Woody invasion into grasslands has been reported world-wide and has affected both the magnitude and spatial heterogeneity of soil carbon (C) and nitrogen (N). Since grasslands cover a large portion of the Earth's land surface, invasion of woody plants could have impacts on regional and global biogeochemistry. To understand large-scale ecological and policy implications of woody invasion, it is critical to understand the spatial pattern and uncertainty of soil C and N and their relationship with vegetation and soil attributes, as well as develop effective approaches to estimate soil C and N over large landscapes and regions. The goal of this study was to improve our understanding of the spatial pattern of soil organic carbon (SOC) and total nitrogen (TN) and their controlling factors in savanna landscapes and develop efficient sampling strategies for evaluating the effects of woody invasion. Specific objectives of this study were to: (1) Quantify the spatial pattern and uncertainty associated with SOC and develop efficient sampling strategies to estimate SOC storage; (2) Assess the influence of soil and vegetation factors on spatial distribution of SOC and TN; and (3) Determine the influence of physical variables related to landscape position and soil on woody vegetation structure. Conditional sequential indicator simulations indicated that woody encroachment into grassland increased both spatial heterogeneity and uncertainty of SOC, which increased errors in estimating SOC storage. Stratified random sampling with higher density in woody patches, plus structured sampling in cluster with strong spatial pattern, substantially increased estimation accuracy. Efficient sampling strategies for estimating SOC storage were developed based on these findings. Direct and spatial correlation and scaling analyses showed that SOC and TN were strongly correlated with litter and root biomass. Invaded woody vegetation has the most impact on spatial distribution of SOC and TN. Canonical correspondence analysis showed that variables related to landscape position were the primary factors determining the spatial distribution of woody species. These new insights will facilitate the estimation of soil C and N pools at landscape and regional scales, and will help evaluate the potential impacts of woody plant encroachment on the biogeochemistry of C and N.

Woody invasion into grasslands has been reported world-wide and has affected both the magnitude and spatial heterogeneity of soil carbon (C) and nitrogen (N). Since grasslands cover a large portion of the Earth's land surface, invasion of woody plants could have impacts on regional and global biogeochemistry. To understand large-scale ecological and policy implications of woody invasion, it is critical to understand the spatial pattern and uncertainty of soil C and N and their relationship with vegetation and soil attributes, as well as develop effective approaches to estimate soil C and N over large landscapes and regions. The goal of this study was to improve our understanding of the spatial pattern of soil organic carbon (SOC) and total nitrogen (TN) and their controlling factors in savanna landscapes and develop efficient sampling strategies for evaluating the effects of woody invasion. Specific objectives of this study were to: (1) Quantify the spatial pattern and uncertainty associated with SOC and develop efficient sampling strategies to estimate SOC storage; (2) Assess the influence of soil and vegetation factors on spatial distribution of SOC and TN; and (3) Determine the influence of physical variables related to landscape position and soil on woody vegetation structure. Conditional sequential indicator simulations indicated that woody encroachment into grassland increased both spatial heterogeneity and uncertainty of SOC, which increased errors in estimating SOC storage. Stratified random sampling with higher density in woody patches, plus structured sampling in cluster with strong spatial pattern, substantially increased estimation accuracy. Efficient sampling strategies for estimating SOC storage were developed based on these findings. Direct and spatial correlation and scaling analyses showed that SOC and TN were strongly correlated with litter and root biomass. Invaded woody vegetation has the most impact on spatial distribution of SOC and TN. Canonical correspondence analysis showed that variables related to landscape position were the primary factors determining the spatial distribution of woody species. These new insights will facilitate the estimation of soil C and N pools at landscape and regional scales, and will help evaluate the potential impacts of woody plant encroachment on the biogeochemistry of C and N.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-06-05T19:47:03Z No. of bitstreams: 1 RENNAN PEREIRA DE GUSMÃO – TESE (PPGEP) 2015.pdf: 4781124 bytes, checksum: fd473ef9686e8dc699f6b0aa1da038e5 (MD5) / Made available in DSpace on 2018-06-05T19:47:03Z (GMT). No. of bitstreams: 1 RENNAN PEREIRA DE GUSMÃO – TESE (PPGEP) 2015.pdf: 4781124 bytes, checksum: fd473ef9686e8dc699f6b0aa1da038e5 (MD5) Previous issue date: 2015-03-25 / O segmento de biscoitos é de extrema importância para o Brasil, que se destaca como o 2º maior produtor mundial. A busca por matérias-primas alternativas ao trigo se torna cada vez mais necessária para desenvolvimento de produtos sem glúten, incremento no valor nutricional e redução de custos no setor de panificação. As vagens da algaroba apresentam alto valor nutritivo e podem ser utilizadas como matéria-prima para o desenvolvimento de novos produtos alimentícios. Com esses aspectos, o objetivo deste trabalho foi desenvolver biscoito enriquecido com farinha de algaroba com elevada qualidade nutricional e importância para o desenvolvimento econômico do semiárido nordestino; para tal, foi utilizada a algaroba madura, com teor de água de 20% (b.u) e realizados experimentos de secagem com temperaturas de 50, 60, 70 e 80°C; os modelos matemáticos de Fick, Page, Cavalcanti Mata, Exponencial de Dois Termos e Henderson & Pabis foram utilizados para ajuste aos dados experimentais; posteriormente, foram desenvolvidos biscoitos com farinha de algaroba e submetidos à análise sensorial. A farinha de algaroba utilizada na formulação do biscoito com maior aceitação, foi submetida à caracterização granulométrica, morfológica, reológica, físico -química, determinação dos minerais e utilizada para produção de biscoitos, mediante planejamento experimental. As cinco melhores formulações de biscoito foram submetidas ao teste de aceitação sensorial; a atividade de água, firmeza, fraturabilidade e cor das três formulações de biscoitos com maior aceitação foram analisadas durante 120 dias de armazenamento; a partir dos resultados obtidos pode-se afirmar que os modelos matemáticos de Fick, Page, Cavalcanti Mata, Exponencial de Dois Termos e Henderson & Pabis, representaram satisfatoriamente os dados experimentais da secagem de algaroba. A farinha de algaroba apresentou características reológicas adequadas à produção de biscoitos. A farinha de algaroba apresentou alta concentração de fibras (15,10.g.100g-1), proteínas (9,12.g.100g-1), cálcio (650,75.mg.100g-1) e fósforo (879,12.mg.100g-1). Os biscoitos elaborados com: 25% de farinha de algaroba, 30% de teor de açúcar e 45% de teor de gordura de palma (experimento 4), 5% de farinha de algaroba, 50% de teor de açúcar e 45% de teor de gordura de palma (experimento 7) e 15% de farinha de algaroba, 40% de teor de açúcar e 35% de teor de gordura de palma (experimento 9) foram os que tiveram maior aceitação e intenção de compra. Decorrido o período de 120 dias de armazenamento, os biscoitos elaborados com farinha de algaroba tiveram sua atividade de água, fraturabilidade e luminosidade aumentadas, e sua firmeza, intensidade de amarelo e vermelho, diminuídas. Conclui-se que os biscoitos elaborados com farinha de algaroba apresentaram nutrientes, como: cálcio, ferro e fósforo, boa aceitação sensorial e características de qualidade com comportamento similar ao de produtos já existentes no mercado, durante o armazenamento. / The segment of cookies is extremely important to Brazil, which stands as the 2nd largest producer. The search for alternative raw materials to wheat becomes increasingly necessary for the development of gluten-free products, increase the nutritional value and cost savings in the bakery sector. The mesquite pods have a high nutritional value and can be used as feedstock for the development of new food products. With these aspects, the objective of this study was to develop cookie enriched with mesquite flour which has high nutritional quality and importance to the economic development of the semi-arid northeast. In this work, the mature mesquite was used with a water content of 20% (wb). Drying experiments were performed at temperatures of 50, 60, 70 and 80 ° C. Mathematical models of Fick, Page, Cavalcanti Mata, Exponential Two Terms and Henderson & Pabis were used to fit the experimental data. Later, cookies were developed with mesquite flour and subjected to sensory analysis. The mesquite flour used in the cookie formulation with greater acceptance, was subjected to size grain, morphological, rheological, physico-chemical, determination of the chemical elements and was used for the production of cookies by using experimental design. The five best cookie formulations were subjected to sensory acceptance test. Water activity, firmness, fracture stress and color of all three formulations of cookies with greater acceptance were analyzed for 120 days of storage. From the results obtained, it can be said that the mathematical models Fick, Page, Cavalcanti Mata, Exponential Two Terms and Henderson & Pabis satisfactorily explained the experimental data of drying mesquite. The mesquite flour presented rheological characteristics suitable for production of cookies. The mesquite flour showed high concentration of fibers (15.10 g.100g-1), protein (9.12 g.100g-1), calcium (650.75.mg.100g-1) and phosphorous (879.12.mg.100g-1). The cookies made with 25% mesquite flour, 30% sugar and 45% palm fat content (experiment 4), 5% of mesquite flour, 50% sugar content and 45% content palm fat (experiment 7) and 15% of mesquite flour, 40% sugar and 35% palm fat content (experiment 9) were those who had greater acceptance and purchase intent. After the 120 days of storage, cookies of mesquite flour had their water activity and luminance increased, while its firmness, fracture stress, yellow and red intensity reduced. It is concluded that the cookies, of mesquite flour presented a high nutritional composition, high sensory acceptance, and similar quality characteristics to existing products on the market during storage.

Thesis (MScConEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: I evaluated the impact of Prosopis invasion and clearing on ecological structure, function and agricultural productivity in heavily grazed Nama Karoo rangeland on two sheep farms near the town of Beaufort West in the Western Cape Province of South Africa. My aims were to (1) determine the effects of invasion and clearing on rangeland vegetation composition, diversity (alien and indigenous species richness) and structure (alien and indigenous species cover), soil vegetation cover (plant canopy and basal cover) and agricultural productivity (grazing capacity), (2) describe the vegetation processes that underlay the invasion and clearing impacts and (3) evaluate the success of clearing in facilitating unaided restoration of ecological structure, function and agricultural productivity in formerly invaded rangeland. I hypothesised that invasion would significantly change rangeland vegetation composition and structure, leading to greater alien species richness and cover and lower indigenous species richness and cover while clearing would lead to lower alien species diversity and cover and greater indigenous species richness and cover. In addition I hypothesized that invasion would reduce rangeland plant canopy and basal cover and grazing capacity while clearing would substantially increase them. Finally I predicted that vegetation composition, alien and indigenous species cover and richness, plant canopy and basal cover and grazing capacity would revert to pre-invasion status and levels within four to six years of clearing. My results suggest that in heavily grazed Nama Karoo rangeland Prosopis invasion (~15 percent canopy cover) and clearing can significantly change rangeland vegetation composition, with invasion leading to greater alien species cover and lower indigenous species richness, while clearing leads to lower alien species richness and cover and greater indigenous species richness and cover. However invasion seems to have no effect on alien species richness and overall indigenous species cover. Clearing appears to facilitate the spontaneous restoration of alien species cover and indigenous species richness within four to six years but not species composition, alien species richness and indigenous species cover. In addition my results also indicate that Prosopis invasion can lower rangeland plant canopy and basal cover and grazing capacity while clearing, even under heavy grazing, can substantially raise them. Clearing however does not seem to facilitate the restoration of rangeland plant canopy and basal cover and grazing capacity to pre-invasion levels within four to six years after clearing. / AFRIKAANSE OPSOMMING: Ek het die impak van Prosopis indringing en verwydering van indringers op ekologiese struktuur, funksie en landbou produktiwiteit in ‘n swaar beweide Nama Karoo gebied op twee skaapplase naby Beaufort-Wes in die Wes-Kaap provinsie van Suid-Afrika geëvalueer. My doelwitte was om (1) te bepaal wat die gevolge van die indringing en verwydering van indringers op die natuurlike plantegroei samestelling, diversiteit (uitheemse en inheemse spesiesrykheid) en struktuur (uitheemse en inheemse spesies bedekking) sal wees, sowel as die effek op plantegroei bedekking (kroon en basalebedekking) en landbou produktiwiteit (weidingkapasiteit), (2) die plantegroei prosesse te beskryf wat onderliggend deur die impakte van indringing en verwydering van indringers veroorsaak word, en (3) die sukses van die verwydering van indringers te evalueer deur die fasilitering van blote restorasie van ekologiese struktuur en funksie en landbou produktiwiteit in voorheen ingedringde gebiede. My hipotese is dat indringing ‘n aansienlike verandering in natuurlike plantegroeisamestelling en struktuur sal veroorsaak, wat sal lei tot groter uitheemse spesiesrykheid en bedekking met minder inheemse spesiesrykheid en bedekking, terwyl die verwydering van indringers sou lei tot minder uitheemse spesie diversiteit en bedekking met 'n groter inheemse spesiesrykheid en bedekking. Verder vermoed ek dat indringing die natuurlike kroon- en basalebedekking en weidingkapasiteit sal verminder, terwyl die verwydering van indringers dit aansienlik sal verhoog. Ten slotte voorspel ek dat plantegroei samestelling, uitheemse en inheemse spesiesbedekking en -rykheid, kroon- en basalebedekking en weidingkapasiteit sou terugkeer na voor-indringing status en vlakke binne vier tot ses jaar na die verwydering van indringers. My resultate daarop dat die indringing van Prosopis (~ 15 persent kroonbedekking) en die verwydering van indringers in swaar beweide Nama Karoo gebiede ‘n aansienlike verandering in die gebied se natuurlike plantegroei samestelling toon, waar indringing gelei het tot groter uitheemse spesiesbedekking en minder inheemse spesiesrykheid, terwyl die verwydering van indringers lei tot minder uitheemse spesiesrykheid en groter inheemse spesiesrykheid en - bedekking. Dit lyk egter of indringing geen effek op uitheemse spesiesrykheid en algehele inheemse spesiesbedekking het nie. Die verwydering van indringers blyk om die spontane herstel van indringerbedekking en inheemse spesiesrykheid binne vier tot ses jaar te fasiliteer, maar nie spesiesamestelling, uitheemse spesiesrykheid of inheemse spesiesbedekking nie. Benewens dui my resultate ook aan dat Prosopis indringing die natuurlike kroon- en basalebedekking sowel as weidingskapasiteit verlaag, terwyl die verwydering van indringers, selfs onder swaar beweiding, die bedekking aansienlik kan verhoog. Verwydering van indringers lyk egter nie asof dit die herstel van die gebied se natuurlike kroon- en basalebedekking en weidingkapasiteit na voor-indringing vlakke toe kan fasiliteer binne vier tot ses jaar na die verwydering van indringers nie.

A report on the vegetation of the Cabeza Prieta NWR, with tables giving statistical representations of the vegetation associations.

Releve plot data for Cabeza Prieta NWR, sampled from 1999 to 2002

Shapefiles of the vegetation, watercourses, and sampling routes traveled, Cabeza Prieta NWR