Na região de Piracicaba, grande parte dos pequenos produtores cultivam cana-de-açúcar em áreas de alta declividade, mas a mecanização da colheita tem inviabilizado seu cultivo nesta condição. Sistemas agroflorestais (SAFs) podem ompatibilizar a produção da cultura neste cenário, com a conservação de recursos naturais, porém, há falta de pesquisa sobre seu cultivo nestes sistemas. Portanto, o uso de modelos de simulação e avaliações de campo da interface árvore-cultura podem desempenhar importante papel para investigar seus potenciais e restrições. Assim, identificamos e selecionamos terras e árvores para cultivo dos SAFs e avaliamos o crescimento e produção de plantas dos SAFs cana-de-açúcar x seringueira e cana-de-açúcar x eucalipto. Realizamos dois experimentos de campo e utilizamos o modelo WaNuLCAS e um modelo que simula a disponibilidade de radiação para culturas intercalares, acionando-o com a produção de matéria seca da cultura. SAFs em aléias em contorno são alternativa viável para cultivo de cana-de-açúcar no município de Piracicaba, havendo diversas espécies arbóreas exóticas e nativas que podem compor estes SAFs, destacando-se seringueira e eucalipto. Luz e água são limitantes ao crescimento da cultura e há aumento da competição de acordo com o crescimento das árvores. A importância relativa entre competição abaixo e acima do solo depende da distância das árvores. Contudo, o SAF cana-de-açúcar x eucalipto tem produção semelhante ao monocultivo de cada espécie. Os modelos permitiram avaliar os SAFs e orientar experimentos, mas suas indicações devem ser verificadas em experimentos de campo. A recomendação dos SAFs deve ser feita após análise econômica dos mesmos. / In Piracicaba, many smallholders grow sugarcane in areas of high solpe, but the mechanization of the harvest process has made inviable its cultivation under this situation. Agroforestry systems (AFs) are an alternative that may join the cultivation of the crop under this scenario with conservation of natural resources. However, there is lack of research of its cultivation in AFs. Therefore, the use of simulation models and evaluation of on-farm tree-crop interfaces may play an important role to investigate its potentials and restrictions. Thus, we identified and selected lands and trees to the cultivation of the AFs and assessed plant growth and yield of sugarcane x rubber and sugarcane x eucalyptus AFs. We did two field experiments and used the WaNuLCAS model and another one that simulates the available irradiance for intercrops, related with their dry matter production. Contourhedgerows are a feasible alternative for sugarcane cultivation in Piracicaba, where many tree species may be part of it, especially rubber and eucalypts. Light and water are limiting factors for crop growth and competition increases with tree growth. The relative importance of each variable depends on the distance from the trees. However, the sugarcane x eucalyptus AF has similar production of the monocropping of each specie. The models allowed to assess the AFs and to drive field trials, but their results should be verified in experiments. The recomendation of the AFs should be done after their economic analysis.

Most of the wood harvested in New Zealand comes from plantations of the exotic species Pinus radiata D. Don. Because forest yield exceeds demand much of the expanding forest production is available for export. Analysis of the export potential for forest products has shown that wood quality will be important to market success. Yet there is concern that intrinsic properties will decline after 1985 with an inevitable reduction in rotation age. This work develops parameters which link silviculture to the two most important intrinsic properties, wood density and tracheid length. Both of these properties vary more or less regularly with geographic region. Within individual trees values depend on wood-age (= rings from pith). The properties of a stand of trees can be assessed if volume per tree can be partitioned into wood age categories. The parameter suggested here as best indicating wood quality whilst also having relevance to silviculture is volume of mature-wood, that is volume of wood age greater than ten years. A replicated spacing/thinning trial of 75, 0.06ha plots provided the data source. Models were developed to predict the wood quality parameter. Diameter growth is projected for a plot by means of an individual tree, distance dependent model based on multiple linear equations. Height is predicted from age and diameter by a system of homologous non-linear equations and volume per tree by a function of diameter squared and height. From diameter, height and age, mean wood age is predicted using a multiple linear equation and the distribution of volume by wood age is predicted using the Weibull function. The distribution is applied to each tree and totalled for the stand. Comparing results at a fixed age for a wide range of silvicultural regimes reveals that silviculture has a greater influence on wood quality than hitherto believed.

This thesis is an examination of the political settlement in Indian forest policy. In the last two decades the rapid degradation of Indian forests has led to a reconsideration of who should manage the forests and with what priorities. An agenda has emerged which identifies the decentralisation of resources to local communities for subsistence as a national priority. This thesis explores the content and development of the consensus over decentralised forest management. My focus in this respect is on a system of common property forest management in the Central Himalaya, and on two villages in District Kurnaun in particular. In chapter 1 argue that the content of agenda is determined by two interest groups, the government and 'a social forestry interest group', comprised of NGOs ahd the international development community. Both have theories about the interaction between environment and society in which their own specific interests are represented as being in the general interest of society as a whole. The 'conventional' position adopted by the government considers central control over local units of management necessary to prevent unrestrained resource use. The 'populist' position of the social forestry interest group maintains that common property regimes were a past tradition, and that their disruption - is a principle cause for deforestation. Both theories fail to explore the material causes for environmental degradation, and the way in which local communities have adapted their patterns of resource use and social relations of production in response to developments in the wider economy. In chapter 3, 5, 6 and 7 I show the inadequacies of populist and conventional explanations for the interaction between environment and society, and why the new agenda fails to offer a comprehensive agenda for development. In chapter 4 and 8 I consider the way in which the discourse over the environment has become entrenched in policy making.

For the past 10 years, thousands of refugees from Central African Republic (CAR) have crossed into Cameroon and settled in villages along the border.  Refugee influxes can produce ecological and social challenges to host communities.  While conflict is often a result, there is also an opportunity for collaboration and successful integration.  Agroforestry, the intentional incorporation and management of trees in agricultural systems, provides a tool that can respond to both social and ecological challenges by providing conservation farming techniques and increasing diversified home production of many needed products.  This research sought to understand the needs of community members for specific practices as well as preferences for social implementation of practices, using a frame of identity to help inform on integration and collaboration potential in agricultural projects.   The participatory research collected demographic data, employed a 20 point oral questionnaire, and utilized illustrated visual ranking and storytelling tools to gather information on 8 agroforestry practice and implementation preferences, identity, and social arrangement preferences among community members.  Agroforestry practices were divided between product-oriented and service-oriented practices.  We collected data from 122 individual interviews evenly divided between men and women, and CAR refugees and host community Cameroonians.   Results show that there are significant differences in agroforestry practice and implementation preferences across the sample, and between refugees and Cameroonians.  Most people felt that refugees and Cameroonians had similar traditions and needs, and that most areas of life should be integrated, however agriculture was an area that the people were more hesitant about mixing, demonstrating that arrangements and implementation of agricultural projects should be carefully designed and executed.  Those who preferred mixing of refugees and Cameroonians in fieldwork included members of all demographic groups, signifying the potential for integrated collaboration on community agricultural projects.  Results demonstrate that agroforestry projects have the potential to provide important valued resources to communities, create an opportunity for knowledge transfer and improved agricultural systems, and be the scene for positive contact between refugees and Cameroonians, leading to successful integration. / Master of Science

No description available.

Trees in silvopastures may provide forage-livestock systems with multiple goods and services, including shade, shelter, and browse. Reports of forage and animal productivity from these systems indicate that, in some cases, animal gains are similar or better despite lower forage yield. The relationship between grazing system, body temperature, grazing behavior, and animal performance was explored in this study. Black walnut and honeylocust-based silvopasture systems were compared with open pastures in a randomized complete block design (r = 3) over three summers. Pastures were rotationally stocked with 5-7 lambs depending on forage availability. Lambs were weighed every four weeks. Behavior measures were recorded within a replicate within a week, and these measures were taken sequentially within three experimental periods. Ewe lambs (n = 3) were equipped with a vaginal temperature sensor (3 days) and an audio recording device (1 day) to detect prehension events. Cameras documented lamb behavior every 60 seconds. Forage measurements taken with a rising plate meter indicated greater productivity in the honeylocust silvopasture (5020 ± 30 kg · ha⁻¹ ) compared to the open pasture (4930 ± 30 kg · ha⁻¹ ; P = 0.0281), though forage availability in the black walnut silvopastures (3560 ± 30 kg · ha⁻¹ ) was lower than within the other treatments (P < 0.0001). There was no difference in animal gains between systems (P ≥ 0.4813), though gains were highest in the honeylocust silvopastures (25.6 ± 3.4 kg · period⁻¹ ), followed by the gains of the black walnut silvopastures (22.3 ± 3.4 kg · period⁻¹ ), and the gains of the open pastures (22.2 ± 3.4 kg · period- 1 ). Lambs in silvopastures spent more time lying down than animals in the open pastures (P ≤ 0.01), while lambs in the open spent more than two hours longer each day standing (P < 0.0001). During the hottest part of the day, ewes in the open pasture were 0.4 °C hotter than ewes in the black walnut silvopastures (P ≤ 0.0202). Lambs in the black walnut silvopastures grazed more (488 ± 14 minutes · day⁻¹ ) than lambs in the honeylocust silvopastures (438 ± 15 minutes · day⁻¹ ; P = 0.0192) and the open pastures (417 ± 14 minutes · day⁻¹ ; P = 0.0009), with no difference between the latter two systems (P = 0.3073). There was no difference in daily bites taken (P ≥ 0.7222), though lambs in the silvopastures grazed more frequently than lambs in the open pastures. In one six week winter grazing study, animal performance in the honeylocust silvopastures was compared with the productivity of lambs grazing the open pastures and the black walnut silvopastures. The objective of this study was to determine the effect of these pods on lamb growth when animals grazed stockpiled tall fescue (Schedonorus arundinaceus). Preand post-graze forage mass was estimated with a double sampling technique using a rising plate meter. Treatment pastures were rotationally stocked with three (walnut) or six lambs per experimental unit depending on forage availability. Fescue grab samples were collected every other rotation. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and total digestible nutrients (TDN) were estimated with a robust equation using NIR spectroscopy. Pre- and post-graze pod mass per hectare was estimated using randomly placed quadrats. Lambs were naïve to pods and did not readily consume the fodder until four weeks into the trial, and the methods for estimating pod intake were not sufficient to detect pod differences in pre- and post-graze pod mass. Forage availability in the honeylocust silvopastures (5130 ± 90 kg · ha⁻¹ ) and open pastures (5050 ± 90 kg · ha⁻¹ ; P=0.7580) was greater (P < 0.0001) than forage availability in the black walnut silvopastures (3790 ± 90 kg · ha⁻¹ ). Treatment had no effect (P = 0.3763) on average daily gains across the six weeks of the study. However, lambs within the honeylocust silvopastures had greater (P = 0.0251) average daily gains in the final period (0.12 ± 0.02 kg · day⁻¹ ) than lambs within the open pastures (0 ± 0.02 kg · day⁻¹ ), and lambs were observed consuming the pods. These data suggest that honeylocust pods may support greater gains of lambs, but that previous exposure and longer study periods in pasture settings may be necessary to see their nutritional benefit when grazing high quality forages. / Ph. D.

Silvopastoral management has potential to diversify and increase the output from livestock production systems. Silvopasture production offers solutions to many management issues associated with grazing systems in the Appalachian region. Several tree species have been proposed for silvopastures in humid temperate regions, but little data comparing animal performance from systems with different deciduous tree species are available. Forage and animal performance was compared from open systems (i.e., no trees) with that from silvopastures containing 13-yr-old honeylocust (Gleditsia triacanthos) or black walnut (Juglans nigra) trees. Cool-season grass-legume pastures were rotationally stocked with hair sheep crosses from mid-June through September. The objective of this project was to determine carcass characteristics and meat quality of hair sheep crosses grazing honey locust or black walnut silvopastures in comparison with traditional pasture systems. Forage production varied by year with black walnut having lower production, especially in the 2009 season with black walnut producing less forage compared to open pastures and honeylocust silvopastures (P=0.0008). Only small differences in forage nutritive value were observed. Total gains and average daily gains (ADG) did not differ by treatment in 2008, but during the 2009 season black walnut silvopastures produced half the total gains (P=0.0427) and ADG (P=0.0513) of open pastures and honeylocust silvopastures. Carcass characteristics evaluated did not vary among treatments except hot carcass weight with black walnut having lower weights (P=.0045). Meat quality characteristics did not vary among treatments (P>0.1). Shear force and fat content showed great differences and varied by year (P<0.05). Overall, carcass and meat quality was similar for all treatments showing great promise for silvopastures. / Master of Science

Incorporating high-sugar varieties of honeylocust (Gleditsia triacanthos L.) or black walnut trees (Jugulans nigra L.) into pasture systems may improve soil and water quality, increase biodiversity, and diversify farm incomes. Studies of productivity and management are needed to understand the trees' potential. Research was conducted in the agroforestry demonstration plots at Virginia Tech's Kentland Farms to 1) estimate both the variability of seedpod yield and nutritive value from juvenile Millwood honeylocust trees, 2) measure changes in nutritive value and digestibility over-winter in Millwood and wild-type honeylocust seedpods, and 3) estimate black walnut biomass productivity, timber quality, nut production, and kernel quality in response to tree density and topography within an emulated silvopasture. Ground Millwood seedpods were comparable to whole-ear dent corn in terms of nutritive value. Both ground pods and seeds were highly digestible (78.7 and 96.3%, respectively) and low in fiber and lignin. Seeds, with over 20% crude protein (CP), have potential as a CP supplement. Millwood trees displayed alternate bearing patterns with 3-yr average yields of approximately 12 kg tree-1. Total aboveground biomass for black walnut trees planted on toe-slopes (109.0 kg) was 72% greater than at back slopes (63.2 kg) and nearly 3-fold more than at shoulder-slopes (37.6 kg). Nut yields ranged from 0 to 7.9 kg of dried, hulled nuts tree-1 year-1. All walnut trees displayed alternate nut bearing patterns and nut production was marked by high variability. / Master of Science

The contribution of rubber to national economic and social development is important for Indonesia. However, smallholding rubber, the dominant rubber producer, has low productivity. Various new technology programmes have been introduced by the Indonesian government with other agencies to increase the productivity of existing traditional rubber and incomes among smallholder rubber farmers in Indonesia. However, the adoption of new technology was low and the reasons for these were still unclear. This study explores how smallholder farmers in Indonesia adopt new technology. Rubber Agroforestry System (RAS) introduced mainly by International Centre for Research in Agroforestry (ICRAF) in Jambi and West Kalimantan provinces in Indonesia is used as a case study. A combination of Ethnographic Decision Tree Modeling (EDTM) proposed by Gladwin (1989a) and a logistic regression model were used as the main methodologies to determine the decision criteria of rubber farmers regarding adoption of clonal rubber. The EDTM as qualitative method helped to identify the main reasons, motivations and constraints that influenced a farmer’s decision to adopt or not adopt the new technology and also present details about the process of the farmers’ decision making. Meanwhile, logit as the quantitative method was useful to identify the significant variables involved in the decision making process. The results of this study show that the decision making process for adoption of clonal rubber is complex and influenced by various factors. The decision tree models for Jambi and West Kalimantan differed showing the importance of social context and infrastructure. The main reasons for a farmer’s decisions to adopt clonal rubber is the expectation that clonal rubber is better in growth and yield and it will increase production per ha and income. The decision to adopt is supported by evidence from demonstration plots, trust in the technology deliverers and availability of incentives. The main constraint in adoption for both areas was limitation of capital as the clonal rubber required more capital to establish. The other constraints are risk and uncertainties including pest and disease problems, the shortage of labour, lack of technical knowledge, lack of access to clonal seedlings, and observation of clonal rubber that has been of low quality or managed inadequately. The decision tree models have been tested and the results show that the models were able to predict the farmers’ decision making with good accuracy of 82% and 83%. In addition, the quantitative model shows the significant factors that determine adoption of clonal rubber in Jambi and West Kalimantan are land, incentives and income factors. The qualitative and quantitative methods contributed to increased robustness of data and give different kinds of valuable data and information to stakeholders and policy makers in Indonesia. In order to encourage rubber farmers in Jambi and West Kalimantan to adopt clonal rubber, this study suggests improving policies to ensure they are aligned with needs of the rubber farmers, improving farmers’ access to capital sources such as credit with simpler mechanisms, increasing the number and skills of extension workers, encouraging farmer to farmer learning, empowering farmers and leadership, improving infrastructure including better access to clonal seedlings and improving partnership with NGOs.

Thesis (M.A.). / Written for the Dept. of Geography. Title from title page of PDF (viewed 2008/08/04). Includes bibliographical references.