A atividade humana tem contribuído com as emissões de gases de efeito estufa (GEE) associadas, principalmente, com queima de combustíveis fósseis e mudanças no uso da terra. Assim, se faz necessário que sejam adotadas medidas visando o retardamento dos efeitos das mudanças climáticas. As florestas exercem papel essencial no balanço de carbono principalmente por funcionarem como sumidouros de CO2. Por outro lado, se desmatadas, promovem emissões e liberam parte do carbono estocado. A quantidade de biomassa florestal e o teor de carbono podem variar em função do tipo florestal, bem como de sua localização. Entretanto, fator importante diz respeito à confiabilidade dos dados mensurados neste tipo de pesquisa. A biomassa e o carbono da parte aérea podem ser determinados via método destrutivo, ou estimados via método não destrutivo. A construção do Rodoanel Mário Covas trecho norte e a supressão de uma área de Mata Atlântica possibilitou a realização de estudo de biomassa da parte aérea via método destrutivo. O objetivo deste trabalho foi estudar o tamanho e forma de parcelas, a intensidade amostral, quantificar a biomassa e o carbono na parte aérea, comparar métodos destrutivos e não destrutivos para a quantificação de biomassa e carbono na parte aérea, estudar a variação da densidade básica da madeira das espécies nas diferentes classes de DAP e grupos sucessionais e comparar as medidas de altura total e DAP obtidas a campo no inventário com as medidas coletadas após o corte. O tamanho mais conveniente de parcela foi 400 m 2, com forma retangular e dimensão de 10 x 40 m. A intensidade amostral variou entre 39 e 75 unidades amostrais. A biomassa da parte aérea obtida, via método destrutivo, foi de 188,3 Mg ha-1 e o carbono, 85,1 Mg ha-1. A biomassa estimada por equações alométricas da literatura foi subestimada, quando comparada ao valor real, obtido via método destrutivo. As menores classes de DAP apresentaram as maiores densidades básicas da madeira. A densidade básica foi 0,488 g cm-3 na média das espécies. A porcentagem de carbono contida nos troncos e galhos não diferiu entre as classes de DAP. O teor de carbono foi 45,41%, na média dos troncos e galhos. Espécies pioneiras acumularam maior quantidade de biomassa e carbono nos galhos e apresentaram maior densidade básica que as não pioneiras. A utilização dos dados coletados na fase de inventário e após o corte não afetaram os valores de biomassa estimados. / Human activity has contributed to the emission of greenhouse gases associated mainly with burning fossil fuels and changes in land use. Thus, it is necessary that measures be adopted to delay the effects of climate change. Forests play an essential role in the carbon balance mainly acting as CO2 sinks. On the other hand, if they are deforested, they will promote emissions and release some of the stocked carbon. The amount of forest biomass and the carbon content may vary depending on the forest type and its location. However, an important factor is about the reliability of the data measured in this type of research. Aboveground biomass and carbon can be determined via destructive method or estimated by non-destructive method. The construction of the north extension of Mário Covas Road and the suppression of an Atlantic forest area made it possible to carry out study of the aboveground biomass via destructive method. The goal of this work was to study the size and shape of plots, the sampling intensity, their aboveground biomass and carbon, compare destructive and non-destructive methods for the quantification of biomass and carbon, study the variation of wood basic density in the species in different classes of diameter of trunk at breast height (DBH) and successional groups and compare the total height and DBH measures obtained on field in the inventory with the measures taken after the cut. The most convenient plot size is 400 m2, with rectangular shape and size of 10 x 40 m. The sampling intensity varied between 39 and 75 sample units. The aboveground biomass obtained, via destructive method, was 188.3 Mg ha-1 and carbon, 85.1 Mg ha-1. The biomass estimated by allometric equations of the literature was underestimated compared to the real value obtained via destructive method. Smaller DBH classes had the highest wood basic density. The basic density was 0.488 g cm-3 in average of the species. The percentage of carbon contained in the trunks and branches did not differ between the DBH classes. The carbon content was 45.41%, in the average of the trunks and branches. Pioneer species accumulated higher amount of biomass and carbon in the branches and had a higher wood basic density than non pioneers species. The utilization of data collected in the inventory phase and after the cut did not affect the estimated biomass values.

Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-06-25T15:13:36Z No. of bitstreams: 2 Mel de Castro Camelo.pdf: 4176032 bytes, checksum: cf15b1197b22a54fd3d5cef1ec8a788a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-25T15:13:36Z (GMT). No. of bitstreams: 2 Mel de Castro Camelo.pdf: 4176032 bytes, checksum: cf15b1197b22a54fd3d5cef1ec8a788a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The species of Araceae are characterized by the presence of inflorescence in spadix, associated to a bract, the spathe. They occur in forest, country and rocky outcrops, presenting many endemic species. Some are highly adapted to specific habitats and few survive under altered conditions. The Caparaó National Park (ParNa Caparaó) has preserved areas and is recognized for the high endemism for species of Brazilian flora and high floristic richness. It is located in Serra do Caparaó, on the border of the states MG and ES, in southeastern Brazil. Located in one of the highest altitudes of the country, and about 70% of this conservation unit is in Espírito Santo. The region is occupied by semideciduous seasonal forest and dense ombrophylous forest at Montana and Upper Montana altitudes, as well as altitude fields. This work aims to inventory species of the Araceae family of the Caparaó National Park. The results are presented in two chapters, in article form, (Two new species of Anthurium Schott (Araceae) from Caparaó National Park, southeastern Brazil), where the first presents two new species of Anthurium sect. Urospadix Engl., which were found during the development of flora of Araceae from ParNa. And the second chapter (Araceae from Caparaó National Park, MG-ES, Brazil) deals with the inventory of Araceae, with 21 species belonging to four genera. In this are presented a key of identification of the species, descriptions, comments on phenology, geographic distribution, habitat and illustrations. / As espécies de Araceae são caracterizadas pela presença de inflorescência em espádice, associada a uma bráctea, a espata. Ocorrem em ambientes florestais, campestres e afloramentos rochosos, apresentando muitas espécies endêmicas. Algumas são altamente adaptadas para hábitats específicos e poucas sobrevivem em condições alteradas. O Parque Nacional do Caparaó (ParNa Caparaó) apresenta áreas preservadas e é reconhecido pelo alto endemismo para espécies da flora brasileira e alta riqueza florística. Está localizado na Serra do Caparaó, na divisa dos estados MG e ES, no sudeste do Brasil. Situado em uma das maiores altitudes do país, e cerca de 70% desta unidade de conservação encontra−se no Espírito Santo. A região é ocupada por Floresta Estacional Semidecidual e Floresta Ombrófila Densa, em altitudes Montana e Alto−Montana, além de campos de altitude. Esse trabalho tem como objetivo inventariar espécies da família Araceae do Parque Nacional do Caparaó. Os resultados são apresentados em dois capítulos, em forma de artigo, (Duas espécies novas de Anthurium Schott (Araceae) para o Parque Nacional do Caparaó, sudeste do Brasil), onde o primeiro apresenta duas espécies novas de Anthurium sect. Urospadix Engl., que foram encontradas durante o desenvolvimento da flora de Araceae do ParNa. E o segundo capítulo (Araceae do Parque Nacional do Caparaó, MG−ES, Brasil) trata-se do inventário de Araceae, com 21 espécies pertencentes a quatro gêneros. Neste são apresentadas uma chave de identificação das espécies, descrições, comentários sobre fenologia, distribuição geográfica, habitat e ilustrações.

The contamination of heavy metals in the environment is a looming concern worldwide. Egeria densa (Planch) (Submerged aquatic plant) from two ponds: Site A with co-ordinates (32º 48’22.04”S; 26°48’58.79” E) and Site B with co-ordinates (32°48’33.25”S; 26°48’33.25”S) in Alice (Eastern Cape) was evaluated for its ability to absorb heavy metals, phytochemical constituents, antimicrobial activity and ultra-structure using standard analytic procedures. Cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), and zinc (Zn) were measured in water, sediments and plant. The concentrations of these metal elements were determined with use of Inductively Coupled Plasma- Optical Emission Spectrometry (ICP-OES). In sediments, the heavy metals (mg/kg) decreased in the order of their average concentration as follows: Fe (40.320) > Zn (1.259) > Pb (0.564) > Mn (0.186) > Cu (0.037) in Pond 1 whereas in Pond 2 Fe (61.527) > Cd (0.999) > Mn (0.648) > Pb (0.586) > Zn (0.156) > Cu (0.045). The highest concentration of Fe was detected in both sites and Cu being the least. The concentrations of the metals in the plants sample (from Pond 1) were found in order of Mn > Pb > Cu > Fe whereas cadmium and zinc were not detected, while the concentration in Pond 2 decreases in order of Zn > Mn > Pb > Cd > Fe > Cu. In the water samples, concentrations of heavy metals (mg/L) decreased in the order of their average concentrations as follows: Pb (35.36) > Fe (3.07) > Mn (0.238) > Cu (0.104), both cadmium and zinc were below the limit of detection in Pond 1, whereas in Pond 2 the concentrations decreased as follows: Pb (13.033) >Fe (1.69) > Cu (0.270) > Mn (0.248) > Cd (0.004) and Zinc was not detected. Phytochemical analyses of the plant extracts revealed the presence of phenols, flavonoids, proanthocyanidin, flavonols, saponins, alkaloid and tannins in all the extracts (water, acetone and n-hexane). Both acetone and water extracts, showed high concentration of proanthocyanidin, while tannin was the lowest in acetone extract. Antimicrobial evaluation using, Gram positive (Staphylococcus aureus, Bacillus pumilus, Bacillus cereus, Streptococcus pyogenes, Enterococcus faecalis) and Gram negative (Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris and Serratia marcescens) bacteria showed negative results for all the strain, except Streptococcus pyogenes which was inhibited at MIC of 0.1 mg/ml. Scanning electron microscopy (SEM) of ultra-structure of Egeria densa, showed that certain bacteria attached to the leaf, However more work has to be done on E. densa to verify the mechanism by which it accumulates heavy metals. The study shows that E. densa has a potential of accumulating heavy metals especial Manganese in plant.

Orientador: Flávio Antonio Maës dos Santos / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T14:03:02Z (GMT). No. of bitstreams: 1 Martins_ValeriaForni_D.pdf: 2854064 bytes, checksum: 524c4f7a6e0351a0b702fdebc6397694 (MD5) Previous issue date: 2011 / Resumo: Muitas espécies arbóreas apresentam distribuição espacial agregada. As dióicas e que ocorrem em baixa densidade geralmente são mais agregadas e geram plântulas que são mais espacialmente associadas às fontes de semente do que as homóicas e as mais densas. Devido a eventos locais de dispersão de sementes, comumente há associação espacial entre adultos, sementes e plântulas. Isto ocorre especialmente entre adultos e sementes, mas nem sempre entre sementes e plântulas. Assim, os processos pós-dispersão também podem ter um efeito na estrutura espacial da população, com mecanismos dependentes de distância e densidade possivelmente reduzindo a agregação da mesma, enquanto a heterogeneidade ambiental geralmente aumenta a agregação. O objetivo deste estudo foi determinar como a densidade das fontes de semente, a dispersão e os processos pós-dispersão influenciam a estrutura espacial de três espécies arbóreas da Floresta Ombrófila Densa de Terras Baixas no litoral norte do estado de São Paulo. Nós amostramos todos os indivíduos das três espécies em duas parcelas de 1 ha cada, identificamos seus estádios ontogenéticos e os mapeamos. Durante dois anos, coletamos mensalmente a chuva de sementes. Por último, avaliamos as plântulas previamente amostradas para determinar se elas haviam morrido, recrutado para estádios ontogenéticos subsequentes ou permanecido no mesmo estádio. Então, comparamos os padrões espaciais da sobrevivência, da taxa de mortalidade e da taxa de recrutamento a seis variáveis preditoras. As sementes e os estádios ontogenéticos das três espécies apresentaram agregação, principalmente em pequenas classes de distância. Não houve um padrão claro da influência da densidade das fontes de semente na estrutura espacial das populações. Os adultos de todas as espécies apresentaram associações espaciais com sementes e plântulas, mas estas estiveram associadas em apenas metade das comparações. A mortalidade das plântulas ocorreu aleatoriamente e não modificou o padrão espacial agregado das populações. Os sobreviventes se localizaram principalmente em áreas com alta densidade inicial de plântulas. As taxas de mortalidade não apresentaram relação com as variáveis preditoras e ocorreram aleatoriamente. O mesmo padrão foi encontrado para as taxas de recrutamento de uma das espécies estudadas, mas outra recrutou mais em áreas com maior área basal da população e maior porcentagem de abertura de dossel, e menos em áreas com maior diferença de altitude. Nossos resultados estão de acordo com outros estudos que mostraram que espécies arbóreas tropicais são geralmente agregadas. No entanto, este padrão não pode ser atribuído à densidade das fontes de semente. Por outro lado, a agregação é explicada pela dispersão, uma vez que adultos ocorrem associados a sementes e plântulas. Os processos pós-dispersão não modificam o padrão espacial das populações após os eventos de mortalidade no estádio de plântula. A sobrevivência é maior em áreas com alta densidade de plântulas, como próximo aos adultos reprodutivos. Porém, não é possível prever onde a mortalidade e o recrutamento ocorrem em maiores taxas no ambiente. De forma geral, parece haver um maior recrutamento perto da planta parental devido à maior abundância de sementes neste local, apesar da baixa sobrevivência das mesmas, como proposto no modelo de recrutamento de Hubbell / Abstract: Many tree species present an aggregated spatial distribution. Dioecious, low-density species tend to be more aggregated and generate seedlings that are more spatially associated to seed sources than homoecious, high-density species. Due to local seed dispersal, adults, seeds and seedlings are generally spatially associated. This is commonly found for adults and seeds, but not always for seeds and seedlings. Therefore, post-dispersal processes can also affect the spatial structure of the population. Distance and density-dependent mechanisms usually decrease the aggregation of the population through ontogeny, while environmental heterogeneity tends to increase the aggregation through ontogeny. This study aimed at determining how density of seed sources, seed dispersal and post-dispersal processes influence the spatial structure of three tree species of a Lowland Atlantic Rainforest in Southeastern Brazil. We sampled every individual of the three species studied within two 1-ha plots. We also identified its ontogenetic stage and mapped the plants. During two years, we monthly sampled the seed rain. Last, we checked the previously sampled seedlings in order to determine if they had died, recruited to further ontogenetic stages or remained at the same stage. Then, we compared the spatial structure of seedling survival, mortality rates and recruitment rates to six predictor variables. The seeds and the ontogenetic stages of the three species studied were aggregated, especially at small distance classes. The influence of density of seed sources on the spatial structure of the populations was not clear. Adults of all species presented associations with seeds and seedlings, but seeds and seedlings were associated in only half of the comparisons. Seedling mortality occurred randomly and did not modify the aggregated spatial pattern of the populations. Survivals were located especially in areas with higher initial seedling density. Mortality rates were not related to the predictor variables and occurred randomly. The same pattern was found for the recruitment rates of one species, but other recruited more in areas with greater population basal area and higher percentage of canopy opening, and less in areas with greater elevation range. Our results agree with previous studies that showed that tropical tree species are generally aggregated. Nevertheless, this spatial pattern cannot be attributed to density of seed sources. On the other hand, the aggregation is explained by seed dispersal, since adults were always spatially associated to seeds and seedlings. Post-dispersal processes do not modify the spatial pattern of the populations after mortality events during the seedling stage. The chance of surviving is enhanced in areas with higher initial seedling density, such as near reproductive adults. However, it is not possible to predict where mortality and recruitment operate at higher rates in the forest due to idiosyncrasies of the species. Overall, recruitment seems to be higher close to the parent plant because of considerably greater seed abundance there, despite very low seed survival, as proposed in the Hubbell's recruitment model / Doutorado / Ecologia / Doutor em Ecologia

Orientadores: Carlos Alfredo Joly, Flavio Antonio Maës dos Santos / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T11:17:29Z (GMT). No. of bitstreams: 1 Vinha_Daniella_D.pdf: 19806435 bytes, checksum: af3818b4640c3acda5f09a0580ff9346 (MD5) Previous issue date: 2015 / Resumo: Estudos prévios demonstraram baixa sazonalidade na frutificação em florestas tropicais não-sazonais, o que poderia influenciar o padrão temporal e espacial da chuva de sementes e do banco de sementes. Entretanto, esses processos não são conhecidos. O objetivo desse estudo foi determinar como ocorre a regeneração natural via sementes em uma floresta tropical Montana no Parque Estadual da Serra do Mar. Foram testadas as hipóteses: (1) a sazonalidade na chuva de sementes é fraca ou ausente e esse padrão não se diferencia dentro dos modos de dispersão; (2) o banco de sementes é florísticamente relacionado com a chuva de sementes e espacialmente acoplado; (3) o banco de sementes apresenta baixa sazonalidade e esse padrão não difere dentro dos modos de dispersão. Em 2 hectares de floresta, nós registramos o total de 29959-62904 diásporos na chuva de sementes (104-106 spp.), 1029-2999 diásporos no banco de sementes da serapilheira (36-38 spp.) e 6288-7824 plântulas no banco de sementes do solo (74-82 spp.) ao longo de dois anos. Asteraceae, Urticaceae e Melastomataceae foram abundantes na chuva de sementes (63-81%), no banco de sementes da serapilheira (70-73%) e no banco de sementes do solo (77-84%). A maior riqueza de espécies foi de arbóreas na chuva de sementes (59-61%) e banco de sementes da serapilheira (72-68%), e de herbáceas no banco de sementes do solo (ca. 55%). Houve maior proporção de sementes arbóreas em todas as vias de regeneração, assim como maior riqueza de espécies zoocóricas (mais de 50%). Entretanto, a anemocoria contribuiu com a maior proporção do total de sementes no banco de sementes do solo (ca. 75%) e da chuva de sementes de uma das áreas (64%). Houve sazonalidade na chuva de sementes com um único pico na abundância (Out-Nov). Esse padrão foi reforçado pela sazonalidade na abundância e riqueza de espécies da chuva de sementes anemocórica e zoocórica, ambas ocorrendo no período de maior precipitação. A chuva de sementes influenciou a composição de espécies das sementes contidas na serapilheira e no solo. Entretanto, o acoplamento espacial entre as vias de regeneração ocorreu somente em uma das áreas. O banco de sementes não apresentou variações na composição florística e houve fraca variação temporal na densidade e riqueza de espécies, repercutindo igualmente dentro dos modos de dispersão. Esse estudo demonstrou que a chuva de sementes pode ser sazonal em condições de baixa sazonalidade ambiental, independente do modo de dispersão das sementes. A relação entre composição da chuva de sementes e das sementes contidas na serapilheira e no solo revela que essas vias são interligadas e dependentes entre si, resultando em padrões espaciais agrupados. Como resultado, a baixa variação temporal do banco de sementes não pode ser atribuída à baixa sazonalidade na chuva de sementes. O fato de não haver acúmulo de sementes no solo após o período de dispersão sugere o baixo tempo de permanência das sementes. Por outro lado, a falta de acoplamento espacial em uma das áreas sugere processos de pós-dispersão atuando na reestruturação espacial do banco de sementes / Abstract: Previous studies have demonstrated low seasonality in the fruiting phenology in aseasonal tropical forests, which could influence the spatial and temporal pattern of seed rain and seed bank. However, these processes are poorly known. The aim of this study was to determine seed natural regeneration in an Atlantic tropical Montane forest located in southeast of Brazil, Serra do Mar State Park. The hipotheses were tested: (1) seasonality of seed rain is weak or absent and this pattern is no different within the dispersal modes; (2) the floristic composition of seed bank is closely related with seed rain and there is a spatial association between them; (3) the seed bank has a low seasonality and this pattern is the same within the dispersal modes. In two hectares of forest we recorded total of 29959-62904 seeds in the seed rain (104-106 spp.), 1029-2999 seeds in the litter seed bank (36-38 spp.) and 6288-7824 seedlings in the soil seed bank (78-82 spp.) over two years. Asteraceae, Urticaceae and Melastomataceae were abundant in the seed rain (63-81%), litter seed bank (70-73%) and soil seed bank (77-84%). Trees accounted to higher species richness in the seed rain (59-61%) and litter seed bank (72-68%). Herbaceous were most important to the species richness of soil seed bank (ca. 55%). There were more of tree seeds in all regeneration modes, as well as greater zoochorous species richness (more than 50%). However, anemochory had the largest proportion of total seeds in the soil seed bank (ca. 75%) as well as one of the areas where the seed rain was sampled (64%). There was seasonality of seed rain with a single peak in abundance (Oct-Nov). This pattern was reinforced by seasonality in the anemochorous and zoochorous abundance and species richness of seed rain, both occurring in the period of greatest rainfall. Seed rain influenced the species composition of the seeds in the litter and soil. However, the spatial coupling between the regeneration modes occurred in only one area. The soil seed bank showed no changes in the floristic composition and there was a weak temporal variation in density and species richness reflecting also within in the dispersal syndromes. This study demonstrated that seasonality in seed rain can occur even in tropical forests where environmental seasonality is low, regardless of the manner in which the seeds are dispersed. The relationship between seed rain and seed bank composition (litter and soil) reveals that these pathways are interconnected and dependent on each other, resulting in clustered spatial patterns. As a result, the low temporal variation of soil seed bank can not be attributed to the low seasonality of seed rain. Since there is no seed accumulation in the soil after a period of seed dispersal, short residence time of the seed in the soil is suggested. On the other hand, the lack of spatial association between seed rain and seed bank in one of the areas suggests post-dispersal processes acting in the spatial restructuring of the seed bank / Doutorado / Biologia Vegetal / Doutor em Biologia Vegetal

[pt] Alvo de intenso estudo da visão computacional, a reconstrução densa 3D teve um importante marco com os primeiros sistemas em tempo real a alcançarem precisão milimétrica com uso de câmeras RGBD e GPUs. Entretanto estes métodos não são aplicáveis a dispositivos de menor poder computacional. Tendo a limitação de recursos computacionais como requisito, o objetivo deste trabalho é apresentar um método de odometria visual utilizando câmeras comuns e sem a necessidade de GPU, baseado em técnicas de Structure from Motion (SFM) com features esparsos, utilizando as informações de uma reconstrução densa. A Odometria visual é o processo de estimar a orientação e posição de um agente (um robô, por exemplo), a partir das imagens. Esta dissertação fornece uma comparação entre a precisão da odometria calculada pelo método proposto e pela reconstrução densa utilizando o Kinect Fusion. O resultado desta pesquisa é diretamente aplicável na área de realidade aumentada, tanto pelas informações da odometria que podem ser usadas para definir a posição de uma câmera, como pela reconstrução densa, que pode tratar aspectos como oclusão dos objetos virtuais com reais. / [en] Aim of intense research in the field computational vision, dense 3D reconstruction achieves an important landmark with first methods running in real time with millimetric precision, using RGBD cameras and GPUs. However these methods are not suitable for low computational resources. Having low computational resources as requirement, the goal of this work is to show a method of visual odometry using regular cameras, without using a GPU. The proposed method is based on technics of sparse Structure From Motion (SFM), using data provided by dense 3D reconstruction. Visual odometry is the process of estimating the position and orientation of an agent (a robot, for instance), based on images. This dissertation compares the proposed method with the odometry calculated by Kinect Fusion. Results of this research are applicable in augmented reality. Odometry provided by this work can be used to model a camera and the data from dense 3D reconstruction, can be used to handle occlusion between virtual and real objects.

This study analyses the impact of land registration and certification scheme on sustainable use of farmlands in Debre Mawi and Densa Bahta rural kebeles of Amhara region in northwestern Ethiopia, with a view to contributing to the theoretical debate on tenure security and more realistic policy advocacy on the sustainable use of farmlands. Within the framework of qualitative research methodology, the case study approach helps to observe and understand the relationship between land titling and sustainable use of farmlands in Densa Bahta and Debre Mawi kebeles of the Amhara region in Ethiopia. Specific methods employed were focus group discussions, in-depth interviews and observation, complemented by context analyses of relevant documents. It was found that land titling has contributed to a high perception of security of land tenure among study respondents. However, results show that land titling has both positive and negative impacts on sustainable use of farmlands. The positive impact of land titling is ascribed to its assurance effect and legal obligation imposed on farmers to adopt proper land management practices. The negative impact of land titling arises from its failure to address the existing inequality in possession of farmlands among the village communities. Failure of farmers’ high perceptions of their security of land tenure to translate into sustainable land use practices has implications for the relative importance of productive asset endowments, self-efficacy and risk perception on the sustainable use of farmlands in the Amhara region. Interviewees that follow unsustainable farming practices were endowed with relatively lower pieces of farmland and disadvantaged in possession of other productive assets. They also demonstrated a low level of self-efficacy and a risk-averse attitude to adopting conservation technologies, as they possessed smaller sizes of farmland compared with the village and regional average. The study urges a holistic approach and comprehensive analytical framework to understand the synergy of several factors that affect the sustainable use of farmlands. / Environmental Sciences / D. Litt. et Phil. (Development Studies)

This study analyses the impact of land registration and certification scheme on sustainable use of farmlands in Debre Mawi and Densa Bahta rural kebeles of Amhara region in northwestern Ethiopia, with a view to contributing to the theoretical debate on tenure security and more realistic policy advocacy on the sustainable use of farmlands. Within the framework of qualitative research methodology, the case study approach helps to observe and understand the relationship between land titling and sustainable use of farmlands in Densa Bahta and Debre Mawi kebeles of the Amhara region in Ethiopia. Specific methods employed were focus group discussions, in-depth interviews and observation, complemented by context analyses of relevant documents. It was found that land titling has contributed to a high perception of security of land tenure among study respondents. However, results show that land titling has both positive and negative impacts on sustainable use of farmlands. The positive impact of land titling is ascribed to its assurance effect and legal obligation imposed on farmers to adopt proper land management practices. The negative impact of land titling arises from its failure to address the existing inequality in possession of farmlands among the village communities. Failure of farmers’ high perceptions of their security of land tenure to translate into sustainable land use practices has implications for the relative importance of productive asset endowments, self-efficacy and risk perception on the sustainable use of farmlands in the Amhara region. Interviewees that follow unsustainable farming practices were endowed with relatively lower pieces of farmland and disadvantaged in possession of other productive assets. They also demonstrated a low level of self-efficacy and a risk-averse attitude to adopting conservation technologies, as they possessed smaller sizes of farmland compared with the village and regional average. The study urges a holistic approach and comprehensive analytical framework to understand the synergy of several factors that affect the sustainable use of farmlands. / Environmental Sciences / D. Litt. et Phil. (Development Studies)

Four forage grasses from botanic alien species - Tripsacum dactyloides, Axonopus scoparius, Panicum maximum and Melinis minutiflora - were found in a fragment of Forest Dense Ombrófila Submontana in process of recruitment, in an urban environment in Blumenau, Santa Catarina state, in the South of Brazil. The vegetation of this forest area was inventoried. The classification of the natural regeneration of secondary vegetation showed a predominance of medium sucessional stages. In initial sucessional stages, herbaceous plants were found among non-native forage grasses. The species Melinis minutiflora and Panicum maximum were found along the border of the fragment, close to highways, isolated and not forming large clumps. Both are recorded in the invasive alien species database managed by the Horus Institute for Environmental Conservation and Development (www.institutohorus.org.br), part of the I3N invasive alien species thematic network, a component of IABIN (Inter American Biodiversity Information Network). Tripsacum dactyloides and Axonopus scoparius don't appear in such a bank, which includes Brazil. Both species were assessed through the software developed by the I3N invasive alien species thematic network, the Risk Assessment Tool for the Establishment and Invasion by nonnative species. The data assessment on Tripsacum dactyloides shows that it poses a high risk for its potential in becoming an invasive species. There was no conclusive resulted about the species Axonopus scoparius due to the inadequacy of information available on the species. / Quatro gramíneas forrageiras exóticas: Tripsacum dactyloides, Axonopus scoparius, Panicum maximum e Melinis minutiflora foram encontradas num fragmento de Floresta Ombrófila Densa Submontana do bioma Mata Atlântica em processo de regeneração natural, em Blumenau, SC (ambiente urbano). Foi feita a caracterização da vegetação presente na área através de inventário florestal com a classificação dos estágios sucessionais de regeneração natural indicando a predominância de uma fitocenose em estágio sucessional médio, com presença de área em estágio sucessional inicial. Aí foram diagnosticadas plantas de porte herbáceo, entre as quais as gramíneas forrageiras tropicais exóticas. As espécies Melinis minutiflora e Panicum maximum ocorreram na borda do fragmento, próximo a rodovias, na forma de plantas isoladas. Ambas constam no banco de dados de plantas invasoras da rede temática para espécies exóticas invasoras (I3N) da Rede Interamericana de Informação sobre Biodiversidade (IABIN). Tripsacum dactyloides e Axonopus scoparius não constam em tal banco, que inclui o Brasil. Ambas as espécies foram submetidas ao Software desenvolvido pela rede I3N, a Ferramenta de Análise de Risco de Estabelecimento e Invasão, e segundo a análise desta ferramenta alimentada com os dados obtidos neste trabalho o risco associado à Tripsacum dactyloides de se transformar numa espécie invasora é considerado alto. Não houve resultado conclusivo sobre a espécie Axonopus scoparius devido à insuficiência de informações sobre a espécie.