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1

Hydraulic redistribution study in two native tree species of agroforestry parklands of West African dry savanna  

NASA Astrophysics Data System (ADS)

Hydraulic redistribution (HR) in karité ( Vitellaria paradoxa) and néré ( Parkia biglobosa) tree species was studied by monitoring the soil water potential ( ?s) using thermocouple psychrometers at four compass directions, various distances from trees and at different soil depths (max depth 80 cm) during the dry seasons of 2004 and 2005. A modified WaNuLCAS model was then used to infer the amount of water redistribued based on ?s values. Tree transpiration rate was also estimated from sap velocity using thermal dissipative probes (TDP) and sapwood area, and the contribution of hydraulically redistributed water in tree transpiration was determined. The results revealed on average that 46% of the psychrometer readings under karité and 33% under néré showed the occurrence of HR for the two years. Soil under néré displayed significantly lower fluctuations of ?s (0.16 MPa) compared to soil under karité (0.21 MPa). The results of this study indicated that the existence of HR leads to a higher ?s in the plant rhizosphere and hence is important for soil water dynamics and plant nutrition by making more accessible the soluble elements. The simulation showed that the amount of water redistributed would be approximately 73.0 L and 247.1 L per tree per day in 2005 for karité and néré, and would represent respectively 60% and 53% of the amount transpired a day. Even though the model has certainly overestimated the volume of water hydraulically redistributed by the two species, this water may play a key role in maintaining fine root viability and ensuring the well adaptation of these species to the dry areas. Therefore, knowledge of the extent of such transfers and of the seasonal patterns is required and is of paramount importance in parkland systems both for trees and associated crops.

Bayala, Jules; Heng, Lee Kheng; van Noordwijk, Meine; Ouedraogo, Sibiri Jean

2008-11-01

2

Classification of agroforestry systems  

Microsoft Academic Search

Classification of agroforestry (AF) systems is necessary in order to provide a framework for evaluating systems and developing action plans for their improvement. The AF Systems Inventory (AFSI) being undertaken by ICRAF provides the background information for an approach to classification.

P. K. R. Nair

1985-01-01

3

The effect of trees on preferential flow and soil infiltrability in an agroforestry parkland in semiarid Burkina Faso  

NASA Astrophysics Data System (ADS)

scarcity constrains the livelihoods of millions of people in tropical drylands. Tree planting in these environments is generally discouraged due to the large water consumption by trees, but this view may neglect their potential positive impacts on water availability. The effect of trees on soil hydraulic properties linked to groundwater recharge is poorly understood. In this study, we performed 18 rainfall simulations and tracer experiments in an agroforestry parkland in Burkina Faso to investigate the effect of trees and associated termite mounds on soil infiltrability and preferential flow. The sampling points were distributed in transects each consisting of three positions: (i) under a single tree, (ii) in the middle of an open area, and (iii) under a tree associated with a termite mound. The degree of preferential flow was quantified through parameters based on the dye infiltration patterns, which were analyzed using image analysis of photographs. Our results show that the degree of preferential flow was highest under trees associated with termite mounds, intermediate under single trees, and minimal in the open areas. Tree density also had an influence on the degree of preferential flow, with small open areas having more preferential flow than large ones. Soil infiltrability was higher under single trees than in the open areas or under trees associated with a termite mound. The findings from this study demonstrate that trees have a positive impact on soil hydraulic properties influencing groundwater recharge, and thus such effects must be considered when evaluating the impact of trees on water resources in drylands.

Bargués Tobella, A.; Reese, H.; Almaw, A.; Bayala, J.; Malmer, A.; Laudon, H.; Ilstedt, U.

2014-04-01

4

Agroforestry systems for the temperate zone  

Microsoft Academic Search

Historical development of a permanent agriculture system based on the use of agroforestry in the temperate zone is traced. In general, reasons for a renewed interest in agroforestry include the end of cheap, subsidized fossil fuels; increased concern about soil erosion and marginal land use; an international awakening as to the dangers of indiscriminate use of pesticides, herbicides and other

Michael A. Gold; James W. Hanover

1987-01-01

5

Birds as predators in tropical agroforestry systems.  

PubMed

Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems provide a good starting point for understanding when and where we can expect predation by birds to be important. We analyze data from bird exclosure studies in forests and agroforestry systems to ask whether birds consistently reduce their arthropod prey base and whether bird predation differs between forests and agroforestry systems. Further, we focus on agroforestry systems to ask whether the magnitude of bird predation (1) differs between canopy trees and understory plants, (2) differs when migratory birds are present or absent, and (3) correlates with bird abundance and diversity. We found that, across all studies, birds reduce all arthropods, herbivores, carnivores, and plant damage. We observed no difference in the magnitude of bird effects between agroforestry systems and forests despite simplified habitat structure and plant diversity in agroforests. Within agroforestry systems, bird reduction of arthropods was greater in the canopy than the crop layer. Top-down effects of bird predation were especially strong during censuses when migratory birds were present in agroforestry systems. Importantly, the diversity of the predator assemblage correlated with the magnitude of predator effects; where the diversity of birds, especially migratory birds, was greater, birds reduced arthropod densities to a greater extent. We outline potential mechanisms for relationships between bird predator, insect prey, and habitat characteristics, and we suggest future studies using tropical agroforests as a model system to further test these areas of ecological theory. PMID:18481517

Van Bael, Sunshine A; Philpott, Stacy M; Greenberg, Russell; Bichier, Peter; Barber, Nicholas A; Mooney, Kailen A; Gruner, Daniel S

2008-04-01

6

Biophysical interactions in tropical agroforestry systems  

Microsoft Academic Search

The rate and extent to which biophysical resources are captured and utilized by the components of an agroforestry system are determined by the nature and intensity of interac- tions between the components. The net effect of these interactions is often determined by the influence of the tree component on the other component(s) and\\/or on the overall system, and is expressed

M. R. RAO; P. K. R. NAIR; C. K. ONG

1998-01-01

7

BIRDS AS PREDATORS IN TROPICAL AGROFORESTRY SYSTEMS  

Microsoft Academic Search

Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and\\/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems provide a

Sunshine A. Van Bael; Stacy M. Philpott; Russell Greenberg; Peter Bichier; Nicholas A. Barber; Kailen A. Mooney; Daniel S. Gruner

2008-01-01

8

Hill agroforestry systems in south Sikkim, India  

Microsoft Academic Search

In the Mamlay watershed of south Sikkim, India, about 80% of the population depend on land for their livelihood. The agricultural land-use activity includes agroforestry, horticulture and animal husbandry besides growing crops in irrigated or unirrigated fields. Trees are maintained in the farms mainly for fodder and rarely for fuel purposes. Cropping system is characterised by cultivation of cereals and

R. C. Sundriyal; S. C. Rai; E. Sharma; Y. K. Rai

1994-01-01

9

Smallholder Agroforestry Systems For Carbon Storage  

Microsoft Academic Search

Most smallholder agroforestry systems in Southeast Asia are tree- and species-rich systems producing non-wood and wood products\\u000a for both home use and market sale. Due to their high biomass, these systems contain large carbon (C) stocks. While the systems\\u000a of individual farmers are of limited size, on a per area basis smallholder systems accumulate significant amounts of C, equaling\\u000a the

James M. Roshetko; Rodel D. Lasco; Marian S. Delos Angeles

2007-01-01

10

Soil cover by natural trees in agroforestry systems  

NASA Astrophysics Data System (ADS)

The dehesa is common agroforestry system in the Iberian Peninsula. These open oak parklands with silvo-pastoral use cover about two million hectares. Traditionally annual pastures have been grazed by cows, sheep and also goats while acorns feed Iberian pig diet. Evergreen oak (Quercus ilex L.) has other uses as fuelwood collection and folder after tree pruning. The hypothesis of this work is that tree density and canopy depend on soil types. We using the spanish GIS called SIGPAC to download the images of dehesa in areas with different soil types. True colour images were restoring to a binary code, previously canopy colour range was selected. Soil cover by tree canopy was calculated and number of trees. Processing result was comparable to real data. With these data we have applied a dynamic simulation model Dehesa to determine evergreen oak acorn and annual pasture production. The model Dehesa is divided into five submodels: Climate, Soil, Evergreen oak, Pasture and Grazing. The first three require the inputs: (i) daily weather data (maximum and minimum temperatures, precipitation and solar radiation); (ii) the soil input parameters for three horizons (thickness, field capacity, permanent wilting point, and bulk density); and (iii) the tree characterization of the dehesa (tree density, canopy diameter and height, and diameter of the trunk). The influence of tree on pasture potential production is inversely proportional to the canopy cover. Acorn production increase with tree canopy cover until stabilizing itself, and will decrease if density becomes too high (more than 80% soil tree cover) at that point there is competition between the trees. Main driving force for dehesa productivity is soil type for pasture, and tree cover for acorn production. Highest pasture productivity was obtained on soil Dystric Planosol (Alfisol), Dystric Cambisol and Chromo-calcic-luvisol, these soils only cover 22.4% of southwest of the Iberian peninssula. Lowest productivity was obtained on Dystric Lithosol.

Diaz-Ambrona, C. G. H.; Almoguera Millán, C.; Tarquis Alfonso, A.

2009-04-01

11

Agroforestry Systems in Zimbabwe: Promoting Trees in Agriculture.  

ERIC Educational Resources Information Center

Agroforestry has been defined as a sustainable crop management system which combines the production of forest crops with field crops. In June, 1987, an agroforestry workshop took place in Nyanga, Manicaland, Zimbabwe. This document was prepared to share the information presented at this workshop with other non-government organizations around the…

Vukasin, Helen L., Ed.

12

Nitrogen dynamics in maize-based agroforestry systems as affected by landscape position in southern Malawi  

Microsoft Academic Search

In Malawi, agroforestry is very promising for N replenishment; however, there are still large variations in the performance of these agroforestry technologies on farmers’ fields. A study was conducted on-farm to determine the influence of three landscape positions on N dynamics in maize (Zea mays L.)-based agroforestry systems. The agroforestry systems were relay fallow using Sesbania sesban (L.) Merr or

Rebbie Harawa; Johannes Lehmann; Festus Akinnifesi; Erick Fernandes; George Kanyama-Phiri

2006-01-01

13

Enhanced biodiversity and pollination in UK agroforestry systems.  

PubMed

Monoculture farming systems have had serious environmental impacts such as loss of biodiversity and pollinator decline. The authors explain how temperate agroforestry systems show potential in being able to deliver multiple environmental benefits. PMID:23553354

Varah, Alexa; Jones, Hannah; Smith, Jo; Potts, Simon G

2013-07-01

14

Agroforestry systems: sources of sinks of greenhouse gases?  

Microsoft Academic Search

The prominent role of forestry and agroforestry systems in the flux and long-term storage of carbon (C) in the terrestrial biosphere has increased global interest in these land-use options to stabilize greenhouse gas (GHG) emissions. Preliminary assessments suggest that some agroforestry systems (e.g., agrosilvicultural) can be CO2 sinks and temporarily store C, while other systems (e.g., ruminant-based silvopastoral systems) are

R. K. Dixon

1995-01-01

15

Carbon storage benefits of agroforestry systems  

Microsoft Academic Search

The process of land degradation is a local phenomenon that occurs field by field. Because of the extent at which it is occurring, however, it also has a global dimension. Agroforestry represents a link between the local and global scales. From the farmer's perspective, agroforestry can be a way to increase crop yields and the diversity of products grown. An

P. Schroeder

1994-01-01

16

Amazonian agroforestry: a market-oriented system in Peru  

Microsoft Academic Search

Most reports on indigenous agroforestry systems of the Amazon region have described patterns employed by tribal groups almost exclusively for their own subsistence. This article discusses a market-oriented cyclic agroforestry system practiced by non-tribal ‘Mestizo’ farmers in Tamshiyacu, Peru. The system produces charcoal, as well as annual, semi-perennial, and perennial crops for local consumption, and for a regional market. The

C. Padoch; J. Chota Inuma; W. DE JONG; J. Unruh

1985-01-01

17

The POIS (Parkland On-Line Information System) Implementation of the IBM Health Care Support/Patient Care System  

PubMed Central

The installation of major components of a comprehensive Hospital Information System (HIS) called POIS, the Parkland On-line Information System, including identified success factors is described for the Dallas County Hospital District (DCHD) known also as the Parkland Memorial Hospital. Installation of the on-line IBM Health Care Support (HCS) Registration and Admissions Packages occurred in 1976 and implementation of the HCS Patient Care System (PCS) began in 1977 which includes on-line support of health care areas such as nursing stations and ancillary areas. The Duke Hospital Information System (DHIS) is marketed as the IBM HCS/Patient Care System (PCS). DCHD was the validation site. POIS has order entry, result reporting and work management components. While most of the patient care components are currently installed for the inpatient service, the Laboratories are being installed for the outpatient and Emergency areas as well. The Clinic Appointment System developed at the University of Michigan is also installed. The HCS family of programs use DL/1 and CICS and were installed in the OS versions, currently running under MVS on an IBM 370/168 Model 3 with 8 megabytes of main memory. ImagesFigure 1-AFigure 1-B

Mishelevich, David J.; Hudson, Betty G.; Van Slyke, Donald; Mize, Elaine I.; Robinson, Anna L.; Brieden, Helen C.; Atkinson, Jack; Robertson, James

1980-01-01

18

Tree root characteristics as criteria for species selection and systems design in agroforestry  

Microsoft Academic Search

This literature review presents information about the role of tree root systems for the functioning of agroforestry associations and rotations and attempts to identify root-related criteria for the selection of agroforestry tree species and the design of agroforestry systems. Tree roots are expected to enrich soil with organic matter, feed soil biomass, reduce nutrient leaching, recycle nutrients from the subsoil

G. Schroth

1995-01-01

19

Insect pest problems in tropical agroforestry systems: Contributory factors and strategies for management  

Microsoft Academic Search

Agroforestry trees are attacked by a wide spectrum of insects at all stages of their growth just like other annual and perennial crops. Pest management in agroforestry has not received much attention so far, but recent emphasis on producing high value tree products in agroforestry and using improved germplasm in traditional systems, and emergence of serious pest problems in some

M. R. Rao; M. P. Singh; R. Day

2000-01-01

20

Assessment of the Extent of Agroforestry Systems in Europe and Their Role Within Transhumance Systems  

Microsoft Academic Search

Agroforestry systems are unevenly distributed across Europe and are often linked to transhumance, the seasonal movement of\\u000a stock which is widely in decline. Whilst the high biodiversity associated with traditional agroforestry is widely recognised,\\u000a the ecology of modern systems is less well understood. The inherent nature of the agroforestry systems means that it is necessary\\u000a to know the characteristics of

R. G. H. Bunce; M. Pérez-Soba; M. Smith

2009-01-01

21

Soil evaporation measurements in an agroforestry system in Kenya  

Microsoft Academic Search

Evaporation from soil (Es) was studied in an agroforestry system using soil microlysimeters, where the tree and crop components were grown together, in monocultures where the two components were grown separately, and in bare soil. All measurements were carried out at an equatorial field site in Kenya. Es varied according to the different shade regimes and as a function of

N. A Jackson; J. S Wallace

1999-01-01

22

WaNuLCAS, a model of water, nutrient and light capture in agroforestry systems  

Microsoft Academic Search

Models of tree-soil-crop interactions in agroforestry should maintain a balance between dynamic processes and spatial patterns of interactions for common resources. We give an outline and discuss major assumptions underlying the WaNuLCAS model of water, nitrogen and light interactions in agroforestry systems. The model was developed to deal with a wide range of agroforestry systems: hedgerow intercropping on flat or

M. VAN NOORDWIJK; B. LUSIANA

1999-01-01

23

AGROFORESTRY SYSTEMS: INTEGRATED LAND USE TO STORE AND CONSERVE CARBON  

EPA Science Inventory

Agroforestry is a promising land use practice to maintain or increase agricultural productivity while preserving or improving fertility. n extensive literature survey was conducted to evaluate the carbon dynamics of agroforestry practices and to assess their potential to store ca...

24

Carbon sequestration in tropical agroforestry systems  

Microsoft Academic Search

Removing atmospheric carbon (C) and storing it in the terrestrial biosphere is one of the options, which have been proposed to compensate greenhouse gas (GHG) emissions. Agricultural lands are believed to be a major potential sink and could absorb large quantities of C if trees are reintroduced to these systems and judiciously managed together with crops and\\/or animals. Thus, the

Alain Albrecht; Serigne T Kandji

2003-01-01

25

Agroforestry systems and soil surface management of a tropical alfisol: I: Soil moisture and crop yields  

Microsoft Academic Search

Field experiments were conducted on a tropical Alfisol at Ibadan, Nigeria, to evaluate the effects on soil moisture and crop yields of three agroforestry systems. Effects of agroforestry treatments involving two perennial shrubs (Leucaena leucocephala and Gliricidia sepium), each at 2-m and 4-m row spacings, were compared with no-till and plow-till systems of seedbed preparation. Measurements were made for soil

R. Lal

1989-01-01

26

The Bioeconomic Potential for Agroforestry in Australia’s Northern Grazing Systems  

Microsoft Academic Search

Although agriculture generates 16% of Australia’s greenhouse gas emissions, it also has the potential to sequester large quantities\\u000a of emissions through land use management options such as agroforestry. Whilst there is an extensive amount of agroforestry\\u000a literature, little has been written on the economic consequences of adopting silvopastoral systems in northern Australia.\\u000a This paper reports the financial viability of adopting

Peter Donaghy; Steven Bray; Rebecca Gowen; John Rolfe; Michael Stephens; Madonna Hoffmann; Anne Stunzer

2010-01-01

27

Carbon sequestration: An underexploited environmental benefit of agroforestry systems  

Microsoft Academic Search

Agroforestry has importance as a carbon sequestration strategy because of carbon storage potential in its multiple plant species\\u000a and soil as well as its applicability in agricultural lands and in reforestation. The potential seems to be substantial; but\\u000a it has not been even adequately recognized, let alone exploited. Proper design and management of agroforestry practices can\\u000a make them effective carbon

F. Montagnini; P. K. R. Nair

2004-01-01

28

The tree\\/crop interface — or simplifying the biological\\/environmental study of mixed cropping agroforestry systems  

Microsoft Academic Search

A key to understanding the biological potentials and restraints of agroforestry systems, and the environmental responses of plant components within them, is the ‘tree\\/crop’ interface. All agroforestry systems can be studied by separating the growth and yield characteristics of the three basic sets of variables (a) the sole agricultural crop (b) the effects of the tree\\/crop interface on the crop

Peter A. Huxley

1985-01-01

29

Homestead agroforestry in Bangladesh  

Microsoft Academic Search

The Homestead agroforestry system is very important in the economy of Bangladesh. The many woody species grown in the homesteads are a significant source of fuelwood; they also provide fodder, building materials and other forms of wood. In the context of the prevailing shortage of fuelwood and excessive deforestation in Bangladesh, this homestead agroforestry system needs to be strengthened.

William A. Leuschner; Kibriaul Khaleque

1987-01-01

30

Modelling soil evaporation in an agroforestry system in Kenya  

Microsoft Academic Search

Soil evaporation measurements from bare soil and shaded soil under an agroforestry tree canopy were used to construct a model to predict soil evaporation with and without tree shade. It was found that a simple daily time step model based on the Ritchie (1972)approach was unable to predict daily soil evaporation accurately, but was capable of providing good estimates of

J. S Wallace; N. A Jackson; C. K Ong

1999-01-01

31

Parklands Partnership: Education through Reforestation.  

ERIC Educational Resources Information Center

Describes New York City's Parklands Partnership Program, in which elementary and secondary students visit natural woodlands areas in their neighborhood, learn about forest ecology, and engage in restoration and reforestation activities that foster a connection between themselves and their local environment. (SV)

Scalia, Josephine A.

1992-01-01

32

Village Agroforestry Systems and Tree-Use Practices: A Case Study in Sri Lanka.  

National Technical Information Service (NTIS)

Village agroforestry systems in Sri Lanka have evolved through farmers' efforts to meet their survival needs. The paper examines farmers' land-use systems and their perceptions of the role of trees in the villages of Bambarabedda and Madugalla in central ...

A. Wickramasinghe

1992-01-01

33

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)  

Microsoft Academic Search

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields),

Shahabuddin; Christian H. Schulze; Teja Tscharntke

2005-01-01

34

Prevalence of antibody to Trypanosoma cruzi in Hispanic-surnamed patients seen at Parkland Health & Hospital System, Dallas, Texas  

PubMed Central

Background Chagas disease constitutes an important public health threat in terms of morbidity and mortality in the areas in the United States where immigrant populations from Latin America are conspicuous. We conducted a survey to assess the prevalence of anti-T. cruzi antibody in Hispanic-surnamed patients seen at Parkland Memorial Hospital in Dallas, Texas. Findings Five hundred serum specimens from Hispanic-surnamed patients were tested by a preliminary ELISA method. On a subset of 50 sera confirmatory testing was also performed using an alternative ELISA, indirect immunofluorescence, and TESA immunoblot. For 274 of 500 Hispanic-surnamed patients, we were able to ascertain immigration status upon medical chart review. Of the 274 sera analyzed, one sample tested as positive for anti-T. cruzi antibody by the preliminary ELISA, and by the three confirmatory methods. Conclusions The goal of this study is to increase the awareness of T. cruzi infection and Chagas disease in areas where the Latin American immigrant communities are growing. Our study highlights the importance of testing for Chagas disease in the populations most at risk, and the need for current data on the actual seroprevalence in areas where such immigrant populations are conspicuous. Larger-scale epidemiologic surveys on Chagas disease in the immigrant communities from Latin America are warranted.

2011-01-01

35

Arbuscular mycorrhizal fungal diversity in neem-based agroforestry systems in Rajasthan  

Microsoft Academic Search

A field study of traditional agroforestry systems in six districts of the arid and semiarid zones of Rajasthan was undertaken where annual rainfall varied from 140 to 1000mm and soil types ranged from coarse fine sand in Jaisalmer to clay loams in Kota. The field investigation showed that Glomus, Gigaspora and Sclerocystis were the genera of arbuscular mycorrhizal fungi present

Manish Pande; J. C Tarafdar

2004-01-01

36

Financial returns, stability and risk of cacao-plantain-timber agroforestry systems in Central America  

Microsoft Academic Search

Diversification of agroecosystems has long been recognized as a sound strategy to cope with price and crop yield variability, thus increasing farm income stability and lowering financial risk. In this study, the financial returns, stability and risk of six cacao (Theobroma cacao L.) – laurel (Cordia alliodora (R&P) Oken) – plantain (Musa AAB) agroforestry systems, and the corresponding monocultures, were

O. A. Ramírez; E. Somarriba; T. Ludewigs; P. Ferreira

2001-01-01

37

SOIL CARBON AND NUTRIENT CONTENTS UNDER CACAO AGROFORESTRY SYSTEMS IN BAHIA, BRAZIL  

Microsoft Academic Search

In Brazil, cacao ( Theobroma cacao ) agroforestry systems (AFS) are established mostly in highly weathered soils with acidic pH and low fertility. The high amount of plant litter that is deposited (estimated to be ca 10 Mg ha-1 yr- 1) is believed to have an important role in maintaining nutrient cycling and microbial activity to support sustainable cacao production

Antonio Carlos Gama; Emanuela F. Gama; Rodrigues Rodrigues; Ramachandran Ramachandran; Nair Nair; V. C. Baligar Baligar; Regina Regina; Machado Machado; Norte Fluminense; Brazil Brazil

38

Nutritional Limitations in Multi-Strata Agroforestry System with Native Amazonian Plants  

Microsoft Academic Search

Multi-strata agroforestry system is mentioned as the most promising option for the sustainable agricultural in infertile upland soils of Central Amazonian. However, studies showed that the sustainability of this land use does not exist. The aim of this work was to evaluate the soil fertility and nutritional state of native Amazon plant species cultivated in a Xanthic Ferralsol (dystrophic Yellow

A. Moreira; N. K. Fageria

2012-01-01

39

Temporal changes in soil carbon and nitrogen in west African multistrata agroforestry systems: a chronosequence of pools and fluxes  

Microsoft Academic Search

The conversion of forests to agroecosystems or agroforests comes with many changes in biological and chemical processes. Agroforestry,\\u000a a tree based agroecosystem, has shown promise with respect to enhanced system nutrient accumulation after land conversion\\u000a as compared to sole cropping systems. Previous research on tropical agroforestry systems has revealed increases in soil organic\\u000a matter and total organic nitrogen in the

M. E. Isaac; A. M. Gordon; N. Thevathasan; S. K. Oppong; J. Quashie-Sam

2005-01-01

40

A strategy for tree-perennial crop productivity: nursery phase nutrient additions in cocoa-shade agroforestry systems  

Microsoft Academic Search

Shade tolerant species response to nutrient additions and light regulation by canopy trees in perennial agroforestry systems\\u000a has been well documented. However, accelerated early growth, particularly in cocoa-shade systems, may be offset by competition\\u000a for limited resources on nutrient poor sites. To date, few agroforestry management strategies focus on nutrient manipulation\\u000a of the shade tree component or strategies for precision

Marney E. IsaacEric; Eric O. Adjei; Roland N. Issaka; Vic R. Timmer

2011-01-01

41

Economics of agroforestry  

Microsoft Academic Search

Although from the start ICRAF recognized the importance of the socio-economic dimensions of agroforestry land-use systems, it was only five years after its official commencement that an economist was added to the staff.

Dirk A. Hoekstra

1987-01-01

42

Agroforestry systems for soil and water conservation and sustainable production from foothill areas of north India  

Microsoft Academic Search

Some conservation based agroforestry systems (AFS) were developed for possible adoption in place of high risk rainfed farming on land capability classes Ito IV of a typical topo-sequence of foothill north India. The agri-silvi-horticulture system integrating leucaena, lemon, papaya and turmeric on class I irrigated land provided sustainable mean net returns of Rs. 17066 against Rs. 7852 ha.–1 yr.–1 from

S. S. Grewal; S. P. Mittal; Surjit Dyal; Y. Agnihotri

1992-01-01

43

Using 3D architectural models to assess light availability and root bulkiness in coconut agroforestry systems  

Microsoft Academic Search

Using 3D architectural models to assess light availability and root bulkiness in agroforestry systems. In many parts of the humid tropics, coconut trees are frequently intercropped with food crops, or tree crops such as cocoa.\\u000a The performance of such systems depends on planting patterns, but also on growing conditions for crops below the coconut canopy\\u000a throughout the development of the

Nathalie Lamanda; Jean Dauzat; Christophe Jourdan; Philippe Martin; Eric Malézieux

2008-01-01

44

Valuing Soil Conservation Benefits of Agroforestry Practices.  

National Technical Information Service (NTIS)

Although advocates of agroforestry have promoted soil conservation as one of its primary benefits, empirical estimates of these benefits have been lacking due to temporal and spatial complexity of agroforestry systems and soil resource dynamics. This stud...

S. Pattanayak D. E. Mercer

1996-01-01

45

Cover crops alter phosphorus soil fractions and organic matter accumulation in a Peruvian cacao agroforestry system  

Microsoft Academic Search

In many tropical soils, excessive weathering of primary minerals confounded by intense agricultural production has resulted\\u000a in the depletion of organic matter and plant available forms of phosphorus (P). Long-term growth of cover crops in tropical\\u000a agroforestry systems have been shown to influence nutrient cycling, and soil organic matter pools. The objective of this experiment\\u000a was to assess the affect

Hollie Hall; Yuncong Li; Nicholas Comerford; Enrique Arévalo Gardini; Luis Zuniga Cernades; Virupax Baligar; Hugh Popenoe

2010-01-01

46

Changes in labile soil organic matter fractions following land use change from monocropping to poplar-based agroforestry systems in a semiarid region of Northeast China.  

PubMed

Labile fractions of soil organic matter (SOM) respond rapidly to land management practices and can be used as a sensitive indicator of changes in SOM. However, there is little information about the effect of agroforestry practices on labile SOM fractions in semiarid regions of China. In order to test the effects of land use change from monocropping to agroforestry systems on labile SOM fractions, we investigated soil microbial biomass C (MBC) and N, particulate organic matter C (POMC) and N (POMN), as well as total organic C (TOC) and total N (TN) in the 0- to 15-cm and the 15- to 30-cm layers in 4-year-old poplar-based agroforestry systems and adjoining monocropping systems with two different soil textures (sandy loam and sandy clay loam) in a semiarid region of Northeast China. Our results showed that poplar-based agroforestry practices affected soil MBC, POMC, and POMN, albeit there was no significant difference in TOC and TN. Agroforestry practices increased MBC, POMC, and POMN in sandy clay loam soils. However, in sandy loam soils, agroforestry practices only increased MBC and even decreased POMC and POMN at the 0- to 15-cm layer. Our results suggest that labile SOM fractions respond sensitively to poplar-based agroforestry practices and can provide early information about the changes in SOM in semiarid regions of Northeast China and highlight that the effects of agroforestry practices on labile SOM fractions vary with soil texture. PMID:22124586

Mao, Rong; Zeng, De-Hui; Li, Lu-Jun; Hu, Ya-Lin

2012-11-01

47

Carbon Storage in Soil Size Fractions Under Two Cacao Agroforestry Systems in Bahia, Brazil  

NASA Astrophysics Data System (ADS)

Shaded perennial agroforestry systems contain relatively high quantities of soil carbon (C) resulting from continuous deposition of plant residues; however, the extent to which the C is sequestered in soil will depend on the extent of physical protection of soil organic C (SOC). The main objective of this study was to characterize SOC storage in relation to soil fraction-size classes in cacao ( Theobroma cacao L.) agroforestry systems (AFSs). Two shaded cacao systems and an adjacent natural forest in reddish-yellow Oxisols in Bahia, Brazil were selected. Soil samples were collected from four depth classes to 1 m depth and separated by wet-sieving into three fraction-size classes (>250 ?m, 250-53 ?m, and <53 ?m)—corresponding to macroaggregate, microaggregate, and silt-and-clay size fractions—and analyzed for C content. The total SOC stock did not vary among systems (mean: 302 Mg/ha). On average, 72% of SOC was in macroaggregate-size, 20% in microaggregate-size, and 8% in silt-and-clay size fractions in soil. Sonication of aggregates showed that occlusion of C in soil aggregates could be a major mechanism of C protection in these soils. Considering the low level of soil disturbances in cacao AFSs, the C contained in the macroaggregate fraction might become stabilized in the soil. The study shows the role of cacao AFSs in mitigating greenhouse gas (GHG) emission through accumulation and retention of high amounts of organic C in the soils and suggests the potential benefit of this environmental service to the nearly 6 million cacao farmers worldwide.

Gama-Rodrigues, Emanuela F.; Ramachandran Nair, P. K.; Nair, Vimala D.; Gama-Rodrigues, Antonio C.; Baligar, Virupax C.; Machado, Regina C. R.

2010-02-01

48

Parkland College LRC/Library Adequacy.  

ERIC Educational Resources Information Center

In Spring 1991, the LRC (Learning Resources Center)/library at Parkland College (PC) was quantitatively assessed in terms of staff size, collection size, budget allocation, circulation, and space allocation. Adequacy indicators from fiscal year (FY) 1991 and FY90 were compared to those from FY88. In addition, PC's LRC/library was compared to…

Hecht, Alfred

49

Student Ethnic Diversity at Parkland College.  

ERIC Educational Resources Information Center

To assist Illinois' Parkland College (PC) in its efforts to provide equal educational opportunities to minority group students, a study was conducted examining enrollment rates for minority group students from 1986-1990 as compared to the United States census district population and to statewide two-year college enrollments. In addition, the study…

Hecht, Alfred

50

Insect diversity responses to forest conversion and agroforestry management  

Microsoft Academic Search

Summary The ongoing loss of pristine tropical rainforests increases the potential im- portance of agroforestry systems for the conservation of tropical arthropod diversity. Shaded agroforestry systems can still support high levels of biodiver- sity, even resembling those supported by undisturbed forests, but intensively managed open agroforestry systems may cause severe losses in insect diver- sity. In this study we evaluate

Merijn M. Bos; Patrick Hohn; Shahabuddin Saleh; Boris Buche; Damayanti Buchori; Ingolf Stean-Dewenter

2007-01-01

51

Distribution of arbuscular mycorrhizal fungi spores in soils of smallholder agroforestry and monocultural coffee systems in southwestern Ethiopia  

Microsoft Academic Search

Arbuscular mycorrhizal fungi (AMF) are associated with the root system of coffee (Coffea arabica L.) plants, but their distribution in smallholder agroforestry and monocultural coffee systems is not well known. This study\\u000a investigates the spatial distribution of AMF spores in a field study in southwestern Ethiopia. Soil samples from different\\u000a depths (0–50 cm) were collected under the tree canopies of Acacia

Diriba Muleta; Fassil Assefa; Sileshi Nemomissa; Ulf Granhall

2008-01-01

52

The state of the art of agroforestry diagnosis and design  

Microsoft Academic Search

Seven years ago the International Council for Research in Agroforestry set out to develop a methodology for the diagnosis of land management problems and design of agroforestry systems. Since then over 60 documents (articles, conference papers and manuals) relating to the D & D methodology have been published by ICRAF and the methodology has been used to develop agroforestry plans

John B. Raintree

1987-01-01

53

Does parkland influence walking? The relationship between area of parkland and walking trips in Melbourne, Australia  

PubMed Central

Background Using two different measures of park area, at three buffer distances, we sought to investigate the ways in which park area and proximity to parks, are related to the frequency of walking (for all purposes) in Australian adults. Little previous research has been conducted in this area, and results of existing research have been mixed. Methods Residents of 50 urban areas in metropolitan Melbourne, Australia completed a physical activity survey (n = 2305). Respondents reported how often they walked for ?10 minutes in the previous month. Walking frequency was dichotomised to ‘less than weekly’ (less than 1/week) and ‘at least weekly’ (1/week or more). Using Geographic Information Systems, Euclidean buffers were created around each respondent’s home at three distances: 400metres (m), 800 m and 1200 m. Total area of parkland in each person’s buffer was calculated for the three buffers. Additionally, total area of ‘larger parks’, (park space???park with Australian Rules Football oval (17,862 m2)), was calculated for each set of buffers. Area of park was categorised into tertiles for area of all parks, and area of larger parks (the lowest tertile was used as the reference category). Multilevel logistic regression, with individuals nested within areas, was used to estimate the effect of area of parkland on walking frequency. Results No statistically significant associations were found between walking frequency and park area (total and large parks) within 400 m of respondent’s homes. For total park area within 800 m, the odds of walking at least weekly were lower for those in the mid (OR 0.65, 95% CI 0.46-0.91) and highest (OR 0.65, 95% CI 0.44-0.95) tertile of park area compared to those living in areas with the least amount of park area. Similar results were observed for total park area in the 1200 m buffers. When only larger parks were investigated, again more frequent walking was less likely when respondents had access to a greater amount of park area. Conclusions In this study we found that more park area in residential environments reduced the odds of walking more frequently. Other area characteristics such as street connectivity and destinations may underlie these associations by negatively correlating with park area.

2012-01-01

54

The role of habitat patches on mammalian diversity in cork oak agroforestry systems  

NASA Astrophysics Data System (ADS)

Habitat patches, depending on the degree of differentiation from the matrix, can add few or many elements to the species pool of a particular landscape. Their importance to biodiversity is particularly relevant in areas with complex landscapes, where natural, naturalized, or managed habitats are interspersed by small patches of habitat types with very different biophysical characteristics; e.g., fruit orchards and riparian areas. This is the case of the montado landscape, a cork oak agroforestry system that largely covers south-western Portugal. We evaluated whether the high mammalian biodiversity found in this system is, in part, the cumulative result of the species found in the non-matrix habitats. Our results indicate that in areas where there are inclusions of orchards/olive yards and riparian vegetation in the cork oak woodland, a significantly higher number of mammalian species are present. We further detected a positive effect of low human disturbance on mammal diversity. Ultimately, our results can be used by managers to augment their management options, since we show that the inclusion and maintenance of non-matrix habitat patches in cork oak agro-silvo-forestry systems can help to maximize mammal biodiversity without compromising services associated with agriculture and forestry.

Rosalino, Luis M.; Rosário, João do; Santos-Reis, Margarida

2009-07-01

55

[Light competition and productivity of agroforestry system in loess area of Weibei in Shaanxi].  

PubMed

Agroforestry is the most effective way for the restoration of disturbed land on Loess Plateau and the development of poorly local economy. Taking the tree-based intercropping systems of walnut or plum with soybean or pepper in the loess area of Weibei as test objects, the photosynthesis, growth, and yield of soybean (Qindou 8) and pepper (Shanjiao 981) in the systems were studied. The results showed that the photosynthetic active radiation (PAR), net photosynthetic rate (Pn), growth, and yield of individual soybean or pepper plants were significantly decreased, with the effects increased with decreasing distance from tree rows. Leaf water potential was not significantly or poorly correlated with the Pn, growth, and yield of the two crops. However, there were significant positive correlations between the soil moisture content in 10-20 cm layer and the biomass and yield of soybean, and the above-ground biomass of pepper. PAR was highly correlated with the yield of both crops, which indicated that light competition was one of the key factors leading to the decrease of crop yield. PMID:19238840

Peng, Xiao-bang; Cai, Jing; Jiang, Zai-min; Zhang, Yuan-ying; Zhang, Shuo-xin

2008-11-01

56

Comparative study on growth performance of two shade trees in tea agroforestry system.  

PubMed

An attempt was made to study the stem growth of two native dominant shade tree species in terms of annual girth increment in three dominant girth size categories for two years in tea agroforestry system of Barak Valley, Assam. Fifty two sampling plots of 0.1 ha size were established and all trees exceeding 10 cm girth over bark at breast height (1.37 m) were uniquely identified, tagged, and annually measured for girth increment, using metal tape during December 2010-12. Albizia lebbeck and A. odoratissima were dominant shade tree species registering 82% of appearance of the individuals studied. The girth class was categorized into six different categories where 30-50 cm, 50-70 cm and 70-90 cm were dominating girth classes and selected for increment study. Mean annual girth increment ranged from 1.41 cm in Albizia odoratissima (50-70 cm girth class) to 2.97 cm in Albizia lebbeck (70-90 cm girth class) for the first year and 1.70 cm in Albizia odoratissima (50-70 cm girth class) to 3.09 cm in Albizia lebbeck (70-90 cm girth class) for the second year. Albizia lebbeck exhibited better growth in all prominent girth classes as compared to Albizia odoratissima during the observation period. The two shade tree species showed similar trend of growth in both the years of observation and significant difference in girth increment. PMID:25004755

Kalita, Rinku Moni; Das, Ashesh Kumar; Nath, Arun Jyoti

2014-07-01

57

[Canopy conductance characteristics of poplar in agroforestry system in west Liaoning Province of Northeast China].  

PubMed

By using Granier' s thermal dissipation probe, the sap flow of poplar in a poplar-maize agroforestry system in west Liaoning was continuously measured, and as well, the environmental factors such as air temperature, air humidity, net radiation, wind speed, soil temperature, and soil moisture content were synchronically measured. Based on the sap flow data, the canopy conductance of poplar was calculated with simplified Penman-Monteith equation. In the study area, the diurnal variation of poplar' s canopy conductance showed a "single peak" curve, whereas the seasonal variation showed a decreasing trend. There was a negative logarithm relationship between the canopy conductance and vapor pressure deficit, with the sensitivity of canopy conductance to vapor pressure deficit change decreased gradually from May to September. The canopy conductance had a positive relationship with solar radiation. In different months, the correlation degree of canopy conductance with environmental factors differed. The vapor pressure deficit in the whole growth period of poplar was the most significant environmental factor correlated with the canopy conductance. PMID:23431778

Li, Zheng; Niu, Li-Hua; Yuan, Feng-Hui; Guan, De-Xin; Wang, An-Zhi; Jin, Chang-Jie; Wu, Jia-Bing

2012-11-01

58

Transpiration rates and canopy conductance of Pinus radiata growing with different pasture understories in agroforestry systems.  

PubMed

We measured tree transpiration and canopy conductance in Pinus radiata D. Don at two low rainfall sites of differing soil fertility in Canterbury, New Zealand. At the more fertile Lincoln site, we also assessed the effects of two common pasture grasses on tree transpiration and canopy conductance. At the less fertile Eyrewell Forest site, the effect of no understory, and the effects of irrigation in combination with mixtures of grass or legume species were determined. Tree xylem sap flux (F(d)') was measured by the heat pulse method. Total canopy conductance to diffusion of water vapor (G(t)) was calculated by inverting a simplified Penman-Monteith model. The different treatment effects were modeled by the simple decaying exponential relationship G(t) = G(tmax)e((-bD)), where D = air saturation deficit. At the Lincoln site, trees with an understory of cocksfoot had lower F(d)' and G(tmax) than trees with an understory of ryegrass, although the sensitivity of G(t) to increasing D (i.e., the value of b) did not differ between treatments. At the Eyrewell site, irrigation only increased F(d)' in the absence of an understory, whereas the presence of understory vegetation, or lack of irrigation, or both, significantly reduced G(tmax) and increased b. We conclude that the selection of understory species is critical in designing successful agroforestry systems for low rainfall areas. PMID:12651344

Miller, Blair J.; Clinton, Peter W.; Buchan, Graeme D.; Robson, A. Bruce

1998-01-01

59

Spatial genetic structuring of baobab (Adansonia digitata, Malvaceae) in the traditional agroforestry systems of West Africa.  

PubMed

This study evaluates the spatial genetic structure of baobab (Adansonia digitata) populations from West African agroforestry systems at different geographical scales using AFLP fingerprints. Eleven populations from four countries (Benin, Ghana, Burkina Faso, and Senegal) had comparable levels of genetic diversity, although the two populations in the extreme west (Senegal) had less diversity. Pairwise F(ST) ranged from 0.02 to 0.28 and increased with geographic distance, even at a regional scale. Gene pools detected by Bayesian clustering seem to be a byproduct of the isolation-by-distance pattern rather than representing actual discrete entities. The organization of genetic diversity appears to result essentially from spatially restricted gene flow, with some influences of human seed exchange. Despite the potential for relatively long-distance pollen and seed dispersal by bats within populations, statistically significant spatial genetic structuring within populations (SGS) was detected and gave a mean indirect estimate of neighborhood size of ca. 45. This study demonstrated that relatively high levels of genetic structuring are present in baobab at both large and within-population level, which was unexpected in regard to its dispersal by bats and the influence of human exchange of seeds. Implications of these results for the conservation of baobab populations are discussed. PMID:21628247

Kyndt, Tina; Assogbadjo, Achille E; Hardy, Olivier J; Glele Kakaï, Romain; Sinsin, Brice; Van Damme, Patrick; Gheysen, Godelieve

2009-05-01

60

Science in agroforestry  

Microsoft Academic Search

Agroforestry research is being transformed from a collection of largely descriptive studies into more scientific approaches, based on process-oriented research. The development of agroforestry as a science should be based on four key features:competition, complexity, profitability and sustainability. Managing thecompetition between trees and crops for light, water and nutrients to the farmers' benefit is the biophysical determinant of successful agroforestry

P. A. Sanchez

1995-01-01

61

Biomass production in agroforestry and forestry systems on salt-affected soils in South Asia: exploration of the GHG balance and economic performance of three case studies.  

PubMed

This study explores the greenhouse gas balance and the economic performance (i.e. net present value (NPV) and production costs) of agroforestry and forestry systems on salt-affected soils (biosaline (agro)forestry) based on three case studies in South Asia. The economic impact of trading carbon credits generated by biosaline (agro)forestry is also assessed as a potential additional source of income. The greenhouse gas balance shows carbon sequestration over the plantation lifetime of 24 Mg CO2-eq. ha(-1) in a rice-Eucalyptus camaldulensis agroforestry system on moderately saline soils in coastal Bangladesh (case study 1), 6 Mg CO2-eq. ha(-1) in the rice-wheat- Eucalyptus tereticornis agroforestry system on sodic/saline-sodic soils in Haryana state, India (case study 2), and 96 Mg CO2-eq. ha(-1) in the compact tree (Acacia nilotica) plantation on saline-sodic soils in Punjab province of Pakistan. The NPV at a discount rate of 10% is 1.1 k€ ha(-1) for case study 1, 4.8 k€ ha(-1) for case study 2, and 2.8 k€ ha(-1) for case study 3. Carbon sequestration translates into economic values that increase the NPV by 1-12% in case study 1, 0.1-1% in case study 2, and 2-24% in case study 3 depending on the carbon credit price (1-15 € Mg(-1) CO2-eq.). The analysis of the three cases indicates that the economic performance strongly depends on the type and severity of salt-affectedness (which affect the type and setup of the agroforestry system, the tree species and the biomass yield), markets for wood products, possibility of trading carbon credits, and discount rate. PMID:23810966

Wicke, Birka; Smeets, Edward M W; Akanda, Razzaque; Stille, Leon; Singh, Ranjay K; Awan, Abdul Rasul; Mahmood, Khalid; Faaij, Andre P C

2013-09-30

62

Improved fodder tree management in the agroforestry systems of central and western Nepal  

SciTech Connect

Ten, three year old, fodder tree species were evaluated at four on-station and three on-farm sites in Nepal. Ficus semicordata (Buchattam. ex Sm.) growth was found to be significantly higher than the rest in diameter and dry foliage weight values. Species were significantly different in height, diameter, and foliage and wood growth. Sites were significantly different in total height growth only. On-farm species evaluation indicated that A. lakoocha and F. semicordata had significantly higher growth. Allometric regression equations were developed to predict foliage, total wood, and total biomass yield of F. semicordata, and B. variegata. Individual-tree models were developed. For B. variegata, diameter at 50 cm. and for F. semicordata, crown diameter and height gave the best fitted equations. Regression equations for three sites did not differ significantly. Therefore, data were pooled and a common model was estimated for each species. In on-farm regression models, height and crown diameter were the best predictors for F. semicordata and dbh gave the best fit for B. variegata. The models for the two species were used to construct regional fodder and fuelwood biomass tables. An improved crop-livestock-fodder agroforestry system was designed for a village in Nepal. Linear programming was used to demonstrate the use of a tool to optimize land allocation maximizing net returns while satisfying the supply of minimum needs of food, fodder, and fuelwood. The optimal solution indicated that, by improving the returns to labor and by applying more compost, the village should be able to increase the annual net farm returns from NRs. 2.94 million to NRs. 3.85 million. The food, fodder and fuelwood production levels were shown to increase by 17%, 130%, and 537% respectively. The labor and compost requirements were up by 138% and 59% respectively, over the five year period. The soil loss through run-off was estimated to decrease by about 15% over the same period.

Karki, M.B.

1992-01-01

63

Effect of selective logging on genetic diversity and gene flow in Cariniana legalis sampled from a cacao agroforestry system.  

PubMed

The fragments of the Atlantic Forest of southern Bahia have a long history of intense logging and selective cutting. Some tree species, such as jequitibá rosa (Cariniana legalis), have experienced a reduction in their populations with respect to both area and density. To evaluate the possible effects of selective logging on genetic diversity, gene flow, and spatial genetic structure, 51 C. legalis individuals were sampled, representing the total remaining population from the cacao agroforestry system. A total of 120 alleles were observed from the 11 microsatellite loci analyzed. The average observed heterozygosity (0.486) was less than the expected heterozygosity (0.721), indicating a loss of genetic diversity in this population. A high fixation index (FIS = 0.325) was found, which is possibly due to a reduction in population size, resulting in increased mating among relatives. The maximum (1055 m) and minimum (0.095 m) distances traveled by pollen or seeds were inferred based on paternity tests. We found 36.84% of unique parents among all sampled seedlings. The progenitors of the remaining seedlings (63.16%) were most likely out of the sampled area. Positive and significant spatial genetic structure was identified in this population among classes 10 to 30 m away with an average coancestry coefficient between pairs of individuals of 0.12. These results suggest that the agroforestry system of cacao cultivation is contributing to maintaining levels of diversity and gene flow in the studied population, thus minimizing the effects of selective logging. PMID:24615028

Leal, J B; Santos, R P; Gaiotto, F A

2014-01-01

64

Root system characteristics with agroforestry relevance of nine leguminous tree species and a spontaneous fallow in a semi-deciduous rainforest area of West Africa  

Microsoft Academic Search

The use of tree root characteristics as criteria in the selection of agroforestry tree species is hampered both by uncertainties in the definition of an ideal tree root system and by the scarcity of information which relates tree root properties to the effects of the trees on the soil and associated plant species. In the present study, carbon and nitrogen

Götz Schroth; Dorothee Kolbe; Balle Pity; Wolfgang Zech

1996-01-01

65

Effects of Land-Use Intensity in Tropical Agroforestry Systems on Coffee Flower-Visiting and Trap-Nesting Bees and Wasps  

Microsoft Academic Search

Tropical landscapes are dominated by agroecosystems, and most species that survive in forest rem- nants interact with these agroecosystems. The potential value of agroecosystems for aiding species survival is often ignored. Essential ecosystem services may suffer when functional groups such as pollinators and preda- tors are affected by land use. We used agroforestry systems differing in land-use intensity to examine

Alexandra-Maria Klein; Ingolf Steffan-Dewenter; Damayanti Buchori; Teja Tscharntke

2002-01-01

66

Tree gardening and taungya on Java: examples of agroforestry techniques in the humid tropics  

Microsoft Academic Search

Agroforestry is a general concept for a land management system combining trees and agricultural crops. For application, various specific techniques can be chosen. Each of these techniques is adjusted to a specific set of environmental as well as socio-economic factors. Agroforestry cultivators or managers belonging to varying social strata and institutional groupings may practice different forms of agroforestry, even within

K. F. Weersum

1982-01-01

67

Modelling agroforestry systems of cacao ( Theobroma cacao ) with laurel ( Cordia alliodora ) and poro ( Erythrina poeppigiana ) in Costa Rica III. Cycles of organic matter and nutrients  

Microsoft Academic Search

Models for cycles for organic matter and nutrients element (N, P, K, Ca and Mg) are presented for the agroforestry systems\\u000a of cacao (Theobroma cacao) withCordia alliodora orErythrina poeppigiana in Turrialba, Costa Rica.\\u000a \\u000a For the models, system reserves (soil, humus, vegetation divided into leaves, branches, stems, fine roots, fruits) and transference\\u000a between compartments (production and decomposition of litter residues) inputs

H. W. Fassbender; L. Alpízar; J. Heuveldop; H. Fölster; G. Enríquez

1988-01-01

68

Interspecific interactions in temperate agroforestry  

Microsoft Academic Search

The ecological principles that define the competitive and complementary interactions among trees, crops, and fauna in agroforestry\\u000a systems have received considerable research attention during the recent past. These principles have not yet, however, been\\u000a adequately integrated and synthesized into an operational approach. This paper reviews the ecological and ecophysiological\\u000a bases for interspecific interactions based on data from site-specific research and

S. Jose; A. R. Gillespie; S. G. Pallardy

2004-01-01

69

Strategies for enhancing the adoptability of agroforestry innovations  

Microsoft Academic Search

Agroforestry has been given a broad and hopeful mandate to assist in devising productive and sustainable systems of land management to meet the demographic and ecological challenges of mankind's somewhat uncertain future. As a new and explicity interdisciplinary field of applied scientific research and technological synthesis, agroforestry is in a unique position to benefit from recent advances in our understanding

J. B. Raintree

1983-01-01

70

Agroforestry: Tenure and Incentives.  

National Technical Information Service (NTIS)

The effect of tree and land tenure on farmers' incentives to plant trees is examined, and lessons for agroforestry project planning are drawn. The validity of the generally accepted security of tenure model, which assumes that without land tenure security...

J. W. Bruce L. Fortmann

1989-01-01

71

Analysis of soil water dynamics in an agroforestry system based on detailed soil water records from time-domain reflectometry  

NASA Astrophysics Data System (ADS)

Time domain reflectometry [TDR] was used to investigate the spatial and temporal variation in surface soil water dynamics under a number of types of vegetation, including both trees and crops grown in isolation, and grown together as an agroforestry system. The installation and operation of this technique are presented, and discussed in terms of its suitability to monitor rapid fluctuations in soil-water content in a spatially heterogeneous system such as that described in this experiment. The relatively small sampling volume of each of the TDR waveguides permitted discrete measurements to be made of soil water content (?v). In the tree-only and tree+crop treatments, this revealed considerable variation in ?v resulting from spatial redistribution of rainfall under the tree canopies, with a significant input to soil close to the base of the trees being made by stemflow, i.e. water intercepted by the tree canopy and channelled down the stem. Over the experimental period (one rainy season) the TDR data suggested that net recharge to the soil profile in the sole crop system was 53 mm, almost 75% more than occurred in either of the two treatments containing trees, reflecting greater rainfall interception by the tree canopies.

Jackson, N. A.; Wallace, J. C.

72

[Temporal and spatial distribution of ants in a light gradient, in a coffee agroforestry system, Turrialba, Costa Rica].  

PubMed

Shade trees are frequently present in coffee (Coffea arabica L.) agroforestry systems of Mesoamerica. These systems can harbor a rich entomofauna, including ants, which could be predators of key pests in these systems. However, the role of shade on the distribution and abundance of these ants is unknown, yet such knowledge could suggest guidelines for manipulating certain environmental conditions of their habitat, thereby achieving their conservation and increase. Therefore, we studied the effect of shade on the spatial and temporal distribution of three ant species (Solenopsis geminata, Pheidole radoszkowskii and Crematogaster curvispinosa) that may prey on the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae), and the mahogany shootborer, Hypsipyla grandella (Lepidoptera: Pyralidae). To do this, abundance was evaluated across a sun-shade gradient in a coffee plantation with four alternate plots (from pure sun to total shade) in Turrialba, Costa Rica. In the community that was studied 28 species of ants were collected, of which S. geminata was the dominant species (79% of the total individuals), followed by P. radoszkowskii (16 %). S. geminata and C. curvispinosa preferred sunny areas, while P. radoszkowskii showed no defined preference. Likewise, with respect to location, S. geminata predominated in the soil, while P. radoszkowskii and C. curvispinosa predominated in coffee bushes. PMID:19086397

Varón, Edgar H; Hanson, Paul; Longino, John T; Borbón, Olger; Carballo, Manuel; Hilje, Luko

2007-01-01

73

Nutrient cycling and Above- and Below-ground Interactions in a Runoff Agroforestry System Applied with Composted Tree Trimmings  

NASA Astrophysics Data System (ADS)

The primary production in arid zones is limited due to shortage of water and nutrients. Conveying flood water and storing it in plots surrounded by embankments allows their cropping. The efficient exploitation of the stored water can be achieved through an agroforestry system, in which two crops are grown simultaneously: annual crops with a shallow root system and trees with a deeper root system. We posit that the long-term productivity of this system can be maintained by intercropping symbiotic N fixing shrubs with annual crops, and applying the pruned and composted shrub leaves to the soil, thus ensuring an adequate nitrogen level (a limiting factor in drylands) in the soil. To test our hypothesis we carried a two year trial in which fast-growing acacia (A. saligna) trees were the woody component and maize (Zea mays L.) the intercrop. Ten treatments were applied over two maize growth seasons to examine the below- and above-ground effects of tree pruning, compost application and interactions. The addition of compost in the first growth season led to an increase of the soil organic matter reservoir, which was the main N source for the maize during the following growth season. In the second growth season the maize yield was significantly higher in the plots to which compost was applied. Pruning the tree's canopies changed the trees spatial and temporal root development, allowing the annual crop to develop between the trees. The roots of pruned trees intercropped with maize penetrated deeper in the soil. The intercropping of maize within pruned trees and implementing compost resulted in a higher water use efficiency of the water stored in the soil when compared to the not composted and monoculture treatments. The results presented suggest that the approach used in this study can be the basis for achieving sustainable agricultural production under arid conditions.

Ilani, Talli; Ephrath, Jhonathan; Silberbush, Moshe; Berliner, Pedro

2014-05-01

74

Prospects for Agroforestry in the Tropics.  

National Technical Information Service (NTIS)

Agroforestry has come of age remarkably during the past 10 to 15 years. However, the lack of a synthesized 'package' of technical and socio-economic information on agroforestry is a serious drawback in channeling development assistance to agroforestry pro...

P. K. R. Nair

1990-01-01

75

The farming system and traditional agroforestry systems in the Maya community of San Jose, Belize  

Microsoft Academic Search

Shifting slash-and-burn agriculture is likely one of the main causes of forest degra- dation in southern Belize. Although many development projects have attempted to reduce the impacts of agriculture on the tropical rainforest, the situation is still a cause for concern. A study of the farming system of the San Jose Maya community was therefore carried out to examine agricultural

V. LEVASSEUR; A. OLIVIER

2000-01-01

76

Fuelwood, agro-forestry, and natural resource management: the development significance of land tenure and other resource management/utilization systems  

SciTech Connect

Using a systems approach and focusing on the social context, the study examines natural resource management in relation to fuelwood production and agroforestry. An initial section describing the use and interlinkage of the concepts of ecozone and ecosystem is followed by a discussion of problem ecozones, human use of ecozones, agricultural ecosystems, resource competition, uses of trees and forest products, and tree planting. Rural resource management strategies at the household, community, local, and state levels are discussed in the context of political economy, land tenure and rights, tenancy and sharecropping, group or public landholding, and acquisition and transfer of land.

Brokensha, D.; Castro, A.P.; Kundu, M.; Hewlett, B.

1984-04-01

77

Synergy of agroforestry and bottomland hardwood afforestation  

USGS Publications Warehouse

Afforestation of bottomland hardwood forests has historically emphasized planting heavy-seeded tree species such as oak (Quercus spp.) and pecan (Caryaillinoensis) with little or no silvicultural management during stand development. Slow growth of these tree species, herbivory, competing vegetation, and limited seed dispersal, often result in restored sites that are slow to develop vertical vegetation structure and have limited tree diversity. Where soils and hydrology permit, agroforestry can provide transitional management that mitigates these historical limitations on converting cropland to forests. Planting short-rotation woody crops and intercropping using wide alleyways are two agroforestry practices that are well suited for transitional management. Weed control associated with agroforestry systems benefits planted trees by reducing competition. The resultant decrease in herbaceous cover suppresses small mammal populations and associated herbivory of trees and seeds. As a result, rapid vertical growth is possible that can 'train' under-planted, slower-growing, species and provide favorable environmental conditions for naturally invading trees. Finally, annual cropping of alleyways or rotational pulpwood harvest of woody crops provides income more rapidly than reliance on future revenue from traditional silviculture. Because of increased forest diversity, enhanced growth and development, and improved economic returns, we believe that using agroforestry as a transitional management strategy during afforestation provides greater benefits to landowners and to the environment than does traditional bottomland hardwood afforestation.

Twedt, D.J.; Portwood, J.

2003-01-01

78

Assessing agroforestry adoption potential utilising market segmentation: A case study in Pennsylvania  

Microsoft Academic Search

In the United States, agroforestry adoption has lagged behind progress in agroforestry systems research. This study sought\\u000a to facilitate the communication of landowner land management objectives, values, knowledge and perceptions of the barriers\\u000a and benefits to agroforestry through applied social marketing research methods and market segmentation analysis. A mail survey\\u000a instrument was sent to 250 members of the Pennsylvania Association

Nicole A. Strong; Michael G. Jacobson

2005-01-01

79

Investigation on effect of Populus alba stands distance on density of pests and their natural enemies population under poplar/alfalfa agroforestry system.  

PubMed

This study was carried out in order to distinguish the effect of agroforestry system (combination of agriculture and forestry) on pests and natural enemy's population in poplar research station. Wood is one of the first substances that naturally was used for a long period of time. Forage is an important production of natural resources too. Some factors such as proper lands deficit, lack of economy, pest and disease attacks and faced production of these materials with serious challenges. Agroforestry is a method for decrease of the mentioned problems. The stands of poplar had have planted by complete randomized design with 4 treatments (stand distance) of poplar/alfalfa include 3x4, 3x6.7, 3x8, 3x10 m and 2 control treatments, alfalfa and poplar. The results showed that Chaitophorus populeti had the highest density in poplar and 3x10 m treatments. Monosteira unicostata is another insect pest that had most density in 3x10 m treatment. And alfalfa had high density of Chrysoperla carnea. The density of Coccinella septempunctata, were almost equal in all treatments. PMID:19579945

Khabir, Z H; Sadeghi, S E; Hanifeh, S; Eivazi, A

2009-01-15

80

Determining options for agroforestry systems for the rehabilitation of degraded watersheds in Alemaya Basin, Hararghe Highlands, Ethiopia  

SciTech Connect

Deforestation, accelerated soil erosion, and land degradation are serious problems in Ethiopia. The uncontrolled removal of natural forests, demographic pressures and cyclical drought has aggravated the situation, resulting in massive environmental degradation and a serious threat to sustainable agriculture and forestry. To overcome these problems efforts have been made to launch an afforestation and conservation program; however, success to data has been limited. Thus, the main objective of this study is to find the reasons for lack of success in tree planting in the Alemaya Basin both from biophysical and socio-economic perspectives. And, based on this analysis, to propose an alternative strategy for agroforestry for the Basin. The study has identified and characterized major land uses, socio-economic constraints and agricultural and forestry practices which have limited forestry development in the Alemaya Basin. To gather the necessary information for the study, existing information sources were reviewed. Two state sampling was used for a land-use survey, and stratified random sampling for the socio-economic study. Decrease in farm size due to population increases, soil erosion, shortage of fuelwood and fodder for livestock and lack of appropriate extension service were found to be the major problems that affect sustainable production in the Alemaya Basin. Agroforestry is one of the appropriate technologies to overcome some of the problem faced by the farmers in the Alemaya Basin. The study proposed a desired state of sustainable agriculture and forestry for the Basin based on population projections, agriculture and forest products needs, and stable or improved living standards for a 20 year planning period. Alley cropping with and without fertilizers was identified as a promising agroforestry technology. Its economic feasibility was assessed by estimating costs and returns both for traditional farming and alley cropping.

Bishaw, B.

1993-01-01

81

Productivity of Theobroma cacao agroforestry systems with timber or legume service shade trees  

Microsoft Academic Search

Timber production and cocoa yields were studied (initial 10–11 years) in two experimental plantations: a Cocoa-Legume system\\u000a (CL, Erythrina\\u000a poeppigiana, Gliricidia\\u000a sepium or Inga\\u000a edulis), and a Cocoa-Timber system (CT, Cordia alliodora, Tabebuia\\u000a rosea or Terminalia\\u000a ivorensis, plus I. edulis for inter-site comparisons). These trials had two major goals: (1) to evaluate the use of mono-specific timber shade canopies\\u000a as an

Eduardo Somarriba; John Beer

2011-01-01

82

Homestead Agroforestry: a Potential Resource in Bangladesh  

Microsoft Academic Search

\\u000a Homestead, the home and adjacent grounds occupied by a family, is the potential production area in Bangladesh, especially\\u000a for the resource poor group. Homestead production system, which is popularly called homestead agroforestry or home gardening\\u000a (the integrated production of crops, trees, and\\/or livestock in the household’s residence and its surrounding areas), has\\u000a been playing an important role in the rural

M. Giashuddin Miah; M. Jahangir Hussain

83

Productivity of annual cropping and agroforestry systems on a shallow Alfisol in semi-arid India  

Microsoft Academic Search

An experiment was conducted at ICRISAT Center, Patancheru, India from June 1984 to April 1988 on a shallow Alfisol to determine whether the productivity of annual\\u000a crop systems can be improved by adding perennial species such as Leucaena leucocephala managed as hedgerows. Except in the first year, crop yields were suppressed by Leucaena due to competition for moisture. The severity

M. R. Rao; C. K. Ong; P. Pathak; M. M. Sharma

1991-01-01

84

Traditional farming systems of south-central Chile, with special emphasis on agroforestry  

SciTech Connect

Results are presented from a brief survey made in Nov-Dec 1982. Owners of small farms (up to 12 ha) generally have complex farming systems with a high diversity of enterprises, including the use of trees for a variety of purposes (food, fodder, wood, construction materials, fuel, etc.).

Altieri, M.A.; Farrell, J.

1984-01-01

85

The espinal: agroforestry systems of the mediterranean — type climate region of Chile  

Microsoft Academic Search

The Central Valley of Chile is largely occupied by a pseudo-savanna called espinal consisting of a single dominant tree species, Acacia caven (Mol.) Mol. (Leguminosae), and some 215 annuals, most of which were inadvertently introduced from the Mediterranean Basin. The probable origin and current distribution of the espino (Acacia caven) and the espinales in Chile are described. Predominant production systems

Carlos Ovalle; James Aronson; Alejandro Del Pozo; Julia Avendano

1990-01-01

86

Tillage and N-source influence soil-emitted nitrous oxide in the Alberta Parkland region  

SciTech Connect

Zero tillage systems are receiving attention as possible strategies for sequestering atmospheric carbon. This benefit may be offset by increased N2O emissions, which have been reported for soils under zero tillage (ZT) compared to those under more intensive tillage (IT). Comparisons of N2O emissions from the two systems have been restricted to the growing season, but substantial losses of N2O have been reported during spring thaw events in many regions. Inorganic and organic additions of nitrogen and fallowing have also been shown to increase levels of soil-emitted N2O. The objectives for this study were: (i) to confirm that losses of N2O are higher under ZT than under IT in Alberta Parkland agroecosystems; (ii) to compare the relative influence of urea fertilizer (56 or 100 kg N h--1), field pea residue (dry matter at 5 Mg h--1), sheep manure (dry matter at 40 Mg h--1) additions, and fallow on total N2O losses; and (iii) to investigate possible interactions between fertility and tillage treatments. Gas samples were collected using vented soil covers at three sites near Edmonton, Alberta during 1993, 1994, and 1995. Gas samples were analyzed using a gas chromatograph equipped with a 63Ni electron capture detector. Estimated annual N2O loss ranged from 0.1 to 4.0 kg N ha-1. Emissions during summer were slightly higher, similar, or lower on ZT compared to those under IT, but were consistently lower on ZT plots during spring thaw. Combined estimates (spring plus summer) of N2O loss under ZT were equal to or lower than those under IT. Highest overall losses were observed on fallow plots, followed by fertilizer, pea residue, and then either manure or control plots. We conclude that ZT management systems have potential for reducing agricultural greenhouse gas emissions in the Alberta Parkland region.

Lemke , R L.; Izaurralde, R Cesar C.; Nyborg, M.; Solberg, E D.

1999-01-01

87

Babassu palm in the agroforestry systems in Brazil's Mid-North region  

Microsoft Academic Search

Babassu palms (Orbignya spp.) cover nearly 200,000 km2 in Brazil, providing cash income, fuel, fibre, edible oil and food to a large number of tenant farm households. Babassu is closely integrated within pastoral and shifting cultivation systems of Mid-North Brazil. In pastures, babassu provides shade for cattle, aids soil moisture retention, produces organic matter, generates supplementary farm income at little

P. H. May; A. B. Anderson; J. M. F. Frazão; M. J. Balick

1985-01-01

88

Interactive effects among ecosystem services and management practices on crop production: pollination in coffee agroforestry systems.  

PubMed

Crop productivity is improved by ecosystem services, including pollination, but this should be set in the context of trade-offs among multiple management practices. We investigated the impact of pollination services on coffee production, considering variation in fertilization, irrigation, shade cover, and environmental variables such as rainfall (which stimulates coffee flowering across all plantations), soil pH, and nitrogen availability. After accounting for management interventions, bee abundance improved coffee production (number of berries harvested). Some management interventions, such as irrigation, used once to trigger asynchronous flowering, dramatically increased bee abundance at coffee trees. Others, such as the extent and type of tree cover, revealed interacting effects on pollination and, ultimately, crop production. The effects of management interventions, notably irrigation and addition of lime, had, however, far more substantial positive effects on coffee production than tree cover. These results suggest that pollination services matter, but managing the asynchrony of flowering was a more effective tool for securing good pollination than maintaining high shade tree densities as pollinator habitat. Complex interactions across farm and landscape scales, including both management practices and environmental conditions, shape pollination outcomes. Effective production systems therefore require the integrated consideration of management practices in the context of the surrounding habitat structure. This paper points toward a more strategic use of ecosystem services in agricultural systems, where ecosystem services are shaped by the coupling of management interventions and environmental variables. PMID:23671073

Boreux, Virginie; Kushalappa, Cheppudira G; Vaast, Philippe; Ghazoul, Jaboury

2013-05-21

89

Adoption of agroforestry in the hills of Nepal: a logistic regression analysis  

Microsoft Academic Search

Widespread deforestation and increasingly intensive use of land to sustain a growing population has increased soil erosion, lowered soil fertility, and reduced agricultural productivity in the hills of Nepal. This has raised concern over sustainability of the hill farming system. There is growing evidence that agroforestry can be a potential solution to above problems. However, the development of agroforestry as

Ramji P. Neupane; Khem R. Sharma; Gopal B. Thapa

2002-01-01

90

The effects of rainfall partitioning and evapotranspiration on the temporal and spatial variation of soil water content in a Mediterranean agroforestry system  

NASA Astrophysics Data System (ADS)

Tree plantation for wood production has been proposed to mitigate CO2-related climate change. Although these agroforestry systems can contribute to maintain the agriculture in some areas placed between rainfed crops and secondary forests, water scarcity in Mediterranean climate could restrict its growth, and their presence will affect the water balance. Tree plantations management (species, plant density, irrigation, etc), hence, can be used to affect the water balance, resulting in water availability improvement and buffering of the water cycle. Soil water content and meteorological data are widely used in agroforestry systems as indicators of vegetation water use, and consequently to define water management. However, the available information of ecohydrological processes in this kind of ecosystem is scarce. The present work studies how the temporal and spatial variation of soil water content is affected by transpiration and interception loss fluxes in a Mediterranean rainfed plantation of cherry tree (Prunus avium) located in Caldes de Montbui (Northeast of Spain). From May till December 2011, rainfall partitioning, canopy transpiration, soil water content and meteorological parameters were continuously recorded. Rainfall partitioning was measured in 6 trees, with 6 automatic rain recorders for throughfall and 1 automatic rain recorder for stemflow per tree. Transpiration was monitored in 12 nearby trees by means of heat pulse sap flow sensors. Soil water content was also measured at three different depths under selected trees and at two depths between rows without tree cover influence. This work presents the relationships between rainfall partitioning, transpiration and soil water content evolution under the tree canopy. The effect of tree cover on the soil water content dynamics is also analyzed.

Biel, C.; Molina, A.; Aranda, X.; Llorens, P.; Savé, R.

2012-04-01

91

Agroforestry In-Service Training.  

National Technical Information Service (NTIS)

The report is to be used to train counterpart teams of PCVs and HCNs in agroforestry and strengthen their personal working relationship. Recommends guidelines for planning and implementing inservice training. Includes a 6-day training program.

J. Fillion J. Weeks

1984-01-01

92

Spatial and temporal effects of drought on soil CO2 efflux in a cacao agroforestry system in Sulawesi, Indonesia  

NASA Astrophysics Data System (ADS)

Climate change induced droughts pose a serious threat to ecosystems across the tropics and sub-tropics, particularly to those areas not adapted to natural dry periods. In order to study the vulnerability of cacao (Theobroma cacao) - Gliricidia sepium agroforestry plantations to droughts a large scale throughfall displacement roof was built in Central Sulawesi, Indonesia. In this 19-month experiment, we compared soil surface CO2 efflux (soil respiration) from three roof plots with three adjacent control plots. Soil respiration rates peaked at intermediate soil moisture conditions and decreased under increasingly dry conditions (drought induced), or increasingly wet conditions (as evidenced in control plots). The roof plots exhibited a slight decrease in soil respiration compared to the control plots (average 13% decrease). The strength of the drought effect was spatially variable - while some measurement chamber sites reacted strongly (responsive) to the decrease in soil water content (up to R2=0.70) (n=11), others did not react at all (non-responsive) (n=7). A significant correlation was measured between responsive soil respiration chamber sites and sap flux density ratios of cacao (R=0.61) and Gliricidia (R=0.65). Leaf litter CO2 respiration decreased as conditions became drier. The litter layer contributed approximately 3-4% of the total CO2 efflux during dry periods and up to 40% during wet periods. Within days of roof opening soil CO2 efflux rose to control plot levels. Thereafter, CO2 efflux remained comparable between roof and control plots. The cumulative effect on soil CO2 emissions over the duration of the experiment was not significantly different: the control plots respired 11.1±0.5 Mg C ha-1 yr-1, while roof plots respired 10.5±0.5 Mg C ha-1 yr-1. The relatively mild decrease measured in soil CO2 efflux indicates that this agroforestry ecosystem is capable of mitigating droughts with only minor stress symptoms.

van Straaten, O.; Veldkamp, E.; Köhler, M.; Anas, I.

2010-04-01

93

Agroforestry in the West African Sahel.  

National Technical Information Service (NTIS)

This report provides an overview of agroforestry on the Sahel today, the basic problems that are encountered in the current practice of agroforestry, and the opportunities that are available to donors such as AID, to promote agroforestry in the region. Tr...

1983-01-01

94

C and N Content in Density Fractions of Whole Soil and Soil Size Fraction Under Cacao Agroforestry Systems and Natural Forest in Bahia, Brazil  

NASA Astrophysics Data System (ADS)

Agroforestry systems (AFSs) have an important role in capturing above and below ground soil carbon and play a dominant role in mitigation of atmospheric CO2. Attempts has been made here to identify soil organic matter fractions in the cacao-AFSs that have different susceptibility to microbial decomposition and further represent the basis of understanding soil C dynamics. The objective of this study was to characterize the organic matter density fractions and soil size fractions in soils of two types of cacao agroforestry systems and to compare with an adjacent natural forest in Bahia, Brazil. The land-use systems studied were: (1) a 30-year-old stand of natural forest with cacao (cacao cabruca), (2) a 30-year-old stand of cacao with Erythrina glauca as shade trees (cacao + erythrina), and (3) an adjacent natural forest without cacao. Soil samples were collected from 0-10 cm depth layer in reddish-yellow Oxisols. Soil samples was separated by wet sieving into five fraction-size classes (>2000 ?m, 1000-2000 ?m, 250-1000 ?m, 53-250 ?m, and <53 ?m). C and N accumulated in to the light (free- and intra-aggregate density fractions) and heavy fractions of whole soil and soil size fraction were determined. Soil size fraction obtained in cacao AFS soils consisted mainly (65 %) of mega-aggregates (>2000 ?m) mixed with macroaggregates (32-34%), and microaggregates (1-1.3%). Soil organic carbon (SOC) and total N content increased with increasing soil size fraction in all land-use systems. Organic C-to-total N ratio was higher in the macroaggregate than in the microaggregate. In general, in natural forest and cacao cabruca the contribution of C and N in the light and heavy fractions was similar. However, in cacao + erythrina the heavy fraction was the most common and contributed 67% of C and 63% of N. Finding of this study shows that the majority of C and N in all three systems studied are found in macroaggregates, particularly in the 250-1000 ?m size aggregate class. The heavy fraction was the most common organic matter fraction in these soils. Thus, in mature cacao AFS on highly weathered soils the main mechanisms of C stabilization could be the physical protection within macroaggregate structures thereby minimizing the impact of conversion of forest to cacao AFS.

Rita, Joice Cleide O.; Gama-Rodrigues, Emanuela Forestieri; Gama-Rodrigues, Antonio Carlos; Polidoro, Jose Carlos; Machado, Regina Cele R.; Baligar, Virupax C.

2011-07-01

95

Agroforestry pathways for the intensification of shifting cultivation  

Microsoft Academic Search

As a system of land use which entails the deliberate association of trees with herbaceous field crops in time, shifting cultivation is one of the most ancient, widespread and, until recently, ecologically stable forms of agroforestry. However, under pressure of population and competing uses for land and labour, traditional swidden systems have been observed historically to undergo more or less

J. B. Raintree; K. Warner

1986-01-01

96

Rainfall partitioning into throughfall, stemflow and interception loss in a coffee ( Coffea arabica L.) monoculture compared to an agroforestry system with Inga densiflora  

NASA Astrophysics Data System (ADS)

SummaryPartitioning of gross rainfall into throughfall, stemflow and rainfall interception was assessed in Costa Rica during two rainy seasons (mean annual rainfall of 2900 mm) in two coffee systems: (1) a monoculture (MC) and (2) an agroforestry system (AFS) including Inga densiflora as the associated shade tree species. Coffee architecture, not LAI, appeared to be the main driver of stemflow as stemflow was higher for shaded coffee plants (10.6% of incident rainfall) than for coffee plants in MC (7.2%), despite the fact that these shaded plants had lower LAI. The presence of Inga trees modified coffee architecture with shaded coffee plants presenting larger stems and branches resulting in higher coffee funneling ratio under shade. In AFS, coffee plants and trees accounted respectively for 88% and 12% of total stemflow which represented 11.8% of incident rainfall. AFS displayed larger cumulative stemflow and smaller total throughfall compared to MC. Cumulative throughfall expressed in % of the gross rainfall, differed between systems and monitoring periods and the trend showed a decrease with increasing LAI. Nevertheless, as stemflow measurement and interception loss estimation were done only during the second year of the study, the shade tree showed a low influence in increasing interception loss, as the combined LAI of coffee plants and shade trees was rather similar in AFS as that of coffee in MC. Furthermore, coffee plants accounted for the largest fraction of the interception loss in AFS as the coffee LAI was more than 3-fold that of shade trees.

Siles, Pablo; Vaast, Philippe; Dreyer, Erwin; Harmand, Jean-Michel

2010-12-01

97

Drought effects on soil COagroforestry system in Sulawesi, Indonesia  

NASA Astrophysics Data System (ADS)

Climate change induced droughts pose a serious threat to ecosystems across the tropics and sub-tropics, particularly to those areas not adapted to natural dry periods. In order to study the vulnerability of cacao (Theobroma cacao) - Gliricidia sepium agroforestry plantations to droughts a large scale throughfall displacement roof was built in Central Sulawesi, Indonesia. In this 19-month replicated experiment, we measured soil surface CO2 efflux (soil respiration) in three simulated drought plots compared with three adjacent control plots. Soil respiration rates peaked at intermediate soil moisture and decreased under increasingly dry conditions (drought induced), but also decreased when soils became water saturated, as evidenced in control plots. The simulated drought plots exhibited a slight decrease in soil respiration compared to the control plots (average 13% decrease). The strength of the drought effect was spatially variable - while some measurement chamber sites reacted strongly ("responsive") to the decrease in soil water content (up to R2=0.70) (n=11), others did not react at all ("non-responsive") (n=7). The degree of soil CO2 respiration drought response was highest around cacao tree stems and decreased with distance from the stem (R2=0.22). A significant correlation was measured between "responsive" soil respiration chamber sites and sap flux density ratios of cacao (R=0.61) and Gliricidia (R=0.65). Leaf litter CO2 respiration decreased as conditions became drier. During dry periods the litter layer contributed approximately 3-4% of the total CO2 efflux and up to 40% during wet periods. A CO2 flush was recorded during the rewetting phase that lasted for approximately two weeks, during which time accumulated labile carbon stocks mineralized. The net effect on soil CO2 emissions over the duration of the experiment was neutral, control plots respired 11.1±0.5 Mg C ha-1 yr-1, while roof plots respired 10.5±0.5 Mg C ha-1 yr-1.

van Straaten, O.; Veldkamp, E.; Köhler, M.; Anas, I.

2009-12-01

98

Mycorrhizal relations in trees for agroforestry and land rehabilitation  

Microsoft Academic Search

The mycorrhizal stimulation of trees by increasing the efficiency of nutrient uptake from soil is discussed with special reference to tree species used in agroforestry\\/sylvopastoral systems. The occurrence of the two major classes of mycorrhizas is indicated as are the soil, plant and fungus factors affecting the size of the response. The low intensity of rooting of many tree species

Kurt Haselwandter; Glynn D. Bowen

1996-01-01

99

Short rotation woody crops: Using agroforestry technology for energy in the United States  

SciTech Connect

Agroforestry in the United States is being primarily defined as the process of using trees in agricultural systems for conservation purposes and multiple products. The type of agroforestry most commonly practiced in many parts of the world, that is the planting of tree crops in combination with food crops or pasture, is the type least commonly practiced in the United States. One type of agroforestry technique, which is beginning now and anticipated to expand to several million acres in the United States, is the planting of short-rotation woody crops (SRWCs) primarily to provide fiber and fuel. Research on SRWC`s and environmental concerns are described.

Wright, L.L.; Ranney, J.W.

1991-12-31

100

Short rotation woody crops: Using agroforestry technology for energy in the United States  

SciTech Connect

Agroforestry in the United States is being primarily defined as the process of using trees in agricultural systems for conservation purposes and multiple products. The type of agroforestry most commonly practiced in many parts of the world, that is the planting of tree crops in combination with food crops or pasture, is the type least commonly practiced in the United States. One type of agroforestry technique, which is beginning now and anticipated to expand to several million acres in the United States, is the planting of short-rotation woody crops (SRWCs) primarily to provide fiber and fuel. Research on SRWC's and environmental concerns are described.

Wright, L L; Ranney, J W

1991-01-01

101

Agroforestry research and development in southern Africa during the 1990s: Review and challenges ahead  

Microsoft Academic Search

The International Centre for Research in Agroforestry (ICRAF) initiated in 1987 the Southern Africa Regional Agroforestry\\u000a Programme in partnership with the national research systems in Malawi, Zambia, Zimbabwe and Tanzania to address the problems\\u000a of low soil fertility and consequent low crop and livestock production, low cash income, and shortages of fuelwood and timber\\u000a that are common to most rural

F. Kwesiga; F. K. Akinnifesi; P. L. Mafongoya; M. H. McDermott; A. Agumya

2003-01-01

102

The domestication and commercialization of indigenous trees in agroforestry for the alleviation of poverty  

Microsoft Academic Search

New initiatives in agroforestry are seeking to integrate into tropical farming systems indigenous trees whose products have\\u000a traditionally been gathered from natural forests. This is being done in order to provide marketable products from farms that\\u000a will generate cash for resource-poor rural and peri-urban households. This poverty-alleviating agroforestry strategy is at\\u000a the same time linked to one in which perennial,

R. R. B. Leakey; A. J. Simons

1997-01-01

103

Tree domestication in tropical agroforestry  

Microsoft Academic Search

We execute tree ‘domestication’ as a farmer-driven and market-led process, which matches the intraspecific diversity of locally\\u000a important trees to the needs of subsistence farmers, product markets, and agricultural environments. We propose that the products\\u000a of such domesticated trees are called Agroforestry Tree Products (AFTPs) to distinguish them from the extractive tree resources\\u000a commonly referred to as non-timber forest products

A. J. Simons; R. R. B. Leakey

2004-01-01

104

Taking stock of agroforestry adoption studies  

Microsoft Academic Search

In light of the large number of empii-ical studies of agroforestry adoption published during the last decade, we believe it is time to take stock and identify general determinants of agroforestry adoption. In reviewing 120 ar- ticles on adoption of agricultural and forestry technology by small holders, we find five categories of factors that explain technology adoption within an economic

Subhrendu K. Pattanayak; D. Evan Mercer

2003-01-01

105

Taking stock of agroforestry adoption studies  

Microsoft Academic Search

In light of the large number of empirical studies of agroforestry adoption published during the last decade, we believe it is time to take stock and identify general determinants of agroforestry adoption. In reviewing 120 articles on adoption of agricultural and forestry technology by small holders, we find five categories of factors that explain technology adoption within an economic framework:

Subhrendu K. Pattanayak; D. Evan Mercer; Erin Sills; Jui-Chen Yang

2003-01-01

106

Effects of climate change and land use on duck abundance in Canadian prairie-parklands  

SciTech Connect

Recent declines in breeding ducks in the Canadian prairie-parklands may be due to loss of habitat to agriculture. However, prairie-parkland also has experienced wetland loss to drought as well as to agriculture. For sucessful habitat restoration, it is important to separate the effects of anthropogenic changes to the landscape from those caused by changes in climate. The researchers used data from annual air-ground surveys and from precipitation records to develop relationships between indices of abundance of each of 10 species of ducks and indices of wetland conditions during 1955-1974. Average annual deficits within Canadian prairie-parkland over the period 1975-1989 were estimated at 1.2 x 10{sup 6} birds for both Mallard (Anas platyrhynchos) and Northern Pintail (A. acuta), 480 000 for Blue-winged Teal (A. discors), 190 000 for American Wigeon (A. americana), 175 000 for Northern Shoveler (A. clypeata), 50 000 for Gadwall (A. strepera), 10 000 for Green-winged Teal (A. crecca), 40 000 for Canvasback (Aythya valisineria), 25 000 for Lesser Scaup (A. affinis), and 5000 for Redhead (A. americana). The effect of agricultural expansion in the east on prime waterfowl habitat since 1951 appears to have been negligible. There, as much as 90% had been already lost prior to 1951. In the west, however, where prime waterfowl habitat was still relatively abundant in 1951, agricultural development has encroached substantially. The relationship between the lost area of the best breeding habitats and the size of population deficits for Mallards and Northern Pintails in the entire Canadian prairie-parkland region was significant for both species (P < 0.0027 and P < 0.0001, respectively). Consequently, habitat restoration programs located where the highest quality waterfowl habitat and the lowest quality agricultural lands overlap most should have the greatest potential to affect recovery of breeding duck populations in the Canadian prairie-parklands. 39 refs., 8 figs., 4 tabs.

Bethke, R.W.; Nudds, T.D. [Univ. of Guelph, Ontario (Canada)

1995-08-01

107

Comparing genetic diversity in agroforestry systems with natural forest: a case study of the important timber tree Vitex fischeri in central Kenya  

Microsoft Academic Search

It is possible that current tree domestication practices undertaken by farmers reduce the genetic base of tree resources on\\u000a farms, raising concerns regarding the productivity, sustainability and conservation value of agroforestry ecosystems. Here,\\u000a we assessed possible changes in genetic variation during domestication in the important and heavily utilised timber species,\\u000a Vitex fischeri Grke (syn. Vitex keniensis), by comparing geographically proximate

Ard G. Lengkeek; Alice Muchugi Mwangi; Caroline A. C. Agufa; Joseph O. Ahenda; Ian K. Dawson

2006-01-01

108

Ecosystem Services from Smallholder Forestry and Agroforestry in the Tropics  

Microsoft Academic Search

\\u000a Smallholder forestry and agroforestry systems in the tropics provide essential products and services for millions of producers,\\u000a their surrounding communities, national and international consumers, and global society. The diversity of products provided\\u000a by these systems meet the needs of smallholder producers for fuelwood, food, animal fodder, and other household and farm needs;\\u000a they provide additional income to supplement major commodity

Travis Idol; Jeremy Haggar; Linda Cox

109

Nitrogen-Fixing Trees with Actinorhiza in Forestry and Agroforestry  

Microsoft Academic Search

Nitrogen-fixing trees with actinorhiza (or actinorhizal trees) form a group that is a key component in many natural ecosystems, agro-ecosystems, and agroforestry systems in the world, and that provides an important source of fixed nitrogen in these ecosystems. The general characteristics of the actinorhizal symbiosis, including aspects of nodule formation, co-evolution of both partners, and nitrogen fixation rates at field

R. O. RUSSO

110

Soil organic carbon (SOC) management for sustainable productivity of cropping and agro-forestry systems in Eastern and Southern Africa  

Microsoft Academic Search

In Eastern and Southern Africa, the shifting from the no-external input agriculture (shifting cultivation through slash and\\u000a burn) to intensified agricultural systems has resulted in widespread agro-ecosystems with high soil organic carbon and nutrient\\u000a depletion. This is quite evident in farming systems with reduced fallow period or those that practice continuous cropping\\u000a without or with little inputs. Long-term experiments indicate

Stephen M. Nandwa

2001-01-01

111

Using Social Science Tools in Agroforestry Research.  

National Technical Information Service (NTIS)

Recent innovations in agroforestry research indicate the need to elicit farmers' participation in technology adaptations. The paper is intended for non-social scientists who wish to use social science research tools in order to assess the role of multipur...

J. L. Marcucci

1990-01-01

112

Research Issues: A Prospectus for Agroforestry.  

National Technical Information Service (NTIS)

Considerable progress is visible in both the concepts and practice of agroforestry projects, over the past few decades. In such circumstances, what might be a useful approach to structure further research or investigations. At least three characteristics ...

W. T. Hinds

1989-01-01

113

Biotechnology and Agroforestry in Indian Arid Regions  

Microsoft Academic Search

\\u000a Agroforestry evolved with agriculture to make the best use of the land and to maintain equilibrium between man, land, livestock\\u000a and plants. In recent years, agroforestry has been developed as an autonomous science that can help farmers to increase profitability\\u000a and land sustainability. Tree growing in combination with agriculture, including individual farms, watersheds and regional\\u000a landscape can be integrated to

Varsha Sharma; Shaily Goyal; K. G. Ramawat

114

Smallholder Cacao (Theobroma cacao Linn.) cultivation in agroforestry systems of West and Central Africa: challenges and opportunities  

Microsoft Academic Search

The cultural features, management practice, environmental sustainability, and economic profitability of smallholder cacao\\u000a (Theobroma cacao)production in West and Central Africa are reviewed. The aim is tohighlight factors affecting the cacao production and marketing\\u000a sectorand to propose appropriate strategies to ensure sustainable and profitable cacao production in the region. The cacao\\u000a cultivation system causes minimum damage to soil resources. In terms

B. Duguma; J. Gockowski; J. Bakala

2001-01-01

115

Impacts of Public Policies and Farmer Preferences on Agroforestry Practices in Kerala, India  

NASA Astrophysics Data System (ADS)

Agroforestry systems are fundamental features of the rural landscape of the Indian state of Kerala. Yet these mixed species systems are increasingly being replaced by monocultures. This paper explores how public policies on land tenure, agriculture, forestry and tree growing on private lands have interacted with farmer preferences in shaping land use dynamics and agroforestry practices. It argues that not only is there no specific policy for agroforestry in Kerala, but also that the existing sectoral policies of land tenure, agriculture, and forestry contributed to promoting plantation crops, even among marginal farmers. Forest policies, which impose restrictions on timber extraction from farmers' fields under the garb of protecting natural forests, have often acted as a disincentive to maintaining tree-based mixed production systems on farmlands. The paper argues that public policies interact with farmers' preferences in determining land use practices.

Guillerme, S.; Kumar, B. M.; Menon, A.; Hinnewinkel, C.; Maire, E.; Santhoshkumar, A. V.

2011-08-01

116

Adoption of agroforestry innovations in the tropics: A review  

Microsoft Academic Search

The period since the early 1990s has witnessed an explosion of research on the adoption of agroforestry innovations in the\\u000a tropics. Much of this work was motivated by a perceived gap between advances in agroforestry science and the success of agroforestry-based\\u000a development programs and projects. Achieving the full promise of agroforestry requires a fundamental understanding of how\\u000a and why farmers

D. E. Mercer

2004-01-01

117

Women and agroforestry: four myths and three case studies  

Microsoft Academic Search

Women are traditionally important participants in both the agricultural and forestry components of agroforestry production. Women are frequently ignored in the design of agroforestry projects because of commonly held myths about their participation in both production activities and in public life. The involvement of women in agroforestry projects and activities are examined in case studies from the Dominican Republic, India

Louise Fortmann; Dianne Rocheleau

1985-01-01

118

Root architecture in relation to tree-soil-crop interactions and shoot pruning in agroforestry  

Microsoft Academic Search

Desirable root architecture for trees differs between sequential and simultaneous agroforestry systems. In sequential systems extensive tree root development may enhance nutrient capture and transfer to subsequent crops via organic pools. In simultaneous systems tree root development in the crop root zone leads to competition for resources.Fractal branching models provide relationships between proximal root diameter, close to the tree stem,

M. Van Noordwijk; P. Purnomosidhi

1995-01-01

119

Forest management and agroforestry to sequester and conserve atmospheric carbon dioxide  

SciTech Connect

As part of the Global Change Research Program of the United States Environmental Protection Agency (USEPA), an assessment was initiated in 1990 to evaluate forest establishment and management options to sequester carbon and reduce the accumulation of greenhouse gases in the atmosphere. Three specific objectives are to: identify site-suitable technologies and practices that could be utilized to manage forests and agroforestry systems to sequester and conserve carbon; assess available data on site-level costs of promising forest and agroforestry management practices; evaluate estimates of technically suitable land in forested nations and biomes of the world to help meet the Noordwijk forestation targets.

Schriwder, P.E.; Dixon, R.K.; Winjum, J.K.

1993-01-01

120

Parkland and Golf Course Management: Managing Wildlife Habitat on Public Open Space  

NSDL National Science Digital Library

This article discusses methods for managing parkland and golf courses in a wildlife-friendly manner. The article contains a number of practical tips for managing parks and golf courses, and covers such topics as lawn size, the use of native plants, and eco-friendly turf-grass management. The piece was authored by Amanda D. Rodewald Ph.D. of the School of Natural Resources at Ohio State University. Anyone in the Turf or Golf Management industry with a desire to improve the environmental consequences will find this article very useful.

Rodewald, Amanda D.

2006-12-04

121

Research issues: A prospectus for agroforestry  

SciTech Connect

Considerable progress is visible in both the concepts and practice of agroforestry projects, over the past few decades. In such circumstances, what might be a useful approach to structure further research or investigations At least three characteristics come to mind that merit consideration: complexity of the phenomena, criteria for priorities, and choices constrained by resource scarcity. In the next few paragraphs, these three topics will briefly examined. Significant research issues for agroforestry remain urgent, but they tend to be generally site-specific in nature in comparison with other disciplines of field-related research. This site-specific characteristic tends to Balkanize scientific attention, so that choices for research effort reflect local perceptions, and perhaps dilute attention to the overall importance of agroforestry as an investigative disciplines. Furthermore, these issues are notorious for their ecological complexity, so this aspect will be the first to be examined. 23 refs.

Hinds, W.T.

1989-04-01

122

Incorporating agroforestry approaches into commodity value chains.  

PubMed

The productivity of tropical agricultural commodities is affected by the health of the ecosystem. Shade tolerant crops such as coffee and cocoa benefit from environmental services provided by forested landscapes, enabling landscape design that meets biodiversity conservation and economic needs. What can motivate farmers to apply and maintain such landscape approaches? Rather than rely on a proliferation of externally funded projects new opportunities are emerging through the international market that buys these commodities. As part of their growing commitment to sustainable supply chains, major companies are supporting agroforestry approaches and requiring producers and traders to demonstrate that the source of their commodities complies with a set of principles that conserves forested landscapes and improves local livelihoods. The paper presents examples of international companies that are moving in this direction, analyzes why and how they are doing it and discusses the impact that has been measured in coffee and cocoa communities in Latin America and Africa. It particularly considers the role of standards and certification systems as a driver of this commitment to promote profitable operations, environmental conservation and social responsibility throughout the coffee and cocoa value chains. Such approaches are already being taken to scale and are no longer operating only in small niches of the market but the paper also considers the limitations to growth in this market-based approach. PMID:21556936

Millard, Edward

2011-08-01

123

Evaporation from soils below sparse crops in contour hedgerow agroforestry in semi-arid Kenya  

Microsoft Academic Search

In many agricultural systems in the semi-arid tropics, crops use only a small fraction of the total rainfall. Agroforestry can greatly reduce some losses, especially on hill slopes, where soil evaporation, runoff and soil losses are important. This paper reports on soil evaporation from a rotation of intercropped maize and cowpea between contour hedgerows of pruned Senna siamea trees as

J. M. Kinama; C. J. Stigter; C. K. Ong; J. K. Ng’ang’a; F. N. Gichuki

2005-01-01

124

Emergy Evaluation of Lacandon Maya Indigenous Swidden Agroforestry in Chiapas, Mexico  

Microsoft Academic Search

The Lacandon Maya of Chiapas, Mexico practice a system of swidden agroforestry that mimics the surrounding ecosystem and its successional stages. Their fields rotate through grass (milpa), and shrub (acahual) and forest fallow stages that regenerate soil, nutrients, and seed banks. Each successional stage, including the fallow stages, produces over 25 types of crops, raw materials, and medicines. Lacandon traditionally

Stewart A. W. Diemont; Jay F. Martin; Samuel I. Levy-Tacher

2006-01-01

125

An evaluation of the Acacia albida -based agroforestry practices in the Hararghe highlands of Eastern Ethiopia  

Microsoft Academic Search

Growing Acacia albida as a permanent tree crop, on farmlands with cereals, vegetables and coffee underneath or in between, is an indigenous agroforestry system in the Hararghe highlands of Eastern Ethiopia. However, there is practically no systematic record or data on the merits and benefits of this practice.

Peter Poschen

1986-01-01

126

Assessing local knowledge use in agroforestry management with cognitive maps.  

PubMed

Small-holder farmers often develop adaptable agroforestry management techniques to improve and diversify crop production. In the cocoa growing region of Ghana, local knowledge on such farm management holds a noteworthy role in the overall farm development. The documentation and analysis of such knowledge use in cocoa agroforests may afford an applicable framework to determine mechanisms driving farmer preference and indicators in farm management. This study employed 12 in-depth farmer interviews regarding variables in farm management as a unit of analysis and utilized cognitive mapping as a qualitative method of analysis. Our objectives were (1) to illustrate and describe agroforestry management variables and associated farm practices, (2) to determine the scope of decision making of individual farmers, and (3) to investigate the suitability of cognitive mapping as a tool for assessing local knowledge use. Results from the cognitive maps revealed an average of 16 +/- 3 variables and 19 +/- 3 links between management variables in the farmer cognitive maps. Farmer use of advantageous ecological processes was highly central to farm management (48% of all variables), particularly manipulation of organic matter, shade and food crop establishment, and maintenance of a tree stratum as the most common, highly linked variables. Over 85% of variables included bidirectional arrows, interpreted as farm management practices dominated by controllable factors, insofar as farmers indicated an ability to alter most farm characteristics. Local knowledge use on cocoa production revealed detailed indicators for site evaluation, thus affecting farm preparation and management. Our findings suggest that amid multisourced information under conditions of uncertainty, strategies for adaptable agroforestry management should integrate existing and localized management frameworks and that cognitive mapping provides a tool-based approach to advance such a management support system. PMID:18820966

Isaac, Marney E; Dawoe, Evans; Sieciechowicz, Krystyna

2009-06-01

127

Socioeconomic Aspects of Agroforestry in Rural Haiti.  

National Technical Information Service (NTIS)

Socioeconomic data on exotic tree planting under A.I.D.'s Agroforestry Outreach Project (AOP) was collected between June 1985 and April 1986 at Fond-des-Blancs and Beaumont on Haiti's southern peninsula. Using these data, the report describes the study ar...

A. Balzano

1986-01-01

128

Agroforestry and the Maintenance of Biodiversity  

NSDL National Science Digital Library

Agroforestry is a land-use method that allows trees to grow in crop and livestock areas. Studies have shown that it is one way to conserve biodiversity, attracts species beneficial to farming, such as pollinators, improves farms by, for example, reducing soil erosion and is economically beneficial to farmers.

Peter Bichier (Migratory Bird Center of the Smithsonian National Zoological Park;)

2006-05-01

129

Can Joint Carbon and Biodiversity Management in Tropical Agroforestry Landscapes Be Optimized?  

PubMed Central

Managing ecosystems for carbon storage may also benefit biodiversity conservation, but such a potential ‘win-win’ scenario has not yet been assessed for tropical agroforestry landscapes. We measured above- and below-ground carbon stocks as well as the species richness of four groups of plants and eight of animals on 14 representative plots in Sulawesi, Indonesia, ranging from natural rainforest to cacao agroforests that have replaced former natural forest. The conversion of natural forests with carbon stocks of 227–362 Mg C ha?1 to agroforests with 82–211 Mg C ha?1 showed no relationships to overall biodiversity but led to a significant loss of forest-related species richness. We conclude that the conservation of the forest-related biodiversity, and to a lesser degree of carbon stocks, mainly depends on the preservation of natural forest habitats. In the three most carbon-rich agroforestry systems, carbon stocks were about 60% of those of natural forest, suggesting that 1.6 ha of optimally managed agroforest can contribute to the conservation of carbon stocks as much as 1 ha of natural forest. However, agroforestry systems had comparatively low biodiversity, and we found no evidence for a tight link between carbon storage and biodiversity. Yet, potential win-win agroforestry management solutions include combining high shade-tree quality which favours biodiversity with cacao-yield adapted shade levels.

Kessler, Michael; Hertel, Dietrich; Jungkunst, Hermann F.; Kluge, Jurgen; Abrahamczyk, Stefan; Bos, Merijn; Buchori, Damayanti; Gerold, Gerhard; Gradstein, S. Robbert; Kohler, Stefan; Leuschner, Christoph; Moser, Gerald; Pitopang, Ramadhanil; Saleh, Shahabuddin; Schulze, Christian H.; Sporn, Simone G.; Steffan-Dewenter, Ingolf; Tjitrosoedirdjo, Sri S.; Tscharntke, Teja

2012-01-01

130

Tradeoffs between income, biodiversity, and ecosystem functioning during tropical rainforest conversion and agroforestry intensification  

PubMed Central

Losses of biodiversity and ecosystem functioning due to rainforest destruction and agricultural intensification are prime concerns for science and society alike. Potentially, ecosystems show nonlinear responses to land-use intensification that would open management options with limited ecological losses but satisfying economic gains. However, multidisciplinary studies to quantify ecological losses and socioeconomic tradeoffs under different management options are rare. Here, we evaluate opposing land use strategies in cacao agroforestry in Sulawesi, Indonesia, by using data on species richness of nine plant and animal taxa, six related ecosystem functions, and on socioeconomic drivers of agroforestry expansion. Expansion of cacao cultivation by 230% in the last two decades was triggered not only by economic market mechanisms, but also by rarely considered cultural factors. Transformation from near-primary forest to agroforestry had little effect on overall species richness, but reduced plant biomass and carbon storage by ?75% and species richness of forest-using species by ?60%. In contrast, increased land use intensity in cacao agroforestry, coupled with a reduction in shade tree cover from 80% to 40%, caused only minor quantitative changes in biodiversity and maintained high levels of ecosystem functioning while doubling farmers' net income. However, unshaded systems further increased income by ?40%, implying that current economic incentives and cultural preferences for new intensification practices put shaded systems at risk. We conclude that low-shade agroforestry provides the best available compromise between economic forces and ecological needs. Certification schemes for shade-grown crops may provide a market-based mechanism to slow down current intensification trends.

Steffan-Dewenter, Ingolf; Kessler, Michael; Barkmann, Jan; Bos, Merijn M.; Buchori, Damayanti; Erasmi, Stefan; Faust, Heiko; Gerold, Gerhard; Glenk, Klaus; Gradstein, S. Robbert; Guhardja, Edi; Harteveld, Marieke; Hertel, Dietrich; Hohn, Patrick; Kappas, Martin; Kohler, Stefan; Leuschner, Christoph; Maertens, Miet; Marggraf, Rainer; Migge-Kleian, Sonja; Mogea, Johanis; Pitopang, Ramadhaniel; Schaefer, Matthias; Schwarze, Stefan; Sporn, Simone G.; Steingrebe, Andrea; Tjitrosoedirdjo, Sri S.; Tjitrosoemito, Soekisman; Twele, Andre; Weber, Robert; Woltmann, Lars; Zeller, Manfred; Tscharntke, Teja

2007-01-01

131

Plant-soil interactions in multistrata agroforestry in the humid tropics  

Microsoft Academic Search

Multistrata agroforestry systems with tree crops comprise a variety of land use systems ranging from plantations of coffee, cacao or tea with shade trees to highly diversified homegardens and multi-storey tree gardens. Research on plant-soil interactions has concentrated on the former. Tree crop-based land use systems are more efficient in maintaining soil fertility than annual cropping systems. Certain tree crop

G. Schroth; J. Lehmann; M. R. L. Rodrigues; E. Barros; J. L. V. Macêdo

2001-01-01

132

Plant-soil interactions in multistrata agroforestry in the humid tropicsa  

Microsoft Academic Search

Multistrata agroforestry systems with tree crops comprise a variety of land use systems ranging from plantations of coffee,\\u000a cacao or tea with shade trees to highly diversified homegardens and multi-storey tree gardens. Research on plant-soil interactions\\u000a has concentrated on the former. Tree crop-based land use systems are more efficient in maintaining soil fertility than annual\\u000a cropping systems. Certain tree crop

G. Schroth; J. Lehmann; M. R. L. Rodrigues; E. Barros; J. L. V. Macêdo

2001-01-01

133

Guide to monitoring carbon storage in forestry and agroforestry projects  

SciTech Connect

As the international Joint Implementation (JI) program develops a system for trading carbon credits to offset greenhouse gas emissions, project managers need a reliable basis for measuring the carbon storage benefits of carbon offset projects. Monitoring and verifying carbon storage can be expensive, depending on the level of scientific validity needed. This guide describes a system of cost-effective methods for monitoring and verification on a commercial basis, for three types of land use; forest plantations, managed natural forests and agroforestry. Winrock International`s Forest Carbon Monitoring Program developed this system with its partners as a way to provide reliable results using accepted principles and practices of forest inventory, soil science and ecological surveys. Perhaps most important, the system brings field research methods to bear on commercial-scale inventories, at levels of precision specified by funding agencies.

MacDicken, K.G.

1997-10-01

134

Engaging in School-Led Multisectoral Collaboration: Implications to Agroforestry Promotion in the Philippine Uplands  

ERIC Educational Resources Information Center

The Agroforestry Support Program for Empowering Communities Towards Self-Reliance (ASPECTS) was conceived to develop a model of two-stage approach in agroforestry promotion by capacitating the upland communities to establish community-managed agroforestry extension services, while strengthening the agroforestry education programs of the three…

Landicho, Leila D.; Cabahug, Rowena D.; De Luna, Catherine C.

2009-01-01

135

Agroforestry and the utilisation of fragile ecosystems  

Microsoft Academic Search

King, K.F.S., 1979. Agroforestry and the utilisation of fragile ecosystems. Forest Ecol. Manage., 2: 161—168. Sixty-five percent of the land in the tropical world occupies fragile ecosystems. The number of people who depend upon these areas for their food and livelihood is 630 million or 35% of the total population of the developing countries. Not only is the physical environment

K. F. S. KING

1979-01-01

136

Eucalyptus in agroforestry: its effects on agricultural production and economics  

Microsoft Academic Search

The economics of eucalyptus in agroforestry and its effects on agricultural crops have been studied with the help of observations made during the harvests in agricultural fields and from the information supplied by progressive farmers. Three rotations of eucalyptus in agroforestry were selected for comparative study of its returns and relative loss to the crops, in order to ascertain the

Parvez Ahmed

1989-01-01

137

Incorporation of indigenous knowledge and perspectives in agroforestry development  

Microsoft Academic Search

Calls for the effective integration of indigenous knowledge and perspective into agroforestry are increasingly familiar in agroforestry programmes. This is the result of a need to better target research, ethical concerns about participation and power and the recognition that indigenous knowledge is a potentially powerful source of understanding that may often be complementary to scientific knowledge.Incorporating indigenous knowledge into development

D. H. Walker; F. L. Sinclair; B. Thapa

1995-01-01

138

Within-crown structural variability of dwarfed mature Abies mariesii in snowy subalpine parkland in central Japan  

Microsoft Academic Search

We investigated mature dwarf Abies mariesii trees growing in conifer thicket–meadow parklands on a snowy subalpine plateau, where these dwarf trees are buried in the\\u000a accumulated snow in winter. We focused on structural variation in the needles, shoots, and branchlets within different crown\\u000a positions (leader crown vs lower crown) of the dwarf trees. In the leader crown, which appears above

Akira S. Mori; Eri Mizumachi

2009-01-01

139

Ethnobotanical knowledge of Philippine lowland farmers and its application in agroforestry  

Microsoft Academic Search

Complex agroforestry systems that mimic local forest structure, so-called ‘analogs’, are assumed to be of specific value to\\u000a rural people as well as the environment. The objective of this study was to document and evaluate the utilization of plant\\u000a resources by Philippine lowland farmers to identify native species suitable for integration in such a system. The interviewed\\u000a farmers maintain a

Gerhard Langenberger; Vanessa Prigge; Konrad Martin; Beatriz Belonias; Joachim Sauerborn

2009-01-01

140

Using agroforestry to improve soil fertility: effects of intercropping on Ilex paraguariensis (yerba mate) plantations with Araucaria angustifolia  

Microsoft Academic Search

This study assessed the use of agroforestry to improve soil nutrient properties in plantations containing Ilex paraguariensis St. Hilaire (yerba mate). Intercropping within tree plantation systems is widely practiced by farmers around the World, but\\u000a the influence of different species combinations on system performance still requires further investigation. I. paraguariensis is a major South American crop commonly cultivated in intensive

Tal IlanyMark; Mark S. Ashton; Florencia Montagnini; Constanza Martinez

2010-01-01

141

Niche differentiation and neutral theory: an integrated perspective on shrub assemblages in a parkland savanna.  

PubMed

Investigations of structure in ecological communities need to move beyond the dichotomy between niche and neutral theory to broader conceptual frameworks that accommodate both neutral stochastic and biological structuring processes in organizing species assemblages. We propose and test a framework that integrates niche and neutral-assembly perspectives and determines their relative contributions in structuring diverse shrub species assemblages in a parkland savanna. Our approach proposes that stochastic dispersal processes initially govern the assemblage of species in discrete shrub clusters developing in grassland, but that community structure subsequently develops through the progressive action of first positive, then negative interactions among species. A comparison of observed patterns of occurrence and niche models for 12 shrub cluster species against neutral predictions revealed that neutral stochastic, island biogeographic processes accounted for most patterns of species occurrence. One species showed strong evidence of successional differentiation, whereas evidence of slight recruitment biases for five others was equivocal. Our results demonstrate the usefulness of an approach that accommodates contributions of both neutral and niche assembly rather than assuming either process alone is sufficient to account for community structure. Further development and testing of robust and falsifiable neutral theory will allow ecologists to critically evaluate the relative roles of niche differentiation and neutral, stochastic processes in structuring communities. PMID:20462129

Stokes, C J; Archer, S R

2010-04-01

142

The potential of agroforestry to increase primary production in the Sahelian and Sudanian zones of West Africa  

Microsoft Academic Search

The article presents a critical evaluation of agroforestry systems as regards their potential to increase primary production in the Sahelian and Sudanian zones of West Africa. The suggestion that trees would always and everywhere be profitable for the region will be counterproductive, the basis for disappointments and a waste of money. One has to consider carefully which properties of woody

J. J. Kessler; H. Breman

1991-01-01

143

Sistemas agrossilvipastoris e o aumento da densidade de nutrientes para bovinos em pastejo (Agricultural-forestry-pasture systems and nutrient density increase for grazing cattle)  

Microsoft Academic Search

The agroforestry systems can be used for feed production to cattle promoting the activity sustainabilty. The aspects to be known about these production systems refer to concepts, characteristics and classification of agroforestry systems; the interactions between trees and the other system components, specially the tree and pasture interaction; and notions about agroforestry systems planning, implementation and management. At this revision

Francisco Eden Paiva Fernandes

144

Agroforestry and the achievement of the Millennium Development Goals  

Microsoft Academic Search

The Millennium Development Goals (MDGs) of the United Nations (UN) are at the heart of the global development agenda. This\\u000a chapter examines the role of agroforestry research and development (R&D) in light of the MDGs. It reviews some of the ways\\u000a in which agroforestry is substantively assisting to achieve the goals and discusses how the agenda can be realigned to

D. P. Garrity

2004-01-01

145

Directions in tropical agroforestry research: past, present, and future  

Microsoft Academic Search

Reflections on the past two decades of organized research in tropical agroforestry raise several issues. Research efforts\\u000a started with an inductive and experiential approach but have subsequently followed a deductive and experimental approach that\\u000a includes hypothesis testing and the development of predictive capability; agroforestry research is thus being transformed\\u000a into a rigorous scientific activity. The research agenda, so far, has

P. K. R. Nair

1997-01-01

146

Trees of prosperity: Agroforestry, markets and the African smallholder  

Microsoft Academic Search

In many developing countries, especially in Africa, farmers have been introduced to agroforestry with little consideration\\u000a for the markets for trees and tree products aside from potential productivity gains to food crops. It is now being recognized\\u000a that expanding market opportunities for smallholders particularly in niche markets and high value products is critical to\\u000a the success of agroforestry innovations. Some

D. Russell; S. Franzel

2004-01-01

147

Agro-ecosystem and socio-economic role of homegarden agroforestry in Jabithenan District, North-Western Ethiopia: implication for climate change adaptation.  

PubMed

Homegarden agroforestry is believed to be more diverse and provide multiple services for household than other monocropping system and this is due to the combination of crops, trees and livestock. The aim of this study was to assess socio-economic and agro-ecological role of homegardens in Jabithenan district, North-western Ethiopia. Two sites purposively and two villages randomly from each site were selected. Totally 96 households; in which 48 from homegarden agroforestry user and 48 from non-tree based garden user were selected for this study. Socio-economic data and potential economic and agro-ecosystem role of homegarden agroforestry over non-tree based garden were collected by using semi-structured and structured questionnaires to the households. Homegarden agroforestry significantly (P?agroforestry practice provides good socio-economical and agro-ecological service for farmers which have a higher implication for climate change adaptation than non-tree based garden. PMID:24790810

Linger, Ewuketu

2014-01-01

148

Eutrophication indices of an atlantic agroforestry catchment  

NASA Astrophysics Data System (ADS)

The main elements causing eutrophication in waters are nitrogen and phosphorus. It is admitted that surface waters productivity is limited by either phosphorus, in lakes, or nitrogen, in rivers. Therefore, this study aims to analyze the seasonal fluctuation of N and P concentrations and to assess the N/P ratio at the outlet of an agroforestry catchment under atlantic climatic conditions in order to assess its eutrophication status. The studied catchment is located in A Coruña province (NW Spain). Water samples were collected at the catchment outlet from 2003 to 2007, amounting to a total of 555 samples. Total phosphorus contents were measured using ICP-MS whereas those of nitrogen were assessed by capilar electrophoresis. Maximum average values were registered in 2006 for nitrogen and 2005 for phosphorus. Nitrogen minimum average values were measured in 2003 and those of phosphorus in 2007. Coefficients of variation were higher for phosphorus than for nitrogen. The highest N/P ratios were observed in 2007 and the lowest ones in 2003. Usually, higher N/P values were related to base flow periods whereas lower values of this ratio occurred during floods. N/P values higher than 7 indicate eutrophication conditions caused by phosphorus and if the ratio is lower than this threshold, nitrogen is the limitant element. Our results indicated that, in this catchment, phosphorus was the limitant element for eutrophication. Moreover, eutrophication risk is higher during flood events with phosphorus supplies by runoff.

Sande-Fouz, P.; Miras-Avalos, J. M.

2009-04-01

149

Energy farming in Brazil: the role of agroforestry on the production of food and energy from biomass in southeast Bahia  

SciTech Connect

This paper analyzes the problem of fuel production from plants, on the basis of information drawn from the literature and from case studies conducted in Brazil. Special reference is made to the production of charcoal and the production of alcohol and vegetable oils to replace gasoline and diesel fuel. The potential and socioeconomic implications of energy farming are discussed. Diversified plant communities are more stable than monocropping systems in terms of prevention of soil degradation by erosion and leaching, and consequently agroforestry is the safest and the most attractive system for the combined production of food and energy from plants in the humid tropics. Agroforestry is especially interesting in the establishment of perennial energy crops, because it provides earlier cash returns.

Alvim, R.

1983-01-01

150

Why tree-crop interactions in agroforestry appear at odds with tree-grass interactions in tropical savannahs  

Microsoft Academic Search

This paper describes recent research findings on resource sharing between trees and crops in the semiarid tropics and attempts\\u000a to reconcile this information with current knowledge of the interactions between savannah trees and understorey vegetation\\u000a by examining agroforestry systems from the perspective of succession. In general, productivity of natural vegetation under\\u000a savannah trees increases as rainfall decreases, while the opposite

C. K. Ong; R. R. B. Leakey

1999-01-01

151

Nutritional and anti-nutritional characters and rumen degradability of dry matter and nitrogen for some multipurpose tree species with potential for agroforestry in Zimbabwe  

Microsoft Academic Search

In a preliminary study on the nutritional value of seven multipurpose trees (MPTs), currently showing potential use in agroforestry systems in Zimbabwe, crude protein values ranged from 189 g kg?1 DM in Flemingia macrophylla to 292 g kg?1 DM in Acacia angustissima. Acid detergent fibre (ADF) content was low especially in Sesbania sesban (99 g kg?1 DM), while ADF contents

B. H. Dzowela; L. Hove; J. H. Topps; P. L. Mafongoya

1995-01-01

152

Economic principles to appraise agro-forestry projects  

SciTech Connect

Basic economic principles and the classical project evaluation technique can be satisfactorily used to solve investment decisions for agroforestry projects. Recommendations made for this type of appraisal are to: concentrate on the small farm participants; study the forestry component and risk diversification; detail the externalities; and consider the cultural environment. 15 references.

Harou, P.A.

1983-01-01

153

Potential for novel food products from agroforestry trees: a review  

Microsoft Academic Search

The domestication of trees for agroforestry approaches to poverty alleviation and environmental rehabilitation in the tropics depends on the expansion of the market demand for non-timber forest products. This paper reviews published data on the nutritive values of the flesh, kernels and seedoils of the seventeen fruit tree species that have been identified, in four ecoregions of the tropics, by

R. R. B Leakey

1999-01-01

154

Contribution of agroforestry trees to nutrient requirements of intercropped plants  

Microsoft Academic Search

A major tenet of agroforestry, that trees maintain soil fertility, is based primarily on observations of higher crop yields near trees or where trees were previously grown. Recently objective analyses and controlled experiments have addressed this topic. This paper examines the issues of tree prunings containing sufficient nutrients to meet crop demands, the timing of nutrient transfer from decomposition to

C. A. Palm

1995-01-01

155

Acacia nilotica and Medicago sativa, suitable plants for agro-forestry in southern coasts of Iran.  

PubMed

Habitats of the multipurpose tree, Acacia nilotica, were identified along the coastline of the Persian Gulf and Oman Sea, south of Iran. Four sites were randomly chosen and in each one, vegetation as well as climatic and soil characteristics were studied. Likewise, biometry of Acacia trees was conducted and compared in the sites. The fodder values in leaf and fruit of Acacia were determined and compared with those of in foliage of Medicago sativa being managed under an agro-forestry system. By analyzing data it was revealed that the biggest trees were found in Dashteyari region and the smallest in Bamani region (both in the Oman Sea coast). Values in most of nutritional elements were higher in foliage of Medicago than in leaf and fruit of Acacia, respectively. From this investigation it is concluded that in south of Iran where the site is favorable for Acacia plantation, cultivation of Medicago or other adaptable crops together with Acacia can be developed as agroforestry systems (such as undercropping and intercropping) if water is available. PMID:19086523

Emtehani, Mohammad Hassan; Tabari, Masoud

2007-05-15

156

Agroforestry Tree Products (AFTPs): Targeting Poverty Reduction and Enhanced Livelihoods  

Microsoft Academic Search

Agroforestry tree domestication emerged as a farmer-driven, market-led process in the early 1990s and became an international initiative. A participatory approach now supplements the more traditional aspects of tree improvement, and is seen as an important strategy towards the Millennium Development Goals of eradicating poverty and hunger, promoting social equity and environmental sustainability. Considerable progress has been made towards the

Roger R. B. Leakey; Zac Tchoundjeu; Kate Schreckenberg; Sheona E. Shackleton; Charlie M. Shackleton

2005-01-01

157

PARTICIPATORY ASSESSMENT OF FARMERS' EXPERIENCES OF TERMITE PROBLEMS IN AGROFORESTRY IN TORORO DISTRICT, UGANDA  

Microsoft Academic Search

As agroforestry technologies are developed and promoted, there is a need to integrate indigenous knowledge about pest identification and management techniques into the scaling-up process in order to improve farmers' pest management practices. This paper documents farmers' knowledge, perceptions and management practices against termites in agroforestry in Tororo District, Uganda. The applicability and implications of such information in the development

Philip Nyeko; Florence M. Olubayo

158

Diameter patterns of 5-year old Karas (Aquilaria malaccensis) agroforestry stands  

Microsoft Academic Search

The work conducted in this study is based on a preliminary data collection for assessing a soil status in a 5-year old Karas agroforestry plantations in Rembau, Negeri Sembilan, Malaysia. Three agroforestry components involved in this study include (1) Karas (Aquilaria malaccensis) monoculture, (2) Karas intercropped with lemongrass, and (3) Karas intercropped with guava. Three replicative plots measuring at 6

Nurul Ain Noor Rahman; Mohd Nazip Suratman; Ab. Rasip Ab. Ghani; Tsan Fui Ying

2011-01-01

159

The central agroforestry hypothesis: the trees must acquire resources that the crop would not otherwise acquire  

Microsoft Academic Search

A simple tree-crop interaction equation is re-interpreted in terms of resource capture. Benefits in physical yields from agroforestry are to be expected only when there is complementarity of resource capture by trees and crops. Most of the current biophysical hypotheses formulated for agroforestry research are based on this central tenet, specified for various resources, soil and climatic conditions.

M. G. R. Cannell; M. Van Noordwijk; C. K. Ong

1996-01-01

160

Assessing the adoption potential of agroforestry practices in sub-Saharan Africa  

Microsoft Academic Search

This paper reviews the application of various types of on-farm trials and methods for collecting and analysing data needed to assess the adoption potential of agroforestry practices. The review is based on farmers' and researchers' experiences in seven case studies in three countries of sub-Saharan Africa assessing the biophysical performance, profitability and acceptability of agroforestry practices. Assessments of adoption potential

S. Franzel; R. Coe; P. Cooper; S. J. Scherr

2001-01-01

161

Economic factors in farmer adoption of agroforestry: Patterns observed in Western Kenya  

Microsoft Academic Search

A study of agroforestry adoption by 3,000 project participants in Siaya and South Nyanza Districts in Kenya supports three hypotheses. 1.(1) Historical increases in tree domestication and management intensity are responses to declining supply of uncultivated tree resources, increased subsistence and commercial demand for tree products, and perceived risks of ecological degradation. Adoption of agroforestry is most likely where consistent

Sara J. Scherr

1995-01-01

162

Decomposition and nutrient release patterns of the leaf biomass of the wild sunflower ( Tithonia diversifolia ): a comparative study with four leguminous agroforestry species  

Microsoft Academic Search

The selection and use of appropriate plant materials to maintain a sufficiently high nutrient supply to meet crop needs remains\\u000a a major challenge of nutrient management under low input systems. Therefore, research on plant biomass quality as it relates\\u000a to decomposition and nutrient release has become imperative. This research was conducted at the Agroforestry Research Station\\u000a of the Kwame Nkrumah

S. T. Partey; S. J. Quashie-Sam; N. V. Thevathasan; A. M. Gordon

2011-01-01

163

Root length dynamics in agroforestry with Gliricidia sepium as compared to sole cropping in the semi-deciduous rainforest zone of West Africa  

Microsoft Academic Search

Tree root systems may improve soil fertility through carbon inputs, uptake of leachable nutrients and maintenance of soil\\u000a biomass, but can at the same time reduce crop yields by competition for water and nutrients. Quantitative information about\\u000a the positive and negative effects of tree roots and their changes in space and time are necessary for the optimization of\\u000a agroforestry associations.

Götz Schroth; Wolfgang Zech

1995-01-01

164

Taxonomic diversity of bacteria associated with the roots of field-grown transgenic Brassica napus cv. Quest, compared to the non-transgenic B. napus cv. Excel and B. rapa cv. Parkland  

Microsoft Academic Search

The composition and diversity of the bacterial community associated with plant roots is influenced by a variety of plant factors such as root density and exudation. In turn, these factors are influenced by plant breeding programs. This study assessed the diversity of root-endophytic and rhizosphere bacterial communities associated with three canola cultivars (Parkland, Brassica rapa; Excel, B. napus; and Quest,

S. D Siciliano; J. J Germida

1999-01-01

165

Immature mosquitoes associated with urban parklands: implications for water and mosquito management.  

PubMed

The aim of the present study was to compare 2 urban habitat types: pools artificially filled with water from damaged or leaking water pipes (AF) and pools naturally filled by rainwater (NF), with regard to their favorability as breeding sites for mosquitoes. Two study areas were analyzed, 1 for 5 months and the other for 9 months, covering the whole period when AF pools contained water. The AF pools held water during the entire study, and showed lower fluctuations in surface area than NF pools. The AF pools showed higher levels of total mosquitoes and of stagnant-water mosquitoes. The floodwater mosquitoes were numerically (but not significantly) more abundant in NF pools. Nine mosquito species were identified. Habitat type, temperature, and season were significant in explaining the variability in species composition according to the canonical correspondence analysis. The most abundant species were Ochlerotatus albifasciatus (= Aedes albifasciatus, predominantly in NF pools), Culex dolosus, and Cx. pipiens (mainly in AF pools). The latter 2 species differed in their temporal dynamics, with Cx. dolosus associated with lower temperatures and Cx. pipiens with higher temperatures. Overall, the results indicate that although both habitat types harbored immature mosquitoes, the AF pools were more favorable than co-occurring rain pools. Easy-to-implement management actions such as the design of adequate drainage systems and the fast repair of broken pipes will be helpful to reduce the risk of human illness associated with mosquitoes in urban green areas. PMID:23687852

Quiroga, Laura; Fischer, Sylvia; Schweigmann, Nicolás

2013-03-01

166

ECOFARMING AND AGROFORESTRY FOR SELF-RELIANCE: Small-scale, Sustainable Growing Practices in Russia  

Microsoft Academic Search

Agroforestry concepts are applicable to both small-scale (family farm) and microscale (e.g., home garden) cultivation. However, there is little research on the relevance of gardening practices in temperate zones to agroforestry and vice versa. In Russia, microscale ecofarming is an extremely widespread, time-tested practice. Despite the minuscule size (600 m2) of individual plots and absence of machinery, cultivators have demonstrated

Leonid Sharashkin; Michael Gold; Elizabeth Barham

167

Indigenous market-oriented agroforestry: dissecting local diversity in western Amazonia  

Microsoft Academic Search

This paper reports on a study of local diversity and variation in indigenous agroforestry practices among Amazonian peasants\\u000a in a traditional community near Iquitos, Peru. Data were gathered through in-depth interviews with agroforestry-reliant households\\u000a n = 36) on farming practices, demographic characteristics, income-expenditures and household wealth. Visits to crop fields\\u000a and forest fallows n = 329) allowed the reconstruction of

O. T. Coomes; G. J. Burt

1997-01-01

168

Role of woody perennials in animal agroforestry  

Microsoft Academic Search

Two main roles are identified in the review: the productive one, where woody perennials yield a material output (fuel, fodder, etc.), and the ‘service’ type, with no tangible product (shelter, nutrient recycling, etc.). In their productive role trees and shrubs may supply fodder in browsing systems, or industrial material, wood products and food in forest and plantation grazing systems. Service

Filemon Torres

1983-01-01

169

Below-ground interactions in dryland agroforestry  

Microsoft Academic Search

This paper discusses the effects of intercropping and tree pruning on root distribution and soil water depletion in an alley cropping system with Acacia saligna and Sorghum bicolor in northern Kenya. Root distribution was determined by destructive sampling, and the soil water suction was measured with tensiometers and gypsum blocks, both up to 150cm depth. The root systems of the

Johannes Lehmann; Inka Peter; Claudia Steglich; Gerhard Gebauer; Bernd Huwe; Wolfgang Zech

1998-01-01

170

Hydrologic Activity of Deciduous Agroforestry Tree : Observed through Monitoring of Stable Isotopes in Stem Water, Solar Radiation Attenuation, and Sapflow  

NASA Astrophysics Data System (ADS)

The net benefit of agroforestry trees for small scale farmers in dryland agricultural systems is debatable because while they provide significant direct and indirect services, they also consume considerable amounts of scare water resources. In this study we monitor the stable isotopes of water to improve a water budget of a Sclerocarya birrea tree in a millet field in South Eastern Burkina Faso. Data obtained from air temperature and humidity, surface temperature, solar radiation, and soil moisture sensors attached to a wireless sensor network uniquely configured around the agroforestry tree provided the initial calculation of the local water balance. Isotopic ratios were determined from water extracted from stems and sub canopy soil, and from nearby ground water, precipitation, and surface water that was sampled weekly. A linear mixing model is used to predict when the tree switched between water sources. The results from the linear mixing model coupled with a tree water balance demonstrate the extreme seasonality of the annual cycle of water use by this deciduous species.

Ceperley, N. C.; Mande, T.; Parlange, M. B.

2012-12-01

171

Farmers, the Practice of Farming and the Future of Agroforestry: An Application of Bourdieu's Concepts of Field and Habitus  

ERIC Educational Resources Information Center

Agroforestry, the practice of raising crops and trees together in ways that are mutually beneficial, provides farmers with an alternative to more conventional farming practices. In this paper, we apply Bourdieu's concepts of "field" and "habitus" in an attempt to better understand the practice of farming and the role that agroforestry may have in…

Raedeke, Andrew H.; Green, John J.; Hodge, Sandra S.; Valdivia, Corinne

2003-01-01

172

Modelling the hydrological behaviour of a coffee agroforestry basin in Costa Rica  

NASA Astrophysics Data System (ADS)

The profitability of hydropower in Costa Rica is affected by soil erosion and sedimentation in dam reservoirs, which are in turn influenced by land use, infiltration and aquifer interactions with surface water. In order to foster the provision and payment of Hydrological Environmental Services (HES), a quantitative assessment of the impact of specific land uses on the functioning of drainage-basins is required. The present paper aims to study the water balance partitioning in a volcanic coffee agroforestry micro-basin (1 km2, steep slopes) in Costa Rica, as a first step towards evaluating sediment or contaminant loads. The main hydrological processes were monitored during one year, using flume, eddy-covariance flux tower, soil water profiles and piezometers. A new Hydro-SVAT lumped model is proposed, that balances SVAT (Soil Vegetation Atmosphere Transfer) and basin-reservoir routines. The purpose of such a coupling was to achieve a trade-off between the expected performance of ecophysiological and hydrological models, which are often employed separately and at different spatial scales, either the plot or the basin. The calibration of the model to perform streamflow yielded a NS coefficient equal to 0.80, while the validation of the water balance partitioning was consistent with the independent measurements of actual evapotranspiration (R2=0.79, energy balance closed independently), soil water content (R2=0.49) and water table level (R2=0.90). An uncertainty analysis showed that the streamflow modelling was precise for nearly every time step, while a sensitivity analysis revealed which parameters mostly affected model precision, depending on the season. It was observed that 64% of the incident rainfall R flowed out of the basin as streamflow, 25% as evapotranspiration and the remaining 11% was attributed to deep percolation. The model indicated an interception loss equal to 4% of R, a surface runoff of 5% and an infiltration component of 91%. The modelled streamflow was constituted by 63% of baseflow originating from the aquifer, 29% of subsurface non-saturated runoff and 8% of surface runoff. Given the low surface runoff observed under the current physical conditions (andisol) and management practices (no tillage, planted trees, bare soil kept by weeding), this agroforestry system on a volcanic soil demonstrated potential to provide valuable HES, such as a reduced superficial displacement-capacity for fertilizers, pesticides and sediments, as well as a streamflow regulation function provided by the highly efficient mechanisms of aquifer recharge and discharge. The proposed combination of experimentation and modelling across ecophysiological and hydrological approaches proved to be useful to account for the behaviour of a given basin, so that it can be applied to compare HES provision for different regions or management alternatives.

Gómez-Delgado, F.; Roupsard, O.; Moussa, R.; Le Maire, G.; Taugourdeau, S.; Bonnefond, J. M.; Pérez, A.; van Oijen, M.; Vaast, P.; Rapidel, B.; Voltz, M.; Imbach, P.; Harmand, J. M.

2010-05-01

173

Sources of water used by trees and millet in Sahelian windbreak systems  

Microsoft Academic Search

The extent to which water use by trees and crops is complementary in agroforestry systems may be affected by the proximity of groundwater to the soil surface. This may have important implications for the planning and management of agroforestry in semi-arid regions such as the Sahel of West Africa. A method of distinguishing uptake of water by plants from different

D. Mark Smith; Paul G Jarvis; Julius C. W Odongo

1997-01-01

174

Relationship between land-use in the agro-forestry system of les Landes, nitrogen loading to and risk of macro-algal blooming in the Bassin d'Arcachon coastal lagoon (SW France)  

NASA Astrophysics Data System (ADS)

Nitrogen loading to the Bassin d'Arcachon coastal lagoon (SW France) was evaluated by studying land-use and nitrogen output in its 3001 km 2 catchment. At present, the catchment is dominated by forestry (79%), while intensive agriculture occupies 9% of the surface. The N-output of two hydrological subunits, i.e. the Tagon subunit dominated by pine forestry and the Arriou II subunit comprising both forestry and intensive agriculture, were monitored for a seven year period (1996-2002). From these observations it was calculated that forestry contributes on average 1.6 kg total N ha -1 yr -1, which is dominated by organic nitrogen (DON + PON are 70% of N). On an areal basis, intensive agriculture contributes 26 times more than forestry, i.e. 41.6 kg total N ha -1 yr -1, which is mainly in the form of nitrate (65% of N). These data were upscaled to the catchment and the upscaling was validated by comparison to gauged nitrogen throughputs for the catchment of the Leyre river that is the major tributary to the system. Taking into account the other known N sources and the interannual variability in the catchment it was estimated that nitrogen loading to the lagoon was on average 90 kg ha -1 yr -1 (range from 54 to 126 kg ha -1 yr -1). The sandy soils of the catchment have a clear potential for denitrification, but anoxic conditions (waterlogged) and input of organic matter to fuel this process are required. Currently, agricultural practices and spatial planning do not make use of this potential. Nitrogen loading in the Bassin d'Arcachon is reflected by 10-40 ?M nitrate concentrations in winter, which became depleted during spring as a result of uptake by vegetation. Short-term uptake experiments showed that the macroalga Monostroma obscurum is well adapted to temperatures between 10 to 20 °C and competitive with respect to the seagrass Zostera noltii when the nitrate concentrations are above 10 ?M. Spring conditions with high nitrate and high insolation are therefore favourable for M. obscurum and this species presents a high risk for algal blooming. In contrast, the macroalga Enteromorpha clathrata well adapted to summertime temperatures around 25 °C, forms occasionally blooms in the lagoon. This phenomenon is limited due to the low DIN concentrations in summer.

De Wit, R.; Leibreich, J.; Vernier, F.; Delmas, F.; Beuffe, H.; Maison, Ph.; Chossat, J.-C.; Laplace-Treyture, C.; Laplana, R.; Clavé, V.; Torre, M.; Auby, I.; Trut, G.; Maurer, D.; Capdeville, P.

2005-02-01

175

Barriers and Coping Mechanisms Relating to Agroforestry Adoption by Smallholder Farmers in Zimbabwe  

ERIC Educational Resources Information Center

Purpose: The purpose of the present study was to investigate agroforestry adoption by smallholder farmers in Gutu District, Zimbabwe. Design/Methodology/Approach: The methodology was based on field data collected through household questionnaires, key informant interviews and direct observations. Findings: Major findings reveal that traditional…

Chitakira, Munyaradzi; Torquebiau, Emmanuel

2010-01-01

176

Agroforestry farming systems in the homesteads of Kerala, southern India  

Microsoft Academic Search

Kerala State on the southwestern coast of India in the tropical humid zone has a predominantly agricultural economy, a very high density of population and therefore high pressure on cultivable land. The farmers there undertake cultivation of an array of crops — tree crops, plantation crops, seasonals and biennials — all in intimate mixtures on the same piece of land

M. Achuthan Nair; C. Sreedharan

1986-01-01

177

Managing genetic variation in tropical trees: linking knowledge with action in agroforestry ecosystems for improved conservation and enhanced livelihoods  

Microsoft Academic Search

Tree species in agroforestry ecosystems contribute to the livelihoods of rural communities and play an important role in the\\u000a conservation of biodiversity. Unless agroforestry landscapes are productive, however, farmers will not maintain or enhance\\u000a the range and quality of tree species in them, and both income opportunities and biodiversity will be lost. Productivity depends\\u000a on both tree species diversity and

Ian K. Dawson; Ard Lengkeek; John C. Weber; Ramni Jamnadass

2009-01-01

178

Fuelwood production in traditional farming systems  

SciTech Connect

Local systems (windbreaks, shade trees, bush fallow, agroforestry, amenity, etc.), uses (fuelwood, timber, light farm wood, and other uses), method of propagation, and site requirements are tabulated for 14 species groups.

Salem, B.B.; Van Nao, T.

1981-01-01

179

Modelling the hydrological behaviour of a coffee agroforestry basin in Costa Rica  

NASA Astrophysics Data System (ADS)

The profitability of hydropower in Costa Rica is affected by soil erosion and sedimentation in dam reservoirs, which are in turn influenced by land use, infiltration and aquifer interactions with surface water. In order to foster the provision and payment for Hydrological Environmental Services (HES), a quantitative assessment of the impact of specific land uses on the functioning of drainage-basins is required. The present paper aims to study the water balance partitioning in a volcanic coffee agroforestry micro-basin (1 km2, steep slopes) in Costa Rica, as a first step towards evaluating sediment or contaminant loads. The main hydrological processes were monitored during one year, using flume, eddy-covariance flux tower, soil water profiles and piezometers. A new Hydro-SVAT lumped model is proposed, that balances SVAT (Soil Vegetation Atmosphere Transfer) and basin-reservoir routines. The purpose of such a coupling was to achieve a trade-off between the expected performance of ecophysiological and hydrological models, which are often employed separately and at different spatial scales, either the plot or the basin. The calibration of the model to perform streamflow yielded a Nash-Sutcliffe (NS) coefficient equal to 0.89 for the year 2009, while the validation of the water balance partitioning was consistent with the independent measurements of actual evapotranspiration (R2 = 0.79, energy balance closed independently), soil water content (R2 = 0.35) and water table level (R2 = 0.84). Eight months of data from 2010 were used to validate modelled streamflow, resulting in a NS = 0.75. An uncertainty analysis showed that the streamflow modelling was precise for nearly every time step, while a sensitivity analysis revealed which parameters mostly affected model precision, depending on the season. It was observed that 64% of the incident rainfall R flowed out of the basin as streamflow and 25% as evapotranspiration, while the remaining 11% is probably explained by deep percolation, measurement errors and/or inter-annual changes in soil and aquifer water stocks. The model indicated an interception loss equal to 4% of R, a surface runoff of 4% and an infiltration component of 92%. The modelled streamflow was constituted by 87% of baseflow originating from the aquifer, 7% of subsurface non-saturated runoff and 6% of surface runoff. Given the low surface runoff observed under the current physical conditions (andisol) and management practices (no tillage, planted trees, bare soil kept by weeding), this agroforestry system on a volcanic soil demonstrated potential to provide valuable HES, such as a reduced superficial displacement-capacity for fertilizers, pesticides and sediments, as well as a streamflow regulation function provided by the highly efficient mechanisms of aquifer recharge and discharge. The proposed combination of experimentation and modelling across ecophysiological and hydrological approaches proved to be useful to account for the behaviour of a given basin, so that it can be applied to compare HES provision for different regions or management alternatives.

Gómez-Delgado, F.; Roupsard, O.; Le Maire, G.; Taugourdeau, S.; Pérez, A.; van Oijen, M.; Vaast, P.; Rapidel, B.; Harmand, J. M.; Voltz, M.; Bonnefond, J. M.; Imbach, P.; Moussa, R.

2011-01-01

180

The biology, ecology and agroforestry potential of the raintree, Samanea saman (Jacq.) Merr  

Microsoft Academic Search

Samanea saman (Jacq.) Merr. (syn. Albizia saman (Jacq.) F. v. Muell.) is a large tree, native to tropical America, which has now become widespread throughout the humid and\\u000a subhumid tropics. Although noted as a promising agroforestry species, there is little specific research that substantiates\\u000a this potential. On the basis of a review of its biology, ecology and recorded uses, it

P. A. Durr

2001-01-01

181

GHG Mitigation potential and cost in tropical forestry - Relative role for agroforestry  

SciTech Connect

This paper summarizes studies of carbon mitigation potential (MP) and costs of forestry options in seven developing countries with a focus on the role of agroforestry. A common methodological approach known as comprehensive mitigation assessment process (COMAP) was used in each study to estimate the potential and costs between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios derived from the demand for forest products and forestland for other uses such as agriculture and pasture. By using data on estimated carbon sequestration, emission avoidance, costs and benefits, the model enables one to estimate cost effectiveness indicators based on monetary benefit per t C, as well as estimates of total mitigation costs and potential when the activities are implemented at equilibrium level. The results show that about half the MP of 6.9 Gt C (an average of 223 Mt C per year) between 2000 and 2030 in the seven countries could be achieved at a negative cost, and the other half at costs not exceeding $100 per t C. Negative cost indicates that non-carbon revenue is sufficient to offset direct costs of about half of the options. The agroforestry options analyzed bear a significant proportion of the potential at medium to low cost per t C when compared to other options. The role of agroforestry in these countries varied between 6% and 21% of the MP, though the options are much more cost effective than most due to the low wage or opportunity cost of rural labor. Agroforestry options are attractive due to the large number of people and potential area currently engaged in agriculture, but they pose unique challenges for carbon and cost accounting due to the dispersed nature of agricultural activities in the tropics, as well as specific difficulties arising from requirements for monitoring, verification, leakage assessment and the establishment of credible baselines.

Makundi, Willy R.; Sathaye, Jayant A.

2004-01-01

182

Mitigation potential and cost in tropical forestry - relative role for agroforestry  

SciTech Connect

This paper summarizes studies of carbon mitigation potential (MP) and costs of forestry options in seven developing countries with a focus on the role of agroforestry. A common methodological approach known as comprehensive mitigation assessment process (COMAP) was used in each study to estimate the potential and costs between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios derived from the demand for forest products and forestland for other uses such as agriculture and pasture. By using data on estimated carbon sequestration, emission avoidance, costs and benefits, the model enables one to estimate cost effectiveness indicators based on monetary benefit per t C, as well as estimates of total mitigation costs and potential when the activities are implemented at equilibrium level. The results show that about half the MP of 6.9 Gt C (an average of 223 Mt C per year) between 2000 and 2030 in the seven countries could be achieved at a negative cost, and the other half at costs not exceeding $100 per t C. Negative cost indicates that non-carbon revenue is sufficient to offset direct costs of about half of the options. The agroforestry options analyzed bear a significant proportion of the potential at medium to low cost per t C when compared to other options. The role of agroforestry in these countries varied between 6% and 21% of the MP, though the options are much more cost effective than most due to the low wage or opportunity cost of rural labor. Agroforestry options are attractive due to the large number of people and potential area currently engaged in agriculture, but they pose unique challenges for carbon and cost accounting due to the dispersed nature of agricultural activities in the tropics, as well as specific difficulties arising from requirements for monitoring, verification, leakage assessment and the establishment of credible baselines.

Makundi, Willy R.; Sathaye, Jayant A.

2004-01-01

183

Local and landscape factors determine functional bird diversity in Indonesian cacao agroforestry  

Microsoft Academic Search

Large-scale intensification of smallholder cacao management is currently affecting the agroforestry landscapes of Sulawesi (Indonesia), the world’s third largest cacao producer. Little is known about how this shift from diverse plantations to full-sun cacao will affect functionally important biodiversity within the agroecosystem, and how this is related to landscape-wide patterns in land-use and natural ecosystems. We recorded birds in 43

Yann Clough; Dadang Dwi Putra; Ramadhanil Pitopang; Teja Tscharntke

2009-01-01

184

The role of agroforestry in industrialized nations: the southern hemisphere perspective with special emphasis on Australia and New Zealand  

Microsoft Academic Search

Agroforestry in Australia and New Zealand is dominated by silvopastoralism. Farmers may employ combinations of shelterbelts, shade trees, widely spaced trees over pasture, or more densely planted woodlots. In addition to wood production and shelter, erosion control, amenity and landscape planting, and conservation of natural forest are often important. Many farm forestry people show considerable innovation.In temperate wetter areas of

D. J. Mead

1995-01-01

185

Farmer costs and benefits from agroforestry and farm forestry projects in Central America and the Caribbean: implications for policy  

Microsoft Academic Search

This paper presents results of an evaluation of the benefits provided by agroforestry and farm forestry projects in Central America and the Caribbean, and the policy implications. Tree planting provided financial benefits to farmers, as well as social, economic and environmental benefits. These justify policy interventions to explicitly recognize the potential of on-farm tree-planting efforts and provide a policy environment

S. J. Scherr

1995-01-01

186

Impact of residue quality on the C and N mineralization of leaf and root residues of three agroforestry species  

Microsoft Academic Search

A laboratory incubation experiment with 15N labeled root and leaf residues of 3 agroforestry species (Leucaena leucocephala, Dactyladenia barteri and Flemingia macrophylla) was conducted under controlled conditions (25 C) for 56 days to quantify residue C and N mineralization and its relationship with residue quality.

B. Vanlauwe; O. C. Nwoke; N. Sanginga; R. Merckx

1996-01-01

187

Decomposition and phosphorus release of agroforestry shrub residues and the effect on maize yield in acidic soils of Rubona, southern Rwanda  

Microsoft Academic Search

Phosphorus release from decomposing leaf biomass of Calliandra\\u000a calothyrsus Meissner, Tithonia diversifolia Hensley A.Gray and Tephrosia vogelii Hook.f. agroforestry species applied alone or combined with triple super phosphate (TSP) was studied at World Agroforestry\\u000a Centre (ICRAF) laboratory for 56 days using an incubation method. The effects of above treatments on maize yield were evaluated\\u000a in the field at Rubona, southern province

A. Mukuralinda; J. S. Tenywa; L. Verchot; J. Obua; S. Namirembe

2009-01-01

188

Guide to monitoring carbon storage in forestry and agroforestry projects  

Microsoft Academic Search

As the international Joint Implementation (JI) program develops a system for trading carbon credits to offset greenhouse gas emissions, project managers need a reliable basis for measuring the carbon storage benefits of carbon offset projects. Monitoring and verifying carbon storage can be expensive, depending on the level of scientific validity needed. This guide describes a system of cost-effective methods for

K. G. MacDicken

1997-01-01

189

Achieving food and nutritional security through agroforestry: a case of Faidherbia albida in sub-Saharan Africa  

Microsoft Academic Search

Faidherbia albida is an ideal agroforestry tree commonly intercropped with annual crops like millet and groundnuts in the dry and densely populated\\u000a areas of Africa. With its peculiar reverse phenology, it makes growth demands at a different time from that of crops. In addition,\\u000a it deposits great amount of organic fertilizer on food crops. Leaves entering soils are comparable to

Neo C. Mokgolodi; Moffat P. Setshogo; Ling-ling Shi; Yu-jun Liu; Chao Ma

2011-01-01

190

Distribution of throughfall and stemflow in multi-strata agroforestry, perennial monoculture, fallow and primary forest in central Amazonia, Brazil  

NASA Astrophysics Data System (ADS)

The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi-strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open-area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open-area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow.

Schroth, Götz; Ferreira da Silva, Luciana; Wolf, Marc-Andree; Geraldes Teixeira, Wenceslau; Zech, Wolfgang

1999-07-01

191

Elephants also like coffee: trends and drivers of human-elephant conflicts in coffee agroforestry landscapes of Kodagu, Western Ghats, India.  

PubMed

Kodagu district produces 2% of the world's coffee, in complex, multistoried agroforestry systems. The forests of the district harbour a large population of the Asian elephant (Elephas maximus). The combined effects of high elephant density and major landscape changes due to the expansion of coffee cultivation are the cause of human-elephant conflicts (HEC). Mitigation strategies, including electric fences and compensation schemes implemented by the Forest Department have met with limited success. Building on previous studies in the area, we assessed current spatial and temporal trends of conflict, analysed local stakeholders' perceptions and identified factors driving elephants into the estates. Our study, initiated in May 2007, shows that the intensity of HEC has increased over the last 10 years, exhibiting new seasonal patterns. Conflict maps and the lack of correlation between physical features of the coffee plantations and elephant visits suggest elephants move along corridors between the eastern and western forests of the district, opportunistically foraging when crossing the plantations. Dung analyses indicate elephants have selectively included ripe coffee berries in their diet. This is, to our knowledge, the first report of wild elephants feeding on coffee berries. If this new behaviour spreads through the population, it will compound an already severe conflict situation. The behavioural plasticity, the multiplicity of stakeholders involved, the difficulty in defining the problem and the limits of technical solutions already proposed suggest that HEC in Kodagu has the ingredients of a "wicked" problem whose resolution will require more shared understanding and problem solving work amongst the stakeholders. PMID:21359868

Bal, P; Nath, C D; Nanaya, K M; Kushalappa, C G; Garcia, C

2011-05-01

192

Erratum to: Elephants also like coffee: Trends and drivers of human-elephant conflicts in coffee agroforestry landscapes of Kodagu, Western Ghats, India.  

PubMed

Kodagu district produces 2% of the world's coffee, in complex, multistoried agroforestry systems. The forests of the district harbour a large population of the Asian elephant (Elephas maximus). The combined effects of high elephant density and major landscape changes due to the expansion of coffee cultivation are the cause of human-elephant conflicts (HEC). Mitigation strategies, including electric fences and compensation schemes implemented by the Forest Department have met with limited success. Building on previous studies in the area, we assessed current spatial and temporal trends of conflict, analysed local stakeholders' perceptions and identified factors driving elephants into the estates. Our study, initiated in May 2007, shows that the intensity of HEC has increased over the last 10 years, exhibiting new seasonal patterns. Conflict maps and the lack of correlation between physical features of the coffee plantations and elephant visits suggest elephants move along corridors between the eastern and western forests of the district, opportunistically foraging when crossing the plantations. Dung analyses indicate elephants have selectively included ripe coffee berries in their diet. This is, to our knowledge, the first report of wild elephants feeding on coffee berries. If this new behaviour spreads through the population, it will compound an already severe conflict situation. The behavioural plasticity, the multiplicity of stakeholders involved, the difficulty in defining the problem and the limits of technical solutions already proposed suggest that HEC in Kodagu has the ingredients of a "wicked" problem whose resolution will require more shared understanding and problem solving work amongst the stakeholders. PMID:21751010

Bal, P; Nath, C D; Nanaya, K M; Kushalappa, C G; Garcia, C

2011-08-01

193

Elephants Also Like Coffee: Trends and Drivers of Human-Elephant Conflicts in Coffee Agroforestry Landscapes of Kodagu, Western Ghats, India  

NASA Astrophysics Data System (ADS)

Kodagu district produces 2% of the world's coffee, in complex, multistoried agroforestry systems. The forests of the district harbour a large population of the Asian elephant ( Elephas maximus). The combined effects of high elephant density and major landscape changes due to the expansion of coffee cultivation are the cause of human-elephant conflicts (HEC). Mitigation strategies, including electric fences and compensation schemes implemented by the Forest Department have met with limited success. Building on previous studies in the area, we assessed current spatial and temporal trends of conflict, analysed local stakeholders' perceptions and identified factors driving elephants into the estates. Our study, initiated in May 2007, shows that the intensity of HEC has increased over the last 10 years, exhibiting new seasonal patterns. Conflict maps and the lack of correlation between physical features of the coffee plantations and elephant visits suggest elephants move along corridors between the eastern and western forests of the district, opportunistically foraging when crossing the plantations. Dung analyses indicate elephants have selectively included ripe coffee berries in their diet. This is, to our knowledge, the first report of wild elephants feeding on coffee berries. If this new behaviour spreads through the population, it will compound an already severe conflict situation. The behavioural plasticity, the multiplicity of stakeholders involved, the difficulty in defining the problem and the limits of technical solutions already proposed suggest that HEC in Kodagu has the ingredients of a "wicked" problem whose resolution will require more shared understanding and problem solving work amongst the stakeholders.

Bal, P.; Nath, C. D.; Nanaya, K. M.; Kushalappa, C. G.; Garcia, C.

2011-05-01

194

Erratum: Erratum to: Elephants Also Like Coffee: Trends and Drivers of Human-Elephant Conflicts in Coffee Agroforestry Landscapes of Kodagu, Western Ghats, India  

NASA Astrophysics Data System (ADS)

Kodagu district produces 2% of the world's coffee, in complex, multistoried agroforestry systems. The forests of the district harbour a large population of the Asian elephant ( Elephas maximus). The combined effects of high elephant density and major landscape changes due to the expansion of coffee cultivation are the cause of human-elephant conflicts (HEC). Mitigation strategies, including electric fences and compensation schemes implemented by the Forest Department have met with limited success. Building on previous studies in the area, we assessed current spatial and temporal trends of conflict, analysed local stakeholders' perceptions and identified factors driving elephants into the estates. Our study, initiated in May 2007, shows that the intensity of HEC has increased over the last 10 years, exhibiting new seasonal patterns. Conflict maps and the lack of correlation between physical features of the coffee plantations and elephant visits suggest elephants move along corridors between the eastern and western forests of the district, opportunistically foraging when crossing the plantations. Dung analyses indicate elephants have selectively included ripe coffee berries in their diet. This is, to our knowledge, the first report of wild elephants feeding on coffee berries. If this new behaviour spreads through the population, it will compound an already severe conflict situation. The behavioural plasticity, the multiplicity of stakeholders involved, the difficulty in defining the problem and the limits of technical solutions already proposed suggest that HEC in Kodagu has the ingredients of a "wicked" problem whose resolution will require more shared understanding and problem solving work amongst the stakeholders.

Bal, P.; Nath, C. D.; Nanaya, K. M.; Kushalappa, C. G.; Garcia, C.

2011-08-01

195

Development Of An Agroforestry Sequestration Project In KhammamDistrict Of India  

SciTech Connect

Large potential for agroforestry as a mitigation option hasgiven rise to scientific and policy questions. This paper addressesmethodological issues in estimating carbon sequestration potential,baseline determination, additionality and leakage in Khammam district,Andhra Pradesh, southern part of India. Technical potential forafforestation was determined considering the various landuse options. Forestimating the technical potential, culturable wastelands, fallow andmarginal croplands were considered for Eucalyptus clonal plantations.Field studies for aboveground and below ground biomass, woody litter andsoil organic carbon for baseline and project scenario were conducted toestimate the carbon sequestration potential. The baseline carbon stockwas estimated to be 45.33 tC/ha. The additional carbon sequestrationpotential under the project scenario for 30 years is estimated to be12.82 tC/ha/year inclusive of harvest regimes and carbon emissions due tobiomass burning and fertilizer application. The project scenario thoughhas a higher benefit cost ratio compared to baseline scenario, initialinvestment cost is high. Investment barrier exists for adoptingagroforestry in thedistrict.

Sudha, P.; Ramprasad, V.; Nagendra, M.D.V.; Kulkarni, H.D.; Ravindranath, N.H.

2007-06-01

196

Depletion of Stem Water of Sclerocarya birrea Agroforestry Tree Precedes Start of Rainy Season in West African Sudanian Zone  

NASA Astrophysics Data System (ADS)

Understanding water use by agroforestry trees in dry-land ecosystems is essential for improving water management. Agroforestry trees are valued and promoted for many of their ecologic and economic benefits but are often criticized as competing for valuable water resources. In order to understand the seasonal patterns of source water used by agroforestry trees, samples from rain, ground, and surface water were collected weekly in the subcatchment of the Singou watershed that is part of the Volta Basin. Soil and vegetation samples were collected from and under a Sclerocarya birrea agroforstry trees located in this catchment in sealed vials, extracted, and analyzed with a Picarro L2130-i CRDS to obtain both ?O18 and ?DH fractions. Meteorological measurements were taken with a network of wireless, autonomous stations that communicate through the GSM network (Sensorscope) and two complete eddy-covariance energy balance stations, in addition to intense monitoring of sub-canopy solar radiation, throughfall, stemflow, and soil moisture. Examination of the time series of ?O18 concentrations confirm that values in soil and xylem water are coupled, both becoming enriched during the dry season and depleted during the rainy season. Xylem water ?O18 levels drops to groundwater ?O18 levels in early March when trees access groundwater for leafing out, however soil water does not reach this level until soil moisture increases in mid-June. The relationship between the ?DH and ?O18 concentrations of water extracted from soil and tree samples do not fall along the global meteoric water line. In order to explore whether this was a seasonally driven, we grouped samples into an "evaporated" group or a "meteoric" group based on the smaller residual to the respective lines. Although more soil samples were found along the m-line during the rainy season than tree samples or dry season soil samples, there was no significant difference in days since rain for any group This suggests that xylem water is always under stress from evapotranspiration and soil water underwent evaporation soon after a rain event. Visual observation of tree confirms conclusion that trees access deep ground water in March and April, before rain begins and before soil is connected to groundwater. Results from the research are being integrated into a local outreach project to improve use of agroforestry.

Ceperley, Natalie; Mande, Theophile; Parlange, Marc B.

2013-04-01

197

Size structure and regeneration of Spanish holm oak Quercus ilex forests and dehesas: effects of agroforestry use on their long-term sustainability  

Microsoft Academic Search

Most evergreen oak forests growing in the flat areas of the southwestern Iberian Peninsula have been gradually transformed into a unique kind of pastoral woodland, the Spanish dehesas and Portuguese montados, by means of an agroforestry use. The opening of dehesas by clearing and ploughing closed forest to obtain savannah-like landscapes with a density of some 40 trees per ha

Fernando J Pulido; Mario D??az; Sebastián J Hidalgo de Trucios

2001-01-01

198

Characterization of nutrient transport below the root zone of a willow plantation irrigated with municipal waste water in the Boreal-Parkland transition zone, Alberta, Canada  

NASA Astrophysics Data System (ADS)

Irrigation of willow and poplar species with municipal waste water offers municipalities a variety of opportunities including reduced energy and waste management costs and preservation of surface water quality. Municipal waste water contains various nutrients that are beneficial to plants such as nitrogen and phosphorus. The woody species reduce treatment costs by further removing many of these nutrients and potentially using the resulting biomass to fuel the facilities. Diversion of municipal waste water from rivers and water bodies improves water quality by reducing the amount of nutrients entering water bodies, decreasing pollution such as eutrophication. As found by many European countries, the bioenergy combined with waste water treatment approach is promising but there are environmental drawbacks including nutrient leaching to groundwater and degradation to soil hydraulic properties. Various nitrogen forms like nitrate are of concern due to impacts on human and environmental health, most notably methemoglobinemia in infants. The overall objective of this research is to assess ecosystem resilience and sustainability with repeated applications of municipal wastewater over the life cycle of a willow plantation. The specific objective of this presentation is to quantify nutrient transport below the root zone of a poplar plantation previously irrigated with municipal waste water under natural climatic conditions using soil solution samplers at 4 depths (50 cm, 90 cm, 120 cm and 150 cm). Meteorological data (precipitation, temperature, evaporimeter) was collected as well. Transport of conservative tracers, bromide and chloride, are compared to the transport of nutrients (nitrogen forms and DOC,). Parameterization of the measured breakthrough curves may be used to predict future nutrient fluxes. The goal of this research is to improve the design of municipal waste water subsurface irrigation systems by minimizing leaching and water losses.

Gainer, A. E.; Dyck, M. F.; Kachanoski, G.

2010-12-01

199

The Influence of Agroforestry and Other Land-Use Types on the Persistence of a Sumatran Tiger ( Panthera tigris sumatrae) Population: An Individual-Based Model Approach  

NASA Astrophysics Data System (ADS)

The importance of preserving both protected areas and their surrounding landscapes as one of the major conservation strategies for tigers has received attention over recent decades. However, the mechanism of how land-use surrounding protected areas affects the dynamics of tiger populations is poorly understood. We developed Panthera Population Persistence (PPP)—an individual-based model—to investigate the potential mechanism of the Sumatran tiger population dynamics in a protected area and under different land-use scenarios surrounding the reserve. We tested three main landscape compositions (single, combined and real land-uses of Tesso-Nilo National Park and its surrounding area) on the probability of and time to extinction of the Sumatran tiger over 20 years in Central Sumatra. The model successfully explains the mechanisms behind the population response of tigers under different habitat landscape compositions. Feeding and mating behaviours of tigers are key factors, which determined population persistence in a heterogeneous landscape. All single land-use scenarios resulted in tiger extinction but had a different probability of extinction within 20 years. If tropical forest was combined with other land-use types, the probability of extinction was smaller. The presence of agroforesty and logging concessions adjacent to protected areas encouraged the survival of tiger populations. However, with the real land-use scenario of Tesso-Nilo National Park, tigers could not survive for more than 10 years. Promoting the practice of agroforestry systems surrounding the park is probably the most reasonable way to steer land-use surrounding the Tesso-Nilo National Park to support tiger conservation.

Imron, Muhammad Ali; Herzog, Sven; Berger, Uta

2011-08-01

200

The homegarden agroforestry system of Bukoba district, North-Western Tanzania. 2. Constrainsts to farm productivity  

Microsoft Academic Search

A questionnaire survey was conducted among 72 randomly selected households in Bukoba district, Tanzania from August to November 1991. The objective of the study was to identify the major constraints to increased productivity in homegardens and farmers response to these constraints. Declining of homegarden productivity seems to have been influenced by the gradual decline of soil fertility mainly as a

G. H. Rugalema; F. H. Johnsen; J. Rugambisa

1994-01-01

201

Financial evaluation of smallholder timber-based agroforestry systems in Claveria, Northern Mindanao, the Philippines  

Microsoft Academic Search

In the Philippines, timber production on small farms has become profitable as a result of reduced supplies due to extensive\\u000a deforestation and increasing demand. In the early 1990s, when the price of timber was high, farmers were promised huge returns\\u000a from tree farming. However, widespread planting of few species has led to oversupply and a sharp decline in the price

M. Bertomeu

2006-01-01

202

Soil properties under young Chinese fir-based agroforestry system in mid-subtropical China  

Microsoft Academic Search

In order to decrease the soil nutrient loss in young planted Chinese fir (Cunningharnia lanceolata (Lamb.) Hook.) forestland\\u000a and to investigate the impact of young Chinese fir plantation intercropped with crops on soil quality, a field experiment\\u000a was set up in the mid-subtropics of China in 1998. The effects of growing crops in combination with young Chinese fir on soil

Hua Wang; Yu Huang; Huang Huang; Ke M Wang; Shang Y Zhou

2005-01-01

203

Spatial variability in the soil water content of a Mediterranean agroforestry system with high soil heterogeneity  

NASA Astrophysics Data System (ADS)

Variability of soil water content is known to increase with the size of spatial domain in which measurements are taken. At field scale, heterogeneity in soil, vegetation, topography, water input volume and management affects, among other factors, hydrologic plot behaviour under different mean soil water contents. The present work studies how the spatial variability of soil water content (SWC) is affected by soil type (texture, percentage of stones and the combination of them) in a timber-orientated plantation of cherry tree (Prunus avium) under Mediterranean climatic conditions. The experimental design is a randomized block one with 3 blocks * 4 treatments, based on two factors: irrigation (6 plots irrigated versus 6 plots not irrigated) and soil management (6 plots tillaged versus 6 plots not tillaged). SWC is continuously measured at 25, 50 and 100 cm depth with FDR sensors, located at two positions in each treatment: under tree influence and 2.5 m apart. This study presents the results of the monitoring during 2012 of the 24 sensors located at the 25 cm depth. In each of the measurement point, texture and percentage of stones were measured. Sandy-loam, sandy-clay-loam and loam textures were found together with a percentage of stones ranging from 20 to 70 %. The results indicated that the relationship between the daily mean SWC and its standard deviation, a common procedure used to study spatial variability, changed with texture, percentage of stones and the estimation of field capacity from the combination of both. Temporal stability analysis of SWC showed a clear pattern related to field capacity, with the measurement points of the sandy-loam texture and the high percentage of stones showing the maximun negative diference with the global mean. The high range in the mean relative difference observed (± 75 %), could indicate that the studied plot may be considered as a good field-laboratory to extrapolate results at higher spatial scales. Furthermore, the pattern in the temporal stability of tree growth was clearly related to that one in SWC. Nevertheless, the treatments that represent the mean conditions in growth were not exactly the same than those in SWC, which could be attributable to other characteristics than soil.

Molina, Antonio Jaime; Llorens, Pilar; Aranda, Xavier; Savé, Robert; Biel, Carmen

2013-04-01

204

Performance evaluation of various agroforestry species used in short duration improved fallows to enhance soil fertility and sorghum yields in Mali  

Microsoft Academic Search

The general soil fertility and crop yield decline constraints have guided the Malian agricultural research institute (Institut\\u000a d’ Economie Rurale, IER), the Sahel Program of the World Agroforestry Centre (ICRAF) and the International Crops Research\\u000a Institute for the Semi Arid Tropics (ICRISAT) to join efforts and undertake research activities aimed at mitigating the constraints\\u000a in Mali. Thus, from the year

Bocary Kaya; Amadou Niang; Ramadjita Tabo; André Bationo

205

Phosphorus monthly losses at the outlet of an agroforestry catchment under Atlantic climate (NW Spain)  

NASA Astrophysics Data System (ADS)

Phosphorus levels in runoff waters help to estimate the possible contamination associated with them and to know the existence of eutrophication conditions. The amounts of P transported from catchments depended on the hydrology, on soil P contents, and on the amount of P added as fertilizer and manure. The aim of this study was to monthly losses of total P (TP), sedimentary P (TSP), and dissolved P (TDP) at the outlet of an agroforestry catchment under Atlantic climate. This research was conducted at Valiñas River catchment in Coruña (NW Spain), a periurban area of 36.3 km2. Land use is as follows: 35% arable land, 20% grassland or pastures and 45% forest. This study reported data from January 1999 to September 2006. The total sample number was 872, varying from 53 in 1999 and 193 in 2003. Sampling time variability was related to rainfall distribution. The different P forms, TP and TDP, were analyzed using inductively coupled plasma-mass spectroscopy (ICP-MS). The TSP was calculated from the difference between TP and TDP. To calculate the mass balance of these P forms, discharge data at the catchment outlet were estimated. Suspended solids were assessed by filtration. Relations between the three P forms and suspended solids were determined using Pearson's correlation coefficient. The concentrations of the three studied P forms varied widely during the whole study period. Total P yearly losses ranged from 0.350 kg ha-1 month-1 in 2004 to 1.199 kg ha-1 month-1 in 2000. From January to September 2006 they were 0.259 kg ha-1 month-1. TSP losses varied between 0.201 kg ha-1 month-1 in 2004 and 0.7315 kg ha-1 month-1 in 1999. Finally, TDP losses oscillated between 0.140 kg ha-1 month-1 in 2005 and 0.508 kg ha-1 month-1 in 2000. The main causes for these variations were rainfall and flow regimes, soil management, and wastewater discharges. Considering the different seasons, flow regime was low from July to September during the studied years, whereas the highest flows were registered in the period from January to March or from October to December, depending on the year. This fact is coincident with the highest rainfall records. Consequently, TP losses were higher during January to March and October to December than during the rest of the year. The period from July to September presented the lowest losses. TSP levels were always greater than those of TDP except in the period from July to September. Significant correlations between suspended solids and TP and TSP were observed throughout the whole study period. This fact indicates the erosive origin of the P exported to this catchment. A significant correlation between TDP and suspended solids was observed only in 2000, 2001, 2003 and 2005. These correlations would indicate that TDP concentrations in this catchment have different origins, not only erosion but wastewater discharges and manure applications. Rainfall was significantly correlated to TP and TSP along the studied period, whereas rainfall and TDP were significantly correlated only in some years, as the relation between flow and the different phosphorus forms. These results may indicate the influence on the season on the phosphorus concentrations although, due to the characteristics of the studied catchment, several origins are possible. For instance, runoff and erosion would increase TSP losses and manure application may increase TDP.

Sande-Fouz, Patricia; Miras-Avalos, Jose Manuel; Mestas-Valero, Roger Manuel; Vidal-Vázquez, Eva

2010-05-01

206

Is soil degradation unrelated to deforestation? Examining soil parameters of land use systems in upland Central Sulawesi, Indonesia  

Microsoft Academic Search

It is generally assumed that declining soil fertility during cultivation forces farmers to clear forest. We wanted to test this for a rainforest margin area in Central Sulawesi, Indonesia. We compared soil characteristics in different land-use systems and after different length of cultivation. 66 sites with four major land-use systems (maize, agroforestry, forest fallow and natural forest) were sampled. Soils

Georg Dechert; Edzo Veldkamp; Iswandi Anas

2004-01-01

207

Pasture production in a silvopastoral system in relation with microclimate variables in the atlantic coast of Spain  

Microsoft Academic Search

Grasses and legumes of high productivity and nutritional quality are a good alternative as pasture supplements in rangelands of low quality forage. Orchardgrass (Dactylis glomerata L. cv. `Artabro') and white clover (Trifolium repens L. cv. `Huia') are known as shade tolerant and low flammability species that have been successfully used in agroforestry systems in Galicia, both diminishing fire hazard compared

F. J. Silva-Pando; M. P. González-Hernández; M. J. Rozados-Lorenzo

2002-01-01

208

Agroforestry In-Service Training. A Training Aid for Asia & the Pacific Islands (Honiara, Solomon Islands, South Pacific, October 23-29, 1983). Training for Development. Peace Corps Information Collection & Exchange Training Manual No. T-16.  

ERIC Educational Resources Information Center

The Forestry/Natural Resources Sector in the Office of Training and Program Support of the Peace Corps conducted an agroforestry inservice training workshop in Honiara, Solomon Islands, in 1983. Participants included Peace Corps volunteers and their host country national counterparts from six countries of the Pacific Islands and Asia (Western…

Fillion, Jacob; Weeks, Julius

209

FOREST MANAGEMENT AND AGROFORESTRY TO SEQUESTER AND CONSERVE ATMOSPHERIC CARBON DIOXIDE  

EPA Science Inventory

Overall, the biological opportunity to conserve and sequester carbon in the terrestrial biosphere, especially in forest systems, appears significant. ith careful planning and implementation, management practices useful for this carbon benefit would appear to have potential to pro...

210

Impacts of climate change on soil erosion in Portuguese watersheds with contrasting Mediterranean climates and agroforestry practices  

NASA Astrophysics Data System (ADS)

Climate change in Mediterranean regions could lead to higher winter rainfall intensity and, due to higher climatic aridity, lower vegetation cover. This could lead to increasing soil erosion rates, accelerating ongoing soil degradation and desertification processes. Adaptation to these scenarios would have costs and benefits associated with soil protection but also agroforestry production and water usage. This presentation will cover project ERLAND, which is studying these impacts for two headwater catchments (<1000 ha) in Portugal, located in distinct climatic conditions within the Mediterranean climate area, and their land-use practices are adapted to these conditions. The Macieira de Alcoba catchment in northern Portugal has a wet Mediterranean climate (1800 mm/yr, but with a dry summer season). The high rainfall allows the plantation of fast growing tree species (pine and eucalypt) in the higher slopes, and the irrigation of corn in the lower slopes. Forest fires are a recurring problem, linked with the high biomass growth and the occurrence of a dry season. Potential impacts of climate change include less favorable conditions for eucalypt growth, higher incidence of wildfires, and less available water for summer irrigation, all of which could lead to lower vegetation cover. The Guadalupe catchment in southern Portugal has a dry Mediterranean climate (700 mm/yr, falling mostly in winter). The land-use is montado, an association between sclerophyllous oaks (cork and holm oaks) and annual herbaceous plans (winter wheat or pasture). The region suffers occasional severe droughts; climate change has the potential to increase the frequency and severity of these droughts, leading to lower vegetation cover and, potentially, limiting the conditions for cork and holm oak growth. Each catchment has been instrumented with erosion measurement plots and flow and turbidity measurements at the outlet, together with surveys of vegetation and soil properties; measurements in Macieira began in 2010 and in Guadalupe they began in 2011. These datasets will be used to parameterize, calibrate and validate the SWAT ecohydrological model, in order to ensure the appropriate simulation of the most important hydrological, vegetation growth and erosion processes which could be impacted upon by climate change. The model will, in turn, be the main tool to study future climate and land-use scenarios. The presentation will focus on the data collected so far, the modeling structure, and preliminary results coming for the work.

Nunes, J. P.; Lima, J. C.; Bernard-Jannin, L.; Veiga, S.; Rodríguez-Blanco, M. L.; Sampaio, E.; Batista, D. P.; Zhang, R.; Rial-Rivas, M. E.; Moreira, M.; Santos, J. M.; Keizer, J. J.; Corte-Real, J.

2012-04-01

211

Soil CO 2 emissions in agricultural watersheds with agroforestry and grass contour buffer strips  

Microsoft Academic Search

The potential for agricultural soils to act as a sink and sequester carbon (C) or a source and emit carbon dioxide (CO2) is largely dependent upon the agricultural management system. The establishment of permanent vegetation, such as trees and\\u000a grass contour buffer strips, may cause accumulation of above- and below-ground C over time, thereby acting as a sink for tropospheric

Neal J. Bailey; Peter P. Motavalli; Ranjith P. Udawatta; Kelly A. Nelson

2009-01-01

212

Biodiversity conservation, ecosystem functioning, and economic incentives under cocoa agroforestry intensification.  

PubMed

World chocolate demand is expected to more than double by 2050. Decisions about how to meet this challenge will have profound effects on tropical rainforests and wild species in cocoa-producing countries. Cocoa, "the chocolate tree," is traditionally produced under a diverse and dense canopy of shade trees that provide habitat for a high diversity of organisms. The current trend to reduce or eliminate shade cover raises concerns about the potential loss of biodiversity. Nevertheless, few studies have assessed the ecological consequences and economic trade-offs under different management options in cocoa plantations. Here we describe the relationships between ant ecology (species richness, community composition, and abundance) and vegetation structure, ecosystem functions, and economic profitability under different land-use management systems in 17 traditional cocoa forest gardens in southern Cameroon. We calculated an index of profitability, based on the net annual income per hectare. We found significant differences associated with the different land-use management systems for species richness and abundance of ants and species richness and density of trees. Ant species richness was significantly higher in floristically and structurally diverse, low-intensity, old cocoa systems than in intensive young systems. Ant species richness was significantly related to tree species richness and density. We found no clear relationship between profitability and biodiversity. Nevertheless, we suggest that improving the income and livelihood of smallholder cocoa farmers will require economic incentives to discourage further intensification and ecologically detrimental loss of shade cover. Certification programs for shade-grown cocoa may provide socioeconomic incentives to slow intensification. PMID:19765036

Bisseleua, D H B; Missoup, A D; Vidal, S

2009-10-01

213

Singletree influences on soil properties in agroforestry: lessons from natural forest and savanna ecosystems  

Microsoft Academic Search

Climate, organisms, topographic relief, and parent material interacting through time are the dominant factors that control\\u000a processes of soil formation and determine soil properties. In both forest and savanna ecosystems, trees affect soil properties\\u000a through several pathways. Trees alter inputs to the soil system by increasing capture of wetfall and dryfall and by adding\\u000a to soil N via N2-fixation. They

C. C. Rhoades

1996-01-01

214

Two-dimensional finite elements model for boron management in agroforestry sites  

Microsoft Academic Search

Agroforesty systems, which are recommended as a management option to lower the shallow groundwater level and to reuse saline\\u000a subsurface drainage waters from the tile-drained croplands in the drainage-impacted areas of Jan Joaquin Valley of California,\\u000a have resulted in excessive boron buildup in the soil root zone. To assess the efficacy of the long-term impacts of soil boron\\u000a buildup in

Gokmen Tayfur; Kenneth K. Tanji; Alper Baba

2010-01-01

215

Phosphorus in agroforestry systems : a contribution to sustainable agriculture in the Zona da Mata of Minas Gerais, Brazil  

Microsoft Academic Search

The Zona da Mata is a region situated in the domain of the Atlantic Coastal Rainforest in the southeast of the state of Minas Gerais, Brazil. This domain stretches along the Brazilian coast from north to south and ranks among the top five of the 25 biodiversity hotspots, the richest and the most threatened reservoirs of plant and animal life

I. M. Cardoso

2002-01-01

216

Personal preferences and intensification of land use: their impact on southern Cameroonian slash-and-burn agroforestry systems  

Microsoft Academic Search

Where long forest-fallows are no longer practiced, productivity declines in the absence of input substitution, as does the\\u000a ability of subsistence farmers to earn an adequate livelihood from shifting cultivation. Land availability, population density\\u000a and productivity-related factors such as soil fertility and labour requirements are not the only factors that affect fallow\\u000a length and land use intensification in shifting cultivation

Douglas R. Brown

2006-01-01

217

Modelling agroforestry systems of cacao ( Theobroma cacao ) with laurel ( Cordia alliodora ) or poro ( Erythrina poeppigiana ) in Costa Rica  

Microsoft Academic Search

Predictive models were developed for Cordia alliodora branch and Theobroma cacao branch or leaf biomass,based on branch basal areas (r2 0.79) but the model of C. alliodora leaf biomass, although significant, was of very low accuracy (r2 = 0.09) due to annual leaf fall. At age 10 years, shade tree stem biomass accounted for 80% of the total above-ground biomass

J. Beer; A. Bonnemann; W. Chavez; H. W. Fassbender; A. C. Imbach; I. Martel

1990-01-01

218

Substrate type, temperature, and moisture content affect gross and net N mineralization and nitrification rates in agroforestry systems  

Microsoft Academic Search

Accurate prediction of soil N availability requires a sound understanding of the effects of environmental conditions and management practices on the microbial activities involved in N mineralization. We determined the effects of soil temperature and moisture content and substrate type and quality (resulting from long-term pasture management) on soluble organic C content, microbial biomass C and N contents, and the

M. Zaman; S. X. Chang

2004-01-01

219

Are Partial Nutrient Balances Suitable to Evaluate Nutrient Sustainability of Land use Systems? Results from a Case Study in Central Sulawesi, Indonesia  

Microsoft Academic Search

Nutrient input–output balances are often used as indicators for the sustainability of land use systems. In a case study on plot scale in Central Sulawesi, Indonesia, we measured nutrient input–output balances of natural rainforest and two unfertilized land use systems (maize, and coffee\\/cacao agroforestry). These are the two major land use systems on converted rainforest sites in this part of

Georg Dechert; Edzo Veldkamp; Rainer Brumme

2005-01-01

220

Nutrient cycling under mixed-species tree systems in southeast Asia  

Microsoft Academic Search

Eucalyptus and Acacia are two tree genera that are commonly used in industrial plantations and as components of agroforestry\\u000a systems in southeast Asia. These fast-growing trees are mostly grown in monocultures. However, questions are now being raised\\u000a about the long-term sustainability of their growth as well as their effects on site quality. Losses of N and P from the site

P. K. Khanna

1997-01-01

221

Comparative water use by dryland trees in Parklands in Senegal  

Microsoft Academic Search

Despite the clear evidence of competition for water between trees and crops, there have been very few studies comparing simultaneous water use by differing tree species in drylands. Comparative water use by dryland trees was measured in Senegal using heat balance gauges at the end of the wet season and in the dry season. Significant differences between tree species were

J. D. Deans; R. C. Munro

2004-01-01

222

Observations on the rooting patterns of some agroforestry trees in an arid region of north-western India  

Microsoft Academic Search

The present study deals with root architecture of 6-year-old trees of 9 indigenous and 3 exotic species growing in arid climate of north-western India. Observations, made on excavated root systems (3 tree replicates of each species) showed large variation in horizontal and vertical spread of roots. In Morus alba, Melia azedarach and Populus deltoides, the roots were confined to 80

O. P. Toky; R. P. Bisht

1992-01-01

223

Seasonal dynamics of arbuscular mycorrhizal fungi in plants of Theobroma grandiflorum Schum and Paullinia cupana Mart. of aN agroforestry system in Central Amazonia, Amazonas State, Brazil  

Microsoft Academic Search

The seasonal dynamics of Arbuscular Mycorrhizal Fungi (AMF) was investigated in the rhizosphere of two fruit species in a terra firme (upland) ecosystem in Central Amazonia. Two host species (Theobroma grandiflorum and Paullinia cupana) and nine sampling months (August, September and December\\/1998, February, April, May and December\\/1999, February and May\\/2000) were studied in a completely randomized design, with five replications,

Arlem Nascimento de Oliveira; Luiz Antonio de Oliveira

2005-01-01

224

Factors Affecting Adoption of Agroforestry Farming System as a Mean for Sustainable Agricultural Development and Environment Conservation in Arid Areas of Northern Kordofan State, Sudan  

Microsoft Academic Search

Arid and semi-arid areas represent about 60 percent of Sudan total area. One of the main environmental problems in the arid and semi-arid areas is desertification which reduces the natural potential of the already fragile ecosystems and renders rural people vulnerable to food shortages, the vagaries of weather and natural disasters. Deforestation which is considered one of the most critical

Siddig El Tayeb Muneer

2008-01-01

225

Shade tree effects in an 8-year-old cocoa agroforestry system: biomass and nutrient diagnosis of Theobroma cacao by vector analysis  

Microsoft Academic Search

Farm product diversification, shade provision and low access to fertilizers often result in the purposeful integration of\\u000a upper canopy trees in cocoa (Theobroma cacao) plantations. Subsequent modification to light and soil conditions presumably affects nutrient availability and cocoa tree\\u000a nutrition. However, the level of complementarity between species requires investigation to minimize interspecific competition\\u000a and improve resource availability. We hypothesized beneficial

M. E. Isaac; V. R. Timmer; S. J. Quashie-Sam

2007-01-01

226

Morphological variation in Balanites aegyptiaca fruits and seeds within and among parkland agroforests in eastern Niger  

Microsoft Academic Search

Balanites aegyptiaca (L.) Delile. is one of the priority indigenous fruit trees for rural communities in the West African Sahel. As part of a\\u000a participatory tree domestication program in Niger, phenotypic variation in fruit and seed morphology was assessed in four\\u000a natural populations in eastern Niger. Measured variables were weight of the fruit, seed coat and kernel; length and width

Tougiani Abasse; John C. Weber; Boubacar Katkore; Moussa Boureima; Mahamane Larwanou; Antoine Kalinganire

2011-01-01

227

Sources of water used by trees and millet in Sahelian windbreak systems  

NASA Astrophysics Data System (ADS)

The extent to which water use by trees and crops is complementary in agroforestry systems may be affected by the proximity of groundwater to the soil surface. This may have important implications for the planning and management of agroforestry in semi-arid regions such as the Sahel of West Africa. A method of distinguishing uptake of water by plants from different sources was used, therefore, at locations with contrasting water table levels, to determine whether Azadirachta indica A. Juss (neem) trees in windbreaks utilised water from the same depths as adjacent crops of pearl millet ( Pennisetum glaucum (L.) R. Br.). Comparisons of ratios of the stable isotopes of oxygen ( 18O/ 16O) in plant sap, groundwater and water in the unsaturated zone of the soil profile were made in the Majjia Valley, in south-central Niger, where groundwater was found at depths of 6-8 m, and at Sadoré in south-western Niger, where the water table was at a depth of 35 m. In the Majjia Valley, the trees obtained large portions of their water from surface layers of the soil only after rain, when water there was abundant. During dry periods, roots of the trees extracted groundwater or deep reserves of soil water, while the millet crop extracted water from closer to the top of the soil profile. In contrast, at Sadoré, both the trees and crop fulfilled their water requirements from the top 2-3 m of the soil throughout the year. Thus, utilisation of water by windbreak trees and crops is more complementary where groundwater is accessible to tree roots. Competition for water is likely reduced at such locations as a consequence, but may affect the productivity of windbreak systems where groundwater is inaccessible. To maximise the benefits of establishing windbreaks, therefore, it is important that planners recommend strategies for reducing competition for water between trees and crops at sites where groundwater cannot be reached by tree roots.

Smith, D. Mark; Jarvis, Paul G.; Odongo, Julius C. W.

1997-11-01

228

Influence of an overstorey tree ( Prosopis glandulosa ) on associated shrubs in a savanna parkland: implications for patch dynamics  

Microsoft Academic Search

The arborescent legume, honey mesquite (Prosopis glandulosa), appears to play a central role in patch dynamics of southern Texas savannas by modifying soils and microclimate and by facilitating the ingress, establishment and\\/or growth of shrubs in its understorey. As an indirect test for the occurrence and persistence of facilitation in mature shrub clusters (patches), we examined the gas exchange, water

Paul W. Barnes; Steve Archer

1996-01-01

229

Re-marriage of crops and trees  

SciTech Connect

Agroforestry is defined and its role in the productive use and conservation of marginal or forested lands explained. Examples are given of existing agroforestry and silvo-pastural systems involving plantation crops (coffee, tea, cacao, rubber) and multipurpose species (Leucaena leucocephale, Casuarina, Almis, Parasponia, Acacia, Prosopis). The origin and activities of ICRAF are outlined.

Nair, P.K.R.

1983-01-01

230

High Bee and Wasp Diversity in a Heterogeneous Tropical Farming System Compared to Protected Forest  

PubMed Central

It is a globally important challenge to meet increasing demands for resources and, at the same time, protect biodiversity and ecosystem services. Farming is usually regarded as a major threat to biodiversity due to its expansion into natural areas. We compared biodiversity of bees and wasps between heterogeneous small-scale farming areas and protected forest in northern coastal Belize, Central America. Malaise traps operated for three months during the transition from wet to dry season. Farming areas consisted of a mosaic of mixed crop types, open habitat, secondary forest, and agroforestry. Mean species richness per site (alpha diversity), as well as spatial and temporal community variation (beta diversity) of bees and wasps were equal or higher in farming areas compared to protected forest. The higher species richness and community variation in farmland was due to additional species that did not occur in the forest, whereas most species trapped in forest were also found in farming areas. The overall regional species richness (gamma diversity) increased by 70% with the inclusion of farming areas. Our results suggest that small-scale farming systems adjacent to protected forest may not only conserve, but even favour, biodiversity of some taxonomic groups. We can, however, not exclude possible declines of bee and wasp diversity in more intensified farmland or in landscapes completely covered by heterogeneous farming systems.

Schuepp, Christof; Rittiner, Sarah; Entling, Martin H.

2012-01-01

231

High bee and wasp diversity in a heterogeneous tropical farming system compared to protected forest.  

PubMed

It is a globally important challenge to meet increasing demands for resources and, at the same time, protect biodiversity and ecosystem services. Farming is usually regarded as a major threat to biodiversity due to its expansion into natural areas. We compared biodiversity of bees and wasps between heterogeneous small-scale farming areas and protected forest in northern coastal Belize, Central America. Malaise traps operated for three months during the transition from wet to dry season. Farming areas consisted of a mosaic of mixed crop types, open habitat, secondary forest, and agroforestry. Mean species richness per site (alpha diversity), as well as spatial and temporal community variation (beta diversity) of bees and wasps were equal or higher in farming areas compared to protected forest. The higher species richness and community variation in farmland was due to additional species that did not occur in the forest, whereas most species trapped in forest were also found in farming areas. The overall regional species richness (gamma diversity) increased by 70% with the inclusion of farming areas. Our results suggest that small-scale farming systems adjacent to protected forest may not only conserve, but even favour, biodiversity of some taxonomic groups. We can, however, not exclude possible declines of bee and wasp diversity in more intensified farmland or in landscapes completely covered by heterogeneous farming systems. PMID:23300598

Schüepp, Christof; Rittiner, Sarah; Entling, Martin H

2012-01-01

232

Evaporation from vegetation in landscapes developing secondary salinity using the ventilated-chamber technique. III. Evaporation from a Pinus radiata tree and the surrounding pasture in an agroforestry plantation  

NASA Astrophysics Data System (ADS)

A 16-m Pinus radiata tree was enclosed in a ventilated chamber, and samples of the underlying pasture were covered with a small horizontal chamber. Vapour flux was measured on one day each month for 14 months. Evaporation from the tree ranged from 301d -1 (0.6 mm d -1) in April, May and June, to 1701d -1 (3.3 mm d -1) in ?eptember. The range of evaporation from the pasture was from zero during the dry season, to 1.4 mm d -1 in October prior to grazing. Total evaporation from the tree, pasture and soil accounted for all the precipitation. The results suggested that over the six-month dry season, soil water was the major factor controlling transpiration. The values of xylem pressure potential in the enclosed tree matched those of its neighbour indicating that bias due to the chamber was small. Evaporation and potential were not consistently related. A description of the root system to 2.8 m depth is given.

Greenwood, E. A. N.; Beresford, J. D.; Bartle, J. R.

233

Creating the Sustainable City: Building a Seminar (and Curriculum) through Interdisciplinary Learning  

ERIC Educational Resources Information Center

Using the wealth of sites available in the Chicago metropolitan area, online learning technologies, and classroom interactions, Roosevelt University's seminar "The Sustainable City" takes a multidisciplinary approach to urban ecology, waste management, green design, climate change, urban planning, parklands, water systems, environmental justice,…

Bryson, Michael A.; Zimring, Carl A.

2010-01-01

234

AGROFORESTRY BIOMASS AVAILABILITY ASSESSMENT IN UMBRIA REGION, PRELIMINARY RESULTS  

Microsoft Academic Search

Biomass resources vary depending on environmental characteristics, that influence Net Ecosystem Production (NEP), biomass is also dispersed through the territory. Estimating availability of biomass resources is important to assess bioenergy production potential and so bioenergy contribution to annual energy demand. In this paper residual biomass resources are analyzed, such as agricultural residues (straw, prunings), agroindustry residues (olive husk, vinasse) and

F. Fantozzi; P. Bartocci; C. Buratti

235

Plant diversity and arthropod communities: Implications for temperate agroforestry  

Microsoft Academic Search

Polyculture in crop agroecosystems has been examined in numerous studies with the aim of reducing pest populations by increasing\\u000a diversity among insect populations over those found in traditional monoculture. Resource concentration and enemies hypotheses\\u000a predict decreased pest populations in more diverse plant communities. Although results have been mixed, insect diversity has\\u000a been generally increased in polyculture over traditional monoculture. Maintaining

W. T. Stamps; M. J. Linit

1997-01-01

236

Cordia alliodora: A Promising Tree for Tropical Agroforestry.  

National Technical Information Service (NTIS)

Much more could be done to help tropical forest conservation if known facts were collated, reviewed and made available in an easily-read form. The Oxford Forestry Institute (OFI), with its unrivalled library and broad professional experience of tropical f...

A. Greaves P. S. McCarter

1990-01-01

237

TropSoils Technical Report, 1986-1987.  

National Technical Information Service (NTIS)

Contents: Introduction; Personnel; Research Network; Legume-Based Pastures; Low-Input Systems; Agroforestry Systems; Continuous Cultivation; Comparative Soil Dynamics; Soil Characterization and Interpretation; Soil Fertility Management in Oxisols of Manau...

N. Caudle

1989-01-01

238

Soil phosphorus dynamics in a humid tropical silvopastoral system  

SciTech Connect

In developing countries of the humid tropics, timber exploitation and agricultural expansion frequently result in deforestation. Extensive land management, coupled with inherently low soil fertility invariably produce declines in agricultural/livestock productivity which eventually lead to land abandonment and further deforestation. Phosphorus is often the major nutrient limiting plant growth in tropical soils. Agroforestry systems have been considered as viable alternatives to current land use practices. Several hypotheses suggest that combining trees with crops or pasture, especially leguminous species will improve soil nutrient cycling, soil structure and soil organic matter. In this experiment Erythrina berteroana (an arboreous legume) was grown in native grass pastures in Costa Rica to determine the effects of tree pruning and cattle grazing on soil P availability. I measured soil P fluxes as well as changes in pasture biomass over an 18-month period. In a separate field experiment, I determined decomposition rates and P release characteristics of Erythrina leaves, pasture grass clippings and cattle dung. Erythrina leaves decomposed faster than both pasture grass and cattle dung. Erythrina and pasture residues released 4-5 times less P than dung. Phosphorus fluxes after tree pruning and grazing were highly dynamic for all treatments. Tree pruning increased labile soil P over time when coupled with grazing. Pasture biomass production was greatest in the grazed tree treatment. Pasture biomass P production and concentration was greatest in the non-grazed treatment. Trees and grazing together tended to increase nutrient (P) turnover which stimulated biomass production. In contrast, trees without grazing promoted nutrient (P) accumulation in pasture biomass.

Cooperband, L.R.

1992-01-01

239

Carbon storage of different soil-size fractions in Florida silvopastoral systems.  

PubMed

Compared with open (treeless) pasture systems, silvopastoral agroforestry systems that integrate trees into pasture production systems are likely to enhance soil carbon (C) sequestration in deeper soil layers. To test this hypothesis, total soil C contents at six soil depths (0-5, 5-15, 15-30, 30-50, 50-75, and 75-125 cm) were determined in silvopastoral systems with slash pine (Pinus elliottii) + bahiagrass (Paspalum notatum) and an adjacent open pasture (OP) with bahiagrass at four sites, representing Spodosols and Ultisols, in Florida. Soil samples from each layer were fractionated into three classes (250-2000, 53-250, and <53 microm), and the C contents in each were determined. Averaged across four sites and all depths, the total soil organic carbon (SOC) content was higher by 33% in silvopastures near trees (SP-T) and by 28% in the alleys between tree rows (SP-A) than in adjacent open pastures. It was higher by 39% in SP-A and 20% in SP-T than in open pastures in the largest fraction size (250-2000 microm) and by 12.3 and 18.8%, respectively, in the intermediate size fraction (53-250 microm). The highest SOC increase (up to 45 kg m(-2)) in whole soil of silvopasture compared with OP was at the 75- to 125-cm depth at the Spodosol sites. The results support the hypothesis that, compared with open pastures, silvopastures contain more C in deeper soil layers under similar ecological settings, possibly as a consequence of a major input to soil organic matter from decomposition of dead tree-roots. PMID:18689740

Haile, Solomon G; Nair, P K Ramachandran; Nair, Vimala D

2008-01-01

240

The contribution of wild plants to human nutrition in the Ferlo (Northern Senegal)  

Microsoft Academic Search

One aspect of agroforestry is the integration of indigenous species into appropriate land use systems. Some local trees and shrubs are particularly appreciated because of their value in human nutrition.

Barbara Becker

1983-01-01

241

Ecological Approach to on-Farm Experimentation.  

National Technical Information Service (NTIS)

In response to increased demand for in situ bio-physical data on agroforestry systems and components, the paper discusses two methodologies for collecting such data. Presented first are practical guidelines for using a grid transect method to collect info...

P. A. Huxley R. Mead

1988-01-01

242

Nitrogen and phosphorus economy of a legume tree-cereal intercropping system under controlled conditions.  

PubMed

Considerable amounts of nitrogen (N) and phosphorus (P) fertilizers have been mis-used in agroecosystems, with profound alteration to the biogeochemical cycles of these two major nutrients. To reduce excess fertilizer use, plant-mediated nutrient supply through N(2)-fixation, transfer of fixed N and mobilization of soil P may be important processes for the nutrient economy of low-input tree-based intercropping systems. In this study, we quantified plant performance, P acquisition and belowground N transfer from the N(2)-fixing tree to the cereal crop under varying root contact intensity and P supplies. We cultivated Acacia senegal var senegal in pot-culture containing 90% sand and 10% vermiculite under 3 levels of exponentially supplied P. Acacia plants were then intercropped with durum wheat (Triticum turgidum durum) in the same pots with variable levels of adsorbed P or transplanted and intercropped with durum wheat in rhizoboxes excluding direct root contact on P-poor red Mediterranean soils. In pot-culture, wheat biomass and P content increased in relation to the P gradient. Strong isotopic evidence of belowground N transfer, based on the isotopic signature (?(15)N) of tree foliage and wheat shoots, was systematically found under high P in pot-culture, with an average N transfer value of 14.0% of wheat total N after 21 days of contact between the two species. In the rhizoboxes, we observed limitations on growth and P uptake of intercropped wheat due to competitive effects on soil resources and minimal evidence of belowground N transfer of N from acacia to wheat. In this intercrop, specifically in pot-culture, facilitation for N transfer from the legume tree to the crop showed to be effective especially when crop N uptake was increased (or stimulated) as occurred under high P conditions and when competition was low. Understanding these processes is important to the nutrient economy and appropriate management of legume-based agroforestry systems. PMID:22446108

Isaac, M E; Hinsinger, P; Harmand, J M

2012-09-15

243

Soil moisture mapping in an alley cropping system in Quebec, Canada  

NASA Astrophysics Data System (ADS)

Alley cropping is an agroforestry practice whereby trees are planted in rows, thus creating alleyways within which companion crops are grown. The alley cropping systems as we call them may not only influence the local thermal energy balance by changes in airflow and solar irradiance, but also affect water uptake in plant roots and evapotranspiration. However, our understanding of the soil water balance and regulating mechanisms in alley cropping systems is very limited compared to what we know about the more common monoculture farming. Root systems of the trees are known to interact with soil water dynamics, in that they tend to grow in the direction of soil layers with a water content corresponding to a pF between 2-2.4, and conversely, water flows in the direction of decreasing hydraulic head, which, close to the root system, is in the direction of the roots when the trees absorb water by applying a suction gradient. As such, the trees in alley cropping systems either improve the resilience to drought by retaining more water in the upper soil layers, or they compete with the crops for water. With the eye on the future environmental conditions that may result from a shift in the local climate in southern Quebec, Canada, our objective is to characterize and evaluate the influence of alley cropping systems on soil water dynamics under various climate conditions. In order to evaluate the interaction between root system and soil water dynamics, we adopt an approach divided into three steps: (i) a field campaign where we monitor soil water patterns on an alley cropping site during the growing season; (ii) simulation of these soil water patterns with the HYDRUS model for two-dimensional movement of water; and (iii) the evolution of these patterns for a given scenario of climate change. Our submission focuses on the field campaign in which we used forty-five frequency domain reflectometers (FDR) along a 25-m transect perpendicular to the tree rows in order to monitor moisture patterns within the first 100 cm of the soil. Analysis showed that the presence of trees has a pronounced influence on the water distribution within the soil. (This submission is part of Climate Change Action Plan 26 funded by Ouranos-ICAR.)

Hallema, D. W.; Rousseau, A. N.; Gumiere, S. J.

2012-12-01

244

Soil carbon sequestration in rainfed production systems in the semiarid tropics of India.  

PubMed

Severe soil organic carbon (SOC) depletion is a major constraint in rainfed agroecosystems in India because it directly influences soil quality, crop productivity and sustainability. The magnitude of soil organic, inorganic and total carbon stocks in the semi-arid bioclimate is estimated at 2.9, 1.9 and 4.8 Pg respectively. Sorghum, finger millet, pearl millet, maize, rice, groundnut, soybean, cotton, food legumes etc. are predominant crop production systems with a little, if any, recycling of organic matter. Data from the long term experiments on major rainfed production systems in India show that higher amount of crop residue C input (Mg/ha/y) return back to soil in soybean-safflower (3.37) system practiced in Vertisol region of central India. Long term addition of chemical fertilizer and organic amendments improved the SOC stock. For every Mg/ha increase in SOC stock in the root zone, there occurs an increase in grain yield (kg/ha) of 13, 101, 90, 170, 145, 18 and 160 for groundnut, finger millet, sorghum, pearl millet, soybean and rice, respectively. Long-term cropping without using any organic amendment and/or mineral fertilizers can severely deplete the SOC stock which is the highest in groundnut-finger millet system (0.92 Mg C/ha/y) in Alfisols. Some agroforestry systems also have a huge potential of C sequestration to the extent of 10Mg/ha/y in short rotation eucalyptus and Leucaena plantations. The critical level of C input requirements for maintaining SOC at the antecedent level ranges from 1.1 to 3.5 Mg C/ha/y and differs among soil type and production systems. National level policy interventions needed to promote sustainable use of soil and water resources include prohibiting residue burning, reducing deforestation, promoting integrated farming systems and facilitating payments for ecosystem services. A wide spread adoption of these measures can improve soil quality through increase in SOC sequestration and improvement in agronomic productivity of rainfed agroecosystems. PMID:24210647

Srinivasarao, Ch; Lal, Rattan; Kundu, Sumanta; Babu, M B B Prasad; Venkateswarlu, B; Singh, Anil Kumar

2014-07-15

245

Diversity and Communities of Foliar Endophytic Fungi from Different Agroecosystems of Coffea arabica L. in Two Regions of Veracruz, Mexico.  

PubMed

Over the past 20 years, the biodiversity associated with shaded coffee plantations and the role of diverse agroforestry types in biodiversity conservation and environmental services have been topics of debate. Endophytic fungi, which are microorganisms that inhabit plant tissues in an asymptomatic manner, form a part of the biodiversity associated with coffee plants. Studies on the endophytic fungi communities of cultivable host plants have shown variability among farming regions; however, the variability in fungal endophytic communities of coffee plants among different coffee agroforestry systems is still poorly understood. As such, we analyzed the diversity and communities of foliar endophytic fungi inhabiting Coffea arabica plants growing in the rustic plantations and simple polycultures of two regions in the center of Veracruz, Mexico. The endophytic fungi isolates were identified by their morphological traits, and the majority of identified species correspond to species of fungi previously reported as endophytes of coffee leaves. We analyzed and compared the colonization rates, diversity, and communities of endophytes found in the different agroforestry systems and in the different regions. Although the endophytic diversity was not fully recovered, we found differences in the abundance and diversity of endophytes among the coffee regions and differences in richness between the two different agroforestry systems of each region. No consistent pattern of community similarity was found between the coffee agroforestry systems, but we found that rustic plantations shared the highest number of morphospecies. The results suggest that endophyte abundance, richness, diversity, and communities may be influenced predominantly by coffee region, and to a lesser extent, by the agroforestry system. Our results contribute to the knowledge of the relationships between agroforestry systems and biodiversity conservation and provide information regarding some endophytic fungi and their communities as potential management tools against coffee plant pests and pathogens. PMID:24887512

Saucedo-García, Aurora; Anaya, Ana Luisa; Espinosa-García, Francisco J; González, María C

2014-01-01

246

Diversity and Communities of Foliar Endophytic Fungi from Different Agroecosystems of Coffea arabica L. in Two Regions of Veracruz, Mexico  

PubMed Central

Over the past 20 years, the biodiversity associated with shaded coffee plantations and the role of diverse agroforestry types in biodiversity conservation and environmental services have been topics of debate. Endophytic fungi, which are microorganisms that inhabit plant tissues in an asymptomatic manner, form a part of the biodiversity associated with coffee plants. Studies on the endophytic fungi communities of cultivable host plants have shown variability among farming regions; however, the variability in fungal endophytic communities of coffee plants among different coffee agroforestry systems is still poorly understood. As such, we analyzed the diversity and communities of foliar endophytic fungi inhabiting Coffea arabica plants growing in the rustic plantations and simple polycultures of two regions in the center of Veracruz, Mexico. The endophytic fungi isolates were identified by their morphological traits, and the majority of identified species correspond to species of fungi previously reported as endophytes of coffee leaves. We analyzed and compared the colonization rates, diversity, and communities of endophytes found in the different agroforestry systems and in the different regions. Although the endophytic diversity was not fully recovered, we found differences in the abundance and diversity of endophytes among the coffee regions and differences in richness between the two different agroforestry systems of each region. No consistent pattern of community similarity was found between the coffee agroforestry systems, but we found that rustic plantations shared the highest number of morphospecies. The results suggest that endophyte abundance, richness, diversity, and communities may be influenced predominantly by coffee region, and to a lesser extent, by the agroforestry system. Our results contribute to the knowledge of the relationships between agroforestry systems and biodiversity conservation and provide information regarding some endophytic fungi and their communities as potential management tools against coffee plant pests and pathogens.

Saucedo-Garcia, Aurora; Anaya, Ana Luisa; Espinosa-Garcia, Francisco J.; Gonzalez, Maria C.

2014-01-01

247

Biodiversity Conservation, Ecosystem Services and Livelihoods in Tropical Landscapes: Towards a Common Agenda  

NASA Astrophysics Data System (ADS)

Trade-offs between ecosystem conservation and agricultural production can more easily be addressed by shifting the view from the plot scale to the scale of the landscape and integrating biodiversity friendly land use systems into development strategies. The provision of ecosystem services such as watershed protection and carbon sequestration by natural and complex agro-ecosystems can play an important role in making such integrated landscape approaches viable. This special issue brings together papers that were presented at a symposium on agroforestry and landscape scale conservation at the Second World Agroforestry Congress in Nairobi in August 2009. It is divided into two sections focusing on: (1) the biological mechanisms and implications of landscape scale conservation strategies as influenced by land use, especially agroforestry; and (2) the economic drivers and public policies that determine to a large extent the success of agroforestry-based landscape conservation strategies. The contributions provide evidence both for the potential and limitations of agroforestry in landscape scale conservation and development strategies and highlight the importance of economic incentives and policies to promote integrated landscape solutions. This introductory paper summarizes and discusses the contributions and concludes with policy recommendations and research needs.

Schroth, Götz; McNeely, Jeffrey A.

2011-08-01

248

A participatory Agroforestry approach for soil and water conservation in Ethiopia  

Microsoft Academic Search

The rates of soil erosion and land degradation in Ethiopia are frighteningly high. Crop production, livestock keeping and energy supply situations are at risk. The highlands are the most affected. Past rehabilitation efforts have been immense. Much labour, capital and trained staff have been mobilized to correct the situation, but the outcome has not been encouraging. There are a number

A. Bekele-Tesemma

1997-01-01

249

Agroforestry: Conifers. (Latest citations from the Cab Abstracts database). NewSearch  

SciTech Connect

The bibliography contains citations concerning the use of lands forested with conifers for crop and livestock production. Citations cover the grazing of livestock and the production of crops, including tomatoes, soybeans, lespedeza, wheat, rape, taro, cotton, cabbages, ginger, watermelons, and strawberries. Livestock discussed include cattle, sheep, geese, and horses. Economic analyses and economic models are presented. (Contains a minimum of 147 citations and includes a subject term index and title list.)

Not Available

1994-10-01

250

POTENTIAL OF FORESTRY AND AGROFORESTRY PRACTICES TO STORE CARBON IN THE TROPICS  

EPA Science Inventory

Terrestrial vegetation plays a pivotal role in the global carbon cycle. ot only are tremendous amounts of. carbon stored in terrestrial egetation, but large amounts are also actively exchanged,between vegetation and the atmosphere. his suggests that vegetation, and specifically f...

251

Rain forest promotes trophic interactions and diversity of trap-nesting Hymenoptera in adjacent agroforestry  

Microsoft Academic Search

Summary 1. Human alteration of natural ecosystems to agroecosystems continues to accelerate in tropical countries. The resulting world-wide decline of rain forest causes a mosaic land- scape, comprising simple and complex agroecosystems and patchily distributed rain for- est fragments of different quality. Landscape context and agricultural management can be expected to affect both species diversity and ecosystem services by trophic

ALEXANDRA-MARIA KLEIN; INGOLF STEFFAN-DEWENTER; TEJA TSCHARNTKE

2006-01-01

252

Land degradation in Mediterranean Europe: can agroforestry be a part of the solution? A prospective review  

Microsoft Academic Search

Vegetation and land degradation, although less acute than in the Southern Mediterranean Basin, is still widespread in the North. Degradation results from various kinds of mismanagement of the land. Wildfires, for instance, favoured by ungrazing, play an increasingly important role as the mean area annually burnt shifted from an average 200,000 ha in the 1960's to over 600,000 ha in

H. N. Houérou

1993-01-01

253

Shade effects on forage crops with potential in temperate agroforestry practices  

Microsoft Academic Search

Thirty forages, including eight introduced cool-season grasses, four native warm-season grasses, one introduced warm-season\\u000a grass, eight introduced cool-season legumes, five native warm-season legumes, and four introduced warm-season legumes, were\\u000a grown in 7.6 L (two gallon) pots in full sun, 50%, and 80% shade created by shade cloth over a greenhouse frame. Experiments\\u000a were conducted during summer--fall 1994, spring--early summer 1995,

C. H. Lin; R. L. McGraw; M. F. George; H. E. Garrett

1998-01-01

254

A model simulating above- and below-ground tree architecture with agroforestry applications  

Microsoft Academic Search

Modelling plant growth and architecture requires two consecutive and complementary approaches. The first is a qualitative botanical analysis, in which the development sequence of a tree is studied by the identification of various levels of organisation and of homogeneous subunits. All of these — architectural unit, axis, growth unit — follow particular growth processes which can be described by using

P. De Reffye; F. Houllier; F. Blaise; D. Barthelemy; J. Dauzat; D. Auclair

1995-01-01

255

Farmers' adoptability of Mucuna fallowing and agroforestry technologies in the coastal savanna of Benin  

Microsoft Academic Search

As technologies to counter soil fertility decline, alley farming with Leucaena leucocephala and Gliricidia sepium, annual short-season Mucuna pruriëns var. Utilis fallowing, and perennial Acacia auriculiformis fallowing have been tested. With alley farming, timely pruning is a critical element in farmers' capacity to match on-station yield levels: 55% of the farmers who delayed pruning suffered about 60% yield losses. Farmers

M. N. Versteeg; F. Amadji; A. Eteka; A Gogan; V. Koudokpon

1998-01-01

256

Understanding why farmers plant trees in the homestead agroforestry in Bangladesh  

Microsoft Academic Search

Because trees cover only 6.4% of the total land area of Bangladesh, while agricultural expansion continues to massively deplete the natural forests, a well-managed homestead forestry practice is vital for reversing the existing trend and promoting the ecological balance of the country. An understanding of the decision-making process of the farmers who practice homestead forestry is important in expanding and

M. A. Salam; T. Noguchi; M. Koike

2000-01-01

257

Towards a natural resource management paradigm for international agriculture: the example of agroforestry research  

Microsoft Academic Search

This paper presents the basis of a new research paradigm, integrated natural resource management, which aims to increase agricultural production in tropical countries in a sustainable manner. Integrated natural resource management (NRM) combines traditional germplasm improvement approaches with NRM concerns. The theoretical framework underlying this approach is based on concepts of natural capital and ecosystem hierarchy, and highlights the role

A.-M. N. Izac; P. A. Sanchez

2001-01-01

258

The potential benefits of agroforestry in the Sahel and other semi-arid regions  

Microsoft Academic Search

This article summarises results of three related studies. The first study is a synthesis and analysis of available knowledge on woody plants in semi-arid regions with an emphasis on the Sahel region, investigating the potential `added value' of woody plants to improve nutrient and water availability for agricultural crop and pasture production goals. The other two are field studies aimed

H. Breman; J. J. Kessler

1997-01-01

259

The tree tenure factor in agroforestry with particular reference to Africa  

Microsoft Academic Search

Rights over trees are often distinct from rights over land. Tree tenure consists of a bundle of rights over trees and their produce which may be held by different people at different times. These rights include the right to own or inherit trees, the right to plant trees, the right to use trees and tree products, the right to dispose

Louise Fortmann

1985-01-01

260

Forest villages: an agroforestry approach to rehabilitating forest land degraded by shifting cultivation in Thailand  

Microsoft Academic Search

The Forest village scheme was introduced by the Forest Industries Organisation (FIO) of Thailand in 1967 as an attempt to stop further spread of the fast increasing shifting cultivation and deforestation in the country. The underlying princple of the scheme is to relate reforestation with social welfare of the people involved. It is essentially a modification of the traditional taungya

S.-A. BOONKIRD; E. C. M. Fernandes; P. K. R. Nair

1985-01-01

261

Recreation and Agroforestry: Examining New Dimensions of Multifunctionality in Family Farms  

ERIC Educational Resources Information Center

Multifunctionality serves as an analytical framework to recognize many services that farms provide to their surrounding communities and society. This study explores an often overlooked dimension of multifunctionality by examining different recreational services provided by landowners in Missouri and analyzing the relationship between recreational…

Barbieri, Carla; Valdivia, Corinne

2010-01-01

262

Distribution and diversity of rhizobia nodulating agroforestry legumes in soils from three continents in the tropics.  

PubMed

The natural rhizobial populations of Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala and Sesbania sesban were assessed in soils from nine sites across tropical areas of three continents. The rhizobial population size varied from undetectable numbers to 1.8 x 104 cells/g of soil depending on the trap host and the soil. Calliandra calothyrsus was the most promiscuous legume, nodulating in eight soils, while S. sesban nodulated in only one of the soils. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analyses of the 16S rRNA gene and the internally transcribed spacer (ITS) region between the 16S and 23S rRNA genes were used to assess the diversity and relative abundance of rhizobia trapped from seven of the soils by C. calothyrsus, G. sepium and L. leucocephala. Representatives of the 16S rRNA RFLP groups were also subjected to sequence analysis of the first 950 base pairs of the 16S rRNA gene. Eighty ITS groups were obtained, with none of the ITS types being sampled in more than one soil. RFLP analysis of the 16S rRNA yielded 23 'species' groups distributed among the Rhizobium, Mesorhizobium, Sinorhizobium and Agrobacterium branches of the rhizobial phylogenetic tree. The phylogeny of the isolates was independent of the site or host of isolation, with different rhizobial groups associated with each host across the soils from widely separated geographical regions. Although rhizobial populations in soils sampled from the centre of diversity of the host legumes were the most genetically diverse, soil acidity was highly correlated with the diversity of ITS types. Our results support the hypothesis that the success of these tree legumes in soils throughout the tropics is the result of their relative promiscuity (permissiveness) allowing nodulation with diverse indigenous rhizobial types. PMID:12753212

Bala, Abdullah; Murphy, Phillip; Giller, Ken E

2003-04-01

263

Agroforestry in the humid lowlands of West Africa: some reflections on future directions for research  

Microsoft Academic Search

Means have to be found for rural people to supply both their own needs and those of the urban dwellers, without further loss\\u000a of natural resources. Some examples from around the humid tropics suggest that complex agroforests may be able to achieve\\u000a this goal. In West Africa, the concepts of the cocoa (Theobroma cacao) farm and compound garden, coupled with

R. R. B. Leakey

1998-01-01

264

Lignocellulosic Feedstock Biorefinery - Combination of technologies of agroforestry and a biobased substance and energy economy  

Microsoft Academic Search

The development of biorefineries represents the key for the access to an integrated production of food, feed, chemicals, materials, goods, and fuels of the future (NATIONAL RESEARCH COUNCIL, USA, 2000). Biorefineries combine the necessary technologies of the biogenic raw materials with those of intermediates and final products. The main fo- cus is directed on the new land use forms for

Birgit Kamm; B. Uwe Schneider; Reinhard F. Hüttl; Holger Grünewald; Hans-Jörg Gusovius; Christian Stollberg; Peter Ay; Michael Kamm

2006-01-01

265

Assessment of promising forest-management practices and technologies for enhancing the conservation and sequestration of atmospheric carbon and their costs at the site level  

SciTech Connect

The objectives of the report are to assess and synthesize current knowledge on three policy-science topics: (1) Identify promising technologies and practices that could be utilized at technically suitable sites in the world to manage forests and agroforestry systems for sequestering and conserving carbon; (2) Assess available data on costs at the site level for promising forest and agroforestry management practices; and (3) Evaluate estimates of land technically suitable in forested nations and biomes of the world to help meet the Noordwijk forestation targets and the proposed Global Forest Agreement goals.

Dixon, R.K.; Schroeder, P.E.; Winjum, J.K.

1991-10-01

266

Acacia albida and other multipurpose trees on the fur farmlands in the Jebel Marra highlands, Western Darfur, Sudan  

Microsoft Academic Search

This paper describes the traditional agroforestry systems based on Acacia albida and other multipurpose trees as practised by the sedentary Fur people on the lower slopes and highlands of the Jebel Marra massif, Sudan. The basic agrosilvopastoral system consists of terraced village fields, where semipermanent rainfed cropping of staple millet and other subsistence crops takes place under stands of multipurpose

S. Miehe

1986-01-01

267

Interaction among N-fixing bacteria and AM fungi in Amazonian legume tree ( Schizolobium amazonicum) in field conditions  

Microsoft Academic Search

The Amazon forest has suffered an accelerated degradation process due to cutting to implant agricultural systems, pasture and electricity generation projects and disorganized mining and wood exploitations. The challenge is to develop new technologies for wood production in agroforestry systems. Schizolobium amazonicum is a legume tree, with fast growth and its wood is employed to make furniture. More and more

Marco Antonio Siviero; Alessandra Marega Motta; Dáfila dos Santos Lima; Renato Rosselli Birolli; Samuel Yun Huh; Ivana Abonizio Santinoni; Letícia Sayuri Murate; Cícera Maria Antonia de Castro; Marina Yumi Horta Miyauchi; Waldemar Zangaro; Marco Antonio Nogueira; Galdino Andrade

2008-01-01

268

AVALIAÇÃO DE ESPÉCIES FLORESTAIS EM ÁREA DE MATA NO ESTADO DE RORAIMA  

Microsoft Academic Search

This study was carried out to evaluate 19 native and exotic species and to identify potential species for plantation in homogeneous stands and in agroforestry systems in forest ecosystem in Roraima State. The species were planted from 1997 to 2000. When the objective was sawn wood production the spacing was 4 x 3 m and when the objective was energy

Helio Tonini; Marcelo Francia Arco-Verde; Dalton Schwengber; Moises Mourão Junior

2006-01-01

269

Interactions among cutting frequency, reserve carbohydrates, and post-cutting biomass production in Gliricidia sepium and Leucaena leucocephala  

Microsoft Academic Search

The ability of trees and shrubs to coppice vigorously after being cut or pruned is of great importance in the management of agroforestry systems. In a study conducted in the seasonally dry climate of Ibadan, Nigeria, frequent cutting progressively decreased concentrations of starch and total reserve carbohydrates in Gliricidia sepium (Jacq.) Walp. and Leucaena leucocephala (Lam.) De Wit. In frequently

C. R. Latt; P. K. R. Nair; B. T. Kang

2000-01-01

270

Trees outside forests: agro-, community, and urban forestry  

Microsoft Academic Search

Planted forests are often considered to consist of tree plantings at a scale large enough to satisfy such objectives as commercial production of timber and fiber, protection of watersheds, and preservation of natural habitats. However, trees are planted also at greatly reduced scales in agroforestry systems or as community woodlots to provide a mixture of products and services to resident

Alan J. Long; P. K. Ramachandran Nair

1999-01-01

271

DOMESTICATION OF DACRYODES EDULIS IN WEST AND CENTRAL AFRICA: CHARACTERISATION OF GENETIC VARIATION  

Microsoft Academic Search

New initiatives in agroforestry are seeking to integrate trees with marketable products into farming systems. This is being done in order to provide marketable timber and non-timber forest products from farms that will enhance rural livelihoods by generating cash for subsistence farmers. Dacryodes edulis (Safou) is one of the candidate tree species in West and Central Africa for domestication, which

R. R. B. LEAKEY; A. R. ATANGANA; E. KENGNI; A. N. WARUHIU; C. USORO; P. O. ANEGBEH; Z. TCHOUNDJEU

2002-01-01

272

Intercropping of two Leucaena spp. with sweet potato: yield, growth rate and biomass  

SciTech Connect

Results of trials with Leucaena leucocephala and Leucaena diversifolia at Wau, Papua New Guinea, showed potential benefits of the agroforestry cropping system. The total biomass yield (sweet potato plus firewood and green manure) was considerably greater than the yield per unit area of sweet potato alone. 3 references.

Swift, J.F.

1982-01-01

273

PHYSIOLOGICAL AND SILVICULTURAL ASPECTS OF BRAZILIAN PALMHEART (Euterpe edulis Martius ) PLANTED IN DIFFERENT TIPES OF CONSORTIUM IN LAVRAS - MINAS GERAIS  

Microsoft Academic Search

The objective of this research was to evaluate the initial growth of the Brazilian palmheart in agroforestry systems. Four treatments were selected: t1: Brazilian palmheart x hondurean pine; t2: Brazilian palmheart x eucalipto; t3: Brazilian palmheart x secondary forest; t4: Brazilian palmheart in full open conditions. Mensurations of the total height (H), \\

Antônio de Arruda; Tsukamoto Filho; Nelson Venturin

274

ASSESSMENT OF PROMISING FOREST MANAGEMENT PRACTICES AND TECHNOLOGIES FOR ENHANCING THE CONSERVATION AND SEQUESTRATION OF ATMOSPHERIC CARBON AND THEIR COSTS AT SITE LEVEL  

EPA Science Inventory

The objectives of this report are to assess and synthesize current knowledge on three policy-science topics: ) Identify promising technologies and practices that could be utilized at technically suitable sites in the world to manage forests and agroforestry systems for sequesteri...

275

Factors affecting the germination of doum palm ( Hyphaene thebaica Mart.) seeds from the semi-arid zone of Niger, West Africa  

Microsoft Academic Search

Hard-seeded tropical tree species such as doum palm (Hyphaene thebaica Mart.), a common component of the traditional agroforestry systems practiced in semi-arid West Africa, often present considerable problems to nursery managers because their hard, impermeable seed coats (pericarps) restrict the entry of both water and oxygen and offer high physical resistance to the growth of the embryo. Such seeds often

Hassane Moussa; Hank A Margolis; Pierre-André Dubé; Julius Odongo

1998-01-01

276

Fine root turnover of irrigated hedgerow intercropping in Northern Kenya  

Microsoft Academic Search

Fine root turnover ( 2 mm) was determined from repeated measurements of root distribution up to 120 cm soil depth by core sampling in four month intervals. Sole cropped Sorghum bicolorand Acacia salignawere compared with the agroforestry combination in an alley cropping system in semiarid Northern Kenya. Three methods for the calculation of root production were used: the max-min, balancing-transfer

Johannes Lehmann; Wolfgang Zech

1998-01-01

277

Erythrina (Leguminosae: Papilionoideae)  

Microsoft Academic Search

The genus Erythrina is of special interest in the development of agroforestry systems because of its adaptability to several uses (e.g., live posts for fences, shade trees for perennial crops such as coffee and cacao, forage for livestock, and others). Rapid plant growth, high biomass production, easy propagation from cuttings, ability to withstand regular pruning plus subsequent rapid sprouting and

Ricardo O. Russo

1991-01-01

278

Fine root dynamics of shaded cacao plantations in Costa Rica  

Microsoft Academic Search

Root turnover may contribute a significant proportion of recycled nutrients in agroforestry systems and competition between trees and crops for nutrients and water may depend on temporal fine root regrowth patterns. Fine root biomass ( 2 mm) and fine root productivity were measured during one year in plantations of cacao (Theobroma cacao) shaded by Erythrina poeppigiana or Cordia alliodora planted

F. Muñoz; J. Beer

2001-01-01

279

The economic linkages between rural poverty and land degradation: some evidence from Africa  

Microsoft Academic Search

This paper focuses on the potential role of policy in influencing the poverty and land degradation problems facing Africa. This is done through exploring a few case studies, chosen from a broad spectrum of African countries — Sudan, Malawi, Nigeria, Ghana and Kenya. The first case study examines the comparative returns to the gum arabic agroforestry system cultivated by poor

Edward B Barbier

2000-01-01

280

Body Systems  

NSDL National Science Digital Library

What are the parts and functions of the different systems in the body? Circulatory System Watch the Circulatory System and the Heart video. Complete one of the Circulatory System quizzes. Excretory System Label the parts of the excretory system. Respiratory System Quiz Complete respiratory system quiz to review parts. Skeletal System Label each part of the skeletal system. Vocabulary Review Change the settings to only include body system terms and play Hangman to review new vocabulary. ...

2011-11-02

281

A geologic guide to Wrangell-Saint Elias National Park and Preserve, Alaska; a tectonic collage of northbound terranes  

USGS Publications Warehouse

Wrangell-Saint Elias National Park and Preserve, the largest unit in the U.S. National Park System, encompasses near 13.2 million acres of geological wonderments. This geologic guide presents history of exploration and Earth-science investigation; describes the complex geologic makeup; characterizes the vast college of accretion geologic terranes in this area of Alaska's continental margin; recapitulates the effects of earthquakes, volcanoes, and glaciers; characterizes the copper and gold resources of the parklands; and describes outstanding locales within the park and preserve area. A glossary of geologic terms and a categorized list of additional sources of information complete this report.

Winkler, Gary R.; with contributions by MacKevett, E. M., Jr.; Plafker, George; Richter, D. H.; Rosenkrans, D. S.; Schmoll, H. R.

2000-01-01

282

Solar system positioning system  

NASA Technical Reports Server (NTRS)

Power-rich spacecraft envisioned in Prometheus initiative open up possibilities for long-range high-rate communication. A constellation of spacecraft on orbits several A.U. from the Sun, equipped with laser transponders and precise clocks can be configured to measure their mutual distances to within few cm. High on-board power can create substantial non-inertial contribution to the spacecraft trajectory. We propose to alleviate this contribution by employing secondary ranging to a passive daughter spacecraft. Such constellation can form the basis of it navigation system capable of providing position information anywhere in the soIar system with similar accuracy. Apart from obvious Solar System exploration implications, this system can provide robust reference for GPS and its successors.

Penanen, Konstantin I.; Chui, Talso

2006-01-01

283

Aerospace Systems  

NSDL National Science Digital Library

This pdf contains a syllabus for a course on aerospace systems as part of the Aerospace Technology Program. This course covers an introduction to expendable and reusable Space Launch Vehicle (SLV) systems including hydraulic, pneumatic, electrical, propulsion, mechanical, HVAC (heating, ventilation and air conditioning), and ECLSS (Environmental Control and Life Support Systems). How systems interact with computer and data acquisition systems is also covered.

2011-08-11

284

Aesthetics Systems.  

National Technical Information Service (NTIS)

The formal structure of aesthetics systems is defined. Aesthetics systems provide for the essential tasks of interpretation and evaluation is aesthetic analysis. Kolmogorov's formulation of information theory is applicable. An aesthetics system for a clas...

J. Gips G. Stiny

1973-01-01

285

Mechanical Systems  

NASA Technical Reports Server (NTRS)

The presentation provides an overview of requirement and interpretation letters, mechanical systems safety interpretation letter, design and verification provisions, and mechanical systems verification plan.

Davis, Robert E.

2002-01-01

286

Operating Systems  

NSDL National Science Digital Library

CSC 342. Operating Systems (3) Prerequisite: CSC 332. Study of supervisory programs. System services and file systems; CPU scheduling; memory management; virtual memory; disk scheduling. Deadlock characterization, prevention, and avoidance; concurrent processes; semaphores; critical sections; synchronization. Distributed systems and communication protocols.

Ferner, Clayton

2003-04-21

287

Solar System  

NSDL National Science Digital Library

At the end of this project, you will be able to explain the components of the Solar System and know the order of the planets starting from the Sun. Objective Question: What is the Solar System? First, listen and read about the Solar System 1. How many planets make up our Solar System? 2. What is at the center of the Solar System? Next,listen and read about the Planets. 1. Can you name all of the planets? Finally, listen and watch The Solar System Movie. 1. Can you list the ...

Ms.west

2009-07-07

288

Forage Production Under and Adjacent to Robinia pseudoacacia in Central Appalachia, West Virginia  

Microsoft Academic Search

Species-diverse production systems, such as agroforestry, provide opportunities to increase the value of total production\\u000a through marketing of multiple products from a given unit of land. Designing successful systems requires an understanding of\\u000a how species compete for resources and grow in proximity to other species with distinctly different growth habits and resource\\u000a demands (Sanchez, 1995; Ong and Leakey, 1999). Systems

C. M. Feldhake; D. P. Belesky; E. L. Mathias

289

Robot Systems.  

National Technical Information Service (NTIS)

This article reviews currently available industrial robots and research on robot systems. A hierarchical control structure concept, which is the basis for NBS research efforts in computer control systems, is used to provide a framework for this review. Co...

J. S. Albus J. M. Evans

1976-01-01

290

Skeptical Systems.  

National Technical Information Service (NTIS)

This report describes the technical components developed for hostile intent recognition, and documents specific experiments to evaluate a demonstration skeptical system in a cyber security domain. Current systems execute any command issued by an authentic...

C. W. Geib

2004-01-01

291

System considerations  

NASA Technical Reports Server (NTRS)

Closing remarks and a general summary of the Alternative Energy Systems Seminar are presented. It was concluded from the seminar that the DOE programs described were focused on trying to make a commercial market develop for the various systems. The question addressed is how this is going to happen. To address this question, social, economical, political and technical aspects are considered with major emphasis placed on systems engineering to provide low cost efficient systems.

Alper, M. E.

1978-01-01

292

Tracking systems  

Microsoft Academic Search

The tutorial is an overview of tracking and data fusion for surveillance systems with applications both to defense and civilian systems. It is divided into four parts: Part 1 - Filtering: Covers the topics related to state estimation for stochastic dynamic systems: optimal Bayesian estimator, Kalman filter, nonlinear filters (extended and unscented Kalman filter, Gaussian sum filter, particle filter); filters

B. Ristic; M. L. Hernandez

2008-01-01

293

Solar System  

NSDL National Science Digital Library

An introduction to to the solar system. How to distinguish between the different planets. Activities to play while getting to know the solar system. Cosmic Cookies Solar System Scavenger Hunt Edible Earth Strawkets and Control Strawkets and Thrust Strawkets and Weight ...

Wright, Ms.

2009-10-09

294

Systems 2020.  

National Technical Information Service (NTIS)

Systems 2020 is the research effort to answer a major portion of the challenge embodied in the DoD's science and technology priority for Engineered Resilient Systems (ERS). As a follow-on to the SERC's work in defining technical approaches for Systems 202...

B. Boehm S. Rifkin

2012-01-01

295

Systems Engineering  

Microsoft Academic Search

Each year at the National Council of Systems Engineering (NCOSE) symposium lots of dedicated people spend a lot of energy assessing, measuring and educating people about an incomplete body of knowledge (systems engineering). The incompleteness is due to the lack of a definition of what that body of knowledge is supposed to cover. Now every systems engineer knows that it

Joe Kasser

1969-01-01

296

Exploiting the potential of indigenous agroforestry trees: Parkia biglobosa and Vitellaria paradoxa in sub-Saharan Africa  

Microsoft Academic Search

Parkia biglobosa (néré) and Vitellaria paradoxa (karité) are indigenous tree species that are economically and socially important for local people in sub-Saharan Africa.\\u000a Farmers deliberately maintain these trees on farms mainly for their fruits and nuts. The kernels of karité yield shea butter,\\u000a which is rich in fatty acids; it is used locally for food and internationally in chocolate, pharmaceutical

Z. Teklehaimanot

2004-01-01

297

Walking a New Path of Life: Learning Tours, "Agroforestry" and the Transformation of the Village of Bann Na Isarn, Thailand  

ERIC Educational Resources Information Center

Rural areas in both developed and developing countries are being increasingly marginalized through structural changes. Furthermore, the disinvestment in state-provided supports and services means that rural people are left to their own devices to cope with these changes. Numerous authors argue that the most effective way of dealing with these…

Thacheen, Piyaporn; Lauzon, Allan C.

2006-01-01

298

Local solutions to global problems: the potential of agroforestry for climate change adaptation and mitigation in southern Africa  

Microsoft Academic Search

Climate change is a global phenomenon that imposes economic, social, and ecological challenges to the global community and, to smallholder farmers particularly in low- income countries. Sustainable land use practices offer opportunities for smallholder farmers to adapt to climate change and related risks, but the challenge is that the adoption of such practices by farmers is low due to policy

Ajayi OC; Akinnifesi FK; Sileshi G; Chakeredza S

299

Modeling carbon sequestration in afforestation, agroforestry and forest management projects: the CO2FIX V.2 approach  

Microsoft Academic Search

The paper describes the Version 2 of the CO2FIX (CO2FIX V.2) model, a user-friendly tool for dynamically estimating the carbon sequestration potential of forest management, agroforesty and afforestation projects. CO2FIX V.2 is a multi-cohort ecosystem-level model based on carbon accounting of forest stands, including forest biomass, soils and products. Carbon stored in living biomass is estimated with a forest cohort

Omar R. Maseraa; J. F. Garza-Caligaris; M. Kanninen; T. Karjalainen; J. Liski; G. J. Nabuurs; A. Pussinen; B. H. J. de Jong; G. M. J. Mohren

2003-01-01

300

PENYEBAB ALIH GUNA LAHAN DAN AKIBATNYA TERHADAP FUNGSI DAERAH ALIRAN SUNGAI (DAS) PADA LANSEKAP AGROFORESTRI BERBASIS KOPI DI SUMATERA  

Microsoft Academic Search

Land use is changing rapidly in SE-Asia from forest to landscape mosaics with various degrees of tree cover. The upper Way Besai watershed - about 40,000 ha upstream the Way Besai hydro-power dam - covers most of the sub- district of Sumberjaya (54,200 ha) and exemplifies the rapid land use changes. It was transformed in the past three decades from

Bruno Verbist

301

System Effectiveness  

SciTech Connect

An effective risk assessment system is needed to address the threat posed by an active or passive insider who, acting alone or in collusion, could attempt diversion or theft of nuclear material. It is critical that a nuclear facility conduct a thorough self-assessment of the material protection, control, and accountability (MPC&A) system to evaluate system effectiveness. Self-assessment involves vulnerability analysis and performance testing of the MPC&A system. The process should lead to confirmation that mitigating features of the system effectively minimize the threat, or it could lead to the conclusion that system improvements or upgrades are necessary to achieve acceptable protection against the threat. Analysis of the MPC&A system is necessary to understand the limits and vulnerabilities of the system to internal threats. Self-assessment helps the facility be prepared to respond to internal threats and reduce the risk of theft or diversion of nuclear material. MSET is a self-assessment or inspection tool utilizing probabilistic risk assessment (PRA) methodology to calculate the system effectiveness of a nuclear facility's MPC&A system. MSET analyzes the effectiveness of an MPC&A system based on defined performance metrics for MPC&A functions based on U.S. and international best practices and regulations. A facility's MC&A system can be evaluated at a point in time and reevaluated after upgrades are implemented or after other system changes occur. The total system or specific subareas within the system can be evaluated. Areas of potential performance improvement or system upgrade can be assessed to determine where the most beneficial and cost-effective improvements should be made. Analyses of risk importance factors show that sustainability is essential for optimal performance. The analyses reveal where performance degradation has the greatest detrimental impact on total system risk and where performance improvements have the greatest reduction in system risk. The risk importance factors show the amount of risk reduction achievable with potential upgrades and the amount of risk reduction actually achieved after upgrades are completed. Applying the risk assessment tool gives support to budget prioritization by showing where budget support levels must be sustained for MC&A functions most important to risk. Results of the risk assessment are also useful in supporting funding justifications for system improvements that significantly reduce system risk.

Powell, Danny H [ORNL] [ORNL; Elwood Jr, Robert H [ORNL] [ORNL

2011-01-01

302

Cryogenic Systems  

NASA Astrophysics Data System (ADS)

In this lecture we discuss the principle of method of cooling to a very low temperature, i.e. cryogenic. The "gas molecular model" will be introduced to explain the mechanism cooling by the expansion engine and the Joule-Thomson expansion valve. These two expansion processes are normally used in helium refrigeration systems to cool the process gas to cryogenic temperature. The reverse Carnot cycle will be discussed in detail as an ideal refrigeration cycle. First the fundamental process of liquefaction and refrigeration cycles will be discussed, and then the practical helium refrigeration system. The process flow of the system and the key components; -compressor, expander, and heat exchanger- will be discussed. As an example of an actual refrigeration system, we will use the cryogenic system for the KEKB superconducting RF cavity. We will also discuss the liquid helium distribution system, which is very important, especially for the cryogenic systems used in accelerator applications. 1 Principles of Cooling and Fundamental Cooling Cycle 2 Expansion engine, Joule-Thomson expansion, kinetic molecular theory, and enthalpy 3 Liquefaction Systems 4 Refrigeration Systems 5 Practical helium liquefier/refrigeration system 6 Cryogenic System for TRISTAN Superconducting RF Cavity

Hosoyama, Kenji

2002-02-01

303

Systems Thinking 2: Thermodynamic Systems  

NSDL National Science Digital Library

This video explains thermodynamic systems, open and closed systems, and the four key properties of a system. This video is part of the Sustainability Learning Suites, made possible in part by a grant from the National Science Foundation. See 'Learn more about this resource' for Learning Objectives, Assessment, and Activities.

Vanasupa, Linda

304

Nitrous oxide emissions following incorporation of improved-fallow residues in the humid tropics  

NASA Astrophysics Data System (ADS)

The rotation of crops with fast-growing tree, shrub, and herbaceous N2-fixing legume species (improved fallows) is a central agroforestry technology for soil fertility management in the humid tropics. Maize yields are increased following improved fallows compared with continuous maize cropping or traditional natural-fallow systems consisting of broadleaved weeds and grasses. However, the effect of these improved-fallow systems on N availability and N2O emissions following residue application has yet to be determined. Emissions from these systems not only have a detrimental effect on the environment, but are of additional concern in that they represent a potentially significant loss of N and a reduction in N-use efficiency. Emissions of N2O were measured from improved-fallow agroforestry systems in western Kenya, being characteristic of agroforestry systems in the humid tropics. Emissions were increased after incorporation of fallow residues and were higher after incorporation of improved-fallow legume residues (Sesbania sesban, Crotalaria grahamiana, Macroptilium atropurpureum) than natural-fallow residues (mainly consisting of Digitaria abyssibica, Habiscus cannabinus, Bidens pilosa, Guizotia scabra, Leonotis nepetifolia, Commelina benghalensis). Following incorporation of Sesbania and Macroptilium residues (7.4 t dry matter ha-1; 2.9% N) in a mixed fallow system, 4.1 kg N2O-N ha-1 was emitted over 84 days. The percentages of N applied emitted as N2O following residue incorporation in these tropical agroforestry systems were of the same magnitude as in temperate agricultural systems. N2O (loge) emissions were positively correlated with residue N content (r = 0.93; P < 0.05), and thus the residue composition, particularly its N content, is an important consideration when proposing management practices to mitigate N2O emissions from these systems.

Millar, N.; Ndufa, J. K.; Cadisch, G.; Baggs, E. M.

2004-03-01

305

The argan tree ( Argania spinosa ) in Morocco: Propagation by seeds, cuttings and in-vitro techniques  

Microsoft Academic Search

In South-western Morocco, the argan tree (Argania spinosa) is basis of a traditional agroforestry system. However, this system is no longer at equilibrium and there is an urgent need\\u000a to renovate it. The natural reproduction of the tree has become difficult, and most attempts of artificial regeneration have\\u000a failed. We have assessed three different propagation methods: seedlings, cuttings, and in-vitro

R. Nouaim; G. Mangin; M. C. Breuil; R. Chaussod

2002-01-01

306

Geothermal systems  

NASA Technical Reports Server (NTRS)

Several tasks of JPL related to geothermal energy are discussed. The major task is the procurement and test and evaluation of a helical screw drive (wellhead unit). A general review of geothermal energy systems is given. The presentation focuses attention on geothermal reservoirs in California, with graphs and charts to support the discussion. Included are discussions on cost analysis, systems maintenance, and a comparison of geothermal and conventional heating and cooling systems.

Mohl, C.

1978-01-01

307

Operating Systems  

NSDL National Science Digital Library

Rashid Bin Muhammad at Kent State University presents his page of lectures notes and other instructional materials on operating systems. The site is divided into a number of topics about operating systems: history, structure, process, threads, Solaris-2, CPU / process scheduling, schedule algorithm, interprocess communication, deadlock, important UNIX commands, and references. The site is then followed by links to outside resources to help supplement the material presented here. This is a great resource for computer science instructors teaching students about operating systems.

Bin Muhammad, Rashid

2009-06-24

308

Operating Systems  

NSDL National Science Digital Library

Stanford's Computer Science department presents this course on operating systems taught by David Mazières in Winter of 2009. The course covers concurrency, synchronization, scheduling, linking, virtual memory, memory allocations, file systems, networking, protection, security, and virtual machines. On the site, visitors will find the course syllabus, lecture notes, reference materials, and old exams from past iterations of the course. There are also four programming projects on the following topics: threads, user programs, virtual memory, and file systems. It's an excellent resource for educators in computer science and technician training courses to help supplement operating systems education.

Maziãâ¨res, David

2009-01-01

309

Carbon Systems  

SciTech Connect

The electronic states of a 'quantum dot-graphene monolayer-SiO{sub 2} + n{sup +}-Si substrate' system in an external magnetic field are studied. An analytical expression for charge transfer in this system is obtained. The electronic states of a 'quantum dot-graphene bilayer-SiO{sub 2} + n{sup +}-Si substrate' system are considered. The systems under study are interesting from the viewpoint of controlling the optical properties of a quantum dot by means of an applied electric field.

Alisultanov, Z. Z., E-mail: zaur0102@gmail.com [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

2013-06-15

310

[Melanocortin system].  

PubMed

Melanocortin system consists of native melanocortin peptides (ACTH, MSH and their fragments), melanocortin receptors (MC1R-MC5R) and their endogenous antagonists. Melanocortins have a wide spectrum of physiological activity. These peptides improve memory and attention, facilitate neuromuscular regeneration, exert neuroprotective action, affect the development of nervous system, modulate sexual behavior, have anti-inflammatory and antipyretic effects, interact with opioid system, affect the pain sensitivity and cardiovascular system, decrease food intake and body weight, influence on exocrine secretions. PMID:19326848

Levitskaia, N G; Kamenski?, A A

2009-01-01

311

SCALPEL system  

NASA Astrophysics Data System (ADS)

We have proposed an approach to projection electron beam lithography, termed the SCALPEL system, which we believe offers solutions to previous problems associated with projection electron beam lithography.

Berger, Steven D.; Biddick, Chris; Blakey, Myrtle; Bolan, Kevin J.; Bowler, Stephen W.; Brady, Kevin; Camarda, Ron; Connelly, Wayne; Farrow, Reginald C.; Felker, Joseph A.; Fetter, Linus A.; Harriott, Lloyd R.; Huggins, Harold A.; Kraus, Joe; Liddle, J. A.; Mkrtchyan, Masis M.; Novembre, Anthony E.; Peabody, Milton; Russell, Tom; Simpson, Wayne M.; Tarascon, Regine G.; Wade, H. H.; Waskiewicz, Warren K.; Watson, Pat

1994-12-01

312

Synergies between Agricultural Intensification and Climate Change Could Create Surprising Vulnerabilities for Crops  

NSDL National Science Digital Library

An inevitable consequence of global climate change is that altered patterns of temperature and precipitation threaten agriculture in many tropical regions, requiring strategies of human adaptation. Moreover, the process of management intensification in agriculture has increased and may exacerbate vulnerability to climate extremes. Although many solutions have been presented, the role of simple agro-ecological and agroforestry management has been largely ignored. Some recent literature has shown how sustainable management may improve resistance to extreme climate events. We comment specifically on a prevalent form of agriculture throughout Latin America, the coffee agroforestry system. Results from the coffee literature have shown that shade management in coffee systems may mitigate the effects of extreme temperature and precipitation, thereby reducing the ecological and economic vulnerability of many rural farmers. We conclude that more traditional forms of agriculture can offer greater potential for adapting to changing conditions than do current intensive systems.

Brenda B. Lin (University of Michigan;); Ivette Perfecto (University of Michigan;); John Vandermeer (University of Michigan;)

2008-10-01

313

Anticipatory systems as linguistic systems  

NASA Astrophysics Data System (ADS)

The idea of system is well established although not well defined. What makes up a system depends on the observer. Thinking in terms of systems is only a convenient way to conceptualize organizations, natural or artificial, that show coherent properties. Among all properties, which can be ascribed to systems, one property seems to be more outstanding than others, namely that of being anticipatory. In nature, anticipatory properties are found only in living organizations. In this way it can be said to separate non-living systems from living because there is no indication that any natural phenomenon occurring in systems where there is no indication of life is anticipatory. The characteristic of living systems is that they are exposed to the evolution contrary to causal systems that do not undergo changes due to the influence of the environment. Causal systems are related to the past in such a way that subsequent situations can be calculated from knowledge of past situations. In causal systems the past is the cause of the present and there is no reference to the future as a determining agent, contrary to anticipatory systems where expectations are the cause of the present action. Since anticipatory properties are characteristic of living systems, this property, as all other properties in living systems, is a result of the evolution and can be found in plants as well as in animals. Thus, it is not only tied to consciousness but is found at a more basic level, i.e., in the interplay between genotype and phenotype. Anticipation is part of the genetic language in such a way that appropriate actions, for events in the anticipatory systems environment, are inscribed in the genes. Anticipatory behavior, as a result of the interpretation of the genetic language, has been selected by the evolution. In this paper anticipatory systems are regarded as linguistic systems and I argue that as such anticipation cannot be fragmented but must be holistically studied. This has the implication that anticipatory behavior can only partially be described in a computer language and, furthermore, it shows that only a restricted class of anticipatory systems can be transferred to computers. .

Ekdahl, Bertil

2000-05-01

314

Anesthesia systems.  

PubMed

Anesthesia systems are used to induce general anesthesia during surgery. In addition, the systems track anesthetic agent and gas concentrations, as well as the patient's condition, using physiologic and multigas monitors. For this Update Evaluation, we present our findings for four newly evaluated models from two manufacturers and summarize our findings for the two previously evaluated models that are still on the market. (Our earlier Evaluations were published in the May-June 1996 and January 1998 issues of Health Devices.) As in the previous Evaluations, our ratings are based largely on the degree of system integration, the suitability of the systems for various types of procedures, and cost. When equipped with the appropriate monitors, all the systems can deliver anesthesia effectively and can meet the minimum monitoring requirements of general surgery. While no system met all our criteria, any limitations of the systems can easily be overcome by the purchaser. We rate two models Preferred. One provides performance and features similar to the other evaluated systems at a significantly lower cost. The second offers exceptional flexibility in meeting monitoring requirements. Three models are rated Acceptable, and the remaining model is rated Acceptable (with Conditions). It is Acceptable only if it is equipped to supply air as an inspired gas. PMID:11989067

2002-04-01

315

Digestive System  

NSDL National Science Digital Library

The digestive system is investigated in this learning activity to help participants learn how food is broken down and prepared for absorption, and list the components of the digestive system as well as their functions. Organs investigated include the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.

Bidlack, Jim

316

Turbocompound system  

Microsoft Academic Search

A turbocompound system is described for improving the performance of an internal combustion engine without substantially increasing an end viewed profile of the engine to which it is mounted in use. The system consists of: (a) an exhaust driven turbocharger means having an exhaust manifold means extending in an axial direction for collecting exhaust gases from engine cylinders and delivering

Fox

1986-01-01

317

ECONOMIC SYSTEMS  

NSDL National Science Digital Library

The information you will explore is: List and categorize the four main types of Economic Systems in our world today. Create graphic Illustrations of thoughts and concepts. Express how economic system structures effect the lives of the people living in that system. Write to express an opinion or point of view. Experience a simulation of the marketplace. Research a country of your choice and find important factors about their economic system. Each country structures their economic system after one of the four main types or a combination of these. The assignments on this page will help you to gain a better understanding of the characteristics of the four main types of economic systems. Process: 1. Click on the following link Marketing Calendar Open the Global Economy power point. Use the Chapter 4 listening guide with the power point. chap4 listening guide 2. List the four main economic systems and find the main characterisitics of each. Compare strengths and weaknesses of each. Economic Systems Characteristics 3.Create a ...

Mrs.owen

2006-10-10

318

Power system  

DOEpatents

A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

Hickam, Christopher Dale (Glasford, IL)

2008-03-18

319

Systems and Components Fuel Delivery System, Water Delivery System, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur , Huntsville, Madison County, AL

320

Trees, soils, and food security  

PubMed Central

Trees have a different impact on soil properties than annual crops, because of their longer residence time, larger biomass accumulation, and longer-lasting, more extensive root systems. In natural forests nutrients are efficiently cycled with very small inputs and outputs from the system. In most agricultural systems the opposite happens. Agroforestry encompasses the continuum between these extremes, and emerging hard data is showing that successful agroforestry systems increase nutrient inputs, enhance internal flows, decrease nutrient losses and provide environmental benefits: when the competition for growth resources between the tree and the crop component is well managed. The three main determinants for overcoming rural poverty in Africa are (i) reversing soil fertility depletion, (ii) intensifying and diversifying land use with high-value products, and (iii) providing an enabling policy environment for the smallholder farming sector. Agroforestry practices can improve food production in a sustainable way through their contribution to soil fertility replenishment. The use of organic inputs as a source of biologically-fixed nitrogen, together with deep nitrate that is captured by trees, plays a major role in nitrogen replenishment. The combination of commercial phosphorus fertilizers with available organic resources may be the key to increasing and sustaining phosphorus capital. High-value trees, 'Cinderella' species, can fit in specific niches on farms, thereby making the system ecologically stable and more rewarding economically, in addition to diversifying and increasing rural incomes and improving food security. In the most heavily populated areas of East Africa, where farm size is extremely small, the number of trees on farms is increasing as farmers seek to reduce labour demands, compatible with the drift of some members of the family into the towns to earn off-farm income. Contrary to the concept that population pressure promotes deforestation, there is evidence that demonstrates that there are conditions under which increasing tree planting is occurring on farms in the tropics through successful agroforestry as human population density increases.

Sanchez, P. A.; Buresh, R. J.; Leakey, R. R. B.

1997-01-01

321

Respiratory system  

NASA Technical Reports Server (NTRS)

The general anatomy and function of the human respiratory system is summarized. Breathing movements, control of breathing, lung volumes and capacities, mechanical relations, and factors relevant to respiratory support and equipment design are discussed.

Bartlett, R. G., Jr.

1973-01-01

322

Earth Systems  

NSDL National Science Digital Library

This self-contained module on Earth systems includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

Science, Houghton M.

323

Hypernuclear systems  

SciTech Connect

The weak and strong interaction components of the hyperon-nucleon interaction in nuclei are discussed via the ..lambda..N system. Also, strangeness S = -2 dibaryon searches are discussed via the ..gamma..N interaction. (AIP)

Barnes, P.D.

1984-11-15

324

Fueling systems  

SciTech Connect

This report deals with concepts of the Tiber II tokamak reactor fueling systems. Contained in this report are the fuel injection requirement data, startup fueling requirements, intermediate range fueling requirements, power range fueling requirements and research and development considerations. (LSR)

Gorker, G.E.

1987-01-01

325

Root systems  

NSDL National Science Digital Library

One purpose that roots serve is that of anchoring the plant in the ground. Roots also take up water and nutrients for the plant. Plants all have different root system types to fit their individual needs and locations.

N/A N/A (U.S. Government;)

2004-10-30

326

Authoring Systems.  

National Technical Information Service (NTIS)

The monograph provides background information about authoring technology and assesses its current status. Part 1 provides basic information about authoring systems and compares them to other authoring approaches. Part 2 examines assumptions made about the...

C. Locatis E. Ullmer V. Carr R. Banvard R. Lo

1992-01-01

327

Navigation systems  

NASA Astrophysics Data System (ADS)

The elements of the measurement and communications network comprising the global deep space navigation system (DSN) for NASA missions are described. Among the measurement systems discussed are: VLBI, two-way Doppler and range measurements, and optical measurements carried out on board the spacecraft. Processing of navigation measurement is carried out using two modules: an N-body numerical integration of the trajectory (and state transition partial derivatives) based on pre-guessed initial conditions; and partial derivatives of simulated observables corresponding to each actual observation. Calculations of velocity correction parameters is performed by precise modelling of all physical phenomena influencing the observational measurements, including: planetary motions; tracking station locations, gravity field structure, and transmission media effects. Some of the contributions to earth-relative orbit estimate errors for the Doppler/range system on board Voyager are discussed in detail. A line drawing of the DSN navigation system is provided.

Jordan, J. F.

1985-10-01

328

Information Systems.  

National Technical Information Service (NTIS)

This report was prepared by Stanford University under contract with the National Iranian Radio Television. The task assignment was the report concerns analysis of information systems and services that could be used to facilitate the storage and retrieval ...

E. B. Parker C. Sartori H. Breitrose E. Elliot

1976-01-01

329

Digestive System  

MedlinePLUS

... of the immune system to a protein called gluten, which is found in wheat, rye, and barley ... and even depression when they eat foods with gluten. Symptoms can be managed by following a gluten- ...

330

Respiratory System  

NSDL National Science Digital Library

The purpose, components, and functions of the respiratory system are presented in this learning through disussion and visualizations. Participants learn about the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.

Bidlack, Jim

331

Microelectromechanical Systems  

NASA Technical Reports Server (NTRS)

Micro-electromechanical systems (MEMS) is an enabling technology that merges computation and communication with sensing and actuation to change the way people and machines interact with the physical world. MEMS is a manufacturing technology that will impact widespread applications including: miniature inertial measurement measurement units for competent munitions and personal navigation; distributed unattended sensors; mass data storage devices; miniature analytical instruments; embedded pressure sensors; non-invasive biomedical sensors; fiber-optics components and networks; distributed aerodynamic control; and on-demand structural strength. The long term goal of ARPA's MEMS program is to merge information processing with sensing and actuation to realize new systems and strategies for both perceiving and controlling systems, processes, and the environment. The MEMS program has three major thrusts: advanced devices and processes, system design, and infrastructure.

Gabriel, Kaigham J.

1995-01-01

332

Endocrine System  

MedlinePLUS

... in regulating mood, growth and development, tissue function, metabolism, and sexual function and reproductive processes. In general, ... in the body, the body's response to stress, metabolism, the immune system, and sexual development and function. ...

333

Embedded Systems  

NSDL National Science Digital Library

Embedded systems are dedicated computers designed to perform a specific task. They are usually fairly simple devices that are used in areas where powerful, customizable computers are unnecessary; however, they can also be quite complex on occasion. Embedded systems can be found almost anywhere, including automobiles and cellular phones, and their importance is reflected in their near omnipresence.An excellent introduction to embedded systems can be found in the first three pages of this online course material (1). The educational module gives a thorough definition of embedded systems, several examples of where they are used, and a discussion of their common components. For a more detailed explanation of how these devices are used to control various appliances, motors, and other real world products, this site (2) is worth a visit. Sixteen sections comprise the site, and each includes background information and an example experiment. Although certain equipment is required for the experiments, much can be learned simply from reading the introductions. This enlightening essay (3) documents the history and development of embedded systems. Despite being somewhat specific to the author's life, it effectively illustrates the evolution of embedded systems and their incorporation into many facets of everyday life. A paper presented at the 2003 International Cryptology Conference (4) considers the vulnerability of embedded cryptosystems to side channel attacks, which are different from normal security violations because they involve monitoring parts of the hardware system instead of the software. The authors propose the design of private circuits that are resistant to such attacks. The Center for Robotics and Embedded Systems at the University of Southern California is the source of this paper (5) about networked robots. Although it is somewhat dated, the paper provides some valuable insights into how robots can be used in human environments and how they can be controlled and coordinated with wireless communications. An article from Dedicated Systems Magazine (6) highlights the role of embedded systems in NASA's Mars Exploration Rovers, which were launched in June and July 2003. The technologies that enabled the rovers to have powerful, reliable operation are described. The April 2003 issue of ACM Queue (7), the online magazine of the Association for Computing Machinery, is dedicated to embedded systems. Seven articles are included in the issue, dealing with the design and construction process of embedded devices and the hardware/software interface. Lastly, a short paper that was presented at a computer architecture symposium in January 2003 looks ahead to the realization of ubiquitous computing (8). This technology revolution, which has been predicted for many years, promises to make tiny computers embedded in virtually everything, even clothing and walls. The author focuses on the area of intelligent vehicles and wheeled mobile robots.

Leske, Cavin.

334

Complex Systems  

PubMed Central

Physiologic systems in health and disease display an extraordinary range of temporal behaviors and structural patterns that defy understanding based on linear constructs, reductionist strategies, and classical homeostasis. Application of concepts and computational tools derived from the contemporary study of complex systems, including nonlinear dynamics, fractals and “chaos theory,” is having an increasing impact on biology and medicine. This presentation provides a brief overview of an emerging area of biomedical research, including recent applications to cardiopulmonary medicine and chronic obstructive lung disease.

Goldberger, Ary L.

2006-01-01

335

Biomedical Systems  

Microsoft Academic Search

\\u000a The phenomenal success and widespread proliferation of microelectronic devices can be attributed in large part to the mass\\u000a production technologies that have been developed for their manufacture. These microfabrication techniques have been honed\\u000a to maximize device yield and microelectromechanical systems (MEMS) capitalize on these semiconductor microfabrication tools\\u000a to create miniature systems that meld electronic and mechanical functions. Miniaturization brings with

Whye-Kei Lye; Michael Reed

336

Digestive System  

NSDL National Science Digital Library

The digestive system is amazing: it takes the foods we eat and breaks them into smaller components that our bodies can use for energy, cell repair and growth. This lesson introduces students to the main parts of the digestive system and how they interact. In addition, students learn about some of the challenges astronauts face when eating in outer space. Engineers figure out how to deal with such challenges.

Integrated Teaching And Learning Program

337

Laser Systems  

NASA Technical Reports Server (NTRS)

Tunable diode lasers are employed as radiation sources in high resolution infrared spectroscopy to determine spectral characteristics of gaseous compounds. With other laser systems, they are produced by Spectra-Physics, and used to monitor chemical processes, monitor production of quantity halogen lamps, etc. The Laser Analytics Division of Spectra-Physics credits the system's reliability to a program funded by Langley in the 1970s. Company no longer U.S.-owned. 5/22/97

1985-01-01

338

Interactions between carbon sequestration and shade tree diversity in a smallholder coffee cooperative in El Salvador.  

PubMed

Agroforestry systems have substantial potential to conserve native biodiversity and provide ecosystem services. In particular, agroforestry systems have the potential to conserve native tree diversity and sequester carbon for climate change mitigation. However, little research has been conducted on the temporal stability of species diversity and aboveground carbon stocks in these systems or the relation between species diversity and aboveground carbon sequestration. We measured changes in shade-tree diversity and shade-tree carbon stocks in 14 plots of a 35-ha coffee cooperative over 9 years and analyzed relations between species diversity and carbon sequestration. Carbon sequestration was positively correlated with initial species richness of shade trees. Species diversity of shade trees did not change significantly over the study period, but carbon stocks increased due to tree growth. Our results show a potential for carbon sequestration and long-term biodiversity conservation in smallholder coffee agroforestry systems and illustrate the opportunity for synergies between biodiversity conservation and climate change mitigation. PMID:24283921

Richards, Meryl Breton; Méndez, V Ernesto

2014-04-01

339

N 2 O, CH 4 and CO 2 emissions from seasonal tropical rainforests and a rubber plantation in Southwest China  

Microsoft Academic Search

The main focus of this study was to evaluate the effects of soil moisture and temperature on temporal variation of N2O, CO2 and CH4 soil-atmosphere exchange at a primary seasonal tropical rainforest (PF) site in Southwest China and to compare these fluxes with fluxes from a secondary forest (SF) and a rubber plantation (RP) site. Agroforestry systems, such as rubber

Christian Werner; Xunhua Zheng; Janwei Tang; Baohua Xie; Chunyan Liu; Ralf Kiese; Klaus Butterbach-Bahl

2006-01-01

340

Root length and nitrate under Sesbania sesban: Vertical and horizontal distribution and variability  

Microsoft Academic Search

Measurements of root and nutrient distributions in agroforestry systems have often been obtained from unreplicated plots.\\u000a We, therefore, measured the vertical and horizontal distribution of root length and soil nitrate in replicated plots of sesbania\\u000a [Sesbania sesban (L.) Merr.] to assess plot-to-plot variation and identify appropriate sampling schemes. Sampling was on profile\\u000a walls exposed from pits at two on-farm sites

Kindu Mekonnen; Roland J. Buresh; Richard Coe; Kering Maru Kipleting

1998-01-01

341

Diversity of plant species in arecanut agroforests of south Meghalaya, north-east India  

Microsoft Academic Search

In south Meghalaya, farmers maintain a variety of economically important plant species in arecanut agroforestry systems. We\\u000a investigated plant species composition of arecanut agroforests of south Meghalaya and encountered 160 plants, which included\\u000a 83 tree species, 22 shrub species, 41 herb species and 14 climber species. The study reveals that arecanut agroforests provide\\u000a cash income, medicine, timber, fuelwood and edibles

H. Tynsong; B. K. Tiwari

2010-01-01

342

Understanding and Integrating Local Perceptions of Trees and Forests into Incentives for Sustainable Landscape Management  

Microsoft Academic Search

We examine five forested landscapes in Africa (Cameroon, Madagascar, and Tanzania) and Asia (Indonesia and Laos) at different\\u000a stages of landscape change. In all five areas, forest cover (outside of protected areas) continues to decrease despite local\\u000a people’s recognition of the importance of forest products and services. After forest conversion, agroforestry systems and\\u000a fallows provide multiple functions and valued products,

Jean-Laurent Pfund; John Daniel Watts; Manuel Boissière; Amandine Boucard; Renee Marie Bullock; Andree Ekadinata; Sonya Dewi; Laurène Feintrenie; Patrice Levang; Salla Rantala; Douglas Sheil; Terence Clarence Heethom Sunderland; Zora Lea Urech

2011-01-01

343

Effects of water stress on water use efficiency and water balance components of Hippophae rhamnoides and Caragana intermedia in the soil–plant–atmosphere continuum  

Microsoft Academic Search

Hippophae rhamnoides (Sea buckthorn) and Caragana intermedia (Intermediate peashrub), which are nitrogen-fixing and perennial temperate shrubs, are extensively used in the agroforestry\\u000a systems in the loess areas of China. In this study, artificially controlled water gradient experiments were carried out with\\u000a both shrubs, based on four levels of water supply (normal precipitation, slight drought, drought, and extreme drought). The\\u000a results

Weihua GuoBo; Bo Li; Xinshi Zhang; Renqing Wang

2010-01-01

344

Regeneration and multiplication of Albizia procera Benth. through organogenesis  

Microsoft Academic Search

Vegetative propagation techniques are recognized as indispensable tools for mass multiplication of important multipurpose\\u000a trees adopted in different agroforestry systems. Albizia procera, one among important species, is difficult to propagate commercially either by stem \\/ root cuttings or layering. A study\\u000a was undertaken to develop procedure for its in vitro regeneration through organogenesis. Explants collected from 152 yr-old mature plus

S. L. Swamy; J. L. Ganguli; S. Puri

2004-01-01

345

Mycorrhizal dependency of micropropagated argan tree ( Argania spinosa ): I. Growth and biomass production  

Microsoft Academic Search

The influence of V.A. mycorrhization was studied on two clones of in-vitro micropropagated plantlets ofArgania spinosa, a slow-growing tree of great importance in agroforestry systems in the semi-arid and arid zones of southwestern Morocco. Inoculation increased total shoot length, stem girth and biomass of the plants, when cultivated in controlled conditions with a phosphorus fertilization of 31 mgP·kg-1 added to

R. Nouaim; R. Chaussod

1994-01-01

346

Sandalwood, markets, and super-ordinate kin: property, propriety, and ecology in contemporary Tonga  

Microsoft Academic Search

The agro-forestry system of Tonga includes crops used for food, medicine, and other purposes. Among these is the 'ahi or sandalwood tree. This paper describes events that occurred in the Ha'apai region, in the early 1980s, when a trader offered to buy 'ahi at unheard of prices. Although farmers have detailed and sophisticated knowledge of the island's ecology; in spite

Mike Evans

2007-01-01

347

Acclimation to sun and shade of three accessions of the Chilean native berry-crop murta  

Microsoft Academic Search

Murta (Ugni molinae Turcz.) is an evergreen shrub of the native forest understorey of southern Chile that produces berries which are consumed\\u000a in the local markets. Because of the natural adaptation of murta to growing under the shade of trees, we propose that an adequate\\u000a way of domesticating this species would be its cultivation in agroforestry systems. In order to

Nicolás Franck; Sylvia Winkler; Claudio Pastenes; Rodrigo Infante

2007-01-01

348

Systemic trauma.  

PubMed

Substantial theoretical, empirical, and clinical work examines trauma as it relates to individual victims and perpetrators. As trauma professionals, it is necessary to acknowledge facets of institutions, cultures, and communities that contribute to trauma and subsequent outcomes. Systemic trauma-contextual features of environments and institutions that give rise to trauma, maintain it, and impact posttraumatic responses-provides a framework for considering the full range of traumatic phenomena. The current issue of the Journal of Trauma & Dissociation is composed of articles that incorporate systemic approaches to trauma. This perspective extends conceptualizations of trauma to consider the influence of environments such as schools and universities, churches and other religious institutions, the military, workplace settings, hospitals, jails, and prisons; agencies and systems such as police, foster care, immigration, federal assistance, disaster management, and the media; conflicts involving war, torture, terrorism, and refugees; dynamics of racism, sexism, discrimination, bullying, and homophobia; and issues pertaining to conceptualizations, measurement, methodology, teaching, and intervention. Although it may be challenging to expand psychological and psychiatric paradigms of trauma, a systemic trauma perspective is necessary on both scientific and ethical grounds. Furthermore, a systemic trauma perspective reflects current approaches in the fields of global health, nursing, social work, and human rights. Empirical investigations and intervention science informed by this paradigm have the potential to advance scientific inquiry, lower the incidence of a broader range of traumatic experiences, and help to alleviate personal and societal suffering. PMID:24617751

Goldsmith, Rachel E; Martin, Christina Gamache; Smith, Carly Parnitzke

2014-01-01

349

Complex Systems  

NASA Astrophysics Data System (ADS)

This book explores the exciting new field of complexity. It features in-depth coverage of important theoretical areas, including fractals, chaos, nonlinear dynamics, artificial life, and self organization. It also provides overviews of complexity in several applied areas, including parallel computation, control systems, neural systems, and ecosystems. Contributors examine some of the properties that best characterize complex systems, including algorithmic richness, nonlinearity, and abundant interactions between components. In this way the book draws themes, especially the ideas of connectivity and natural computation, that reveal deep, underlying similarities among phenomena that have formerly been treated as completely distinct. Researchers in a wide array of fields, including ecology, neuroscience, computer science, and mathematics, will find this volume to be a fascinating collection of ideas.

Bossomaier, Terry R. J.; Green, David G.

2000-07-01

350

System Overview  

NSDL National Science Digital Library

This is a description for a learning module from Maricopa Advanced Technology Education Center. This PDF describes the module; access may be purchased by visiting the MATEC website. Technicians face the challenge of building and maintaining knowledge and skills that are applicable to microcomputer architecture. These challenges include keeping up to date on improvements in PC components, changes in PC hardware configurations, integration of new devices within PC systems, and the ability to readily apply their knowledge within the microcomputer manufacturing industry. This module provides an introduction and overview to the major system features that define the architecture of an Intel-based PC. A unique multimedia self-tutorial is included.

2011-08-22

351

Manufacturing Systems  

NSDL National Science Digital Library

Objective 7:05 - Students will develop an awareness of the designed World through : Describing a manufacturing system; listing and describing the basic type of manufacturing; defining production and manufacturing enterprise;defining AGV, CAD, CIM, CAM, CNC, production tooling, automation, and material processes. Day 1: Introduction/Background Objective Preassessment: Use a KWL chart to assess your students prior knowledge. This will also help you deal with any misconceptions regarding manufacturing system. Students will use the curriculum companion PowerPoint and Objective 7.05 Outline to develop an awarness of: Define manufacturing List and describe the basic types of Manufacturing Student ...

Wallace, S.

2010-07-16

352

Microbiology System  

NASA Technical Reports Server (NTRS)

Technology originating in a NASA-sponsored study of the measurement of microbial growth in zero gravity led to the development of Biomerieux Vitek, Inc.'s VITEK system. VITEK provides a physician with accurate diagnostic information and identifies the most effective medication. Test cards are employed to identify organisms and determine susceptibility to antibiotics. A photo-optical scanner scans the card and monitors changes in the growth of cells contained within the card. There are two configurations - VITEK and VITEK JR as well as VIDAS, a companion system that detects bacteria, viruses, etc. from patient specimens. The company was originally created by McDonnell Douglas, the NASA contractor.

1992-01-01

353

Neuromodulatory systems  

PubMed Central

We examine the interactions and interdependencies between Neuroglia, the Brain-Cell Microenvironment, and the processes commonly subsumed under Neuromodulation. The interactions of the component processes covering a wide spectrum of frequencies are designated as Neuromodulatory Systems (NMS). This implies NMS's scale-invariance as the capacity of linking actions across many time scales, and self-similarity at any scale. These features endow NMS with the ability to respond adaptively to neural impulse traffic of an unpredictably wide frequency spectrum. In this preliminary perspective, the components of NMS are only outlined based on concepts of Complex Systems Dynamics. However, their interactions must be formally elaborated in further investigations.

Werner, Gerhard; Mitterauer, Bernhard J.

2013-01-01

354

Anesthesia systems.  

PubMed

This Evaluation presents ECRI's detailed findings for three newly tested anesthesia systems and updated ratings for three previously evaluated ones. The study focuses on models intended for the full range of inpatient surgical applications. That is, we consider whether and how well the systems--three supplied by Datex-Ohmeda and three supplied by Draeger Medical--can meet the needs of patients covering a wide range of ages, sizes, and conditions. We also consider the adequacy of the systems' safety features, the comprehensiveness of their pre-use checks, and ease of use. We found that all the evaluated units generally perform well, displaying comparable accuracy and consistency of delivery when similarly equipped (e.g., with comparable ventilation modes). However, all the systems also have critical limitations associated with their pre-use check procedures. Several units also exhibit problems with the handling of important alarms under certain conditions. Our ratings will help guide healthcare facilities both when selecting a model and when determining which options to purchase. In several cases, models that are otherwise appropriate for use are rated Not Recommended for purchase if they are not equipped with certain options. And in one case, we rate a unit Unacceptable for purchase if it is not equipped with a safety feature that can help reduce the risk of surgical fires. PMID:16913466

2006-07-01

355

Circulatory system  

NSDL National Science Digital Library

The circulatory system includes the heart, blood vessels, and blood. Arteries take blood with oxygen to our organs; veins bring deoxygenated blood to the heart (to be pumped to the lungs to get oxygen). Arteries and veins bring essential nutrients from digestion (such as glucose) to our tissues as well.

Katie Hale (CSUF;)

2007-01-22

356

Embedded Systems  

NSDL National Science Digital Library

The April 2003 issue of ACM Queue, the online magazine of the Association for Computing Machinery, is dedicated to embedded systems. Seven articles are included in the issue, dealing with the design and construction process of embedded devices, programming, and the hardware/software interface.

2008-02-08

357

D System  

NSDL National Science Digital Library

D-System is conducting research into program analysis, code generation, and programming tools for data-parallel languages like High Performance Fortran. If this research is successful, computational scientists and engineers will be able to write machine-independent, data-parallel programs for a broad spectrum of scientific applications, and achieve high performance with these programs on a variety of parallel architectures.

358

System Dynamics  

NASA Astrophysics Data System (ADS)

System dynamics is an approach for thinking about and simulating situations and organisations of all kinds and sizes by visualising how the elements fit together, interact and change over time. This chapter, written by John Morecroft, describes modern system dynamics which retains the fundamentals developed in the 1950s by Jay W. Forrester of the MIT Sloan School of Management. It looks at feedback loops and time delays that affect system behaviour in a non-linear way, and illustrates how dynamic behaviour depends upon feedback loop structures. It also recognises improvements as part of the ongoing process of managing a situation in order to achieve goals. Significantly it recognises the importance of context, and practitioner skills. Feedback systems thinking views problems and solutions as being intertwined. The main concepts and tools: feedback structure and behaviour, causal loop diagrams, dynamics, are practically illustrated in a wide variety of contexts from a hot water shower through to a symphony orchestra and the practical application of the approach is described through several real examples of its use for strategic planning and evaluation.

Morecroft, John

359

Denitrification system  

Microsoft Academic Search

An improved multi-stage treatment system is described for biological denitrification of and suspended solids removal from water which comprises: a biological reactor, an aeration chamber and an automatic backwash filter, the reactor including a tank having a lower tank portion, a central tank portion and an upper tank portion, influent distribution means positioned in the lower tank portion, rigid media

Kanow

1993-01-01

360

Auditory system  

NASA Technical Reports Server (NTRS)

The physical correlations of hearing, i.e. the acoustic stimuli, are reported. The auditory system, consisting of external ear, middle ear, inner ear, organ of Corti, basilar membrane, hair cells, inner hair cells, outer hair cells, innervation of hair cells, and transducer mechanisms, is discussed. Both conductive and sensorineural hearing losses are also examined.

Ades, H. W.

1973-01-01

361

STAR System.  

ERIC Educational Resources Information Center

The STAR System is a developmental guidance approach to be used with elementary school children in the 5th or 6th grades. Two basic purposes underlie STAR: to increase learning potential and to enhance personal growth and development. STAR refers to 4 basic skills: sensory, thinking, adapting, and revising. Major components of the 4 skills are:…

Doverspike, James E.

362

Cardiovascular system  

MedlinePLUS Videos and Cool Tools

... from the tissues to the systems of the body through which they are eliminated. Most of the blood is made up of a watery, protein-laden fluid called plasma. A little less than half of this blood volume is composed of red and white blood cells, and other solid elements called platelets.

363

Digestive System  

NSDL National Science Digital Library

This site contains a section of an online Biology Textbook - developed by Dr. Michael Gregory of Clinton Community College - providing a concise overview of the digestive system. It describes the enzymes, carbohydrates, proteins, and lipids involved in digestion and outlines the role that each part of the body plays from the mouth the large intestine.

Gregory, Michael

1969-12-31

364

Systems Biology  

SciTech Connect

The biology revolution over the last 50 years has been driven by the ascendancy of molecular biology. This was enthusiastically embraced by most biologists because it took us into increasingly familiar territory. It took mysterious processes, such as the replication of genetic material and assigned them parts that could be readily understood by the human mind. When we think of ''molecular machines'' as being the underlying basis of life, we are using a paradigm derived from everyday experience. However, the price that we paid was a relentless drive towards reductionism and the attendant balkanization of biology. Now along comes ''systems biology'' that promises us a solution to the problem of ''knowing more and more about less and less''. Unlike molecular biology, systems biology appears to be taking us into unfamiliar intellectual territory, such as statistics, mathematics and computer modeling. Not surprisingly, systems biology has met with widespread skepticism and resistance. Why do we need systems biology anyway and how does this new area of research promise to change the face of biology in the next couple of decades?

Wiley, H S.

2006-06-01

365

Rabbit System.  

National Technical Information Service (NTIS)

A rabbit system for ultrafast transport of a sampler between a sampling point and an analysis position is described. The sampler is transported pneumatically in a carrier capsule first to a sampling point and then to a separating structure in front of the...

1978-01-01

366

Ventilation systems  

NASA Astrophysics Data System (ADS)

Two different types of ventilation systems and their components are addressed: general ventilation and local or process ventilation. Calculation of the flow rates used in the different systems is addressed. The many different types of flow calculations, how they are used, and some of the computer programs that could be used for these calculations are described. Some calculations start with assumptions regarding air flow rates in rooms and locals. The flow rates can be chosen from rule of thumb or regulations or standards. Thereafter the designer calculates necessary heat and cooling loads, pressure drops, fan effect, etc. The other type of calculation is not very common. By using demands on concentrations, temperatures or air velocities the flow rates are calculated. These calculations include contaminant source generation rates, use of models (physical and theoretical), and computational fluid dynamics. The latter are focused upon.

Olander, L.

367

Burner systems  

DOEpatents

A burner system particularly useful for downhole deployment includes a tubular combustion chamber unit housed within a tubular coolant jacket assembly. The combustion chamber unit includes a monolithic tube of refractory material whose inner surface defines the combustion zone. A metal reinforcing sleeve surrounds and extends the length of the refractory tube. The inner surface of the coolant jacket assembly and outer surface of the combustion chamber unit are dimensioned so that those surfaces are close to one another in standby condition so that the combustion chamber unit has limited freedom to expand with that expansion being stabilized by the coolant jacket assembly so that compression forces in the refractory tube do not exceed about one-half the safe compressive stress of the material; and the materials of the combustion chamber unit are selected to establish thermal gradient parameters across the combustion chamber unit to maintain the refractory tube in compression during combustion system start up and cool down sequences.

Doherty, Brian J. (Marblehead, MA)

1984-07-10

368

Gasification system  

DOEpatents

A method and system for injecting coal and process fluids into a fluidized bed gasification reactor. Three concentric tubes extend vertically upward into the fluidized bed. Coal particulates in a transport gas are injected through an inner tube, and an oxygen rich mixture of oxygen and steam are injected through an inner annulus about the inner tube. A gaseous medium relatively lean in oxygen content, such as steam, is injected through an annulus surrounding the inner annulus.

Haldipur, Gaurang B. (Hempfield, PA); Anderson, Richard G. (Penn Hills, PA); Cherish, Peter (Bethel Park, PA)

1985-01-01

369

Imaging System  

NASA Technical Reports Server (NTRS)

The 1100C Virtual Window is based on technology developed under NASA Small Business Innovation (SBIR) contracts to Ames Research Center. For example, under one contract Dimension Technologies, Inc. developed a large autostereoscopic display for scientific visualization applications. The Virtual Window employs an innovative illumination system to deliver the depth and color of true 3D imaging. Its applications include surgery and Magnetic Resonance Imaging scans, viewing for teleoperated robots, training, and in aviation cockpit displays.

1995-01-01

370

Gasification system  

DOEpatents

A method and system for injecting coal and process fluids into a fluidized bed gasification reactor. Three concentric tubes extend vertically upward into the fluidized bed. Coal particulates in a transport gas are injected through an inner tube, and an oxygen rich mixture of oxygen and steam are injected through an inner annulus about the inner tube. A gaseous medium relatively lean in oxygen content, such as steam, is injected through an annulus surrounding the inner annulus.

Haldipur, Gaurang B. (Hempfield, PA) [Hempfield, PA; Anderson, Richard G. (Penn Hills, PA) [Penn Hills, PA; Cherish, Peter (Bethel Park, PA) [Bethel Park, PA

1983-01-01

371

Adrenergic System  

Microsoft Academic Search

\\u000a The adrenergic system is an essential regulator of cardiovascular, endocrine, neuronal, vegetative, and metabolic function.\\u000a The biological effects of the endogenous catecholamines epinephrine and norepinephrine are mediated by nine distinct G protein-coupled\\u000a receptor subtypes. These adrenergic receptors can be divided into three different groups, the a1-receptors (?1A, ?1B, ?1D), ?2-receptors (?2A, ?2B ?2C) ?-receptors (?1, ?2, ?3). In the absence

S. Engelhardt; L. Hein

372

Bioregenerative system  

NASA Technical Reports Server (NTRS)

The design course is an eight semester credit multi-disciplinary engineering design course taught primarily to Engineering Science, Aerospace, Electrical and Mechanical Engineering seniors. This year the course project involved the design of the three interrelated loops: atmospheric, liquid nutrient and solid waste management, associated with growing higher plants to support man during long-term space missions. The project is complementary to the NASA Kennedy Space Center Controlled Environmental Life Support System (CELSS) project. The first semester the class worked on a preliminary design for a complete system. This effort included means for monitoring and control of composition, temperature, flow rate, etc., for the atmosphere and liquid nutrient solution; disease and contaminant monitoring and control; plant mechanical support, propagation and harvesting; solid and liquid waste recycling; and system maintenance and refurbishing. The project has significant biological, mechanical, electrical and Al/Robotics aspects. The second semester a small number of subsystems or components, identified as important and interesting during the first semester, were selected for detail design, fabrication, and testing. The class was supported by close cooperation with The Kennedy Space Center and by two teaching assistants. The availability of a dedicated, well equipped project room greatly enhanced the communication and team spirit of the class.

1987-01-01

373

Purification system  

NASA Technical Reports Server (NTRS)

A system for prolonging the life of a granulated activated charcoal (GAC) water treatment device is disclosed in which an ultraviolet light transparent material is used to constrain water to flow over carbon surfaces. It is configured to receive maximum flux from a UV radiation source for the purpose of preventing microbial proliferation on the carbon surfaces; oxidizing organic contaminants adsorbed from the water onto the carbon surfaces and from biodegradation of adsorbed microbial forms; disinfecting water; and oxidizing organic contaminants in the water.

Flanagan, David T. (inventor); Gibbons, Randall E. (inventor)

1992-01-01

374

Relaxation System  

NASA Technical Reports Server (NTRS)

Environ Corporation's relaxation system is built around a body lounge, a kind of super easy chair that incorporates sensory devices. Computer controlled enclosure provides filtered ionized air to create a feeling of invigoration, enhanced by mood changing aromas. Occupant is also surrounded by multidimensional audio and the lighting is programmed to change colors, patterns, and intensity periodically. These and other sensory stimulators are designed to provide an environment in which the learning process is stimulated, because research has proven that while an individual is in a deep state of relaxation, the mind is more receptive to new information.

1987-01-01

375

Balance System  

NASA Technical Reports Server (NTRS)

TherEx Inc.'s AT-1 Computerized Ataxiameter precisely evaluates posture and balance disturbances that commonly accompany neurological and musculoskeletal disorders. Complete system includes two-strain gauged footplates, signal conditioning circuitry, a computer monitor, printer and a stand-alone tiltable balance platform. AT-1 serves as assessment tool, treatment monitor, and rehabilitation training device. It allows clinician to document quantitatively the outcome of treatment and analyze data over time to develop outcome standards for several classifications of patients. It can evaluate specifically the effects of surgery, drug treatment, physical therapy or prosthetic devices.

1988-01-01

376

Sterilization System  

NASA Technical Reports Server (NTRS)

Cox Sterile Products, Inc.'s Rapid Heat Transfer Sterilizer employs a heat exchange process that induces rapid air movement; the air becomes the heat transfer medium, maintaining a uniform temperature of 375 degrees Fahrenheit. It features pushbutton controls for three timing cycles for different instrument loads, a six-minute cycle for standard unpackaged instruments, eight minutes for certain specialized dental/medical instruments and 12 minutes for packaged instruments which can then be stored in a drawer in sterile condition. System will stay at 375 degrees all day. Continuous operation is not expensive because of the sterilizer's very low power requirements.

1990-01-01

377

D0 Cryo System Control System Autodialer  

Microsoft Academic Search

The DO cryogenic system is controlled by a TI565-PLC based control system. This allows the system to be unmanned when in steady state operation. System experts will need to be contacted when system parameters exceed normal operating points and reach alarm setpoints. The labwide FIRUS system provides one alarm monitor and communication link. An autodialer provides a second and more

J. Urbin

1990-01-01

378

Solar System  

NSDL National Science Digital Library

NASA is charting a bold new course into the cosmos, a journey that will take humans back to the Moon, and eventually to Mars and beyond. Exploration of the solar system and beyond will be guided by compelling questions of scientific and societal importance. NASA exploration programs will seek profound answers to questions about the origins of our solar system, whether life exists beyond Earth, and how we could live on other worlds. The NASA Vision for space exploration calls for a combination of human and robotic missions to achieve new exploration goals. Robotic missions to the Moon will be followed by an extended human expedition as early as 2015. Lunar exploration will lay the groundwork for future exploration of Mars and other destinations. A new spacecraft to support these journeys--the Crew Exploration Vehicle--will be tested before the end of this decade. Space exploration holds a special place in the human imagination. Youth are especially drawn to Mars rovers, astronauts, and telescopes. If used effectively and creatively, space can inspire children to seek careers in math, science, and engineering. Exploration and discovery are key agents of growth in society--technologically, economically, socially, internationally, and intellectually. This module is a first step in engaging today's youth in space exploration and serves as an invitation to participate in the excitement of discovery.

National Science Teachers Association (NSTA)

2005-04-01

379

A model of greenhouse gas emissions from the management of turf on two golf courses.  

PubMed

An estimated 32,000 golf courses worldwide (approximately 25,600 km2), provide ecosystem goods and services and support an industry contributing over $124 billion globally. Golf courses can impact positively on local biodiversity however their role in the global carbon cycle is not clearly understood. To explore this relationship, the balance between plant–soil system sequestration and greenhouse gas emissions from turf management on golf courses was modelled. Input data were derived from published studies of emissions from agriculture and turfgrass management. Two UK case studies of golf course type were used, a Links course (coastal, medium intensity management, within coastal dune grasses) and a Parkland course (inland, high intensity management, within woodland).Playing surfaces of both golf courses were marginal net sources of greenhouse gas emissions due to maintenance (Links ?2.2 ± 0.4 Mg CO2e ha(?1) y(?1); Parkland ? 2.0 ± 0.4 Mg CO2e ha(?1) y(?1)). A significant proportion of emissions were from the use of nitrogen fertiliser, especially on tees and greens such that 3% of the golf course area contributed 16% of total greenhouse gas emissions. The area of trees on a golf course was important in determining whole-course emission balance. On the Parkland course, emissions from maintenance were offset by sequestration from turfgrass, and trees which comprised 48% of total area, resulting in a net balance of ?5.4 ± 0.9 Mg CO2e ha(?1) y(?1). On the Links course, the proportion of trees was much lower (2%) and sequestration from links grassland resulted in a net balance of ?1.6 ± 0.3 Mg CO2e ha(?1) y(?1). Recommendations for golf course management and design include the reduction of nitrogen fertiliser, improved operational efficiency when mowing, the inclusion of appropriate tree-planting and the scaling of component areas to maximise golf course sequestration capacity. The findings are transferrable to the management and design of urban parks and gardens, which range between fairways and greens in intensity of management. PMID:22066130

Bartlett, Mark D; James, Iain T

2011-11-01

380

A model of greenhouse gas emissions from the management of turf on two golf courses.  

PubMed

An estimated 32,000 golf courses worldwide (approximately 25,600 km(2)), provide ecosystem goods and services and support an industry contributing over $ 124 billion globally. Golf courses can impact positively on local biodiversity however their role in the global carbon cycle is not clearly understood. To explore this relationship, the balance between plant-soil system sequestration and greenhouse gas emissions from turf management on golf courses was modelled. Input data were derived from published studies of emissions from agriculture and turfgrass management. Two UK case studies of golf course type were used, a Links course (coastal, medium intensity management, within coastal dune grasses) and a Parkland course (inland, high intensity management, within woodland). Playing surfaces of both golf courses were marginal net sources of greenhouse gas emissions due to maintenance (Links 0.4 ± 0.1Mg CO(2)e ha(-1)y(-1); Parkland 0.7 ± 0.2Mg CO(2)e ha(-1)y(-1)). A significant proportion of emissions were from the use of nitrogen fertiliser, especially on tees and greens such that 3% of the golf course area contributed 16% of total greenhouse gas emissions. The area of trees on a golf course was important in determining whole-course emission balance. On the Parkland course, emissions from maintenance were offset by sequestration from trees which comprised 48% of total area, resulting in a net balance of -4.3 ± 0.9 Mg CO(2e) ha(-1)y(-1). On the Links course, the proportion of trees was much lower (2%) and sequestration from links grassland resulted in a net balance of 0.0 ± 0.2Mg CO(2e) ha(-1)y(-1). Recommendations for golf course management and design include the reduction of nitrogen fertiliser, improved operational efficiency when mowing, the inclusion of appropriate tree-planting and the scaling of component areas to maximise golf course sequestration capacity. The findings are transferrable to the management and design of urban parks and gardens, which range between fairways and greens in intensity of management. PMID:21288561

Bartlett, Mark D; James, Iain T

2011-03-15

381

Ternary System  

NASA Astrophysics Data System (ADS)

Piezoelectric ceramics in the PbSnO3-PbZrO3-PbTiO3 (PZST) ternary system with pure perovskite structure were synthesized by a conventional solid state reaction method with the compositions near the morphotropic phase boundary (MPB). The influences of Sn content on dielectric, piezoelectric, and ferroelectric properties of Pb(Zr x Sn y Ti1- x- y )O3 ceramics were investigated. The experimental results showed that, with increasing the Sn content along the Ti = 0.48 line, the optimized sintering temperature, tetragonality, and Curie temperature ( T C) decreased monotonically. The polarization-electric field hysteresis loops show a pinning effect in some low Sn compositions. Frequency dependence of the pinning effect was studied accompanied with current-electric field curve analysis. The PZST compositions near MPB show promising advantages for practical applications.

Xing, Zhuo; Jin, Li; Feng, Yujun; Wei, Xiaoyong

2014-07-01

382

Photopolymer Systems  

NASA Astrophysics Data System (ADS)

Photopolymers, in the context of this chapter, are systems of organic molecules that rely on photoinitiated polymerization to record volume phase holograms. Characteristics such as good light sensitivity, real-time image development, large dynamic range, good optical properties, format flexibility, good image stability, and relatively low cost make photopolymers one of the most promising materials for write-once, read-many (WORM) holographic data storage applications. We first present a brief description of the chemistry of photopolymers. This is followed by a discussion of photopolymer properties that are particularly relevant to the requirements of recording holograms for data storage. The intent of this chapter is to provide the nonspecialist with an appreciation of the possibilities and promise offered by photopolymers as candidate materials for holographic data storage, and to highlight areas where additional material development is desired. Readers interested in other aspects of photopolymers in holography can consult reviews by Lessard and Manivannan [1], Lougnot [2], and Colburn [3].

Ingwall, R. T.; Waldman, D.

383

Transfer system  

SciTech Connect

A transport system includes a traveling rail (1) which constitutes a transport route and a transport body (3) which is capable of traveling on the traveling rail in the longitudinal direction of the traveling rail. Flexible drive tubes (5) are arranged on the traveling rail in the longitudinal direction of the traveling rail. The transport body includes a traveling wheel (4) which is capable of rolling on the traveling rail and drive wheels (2) which are capable of rolling on the drive tubes upon receiving the rotational drive power generated by pressure of a pressure medium supplied to the drive tubes while depressing the drive tubes. The traveling rail includes a plurality of transport sections and the transport body is capable of receiving a rotational drive force from the drive tubes at every transport sections. If necessary, a transport route changeover switch which changes over the transport route can be provided between the transport sections.

Kurosawa, Kanji (Tokyo, JP); Koga, Bunichiro (Miyagi, JP); Ito, Hideki (Miyagi, JP); Kiriyama, Shigeru (Miyagi, JP); Higuchi, Shizuo (Kanagawa, JP)

2003-05-20

384

Intelligent Engine Systems: Bearing System  

NASA Technical Reports Server (NTRS)

The overall requirements necessary for sensing bearing distress and the related criteria to select a particular rotating sensor were established during the phase I. The current phase II efforts performed studies to evaluate the Robustness and Durability Enhancement of the rotating sensors, and to design, and develop the Built-in Telemetry System concepts for an aircraft engine differential sump. A generic test vehicle that can test the proposed bearing diagnostic system was designed, developed, and built. The Timken Company, who also assisted with testing the GE concept of using rotating sensors for the differential bearing diagnostics during previous phase, was selected as a subcontractor to assist General Electric (GE) for the design, and procurement of the test vehicle. A purchase order was prepared to define the different sub-tasks, and deliverables for this task. The University of Akron was selected to provide the necessary support for installing, and integrating the test vehicle with their newly designed test facility capable of simulating the operating environment for the planned testing. The planned testing with good and damaged bearings will be on hold pending further continuation of this effort during next phase.

Singh, Arnant P.

2008-01-01

385

Space Station propulsion system  

NASA Astrophysics Data System (ADS)

Viewgraphs on space station propulsion systems are presented. Topics covered include: space station propulsion system requirements; space station propulsion system design; space station propulsion system drivers; hydrazine technology development; waste fluid disposal system; space station propulsion system evolution; propellant selection trade study; technology needs to water electrolysis/oxygen-hydrogen propulsion system; and technology needs for bipropellant systems.

Henderson, J.

386

Separation system  

DOEpatents

A separation system for dewatering radioactive waste materials includes a disposal container, drive structure for receiving the container, and means for releasably attaching the container to the drive structure. Separation structure disposed in the container adjacent the inner surface of the side wall structure retains solids while allowing passage of liquids. Inlet port structure in the container top wall is normally closed by first valve structure that is centrifugally actuated to open the inlet port and discharge port structure at the container periphery receives liquid that passes through the separation structure and is normally closed by second valve structure that is centrifugally actuated to open the discharge ports. The container also includes coupling structure for releasable engagement with the centrifugal drive structure. Centrifugal force produced when the container is driven in rotation by the drive structure opens the valve structures, and radioactive waste material introduced into the container through the open inlet port is dewatered, and the waste is compacted. The ports are automatically closed by the valves when the container drum is not subjected to centrifugal force such that containment effectiveness is enhanced and exposure of personnel to radioactive materials is minimized.

Rubin, Leslie S. (Newton, MA)

1986-01-01

387

System safety education focused on system management  

NASA Technical Reports Server (NTRS)

System safety is defined and characteristics of the system are outlined. Some of the principle characteristics include role of humans in hazard analysis, clear language for input and output, system interdependence, self containment, and parallel analysis of elements.

Grose, V. L.

1971-01-01

388

Mass Storage System Reference Model System Management.  

National Technical Information Service (NTIS)

System Management is the collection of functions that are primarily concerned with the control, performance and utilization of the Mass Storage System defined by the Mass Storage System Reference Model. These functions are often very site-dependent, invol...

B. Collins T. McLarty

1988-01-01

389

Distinguishing Systemic from Systematic.  

ERIC Educational Resources Information Center

Describes the difference between systemic and systematic as they relate to school reform and instructional design. Highlights include a history of systems theory; systems engineering; instructional systems design; systemic versus reductionist thinking; social systems; and systemic change in education, including power relationships. (LRW)

Carr, Alison A.

1996-01-01

390

Hybrid System Modeling and Autonomous Control Systems  

Microsoft Academic Search

Hybrid control systems contain two distinct types of systems, continuous state and discrete-state, that interact with each other. Their study is essential in designing sequential supervisory controllers for continuous-state systems, and it is central in designing control systems with high degree of autonomy.

Panos J. Antsaklis; James A. Stiver; Michael D. Lemmon

1992-01-01

391

The complement system in systemic autoimmune disease  

Microsoft Academic Search

Complement is part of the innate immune system. Its major function is recognition and elimination of pathogens via direct killing and\\/or stimulation of phagocytosis. Activation of the complement system is, however, also involved in the pathogenesis of the systemic autoimmune diseases. Activation via the classical pathway has long been recognized in immune complex-mediated diseases such as cryoglobulinemic vasculitis and systemic

Min Chen; Mohamed R. Daha; Cees G. M. Kallenberg

2010-01-01

392

System on Chip or System on Package?  

Microsoft Academic Search

The authors propose a new system design paradigm, the system on package, which uses electronic product reengineering to meet time-to-market and performance requirements. The system on package promises a higher return on investment than the system on chip

Rao R. Tummala; Vijay K. Madisetti

1999-01-01

393

System design description cone penetrometer system  

SciTech Connect

The system design description documents in detail the design of the cone penetrometer system. The systems includes the cone penetrometer physical package, raman spectroscopy package and moisture sensor package. Information pertinent to the system design, development, fabrication and testing is provided.

Seda, R.Y., Westinghouse Hanford

1996-08-12

394

System engineering for the 777 autopilot system  

Microsoft Academic Search

This paper describes the systems engineering process used in developing the 777 Autopilot Flight Director System (AFDS). It includes discussions regarding requirements capture, requirements allocation to hardware and software, system architecture considerations (including the architectural impact of safety requirements), change management, requirements and verification traceability, and requirements-based verification. Additionally, the organizational structure employed and its interaction with the systems engineering

M. J. Gries

1997-01-01

395

D0 Cryo System Control System Autodialer  

SciTech Connect

The DO cryogenic system is controlled by a TI565-PLC based control system. This allows the system to be unmanned when in steady state operation. System experts will need to be contacted when system parameters exceed normal operating points and reach alarm setpoints. The labwide FIRUS system provides one alarm monitor and communication link. An autodialer provides a second and more flexible alarm monitor and communication link. The autodialer monitors contact points in the control system and after receiving indication of an alarm accesses a list of experts which it calls until it receives an acknowledgement. There are several manufacturers and distributors of autodialer systems. This EN explains the search process the DO cryo group used to fmd an autodialer system that fit the cryo system's needs and includes information and specs for the unit we chose.

Urbin, J.; /Fermilab

1990-04-17

396

Mass storage system reference model system management  

SciTech Connect

System Management is the collection of functions that are primarily concerned with the control, performance and utilization of the Mass Storage System defined by the Mass Storage System Reference Model. These functions are often very site-dependent, involve human decision making, and span multiple ''severs'' of the Mass Storage System. The functions may be implemented as standalone programs, may be integrated with the other Mass Storage System software, or may just be policy. 4 refs.

Collins, B.; McLarty, T.

1988-01-01

397

Open Systems (Architecture) Engineering.  

National Technical Information Service (NTIS)

Overview of this document: discussion of key open system concepts and definitions, conformance and compatibility management, open system engineering approach, open system policy, today's transition environment and open system transition process.

N. W. Kowalski

1996-01-01

398

Mechanical systems: A compilation  

NASA Technical Reports Server (NTRS)

A compilation of several mechanized systems is presented. The articles are contained in three sections: robotics, industrial mechanical systems, including several on linear and rotary systems and lastly mechanical control systems, such as brakes and clutches.

1975-01-01

399

Hybrid Navigation Systems.  

National Technical Information Service (NTIS)

Contents: Hybrid guidance and navigation systems; Characteristics of a satellite navigation system operated in conjunction with a user inertial system; Global navigation/traffic surveillance/communication satellite system for military and civil vehicles; ...

G. R. Marner, B. P. Leonard, M. W. Mitchell, F. S. Stringer, M. G. Pearson

1970-01-01

400

System Design Specification Brayton Isotope Power System (BIPS) Flight System (FS), and Ground Demonstration System (GDS).  

National Technical Information Service (NTIS)

The system design specification for ground demonstration, development, and flight qualification of a Brayton Isotope Power System (BIPS) is presented. The requirements for both a BIPS conceptual Flight System (FS) and a Ground Demonstration System (GDS) a...

1976-01-01

401

The V distributed system  

Microsoft Academic Search

The V distributed System was developed at Stanford University as part of a research project to explore issues in distributed systems. Aspects of the design suggest important directions for the design of future operating systems and communication systems.

David R. Cheriton

1988-01-01

402

A Stimuli Presentation System.  

National Technical Information Service (NTIS)

Laboratory and research field trip requirements have revealed the need for a programmable audio switching system. This system, the stimuli presentation system (SPS), is designed with general versatility in mind. Although the system was conceived for use i...

W. D. Harrington H. Hollien H. Rothman

1969-01-01

403

Expert systems in transportation  

SciTech Connect

The 5 papers in the report deal with the following areas: Knowledge representation and software selection for expert-systems design; Expert-system architecture for retaining-wall design; Development of expert-systems technology in the California Department of Transportation; Development of an expert system to assist in the interactive graphic transit system design process; Expert systems development for contingency transportation planing.

O'Leary, K.P.

1988-01-01

404

Serverless network file systems  

Microsoft Academic Search

We propose a new paradigm for network file system design: serverless network file systems. While traditional network file systems rely on a central server machine, a serverless system utilizes workstations cooperating as peers to provide all file system services. Any machine in the system can store, cache, or control any block of data. Our approach uses this location independence, in

Thomas E. Anderson; Michael D. Dahlin; Jeanna M. Neefe; David A. Patterson; Drew S. Roselli; Randolph Y. Wang

1996-01-01

405

Serverless Network File Systems  

Microsoft Academic Search

In this paper, we propose a new paradigm for network file system design, serverless network file systems. While traditional network file systems rely on a central server machine, a serverless system utilizes workstations cooperating as peers to provide all file system services. Any machine in the system can store, cache, or control any block of data. Our approach uses this

Thomas E. Anderson; Michael Dahlin; Jeanna M. Neefe; David A. Patterson; Drew S. Roselli; Randolph Y. Wang

1995-01-01

406

Modular robot system architecture  

Microsoft Academic Search

In comparison with dedicated robot systems, the main goal of modular robot systems is to achieve system adaptability by providing various modular configuration variations to meet possible task requirements. System architecture determines the system configuration variations, as the architecture specifies primary building blocks and the types of ways they are connected. In order to make systems more adaptive, configuration variations

Z. M. Bi; W. J. Zhang; Sherman Y. T. Lang

2002-01-01

407

System of systems modeling and analysis.  

SciTech Connect

This report documents the results of an LDRD program entitled 'System of Systems Modeling and Analysis' that was conducted during FY 2003 and FY 2004. Systems that themselves consist of multiple systems (referred to here as System of Systems or SoS) introduce a level of complexity to systems performance analysis and optimization that is not readily addressable by existing capabilities. The objective of the 'System of Systems Modeling and Analysis' project was to develop an integrated modeling and simulation environment that addresses the complex SoS modeling and analysis needs. The approach to meeting this objective involved two key efforts. First, a static analysis approach, called state modeling, has been developed that is useful for analyzing the average performance of systems over defined use conditions. The state modeling capability supports analysis and optimization of multiple systems and multiple performance measures or measures of effectiveness. The second effort involves time simulation which represents every system in the simulation using an encapsulated state model (State Model Object or SMO). The time simulation can analyze any number of systems including cross-platform dependencies and a detailed treatment of the logistics required to support the systems in a defined mission.

Campbell, James E.; Anderson, Dennis James; Longsine, Dennis E. (Intera, Inc., Austin, TX); Shirah, Donald N.

2005-01-01

408

System Software Framework for System of Systems Avionics  

NASA Technical Reports Server (NTRS)

Project Constellation implements NASA's vision for space exploration to expand human presence in our solar system. The engineering focus of this project is developing a system of systems architecture. This architecture allows for the incremental development of the overall program. Systems can be built and connected in a "Lego style" manner to generate configurations supporting various mission objectives. The development of the avionics or control systems of such a massive project will result in concurrent engineering. Also, each system will have software and the need to communicate with other (possibly heterogeneous) systems. Fortunately, this design problem has already been solved during the creation and evolution of systems such as the Internet and the Department of Defense's successful effort to standardize distributed simulation (now IEEE 1516). The solution relies on the use of a standard layered software framework and a communication protocol. A standard framework and communication protocol is suggested for the development and maintenance of Project Constellation systems. The ARINC 653 standard is a great start for such a common software framework. This paper proposes a common system software framework that uses the Real Time Publish/Subscribe protocol for framework-to-framework communication to extend ARINC 653. It is highly recommended that such a framework be established before development. This is important for the success of concurrent engineering. The framework provides an infrastructure for general system services and is designed for flexibility to support a spiral development effort.

Ferguson, Roscoe C.; Peterson, Benjamin L; Thompson, Hiram C.

2005-01-01

409

Intelligent systems technology infrastructure for integrated systems  

NASA Technical Reports Server (NTRS)

Significant advances have occurred during the last decade in intelligent systems technologies (a.k.a. knowledge-based systems, KBS) including research, feasibility demonstrations, and technology implementations in operational environments. Evaluation and simulation data obtained to date in real-time operational environments suggest that cost-effective utilization of intelligent systems technologies can be realized for Automated Rendezvous and Capture applications. The successful implementation of these technologies involve a complex system infrastructure integrating the requirements of transportation, vehicle checkout and health management, and communication systems without compromise to systems reliability and performance. The resources that must be invoked to accomplish these tasks include remote ground operations and control, built-in system fault management and control, and intelligent robotics. To ensure long-term evolution and integration of new validated technologies over the lifetime of the vehicle, system interfaces must also be addressed and integrated into the overall system interface requirements. An approach for defining and evaluating the system infrastructures including the testbed currently being used to support the on-going evaluations for the evolutionary Space Station Freedom Data Management System is presented and discussed. Intelligent system technologies discussed include artificial intelligence (real-time replanning and scheduling), high performance computational elements (parallel processors, photonic processors, and neural networks), real-time fault management and control, and system software development tools for rapid prototyping capabilities.

Lum, Henry, Jr.

1991-01-01

410

Evolving Information Systems: Beyond Temporal Information Systems.  

National Technical Information Service (NTIS)

The need for information systems which are capable of evolving to the same extent as organizations do is discussed. Requirements of evolving organizations on their information systems are identified, and this is followed by alternative approaches to adequ...

E. D. Falkenberg J. L. H. Oei H. A. Proper

1992-01-01

411

Language as a System of Systems  

ERIC Educational Resources Information Center

Based on Mulder's previous classification of all semiotic systems designed to describe the system of discrete features in human languages, this article explores a further subclassification of the genus language into species. (CLK)

Mulder, J. W. F.; Hervey, S. G. J.

1975-01-01

412

Integrated Systems Health Management for Intelligent Systems.  

National Technical Information Service (NTIS)

The implementation of an integrated system health management (ISHM) capability is fundamentally linked to the management of data, information, and knowledge (DIaK) with the purposeful objective of determining the health of a system. Management implies sto...

F. Figueroa K. Melcher

2011-01-01

413

Freedom System Text and Graphics System (TAGS)  

NASA Technical Reports Server (NTRS)

The Text and Graphics System (TAGS) is a high-resolution facsimile system that scans text or graphics material and converts the analog SCAN data into serial digital data. This video shows the TAGS in operation.

1989-01-01

414

Stellar systems as dissipative dynamical systems  

SciTech Connect

The evolution of a stellar system containing a massive central body is investigated by the methods of the theory of dynamical systems and catastrophe theory. The problem is reduced to the study of a two-dimensional dissipative system - a simple attractor. The presence of stable and unstable singular points (nodes and focuses) and cycles is shown. In the system there may be subcritical and supercritical Hopf bifurcations with a separatrix corresponding to a symmetric butterfly catastrophe of type A..mu..- 5.

Gurzadyan, V.G.; Kocharyan, A.A.

1987-09-01

415

An Operating System Independent WORM Archival System  

Microsoft Academic Search

SUMMARY We describe the organization of a general purpose data archival system for Write-Once, Read-Many (WORM) optical disks. The system has been designed for large-scale and long-term data storage and retrieval. The archival system is independent of the operating system, flat, self-consistent, does not use any write cache on magnetic disk, and allows the exploitation of auxiliary information on magnetic

Guido Russo; Stefano Russo

1995-01-01

416

Systems of systems and coordinated atomic actions  

Microsoft Academic Search

System of systems (SoS) is an emerging field in the design and development of complex systems that are built from large scale component systems. A SoS has the following attributes: operational and managerial independence of components, a geographic extent that limits control mechanisms to information exchange, an evolutionary nature, and emergent behavior. The subsystems that comprise the SoS often are

Robert Schaefer

2005-01-01

417

Intelligent tutoring systems for systems engineering methodologies  

NASA Technical Reports Server (NTRS)

The general goal is to provide the technology required to build systems that can provide intelligent tutoring in IDEF (Integrated Computer Aided Manufacturing Definition Method) modeling. The following subject areas are covered: intelligent tutoring systems for systems analysis methodologies; IDEF tutor architecture and components; developing cognitive skills for IDEF modeling; experimental software; and PC based prototype.

Meyer, Richard J.; Toland, Joel; Decker, Louis

1991-01-01

418

System Design of the SWRL Financial System.  

ERIC Educational Resources Information Center

To produce various management and accounting reports in order to maintain control of SWRL (Southwest Regional Laboratory) operational and financial activities, a computer-based SWRL financial system was developed. The system design is outlined, and various types of system inputs described. The kinds of management and accounting reports generated…

Ikeda, Masumi

419

General Systems Theory and Instructional Systems Design.  

ERIC Educational Resources Information Center

Describes basic concepts in the field of general systems theory (GST) and identifies commonalities that exist between GST and instructional systems design (ISD). Models and diagrams that depict system elements in ISD are presented, and two matrices that show how GST has been used in ISD literature are included. (11 references) (LRW)

Salisbury, David F.

1990-01-01

420

Energy Systems Design  

NASA Technical Reports Server (NTRS)

PRESTO, a COSMIC program, handles energy system specifications and predicts design efficiency of cogeneration systems. These systems allow a company to use excess energy produced to generate electricity. PRESTO is utilized by the Energy Systems Division of Thermo Electron Corporation in the custom design of cogeneration systems.

1986-01-01

421

FNAL system patching design  

Microsoft Academic Search

FNAL has over 5000 PCs running either Linux or Windows software. Protecting these systems efficiently against the latest vulnerabilities that arise has prompted FNAL to take a more central approach to patching systems. Due to different levels of existing support infrastructures, the patching solution for linux systems differs from that of windows systems. In either case, systems are checked for

Jack Schmidt; Al Lilianstrom; Andy Romero; Troy Dawson; Connie Sieh

2004-01-01

422

Naval shipboard power system  

Microsoft Academic Search

Different naval shipboard power system architectures and their basic characteristics have been discussed in the paper. In addition the paper discusses about incorporation of platform management systems into the ship automation system that would enable monitoring and control of the shipboard power system, assessing and diagnosing system failures\\/damages and reconfiguring and restoring power to service loads with reduced manpower and

R. Jayabalan; B. Fahimi

2005-01-01

423

Intelligent test integration system  

NASA Technical Reports Server (NTRS)

A new test technology is described which was developed for space system integration. The ultimate purpose of the system is to support the automatic generation of test systems in real time, distributed computing environments. The Intelligent Test Integration System (ITIS) is a knowledge based layer above the traditional test system components which can generate complex test configurations from the specification of test scenarios.

Sztipanovits, J.; Padalkar, S.; Rodriguez-Moscoso, J.; Kawamura, K.; Purves, B.; Williams, R.; Biglari, H.

1988-01-01

424

Heliospheric coordinate systems  

Microsoft Academic Search

This article gives an overview and reference to the most common coordinate systems currently used in space science. While coordinate systems used in near-Earth space physics have been described in previous work we extend that description to systems used for physical observations of the Sun and the planets and to systems based on spacecraft location. For all systems, we define

M. Fränz; D. Harper

2002-01-01

425

Manager's assistant systems for space system planning  

NASA Technical Reports Server (NTRS)

This paper describes a class of knowledge-based 'assistant' systems for space system planning. Derived from technology produced for the DARPA/USAF Pilot's Associate program, these assistant systems help the human planner by doing the bookkeeping to maintain plan data and executing the procedures and heuristics currently used by the human planner to define, assess, diagnose, and revise plans. Intelligent systems for Space Station Freedom assembly sequence planning and Advanced Launch System modeling will be presented as examples. Ongoing NASA-funded work on a framework supporting the development of such tools will also be described.

Bewley, William L.; Burnard, Robert; Edwards, Gary E.; Shoop, James

1992-01-01

426

DDL system: Design systhesis of digital systems  

NASA Technical Reports Server (NTRS)

Digital Systems Design Language was integrated into the CADAT system environment of NASA-MSFC. The major technical aspects of this integration are summarized. Automatic hardware synthesis is now possible starting with a high level description of the system to be synthesized. The DDL system provides a high level design verification capability, thereby minimizing design changes in the later stages of the design cycle. An overview of the DDL system covering the translation, simulation and synthesis capabilities is provided. Two companion documents (the user's and programmer's manuals) are to be consulted for detailed discussions.

Shiva, S. G.

1983-01-01

427

Microwave landing system autoland system analysis  

NASA Technical Reports Server (NTRS)

The objective was to investigate the ability of present day aircraft equipped with automatic flight control systems to fly advanced Microwave Landing Systems (MLS) approaches. The tactical approach used to achieve this objective included reviewing the design and autoland operation of the MD-80 aircraft, simulating the MLS approaches using a batch computer program, and assessing the performance of the autoland system from computer generated data. The results showed changes were required to present Instrument Landing System (ILS) procedures to accommodate the new MLS curved paths. It was also shown that in some cases, changes to the digital flight guidance systems would be required so that an autoland could be performed.

Feather, J. B.; Craven, B. K.

1991-01-01

428

Systems biology approach to developing "systems therapeutics".  

PubMed

The standard drug development model uses reductionist approaches to discover small molecules targeting one pathway. Although systems biology analyzes multiple pathways, the approach is often used to develop a small molecule interacting at only one pathway in the system. Similar to that in physics where a departure from the old reductionist "Copenhagen View" of quantum physics to a new and predictive systems based, collective model has emerged yielding new breakthroughs such as the LASER, a new model is emerging in biology where systems biology is used to develop a new technology acting at multiple pathways called "systems therapeutics." PMID:24900858

Maguire, Greg

2014-05-01

429

Biological and social feasibility of Sesbania fallow practice in small holder agricultural farms in developing countries: a Zambian case study.  

PubMed

Many small holder farmers in developing countries face problems of declining soil fertility and crop yields and insufficient money to buy expensive inorganic fertilizers. The Sesbania fallow system, an agroforestry technology, seems to hold a key to these problems. Based on field studies in eastern Zambia, this paper reports that fallow system has the potential to improve and sustain soil productivity in the small holder farms. However, the paper also reports that the ability for subsistence farmers to adopt the Sesbania fallow system is affected by gender differences in resource allocation to productive resources and institutional, cultural, and social structural settings in which farmers exist and make decisions. PMID:11083909

Opio, C

2001-01-01

430

systems of linear equations  

NSDL National Science Digital Library

Solve a system of linear equations by graphing and finding the intersection of the lines of the equations. Create a system of equations, examine its graph, matrix, and table of values, and determine the solution of the system.

Exploremath.com; Sharp, Brian

2001-01-01

431

Steam System Survey Guide.  

National Technical Information Service (NTIS)

This Steam System Survey Guide provides technical information for steam system operational personnel and plant energy managers on some of the major opportunities available to improve the energy efficiency and productivity of industrial steam systems. The ...

G. Harrell

2001-01-01

432

Multimode ergometer system  

NASA Technical Reports Server (NTRS)

System overcomes previous ergometer design and calibration problems including inaccurate measurements, large weight, size, and input power requirements, poor heat dissipation, high flammability, and inaccurate calibration. Device consists of lightweight, accurately controlled ergometer, restraint system, and calibration system.

Bynum, B. G.; Gause, R. L.; Spier, R. A.

1971-01-01

433

Power System Stability.  

National Technical Information Service (NTIS)

The following papers are included: exact Lagrangians for linear nonconservative systems; linear nonconservative systems with asymmetric parameters derivable from a Lagrangian; some remarks on the derivability of linear nonconservative systems from a Lagra...

1984-01-01

434

Systemic Lupus Erythematosus  

MedlinePLUS

newsletter | contact Share | Systemic Lupus Erythematosus Information for adults A A A This image displays the red, slightly scaly, and elevated lesions on the cheeks and nose in systemic lupus erythematosus. Overview Systemic lupus erythematosus (SLE), also called ...

435

University Examination System.  

National Technical Information Service (NTIS)

A computer based information system called UNIVERSITY EXAMINATION SYSTEM has been developed for Quaid-i-Azam University (QAU). The system provides efficient means of data storage and retrieval through a variety of fields. During the storage of information...

S. H. Siddiqui

1991-01-01

436

Unlocking the Endocrine System  

NSDL National Science Digital Library

Students learn how the endocrine system works and compare it to the mail delivery system. Students discuss the importance of communication in human body systems and relate that to engineering and astronauts.

Integrated Teaching And Learning Program

437

Lim Guidance Control Systems.  

National Technical Information Service (NTIS)

The feasibility of control systems for positioning the LIM with respect to the reaction rail without physical contact is examined. Preliminary design analyses are made for several representative systems. Systems for use with both a ferrous or composite re...

J. D. Muhlenberg

1970-01-01

438

Space Shuttle Avionics System.  

National Technical Information Service (NTIS)

The Space Shuttle avionics system, which was conceived in the early 1970's and became operational in the 1980's represents a significant advancement of avionics system technology in the areas of systems and redundacy management, digital data base technolo...

J. F. Hanaway R. W. Moorehead

1989-01-01

439

Lesson 44: Nonlinear Systems  

NSDL National Science Digital Library

Using a cost/revenue application problem, the lesson begins with systems involving quadratic equations. Systems with conics are introduced next along with the elimination method for solving these systems.

2011-01-01

440

The Data System.  

National Technical Information Service (NTIS)

This thesis presents the DATA (Dynamic Alerting Transaction Analysis) System as an alternative to a conventional database management system. The DATA System contains no records corresponding to entities but rather is simply a time ordered list of transact...

K. A. Kimball

1978-01-01

441

Maglev systems development status  

Microsoft Academic Search

The current status and future potential of Maglev systems is reviewed. Modes of noncontact suspension and propulsion are described, and prototype systems and design concepts are indicated. A number of existing systems are described in more detail

A. R. Eastham; W. F. Hayes

1988-01-01

442

What Are Expert Systems?  

ERIC Educational Resources Information Center

Intended for potential business users, this paper describes the main characteristics of expert systems; discusses practical use considerations; presents a taxonomy of the systems; and reviews several expert system development projects in business and industry. (MBR)

d'Agapeyeff, A.

1986-01-01

443

Immune System (For Parents)  

MedlinePLUS

... immune system is the body's defense against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause ...

444

Wind energy systems  

NASA Technical Reports Server (NTRS)

A discussion on wind energy systems involved with the DOE wind energy program is presented. Some of the problems associated with wind energy systems are discussed. The cost, efficiency, and structural design of wind energy systems are analyzed.

Stewart, H. J.

1978-01-01

445

Hybrid Image Processing System.  

National Technical Information Service (NTIS)

A hybrid optical/digital image processing system has been developed for an ongoing research program in hybrid image processing. This system is described and its capabilities and limitations are discussed. Major system components include a coherent optical...

T. H. May J. A. Blodgett

1980-01-01

446

Intelligent Test Integration System.  

National Technical Information Service (NTIS)

A new test technology is described which was developed for space system integration. The ultimate purpose of the system is to support the automatic generation of test systems in real time, distributed computing environments. The Intelligent Test Integrati...

J. Sztipanovits S. Padalkar J. Rodriguez-Moscoso K. Kawamura B. Purves

1988-01-01

447

The Solar System  

NSDL National Science Digital Library

Identify basic components of our solar system, including the sun, planets, and Earth's moon. We have just learned about the Solar System. Click here to watch an informational overview of the Solar System: Overview of the Solar System.. The planets in our Solar System are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. Every planet in our Solar System revolves around the sun. The sun provides the energy ...

Smithson, Ms.

2009-07-07

448

System status display information  

NASA Technical Reports Server (NTRS)

The system Status Display is an electronic display system which provides the flight crew with enhanced capabilities for monitoring and managing aircraft systems. Guidelines for the design of the electronic system displays were established. The technical approach involved the application of a system engineering approach to the design of candidate displays and the evaluation of a Hernative concepts by part-task simulation. The system engineering and selection of candidate displays are covered.

Summers, L. G.; Erickson, J. B.

1984-01-01

449

Photovoltaic systems performance experience  

NASA Astrophysics Data System (ADS)

The photovoltaic power systems at Natural Bridges National Monument in southeastern Utah and at radio station WBNO in Bryan, Ohio, provided reliability experience and case histories on failures and repairs of large photovoltaic systems. The PV systems are used for illustration of potential sources of system outages and measures that can be taken to improve the reliability and repair economy of present and future PV systems. Both systems have experienced lighting strikes, and the results are reported.

Solman, F. J.

1981-08-01

450

Propulsion Systems Panel deliberations  

NASA Technical Reports Server (NTRS)

The Propulsion Systems Panel was established because of the specialized nature of many of the materials and structures technology issues related to propulsion systems. This panel was co-chaired by Carmelo Bianca, MSFC, and Bob Miner, LeRC. Because of the diverse range of missions anticipated for the Space Transportation program, three distinct propulsion system types were identified in the workshop planning process: liquid propulsion systems, solid propulsion systems and nuclear electric/nuclear thermal propulsion systems.

Bianca, Carmelo J.; Miner, Robert; Johnston, Lawrence M.; Bruce, R.; Dennies, Daniel P.; Dickenson, W.; Dreshfield, Robert; Karakulko, Walt; Mcgaw, Mike; Munafo, Paul M.

1993-01-01

451

Five native tree species and manioc under slash-and-mulch agroforestry in the eastern Amazon of Brazil: plant growth and soil responses  

Microsoft Academic Search

Throughout the Amazon of Brazil, manioc (Manihot esculenta) is a staple crop produced through slash-and-burn agriculture. Nutrient losses during slash-and-burn can be large and nutrient\\u000a demand by food crops so great that fields are often abandoned after two years. In recent decades, farmers have reduced the\\u000a fallow phase from 20 to ~5 years, limiting plant nutrient accumulation to sustain crop yields.

Aaron H. Joslin; Daniel Markewitz; Lawrence A. Morris; Francisco DeAssis Oliveira; Ricardo O. Figueiredo; Oswaldo R. Kato

2011-01-01

452

Mesorhizobium shonense sp. nov., Mesorhizobium hawassense sp. nov. and Mesorhizobium abyssinicae sp. nov., isolated from root nodules of different agroforestry legume trees.  

PubMed

A total of 18 strains, representing members of the genus Mesorhizobium, obtained from root nodules of woody legumes growing in Ethiopia, have been previously shown, by multilocus sequence analysis (MLSA) of five housekeeping genes, to form three novel genospecies. In the present study, the phylogenetic relationship between representative strains of these three genospecies and the type strains of their closest phylogenetic neighbours Mesorhizobium plurifarium, Mesorhizobium amorphae, Mesorhizobium septentrionale and Mesorhizobium huakuii was further evaluated using a polyphasic taxonomic approach. In line with our earlier MLSA of other housekeeping genes, the phylogenetic trees derived from the atpD and glnII genes grouped the test strains into three well-supported, distinct lineages that exclude all defined species of the genus Mesorhizobium. The DNA-DNA relatedness between the representative strains of genospecies I-III and the type strains of their closest phylogenetic neighbours was low (?59?%). They differed from each other and from their closest phylogenetic neighbours by the presence/absence of several fatty acids, or by large differences in the relative amounts of particular fatty acids. While showing distinctive features, they were generally able to utilize a wide range of substrates as sole carbon and nitrogen sources. The strains belonging to genospecies I, II and III therefore represent novel species for which we propose the names Mesorhizobium shonense sp. nov., Mesorhizobium hawassense sp. nov. and Mesorhizobium abyssinicae sp. nov. The isolates AC39a(T) (?=?LMG 26966(T)?=?HAMBI 3295(T)), AC99b(T) (?=?LMG 26968(T)?=?HAMBI 3301(T)) and AC98c(T) (?=?LMG 26967(T)?=?HAMBI 3306(T)) are proposed as type strains for the respective novel species. PMID:22941297

Degefu, Tulu; Wolde-Meskel, Endalkachew; Liu, Binbin; Cleenwerck, Ilse; Willems, Anne; Frostegård, Åsa

2013-05-01

453

Effects of chemical composition on N, Ca, and Mg release during incubation of leaves from selected agroforestry and fallow plant species  

Microsoft Academic Search

Nitrogen, Ca and Mg release from leaves of ten selected plant residues with varying chemical compositions was studied under laboratory conditions. Three patterns of N-release were observed over a seven week incubation period: (a)Gliricidia sepium, Leucaena leucocephala, Mucuna pruriens andCentrosema pubescens leaves showed rapid N release, (b)Acioa barteri andDialium guineense leaves immobilized N, and (c)Alchornea cordifolia, Anthonata macrophylla, Cassia siamea

G. Tian; B. T. Kang; L. Brussaard

1992-01-01

454

Evidence of hydraulic lift for pre-rainy season leaf out and dry-season stem water enrichment in Sclerocarya birrea, a tropical agroforestry tree  

NASA Astrophysics Data System (ADS)

We use stable isotopes of water as tracers to follow water use by five Sclerocarya birrea trees in a catchment in South Eastern Burkina Faso interspersed with millet fields, gallery forest, Sudanian savanna, and fallow fields. Isotopic ratios were determined from water extracted from stems of the trees and sub-canopy soil of two of them, while nearby ground water, precipitation, and surface water was sampled weekly. A unique configuration of sensors connected with a wireless sensor network of meteorological stations measured sub-canopy shading, the temperature and humidity in the canopy, through-fall, and soil moisture under two of the trees. Both water extracted from sap and water extracted from soil is extremely enriched in the dry season, but drop to levels close to the ground water in February or March, which coincides with the growth of leaves. Dates of leaf out were confirmed by changes in ?DH and ?O18 concentrations of water, photographic documentation & pixel analysis, and analysis of sub-canopy radiation and proceeded the rise in humidity and flow that was later detected in the sub-canopy soil, the trunk of the tree (sap-flow), and atmosphere (canopy VPD). Examination of the isotopic signature suggests that size of tree plays an important role in duration and timing of this leaf-out as well as the degree of enrichment during the peak of the dry season. Further examination of the isotopic signatures of the roots suggested that the trees are performing hydraulic redistribution, or lifting the ground water and "sharing it" with the soil in the rooting zone in the dry season. The enriched level of xylem in this case is a product of water loss, and enrichment, along the travel path of the water from the roots to the tip of the stem, as evidenced by the variation according to size of tree. Vapor pressure deficit, soil water, and soil moisture interactions support this picture of interacting controls, separate from hydrologic triggers on the water movement in the tree.

Ceperley, Natalie; Mande, Theophile; Rinaldo, Andrea; Parlange, Marc B.

2014-05-01

455

Conservation value of cacao agroforestry for amphibians and reptiles in South-East Asia: combining correlative models with follow-up field experiments  

Microsoft Academic Search

Summary 1. Although agricultural expansion is a primary threat to tropical biodiversity, experimental stud- ies evaluating the conservation value of tropical agricultural habitats are scarce. In particular, little is known about the sensitivity of amphibians and reptiles to habitat disturbance in areas of very high diversity such as South-East Asia. 2. We used a two-step approach to determine the relationship

Thomas C. Wanger; Akbar Saro; Djoko T. Iskandar; Barry W. Brook; Navjot S. Sodhi; Yann Clough; Teja Tscharntke

2009-01-01

456

Control system design method  

DOEpatents

A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

Wilson, David G. (Tijeras, NM); Robinett, III, Rush D. (Tijeras, NM)

2012-02-21

457

Computer system isolates faults  

SciTech Connect

Maintaining transaction processing systems in continuous operation, a minicomputer system made by tolerant systems detects and isolates faults, then transfers work loads to the appropriate backup resource. An eternity system is actually 1 to 15 computer systems, called system building blocks, interconnected by a communication network. Modularity is provided by tolerant's flexible architecture technique. This allows a user to expand system capacity with nondedicated computers which can be assigned to tasks such as increasing processing power, user accessibility and database size as dictated by needs. The loosely-coupled nature of the system increases reliability.

Hall, D.E.

1983-11-01

458

Automated surface observing systems  

NSF Publications Database

Title : Automated surface observing systems Type : Antarctic EAM NSF Org: OD / OPP Date : August 19 ... Action Memorandum (Installation of Automated Surface Observing Systems [ASOS}) To: Director, Office ...

459

Systemic lupus erythematosus  

MedlinePLUS

Disseminated lupus erythematosus; SLE; Lupus; Lupus erythematosus; Discoid lupus ... Systemic lupus erythematosus (SLE) is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue. It ...

460

Lightside Atmospheric Revitalization System  

NASA Technical Reports Server (NTRS)

The system was studied as a replacement to the present baseline LiOH system for extended duration shuttle missions. The system consists of three subsystems: a solid amine water desorbed regenerable carbon dioxide removal system, a water vapor electrolysis oxygen generating system, and a Sabatier reactor carbon dioxide reduction system. The system is designed for use on a solar powered shuttle vehicle. The majority of the system's power requirements are utilized on the Sun side of each orbit, when solar power is available.

Colling, A. K.; Cushman, R. J.; Hultman, M. M.; Nason, J. R.

1980-01-01

461

Automation of the Technical Services Department in the Community College Library.  

ERIC Educational Resources Information Center

Describes Parkland College Library's efforts to review technical service activities and make recommendations concerning the automation of cataloging, acquisitions, and the public catalog. Traces the steps that have been taken in the development of a "paperless office." (DMM)

Bial, Raymond; Strickler, Ken

1987-01-01

462

77 FR 22551 - Proposed Flood Elevation Determinations  

Federal Register 2010, 2011, 2012, 2013

...parkland), Clover Creek (overflow at golf course), Clover Creek (overflow near... 5, Puyallup River (overflow through golf course between State Route 162 and Puyallup...River), Puyallup River (overflow through golf course to Hylebos Waterway),...

2012-04-16

463

23 CFR Appendix A to Part 773 - FHWA Environmental Responsibilities That May Be Assigned Under Section 6005  

Code of Federal Regulations, 2013 CFR

...4001-4128 Parklands Section 4(f) of the Department of Transportation Act of 1966, 49 U.S.C. 303 Land and Water Conservation Fund (LWCF), 16 U.S.C. 4601-4604 Hazardous Materials Comprehensive Environmental Response,...

2013-04-01

464

Integrated Systems Health Management for Intelligent Systems  

NASA Technical Reports Server (NTRS)

The implementation of an integrated system health management (ISHM) capability is fundamentally linked to the management of data, information, and knowledge (DIaK) with the purposeful objective of determining the health of a system. It is akin to having a team of experts who are all individually and collectively observing and analyzing a complex system, and communicating effectively with each other in order to arrive at an accurate and reliable assessment of its health. In this paper, concepts, procedures, and approaches are presented as a foundation for implementing an intelligent systems ]relevant ISHM capability. The capability stresses integration of DIaK from all elements of a system. Both ground-based (remote) and on-board ISHM capabilities are compared and contrasted. The information presented is the result of many years of research, development, and maturation of technologies, and of prototype implementations in operational systems.

Figueroa, Fernando; Melcher, Kevin

2011-01-01

465

Epilogue: Systems Approaches and Systems Practice  

NASA Astrophysics Data System (ADS)

Each of the five systems approaches discussed in this volume: system dynamics (SD), the viable systems model (VSM), strategic options development and analysis (SODA), soft systems methodology (SSM) and critical systems heuristics (CSH) has a pedigree. Not in the sense of the sometimes absurd spectacle of animals paraded at dog shows. Rather, their pedigree derives from their systems foundations, their capacity to evolve and their flexibility in use. None of the five approaches has developed out of use in restricted and controlled contexts of either low or high levels of complicatedness. Neither has any one of them evolved as a consequence of being applied only to situations with either presumed stakeholder agreement on purpose, or courteous disagreement amongst stakeholders, or stakeholder coercion. The compilation is not a celebration of abstract ‘methodologies', but of theoretically robust approaches that have a genuine pedigree in practice.

Reynolds, Martin; Holwell, Sue

466

Systems engineering for very large systems  

NASA Technical Reports Server (NTRS)

Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

Lewkowicz, Paul E.

1993-01-01

467

Forming different planetary systems  

NASA Astrophysics Data System (ADS)

With the increasing number of detected exoplanet samples, the statistical properties of planetary systems have become much clearer. In this review, we summarize the major statistical results that have been revealed mainly by radial velocity and transiting observations, and try to interpret them within the scope of the classical core-accretion scenario of planet formation, especially in the formation of different orbital architectures for planetary systems around main sequence stars. Based on the different possible formation routes for different planet systems, we tentatively classify them into three major catalogs: hot Jupiter systems, standard systems and distant giant planet systems. The standard system can be further categorized into three sub-types under different circumstances: solar-like systems, hot Super-Earth systems, and subgiant planet systems. We also review the theory of planet detection and formation in binary systems as well as planets in star clusters.

Zhou, Ji-Lin; Xie, Ji-Wei; Liu, Hui-Gen; Zhang, Hui; Sun, Yi-Sui

2012-08-01

468

Recommender System: A Personalized TV Guide System  

Microsoft Academic Search

\\u000a The Electronic Programming Guide helps viewers to navigate between channels, but the measure that new channels are available\\u000a it is inevitable that information overload occurs making systems EPG inadequate. This situation arises the need of personalized\\u000a recommendation systems. In this paper we present a recommendation system compliant with the middleware Ginga. Are presented\\u000a the results obtained with three different mining

Paulo Muniz de Ávila; Sérgio Donizetti Zorzo

469

Novel central nervous system drug delivery systems.  

PubMed

For decades, biomedical and pharmaceutical researchers have worked to devise new and more effective therapeutics to treat diseases affecting the central nervous system. The blood-brain barrier effectively protects the brain, but poses a profound challenge to drug delivery across this barrier. Many traditional drugs cannot cross the blood-brain barrier in appreciable concentrations, with less than 1% of most drugs reaching the central nervous system, leading to a lack of available treatments for many central nervous system diseases, such as stroke, neurodegenerative disorders, and brain tumors. Due to the ineffective nature of most treatments for central nervous system disorders, the development of novel drug delivery systems is an area of great interest and active research. Multiple novel strategies show promise for effective central nervous system drug delivery, giving potential for more effective and safer therapies in the future. This review outlines several novel drug delivery techniques, including intranasal drug delivery, nanoparticles, drug modifications, convection-enhanced infusion, and ultrasound-mediated drug delivery. It also assesses possible clinical applications, limitations, and examples of current clinical and preclinical research for each of these drug delivery approaches. Improved central nervous system drug delivery is extremely important and will allow for improved treatment of central nervous system diseases, causing improved therapies for those who are affected by central nervous system diseases. PMID:24325540

Stockwell, Jocelyn; Abdi, Nabiha; Lu, Xiaofan; Maheshwari, Oshin; Taghibiglou, Changiz

2014-05-01

470

Cogeneration power systems  

NASA Technical Reports Server (NTRS)

Cogeneration is defined as the combination of electrical generation and process heat for more efficient use of fuel. Comparisons of energy utilization in conventional electric power plants and cogeneration electric power plants are presented. Characteristics of various cogeneration systems are also presented. Systems are analyzed for use in utility systems and industrial systems. Economic and cost analysis are reviewed.

Davis, H. S.

1978-01-01

471

The JX Operating System  

Microsoft Academic Search

This paper describes the architecture and performance of the JX operating system. JX is both an operating system completely written in Java and a runtime system for Java applications. Our work demonstrates that it is possible to build a com- plete operating system in Java, achieve a good perfor- mance, and still benefitfrom the modern software-technol- ogy of this object-oriented,

Michael Golm; Meik Felser; Christian Wawersich; Jürgen Kleinöder

2002-01-01

472

Transaction Security System  

Microsoft Academic Search

Components of previous security systems were deslgned Independently from one another and were often dlfficult to integrate. Described is the recently available IBM Transaction Security System. It im iements the Common Cryptograph6 Architecture and offers a comprehensive set of security products that allow users to Implement end-to-end secure systems with IBM components. The system includes a mainframe host-attached

Dennis G. Abraham; George M. Dolan; Glen P. Double; James V. Stevens

1991-01-01

473

Electronic Document Supply Systems.  

ERIC Educational Resources Information Center

Describes electronic document delivery systems used by libraries and document image processing systems used for business purposes. Topics discussed include technical specifications; analogue read-only laser videodiscs; compact discs and CD-ROM; WORM; facsimile; ADONIS (Article Delivery over Network Information System); DOCDEL; and systems at the…

Cawkell, A. E.

1991-01-01

474

The outer solar system  

Microsoft Academic Search

The outer solar system extends beyond a heliocentric distance of 5 AU. It contains the giant planets and their systems (rings and satellites), the Kuiper belt, the comets (except those which approach episodically the inner solar system) and, at its outer edge, the Oort cloud. The outer solar system physically corresponds to the region located outside the « snow line

T. Encrenaz

2009-01-01

475

Authentification for Distributed Systems  

Microsoft Academic Search

A fundamental concern in building a secure distributed system is authentication of local and remote en- tities in the system. We survey authentication issues in distributed system design. Two basic paradigms underlying the design of authentication protocols are presented. We then propose an authentication framework that can be used for designing secure distributed systems, including specific protocols for secure bootstrapping,

Thomas Y. C. Woo; Simon S. Lam

1992-01-01

476

Normative system games  

Microsoft Academic Search

We develop a model of normative systems in which agents are as- sumed to have multiple goals of increasing priority, and investi- gate the computational complexity and game theoretic properties of this model. In the underlying model of normative systems, we use Kripke structures to represent the possible transitions of a multi- agent system. A normative system is then simply

Thomas Ågotnes; Wiebe Van Der Hoek; Michael Wooldridge

2007-01-01

477

Reasoning about naming systems  

Microsoft Academic Search

This paper reasons about naming systems as specialized inference mechanisms, It describes a preference )-zierarch.v that can be used to specify the structure of a naming system's inference mechanism and defines criteria by which different naming systems can be evaluated, For example, the preference hierarchy allows one to compare naming systems based on how dkcrzmznating they are and to identify

Mic Bowman; Saumya K. Debray; Larry L. Peterson

1993-01-01

478

Systems Inquiry in Education  

ERIC Educational Resources Information Center

Four levels of systems inquiry are projected on an abstract-concrete continuum. Most abstract is exposition of general theories of systems, and most concrete is use of specific technical tools. Specific models of systems approaches to instructional development are examined, and a systems-models approach is outlined. (Author)

Banathy, Bela H.; Hayman, John L.

1975-01-01

479

Towards Understanding System Building  

Microsoft Academic Search

Large software systems are composed of complex subsystems which are related to one another as well as underlying platform technologies. These relationships must be captured in a system's build artifacts; they are used by the build process to produce a properly functioning application from the system's source code. These build artifacts evolve along with the system's source code, and understanding

Mina Askari; Rolando Blanco; Alan Grosskurth

480

Medical imaging systems  

DOEpatents

A medical imaging system provides simultaneous rendering of visible light and diagnostic or functional images. The system may be portable, and may include adapters for connecting various light sources and cameras in open surgical environments or laparascopic or endoscopic environments. A user interface provides control over the functionality of the integrated imaging system. In one embodiment, the system provides a tool for surgical pathology.

Frangioni, John V

2013-06-25

481

Broad Bandwidth Telecommunications Systems.  

ERIC Educational Resources Information Center

Broad bandwidth transmission systems have been around for years. They include microwave, assorted cable systems, and recently, satellites. With the exception of some privately owned systems, broadband services have been furnished by the common carriers. Recently, a new element has been added--Cable Antenna Television (CATV) distribution systems.…

Sodolski, John

482

Polymer Electronics Systems - Polytronics  

Microsoft Academic Search

Current trends in the development of electronics systems show that the provision of thin flexible components and semiconductors plays a decisive role in the steadily progressing development of highly integrated systems. A new generation of thin flexible electronic systems arises. At Fraunhofer IZM, inline manufacturing processes for polymer electronic systems are developed on production type equipment. A low-cost process for

KARLHEINZ BOCK

2005-01-01

483

Universal Index System  

NASA Technical Reports Server (NTRS)

The Universal Index System (UIS) is an index management system that uses a uniform interface to solve the heterogeneity problem among database management systems. UIS provides an easy-to-use common interface to access all underlying data, but also allows different underlying database management systems, storage representations, and access methods.

Kelley, Steve; Roussopoulos, Nick; Sellis, Timos; Wallace, Sarah

1993-01-01

484

Digital wireless control system  

Microsoft Academic Search

The Digital Wireless Control System (DWCS) is designed to initiate high explosives safely while using a wireless remote control system. Numerous safety features have been designed into the fire control system to mitigate the hazards associated with remote initiation of high explosives. These safety features range from a telemetry (TM) fire control status system to mechanical timers and keyed power

R. Smith

1993-01-01

485

Noncooperative rendezvous radar system  

NASA Technical Reports Server (NTRS)

A fire control radar system was developed, assembled, and modified. The baseline system and modified angle tracking system are described along with the performance characteristics of the baseline and modified systems. Proposed changes to provide additional techniques for radar evaluation are presented along with flight test data.

1974-01-01

486

Acoustical analysis system  

NASA Technical Reports Server (NTRS)

Integrated system is described which replaces several instruments normally used to analyze acoustical data in failure detection of mechanical or fluid systems. Analysis system extracts and measures repetitive waveforms superimposed on noisy background and compares amplitude with internally stored waveforms. Equipment used in system may be interfaced with general purpose digital computer.

Tatge, R. B.; Scott, P. F.

1972-01-01

487

Photovoltaic systems performance experience  

Microsoft Academic Search

The photovoltaic power systems at Natural Bridges National Monument in southeastern Utah and at radio station WBNO in Bryan, Ohio, provided reliability experience and case histories on failures and repairs of large photovoltaic systems. The PV systems are used for illustration of potential sources of system outages and measures that can be taken to improve the reliability and repair economy

F. J. Solman

1981-01-01

488

Systems for finding people  

Microsoft Academic Search

Finding a previously unknown person with the skills and knowledge to answer a question or perhaps to collaborate with is an effective use of a computer?mediated communication (CMC) system. This article discusses two aspects of systems for finding people, system architectures, and organizational implications.The architectures considered are special interest groups, centralized servers, and decentralized systems. The organizational implications are the

1992-01-01

489

Transients in Power Systems  

Microsoft Academic Search

Power system engineering largely focuses on steady state analysis. The main areas of power system engineering are power flow studies and fault studies - both steady state technologies. But the world is largely transient, and power systems are always subject to time varying and short lived signals. This technical report concerns several important topics in transient analyses of power systems.

M. Belkhayat; J. Edwards; N. Hoonchareon; O. Marte; D. Stenberg; E. Walters

1995-01-01

490

Linear Systems: Using Algebra  

NSDL National Science Digital Library

Students learn to solve a system of linear equations (2 equations with 2 variables) by substitution and elimination methods. They also review the definitions of consistent (independent and dependent) and inconsistent systems, and associate the number of solutions of a system with them. Detailed instructions guide students in using their graphing calculators to solve the systems of equations.

2009-06-14

491

The solar system  

NASA Astrophysics Data System (ADS)

The main concern of this introductory textbook on the solar system is with the present state of knowledge of the solar system. The main features of the solar system are examined, taking into account the semimajor axes of the planets' orbits and the Titius-Bode law, orbits, the center of mass, and axial spins. The earth's interior is considered along with the earth's atmosphere and surface volatiles, Mars, Venus, the acquisition of volatiles by the terrestrial planets, the moon, Mercury, impact cratering of the terrestrial planets, the Jovian system, the Saturnian system, planetary rings, the system of Uranus, the system of Neptune, Pluto, comets, asteroids, meteoroids, and questions regarding the origin and the end of planetary systems. Attention is given to molecular clouds, star formation, cosmogenic theories, the death of stars and of planetary systems, and the possibility of the existence of civilizations on other planetary systems.

Jones, B. W.

492