Land Use and Production 1955-1979. 1980

Community statistics of vegetable products include data relating, on the one hand, to land use, and on the other hand to production, cultivated areas and yields of different products or groups of products, including fodder products, vegetables and fruits.

Alternatives workbook for the south slope development concept plan : Denali National Park and Preserve, Alaska.

Mode of access: Internet.

Improved slope adjustment functions for soil erosion prediction

Numerous studies in the last 60 years have investigated the relationship between land slope and soil erosion rates. However, relatively few of these have investigated slope gradient responses: ( a) for steep slopes, (b) for specific erosion processes, and ( c) as a function of soil properties. Simulated rainfall was applied in the laboratory on 16 soils and 16 overburdens at 100 mm/h to 3 replicates of unconsolidated flume plots 3 m long by 0.8 m wide and 0.15 m deep at slopes of 20, 5, 10, 15, and 30% slope in that order. Sediment delivery at each slope was measured to determine the relationship between slope steepness and erosion rate. Data from this study were evaluated alongside data and existing slope adjustment functions from more than 55 other studies from the literature. Data and the literature strongly support a logistic slope adjustment function of the form S = A + B/[1 + exp (C - D sin theta)] where S is the slope adjustment factor and A, B, C, and D are coefficients that depend on the dominant detachment and transport processes. Average coefficient values when interill-only processes are active are A - 1.50, B 6.51, C 0.94, and D 5.30 (r(2) = 0.99). When rill erosion is also potentially active, the average slope response is greater and coefficient values are A - 1.12, B 16.05, C 2.61, and D 8.32 (r(2) = 0.93). The interill-only function predicts increases in sediment delivery rates from 5 to 30% slope that are approximately double the predictions based on existing published interill functions. The rill + interill function is similar to a previously reported value. The above relationships represent a mean slope response for all soils, yet the response of individual soils varied substantially from a 2.5-fold to a 50-fold increase over the range of slopes studied. The magnitude of the slope response was found to be inversely related ( log - log linear) to the dispersed silt and clay content of the soil, and 3 slope adjustment equations are proposed that provide a better estimate of slope response when this soil property is known. Evaluation of the slope adjustment equations proposed in this paper using independent datasets showed that the new equations can improve soil erosion predictions.

Are US coral reefs on the slippery slope to slime?

Conservation of U.S. coral reefs has been sidetracked by the partial implementation of management plans without clearly achievable goals. Historical ecology reveals global patterns of coral reef degradation that provide a framework for reversing reef decline with ecologically meaningful metrics for success. The authors of this Policy Forum urge action now to address multiple threats simultaneously, because the harmful effects of stressors like overfishing, pollution, poor land-use practices, and global warming are interdependent. Prompt implementation of proven, practical solutions would lead to both short- and long-term benefits, including the return of keystone species and the economic benefits they entail.

Management of a previously eroded tropical Alfisol with herbaceous legumes: Soil loss and physical properties under mound tillage

A study was carried out on a previously eroded Oxic Paleustalf in Ibadan, southwestern Nigeria to determine the extent of soil degradation under mound tillage with some herbaceous legumes and residue management methods. A series of factorial experiments was carried out on 12 existing runoff plots. The study commenced in 1996 after a 5-year natural fallow. Mound tillage was introduced in 1997 till 1999. The legumes - Vigna unguiculata (cowpea), Mucuna pruriens and Pueraria phaseoloides - were intercropped with maize in 1996 and 1998 while yam was planted alone in 1997 and 1999. This paper covers 1997-1999. At the end of each year, residues were either burned or mulched on respective plots. Soil loss, runoff, variations in mound height, bulk density, soil water retention and sorptivity were measured. Cumulative runoff was similar among interactions of legume and residue management in 1997 (57-151 mm) and 1999 (206-397 mm). However, in 1998, cumulative runoff of 95 mm observed for Mucuna-burned residue was significantly greater than the 46 mm observed for cowpea-burned residue and the 39-51 mm observed for mulched residues of cowpea, Mucuna and Pueraria. Cumulative soil loss of 7.6 Mg ha(-1) observed for Mucuna-burned residue in 1997 was significantly greater than those for Pueraria-mulched (0.9 Mg ha(-1)) and Mucuna-mulched (1.4 Mg ha(-1)) residues whereas in 1999 it was similar to soil loss from cowpea treatments and Pueraria-burned residue (2.3-5.3 Mg ha(-1)). There were no significant differences in soil loss in 1998 (1-3.2 Mg ha(-1)) whereas Mucuna-burned residue had a greater soil loss (28.6 Mg ha(-1)) than mulched cowpea (6.9 Mg ha(-1)) and Pueraria (5.4 Ms ha(-1)). Mound heights (23 cm average) decreased non-linearly with cumulative rainfall. A cumulative rainfall of 500 mm removed 0.3-2.3 cm of soil from mounds in 1997, 3.5-6.9 cm in 1998 and 2.3-4.6 cm in 1999, indicating that (detached but less transported) soil from mounds was far higher than observed soil loss in each year. Soil water retention was improved at potentials ranging from -1 to -1500 kPa by Mucuna-mulched residue compared to the various burned-residue treatments. Also, mound sorptivity at -1 cm water head (14.3 cm h(-1/2)) was higher than furrow sorptivity (8.5 cm h(-1/2)), indicating differences in hydraulic characteristics between mound and furrow. Pueraria-mulched residues for mounds had the highest sorptivity of 17.24 cm h(-1/2), whereas the least value of 6.96 cm h(-1/2) was observed in furrow of Mucuna-burned residue. Pueraria phas eoloides was considered the best option for soil conservation on the previously eroded soil, cultivated with mound tillage. (c) 2005 Elsevier B.V. All rights reserved.

The Application of Geographic Information Systems to climate change & land evaluation : a study of the effects of climate change upon crop productivity in a sub-tropical environment

This research investigates the contribution that Geographic Information Systems (GIS) can make to the land suitability process used to determine the effects of a climate change scenario. The research is intended to redress the severe under representation of Developing countries within the literature examining the impacts of climatic change upon crop productivity. The methodology adopts some of the Intergovernmental Panel on Climate Change (IPCC) estimates for regional climate variations, based upon General Circulation Model predictions (GCMs) and applies them to a baseline climate for Bangladesh. Utilising the United Nations Food & Agricultural Organisation's Agro-ecological Zones land suitability methodology and crop yield model, the effects of the scenario upon agricultural productivity on 14 crops are determined. A Geographic Information System (IDRISI) is adopted in order to facilitate the methodology, in conjunction with a specially designed spreadsheet, used to determine the yield and suitability rating for each crop. A simple optimisation routine using the GIS is incorporated to provide an indication of the 'maximum theoretical' yield available to the country, should the most calorifically significant crops be cultivated on each land unit both before and after the climate change scenario. This routine will provide an estimate of the theoretical population supporting capacity of the country, both now and in the future, to assist with planning strategies and research. The research evaluates the utility of this alternative GIS based methodology for the land evaluation process and determines the relative changes in crop yields that may result from changes in temperature, photosynthesis and flooding hazard frequency. In summary, the combination of a GIS and a spreadsheet was successful, the yield prediction model indicates that the application of the climate change scenario will have a deleterious effect upon the yields of the study crops. Any yield reductions will have severe implications for agricultural practices. The optimisation routine suggests that the 'theoretical maximum' population supporting capacity is well in excess of current and future population figures. If this agricultural potential could be realised however, it may provide some amelioration from the effects of climate change.

Mount Carmel in the Commune: Promoting the Holy Land in Central Italy in the 13th and 14th Centuries

The Carmelite friars were the last of the major mendicant orders to be established in Italy. Originally an eremitical order, they arrived from the Holy Land in the 1240s, decades after other mendicant orders, such as the Franciscans and Dominicans, had constructed churches and cultivated patrons in the burgeoning urban centers of central Italy. In a religious market already saturated with friars, the Carmelites distinguished themselves by promoting their Holy Land provenance, eremitical values, and by developing an institutional history claiming to be descendants of the Old Testament prophet Elijah. By the end of the 13th century the order had constructed thriving churches and convents and leveraged itself into a prominent position in the religious community. My dissertation analyzes these early Carmelite churches and convents, as well as the friars’ interactions with patrons, civic governments, and the urban space they occupied. Through three primary case studies – the churches and convents of Pisa, Siena and Florence – I examine the Carmelites’ approach to art, architecture, and urban space as the order transformed its mission from one of solitary prayer to one of active ministry.

My central questions are these: To what degree did the Carmelites’ Holy Land provenance inform the art and architecture they created for their central Italian churches? And to what degree was their visual culture instead a reflection of the mendicant norms of the time?

I have sought to analyze the Carmelites at the institutional level, to determine how the order viewed itself and how it wanted its legacy to develop. I then seek to determine how and if the institutional model was utilized in the artistic and architectural production of the individual convents. The understanding of Carmelite art as a promotional tool for the identity of the order is not a new one, however my work is the first to consider deeply the order’s architectural aspirations. I also consider the order’s relationships with its de facto founding saint, the prophet Elijah, and its patron, the Virgin Mary, in a more comprehensive manner that situates the resultant visual culture into the contemporary theological and historical contexts.

Baseline characteristics of climate, permafrost, and land cover from Samoylov Island, Lena River Delta, Siberia

Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation and snow cover), soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.3 to 1.3 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years.

Major ion chemistry and selected snow accumulation rates of snow cores along two transects in central Dronning Maud Land and Princess Elizabeth Land

This dataset includes basic information (location and depth) and major ion chemistry (Sodium, Chloride, Calcium, Nitrate) of snow cores from East Antarctic ice sheet. The snow cores were collected from two different regions - central Dronning Maud Land (cDML) and Princess Elizabeth Land (PEL) during the austral summer of 2008-09.

Sediment Budget for Cane Land on the Lower Herbert River Floodplain, North Queensland, Australia

Land use in the river catchments of tropical North Queensland appears to have increased the export of sediment and nutrients to the coast. Although evidence of harmful effect of sediment on coastal and riverine ecosystems is limited, there is a growing concern about its possible negative impacts. Sugarcane cultivation on the floodplains of the tropical North Queensland river catchments is thought to be an important source of excess sediment in the river drainage systems. Minimum-tillage, trash blanket harvesting has been shown to reduce erosion from sloping sugarcane fields, but in the strongly modified floodplain landscape other elements (e.g. drains, water furrows and headlands) could still be important sediment sources. The main objectives of this thesis are to quantify the amount of sediment coming from low-lying cane land and identify the important sediment sources in the landscape. The results of this thesis enable sugarcane farmers to take targeted measures for further reduction of the export of sediment and nutrients. Sediment budgets provide a useful approach to identify and quantify potential sediment sources. For this study a sediment budget is calculated for a part of the Ripple Creek catchment, which is a sub-catchment of the Lower Herbert River. The input of sediment from all potential sources in cane land and the storage of sediment within the catchment have been quantified and compared with the output of sediment from the catchment. Input from, and storage on headlands, main drains, minor drains and water furrows, was estimated from erosion pin and surface profile measurements. Input from forested upland, input from fields and the output at the outlet of the catchment was estimated with discharge data from gauged streams and flumes. Data for the sediment budget were collected during two ‘wet’-seasons: 1999-2000 and 2000-2001. The results of the sediment budget indicate that this tropical floodplain area is a net source of sediment. Plant cane fields, which do not have a protective trash cover, were the largest net source of sediment during the 1999-2000 season. Sediment input from water furrows was higher, but there was also considerable storage of sediment in this landscape element. Headlands tend to act as sinks. The source or sink function of drains is less clear, but seems to depend on their shape and vegetation cover. An important problem in this study is the high uncertainty in the estimates of the sediment budget components and is, for example, likely to be the cause of the imbalance in the sediment budget. High uncertainties have particularly affected the results from the 20002001 season. The main source of uncertainty is spatial variation in the erosion and deposition processes. Uncertainty has to be taken into consideration when interpreting the budget results. The observation of a floodplain as sediment source contradicts the general understanding that floodplains are areas of sediment storage within river catchments. A second objective of this thesis was therefore to provide an answer to the question: how can floodplains in the tropical North Queensland catchments can be a source of sediment? In geomorphic literature various factors have been pointed out, that could control floodplain erosion processes. However, their importance is not 'uniquely identified'. Among the most apparent factors are the stream power of the floodwater and the resistance of the floodplain surface both through its sedimentary composition and the vegetation cover. If the cultivated floodplains of the North Queensland catchments are considered in the light of these factors, there is a justified reason to expect them to be a sediment source. Cultivation has lowered the resistance of their surface; increased drainage has increased the drainage velocity and flood control structures have altered flooding patterns. For the Ripple Creek floodplain four qualitative scenarios have been developed that describe erosion and deposition under different flow conditions. Two of these scenarios were experienced during the budget study, involving runoff from local hillslopes and heavy rainfall, which caused floodplain erosion. In the longer term larger flood events, involving floodwater from the Herbert River, may lead to different erosion and deposition processes. The present study has shown that the tropical floodplain of the Herbert River catchment can be a source of sediment under particular flow conditions. It has also shown which elements in the sugarcane landscape are the most important sediment sources under these conditions. This understanding will enable sugarcane farmers to further reduce sediment export from cane land and prevent the negative impact this may have on the North Queensland coastal ecosystems.

Chemical changes and heavy metal partitioning in an oxisol cultivated with maize (Zea mays, L.) after 5 years disposal of a domestic and an industrial sewage sludge.

The need for solutions to minimize the negative environmental impacts of anthropogenic activities Fhas increased. Sewage sludge is composed of predominantly organic matter and can be used to improve soil characteristics, such as fertility. Therefore, its application in agriculture is an adequate alternative for its final disposal. However, there is a lack of information on its long-term effects on soil changes in tropical areas. Thus, the objectives of this study were to determine (i) the effect of sewage sludge application on heavy metal build-up in soil and maize grains and leaves, and (ii) the effects of soil amendment with sewage sludge on the chemical properties of a Brazilian oxisol. Besides the increasing levels of Zn, Cu, Ni, and Cr, amending soil with sewage sludge also alters the distribution of these metals by increasing the mobile Phases, which correlated significantly with the increase in metal extraction with two single extractants, Mehlich 1 and DTPA (Diethylene triamine pentaacetic acid). The levels of Fe, Mn, Zn, and Cu in maize grains and leaves increased with the type and rate of sewage sludge application. Nevertheless, metal build-up in soil and plants was within the allowed limits. Significant differences were also found in soil characteristics like humic fractionation with the applied sewage doses. The data obtained does not indicate any expressive drawbacks in the use of sewage sludge as a soil amendment, as the heavy metal concentrations observed are unlikely to cause any environmental or health problems, even overestimated loadings, and are in accordance with the Brazilian regulations on farming land biosolid disposal.

Relações entre o relevo e a organização espacial do uso e cobertura do solo no sudoeste do estado de Goiás

Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Pós-Graduação em Geologia, 2016.

Contrasting Effects Of Land Use Intensity And Exotic Host Plants On The Specialization Of Interactions In Plant-herbivore Networks.

Human land use tends to decrease the diversity of native plant species and facilitate the invasion and establishment of exotic ones. Such changes in land use and plant community composition usually have negative impacts on the assemblages of native herbivorous insects. Highly specialized herbivores are expected to be especially sensitive to land use intensification and the presence of exotic plant species because they are neither capable of consuming alternative plant species of the native flora nor exotic plant species. Therefore, higher levels of land use intensity might reduce the proportion of highly specialized herbivores, which ultimately would lead to changes in the specialization of interactions in plant-herbivore networks. This study investigates the community-wide effects of land use intensity on the degree of specialization of 72 plant-herbivore networks, including effects mediated by the increase in the proportion of exotic plant species. Contrary to our expectation, the net effect of land use intensity on network specialization was positive. However, this positive effect of land use intensity was partially canceled by an opposite effect of the proportion of exotic plant species on network specialization. When we analyzed networks composed exclusively of endophagous herbivores separately from those composed exclusively of exophagous herbivores, we found that only endophages showed a consistent change in network specialization at higher land use levels. Altogether, these results indicate that land use intensity is an important ecological driver of network specialization, by way of reducing the local host range of herbivore guilds with highly specialized feeding habits. However, because the effect of land use intensity is offset by an opposite effect owing to the proportion of exotic host species, the net effect of land use in a given herbivore assemblage will likely depend on the extent of the replacement of native host species with exotic ones.

Colheita de cana-de-açúcar com auxílio mecânico

Civil society and sugarcane farmer demands indicate that harvesting technology has enough limitations to jeopardize production in large sugar cane producing areas. This work analyses the current mechanical harvesting compared to a semi-mechanical harvesting proposal, on the bases of eleven characteristics considered determinant for a quick spreading of green cane harvesting on hilly areas, with lower impact on agricultural labor and farmers investment capacity.

Uma teoria termodinâmica para brisas: teste utilizando simulações numéricas

O objetivo deste trabalho foi testar uma teoria termodinâmica em brisas marítimas-terrestres acopladas com brisas de vale-montanha através de simulações numéricas tridimensionais em uma região da costa leste do Nordeste Brasileiro, considerando a presença e a ausência da topografia. Embora o contraste de temperatura entre as superfícies seja importante na formação da brisa, a eficiência termodinâmica é fundamental na determinação da sua intensidade. Tem-se que a inclinação faz com que a diferença de pressão entre dois pontos fique maior durante o dia e menor durante a noite contribuindo para a formação de brisas marítimas mais intensas e de brisas terrestres menos intensas, respectivamente. A máxima queda de pressão ocorre por volta de três horas antes da máxima intensidade da brisa. Isso porque grande parte da energia disponibilizada para as circulações é gasta para vencer dissipação, principalmente, no período diurno, quando esses processos são realmente efetivos. Do ponto de vista puramente termodinâmico a inclinação da montanha atua para intensificar a brisa durante o dia e para enfraquecê-la durante a noite.