The purpose of this study is to understand the composition of the secondary forest of Nanjenshan area. A 5-ha plot was established at altitudes 200-264m on the north ridge of Nanjenshan. All free-standing woody plantsin the plot with DBH¡Ù1cm were identified, measured, tagged and mapped. A total of 108 tree species belonging to 40 families and 77 genera was recorded. The dominant species are Acacia confusa, Lagerstroemia subcostata, Psychotria rubra, Ficus septica¤ÎDendrocnide meyeniana. The dominant families are Fabaceae, Moraceae, Euphorbiaceae, Rubiaceae¤ÎLythraceae. TWINSPAN analysis reveales four groups. Group 1 is dominanted by Acacia confusa, Glochidion philippicum and Psychotria rubra. Group 2 is dominanted by Acacia confusa, Psychotria rubra and Lagerstroemia subcostata. Group 3 is dominanted by Acacia confusa, Psychotria rubra and Glochidion rubrum. Group 4 is dominanted by Acacia confusa, Lagerstroemia subcostata and Dendrocnide meyeniana. There are four kind of distribution pattern in this plot. Machilus obovatifolia and Osmanthus marginatus occurred on the hilltop; Dendrocnide meyeniana and Ficus virgata occurred on the middle-woody site; Zanthoxylum ailanthoides and Wendlandia uvariifolia only occurred along the steamside; Acacia confusa and Psychotria rubra were commonly distributed over the plot.

Human activities that lead to fragmentation and habitat loss are big problems in the world. Due to global climate change the negative effects of fragmented habitats can be catastrophic for many organisms. In the Amazon rainforest, that is most sensitive to human impact, stands a big risk to lose its species diversity. Fragmentation and climate change together seems to escalate the death rate of rainforest plants and that will change the whole ecosystem. Birds and insects are depending on the trees and the trees faces big challenges now. Many of the rainforest organisms have been noticed to emigrate further up to northern altitudes due to the warmer climate and maybe also because of deforestation. Many of the lowland forest birds are predicted to distribute from their origin habitats. The national reserve Allpahuayo Mishana in the Peruvian Amazon is known for its diversity of birds. It is a big challenge for the reserve to maintain the origin forest composition from climate change, which will lead to losses of species. The reserve allows the local community to utilize the land for small-scale uses inside the protected zone. Many of the birds are sensitive for external disturbance. Most human activities are resulting in that the forest becomes less dense, which can lead to that the territory for the birds decreases. This makes it important for the reserve to improve the human land use not to restrict the birds' habitat inside the reserve. This project will investigate if the small-scale land uses affects the understory birds’ diversity and habitat negative. The purpose is to see if the fragmented forests in the reserve, closest to the utilized land, can functioning as a secondary forest for the understory birds, or are the understory birds limited by the small-scale land use, in the national reserve Allpahuayo Mishana? Four sites with various human activities were chosen to investigate if the sites contain any understory birds. The result showed that the most disturbed sites had poor bird diversity compare to the sites with no human disturbance.

The purpose of this study is to compare the bird communities between mature secondary forests and Cryptomeria (Cryptomeria japonica) plantations. Bird census was carried out in Teng-jhih National Forest Recreation Area, Kaohsiung county, Taiwan during both breeding season and non-breeding season from March to November in 2007. To compare bird communities between two types of forests, diversity index, evenness index, species richness and densities of bird were calculated. Densities of birds were estimated by variable circular-plot point count method. All birds were classified into 10 assemblage guilds. ANOVA was used to examine whether forest types, breeding season and monthly changes will effect the composition of bird communities. A total of 36 bird species of 19 families were recorded during the study period. All of these species were found in secondary forests, and only 27 of them were observed in Cryptomeria plantations. The results showed that bird diversity, abundance and total densities were higher in secondary forests than those in Cryptomeria plantations, either during breeding season or non-breeding season. Canopy tree species of families, Lauraceae and Fagaceae of the secondary forests which can provide more foods than Cryptomeria, canopy foliage omnivores and woodpeckers were more in secondary forests than in Cryptomeria plantations. On the other hand, the openess of shrubs and understory vegetation in the Cryptomeria plantations, shrub foliage omnivores were more in Cryptomeria plantations than in secondary forests.

In tropical forest systems, attine ants are the dominant herbivores. They construct large nest structures that include foraging trails that extend to multiple plant sources throughout the forest. These foraging areas vary from nest to nest and they are highly dynamic over time and season changes. It was expected that characteristics of both the nest structure and the surrounding environment would affect the size of nest foraging areas. In this study, COMPASS survey software and ArcGIS were used to map the foraging trails and calculate the foraging areas of 12 attine ant nests located on the Firestone Reserve, over the course of 6 weeks. Data collected at the ant nest sites on nest area, flow rate, trail number and neighboring nest proximity were combined with data collected from previous studies on soil pH and light fractions in order to test correlation hypotheses between these factors and foraging area. The mean foraging areas differed significantly from each other and significant correlations were found between foraging area and trail number, flow rate, neighbor distance and soil pH. Understanding foraging behavior of attine ants is important in the field of restoration ecology because these ants are important in determining overall structure and nutrient distribution in tropical forests.

Factors relating to natural regeneration and tree community recovery after slash and burn agricultural practices were investigated in secondary seasonally dry tropical forests (SDTF) of varying land use intensity and post-disturbance management. Patterns and processes of regeneration were explored by collecting community composition data at secondary and primary sites, by conducting seedling experiments, and by investigating existing forest rehabilitation efforts in both Lao PDR (Laos) and Vietnam. In the forests surveyed in Laos, forest recovery in terms of the composition of primary forest tree species juveniles in fallow forests was high at most sites regardless of previous land use intensity. While community compositional studies indicated significant differences between primary and secondary communities, little or no significant differences were found in terms of primary tree species or family diversity, evenness, or dominance of regenerating juveniles. Significant differences appeared to be due to changes in the relative abundances of different species rather than the absence of primary forest obligate species in the secondary communities. This effect is expected to be due to the relatively common resprouting ability of SDTF species, the wide range of ecological conditions that these species can persist under, and the mosaic pattern of land-uses across the landscape. Evidence of environmental filtering affecting composition patterns in secondary communities was found for two plant traits; dispersal syndrome and plasticity of specific leaf area (SLA). Ecological strategies of primary SDTF tree species were investigated in two ways. Within the narrow range of species capable of regenerating within the primary forest environment, evidence of different life history strategies was found, indicated by significant correlations between continuous plant traits of seed size, fruit size, maximum tree height, SLA, leaf size and wood density. The correlations found largely mirrored patterns found in similar studies in Neotropical forests. Evidence of different seedling regeneration strategies was investigated by comparing species of two different successional preference groups in a seedling/light experiment. Seedlings of non-pioneer later successional species responded differently than species more associated with disturbed environments (long-lived pioneers) when exposed to both increasing absolute light treatments, and to light received under various sunfleck treatments. Earlier successional species demonstrated greater plasticity of SLA, leaf area ratio (LAR), stem elongation, and root mass ratio to increasing light. Regeneration under minimally managed monoculture and pair-wise plantations of both native and exotic species at the Laos field site was not significantly different when compared with nearby remnant primary forest in terms of diversity, evenness, and richness. Therefore, plantation overstoreys did not appear to be suppressing the regeneration of primary forest species. Seedlings grown in enrichment designs nearby had survival rates of approximately 50%, and diameter increments of less than 0.2 cm/yr after 6 to 9 years of growth. The performance of seedlings in such plantings is expected to be sufficient for conservation aims but is unlikely to encourage private investment for forestry purposes due to long expected rotation lengths. At Hai Van Pass in central Vietnam, the combination of a fast growing exotic species to capture a degraded site and ameliorate site conditions, followed by enrichment planting of native species was demonstrated to be a successful approach to reforesting degraded land, whilst funding itself through the sale of timber. The results indicate the high regeneration potential of the studied secondary forests, both in terms of observed patterns of regeneration in slash and burn fallow forests, and in terms of the general regenerative abilities of SDTF species. Decisions regarding future land-uses and secondary forest management should have consideration of this possible high level of recovery, and simple diversity sampling techniques should be included in any related processes to confirm the regeneration potential of a particular secondary forest.

O estudo da dinâmica de áreas alteradas na Amazônia pode contribuir para a elucidação dos possíveis impactos dos atuais modelos de uso do solo sobre o sistema florestal bem como sua capacidade de recuperação ao longo do tempo, permitindo assim, que sejam feitas previsões quanto ao futuro ambiental da região. O objetivo deste trabalho foi investigar a dinâmica de nitrogênio ao longo de florestas secundárias formadas pela agricultura de corte e queima no município de São Francisco do Pará, e ao longo de clareiras formadas pela exploração seletiva de madeira na Floresta Nacional do Tapajós, ambas no Estado do Pará. Foram selecionadas florestas secundárias de diferentes idades (6, 20 e 40 anos) e clareiras de diferentes idades de formação (1, 3 e 5 anos) bem como áreas de florestas de terra-firme não perturbadas. Nestas áreas, foram avaliadas a abundância natural de 15N e concentrações de N e C em solo, serapilheira e vegetação. Nas clareiras e floresta não perturbada em áreas de exploração seletiva também foram realizados experimentos de mineralização e nitrificação. De um modo geral, todas as áreas investigadas apresentaram um aumento nos valores de &23515N no solo de acordo com a profundidade. Ao longo da cronossequência de florestas secundárias foi observado um aumento no ð15N e na concentração de N foliar, assim como uma diminuição na razão C/N foliar. As concentrações de N foliar foram maiores em espécies de leguminosas e a razão C/N foi mais elevada em espécies de não leguminosas em todas as áreas amostradas. O ð15N da serapilheira também aumentou com a idade da vegetação. Estes resultados indicam que as florestas secundárias tornam-se mais ricas em N à medida que o sistema recupera-se da perturbação, sugerindo uma mudança na ciclagem de N, de mais fechada nos primeiros estágios da sucessão, à mais aberta à medida que esta se aproxima da fisionomia original. Já na área de exploração seletiva de madeira, foram observadas menores taxas de mineralização e nitrificação nas clareiras de 1 ano, porém estas taxas não diferiram entre as demais idades de clareira e entre estas e a floresta de terra-firme. Os valores de ð15N foliar não diferiram entre as áreas, nem entre leguminosas e não-leguminosas dentro de uma mesma área, no entanto, as concentrações de N foliar foram maiores em espécies de leguminosas em todas as áreas amostradas e a razão C/N foi mais elevada em espécies de não leguminosas. Estes fatores indicam a ocorrência de uma ciclagem aberta de N nestas áreas independentemente da perturbação, sugerindo assim, que impactos, como a abertura de uma clareira em florestas ricas em N, não sejam de intensidade suficiente a ponto de causar uma alteração significativa na ciclagem de N nestas áreas, como o que foi observado no estudo enfocando as florestas secundárias estabelecidas em áreas previamente utilizadas para agricultura, onde a perturbação no sistema foi mais intensa. / The study of nutrient dynamics in disturbed areas of the Amazon region helps to provide understanding of how the current land-use models affect the forest ecosystem and its capacity to recover over time. The object of this study was to investigate the nitrogen dynamics along a chronosequence of secondary forests (6, 20 and 40 yearold), following slash-and-burn agriculture that occurred in the municipality of São Francisco do Pará, and along gaps in different stages of development (1,3 and 5 yearold) created by selective logging in the Tapajós National Forest, both in the state of Pará. In order to understand the effects of land cover changes in the nitrogen cycle, we investigated the ð15N, C and N concentrations in soil, litter, and vegetation in these areas. At the selective logging sites, mineralization and nitrification rates were measured. All sites showed an increase in ð15N values in the soil, correlated with depth, in the first 50 cm. There were significant increases in ð15 N and N concentrations in the vegetation along the chronosequence of secondary forests and a decrease in the C/N ratio. The litter ð15N measurements also increased with secondary forest age. These parameters suggest an increasing N availability with stand age. That is, nitrogen cycling is more closed due to N limitation during the first stages of secondary succession, and becomes more open as the secondary forest ages and as rates of N cycling accelerate. At the selective logging sites, mineralization and nitrification rates were lower in the oneyear gap. However, differences were not found within the other gap ages and between those gaps and the undisturbed forest. Significant differences in the foliar ð15N were not found among the various areas, including legume and non-legume groups that belong to a common area. Foliar N contents were greater in legume than in non-legume species and the C/N ratio was higher in the non-legume species in all areas. Nevertheless, these parameters did not differ among the overall areas. These results indicate an open nitrogen cycle occurring in these areas, suggesting that disturbances such as canopy opening in forests originally enriched in nitrogen, are not strong enough to alter significantly this nutrient cycling, as is the conversion of mature to secondary forest through slash and burn agriculture.

Forests at the tropical Valley of the Apurimac and Ene rivers (VRAE), the second coca-growing region of Peru, are public common resources and nevertheless privately managed mainly by coca farmers, without effective State control of such use. The need for survival of the coca farmers, their chrematistic perception of the forest, the cultivation of cocoa (theobroma cacao) and land availability are crucial factors influencing the rates of deforestation of primary and secondary forest. Variables such as the legality of land tenure seem to have no influence. However, other institutional factors such as state policies in titling processes and its weakness or absence facilitate the destructive patterns of settlement in the upper forest.  Grassroots organizations of farmers focused on defending coca cultivation and access to credit and technical conditions for their legal products do not consider the defense of the forest as a fundamental aspect of their agenda. Nor were grassroots organizations whose core agenda was the control and monitoring of the management of forest resources. All this leads to argue that the Amazonian farmers are trapped in the "prisoner's dilemma". On the one hand, institutional and media pressure press them strongly not to grow coca and on the other hand, if they do not grow coca o clear the forest, others will follow this destructive path and benefit immediately of such a decision / Los bosques en el Valle del río Apurímac y Ene (VRAE), la segunda región cocalera del Perú, son recursos comunes públicos que se manejan como privados por los agricultores principalmente cocaleros, sin un control efectivo de tal uso por parte del Estado. La necesidad de sobrevivencia de los agricultores cocaleros, su percepción crematística sobre el bosque, y la mayor o menos disponibilidad de tierras constituyen factores determinantes en el ritmo de deforestación del bosque primario y secundario. Variables tales como la legalidad de tenencia del predio no parecen tener influencia. Sin embargo, otros factores también institucionales facilitan una ocupación del espacio muy desordenada y destructiva, tales como las políticas de Estado en los procesos de titulación y la debilidad o ausencia del mismo.  Las organizaciones de base de los agricultores centradas en defender el cultivo de la coca y/o acceder a condiciones crediticias y técnicas para sus productos legales no consideran a la defensa del bosque como un aspecto fundamental de su agenda. Tampoco existían organizaciones de base cuya agenda central fuese el control y la vigilancia del manejo de los recursos forestales. Los agricultores son conscientes del daño ambiental y de salud que provoca la economía de la coca. Todo ello nos induce a argumentar que los productores rurales amazónicos se encuentran atrapados en el “dilema del prisionero”. Por un lado, la presión institucional y mediática los presiona fuertemente a no cultivar coca y por otro lado, si ellos no siembran coca y no deforestan otros seguirán ese camino destructivo y se beneficiaran de manera inmediata de tal decisión.

O estudo da dinâmica de áreas alteradas na Amazônia pode contribuir para a elucidação dos possíveis impactos dos atuais modelos de uso do solo sobre o sistema florestal bem como sua capacidade de recuperação ao longo do tempo, permitindo assim, que sejam feitas previsões quanto ao futuro ambiental da região. O objetivo deste trabalho foi investigar a dinâmica de nitrogênio ao longo de florestas secundárias formadas pela agricultura de corte e queima no município de São Francisco do Pará, e ao longo de clareiras formadas pela exploração seletiva de madeira na Floresta Nacional do Tapajós, ambas no Estado do Pará. Foram selecionadas florestas secundárias de diferentes idades (6, 20 e 40 anos) e clareiras de diferentes idades de formação (1, 3 e 5 anos) bem como áreas de florestas de terra-firme não perturbadas. Nestas áreas, foram avaliadas a abundância natural de 15N e concentrações de N e C em solo, serapilheira e vegetação. Nas clareiras e floresta não perturbada em áreas de exploração seletiva também foram realizados experimentos de mineralização e nitrificação. De um modo geral, todas as áreas investigadas apresentaram um aumento nos valores de &23515N no solo de acordo com a profundidade. Ao longo da cronossequência de florestas secundárias foi observado um aumento no ð15N e na concentração de N foliar, assim como uma diminuição na razão C/N foliar. As concentrações de N foliar foram maiores em espécies de leguminosas e a razão C/N foi mais elevada em espécies de não leguminosas em todas as áreas amostradas. O ð15N da serapilheira também aumentou com a idade da vegetação. Estes resultados indicam que as florestas secundárias tornam-se mais ricas em N à medida que o sistema recupera-se da perturbação, sugerindo uma mudança na ciclagem de N, de mais fechada nos primeiros estágios da sucessão, à mais aberta à medida que esta se aproxima da fisionomia original. Já na área de exploração seletiva de madeira, foram observadas menores taxas de mineralização e nitrificação nas clareiras de 1 ano, porém estas taxas não diferiram entre as demais idades de clareira e entre estas e a floresta de terra-firme. Os valores de ð15N foliar não diferiram entre as áreas, nem entre leguminosas e não-leguminosas dentro de uma mesma área, no entanto, as concentrações de N foliar foram maiores em espécies de leguminosas em todas as áreas amostradas e a razão C/N foi mais elevada em espécies de não leguminosas. Estes fatores indicam a ocorrência de uma ciclagem aberta de N nestas áreas independentemente da perturbação, sugerindo assim, que impactos, como a abertura de uma clareira em florestas ricas em N, não sejam de intensidade suficiente a ponto de causar uma alteração significativa na ciclagem de N nestas áreas, como o que foi observado no estudo enfocando as florestas secundárias estabelecidas em áreas previamente utilizadas para agricultura, onde a perturbação no sistema foi mais intensa. / The study of nutrient dynamics in disturbed areas of the Amazon region helps to provide understanding of how the current land-use models affect the forest ecosystem and its capacity to recover over time. The object of this study was to investigate the nitrogen dynamics along a chronosequence of secondary forests (6, 20 and 40 yearold), following slash-and-burn agriculture that occurred in the municipality of São Francisco do Pará, and along gaps in different stages of development (1,3 and 5 yearold) created by selective logging in the Tapajós National Forest, both in the state of Pará. In order to understand the effects of land cover changes in the nitrogen cycle, we investigated the ð15N, C and N concentrations in soil, litter, and vegetation in these areas. At the selective logging sites, mineralization and nitrification rates were measured. All sites showed an increase in ð15N values in the soil, correlated with depth, in the first 50 cm. There were significant increases in ð15 N and N concentrations in the vegetation along the chronosequence of secondary forests and a decrease in the C/N ratio. The litter ð15N measurements also increased with secondary forest age. These parameters suggest an increasing N availability with stand age. That is, nitrogen cycling is more closed due to N limitation during the first stages of secondary succession, and becomes more open as the secondary forest ages and as rates of N cycling accelerate. At the selective logging sites, mineralization and nitrification rates were lower in the oneyear gap. However, differences were not found within the other gap ages and between those gaps and the undisturbed forest. Significant differences in the foliar ð15N were not found among the various areas, including legume and non-legume groups that belong to a common area. Foliar N contents were greater in legume than in non-legume species and the C/N ratio was higher in the non-legume species in all areas. Nevertheless, these parameters did not differ among the overall areas. These results indicate an open nitrogen cycle occurring in these areas, suggesting that disturbances such as canopy opening in forests originally enriched in nitrogen, are not strong enough to alter significantly this nutrient cycling, as is the conversion of mature to secondary forest through slash and burn agriculture.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-07-26T15:34:54Z No. of bitstreams: 1 Juliana Ramos de Andrade.pdf: 1469366 bytes, checksum: 3785d2ee3c526b6cc3aa54c3155c5d26 (MD5) / Made available in DSpace on 2016-07-26T15:34:54Z (GMT). No. of bitstreams: 1 Juliana Ramos de Andrade.pdf: 1469366 bytes, checksum: 3785d2ee3c526b6cc3aa54c3155c5d26 (MD5) Previous issue date: 2016-06-22 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The dry tropical forests are being changed by human actions. The historical use of the area suffered and its proximity to preserved fragments should be considered in order to better understand the successional process of these areas, as well as influence the regeneration mechanisms and dynamics of re-established populations, affect the speed of recovery. Populations established in modified areas experience different microclimate variations found in mature forests, and little known species response to these changes. Thus, this thesis aimed to: a) to characterize and compare the density, wealth, height, diameter and basal area of the community of a secondary forest savanna who suffered human intervention in a range of five years; b) analyze the effect of interannual and seasonal variations in precipitation and microclimate variations in the dynamics of three populations of mature forests and young. To evaluate the potential recovery of the area were established 200 plots (5 x 10 m) in an area of caatinga secondary forest in the municipality of Caruaru, Pernambuco, Brazil. In 2008 and 2013 each of the plots had all living individuals with stem diameter at ground level ≥ 3 cm identified and measured for height and diameter. For the study of population dynamics, 100 subplots of 25 m² were established in the young forest and the same amount in a mature forest, with a monthly monitoring during the period 2013-2015 and noted the numbers of individuals born and dead Poincianella pyramidalis, Schinopsis brasiliensis and Myracrodruon urundeuva. They were also measured the microclimate variables (light, temperature, wind and humidity) in order to correlate them with the demographic parameters of the species. Over the five years the number of species was almost the same, there was a reduction in the total density and basal area average due to the maturation of the forest and probably prolonged drought of 2012. In 2008 the total basal area was 10.59 m².ha-1, increasing to 11.01 m².ha-1. The average height of the community had no significant increase of 3.59 m in 2008 to 3.65 m in 2013. The amount of individuals inserted in the smaller diameter classes declined from 2008 to 2013, while the opposite occurred in the larger classes. The population dynamics varied between forests, seasons and years (interannual variation of precipitation). Despite the age of the forest have low explanatory power of the births and deaths of P. pyramidalis in short time scale, 30% of the density was explained by the age of the forest, suggesting that recruitment for advanced ontogenetic stages is influencido by interannual variations occurring in microclimate conditions of each forest, and negatively correlated with light in young forest. Mortality was correlated with light, tempetaratura and humidity in the mature forest and light and moisture in the young forest. In S. brasiliensis was no correlation between light and density, as well as between wind and humidity in the number of deaths only in the young forest. The power of influence of forest age and interannual and seasonal variations in precipitation on births was low and no microclimate variable was correlated with birth. In M. urundeuva, temperature and humidity were correlated to birth in mature forest, but in the young forest only light correlated to birth. Overall, forest age influenced the density and seasonal and annual rainfall totals influenced mortality and births, respectively, but in general, the explanatory power was also low. It was concluded that the speed of the regenerative process and resilience of the forest is affected by the abandonment of time, and the changes that happen in the space of five years considered slow and may not detect major changes in advance of the recovery process of a forest that already presents 19 years of age. In addition to the age of the forest, the temporal variation (between years and between seasons) linked to the influence of microcimáticas variations alter the density and the number of dead individuals and born in forests with different ages. It has been seen that demographic responses of woody plants to micro-climatic variations can be complex in dry forests and dissimilarities in the microclimate between forests suggest slow the return of such conditions. Such a return is extremely important for future projection of time required for the formation of new post-forest land use for agricultural activities in semiarid environments. / As florestas tropicais secas estão sendo alteradas por ações antrópicas. O histórico de uso que a área sofreu e sua proximidade a fragmentos preservados devem ser considerados a fim de melhor compreender o processo sucessional dessas áreas, pois além de influenciar os mecanismos de regeneração e dinâmica das populações reestabelecidas, afetam a velocidade de recuperação. As populações estabelecidas em áreas modificadas experimentam variações microclimáticas distintas das encontradas em florestas maduras, sendo pouco conhecidas as respostas das espécies a essas mudanças. Assim, esta tese teve como objetivo: a) caracterizar e comparar a densidade, riqueza, altura, diâmetro e área basal da comunidade de uma floresta secundária da caatinga que sofreu intervenção antrópica em um intervalo de cinco anos; b) analisar o efeito das variações interanuais e sazonais na precipitação e das variações microclimáticas na dinâmica de três populações entre florestas madura e jovem. Para avaliar o potencial de recuperação da área foram estabelecidas 200 parcelas (5 x 10 m) em uma área de floresta secundária de caatinga localizada no município de Caruaru-PE, Brasil. Nos anos de 2008 e 2013 cada uma das parcelas teve todos os indivíduos vivos com diâmetro do caule ao nível do solo ≥ 3 cm identificados e medidos quanto à altura e diâmetro. Para o estudo de dinâmica populacional, 100 subparcelas de 25 m² foram estabelecidas na floresta jovem e a mesma quantidade em uma floresta madura, havendo um monitoramento mensal durante o período de 2013 a 2015 sendo anotados os números de indivíduos nascidos e mortos de Poincianella pyramidalis, Schinopsis brasiliensis e Myracrodruon urundeuva. Também foram mensuradas as variáveis microclimáticas (luz, temperatura, vento e umidade) com o intuito de correlacioná-los com os parâmetros demográficos das espécies. Com o passar dos cinco anos a quantidade de espécies foi praticamente à mesma, Houve redução na densidade total e na área basal média devido ao amadurecimento da floresta e provavelmente, a seca prolongada de 2012. Em 2008 a área basal total era de 10,59 m².ha-1, aumentando para 11,01 m².ha-1. A altura média da comunidade não apresentou aumento significativo de 3,59 m em 2008 para 3,65 m no ano de 2013. O quantitativo dos indivíduos inseridos nas menores classes de diâmetro diminuiu de 2008 para 2013, ocorrendo o inverso nas maiores classes. A dinâmica das populações variou entre as florestas, estações climáticas e anos (variação interanual de precipitação). Apesar da idade da floresta ter baixo poder de explicação sobre os nascimentos e mortes de P. pyramidalis em curta escala temporal, 30% da densidade foi explicada pela idade da floresta, sugerindo que o recrutamento para estádios ontogenéticos avançados seja influencido pelas variações interanuais ocorrentes nas condições microclimáticas de cada floresta, sendo negativamente correlacionada com luz na floresta jovem. A mortalidade foi correlacionada a luz, tempetaratura e umidade na floresta madura e, a luz e umidade na floresta jovem. Em S. brasiliensis houve correlação entre luz e densidade, bem como entre vento e umidade no número de mortes apenas na floresta jovem. O poder de influência da idade da floresta e das variações interanual e sazonal de precipitação sobre os nascimentos foi baixo e nenhuma variável microclimática teve correlação com os nascimentos. Em M. urundeuva, temperatura e umidade foram correlacionadas aos nascimentos na floresta madura, mas na floresta jovem apenas luz se correlacionou aos nascimentos. No geral, a idade da floresta influenciou a densidade e os totais sazonais e anuais de precipitação influenciaram a mortalidade e os nascimentos, respectivamente, mas de maneira geral, o poder de explicação foi também baixo. Concluiu-se que a velocidade do processo regenerativo e a resiliência da floresta é afetada pelo tempo de abandono, sendo as alterações que acontecem num espaço de cinco anos consideradas lentas e não permitem detectar grandes mudanças no avanço do processo de recuperação de uma floresta que já apresente 19 anos de idade. Além da idade da floresta, a variação temporal (entre anos e entre estações climáticas) atrelada à influência das variações microcimáticas alteram a densidade e o número de indivíduos mortos e nascidos em florestas com idades distintas. Foi visto que as respostas demográficas das plantas lenhosas às variações microclimáticas podem ser complexas nas florestas secas e as dessemelhanças nas condições microclimáticas entre florestas sugerem lentidão no retorno de tais condições. Tal retorno é de extrema importância para projeção futura do tempo necessário para a formação de novas florestas pós-uso da terra para atividades agrícolas em ambientes semiáridos.

O presente trabalho teve como objetivo avaliar a variação da fertilidade na camada superficial do solo em áreas com cobertura de Mata Atlântica primaria, nos estágios sucessionais iniciais e tardios localizados na Serra do Mar e Serra da Mantiqueira e áreas de pastagem com o objetivo de se quantificar os níveis de degradação e recuperação através de indicadores químicos de impacto ambiental do solo. Foi estudada a disponibilidade de nutrientes nas camadas superficiais do solo em função da ciclagem de matéria orgânica correlacionando com diferentes tipos cobertura vegetal. Foram coletadas amostras considerando cinco pontos por fragmentos distribuídos aleatoriamente coletando o solo nas camadas 0-20 e 20-40 cm de profundidade após ter sido retirado à camada de serapilheira. Foram analisados os atributos químicos relacionados à disponibilidade de nutrientes avaliando-se os teores de MO%, C%, N%, K, Ca, Mg, H, Al, P, e os índices de fertilidade pH, SB, T, V% e m%. Para o estudo da variação comparativa da quantidade da serapilheira foram coletadas cinco amostras aleatoriamente nos fragmentos florestais retirando-se o material orgânico superficial em uma área de 1m2 de pontos previamente escolhidos. A análise dos dados demonstrou que a produção de serapilheira da mata primária foi 41,48% superior à da mata secundária tardia e 62,45% à da mata inicial. O teor de matéria orgânica da camada 0-20 cm da mata primária foi 14,23% superior ao da mata tardia e 25,18% ao da mata inicial. Quanto à disponibilidade de macronutrientes observou-se em geral que na camada 0-40 cm os teores dos macronutrientes se encontram nas classes de alta a média para a cobertura de mata primária e média a baixa para os fragmentos de mata secundárias tardia, inicial e de pastagens. A análise percentual demonstrou que os nutrientes que apresentaram maiores variações da cobertura de mata primária em relação às demais coberturas foi inicialmente o cálcio, seguidos do potássio, nitrogênio e fósforo. O magnésio foi o que apresentou a menor variação. O balanço do estado nutricional do solo demonstrou que a cobertura de mata primária apresenta as melhores condições de disponibilidade de nutrientes para o desenvolvimento das plantas caracterizando como um ecossistema em equilíbrio com o retorno de nutrientes ao solo pelo processo de ciclagem. / In present study we evaluate the fertility variation in superficial layer of the soil in areas with primary Atlantic Forest cover, initial and late successions stages placed in Serra do Mar and Serra da Mantiqueira and pasture areas with aims to quantify the levels of degradation and recuperation through environmental chemical impacts in soil indicators. The nutrients available were studied on superficial layers in function of organic matter cyclage, correlating with different kinds of plant cover. Samples were randomly collected in five points per fragments getting the soil in layers with 0-20 and 20-40 cm of deepness, after litter removal. Chemicals attributes related to nutrients available were analyzed by MO%, C%, N%, K, Ca, Mg, H, Al, P indicators and fertility indexes pH, SB, T, V% and m%. To comparative study of litter variation we collected randomly five samples in forestals fragments, taken off the organic matter in a place with 1m2 from points previously chosen. The analysis showed that litter production from primary forest was 41.48% superior to late secondary forest and 62.45% than initial secondary forest. Organic matter data in layer 0-20 cm from primary forest was 14.23% superior to late forest and 25.18% than initial forest. Macronutrients in 0-40 cm layer is classified high to medium to primary forest cover and medium to low for the fragments of late and initial secondary forest and pastures. The percentage analyses shows that the most nutrients fond in primary forest cover in relationship to others cover was initialing calcium, fallowed to potassium, nitrogen and phosphorus. Magnesium showed less variation. The nutritional balance state of the soil, demonstrate that primary forest cover shows the best conditions of nutrients available to plant growing, characterizing an ecosystem in equilibrium with nutrients returns to soil through cyclage process.