Human activities, such as deforestation and industrial development, have drastically altered natural environments throughout the world, ranging from the loss of biodiversity to possible climatic changes on a global scale. The mapping of vegetation cover is an important source of information for the evaluation of the evolution of landscapes over time and space. The present study is based on a pioneering multitemporal analysis of the Atlantic Forest and Caatinga biomes on the right bank of the lower São Francisco River. This approach was used specifically to assess the effects of the deforestation process on the remaining populations of two endangered tit monkey species, Callicebus coimbrai Kobayashi & Langguth (1999), which inhabits the Atlantic Forest and is classified as endangered by the IUCN, and Callicebus barbarabrownae Hershkovitz (1990), which is found in the Caatinga, and is classified as critically endangered. The objective of this study was to produce a mutitemporal analysis of the historical deforestation process (1980-2010) in the study area and diagnose its effects on the distribution of Callicebus populations within this area. The study area (8º27 56 -12º3 35 S, 36º14 43 -40º59 4 W) encompasses the whole of the Brazilian state of Sergipe and the northern extreme of the neighboring state of Bahia, with a total area of approximately 80,000 km². Pre-processing involved the collection of images and the collection of data in the field. The multitemporal analysis included arithmetic operations (VI - Vegetation Index and PCA - Principal Components Analysis), visual interpretation, supervised classification, based on the Euclidian distance classifier, post classification, edition, and the production of the mosaic of the classified scenes. Eight classes were mapped - arboreal Caatinga, arboreal-shrub Caatinga, shrub Caatinga, Atlantic Forest, pasture, urban areas, water features, and cloud. The deforestation analysis took into account the biome, vegetation type, fragmentation processes and patterns, and records of Callicebus. The data from the 25 scenes were found to have errors of less than half a pixel (less than 15 meters), varying from 0.403 to 0.498 pixels. A total of 750 points were collected during the field excursions, supported GPS readings and approximately 8000 photographs. Large tracts of arboreal-shrubby Caatinga were found to persist in some areas over the three decades of the study period, whereas the Atlantic Forest was characterized by extensive deforestation and an increase in the areas of pasture. A total of 279 records of the presence/absence of titi monkeys were classified as presence, unconfirmed report, local extinction, and absence. A number of scenarios were analyzed and two theoretical models of deforestation created - (a) fragmentation and (b) nucleus. Model (a) is consistent with a greater probability of extinction of titi monkeys, due to the reduced size of the fragments, their isolation and lack of connectivity, whereas model (b) represents a more favorable scenario for conservation, with larger fragments and better connectivity. The area of transition between the distributions of the two species, where the genus appears to be absent, was also investigated. The data provide a number of insights into the conservation status of the species and their ecological requirements, as well as guidelines for decision-making on management strategies for the conservation of these taxa and the forest fragments they inhabit. / As atividades humanas têm mudado drasticamente a cobertura natural de nosso planeta. Mundialmente, a destruição de ecossistemas e o desenvolvimento industrial desenfreado provocam graves problemas ambientais, que vão desde a perda de biodiversidade até eventuais mudanças climáticas globais. O mapeamento da cobertura vegetal é um insumo científico essencial para avaliar a evolução da paisagem no tempo e no espaço. Neste trabalho, utilizamos a análise multitemporal, o qual teve caráter inédito para os biomas da região, a Mata Atlântica e a Caatinga, na verificação do histórico de desmatamento da região. Estas técnicas foram utilizadas para avaliar os efeitos do processo de desmatamento sobre as populações remanescentes de duas espécies ameaçadas, os macacos guigós, Callicebus coimbrai Kobayashi & Langguth (1999), que habita a Mata Atlântica e está classificada como ameaçada de extinção na categoria em perigo pela IUCN e Callicebus barbarabrownae Hershkovitz (1990) que habita a Caatinga e está classificada atualmente como criticamente em perigo de extinção. O objetivo foi realizar uma análise multitemporal do processo de desmatamento (1980-2000) da área de estudo e diagnosticar seus efeitos sobre as populações de Callicebus. A área de estudo (8º27 56 -12º3 35 de latitude Sul e 36º14 43 -40º59 4 de longitude Oeste) compreende o estado de Sergipe e parte da região do extremo norte do estado da Bahia atingindo uma área de aproximadamente 80.000 km2. O pré-processamento compreendeu a coleta e registro das imagens e trabalho de campo. A análise multitemporal incluiu operações aritméticas (IV Índice de Vegetação e ACP Análise por Componentes Principais), interpretação visual, classificação supervisada através do classificador de distância euclidiana, pós-classificação, edição e mosaico das cenas classificadas. Oito classes foram mapeadas: Caatinga arbórea, Caatinga arbórea-arbustiva, Caatinga arbustiva, Mata Atlântica, Pasto, Área Urbana, Hidrografia e Nuvens. A análise do desmatamento levou em conta o bioma, o tipo de vegetação, a fragmentação, a distribuição desta fragmentação, a redução ou aumento dos fragmentos de vegetação e o tipo de registro de Callicebus. O registro das 25 cenas atingiram erros menores que meio pixel (menor que 15 metros) variando de 0,403 a 0,498 pixels. Foram coletados 750 pontos nos trabalhos de campo, através do receptor GPS e aproximadamente 8000 fotos. Foram identificadas grandes áreas de Caatinga arbórea-arbustiva que se mativeram nas três décadas, enquanto que a Mata Atlântica foi caracterizada por extenso desmatamento e o aumento das áreas de pasto. Foram coletados 279 registros de presença/ausência do macaco guigó divididos nas categorias: registro de presença, relatos não confirmados, extinções locais e áreas vistoriadas sem registro. Diversos cenários foram analisados para dois modelos teóricos criados, o de fragmentação (a) e de redução de núcleo (b). O modelo (a) apresenta cenários que indicam a maior probabilidade de extinção do macaco guigó, devido ao tamanho reduzido dos fragmentos, isolamento e a falta de conectividade, enquanto o modelo (b) apresenta cenários mais favoráveis para conservação com grandes fragmentos e melhor conectividade. A área de transição entre a distribuição das duas espécies,onde o género parece estar ausente, também foi investigad. Os dados fornecem uma série de insights sobre o estado de conservação das espécies e seus requisitos ecológicos, bem como diretrizes para a tomada de decisões sobre as estratégias de manejo para a conservação destas espécies e os fragmentos florestais que elas habitam.

Thesis (PhD(For))--Stellenbosch University, 2012. / The subtropical ecosystem of the Zululand coastal plain is prized by the South African commercial plantation forestry industry for its rapid clonal Eucalyptus growth, short rotations (6 to 7 years) and high yields. This region is typified by sandy soils that are low in clay and organic matter, have small nutrient reserves and are poorly buffered against nutrient loss. The subtropical climate induces rapid decomposition of residues and tree litter resulting in small litter nutrient pools and rapid nutrient release into the soil, particularly after clearfelling. A combination of large nutrient demands through rapid growth, rapid nutrient turnover and small soil nutrient reserves implies that sites in this region are sensitive and may be at risk of nutrient decline under intensive management. The work in this study set out to determine the risk of nutrient depletion through harvesting and residue management on a site within the Zululand region, to assess nutritional sustainability and the risk of yield decline in successive rotations. Some bulk biogeochemical cycling processes of macro-nutrients nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) were assessed, and assessments also included sodium (Na). An existing Eucalyptus stand was clearfelled and treatments were imposed on the residues after broadcasting to simulate various levels of nutrient loss through levels of harvesting intensity and residue management. These included residue burning (Burn), residue retention (No-Burn), fertilisation (stem wood nutrient replacement), whole tree harvesting and residue doubling. Outer blocks of the stand were not felled, but included as replicates of an undisturbed standing crop treatment. Biogeochemical nutrient cycling processes were assessed primarily in the standing crop, Burn and No-Burn treatments, in the assumption that these represented the furthest extremes of nutrient loss. Data collection commenced a year prior to clearfelling and continued to two years and six months after planting with key data collection over a 20.1 month period from clearfelling to canopy closure (one year after planting). Water related nutrient pools and fluxes were assessed as atmospheric deposition (bulk rainfall, throughfall and stemflow) and gravitational leaching to 1m soil depth. Drainage fluxes were predicted using the Hydrus model and real-time soil moisture data. Zero tension lysimeters collected soil solution for chemical analysis. Sequential coring in the 0 to 30cm soil layer was used to determine in situ soil N mineralisation. Soil chemical and physical properties were assessed over the first meter of soil at clearfelling and new crop canopy closure to determine soil nutrient pools sizes. Biomass nutrient fluxes were assessed from litterfall, residue and litter decomposition, and above ground accretion into the tree biomass. Leaching and N mineralisation were monitored in the No-Burn, Burn and standing crop treatments only. Atmospheric deposition, while variable, was shown to be responsible for large quantities of nutrients added to the Eucalyptus stand. Nitrogen and K additions were relatively high, but within ranges reported in previous studies. Rapid tree canopy expansion and subsequent soil water utilisation in the standing crop permitted little water to drain beyond 1m resulting in small leaching losses despite a sandy well drained soil. Further leaching beyond this depth was unlikely under the conditions during the study period. Mineralisation and immobilisation of N also remained low with net immobilisation occurring. The standing crop was shown to be a relatively stable system that, outside of extreme climatic events, had a relatively balanced or positive nutrient budget (i.e. nutrient inputs minus outputs). Large quantities of nutrients were removed with stem-wood-only harvesting in the No-Burn treatment leaving substantial amounts on the soil surface in the harvest residues. Whole tree removal increased losses of all nutrients resulting in the largest losses of P and base cations compared to all other treatments. This was mostly due to high nutrient concentrations in the removed bark. Loss of N in the Burn treatment exceeded whole tree N losses through combustion of N held in the harvest residues and litter layer. The majority of K leached from the residues prior to burning and a relatively small fraction of the base cations were lost from the partially decomposed residues during burning. Ash containing substantial amounts of Ca and relatively large amounts of N and Mg remained after burning. Surface soil Ca and Mg was significantly increased by the ash which moved into the soil with rainfall directly after burning. Rapid soil moisture recharge occurred within a few months after clearfelling, increasing leaching from the upper 50cm of soil. Clearfelling increased net N mineralisation rates, increasing mobile NO3-N ions in the soil surface layers. Nitrate concentration peaked and K concentration dipped in the upper soil layers of the Burn treatment directly after burning. Deep drainage and leaching (beyond 1m depth) over the 20.1 month period was, however, not significantly different between the Burn and No-Burn treatments. Rapid soil moisture depletion and nutrient uptake with new crop growth reduced leaching fluxes to levels similar to the standing crop by six months after planting. Taking the full rotation into account, clearfelling induced a short-lived spike in N and cation leaching compared with the low leaching losses in the undisturbed standing crop. Soil N mineralisation over the 20.1 month period in the burnt treatment was half that of the No-Burn treatment. Growth and nutrient accumulation was significantly higher in the fertilised treatment than in other treatments up to 2.5 years of age. Growth in the Burn treatment was greatest compared to other treatments during the first few months, but slowed thereafter. No significant growth differences were found between all other treatments from a year to 2.5 years after planting. Early growth was therefore apparently not limited by N supply despite large differences in N mineralisation between Burn and No-Burn. Foliar vector analysis indicated that fertilisation improved growth initially through increased foliar N and P at six months after planting followed by Mg and Ca at one year. The Burn treatment was not nutrient limited. These growth results contrasted with similar international research on sandy tropical sites where growth was reduced after residue removal and increased after residue doubling. The combined nutrients released from pools in the litter layer or ash and soil in addition to atmospheric inputs were sufficient to provide most nutrients required to maintain similar growth rates across all treatments. This demonstrated the importance of residue derived nutrients to early growth nutrient supply. Reduced N mineralisation through a lack of substrate may limit N supply later in the rotation where residue had been removed. Construction of a nutrient budget for the system revealed that high levels of atmospheric inputs have the potential to partially replenish a large proportion N, K, and Ca lost during clearfelling, provided losses are constrained to stemwood removal only. However, loss of Mg that occurred primarily through leaching may not be replaced under the low Mg inputs recorded in this study. Larger nutrient removals (i.e. stemwood plus other plant parts) placed a heavier reliance on the small soil nutrient pools at this site which can limit future productivity. More intense harvesting and residue management practices dramatically increased the risk of nutrient depletion. Losses of specific nutrients depended on a combination of clearfelling biomass removal, residue burning and subsequent leaching. Nitrogen losses due to harvesting and burning were more substantial than those due to leaching. Mg and K losses depended most strongly on the time after clearfelling before re-establishment of the new crop and rainfall patterns, while Ca and P losses depended directly on the amount of biomass removed. Depletion risk was the greatest for Mg and K through rapid leaching, even after stem wood only removal. Deep root uptake and deep drainage with associated cation loss needs to be investigated further to quantify ecosystem losses and recovery of cations displaced beyond 1m. Atmospheric deposition is one of major factors countering nutrient losses. However, atmospheric inputs may not be reliable as these may lessen in future through pollution control legislation and climate change. Changes in growth rate under poor nutrient management practices are small and difficult to detect relative to the large impacts of changing weather patterns (drought), wildfire and pest and disease. This makes it difficult to prove nutrient related growth decline. It may be possible that improvements in genetics, silvicultural technologies and atmospheric inputs may also be masking site decline (in general) and in part explain the lack of evidence of a growth reduction in the region. As the poorly buffered sandy soils on the Zululand Coast are at risk of nutrient depletion under the short rotation, high productivity stands, it may be necessary to stipulate more conservative harvesting and residue management practices. A more conservative stem-wood only harvesting regime is recommended, retaining all residues on site. Residue burning should be avoided if N losses become a concern. The length of the inter-rotation period must be kept short to reduce cation leaching losses. Site nutrient pools need to be monitored and cations may eventually need to be replenished through application of fertilisers or ash residues from pulp mills. Management practices therefore need to be chosen based on the specific high risk nutrients in order to maintain a sustainable nutrient supply to current and future plantation grown Eucalyptus.

Há muito que a humanidade sabe que os recursos são finitos. Porém, nem sempre o desenvolvimento almejado por uma determinada sociedade estabelecida em determinado território é condizente com a disponibilidade dos recursos naturais, refletindo diretamente na qualidade do solo e instalando um desenvolvimento “insustentável”. Nesse cenário, a pesquisa objetivou analisar o desmatamento utilizando como ponto de partida autos de infração ambiental e características pedológicas do solo na Região de Pato Branco, Paraná. Os resultados foram obtidos por meio da análise de diversos conceitos em diferentes disciplinas e, também, pela utilização de geotecnologias na elaboração de mapas temáticos. Foram observadas cinco zonas de pressão ambiental, nas quais a classe de solo que possui maior incidência no desmatamento é também a classe de solo que abriga a atividade predominante. Outrossim, verificou-se que o desmatamento ocorre em solos mais sensíveis e propensos à erosão, como resultado histórico da colonização, que primeiramente ocupou os solos com maior capacidade de produção. A longo prazo, a solução será sempre a educação ambiental e a erradicação das desigualdades sociais e econômicas. Mas a curto prazo, no quesito meio ambiente, o fortalecimento da política pública ambiental representa uma alternativa de resposta à crise. / Humanity has long known that resources are finite. However, not always the development desired by a certain society established in a given territory is consistent with the availability of natural resources, reflecting directly on the quality of the soil and installing an "unsustainable" development. In this scenario, the objective of this research was to analyze deforestation using as a starting point cases of environmental infraction and pedological characteristics in the Pato Branco Region, Paraná. The results were obtained through the analysis of several concepts in different disciplines and also by the use of geotechnologies in the elaboration of thematic maps. Five zones of environmental pressure were observed, in which the class of soil that has the highest incidence of deforestation is also the class of soil that houses the predominant activity. In addition, deforestation occurred in more sensitive and erosion-prone soils, as a historical result of colonization, which first occupied soils with higher production capacity. In the long run, the solution will always be environmental education and the eradication of social and economic inequalities. But in the short term, in the environmental issue, the strengthening of public environmental policy represents an alternative response to the crisis.

Thesis (MSc(For))--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Recognizing the biological significance of gaps, the South African Department of Water Affairs and Forestry (DWAF) in 1989 initiated a Gap Dynamics Project in the indigenous forests of Tsitsikamma (Eastern Cape, South Africa). This consists of three sub-projects: Koomansbos (9300 m2), created by a ground fire in 1989; Plaatbos (1600 m2), made by a Podocarpus falcatus (Thunb.) R. Br. ex Mirb. (Podocarpaceae) windfall in 1994; and nine gaps of different sizes, artificially created by selective tree felling in 1995: three small (100-150 m2), three medium (300-500 m2) and three large (800-1000 m2). All the gaps were surveyed after creation and permanent plots were established for subsequent monitoring. The current timber harvesting system practiced in South African indigenous forests attempts to minimize gap size. It has been proposed by Euston-Brown et al. (1996) that this practice is likely to benefit the more shade tolerant species, but may inhibit the regeneration of less shade tolerant plants in the forest. Therefore, the present study aimed to verify two hypotheses: gaps may close in a process that is determined by their size, their origin and the plant species characteristics; soil quality might change inside those gaps. For the purpose of the study, the gaps cited above were re-surveyed between 2002 and 2003. It was found that: 1) there was little clear difference in the community structure of plant species between gaps of different sizes and origins; as expected from the species-area relationship, large gaps had higher species richness, plant diversity and herbaceous percentage cover than medium and small gaps; diversity indices were higher in the large windfall gap than in the large fire and artificial gaps; generally, context and stochastic events were largely more important in determining gap diversity and regeneration than gap sizes and origins; 2) diversity indices in the gaps were higher than recorded previously; 3) soil pH and Electrical Conductivity were respectively lower and higher inside the gaps than adjacent to them; these variations were statistically significant. Present data on the vegetation in the gaps were compared to past measurements, and future vegetation structure has been predicted, as a function of current gap vegetation. Recommendations have been made for sustainable management of the indigenous forest of Tsitsikamma. / AFRIKAANSE OPSOMMING: Voortspruitend uit die erkenning van die biologiese belang van gapings, het die Suid-Afrikaanse Departement van Waterwese en Bosbou (DWB) in 1989 'n projek oor gapingsdinamika in die inheemse woude van Tsitsikamma (Oos-Kaap, Suid-Afrika) geïnisieer. Dit bestaan uit drie subprojekte: die gaping in Koomansbos (9300 m2) wat in 1989 deur 'n grondvuur geskep is; die gaping in Plaatbos (1600 m2) wat veroorsaak is toe bome van die spesie Podocarpus falcatus (Thunb.) R. Br. ex Mirb. (Podocarpaceae) in 1994 omgewaai is; en nege gapings van verskillende groottes wat in 1995 kunsmatig deur geselekteerde boomkappery geskep is: drie is klein (100-150 m2), drie mediumgrootte (300-500 m2) en drie groot (800-1000 m2). Alle gapings is ná hulle ontstaan opgemeet en ondersoek en permanente terreine is vir daaropvolgende monitering gevestig. Die stelsel wat tans vir die oes van hout in Suid-Afrikaanse inheemse woude gebruik word, poog om die grootte van gapings te minimaliseer. Euston Brown et al. (1996) doen aan die hand dat hierdie praktyk spesies wat meer skaduweeverdraagsaam is waarskynlik sal bevoordeel, maar die regenerasie van plante in die woud wat minder skaduweeverdraagsaam is, kan inhibeer. Hierdie studie het dus ten doel gehad om twee hipoteses te verifieer: Gapings kan toegroei in 'n proses wat deur hul grootte, oorsprong en die eienskappe van die plantspesies bepaal word; en die gehalte van die grond binne daardie gapings kan verander. Die gapings waarna hierbo verwys is, is vir die doel van hierdie studie tussen 2002 en 2003 weer gemonitor. Daar is bevind dat: 1) daar min duidelike verskille was tussen die gemeenskapstruktuur van plantspesies tussen gapings van verskillende groottes en oorsprong; soos van die verhouding tussen spesies en area verwag kan word, het groter gapings 'n hoër spesierykheid, plantdiversiteit en persentasie niehoutagtige dekking as medium- en klein gapings gehad; diversiteitsindekse was hoër in die groot Plaatbosgaping as in die groot Koomansbosgaping of die kunsmatige gapings; in die algemeen was konteks en stochastiese gebeure grootliks belangriker in die bepaling van gapingsdiversiteit en -regenerasie as gapingsgrootte of -oorsprong; 2) diversiteitsindekse in die gapings was hoër as wat voorheen aangeteken is; en 3) grond-pH en elektriese geleidingsvermoë was onderskeidelik laer en hoër binne die gapings as neffens hulle; hierdie variasies was statisties beduidend. Huidige data oor die plantegroei in die gapings is met vorige metings vergelyk, en 'n toekomstige plantegroeistruktuur is as 'n funksie van huidige gapingsplantegroei voorspel. Aanbevelings is gemaak rakende die volhoubare bestuur van Tsitsikamma se inheemse woud.

The increased demand for wood and fiber from a continually shrinking land base has resulted in the use of intensively managed forest plantations. The concentration of timber production on the most suitable sites allows the world's demand for forest products to be met on less land and enable native forests to be conserved. Because much of the water flowing in rivers in the U.S. originates as precipitation in forests, there is a justified concern about the impacts of forest management on water quality. Nutrient concentrations were measured in eight streams from October 2002 to September 2011 to assess nutrient response to contemporary forest practices at the Hinkle Creek Paired Watershed Study in the Oregon Cascades. This period of time included a two-year pre-treatment calibration between control and treatment watersheds, a fertilization treatment of both basins in October 2004, and a post-treatment period from 2005 to 2011. A treatment schedule comprised of two temporally explicit harvest entries was used to assess the effects of clearcutting at the non-fish-bearing headwater scale and the fish-bearing watershed scale. Stream water samples were analyzed for nitrogen, phosphorus, calcium, sodium, potassium, magnesium, sulfate, chloride, and silicon as well as specific conductance, pH, and alkalinity. Programmable water samplers were used to take water samples during fall freshets in November 2009 to assess the stream water discharge versus NO₃ + NO₂ concentration relationship. All treatment watersheds showed a statistically significant increase in NO₃ + NO₂ concentrations after clearcutting (p < 0.001). The slope of the streambed through the disturbance was a stronger predictor of the magnitude of the response than was the magnitude of disturbance. Ammonia and organic nitrogen displayed notable increases after harvest treatment, but these increases were attributed to increases in the control watersheds. Phosphorus showed a response to timber harvest in one headwater stream. The remaining nutrients showed a small decrease in the control and treatment watersheds for the period after harvest. There was some evidence to suggest that the addition of urea nitrogen to both basins may have caused an increase in in-stream biota uptake of these nutrients. The storm response results showed that NO₃ + NO₂ concentrations in stream water increase with discharge during small storms that occur after periods of negligible precipitation. Concentrations of NO₃ + NO₂ observed during the calibration period were similar to concentrations observed in an old-growth forest in the H.J. Andrews, suggesting that nutrient processing within the Hinkle Creek watershed had returned to levels that existed prior to its initial harvest sixty years ago. This finding helps to assess long-term impacts of shorter rotation timber harvest of regenerated Douglas-fir stands characteristic of industrialized timber harvest in Oregon. / Graduation date: 2012