intermediárias. Por outro lado, as análises de variância dos parâmetros estruturais indicaram um aumento significativo da cobertura do estrato arbóreo, das alturas máximas e mínimas e da estratificação da floresta (variância da altura do dossel), já a partir 26 anos após o abandono, assemelhando-se às áreas de referência. Na análise funcional das comunidades, os atributos que maximizaram os padrões de convergência ao longo do gradiente foram: LNC, LPC, LMA, Ac and Rb ("(TE) = 0,44, P= 0,01); e aqueles que maximizaram a divergência foram: LA, LNC, Ac, Rb, SA ("(XE.T)= 0,378; P=0,007). Análises exploratórias indicaram a ocorrência de espécies arbóreas mais altas e perenifólias nas florestas avançadas, em contraste às pioneiras de crescimento rápido, com capacidade de rebrotar e sobreviver após distúrbios antrópicos, ocorrendo nos estágios iniciais. A diversidade funcional aumenta com a maturação da floresta. Todavia, os valores elevados encontrados nos estágios intermediários indicam a coocorrência de espécies de etapas iniciais e finais da sucessão nesta fase. Podemos concluir que a estrutura das florestas secundárias nessa região, assim como sua diversidade funcional, começam a adquirir valores semelhantes aos de florestas em estágio avançado de sucessão a partir dos 26 anos, no entanto a composição destas ainda permanece muito distinta. / The structuring of plant communities patterns and processes occur in time and space and are mediated by plant adaptations (species traits) to biotic and abiotic conditions to which they are subjected. This study looks for structural and floristic community patterns through the use of species identity, as well as for traits convergence (TCAP) and divergence (TDAP) assembly patterns in relation to the successional gradient. Spatially separated communities of different ages since abandonment (space-for-time substitution) were demarcated for the investigation of these patterns in the Atlantic Forest, Rio Grande do Sul state, southern Brazil. Local informants indicated the land use history and time of forest regeneration, which ranged between 6 and 45 years, and reference areas (without signal of clear-cut). The trees (DBH ! 10 cm) were surveyed in 28 plots consisting of three 100 m2 sub-plots, composing the species abundance per sites matrix. Abiotic variables of local climate, soil and space have been collected, and were considered as environmental variables, together with the regeneration time in the analysis of community structure. From a pool of 96 species, the 52 most frequent (! 8%) were evaluated for the following attributes: leaf nitrogen (LNC) and phosphorus (LPC) content, the relationship among them, leaf dry matter content, leaf area (LA), leaf mass per area (LMA), leaf thickness, leaf shape, leaf seasonality (SA), maximum potential height, estimated maximum in the field (Ac), wood density and resprouting ability (Rb). The results indicated that the time of abandonment (correlation =0.38, p = 0.001) have greater influence on plant community than the others sets of environmental variables. Reference sites are clearly distinct in species composition from the initial and intermediate areas. Moreover, analysis of variance of the structural parameters indicated a significant increase in tree cover, in the maximum and minimum heights, and in the forest stratification (canopy height variance) along the succession time. Sites with 26 years after abandonment are already similar to the reference areas for such parameters. In the functional analysis of the communities, the traits that maximized convergence assembly patterns along the gradient were: LNC, LPC, LMA, Ac and Rb (! (TE) = 0.44, P = 0.01) and those that maximized divergence were: LA, LNC, Ac, Rb, SA (! (XE.T) =0.378, P = 0.007). Exploratory analysis indicated the occurrence of taller evergreen trees species at the reference sites, in contrast to the fast growth pioneer species, able to resprout and survive after human disturbances, occurring in the early stages. The functional diversity increases with the maturation of the forest. However, the high values found in the intermediate stages indicate the co-occurrence of early- and late-successional species in this phase. We can conclude that the structure and the functional diversity of secondary forests in this region begin to be similar to forests in advanced stages of succession from 26 years, however the species composition of which still remains very distinct.

Submitted by Rebeka Godeiro (rebeka_carvalho@hotmail.com) on 2018-05-21T12:20:55Z No. of bitstreams: 1 DELYANE LIMA SOARES - DISSERTAÇÃO ZOOTECNIA 2017.pdf: 1682795 bytes, checksum: 1bd089d8abe5d66a04ed8274a1741d9f (MD5) / Made available in DSpace on 2018-05-21T12:20:55Z (GMT). No. of bitstreams: 1 DELYANE LIMA SOARES - DISSERTAÇÃO ZOOTECNIA 2017.pdf: 1682795 bytes, checksum: 1bd089d8abe5d66a04ed8274a1741d9f (MD5) Previous issue date: 2017-08-31 / Capes / A região Semiárida do nordeste brasileiro tem a Caatinga como vegetação predominante. Devido ao seu histórico de uso, grande parte da vegetação se encontra em sucessão secundária, mesmo assim ela apresenta um grande número de espécies vegetais em seus estratos lenhoso, arbustivo e herbáceo. Com a finalidade de utilizar de forma sustentável as espécies lenhosas da Caatinga, algumas técnicas de manejo foram desenvolvidas, como raleamento e rebaixamento. Assim, objetivou-se avaliar a composição de lenhosas, como também o manejo da Mimosa tenuiflora com o controle de suas rebrotas em áreas de caatinga raleada e rebaixada no sertão da Paraíba. A pesquisa foi realizada na Universidade Federal de Campina Grande - CSTR/UFCG, Brasil. Para tanto, foram utilizadas 4 áreas de 1 ha que eram pastejadas por ovinos e bovinos de janeiro de 2003 até outubro de 2015. A vegetação da área experimental foi submetida ao raleamento da Poincianella bracteosa e do Croton sonderianus, e o rebaixamento da M. tenuiflora em dezembro de 2015. Durante o período experimental, ocorreram precipitações nos meses de dezembro de 2015 (16,1 mm) à abril de 2016 (65 mm). A frequência e a densidade de espécies lenhosas foram determinadas utilizando como unidade amostral o sistema quadrantes com duas varetas cruzadas no ponto sorteado, com anotação da presença e distância da árvore/arbusto mais próxima ao centro para cada quadrante. Foram realizadas a cada mês 20 amostras por área, nos meses de fevereiro à novembro de 2016. Para o manejo da M. tenuiflora, foram sorteadas seis plantas por tratamento (sem controle, controle com 1 rebrota, 2 rebrotas e 3 rebrotas), as plantas foram avaliadas quanto ao número de rebrotas, diâmetro do caule da planta e das rebrotas, foram realizadas duas coletas, nos meses de abril de 2016 e setembro de 2016. Na primeira coleta as rebrotas foram encaminhadas para o laboratório para análises de teores de MS, PB, FDN, FDA e TT. Nas quatro áreas a frequência relativa mais significativas foram da M. tenuiflora (55-100%), P. bracteosa (45-80%), C. sonderianus (15-50%), Jatropha mollissima (25-50%). Para densidade específica a M. tenuiflora apresentou valores entre 80-182. Para o manejo da M. tenuiflora foi observado efeito entre o número de rebrotas e épocas. O maior número de rebrotas ocorreu no mês de abril, 13,6 em abril e o menor 9,7 em setembro. Os valores de MS variaram entre 39,9 e 44,83. O raleamento das espécies indesejáveis e o rebaixamento da M. tenuiflora não altera a frequência e a densidade das espécies lenhosas nas áreas avaliadas. A rebrotação da M. tenuiflora é afetada pelo manejo da vegetação, proporcionando teores de MS e PB diferente, mas sem alterar FDN e FDA. / The semi-arid region of the Brazilian northeast has the Caatinga as predominant vegetation. Due to its history of use, great part of the vegetation is in secondary succession, nevertheless it presents / displays a great number of vegetal species in its strata woody, shrub and herbaceous. In order to use the Caatinga woody species in a sustainable manner, some management techniques were developed, such as thinning and rearing. The objective of this study was to evaluate the woody composition, as well as the management of Mimosa tenuiflora with the control of its regrowth in thinned and low caatinga areas in the Paraíba hinterland. The research was carried out at the Federal University of Campina Grande - CSTR / UFCG, Brazil. For this purpose, 4 areas of 1 ha were grazed by sheep and cattle from January 2003 to October 2015. The vegetation of the experimental area was submitted to Poincianella bracteosa and Croton sonderianus thinning, and the rearing of M. tenuiflora in December 2015. During the experimental period, precipitations occurred in the months of December 2015 (16.1 mm) to April 2016 (65 mm). The frequency and density of woody species were determined using the quadrant system with two crossed rods at the selected point, with an annotation of the presence and distance from the tree / shrub closer to the center for each quadrant. Twenty samples per area were performed each month, from February to November 2016. Six plants were randomly selected for the management of M. tenuiflora (without control, control with 1 regrowth, 2 regrowths and 3 regrowths). plants were evaluated for the number of regrowths, diameter of the stem of the plant and of the regrowths, two collections were carried out in the months of April 2016 and September 2016. In the first collection the regrowths were sent to the laboratory for analyzes of MS, PB, FDN, FDA and TT. The four most significant relative frequencies were M. tenuiflora (55-100%), P. bracteosa (45-80%), C. sonderianus (15-50%), Jatropha mollissima (25-50%). For specific density, M. tenuiflora presented values between 80-182. For the management of M. tenuiflora an effect was observed between the number of regrowths and seasons. The highest number of regrowths occurred in April, 13.6 in April and the lowest 9.7 in September. MS values ranged from 39.9 to 44.83. The thinning of undesirable species and the lowering of M. tenuiflora do not alter the frequency and density of the woody species in the evaluated areas. The regrowth of M. tenuiflora is affected by vegetation management, providing different MS and PB levels, but without altering FDN and FDA.

A estruturação de padrões e processos das comunidades vegetais ocorrem no espaço e no tempo e é mediada pelas adaptações das plantas (características das espécies) às condições bióticas e abióticas a que estão submetidas. Nesse sentido, este estudo usa a identidade das espécies e seus atributos na busca de padrões florístico-estruturais das comunidades e de padrões de convergência (TCAP) e divergência (TDAP) de atributos ao longo do gradiente sucessional. Comunidades espacialmente separadas e com diferentes idades de abandono (substituição espaço-tempo) foram demarcadas para a investigação destes padrões numa região de Mata Atlântica, no Rio Grande do Sul, Brasil. Informantes locais indicaram o histórico de uso do solo e o tempo de regeneração da floresta, o qual variou entre 6 e 45 anos e áreas de referência (sem indicativo de corte raso). O levantamento da vegetação arbórea (DAP !10cm) foi realizado em 28 parcelas constituídas de 3 sub-parcelas de 100m2 cada, compondo a matriz de cobertura das espécies em seus sítios. Variáveis locais de clima, solo e espaço foram levantadas, as quais, juntamente com o tempo de regeneração, compuseram matrizes de variáveis ambientais usadas para identificar a importância do ambiente e do tempo na estruturação das comunidades. De um pool de 96 espécies, aquelas 52 mais frequentes (! 8%) tiveram os seguintes atributos avaliados: conteúdo de nitrogênio (LNC) e fósforo foliar (LPC), a relação entre eles, conteúdo de massa seca da folha, área foliar (LA), a massa foliar por área (LMA), espessura foliar, forma da folha, sazonalidade foliar (SA), altura potencial máxima da espécie, altura máxima das espécies estimada em campo (Ac), densidade da madeira e capacidade de rebrote (Rb). Os resultados indicaram que o tempo de abandono (correlação= 0,38, p= 0,001) tem influência maior sobre a comunidade vegetal do que os outros conjuntos de variáveis ambientais consideradas. As áreas de referência apresentaram-se claramente distintas em relação à composição de espécies das áreas iniciais e intermediárias. Por outro lado, as análises de variância dos parâmetros estruturais indicaram um aumento significativo da cobertura do estrato arbóreo, das alturas máximas e mínimas e da estratificação da floresta (variância da altura do dossel), já a partir 26 anos após o abandono, assemelhando-se às áreas de referência. Na análise funcional das comunidades, os atributos que maximizaram os padrões de convergência ao longo do gradiente foram: LNC, LPC, LMA, Ac and Rb ("(TE) = 0,44, P= 0,01); e aqueles que maximizaram a divergência foram: LA, LNC, Ac, Rb, SA ("(XE.T)= 0,378; P=0,007). Análises exploratórias indicaram a ocorrência de espécies arbóreas mais altas e perenifólias nas florestas avançadas, em contraste às pioneiras de crescimento rápido, com capacidade de rebrotar e sobreviver após distúrbios antrópicos, ocorrendo nos estágios iniciais. A diversidade funcional aumenta com a maturação da floresta. Todavia, os valores elevados encontrados nos estágios intermediários indicam a coocorrência de espécies de etapas iniciais e finais da sucessão nesta fase. Podemos concluir que a estrutura das florestas secundárias nessa região, assim como sua diversidade funcional, começam a adquirir valores semelhantes aos de florestas em estágio avançado de sucessão a partir dos 26 anos, no entanto a composição destas ainda permanece muito distinta. / The structuring of plant communities patterns and processes occur in time and space and are mediated by plant adaptations (species traits) to biotic and abiotic conditions to which they are subjected. This study looks for structural and floristic community patterns through the use of species identity, as well as for traits convergence (TCAP) and divergence (TDAP) assembly patterns in relation to the successional gradient. Spatially separated communities of different ages since abandonment (space-for-time substitution) were demarcated for the investigation of these patterns in the Atlantic Forest, Rio Grande do Sul state, southern Brazil. Local informants indicated the land use history and time of forest regeneration, which ranged between 6 and 45 years, and reference areas (without signal of clear-cut). The trees (DBH ! 10 cm) were surveyed in 28 plots consisting of three 100 m2 sub-plots, composing the species abundance per sites matrix. Abiotic variables of local climate, soil and space have been collected, and were considered as environmental variables, together with the regeneration time in the analysis of community structure. From a pool of 96 species, the 52 most frequent (! 8%) were evaluated for the following attributes: leaf nitrogen (LNC) and phosphorus (LPC) content, the relationship among them, leaf dry matter content, leaf area (LA), leaf mass per area (LMA), leaf thickness, leaf shape, leaf seasonality (SA), maximum potential height, estimated maximum in the field (Ac), wood density and resprouting ability (Rb). The results indicated that the time of abandonment (correlation =0.38, p = 0.001) have greater influence on plant community than the others sets of environmental variables. Reference sites are clearly distinct in species composition from the initial and intermediate areas. Moreover, analysis of variance of the structural parameters indicated a significant increase in tree cover, in the maximum and minimum heights, and in the forest stratification (canopy height variance) along the succession time. Sites with 26 years after abandonment are already similar to the reference areas for such parameters. In the functional analysis of the communities, the traits that maximized convergence assembly patterns along the gradient were: LNC, LPC, LMA, Ac and Rb (! (TE) = 0.44, P = 0.01) and those that maximized divergence were: LA, LNC, Ac, Rb, SA (! (XE.T) =0.378, P = 0.007). Exploratory analysis indicated the occurrence of taller evergreen trees species at the reference sites, in contrast to the fast growth pioneer species, able to resprout and survive after human disturbances, occurring in the early stages. The functional diversity increases with the maturation of the forest. However, the high values found in the intermediate stages indicate the co-occurrence of early- and late-successional species in this phase. We can conclude that the structure and the functional diversity of secondary forests in this region begin to be similar to forests in advanced stages of succession from 26 years, however the species composition of which still remains very distinct.